bluuebunny/crossref_metadata_2025 huggingface dataset:
NUCLEIC ACID SYNTHESIS AND TRANSFER IN NORMAL, SECOND GENERATION CHICK EMBRYO FIBROBLASTS
Authors: Bather R. , Purdie-Pepper Elizabeth
Published: December 2009

The stripping film technique of autoradiography has been used to study some aspects of RNA and DNA metabolism in chick embryo fibroblasts in second generation tissue culture.Approximately one third of the cells incorporated thymidine-H3into DNA in a 20-minute uptake period. The duration of DNA synthesis, the generation time (time elapsing between two successive cell divisions), and the duration of mitosis have been calculated and are very similar to the values obtained for pure strains of hamster cells maintained in culture for several months by another author.RNA synthesis, as measured by uridine-H3incorporation, occurred only in the nucleus and nucleolus. Both sites synthesized RNA simultaneously beginning at zero time. The ratio of the number of grains over the nucleolus to that over the whole nucleus remained constant throughout the uptake of uridine-H3and its transfer to the cytoplasm.A small amount of labelled soluble RNA precursors remain in the nucleus after removal of uridine-H3from the medium. This results in a slight rise in radioactivity of the nucleus after uridine-H3removal. RNA then leaves the nucleus rapidly and appears in the cytoplasm. The half life of RNA in the nucleus is about 4 hours. Some turnover of cytoplasmic RNA seems to occur after 8 hours but quantitative estimates of its rate cannot be made due to changing geometry of the cells as the RNA migrates from the nuclear to the peripheral parts of the cell.Finally, little or no RNA synthesis occurs for a period of about 30 minutes during contraction of the chromosomes in mitosis.
BLOOD AMINO ACID STUDIES: III. EFFECTS OF AMOUNT AND QUALITY OF DIETARY PROTEIN AND LENGTH OF TEST PERIOD ON PLASMA FREE LYSINE LEVELS IN THE RAT
Authors: Morrison A. B. , McLaughlan J. M. , Noel F. J. , Campbell J. A.
Published: December 2009

Male rats were given diets containing 10 or 20% protein from fish flour or wheat gluten plus histidine, methionine, threonine, and tryptophan, and plasma free lysine levels were determined after 3 and 7 days. The levels dropped by approximately 50% from initial values when the diet contained gluten and rose by approximately 100% when the diet contained fish flour. The protein level of the diet had no significant effect on plasma free lysine levels. Values found after 3 days were similar to those found after 7 days.In further studies, male rats were fasted for 19 hours and given diets containing 10% protein from bread or fish flour for 2 hours, 1 day, or 3 days. No marked effects of diet on plasma free lysine values were found after 2 hours, but after 1 or 3 days values found with bread were much lower than those with fish flour. Plasma free lysine levels of animals given heat-damaged casein or soy flour were lower than those of animals given unheated proteins. It was concluded that plamsa free lysine levels reflect the amount and availability of lysine in the food.
ESTIMATION OF THE BIOLOGICAL POTENCY OF VARIOUS FORMS OF VITAMIN A
Authors: Murray T. K. , Campbell J. A.
Published: December 2009

The low biological potency of 9-cis and 9,13-di-cis vitamin A, heretofore measured by growth and liver storage assays, has been confirmed by vaginal smear assays. Appreciable quantities of these isomers in pharmaceuticals would lead to overestimation of biological potency by the U.S.P. XV or the antimony trichloride methods. In an extensive series of assays the U.S.P. method accurately estimated the biological potency of most oil-soluble, water-dispersed, and dry, stabilized samples of vitamin A. The antimony trichloride method did not accurately estimate biological potency but, for many samples, correction of these values in accordance with their maleic values was not justified. Water-dispersed and dry, stabilized samples of vitamin A were not better utilized than oil solutions of the vitamin.
SUGAR IN PULSES
Authors: Nigam Vijai N. , Giri K. V.
Published: December 2009

The occurrence of at least four non-reducing oligosaccharides has been observed in pulses. Three of the saccharides have been separated from resting seeds of green gram and have been characterized as raffinose, stachyose, and verbascose. A fairly similar pattern of composition of these sugars exists in a variety of pulses. The changes in the saccharides and the hydrolytic enzymes developed during germination have been studied.
MAST CELLS IN THE SKIN OF THE EAR OF THE RAT EXPOSED TO COLD
Authors: Héroux O.
Published: December 2009

Mast cells have been counted in ear sections of white rats exposed to 6 °C for different periods of time varying from 0 to 16 weeks. There was a greater concentration of mast cells at the tip of the ear than at the base and at the tip more of these cells were lined up at the periphery under the epidermis than internally close to the cartilage. This difference gradually decreased towards the base, where there were more internal cells than peripheral ones. Upon exposure of the rats to cold, the number of mast cells dropped, the peripheral cells disappearing faster than the internal ones, with this differential being greater at the tip than at the base of the ear. Cold injury, like other types of injury, was accompanied by a disappearance of granules in mast cells; however, unlike other types of injuries studied in animals kept at normal room temperature, when cold injury subsided and fibrillogenesis took place there was no concomitant increase in the number of mast cells. The suggestion is made that under cold conditions an excess of ground substance to be stored in the mast cells is not produced during fibrillogenesis. Upon return of the animals to 30 °C, the number of mast cells did not start increasing before the 7th day, and this slow recovery suggests a slow mitotic rate.
STUDIES OF LIGNIN BIOSYNTHESIS USING ISOTOPIC CARBON: X. FORMATION OF LIGNIN FROM PHENYLPROPANOIDS IN TISSUE CULTURE OF WHITE PINE
Authors: Higuchi Takayoshi
Published: December 2009

The incorporation of phenylalanine-R-C14, p-coumaric acid-2-C14, ferulic acid-2-C14, and sinapic acid-2-C14 into conifer lignin was studied by using tissue culture of white pine. The first three compounds were quite good precursors of conifer lignin. The lignin was degraded by ethanolysis to yield vanilloyl methyl ketone in approximately 0.2% yield of the lignin. When sinapic acid was fed no corresponding syringoyl methyl ketone could be isolated but the vanilloyl methyl ketone was radioactive. This suggests that demethoxylation of sinapyl compounds can occur in lignification. The results show that the enzymes responsible for the biosynthesis of lignin from these precursors are present in the cambium, and that the lignification route via phenylpropanoid acids is operative in this tissue as well as in other species.
THE ACTIVE CENTER OF HUMAN PLASMIN
Authors: Ronwin Edward
Published: December 2009

Studies on the active center of human plasmin indicate that it is functionally identical with those of bovine plasmin and bovine trypsin. Its similarities to and differences from bovine thrombin duplicate those previously demonstrated between the latter and both bovine plasmin and trypsin. The data suggest that the basic structural geometry and group function of an active center capable of catalyzing a successful enzymatic mechanism, in these studies the tryptic function, is maintained for the active centers of different tryptic enzymes both within a species and in evolutionary shifts from species to species.
THE CONSTRUCTION OF AN ULTRAFILTRATION UNIT TO MEASURE THE BINDING OF CERTAIN NITROGEN MUSTARDS TO SERUM PROTEIN
Authors: Linford J. H. , Legal J. , Zacharias E.
Published: December 2009

An ultrafiltration unit has been designed, and constructed to contain a 10-ml volume. The unit is leakproof, is self-contained, and can be operated inside a small refrigerator or oven. It has been used with "Visking" cellulose acetate membrane to separate the colloidal protein phase of human blood serum from the aqueous dispersing phase, and to study the distribution of certain nitrogen mustards between these phases. The results indicate that these drugs are adsorbed to the protein to a high degree and that the presence of the benzene rings in the nitrogen mustards is mainly responsible for this adsorption.
THE INCORPORATION OF TRYPTOPHAN ANALOGUES INTO RAT PLASMA PROTEINS
Authors: Berecz Anita , Godin C.
Published: December 2009

When 7-azatryptophan and 5-methyltryptophan are fed to protein-depleted rats, the animals lose weight more rapidly than control rats. Protein-depleted rats fed a diet containing tryptophan gain weight. 7-Azatryptophan is incorporated in vivo into rat plasma proteins, whereas 5-methyltryptophan is not incorporated.
BLOOD PRESSURE BEFORE, DURING, AND AFTER OVIPOSITION IN THE HEN
Authors: Hunsaker W. G. , Sturkie P. D.
Published: December 2009

The central arterial pressure was recorded continuously in eight hens before, during, and after oviposition. Blood pressure remained relatively stable for the 2-hour period prior to oviposition. Approximately 30 seconds prior to oviposition, there was a marked change in the pressure pattern. While there was no marked increase in the maximum level of systolic pressure or decrease in the minimum level of the diastolic pressure, there were large fluctuations within this range. Immediately after oviposition there was a decrease in pressure in seven of the eight birds studied. The average decrease in systolic pressure was 17.6 mm Hg and in diastolic pressure 7.6 mm Hg. There were indications of an increase in pressure within about 15 minutes after oviposition.
STUDIES ON WHEAT PLANTS USING CARBON-14 COMPOUNDS: XVI. FRACTIONATION OF A PERFORMIC ACID OXIDIZED PROTEIN
Authors: Finlayson A. J. , McConnell W. B.
Published: December 2009

Wheat gliadin-C14was separated into ammonia-soluble and alkali-soluble fractions. Oxidation of the ammonia-soluble fraction with performic acid rendered the material water soluble and quantitatively converted the cystine and cysteine residues to cysteic acid. Little, if any, peptide bond hydrolysis resulted from the oxidation step. Five "protein-like" fractions were isolated by chromatography of the oxidation mixture on N,N′-diethylaminoethylcellulose (DEAE-cellulose).The specific activities of glutamic acid, proline, and leucine were found to vary widely with the fraction from which they were isolated. The fractions isolated are therefore characteristic of protein components with different biosynthetic histories.
LES NEURONES DE LA FORMATION RÉTICULAIRE PONTO-BULBAIRE ET LA STIMULATION TRIGÉMINALE
Authors: Lamarche Guy , Langlois J.-M.
Published: December 2009

A microphysiological study of 209 neurons of the bulbopontine reticular formation was carried out in 80 "encéphales isolés" cats. After physiological stimulations of the trigeminal nerve the following conclusions were arrived at: (1) A functional arrangement exists in the lower recticular formation. Clear differences were found between the medulla and pons. (2) The pontine reticular neurons receive mostly tactile impulses from very large receptive fields. (3) The bulbar neurons receive all modalities of the trigeminal nerve from usually limited and bilateral fields (except proprioception). Pain projects mainly in this part of the reticular core. A central zone of the medulla has all physiological types of cells and is coincidental with Magoun and Rhine's inhibitory zone. (4) There was no neuronal response typical of any sensation. (5) An increase in frequency of a response was obtained in various ways: by changing the origin of the stimulus, by-increasing the intensity of the stimulus or the area of stimulation, or by applying a painful stimulus when the cell also responded to touch. (6) It is suggested that the sensory afferents lose their specificity when they reach the reticular formation but that via this formation they serve to increase awareness and perception of sensation at higher level.
IMPAIRMENT OF TESTICULAR FUNCTION IN THE WHITE RAT CHRONICALLY EXPOSED TO A LOW AMBIENT TEMPERATURE
Authors: Dugal L. P. , Saucier G. , DesMarais A. , Léveillé A.
Published: December 2009

not available
GROWTH HORMONE AND CARDIAC GLYCOGEN: INFLUENCE OF ENVIRONMENTAL AND GENETIC FACTORS
Authors: Fenton Paul F. , Duguid Jane R.
Published: December 2009

The rise in cardiac glycogen levels observed in the rat during fasting and after growth hormone administration is more difficult to demonstrate in the mouse. At room temperature fasting lowers the cardiac glycogen of the mouse. Large doses of growth hormone are needed to maintain the cardiac glycogen at the level seen in fed animals. At 30 °C mice of the A strain increase their cardiac glycogen during a 24-hour fast. Growth hormone increases the glycogen level still further. At this elevated temperature (close to the critical temperature of the mouse) fasting lowers the cardiac glycogen of the I strain mouse, but growth hormone raises the glycogen above the level of fed animals. It is suggested that the fasting stimulus evokes a greater secretion of growth hormone in A strain mice or that the tissues of these mice are more sensitive to the hormone.
STUDIES ON THE NUMBER AND VOLUME OF FAT CELLS IN ADIPOSE TISSUE
Authors: Zingg W. , Angel A. , Steinberg M. D.
Published: December 2009

The changes in number and volume of fat cells accompanying changes in the size of the perirenal fat depots of rats induced by dietary and other means have been investigated by direct histological examination and by estimation of the total desoxyribonucleic acid (DNA) and fat content. With both methods, an increase in cell volume and in cell number was found to accompany an increase in depot volume.
THE OXIDATION OF ESTRONE-16-C14BY PEROXIDASE
Authors: Jellinck P. H. , Irwin Louise
Published: December 2009

Aerobic incubation of estrone-16-C14with peroxidase in the presence of serum albumin and other proteins resulted in the formation of water-soluble, ether-insoluble metabolites in high percentage yields. Similar products were formed when protein was replaced by cysteine or tryptophan but none of the other amino acids tested had any effect. The evidence points to an initial generation of hydrogen peroxide from these nitrogenous compounds by the enzyme acting as an aerobic oxidase, and the subsequent peroxidation of estrone to highly reactive products. These then combine with the protein or amino acid or else undergo alternative reactions. A strong chemical bond is formed with albumin and attempts to release the estrone metabolites from it were unsuccessful. Uterine homogenates from estrogen-treated rats showing high DPNH oxidase activity contained no "peroxidase" as measured by the formation of water-soluble products from estrone in the presence of protein.
TETRACYCLINE LABELLING OF BONE AND THE ZONE OF DEMARCATION OF OSTEOID SEAMS
Authors: Frost Harold M.
Published: December 2009

In human lamellar bone, mineralization begins in a plane, termed the zone of demarcation, which separates osteoid seams from mineralized bone. Permanently fixed tetracycline antibiotics are deposited in the zone of demarcation in vivo, and in no other locus in lamellar bone.
ISOLATION OF 20β-DIHYDROCORTISONE FROM SOCKEYE SALMON (ONCORHYNCHUS NERKA) PLASMA
Authors: Idler D. R. , Schmidt P. J. , Ronald A. P.
Published: December 2009

20β-Dihydrocortisone has been isolated from the peripheral plasma of spawned male and female salmon. The plasma steroid was identified by its chromatographic mobility and that of its diacetate as well as the sulphuric acid chromogen of the steroid. The steroid was transformed, by sodium bismuthate, to adrenosterone, which was identified by chromatography and sodium borohydride reduction to 17β-ol-Δ4-androstene-3,11-dione. Spawned females had 2.1 μg of 20β-dihydrocortisone per 100 ml of plasma. An ultraviolet-absorbing substance with the chromatographic mobility of 20α- and 20β-dihydrocortisol could not be identified with either of these substances.
THE PURIFICATION OF TRYPSINOGEN BY ION-EXCHANGE CHROMATOGRAPHY
Authors: Smillie L. B. , Mabbott G. Y. , Neufeld G. R.
Published: December 2009

The purification of trypsinogen by several methods of ion-exchange chromatography has been investigated. The use of phosphate–urea buffers on Bio-Rex 70 was not a suitable preparative procedure because of considerable inactivation of the zymogen. Chromatography on carboxymethyl cellulose at pH 3.2 produced no significant increase in the potential tryptic activity. In the presence of soybean trypsin inhibitor, trypsinogen was successfully chromatographed on Bio-Rex 70 to yield a product of high potential activity and of low free tryptic and chymotryptic activity. It was essentially free from soybean trypsin inhibitor and possessed the physical parameters previously published for this protein.
AUTOPROTHROMBIN C: A SECOND ENZYME FROM PROTHROMBIN
Authors: Marciniak Ewa , Seegers Walter H.
Published: December 2009

In addition to thrombin, there is another derivative of prothrombin which is an end product of prothrombin activation. It is an accelerator of prothrombin activation, and is called autoprothrombin C. The activity develops from purified bovine prothrombin in 25% sodium citrate solution simultaneously with thrombin. It has been separated from thrombin by chromatography on Amberlite IRC-50 under the conditions previously used for the isolation of thrombin. The fraction which separates from thrombin has esterase activity and very likely this esterase activity is associated with the autoprothrombin C molecule. Since the autoprothrombin C and the thrombin are both derived from prothrombin, at least two enzymes are the end products of prothrombin activation. Autoprothrombin C catalyzed the activation of purified prothrombin in 25% sodium citrate solution, and this function was easily inhibited with p-toluenesulphonyl-L-arginine methyl ester. Autoprothrombin C preparations were mixed with platelets, Ac-globulin, and calcium ions to obtain rapid conversion of purified prothrombin to thrombin. This activation mixture did not generate autoprothrombin C and some unspecified substance most likely needs to be added in order to obtain the autoprothrombin C activity. The activity developed together with thrombin when tissue extracts, Ac-globulin, and calcium ions were used for the activation of prothrombin. Autoprothrombin C is relatively stable over the pH range 5.5 to 8.5. It is stable up to 56 °C for 30 minutes. Plasma contains a substance that inactivates autoprothrombin C.
THE EFFECT OF INCUBATION ON THE CHARACTERISTICS OF THE LIPOLYTIC ACTIVITY OF RAT ADIPOSE TISSUE
Authors: Hollenberg C. H.
Published: December 2009

A study has been made of the changes produced in the characteristics of the lipolytic activity of rat adipose tissue homogenates by prolonged preincubation of the intact tissue in phosphate buffer. Fresh tissue homogenates were markedly more active on a serum–triglyceride medium (activated substrate) than on triglyceride alone while little difference was noted with homogenates of preincubated tissue. The activity of fresh tissue homogenates was increased by addition of heparin; homogenates of incubated tissue were not affected. Fresh tissue homogenates were inhibited to a greater extent by protamine than were preparations of incubated material. Addition of glucose and insulin to the buffer partially maintained the activity of incubated tissue on activated substrate. These results indicate that while lipolytic activity of fresh rat adipose tissue has characteristics similar to lipoprotein lipase, the activity of incubated tissue differs from this enzyme in several respects. This study demonstrates the lability of lipoprotein lipase in rat adipose tissue and suggests the presence in this tissue of a separate type of lipolytic activity.
THE WEIGHT-DEPRESSING ACTION OF α-METHYL-DL-TRYPTOPHAN IN THE RAT
Authors: Sankoff I. , Sourkes T. L.
Published: December 2009

α-Methyl-DL-tryptophan, injected intraperitoneally into rats, has a weight-depressing action lasting up to 72 hours. Dosages in the range 0.015–2.0 millimoles/kg body weight (3.3–436 mg/kg) are effective. Attempts to antagonize the weight-depressing action by giving essential amino acids and B vitamins were unsuccessful. Metabolic studies have shown that about half the injected dose of the compound (or its derivatives), as measured by the Hopkins–Cole glyoxylic acid reaction, is excreted in the urine in 24 hours; most of this appears during the first 4 hours after the injection. Ina search for an explanation for the weight-depressing action of α-methyltryptophan, tryptophan pyrrolase activity in the liver was estimated. This enzymic activity increases for 8 hours after the injection of α-methyltryptophan, and thereafter remains high for 72 hours. Tryptophan-injected animals showed increases in tryptophan pyrrolase level for 1.5 hours, and a return to normal concentrations within 24 hours. Other α-methyl amino acids which were tested had no comparable effect on body weight.
LIGNIN ABNORMALITIES OF "RUBBERY APPLE WOOD"
Authors: Sondheimer E. , Simpson W. G.
Published: December 2009

The lignin from healthy and from rubbery wood virus-infected apple trees has been examined. Although the Klason lignin from healthy specimen was found to be similar to that of other hardwood species, the lignin from the diseased samples has a lower methoxyl content and yields less syringaldehyde on nitrobenzene oxidation. More alcohol-soluble material but less Klason lignin was obtained from the diseased samples than from the healthy wood. Since the lignins from the healthy and the diseased samples have a similar oxygen content, it is suggested that methylation of the lignin is interfered with in the infected wood. Evidence for the validity of this theory is discussed. A similarity was noted between the characteristics of rubbery wood virus and those of "juvenile" lignin from other sources.
GLUCOSE UTILIZATION AND INSULIN RESPONSIVENESS OF LEUCOCYTES IN DIABETES
Authors: Kalant N. , Schucher R.
Published: December 2009

Measurements were made of the uptake of glucose by leucocytes obtained from normal and diabetic subjects, on incubation in plasma and in synthetic media, with and without insulin. Cells of diabetics in bicarbonate medium showed an uptake of glucose which was lower than that of cells from non-diabetics. In plasma and bicarbonate medium they showed a decreased response to insulin. These results are compatible with prior findings of decreased glucose utilization and decreased insulin responsiveness in human diabetes of the maturity-onset type.
MUSCLE PROTEINS OF PACIFIC SALMON (ONCORHYNCHUS): II. AN INVESTIGATION OF MUSCLE PROTEIN AND OTHER SUBSTANCES SOLUBLE IN SALT SOLUTIONS OF LOW IONIC STRENGTH BY COLUMN CHROMATOGRAPHY
Authors: Tsuyuki H. , Roberts E. , Gadd R. E. A.
Published: December 2009

The muscle myogens and other components of the spring salmon (O. tshawytscha), chum salmon (O. keta), coho salmon (O. kisutch), and sockeye salmon (O. nerka), as well as the lingcod (Ophiodon elongatus), were separated by the use of diethylaminoethyl (DEAE) cellulose columns. Significant amounts of slowly dialyzable inosine and inosinic acid which may lead to spurious peaks in moving-boundary electrophoretic separations have been shown to be present in the muscle myogen preparations. The basic differences in the muscle myogen components of the Pacific salmon and the lingcod are compared.
THE UNCOUPLING OF OXIDATIVE PHOSPHORYLATION BY IONIZING RADIATION
Authors: Scaife J. F. , Hill B.
Published: December 2009

Whole body irradiation of rabbits or rats with X-rays or Co60γ-rays causes uncoupling of oxidative phosphorylation in thymus mitochondria, which is not prevented by the prior administration of AET. Whole body irradiation was not found to affect oxidative phosphorylation in liver or mouse ascites cell mitochondria. The radiation lesion can be repaired in vitro by the addition of cytochrome c, bovine serum albumin, or vitamin K1to mitochondria. Vitamin E and coenzyme Q10 were without effect. Both phosphorylating steps in the electron transport chain associated with succinate oxidation are affected by irradiation. The diphosphopyridine nucleotide dependent steps in the oxidation of α-ketoglutarate by thymus mitochondria are damaged by in vivo irradiation. Diphosphopyridine nucleotide levels of thymus and spleen but not liver or ascites cells are reduced by in vivo irradiation. No effect of in vitro irradiation on oxidative phosphorylation could be found for thymocyte cell suspensions, isolated thymus or liver mitochondria, or ascites or HeLa cell suspensions. Respiration of ascites or thymocyte cells was unaffected by in vitro irradiation.
COMPOSITION AND PROPERTIES OF SOLUBLE LIPOPROTEINS IN RELATION TO STRUCTURE
Authors: Cook W. H. , Martin W. G.
Published: December 2009

Lipoproteins from diverse sources have total lipid contents extending over an essentially continuous range but do show strong evidence of a transition in their composition in the region where protein, phospholipid, and neutral lipid are present in essentially 1:1:1 proportions. Those with protein contents below 33% (LPL) have neutral lipid–phospholipid ratios ranging from 1:1 to 10:1; but this ratio remains at about 1:1 in all those with protein contents above 33% (HPL). The protein content of the LPL type decreases with increasing particle size and is sufficient to provide only a surface film. If the protein is present in this form, the particle must have a lipid core; if it is present in more globular form, much of the particle surface must be phospholipid, and such structures resemble microemulsions or micelles. The composition and properties of the HPL type, however, are consistent with their having a structural integrity approaching that of a protein molecule. For example, their molecular weight appears to be independent of their lipid content, and egg yolk HPL exhibits pH-dependent reversible dissociation into two subunits comparable to that observed in certain proteins. Differences in the N-terminal residues (serum lipoproteins) and amino acid composition (yolk lipoproteins) of the proteins of most LPL and HPL types indicate that, if their interconversion does occur, it would involve more drastic changes than either alterations in structure or a simple loss or gain of lipid.
ELECTROPHORETIC DIFFERENCES IN THE EGG-WHITE PROTEINS OF THE HEN
Authors: Cochrane Delma , Annau E.
Published: December 2009

The whites of 339 eggs laid by 64 White Rock – Leghorn crossbred hens and 48 pedigreed pullet progeny of 23 of these hens have been examined by Smithies' starch gel electrophoretic procedure. All samples exhibited three to five distinct bands in the region of the electrophoretic diagram comparable to that of alpha and beta globulins of chicken serum. Six characteristic patterns were formed from different combinations of these bands. An attempt is made to explain these patterns as being genetically controlled.
THE UBIQUINONE AND CRUDE STEROL CONTENT OF THE LIVER WITH VARIATIONS IN THE INTAKE OF TOCOPHEROL IN THE VITAMIN A DEFICIENT RAT
Authors: Phillips W. E. J.
Published: December 2009

Some non-saponifiable constituents of rat liver have been studied in animals differing in their nutritional status in vitamin A and E. Liver levels of ubiquinone were negatively correlated with the vitamin A status of the animal but not with the vitamin E status. The crude sterol content of the liver was not affected by variations in the intake of either vitamin, except that there was a slight but significant increase when vitamin A deficiency was pronounced.
EFFECT OF DUST AND AEROSOL INHALATION ON SURFACE AND TISSUE ELASTICITY OF RAT LUNGS
Authors: Rosenberg Edith , Alarie Y. , Robillard Eugène
Published: December 2009

Rats were exposed to an atmosphere containing submicronic aluminum oxide particles or to aerosols of carbachol or isoproterenol. The static pressure – volume curves of their lungs, rendered gas-free and removed after exposure, were then compared to those of normal rats studied similarly. The lungs were filled and emptied gradually both with air and with saline so that in every case the force due to tissue elasticity, as well as that due to the surface tension of the alveolar lining, could be determined. Carbachol aerosol (1%) inhalation for 7 minutes produced an increase in the force due to tissue elasticity. The inhalation of aluminum oxide particles, less than one micron in diameter, for half an hour also increased the force due to tissue elasticity slightly, but it greatly decreased the force due to the surface tension of the alveolar lining.
UTILIZATION BY THE RAT OF LARGE LIVER RESERVES OR OF A SMALL DAILY INTAKE OF VITAMIN A
Authors: Murray T. K.
Published: December 2009

Weanling female rats were given a massive dose of vitamin A and thereafter fed a vitamin A free diet while similar rats were provided with the same diet plus a small daily intake of vitamin A for the entire period. Some of the rats from each group were bred to normal males. There were no differences in the growth rate, the number of young produced and weaned, nor in the weight of the young. Somewhat more vitamin A was transferred to the liver and kidney of the young by mothers with large liver stores but these differences had disappeared by weaning age. It was concluded that sufficient vitamin A could be given a rat at weaning to allow normal development and the production of at least one normal litter.
CAFFEINE-INDUCED ULCEROGENESIS IN THE RAT
Authors: Pfeiffer C. J. , Gass G. H.
Published: December 2009

The present investigation has demonstrated that administration of caffeine alkaloid (6.25 mg/kg, 25 mg/kg, and 100 mg/kg) by stomach tube induces acute gastric ulcers in the fundus, pylorus, and antrum of fasting male and female rats. The ulcers are histologically characterized as superficial erosions of the glandular mucosa. Statistical evaluation of ulcer indices indicated a linear, log dose–response relationship for caffeine alkaloid, and a similar ulcerogenic effect in both male and female rats.
BIOSYNTHESIS OF MUSTARD OIL GLUCOSIDES: I. ADMINISTRATION OF C14-LABELLED COMPOUNDS TO HORSERADISH, NASTURTIUM, AND WATERCRESS
Authors: Underhill E. W. , Chisholm M. D. , Wetter L. R.
Published: December 2009

Biosynthetic investigations with C14-labelled compounds indicate that the aromatic isothiocyanate moieties of mustard oil glucosides obtained from garden nasturtium (Tropaeolum majus L.) and watercress (Nasturtium officinale R.Br.) are derived from phenylalanine. Similar investigations on sinigrin, the mustard oil glucoside isolated from horseradish (Armoracia lapathifolia Gilib.) demonstrate that glycine is incorporated into allyl isothiocyanate. The methyl carbon of acetate was readily incorporated into sinigrin and gluconasturtium and was found almost exclusively in the 'isothiocyanate carbon'; on the other hand the carboxyl carbon is a poor precursor of sinigrin.
MALIC DEHYDROGENASE IN THE TWO-SPOTTED SPIDER MITE, TETRANYCHUS TELARIUS (L.)
Authors: Mehrotra K. N.
Published: December 2009

The presence of NAD-speciric malic dehydrogenase was demonstrated in the two-spotted spider mite. The Michaelis–Menten constant (Km) of the enzyme for malate was found to be 1.25 × 10−3 M and for oxalacetate 5.0 × 10−5 M.
EFFECTS OF X-RADIATION AND OF METABOLIC INHIBITORS ON RAT THYMOCYTES IN VITRO
Authors: Myers D. K. , DeWolfe Donna E. , Araki Kimiko
Published: December 2009

The survival of X-irradiated thymocytes in vitro was studied after incubation for various periods of time and at different pH values as well as at different temperatures. Death at 25 °C following exposure to high doses of X-radiation may be due to the liberation of destructive enzymes. The effects of high doses could be largely prevented by addition of nicotinamide after irradiation.The cause of cell death at 37 °C following exposure to low doses of X-radiation is still uncertain. Some metabolic inhibitors also showed a considerable difference in their toxicity to thymocytes at 37 °C and at 25 °C. Dinitrophenol, for example, was highly toxic at 37 °C but almost ineffective in killing cells at 25 °C, even though it produced similar decreases in ATP levels at both temperatures. The marked difference in survival of irradiated thymocytes at 37 °C and at 25 °C could therefore be explained if low doses of X-radiation interfered with the normal cell metabolism. However, low doses of radiation, unlike dinitrophenol, did not produce any immediate decrease either in ATP levels or in oxygen consumption of thymocyte suspensions.
GAS–LIQUID CHROMATOGRAPHIC ANALYSIS OF THE TRIGLYCERIDE COMPOSITION OF MOLECULAR DISTILLATES OF BUTTER OIL
Authors: McCarthy M. J. , Kuksis A. , Beveridge J. M. R.
Published: December 2009

A quantitative gas–liquid chromatographic analysis of the triglycerides of butter oil and its distillates has shown that molecular distillation can effect a significant fractionation of butterfat. The most volatile 2.5% distillate contained nine triglyceride types (C24–C40), six of which were present in concentrations representing 3- to 20-fold enrichments, when compared with the original oil. Eighty-six percent of the C30and shorter triglycerides occurred in the most volatile fractions, which comprised 5% of the total fat. The residue, which represented 50% by weight of the oil, contained 10 triglyceride types (C36–C54), seven of which were present in concentrations exceeding those in the original oil. This residue contained 93% of the triglycerides longer than C46. The other distillates contained triglycerides the mean molecular weights of which increased with decreasing volatility. In all cases the triglyceride composition of the butter-oil distillates was markedly different from that of butterfat.
THE LIPIDS OF MOUSE BROWN FAT
Authors: Spencer W. A. , Dempster G.
Published: December 2009

The lipids of the interscapular brown fat of the white mouse have been examined by means of silicic acid column chromatography and quantitative paper chromatography. The fatty acid composition of the glycerides and phosphatides was determined by gas chromatography. Comparative studies of mouse brown and white fat are presented.The fatty acid composition of the glycerides of the two tissues was similar at all ages examined. In both tissues, the average chain length of the glyceride fatty acids increased with age. The glycerides of brown fat at all ages contained less palmitoleic acid and more stearic acid than the corresponding white fat.The adult brown fat contained more polyglycerophosphatide and less sphingomyelin than white fat. The fatty acid composition of the lecithins of the two tissues was very similar. The similarity of brown fat and liver phosphatides is discussed.
STUDIES ON CORTICOSTERONE C-20 REDUCTION IN THE MOUSE
Authors: Krehbiel R. E. , Burton A. F. , Darrach Marvin
Published: December 2009

The intravenous injection of corticosterone in the mouse was followed by liver assays for corticosterone and 20α- and 20β-dihydrocorticosterone. The 20α-epimer proved to be the more abundant product. Corticosterone 20α-reductase activity of mouse liver was shown to be associated with the dialyzed soluble fraction of the cell which served as an enzyme preparation for a study of certain properties of corticosterone 20α-reductase and the kinetics of the forward and reverse reactions.
THE LOCALIZATION AND PROPERTIES OF AN AMINOPEPTIDASE IN ESCHERICHIA COLI B
Authors: Matheson A. T.
Published: December 2009

Two types of intracellular aminopeptidase activity are present in E. coli B. One type, present in the 'soluble' fraction, is completely inactivated by chymotrypsin or trypsin; the other, in the particulate fractions ('ribosome' and 'membrane'), is resistant to these enzymes. The 'ribosomal' peptidase activity is present partially in a latent form which becomes activated on disruption of the ribosome structure. During the transition from log phase to post-log phase growth there is a progressive increase in the specific activity of the peptidase in the 'soluble' and 'membrane' fraction and a corresponding decrease in the 'ribosome' fraction.
CONJUGATED TESTOSTERONE IN THE BLOOD AND TESTES OF SPAWNED FRASER RIVER SOCKEYE SALMON (ONCORHYNCHUS NERKA)
Authors: Grajcer Dov , Idler D. R.
Published: December 2009

Testosterone was isolated from the conjugated steroid fractions of both plasma and testes of spawning male sockeye salmon. The structure of the steroid was confirmed by several criteria including infrared spectra. Glucuronoside conjugation was indicated by the use of a specific glucuronidase inhibitor, glucosaccharo-1, 4-lactone, and the inability of the enzyme to hydrolyze testosterone sulphate.
STUDIES OF LIGNIN BIOSYNTHESIS USING ISOTOPIC CARBON: XI. REACTIONS RELATING TO LIGNIFICATION IN YOUNG WHEAT PLANTS
Authors: Higuchi Takayoshi , Brown Stewart A.
Published: December 2009

L-Phenylalanine-G-C14, p-hydroxycinnamic acid-2-C14, ferulic acid-2-C14, and sinapic acid-2-C14were administered to wheat plants aged both 30 and 73 days. Radioactive vanilloyl- and syringoyl-methyl ketones were then recovered after ethanolysis of the cell wall residues. When corrected for differences in endogenous lignin, the C14dilution values calculated for the younger plants were generally greater, indicating, as expected, a slower rate of lignification. The difference between the younger and older plants was less for sinapic and ferulic acids than for p-hydroxycinnamic acid or phenylalanine. This suggested that slower lignification in young plants may be due not to relative inactivity of an enzyme system at any one stage of the biosynthetic pathway but to the cumulative effect of slower reactions at several stages. Sinapic acid is converted in the younger plants to lignin yielding vanilloyl-, as well as syringoyl-, methyl ketone, suggesting a demethoxylation. Glucose esters of the radioactive phenolic cinnamic acids corresponding to the labelled compound administered were recovered from the plant extracts. A small percentage of the activity in the cell wall residue was in the form of ferulic acid joined by ester linkages.
CHARACTERISTICS OF ACIDIC AMINO ACID TRANSPORT IN MAMMALIAN KIDNEY
Authors: Webber William A.
Published: December 2009

A series of clearance experiments on dogs were carried out which were designed to confirm and characterize the renal tubular reabsorption of glutamic and aspartic acids. Tubular reabsorption was measured and found to reach a maximum of about 100 μmole/minute for L-glutamic and L-aspartic acids and a slightly lower level for D-aspartic. Competitive studies using substituted amino acids were performed and three patterns of inhibition of amino acid reabsorption observed. Acidic amino acids inhibited the reabsorption of each other, while neutral amino acids (and an acidic amino acid substituted so as to have a neutral side chain) inhibited the reabsorption of a wide range of other amino acids. Compounds with the amino group or either carboxyl group substituted or absent, but not resembling neutral amino acids, were not inhibitory. There appears to be a specialized mechanism for acidic amino acid transport which probably requires all three functional groups but which may be interfered with by a compound with alpha carboxyl and amino groups and a neutral side chain.
METABOLIC EFFECTS OF DIETARY PROTEIN LEVEL IN COLD-EXPOSED RATS
Authors: Beaton John R. , Orme T. , Turner A. , Laufer J.
Published: December 2009

Male albino rats were fed ad libitum isocaloric diets containing 5%, 20%, and 40% protein and 10% corn oil by weight. Measurements were made of nitrogen retention, urine volume, water intake, body composition, and blood levels of glucose, amino nitrogen, and urea at environmental temperatures of 22 ± 2 °C (7 days) followed by 2 ± 1 °C (8 days). Significant metabolic differences were evident among the three dietary groups at 22 °C but these differences were, in general, reduced under conditions of cold exposure. It is of interest that the rats on the 40% protein diet did not exhibit the typical increases in food consumption and urine volume when exposed to cold and, further, that these animals appeared able to maintain body weight and synthesize body fat during cold exposure. It seems that dietary protein level may play an important role during exposure to cold.
METABOLIC EFFECTS OF THREE DIETARY PROTEIN LEVELS FED ISOCALORICALLY TO COLD-EXPOSED RATS
Authors: Beaton John R. , Orme T. , Laufer J. , Turner A.
Published: December 2009

Male albino rats were fed isocalorically on diets containing 5%, 20%, and 40% protein (casein) and 10% corn oil by weight at environmental temperatures of 22 °C and 2 °C. Since the 5% protein fed group consumed less than normal amounts of food, consequently the food intake of all groups was moderately restricted. Measurements were made of urinary excretion of nitrogen, potassium, sodium, phosphorus, and creatinine, of blood levels of glucose, urea, amino nitrogen, packed cell volume, and serum total proteins and of total body content of protein, water, and crude fatty acids. Metabolic effects of dietary protein level were readily apparent at both environmental temperatures. Unlike earlier studies with ad libitum and severely restricted feeding, superimposition of cold exposure did not eliminate metabolic differences among groups. As observed in previous studies, reduction of dietary protein level from 20% to 5% had a deleterious effect in cold-exposed rats. In the present study no beneficial effects due to increasing dietary protein level from 20% to 40% were observed.
BLOOD AMINO ACID STUDIES: IV. SOME FACTORS AFFECTING PLASMA AMINO ACID LEVELS IN HUMAN SUBJECTS
Authors: McLaughlan J. M. , Noel F. J. , Morrison A. B. , Campbell J. A.
Published: December 2009

Free lysine, methionine, threonine, and tryptophan were determined in small samples of blood obtained by finger punch from human subjects. The levels of the four amino acids rose rapidly after the subjects consumed protein as baked halibut; the extent and duration of the increases were roughly proportional to the amount of protein eaten and to the amino acid composition of the protein. The increases of free methionine and threonine in plasma were somewhat less when butter was taken with fish but starch (as potato) or sucrose did not affect the values. Other foods tested at the 19.0-g level of protein included egg, a commercial breakfast cereal, and the same cereal plus milk. In general the increase or decrease of each amino acid tested was related to the amount of that amino acid in the test food. The plasma amino acid (PAA) ratio of Longenecker and Hause was calculated for each food and was useful in evaluating the increase or decrease of each specific amino acid. The present work appears to offer a practical procedure for studying the plasma amino acid response of groups of human subjects to variations in dietary protein.
PURIFICATION OF STAPHYLOCOCCAL-ALPHA-LYSIN
Authors: Jackson A. W.
Published: December 2009

A method for the purification and concentration of staphylococcal-α-lysin is described. Zinc–lysin complex, formed by addition of zinc–acetate to dialyzed, crude solutions of lysin, is precipitated with ethanol at low temperature. All but traces of zinc, together with some inactive material is removed from the precipitate by extraction with ethanol–water mixtures under conditions of pH and ethanol content which maintain the lysin in precipitated form. Further purification of the active material is achieved by chromatography employing columns composed of hydroxylapatite. The purified lysin is 250 times as active as the crude starting material in terms of hemolytic units per milligram of nitrogen.Rabbit erythrocytes are susceptible whereas human erythrocytes are resistant to the hemolytic activity of purified α-lysin. It is dermonecrotic when injected intradermally into rabbits and lethal when introduced intraperitoneally into mice in quantities of 20 hemolytic units per 25 g mouse.
OBSERVATIONS ON THE EFFECTS OF METHANOL AND FORMALDEHYDE ON ESTABLISHED CELL LINES CULTIVATED IN VITRO
Authors: Elliott Alice , Pace Donald M.
Published: December 2009

Short-term experiments were used to investigate the effects of various concentrations of methanol and formaldehyde upon cells grown in vitro. Mouse liver epithelial, HeLa, human lung, and skin cells were exposed to several concentrations of methanol. The same cell lines, except HeLa, were subjected to different concentrations of formaldehyde.Relatively high concentrations of methanol were required to produce rapid toxic effects. Not all cell lines responded alike to methanol. Concentrations of 15 mg/ml were decidedly inhibitory in case of human skin, lung, and HeLa cells. This concentration, however, appeared to enhance growth in liver cells. At higher concentrations the methanol was toxic to liver cells as well as to the others.Concentrations of formaldehyde greater than 0.035 mg/ml were toxic to mouse liver, human lung and skin cells. A concentration of 0.01 mg/ml of formaldehyde inhibited proliferation of these same cells. These three cell lines did not appear to differ significantly in respect to their sensitivity to formaldehyde. Of the substances investigated to date, formaldehyde appears to be the most toxic.
THE ROLE OF GLUCOSE IN THE INITIATION AND MAINTENANCE OF VENTRICULAR FIBRILLATION
Authors: Tétreault L. , Beaulnes A.
Published: December 2009

Perfusion of isolated rabbit hearts with a glucose-free physiological solution facilitates the production of ventricular arrhythmias. On the other hand, glucose deprivation limits the duration of such arrhythmias. An hypothesis is proposed to explain the effect of glucose deprivation on the induction of fibrillation.
FACTORS AFFECTING THE VIABILITY OF AIR-BORNE BACTERIA: VI. THE ACTION OF INOSITOL ON LACTOSE OXIDATION BY DESICCATED ESCHERICHIA COLI
Authors: Webb S. J.
Published: December 2009

The effect of desiccation on the ability of Escherichia coli to oxidize lactose has been studied. The enzyme system responsible for lactose oxidation is adaptive in E. coli, and amino acids are required for its synthesis. Of the amino acids required, glutamic and aspartic acids proved to be the most active in stimulating the synthesis of the enzymes. The cells of E. coli lose their ability to oxidize lactose on desiccation but if drying is carried out in the presence of i-inositol this loss is prevented. The findings add support to the hypothesis that the death of a cell on desiccation results from the destruction of a component concerned in protein synthesis.
STATIC VOLUME–PRESSURE RELATIONS IN GUINEA PIG LUNGS AFTER INHALATION OF ALUMINUM OR IRON OXIDE PARTICLES AND BRONCHODILATOR AEROSOLS
Authors: Robillard E. , Alarie Y.
Published: December 2009

Volume–pressure curves obtained from isolated atelectatic guinea pig lungs under normal controlled conditions are compared with those obtained from animals having inhaled fine aluminum or iron oxide particles. After particles inhalation, the inflation curves are deviated to the right, showing a constricting effect. Previous exposure to low concentration of isoproterenol aerosol fails to reverse completely the constricting effect induced by a prior inhalation of aluminum oxide particles although in combination with diphenhydramine or at a higher concentration an antagonistic action appears. Cyproheptadine aerosolation also prevents the constricting effect of inhaled aluminum oxide particles The constricting effect of iron oxide was not prevented by those dilating aerosols at concentrations used.
CAROTENOID CHANGES IN DIFFERENT MAIZE VARIETIES DURING RIPENING
Authors: Zsolt J. , Schneider Gy. , Matkovics B.
Published: December 2009

The authors investigated the carotenoids of different maize varieties of white, yellow, and red-colored grains in different phases of ripening. The carotenoids extracted from the grains were separated into benzene-soluble (epiphasic) and benzene-insoluble (hypophasic) fractions, and the components of these fractions were quantitatively measured and separated. The cause of the characteristic color of the grains is the difference in concentration of zeaxanthin, the main component of the hypophasic fraction. The following other carotenoids were demonstrated also: β-carotene, β-carotene-monoepoxide, violaxanthin, β-cryptoxanthin, antheraxanthin, xanthophyll, xanthophyll-monoepoxide, α-carotene. We could best explain the origin of the different carotenoids in terms of Cholnoky's theory.