bluuebunny/crossref_metadata_2025 huggingface dataset:
INFLUENCE OF DIET COMPOSITION AND CALORIC INTAKE ON BODY WEIGHT OF WARM- AND COLD-ACCLIMATED RATS
Authors: DesMarais A. , Lachance P. A.
Published: December 2009

The well known reduction in growth rate of cold-acclimated rats has been shown to depend on a decreased gain in total body fat, without change in the gain in lean body weight. This has been observed in rats fed Lab Chow or a high-fat diet ad libitum. In those groups fed a high-carbohydrate diet ad libitum or calorie-restricted high-fat or high-carbohydrate diets, exposure to cold had no effect on the gain in neither total body weight nor lean body weight, which were already reduced by the diet; in those animals, the significant decrease in the gain in total body fat upon exposure to cold was compensated by a slight but unsignificant increase in the gain in lean body weight, so that differences in gain in total body weight were not significant.
TOBACCO POLYPHENOLS: II. ON THE BIOSYNTHESIS OF CHLOROGENIC ACID
Authors: Runeckles V. C.
Published: December 2009

Leaf disks of Nicotiana tabacum var. Delcrest were supplied with α-C14-labelled cinnamic, p-coumaric, and caffeic acids, p-coumaroyl-quinic acid, and the 1-glucose esters of cinnamic and p-coumaric acids. Considerable incorporation of radioactivity into chlorogenic acid occurred in 40 hours from all substrates except caffeic acid. In particular, p-coumaric acid was found to be a good precursor of chlorogenic acid in contrast to the findings of other workers with potato tuber tissue. More p-coumaric acid than cinnamic acid is converted to chlorogenic acid, although the reverse holds for conversion to p-coumaroyl-quinic acid. Chlorogenic acid synthesis from caffeic acid involves breakdown and resynthesis of the acid supplied, leading to the incorporation of radioactivity into other positions in the caffeic acid molecule and into the quinic acid moiety. Cinnamic and p-coumaric acids, on the other hand, are incorporated essentially intact into both p-coumaroyl-quinic and chlorogenic acids. These findings are discussed in relation to the pathway of chlorogenic acid biosynthesis postulated for potato tuber tissue.
THE CARDIAC OUTPUT AND CAROTID AND TIBIAL BLOOD PRESSURE OF THE TURKEY
Authors: Speckmann Elwood W. , Ringer Robert K.
Published: December 2009

The cardiac output of untreated mature male Broad Breasted Bronze (BBB) turkeys was determined by an isotope dilution technique using radioactive phosphorus (P32). A Geiger–Mueller tube was connected to a rate meter which in turn was connected to a moving graph to continuously record the indicator concentration, thus obtaining the initial dilution curve. Posterior tibial and common carotid arterial blood pressures were measured directly and were recorded simultaneously with the cardiac output determinations by means of two strain gauges connected to a recording polygraph.From the cardiovascular measurements systemic resistance was calculated. The mean cardiac output of the mature male BBB turkey was 231 ml per kg body weight0.734 per minute. The mean carotid hemodynamic parameters were: systolic BP, 302 mm Hg; diastolic BP, 204 mm Hg; and pulse pressure, 98 mm Hg. Heart rate was 149 beats per minute. The mean tibial hemodynamic parameters were; systolic BP, 286 mm Hg; diastolic BP, 200 mm Hg; and pulse pressure, 85 mm Hg. The mean systemic resistance units were 0.17 and 0.16 for carotid and tibial arteries respectively on a bird basis and 1.13 and 1.08 respectively per kg body weight0.734.
SERUM RIBONUCLEASE DURING THE PROCESS OF DAB CARCINOGENESIS AND TUMOR GROWTH
Authors: Zytko J. , Cantero A.
Published: December 2009

The activity of serum ribonuclease (RNase) of rats fed a diet containing 4-dimethylaminoazobenzene was depressed by 50–60% at the third week of feeding compared to that of control rats fed the basal diet alone for the same period of time. Tumor cells of the Novikoff hepatoma contained 7–8% of the RXase activity of normal liver cells.
REDUCING SUBSTANCES IN THE BLOOD OF NORMAL AND ALLOXAN-TREATED FISH
Authors: Moule Margaret L. , Nace Paul Foley
Published: December 2009

Blood sugar changes in fish, after the intravenous injection of alloxan, were determined by a modified Folin method and by an enzymatic method using glucose oxidase. The rest reduction was calculated as the difference between the two methods. The blood rest reduction levels were normally 15 mg% in toadfish and 11 mg% in bullheads (glucose 19 and 22 mg% respectively). One hour after alloxan administration, the rest reduction had increased on the average several times while the glucose level was only slightly above normal. From a maximum at 1 hour the rest reduction level dropped while the glucose level began to rise. Considerable variation in the response to alloxan occurred.The reducing substances in the blood were studied by paper chromatography. In normal blood, glucose and another compound (Rfvalue approximately one-half that of glucose) were detected by alkaline silver nitrate. No increase in reducing material in alloxan-treated samples could be shown on the chromato-grams by the methods used.
THE EFFECT OF INSULIN ON THE DISTRIBUTION OF GLUCOSE BETWEEN THE BLOOD PLASMA AND THE LIVER IN ALLOXAN-DIABETIC AND ADRENALECTOMIZED RATS
Authors: Hetenyi Jr. G. , Kopstick F. K. , Retelstorf L. J.
Published: December 2009

In diabetic rats the concentration of glucose in the liver was less than in the plasma. The relative accumulation of glucose in the liver cell after the injection of insulin was also found to be significantly less in previously untreated diabetic than in normal rats. Pretreatment with insulin restored the response to normal. Experiments with labeled glucose indicated that the rate at which glucose is carried through the hepatic cell membrane is very high compared to the rate at which glucose is being formed in the liver cells in diabetic rats. The relatively small amount of glucose accumulating after insulin in livers of diabetic rats originates from the plasma. In adrenalectomized rats which have very little liver glycogen, the relative accumulation of glucose in liver cells, following the injection of insulin, was less than that in normals. These experiments indicate that in normal rats a large part of the glucose retained in the liver after the injection of insulin originates from non-labeled endogenous hepatic sources, presumably glycogen.
ELECTROPHORESIS OF HISTONES ON POLYACRYLAMIDE GELS
Authors: Driedger A. , Johnson L. D. , Marko A. M.
Published: December 2009

Histories extracted from various organs of the rat have been fractionated by electrophoresis on Polyacrylamide gels. The most convenient reagents to form the gel were selected and the effects of varying concentrations of these reagents on the resolution of histones were investigated. Optimum conditions for the separation of histones were found to be the same as those for starch gel electrophoresis. More consistent results were obtained with the use of Polyacrylamide gels because these gels were equilibrated to constant pH and ionic strength prior to electrophoresis and the gels were electrophoretically destained to demonstrate the histone bands.
THE CYTOLOGICAL LOCALIZATION OF HUMAN CHORIONIC GONADOTROPIN
Authors: Leznoff Arthur , Davis Bernard A.
Published: December 2009

The indirect fluorescent antibody technique was used to determine the cellular site of human chorionic gonadotropin (H.C.G.) in normal and toxaemic placentas, and in choriocarcinomas. In placental tissue specific fluorescence was located in the syncytial cells of the chorionic villi but not in the cytotrophoblast cells. In choriocarcinomas specific fluorescence was seen in the syncytial giant cells. No distinct difference could be demonstrated between normal and "toxic" placentas. Differences in the content of H.C.G. in placentas at various stages of pregnancy were noted. Maximum amounts were demonstrated in tissue of less than 14 weeks gestation. Lesser quantities could be seen in more mature placentas and some specific fluorescence could be seen in most full term placentas.
INCORPORATION OF RADIOACTIVE PURINE AND PYRIMIDINE BASES AND OF THYMIDINE INTO THE DEOXYRIBONUCLEIC ACID OF SALMON MILTS
Authors: Tarr H. L. A.
Published: December 2009

C14-labeled adenine, guanine and cytosine, and tritiated thymidine were incorporated into the deoxyribonucleic acid of salmon milts, either by injection into the milts of live fish or into excised milts. The amount incorporated was very small. Under the experimental conditions radioactive nucleosides, deoxyuridine, adenosine 5′-mono- and tri-phosphates, orotic acid, uracil, ribose 1-phosphate, and ribose 5-phosphate were not incorporated. It is suggested that these results may be due to the comparative impermeability of the cells to the various compounds.
THE COMPOSITION, STRUCTURE, AND MECHANISM OF FORMATION OF THE LINING OF THE GIZZARD OF THE CHICKEN
Authors: Webb T. E. , Colvin J. Ross
Published: December 2009

The extracellular protein layer which surrounds the lumen of the gizzard of the chicken has been reinvestigated to determine if it is a keratin. The lining is insoluble in keratin solvents such as urea-bisulphite or Swan's reagent as well as thioglycollate and performic acid. In addition, it contains only 1.45% sulphur so that disulphide bonds cannot play a major role in its consolidation. The lining is insoluble in acids but readily dispersed in alkali without breaking of covalent bonds. The dispersion in alkali is retarded by electrolytes. The lining is hydrolyzed by trypsin and chymotrypsin at pH 8.0 but is resistant to pepsin at pH 2.0. An alkaline dispersion of the lining is heterogeneous in the ultracentrifuge, but not grossly so, with a mean sedimentation coefficient of 5.6 svedbergs. Electron microscope studies of the lining suggest it is an amorphous, precipitated protein, which is consistent with the observation of three hazy rings in X-ray diffraction powder patterns reflecting spacings of 3.5, 4.6, and 9.4 Å. Amino acid analysis shows a ratio of more than three acidic groups to one basic, with no carbohydrate residues and little lipid in the protein layer. These observations are interpreted as indicating the precipitation of an amorphous, non-keratin, acidic, abrasion-resistant protein from the glandular mucosa by the acid in the gizzard.
STUDIES ON PROTEIN METABOLISM OF THE CORNEA: 2. THE INCORPORATION OF C14-LABELED AMINO ACIDS INTO COMPONENTS OF THE RABBIT CORNEA
Authors: French R. C. , Duma Z.
Published: December 2009

Preliminary studies were made on the incorporation of C14-labeled glycine and proline into tissue cultures of rabbit stromal cells, excised rabbit corneas, and rabbit corneas in vivo. Some evidence has been presented that this incorporation reflects synthesis, chiefly into proteins. With rabbit corneas in vitro, no evidence was found that the presence of epithelium increased the incorporation of amino acid into constituents of the stroma. During in vivo incorporation it was found that the proteins of the endothelium were about twice and the proteins of the epithelium about four times as active as those of the stroma.
QUANTITATIVE ISOLATION AND ASSAY OF NEUTRAL GLYCERIDE GLYCEROL AND PHOSPHOGLYCERIDE GLYCEROL
Authors: DeFreitas A. S. W. , Depocas Florent
Published: December 2009

Neutral glyceride glycerol and phosphoglyceride glycerol obtained by acid-catalyzed methanolysis of 10-100 mg quantities of mixed lipids are separated by paper chromatography. Quantitative elution of the compounds is followed by a periodate oxidation – chromotropic acid assay of the released formaldehyde. Application of this method to the assay of carbon-14-labelled material permits accurate specific activity determinations by radioactivity measurements on phosphoglycerol and on glycerol complexed with sodium borate.
SEPARATION OF AUTOPROTHROMBIN III FROM BOVINE PROTHROMBIN PREPARATIONS
Authors: Seegers Walter H. , Cole Edmond R. , Aoki Nobuo , Harmison Charles R.
Published: December 2009

Purified prothrombin was activated by means of purified thrombin, Ac-globulin, calcium ions, and crude "cephalin." Thrombin and autoprothrombin III generated. The latter was isolated as a single component by the same methods found suitable for the isolation of autoprothrombin C. It contained no autoprothrombin C activity, but some generated spontaneously, and also in 25% sodium citrate solution. It may be that autoprothrombin C generally does not form in normal blood clotting unless tissue extracts are involved. This implies the possibility that the most potent procoagulant power in the genesis of thrombosis is derived from tissues.
CREATINE KINASE IN MUSCLE OF NORMAL AND DYSTROPHIC MICE OF STRAIN 129
Authors: Nichol C. J.
Published: December 2009

Hind leg muscle of normal and dystrophic mice of strain 129 was taken for individual analyses of creatine phosphokinase, total nitrogen, and collagen nitrogen. Young mice (18 to 25 days old) from one colony and adult mice (6 weeks to 3 months old) from another colony were used. The enzyme was assayed by measuring the formation of creatine from added creatine phosphate and adenosine diphosphate. Sulphydryl compounds were found to cause a large increase in activity. The enzyme activity was based on non-collagen nitrogen. The values in dystrophic mice were lower than in unaffected littermates, whether young or old, but the difference was significant only in young mice. The total nitrogen content was significantly lower than normal in all dystrophic mice, but there was no difference between dystrophics and normals in collagen nitrogen.
THE DIFFERENTIAL-PHOTOMETRIC ESTIMATION OF COPROSTANOL IN THE PRESENCE OF CHOLESTEROL, SITOSTEROL, AND OTHER 3β-HYDROXYSTEROLS
Authors: Haust H. L. , Beveridge J. M. R.
Published: December 2009

A method is described for the differential-photometric estimation of coprostanol in faeces, based upon the change in extinction coefficients of cholesterol and coprostanol with time in the Liebermann-Burchard reaction. Recoveries of coprostanol added to artificial sterol mixtures averaged 97.9 ± 6.4% (S.D.). Recoveries after its addition to crude alcoholic extracts of faecal lipids averaged 102.7 ± 4.5%.Corrections can be readily made for the presence of Δ7-stenols by application of the Rosenheim-Callow reaction and a modified Liebermann-Burchard reagent.A distinct advantage of this procedure for coprostanol is the fact that the presence of sitosterol (β- and (or) γ-isomer) does not interfere because its chromogenic behavior in the Liebermann-Burchard reaction enables one to treat it and cholesterol as a single entity despite the relatively large differences in the extinction coefficients.
DIFFERENTIAL-PHOTOMETRIC ESTIMATION OF CHOLESTEROL AND SITOSTEROL IN THE PRESENCE OF CERTAIN OTHER 3β-HYDROXYSTEROLS
Authors: Haust H. L. , Beveridge J. M. R.
Published: December 2009

Material differences in the extinction coefficients of cholesterol and sitosterol (β- and γ-isomer) in the Liebermann-Burchard reaction contrast with the fact that the extinction coefficients of these sterols are identical in the Tschugaeff reaction. This forms the basis for the quantitative differentiation between these sterols by mathematical treatment of data obtained in the two reactions. The principles involved form an extension of analytical steps reported elsewhere for the estimation of 7-dehydrocholesterol, Δ7-cholestenol, and coprostanol.When the concentrations of these five sterols have been determined in faeces excreted by subjects subsisting on formula rations high in corn oil, an estimate of cholestanol plus stigmastanol may be obtained by subtracting the sum of their concentrations from the value for total 3β-hydroxysterol, as determined by the anthrone procedure.Recoveries were as follows: cholesterol, 100.7 ± 7.9%; sitosterol isomers, 99.1 ± 7.6%; cholestanol and (or) stigmastanol, 90.4 ± 10.1%.
CONFIRMATION OF PLASMA PROTEIN CHANGES IN AVIAN ERYTHROBLASTOSIS
Authors: Merriman M. , Darcel C. le Q.
Published: December 2009

Alterations of the plasma proteins have been previously demonstrated in avian erythroblastosis by paper and now by starch gel electrophoresis. With the latter technique, eight protein zones are recognized in normal plasmas. Heparin contributes an additional non-staining zone. In leukemic plasmas two more zones occur while another zone shows significant retardation.Heparin is not responsible for these changes because they are also observed in oxalated plasmas, but there is evidence of increased binding of heparin in leukemic plasma.
FATTY ACID COMPOSITION OF PHOSPHATIDYL ETHANOL-AMINE AND PHOSPHATIDYL SERINE FROM DOG BILE
Authors: Misra U. K. , Turner D. A.
Published: December 2009

Phosphatidyl ethanolamine and phosphatidyl serine extracted from dog bile have been separated by means of ammonium silicate column chromatography. Concentration of phosphatidyl serine in dog bile is about seven times higher than phosphatidyl ethanolamine. Fatty acid analysis by gas chromatography showed that phosphatidyl ethanolamine contains about 26% palmitic acid, 18% stearic acid, 11% linoleic acid, 2% linolenic acid, 9% arachidonic acid, 3% C22:5 fatty acid, and 6% C22:6 fatty acid. The concentrations of these fatty acids observed in phosphatidyl serine are different; palmitic acid represents about 43%, stearic acid 9%, linoleic acid 24%, linolenic acid a trace amount, and arachidonic acid 5%; C22:5 and C22:6 fatty acids are absent.
THE METABOLISM OF VALERATE-3-C14 AND -5-C14 BY WHEAT STEM RUST UREDOSPORES
Authors: Reisener H. , Finlayson A. J. , McConnell W. B.
Published: December 2009

Uredospores of wheat stem rust took up about 90% of the carbon-14 present either as valerate-3-C14 or as valerate-5-C14 in M/30 phosphate buffer pH 6.2 in 3 hours. The initial valerate concentration was 0.017 mM and spores were supplied at the rate of 250 mg/30 ml of buffer. Carbon 3 of the valerate was largely respired as carbon dioxide but carbon 5 was extensively incorporated into spore components. Free amino acids contained about 40% of the radioactivity in the spores labelled with valerate-5-C14 and glutamic acid was highly labelled. Carbon 1 contained 8.1% and carbon 5, 3.8% of the carbon-14 in this glutamic acid and thus internal carbons contained 88%. The results with valerate-3-C14 and with valerate-5-C14 compare well with those of experiments done earlier with propionate-1-C14 and propionate-3-C14 respectively. It is concluded that propionate is formed from carbons 3, 4, and 5 of valerate, and thus that carbon 3 is converted to carbon dioxide, and carbons 4 and 5 to the carboxyl and methyl groups respectively of acetate.
DIRECT GAS CHROMATOGRAPHIC FRACTIONATION OF MIXED NEUTRAL LIPIDS OF NATURAL ORIGIN
Authors: Kuksis A.
Published: December 2009

The experimental conditions previously developed for the gas chromatographic separation of natural triglyceride mixtures are also satisfactory for a direct gas chromatographic fractionation of mixed neutral lipids. This type of analysis has been shown to be readily applicable to the mixtures of free sterol, steryl ester, and triglyceride found in lymph, blood plasma, and certain molecular distillates of corn oil. The separations are based primarily on the carbon number or molecular weight of the material and are effective because of the virtual absence of short chain triglycerides from these samples. The results are essentially quantitative and can be obtained within an hour on 10 to 50 μg of total lipid. For these analyses a solvent-refined lipid extract is usually satisfactory.
RESPIRATION OF STRAIN L CELLS AND OF THEIR VARIANT, LE CELLS
Authors: Fedoroff S. , Woodford V. R.
Published: December 2009

The oxygen uptake and carbon dioxide production of strain L cells and their variant LE cells were measured by using Warburg techniques with glucose as the sole substrate. The variant LE cells consumed oxygen at a greater rate than did the parent strain L cells. Under anaerobic conditions the situation was reversed, that is, LE cells released less carbon dioxide than did the parent strain L cells.
URINARY CONVERSION PRODUCTS OF 16-EPIESTRIOL-16-C14IN THE DOMESTIC FOWL
Authors: Ainsworth L. , Carter A. L. , Common R. H.
Published: December 2009

16-Epiestriol-16-C14was injected intravenously into two non-laying hens. The urine and the feces for succeeding days were collected separately and estrogen extracts thereof were prepared by use of enzymic hydrolysis. The urine contained two major radioactive products. The two major products were identified as 16-epiestriol-16-C14and 16-oxoestradiol-17β-16-C14. The two minor radioactive products were not identified but neither was estriol or 17-epiestriol or 16β-hydroxyestrone. The results are discussed in relation to the view that 16-epiestriol is an important estrogen conversion product in the fowl.
COMPARISON OF THE EFFECTS OF VISIBLE, ULTRAVIOLET, AND X-RADIATION ON RAT THYMOCYTES
Authors: Myers D. K. , DeWolfe-Slade Donna
Published: December 2009

Ultraviolet and X-irradiation produce many of the same effects on rat thymocytes in vitro. Exposure of the cells to low doses results in a latent lethal effect, which requires incubation at 37 °C for its expression, and in an apparent increase in the rate at which deoxyribonucleoprotein from the cells dissolves to form a gel in 2 M NaCl. As the doses are increased, a decrease in the viscosity of the deoxyribonucleoprotein gel, an immediate "death" and swelling of the cells, and an immediate destruction of nucleotide bases become evident. For either radiation, doses which do not appear to have any immediate effect on the intact cell lead to loss of soluble materials (potassium ion, ribonucleotides) from the cells after incubation at 37 °C for several hours. The amount of ultraviolet energy required to produce most of the above effects is nearly 1000 times greater than the amount of X-ray energy required to produce the same effect.Three differences between the effects of ultraviolet and X-irradiation were observed: Ultraviolet light was relatively inefficient in breaking down the long deoxyribonucleoprotein chains but appeared to destroy hydrogen-bonding in the native nucleic acid structure at the same time as it destroyed the nucleotide basis. Moreover, the lethal effects of low doses of ultraviolet light on thymus cells require a longer time to develop than do the effects of X-irradiation.Thymocytes can also be killed by high intensities of visible light, particularly in the presence of photoreducible dyes. However, visible light produces little or no latent damage to the cells, nor was any evidence of nucleic acid damage observed.
FORMATION OF RIBOMONONUCLEOTIDES FROM PURINE AND PYRIMIDINE BASES AND 5′-PHOSPHORIBOSYLPYROPHOSPHATE BY A SALMON MILT EXTRACT
Authors: Tarr H. L. A.
Published: December 2009

Soluble extracts of immature sockeye salmon milts were prepared by blending them with 0.66 M lithium chloride solution to effect plasmolysis, followed by dilution to 0.10 M concentration with water and removal of the precipitated nucleoprotamine by centrifuging. By means of radioactive tracer technique it was shown that these extracts phosphorylated adenine, guanine, hypoxanthine, thymine, uracil, cytosine, and orotic acid in the presence of α-phosphoribosylpyrophosphate to yield ribomononucleotides.
ALL-VEGETABLE PROTEIN MIXTURES FOR HUMAN FEEDING: XII. BIOCHEMICAL OBSERVATIONS ON RATS FED INCAP VEGETABLE MIXTURE 9 AND ANIMAL PROTEINS
Authors: Bressani R. , Braham J. E. , Elías L. G. , Zaghi S. G. de
Published: December 2009

Biological tests were carried out to study the effect of INCAP (Institute of Nutrition of Central America and Panama) Vegetable Mixture 9, casein, and skim milk on the carcass, liver, blood, and bone composition of rats. At low levels of protein intake body and liver fat levels were higher in the animals fed the vegetable mixture. Higher values for total serum protein, albumin, globulin, and urea nitrogen concentration were obtained with skim milk, but the albumin/globulin ratio and the red and white blood cell count were similar for both protein foods. The fresh weights of the femur and tibia were found to be significantly lower for the rats fed Vegetable Mixture 9, while bone moisture and fat were significantly higher. Likewise, the percentages of ash, calcium, and phosphorus were also significantly lower in the animals fed the vegetable mixture.At higher levels of protein intake, carcass and liver fat were again higher for the animals fed the vegetable mixture. The blood analyses revealed no differences between the two proteins tested, except for a higher urea content in the animals fed skim milk.The differences in carcass, liver, and bone composition between animals fed the vegetable mixture and the animal proteins were probably due to minor essential amino acid deficiencies in the mixture, since supplementation with lysine, threonine, and methionine resulted in similar chemical composition values. Higher protein levels of intake also decreased the differences in carcass, liver, and bone composition of rats fed INCAP Vegetable Mixture 9, casein, or skim milk.
ACETYLCHOLINESTERASE
Authors: Krupka R. M.
Published: December 2009

The general characteristics of acetylcholinesterase are described. The mechanism of action of the enzyme is considered primarily in relation to the two steps in the hydrolysis of acetylcholine, the acetylation and deacetylation reactions. Competitive and non-competitive inhibition, and inhibitions by hydrogen ion and by substrate, are explained in terms of this two-step process. On the basis of the available evidence, a suggestion is made regarding the configuration of groups in the active center.
REAGENT-INDUCED CHANGES IN THE STRUCTURE AND CATALYTIC ACTIVITY OF GLUTAMIC DEHYDROGENASE
Authors: Yielding K. Lemone , Tomkins Gordon M. , Bitensky Mark W. , Talal Norman
Published: December 2009

Glutamic dehydrogenase has been presented as a model where control of an enzyme function is related to control of its structure. Glutamic dehydrogenase is responsive to a number of small regulator molecules which bind in a highly specific manner and induce conformational changes in the enzyme molecule. Regulation of the enzyme structure is, in several instances, a multivalent process and requires the simultaneous binding of more than one regulator molecule. Conformational changes on disaggregation of the enzyme induced by various regulator reagents as well as dilution have been shown to correlate with stimulation of alanine dehydrogenase activity of the crystalline enzyme, confirming the conclusion that such changes in the molecule are important variables in determining enzymic activity.
THE AMINO ACID SEQUENCE OF CYTOCHROMEcIN RELATION TO ITS FUNCTION AND EVOLUTION
Authors: Margoliash E.
Published: December 2009

A comparison of the amino acid sequences of the cytochromes c from horse, pig, rabbit, chicken, and man leads to the conclusion that all have derived phylogenetically from a common primordial cytochrome c. The significance of the constant and of the variable features of these sequences with regard, on the one hand, to the structural aspects of the functional activities of the protein, and on the other, to the evolutionary relations between the various cytochromes c is discussed.
SOME ASPECTS OF THE STRUCTURE OF HEMOGLOBIN
Authors: Smith David B.
Published: December 2009

An outline of present ideas concerning the arrangement, folding, and chemistry of the polypeptide chains of hemoglobin is given with some references to present know ledge of myoglobin.New material includes a partial amino acid sequence of the β-chain of horse hemoglobin, details concerning the amino acids lining the heme pocket of horse hemoglobin, and the effects of carboxypeptidases A and B on horse oxy- and horse deoxy-hemoglobin. The kinetics of the latter reactions are not simple. The C-terminal amino acids are released more rapidly from the oxygenated form.
CONJUGATED HYDROXYSKATOLES IN HUMAN URINE
Authors: Heacock R. A. , Mahon M. E.
Published: December 2009

A spot, occasionally observed on chromatograms of urinary indoles, described as being due to "6-sulphatoxyskatole", and implicated by some workers in certain pathological conditions, has been shown by enzymatic hydrolysis and thin layer chromatography to be probably due to a mixture of the sulphate conjugates of 5-, 6-, and 7-hydroxyskatole.
THE EFFECT OF DIETARY DEFICIENCIES OF TRYPTOPHAN AND NIACIN ON CATECHOLAMINE PRODUCTION IN THE RAT
Authors: Woodford V. R. , Barthwal J. P.
Published: December 2009

The effects of dietary deficiencies of tryptophan and of niacin on the catecholamine production of various organs of the young, growing rat were studied. It was found that a dietary deficiency of niacin had little effect on the production of catecholamines in any of the organs investigated when the deficient diet was fed over a period of up to 41 days. On the other hand, when a diet deficient in tryptophan was administered for a similar period of time, there was a marked diminution in the production of adrenaline and noradrenaline of the adrenals, the noradrenaline of the brain, liver, and spleen, and the 3,4-dihydroxyphenyl-ethylamine of the brain. The diminution effect of tryptophan deficiency was not observed in the adrenals unless prior treatment of the animals with reserpine had been carried out.
THE EFFECT OF DIETARY FAT ON BILE ACID METABOLISM IN MAN
Authors: Gordon B. A. , Kuksis A. , Beveridge J. M. R.
Published: December 2009

The influence of dietary fat on the biliary bile acid metabolism was studied in a 22-year-old male volunteer by using cholic acid-24-C14. The subject was maintained for 3 successive 15-day periods on homogenized formula diets which provided 45% of calories from butterfat or corn oil, or which were fat-free. The cholic acid turnover was assessed during the final 9 days of each period by analyzing bile samples obtained from the duodenum. On butterfat the daily cholic acid production was 0.13 g, while on corn oil and the fat-free diet it was 0.28 and 0.25 g, respectively. On changing from a free choice to a formula type diet, the glycine/taurine conjugation ratio decreased abruptly from about 2 to nearly 1, and remained at this level as long as the homogenized diet was fed. There was an increase in the proportion of cholic and a corresponding decrease in the deoxycholic acid in the bile with both high fat diets. The reverse changes in these bile acid proportions were associated with the fat-free diet. The fluctuations in the relative concentrations of the other bile acids were less pronounced.
INTRODUCTORY SURVEY
Authors: Quastel J. H.
Published: December 2009

This introduction to the Symposium deals briefly with problems of transport of sugars, amino acids, and ascorbic acid at the cell membrane, with the bearing of energetics on transport processes, with exchange diffusion, the influence of cationic equilibria on transport reactions, and with the effects of modification of the cell membrane on cell metabolism.
CARBOHYDRATE INHIBITORS OF SUCROSE UPTAKE BY RESTING CELLS OF AGROBACTERIUM TUMEFACIENS
Authors: Fukui S. , Hochster R. M.
Published: December 2009

The rapid uptake of sucrose-C14from the surrounding medium by resting cells of Agrobacterium tumefaciens is strongly inhibited in a competitive manner by D-glucose, D-galactose, D-xylose, D-fucose, and L-arabinose while their enantiomorphs do not inhibit. It has been possible to formulate specific structural requirements for the monosaccharides which are necessary to produce such powerful inhibitory effects of sucrose uptake.Strong inhibition has also been obtained with 3-ketoglucose, 3-ketosucrose, 3-ketomaltose, 3-ketolactose, and 3-ketotrehalose, as well as with the disaccharides maltose and cellobiose. In these cases, however, specific structural requirements for inhibition have not been determined as yet.
THE HETEROGENEITY OF GAMMA-GLOBULIN IN POST-EXERCISE URINE
Authors: Freedman M. H. , Connell G. E.
Published: December 2009

Post-exercise urine was collected and the protein was precipitated with ammonium sulphate. The γ-globulin was separated from other urinary proteins by preparative starch block electrophoresis. The γ-globulin was then separated by gel filtration into two fractions, the faster one consisting mainly of 7 S γ-globulin while the slower one contained "low molecular weight" γ-globulin sedimenting at 3.5 S. The low molecular weight γ-globulins were further fractionated on CM-Sephadex to yield four fractions. Each of the chromatographic fractions was shown to be heterogeneous by starch gel electrophoresis at pH 4. The same degree of heterogeneity was observed in preparations of pooled urinary γ-globulin and γ-globulin from a single individual. The two major electrophoretic components of each chromatographic fraction formed precipitates in agar diffusion tests with antiserum to 7 S γ-globulin and to the L-polypeptide chain of 7 S γ-globulin. Two chromatographic fractions reacted with antiserum to the H-polypeptide chain of 7 S γ-globulin. All of the fractions failed to react with antiserum to β2A-globulin and β2M-globulin. Amino acid analysis showed distinct differences among the chromatographic fractions. One of the fractions closely resembled the L-chain of 7 S plasma γ-globulin with respect to amino acid composition. After reduction of disulphide bonds and alkylation most of the urinary γ-globulin resembles L-chain in electrophoretic behavior. The γ-globulins of post-exercise urine were found to be qualitatively similar to the γ-globulins of normal urine but post-exercise γ-globulins were present quantitatively in much larger amounts.
STUDIES ON THE LIVETINS OF HEN'S EGG YOLK: II. IMMUNOELECTROPHORETIC IDENTIFICATION OF LIVETINS WITH SERUM PROTEINS
Authors: Mok Chi-Ching , Common R. H.
Published: December 2009

Ten antigens have been distinguished in the sera of cocks and non-laying hens by immunoelectrophoretic analysis (IEA) against homologous rabbit antisera. An additional antigen has been found in the sera of laying hens by IEA against anti-laying-hen serum.Four of the serum antigens obtained by IEA have been correlated electrophoretically with the filter paper electrophoretic fractions serum albumin, serum α2-globulin, serum β-globulin, and serum γ-globulin.Serum albumin, serum α1-globulin, serum β-globulin, and serum γ-globulin have been identified immunologically with alpha-livetin, a livetin antigen (livetin 2), gamma1-livetin and gamma2-livetin respectively. Another antigen of cock serum and hen serum has been identified by IEA with a livetin antigen detected by IEA of livetin against anti-cock, anti-hen, and anti-yolk sera.
KETONE BODY METABOLISM IN NUTRITIONAL MYOPATHY
Authors: Jenkins K. J.
Published: December 2009

A study was conducted on the metabolism of ketone bodies in tissue preparations from normal and dystrophic chicks. The data indicated that the production of ketone bodies in liver homogenates, as a result of fatty acid oxidation, was not markedly altered by development of the dystrophic condition. Whereas acetoacetate was oxidized by normal and degenerative pectoral muscle to approximately the same extent, utilization of β-hydroxybutyrate in dystrophic muscle was markedly poorer. In view of present concepts of the reactions involved in the metabolism of ketone bodies the results suggest that in the chick myopathy the conversion of β-hydroxybutyrate to acetoacetate may be impaired.
STUDIES IN PHOSPHOLIPID METABOLISM: I. EFFECT OF GUANIDOACETIC ACID AND CHOLINE ON LIVER PHOSPHOLIPIDS
Authors: Blumenstein J.
Published: December 2009

An attempt was made to produce 'forced methylation' and subsequent reduction of lecithin content of livers of rats fed a semipurified diet. The addition of guanidoacetic acid to the diet of the rats did not alter either the total phospholipid extracted from their livers or the liver lecithin content significantly. This constant pattern was observed whether choline was included in the diet or not. However, in animals fed a diet deficient in choline, the ratio of lecithin and cephalin extracted from their livers was altered, although the total phospholipid content remained constant.
THE BIOCHEMISTRY OF THE NITRIFYING ORGANISMS: PART 8. THE EFFECTS OF OXYGEN TENSION, NITRITE CONCENTRATION, AND CYANATE CONCENTRATION ON NITRITE OXIDATION BY NITROBACTER
Authors: Butt W. D. , Lees H.
Published: December 2009

The effects of various nitrite concentrations and oxygen tensions on nitrite oxidation by whole cells of Nitrobacter and by cell-free extracts have been investigated. The results, taken together with the effect of cyanate on the oxidation, suggest that cyanate inhibits nitrite oxidation in whole cells by impeding transfer of nitrite from the medium to the site of nitrite oxidation.
DOUBLE ISOTOPE DERIVATIVE ASSAY OF ALDOSTERONE, CORTICOSTERONE, AND CORTISOL
Authors: Stachenko J. , Laplante C. , Giroud C. J. P.
Published: December 2009

A method of double isotope derivative assay of aldosterone, corticosterone, and cortisol is described. It involves acetylation with acetic-3H anhydride of high specific activity followed by the purification of the steroids through four paper chromatographies and the formation of a derivative by chromium trioxide oxidation. The method is particularly suited to the quantitative measurement of these steroids in the incubation media of either rat or beef adrenal slices.
STUDIES ON WHEAT PLANTS USING CARBON-14 COMPOUNDS: XXI. THE METABOLISM OF GLYCINE-2-C14
Authors: McConnell W. B.
Published: December 2009

Glycine-2-C14was administered to 83-day-old wheat plants. The plants were allowed to mature fully and the carbon-14 distribution was then examined. About 80% of the radioactivity injected was recovered in the upper portions of the plant, the kernels themselves containing 66%. Proteins had a higher specific activity than other kernel constituents but the starch contained about one-half the total carbon-14 of the kernels. Glycine and serine were by far the most radioactive amino acids of the gluten protein. They had specific activities of 2720 and 2900 μc/mole C respectively while alanine, histidine, methionine, glutamic acid, and proline had specific activities ranging from 150 to 300 μc/mole C. The specific activities of carbons 1 and 2 of glycine recovered from the protein were 550 and 4900 μc/mole respectively while the specific activities of carbons 1, 2, and 3 of serine were 490, 4300, and 3100 μc/mole respectively. The results confirm previous views regarding extensive interconversion of glycine and serine in maturing wheat. Extensive labelling in carbon 3 of serine is interpreted as evidence that glycine is degraded to "active formaldehyde" and carbon dioxide.
A STUDY ON THE "IN VITRO" SYNTHESIS OF CITRULLINE: PART I. EFFECT OF SOME N-ALKYL DERIVATIVES OF ASPARTIG ACID
Authors: Berlinguet Louis , Charbonneau René
Published: December 2009

The effects of various N-alkyl derivatives of aspartic acid on the synthesis of citrulline in the presence of a particulate fraction obtained from a rat liver homogenate were studied. Even though aspartic acid has no role in this synthesis, both N-methyl and N-isopropyl aspartic acids were found to increase the synthesis of citrulline by 60%, whereas N-cyclohexyl aspartic acid decreased it by 50%. N-Allyl aspartic acid has the strongest effect which is an almost complete inhibition at low concentration of 1.2 × 10−2 M.It seems that N-allyl aspartic acid inhibits directly or indirectly the first step in the synthesis of citrulline leading to the formation of carbamyl phosphate. At various concentrations, none of the intermediates in this synthesis, except magnesium ion, can reverse the inhibition. In order that N-allyl aspartic acid retain its inhibitory action, the ω-carboxyl group has to be free and the double bond in the allyl group must be intact. From these results, it is postulated that N-allyl aspartic acid acts as a chelating agent for magnesium.
ISOLATION OF 22-DEHYDROCHOLESTEROL FROM SCALLOP
Authors: Tamura T. , Wainai T. , Truscott B. , Idler D. R.
Published: December 2009

22-Dehydrocholesterol has been isolated from the sterols of the scallop Placopecten magellanicus (Gmelin). The azoyl esters of the unsaponifiable fats were separated into four zones by chromatography. The Δ22-sterol accounted for 31.3% of the chromatographic γ-zone and 14.1% of the total sterol fraction. The homogeneity and structure of the isolated sterol were established by gas chromatography. Further confirmation of its identity was afforded by comparison of its physical properties with synthetic 22-dehydrocholesterol and with 22-dehydrocholesterol isolated from a species of red algae.
NUCLEOTIDES OF THE PACIFIC OYSTER CRASSOSTREA GIGAS (THUNBERG)
Authors: Wylie V. , Smith M.
Published: December 2009

The nucleotides of the Pacific oyster Crassostrea gigas (Thunberg) have been fractionated by chromatography on diethylaminoethyl cellulose and characterized by their ultraviolet absorption and paper chromatographic properties. Major components were adenosine-5′ phosphate, adenosine-5′ diphosphate, and adenosine-5′ triphosphate. Other nucleotides isolated were uridine-5′ phosphate, uridine-5′ diphosphate, uridine-5′ triphosphate, uridine-5′ diphosphate N-acetylglucosamine, guanosine-5′ phosphate, and guanosine-5′ diphosphate. Two other nucleotides, one derived from guanine and the other from an unidentified base, were isolated and partially characterized.
CHARACTERISTICS OF DISCONTINUOUS STARCH GEL ELECTROPHORESIS APPLIED TO MYOGEN FROM CHICKEN BREAST MUSCLE
Authors: Neelin J. M.
Published: December 2009

The essential characteristics of discontinuous starch gel electrophoresis, introduced by Poulik (1), were studied by varying the compositions of gel and bridge buffers, by conductivity measurements within the gel during electrophoresis, and by examination of electropherograms of chicken breast myogen, a protein mixture prone to influence by the buffer medium. The obligatory ingredients of discontinuous buffer systems were Tris cation in the gel medium, and borate anion in the bridge solution. The cation of the bridge solution was immaterial, and any anion other than borate was adequate in the gel. A flux of borate, migrating through the gel across a matrix of Tris adsorbed to starch, profoundly reduced conductivity and displaced protein-ion complexes from the support phase in an electrochromatographic manner. Some new discontinuous systems are introduced, but despite the striking patterns obtained these conditions are not necessarily the most informative for starch gel electrophoresis of cationic proteins, including major components of myogen.
BETA-2 LIPOPROTEIN MYELOMATOSIS
Authors: Neufeld A. H. , Halpenny G. W. , Morton H. S.
Published: December 2009

Studies are reported on a patient who developed, apparently simultaneously, xanthomatosis (with hypercholesterolaemia) and myelomatosis. There was little biochemical change throughout his illness, about 6 years. The two conditions were shown to be related, namely the patient apparently had a very rare type of beta-2 lipoprotein myelomatosis. Evidence is presented suggesting that the abnormal beta-2 lipoprotein was synthesized in the abnormal plasma cells of the bone marrow. There were also definite indications that the low-density Sf0–12 lipoproteins were primarily involved, and the Sf20–400 serum lipoproteins increased because of the great demand for cholesterol by the bone marrow. Curiously, there was normal erythropoiesis in the bone marrow with resulting normal blood haemoglobin levels. The principal clinical problem was the continued loss of minerals from bone with progressive osteoporosis.
THE SPECTRUM OF PLASMA ESTERASE ACTIVITY IN YOUNG, OLD, AND COLD-ACCLIMATED RATS
Authors: Baker D. G. , Ghys R. , Coles D. , Christie S.
Published: December 2009

Qualitative changes occurred in the spectrum of plasma esterase activity with increasing age. The trend was toward a decrease in the number of specific proteins having esterase activity. Acclimation to cold did not accelerate the onset of this trend. In the plasma esterase activity during acclimation to cold, there were no changes which would suggest accelerated aging.
THE ROLE OF THIOL GROUPS IN THE DEVELOPMENT OF RADIATION DAMAGE IN THYMOCYTES AND EHRLICH ASCITES CARCINOMA CELLS
Authors: Scaife J. F.
Published: December 2009

The effect of 800–1000 rads of X-irradiation on the thiol content of thymocytes and Ehrlich ascites carcinoma cells has been compared. Four hours after irradiation there was a decrease in the non-protein thiol (NP.SH) content of thymus and thymocytes but no change in ascites cells. In both cells the main NP.SH compound was glutathione. There was no significant effect of irradiation on the protein thiol (P.SH) content of thymus or ascites cells, but there was a slight decrease in P.SH in thymocytes after 4 hours incubation. Isolated thymus nuclei showed an immediate small decrease in P.SH content following 800 rads in vitro. Nuclei isolated from rat thymus 1 hour after 1000 rads in vivo showed an increase in the SH content of the globulin fraction and a decrease in the SH content of the nucleohistones. The total SH content of thymocytes and ascites cells was reduced by slow diffusion of H2O2into the cell suspension, but no effect of prior irradiation on this decrease of SH was found. Inhibition of catalase in vivo and in vitro did not produce any of the morphological signs of irradiation damage in thymocytes. There was no effect of irradiation on the copper content of thymus, thymocytes, or ascites cells. The ratio of NP.SH/P.SH is higher in thymocytes than in ascites cells, but, allowing for the difference in cell size, the overall total thiol concentration was the same. Anoxia produced only a small increase in NP.SH content in both cells and a small and doubtful increase in P.SH. It is concluded that, if thiol groups are involved in cell sensitivity to radiation, only a small fraction of the total SH groups are involved at critical sites.
THE EFFECT OF NECROGENIC DIETS ON THE ACTIVITIES OF CERTAIN ENZYME SYSTEMS IN THE RED BLOOD CELLS OF RATS
Authors: Lazier Beverley B. , Beveridge J. M. R.
Published: December 2009

The enzymic activities of glucose-6-phosphate dehydrogenase, glutathione reductase, and catalase were studied in the red blood cells of male rats which were fed a basal diet designed to induce acute hepatic necrosis. Significant decreases in the activity were found for all three systems. These changes were prevented by supplementing the basal diet with one of the following: methionine, sodium selenite, DL-α-tocopherol acetate, or all three factors plus cystine.There was no significant change in 6-phosphogluconic dehydrogenase activity when it was investigated under similar circumstances.
9-β-D-ARABINOFURANOSYLADENINE AS AN INHIBITOR OF METABOLISM IN NORMAL AND NEOPLASTIC CELLS
Authors: Brink John J. , LePage G. A.
Published: December 2009

Treatment of L1210 ascites tumors in vivo with combinations of 9-β-D-arabinosyladenine and 6-methyladenine nucleosides repressed cell growth by approximately 30%. This repression was measured by the volume of accumulated cells after 6 days of treatment with these compounds. No significant increase of the survival time of L1210 tumor-bearing mice was obtained when the mice were treated under identical conditions. Incubation of TA3 or L1210 ascites cells in vitro with 6-methyIadenosine inhibited the deamination of added arabinosyladenine by 95% for TA3 and 50% for L1210. The cleavage of adenosine or deoxyadenosine in the presence of arabinosyladenine was unaffected. Incorporation of C14-adenine or C14-uracil into the DNA of TA3 cells was inhibited when arabinosyladenine and the four natural deoxynucleosides were incubated in vitro. This inhibition was relieved specifically by adenosine but not by deoxyadenosine. Arabinosyladenine affected the uptake of C14-amino acids into the proteins of TA3 cells and liver. Elevation or depression of incorporation varied with the amino acid used. Incorporation of arabinosyladenine-C14into the RNA of subcellular components of TA3 and liver cells was greatest in the nuclear and soluble fractions.