bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE RELATION OF EXERCISE TO BUBBLE FORMATION IN ANIMALS DECOMPRESSED TO SEA LEVEL FROM HIGH BAROMETRIC PRESSURES
Authors: Harris Morgan , Berg W. E. , Whitaker D. M. , Twitty V. C. 
Published: May 2004

1. Bullfrogs (Rana catesbiana) and rats have been subjected to high barometric pressures and studied for bubble formation on subsequent decompression to sea level. Pressures varying from 3 to 60 pounds per square inch, in excess of atmospheric pressure, were used.
2. Muscular activity after decompression is necessary for bubble formation in bullfrogs after pressure treatment throughout the above range. Anesthetized frogs remained bubble-free following decompression. Rats compressed at 15 to 45 pounds per square inch likewise did not contain bubbles unless exercised on return to sea level.
3. Bubbles form without voluntary muscular activity in anesthetized rats previously subjected to pressure of 60 pounds per square inch. Small movements involved in breathing and other vital activities are believed sufficient to initiate bubbles in the presence of very high supersaturations of N2.
4. Bubbles appear (with exercise) in rats previously compressed at 15 pounds per square inch, and in bullfrogs subjected to pressure at levels as low as 3 pounds per square inch above atmospheric pressure. The percentage drop in pressure necessary for bubble formation is less in compressed animals than in those decompressed from sea level to simulated altitudes.
5. The action of exercise on bubble formation in compressed frogs and rats is attributed to mechanical factors associated with muscular activity, combined with the high supersaturation of N2. CO2 probably is not greatly involved, since its concentration does not reach supersatuation, as it does at high altitude.
6. Anoxia following decompression from high barometric pressures has no observable facilitating effect on bubble formation.
STREPTOCOCCAL FIBRINOLYSIS: A PROTEOLYTIC REACTION DUE TO A SERUM ENZYME ACTIVATED BY STREPTOCOCCAL FIBRINOLYSIN
Authors: Christensen L. R. 
Published: May 2004

1. Methods for the preparation and partial purification of streptococcal fibrinolysin are described.
2. The lysis of fibrin clots in the presence of streptococcal fibrinolysin is associated with proteolysis of the fibrin. Digestion is due to an enzyme normally present in serum or plasma in an inactive state, which is activated by fibrinolysin. Fibrinolysin alone has no demonstrable proteolytic activity.
3. The lysin factor-fibrinolysin system brings about proteolysis of other proteins such as gelatin or casein, in addition to fibrin and fibrinogen.
4. It is suggested that lysin factor exists in serum or plasma as a zymogen, and that it is activated by fibrinolysin, a kinase, in a manner similar to the activation of trypsinogen by enterokinase or the mold kinase of Kunitz (1938).
THE EFFECT OF PENICILLIN ON EGGS OF THE SEA URCHIN, ARBACIA PUNCTULATA
Authors: Henry Richard J. , Henry Maryon D. 
Published: May 2004

1. Penicillin in the range of concentration from 250 U/ml. to approximately 2650 U/ml. inhibits the rate of cell division of the fertilized sea urchin egg from 0 to 100 per cent.
2. Penicillin in the same range of concentrations has no effect on the oxygen consumption of the unfertilized or the fertilized eggs.
3. Penicillin is bound by some component of the sea urchin egg in amounts sufficiently large to lower the initial concentration, this binding apparently not being related to the inhibitory action.
THE EFFECT OF PENICILLIN ON METHYLENE BLUE ADSORPTION ONTO ACTIVATED CHARCOAL
Authors: Henry Richard J. , Henry Maryon D. 
Published: May 2004

Penicillin inhibits the adsorption of methylene blue onto activated charcoal in concentrations as low as 100 units/ml.
Penicillin in the low inhibitory concentration of 100 units/ml, antagonizes to a small extent the strong inhibition of MB adsorption by 0.1, 0.2, and 1 per cent peptone.
IMMUNOCHEMICAL PROPERTIES OF NATIVE AND DENATURED HORSE SERUM GLOBULINS
Authors: Erickson John O. , Neurath Hans 
Published: May 2004

1. The influence of guanidine hydrochloride on the denaturation and regeneration of Type I antipneumococcal horse serum globulin was determined by measurements of viscosity, diffusion, and sedimentation in the ultracentrifuge. In addition, the effect of NaCNS on the antibody globulin was studied.
2. Both the irreversibly denatured and the regenerated fractions were found to be precipitable by SI. The observed changes in combining ratio have been tentatively explained in terms of (a) changes in the mean molecular weight, or alternatively (b) an increase in the number of serologically active groups upon denaturation, followed by masking of the latter upon regeneration. Discounting a specific effect of NaCNS on either fraction, the extent of specific precipitation is of the same order of magnitude for native and irreversibly denatured antibody.
3. Quantitative precipitin titrations have been performed on rabbit antisera to native and irreversibly denatured horse antibody, and normal globulin GI, respectively. No significant differences in the antigenic activity of these proteins were found. Measurements of their cross-reactivity led to the conclusion that the native and irreversibly denatured fractions of antibody globulin are antigenically more closely related to each other than to the corresponding fractions of normal globulin, and vice versa.
ANOXIA AND BRIGHTNESS DISCRIMINATION
Authors: Hecht Selig , Hendley Charles D. , Frank Sylvia R. , Haig Charles 
Published: May 2004

1. Brightness discrimination has been studied with individuals breathing oxygen concentrations corresponding to 7 altitudes between sea level and 17,000 feet. The brightnesses were 0.1, 0.01, and 0.001 millilambert involving only daylight (cone) vision.
2. At these light intensities, brightness discrimination begins to deteriorate at fairly low altitudes. The deterioration is obvious at 8,000 feet, and becomes marked at 15,000 feet, where at low brightness, the contrast must be increased 100 per cent over the sea level value before it can be recognized.
3. The impairment of brightness discrimination with increase in altitude is greater at higher altitudes than at lower. The impairment starts slowly and becomes increasingly rapid the higher the altitude.
4. Impairment of brightness discrimination varies inversely with the light intensity. It is most evident under the lowest light intensities studied, but shows in all of them. However, it decreases in such a way that the deterioration is negligible in full daylight and sunlight.
5. The thresholds of night (rod) vision and day (cone) vision are equally affected by anoxia.
6. The quantitative form of the relation between brightness discrimination ΔI/I and the prevailing brightness I remains the same at all oxygen concentrations. The curve merely shifts along the log I axis, and the extent of the shift indicates the visual deterioration.
7. The data are described in terms of retinal chemistry. Since anoxia causes only a shift in log I it is shown that the photochemical receptor system cannot be affected. Instead the conversion of photochemical change into visual function is impaired in such a way that the conversion factor varies as the fourth power of the arterial oxygen saturation.
CRYSTALLINE HEXOKINASE (HETEROPHOSPHATESE)
Authors: Kunitz M. , McDonald Margaret R. 
Published: May 2004

1. Crystalline hexokinase has been isolated from baker's yeast.
2. Crystalline hexokinase is a protein of albumin type of a molecular weight of 96,000. Its isoelectric point is at about pH 4.8.
3. The method of isolation consists in separating the proteins of an aqueous extract of toluene-treated yeast by means of fractional precipitation with ammonium sulfate and with alcohol.
4. The procedure involves also the separation of several crystalline proteins, including one yellow crystalline protein, which do not possess hexokinase activity. The biological and the physicochemical properties of these proteins are still under investigation.
5. The crystallization of hexokinase proceeds at about 5°C. in the presence of ammonium sulfate and dilute phosphate buffer pH 7.0.
6. Crystalline hexokinase becomes relatively pure after 2 or 3 recrystallizations as tested by solubility, sedimentation in the ultracentrifuge, and electrophoresis. The enzymatic activity remains constant on repeated crystallization.
7. The enzymatic activity is associated with the protein nature of the material. Inactivation is accompanied by denaturation of the protein.
8. Crystalline hexokinase is relatively stable when stored in the form of crystalline filter cake. Solutions of hexokinase in dilute buffers are most stable at pH 5.0.
9. Crystalline hexokinase requires the presence of magnesium ions for its catalytic activity.
THE PORPHYRIN REQUIREMENTS OF HAEMOPHILUS INFLUENZAE AND SOME FUNCTIONS OF THE VINYL AND PROPIONIC ACID SIDE CHAINS OF HEME
Authors: Granick S. , Gilder H. 
Published: May 2004

1. Iron protoporphyrin IX was required for the growth of H. influenzae. It could be replaced by protoporphyrin IX. When grown on protoporphyrin evidence was obtained for the presence of Fe porphyrin in the organism. It was concluded that the organism could insert iron into the protoporphyrin ring.
2. In the smooth strains, other porphyrins containing no iron such as deutero-, hemato-, meso-, and coproporphyrins could not replace protoporphyrin for growth. Since protoporphyrin has two vinyl groups which other porphyrins lack, it was concluded that the two vinyl groups were essential for growth.
3. When porphyrins lacking vinyl groups were converted chemically into iron porphyrins and then supplied to the organisms it was found that these iron porphyrins supported growth. It was concluded that the "smooth" organisms were able to insert iron only into the porphyrin containing the vinyl groups; i.e., protoporphyrin. One function of the vinyl groups then was to permit iron to be inserted biologically into the porphyrin ring.
4. An anomalous behavior in the rough Turner strain was observed and discussed. This organism was able to insert iron into mesoporphyrin at low concentrations but was inhibited by this compound at higher concentrations. In all other reactions with the porphyrins this rough strain behaved in the same was as did the smooth strains.
5. All strains which were grown on iron porphyrins lacking vinyl groups could not reduce nitrate to nitrite. When grown on protoporphyrin or Fe protoporphyrin reduction of nitrate occurred. It was concluded that the nitrate-reducing mechanism required the presence of the vinyl groups either for its formation or function.
6. The porphyrins lacking iron and lacking vinyl groups inhibited the growth of H. influenzae on Fe protoporphyrin. The inhibition between a porphyrin and Fe protoporphyrin was a competitive one. It was suggested that the porphyrin inhibited the growth-promoting properties of Fe protoporphyrin by attaching on to a particular apoprotein, thus preventing the formation of a heme catalyst. Likewise, competition between two growth-promoting Fe porphyrins for apoenzymes could be shown to occur.
7. Protoporphyrin and Fe protoporphyrin supported growth. When their propionic acid side chains were esterified they no longer supported growth. It was suggested that the esterified carboxyl groups could not attach to the specific apoproteins to form the heme enzymes and so could not act to support growth. For the same reason the inhibitory action of porphyrins lacking vinyl groups could be prevented by esterifying their propionic acid groups.
CHROMOSIN, A DESOXYRIBOSE NUCLEOPROTEIN COMPLEX OF THE CELL NUCLEUS
Authors: Mirsky A. E. , Pollister A. W. 
Published: May 2004

A desoxyribose nucleoprotein complex, which we have referred to as a chromosin, has been prepared from a great variety of cells, mainly animal but also plant and bacterial. A chromosin is derived from the cell nucleus. In the course of preparation precautions have been taken to prevent contamination by cytoplasmic constituents. To assure the nuclear origin of all components of chromosin, nuclei have in several instances been isolated before extraction was begun. Because of the precautions taken, chromosins do not contain detectable quantities of ribose nucleoproteins; but, incidentally, extraction of ribose nucleoproteins, free of desoxyribose compounds, has also been described in this paper.
A typical chromosin contains 3 components: desoxyribose nucleic acid, histone, and non-histone protein. The nucleic acid, being highly polymerized, is exceedingly viscous when dissolved and fibrous when precipitated. Histone and non-histone protein differ from each other in a number of ways, of which one of the most definite is that whereas a histone contains no more than traces of tryptophane, the non-histone protein of chromosin contains nearly 1 per cent of tryptophane. In neutral physiological saline both proteins can combine with nucleic acid. With the isolation of chromosins from so many different kinds of cells, it can now be seen that (contrary to the view expressed by Kossel) histones are present in most animal cells and at least in some plant and bacterial cells.
Chromosin prepared from the Type III pneumococcus is active in transforming the type of a pneumococcus culture. It has been pointed out that it is not yet known whether or not protein is a necessary constituent of the transforming agent.
To extract chromosin from a cell M NaCl is used. When dissolved in M NaCl the nucleic acid and histone components of a chromosin are to a considerable extent dissociated. They are not dissociated when the chromosin is dissolved in 0.02 M NaCl, but in this medium a partial depolymerization of the nucleic acid occurs.
A chromosin should certainly not be considered to be a definite chemical compound. It is a complex extracted from chromatin, which is itself a complicated nuclear structure. And in the course of extraction, it need hardly be said, the structure of chromatin has been considerably changed. To avoid complications it has been considered an advantage in this work to begin with isolated nuclei, and it would clearly be a further simplification to begin chemical procedures only after the chromosomes themselves have been isolated. This is now being accomplished, and it is found that the methods described in this paper are of value in learning how the substances present in a chromosin are put together in a chromosome.
THE ACTIVATION OF PLASMINOGEN BY CHLOROFORM
Authors: Christensen L. R. 
Published: May 2004

1. Treatment of serum with chloroform results in immediate inactivation of the protease inhibitor present.
2. Following a lag period of less than one to several days, proteolytic activity begins to appear in the chloroform-treated serum. Activity increases over a period of several days and then begins to diminish gradually. At about the time when the spontaneous activity begins to diminish, the total proteolytic activity of the preparation also begins to fall until finally the two curves coincide.
3. Chloroform treatment of serum appears to result in some destruction of plasminogen because not only is the total proteolytic activity of the chloroform-treated serum less than that of the serum before chloroform treatment, but the maximum spontaneous activity that develops is only about one-half the total proteolytic activity of serum before treatment with chloroform.
4. The spontaneous activation of plasminogen which occurs following removal of inhibitor appears to be autocatalytic in nature.
5. In the presence of active plasmin, both plasmin and plasminogen are destroyed.
SALTANT PRODUCTION BY WAVE LENGTHS OF VISIBLE AND LONG ULTRAVIOLET MONOCHROMATIC IRRADIATION, AND A COMPARISON WITH SALTANTS PRODUCED BY SHORT WAVE LENGTHS OF MONOCHROMATIC ULTRAVIOLET IRRADIATION IN THE FUNGUS CHAETOMIUM GLOBOSUM
Authors: Ford Joan Munro 
Published: May 2004

1. Saltants have been produced in the fungus Chaetomium globosum by longer wave lengths than previously reported—by 365 mµ and by a visible line 404 mµ.
2. Absence at these wave lengths of the K saltant, which is so abundant at short wave lengths, is marked.
3. Ratio of percentage irradiated spores germinating to control spores germinating decreases from 83 per cent at 265 mµ, a short ultraviolet wave length, to 57 per cent at 404 mµ, a visible violet wave length.
THE OXYGEN CONSUMPTION ASSOCIATED WITH GROWTH IN ESCHERICHIA COLI AND THE EFFECT OF SULFATHIAZOLE AND OF n-PROPYL CARBAMATE ON IT
Authors: Armstrong Florence H. , Fisher Kenneth C. 
Published: May 2004

1. The rate of oxygen consumption by E. coli has been observed both in the presence and absence of ammonia which substance is used by this organism in these experiments as the sole source of nitrogen for growth.
2. After the ammonia has been completely taken up in a culture of E. coli, the rate of oxygen consumption by the culture is observed to fall rapidly. It becomes relatively constant again at a rate approximately 45 per cent of that existing immediately prior to the exhaustion of the nitrogen source. It appears that the fixation of ammonia, that is, growth, requires approximately 55 per cent of the oxygen consumed by the growing cell.
3. Inhibition of the oxygen consumption which is associated with ammonia fixation, by both sulfathiazole (ST) and n-propyl carbamate (PC) closely parallels the inhibition of growth by these compounds (as measured by viable cell counts, etc.).
4. The concentrations of ST and PC which inhibit growth exert little or no inhibitory effect on the rate of oxygen consumption by cells after the rate has fallen to the resting value.
5. It is pointed out that the above observations would be adequately accounted for if growth depended on a discrete fraction of the total oxygen consumption of the growing cell.
6. It is noted that PC, but not ST, has a significant accelerating effect on the oxygen consumption of the resting cell; and that for a given inhibition of growth, PC produces less inhibition of the total oxygen consumption of the cells, than does ST. The latter of these two observations would follow from the former if the resting oxygen consumption were a discrete entity.
METABOLIC INTERMEDIATES IN ADAPTIVE FERMENTATION OF GALACTOSE BY YEAST
Authors: Reiner John M. 
Published: May 2004

Pyruvic acid, which is known to be an intermediate of glucose fermentation, was added to yeast during adaptation to galactose fermentation. It was found to neutralize the inhibition by sodium fluoride, and to decrease the apparent time of adaptation from 90 to about 45 or 60 minutes. In control experiments, it was shown that intact yeast is unable appreciably to ferment or decarboxylate alone, although it oxidizes the compound readily.
Experiments in which galactose and pyruvate were added at various times and in different orders were used to eliminate the possible complications of the rates at which these compounds penetrate the cells. Under these conditions, it was not possible to reduce the time of adaptation below 45 minutes. It was concluded that the rôle of added pyruvate was to serve as a source of acetaldehyde, which in turn could accept hydrogen and be reduced to alcohol. Substances, such as triose phosphate, which could serve as hydrogen donors were not produced from galactose in appreciable quantities until 45 minutes had elapsed. This time was therefore inferred to be the true adaptation time, during which the first synthesis of adaptive enzymes occurred.
Some determinations of the distribution of phosphorylated intermediates at various stages during the adaptive process were carried out. It was found that ATP, which usually serves to phosphorylate hexoses, accumulates during the preadaptive phase, diminishes rapidly after 60 minutes, and subsequently increases once more. The source of the ATP phosphate appeared to be PPA or triose phosphate initially present in the cells. It was inferred that the adaptive enzyme was concerned with the phosphorylation of galactose and the conversion of the phosphate ester to a glucose ester, which could then be fermented by the normal enzymes of the cell.
Added ATP was found to stimulate adaptation to a considerable extent, but did not shorten the time of adaptation below 75 minutes. This seemed consistent with the rôle of ATP as a phosphate donor for galactose. Creatine was found to inhibit adaptation to some degree, in agreement with its known ability to act as a competitive phosphate acceptor.
It was demonstrated that yeast produces, during and after adaptation, substances which shorten the apparent adaptation time of fresh samples of yeast. In agreement with our other findings, it appeared that such substances were not formed before about 45 minutes. They are probably not metabolic intermediates, and may be identical with the adaptive principle which can be extracted from adapted cells.
STUDIES ON THE PHYSIOLOGICAL EFFECTS OF NON-POLAR-POLAR ORGANIC ELECTROLYTES
Authors: Höber Rudolf 
Published: May 2004

1. The commonly used detergents have a poisonous effect, which is due to the non-polar-polar configuration of their organic anion. The non-polar organophilic half of the ion is built up by a long chain of alkyl radicals (8 to 18 carbon atoms), the polar hydrophilic half by a sulfonate or sulfate. If brought into contact with the organic surface membrane of a cell, this structure, due to the strong attachment of the alkyl chains to its surface, and due to the pull of the hydrophilic part towards the surrounding water, is subjected to a heavy stress terminating in tearing to pieces the membrane (by denaturing and loosening the membrane components; bacteriolysis, cytolysis). Correspondingly, with frog muscle, one end of which has been treated with the detergent solution, an irreversible negative injury potential is produced.
2. Applying, instead, the compounds bearing short chains of alkyl radicals (1 to 6 carbon atoms), producing less stress on the membrane and correspondingly a slighter derangement of its architecture, a reversible positive resting potential appears. This is interpreted to be the effect of the non-polar part of the anion, which, due to its surface activity, intrudes into the pores of the membranes, notwithstanding the negative charge of their walls.
3. The short chained detergents seem to be replaceable by various organic "semidetergents," the organophilic behavior of their anion being represented by a slight chemical affinity (NH2), the hydrophilic by the effect of a carboxyl group (COO) instead of sulfate or sulfonate. The effect of the semidetergents on muscle is a positive reversible potential. Their physiological significance may be visualized as a functional activation.
PROTAMINE PURIFICATION OF STREPTOKINASE AND EFFECT OF pH AND TEMPERATURE ON REVERSIBLE INACTIVATION
Authors: Christensen L. R. 
Published: May 2004

1. Treatment of crude concentrates of streptokinase with protamine results in removal of about 90 per cent of the nitrogenous material, including nucleic acid and protease inhibitor, with little or no loss of activity.
2. Streptokinase solutions undergo reversible inactivation with changes in pH. The rate and extent of inactivation are dependent on pH, being greatest over a very narrow range about pH 5. The rate and extent of inactivation are also a function of temperature, both increasing with the temperature of incubation. The rate of reactivation is a function of pH and temperature, increasing as either is raised. However, as the temperature is raised above about 23°C., or the pH above about 9, a secondary, irreversible inactivation of streptokinase occurs.