bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDIES ON THE TRANSPLANTATION OF A RAT TUMOR TO MICE
Authors: Wallace A. Cameron , Davis Susan
Published: December 2009

The growth and survival of Walker 256 rat tumor grafted direct from rat into mouse thigh was compared with that of the same tumor after long continued residence in mouse brain, and also with that of tumors cultivated for a prolonged period in vitro. It was found that the pattern of growth and regression with tumor grown for 8 months in tissue culture was identical with that produced with tumor direct from rats. Tumor previously grown for 30 generations in mouse brain showed poorer growth and earlier regression. Since both prolonged growth in vitro and serial passage in mouse brain should have removed all the original rat stroma, it is concluded that loss of foreign stroma does not appreciably affect heterologous transplantation. Similarly, prolonged growth of this tumor in a foreign species under the conditions outlined apparently fails to produce any selective adaptation of the tumor to the host.
THE TREATMENT OF DIABETES MELLITUS WITH ORAL TOLBUTAMIDE
Authors: Gold Allen
Published: December 2009

Experience in the treatment of 76 diabetic patients with tolbutamide is described. In 25 patients the drug was discontinued after trials of from 1 week to several months because of poor diabetic control. These treatment failures could be divided into: Group A, completely unresponsive to tolbutamide; Group B, showing hypoglycemic response in the presence of exogenous insulin only; and Group C, responsive in the absence of added insulin, but response inadequate for proper diabetic control.Fifty-one patients who would otherwise have needed insulin were considered adequately controlled on diet and tolbutamide, 1.0 to 3.0 g. daily. No toxic effects were observed. Patients who responded to the drug had a higher mean age, a shorter duration of diabetes, and a lower mean insulin dose. Many exceptions to these individual criteria occurred.It is the author's opinion that oral tolbutamide is established as an adequate replacement for insulin injections in a large proportion of diabetics in the older age group.
THE EXTRACTION AND ASSAY OF THE TYROSINASE FROM FROG SKIN: A STUDY ON THE INFLUENCE OF THE MELANOPHORE-STIMULATING HORMONE ON THE SYNTHESIS OF THE ENZYME
Authors: Purvis John L. , Denstedt Orville F.
Published: December 2009

A soluble (microsomal) preparation of tyrosinase was obtained from frog skin (Rana pipiens) by pretreatment of strips of dorsal skin with trypsin. The relatively high activity of the enzyme towards tyrosine compared with that against dopa and other catechols would indicate that the enzyme is predominantly of the nature of a monophenolase. The rate of oxidation of D-tyrosine is about one-third that obtained with L-tyrosine. The activity of the enzyme (measured by oxygen consumption of the system) with dialyzed preparations could be increased up to fivefold by the addition of cupric ions. The enzyme is inhibited in the presence of copper-binding agents such as diethyldithiocarbamate. Highly purified specimens of intermedin had no effect on the production or turnover of tyrosinase in the frog skin, nor was there any effect on the tyrosinoxidase. There was little difference in the activity of the tyrosinase in light- or dark-adapted frogs, or in frogs which had received a series of injections of intermedin. The tyrosinase activity of the skin is subject to a large seasonal variation. The activity is about ten times greater during the period September to November than in the earlier period of the year.
ANTIDIURESIS AS A MEASUREMENT OF LABORATORY INDUCED MOTION SICKNESS
Authors: Taylor N. B. G. , Hunter J. , Johnson W. H.
Published: December 2009

Eighty-one human subjects and two bitches have been exposed to accelerations on a turntable or a swing for the purpose of inducing motion sickness. An inhibition of water diuresis consistently accompanied laboratory-induced motion sickness. Subjects who failed to become motion sick exhibited a much smaller inhibition of diuresis or none at all. The inhibition of diuresis is related to the motion sickness itself and is not due to the direct effects of centrifugal and rotational forces on the circulation.
STEROIDS AND RELATED PRODUCTS: X. 17α-BROMOPROGESTERONE, A NEW POTENT GESTOGEN
Authors: Engel Ch. R. , Jahnke H.
Published: December 2009

The synthesis of a new derivative of progesterone, 17α-bromoprogesterone, from pregnenolone acetate, is reported. The product was found to be a potent gestogen in contradistinction to its isomer, 21-bromoprogesterone.
SARIN AND PARAOXON ANTAGONISM IN DIFFERENT SPECIES
Authors: deCandole C. A. , McPhail M. K.
Published: December 2009

The intravenous LD50of sarin, alone and in combination with antagonists, has been determined in mice by a procedure standardized to control certain variables, namely rate of injection, weight, and sex of animals, and volume of fluid injected, all of which are known to influence the test.Trial of the antagonistic potency of atropine sulphate against sarin and paraoxon was also made in anaesthetized animals belonging to four additional species—cat, dog, rabbit, and monkey. Relatively fewer animals were used and a graded response (effect on the respiratory volume) was used for assessment, as well as the quantal response of death or survival. Pentamethonium was studied for its adjuvant action as an antagonist in these species. Varying with the species, a wide difference is shown to exist in the protection afforded by atropine sulphate against intravenous sarin. Thus prior atropinization was found to increase resistance in the monkey one thousand times, in the dog about one hundred and fifty times, in the cat about ten times, in the rabbit about three times, and in the mouse less than twice. A parallel, but less extreme, species difference was found to exist in the protection afforded by atropine against intravenous paraoxon.A synergistic effect was obtained when pentamethonium bromide was given along with atropine, part at least of which is attributable to improved conduction at the neuromuscular junction. Its value as a synergist was greatest in those species where the antagonistic potency of atropine was least. To obtain the maximum benefit from the combination of atropine sulphate and pentamethonium bromide in mice it was necessary to give them aftercare in the form of warmth and oxygen.Three oximes, and one hydroxamic acid, were tested in mice in combination with the therapy described. None of the four conferred any added benefit, nor did they allow aftercare to be dispensed with.Prior administration of pentobarbital intravenously was not found to lessen the toxicity of sarin to mice.
THE STANDARDIZATION OF STRESS IN THE PRODUCTION OF HEMORRHAGIC SHOCK: THE RELATION OF THE DURATION OF STRAIN AND THE RESISTANCE OF THE ANIMAL TO THE ONSET OF IRREVERSIBLE SHOCK
Authors: Lansing A. M. , Stevenson J. A. F.
Published: December 2009

When hemorrhagic shock is produced by bleeding from an artery into a reservoir at a height fixed to provide a constant level of hypotension, compensatory vasoconstriction eventually fails and the blood in the reservoir spontaneously reinfuses into the animal. The value of the onset of this spontaneous reinfusion as a criterion for the production of a standardized and irreversible hemorrhagic shock has been investigated in the rat. The animal was bled into the reservoir until the arterial pressure fell to 30 mm. Hg, which was maintained until a reduction of the volume of blood in the reservoir at three successive 2-minute intervals signified that spontaneous reinfusion had just begun. Reinfusion of the remainder of the blood was quickly completed by raising the reservoir. The animal was observed for 48 hours.A good correlation between the volume of blood forced into the reservoir early in hypotension and the duration of hypotension until the occurrence of spontaneous reinfusion was observed. With a regression equation of time (expressed as percentage of the total hypotensive period) against the volume of blood in the reservoir at various times it was possible to predict from early bleeding volumes, with fair accuracy, the duration of hypotension necessary to produce spontaneous reinfusion. In general, animals forcibly reinfused before this predicted spontaneous reinfusion survived while those exposed to the total duration died. Spontaneous reinfusion under these conditions appears to be closely associated in time with the onset of irreversible shock. The prediction from early bleeding volumes of duration to spontaneous reinfusion should permit the determination of the effect of various treatments on the resistance to hemorrhagic hypotension without the necessity for sacrifice of the animal.
THE RELATION BETWEEN HEART RATE AND VAGAL STIMULATION FREQUENCY IN THE RAT AT DIFFERENT BODY TEMPERATURES
Authors: Mainwood G. W.
Published: December 2009

The peripheral end of the right vagus was stimulated in acutely vagotomized rats under anaesthesia at different body temperatures. A fairly abrupt increase in the R–R time on the electrocardiogram was observed when a critical stimulation frequency was reached. At a body temperature of 35 °C. the critical frequency is 10 per second or more. On lowering of the body temperature to 28 °C. the critical frequency is greatly reduced so that considerable slowing may be elicited at frequencies as low as one to five per second. Possible theoretical models to account for the critical frequency and its variation with temperature are considered. The temperature effect is too great to be accounted for either on the basis of the increased number of impulses which reach the heart per cardiac cycle, or the reduced rate of cholinesterase activity. The theory most consistent with the results is that each vagal impulse liberates or inactivates a substance, the concentration of which varies directly with heart rate. The interimpulse interval at the critical frequency would then represent the regeneration time of this substance. The temperature coefficient of the regeneration process appears to be about 3.3 per 10 °C.
THE CHROMATOGRAPHIC DETERMINATION OF GLUTAMIC, ASPARTIC, AND CYSTEIC ACIDS USING AN ANION EXCHANGE RESIN
Authors: Marko A. M.
Published: December 2009

Optimum conditions for the separation of the acidic amino acids glutamic, aspartic, and cysteic on an anion exchange resin, Dowex-1 × 8, have been studied. The sample to be analyzed is adjusted to pH 7 and placed on a column of Dowex-1 × 8 previously equilibrated with 0.1 M acetate buffer at pH 4. Glutamic and aspartic acids are separated by elution with 0.1 M acetate buffer at pH 4.0–4.6. Cysteic acid is eluted with 0.2 M acetate buffer at pH 5.5–5.9. With this method quantitative separation of synthetic mixtures of the acidic amino acids has been achieved. This method has also been used to determine the dicarboxylic amino acids in acid hydrolyzates of various proteins, of normal protein-free plasma, and of normal urine.
THE ROLE OF THE SALIVARY DUCT SYSTEM IN THE FORMATION OF THE SALIVA
Authors: Burgen A. S. V. , Seeman P.
Published: December 2009

A method is described for testing whether the saliva changes in composition as it passes down the secretory ducts. The use of radioactive potassium, sodium, and urea shows an exchange of these materials with the blood after secretion by the acini. Analysis of the relationships between specific activity of the isotope in the saliva and venous blood leads to the conclusion that the exchange is occurring between the saliva in the ducts and blood flowing in a capillary system surrounding the ducts. In these capillaries the blood is flowing in a direction counter to that of the saliva. A mathematical analysis of the behavior of urea in the ducts has been made. A theory of salivary secretion is presented in which the primary secretory event is the extrusion of potassium and accompanying anions into the acini. Water follows the ions passively. In the ducts the potassium is reabsorbed and only partly replaced by sodium ions diffusing in from the plasma. The potassium is recycled to the acini by the tubule portal system.
THE HYDROLYSIS OFp-ACETOXYPHENYLETHYLAMINES BY INSECT CHOLINESTERASE
Authors: Wolfe L. S. , Thorn G. D.
Published: December 2009

The synthesis of the acetyl derivatives of tyramine and hordenine is described. The O-monoacetyl derivatives are hydrolyzed at significant rates by bovine erythrocyte cholinesterase, human serum, and fly head cholinesterase despite a nitrogen to carbonyl oxygen separation approximately twice that of acetylcholine. The pS-activity relationships, when O-acetyltyramine and acetylcholine were substrates for fly head cholinesterase, were similar, but the hydrolysis rate of O-acetyltyramine was much higher than that of acetylcholine. N-Acetylation of the O-acetyl compounds reduced the hydrolysis rate. None of the cholinesterases removed the acetyl group attached to nitrogen. The pI-activity relationships with the inhibitors Nu-683, Nu-1250, TEPP, and eserine showed that the hydrolysis of p-acetoxyphenylethylamine derivatives and acetylcholine by fly head preparations was accomplished by the same cholinesterase and not by aromatic or aliesterases. O-Acetylation of hordenine methiodide destroyed its nicotinelike action on frog rectus abdominis muscle.
PREPARATION AND MOLECULAR WEIGHT OF γ-LIVETIN FROM EGG YOLK
Authors: Martin W. G. , Cook W. H.
Published: December 2009

A 20% solution of egg yolk in ammonium sulphate at 16% of saturation was centrifuged to float the low density components and the γ-livetin was then precipitated from the subnatant with ammonium sulphate at 40% of saturation. The precipitate was dissolved and reprecipitated several times with ammonium sulphate at 34% of saturation before ether extraction. γ-Livetin prepared in this way contained only a small amount of a heavier component. On purification γ-livetin has the solubility behavior of a euglobulin but loses its solubility irreversibly on prolonged dialysis against water or on freeze-drying. It can be preserved for reasonable periods as a precipitate in saturated ammonium sulphate solution. γ-Livetin has an anomalous sedimentation behavior, the sedimentation rate increasing sharply over a short range of protein concentration. A molecular weight of 1.5 × 105and an axial ratio of about 8 were obtained from sedimentation and diffusion measurements. Other methods gave higher values but are considered less reliable.
POLYGLYCERYLPHOSPHORIC ACIDS: I. SYNTHESIS OF BIS(L-α-GLYCERYL) PHOSPHORIC ACID
Authors: Baer Erich , Buchnea Dmytro
Published: December 2009

Bis(L-α-glyceryl) phosphoric acid has been prepared by synthesis. It was obtained by phosphorylating D-acetone glycerol with phenylphosphoryl dichloride in the presence of pyridine, and freeing the intermediate product, bis(acetone L-α-glyceryl) phosphoric acid phenyl ester, of its protective groups by catalytic hydrogenolysis and mild acid hydrolysis.
A HISTOCHEMICAL AND BIOCHEMICAL STUDY OF THE POLYSACCHARIDIC SUBSTANCES OF THE DEVELOPING NERVOUS SYSTEM OF THE RAT IN RELATION WITH THE APPEARANCE OF CHOLINESTERASE ACTIVITY
Authors: Crevier Marc
Published: December 2009

The PAS reaction and the cholinesterase reaction run parallel in the lower centers of the developing nervous system in the rat. Also, the two reactions appear progressively between the 10th and 15th day as the result of a chemical maturation of the neurons. Extraction of sections with methanol–chloroform does not alter the PAS reaction while acetylation inhibits it reversibly. These two facts suggest that 1,2-glycol groups are detected. Inhibition by hyaluronidase increases this evidence, despite the fact that diastase has a slight and irregular action. To elucidate the nature of the PAS reaction further, chemical fractionation of the brain substance has been attempted. (A) A fraction soluble in methanol–chloroform is metachromatic and PAS-positive in vitro. (B) A fraction soluble in a potassium chloride – potassium carbonate mixture is non-dialyzable, non-metachromatic, but PAS-positive. After acid hydrolysis it yields glucose but no hexosamine. (C) A fraction extracted from the residue by sodium hydroxide is non-dialyzable, non-metachromatic, but also PAS-positive. By chromatography and electrophoresis it is found to contain a non-sulphated mucoprotein yielding hexosamine in a high concentration following acid hydrolysis. The physiological significance of this mucoprotein is discussed.
THE SECRETION OF LITHIUM IN SALIVA
Authors: Burgen A. S. V.
Published: December 2009

Lithium was secreted in the saliva at a higher concentration than it was present in the plasma. The saliva/plasma ratio was independent of the plasma concentration, but inversely related to the rate of saliva secretion. No significant concentration of lithium in the gland tissue occurred.
LIBERATION OF HEXOSAMINE, HEXURONIC ACID, AND HYDROXYPROLINE FROM TISSUES BY RESIN HYDROLYSIS
Authors: Anastassiadis P. A. , Common R. H.
Published: December 2009

Excess sulphonated polystyrene resin (Dowex-50, 200–400 mesh) suspended in 0.05 N hydrochloric acid has been found suitable as a catalyst for the hydrolysis of tissue samples preparatory to the determination of hexosamine, hexuronic acid, and hydroxyproline. This technique protected hexuronic acid from destruction during hydrolysis sufficiently well to permit of its determination. The resin used in hydrolysis has been used also for separation of sugars and hexuronic acid from hexosamine and hydroxyproline by differential elution.
METABOLIC CHANGES IN TRAUMA-RESISTANT RATS FOLLOWING TRAUMA
Authors: Chytil F. , Hruza Z.
Published: December 2009

Some metabolites were followed in rats which had been made resistant to trauma by exposure to Noble–Collip drum injury. In trauma-resistant rats liver glycogen levels are 50% lower than in control animals. If trauma-resistant rats are subjected to trauma that does not kill control animals then the metabolic response during the first 2 hours after trauma, determined by measuring changes in blood glucose, pyruvic acid, amino nitrogen, urea, and total acetone bodies, differs from that of control animals only by being less pronounced quantitatively. The course of metabolic changes in trauma-resistant rats differs considerably from that of control animals between the 2nd and 24th hour after trauma, especially in the levels of acetone bodies and urea in the blood. The development of the resistance to trauma is accompanied by a change in the metabolic response to trauma.
EFFECTS OF DIFFERENT DIETARY FATS AND OF CHOLINE ON HEPATIC AND SERUM LIPIDS OF RATS
Authors: Best C. H. , Lucas C. C. , Patterson Jean M. , Ridout Jessie H.
Published: December 2009

The effects in young male rats of 10 edible oils and fats on total hepatic lipids and serum cholesterol have been compared in the presence of various amounts of dietary choline. The fats were incorporated at the 20% level in a basal hypolipotropic diet (15% protein) free from cholesterol. The diets were fed for 3 weeks. Food intake and efficiency of conversion of food to body tissue were similar with the different fats when choline was adequate; diets containing corn oil were possibly slightly less efficient. The fat-free basal ration caused heavy mortality from hemorrhagic kidney lesions. The survival rate was improved by all fats except Primex or beef fat. Coconut oil gave complete protection against renal damage.There was a negligible difference in the tendency for different fats to cause deposition of total hepatic lipids, although sunflower seed oil produced less accumulation at lower dosages of choline than did the others. The fats did differ in the extent to which they promoted deposition of cholesteryl esters.No significant differences were found in the total cholesterol of serum of rats fed the different fats. The decrease in serum cholesterol that occurs in the absence of dietary choline does not appear to be influenced by the nature of the dietary fat.
RIBONUCLEASE ACTIVITY OF FISH MUSCLE EXTRACTS
Authors: Tomlinson Neil
Published: December 2009

A ribonuclease was partially purified from muscle of lingcod (Ophiodon elongatus). The preparation degraded yeast and lingcod ribonucleic acid. Four 3′-mononucleotides were identified as digestion products. The enzyme was readily destroyed by heat and acid (10 minutes at 58 °C, pH 2.5), and was inhibited strongly by Zn++, Cu++, monoiodoacetate, formaldehyde, and NaF. Its pH optimum was 6.5. Ribonuclease activity was also demonstrated in muscle extracts from spring salmon, lemon sole, dogfish, sculpin, herring, and swordfish. The muscle extracts of all fish examined possessed phosphodiesterase activity. The ribonuclease in lingcod extract could be separated from two phosphodiesterases also present by zone electrophoresis.
PLATELET FACTOR 1 RELATED TO PROTHROMBIN ACTIVATION
Authors: Fell Colin , Seegers Walter H.
Published: December 2009

Concentrates of platelet factor 1 were made from bovine platelets. Being bound to fine particles, the activity was not obtained in solution. The activity of the concentrates is destroyed by heating at 53 °C., at pH 5.2, by extraction with ether, by drying with acetone, or by standing at −20 °C. The concentrates accelerated the clotting of whole blood, and also the activation of prothrombin either to form thrombin or a non-thrombin derivative. Activation of purified prothrombin occurred under several different circumstances, and different end products formed. Platelet factor 1 concentrates appear to have a general property of accelerating alterations in the prothrombin molecule independently of these variants.
CHEMICAL THERMOGENESIS IN THE FUNCTIONALLY EVISCERATED COLD-ACCLIMATED RAT
Authors: Depocas Florent
Published: December 2009

The effect of functional evisceration (ligation of rectal colon, superior mesenteric and coeliac arteries, and portal vein) on the rise in oxygen consumption by rats which have been acclimated at 30° and at 6 °C. and then anesthetized or curarized and exposed to 6 °C. has been examined. At 30 °C., the O2 consumption of anesthetized cold-acclimated rats was higher than that of anesthetized warm-acclimated rats, but after functional evisceration there was no significant difference between the lower levels of O2 consumption obtained in the two groups. In anesthetized warm-acclimated rats the increase in O2 consumption in the cold after evisceration was smaller than that seen after sham-operation but both increases were suppressed by injection of tubocurarine. Anesthetized cold-acclimated rats, whether eviscerated or sham-operated, gave essentially the same increase in O2 consumption when exposed to 6 °C. and injection of tubocurarine did not lower the O2 consumption to the levels observed before the cold-induced rise took place. In cold-acclimated curarized rats, functional evisceration before exposure to cold did not always prevent increases in O2 consumption but the average increase was not significant in the group. Also, functional evisceration after increase in O2 consumption had taken place in cold-acclimated curarized rats exposed to 6 °C. did not immediately lower the O2 consumption to the level observed after evisceration at 30 °C. It is concluded that the presence of the abdominal viscera is not essential for the manifestation of chemical thermogenesis in the cold-acclimated white rat.
THE DETERMINATION OF PROTEIN-BOUND IODINE
Authors: Robinson G. A. , DeLuca H. A.
Published: December 2009

A method for the determination of protein-bound iodine in plasma is described. It is based essentially on the method of Barker, Humphrey, and Soley, which makes use of the catalytic effect of iodide on the reduction of ceric ion by arsenious acid. A number of improvements have been made in the direction of ease of manipulation and an over-all saving of time.
PARTITION CHROMATOGRAPHY OF ORGANIC ACIDS: VARIATIONS IN SOLVENT COMPOSITION
Authors: Harpur R. P.
Published: December 2009

In order to facilitate the analysis of nonvolatile organic acids by partition chromatography with silica, the relation of solvent composition to the rate of movement of the acids has been investigated. It was found that with chloroform, n-amyl alcohol, and dilute sulphuric acid the logarithm of the peak volume, and hence of the partition coefficient, is proportional to the logarithm of the alcohol concentration. The spread of the zones bears a direct linear relation to the peak volume. A simple graphical method is shown for planning a suitable solvent program for any particular set of acids. Stepwise elution is more suitable than a logarithmic gradient for this type of system.
STUDIES ON HUMAN ADRENAL STEROIDS: 2. ISOLATION OF 20α-DIHYDROCORTICOSTERONE FROM THE PLASMA OF NORMAL MALES TREATED WITH CORTICOSTERONE
Authors: Southcott C. M. , Sproule V. A. , McIntosh Hamish , Darrach Marvin
Published: December 2009

Five fasting normal male humans were infused intravenously with 200 mg. of corticosterone. Blood samples were then withdrawn at various time intervals and the plasma was analyzed for individual Δ4-3-keto C21adrenal steroids. In each case 20α-dihydrocorticosterone appeared as a metabolite. The isolated corticosterone and 20α-dihydrocorticosterone were characterized chemically and quantitative plasma levels of each are reported.
BIOCHEMICAL STUDIES ON SOCKEYE SALMON DURING SPAWNING MIGRATION: IV. THE NON-PROTEIN NITROGENOUS CONSTITUENTS OF THE MUSCLE
Authors: Wood J. D.
Published: December 2009

The non-protein nitrogenous constituents of muscle of migrating sockeye salmon were investigated. These constituents were found to be the same in both male and female fish and were present in approximately the same amounts in both sexes. The histidine content of the muscle in all fish decreased to one fifth of the original value during the early stages of the migratory journey and remained at the low level thereafter. Some of the other constituents changed to a smaller extent, usually increasing in the later stages of the migration. This was especially noticeable in female fish. However, the increase in the concentration of these constituents in the muscle was due to a decrease in the amount of muscle in the fish rather than to an increase in the amounts of the compounds themselves.
THE UTILIZATION OF ETHANOL FOR BIOSYNTHESIS IN ESCHERICHIA COLI
Authors: Leon R. P. de , Creaser E. H.
Published: December 2009

Radioactivity from 1-C14-ethanol was incorporated into the macromolecular components of Escherichia coli when this organism was grown on a synthetic glucose–salts medium. No significant incorporation was observed with mammalian tissues.Incorporation was greater in E. coli cells growing anaerobically than in non-growing or aerobically growing cells. The addition of sodium fumarate increased the incorporation in anaerobically growing cells approximately threefold.Over 90% of the incorporated radioactivity was found in the lipid and protein fractions of the cell, only a small amount being detectable in the nucleic acid fraction. The distribution of radioactivity among the various cell components was such that it appeared that ethanol was utilized by the same biosynthetic pathways as acetate. No evidence could be found to support the view that ethanol carbon was incorporated into deoxyribose of the deoxyribose nucleic acid (DNA) via acetaldehyde.
OBSERVATIONS ON THE UPTAKE OF RADIOSULPHATE BY THE GASTRIC TISSUE AND GASTRIC SECRETION IN HISTAMINE-TREATED GUINEA PIGS
Authors: Kowalewski K. , Williams H. T. G.
Published: December 2009

The effect of histamine on the uptake of radiosulphate by gastric tissue and gastric juice in guinea pigs was investigated. Radioactivity was recorded 4 hours after the administration of S35-labelled sulphate to normal controls and to histamine-treated animals.The radioactivity of fractions considered to contain sulphated mucopolysaccharides was also investigated.The uptake of radiosulphate by gastric tissue and juice was significantly higher in histamine-treated animals than in control guinea pigs.The S35 uptake by gastric sulphomucopolysaccharides was considered to represent the concentration of isotope by mucous cells and its secretion. This selective uptake was also markedly effected by histamine.Histamine may be a stimulant of the gastric mucous cells under the experimental conditions described.
AN AUSCULTATORY TECHNIQUE FOR MEASURING THE DIGITAL BLOOD PRESSURE
Authors: Gaskell P. , Krisman A. M.
Published: December 2009

The digital systolic and diastolic blood pressures in human subjects were estimated by means of an auscultatory technique similar to the clinical auscultatory method of measuring brachial blood pressure. The stethoscope was modified by substituting a digital plethysmograph (into which the finger was sealed) for the usual diaphragm. Korotkoff sounds were heard through the stethoscope as a pneumatic cuff around the base of the finger was deflated from a suprasystolic level. In comparison of this method with the plethysmographic method of measuring digital systolic pressure and with a method involving direct observation of resumption of blood flow in capillary loops of the nailfold as an end point when a cuff on the finger was deflated from a supra-systolic level, it was found that the first sound is as reliable an index of systolic pressure as those used in the other methods.
MESENTERIC NEUTRAL FAT IN OBESE RATS
Authors: Boyd Eldon M. , Crandell Eleanor M.
Published: December 2009

The relationship of increasing obesity to storage of neutral fat in the mesentery was investigated in 48 albino rats. Calculated as grams per 100 g nonlipid dry weight, levels of mesenteric neutral fat were positively correlated with levels of mesenteric free cholesterol, phospholipid, and water, the correlation coefficient for water being higher in male than in female rats. These results suggest that storage of neutral fat is an active physiologic function of mesentery. On the other hand, the relative amount of body neutral fat which is stored in the mesentery became less as the animals became more obese. This indicates that in obese rats, some tissue other than mesentery is storing neutral fat at a rate greater than occurs in the mesenteric fat depots.
MOLECULAR WEIGHT AND PHYSICAL PROPERTIES OF A LIPOPROTEIN FROM THE FLOATING FRACTION OF EGG YOLK
Authors: Turner K. J. , Cook W. H.
Published: December 2009

Ether extraction removes 80% of the floating fraction of egg yolk from its solution in 2.5% sodium chloride. On removal of the ether and dialysis against specific solvents two thirds of the remaining lipoprotein (40% lipid) precipitates, leaving a soluble fraction containing 50% lipid. The soluble and insoluble portions probably represent different levels of degradation rather than different lipoproteins since both materials are apparently derived by ether extraction from a natural entity of much higher lipid content. The soluble fraction is heterogeneous and has mean molecular weights of M w = 5.4 × 105by light-scattering methods, and M n = 3.4 × 105by osmotic pressure. A "light" fraction obtained by centrifuging and representing 38% of the soluble material had M w = 3.4 to 3.5 × 105. Heterogeneity in lipid content appears to be responsible for the low molecular weight (M w = 2.4 × 105) obtained by sedimentation.
ACTIVATION OF FACTOR VII BY ASBESTOS IN BEEF PLASMA AND SERUM
Authors: Israels L. G. , Friesen E. , Sinclair C.
Published: December 2009

The adsorption of beef plasma on asbestos markedly shortens the one-stage prothrombin time of the plasma when tissue thromboplastin is used as the throm boplastic agent. This adsorption on asbestos does not affect the Russell viper venom time of the plasma. The adsorbed plasma exhibits increased factor VII activity over that of the original plasma. An eluate can be prepared from the asbestos which prolongs the one-stage prothrombin time sof beef and human plasma.
THE ELECTRICAL PROPERTIES OF THE SMOOTH MUSCLE CELL MEMBRANE
Authors: Daniel E. E. , Singh H.
Published: December 2009

In myometrium from pregnant cat, repetitive action potentials have been recorded during contraction. Using intracellular electrodes the depolarizations averaged 35 mv. Maximum rate of depolarization was 1–2 v/sec and the action potential duration varied from 250 milliseconds to much longer periods. Membrane reversal of up to 10 mv sometimes occurred. Total resistance decreased during depolarization and recovered during repolarization. Typical biphasic potentials were also recorded with extracellular electrodes. Their amplitude (peak to peak) varied from 0.3 to several millivolts and their duration (peak to peak) from 10–40 milliseconds. Reduction of external sodium concentration to as little as one-ninth normal (choline chloride or sucrose replacement) did not reduce the amplitudes of the resting or action potentials measured intracellularly or extracellularly, but decreased the action potential frequency. Membrane reversal still occurred with intracellular electrodes and the maximum rate of depolarization was unchanged. The rate of repolarization was increased so that the total duration of the action potential was 150 to 200 milliseconds. With extracellular electrodes, the peak to peak amplitudes were increased and the durations were unchanged. Further reduction of external sodium concentration to less than 15–20 meq/liter caused a contraction without further change in action potential configuration. Gradual relaxation and slowing of the repetition rate of action potentials occurred and resulted eventually in complete mechanical and electrical inactivity.Rabbit taenia coli were also studied and their electrical properties contrasted to those of cat myometrium. The conclusions were reached that: (1) the available evidence opposes the hypotheses that an inward sodium current accounts for depolarization in smooth muscle and (2) smooth muscles differed in their electrical properties and mechanisms of ion distribution not only from striate muscles but also from one another.
EFFECT OF POSTERIOR PITUITARY EXTRACT ON THE DEVELOPMENT OF POSTHISTAMINIC GASTRIC ULCERS IN DOGS
Authors: Kowalewski K. , Lyon R. K. , Edwards G. E. , Shnitka T. K.
Published: December 2009

Prolonged treatment of dogs with histamine resulted in acute and chronic ulceration in Heidenhain gastric pouches in all animals under investigation. Only 16% of dogs given histamine and pitressin developed chronic mucosal lesions in pouches. Gastric acidity and secretion were high and of comparable magnitude in both groups of dogs.These findings suggest that the vascular component of the gastric response to histamine is more important than the secretory component in the etiology of histamine ulcers.Detailed gross and microscopical study of mucosal lesions was performed.
ACTION OF ANTIHISTAMINES AND TRANQUILIZERS ON THE CONVERSION OF FIBRINOGEN TO FIBRIN
Authors: Kátó László , Gözsy Béla
Published: December 2009

Antihistamines and tranquilizers with antihistaminic effect interfere in vitro with the conversion of fibrinogen to fibrin in the presence of thrombin. Clot opacity measurements of such systems show that the presence of moderate amounts of these reagents permits the formation of polymers, which exhibit low opacity at the time of clotting and are characterized as "fine clot". The reagent, which prolonged clotting time, also produced gels of high rigidity and slight tendency to syneresis. Evidence is presented to show that the compounds act upon fibrinogen rather than on thrombin and that the effects are reversible. The effects are assumed to be the results of interference with van der Waals' forces.
THE SIGNIFICANCE OF THE NUMBER OF PRECIPITIN BANDS IN AGAR GEL MEDIUM FOR THE DETERMINATION OF THE COMPLEXITY OF ANTIGENS
Authors: Richter M. , Rose B. , Sehon A. H.
Published: December 2009

A new interpretation is presented to account for inconsistancies which may arise when comparing data obtained with antibody–antigen systems in agar and in liquid media. For a model system, different haptens (p-aminobenzoic acid and p-sulphanilic acid) coupled to proteins were used. It has been demonstrated that the number of precipitin bands formed in agar medium by these antibody–antigen systems may be smaller than the number of optimal proportion zones detected for these systems in liquid medium, provided the different haptens are coupled to the same carrier. This effect is not due to a lesser sensitivity of the reaction in agar but rather to the inherent limitations of this method. Thus, by the agar technique, not more than one antigenic moiety (present on a molecule) is detected, whereas by the precipitin test in liquid medium optimal proportion zones with respect to each of the antigenic moieties (on the molecule) may be detected. This limitation in agar is not considered to detract from the value of the agar gel technique when it is used for the detection of independent antigens.
A RAPID METHOD FOR THE LARGE SCALE PREPARATION OF CALF THYMUS DEOXYRIBONUCLEATE
Authors: Hurst R. O.
Published: December 2009

Isolation of deoxyribonucleate from a concentrated solution of thymonucleoprotein has been achieved by disruption of the protein nucleate bond with potassium thiocyanate, adsorption of the protein on celite, and alcohol precipitation of the deoxyribonucleate from aqueous salt solution. Highly polymerized nucleate can be obtained readily from 1 lb of calf thymus tissue in high yield.
STUDIES ON A LIPOXIDASE SYSTEM FROM SUNFLOWER SEEDS AND SEEDLINGS
Authors: Gamborg Oluf L. , Zalik Saul
Published: December 2009

Lipoxidase activity was obtained in enzyme preparations from sunflower seeds and seedlings. A partly purified preparation from seedlings was used for enzyme kinetic studies. The pH optimum was 6.8 and 100% oxygen was required for maximum activity. The Michaelis constant, with potassium linoleate as substrate, was 1.64 × 10−3 M. The reaction products were conjugated dienes. Enzyme activity was not affected by various metal and sulphydryl inhibitors nor by α-tocopherol, but catechol, α-naphthol, ethanol, and potassium oleate were inhibitory. Oil from flax, rape, and sunflower seeds reduced total oxidation of linoleate by the enzyme. Copper sulphate increased the rate and total oxidation of the linoleate–lipoxidase system, but iron, manganese, magnesium, and calcium were without effect. Lipoxidase activity was associated with mitochondrial (15,000 × g), intermediate (25,000 × g), and microsomal (100,000 × g) fractions, as well as with the soluble cytoplasmic proteins. Lipoxidase activity in seedlings increased during initial stages of germination, then decreased. The most rapid depletion of total fat in the seedlings coincided with maximum lipoxidase activity.
NITROGEN EXCRETION IN SOME MARINE TELEOSTS
Authors: Wood J. D.
Published: December 2009

The nitrogen-containing compounds excreted by the sculpin, starry flounder, and blue sea-perch were investigated. Approximately four-fifths of the nitrogenous material was excreted via the gills. Ammonia and urea were the main components of the excreta in all three species. The amount excreted in 24 hours varied greatly between fish of any one species, but the percentage composition was reasonably constant. A greater variation in the composition occurred between species. Trimethylamine oxide was present in only small amounts in the total excreta. It was concluded from this that the compound was not an important end product of protein metabolism.
REACTION OF THE THYMUS TO TRAUMA IN DRUM-RESISTANT RATS
Authors: Hruza Z. , Chytil F.
Published: December 2009

The reaction of the adrenals and thymus to trauma in a Noble–Collip drum was studied in control rats and in rats that had developed trauma-resistance by increasing traumatization in this drum. Although the reaction of the adrenals is the same in both groups as determined by the ascorbic acid and cholesterol content, the thymus decreases in weight only in control animals exposed to trauma for the first time. Thymus regresses in trauma-resistant rats only after a mortal dose of trauma. Trauma-resistant rats have heavier adrenal glands than control animals. This difference is more expressed in males than in females. Catabolic doses of cortisone cause a lesser loss in thymus weight in resistant animals than in control rats. After sterile abscess, the loss of thymus weight was only slightly smaller in trauma-resistant rats.
THE ELECTROPHORETIC ANALYSIS OF PLANT VIRUS PREPARATIONS
Authors: Townsley P. M.
Published: December 2009

Zone electrophoresis in agar gel has been used for separating tobacco mosaic virus and potato virus X from crude plant extracts and reaction mixtures. The viruses were located within the gel by autoradiographic, serological, and protein-staining methods.
EFFECTS OF CONTRACTILE STIMULI ON EXCHANGES OF ELECTROLYTES BETWEEN UTERINE TISSUES AND A SALINE–BICARBONATE MEDIUM
Authors: Daniel Edwin E. , Daniel Betty N.
Published: December 2009

(1) Evidence has been presented suggesting that progesterone pretreatment in vivo increases the rate of leakage of potassium from rabbit uterine segments into a saline–bicarbonate medium.(2) Various types of evidence indicate that in uterine tissues, the loss of potassium from cells into potassium-free solutions is increased during the contractile actions of drugs. There was no clear-cut concomitant increase in tissue sodium concentrations. The results tend to confirm previous findings indicating that increases in potassium (but not in sodium) permeability are associated with contraction of smooth muscle.(3) Epinephrine effects on potassium loss occurred only in uteri which contracted in response to epinephrine. Norepinephrine, but not iproterenol, had a similar effect. Dibenamine, alone, decreased potassium loss and partly blocked the effects of epinephrine. Direct measurement of glycogen content suggested that these findings were not related to a glycogenolytic action of the epinephrine. Rather, the effect of epinephrine to increase potassium loss seemed to be closely related to its contractile action. In long-term experiments, both epinephrine and calcium slowed the rate of K loss and of water and sodium gain. This effect also was absent in uterine tissues which were not contracted by epinephrine.
THE DETERMINATION OF CALCIUM AND MAGNESIUM IN BLOOD USING ONE INDICATOR
Authors: Robinson H. M. Czajkowska , Rathbun J. C.
Published: December 2009

A rapid ethylenediaminetetraacetic acid titration for calcium and magnesium in serum requiring 0.1 ml of blood is described. Eriochrome black T is used as the sole indicator and the end point is observed photometrically. After determination of total calcium and magnesium, the calcium is removed as oxalate, the magnesium determined separately, and the calcium obtained by difference. The method is highly reproducible and is sensitive to ± 0.1 mg% of either calcium or magnesium.
THE DESTRUCTION OF O,O-DIETHYL-S-2-DIETHYLAMINOETHYL PHOSPHOROTHIOLATE BY LIVER MICROSOMES
Authors: Scaife J. F. , Campbell D. H.
Published: December 2009

Liver homogenates prepared from the rat, rabbit, mouse, and guinea pig possess an enzyme system capable of destroying O,O-diethyl-S-2-diethylaminoethyl phosphorothiolate at the rate of 150 to 200 μg/hr/g of fresh tissue. The homogenates prepared from the pig, dog, cow, and frog destroyed this compound at a rate of 50 to 100 μg/hr/g, but those prepared from man and the cat possessed negligible activity. Rat plasma, brain, kidney, diaphragm, whole gut, and spleen also possessed little or no activity. This enzyme system is located in the microsomes, disruption of which is accompanied by loss of enzymatic activity. The activity is dependent upon oxygen, inorganic phosphate, and diphosphopyridine nucleotide. Inhibitor studies indicate that enzymic SH-groups are necessary. The enzyme has no action on diisopropyl phosphorofluoridate, isosystox, or tetraethyl pyrophosphate, although these compounds are rapidly destroyed by the liver.
STRUCTURAL STUDIES ON CLINICAL DEXTRANS: PART 1. METHYLATION AND PERIODATE OXIDATION STUDIES
Authors: Jones J. K. N. , Wilkie K. C. B.
Published: December 2009

Determinations have been made of the structures of four clinical dextrans, i.e. partially depolymerized dextrans which, in solution, are used as blood-volume expanders. By methylation studies, the major fractions of the dextrans have been shown to consist of chains of α 1 → 6 linked glucopyranose residues about 1 in every 9.5 – 11 of which also have branch points at C3. Two of the dextrans are probably also branched to a minor extent on C4. Periodate oxidation studies are reported on the clinical dextrans and on fractions obtained by ultrafiltration.
METABOLISM OF PHENYLPROPANOID COMPOUNDS IN SALVIA: II. BIOSYNTHESIS OF PHENOLIC CINNAMIC ACIDS
Authors: McCalla D. R. , Neish A. C.
Published: December 2009

p-Coumaric, caffeic, ferulic, and sinapic acids were found to occur in Salvia splendens Sello in alkali-labile compounds of unknown constitution. A number of C14-labelled compounds were administered to leafy cuttings of salvia and these phenolic acids were isolated after a metabolic period of several hours and their specific activities measured. Cinnamic acid, dihydrocinnamic acid, L-phenylalanine, and (−)-phenyllactic acid were found to be good precursors of the phenolic acids. D-Phenylalanine, L-tyrosine, and (+)-phenyllactic acid were poor precursors. A kinetic study of the formation of the phenolic acids from L-phenylalanine-C14gave data consistent with the view that p-coumaric acid → caffeic acid → ferulic acid → sinapic acid, and that these compounds can act as intermediates in lignification. Feeding of C14-labelled members of this series showed that salvia could convert any one to a more complex member of the series but not so readily to a simpler member. Caffeic acid-β-C14was obtained from salvia after the feeding of L-phenylalanine-β-C14or cinnamic acid-β-C14, and caffeic acid labelled only in the ring was obtained after feeding generally labelled shikimic acid.
THE EFFECTS OF SARIN AND ATROPINE ON THE RESPIRATORY CENTER AND NEUROMUSCULAR JUNCTIONS OF THE RAT
Authors: Stewart W. C.
Published: December 2009

Records were made of the contractions of a slip of diaphragm muscle which was isolated from the circulation of the rat, while the nerve supply was preserved. Simultaneous records were also made of the contractions of the opposite (circulated) hemidiaphragm, of respiratory rate, of the Hering-Breuer reflex, and of contractions of the gastrocnemius muscle in response to stimulation of the sciatic nerve.Low doses of sarin caused immediate respiratory arrest, purely central in origin; respiration was restored to normal at once when a large dose of atropine was given. When atropine was injected before sarin, much higher doses of sarin were required to depress the respiration, and now the respiratory paralysis took place at the neuromuscular junctions in the diaphragm, the respiratory center remaining relatively unaffected. It was concluded that respiratory paralysis by sarin could be purely central, purely peripheral, or both central and peripheral, depending on the doses of sarin and atropine employed.
EVALUATION OF PROTEIN IN FOODS: 1. A METHOD FOR THE DETERMINATION OF PROTEIN EFFICIENCY RATIOS
Authors: Chapman D. G. , Castillo Raul , Campbell J. A.
Published: December 2009

A bioassay procedure for the evaluation of the nutritional quality of the protein in foods is described. This method involves measurement of the protein efficiency ratio (grams gain per gram protein consumed) under standardized conditions. Male rats of the Wistar strain 20–23 days of age are fed ad libitum an otherwise adequate reference diet containing 10% protein supplied by a standard sample of casein. Foods to be assayed are added to the diet as the sole source of protein at the expense of the casein and corn starch to maintain a protein level of 10%. Protein efficiency ratios (P.E.R.'s) are calculated after 4 weeks and are adjusted to a constant value of 2.5 for casein. Although influenced by the age of rat and subject to certain inherent criticisms, determination of P.E.R. values was found to be a simpler method for evaluating protein quality than determination of net protein retention or net protein utilization and equally sensitive.