pubMedId
stringlengths 2
1.61k
| title
stringlengths 1
2k
⌀ | abstract
stringlengths 1
10.1k
⌀ |
|---|---|---|
5894045 | Acid hydrolases of the rat uterus in relation to pregnancy, post-partum involution and collagen breakdown. | 1. The rat uterus contains acid cathepsin, beta-glucuronidase, beta-galactosidase, acid phosphatase and deoxyribonuclease II at parable with those found in liver. Two non-hydrolytic uterine enzymes, cytochrome c oxidase and aspartate aminotransferase, display only 2-6% of the activity found in liver. 2. The concentrations of acid cathepsin and beta-glucuronidase are significantly decreased in pregnancy and increase 3-4-fold during post-partum involution. 3. The concentrations of beta-galactosidase and acid phosphatase are not decreased in pregnancy and increase only 2-3-fold during involution. 4. The concentrations of these four acid hydrolases increase linearly during the first 4 days post partum and reach their peak values at the same time that wet weight and collagen content fall to their lowest point. 5. The concentration of deoxyribonuclease is depressed in pregnancy but does not rise above normal in the post-partum period. 6. Only a small proportion of each hydrolytic activity can be isolated in the mitochondrial-lysosomal fraction of sucrose homogenates of the rat uterus. This proportion increases during involution. However, the extensive mitochondrial rupture occurring during homogenization indicates that the technique is probably too harsh to obtain a true measure of the proportion of lysosomes present in the intact tissue. 7. There are no significant changes in either the concentration or subcellular distribution of the five acid hydrolases in the livers of the experimental rats during pregnancy or involution. In each case the largest proportion of the activity is found in the mitochondrial-lysosomal fraction of liver homogenates. 8. The results are interpreted in terms of the lysosomal theory of intracellular digestion. |
5894227 | Delayed dermal hypersensitivity in mice to spherule and mycelial extracts of Coccidioides immitis. | Kong, Yi-chi M. (University of California, Berkeley), D. C. Savage, and Leighton N. L. Kong. Delayed dermal hypersensitivity in mice to spherule and mycelial extracts of Coccidioides immitis. J. Bacteriol. 91:876-883. 1966.-A delayed hypersensitivity reaction to spherule and mycelial extracts of Coccidioides immitis was elicited in the footpads of mice vaccinated with killed spherules. Emulsification of the spherules with Freund's adjuvants was unnecessary, but a high concentration of antigen was required to elicit the reaction. Injection of the extracts produced, initially, a swelling which subsided within 4 hr, and then induration, which began at 6 to 8 hr and reached a maximum at 24 hr. The time course of the reaction corresponded to that of the tuberculin reaction in BCG-vaccinated mice. The histological response to coccidioidal extracts was characterized by the early infiltration of both polymorphonuclear and mononuclear cells, and the subsequent predominance of mononuclear cells at 24 to 48 hr. By 72 hr, the mononuclear prised >90% of the cellular infiltrate. Animals infected intranasally with arthrospores (1 to 5 ld(50)) reacted negatively before and during the crisis period; thereafter (by 28 to 31 days after infection), up to 50% of the survivors showed a delayed reaction. |
5894312 | Electrical impedance of isolated amnion. | The electrical impedance of the guinea pig amniotic membrane was measured, under standardized conditions, over the frequency range of 20 to 7000 cycles/second. This impedance can be represented analytically by a simple frequency-dependent function which is precisely of the form of the Debye relaxation equation. The observed data exhibit a broad dispersion centered at a frequency of 1050 cycles/second and a narrow distribution of time constants centered about 152 microseconds, both effects being due to the polydisperse nature of amniotic tissue. If the narrow time-constant distribution is approximated by a single time constant, amnion impedance can be simulated by a simple electrical circuit of frequency-independent elements. The Maxwell-Wagner interfacial treatment, although successfully adapted for cell suspensions, is shown to lose its quantitative significance in the case of the tightly structured amnion. In addition, determinations were made on the position of amniotic fluid, fetal blood and urine, and maternal blood and urine; the DC potential across the amniotic membrane was also measured. |
5894452 | The effect of actidione on mitosis in the slime mold Physarum polycephalum. | Actidione, reportedly a specific inhibitor of protein synthesis, was found to reduce the incorporation of labeled amino acids into proteins of the slime mold Physarum polycephalum without drastically inhibiting the incorporation of nucleic acid precursors into RNA. This inhibitor was found pletely block the ensuing mitosis if it was added at any time between telophase and late prophase. Plasmodia given Actidione in late prophase (about the time of nucleolar dissolution) went on through telophase to reconstruction even though nuclear amino acid incorporation was drastically reduced during that period. |
5897259 | Personnel administration: management of large medical libraries. | Machines themselves are not dehumanizing. Employed with proper management in total systems they enable us better to achieve human goals. Large libraries plex systems involving man-machine relationships which must be studied with the new management techniques of systems analysis and operations research. Management science deals with a wide variety of problems encountered in the economy of the modern library. Librarians must know about these techniques if they are to fulfill their roles as managers of information services and systems. Good management also involves taking cognizance of the human factors in the old meaning of the term. Some parallels may be found between child rearing and personnel management, but the primary one is that managers must pay the same kind of thoughtful attention to their problems. Good management techniques may be learned empirically by trial and error, but they are better acquired systematically through consultation and study. |
5897412 | Serum enzymes in diseases of the thyroid gland. | Serum enzyme assays have been carried out in 66 patients suffering from diseases of the thyroid gland. Sixty per cent. of the hypothyroid patients had increased levels of aldolase and glutamic oxaloacetic transaminase, and 90% had high activities of creatine kinase. The significance of these findings, especially with regard to creatine kinase, is discussed. |
5897508 | Morphogenetic effects of 6-azauracil and 6-azauridine. | When 6-azauracil and 6-azauridine are fed to larvae of the tu(w) rc strain of Drosophila melano-gaster which has the normal wing shape, adults hatch with shortened, obliquely truncated wings. This wing shape resembles that of the mutant dumpy. On the other hand, administration of these drugs to the mutant dumpy strain increases wing length, and flies with normal wings are obtained. |
5898943 | Effects of intravenous infusions of acetate, beta-hydroxybutyrate, triglyceride and other metabolites on the composition of the milk fat and blood in cows. | 1. The effects in the cow of intravenous infusions of sodium acetate, butyrate, propionate, beta-hydroxybutyrate, malonate, citrate or succinate, of glucose or of an emulsion of cottonseed oil on the secretion of ponent fatty acids of milk fat and on position of the blood plasma of the jugular vein have been studied. 2. Glucose and cottonseed oil were the only metabolities consistently to affect the yield of milk fat. Glucose decreased the yield of milk fat through a diminished secretion of the C(18) fatty acids and in two out of three cows also of the steam-volatile fatty acids (C(4)-C(10)). The cottonseed oil caused an increase in the yield of milk fat through an increased secretion of linoleic acid, the ponent acid of the cottonseed oil. In three out of four cows, acetate caused an increase in the yield of milk fat through an increased secretion of mainly palmitic acid. 3. The effects of the infusions on milk-fat secretion are discussed in relation to existing knowledge on the origin of the fatty acids of milk fat. |
5900208 | Composition of lipids in human serum and adipose tissue during prolonged feeding of a diet high in unsaturated fat. | Elderly institutionalized men were assigned at random to two groups, one of which received a conventional diet while the other was fed a diet in which the major modification was substitution of unsaturated for saturated fat. Changes in serum lipids and in adipose tissue over periods up to 5 years are described. In control subjects, mean serum cholesterol rose 4% over the first 20 months, then fell during the next 40 months to a level 10% below the starting concentration. In the experimental group there was an immediate drop, followed by further changes roughly parallel to those in the control subjects. The mean difference between the control and experimental groups was 14.0% of the starting level. Changes in serum total lipid were similar, but the percentage difference between control and experimental groups was only 6.8% of the baseline level. All major esterified serum lipid fractions of experimental subjects contained increased concentrations of linoleic acid. This was most marked in triglyceride, which at 3 years had position similar to that of the dietary fat in both groups of subjects. Adipose tissue linoleic acid rose in men on the experimental diet from 11% of total fatty acid at time zero to 32% at 5 years. The rise could be fitted to an exponential function with a half-time of 680 days. The rate of rise during the 1st year was correlated negatively with initial body weight and positively with weight gain; the influence of adherence to the diet was much less pronounced. |
5900209 | Diurnal changes in liver and plasma lipids of choline-deficient rats. | Early effects of choline deficiency were studied in rats. Nonphospholipid ("neutral lipid") and phospholipid were measured in plasma and in three fractions of a liver homogenate: sediment, supernatant fraction, and "floating fat." A single choline-deficient meal caused significant aberrations from the typical diurnal changes observed in the lipid fractions of the controls. These changes occurred in the following sequence: (a) failure of phospholipid to increase, after feeding, in the sediment fraction; (b) increase of neutral pared with controls, exclusively in the floating fraction; and (c) failure of neutral lipid to return to control levels. The rate of accumulation of neutral lipid increased during the first 4 days of deficiency. The occurrence of NADH-cytochrome c dehydrogenase in the floating fat and the absence of succinate dehydrogenase activity point to microsomal origin of the floating fat. Early effects of choline deficiency on plasma lipids were limited to phospholipid, and occurred later than changes in the liver. Plasma nonphospholipid levels were unchanged during the first 2 days; this does not support impaired secretion or transportation of glyceride as the cause of fatty liver in the early stages of choline deficiency. |
5900210 | Changes in sphingosine and fatty acid components of the gangliosides in developing rat and human brain. | Rat brain increases in weight after birth in three stages: (I) rapidly for the first 2 weeks, (II) at a lower rate from 2 to 5 weeks, and (III) at a still lower rate from 5 weeks to 5 months. During the succeeding period, designated IV, it maintains constant weight up to 1 year of age. Brain ganglioside content increased linearly during I and II, more slowly during III, and diminished during IV. The appearance of measurable amounts of brain sphingomyelin and cerebroside succeeded that of ganglioside. Ceramide with C18-sphingosine and C18 fatty acid was found in a large proportion of all three sphingolipids upon their first appearance in measurable quantity. C18 fatty acid in cerebroside rapidly declined to a negligible level, while in gangliosides and sphingomyelin it declined slowly but remained the major fatty ponent. Cerebrosides and sphingomyelin contained C18-sphingosine almost exclusively at all stages of rat brain growth. Gangliosides contained C18-sphingosine almost exclusively at birth, but subsequently accumulated C20-sphingosine until they had nearly equal quantities of each base type. Changes in human brain gangliosides resemble those in rat. In Tay-Sachs disease, gangliosides have C18-sphingosine predominantly, and a high content of C18 fatty acid. |
5900211 | Determination of brain gangliosides by determination of ganglioside stearic acid. | A new method is described for the determination of brain gangliosides by measuring stearic acid, the chief acid of gangliosides, in an appropriately purified brain extract. The method includes extraction of tissue with chloroform-methanol, extraction of gangliosides from the extract with 0.1 M KCl, evaporation of the aqueous phase, methanolysis, and gas-liquid chromatography of the resultant methyl esters with a double internal standard. The method depends on the position of ganglioside fatty acids (80% stearic acid) and allows determination of less than 0.05 micromole of gangliosides. Interfering lipids are removed from the ganglioside extract by washing with chloroform-methanol-water. The effects of contamination with nonlipid N-acetylneuraminic acid are avoided. |
5900212 | Use of a filter-paper disk assay in the measurement of lipid biosynthesis. | The precipitation by trichloroacetic acid (TCA) of radioactive lipids on disks of filter-paper, followed by extraction with TCA and water to remove soluble radioactive precursors, provides the means for a convenient assay for lipid biosynthesis. Large numbers of disks can be washed in the same vessel, dried, and assayed for radioactivity with liquid scintillation counting equipment. Extraction of disks with lipid solvents provides a convenient control for the possible presence of TCA- and water-insoluble, nonlipid products. The application of the method to the assay of cyclopropane fatty acid synthetase is shown. |
5900213 | Origin and characteristics of endogenous lipid in thoracic duct lymph in rat. | Thoracic duct lymph of rats eating a fat-free diet contained 7 mg of lipid per hr. The lipid was 70% triglyceride, and largely in the d < 1.006 lipoprotein fraction. Lipid of the d < 1.006 fraction of the lymph was many times more concentrated than that of the blood plasma at the same time. It reached the thoracic duct via lymphatics from the intestine; little entered from the liver. The fatty acid posing over three-fourths of the lymph lipid mass was undoubtedly derived in part from bile lipid-possibly to the extent of roughly 50%, and in some part from other intraluminal materials. Studies with labeled palmitic acid indicated that little circulating free fatty acid was taken up by the intestinal mucosa and incorporated into lymph lipid. |
5900214 | Modified enzymatic procedure for the routine determination of glycerol and triglycerides in plasma. | A modification of Wieland's enzymatic procedure for glycerol analysis is presented. It is simple and precise, and readily applicable to the routine analysis of plasma and tissue glycerol and triglycerides. Optimal precision is obtained in samples containing 0.003-0.400 micromole of glycerol per ml, which in this method is equivalent to plasma levels of 0.011 to 1.40 micromoles/ml. |
5900215 | Quantitative micro determination and isolation of plasmalogen aldehydes as 2,4-dinitrophenylhydrazones. | A micro spectrophotometric procedure for the quantitative determination of plasmalogen aldehydes is described which utilizes simultaneous methanolysis and formation of 2,4-dinitrophenylhydrazones. After isolation of the hydrazones by thin-layer chromatography, the aldehydes can be regenerated, reduced, acetylated, and then analyzed by gas-liquid chromatography. Identification of the plasmalogen aldehydes obtained from rumen holotrich protozoa is described. |
5900216 | Synthesis of fatty acid anhydrides by reaction with dicyclohexylcarbodiimide. | A simple method is described for the preparation of caprylic, palmitic, stearic, and oleic anhydrides. Reaction of the free fatty acid and dicyclohexylcarbodiimide in carbon tetrachloride at room temperature gives the corresponding anhydrides in high yield (87-94%). |
5900217 | Environmental temperature and choline requirement in rats. I. Choline deficiency in rats at various temperatures. | Rats were maintained at 2 degrees, 21 degrees, and 33 degrees for 3 weeks on a choline-supplemented or a choline-deficient diet. In contrast to the findings of some other workers, choline deficiency produced fatty livers at all temperatures. The ratio of the total liver lipid to the total food intake was the same in all choline-supplemented rats. In choline-deficient rats this ratio was always higher and varied directly with temperature. |
5900218 | Environmental temperature and choline requirements in rats. II. Choline and methionine requirements for lipotropic activity. | Young rats were fed choline-deficient diets and maintained at different environmental temperatures. The hepatic lipid level remained normal in rats at 2 degrees when 25 mg of choline per 100 g of food was fed; 50 mg of choline per 100 g food was required at 21 degrees and 100 mg of choline per 100 g food at 33 degrees to prevent excessive lipid accumulation. These values were equivalent to a mean daily intake per rat of 3 mg of choline at 2 degrees, 5.5 mg at 21 degrees, and 7 mg at 33 degrees respectively. When the growth rate was slower owing to a slight inadequacy of histidine in the basal choline-deficient diet, normal hepatic lipid was maintained by supplements of 50 mg of choline per 100 g food at 21 degrees and 33 degrees. Increasing the methionine content of the diet two- or three-fold from a basal value of 340 mg per 100 g food was as effective as 200 mg of choline per 100 g of food in lowering hepatic lipids at 2 degrees, 21 degrees, and 33 degrees. |
5900219 | In vivo studies on pathways for the biosynthesis of lecithin in the rat. | The in vivo biosynthesis of lecithin in rats has been studied with the precursors choline-1,2-(14)C, ethanolamine-1,2-(14)C and methionine-CH(3)-(14)C or -CH(3)-(3)H. Lecithin synthesis from choline is rapid in all organs. No sex difference was observed in this pathway. The biosynthesis of lecithin by methylation of phosphatidyl ethanolamine is of quantitative significance in the liver, but not in extrahepatic tissues. More lecithin is synthesized by this pathway in female rats. In liver the lecithin synthesized via both pathways enters mon pool which is in rapid equilibrium with lecithin of blood plasma. A sex difference in the utilization of radioactive ethanolamine for the formation of phosphatidyl ethanolamine was observed (greater utilization in the female). Incorporation of ethanolamine into phospholipids of extrahepatic tissues was slow in both sexes. With labeled methionine as precursor the liver cytidine diphosphate (CDP) choline had a specific activity identical with that of liver lecithin after 20 min, while the specific activity of phosphoryl choline remained low. With labeled choline as precursor the phosphoryl choline reached a specific activity 50 times that of lecithin after 20 min, while the specific activity of CDP choline was only four times that of lecithin. These findings indicate that the reaction: CDP choline + diglyceride right harpoon over left harpoon phosphatidyl choline + CMP is freely reversible in vivo. |
5900220 | Formation and enterohepatic circulation of metabolites of retinol and retinoic acid in bile duct-cannulated rats. | Four hours after intraportal injection of retinoic acid-(14)C into bile duct-cannulated rats, less than 10% of the radioactivity was recovered in the liver, intestine, and kidneys. Within 6 hr, 40% of the radioactivity had appeared in bile. When suspensions of retinol-(14)C or retinal were similarly injected, 25-35% of the dose was excreted in bile within 24 hr and equivalent amounts were deposited in the liver as retinol ester. The isolated perfused liver also produced these bile metabolites and is probably the major site of their formation in vivo. The intestine may metabolize retinoic acid, however, since some metabolites were found in the intestinal wall and lumen, even in bile duct-cannulated rats. The bile metabolites of retinol-(14)C and retinoic acid-(14)C undergo extensive enterohepatic circulation. The bile radioactivity was not volatilized on boiling at acid pH, was not present in digitonin-precipitated sterols, and did not migrate with bile salts on reversed-phase paper chromatography. Anion-exchange chromatography resolved the metabolites of bile into three fractions containing pounds, acidic substances like retinoic acid, and more polar acidic derivatives. |
5900221 | Adaptive changes in enzyme activity and metabolic pathways in adipose tissue from meal-fed rats. | A number of metabolic factors and the activity of a number of enzymes were determined in meal-fed (animals fed a single daily 2 hr meal) and nibbling (ad libitum-fed) rats. The dependency of the observed adaptive changes on the ingestion of carbohydrate was studied by feeding diets high in carbohydrate or fat. Glucose-6-phosphate dehydrogenase and NADP-malic dehydrogenase were more active in adipose tissue from high carbohydrate meal-fed rats than in tissue from ad libitum-fed rats. The activity in adipose tissue of isocitric dehydrogenase, 6-phosphogluconate dehydrogenase, and NAD-malic dehydrogenase did not increase significantly in response to meal-feeding the high carbohydrate diet. No increase in lipogenesis or enzyme activity could be demonstrated in adipose tissue from rats meal-fed a high fat diet. Lipase activity of adipose tissue was increased by high carbohydrate meal-feeding and decreased by feeding a high fat diet. The in vitro uptake of palmitate-1-(14)C by adipose tissue was depressed by a high fat diet and enhanced in rats meal-fed a high carbohydrate diet. Diaphragm or slices of liver from high fat-fed rats oxidized palmitate-1-(14)C more rapidly than did tissue from ad libitum-fed animals. Evidence is presented for the quantitative importance of citrate as a source of extramitochondrial acetyl CoA in adipose tissue of meal-eating and ad libitum-fed rats. The relationship of extramitochondrially formed citrate to the NAD-malic dehydrogenase-malic enzyme system in adipose tissue is discussed. |
5900222 | Stereospecific analyses of several vegetable fats. | The distribution of fatty acids among the positions 1, 2, and 3 of triglycerides of seven vegetable fats has been determined. The fatty positions in positions 1 and 3 are very similar in most cases, but in none of the fats is the pletely symmetrical. |
5900223 | Particle-size distribution of very low density plasma lipoproteins during fat absorption in man. | The size distributions of electrophoretically isolated subfractions of the very low density human plasma lipoproteins have been determined using electron microscopy. The primary and secondary particles observed in plasma of normal subjects after fat ingestion appear to have similar size distributions. Particles produced by corn oil feeding can be fixed by the osmium tetroxide reaction while those produced by butter fat feeding could not be fixed or made visible by this technique. Good agreement between particle size as measured by electron microscopy and particle size as predicted by ultra-centrifugal analysis was obtained. |
5900224 | Catabolism and elimination of cholesterol in germfree rats. | Three-month old germfree and conventional male rats were maintained on plete steam-sterilized, semisynthetic diet. After intravenous injection of cholesterol-26-(14)C the animals were housed in a plastic metabolism chamber for 72 hr. Expired CO(2) was collected throughout the period. The conventional rats released 50% more (14)C as (14)CO(2) than the germfree animals. The total amount of the label recovered as (14)CO(2) during the 72 hr period amounted to 30% and 19% respectively, of the original dose. In both conventional and germfree rats the release of (14)CO(2) accounted for approximately 75% of the (14)C recovered in forms other than the original cholesterol-26-(14)C; 15-20% was found incorporated in water-soluble and fat-soluble fractions other than 3Beta-OH sterol of liver and carcass while the remainder was excreted with feces and urine. After the 72 hr period the specific activities of the cholesterol in plasma and liver were lower in conventional than in germfree animals. The data express the accelerating effect of the intestinal microflora on systemic cholesterol catabolism. They demonstrate that the release of (14)CO(2) from cholesterol-26-(14)C in the intact rat is a suitable and convenient indicator of the oxidative catabolism of cholesterol. |
5900225 | Bile acids in the rat: studies in experimental occlusion of the bile duct. | Bile acids in the plasma, urine, and small intestine of adult male rats with occluded bile ducts have been studied using a method of high specificity for their determination. After bile duct ligation cholic acid rapidly accumulates in the plasma for 8 hr, remains high for a further 8 hr, and subsequently diminishes; bile acids disappear from the small intestine. During the first 12 hr after bile duct ligation the excretion of trihydroxy acids in the urine was 10 times that of the dihydroxy acids. Subsequently the two excretion rates became equal. Because bile acids have been implicated in the etiology of hepatic damage following bile duct ligation, studies have been made of the effect on the liver of removing (with cholestyramine) and supplementing (with cholic acid) the intestinal bile acid pool. The addition of cholestyramine to the stock diet prevented the rise in trihydroxy bile acids after bile duct ligation, but did not prevent the development of histological abnormalities in the liver. Supplementing the diet with cholic acid raised the plasma cholic acid levels but had little effect on the hepatic histological findings. |
5900226 | Specific sites of fatty acid sterol synthesis in isolated skin components. | Metabolic studies on isolated mouse ponents were undertaken to determine the specific sites of fatty acid and sterol synthesis. The concentrations of long-chain fatty acids and sterols and the incorporation of radioactivity from acetate-1-(14)C into these lipids are reported for various ponents and intact whole skin. Only fatty acids having chain lengths of 18 carbons or less were produced by the connective tissue cells of the dermis, while fatty acids containing 20 carbons or more, as well as the acids of 18 carbons or less, were synthesized in the upper dermis (papillary reticulum). The upper dermis also produced significant quantities of eicosenoic acid and of an octadecadienoic acid (not linoleic acid), and incorporated labeled acetate into fatty acids containing an odd number of carbons. Removal of the epidermis and adnexa diminished sterol synthesis. However, the upper region of the dermis was capable of synthesizing, from acetate, large quantities of unidentified nonsaponifiable lipids which were neither sterols nor squalene. |
5900236 | Effect of sympathomimetic compounds with beta-adrenergic effects on plasma free fatty acids in man. | Nine pounds were infused intravenously in man, and their effects on the level of plasma free fatty acids, pulse rate, and blood pressure were recorded. pound raised the level of plasma free fatty acids. Its activity in this respect could be correlated with its activity in producing Beta-adrenergic effects on the circulation; both effects were abolished by pretreatment with propranolol. It is concluded that pounds that stimulate -receptors will raise the plasma concentration of free fatty acids. |
5901154 | Glomerulonephritis: a review based on 52 renal biopsies. | The pathological findings in 52 renal biopsies are described, with emphasis on the changes seen in glomerulonephritis. There were 12 cases of poststreptococcal glomerulonephritis, eight of idiopathic membranous glomerulonephritis, and 10 of lipoid nephrosis. Poststreptococcal glomerulonephritis is subdivided into acute and persistent phases, and the latter is further defined as subacute, latent or chronic. The characteristic but not specific lesion of post-streptococcal glomerulonephritis is the development of mesangial scars. In lipoid nephrosis there are subendothelial deposits in the glomerulus. Membranous glomerulonephritis is characterized by massive heterogeneous deposits on the outside surface of the basement membrane. It is concluded that there are three well-defined types of glomerulonephritis, and although future studies may reveal interrelationships, the clinical and pathological evidence to date is sufficient to warrant their separate classification. |
5901155 | Chromosomal studies in children with mumps, chickenpox, measles and measles vaccination. | A study to assess chromosomal damage in persons with acute viral diseases was undertaken in view of conflicting reports in the literature concerning such damage. Forty children with measles, mumps, and chickenpox, or who had received measles vaccine, were investigated pared with a control group of 12 children. No greater incidence of chromosomal abnormalities was found in the study group than in the control group. |
5901156 | Cardiac myoglobin in myoglobinuria. | Studies were undertaken to determine whether significant abnormalities were present in cardiac myoglobin in a case of primary paroxysmal myoglobinuria.No qualitative abnormality was found in cardiac myoglobin from a patient with pared to normal controls, using urea starch gel electrophoresis. Quantitative analysis, however, revealed depletion of cardiac myoglobin in the patient with myoglobinuria.It is considered that the basic defect in primary paroxysmal myoglobinuria is not related to myoglobin per se, and although evidence is lacking, an autoimmune process, as encountered in some of the hemolytic anemias, may be involved in this condition. |
5901159 | Effect of dichlorphenamide on gas exchange and CSF acid-base state in chronic respiratory failure. | Dichlorphenamide was administered to 13 patients with chronic respiratory failure, and the effects on gas exchange at rest and during exercise and on the acid-base state of CSF were observed. The ventilation for a given level of CO(2) production was increased both at rest and during exercise, resulting in an increased arterial Po(2) and decreased Pco(2).The ventilatory stimulation paralleled the development of a metabolic acidosis but was not associated with tissue CO(2) accumulation. Indeed, CSF Pco(2) and the oxygenated mixed venous (rebreathing) Pco(2) fell by the same amount as arterial Pco(2). The level of CO(2) elimination after two minutes of exercise was as great for a given work load after dichlorphenamide as before. These findings do not support the view that the drug impairs CO(2) transport from tissues either at rest or during exercise. They are most consistent with the view that the primary locus of action of dichlorphenamide in therapeutic doses is the kidney. The metabolic acidosis which results is likely the basis of the respiratory stimulatin, perhaps by its effects on the CSF H(2)CO(3)-HCO(3) - system. Inhibition of carbonic anhydrase in the red cell and choroid plexus are probably unimportant effects. |
5901160 | The working capacity of subjects from an exhibition crowd. | A standard bicycle ergometer test was performed on 60 male volunteers at the Canadian National Exhibition. Most were drawn from Toronto and its environs, and "white-collar" workers predominated. Ages ranged from 19 to 61 years. The Astrand nomogram was used to predict the oxygen uptake of the 45 subjects with a normal resting pulse rate. The older subjects had a lower oxygen uptake than Scandinavian office workers, particularly relative to body weight. This conclusion is subject to the limitations of a non-random sample, but seems independent of the professional-class bias. Almost all subjects exceeded the "ideal" body weight. Working capacity was 20% greater in subjects taking regular exercise than in those who were inactive. |
5901161 | Branchial cleft anomalies: a review of 87 cases treated at the Toronto General Hospital. | The embryology, anatomy and pathology of branchial cleft anomalies are discussed and 87 cases reviewed.The most frequent anomaly was branchial cleft cyst, of which there were 77 cases. Treatment in all cases consisted plete excision.There were five cases of external branchial sinus and five cases plete branchial fistula. Sinograms were helpful in demonstrating these lesions. Excision presented little difficulty.No proved case of branchiogenic carcinoma has been found in the Toronto General Hospital. Five cases are described in which the original diagnosis was branchiogenic carcinoma-in four of these a primary tumour has already been found. The authors believe that the diagnosis of branchiogenic carcinoma should never be accepted until repeated examinations over a period of at least five years have failed to reveal a primary tumour. |
5901162 | A-scan echoencephalography. | The technique of A-scan echoencephalography is criticized in so far as it lacks objectivity and reproducibility. In the author's laboratory, the M-echo, being of higher amplitude than other intracranial echoes, is distinguished from other echoes by an averaging technique-a time exposure. Double transmission pulses indicate the theoretical position of echoes from the true mid-line and superimposition of far-side echoes ensures that the transducers are correctly aligned.The very considerable difficulties in identifying the anatomical structures giving rise to other echoes seen within the skull are outlined. They are largely due to variations in the reflected energy, depending upon the shape and orientation and position of the various interfaces with respect to the ultrasonic beam.Despite these difficulties and limitations, A-scan echoencephalography appears to have an important part to play as a simple, safe and quick form of neurological examination, if the technique can be made truly objective. |
5901354 | The MEDLARS project at the UCLA Biomedical Library. | The National Library of Medicine has established at the Biomedical Library, UCLA, a remote MEDLARS search station. The agreement between the libraries provided that the Biomedical Library in cooperation with the UCLA Health Sciences Computing Facility would reprogram MEDLARS for the IBM puter, provide personnel to be trained in machine searching at NLM, and engage in a pilot demonstration of search service to the medical staff of UCLA. This paper describes the place of the search section in the organization of the Biomedical Library and the training of personnel at NLM (the article by Garvis in this issue of the Bulletin relates the problems encountered in making two puter patible). Search service had not begun when this paper was written; it was scheduled to begin late in 1965. Plans for the future include the enlargement of the UCLA MEDLARS staff and extension of search service to a larger geographical area. |
5901355 | The UCLA MEDLARS computer system. | Under a subcontract with UCLA the Planning Research Corporation has changed the MEDLARS system to make it possible to use the IBM 7094/7040 puter instead of the Honeywell 800 for demand searches. The major tasks were the rewriting of the programs in COBOL and copying of the stored information on the narrower tapes that puters require. (In the future NLM will copy the tapes for puter users.) The differences in the software required by the puters are noted. Major and costly revisions would be needed to adapt the large MEDLARS system to the smaller IBM 1401 and puters. In general, MEDLARS is transferrable to puters of the IBM 7000 class, the new IBM 360, and those of like size, such as the CDC 1604 or UNIVAC 1108, although additional changes are necessary. Potential future improvements are suggested. |
5901356 | Topics in library technology: copying techniques. | Photocopying applications in the library include bining of previously separate material, the separation of a single item into two or more of its parts, and the selection of parts of existent material by the use of overlays. The production of catalog cards, the creation of sheet material (new book lists, reference bibliographies) from card-form materials, an Index Medicus-derived alerting service, and overdue notices copied from charge cards are among the applications exemplifying these general types. Larger-scale operations employing microfilm are noted. The distinction between copying and printing, in the light of equipment advances, is discussed. |
5901357 | MEDLARS operating experience at the University of Colorado. | For a six-month period in 1965 the University of Colorado Medical Center Library conducted a demonstration project in which MEDLARS tapes received from the National Library of Medicine were searched on a Honeywell puter located in Denver. Eighty-seven search requests were received from members of the UCMC staff during this period and successfully run. The average relevance and recall ratios were each in the neighborhood of 80 percent. Cost figures are given; it is calculated that an average search through two years' tapes costs about $200. The concept of the "search-month" is introduced, and it is shown that the average machine time per search-month will vary from 0.67 to 2 minutes. It is concluded that the technical and economic feasibility of decentralized search centers using a centrally prepared input has been demonstrated. Data are presented on the basis of which the performance of the system may be judged. |
5901358 | Topics in library technology: binding techniques. | The purpose of the library binding industry is to help the librarian maintain a valuable inventory of printed material for maximum use now and in the future. Standardization of approved materials and methods in the industry have encouraged manufacturers to develop materials and machinery for its use, and these, in turn, have enabled it to meet the increasing and changing needs of libraries with a uniform product of high quality and an economical and constantly improving service. The librarian, as custodian of the library's materials, must be the originator of the binding program and is the only one who knows the end use of each item, which is usually the factor that determines the selection of the most suitable binding. |
5901359 | Topics in library technology: labeling techniques. | Labels which do not fit on the spines of books should be placed on the upper rather than lower left corner of the front cover, because the upper corner es visible first when a volume is tilted from the shelf. None of the past methods of marking call numbers on the spines or covers of books-direct hand lettering by pen, brush, or stylus; affixing cold release characters; embossing by hot type; or gluing labels which are handlettered, typed, or printed-nor even present automatic data processing systems have offered all the advantages of the relatively new Se-Lin labeling system: legibility, reasonable speed of application, automatic protective covering, permanent bonding, and no need for a skilled letterer. Labels seem unaesthetic to some librarians, but their advantages outweigh this consideration. When only one or a few copies of the same call number are required, Se-Lin is the best system now available for libraries marking over 1,000 books a year. |
5901360 | Topics in library technology: charging systems. | Methods of circulation control, using the Newark Charging System as a prototype, are reviewed. Two criteria for a charging system in a university and special library are that it must show both location and due date of materials taken out of the library. The transaction card, charging machine, punched card, puter are devices designed to speed up conventional procedures. They are described and evaluated according to the aforementioned criteria. |
5901361 | Recent trends of biomedical offprint distribution. | The total number of substantive articles published in a random group of U. S. biomedical journals increased 34 percent from 1957 through 1962 and 52 percent from 1952 through 1962. Likewise, the total number of subscriptions increased 28 percent from 1957 through 1962 and 47 percent from 1952 through 1962. On the other hand, the rise in the number of preprints and reprints distributed reached its peak from 1952 to 1957 (37 percent); by 1962 the rate had declined, with an increase of only 4 percent from 1957 to 1962 and thus of only 43 percent for the entire period, 1952 through 1962. Replies from publishers indicate that at present the provision of preprints and reprints is merely a service in the case of almost 90 percent of the journal titles and not an enterprise undertaken for significant profit. The cause of the decline in offprint distribution should be investigated. |
5901362 | Analysis of one year's circulation at the Downstate Medical Center Library. | A survey of the circulation of books and journals at the Downstate Medical Center Library was conducted, based on cancelled circulation cards accumulated during a one-year period. Analysis of the results shows the frequency of use of various materials by several groups of borrowers and brings out important differences between circulation of books and that of journals. One of the results was pilation of a list of most frequently used journals. The findings are graphically represented by several tables and charts. |
5901363 | American medical literary firsts, 1700--1820, in the Countway Library. | bination of two major collections, those of the Harvard Medical and the Boston Medical Libraries, took place at a formal dedication of the Francis A. Countway Library of Medicine in May of 1965. As a result of this unification the historian may now consult many significant primary source materials in one research collection in Boston. Many of these works are early imprints of medical Americana. This paper discusses twenty-four imprints, from 1700 to 1820, which were firsts of their kind in American medical literature. Presented are the first American medical publication, book, pharmacopeia, mortality statistics, anatomical illustrations, transactions of a medical society, medical journal, textbook of obstetrics, medical dictionary, textbook of medicine, and official pharmacopeia. Also discussed are the first works in this country on smallpox inoculation, scarlet fever, pleurisy, public health, medical education, medical ethics, the history of medicine, surgery, epidemiology, smallpox vaccination, dentistry, meningitis, and psychiatry. An exhibit of these items in the Countway Library is planned for the spring and summer of 1966. |
5901398 | Cervical traction in the home. | The indications for and contraindications to cervical traction are discussed. The social and economic advantages to be obtained from carrying out such treatment at home are obvious. A special technique is described which does not make use of weights and in which traction is applied in a position of flexion rather than of extension. |
5901400 | A follow-up evaluation of the treatment of chronic alcoholics. | The records of 95 chronic alcoholic patients first admitted to the Addiction Research Foundation hospital, Toronto, in 1962 were examined; in 63 of these sufficient follow-up information was available for six months after hospitalization to permit further study.It was found that the prescription of tranquillizers or deterrent drugs could be related only to the individual physician's inclination toward drug therapy. Significantly more female than male patients received antidepressants and proportionately more females than males were found in the 41-50 year age group, suggesting a possible connection between menopausal age, onset of depressive symptoms, and uncontrolled drinking. No correlation was found between relative degree of sobriety and the consumption of tranquillizers or deterrent drugs, the number of follow-up interviews, or regular psychotherapy. The mean age of the totally abstinent patients was significantly higher than that of the whole group, suggesting a connection between ageing and a decline in addiction to alcohol. |
5901494 | The organization of flight muscle fibers in the Odonata. | The cytological organization of flight muscle fibers of Odonata has been investigated. These fibers, in representatives of the Zygoptera and Anisoptera, have pared and found to be similar, except that, in the former, pairs of lamellar fibrils, rather than single fibrils, alternate with the mitochondria. In each instance, in these synchronous muscles, the actin filaments of the myofibrils are found to lie opposite to and midway between pairs of myosin filaments-a configuration previously reported in asynchronous flight muscle fibers. The disposition of the T system and sarcoplasmic reticulum membranes in glutaraldehyde-fixed anisopteran muscle is described in detail: the T system tubules are shown to be radially continuous across the fiber, and are derived as openmouthed invaginations from the surface cell-membrane. The detailed organization of the dyad junctions between these tubules and the adjoining cisternae of the sarcoplasmic reticulum is described. The accessibility of the T system interior to diffusion exchange with the general extracellular milieu has been investigated by studies on the penetration of ferritin into the fiber: molecules of this marker have been found to diffuse solely along the T system tubules, and their presence in the tubule extremities adjoining the centrally placed nuclei confirms the morphological evidence suggesting that these tubules provide open diffusion channels extending across the radius of the fiber. The possible physiological role of these ponents and their distribution in synchronous muscles of insects and vertebrates and in asynchronous insect flight muscle are discussed. |
5901495 | Increased numbers of annulate lamellae in myocardium of chick embryos incubated at abnormal temperatures. | Annulate lamellae have been observed in the myocardium of 18-day-old chick embryos maintained at the normal temperature of 100 degrees F and at 90 degrees F during the last week of incubation. An increased number of annulate lamellae was observed in heart muscle of embryos incubated at 90 degrees F. This is probably caused by a persistent production of these organelles, since annulate lamellae are present in greater frequency than in 11-day-old embryos incubated at 100 degrees F. In the hypertrophic hearts of 18-day-old embryos incubated at 90 degrees F, the annulate lamellae were associated with a net increase of protein content and an elevated concentration of myocardial glycogen. It is suggested that the increased number of annulate lamellae is a sequela of reduced environmental temperature during incubation. |
5901497 | Feulgen hydrolysis of normal cells and mouse ascites tumor cells. | The effect of HCl hydrolysis on the dye content (Feulgen reaction) of normal cells and mouse ascites tumor cells was examined by means of cytophotometric measurements. After 11 min of hydrolysis, 16-day-old tumor cells showed a hypotetraploid DNA line with doubling peaks. The DNA values were in the ratios of 1:2:4:8 during all the tested hydrolysis times (3 to 21 min). The size of the nucleus and the DNA concentration did not influence the hydrolysis and the dye content. However, the time of the hydrolysis considerably influenced the dye content of normal and tumor cells. The course of the curves obtained by plotting dye absorption against hydrolysis time showed an inflection of the curve at 9 min' hydrolysis time in tumor cells, whereas the inflection occurred at 8 min in mitotic cells. These inflections were statistically significant. The DNA stem-line(1) for tumor cells shifted during different hydrolysis times pared to normal cells. The possibility is discussed of two types of DNA which differed in their acid sensitivity and which yielded atypical hydrolysis curves. |
5901498 | The permeability of rat transitional epithelium. Kertinization and the barrier to water. | Permeability barriers must exist in transitional epithelium to prevent the free flow of water from underlying blood capillaries through the epithelium into the hypertonic urine, and such a barrier has now been demonstrated in isolated bladders. This barrier is passive in function and can be destroyed by damaging the luminal surface of the transitional epithelium with sodium hydroxide and 8 M urea solutions, by digesting it with trypsin, lecithinase C, and lecithinase D, or by treating it with lipid solvents such as Triton x 100 and saponin. From this it is concluded that the barrier depends on the integrity of lipoprotein cell membranes. The barrier function is also destroyed by sodium thioglycollate solutions, and electron microscope investigations show that sodium thioglycollate damages the thick asymmetric membrane which limits the luminal face of the superficial squamous cell. Cytochemical staining shows the epithelium to contain disulfide and thiol groups and to have a concentration of these groups at the luminal margin of the superficial cells. It thus appears that the permeability barrier also depends on the presence of disulfide bridges in the epithelium, and it is presumed that these links are located in keratin. Because of the effect of thioglycollates, both on the barrier function and on the morphology of the membrane, it is suggested that keratin may be incorporated in the thick barrier membrane. It is proposed that the cells lining the urinary bladder and ureters should be regarded as a keratinizing epitheluim. |
5901499 | The fine structure of the oxytalan fiber. | Maraglas-embedded sections of periodontal membranes around continually growing incisors of Sprague-Dawley rats fixed consecutively in cold glutaraldehyde and Palade's 1 % buffered osmium tetroxide were examined under the electron microscope for oxytalan connective tissue fibers. Oxytalan fibers were noted to consist of bundles of filaments approximately 150 A in diameter with an interfilamentous amorphous substance of approximately the same diameter. A periodicity of fibrillar elements was not obvious. |
5901500 | Fine structure of desmosomes. , hemidesmosomes, and an adepidermal globular layer in developing newt epidermis. | The skin of late embryonic, larval, and young postmetamorphic newts, Taricha torosa, has been examined with particular reference to areas of cellular attachment. Stereo electron microscopic techniques and special staining methods for extracellular materials were utilized in addition to conventional avenues of ultrastructural study to investigate the fine architecture of desmosomes, hemidesmosomes, their associated filament systems, and extracellular materials. No evidence has been found that continuity of tonofilaments between adjacent cells exists at desmosomes. Rather, most of the tonofilaments which approach desmosomes (and perhaps also hemidesmosomes) course toward the "attachment plaque" and then loop, either outside the plaque or within it, and return into the main filament tracts of the cell. These facts suggest that the filamentous framework provides intracellular tensile support while adhesion is a product of extracellular materials which accumulate at attachment sites. Evidence is presented that the extracellular material is arranged as pillars or partitions which are continuous with or layered upon the outer unit cell membrane leaflets and adjoined in a discontinuous dense midline of the desmosome. A similar analysis has been made of extracellular materials associated with hemidesmosomes along the basal surface of epidermal cells. An adepidermal globular zone, separating the basal cell boundary from the underlying basal lamina and collagenous lamellae during larval stages, has been interpreted from enzyme and solvent extraction study as a plex, the function of which remains obscure. These observations are discussed in relation to prevailing theories of cellular adhesion and epidermal differentiation. They appear consistent with the concept that a wide range of adhesive specializations exists in nature, and that the more highly organized of these, such as large desmosomes and hemidesmosomes, serve as strong, highly supported attachment sites, supplemental in function to a more generalized aggregating mechanism. |
5901501 | Redundant myelin sheaths and other ultrastructural features of the toad cerebellum. | Some of the myelin sheaths in the cerebellum of normal adult toads exhibit extensive evaginations of their full thickness. These redundant flaps of myelin are collapsed; i.e., they contain no axon and have no lumen. They extend away from the parent axonal myelin sheaths and tend to enfold other myelinated fibers or granule cell perikarya, producing bizarre configurations of myelin and what appear to be partially pletely myelinated cell bodies. In some instances, only the redundant flap of myelin appears in the plane of section, and its attachment to an axonal myelin sheath in another plane is only inferred. Single lamellae of myelin also tend to invest cerebellar granule cells and other processes, and these too appear to fold on themselves producing two- or four-layered segments. It is suggested that there are two phases of myelinogenesis: an initial "wrapping" phase, followed by a prolonged second phase during which internodes of myelin increase in both length and girth by a process other than wrapping, and that the occurrence of redundant myelin sheaths may reflect overgrowth of myelin during the second phase. Observations on the general organization of the toad cerebellum and on the ultrastructural cytology of its layers are also presented. |
5901502 | A fine structural analysis of the epidermis of the earthworm, Lumbricus terrestris L. | A fine structural analysis of the cuticle, epidermal epithelium, and underlying fibrous tissue of the earthworm is presented. The extreme scarcity or absence of fibroblasts in this animal is pointed out. This finding is further evidence for the epithelial origin of the cuticular fibers, and suggests that at least some of the collagenous connective tissue fibers in the interior of this animal are epithelial in origin. The junctional specializations that unite epithelial cells in the epidermis and intestine are described. Of special interest is the fact that the septate desmosome rather than the tight junction is found in these epithelia. It is shown that the septa are not extensions of the plasma membrane across the intercellular gap. Finally, the nature of the small ellipsoidal bodies that are embedded in the outer layer of the cuticle is discussed. |
5901503 | A radioautographic study with H3-thymidine on adrenal medulla nuclei of rats intermittently exposed to cold. | A considerable decrease (24 to 40%) of DNA content per nucleus previously observed in the adrenal medulla of rats exposed intermittently to cold is followed by restoration to normal and supranormal values. This phenomenon has now been studied by use of H(3)-thymidine, which was given to normal rats, to rats exposed to cold, and to animals brought to room temperature after cold exposure. In the first two conditions, no significant labeling of nuclei was observed. In the third, labeling took place clearly in the 1st 3 days. The grain counts showed that the early labeled nuclei had more grains than those labeled later, indicating differences in the rate of DNA synthesis. A statistically significant correlation was found, on the same nuclei, between amount of Feulgen dye and number of grains. It is concluded that net synthesis of DNA takes place in the phase of recovery from cold. This fact is not related to cell division, as no mitoses could ever be detected, but rather to the cold-induced loss of DNA. Clear demonstration is thus given of a marked variation in the amount of DNA per nucleus in relation to the functional conditions of adrenal medulla cells. |
5901591 | Polycystic ovaries associated with congenital adrenal hyperplasia. | Polycystic ovaries were found in a 16-year-old female with congenital absence of vagina, male-like external genitalia, and congenital adrenal hyperplasia. Masculinization was sufficiently severe to cause the patient to be reared as a male. Biochemical studies of ovarian tissue revealed hyperactivity and an imbalance of enzyme systems concerned with steroid-hormone biosynthesis, which led to production of large amounts of androgens. The pathway towards estrogens was preserved but less efficient than normal. Urinary steroid metabolites before and after hysterectomy and bilateral salpingo-oophorectomy revealed an absence of Porter-Silber chromogens and tetrahydrocortisone. Excretion of aldosterone was normal and that of corticosterone slightly higher than normal. The patterns of urinary 17-ketosteroids, pregnanediol, pregnanetriol and pregnanetriolone were similar to monly seen in congenital adrenal hyperplasia with steroid 21-hydroxylase deficiency. Urinary estrogens after panhysterectomy were low, being in the post-menopausal range. The pathogenesis of polycystic ovaries and their possible contribution to masculinization are discussed. |
5902237 | Thrombohemorrhagic response to noradrenaline following heterologous blood transfusion: a preliminary report. | Normal rats are extremely tolerant to heterologous blood transfusion; however, after subcutaneous injection of noradrenaline, they lose this tolerance and respond with severe thrombohemorrhagic reactions both at the site of injection and in internal organs, particularly the kidney.In histological structure, the topical and general manifestations of this thrombohemorrhagic response are virtually identical with those of the local and general Sanarelli-Shwartzman phenomenon, respectively.Among the blood specimens tested, those of the dog, cat, rabbit, guinea pig, chicken and man were most effective in inducing this type of noradrenaline hypersensitivity. The blood of the duck and hamster as well as homologous rat blood proved to be virtually pletely inefficacious.The possible theoretical and clinical implications of a noradrenaline test for potential blood-borne thrombohemorrhagic factors are briefly discussed. |
5902238 | Accidental deaths among British Columbia Indians. | A statistical and epidemiological review of British Columbia native Indian and non-Indian mortality revealed that accidents were the leading cause of death among Indians but ranked only fourth among non-Indians. Comparison of accidental death rates by age and sex showed that, without exception, the rates among Indians were considerably higher than the corressponding rates for non-Indians. While the Indians represented some 2% of the total population of British Columbia, they accounted for over 10% of the total accident fatalities, 29% of drownings, and 21% of fatal burns.Socioeconomic, environmental and psychosocial factors and excessive drinking are considered the chief causes responsible for this rather unusual epidemiological phenomenon.This study revealed certain hazardous conditions which are specific to the Indian's present way of life. In the authors' opinion the recognition of these specific hazards is imperative for the planning of effective preventive campaigns. |
5902239 | Psychiatric seminars for the general practitioner. | A program of case-centred seminars in psychiatry designed for general practitioners was begun in Ontario during 1965. It came into being as the result of the cooperative endeavour of the Ontario Chapter, College of General Practice, the Ontario Psychiatric Association and the Division of Postgraduate Medicine, University of Toronto. The program was conducted on a regional rather than on a centralized basis. No general practitioner had to travel more than 30 miles to his seminar, thus ensuring regular weekly attendance for an average of 12 weeks. The Ontario Chapter recruited the general practitioners, the Psychiatric Association selected appropriate regional psychiatrists, and the University gave a brief preliminary course for these psychiatrists. Nineteen separate groups were formed in 13 different Ontario cities, with an average total weekly attendance of 120. A review conference of participating psychiatrists and general practitioners, held in November 1965, developed plans for renewal and extension of the program for 1966. This approach seems especially appropriate for large geographic regions with scattered populations. |
5902385 | Endocarditis in mice infected with Coxsackie virus B4. | Endocarditis has not been generally considered to be plication of viral infection. We show that mural and valvular endocarditis can be produced in mice infected with Coxsackie virus B(4). Because this monly infects man and is highly cardiotropic, it is important to know whether it produces valvular lesions in man similar to those we describe in mice. |
5902386 | Hormone-induced repression of a peroxidase isozyme in plant tissue. | Young stem sections of dwarf peas (Progress No. 9) grown in light contain at least seven peroxidase isozymes separable by electrophoresis on starch gel. An eighth isozyme appears as the tissue elongates and ages, on or off the plant. The appearance of this isozyme in excised sections is repressed by application of the plant growth hormone, indole-3-acetic acid. |
5902387 | Radium isotope accumulation in animal thyroids. | Uranium and thorium daughters are ten times more concentrated in thyroids from some bovine animals than in the teeth of the same animals. These radioactive isotopes are believed to be from natural sources, but their resulting annual dosage of thyroid radiation has exceeded that from iodine-131 fallout. |
5902388 | Blood oxygen and ecology of porpoises of three genera. | Blood volumes, hemoglobin concentrations, packed-cell volumes, and heart weights were determined in three genera of propoises which differ from one another in behavior and ecology. The estimate for the total blood-oxygen content of the highly active, deep-diving, pelagic species Phocoenoides dalli was almost three times greater than that for the coastaldwelling species Tursiops truncatus, and about 70 percent greater than for the less active pelagic species, Lagenorhynchus obliquidens. Heart weights of Phocoenoides dalli were about 140 percent greater than in Tursiops truncatus and 55 percent greater than in Logenorhynchus obliquidens. |
5902389 | Hyperphagia in ruminants induced by a depressant. | Attempts at causing ventromedial hyperphagia in ruminants have been hitherto unsuccessful. In our experiments perfusion of the ventriculocisternal system with pentobarbital caused marked hyperphagia. This suggests that the ventromedial hypothalamic area is functioning in ruminants, probably as in monogastric animals, by inhibiting the lateral area. |
5902390 | Serum concentration: effects on cycle and x-ray sensitivity of mammalian cells. | If the content of serum in the culture medium of exponentially growing Chinese hamster cells is below optimum (15 percent), the doubling time and the resistance to x-irradiation of the cells are increased. In synchronously dividing populations the increase in doubling time is primarily caused by increase in duration of the postmitotic (G(1)) phase of the cells; this phase is relatively radiation resistant. The response of the cells growing synchronously is related quantitatively to the response of the cells dividing randomly. |
5902391 | Patterns of alkaline phosphatase in developing Drosophila. | Electrophoretic study of alkaline phosphatase in developing Drosophila shows that different stages are characterized by the appearance and disappearance of organ-specific enzyme bands. A new electrophoretic variant, from adult hindgut, is controlled by the second chromosome locus Aph-2. |
5902392 | Transverse gradient electrophoresis: protein homogeneity test and subfractionation technique. | Electrophoresis of protein (including enzyme) was conducted in a gel medium across which, transverse to the direction of protein migration, a continuous (p)H gradient extends. Any splitting of a resultant trace for the change of protein mobility with (p)H suggests both protein heterogeneity and the (p)H conditions under which further purification and subfractionation may best be pursued. |
5902393 | Hyperbaric oxygenation: the eye as a limiting factor. | In dogs exposed to 100 percent oxygen at 3 atmospheres absolute pressure for more than 4 hours, a characteristic retinal lesion, manifested as the cytoid-body change, occurs. The selectivity of this injury suggests that the eye may be used as a sensitive indicator and as a site for study of oxygen toxicity. The cytoid body, an entity of disputed genesis, was produced experimentally for the first time. |
5902394 | Salt transport organelle in Artemia salenis (brine shrimp). | The branchiae of Artemia adapted to triple-strength sea water (105 per mil salinity) were studied with the electron microscope. The epithelial lining of the metepipodite segment possesses posed of stacks of disc-shaped mitochondria interlaced with flattened extensions of a canalicular system that in municates with the plasma-bound surface of the cells. The distance between the canalicular and mitochondrial membranes is small and quite constant. The marked similarity to "mitochondrial pumps" in the anal papillae of tosquito larvae suggests that the organelle is concerned with salt transport. |
5902395 | Weaning of young rats: effect of time on behavior. | Male rats were weaned on the 15th, 16th, 17th, 25th, and 30th day of postnatal life. The rate of elaboration of the conditioned reflex at 8 months of age and the stability of the memory trace at 12 months were studied. Compared with rats weaned at 30 days of age, those weaned on day 15 elaborated the conditioned reflex much more slowly and the memory trace was less firm. Rats weaned on days 16 and 17 elaborated the conditioned reflex more quickly than rats weaned on day 15 but more slowly than those weaned on day 30. In all groups the memory trace showed the same stability and was significantly firmer than in rats weaned on day 15. The higher nervous activity of rats weaned at the age of 25 days more nearly resembles that of rats weaned at 15 days than the 30th day. |
5902569 | Thymus-dependent areas in the lymphoid organs of neonatally thymectomized mice. | Specific areas of lymphocyte depletion, termed thymus-dependent areas, have been delineated in neonatally thymectomized C3H/Bi and F(1) (C57BL x C3H/Bi) mice. They occur within the lymphoid follicles of the spleen immediately surrounding the central arterioles, and constitute the mid and deep cortical zones of the lymph nodes. These depleted areas appear in healthy thymectomized mice as early as 3 wk after operation but, in mice which survive for more than 6 to 7 wk, the thymus-dependent areas are repopulated by rapidly dividing pyroninophilic cells, the majority of which are immature plasma cells. Syngeneic thymus cells, labeled in vitro with tritiated adenosine localize preferentially in the thymus-dependent areas after intravenous injection. Similarly labeled spleen cells also accumulate in these areas but, in addition, are distributed at the periphery of splenic follicles and in the outer cortical zone of the lymph nodes. Many more spleen than thymus cells enter the lymphoid tissues and the spleen appears to be the primary target. The apparent paradox that syngeneic thymus cells are less efficient than spleen cells in restoring neonatally thymectomized mice to normality is discussed in the light of these results and possible routes by which the migrating cells could enter the lymphoid tissues are considered. The origin of the plasma cells which repopulate the lymphocyte depleted areas is also discussed. It is concluded that the normal thymus produces cells which contribute directly to the migratory or circulatory lymphocyte population but that there also exists another source of supply for the plasma cell series. These two systems may function synergistically so that the thymus may control, directly or indirectly, the balance of cell populations within the body. |
5902570 | In vitro studies on radiation lymphoid recovery of mouse spleen. | In vitro studies, utilizing an organ culture method were reported on mutual interactions between irradiated spleen, normal bone marrow, and thymus. It has been shown; (a) that singly isolated spleen explants were incapable of lymphoid regeneration, (b) thymus had no stimulatory effect on spleen regeneration, (c) bone marrow interacted synergistically with spleen leading to appearance of lymphoid cells which were not detected in singly isolated bone marrow or spleen, and (d) no stimulation of lymphopoiesis in bone marrow was conferred by thymus in the absence of spleen. The results are discussed in terms of possible mechanisms involved in lymphoid radiation recovery in vivo. |
5902571 | Alterations in protein and nucleic acid metabolism of lymphoma 6C3HED-og cells in mice given guinea pig serum. | Lymphoma 6C3HED-OG cells, known from previous work to be susceptible to the effects of guinea pig serum in vivo and dependent upon extrinsic asparagine for protein synthesis and growth in vitro, remained for the most part morphologically intact and countable in the electronic cell counter following exposures of 1 and 2 hr to the effects of heated (56 degrees C, 30 min) guinea pig serum injected into the peritoneal cavities of mice in which the lymphoma cells were growing rapidly; after exposures of 4 and 6 hr the bulk of the -OG cells remained still intact and countable in the cell counter, though by this time a small proportion of them (5 to 12%) proved stainable with eosin in wet preparations) hence were presumably nonviable. After 12, 16, and 24 hr of exposure, however, the bulk of the -OG cells were either lysed or fragmented, to the extent that they did not register in the cell counter. Morphologic studies of the cells exposed 16 and 24 hr to the effects of heated guinea pig serum in vivo, disclosed that most of the cells then remaining were either frankly necrotic or greatly altered otherwise, marked vacuolation of the cytoplasm being the most conspicuous alteration in cells not yet obviously necrotic. Long before the bulk of the Lymphoma 6C3HED-OG cells had e conspicuously changed morphologically following exposure to the effects of heated guinea pig serum in vivo, they manifested striking alterations in protein metabolism, as was disclosed by "pulse" studies with radioactive valine. For example, the protein metabolism of -OG cells, as measured by their incorporation of L-valine-C(14), was sharply curtailed following 15 min of exposure to heated guinea pig serum in vivo, pared with valine incorporation by cells labeled immediately after exposure to the guinea pig serum. Following exposure to heated guinea pig serum during 60 min, -OG cells incorporated less than half as much L-valine-C(14) as did cells labeled immediately after exposure, and the incorporation of L-valine-C(14) was still less after 120 min of exposure. By contrast, Lymphoma -RG1 cells, known from previous work to be wholly insusceptible to the effects of guinea pig serum in vivo and independent of need for extrinsic asparagine for protein synthesis and growth in vitro, showed no curtailment whatever of protein synthesis following exposures to the effects of heated guinea pig serum in vivo during periods of 15, 60, and 120 min. Reasons are given for considering the prompt inhibition of protein synthesis in the asparagine-dependent -OG cells a direct result of asparagine-deprivation induced in vivo by the injected guinea pig serum, the L-asparaginase of which presumably converted the available L-asparagine of the host to L-aspartic acid that was not taken up by the -OG cells. The synthesis of deoxyribonucleic acid by Lymphoma 6C3HED-OG cells, as measured by the incorporation of thymidme-H(3), determined with the aid of liquid scintillation counting and autoradiography, was also altered by exposure of the lymphoma cells to the effects of heated guinea pig serum in vivo, though not during exposures of 15 and 60 min; only after an exposure of 120 min did the population of -OG cells incorporate notably less thymidine-H(3) than did control populations, though after 240 min of exposure the -OG cells incorporated less than one-fifth as much tritiated thymidineas had -OG cells exposed to heated guinea pig serum for 60 min or to heated horse serum for periods up to 240 min. Autoradiographs indicated that DNA synthesis by -OG cells normally proceeds at an intense level that leads to some 60% of these cells being heavily labeled in autoradiographs at any given time; after exposure to the effects of heated guinea pig serum during 2 and 4 hr in vivo, however, the lymphoma cells lost their ability to incorporate enough tritiated thymidine to e heavily labeled, but approximately the same proportion of them (56 to 58%) retained their ability to incorporate sufficient tritiated thymidine to e lightly labeled. The possibility is considered that the inhibition of DNA synthesis in the asparagine-dependent -OG cells exposed to the effects of heated guinea pig serum in vivo may be secondary to the previously manifest inhibition of protein synthesis. Further, in tests of ribonucleic acid metabolism of Lymphoma 6C3HED-OG cells after exposure to the effects of heated guinea pig serum in vivo during periods of 15, 60, 120, and 240 min, the findings indicated that the ability of the lymphoma cells to synthesize RNA, as measured by their capacity to incorporate uridine-5-H(3), remained unaltered during the exposures of 15, 60, and 120 min, but was substantially reduced following 240 min of exposure. The findings are considered in relation to the probability, disclosed in part by previous studies, that heated guinea pig serum brings about its effects upon Lymphoma 6C3HED-OG cells in vivo by providing active L-asparaginase in large amounts, which presumably converts the available (extracellular) asparagine of the host to aspartic acid, the latter not being taken up by the lymphoma cells in vivo or in vitro. Hence it seems likely that heated guinea pig serum in this way brings about a state of asparagine deprivation that is responsible for the sequential metabolic and morphologic alterations that e manifest in asparagine-dependent Lymphoma 6C3HED-OG cells following their exposure to the effects of guinea pig serum in vivo, as here described. |
5902703 | Anorexia nervosa: the course of 15 patients treated from 20 to 30 years previously. | A follow-up study, after 20 to 30 years, of 15 patients with anorexia nervosa, formerly treated by the authors, revealed that only one patient failed to recover from the initial illness, and she ultimately became permanently incapacitated. Three patients have had neurotic symptoms periodically during the years following recovery, and one other became very thin in later life, but these four have been able to carry on fairly adequately for the most part. The remaining 10 patients have lived useful, well-adjusted lives, free of symptoms over the years.This study shows that despite the apparently severe emotional disturbances reflected in the marked physical changes that take place in young people suffering from this syndrome, a deep-rooted psychoneurotic or psychotic predisposition does not necessarily exist; the majority of the patients in this series recovered and remained well after relatively simple treatment. |
5902704 | Selective coronary arteriography. | The technique of selective coronary arteriography, as described originally by Sones, was employed in 255 patients. Successful catheterization of both coronary arteries was carried out in 88% of these patients, and in the last 100 examinations both coronary arteries were entered in 95 patients. Selective coronary arteriography is a useful diagnostic tool but is a potentially hazardous form of examination as we encountered four episodes of ventricular fibrillation in the present series. |
5902705 | Intrauterine contraception. | Intrauterine devices have been used for over 2000 years. The modern devices (loop, coil and bow) were developed in 1959. The data on 11,222 first insertions from 43 contributing institutions were analyzed by the National Committee on Maternal Health. With the intrauterine loop, expulsions occurred in less than 10% of patients, removals for medical and personal reasons in a further 15%, and pelvic infections in 1.7% during the first year following insertion. Pregnancies occurred during the first year in 2.4% of patients fitted with a loop. Typical of the modern intrauterine devices, the loop is highly effective, readily accepted, and well tolerated by approximately 75% of patients. |
5902706 | Progress in tetanus prophylaxis: the advent of human antitoxin. | Injections of tetanus antitoxin of animal origin frequently cause serious disability and sometimes death. Despite world-wide knowledge of these effects, millions of prophylactic injections of equine tetanus antitoxin are given annually, and it is continually proposed that the dosage be increased in order to obtain higher "protective" levels in the serum, a procedure which would increase the incidence and severity of reactions. Furthermore, equine antitoxin frequently fails to prevent tetanus.Tetanus antitoxin of human origin is available which carries no risk plications and confers a higher degree of immunity more quickly than equine antitoxin. The cost of treating reactions to horse serum, together with the financial loss incurred by work-absence, far outweighs the cost of human antitoxin. In the author's opinion, the use, in this country, of antitoxin of animal origin is no longer medically acceptable and may well prove legally indefensible. |
5903089 | Repair of thermal injury of Staphylococcus aureus. | Iandolo, John J. (University of Illinois, Urbana), and Z. John Ordal. Repair of thermal injury of Staphylococcus aureus. J. Bacteriol. 91:134-142. 1966.-Exposure of Staphylococcus aureus MF 31 to sublethal temperatures produced a temporary change in the salt tolerance and growth of the organism. After sublethal heat treatment at 55 C for 15 min, more than 99% of the viable population was unable to reproduce on media containing 7.5% NaCl. The data presented demonstrate that thermal injury, in part, occurred owing to changes in the cell membrane, which allowed soluble ponents to leak into the heating menstruum. When the cells were placed in a limiting plete recovery did not occur, regardless of the incubation time. The temperature and the pH which produced the optimal rate of recovery were similar to those described previously for the multiplication of uninjured cells. However, the rate of recovery as well as the unchanging total count during recovery indicated that cell multiplication was not a factor during the recovery process. The nutrient requirements for plete recovery of injured cells consisted of a solution containing an energy source, such as glucose, a mixture of amino acids, and phosphate. The use of the metabolic inhibitors, penicillin, cycloserine, 2,4-dinitrophenol, and chloramphenicol, did not inhibit recovery. Actinomycin D, pletely suppressed recovery. This result implied that ribonucleic acid synthesis was particularly involved; this inference was substantiated by radio tracer experiments. The rate at which label was incorporated in the nucleic acid fraction paralleled that of recovery and the return of salt tolerance. |
5903090 | Genetic relatedness among mycoplasmas as determined by nucleic acid homology. | Reich, Paul R. (National Institutes of Health, Bethesda, Md.), Norman L. Somerson, James A. Rose, and Sherman M. Weissman. Genetic relatedness among mycoplasmas as determined by nucleic acid homology. J. Bacteriol. 91:153-160. 1966.-A sensitive membrane filter method to detect nucleic acid homology was used to determine genetic relatedness among mycoplasma isolates. Deoxyribonucleic acid (DNA) was isolated from mycoplasmas and used as a primer for synthesis of plementary ribonucleic acid (RNA) by the enzyme RNA polymerase. DNA from each mycoplasma isolate tested was reacted separately plementary RNA synthesized with homologous or heterologous DNA as primer. The quantity of DNA-RNA hybrids formed was assayed by the nitrocellulose membrane filter method. The amount of radioactivity bound to the membrane filter was used to measure the degree of homology between the nucleic acids. The three mycoplasma isolates from human oral cavities (DC 63, V2785, Botteicher) and the prototype strain PG21 placed in the Mycoplasma hominis type 1 group by gel diffusion plement-fixation testing were investigated with this technique. Analysis of the data confirmed their immunological grouping with the M. hominis type 1 and their distinction from other human mycoplasmas. In contrast to the data from immunological studies, none of the four isolates tested appeared to be identical to any other. Preliminary experiments with DNA from four other mycoplasma isolates from tissue cultures inoculated with human material revealed them to be closely related, and possibly identical. The advantages of this nucleic acid homology technique for the study of relatedness among mycoplasmas are described. |
5903088 | Arginine metabolism in Halobacterium salinarium, an obligately halophilic bacterium. | Dundas, Ian E. D. (University of Illinois, Urbana), and H. Orin Halvorson. Arginine metabolism in Halobacterium salinarium, an obligately halophilic bacterium. J. Bacteriol. 91:113-119. 1966.-Arginine was shown to be essential for growth of Halobacterium salinarium strain 1 in a chemically defined medium. Citrulline was the pound which could substitute for arginine without affecting growth. Resting cells of H. salinarium converted arginine to citrulline and citrulline to ornithine. Cells grown in an arginine-free medium with C(14)-ureido-labeled citrulline incorporated the isotope mainly into the arginine of their proteins. The enzymes arginine desimidase and ornithine transcarbamylase were found and studied in cell-free extracts of H. salinarium. Experiments indicated that arginine was degraded in H. salinarium by arginine desimidase to citrulline, and that citrulline was further degraded by ornithine transcarbamylase to carbamyl phosphate and ornithine. Synthesis of arginine from citrulline seems to occur via the formation of argininosuccinic acid. |
5903092 | Elution of exocellular enzymes from Saccharomyces fragilis and Saccharomyces cerevisiae. | Weimberg, Ralph (Northern Regional Research Laboratory, Peoria, Ill.), and William L. Orton. Elution of exocellular enzymes from Saccharomyces fragilis and Saccharomyces cerevisiae. J. Bacteriol. 91:1-13. 1966.-Invertase and acid phosphatase are repressible exocellular enzymes in Saccharomyces fragilis and S. cerevisiae. The conditions for eluting these enzymes from both organisms pared. Either KCl or beta-mercaptoethanol eluted the enzymes from S. fragilis, and the amounts eluted varied quantitatively according to the physiological age of the organism. In addition to eluting enzymatic activity from the cells, these reagents also caused a large increase in the amount of activity that remained associated with the cells of S. fragilis. Invertase and acid phosphatase were not removed from cells of S. cerevisiae by KCl or beta-mercaptoethanol. These enzymes were separated from S. cerevisiae cells only when there was some degree of cell-wall digestion by snail gut fluid. |
5903091 | Properties and distribution of intracellular putrescine in a pseudomonas. | Kim, Ki-Han (Wayne State University, Detroit, Mich.). Properties and distribution of intracellular putrescine in a Pseudomonas. J. Bacteriol. 91:193-197. 1966.-A Pseudomonas species which contains putrescine as the only intracellular polyamine was used to study the distribution of putrescine in the cells and the changes in putrescine content upon nitrogen or carbon and nitrogen starvation. In the cell-free extract, approximately 80 to 90% of the putrescine was found in the soluble fraction, and the rest was found in the ribosomal fraction; 50% of the putrescine could be removed from the cells by nitrogen starvation. Putrescine content in the ribosomes prepared from nitrogen-starved cells was about one-half of that in the unstarved cells. Putrescine was found in both 30S and 50S ribosomal particles. In the presence of 10(-3)m Mg(++), the ribosomal particles did not exchange bound putrescine for free putrescine, but did incorporate free spermine from the medium. Cells grown on glucose-NH(3) medium contained large amounts of acetyl putrescine. Cells grown on putrescine contained negligible amounts of acetyl putrescine, but readily formed acetyl putrescine when subjected to starvation. |
5903094 | Biochemistry of nitrate respiration in Pseudomonas stutzeri. I. Aerobic and nitrate respiration routes of carbohydrate catabolism. | Spangler, W. J. (Oregon State University, Corvallis), and C. M. Gilmour. Biochemistry of nitrate respiration in Pseudomonas stutzeri. I. Aerobic and nitrate respiration routes of carbohydrate catabolism. J. Bacteriol. 91:245-250. 1966.-The metabolic pathways of glucose catabolism were studied in Pseudomonas stutzeri under aerobic conditions and under conditions of nitrate respiration. Studies on both glucose and gluconate catabolism, by the radiorespirometric method, indicated that these substrates are degraded in the same manner, i.e., the Entner-Doudoroff and pentose phosphate pathways. There appeared to be no major shift in primary metabolic pathways when nitrate was used as the terminal hydrogen acceptor in nitrate respiration as opposed to aerobic respiration with free molecular oxygen. It was shown that glucose is not degraded to any appreciable extent under anaerobic conditions in the absence of nitrate. Tentative evidence suggests that the tricarboxylic acid cycle functions under both conditions of oxygen relationships and that the rate of carbon oxidation via the tricarboxylic acid cycle is slower with nitrate respiration than under aerobic conditions. |
5903095 | Agrobacterium tumefaciens Conn. 3. Effect of thermal shock on bacteria in relation to tumorinducing ability. | Stonier, Tom (Manhattan College, Bronx, N.Y.), Robert E. Beardsley, Lowell Parsons, and James McSharry. Agrobacterium tumefaciens Conn. III. Effect of thermal shock on bacteria in relation to tumor-inducing ability. J. Bacteriol. 91:266-269. 1966.-Bacteria heated to 42 C for 30 min exhibit a decrease in tumor-initiating ability without a detectable loss in viability. The thermal shock inhibits subsequent bacterial growth for up to 1.5 hr. As bacterial growth recovers, so does tumor-initiating ability. Respiration of the culture is somewhat increased by the heat treatment. The data suggest that living, actively respiring bacteria do not induce tumors unless they are also growing. The results also point to the necessity for excluding bacterial growth inhibition when interpreting data on the effect of various agents on tumor initiation. |
5903093 | Adenovirus antibody measured by the passive hemagglutination test. | Lefkowitz, Stanley S. (Variety Children's Research Foundation, Miami, Fla.), Julia A. Williams, Bernard E. Howard, and M. Michael Sigel. Adenovirus antibody measured by the passive hemagglutination test. J. Bacteriol. 91:205-212. 1966.-Rabbits immunized intravenously with adenovirus type 5 antigen were tested for antibody titers by use of the passive hemagglutination test (PHA). Primary and secondary responses were studied, and the class of antibody was determined by means of density gradient centrifugation and reduction with 2-mercaptoethanol (ME). It was found that the PHA was 10 to 100 times more sensitive plement-fixation and neutralization tests for the detection of antibodies to adenovirus. The immunological response to primary immunization was dependent on the dose of antigen, with antibody appearing in as early as 3 days. After secondary stimulation with the same antigen, there was a rapid response which appeared to be less dose-dependent. It was found that a heavy 19S antibody sensitive to ME was produced early and was followed by a lighter, presumably 7S, ME-resistant antibody. Upon secondary stimulation, both 7S and 19S antibody increased to levels greater than those of the primary injection. |
5903096 | Effect of actinomycin D on immune antibody, normal antibody, and complement. | Muschel, Louis H. (University of Minnesota, Minneapolis), Jean L. Jackson, and Karen Schmoker. Effect of actinomycin D on immune antibody, normal antibody, plement. J. Bacteriol. 91:270-272. 1966.-The effect of actinomycin D on the immune response, when the antibiotic was administered to rabbits simultaneously with antigen, and its effect on naturally occurring levels of antibody plement were determined. Those amounts of the antibiotic that effected a significant suppression of the immune response against deliberately injected antigens did not cause a decline in levels of naturally occurring antibody. Complement titers were also refractory to the antibiotic. |
5903098 | Cyst formation and poly-beta-hydroxybutyric acid accumulation in Azotobacter. | Stevenson, L. H. (Louisiana State University, Baton Rouge), and M. D. Socolofsky. Cyst formation and poly-beta-hydroxybutyric acid accumulation in Azotobacter. J. Bacteriol. 91:304-310. 1966.-The relationship between cyst formation and the accumulation of poly-beta-hydroxybutyric acid (PHB) in Azotobacter vinelandii (A. agilis) was investigated. After various periods of growth, the cells were harvested, and the amount of PHB and the extent of encystment were determined. The polymer content of the cells increased sharply and reached a maximum on the 2nd day of growth followed by a gradual decline as the culture aged. At maximal accumulation, the PHB content was 35% of the dry weight, and the PHB-nitrogen ratio was 11:1. Those substrates promoting the highest polymer content (glucose, butanol) also promoted 95 to 100% encystment. Manipulation of the carbon and nitrogen supply in the medium indicated that both the maximal PHB content and the extent of cyst formation could be controlled. A direct correlation was noted between the amount of polymer accumulated and the percentage of cysts formed, indicating a possible role of PHB as a carbon or energy source, or both, for the encystment process. |
5903097 | Nutritional requirements of anaerobic spirochetes. I. Demonstration of isobutyrate and bicarbonate as growth factors for a strain of Treponema microdentium. | Hardy, Paul H., Jr. (The Johns Hopkins University School of Medicine, Baltimore, Md.), and Carole O. Munro. Nutritional requirements of anaerobic spirochetes. I. Demonstration of isobutyrate and bicarbonate as growth factors for a strain of Treponema microdentium. J. Bacteriol. 91:27-32. 1966.-The previously reported ability of a microaerophilic diphtheroid to support the growth of some oral spirochetes resides in the acid-distillable fraction of the culture fluid. This fraction can be replaced by isobutyrate and, to a lesser extent, by 2-methylbutyrate. When media are supplemented with isobutyrate alone, there is a prolonged lag phase before spirochetal mences, but when sodium bicarbonate is also added the lag phase is shortened, and both the growth rate and the total yield are increased. Serum, in low concentration, also acts as a growth stimulant, but it is inhibitory when present at higher concentrations. |
5903099 | Ribonucleic acid and ribosomes of Bacillus stearothermophilus. | Saunders, Grady F. (University of Illinois, Urbana), and L. Leon Campbell. Ribonucleic acid and ribosomes of Bacillus stearothermophilus. J. Bacteriol. 91:332-339. 1966.-The ability of some thermophilic bacteria to grow at temperatures as high as 76 C emphasizes the remarkable thermal stability of their crucial macromolecules. An investigation of the ribonucleic acid (RNA) and ribosomes of Bacillus stearothermophilus was conducted. Washed log-phase cells were disrupted either by sonic treatment or by alumina grinding in 10(-2)m MgCl(2)-10(-2)m tris-(hydroxymethyl)aminomethane buffer, pH 7.4 (TM buffer). Ultracentrifugal analysis revealed peaks at 72.5S, 101S, and 135S, with the 101S peak being the most prominent. By lowering the Mg(++) concentration to 10(-3)m, the ribosome preparation was dissociated to give 40S, 31S, and 54S peaks. These in turn were reassociated in the presence of 10(-2)m Mg(++) to give the larger 73S and 135S particles. When heated in TM buffer, Escherichia coli ribosomes began a gradual dissociation at 58 C, and at 70 C underwent a large hyperchromic shift with a T(m) at 72.8 C. In contrast, B. stearothermophilus ribosomes did not show a hyperchromic shift below 70 C; they had a T(m) of 77.9 C. The thermal denaturation curves of the 4S, 16S, and 23S RNA from both organisms were virtually identical. The gross amino position of B. stearothermophilus ribosomes showed no marked differences from that reported for E. coli ribosomes. These data suggest that the unusual thermal stability of B. stearothermophilus ribosomes may reflect either an unusual packing arrangement of the protein to the RNA or differences in the primary structure of the ribosomal proteins. |
5903100 | Oxidation and assimilation of carbohydrates by Micrococcus sodonensis. | Perry, Jerome J. (North Carolina State University, Raleigh), and James B. Evans. Oxidation and assimilation of carbohydrates by Micrococcus sodonensis. J. Bacteriol. 91:33-38. 1966.-Micrococcus sodonensis is a biotin-requiring strict aerobe that cannot utilize carbohydrates as sole sources of carbon and energy. However, addition of mannose, glucose, sucrose, or maltose to a medium on which the organism can grow resulted in an increase in total growth. M. sodonensis oxidized these sugars without induction, thus indicating the presence of constitutive enzymes for their transport, activation, and metabolism. Under appropriate nonproliferating cell conditions, glucose was readily incorporated into essential constituents of the cell. When glucose-1-C(14) and glucose-6-C(14) were oxidized by nonproliferating cells, the label was found in both the protein and nucleic acid fractions of the cell. The respiratory quotients of cells oxidizing glucose in saline and in phosphate buffer indicated assimilation of sugar carbon in buffer and virtually no assimilation in saline. The ability of M. sodonensis pletely oxidize glucose and to grow on intermediates of glucose oxidation but not on glucose suggests that glucose may suppress or repress some reaction(s) necessary for growth, and that growth substrates either derepress or circumvent this block. |
5903101 | Characterization of a thermophilic bacteriophage for Bacillus stearothermophilus. | Saunders, Grady F. (University of Illinois, Urbana), and L. Leon Campbell. Characterization of a thermophilic bacteriophage for Bacillus stearothermophilus. J. Bacteriol. 91:340-348. 1965.-The biological and physical-chemical properties of the thermophilic bacteriophage TP-84 were investigated. TP-84 was shown to be lytic for 3 of 24 strains of Bacillus stearothermophilus tested over the temperature range of 43 to 76 C. The latent period of TP-84 on B. stearothermophilus strain 10 was 22 to 24 min. TP-84 has a hexagonal head, 53 mmu in diameter and 30 mmu on a side; its tail is 130 mmu long and 3 to 5 mmu wide. The phage has an S(50) (20,w) of 436, and bands at a density of 1.508 g/cc in CsCl (pH 8.5). The diffusion coefficient of TP-84 was calculated to be 6.19 x 10(-8) cm(2)/sec. From the sedimentation and diffusion data, a particle molecular weight of 50 million daltons was calculated for TP-84. The phage DNA has a position of 42% guanine + cytosine, deduced from buoyant density and melting temperature measurements. |
5903103 | Effect of mixed culture on Nitrosomonas europaea simulated by uptake and utilization of pyruvate. | Clark, Connie (University of Minnesota, Minneapolis), and E. L. Schmidt. Effect of mixed culture on Nitrosomonas europaea simulated by uptake and utilization of pyruvate. J. Bacteriol. 91:367-373. 1966.-Contamination of a 5-liter culture of Nitrosomonas europaea resulted in enhanced nitrite formation pared with pure cultures. The dominant contaminant, a yellow-pigmented, heterotrophic bacterium, was isolated and studied both in pure culture and in deliberate mixture with N. europaea. Growth of N. europaea was stimulated in mixed cultures with the heterotrophic isolate to varying degrees, apparently depending on the age and density of autotrophic inocula. Mixed culture stimulation of N. europaea was evidenced only by a shortened lag phase, since post-lag phase growth of the autotroph was equivalent in both pure and mixed cultures. The ponent had a nutritional requirement for amino acids when grown on simple media; presumably, in the mixed culture system, the heterotroph was provided with amino acids synthesized by the autotroph. The mixed culture effect was reproduced in all essential features by the addition of sodium pyruvate to the nitrification medium. Pure cultures of N. europaea were shown to incorporate sodium pyruvate-2-C(14) during growth. Labeled carbon was widely distributed in cell fractions. The more pronounced and consistent pyruvate effect was observed on old inocula of N. europaea. |
5903102 | Effect of light intensity on the formation of the photochemical apparatus in the green bacterium Chloropseudomonas ethylicum. | Holt, Stanley C. (Dartmouth Medical School, Hanover, N.H.), S. F. Conti, and R. C. Fuller. Effect of light intensity on the formation of the photochemical apparatus in the green bacterium Chloropseudomonas ethylicum. J. Bacteriol. 91:349-355. 1966.-When the green bacterium Chloropseudomonas ethylicum was grown at various light intensities, the formation of the photosynthetic vesicles was found to be an inverse function of the light intensity at which the cells were grown. The specific chlorophyll content of isolated vesicles varied as the light intensity was changed over a wide range. Thus, the regulation of chlorophyll content in C. ethylicum in response to a change in light intensity is achieved both by a change in the number of vesicles that are formed and by a change in the specific chlorophyll content of these vesicles. |
5903104 | New approach to the genetics of Streptomyces coelicolor. | Sermonti, G. (Istituto Superiore di Sanità, Rome, Italy), Milena Bandiera, and Isabella Spada-Sermonti. New approach to the genetics of Streptomyces coelicolor. J. Bacteriol. 91:384-392. 1966.-Mixed cultures plementary auxotrophic strains of Streptomyces coelicolor A3(2) were preincubated on discs of cellophane plete medium and were then transferred onto selective media. When one strain was streptomycin-resistant and the other was streptomycin-sensitive, and the transfer medium contained streptomycin, distinct minute tufts of aerial mycelium appeared on the background growth of the mixed culture. They turned out to be heterozygous clones (heteroclones) in which the streptomycin-sensitive allele was, as a rule, missing. The pattern of marker contribution of the streptomycin-sensitive parent to the zygotes was indicative of a continuous structure carrying the hereditary material. A gradual transfer of the donor genome during conjugation was suggested by the pletion of the zygotes obtained by increasing preincubation time. |
5903105 | Structure of purified cell walls of dense forms of meningopneumonitis organisms. | Manire, G. P. (Institute for Virus Research, Kyoto University, Kyoto, Japan). Structure of purified cell walls of dense forms of meningopneumonitis organisms. J. Bacteriol. 91:409-413. 1966.-Purified suspensions of the dense form of the meningopneumonitis organism were prepared by differential centrifugation, sonic treatment, enzyme treatment, and sucrose gradient centrifugation. When mixed with glass beads and sonically treated at 10 kc/sec, the particles pletely disrupted in 15 min when 10-ml volumes were used, and in 5 min when 2-ml volumes were used. Purified cell walls were prepared by enzyme treatment and sucrose gradient centrifugation. When shadow-cast in high vacuum with platinum-palladium alloy, the cell walls appeared to posed of an inner layer of hexagonally packed macromolecular structures approximately 100 A in diameter and an outer layer of unknown material. |
5903106 | Some singular properties of bacterial flagella, with special reference to monotrichous forms. | Roberts, F. F., Jr. (University of Maryland, College Park), and R. N. Doetsch. Some singular properties of bacterial flagella, with special reference to monotrichous forms. J. Bacteriol. 91:414-421. 1966.-Heat (60 C for 30 min), 10 m acetamide, and 8 m urea all brought about rapid plete dissolution of flagella from monotrichous bacteria; hence, these flagella respond similarly to those of peritrichous forms. Chloramphenicol (10(3) mug/ml) inhibited regeneration of flagella in all peritrichously flagellated cultures; however, monotrichous forms were able to regenerate their flagella in a concentration 10(2) times that required to inhibit multiplication. Peritrichous bacteria did not synthesize flagella when infected by lytic bacteriophages. In these experiments, the time from infection to lysis was sufficient for uninfected controls to resynthesize their flagella. Monotrichous bacteria, however, in all but one instance, were able to resynthesize their flagella before lysis occurred. A study of flagella resynthesis in a non-nutritive milieu indicated that only a small amount of flagellum precursor is present in any given cell. The effect of temperature on synthesis of flagella indicated that, although some bacteria multiply and are motile at a given temperature, they are unable to resynthesize their flagella at that same temperature. This strongly suggests that initial flagellum synthesis and flagellum regeneration are not necessarily identical processes. |
5903107 | Patterns of human antibody reactions in coccidioidomycosis. | Sawaki, Y. (Veterans Administration Hospital, San Fernando, Calif.), M. Huppert, J. W. Bailey, and Y. Yagi. Patterns of human antibody reactions in coccidioidomycosis. J. Bacteriol. 91:422-427. 1966.-At least two antigen-antibody systems in coccidioidomycosis have been demonstrated by immunodiffusion and immunoelectrophoresis, including the use of I(131)-coccidioidin. Sera which were positive in the plement-fixation (CF) test, but negative in the tube precipitin (TP) test, yielded only one line of precipitate in the immunodiffusion test. In immunoelectrophoresis, also, there was only one precipitate arc which appeared in the gamma(2)-globulin region. On the other hand, sera which were positive in both CF and TP tests yielded two different lines in the immunodiffusion test. In immunoelectrophoresis, also, there were two precipitate arcs: one in the gamma(2)-globulin region and the other in the gamma(1)-globulin area. Radioimmunoelectrophoresis demonstrated that the antibody activity in IG-G globulin, roughly parallels the CF titer. A similar correlation existed between the IG-M antibody activity and the TP reactivity. Antibody activity was present in the IG-A globulin but it did not reflect either CF or TP activity. |
5903108 | Structural changes in the cell wall of Schizosaccharomyces pombe during cell division. | Streiblová, Eva (Czechoslovak Academy of Sciences, Prague, Czechoslovakia), I. Málek, and K. Beran. Structural changes in the cell wall of Schizosaccharomyces pombe during cell division. J. Bacteriol. 91:428-435. 1966.-Individual stages of growing and dividing cells of Schizosaccharomyces pombe were studied by means of fluorescence and electron microscopy with the use of metal-shadowed isolated walls, replicas, and ultrathin sections. Vegetative cells were found to contain division scars (six at the most); their formation and structure are described. More data on the growth of arthrospores were obtained. New structural observations were made on the architecture of the cell wall (original wall ring, polar cell wall, plug wall band, additional wall ring). Structural changes of cell surfaces and lateral walls during fission are represented schematically to the fourth generation. The question of origin of the septum is discussed, and on this basis the entire structure of the cell wall is interpreted. |
5903109 | Comparison of two serologically distinct ribonucleic acid bacteriophages. I. Properties of the viral particles. | Overby, L. R. (University of Illinois, Urbana), G. H. Barlow, R. H. Doi, Monique Jacob, and S. Spiegelman. Comparison of two serologically distinct ribonucleic acid bacteriophages. I. Properties of the viral particle. J. Bacteriol. 91:442-448. 1966.-Two ribonucleic acid (RNA) coliphages, MS-2 and Qbeta, have been characterized physically and serologically. MS-2 has an S(20, w) value of 79, a molecular weight of 3.6 x 10(6), a density of 1.422, and pH 3.9 as its isoelectric point. Qbeta has an S(20, w) of 84, a molecular weight of 4.2 x 10(6), a density of 1.439, and an isoelectric point at pH 5.3. One host (Escherichia coli A-19) permits a distinction between the two on the basis of a marked difference in plaque size. They are distinct immunochemically, no serological cross-reaction being detectable. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.