bluuebunny/crossref_metadata_2025 huggingface dataset:
FURTHER STUDIES ON THE PURIFICATION OF THROMBIN
Authors: Seegers Walter H. , Levine Walter G. , Shepard Robert S.
Published: December 2009

Purified biothrombin (bovine) was fractionated with the use of amberlite IRC-50 columns to obtain resin thrombin with an activity of 4100 units/mg. dry weight or 45,000 units/mg. tyrosine. As obtained from a resin column in 0.3 M phosphate buffer, pH 8.0, the thrombin is stable for 5 days at room temperature. At 4 °C. about 70% of the activity remains after 20 weeks. The maximum molecular weight is estimated by comparing with the specific activity (2000 units/mg.) and molecular weight (62,700) of purified prothrombin as follows: 2000/4100 × 62,700 or 30,600 as the probable molecular weight. Resin thrombin can lose its fibrinogen-clotting power while esterase activity is retained. On the other hand the esterase activity can be depressed without diminishing the clotting activity. Resin thrombin lyses fibrin. When examined in an ultracentrifuge a single symmetrical peak was found with a sedimentation constant of S = 3.9 (20 °C., 0.1 M KCl, 5.5 mg./ml.) Citrate thrombin was also fractionated with the use of IRC-50 to obtain material with a specific activity of 47,000 units/mg. tyrosine.
PRODUCTION WITH SODIUM SULPHATES OF AN ELECTROLYTE–STEROID-GARDIOPATHY CHARACTERIZED BY NECROSES (ESCN), AND ITS PREVENTION BY MgCl2 AND KCl
Authors: Selye Hans
Published: December 2009

Massive myocardial necroses and hemorrhagic necroses of the liver can be produced by combined treatment with monosodium or disodium sulphate (NaHSO4 or Na2SO4) and 2α-methyl-9α-chlorocortisol (Me-Cl-COL) in the rat. In this respect, the effect of the sulphates resembles that previously described for sodium phosphates and perchlorate. It differs from that of most other sodium salts that have been tested for this activity up to the present time.NaCl slightly inhibits the cardiotoxic and hepatotoxic effect of concurrent treatment with Na2SO4 plus Me-Cl-COL. Equimolecular amounts of MgCl2 or KCl are even considerably more effective in this respect. It is noteworthy that, under these experimental conditions, the effect of 1 mM. of Na2SO4 can be inhibited by 0.5 mM. of MgCl2 or KCl.We may conclude from these observations that, in rats conditioned by a highly active corticoid, such as Me-Cl-COL, the production of an "infarctoid cardiopathy" (as well as of the accompanying hepatic changes) does not only depend upon the sodium ion, but is largely influenced by the simultaneous presence of other anions and cations.
BIOCHEMICAL STUDIES ON SOCKEYE SALMON DURING SPAWNING MIGRATION: I. PHYSICAL MEASUREMENTS, PLASMA CHOLESTEROL, AND ELECTROLYTE LEVELS
Authors: Idler D. R. , Tsuyuki H.
Published: December 2009

Physical measurements have been made on all major organs and tissues of a pure race of migrating adult Oncorhynchus nerka. The data show that the population was sufficiently uniform in size that average weights and measurements performed on fish taken at three locations on the migration route quite accurately represented a standard fish of both sexes. The results will enable chemical analyses to be interpreted as changes in absolute amounts of a given tissue component rather than only on a percentage basis. The merits of this approach to an evaluation of changes in migrating salmon is demonstrated by the magnitude of the weight changes in many tissues during the 715-mile migration. A standard male lost only 11% of its body flesh whereas a standard female lost 30%. The alimentary tract decreased to one sixth of the initial weight. The milt increased by 51% w hile the roe increased by 272%. Thus, it is apparent that percentage composition data cannot show quantitative changes in a fish as it moves up the river. The results are discussed in relation to the findings of others on Salmonidae.Plasma cholesterol, magnesium, calcium, sulphate, and urea levels were measured on pooled blood samples from the 216 fish.
DISUSE ATROPHY OF SKELETAL MUSCLE IN THE RAT, AGGRAVATED BY CORTISOL AND VARIOUS STRESS CONDITIONS
Authors: Bajusz Eörs
Published: December 2009

Slight atrophy of the triceps surae muscle of the rat was produced by immobilization of one hind limb in a plaster of Paris cast. The development of disuse atrophy was significantly aggravated when the immobilized animal was exposed to stressors and/or treated with cortisol. These results indicate that immobilization of one limb, which did not produce any visible local damage through compression, can act as a "conditioning" factor which selectively sensitizes the muscular tissue to the catabolic effect of endogenous and exogenous corticoids. It is probable that the conditioning is due to a circulatory disturbance caused by the immobilization, but this assumption has not been definitely proved. These experiments also indicate that the type of immobilization used here can act as a "neurogenic" stressor agent, and by thus producing general catabolism predisposes the muscular tissue for the development of a greater degree of atrophy.
PAROTID SECRETION OF PROTEIN IN MAN
Authors: Ferguson Marion H. , Krahn H. P. , Hildes J. A.
Published: December 2009

In unstimulated saliva, total protein concentration averaged 186 mg per 100 ml and amylase activity 146 units per 100 ml. The protein concentration was lower in the early morning than at midday. After dilute acetic acid stimulation, both total protein concentration and amylase activity were increased but the concentrations were not affected by rates of secretion above 0.1 ml per minute. Unlike protein, the potassium concentration fell with stimulation.Using zone electrophoresis on filter paper, as many as nine protein components were found, none of which corresponded to the serum proteins. The amylase activity was restricted to a component of low mobility which moved to the anode. There were two or three bands containing glycoproteins; all moved towards the cathode. There were qualitative and quantitative differences between stimulated and unstimulated secretions. Saliva collected 2 or 24 hours after a tracer dose of I131showed less than 1% residual radioactivity after dialysis or treatment with an anion exchange resin, indicating that little if any of the salivary iodide is organically bound.
PROBLEMS ASSOCIATED WITH THE USE OF THE EXPOSED PLATINUM ELECTRODE FOR MEASURING OXYGEN TENSION IN VIVO
Authors: Inch William Rodger
Published: December 2009

The equation governing the distribution of oxygen around a stationary exposed platinum electrode was solved for the size of electrode used and for a number of different times. In protein solutions the oxygen polarogram could be satisfactorily monitored by measuring the diffusion current at −0.6 and −0.7 volts. After using the platinum electrode in solutions containing protein it was found necessary and sufficient to clean it in acid dichromate solution followed by neutralization in a buffer solution. This procedure reproduced the original diffusion current. In solutions containing heterogeneities with small coefficients of oxygen diffusion, the electrode current was found to be less than when the heterogeneities were not present.
THE INFLUENCE OF THIOURACIL ON THE RESPONSES OF THE IMMATURE PULLET TO ESTROGEN, WITH REFERENCE TO OVIDUCT HYPERTROPHY, SERUM CALCIUM, AND LIVER COMPOSITION
Authors: Common R. H. , Maw W. A. , Layne D. S. , McCully K. A.
Published: December 2009

Thiouracil was given to sexually immature pullets at a level of 0.05% of the diet for 14 days before and also during treatment with 0.5 mg estradiol benzoate (ODB) or 1.0 mg ODB daily for 14 days. The thiouracil treatment did not modify the estrogen-induced hypercalcemia after 7 days, but after 14 days it enhanced significantly the blood calcium response to 1.0 mg ODB per day. The positive effects of thiouracil and of estrogen on liver weight per kg live weight were significant and additive. The comparatively low level of thiouracil used did not increase liver fat per kg live weight significantly, but it increased significantly the positive effect of estrogen on liver fat. The thiouracil treatment had no significant effect on liver deoxyribonucleic acid phosphorus (DNAP) but it increased liver pentose nucleic acid phosphorus (RNAP) per kg live weight significantly both in absence and presence of estrogen. The thiouracil treatment had no effect on the responses of the oviduct to estrogen.In a second experiment the effects of (a) 1.0% thiouracil for 10 days before and also during a 14-day estrogen treatment of 1.0 mg ODB per day and of (b) 1.0% thiouracil given concurrently with 1.0 mg ODB per day were studied. Neither thiouracil treatment affected the response of the oviduct to estrogen. The other results confirmed previous observations.In a third experiment, 1.5 mg ODB was given every other day for 14 days. When thiouracil at a level of 1% was given concurrently with the estrogen, it enhanced significantly the response of the oviduct. When 1% thiouracil was given also for 10 days before the estrogen, then it did not enhance the response of the oviduct. This experiment suggests that the conditions under which thiouracil will enhance estrogen-induced hypertrophy of the oviduct are narrowly defined. Other results were in general agreement with previous observations.
THE USE OF FURFURAL FOR THE DETERMINATION OF ACETONE BODIES IN BIOLOGICAL FLUIDS
Authors: Lyon Jr. John B. , Bloom Walter L.
Published: December 2009

A rapid and sensitive method for the determination of acetone plus acetoacetate, and total acetone bodies in blood and urine is described. It is based upon the condensation of acetone and furfural in the presence of a strong base to form difurfurylidene–acetone, which develops a red to violet color in strong acid. A standard Thunberg tube, which is heated and cooled in a water bath, is used as a microrefluxing and a microdistillation unit. The effective range is from 1 to 6 μg of acetone per sample. The average standard deviation, based on recoveries of added material, was 5%. When the method was applied to determinations of blood and urine of several species, the results agreed with those reported by others.
THE METABOLISM OF THE ERYTHROCYTE: XV. ADENYLATE KINASE OF THE ERYTHROCYTE
Authors: Kashket Shelby , Denstedt Orville F.
Published: December 2009

Adenylate kinase has been found in the membrane and the cytoplasm of rabbit and human erythrocytes. ADP, when added to a suspension of washed erythrocytes, causes an increase in the rate of glucose utilization by the cells. The ADP evidently can enter the cell membrane where it is converted by the adenylate kinase to equimolar quantities of ATP and AMP. The ATP can pass either into the interior of the cell or into the external medium. Added ATP or AMP apparently cannot pass through the erythrocyte membrane. The role of adenylate kinase in these reactions, and its location within the erythrocyte membrane, are discussed.
MECHANISM OF ACTION OF THE LACTIC DEHYDROGENASE OF THE MAMMALIAN ERYTHROCYTE: II. THE MECHANISM OF SUBSTRATE INHIBITION
Authors: Ottolenghi Paul , Denstedt Orville F.
Published: December 2009

The inhibition of lactic dehydrogenase produced by an excess of the substrate pyruvate has been shown to be of the noncompetitive type. Thus, two sites on the enzyme appear to be involved: one for the activation of pyruvate, and a second one which, when complexed with a molecule of pyruvate, renders the enzyme inactive.
THE BIOSYNTHESIS FROM ACETATE-1-C14OF FATTY ACIDS AND CHOLESTEROL IN FORMED BLOOD ELEMENTS
Authors: O'Donnell V. J. , Ottolenghi P. , Malkin A. , Denstedt O. F. , Heard R. D. H.
Published: December 2009

The biogenesis, in vitro, of cholesterol and fatty acids from acetate-1-C14in the cellular elements of blood has been studied. From the results obtained it is apparent that whereas the normocytes (nucleated) from the chicken and from the mammal (nonnucleated) are devoid of the capacity to synthesize cholesterol and fatty acids, the reticulocytes and the normoblasts from the rabbit, with an experimentally produced reticulocytosis, possess the ability to synthesize these lipids. Studies on the leucocytes from normal mammalian blood and thymus tissue showed little or no activity. On the other hand, the leucocytes from the thymus tissue and blood of chickens and from the blood of a patient with chronic myelocytic leukemia and from another with monocytic leukemia (Naegeli type) were capable of utilizing CI4-acetate for the synthesis of lipids. The leucocytes from patients with chronic lymphatic leukemia were found to be devoid of this activity.
ACETATE AND OCTANOATE UTILIZATION BY LIVER AND ADIPOSE TISSUE OF CASTRATED AND GONADAL HORMONE-TREATED RATS
Authors: Perry W. F. , Bowen Helen F.
Published: December 2009

The incorporation of C14-labelled acetate into fatty acids and cholesterol was studied in vitro in castrated and gonadal hormone-treated male and female rats. Measurements were also made on the incorporation of C14-labelled octanoic acid into acetoacetic acid by liver tissue and the incorporation of acetate and octanoate into CO2.Castration in the male, but not in the female, was followed by an increased incorporation of acetate into both liver and adipose tissue fatty acids and into liver cholesterol.Testosterone treatment led to a decreased incorporation into fatty acids by liver tissue in the male, whereas estradiol treatment of the female led to an increase in the incorporation of acetate into fatty acids by both liver and adipose tissue. Acetate incorporation into cholesterol was unaltered by hormone treatment in both sexes. The incorporation of octanoic acid into acetoacetic acid by liver tissue was decreased in the estradiol-treated female rat but was unaltered in the testosterone-treated male rat or by castration in either sex.
THE EFFECT OF PYRIDOXINE DEFICIENCY ON BLOOD UREA IN MICE
Authors: Lyon Jr. John B. , Arnold Eugene A. , Farmer Rita
Published: December 2009

Blood urea levels were determined in weanling, young, and adult C57and I strain mice fed vitamin B6-deficient or complete rations. Elevations in blood urea were found in some of the deprived groups, but they were transient, and the maxima occurred early in the deficiency, at 2 weeks. Although the I strain is more susceptible to a B6deficiency, strain differences were found in only one age group. Increases in blood urea were also induced by simple environmental changes. It was concluded that elevations in blood urea are not directly related to a pyridoxine deficiency in these inbred strains of mice.
BIOCOLLOIDS IN NORMAL HUMAN URINE: I. AMOUNT AND ELECTROPHORETIC CHARACTERISTICS
Authors: Webb T. , Rose B. , Sehon A. H.
Published: December 2009

The biocolloids of normal urine have been isolated and characterized by free electrophoresis and electrophoresis on filter paper. An average of 133 mg of material was recovered from 24-hour aliquots of normal urine. This material was composed of at least seven components as revealed by free electrophoresis at pH 8.6. Five of these components were similar in electrophoretic mobility to the five serum components. A relatively large amount of material was present which behaved like the acid mucoproteins of normal serum. No lipoproteins were detected. Some of the components of the urinary biocolloids were shown to be derived from human serum γ-globulins by labelling the latter with radioactive iodine.
THE INCORPORATION OF C14-LABELLED FORMATE INTO THE TISSUE NUCLEIC ACIDS OF RATS BEARING THE NOVIKOFF HEPATOMA
Authors: Zbarsky S. H. , Hori Aiko , Findlay Barbara S.
Published: December 2009

A study was made of the incorporation in vivo of C14-labelled formate into purines and pyrimidines of the nucleic acids of various tissues of normal rats and rats bearing the Novikoff hepatoma. The purines of the intestinal mucosa and the hepatoma had the highest specific activities, followed in descending order by those of spleen, kidney, testes, and liver. The pyrimidines of the mucosa and hepatoma also exhibited comparatively high specific activities. It was felt that the incorporation of radioactivity by a given tissue was related to its rate of cell renewal and that the present findings did not indicate a difference between tumor and normal tissue with respect to mechanisms involved in the biosynthesis of the nucleic acids. The results indicated that the tissue nucleic acids of the tumor-bearing animals incorporated more radioactivity than did those of normal rats. Chemical degradation of the radioactive purines showed that part of the radioactivity was derived from the injected C14-formate and part from C14O2formed by metabolic oxidation of the formate.
SODIUM, POTASSIUM, AND LACTIC ACID AFTER MUSCULAR EXERCISE IN THE RAT
Authors: Sréter F. A. , Friedman Sydney M.
Published: December 2009

Untrained young rats were exercised on a treadmill for a standard time at different speeds. A linear correlation between the intensity of the exercise and the degree of plasma [K] rise was observed. On the other hand, exercise at standard speed for varying durations was found to cause an increase in plasma [K] only during the early stages of the exercise. A fall in plasma [Na] was a constant accompaniment of exercise but no definite correlation to either intensity or duration was found. Lactic acid rose only with relatively severe exercise or with excitement. Blood sugar did not vary. Old rats responded to even mild exercise with a marked [K] shift accompanied by a well-defined rise in lactic acid.
A SPECTROMETRIC STUDY OF THE REACTIONS OF KETOSTEROIDS IN SULPHURIC ACID
Authors: Goldberg Hilda F. , Linford J. H.
Published: December 2009

The reactions of C3 ketosteroids in concentrated sulphuric acid and in fuming sulphuric acid have been studied by following the development of their absorption spectra. The results are attributed to protonation of the C3 keto oxygen in 98%–100% acid, and to removal of the C3 keto oxygen in fuming acid. These reactions proceed at a higher rate at 100 °C than at room temperature, but the reaction is the same.It is suggested that in the presence of conjugated protonated ketone, double bonds take part in addition reactions to form the hydrogen sulphates. In the absence of conjugated ketone, or when the acid is diluted to prevent the occurrence of protonation, double bonds react with protonated molecules of acid solvent, or of diluent, or of added reactive compounds, to form carbonium ions.
THE ANTHOCYANINS OF SOME CANADIAN PLANTS
Authors: Acheson R. M.
Published: December 2009

The anthocyanins of a number of Canadian flowers and berries have been examined and the anthocyanidins identified. No new types were detected.
THE EFFECT OF VAGOTOMY AND DENERVATION OF THE CAROTID SINUS ON DIURESIS FOLLOWING PLASMA VOLUME EXPANSION
Authors: Pearce J. W.
Published: December 2009

The hypothesis exists that afferent vagal fibers, arising in cardiac atrial stretch receptors, serve as the sensory limb of a reflex mechanism sensitive to variations in blood volume and producing corresponding changes in urine flow. Section of the vagi did not, however, prevent the diuretic and chloruretic response to expansion of the plasma volume with isotonic infusions. Carotid sinus denervation alone or combined with vagotomy also failed to prevent the diuresis and chloruresis following infusion in most experiments, although in a few cases the response was absent or diminished after the combined procedure. Reasons are given for believing that the bovine albumin infusion used did not act directly on the kidney to increase urine output, but rather through a reflex mechanism which could not have depended on the integrity of the vagi. It is concluded that receptors additional to those in the cardiac atria and the carotid sinus must contribute to the sensory component of a reflex mechanism regulating plasma volume.
THE MODE AND SITE OF THE RENAL ACTION OF PARATHYROID EXTRACT IN THE DOG
Authors: Nicholson T. F.
Published: December 2009

When 20 U.S.P. units per kg of parathyroid extract were injected intravenously into dogs with unilateral distal tubular nephrosis, the phosphate excretion from the normal kidney increased significantly, but there was no change in the amount of phosphate excreted by the nephrotic kidney. In dogs with unilateral nephrosis affecting the first third or the last two thirds of the proximal tubules, parathyroid extract produced a similar increase in phosphate excretion by the normal and the nephrotic kidneys. It is concluded that the site of renal action of parathyroid extract is in the distal tubule and that its mode of action is to stimulate active excretion of phosphate.
SILICA METABOLISM IN GUINEA PIGS
Authors: Sauer F. , Laughland D. H. , Davidson W. M.
Published: December 2009

The excretion of silica (SiO2)n in urine and feces was determined following the oral and intraperitoneal administration of silica to guinea pigs. The urinary excretion of silica after oral administration generally reached a maximum value that was not exceeded by increasing the dose. The urinary excretion after intraperitoneal administration was considerably greater than after oral administration. The results of these experiments suggested that orally and intraperitoneally administered silica is depolymerized to the soluble form prior to excretion in the urine.
PREPARATION AND ASSAY OFD-ERYTHROSE 4-PHOSPHATE
Authors: Baxter J. N. , Perlin A. S. , Simpson F. J.
Published: December 2009

The oxidation of D-glucose 6-phosphate by lead tetraacetate in cold acetic–propionic acid produces D-erythrose 4-phosphate contaminated with a small proportion of D-glyceraldehyde 3-phosphate. The product is a suitable substrate for certain enzymic studies, as illustrated by its use in the assay of transaldolase and transketolase. D-Erythritol 4-phosphate may readily be obtained in high yield by reducing the crude oxidation mixture with sodium borohydride. Oxidation of D-fructose 6-phosphate with 1 mole of lead tetraacetate gives chiefly D-erythrose 4-phosphate, whereas oxidation with 2 moles produces mainly D-glyceraldehyde 3-phosphate. The stability of D-erythrose 4-phosphate under a variety of conditions was also examined.
THE ACTIVATION AND DETERMINATION OF PLASMIN IN THE RAT
Authors: Levy S. W.
Published: December 2009

The presence of a proteolytic enzyme precursor (plasminogen) in the euglobulin fraction of rat plasma was demonstrated and optimum conditions for its activation and determination were studied. Rat plasmin activity was estimated (casein-digestion method) following activation of the enzyme with streptokinase-activated human serum euglobulin under various conditions of temperature, time, activator concentration, and pH. The activation and subsequent inactivation of plasmin in the presence of activated human euglobulin were shown to be accompanied by the appearance of acid-soluble, ultraviolet-absorbing substances in the activation mixture. The results of these studies were discussed in terms of the concept that the activation and inactivation of rat plasmin are essentially auto-catalytic reactions and represent stages in the progressive degradation of the plasminogen molecule.
ACETYLCHOLINE IN PERIPLANETA AMERICANA L.: III. ACETYLCHOLINE IN ROACHES TREATED WITH TETRAETHYL PYROPHOSPHATE AND 2,2-BIS(p-CHLOROPHENYL)-1,1,1-TRICHLOROETHANE
Authors: Colhoun E. H.
Published: December 2009

The levels of acetylcholine (ACh) in the thoracic nerve cords of cockroaches were increased by the topical application of 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) and of tetraethyl pyrophosphate (TEPP), but only TEPP inhibited cholinesterase (ChE). Improvements in the correlation of symptoms, nervous activity, and ACh levels with ChE were obtained when nerve cords were homogenized in saline containing ACh, which prevented further inhibition of ChE by TEPP found to be present in blood and nervous tissue. There was a similarity in the distribution of ACh in thoracic nerve cords of roaches after topical treatment with TEPP and DDT but the physiological properties of the blood revealed differences in the mode of action of the two insecticides. The effects of blood from the poisoned insects on the electrical activity of the isolated nerve cord of roaches are discussed in relation to the penetration of the nerve cord by known neurohumors.
STUDIES ON THE TIME COURSE OF THE RESPONSE OF THE ADRENAL CORTEX TO HISTAMINE AND COLD
Authors: Schönbaum E. , Casselman W. G. Bruce , Large Rosemary E.
Published: December 2009

Rats were injected with histamine or exposed to cold. In either case there was a transient elevation in the output of corticosteroids by the excised adrenal glands in vitro but a prolonged fall in adrenal ascorbic acid. The return of steroid formation to pre-exposure or even lower rates within three hours was not accompanied by any further change of the concentration of adrenal ascorbic acid.
LE DOSAGE DE L'ADRÉNALINE ET DE LA NORADRÉNALINE : I. RÉACTION MODIFIÉE DES CATÉCHOLAMINES AVEC L'ÉTHYLÈNEDIAMINE
Authors: Nadeau Guy , Sobolewski Georges
Published: December 2009

A modification to the method of Weil-Malherbe and Bone for the estimation of adrenaline and noradrenaline is suggested. The catecholamines are first allowed to react with ammonium molybdate at room temperature. Ethylenediamine reagent is then added to the catecholamine–molybdate complexes, and the reaction is carried out in two different steps: at room temperature, and at 50 °C. This procedure ensures a more adequate oxidation of the catecholamines and controls the variable effect of metallic ions either present in biologic samples or introduced during adsorption on alumina. The fluorescence is also significantly increased, although the amount of ethylenediamine added is reduced, thus decreasing the fluorescence of the reagent blanks. Another modification of the original method for the differential estimation of both catecholamines is based solely on the different rates of reaction of the molybdate complexes with ethylenediamine; this eliminates the need of reading the fluorescence at two different wavelengths.
THE EXTRACELLULAR POLYSACCHARIDE OF XANTHOMONAS PHASEOLI
Authors: Lesley S. M. , Hochster R. M.
Published: December 2009

The extracellular polysaccharide produced by Xanthomonas phaseoli has been purified and shown to be homogeneous by examination in the analytical ultra-centrifuge, by moving boundary electrophoresis, and by gradient precipitation with ethanol. Following hydrolysis the constituent sugars of the polysaccharide were isolated and positively identified as the crystalline derivatives of D-glucose and of D-mannose and as the crystalline lactone of D-glucuronic acid. The above hexoses were found to be present in the relative proportions of 1:1:1.The results of a preliminary investigation in which C14-labelled glucose was supplied to rapidly growing cells indicate that it is unlikely that a single six-carbon precursor is formed from which all three sugar components of the polysaccharide are synthesized directly.
METABOLISM OF PHENYLPROPANOID COMPOUNDS IN SALVIA: I. BIOSYNTHESIS OF PHENYLALANINE AND TYROSINE
Authors: McCalla D. R. , Neish A. C.
Published: December 2009

C14-Labelled shikimic acid, L-phenylalanine, D-phenylalanine, L-tyrosine, and cinnamic acid were fed separately to leafy cuttings of salvia. After a metabolic period of 24 hours the free and bound phenylalanine, tyrosine, and glutamic acid were isolated from the stems, and their specific activities measured. Shikimic acid was found to be a good precursor of both phenylalanine and tyrosine. There was little interconversion of phenylalanine and tyrosine, and hardly any oxidative breakdown of these compounds to glutamic acid precursors. D-Phenylalanine was metabolized more slowly than L-phenylalanine but it was superior to cinnamic acid as a precursor of bound phenylalanine and tyrosine.
DIETARY CHOLESTEROL AND PLASMA CHOLESTEROL LEVELS IN MAN
Authors: Beveridge J. M. R. , Connell W. F. , Haust H. L. , Mayer G. A.
Published: December 2009

Sixty-three men and twenty women (university students) consumed a fat-free, homogeneous liquid formula ration for 8 days. Groups of 8 to 11 individuals were then transferred to diets in which 30% of the calories were supplied in the form of butter oil fractions which were substituted equicalorically for carbohydrate. The most volatile fraction, which was high in cholesterol (3.83%), caused a great increase in plasma cholesterol. The cholesterol-poor fractions led to relatively small increases but when supplemented with an amount of cholesterol equivalent to that provided by the cholesterol-rich fraction, increases of comparable magnitude were obtained. Supplementation of the fat-free diet with the completely saturated medium chain length triglycerides, C6–C12, derived from coconut oil with or without cholesterol, did not cause a significant increase whereas coconut oil did. These results have been interpreted as indicating that relatively small amounts of cholesterol, depending upon the nature of fat with which it is associated, can in fact effect highly significant increases in plasma cholesterol in man. It is suggested that the substance with which cholesterol reacts is a specific type of triglyceride having certain fatty acids attached at the alpha, beta, and alpha1positions on the glycerol moiety.
DERIVATIVES OF HYDROXY-L-PROLINE
Authors: Baer Erich , Stedman R. John
Published: December 2009

N-Carbobenzoxy-hydroxy-L-proline benzyl ester has been obtained by treating N-carbobenzoxy-hydroxy-L-proline or its cyclohexylammonium salt with benzyl chloride and triethylamine.
ARGININE UPTAKE AND ARGINASE ACTIVITY IN EHRLICH ASCITES CARCINOMA CELLS
Authors: Johnstone R. M.
Published: December 2009

Anaerobic glycolysis in Ehrlich ascites tumor cells exposed to amino acids leads to an increased uptake of a number of the amino acids to levels comparable with those obtained under aerobic conditions. The arginine uptake in the cell is not increased by glucose. Anaerobically the arginase activity is inhibited when glucose is present. The inhibition appears to be the result of an increased retention in the cell of the ornithine produced by arginase activity.
ACCLIMATIZATION TO COLD: IMMEDIATE ADRENAL RESPONSE AND SURVIVAL OF ACCLIMATIZED RATS EXPOSED TO MORE SEVERE COLD
Authors: Molloy Rosemary , Nicholls Doris , Farrington William , Rossiter R. J.
Published: December 2009

Further observations are described on the measurement of the incorporation of inorganic phosphate labelled with P32 into the inorganic phosphate of the adrenal gland to assess the immediate pituitary–adrenal response when cold acclimatized and non-acclimatized rats are exposed to more severe cold (2 hours at −5 °C). In rats acclimatized to cold by conditioning to 3 °C for 4 weeks, this immediate pituitary–adrenal response was considerably less than that in non-acclimatized rats maintained at room temperature (22 °C). The reduction in the immediate pituitary–adrenal response took 3 to 4 weeks to develop and persisted for 12 hours, but not for 4 days. Rats that were conditioned to −5 °C by exposures for 2 or 6 hours daily for 4 weeks showed no reduction in the immediate pituitary–adrenal response to more severe cold, but there was a significant decrease in this response in rats conditioned for 6 hours daily for 8 weeks.Rats acclimatized to cold by conditioning to 3 °C for 4 weeks showed greater survival when exposed to an environmental temperature of −15 °C than rats conditioned to 22 °C. Rats that were conditioned to −5 °C for brief daily periods (2 hours or 6 hours) for 4 weeks or 8 weeks also survived exposure to severe cold (−22 °C) better than rats maintained at room temperature.In general, significant increases in adrenal weight were found in those cold-conditioned rats that showed a reduced pituitary–adrenal response. However, it is concluded that the development of increased survival on exposure to severe cold, by a process of conditioning to less severe cold, is not necessarily accompanied by a reduction in the immediate pituitary–adrenal response to severe cold, or by an increase in weight of the adrenal glands.
EFFECTS OF DIHYDROSTREPTOMYCIN ON AMINO ACID INCORPORATION INTO THE PROTEINS OF M. TUBERCULOSIS (BCG)
Authors: Stachiewicz E. , Quastel J. H.
Published: December 2009

A study has been made of the effects of dihydrostreptomycin on amino acid incorporation into the proteins of M. tuberculosis (BCG). Suspensions of this organism on incubation at 37° with glycine-1-C14give rise, aerobically, to labelled proteins in which 80% of the radioactivity appears in the glycine and serine moieties of the proteins and about 20% in alanine and aspartic acid. In presence of glycine-2-C14, radioactivity appears in a larger number of amino acids of the protein. Incubation with serine-3-C14leads to a distribution of radioactivity in the amino acids in BCG proteins but alanine-1-C14and valine-1-C14give rise to proteins with the radioactivity almost entirely in the corresponding amino acids. The process of aerobic incorporation of radioactivity from glycine-1-C14in BCG proteins is stimulated by the presence of glucose, glycerol, sodium pyruvate, sodium stearate, or sodium benzoate in the medium in which the cells are incubated, the rate of incorporation being approximately constant over a period of 4 hours. The incorporation depends largely on the presence of oxygen. Dihydrostreptomycin (33 μg per ml) markedly inhibits labelling of proteins in the cell suspensions in presence of radioactive amino acids, the inhibition increasing with concentration of the streptomycin to an optimal concentration of 200 μg/ml. Penicillin and isonicotinic hydrazide are inactive but chloromycetin is an effective inhibitor. Cyanide, arsenite, and azide are inhibitory. The presence of lecithin stimulates incorporation of radioactivity from glycine-1-C14into BCG proteins. Dihydrostreptomycin inhibitions of amino acid incorporation into BCG proteins increase with time of incubation of the cells with the drug. Concentrations of dihydrostreptomycin that inhibit labelled amino acid incorporation into labelled proteins by 50% have no effect on BCG respiration. The drug has no inhibitory effect on labelled amino acid incorporation in E. coli or Ehrlich ascites carcinoma cells in vitro but is effective with M. phlei. It does not affect selectively the distribution of radioactivities of the component amino acids of BCG proteins; only the total radioactivity incorporated into the proteins is diminished. The results lead to the conclusion that dihydrostreptomycin brings about an inhibition of protein synthesis in the BCG strain of M. tuberculosis at concentrations at which it exerts antibiotic effects.
STUDIES ON THE DISTRIBUTION AND KINETICS OF THE ALKALINE PHOSPHATASE OF RAT SMALL INTESTINE
Authors: Triantaphyllopoulos Eugenie , Tuba Jules
Published: December 2009

Alkaline phosphatase activity was demonstrated throughout the entire length of the small intestine of the albino rat and the relative amounts present seemed to decrease exponentially from the pylorus to the ileocolic valve. All subcellular fractions of intestinal homogenates were found to hydrolyze sodium β-glycero-phosphate. The distribution of activity of the enzyme was as follows: "microsomes", about 76%; nuclei, 10%; mitochondria, 8%; and in the nongranular, supernatant fraction, 9%. The specific activity for these fractions was: 52, 3, 10, and 3, respectively. The effects of the time of incubation, pH of the hydrolytic mixture, and the concentration of the enzyme were similar in all fractions. For the enzyme in the various fractions slight differences were observed in the values of the Michaelis constants, and in the degree of activation by magnesium ion. These variations may be explained on the basis of differences in the accessibility of substrate and magnesium ion to the enzymes in the various fractions. The finding that the "microsomes" contained the highest levels of alkaline phosphatase suggests that this intestinal enzyme is produced almost entirely by these submicroscopic particles.
CHANGES IN INTESTINAL AND SERUM ALKALINE PHOSPHATASE LEVELS DURING ABSORPTION OF CERTAIN AMINO ACIDS
Authors: Triantaphyllopoulos Eugenie , Tuba Jules
Published: December 2009

After force-feeding fasted male albino rats with solutions of amino acids it was observed that:(a) Intestinal alkaline phosphatase levels were significantly increased after ingestion of glycine, leucine, threonine, serine, glutamic acid, methionine, arginine, and large doses of glycine – glutamic acid – histidine mixtures, while a decrease was noted after force-feeding tryptophan.(b) Serum alkaline phosphatase activity was stimulated by solutions of glycine, histidine, and glutamic acid when each amino acid was given singly and even more when a mixture of these three amino acids was force-fed. Methionine on the other hand produced a highly significant depression of the activity of this enzyme.(c) Serum inorganic phosphorus levels were significantly decreased after ingestion of glycine, leucine, serine, threonine, methionine, glutamic acid, histidine, phenylalanine, tyrosine, and tryptophan.(d) Serum α-amino nitrogen concentration was increased in all cases except with cystine and lysine, when no change was observed, whereas arginine produced a highly significant drop, attributed to stimulation of urea cycle.(e) The α-amino nitrogen concentration of intestinal homogenates was increased after force-feeding glycine, leucine, cystine, methionine, glutamic acid, lysine, histidine, phenylalanine, and large amounts of glycine – histidine – glutamic acid mixtures.
THYROXINE AND INSULIN INTERACTION
Authors: Dow Dorothy S. , Allen C. E.
Published: December 2009

Rate of body weight gain of both the young chick and the young rat was markedly inhibited following ingestion of amounts of thyroxine which were greatly in excess of physiological requirements. The rate of body weight gain of the young rat was also markedly inhibited in alloxan diabetes. The administration of insulin partly or largely prevented the observed effect on body weight in both conditions. The administration of thyroxine caused a reduction of rat skeletal muscle mass which was partially prevented when insulin was given concurrently with thyroxine.Reduced body weight gain and muscle mass in the rat were accompanied by marked increases in the muscle DNA and nuclei concentration. Nuclear diameter and the amount of DNA per nucleus remained unchanged. RNA concentration of the muscle was not reduced. The beneficial effect of insulin administration on body weight and muscle mass was accompanied by a preventive effect against changes in muscle DNA and nuclei concentration. However, since the DNA content of muscle bundles remained relatively unchanged and since muscle bundle weights changed proportionately with body weight it would appear that DNA content does not reflect change in muscle mass.The effectiveness of insulin in the thyroxine-treated animal appears to be due to an improved utilization of energy. A hypoglycemic action of thyroxine implies an antagonism between the two hormones in their mechanism of action. The relationship between the two hormones is not direct since the administration of insulin does not affect the increased plasma protein-bound iodine levels resulting from thyroxine treatment.
FREEZING DAMAGE TO BOVINE CREAM INDICATED BY RELEASE OF ENZYMES
Authors: Cole L. J. N. , Kluepfel D. , Lusena C. V.
Published: December 2009

When washed cream was frozen slowly and thawed, some breaking of the emulsion occurred and on centrifugation a pellet, mostly membrane material, was obtained. Xanthine oxidase and alkaline phosphatase were present in this pellet, but little enzyme activity was found in the aqueous phase. The main effect of slow freezing was to force the fat globules together so that alteration and redistribution of the membranes could occur, and, on thawing, fat could coalesce. Rapid freezing on the other hand distributed fat globules more evenly so that less coalescence could occur on thawing.
THE INTERCONVERSION OF GLYCINE AND SERINE IN ZEA MAYS
Authors: Hauschild A. H. W.
Published: December 2009

Glycine and formaldehyde are converted into serine in the presence of a dialyzed, lyophilized enzyme preparation from corn seedlings, with tetrahydropteroylglutamic acid and pyridoxal phosphate as coenzymes. The equilibrium constant of the reaction was calculated for the system at 37.5 °C as K = 3.1 × 103. The pH activity curve showed a maximum between 6.6 and 7.0. The effects of the concentrations of the coenzymes were studied. The glycine–serine interconverting enzyme is present throughout the seedling and occurs exclusively in the soluble fraction of the cells.
ACID-LABILE PHOSPHATE CONTENT OF INCUBATED BRAIN SLICES
Authors: Pappius Hanna M. , Johnson Dorothy McLean , Elliott K. A. C.
Published: December 2009

During aerobic incubation of brain cortex slices in glucose-containing medium at 38° the pyrophosphate content of the tissue increases rapidly for 15 minutes and then more slowly. The creatine phosphate content increases rapidly during the first 5 minutes and then falls. Anaerobically, the pyrophosphate falls during the first 30 minutes; the creatine phosphate tends to rise initially and then falls to a lower level than that found aerobically. In the absence of glucose and oxygen the levels of both substances fall rapidly to low levels but can be raised again by aerobiosis in the presence of glucose. In the absence of glucose and oxygen in ice-cold medium, or at 38° in the absence of any medium, the levels of pyrophosphate and creatine phosphate are preserved. More inorganic phosphate is produced when slices are incubated than can be accounted for by breakdown of acid-labile phosphate compounds.It is shown that the initial rate of anaerobic glycolysis by slices which have been subjected to various pretreatments is strongly correlated with the pyrophosphate content of the tissue.The failure of slices to concentrate potassium when immersed in sodium-free media is not due to failure to maintain pyrophosphate levels.
ZONE ELECTROPHORESIS OF TOBACCO MOSAIC VIRUS
Authors: Townsley P. M.
Published: December 2009

An apparatus is described for the preparative zone electrophoresis of tobacco mosaic virus in agar gel. The isolated virus does not have any detectable ribonuclease activity.
THE CATALYSIS OF ASCORBIC ACID OXIDATION BY COPPER AND ITS COMPLEXES WITH AMINO ACIDS, PEPTIDES, AND PROTEINS
Authors: Scaife J. F.
Published: December 2009

The oxidation of solutions of ascorbic acid catalyzed by copper and the copper complexes of amino acids, peptides, and proteins has been investigated by manometric and chemical means. The copper-containing solutions were prepared by equilibration with the sparingly soluble salt malachite. The catalytic activity of the complexed copper was found to be dependent upon the type of complexing molecule. For amino acids the more firmly bound copper atoms tended to be the best catalysts. The catalytic activity of the copper complexed to several glycine peptides was approximately one half of the mean value of that of the copper complexed to amino acids. The catalytic activity of copper complexed to bovine plasma albumen and pepsin was lower than that of copper complexed with amino acids or peptides. The more firmly bound copper atoms on pepsin showed a higher catalytic activity than the mean value for all the complexed copper atoms. Sodium chloride markedly reduced the catalytic activity of both free copper and complexed copper. In the absence of sodium chloride free copper was 10 times as effective a catalyst as copper complexed to glycine. In the presence of 0.178 M sodium chloride the complexed copper was twice as effective as free copper.
ISOLATION OF RAT HEPARIN
Authors: Jaques L. B.
Published: December 2009

Heparin was isolated from the whole carcass and skin of rats of the Wistar strain and crystallized as the barium salt. The sodium salt derived from this had a specific anticoagulant activity (Howell assay) of 47.5 International Units/mg and specific metachromatic activity of 101.5 International Units/mg. Yield of heparin was 0.55 mg/100 g body weight.
UREA PRODUCTION IN CHICK LIVER SLICES
Authors: Lemonde André
Published: December 2009

Liver slices of very young white Leghorn chicks have been found capable of urea production. A correlation seems to exist between the protein level of the diet and the urea formation in the liver. When birds are subjected to a relatively long fasting period, they metabolize their own tissue proteins, and urea appears in the liver.
COMPARISON BETWEEN SEASONAL AND THERMAL ACCLIMATION IN WHITE RATS: III. STUDIES OF THE ADRENAL CORTEX
Authors: Héroux O. , Schönbaum E.
Published: December 2009

The rate of production of corticosteroids in vitro as well as the histological picture of the adrenal glands was studied in white rats exposed to cold for 3 months, either indoors at 6 °C in individual cages or outdoors during the winter in groups of 10.Under the indoor cold conditions, the adrenals hypertrophied within 1 week and their weight then remained constant for the following 11 weeks. The hypertrophy was due to an increase in the number of cells in the zona fasciculata. Relative to adrenal weight, the production of corticosteroids in vitro was less in the 6 °C rats than in the 30 °C controls. Under the outdoor cold conditions, the adrenal weight as well as the number of fasciculata cells remained normal, but the steroid production "in vitro" was greater than in the "summer controls". Since both "indoor" and "outdoor" cold-exposed rats have been shown previously to develop a similar degree of cold resistance as well as a similar capacity for elevating their metabolism through a non-shivering heat production mechanism, it appears that similar degrees of adaptation to cold can exist with different requirements of adrenocortical hormones.
ANTIGENIC PROPERTY AND ELECTROPHORETIC BEHAVIOR OF THE SERUM ALBUMIN OF RATS BEARING THE WALKER TUMOR
Authors: Dufour D. , Berlinguet L. , Loiselle J. M.
Published: December 2009

The serum of Walker tumor-bearing rats contains antigens which give an immunological response with rabbit anti-Walker antibodies. These antigens are located in the albumin fraction of the serum. The albumins of the normal and cancerous rats have different migration rates during electrophoresis and different levels of polysaccharides.
THE INCORPORATION OF FORMATE-C14INTO THE NUCLEIC ACIDS OF RATS WITH REGENERATING LIVER AND NOVIKOFF HEPATOMA
Authors: Nixon J. C. , Zbarsky S. H.
Published: December 2009

A study was made of the incorporation in vivo of formate-C14into the purines and thymine of regenerating liver and Novikoff hepatoma in the rat, during the period of maximum mitotic activity of these tissues. The effects of these tissues on one another and on certain host tissues were also studied. The maximum mitotic frequency of Novikoff hepatoma was observed on the 4th day of growth following transplantation. This tumor caused a decrease in formate incorporation into the nucleic acid purines and thymine of the host's spleen and intestinal mucosa but had little effect on liver. The results also indicated that the uptake of formate by the RNA adenine of spleen and intestinal mucosa and the DNA thymine of intestinal mucosa was diminished by the presence of regenerating liver. The simultaneous presence of both regenerating liver and Novikoff hepatoma generally lowered the incorporation of formate-C14into the nucleic acids of the host spleen and intestinal mucosa. It was observed further that the utilization of formate by the nucleic acids of Novikoff hepatoma and regenerating rat liver was decreased in animals containing both of these rapidly dividing tissues.