bluuebunny/crossref_metadata_2025_split huggingface dataset:
PROLYTIC ION EXCHANGES PRODUCED IN HUMAN RED CELLS BY METHANOL, ETHANOL, GUAIACOL, AND RESORCINOL
Authors: Ponder Eric 
Published: May 2004

When the washed red cells of heparinized human blood are exposed at 4°C. to methanol, ethanol, guaiacol, or resorcinol in hypolytic concentrations in isotonic NaCl, the prolytic loss of K at the end of 20 hours varies from about 25 per cent of the initial K content of the cells in the case of 3.1 M methanol to about 55 per cent of the initial K in the case of 0.04 M resorcinol. As in the case of the prolytic losses observed with other lysins, the K loss is rapid at first and then slows down so that what appears to be a new steady state is reached logarithmically.
The K lost from the cells during the period of the prolytic loss is replaced by an approximately equivalent amount of Na, derived from the isotonic NaCl in which the cells are suspended. The Na which enters can be replaced by K by washing the cells in isotonic KCl, and this K can again be replaced by Na by washing the cells in isotonic NaCl. The remainder of the cell K., i.e. the K which was not lost during the period of the prolytic loss, is retained in the cell unaffected by these washing procedures.
The capacity of red cells for undergoing disk-sphere transformations is scarcely affected by their having been exposed to hypolytic concentrations of methanol, ethanol, guaiacol, or resorcinol in isotonic NaCl, and their resistance to osmotic hemolysis and to lysis by saponin and digitonin is altered only in minor respects even when as much as 50 per cent of the cell K has been exchanged for Na.
Some restriction to the movement of K between the cell and its environment is apparently modified irreversibly when the cell is exposed to hypolytic concentrations of lysins, and the modification is such that only a fraction of the cell K is affected, the fraction being a function of the lysin concentration, the duration of its action, and other factors. A modification of some part of the cell structure and of the properties dependent on its integrity is probably involved: K may be lost more readily from some cells than from others, from some parts of the cell more readily than from other parts, or the explanation may lie in changes in the extent to which Hb binds ions or in modifications of metabolic processes.
THE EFFECT OF ENVIRONMENTAL POTASSIUM AND CALCIUM CONCENTRATIONS ON THE RECOVERY OF THE ACTION POTENTIAL AND RELATED FUNCTIONS OF NERVE
Authors: Graham Helen Tredway , Blair H. A. 
Published: May 2004

1. When the Ringer's solution applied to isolated frog sciatic nerve contains K+ in concentrations greater than 2 x standard, the height of the spike and of the after-potential is decreased, as is the duration of the after-potential; recovery of height and of excitability following response is delayed; degree and duration of supernormal excitability are decreased; postcathodal depression and postanodal enhancement are increased and prolonged.
2. The nerve functions just listed in general all change in the opposite direction when exposed' to increased environmental [Ca++]. (4.5–20 x standard) or decreased [K+] (0.05–0.2 x standard). The effects of decreased [Ca++] (0.20–0.25 x standard) are indeterminate.
3. When [K+] and [Ca++] are both greater than 2 x standard, whatever the ratio between the concentrations the effects characteristic of high [K+] eventually predominate. However, these effects, except for those involving spike height, are preceded by effects characteristic of high [Ca++] when this cation is present in sufficient excess.
4. When [K+] and [Ca++] are reduced to equal low levels (0.1–0.2 x standard), effects characteristic of low [K+] and high [Ca++] are obtained.
5. The experimentally determined order of ability of the environments to produce changes characteristic of high K+ (which is the reverse of the order of their ability to produce changes characteristic of high [Ca++]), is not the order of their K+ or Ca++ concentrations, nor of the ratio between these concentrations (Table II).
6. The results may be explained by the assumption that the functions investigated are all to greater or less degree controlled by (1) the [K+]/[Ca++] ratio and (2) the K+ concentration, at least when this exceeds a critical level. Control by [K+] is more effective for spike height and its recovery after stimulation than for the other functions. The special rôle of K+ is attributed to an unknown specific effect of this ion which Ca++ is unable to oppose. It is suggested that this K+ effect in general becomes marked on the frog nerve functions investigated when the K+ concentration is somewhat above 2 x standard, while the [K+]/[Ca++] ratio must be changed by a factor of 4 or more before it exerts a definite effect on these functions.
7. In standard and in modified cationic environments, nerve functions vary in the ease with which they manifest changes characteristic of high [K+] or of high [Ca++].
8. The after-potential functions are less completely controlled by the cationic environment than are the other functions investigated.
THE PREADAPTIVE OXIDATION OF GALACTOSE BY YEAST
Authors: Reiner John M. , Spiegelman S. 
Published: May 2004

A preadaptive purely aerobic utilization of galactose by yeast cells has been demonstrated. Hence, the adaptation by yeast to galactose is not to its utilization per se, but specifically to its metabolism by a glycolytic mechanism. An examination of this preadaptive oxidation of galactose reveals that it has many characteristics in common with the endogenous metabolism of yeast. Included among these are the similarities of the R.Q. values and the response of the QOO2 and QCOCO2O2 to KCN and iodoacetic acid. Further, a competitive interaction appears to exist between the endogenous respiration and the preadaptive oxidation of the galactose. The latter can replace the endogenous respiration as a source of energy for the adaptation to the fermentation of the galactose. Carbon balance studies of the galactose oxidation revealed that polysaccharide could be formed as a result of this metabolism during the preadaptive period.
Non-adaptable cells were also found to possess the capacity to oxidize galactose in the complete absence of any ability to metabolize it anaerobically.
The significance of these findings for the biochemistry and physiology of the adaptation is discussed.
THE BIOSYNTHESIS OF C13 COMPOUNDS
Authors: Livingston L. G. , Medes Grace ,   With the Technical Assistance of Alice Shapiro
Published: May 2004

1. Starch, containing 7.05 atom per cent C13 excess has been produced in the mesophyll cells of bean leaves, starting with C13O2 containing 7.26 atom per cent C13 excess. Approximately 67 per cent of the C13 taken up by the leaves was determined in the starch fraction.
2. The soluble carbohydrate, containing 6.72 atom per cent C13 excess, accounts for approximately 23 per cent of the C13 taken up by the leaves. The remainder was principally in the coarse tissue fragments fraction (9.73 per cent of the C13 utilized).
3. The apparatus and procedures used in this experiment are described.
STUDIES ON THE SONIC TREATMENT OF TOBACCO MOSAIC VIRUS
Authors: Oster Gerald 
Published: May 2004

Centrifugally purified samples of tobacco mosaic virus were subjected to intense sound vibrations of 9,000 cycles per second for 0, 2, 8, 16, 32, and 64 minutes. The viscosity and stream birefringence of the samples decreased with time of sonic treatment, but no chemical changes were found. Electron micrographs of the samples show that the particles are broken perpendicular to their long axis. In the untreated sample 62 per cent of the particles are about 280 mµ in length. As sonic treatment continued, the number of particles of this length decreased exponentially with time, the number half this length increased and then decreased, and the number of quarter length particles subsequently increased and then decreased. The biological activity of the samples, as determined by the half leaf lesion method, decreased exponentially with time of sonic treatment with a rate constant given by k = 0.13 min.–1. A correlation exists between the size distributions and biological activity and shows that only the particles of length 280 mµ are the biologically active units.
Tobacco mosaic virus particles can be made to aggregate end-to-end when the material is heated at its isoelectric point and reheated after being brought back to pH 7. Material which was not sonic treated and was made to aggregate showed reduced biological activity, but the activity was increased when the aggregated material was subjected to strong mechanical stirring. Material which was sonic treated for 32 minutes and which was made to aggregate showed the same biological activity as the material which was sonic treated but not aggregated.
INTERACTIONS BETWEEN ENZYME-FORMING SYSTEMS DURING ADAPTATION
Authors: Spiegelman S. , Dunn Reba 
Published: May 2004

Experiments on enzymatic adaptations in yeast to galactose and maltose under various conditions are examined. The pertinent facts established may be summarized as follows:—
1. The presence of exogenous nitrogen stimulates the rate of adaptation and raises considerably the attainable level of enzyme activity.
2. This stimulation is absent if the cells are unable to assimilate the added nitrogen.
3. Competitive interactions can be exhibited between two adaptive enzyme systems induced either serially or simultaneously in the same cell.
4. A similar kind of interaction was observed between an adaptive and a so called "constitutive" enzyme.
5. The presence of exogenous nitrogen modifies greatly the nature and extent of the interaction between the enzyme-forming systems.
The significance of these results to our understanding of the mechanism of the modification and maintenance of cellular enzymatic constitution is discussed. The validity of the distinction between "constitutive" and "adaptive" enzymes is reexamined in the light of the data presented.
STUDIES ON A NEW METABOLITE AND ITS OXIDATION IN THE PRESENCE OF ASCORBIC ACID
Authors: Bernheim Frederick , Wilbur Karl M. , Fitzgerald Dorothea B. 
Published: May 2004

1. A number of tissues, in particular, brain, liver, and kidney, incubated aerobically in vitro as slices or ground suspensions produce a compound which combines with p-aminobenzoic acid in acid solution to form a yellow color.
2. A study of this reaction in rat brain has shown that this compound can be produced when washed boiled brain protein is incubated aerobically with ascorbic acid. The latter acts as a catalyst to break the linkage between the protein and the compound. Oxygen is taken up in the process.
3. A number of aromatic hydroxy compounds such as epinephrine and catechol inhibit the reaction. Cyanide has little or no effect. No reaction occurs anaerobically.
4. The occurrence of the reaction in some animals has been described.
ABNORMAL PROTOPLASMIC PATTERNS AND DEATH IN SLIGHTLY HYPERTONIC SOLUTIONS
Authors: Osterhout W. J. V. 
Published: May 2004

Some interesting properties of protoplasm are revealed when slightly hypertonic solutions of sugars or of electrolytes are applied to Nitella.
The chloroplasts contract and the space between them increases and forms a characteristic pattern consisting of clear areas extending lengthwise along the cell and tapering off at both ends.
The development of these areas is irreversible from the start. If the cell is returned to water after plasmolysis begins these areas continue to enlarge in much the same fashion as when no change is made in the external solution. The cell soon dies whether returned to water or left in the plasmolyzing solution. Similar results are obtained with other sugars, with NaCl, CaCl2, and sea water.
Similar reactions are also brought about by strong ingoing or outgoing currents of water. This suggests that mechanical action may be chiefly responsible for the result and this idea is in harmony with other facts. It seems possible that the retraction of the protoplasm from the cellulose wall may disturb the delicate non-aqueous film which covers the outer surface of the protoplasm and thus produce injury. Such an effect might take place even without visible retraction if the injury occurred in protoplasmic projections extending into the cellulose wall.
A study of this behavior may throw light on the nature of the protoplasmic surface and on the properties of protoplasmic gels as well as on the process of death. An understanding of the mechanism involved may help to explain the action of hypertonic solutions in other cases as, for example, in the artificial parthenogenesis of marine eggs.
THE REACTION BETWEEN ACTOMYOSIN AND ADENOSINE TRIPHOSPHATE
Authors: Mommaerts W. F. H. M. 
Published: May 2004

1. A study is made of the effect of adenosine triphosphate (ATP) upon the viscosity of solutions of actomyosin in 0.5 M KCl.
2. The observed effects are discussed in terms of an initial drop of the viscosity (viscosity response) and its subsequent slow reversal (recovery effect). The latter is ascribed to a decrease in the ATP concentration through enzymatic hydrolysis.
3. The recovery effect is inhibited by Mg, activated by Ca, in accordance with the effect of these ions on the activity of myosin-ATPase.
4. The viscosity response is not inhibited, probably promoted by Mg. It is not promoted, probably inhibited by Ca.
5. The viscosity response is induced not only by ATP, but to a certain extent also by inosinetriphosphate, inorganic triphosphate, and inorganic pyrophosphate, not by adenosine diphosphate or monophosphate.
6. The viscosity response could be obtained with enzymatically inactive myosin.
7. It is concluded that the effect of ATP upon myosin does not depend on its enzymatic hydrolysis.
THE SYNTHESIS FROM VITAMIN A1 OF "RETINENE1" AND OF A NEW 545 mµ CHROMOGEN YIELDING LIGHT-SENSITIVE PRODUCTS
Authors: Wald George 
Published: May 2004

Ball, Goodwin, and Morton (1946) have reported that vitamin A1 in contact with solid manganese dioxide is transformed slowly into a substance which displays spectroscopic properties of retinene1. The latter is known to be the precursor of vitamin A1 in the rhodopsin cycle of the retinal rods. The synthetic product is here referred to as "retinene1."
In the present experiments this observation is confirmed. The procedure is recast in the form of a chromatographic oxidation. Manganese dioxide is packed in a column, vitamin A1 solution poured in at the top, and the product drawn off in the filtrate. Depending upon the proportions of manganese dioxide and vitamin A1, the product is either "retinene1," or a new substance which yields with antimony chloride a wine-red product with maximal absorption at 545 mµ (545 mµ chromogen). This procedure is an example of a potentially important class of chromatographic reactions.
The synthetic "retinene1" is virtually identical with the natural substance in absorption spectrum and antimony chloride reaction. It lacks the pH indicator properties of crude natural retinene1.
The 545 mµ chromogen possesses absorption maxima at 380 and 290 mµ in chloroform; at 376 and 290 mµ in ethanol; and at 361 and 277 mµ in hexane. It is non-fluorescent. It has no acidic character, but on the contrary is mildly basic, being extracted from hexane by sulfuric or hydrochloric acids to form orange-red products. In partition between petroleum ether and aqueous methanol it is highly hypophasic. It is adsorbed strongly on calcium carbonate.
Certain peculiarities in spectral behavior indicate the presence of a carbonyl group in the 545 mµ chromogen, and support Morton's proposal that such a group occurs in retinene1. Other properties of the 545 mµ chromogen indicate hydroxyl groups. This substance therefore appears to be a hydroxy-carbonyl derivative of vitamin A1.
The red products which the 545 mµ chromogen forms with antimony chloride or with sulfuric or hydrochloric acids are all markedly light-sensitive. They appear to be formed by the condensation of two molecules with loss of water; and to bear a close generic relation to the prosthetic groups of the visual photopigments.
STUDIES ON THE PHYSIOLOGICAL EFFECTS OF NON-POLAR-POLAR ORGANIC ELECTROLYTES
Authors: Höber Rudolf , Langston Mary , Strausser Helen , Macey Robert 
Published: May 2004

In a previous paper it has been shown that the nonpolar-polar anionic detergents can be divided into two main groups. One chemically characterized by a relatively long chain of non-polar alkyl groups, which in solution are in contact with one end of a muscle and, locally adhering to it, produce a permanent negative injury potential. This is generally accompanied by a loss of excitability. The second group, distinguished by a relatively short chain of non-polar alkyl groups acts reversibly, ordinarily preserves the excitability and, in contrast to the first group, produces locally a reverse positive potential. For reasons mentioned before, this appears likely to correspond to an increased activity.
These concepts have been tested in this second paper. The measurements of the resting potentials of muscles have been supplemented by measurements on frog sciatics with the result that there are brought about, again by the detergents with long alkyl chains, regular irreversible negative resting potentials and with the short chain compounds reversible positive potentials are aroused. Furthermore, in addition there appeared the hardly expected result that muscle stimulated in the presence of short chain detergents responded with an even higher contraction. We have endeavored to explain this on the basis of general considerations concerning the physical chemistry of the excitatory process.
More direct evidence of this rise of excitability under the influence of the short chain non-polar-polar detergents will be presented in the next papers on studies concerning chronaximetric measurements on nerve, referring particularly to the semidetergents, and concerning the effects of detergents in general upon the heart beat of a clam.
THE CHANGE IN OSMOTICALLY INACTIVE FRACTION PRODUCED BY CELL ACTIVATION
Authors: Shapiro Herbert 
Published: May 2004

1. Resting and activated eggs of the sea urchin Arbacia punctulata were swollen in hypotonic sea water (60, 70, 80, and 90 per cent), and allowed to attain equilibrium volumes (Figs. 1 and 2).
2. Both fertilized and unfertilized eggs obey the Boyle-van't-Hoff law, but the value for b, the "osmotically inactive fraction" or non-swellable volume, was different for the two, averaging in the cases studied 7.3 per cent for unfertilized and 27.4 per cent for fertilized.
3. On activation, the eggs of the sea urchin undergo a definite increase in total cell volume, of approximately 2.7 per cent.
4. Some evidence is adduced for the possibility that the alteration in cell volume and in o.i.f. may depend upon the species in question.
5. A parallelism between change in b and alteration of respiratory metabolism in Arbacia, Chaetopterus, and Arbacia fragments is pointed out. This requires further investigation in other species to establish generality.
6. Equations for the calculation of the point at which osmotic pressures and cell volumes are identical for unfertilized and fertilized eggs are included.
7. A mechanical analogue of the phenomena is introduced (Fig. 3).
NITRATE REDUCTION AND ASSIMILATION IN CHLORELLA
Authors: Cramer Marian , Myers Jack 
Published: May 2004

1. Nitrate reduction and assimilation have been studied in Chlorella pyrenoidosa under growth conditions by observing effects on the CO2/O2 gas exchange quotient.
2. During assimilation of glucose in the dark, nitrate reduction is noted as an increase in the R.Q. to about 1.6 caused by an increased rate of carbon dioxide production.
3. During photosynthesis at low light intensity nitrate reduction is evidenced by a reduction in the CO2O2 quotient to about 0.7 caused by a decreased rate of carbon dioxide uptake.
4. Chlorella will assimilate nitrogen from either nitrate or ammonia. When both sources are supplied, only ammonia is utilized and no nitrate reduction occurs. It is inferred that under the usual conditions of growth nitrate is reduced only at a rate required for subsequent cellular syntheses. The effect of nitrate reduction on the CO2O2 quotient therefore provides a measure of the relative rate of nitrogen assimilation.
5. Over-all photosynthetic metabolism may be described from elementary analysis of the cells since excretory products are negligible. The gas exchange predicted in this way is in good agreement with the observed CO2/O2 quotients.
REGULATORY MECHANISMS OF CELLULAR RESPIRATION
Authors: Barron E. S. Guzman , Nelson Leonard , Ardao Maria Isabel 
Published: May 2004

Oxidizing agents of sulfhydryl groups such as iodosobenzoate, alkylating agents such as iodoacetamide, and mercaptide-forming agents such as cadmium chloride, mercuric chloride, p-chloromercuribenzoate, sodium arsenite, and p-carboxyphenylarsine oxide, added in small concentrations to a suspension of sea urchin sperm produced an increase in respiration. When the concentration was increased there was an inhibition. These effects are explained by postulating the presence in the cells of two kinds of sulfhydryl groups: soluble sulfhydryl groups, which regulate cellular respiration, and fixed sulfhydryl groups, present in the protein moiety of enzymes. Small concentrations of sulfhydryl reagents combine only with the first, thus producing an increase in respiration; when the concentration is increased, the fixed sulfhydryl groups are also attacked and inhibition of respiration is the consequence.
Other inhibitors of cell respiration, such as cyanide and urethanes, which do not combine with —SH groups, did not stimulate respiration in small concentration.
THE CHEMICAL STATE OF THE CALCIUM REACTING IN THE COAGULATION OF BLOOD
Authors: Quick Armand J. , Stefanini Mario 
Published: May 2004

1. The widely accepted theory that calcium participates in the coagulation mechanism in the form of Ca++ and acts as a catalyst is not in accord with several important experimental findings:
(a) The anticoagulant action of sodium oxalate is much slower than the precipitation of ionized calcium as the oxalate salt.
(b) Sodium citrate begins to depress prothrombin activity at a concentration at which ionized calcium is still present. The inability of tricalcium phosphate to adsorb prothrombin from citrated plasma indicates that citrate forms a complex with prothrombin and it is postulated that prothrombin is thereby inactivated.
(c) In plasma which is decalcified, i.e. in which the Ca++ is markedly reduced, the labile factor of prothrombin rapidly decreases. A concentration of 0.01 M sodium citrate sufficient to inhibit coagulation does not depress Ca++ enough to cause diminution of the labile factor, whereas when the concentration is increased to 0.02 M the labile factor decreases as rapidly as in oxalated plasma.
2. It is postulated that calcium functions in coagulation not as Ca++ but as combined with a component which is part of the prothrombin complex that is not adsorbed by tricalcium phosphate. A concentration of sodium citrate just sufficient to inhibit coagulation is not enough to remove calcium from the essential prothrombin component. The primary anticoagulant action of sodium citrate is therefore not decalcification but antiprothrombic.
3. It has been shown that citrated plasma is basically different from oxalated plasma in several important aspects. Unless cognizance is taken of these differences, serious errors and misinterpretations of experimental findings may be made.