bluuebunny/crossref_metadata_2025 huggingface dataset:
TONIC ADAPTIONS IN DEAFFERENTED LIMBS OF THE CAT
Authors: Teasdall R. D. , Stavraky G. W.
Published: October 2017

In 26 cats postural reflexes and tonic adjustments in the chronically deafferented and intact limbs were studied by means of moving picture and other photographic recordings for a period of four to six months. The positive supporting reactions which were dependent on an intrinsic reflex arc were permanently abolished by the deafferentation. Other segmental reflexes such as the crossed extensor and Philippson's reflex were readily elicited in the deafterented extremity within 24 to 48 hr. after section of the posterior nerve roots, and after longer intervals following the deafferentation these reflexes became greatly exaggerated. They appeared sooner after the operation and became more prominent in the hind limb than in the fore limb.The intersegmental postural reflexes and the scratch reflex were consistently present in the deafferented limbs of chronic animals and the latter reflex became markedly hyperactive within one week after section of the posterior nerve roots. The normal reflex responses to linear acceleration were first depressed by section of the posterior nerve roots, but in one to four weeks after the operation they were readily demonstrable, became exaggerated in the deafferented extremity, and remained so for the rest of the period of observation. Unlike the crossed extensor reflex, these reflexes reappeared first in the fore limb and reached greater prominence in this extremity than they did in the hind limb. A reversal of the tonic labyrinthine and neck reflexes was demonstrated in the deafferented extremities of the chronic animal. This reversal appeared one to two months after section of the posterior nerve roots in the fore limb, and two to three months following deafferentation of the hind limb. When established, the reversal was readily elicited and took place simultaneously with a normal response in the intact extremities on the opposite side of the body. Simultaneously with the changes in postural reflexes, alterations in tone became prominent.The modified and exaggerated postural reflexes and tonic adjustments observed in the deafferented limbs were attributed to a sensitization of the partially denervated spinal neurones to nerve impulses reaching them from various receptive fields other than those originating in the extremity itself. It is felt that the modifications in postural reflexes and subsequent alterations of muscle tone which have been demonstrated in the chronically deafferented extremities of animals may play an important part in the pathogenesis of human sensory ataxia.
FURTHER STUDIES ON CARBOHYDRATE METABOLISM IN THE VITAMIN-B6-DEPRIVED RAT
Authors: Beaton John R.
Published: October 2017

Earlier studies in this laboratory demonstrated abnormalities in carbohydrate metabolism in the vitamin-B6-deprived rat. The results of further studies are reported in this communication. Following three weeks of vitamin B6 restriction, rats have significantly elevated levels of inorganic phosphorus and glutathione in blood and liver. These elevations in blood inorganic phosphorus and glutathione levels have been similarly demonstrated after only one week of vitamin B6 deprivation. Contrary to changes in liver glycogen levels, muscle glycogen levels are not altered by vitamin B6 deprivation in the rat. Insulin administration had a slightly more pronounced effect on blood sugar levels in vitamin-B6-deprived than in pair-fed control rats. Alloxan administration elevated blood sugar levels of deprived rats to a slightly greater extent than the levels of controls. In accord with the earlier studies, disturbances of carbohydrate metabolism can be readily demonstrated in vitamin-B6-deprived rats.
CHROMATOGRAPHY OF STEROIDS PRODUCED BY RAT ADRENALS IN VITRO
Authors: Elliott F. H. , Schally A. V.
Published: October 2017

As further evidence that rat adrenals in vitro produce corticoids, the chloroform-soluble substances formed by rat adrenals have been chromatographed on paper in two different solvent systems to compare their mobilities with those of known corticoids. The chromatography was carried out for the shortest possible time compatible with some resolution in order to prevent losses by excessive exposure or by transfer. Eluates of sections of the chromatograms were analyzed for α, β-unsaturated ketone groups and for groups that reduce a tetrazolium derivative (M. and B. 1767). The data may be interpreted as follows: 1. Rat adrenals in vitro produce ultraviolet-absorbing substances with chromatographic mobilities resembling hydrocortisone and corticosterone. Of these substances only 40–70% can be typical corticoids as judged by the reducing: ultraviolet-absorbing ratio. Ultraviolet-absorbing material without reducing properties is also present, most of which has a polarity greater than corticosterone. 2. ACTH, added to rat adrenal glands in vitro, stimulates primarily the production of substances with a polarity similar to that of corticosterone; the production of the other components is also somewhat increased.
EFFECT OF COLD STRESS ON THE PHOSPHORUS METABOLISM OF THE ADRENAL GLAND
Authors: Nicholls Doris , Rossiter R. J.
Published: October 2017

Observations were made on the effects of cold stress (3° ± 1 °C.) on the concentration of phosphorus and the incorporation of inorganic phosphate labelled with radioactive phosphorus (P32) into the following P-containing fractions in the rat: the inorganic P of the plasma, the inorganic P, 20-min. hydrolyzable P, and total acid-soluble P of the adrenal gland. With short periods of cold stress (2, 3, 6, 24 hr.) there was an increase in the relative specific activity of each of the adrenal fractions, greatest for an exposure of 2–3 hr. and least for 24 hr., with no significant change in the specific activity of the inorganic P of the plasma. With longer periods in the cold (2, 4, 8, 16 days), in addition to the usual increase in adrenal weight, there was an increase in the relative specific activity of each of the three acid-soluble P fractions of the adrenal. The increase in specific activity was not due to a decrease in the concentration of P in any of the fractions.Evidence is presented for the view that this change in the phosphorus metabolism of the adrenal can be interpreted in terms of an increase in the rate at which inorganic P32 passes across the cell membrane, i.e. from the extracellular to the cellular fluid. It is suggested that the change after a short (2–3 hr.) exposure to the cold is brought about by the stimulation of the adrenal cortex by endogenous ACTH from the pituitary. The change after longer (several days) exposures may be related to the function of the thyroid gland.
THE SEPARATION OF CALF THYMUS NUCLEIC ACID AND HISTONE BY ALCOHOL–SALT PRECIPITATION
Authors: Smillie L. B. , Marko A. M. , Butler G. C.
Published: October 2017

Extraction of the histone of thymonucleoprotein with alcohol and salt has been studied with varying concentrations of alcohol, sodium chloride, and nucleoprotein and with varying pH and temperature. The addition of 0.5–1.0 volumes of ethanol to a solution of nucleoprotein (approximately 1 mgm. N/ml.) in 3 M sodium chloride has been found to effect an almost quantitative separation of desoxyribonucleic acid and protein. It has proved feasible to prepare concentrated aqueous solutions of the extracted protein by successive dialysis against strong salt solutions at −10 °C. and against distilled water at 5 °C. followed by pervaporation at 5 °C. The properties of the isolated nucleate have indicated a highly polymerized product.
THE METABOLISM OFASCARIS LUMBRICOIDESOVARIES: I. NITROGEN DISTRIBUTION
Authors: Pollak John K. , Fairbairn Donald
Published: October 2017

The protein fraction obtained from Ascaris lumbricoides ovaries was analyzed for total, α-amino, and amide nitrogen, as well as amino acids and nucleic acids. In the corresponding non-protein fraction total, α-amino, amide, and ammonia nitrogen, and free amino acids and urea, were determined. Free and protein amino acids were qualitatively similar, but quantitatively dissimilar. Unusually large amounts of proline and alanine were found in the proteins, whereas arginine and methionine could not be identified in protein or free acids. Glutamic acid and alanine comprised one-half of the free acids. Ammonia was present in relatively high concentration, but urea was absent. Much of the non-protein nitrogen was not identified. Ribo- and desoxyribonucleic acids were found in approximately the relative proportions occurring in rat liver, but in much lower concentration. The existence of phosphoproteins was not clearly established. Glycogen and total reducing substances, however, were present initially in high concentrations which decreased markedly when the parasites were maintained in a non-nutrient medium.
THE DEMONSTRATION OF ACETYL PHOSPHATIDE (PLASMALOGEN) IN THE DEPOT FAT OF FOWL TREATED WITH DIETHYLSTILBESTROL
Authors: McKinley W. P. , Grice H. , Connell M. R. E.
Published: October 2017

The abdominal depot fat from young cockerels, male castrate fowl, or male turkeys which have been treated with diethylstilbestrol, or from hens in egg production, contains a material which responds to the Feulgen plasmalogen test. After treatment with mercuric chloride under specified conditions, fat from such birds reacts with fuchsin – sulphurous acid to give a purple colored product. The material responsible is considered to be plasmalogen. Fat from corresponding regions of non-laying hens, cockerels and male turkeys of varying ages, and castrated males does not give the reaction when it is performed under the specified conditions. A technique based on these findings is described and has been used to distinguish chickens or turkeys which have been treated with estrogen from birds which have not been thus treated.
THE EFFECT OF CORTICOTROPIN AND CORTICOSTERONE ON THE PRODUCTION OF HEMOLYTIC ANTIBODIES IN THE MOUSE
Authors: Newsom Shirley E. , Darrach Marvin
Published: October 2017

It has been demonstrated by quantitative immunochemical methods that corticotropin, when administered at sufficiently high levels, will suppress the formation of circulating hemolytic antibodies in the mouse; this apparent block on the antibody producing mechanism can be overcome by increasing the dose of antigen. Furthermore, it has been shown that corticosterone, which appears in greater amounts in the blood of mice after treatment with corticotropin, will also suppress the normal rise of circulating immune hemolysins in the mouse.
THE METABOLISM OF NORMAL BRAIN AND HUMAN GLIOMAS IN RELATION TO CELL TYPE AND DENSITY
Authors: Heller Irving H. , Elliott K. A. C.
Published: October 2017

Per unit weight, cerebral and cerebellar cortex respire much more actively than corpus callosum. The rate per cell nucleus is highest in cerebral cortex, lower in corpus callosum, and still lower in cerebellar cortex. The oxygen uptake rates of the brain tumors studied, with the exception of an oligodendroglioma, were about the same as that of white matter on the weight basis but lower than that of cerebral cortex or white matter on the cell basis. In agreement with previous work, an oligodendroglioma respired much more actively than the other tumors. The rates of glycolysis of the brain tumors per unit weight were low but, relative to their respiration rate, glycolysis was higher than in normal gray or white matter. Consideration of the figures obtained leads to the following tentative conclusions: Glial cells of corpus callosum respire more actively than the neurons of the cerebellar cortex. Neurons of the cerebral cortex respire on the average much more actively than neurons of the cerebellar cortex or glial cells. Considerably more than 70% of the oxygen uptake by cerebral cortex is due to neurons. The oxygen uptake rates of normal oligodendroglia and astrocytes are probably about the same as the rates found per nucleus in an oligodendroglioma and in astrocytomas; oligodendroglia respire much more actively than astrocytes.
THE RELEASE OF CORTICOTROPHIN BY ANTERIOR PITUITARY TISSUE IN VITRO
Authors: Saffran Murray , Schally A. V.
Published: October 2017

The release of ACTH by rat anterior pituitary tissue in vitro was used as a test system for the detection of factors that stimulate ACTH-release. The results indicate that:1. Epinephrine or arterenol, added by themselves, are without effect.2. Hypothalamic tissue alone is also ineffective.3. The combination of hypothalamic tissue with epinephrine or arterenol increases the release of ACTH about threefold.4. Brain cortex can replace hypothalamus.5. Liver cannot replace neural tissue; acetyl choline and serotonin cannot replace epinephrine or arterenol.6. The greatest stimulation of ACTH-release (six- to eight-fold) occurs with posterior pituitary tissue plus arterenol. The arterenol may be replaced by hypothalamus or sphingosine, but not by dopamine (3,4-dihydroxyphenylethylamine), which is structurally similar to arterenol.7. The posterior pituitary is probably involved in the response of the anterior pituitary–adrenocortical system to stress.
SOME EFFECTS OF TESTOSTERONE PROPIONATE ON THE IMMATURE PULLET
Authors: Layne D. S. , Common R. H.
Published: October 2017

Sexually immature pullets were treated for 10 days with testosterone propionate (TST) in doses of hormone ranging from 0.25 to 5.0 mgm. per day. TST increased live weight gains, the effect being significant for the highest dosage; TST also increased oviduct weight. Both these results are in agreement with those of previous workers. TST did not affect significantly the net liver weight or the liver weight per kgm. live weight. Liver deoxyribonucleic acid phosphorus (DNAP) per kgm. live weight was not affected by lower dosage levels, but was slightly and significantly increased by higher dosage levels. Liver pentose nucleic acid phosphorus (RNAP) was affected in the same way as liver DNAP; and hence TST had no effect on the ratio RNAP/DNAP in the liver. TST depressed kidney weight, thus confirming previous observations. TST also depressed kidney DNAP and increased kidney RNAP, thereby increasing the ratio RNAP/DNAP in kidney to a marked extent. Spleen weight was depressed by TST, though the effect did not attain statistical significance.
ACID PHOSPHATASE HYDROLYSIS OF PHOSPHORIC ESTERS
Authors: Delory G. E. , Wiberg G. S. , Hetherington Merle
Published: October 2017

The rate of hydrolysis and optimum pH of hydrolysis of seminal fluid acid phosphatase have been studied for a number of phosphoric esters. As the acidity of the substrate increases there is a tendency for the rate of hydrolysis to increase and for the optimum pH to move farther away from neutrality. The increased rate of hydrolysis of phenol phosphates or of substituted phenol phosphates can not be accounted for by phenolase activity.
THE ANTICOAGULANT ACTION IN BLOOD OF SULPHATED DERIVATIVES OF LAMINARIN
Authors: Hawkins W. W. , O'Neill A. N.
Published: October 2017

Laminarin, a polysaccharide from brown seaweeds, has been sulphated to produce compounds which show anticoagulant activity in blood in vivo. Derivatives of sulphamic acid were more active than simple sulphate esters, although the amount of sulphate also affected the activity. When tested in rats one sulphated β-aminoethyl ether derivative was 40–50% as potent as heparin, and one ester about 30%. Tests with rats and dogs indicated no harmful effects in the doses used.
A COMPARISON OF OPTICAL AND MANOMETRIC METHODS FOR THE ASSAY OF HUMAN SERUM CHOLINESTERASE
Authors: Kalow W. , Lindsay H. A.
Published: October 2017

A method for the assay of human serum cholinesterase (pseudocholinesterase) is described in detail. The disappearance of benzoylcholine is measured by ultraviolet spectrophotometry. Minute amounts of serum and of the substrate are sufficient for a rapid and convenient test of good accuracy. The influence of temperature on the reaction rate is given particular attention, since temperature control is not as easily achieved in the spectrophotometer as for instance in a Warburg apparatus. Although the results of the spectrophotometric assay are fundamentally the same as those obtained by using a conventional gasometric method with acetylcholine as a substrate, small but significant differences between the two answers occur. These differences depend on the substrates and not on the methods as such. The ratio of hydrolysis rates of the two substrates, benzoylcholine and acetylcholine, varies slightly from person to person. If benzoylcholine is used in the Warburg apparatus, a concentration above the optimum must be employed in order to develop sufficient gas for measurement.
HYDROLYSIS OF LECITHIN BY PLANT PLASTID ENZYMES
Authors: Kates Morris
Published: October 2017

Enzymatic liberation of choline from egg lecithin by plastid fractions from sugar beet, spinach, and cabbage leaves and from carrot root was a rapid, first order reaction (up to 70% hydrolysis), and was not preceded by a lag phase. None of the choline-containing products of lecithin degradation (lysolecithin, glycerylphosphorylcholine, or phosphorylcholine) lost choline on incubation with spinach chloroplasts. Inorganic phosphate liberation from lecithin by the plastids was preceded by a lag phase and was much slower than choline liberation. Spinach chloroplasts catalyzed the liberation of inorganic phosphate from L-α-phosphatidic acid and from L-α-glycerophosphate. The water-soluble organic phosphate liberated from lecithin by spinach chloroplasts was identified chromatographically as phosphorylcholine. The ether-soluble organic phosphate produced during the hydrolysis of egg lecithin by carrot plastids was isolated and identified as L-α-phosphatidic acid. These observations suggest that the enzymatic hydrolysis of lecithin by plant plastids involves the following reactions: (1) lecithin → L-α-phosphatidic acid + choline; (2) L-α-phosphatidic acid → inorganic phosphate + diglyceride and/or (3) L-α-phosphatidic acid → glycerophosphate + fatty acids and (4) glycerophosphate → inorganic phosphate + glycerol; and (5) lecithin → phosphorylcholine + diglyceride. The L-α-structure for egg lecithin was confirmed.
THE CONVERSION OF UROCANIC ACID TO GLUTAMIC ACID IN THE INTACT RAT
Authors: Kraml M. , Bouthillier L. P.
Published: October 2017

Urocanic-α-C14acid and imidazolepropionic-α-C14acid have been synthesized and their metabolism has been studied in the intact rat. Urocanic acid has been found to be extensively catabolized and to give rise to glutamic acid. The fact that no radiocarbon could be found in tissue histidine indicates that the formation of urocanic acid from histidine is a non-reversible reaction. Imidazole-propionic acid has been found to undergo very little catabolism and thus should be excluded as a possible intermediate in the degradation of urocanic acid.
THE ANAEROBIC DISSIMILATION OF D-RIBOSE-1-C14, D-XYLOSE-1-C14, D-XYLOSE-2-C14, AND D-XYLOSE-5-C14 BY AEROBACTER AEROGENES
Authors: Altermatt H. A. , Simpson F. J. , Neish A. C.
Published: October 2017

The lactic acid produced from D-ribose-1-C14 or D-xylose-1-C14 had only a trace of isotopic carbon in the carbinol group, while the methyl carbon had 40% and carboxyl carbon 20% of the specific activity of carbon-1 of the pentose. The lactic acid from D-xylose-2-C14 was labelled to a slight extent in the methyl group, while the carbinol carbon and the carboxyl carbon had 40% and 20% respectively of the C14 concentration of carbon-2 of the sugar. D-Xylose-5-C14 gave lactic acid labelled mainly in the methyl carbon, which had about 60% of the specific activity of carbon-5 of the pentose. The other fermentation products (2,3-butanediol, ethanol, acetic acid, formic acid, and carbon dioxide) were labelled as if they had been formed from pyruvate with the same labelling as the lactic acid. These results offer additional support to the hypothesis whereby complete conversion of pentose to triose occurs via a heptulose.
EFFECTS OF α-METHYL-DL-TRYPTOPHAN ON THE OXIDATION OF TRYPTOPHAN
Authors: Sourkes T. L. , Townsend Edith
Published: October 2017

α-Methyl-DL-tryptophan (AMT) inhibits the oxidation of DL-tryptophan by isotonic suspensions of rat liver, and the oxidation of L-tryptophan, L-tyrosine, DL-phenylalanine, and DL-methionine by cobra venom. The oxidation of L-tryptophan is accompanied by the appearance of a yellow color in the reaction mixtures. AMT also inhibits the formation of kynurenine, detected by its specific absorption at 360 mμ and by diazotization, from L-tryptophan. It protects the kynurenine-forming enzyme system against the inactivation which occurs in the absence of substrate. When injected into the rat, AMT, like tryptophan, causes an adaptive increase in the tryptophan peroxidase–oxidase complex. AMT is not oxidized by the liver and venom preparations used.
THE INFLUENCE OF ADRENERGIC BLOCKING AGENTS ON METABOLIC EVENTS IN HEMORRHAGIC SHOCK IN THE DOG
Authors: Lotz F. , Beck L. , Stevenson J. A. F.
Published: October 2017

Dibenamine hydrochloride administered intravenously 30 min. after the onset of hemorrhage in anesthetized dogs, in which hemorrhagic hypotension (43–45 mm. Hg for 90 min.) of the Wiggers' type had been produced, resulted in an increased rate of survival as compared to that of untreated controls. The mean increase in plasma amino nitrogen and the percentage decrease in total arterial oxygen transport were significantly less in the Dibenamine-treated group. In animals treated with Dibenamine or Dibenzyline hydrochloride 85 min. after hemorrhage as compared to untreated controls, there were no significant differences in survival rate, plasma amino nitrogen, lactate, pyruvate, lactate/pyruvate ratio, bicarbonate content, or blood pH. The arterial oxygen transport, however, was significantly higher after than before treatment and also in the postinfusion period was higher in the two treated groups than in the untreated group. In these two late-treated groups, however, the plasma amino nitrogen increase was significantly greater in the fatalities than in the survivors during both the hypotensive and postinfusion periods. In the untreated group, differences between survivors and fatalities appeared only after the reinfusion of the withdrawn blood.
RELIABILITY OF THE RIBOFLAVIN EXCRETION TECHNIQUE IN DETERMINING AVAILABILITY OF COATED TABLETS
Authors: Chapman D. G. , Campbell J. A.
Published: October 2017

Further studies have been carried out to assess the reliability of the human bio-assay technique using the excretion of riboflavin to estimate the availability of sugar-coated tablets. Using eight individuals, it has been shown that for 1, 3, and 5 mgm. amounts of riboflavin the excretion is the same whether these amounts are taken as a single dose or in 10 small doses totalling the same amount. For doses of riboflavin of 1, 3, 5, 7.5, and 10 mgm. a linear relationship was found to exist between the amount ingested and excreted. The equation for this dose response line was found to be y = 0.580x − 0.610. The intercept − 0.610 was significantly different from zero, indicating that the line did not pass through the origin. The results furnish further evidence of the validity of the urinary excretion of riboflavin for determining the physiological availability of coated tablets.
FACTORS AFFECTING THE ACTIVITY OF ALLOXANIN VITRO
Authors: Klebanoff S. J.
Published: October 2017

The effect of alloxan on the oxygen uptake and the succinic dehydrogenase activity of rat liver homogenates has been studied in an attempt to gain some insight into the activity of alloxan within the cell. The increased oxygen uptake on the addition of alloxan to liver homogenates was found to be non-enzymatic in nature and to depend on some heat stable factor or factors in the preparation. The ability of reduced glutathione to substitute for the homogenate suggests that this substance may be concerned. It is thought that alloxan is reduced to dialuric acid by a number of factors in the homogenate, and that the increased oxygen uptake results from the spontaneous reoxidation of this latter substance. Experiments with dialuric acid tend to confirm this hypothesis. The inactivation of succinic dehydrogenase by alloxan is greatly influenced by the pH of the solution in which the alloxan is dissolved, as well as by the pH of the enzyme preparation, with acidity increasing and alkalinity decreasing the effect. The progressive nature of the inactivation with time is shown to depend upon the lowering of the pH which is brought about by the addition of alloxan to an unbuffered enzyme mixture. The experimental results are discussed in relation to the possible importance of pH in the selective toxicity of alloxan.
THE BINDING OF SULPHATASE BY RAT-LIVER PARTICLES AS COMPARED TO THAT OF ACID PHOSPHATASE
Authors: Viala Renée , Gianetto R.
Published: October 2017

One of the sulphatases of rat liver, like acid phosphatase, is enclosed within cytoplasmic granules. The two enzymes are released from these granules in similar proportions by various treatments.
BIOLOGICAL ASSAY OF THE TOXIN FROM SHELLFISH
Authors: Stephenson N. R. , Edwards H. I. , MacDonald B. F. , Pugsley L. I.
Published: October 2017

A conventional quantal response assay procedure was employed to determine the LD50 of shellfish extracts. The slope of the log dose – response line obtained with butter clam extracts was not significantly different from that found with scallop liver extracts. When kept in a dry, cold state, a lyophilized extract of scallop liver was stable throughout a test period of nearly three years. Such a preparation could be used as a reference standard for the bio-assay of shellfish toxin. Female mice were more susceptible to the paralytic poison than male mice. The LD50 per mouse was related directly to the average body weight of the test animals. The volume of the injection medium had no effect on either the magnitude of the LD50 or the slope of the probit regression line. A highly significant inverse relationship was demonstrated between the toxicity measured in mouse units, a procedure based on the mean death time of the test animals, and the LD50 per kgm. of mouse determined by an assay with an all-or-none response.
LEVELS AND PARTITION OF THE FOWL'S SERUM PROTEINS IN RELATION TO AGE AND EGG PRODUCTION
Authors: Vanstone W. E. , Maw W. A. , Common R. H.
Published: October 2017

The level of total serum protein in the fowl has been followed from the 14th day of incubation to the 13th week of egg production. Serum proteins have been fractionated concurrently by zone electrophoresis in filter paper. Serum protein level in the 14-day embryo was 0.9 gm./100 ml. and the protein comprised a prealbumin fraction, albumin, α2- and β-globnlins. Sera from chicks aged seven days no longer contained a prealbumin fraction but α1-,α3- and γ-globulin fractions had appeared by this stage and the protein level had reached 2.3 gm./100 ml. Total serum protein in females increased to a maximum of about 5.4 gm./100 ml. in the week before laying of the first egg. By that time two new protein fractions had appeared. These new fractions accounted for the greater part of the increase over the levels (4.0 gm./100 ml.) prevailing in the prepuberal stage. Serum protein level declined during the first three weeks of laying to average levels below 4.0 gm./100 ml.; and this decline appeared to affect albumin and α1-globulin as well as the new fractions. As laying progressed, the total serum protein tended to regain a level around 4.0 gm./100 ml. The electrophoretic pattern also tended to return towards that prevailing in the week before laying. Some tentative correlations of the results of zone electrophoresis with published results for free electrophoresis of fowl serum proteins are presented.
CYTOCHROME OXIDASE AND SUCCINIC OXIDASE ACTIVITY IN MAMMARY GLAND MITOCHONDRIA OF LACTATING RATS
Authors: Tuba Jules , Orr Patricia F. , Wiberg G. Stuart
Published: October 2017

The effect of lactation on some oxidative enzymes of rat mammary gland mitochondria was examined. Cytochrome oxidase levels were nearly doubled during lactation. Succinic oxidase activity was not demonstrable in breeder female rats four days after the cessation of nursing, or in a control group (non-lactating breeder females, which had weaned their young at least four weeks previously), but during the nursing period considerable activity of the enzyme was observed. Succinic dehydrogenase activity was negligible in mitochondria during involution of rat mammary tissue. On the other hand appreciable anaerobic glycolysis occurred in the resting gland. The greatly increased metabolic activity associated with lactation is reflected in the altered behavior of some of the enzymes of rat mammary gland mitochondria.
THE EFFECT OF DIFFERENT DEGREES OF SUBDIAPHRAGMATIC AORTIC CONSTRICTION ON HEART WEIGHT AND BLOOD PRESSURE OF NORMAL AND HYPOPHYSECTOMIZED RATS
Authors: Beznák Margaret
Published: October 2017

The aortae of groups of normal and hypophysectomized rats were constricted with rings of five different sizes (0.93, 0.83, 0. 74, 0.71, and 0.63 mm. diameter). In normal rats constriction caused an increase in heart weight and blood pressure which was the greater the narrower the constriction. If constriction exceeded 0.74 mm., cardiac hypertrophy reached extremely high values, while the blood pressure was lower than in groups with less constriction. The blood pressure response to Adrenalin or Infundin increased in proportion to the degree of constriction down to 0.74 mm.; greater constriction reduced the response. In hypophysectomized rats no degree of aortic constriction produced hypertension or cardiac hypertrophy, yet the increase in blood pressure after Adrenalin or Infundin was as great as in the normal intact rats.
CHANGES IN HEART WEIGHT AND BLOOD PRESSURE FOLLOWING AORTIC CONSTRICTION IN RATS
Authors: Beznák Margaret
Published: October 2017

Blood pressure measurements in the carotid and femoral arteries of rats after subdiaphragmatic aortic constriction, taken at times varying from immediately afterwards to five days after, indicate that increased carotid pressure precedes cardiac enlargement in these animals. The large drop in femoral blood pressure within the first few hours after aortic constriction seems to be due—at least partly—to stimulation of the pressoreceptors by the increased aortic–carotid pressure. Hypertrophy of the left ventricle can be demonstrated on the second day after constriction. The maximum height of carotid pressure obtainable after epinephrine injection rises with the time after constriction, while the rise over the preinjection value does not increase.
THE STIMULATION AND INHIBITION OF ENZYME CATALYZED REACTIONS
Authors: Scholefield P. G.
Published: October 2017

An analysis has been made of the effect of complexing agents on the velocity of enzyme catalyzed reactions. Complexing agents are here defined as agents which combine with enzyme proteins in a manner which results in a change in the catalytic activity of the enzyme, i.e. they produce inhibitions or stimulations. From the analysis it is possible to deduce equations governing competitive, non-competitive, "apparent" competitive, and "apparent" non-competitive inhibitions. The cases of competitive and non-competitive stimulations where the complexing agent is non-essential are considered and the corresponding equations deduced. The effects of coenzymes having various affinities for the enzyme and for the enzyme combined with substrate are also analyzed. In the case of the "apparent" non-competitive stimulation of fumarase by phosphate, it is shown that the results obtained by previous workers are entirely in agreement with the present kinetic analysis.
OPTIMUM RATIO OF SATURATED TO MONO-UNSATURATED FATTY ACIDS IN RAT DIETS
Authors: Hopkins C. Y. , Murray T. K. , Campbell J. A.
Published: October 2017

Fat mixtures were prepared in which the content of linoleic acid was held constant at approximately 10% of the total fatty acids, but the ratio of saturated to mono-unsaturated acids was varied from 3.5: 1 to 1: 8. These mixtures were added to a low-fat fox chow diet at the rate of 20 parts fat to 80 parts fox chow and the resulting mixtures were fed to weanling rats in one experiment and to semiadult rats in another. The feeding period was nine weeks. In both experiments the male rats showed significant differences in final weight between the diets. Best weight gains were made on the fat mixture in which the fatty acid ratio was close to that of normal rat depot fat, viz. one part of saturated acid to two parts of mono-unsaturated acid. Female rats did not show significant differences in weight gain on the various fat mixtures. Excretion of lipid in the feces showed a tendency to increase with increasing ratios of unsaturated to saturated fatty acids in the diet.
METABOLISM OF RADIOACTIVE β-(3,4-DIHYDROXYPHENYL)-ALANINE-α-C14IN THE ALBINO RAT
Authors: Pellerin Joseph , D'Iorio Antoine
Published: October 2017

When DL-3,4-dihydroxyphenylalanine-α-C14(DL-dopa-α-C14) was injected into rats, 80% of the radioactivity was recovered from urine and 2% from respiratory carbon dioxide. The urine was examined by descending paper chromatography and the following radioactive substances have been identified: dopa, hydroxytyramine, 3,4-dihydroxyphenylpyruvic acid, and 3,4-dihydroxyphenylacetic acid. The urinary hydroxytyramine is partially conjugated, presumably as a glucuronide or as a sulphate. Evidence is also presented which indicates that 5,6-dihydroxyindole is one of the metabolites present in urine. Radioactive epinephrine or norepinephrine could not be detected in either urine or suprarenal gland.
BIOCHEMISTRY OF THE USTILAGINALES: XII. CHARACTERIZATION OF EXTRACELLULAR GLYCOLIPIDS PRODUCED BY USTILAGO SP.
Authors: Boothroyd B. , Thorn J. A. , Haskins R. H.
Published: October 2017

A water-soluble compound formed by Ustilago sp. (PRL 627) in aerobic, submerged culture has been identified as D-mannopyranosyl-1-meso-erythritol. The extracellular "oil" produced at the same time by this fungus contains D-mannose, meso-erythritol, acetic acid, and a number of saturated and unsaturated fatty acids, probably as a mixture of D-mannosido-meso-erythritol residues to which the various acids are joined by ester linkages.
THE METABOLISM OF THE ERYTHROCYTE: IX. DIPHOSPHOPYRIDINE NUCLEOTIDASE OF ERYTHROCYTES
Authors: Alivisatos S. G. A. , Kashket S. , Denstedt O. F.
Published: October 2017

The rabbit erythrocyte possesses an active DPN-ase which is firmly attached to the membrane of the cell. Evidently, the enzyme is oriented in the membrane in such a way as to be able to act upon DPN added to the external medium. The enzyme splits DPN at the bond linking the quaternary nitrogen of the nicotinamide moiety with the ribose component. Despite the release of an H+ion during hydrolysis of DPN, the activity of the enzyme remains practically constant over the pH range from 4.5 to 10.0. DPN-ase also splits nicotinamide from TPN, but its affinity for the latter is only about one third of that for DPN. Nicotinamide, adenine, and the substituted purine derivatives theobromine, theophylline, and xanthine inhibit DPN-ase, while compounds such as ribose, adenylic acid, caffeine, and nembutal are without effect in this respect. Of all the substances tested theobromine proved to be the most powerful inhibitor. The mode of enzyme–substrate attachment and the possible involvement of DPN-ase in ion transport are discussed in the light of these findings.
SEASONAL RECRUDESCENCE OF THE THYMUS IN ADULT BIRDS
Authors: Höhn E. O.
Published: October 2017

The thymus of adult mallards and house sparrows of both sexes and of female robins shows a marked enlargement following the annual breeding season. In male robins the thymus begins to enlarge earlier, almost synchronously with the testes. Histologically the enlarged thymus becomes indistinguishable from the uninvoluted thymus of immature birds, showing lobulation and development of a cortex and medulla. In the atrophic thymus found in adults for most of the year these two zones are not recognizable. The bursa Fabricii of adults does not enlarge at any time. Evidence of a similar thymus enlargement in some other species of birds is presented. The distribution of thymus tissue in passerine birds and hawks differs from the well known arrangement in the chicken; the passerine pattern is illustrated. It was not possible to bring about thymic enlargement out of season by castration or unilateral adrenalectomy in mallards.
A STUDY OF THE EFFECT OF ANTIHISTAMINES ON THE METABOLISM OF HISTAMINE IN THE INTACT RAT
Authors: Goldner M. , Bouthillier L. P.
Published: October 2017

The effect of the antihistamines Neohetramine and Neo-Antergan on the catabolism of histamine-β-C14in the intact rat was investigated. Our results, obtained by the application of paper chromatographic and isotope dilution techniques, indicate that the urinary pattern of imidazole compounds is not altered by these antihistaminic substances.
THE METABOLISM OF THE ERYTHROCYTE: X. THE INORGANIC PYROPHOSPHATASE OF THE ERYTHROCYTE
Authors: Malkin A. , Denstedt O. F.
Published: October 2017

The activity of the pyrophosphatase which catalyzes the hydrolysis of inorganic pyrophosphate in the erythrocyte of the human, the rabbit, and the chicken is confined entirely to the cytoplasm of the cell. Following preincubation, the enzyme activity in the human erythrocyte is diminished, but pre-incubation in the presence of cysteine or glutathione prevents the diminution of the enzyme activity. Aging of the hemolyzate of the human erythrocytes results in a marked loss of the inorganic pyrophosphatase activity. The diminished activity can be restored by the addition of cysteine or glutathione to the reaction mixture; but after the hemolyzate has aged for five or six days at 5 °C, the loss in the enzyme activity can no longer be restored with these reagents. Fluoride and calcium ions inhibit the activity of the enzyme, while magnesium ions are essential for its activity. Calcium is a noncompetitive inhibitor, while the inhibition by fluoride is of a "quadratic" nature. If a constant ratio of magnesium to pyrophosphate is maintained, the quadratic inhibition can be converted to the "uncompetitive" type of inhibition.
THE METABOLISM OF THE ERYTHROCYTE: XII. DIPHOSPHOPYRIDINE NUCLEOTIDE NUCLEOSIDASE OF THE RABBIT ERYTHROCYTE
Authors: Malkin A. , Denstedt O. F.
Published: October 2017

Evidence is presented in support of the hypothesis that in the hydrolysis of DPN by the DPN nucleosidase of rabbit erythrocyte stroma, the substrate is attached to the enzyme at more than one site. Cleavage of DPN at the nicotinamide–ribose bond is inhibited by nicotinamide, ADP, and adenine. Considering the nature of the inhibition and the extent of the inhibition, it is suggested that DPN attaches to the enzyme surface at the quaternary nitrogen of the nicotinamide and at the pyrophosphate group of the DPN molecule. Additional support for this supposition accrues from the observation that NMN, a cleavage product of DPN, can serve as a substrate for DPN-ase but the rate of hydrolysis is much slower than that with DPN.
EFFECT OF CORTISONE ON THE INTRACELLULAR DISTRIBUTION OF PHOSPHATASES AND RIBONUCLEASES IN RAT LIVER
Authors: Allard Claude , Lamirande Gaston De , Weber George , Cantero Antonio
Published: October 2017

The effect of cortisone acetate administration on the mitochondrial population and intracellular distribution of phosphatases and ribonucleases was investigated. Cortisone acetate was administrated at a dosage of 25 mgm. per 100 gm. body weight, daily, during five days and sacrificed on the sixth day. The livers of these animals were removed and homogenized in 0.25 M sucrose and subjected to differential centrifugation to prepare nuclear, mitochondrial, microsomal, and supernatant fractions. Nuclear and mitochondrial counts were made for each homogenate prepared. From these the number of mitochondria per average cell was computed. The intracellular distribution of RNAase and PO4ase activities was determined and expressed per average cell and per liver/body weight ratio. The activity of the mitochondrial fraction was also expressed per average mitochondrion. Results of this investigation showed that cortisone lowered the number of large granules per liver cell without influencing the acid PO4ase and acid and alkaline RNAase activities per cell. This suggested that mitochondria isolated from cortisone treated rats possessed abnormally high acid PO4ase and RNAase activities or/and that the remaining population of granules was different from the one in liver cells of untreated animals. The investigation of alkaline phosphatase revealed that cortisone increased the Mg++ sensitive alkaline PO4ase localized in the supernatant fluid without influencing the Mg++ insensitive enzyme.
CHEMISTRY OF THE SPHINGOLIPIDES
Authors: Carter H. E. , Galanos Demetrius S. , Fujino Y.
Published: October 2017

Chemical studies leading to the elucidation of the structures of sphingosine, cerebrosides, sphingomyelin, and cerebroside sulphuric acid are reviewed. The general nature of the complex sphingolipides (ganglioside, hematoside, globoside, strandin, polycerebroside) is discussed. Preliminary studies on the nature of the phytosphingosine-containing lipides of corn phosphatides are presented.
THE BIOLOGICAL SYNTHESIS OF PHOSPHOLIPIDS
Authors: Kennedy Eugene P.
Published: October 2017

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METABOLISM OF PHOSPHOLIPIDS IN VITRO
Authors: Hokin L. E. , Hokin Mabel R.
Published: October 2017

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UTILIZATION OF BODY RESERVES DURING EXPOSURE OF MICE TO LOW TEMPERATURES
Authors: Hart J. S. , Heroux O.
Published: October 2017

White mice acclimated for four weeks to 6 °C. had a body water content on an absolute and on a fat-free basis that was greater than that of mice acclimated to 23 °C. When exposed to freezing temperatures, the weight loss and loss of water were greater in the cold acclimated group. Fat was the major tissue energy reserve utilized under these conditions. In both acclimation groups it accounted for 85 to 89% of the total calories, the remainder being supplied mostly by protein. There was a reduction in heat of combustion of the fat of mice during exposure to freezing temperatures that signifies an alteration in chemical composition of the fat.
PHOSPHOLIPID METABOLISM IN LIVER SLICES: LABELLING OF PHOSPHOLIPIDS WITH ACETATE-1-C14
Authors: Kline Dorothy L. , DeLuca H. A.
Published: October 2017

A study has been made of the labelling of the phospholipids, the fatty acids from the acetone-soluble lipid, and the non-esterified cholesterol in slices of rat and guinea pig liver respiring in a suitably buffered Krebs–Ringer medium containing acetate-1-C14. The time course of the reactions and the effects of the concentration of potassium ion and the pH of the incubating medium have been defined. For phospholipid and fatty acids of the acetone-soluble lipid, the optimum pH was in the range 6.8–7.4, whereas for cholesterol there was a much sharper optimum at pH 6.6–6.8. When the oxygen of the gas phase was replaced with nitrogen, the labelling of all three lipid fractions was abolished. The addition of glucose to the incubating medium slightly increased the labelling of the phospholipids and the fatty acids of the acetone-soluble lipid, but had no consistent effect on the labelling of the non-esterified cholesterol. Purification of the cholesterol by the method of bromination and debromination caused only a slight change in specific activity, indicating that the cholesterol was not contaminated with large amounts of companion substances with specific activities greatly different from that of the cholesterol itself. The addition of cyanide, fluoride, iodoacetate, or 2,4-dinitrophenol to the incubating medium caused a great decrease in the labelling of all fractions studied. With the exception of 2,4-dinitrophenol, the inhibitors were used in concentrations that inhibit the oxygen consumption. Malonate inhibited the incorporation of acetate-1-C14into cholesterol, but did not affect the labelling of the phospholipids. When the acetate-1-C14was replaced with other C14-labelled precursors, good labelling of phospholipids was observed with glycine-2-C14, glycerol-1-C14, and fructose-C11, but not with formate-C14, lactate-1-C14, or glucose-C14. The cholesterol was not significantly labelled from any of the precursors other than acetate-1-C14.
DIETARY FACTORS AFFECTING THE LEVEL OF PLASMA CHOLESTEROL IN HUMANS: THE ROLE OF FAT
Authors: Beveridge J. M. R. , Connell W. F. , Mayer G. A.
Published: October 2017

Three dietary experiments have been performed in which 36, 37, and 49 male medical students and staff members participated as experimental subjects. In each study, everyone consumed the same homogeneous formula diet for eight days at which time they were divided into five groups. One group was maintained on the original diet for a further eight days and the others were given diets varying in respect of the level and nature of the fat moiety. Protein supplied 16.9% of total calories in all experimental rations. In the first experiment, 37 subjects ingested a diet providing 58.5% of calories as corn oil. During the initial period the average of the individual percentage decreases in plasma cholesterol was 32.0 (P = < 0.01). Those continuing on corn oil displayed a further insignificant decrease. The others, receiving diets high in beef dripping, chicken fat, lard, and butter showed average individual percentage increases of 11.7 (P = > 0.05), 12.7 (P = > 0.05), 15.4 (P = < 0.01), and 28.8 (P = < 0.01), respectively. In the second experiment, 49 subjects consumed a fat-free diet for eight days. The average individual percentage decrease in plasma cholesterol was 22.2 (P = < 0.01). Those continuing on the fat-free diet showed little further change. Those ingesting 20 and 60% of calories as corn oil showed further percentage decreases of 6.9 (P = > 0.05) and 15.2 (P = < 0.01), respectively. By contrast, those receiving diets providing 20 and 60%, of calories as butterfat showed respectively percentage increases of 6.6 (P = > 0.05) and 21.7 (P = < 0.01). In the third experiment, 36 subjects ingested for eight days a diet in which butterfat provided 60% of calories. The plasma cholesterol level remained essentially constant, and did not change significantly in those continuing on this diet for a further eight days. The composition of the fat moiety in the remaining groups in terms of per cent calories derived from butter-fat and corn oil respectively was: 45: 15; 30: 30; 15: 45; and 0: 60. The averages of the individual percentage decreases in plasma cholesterol values were, respectively, 3.9, 15.9, 27.1, and 32.0. Except for the lowest of these values all the changes are highly significant (P = < 0.01). In addition to other conclusions that may be drawn from this work, these studies reveal that (1) there is a factor (or are factors) in certain animal fats that acts to elevate plasma cholesterol levels, and (2) there is a factor (or are factors) in corn oil that acts to depress plasma cholesterol levels.
POLYHYDRIC ALCOHOL PRODUCTION BY OSMOPHILIC YEASTS: STUDIES WITH C14-LABELED GLUCOSE
Authors: Spencer J. F. T. , Neish A. C. , Blackwood A. C. , Sallans H. R.
Published: October 2017

D-Glucose was dissimilated aerobically by a strain of osmophilic yeast producing glycerol, D-arabitol, ethanol, carbon dioxide, and a small amount of succinic acid. Glucose-1-C14 gave glycerol labeled in the terminal carbons, D-arabitol labeled in carbon-1 and carbon-5, methyl labeled ethanol, and succinic acid with 30% of the labeling in the carboxyl carbons and 70% in the methylene carbons. Glucose-2-C14 gave glycerol labeled in carbon-2, D-arabitol labeled in carbon-1, carbon-2, and carbon-4, carbinol labeled ethanol, and succinic acid having 70% of the labeling in the carboxyl carbons and 30% in the methylene carbons. Labeled carbon dioxide was produced from both carbon-1 and carbon-2 labeled glucose but the specific activity of carbon dioxide from glucose-1-C14 was higher than that from glucose-2-C14. The distribution of radioactive carbon in the products is explained by assuming that glucose is dissimilated via a combination of the Embden–Meyerhof and the phosphogluconate oxidation pathways, with transketolase-catalyzed reactions playing an important part in D-arabitol formation.