bluuebunny/crossref_metadata_2025 huggingface dataset:
THE EFFECTS OF A CARDIAC GLYCOSIDE ON SUBCELLULAR STRUCTURES WITHIN NERVE CELLS AND THEIR PROCESSES IN SYMPATHETIC GANGLIA AND SKELETAL MUSCLE
Authors: Birks R. I.
Published: October 2017

Nerve cells and their processes in cat sympathetic ganglia and frog skeletal muscle have shown on electron microscopic examination alterations in subcellular morphology as a result of treatment with digoxin. Non-nervous cells were unaffected by the drug. These changes included, in ganglia, swelling of the affected cells, shrinkage of mitochondria with pronounced increase in internal density, swelling of Nissl substance in nerve cell bodies, and loss of structural detail in nerve processes. At the myoneural junction the motor nerve endings were swollen, mitochondria were altered, and the synaptic vesicles were reduced in numbers, those that remained being swollen. These changes were accompanied by invagination of the axon surface by Schwann cell processes.Cell swelling, but not the subcellular changes, was prevented by substitution of sulphate for chloride ions in the extracellular space. When the extracellular sodium ion concentration was reduced to 20 meq/l. the cells were completely protected against digoxin. It is concluded that swelling is caused by net uptake of sodium and chloride as a result of the known inhibitory action of digoxin on sodium extrusion by nerve cells. The possibility that these structural changes in subcellular organelles may be caused by a raised concentration of intracellular sodium ions, such as might occur during activity of excitable cells, is discussed.
FACTORS AFFECTING THE THIOBARBITURIC ACID (TBA) TEST FOR LIPID PEROXIDATION IN RAT TISSUE HOMOGENATES
Authors: Singh H. , Pritchard E. T.
Published: October 2017

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IMPAIRMENT OF TESTICULAR FUNCTION IN THE WHITE RAT CHRONICALLY EXPOSED TO A LOW AMBIENT TEMPERATURE
Authors: Dugal L. P. , Saucier G. , DesMarais A. , Léveillé A.
Published: October 2017

not available
GROWTH HORMONE AND CARDIAC GLYCOGEN: INFLUENCE OF ENVIRONMENTAL AND GENETIC FACTORS
Authors: Fenton Paul F. , Duguid Jane R.
Published: October 2017

The rise in cardiac glycogen levels observed in the rat during fasting and after growth hormone administration is more difficult to demonstrate in the mouse. At room temperature fasting lowers the cardiac glycogen of the mouse. Large doses of growth hormone are needed to maintain the cardiac glycogen at the level seen in fed animals. At 30 °C mice of the A strain increase their cardiac glycogen during a 24-hour fast. Growth hormone increases the glycogen level still further. At this elevated temperature (close to the critical temperature of the mouse) fasting lowers the cardiac glycogen of the I strain mouse, but growth hormone raises the glycogen above the level of fed animals. It is suggested that the fasting stimulus evokes a greater secretion of growth hormone in A strain mice or that the tissues of these mice are more sensitive to the hormone.
THE FORMATION OF PHOSPHOLIPIDS FROM C14-LABELLED PRECURSORS IN SLICES FROM IMMATURE RAT BRAIN
Authors: Pritchard E. T.
Published: October 2017

The relative incorporation of several C14-labelled compounds into the phospholipid and free cholesterol of developing rat brain slices at various ages from 1 to 19 days was examined. Experiments have shown that labelling of saturated fatty acids of phospholipids and cholesterol from acetate-1-C14and propanoate-1-C14was much more in 1- to 9-day animals than in older animals while the labelling from non-fatty acid precursors such as ethanolamine-1,2-C14and choline-Me-C14was not greatly affected by the aging processes. Palmitic acid was the major acid labelled by acetate, but both stearic and myristic acids received appreciable activity.The results tend to indicate that the saturated fatty acids of rat brain phospholipids are formed rapidly at a very early stage in brain development. The activity of this synthetic system then appears to decrease to the low level apparent in the adult rat. The glycerol–phosphate-base moieties of the phospholipids, on the other hand, appear to retain their relatively high replacement activity at all ages.
COMPOSITION OF EPIPHYSEAL CARTILAGE: III. DIFFERENCES IN ENZYMATIC ACTIVITIES OF EPIPHYSEAL AND ARTICULAR CARTILAGES OF RACHITIC CHICKS
Authors: Cipera J. D. , Willmer J. S.
Published: October 2017

From a comparative study of enzymatic activities in epiphyseal and articular cartilages of 3-week-old rachitic chicks it appears that the activities of pyrophosphatase and adenosine triphosphatase are approximately four times higher in epiphyseal than in articular cartilage. The greater activity of epiphyseal cartilage is even more pronounced in the cases of alkaline phosphatase and hexosamine synthetase. Phosphorylase, on the other hand, is more active in articular cartilage. The significance of these observations is discussed.
CREATINE KINASE IN NORMAL AND DYSTROPHIC MOUSE MUSCLE
Authors: Nichol C. , McGeer P. L. , Miller J. R.
Published: October 2017

The hind leg muscle of normal mice and mice with hereditary muscular dystrophy was taken for individual analyses of the creatine-phosphorylating enzyme, creatine kinase. Creatine kinase activity was always found to be higher in the muscle of normal mice than in that of dystrophic mice, and the values in each group decreased with increasing age of the mice. The difference was greatest in mice of 2 weeks of age, and in the light of these findings some suggestions are made about the pathogenesis of muscular dystrophy.
STUDIES ON THE UPTAKE OF RAGWEED POLLEN ALLERGENS BY POLYAMINOSTYRENE
Authors: Richter M. , Delorme P. , Grant S. , Rose B.
Published: October 2017

Polystyrene (PS), polyaminostyrene (PAS), and the diazonium salt of polyaminostyrene (DPAS) were compared for their capacity to bind ragweed pollen allergens. PAS was slightly more efficient than DPAS in this respect although the binding was non-specific. Nevertheless, the allergens could not be eluted from PAS with saline. PS appeared to be unable to bind the pollen allergens. DPAS coupled to tyrosine was as efficient as DPAS in binding the pollen allergens.
PHARMACOLOGY OF PEMOLINE
Authors: McColl J. D. , Rice W. B.
Published: October 2017

Pemoline (5-phenyl-2-imino-4-oxo oxazolidine) produced an increase in spontaneous motor activity of a co-ordinated type in mice. It was observed to prevent and to reverse reserpine-induced motor depression in a manner analogous to that of d-amphetamine. The order of activity as a motor stimulant fell between that of d-amphetamine and caffeine but had a slower onset of action. At low doses, pemoline potentiated the loss of righting reflex induced by hexobarbital and ethanol but it antagonized these agents at high doses. Pemoline antagonized nicotine-induced clonic convulsions in mice. Like amphetamine it produced an increase in urine output and sodium and potassium excretion in the male guinea pig.
STUDIES ON THE UPTAKE OF REAGIN BY POLYAMINOSTYRENE–RAGWEED COMPLEXES
Authors: Delorme P. , Richter M. , Grant S. , Rose B.
Published: October 2017

The various factors governing the uptake of reagin by insoluble antigenic complexes prepared by incubating ragweed pollen extract (WSR) with either polyaminostyrene (PAS) or diazopolyaminostyrene (DPAS) have been investigated. It was found that PAS–WSR was as capable of binding reagin as DPAS–WSR. This reaction was shown to be specific and the quantity of reagin bound to the complex was found to vary with the amount of reagin present during the incubation and the duration of incubation. The binding was independent of the concentration of reagin in the incubation mixture and of the temperature of incubation.
ISOLATION OF 20β-DIHYDROCORTISONE FROM SOCKEYE SALMON (ONCORHYNCHUS NERKA) PLASMA
Authors: Idler D. R. , Schmidt P. J. , Ronald A. P.
Published: October 2017

20β-Dihydrocortisone has been isolated from the peripheral plasma of spawned male and female salmon. The plasma steroid was identified by its chromatographic mobility and that of its diacetate as well as the sulphuric acid chromogen of the steroid. The steroid was transformed, by sodium bismuthate, to adrenosterone, which was identified by chromatography and sodium borohydride reduction to 17β-ol-Δ4-androstene-3,11-dione. Spawned females had 2.1 μg of 20β-dihydrocortisone per 100 ml of plasma. An ultraviolet-absorbing substance with the chromatographic mobility of 20α- and 20β-dihydrocortisol could not be identified with either of these substances.
RADIOAUTOGRAPHIC STUDY OF S35O4 UPTAKE BY EPIPHYSEAL CARTILAGE IN EXPERIMENTAL LATHYRISM
Authors: Shintani Yurika K. , Taylor H. E.
Published: October 2017

Disturbances in the uptake of radiosulphate were observed in radioautographs of the epiphysis of rats made lathyritic by giving either beta-aminopropionitrile or semicarbazide. There was a decreased uptake of sulphate which became more marked as the lesions advanced and an increased uptake was noted as the lesions regressed when the rats were returned to a normal diet. In normal rats, the radio-sulphate shifted to the zone of calcifying cartilage by the 4th day postinjection and, by the 7th day, it was concentrated over the ossifying trabeculae. In lathyrism this shift was delayed and the radiosulphate image was still concentrated in the cartilage matrix at days 4 and 7 postinjection. It is believed these findings reflect a disturbance in the matrix acid mucopolysaccharides and an interference with endochondral growth in lathyrism.
ACID-SOLUBLE PHOSPHORUS COMPOUNDS AND FREE SUGARS IN FISH MUSCLE AND THEIR ORIGIN
Authors: Tarr H. L. A. , Leroux M.
Published: October 2017

An ion-exchange system capable of separating the principal sugar phosphates and nucleotides in fish muscles was developed and used to study the distribution of these in muscles of freshly killed fish, and in certain of these muscles after several days at 0 °C. The results indicate that there are extreme quantitative variations in these compounds. Intravenous introduction of C14-labelled glucose or G6P* into salmonoid fish results in rapid labelling of glycolytic intermediates such as F6P, FDP, and lactate in both muscle and liver. Evidence was obtained, using C14fish muscle glycogen, which indicates that this substance is degraded to maltose and glucose post mortem both by an amylase and by the Embden–Meyerhof system, and that very little glucose arises by hydrolysis of G6P. When introduced into fish muscle post mortem, C14ATP yielded radioactive IMP and ribose, G6P and glucose being unlabelled. Radioactive R5P (or ribose) was never found in muscle of fish injected with C14-labelled glucose or G6P, indicating that these are not formed via the hexosemonophosphate shunt system. R5P was not found in muscle of living fish and only in comparatively small amounts post mortem. Evidence is presented which shows that F1P does not occur in appreciable amounts in fish muscles, and that the evidence so far presented in support of the occurrence of R1P is unsatisfactory.
THE INFLUENCE OF IPRONIAZID AND PYROGALLOL ON THE THERMOGENIC EFFECTS OF NORADRENALINE
Authors: Johnson Gordon E. , Sellers E. A.
Published: October 2017

The effects of administering a monoamine oxidase inhibitor (iproniazid) or an inhibitor of catechol-O-methyl transferase (pyrogallol) on the calorigenic response produced by injecting noradrenaline intravenously or subcutaneously to Wistar rats are described. The influence of isoniazid on the calorigenic response to subcutaneously administered noradrenaline was also studied. The effects of syrosingopine and tetrabenazine, with and without inhibitors, and of dl-normetanephrine, were also observed. Inhibition of monoamine oxidase increased and prolonged the calorigenic response to exogenous noradrenaline or to noradrenaline released endogenously. Isoniazid, chemically related to iproniazid but not an inhibitor of monoamine oxidase, or pyrogallol, caused little change in the calorigenic response. Thus oxidative deamination appears to be the primary reaction responsible for the termination of the calorigenic response.
A SENSITIVE METHOD FOR MEASUREMENT OF AMINO ACYL RIBONUCLEIC ACID SYNTHETASE ACTIVITIES
Authors: Fraser Murray J.
Published: October 2017

A sensitive method for the measurement of amino acyl RNA synthetase activities (amino acid activating enzymes) is described. The method is based on measurements of the rates of labelling of soluble ribonucleic acid with14C-amino acids. Determinations of α-glutamyl-RNA, glutaminyl-RNA, and glycyl-RNA synthetase activities in the "pH 5 enzymes" fractions from rat liver and mouse Ehrlich ascites carcinoma cells have been made.
SENSITIVITY OF THE RAT TO INCREASING DOSES OF DEXTRAN
Authors: Jasmin Gaetan , Bois Pierre , Su Mai-Shian
Published: October 2017

Increasing doses of dextran, a commercial 6% solution, were injected intravenously into both intact and adrenalectomized rats to evaluate the dose–response relationship. The minimum dose capable of producing an edema with 100% incidence was approximately 30 mg/kg in intact and only 4 mg/kg in adrenalectomized rats. Lower doses produced responses of decreasing intensity and incidence with a longer period of onset. Conversely, higher doses resulted in a shorter period of onset and a more intense reaction until a toxic dose was reached, beyond which cyanosis and shock appeared. Adrenalectomized rats reacted similarly to intact ones except that their response occurred at a lower dose range; they could not withstand the toxic effect of higher doses and died of circulatory failure. The fact reported by other workers that the edema is more intense and appears more rapidly after intravenous injection of minute rather than large quantities of dextran was not confirmed; the existence of a "critical dose" that does not produce any edema was not substantiated.
THE EFFECT OF INCUBATION ON THE CHARACTERISTICS OF THE LIPOLYTIC ACTIVITY OF RAT ADIPOSE TISSUE
Authors: Hollenberg C. H.
Published: October 2017

A study has been made of the changes produced in the characteristics of the lipolytic activity of rat adipose tissue homogenates by prolonged preincubation of the intact tissue in phosphate buffer. Fresh tissue homogenates were markedly more active on a serum–triglyceride medium (activated substrate) than on triglyceride alone while little difference was noted with homogenates of preincubated tissue. The activity of fresh tissue homogenates was increased by addition of heparin; homogenates of incubated tissue were not affected. Fresh tissue homogenates were inhibited to a greater extent by protamine than were preparations of incubated material. Addition of glucose and insulin to the buffer partially maintained the activity of incubated tissue on activated substrate. These results indicate that while lipolytic activity of fresh rat adipose tissue has characteristics similar to lipoprotein lipase, the activity of incubated tissue differs from this enzyme in several respects. This study demonstrates the lability of lipoprotein lipase in rat adipose tissue and suggests the presence in this tissue of a separate type of lipolytic activity.
THE EFFECT OF INDUCED HYPOXIA ON OXYGEN UPTAKE DURING MUSCULAR EXERCISE IN NORMAL SUBJECTS
Authors: Cronin R. F. Patrick , MacIntosh Donald J.
Published: October 2017

During the moderate exercise of treadmill walking, steady-state oxygen uptake bears a linear relationship to the work performed (i.e. to the slope of the treadmill), when the speed of walking is kept constant. Four normal male subjects were studied on the treadmill at several levels of exercise while they were breathing air and again while breathing a mixture of approximately 11% oxygen in nitrogen. An alteration in the linear relationship between oxygen uptake and work, established with the subjects breathing air, was observed when the subjects were restudied breathing 11% oxygen. In each case, this alteration indicated that the subject took up less oxygen while breathing a low-oxygen mixture despite the accomplishment of similar work loads. That this phenomenon is explicable on the basis of slower attainment of the steady state was excluded by prolonging each exercise period in two subjects. Another possible explanation, i.e. that the subjects effect greater utilization of anaerobic metabolic sources while hypoxic, was excluded by direct measurement of the oxygen debt after each period of exercise. It is concluded that exercising normal subjects exhibit an adaptive mechanism under conditions of induced hypoxia permitting reduced oxygen uptake for a given work load.
THE WEIGHT-DEPRESSING ACTION OF α-METHYL-DL-TRYPTOPHAN IN THE RAT
Authors: Sankoff I. , Sourkes T. L.
Published: October 2017

α-Methyl-DL-tryptophan, injected intraperitoneally into rats, has a weight-depressing action lasting up to 72 hours. Dosages in the range 0.015–2.0 millimoles/kg body weight (3.3–436 mg/kg) are effective. Attempts to antagonize the weight-depressing action by giving essential amino acids and B vitamins were unsuccessful. Metabolic studies have shown that about half the injected dose of the compound (or its derivatives), as measured by the Hopkins–Cole glyoxylic acid reaction, is excreted in the urine in 24 hours; most of this appears during the first 4 hours after the injection. Ina search for an explanation for the weight-depressing action of α-methyltryptophan, tryptophan pyrrolase activity in the liver was estimated. This enzymic activity increases for 8 hours after the injection of α-methyltryptophan, and thereafter remains high for 72 hours. Tryptophan-injected animals showed increases in tryptophan pyrrolase level for 1.5 hours, and a return to normal concentrations within 24 hours. Other α-methyl amino acids which were tested had no comparable effect on body weight.
KINETIC FORMULATIONS FOR ENZYMIC REACTIONS INVOLVING TWO SUBSTRATES
Authors: Wong J. Tze-Fei , Hanes Charles S.
Published: October 2017

The general mechanism for enzymic group-transfer reactions is shown to be of considerable complexity. In order to deal with this complexity, an analysis has been made of the structure of steady-state rate equations, which permits the establishment of direct relationships between specified features of mechanism and of rate behavior. This has opened up the possibility of a featurewise approach for the progressive elucidation of complex enzymic mechanisms. In particular, a theoretical basis has been provided for the comprehensive consideration and systematic differentiation of mechanisms of enzymic group-transfer reactions.
STUDIES ON THE IN VITRO ANTITUMOR ACTIVITY OF FATTY ACIDS: V. UNSATURATED ACIDS
Authors: Tolnai Susan , Morgan Joseph F.
Published: October 2017

Previous studies on the in vitro antitumor activity of saturated mono- and dicarboxylic fatty acids have been extended to a series of unsaturated fatty acids ranging in carbon chain length from C6to C20- All 10 compounds tested exhibited some activity at pH 4.0 against the ascites forms of the Ehrlich carcinoma, 6C3HED lymphosarcoma, and TA3mammary carcinoma. Only three compounds (2-decenoic, linoleic, and linolenic acids) were found to be active at neutrality against all three tumors, while four compounds (2-nonenoic, 10-undecenoic, oleic, and arachidonic acids) were active against one or two tumors under neutral conditions. Considerable variations were encountered in the relative effectiveness of these compounds against the three ascites tumors. The compounds with the most marked in vitro antitumor activity were linoleic and linolenic acids.
ENZYMATIC AND METABOLIC ADAPTATIONS: I. CHANGES IN INTACT RATS SUBJECTED TO DIETARY MODIFICATIONS
Authors: Willmer J. S. , Foster T. S.
Published: October 2017

A study of hepatic enzymes concerned in glucose metabolism was made after transfer of rats from a standard laboratory ration to three experimental diets. The change to two high-carbohydrate diets resulted in elevated levels of enzymes of the hexosemonophosphate shunt. Glucose-6-phosphatase, phosphoglucomu-tase, and phosphoglucoseisomerase exhibited an initial transitory decrease in activity, succeeded by restoration to normal or above-normal levels. Animals fed a low-glucose diet showed a tendency towards decreased activity of all enzymes except glucose-6-phosphatase. Hepatic oxidation of glucose-1-C14and glucose-6-C14and liver glycogen levels were also measured. These results are discussed in relation to the observed enzyme changes.
BIOSYNTHESIS OF CHLOROPHYLL FROM ACETATE-1-C14 AND GLYCINE-1-C14 BY WHEAT LEAVES
Authors: Roberts D. W. A. , Perkins Harold J.
Published: October 2017

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THE ENOLASE OF THE HUMAN ERYTHROCYTE
Authors: Blostein Rhoda , Denstedt Orville F.
Published: October 2017

The enolase activity of the human erythrocyte has been studied with a partially purified preparation of the enzyme. The enzyme was found to have an absolute requirement for Mg2+ions. A kinetic study of the influence of the concentration of Mg ions and 2-phosphoglycerate on the formation of phosphoeno/pyruvate from 2-phosphoglycerate has shown that the active complex of enzyme, substrate, and activator (Mg2+) can be formed in several ways. With low concentrations of substrate and Mg2+the reaction was maximum at pH 7.0; with high concentrations of both, the activity was maximum over a wide range of hydrogen ion concentrations on the acid side of neutrality (at least from pH 6.3 to 7.0) and decreased above pH 7.0.
ELEVATED INCIDENCE OF EXPERIMENTAL THROMBOSIS AFTER HEPARIN
Authors: Ashwin James G.
Published: October 2017

Increased incidence of thrombosis after anticoagulants has been reported intermittently. The present work utilizes a new technique for studying the effect of various drugs and procedures on thrombus production in rats. Two hundred and forty rats in lots of 24 were given single or repeated intravenous injections of saline or heparin. At various intervals after clotting times had returned to normal, the jugular vein was bared, 10% formalin solution applied, and the incision closed. Four hours later veins were examined for clots. Rats receiving heparin averaged 73.9% thrombosis. Those receiving saline averaged 58.6% thrombosis. The differences between the groups were consistent. A single high dose of heparin given 1 minute before the operation reduced the incidence of thrombosis to 16%. Tests for platelet stickiness on blood taken from rats 4 and 24 hours after heparin injection showed that heparin had not caused increased stickiness in rat platelets over these periods.
NEUROANATOMICAL STUDY OF OBESE AND NON-OBESE HYPOTHALAMIC MONKEYS IN RELATION TO FOOD INTAKE, LOCOMOTOR ACTIVITY, AND TEMPERATURE REGULATION
Authors: Poirier Louis J. , Mouren-Mathieu Anne-Marie , Richer Claude-Lise
Published: October 2017

Obesity, hypoactivity, and an impairment of ability to maintain body temperature in moderate cold were encountered in combination, or separately, following experimental bilateral destruction between the optic chiasma and the mammillary bodies in the hypothalamus. An impairment in the ability to regulate temperature against cold was present in all six obese monkeys of this series following lesions which destroyed extensively the periventricular system and the paraventricular and dorsomedial hypothalamic nuclei. This was associated with hypoactivity in two out of three obese animals in which this function was studied. Obesity occurred without any increase in food intake in three animals in which the diet was controlled; only one of these showed a slight hyperphagia when free access to food was permitted. One non-obese animal showed marked hyperactivity associated with a voracious appetite and an inability to regulate against cold following small bilateral lesions in the central area of the hypothalamus.
THE EFFECT OF GLYCEROL MEDIUM ON THE ACTIVATION OF HUMAN PLASMINOGEN BY STREPTOKINASE AND ON THE ACTION OF THE ENZYME, PLASMIN
Authors: Roberts Phyllis S.
Published: October 2017

A 50% glycerol medium affected the activation of plasminogen by streptokinase (SK) and the activity of plasmin (formed by glycerol incubation) on p-toluene-sulphonyl-L-arginine methyl ester (TAMe) in the following ways:(1) TAMe interfered strongly with the activation of plasminogen by SK in a glycerol medium but not in a water medium under the same conditions.(2) SK inhibited the action of plasmin on TAMe in a glycerol medium, but in a water medium SK increased the rate of hydrolysis of TAMe, the extent of the increase depending upon pH.(3) Phosphate buffer inhibited the activation of plasminogen by SK in a glycerol medium but not in a water medium. In the glycerol medium a lag period in the formation of enzyme was found, particularly noted with a phosphate buffer, and the lag period increased with increasing concentration of the buffer.(4) Phosphate buffer inhibited the action of plasmin on TAMe in a glycerol medium but not in a water medium.Mechanisms of activation of plasminogen by SK are discussed. The data presented support the postulate that a reaction takes place between plasmin and SK to form an enzyme called "activator".
INSULIN AND THE "MINERALOCORTICOID" ACTIVITY OF CERTAIN STEROIDS
Authors: Adamkiewicz V. W. , Fortier A. A.
Published: October 2017

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COMPOSITION AND PROPERTIES OF SOLUBLE LIPOPROTEINS IN RELATION TO STRUCTURE
Authors: Cook W. H. , Martin W. G.
Published: October 2017

Lipoproteins from diverse sources have total lipid contents extending over an essentially continuous range but do show strong evidence of a transition in their composition in the region where protein, phospholipid, and neutral lipid are present in essentially 1:1:1 proportions. Those with protein contents below 33% (LPL) have neutral lipid–phospholipid ratios ranging from 1:1 to 10:1; but this ratio remains at about 1:1 in all those with protein contents above 33% (HPL). The protein content of the LPL type decreases with increasing particle size and is sufficient to provide only a surface film. If the protein is present in this form, the particle must have a lipid core; if it is present in more globular form, much of the particle surface must be phospholipid, and such structures resemble microemulsions or micelles. The composition and properties of the HPL type, however, are consistent with their having a structural integrity approaching that of a protein molecule. For example, their molecular weight appears to be independent of their lipid content, and egg yolk HPL exhibits pH-dependent reversible dissociation into two subunits comparable to that observed in certain proteins. Differences in the N-terminal residues (serum lipoproteins) and amino acid composition (yolk lipoproteins) of the proteins of most LPL and HPL types indicate that, if their interconversion does occur, it would involve more drastic changes than either alterations in structure or a simple loss or gain of lipid.
THE UBIQUINONE AND CRUDE STEROL CONTENT OF THE LIVER WITH VARIATIONS IN THE INTAKE OF TOCOPHEROL IN THE VITAMIN A DEFICIENT RAT
Authors: Phillips W. E. J.
Published: October 2017

Some non-saponifiable constituents of rat liver have been studied in animals differing in their nutritional status in vitamin A and E. Liver levels of ubiquinone were negatively correlated with the vitamin A status of the animal but not with the vitamin E status. The crude sterol content of the liver was not affected by variations in the intake of either vitamin, except that there was a slight but significant increase when vitamin A deficiency was pronounced.
EFFECT OF DUST AND AEROSOL INHALATION ON SURFACE AND TISSUE ELASTICITY OF RAT LUNGS
Authors: Rosenberg Edith , Alarie Y. , Robillard Eugène
Published: October 2017

Rats were exposed to an atmosphere containing submicronic aluminum oxide particles or to aerosols of carbachol or isoproterenol. The static pressure – volume curves of their lungs, rendered gas-free and removed after exposure, were then compared to those of normal rats studied similarly. The lungs were filled and emptied gradually both with air and with saline so that in every case the force due to tissue elasticity, as well as that due to the surface tension of the alveolar lining, could be determined. Carbachol aerosol (1%) inhalation for 7 minutes produced an increase in the force due to tissue elasticity. The inhalation of aluminum oxide particles, less than one micron in diameter, for half an hour also increased the force due to tissue elasticity slightly, but it greatly decreased the force due to the surface tension of the alveolar lining.
STUDIES ON THE IN VITRO ANTITUMOR ACTIVITY OF FATTY ACIDS: VI. DERIVATIVES OF MONO- AND DI-CARBOXYLIC AND UNSATURATED FATTY ACIDS
Authors: Tolnai Susan , Morgan Joseph F.
Published: October 2017

Previous studies on the in vitro antitumor activity of saturated and unsaturated fatty acids have been extended to a series of hydroxy and keto derivatives and methyl esters of fatty acids. All compounds were tested against the ascites forms of the Ehrlich carcinoma, the Gardner lymphosarcoma, and the TA3 mammary carcinoma. Marked differences between the antitumor activity of the parent compounds and those of the substituted derivatives were observed. Most consistent in vitro antitumor activity was shown at both acid and neutral pH levels by the keto-derivatives of unsaturated fatty acids.
THE INFLUENCE OF APPARENT DIGESTIBLE ENERGY AND APPARENT DIGESTIBLE NITROGEN IN THE DIET ON WEIGHT GAIN, FEED CONSUMPTION, AND NITROGEN RETENTION OF GROWING MINK
Authors: Sinclair D. G. , Evans E. V. , Sibbald I. R.
Published: October 2017

The influences of the apparent digestible energy (A.D.E.) and the apparent digestible nitrogen (A.D.N.) content of the diet on the food consumption, nitrogen retention, and growth of mink from weaning to pelting age have been determined. It was demonstrated with diets containing from 3.33 to 4.21 Cal of A.D.E. and 26.14 to 39.76 mg of A.D.N. per g of dry matter that increasing the available energy and nitrogen in the diet had a beneficial influence on the growth of mink from 6 to 26 weeks of age. A linear relationship existed between the weight of food consumed and the reciprocal of the A.D.E. content of the food, which indicated that food consumption was largely regulated by the digestible energy content of the diet. The percentage of digestible nitrogen retained was curvilinearly related to the A.D.E.:A.D.N. ratio and appeared to be maximal when the diet contained 140 Cal of digestible energy per g of digestible nitrogen.
GASTROINTESTINAL ABSORPTION OF GRISEOFULVIN: I. EFFECT OF PARTICLE SIZE, ADDITION OF SURFACTANTS, AND CORN OIL ON THE LEVEL OF GRISEOFULVIN IN THE SERUM OF RATS
Authors: Kraml Michael , Dubuc Jean , Beall Desmond , L'Heureux Nicole
Published: October 2017

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CAFFEINE-INDUCED ULCEROGENESIS IN THE RAT
Authors: Pfeiffer C. J. , Gass G. H.
Published: October 2017

The present investigation has demonstrated that administration of caffeine alkaloid (6.25 mg/kg, 25 mg/kg, and 100 mg/kg) by stomach tube induces acute gastric ulcers in the fundus, pylorus, and antrum of fasting male and female rats. The ulcers are histologically characterized as superficial erosions of the glandular mucosa. Statistical evaluation of ulcer indices indicated a linear, log dose–response relationship for caffeine alkaloid, and a similar ulcerogenic effect in both male and female rats.
CARDIOVASCULAR EFFECTS OF THYROXINE TREATMENT IN NORMAL RATS
Authors: Beznák Margaret , Marcsán A. , Fournier T.
Published: October 2017

Metabolic rate, blood pressure, weight and rate of the heart, cardiac output, and work were determined at weekly intervals in groups of normal rats receiving thyroxine. The measurements were made before and during the infusion of polyvinylpyrrolidone into the right side of the heart. The maximum values of cardiac output and work obtained during infusion were considered to be an approximate measure of the strength of the heart. Cardiac output and work in thyroxine-treated rats far exceeded the normal values before as well as during infusion. The greater strength was not merely the consequence of the greater size of the heart which developed in the course of thyroxine treatment. Hearts of similar size — coming from larger normal rats or from smaller normal rats with cardiac hypertrophy due to aortic constriction — did significantly less work than the hearts of thyroxine-treated rats.
EVALUATION OF PROTEIN IN FOODS: VII. FACTORS INFLUENCING NET PROTEIN UTILIZATION AS DETERMINED BY CARCASS ANALYSIS
Authors: Morrison A. B. , Sabry Z. I. , Campbell J. A.
Published: October 2017

The effects of deficiency of vitamins and minerals on net protein utilization (N.P.U.) values obtained with casein at various protein levels were studied in growing male rats. Animals given diets without added vitamins and minerals lost weight and had reduced N.P.U. values. Carcass analysis data indicated that nitrogen retention occurred in these animals concomitantly with loss of body water and fat. In further studies, a direct relationship was observed between N.P.U. values and the dietary lysine content, at lysine concentrations varying from 0.32 to 0.72%. The use of various control groups to estimate endogenous and metabolic nitrogen losses gave similar N.P.U. values.
EFFECT OF COLD ON RATS CHRONICALLY EXPOSED TO MALATHION
Authors: Marton A. V. , Sellers E. A. , Kalow W.
Published: October 2017

Wistar rats received 4000 p.p.m. of malathion in their daily diet without showing evidence of intoxication (normal appearance, growth, food intake). When the animals were clipped and exposed to an ambient temperature of 1.5 °C they survived for a much shorter period in the cold environment than did control animals not receiving malathion. In both experimental and control groups, deaths occurred when body temperatures had dropped to about 18 °C. During the initial period in the cold environment, animals of both groups were able to increase their oxygen consumption to the same extent. There was no indication of an increased heat loss by the malathion-treated rats. It thus appeared likely that the insecticide decreased the ability of rats to produce heat continuously over a prolonged period at a high rate. The activities of cholinesterase in plasma were reduced in the malathion-treated rats but were not affected by the cold stress.
THE DISTRIBUTION OF CHROMIUM-51 IN MICE AFTER INTRAPERITONEAL INJECTION
Authors: Vittorio P. V. , Wight E. W. , Sinnott B. E.
Published: October 2017

Sodium radiochromate in tracer amounts was injected intraperitoneally into mice; Cr51content of various organs was studied and the following points were noted.(i) On a percentage basis, Cr51distribution was fairly similar for corresponding organs at different time intervals after Cr51injection.(ii) The Cr51content of all organs studied was highest within the first hour after intraperitoneal injection.(iii) As the mice increased in age there was a decrease in Cr51incorporation but there was no great change in Cr51distribution in the organs studied.
THE TOXICITY OF BENZYLPENICILLIN IN ANIMALS ON VITAMIN A DEFICIENT TEST DIET, U.S.P. XIV
Authors: Boyd Eldon M. , Mulrooney Dorothy A. , Sargeant Everett J.
Published: October 2017

Young, adult albino mice and rats became more susceptible to the acute and chronic toxic effects of benzylpenicillin after they had been fed vitamin A deficient test diet, U.S.P. XIV, for about 1 month. At and after this interval, there occurred a significant increase in the percentage mortality from a single oral or subcutaneous LD50of benzylpenicillin in mice and the chronic toxicity of a daily oral 0.1 L-LD50of benzylpenicillin was augmented in rats. Replacement of vitamin A, in the deficient diet or by daily intramuscular injection, did not affect the increased susceptibility to benzylpenicillin toxicity. A dietary supplement containing nine other vitamins was also without effect. Change in diet alone was not a factor since rats did not become appreciably more susceptible to the toxic effects of a daily oral 0.1 L-LD50of benzylpenicillin when their diet was changed from a standard laboratory chow to a rachitogenic test diet. Some unknown factor or factors in vitamin A deficient test diet, U.S.P. XIV, therefore, made the animals more susceptible to the toxic effects of benzylpenicillin.
THE LIPIDS OF MOUSE BROWN FAT
Authors: Spencer W. A. , Dempster G.
Published: October 2017

The lipids of the interscapular brown fat of the white mouse have been examined by means of silicic acid column chromatography and quantitative paper chromatography. The fatty acid composition of the glycerides and phosphatides was determined by gas chromatography. Comparative studies of mouse brown and white fat are presented.The fatty acid composition of the glycerides of the two tissues was similar at all ages examined. In both tissues, the average chain length of the glyceride fatty acids increased with age. The glycerides of brown fat at all ages contained less palmitoleic acid and more stearic acid than the corresponding white fat.The adult brown fat contained more polyglycerophosphatide and less sphingomyelin than white fat. The fatty acid composition of the lecithins of the two tissues was very similar. The similarity of brown fat and liver phosphatides is discussed.
THE SIGNIFICANCE OF HUMAN BLOOD TRYPSIN; DIRECT DETERMINATION OF THROMBIN AND PLASMIN IN HUMAN PLASMA
Authors: Ronwin Edward
Published: October 2017

The previously described method for human plasmin determination has been simplified and applied directly to plasma. A virtually identical method for the direct determination of human thrombin in plasma is also presented. Both procedures are quantitative and clinically feasible. The existence in plasma of a non-clotting, only slightly fibrinolytic, active tryptic enzyme, Human Blood Trypsin, is firmly established by the data. The suggestion is made that human blood trypsin may be the activator in the proenzyme to enzyme conversion system for both plasmin and thrombin. Further, both enzymes may arise from different derivatives of a common precursor protein.
STUDIES ON THE FORMATION OFD-ARABITOL BY OSMOPHILIC YEASTS
Authors: Blakley E. R. , Spencer J. F. T.
Published: October 2017

The formation of D-arabitol by a strain of osmophilic yeast has been studied. Both D-ribulose and D-xylulose were good substrates for the respiration of yeast, but D-xylulose was a better growth substrate than D-ribulose and produced larger amounts of D-arabitol. The utilization of D-xylulose-5-C14by the yeast resulted in the production of D-arabitol having two-thirds of the radioactivity in carbon-1. Extracts of the yeast contain an enzyme system which reduces D-xylulose to arabitol in the presence of NADH. The enzymatic activity increases with decreasing pH to 4.5, but the activity is readily destroyed below pH 7. The data presented suggests that D-xylulose is a precursor in the formation of D-arabitol by the osmophilic yeast.
AN INCREASED RATE OF CHOLESTEROL BIOSYNTHESIS WITH MICROSOME FRACTIONS OF LIVER FROM KETOTIC GUINEA PIGS
Authors: Sauer F.
Published: October 2017

Cholesterol synthesis was studied in liver fractions obtained by differential centrifugation from young, adult, and ketotic guinea pigs. Both 10,000 × g and 105,000 × g sediment was required for maximum activity. Incubations were carried out in the presence of appropriate liver fractions from young guinea pigs in order to overcome the low rates of cholesterol synthesis in liver homogenates from adult guinea pigs. Microsome fractions from ketotic hyperlipemic guinea pigs actively promoted sterol synthesis when incubated with mitochondria plus supernatant from young guinea pigs, while microsome fractions from adult controls (fed or starved) decreased the rate of sterol synthesis in the same incubation system. The results of this investigation indicate that microsomes from hyperlipemic ketotic guinea pigs do not have a block in cholesterol synthesis characteristic of microsomes from starved animals, and that this microsome fraction has increased activity of HMG-CoA2reductase, one of the key enzymes of cholesterol synthesis.
THE ISOLATION AND IDENTIFICATION OF BOUND COUMARIN FROM MELILOTUS ALBA
Authors: Stoker J. R. , Bellis D. M.
Published: October 2017

A method is described for the isolation and purification of bound coumarin from seeds of Melilotus alba. Synthetic coumarinic acid β-glucoside has been prepared and its properties compared with those of bound coumarin. The results of these experiments confirm that bound coumarin and coumarinic acid β-glucoside are identical.
THE PREPARATION AND PROPERTIES OF 20α-DIHYDROCORTICOSTERONE
Authors: Darrach Marvin , Krehbiel Ruth
Published: October 2017

The preparation of 20α-dihydrocorticosterone chemically and enzymatically is described, proof of structure is given, and the physical properties of 20α-dihydrocorticosterone and its 20α,21-diacetate are recorded.
VARIATIONS IN RATE OF HUMAN OSTEON FORMATION
Authors: Sedlin Elias D. , Frost Harold M.
Published: October 2017

The authors' method depends on labelling in vivo the zone of demarcation of actively forming osteons by tetracycline antibiotics. The drugs, thus deposited in bone, are visualized by fluorescence microscopy. The label is a circular or elliptical ring whose diameter indicates the degree of completeness of the osteon at the time of drug administration. A histogram of the ring diameters therefore classifies labelled osteons as regards stage of completion at the time of drug administration. If an average formation time is assigned to osteons measured, conclusions relative to the rate of formation of the average osteon can be derived.In a histogram plotted from more than 900 labelled osteons in bones of three patients, most of the labels were concentrated in the inner half of the osteon. The authors conclude that osteon formation is initially rapid both in terms of cubic microns of bone formed in a unit time and in terms of decrease in diameter of the Haversian canal; it decreases with passage of time, and it ends with a critical minimum diameter of the Haversian canal. A 2-week cyclic variation in rate may be superimposed on the overall plot.
INFLUENCE OF SELECTIVE AND NON-SELECTIVE HYDROGENATION OF RAPESEED OIL ON CARCASS FAT OF RATS
Authors: Craig B. M. , Youngs C. G. , Beare Joyce L. , Campbell J. A.
Published: October 2017

Two rapeseed oils with erucic acid contents of 23 and 42%, their hydrogenated products produced under selective and non-selective conditions, corn oil, and a lard – olive oil mixture were fed to separate groups of rats for 4 weeks. Fatty acid composition of dietary oils and carcass fats was determined. The rapeseed oils and their hydrogenated products were associated with lower food intakes and lower body weight gains than were corn oil and the lard – olive oil mixture. Small amounts of erucic acid were incorporated into the body fats. It is possible that the amount of palmitic acid in the rapeseed oils and their products is too small for a good balance of dietary fatty acids, and is partially responsible for the lower weight gains.
THE WHEAT LEAF PHOSPHATASES: V. SOME PROPERTIES OF THE ENZYME SYSTEM HYDROLYZING β-GLYCEROPHOSPHATE IN CRUDE JUICE PREPARATIONS
Authors: Roberts D. W. A.
Published: October 2017

Wheat leaf press juice contains an enzyme that has β-glycerophosphatase activity, which has a pH optimum close to pH 5.7. The enzyme is inhibited by orthophosphate, pyrophosphate, and 10−4 M fluoride. Fluoride inhibition can be abolished by thorough dialysis. Fluoride partially protects the enzyme from denaturation by heat.Enzyme kinetics shows that the log of the enzyme concentration is proportional to the log of the rate of liberation of orthophosphate from the substrate in the presence of excess substrate (0.2 M to 0.6 M) at pH 5.7. This observation can be used for quantitation of the enzyme.
THE RELEASE OF CATECHOLAMINES FROM THE ISOLATED CHROMAFFINE GRANULES OF THE ADRENAL MEDULLA BY ADRENOLYTIC DRUGS
Authors: D'Iorio A. , Laguë J. G.
Published: October 2017

The effect of various adrenolytic substances on the in vitro release of catecholamines has been studied. Phentolamine, benzodioxane, dibenamine, and phenoxybenzamine at a concentration of 10−2 M have been found to release the catecholamines and ATP of the isolated ox adrenal chromaffine granules. This release is instantaneous in phentolamine but is progressive for the other substances tested.It has also been shown that equal concentrations of glutathione will partly impair the releasing activity of these substances.
METABOLIC EFFECTS OF DIETARY PROTEIN LEVEL WITH CALORIC RESTRICTION IN COLD-EXPOSED RATS
Authors: Beaton John R. , Orme T. , Turner A. , Laufer J.
Published: October 2017

Male albino rats were fed isocaloric diets (5%, 20%, and 40% protein and 10% corn oil by weight) in restricted amounts (6 g/rat per day) at environmental temperatures of 22 °C and 2 °C. Measurements were made of urinary excretion of nitrogen, potassium, sodium, phosphorus, and creatinine, of blood levels of glucose, urea, amino nitrogen, packed cell volume, and serum total proteins and of body contents of protein, moisture, and total crude fatty acids. Metabolic effects of food restriction were readily apparent at 22 °C and the diet appeared to play a role in modifying some of these effects in approximate proportion to the dietary protein level. With superimposition of cold exposure, metabolic differences among groups were decreased in degree with some suggestive evidence of a beneficial effect of increased dietary protein level and of a deleterious effect of decreased dietary protein (high carbohydrate) under these conditions.
METABOLIC EFFECTS OF THREE DIETARY PROTEIN LEVELS FED ISOCALORICALLY TO COLD-EXPOSED RATS
Authors: Beaton John R. , Orme T. , Laufer J. , Turner A.
Published: October 2017

Male albino rats were fed isocalorically on diets containing 5%, 20%, and 40% protein (casein) and 10% corn oil by weight at environmental temperatures of 22 °C and 2 °C. Since the 5% protein fed group consumed less than normal amounts of food, consequently the food intake of all groups was moderately restricted. Measurements were made of urinary excretion of nitrogen, potassium, sodium, phosphorus, and creatinine, of blood levels of glucose, urea, amino nitrogen, packed cell volume, and serum total proteins and of total body content of protein, water, and crude fatty acids. Metabolic effects of dietary protein level were readily apparent at both environmental temperatures. Unlike earlier studies with ad libitum and severely restricted feeding, superimposition of cold exposure did not eliminate metabolic differences among groups. As observed in previous studies, reduction of dietary protein level from 20% to 5% had a deleterious effect in cold-exposed rats. In the present study no beneficial effects due to increasing dietary protein level from 20% to 40% were observed.
EFFECT OF LYSINE AND WETTING AGENTS ON ACTIVATED PLASMINOGEN SOLUTIONS
Authors: Richard Maurel N. , Sanders Benjamin E.
Published: October 2017

The inclusion of lysine or of lysine with Emulphor 620 or Pluronics F68 increases the stability of a solution of streptokinase-activated plasminogen. Lysine plus Emulphor 620 greatly speeds up the development of caseinolytic activity in a solution of Cohn fraction III-3. Proteolytic activity thus produced may, within 5 hours, equal that produced by streptokinase. Where lysine and Emulphor 620 are present in the reaction mixture between Cohn fraction III-3 and streptokinase, higher fibrinolytic values appear than are produced by the same quantity of reactants without Emulphor and lysine.
PURIFICATION OF STAPHYLOCOCCAL-ALPHA-LYSIN
Authors: Jackson A. W.
Published: October 2017

A method for the purification and concentration of staphylococcal-α-lysin is described. Zinc–lysin complex, formed by addition of zinc–acetate to dialyzed, crude solutions of lysin, is precipitated with ethanol at low temperature. All but traces of zinc, together with some inactive material is removed from the precipitate by extraction with ethanol–water mixtures under conditions of pH and ethanol content which maintain the lysin in precipitated form. Further purification of the active material is achieved by chromatography employing columns composed of hydroxylapatite. The purified lysin is 250 times as active as the crude starting material in terms of hemolytic units per milligram of nitrogen.Rabbit erythrocytes are susceptible whereas human erythrocytes are resistant to the hemolytic activity of purified α-lysin. It is dermonecrotic when injected intradermally into rabbits and lethal when introduced intraperitoneally into mice in quantities of 20 hemolytic units per 25 g mouse.