bluuebunny/crossref_metadata_2025_split huggingface dataset:
ON THE EFFECT OF COCAINE UPON SODIUM-DEFICIENT FROG NERVE
Authors: Lorente de Nó R. 
Published: May 2004

Cocaine diffuses through the epineurium with remarkable rapidity. The coefficient of diffusion of cocaine in the epineurium cannot be less than 0.44 x 10–4 cm.2/min.; it probably is not less than 1.22 x 10–4 cm.2/min.
Lack of sodium markedly sensitizes the nerve fibers to the anesthetic action of cocaine.
With sodium-deficient A fibers the action of cocaine develops in two phases. During the first phase cocaine substitutes for sodium and restores to A fibers the ability to conduct impulses; during the second phase cocaine produces anesthesia.
It is suggested that cocaine anesthetizes the nerve fibers through the sodium mechanism; i.e., by interfering with some of those chemical reactions in which, directly or indirectly, the internal sodium takes part.
CRYSTALLINE INORGANIC PYROPHOSPHATASE ISOLATED FROM BAKER'S YEAST
Authors: Kunitz M. 
Published: May 2004

Crystalline inorganic pyrophosphatase has been isolated from baker's yeast. The crystalline enzyme is a protein of the albumin type with an isoelectric point near pH 4.8. Its molecular weight is of the order of 100,000. It contains about 5 per cent tyrosine and 3.5 per cent tryptophane. It is most stable at pH 6.8.
The new crystalline protein acts as a specific catalyst for the hydrolysis of inorganic pyrophosphate into orthophosphate ions. It does not catalyze the hydrolysis of the pyrophosphate radical of such organic esters as adenosine di- and triphosphate, or thiamine pyrophosphate.
Crystalline pyrophosphatase requires the presence of Mg, Co, or Mn ions as activators. These ions are antagonized by calcium ions. Mg is also antagonized by Co or Mn ions.
The rate of the enzymatic hydrolysis of inorganic pyrophosphate is proportional to the concentration of enzyme and is a function of pH, temperature, concentration of substrate, and concentration of activating ion. The approximate conditions for optimum rate are: 40°C. and pH 7.0 at a concentration of 3 to 4 x 10–3 M Na4P2O7 and an equivalent concentration of magnesium salt. The enzymatic hydrolysis of Na4P2O7 or K4P2O7 proceeds to completion and is irreversible under the conditions at which hydrolysis is occurring.
Details are given of the method of isolation of the crystalline enzyme.
THE EFFECT OF VARIOUS CULTURE MEDIA ON INFECTION, GROWTH, LYSIS, AND PHAGE PRODUCTION OF B. MEGATHERIUM
Authors: Northrop John H. 
Published: May 2004

B. megatherium cells were grown in various culture media, centrifuged and washed, and suspended in other culture media containing "C" or "T" phage.
The per cent of infection, rate of growth, lysis, and phage production were determined.
The behavior of the system depends on the culture medium in which the cells were grown and also on the culture medium in which they were mixed with phage.
With the T phage it is possible to set up systems which yield the following results:
1. No infection, normal growth, no phage production.
2. Infection, normal growth, no lysis) phage production.
3. Infection, growth for several hours, lysis, and phage production.
4. Infection, no growth, lysis, and phage production.
The C phage system is less affected by changes in the culture medium.
The change in the behavior of the cells with T phage probably is not due to selection since it occurs without much growth of the culture, and is readily reversible.
SOME ENZYMES OF ISOLATED NUCLEI
Authors: Stern H. , Allfrey V. , Mirsky A. E. , Saetren H. 
Published: May 2004

The composition of isolated nuclei and cell preparations from tissues of calf, beef, horse, and fowl was studied with respect to the following components:
1. Liver and kidney arginase, catalase, and uricase; pancreatic lipase and amylase; cardiac muscle myoglobin; erythrocyte hemoglobin; intestinal alkaline phospharase. These are referred to as "special" components in view of their characteristically restricted distribution reflecting the differentiated nature of the tissues in question.
2. Esterase, ß-glucuronidase, alkaline and nucleotide phosphatases, adenosine deaminase, guanase, and nucleoside phosphorylase. These are enzymes of general distribution.
The differences in nuclear composition noted with respect to the "special" components, together with the broad variability in nuclear activity found for enzymes of general distribution, led to the conclusion that nuclei are differentiated structures.
The following distribution was observed:
1. "Special" components: Hemoglobin was found to be present in fowl and goose erythrocyte nuclei, but myoglobin was entirely absent from heart muscle nuclei; of the special enzymes listed, only catalase and arginase appeared to be concentrated in some of the nuclei. There was no significant nuclear concentration of lipase, amylase, uricase, or alkaline phosphatase. No simple relationship was found between the concentration of a special enzyme in a tissue and its activity in the corresponding nuclei. For example, arginase activity, which is high in mammalian liver and in fowl kidney, was found in liver, not kidney, nuclei. Similarly, catalase activity was demonstrated only in mammalian liver nuclei, although, in mammals, both liver and kidney are rich sources of this enzyme.
2. Enzymes of general distribution fell into three classes:
(a) Those present in low concentrations, if at all, in the nuclei—alkaline phosphatase, the nucleotide phosphatases) and ß-glucuronidase.
(b) Those present in nuclei in varying concentrations—esterase.
(c) Those present in high proportions in most nuclei—adenosine deaminase, nucleoside phosphorylase, and guanase. The exceptionally low nuclear activity of intestinal mucosa with respect to these enzymes was discussed in relation to physiological considerations.
The response of nuclei to changes in physiological state was demonstrated by experiments on starvation. The outstanding aspect of this response was a change in nuclear enzymatic activity opposing that observed in the cytoplasm.
A comparison of fetal and adult mucosa cells led to the following tentative interpretation of the observed intracellular enzyme distribution: In cells tending to moribundity, as in those subjected to starvation, relative nuclear enzymatic activity falls.
The occurrence of special enzymes in nuclei was considered in terms of differentiation, and the high nuclear concentration of the nucleoside-specific enzymes was interpreted in terms of general nuclear metabolic activity.
FACTORS AFFECTING THE HEMOLYTIC ACTION OF "LYSOLECITHIN" UPON RABBIT ERYTHROCYTES
Authors: Collier H. Bruce 
Published: May 2004

1. Lysolipid was prepared by the action of snake venom on egg yolk, and a study was made of the factors affecting its hemolytic action upon rabbit erythrocytes.
2. Lysis proceeded very rapidly at first, then ceased within a few minutes at room temperature. A given amount of lysin appeared to hemolyze a fixed number of cells, under specified conditions.
3. The more dilute erythrocyte suspensions required relatively more lysin per cell, for 50 per cent hemolysis of the suspension. There may be an equilibrium between the lysin dissolved in the medium and that adsorbed on the cells.
4. The degree of hemolysis for varying lysin concentrations was measured, and the cells showed a typical distribution of resistance to hemolysis.
5. As the temperature was lowered lysis was more extensive. Adsorption of the lysin on the cell surface was apparently increased.
6. The resistance of the erythrocytes to lysis increased slightly as the pH was raised from 5.5 to 7.8.
7. Resistance to lysis was independent of the tonicity of the medium and of initial cell volume. The magnitude of the cell surface was probably the determining factor.
8. A marked shrinkage of the erythrocytes was observed in the presence of calcium ions and lysin, but not in the absence of the lysin.
9. Hemolytic resistance curves obtained by the Wilbrandt technique were of the "colloid-osmotic" type. However, there was no evidence of prolytic loss of potassium ions.
10. Hypotonic fragility of the cells was slightly increased in the presence of the lysin. The rate of penetration of thiourea was greatly increased.
THE INCORPORATION OF N15-GLYCINE BY AVIAN ERYTHROCYTES AND RETICULOCYTES IN VITRO
Authors: Allfrey V. , Mirsky A. E. 
Published: May 2004

A study of the incorporation of glycine-N15 by chicken red cells in vitro has shown that:
1. There is no detectable nitrogen turnover in the histone or desoxyribonucleic acid of erythrocytes or reticulocytes.
2. Hemoglobin synthesis in the nucleated reticulocyte proceeds at 2 to 3 times the rate observed in the mature erythrocyte.
3. The uptake of glycine-N15 by heme is 9 to 14 times the corresponding uptake into hemoglobin, and 12 to 20 times the calculated uptake into globin.
4. Maturation of the red cell results in a decline in the rate of synthesis of both heme and globin, but the deceleration is much more marked in globin. synthesis.
5. No significant differences could be detected in the low N15 incorporations of nuclear and cytoplasmic hemoglobins.
THE B. MYCOIDES N HOST-VIRUS SYSTEM
Authors: Baer B. S. , Krueger A. P. 
Published: May 2004

There were differences in the way the lysogenic strain N of B. mycoides and the parent indicator strain grew on nutrient agar and in nutrient broth.
1. On agar, the indicator culture traveled more quickly over the agar surface than the phage-carrying strain; the total extent of spread was greater.
2. In broth, the indicator strain grew diffusely throughout the liquid, the lysogenic cells in clumps. The virus-infected strain appeared to grow more slowly. This may reflect (a) the effect of aggregation on the generation time of the lysogenic strain, (b) an active lytic process in the lysogenic population which is further enhanced by the effect of clump formation on the environment of the cell.
THE B. MYCOIDES N HOST-VIRUS SYSTEM
Authors: Baer B. S. , Krueger A. P. 
Published: May 2004

In nutrient broth at 30 to 32°C., the cycle of virus growth (following adsorption) in lag phase cells of B. mycoides N included a period of intracellular multiplication, ranging from 0.8 to 1.3 hours, succeeded by a sharp rise in the free phage titer and then by a slower rise or a plateau in the extracellular phage content. The yield of virus per infected cell at 30°C., as determined by a modified Burnet dilution technique, was about 76 plaque-forming particles.
During the latent period, multiply infected cells showed no change in numbers. Coinciding with phage release, incomplete clearing occurred. The unlysed, remaining cells multiplied and the turbidity rose again. These survivors and their progeny were lysogenic.
THE B. MYCOIDES N HOST-VIRUS SYSTEM
Authors: Baer B. S. , Krueger A. P. 
Published: May 2004

Experiments were performed to determine the mechanism of release of phage from the lysogenic strain of B. mycoides N. The results suggest that qualitatively the same situation obtains as in the phage-carrying cultures of B. megatherium 899 and E. coli Li; i.e., the population consists of two kinds of cells: "lysogènes potentiels" and "producteurs." Quantitatively, however, there are more "producers" in a broth culture of the lysogenic B. mycoides N, at least curing the first 4 to 8 hours after cells have been suspended in fresh medium, suggesting that the interaction between host and parasite is one in which the balance is easily swung in favor of the virus.
These conclusions are based upon the following lines of evidence: (1) the slow "growth rate" of the lysogenic culture, (2) the fact that the colony count falls far below the plaque count or the filament count (which correspond) for a well washed suspension, (3) the increase in phage output in a large number of tubes, each containing a small number of lysogenic cells, after a few hours' incubation in nutrient broth at 30°C.
THE PERMEABILITY OF THE HUMAN ERYTHROCYTE TO SODIUM AND POTASSIUM
Authors: Solomon A. K. 
Published: May 2004

Measurements have been made on the permeability of the human erythrocyte to Na and K in vitro, using radioactive tracers to observe the system in the steady state. The average inward K flux is 1.67 m.eq./liter cells hour, and the apparent activation energy is 12,300 ± 1300 calories/mol. The inward K flux is independent of the external K concentration in the range of concentrations studied (4 to 16 m.eq. K/liter plasma). Rb appears to compete with K for transport into the cell, whereas Na and Li do not. The average inward Na flux is 3.08 ± 0.57 m.eq. Na/liter cells hour, and the apparent activation energies are 20,200 ± 2700 calories/mol for inward transport, and 14,900 ± 3,400 calories/mol for outward transport. The inward Na flux is dependent on the external Na concentration, but not in a linear fashion. Li appears to compete with Na for inward transport, whereas K and Rb do not.
An approximate maximum estimate shows that the energy required for cation transport is only 8.8 calories/mol liter cells hour of the 110 calories/mol liter cells hour available from the consumption of glucose. A working hypothesis for the transport of Na and K is presented.
CONTRACTILE PROPERTIES OF COMPRESSED MONOLAYERS OF ACTOMYOSIN
Authors: Hayashi Teru 
Published: May 2004

1. Surface-spread actomyosin, compressed into fibers, shows biological properties of contractility and enzymic activity.
2. In unloaded contractions, wet and dry weight determinations show no appreciable water loss in contraction. The fibers also evince a strong ATP-ase activity.
3. A structural continuity in the fibers by intermolecular linkages of the component actomyosin molecules is established during the formation of the fibers. Evidence includes their visible longitudinal structural organization, the lack of elongation effect of ATP when under tension, and their ability to lift appreciable loads, so that, like muscle, they can transform chemical energy into mechanical work.
4. Up to a limiting critical weight, the fibers perform more work with increasing imposed weight load.
5. Theoretical aspects are discussed, including the possibility that surface-spread protein is involved in the formation of cell structures. Possible explanations for the relative slowness of the fiber contractions are offered.
THE ISOLATION OF WHEAT GERM NUCLEI AND SOME ASPECTS OF THEIR GLYCOLYTIC METABOLISM
Authors: Stern H. , Mirsky A. E. 
Published: May 2004

1. A procedure for isolating nuclei of the wheat germ in non-aqueous media has been described.
2. Such nuclei were shown to constitute about 50 per cent of the protoplasmic mass and to have a ribonucleic acid content of an order equivalent to that of the cytoplasm.
3. Studies of the distribution of the enzymes—aldolase, phosphoglyceraldehyde dehydrogenase, enolase, and pyruvate kinase—have revealed that the nuclei are the most vigorous sites of glycolytic activity.
4. Analysis of the DPN content of the nuclei in calf tissues—liver, pancreas, and heart—pointed to the probability that glycolytic activity is a characteristic common to many nuclei.
5. The significance of glycolytic activity to nuclear function has been discussed and some suggestive comparisons made between the two energy-yielding systems of glycolytic and oxidative phosphorylation.
SOME ASPECTS OF THE DESOXYRIBONUCLEASE ACTIVITIES OF ANIMAL TISSUES
Authors: Allfrey V. , Mirsky A. E. 
Published: May 2004

It has been found that many animal tissues contain "acid" desoxyribonucleases with pH optima near 5.2. A chemical method for the determination of this activity is described.
The pancreatic desoxyribonuclease crystallized by Kunitz and shown to have a neutral pH optimum occurs in the pancreas together with the "acid" enzyme, but only the "neutral" enzyme occurs in the pancreatic juice. The ratio of "neutral" to "acid" DNAase activities in the pancreas is greater than 200, but in all other tissues examined there is no appreciable concentration of the neutral enzyme. It is concluded that neutral DNAase, like trypsin or lipase, has a digestive function. Some problems in the activation of the secretory enzyme in neutral pancreatic extracts are described. This activation can be interpreted in terms of a specific inhibitor or an inactive form of the enzyme.
A comparison of the "acid" DNAase activities of different organs of the calf, horse, chicken, mouse, and rat indicates a possible connection between the DNAase concentration of a tissue and its capacity for proliferation or regeneration. However, the comparative DNAase activities of fetal and adult tissues do not support the view that DNAase function is limited to some simple role in the mechanics of cell division.
Studies on the incorporation of glycine-N15 into the desoxypentose nucleic acids of avian red cells, and mouse liver, pancreas, and kidney show that the N15 uptake into the DNA of the chromosome is most rapid in tissues with high DNAase concentrations. No N15 incorporation is observed in the DNA of avian red cells, which have negligible concentrations of the enzyme.
The analyses of tissues and nuclei isolated in non-aqueous media show that the bulk of the enzyme occurs in the cytoplasm of the cell, and that nuclear concentrations vary from tissue to tissue. A theory relating the DNAase activity of the cell to its over-all desoxypentose nucleotide metabolism is discussed.
No evidence has been found for the presence of inhibitors of the "acid" DNAase in animal tissues.
NUTRITION OF THE EUROPEAN CORN BORER, PYRAUSTA NUBILALIS (HBN.)
Authors: Beck Stanley D. 
Published: May 2004

1. The European corn borer larva has been shown to require a dietary source of one or more unidentified factors contained in corn leaves, grass juice concentrate, and certain other plant materials. The required factor or factors has been termed the corn leaf factor.
2. The corn leaf factor does not appear to be identical with any of the known B vitamins, or with ascorbic acid, sodium nucleate, citrovorum factor, or carnitine.
3. The corn leaf factor is heat-stable, acid-stable, water-soluble, and dialyzable.
PROTECTION OF BACTERIOPHAGE AGAINST X-RAYS BY HIGH CONCENTRATIONS OF A NEUTRAL SALT
Authors: Bachofer C. S. , Pottinger M. Aelred 
Published: May 2004

Protection of bacteriophage T1 against x-rays was tested in the presence of concentrations of (NH4)2SO4 ranging from 10–6 M to saturation (4.26 M). Survival of T1 in concentrations of 10–6 to 10–3 M after irradiation did not differ significantly from survival in distilled water after irradiation. From 10–3 M to 10–1 M there was a steep rise in survival, with a leveling off as the concentration approached saturation, giving over-all a 2,000-fold increase in survival. The mechanism of salting out protection in these experiments is apparently due chiefly to dehydration, which protects the virus particles against the indirect effects of x-irradiation.
Postirradiation effects, tested by the inactivation of phage added to irradiated media, approach in magnitude the effects obtained by irradiation of the phage particles themselves in the various solutions.
Filter paper adsorption analyses indicate a close correlation between concentrations of (NH4)2SO4, ability of the filter paper to adsorb phage, and protection against x-rays, both during and after irradiation.
INVESTIGATIONS ON THE MITOCHONDRIA OF THE HOUSE FLY, MUSCA DOMESTICA L
Authors: Sacktor Bertram 
Published: May 2004

1. The ATPase activity of insect mitochondria has been investigated. A comparison was made to determine the distribution and nature of such activity in other isolated fractions of the house fly, Musca domestica L.
2. The ATPase in insect mitochondria is specific in that orthophosphate can be cleaved only from ATP. The Michaelis-Menten constant K8 = 2.78 x 10–3 M and Vmax. = 76 micrograms P min.–1 mg.–1 dry weight.
3. Mg++ and Mn++ activate this enzymatic reaction in mitochondria, but Ca++ does not. The extent of activation is 60 per cent with the optimal concentration 6 x 10–4 M. Experiments with combinations of Mg++ and Mn++ show that either ion can replace the other and that the effects are additive, depending solely on the final concentration of the combination. Concentrations of Mg, Mn, or Ca ions higher than 6 x 10–3 M inhibit the enzyme.
4. Fluoride does not inhibit the ATPase of insect mitochondria, whereas azide and chloromercuribenzoate do. The per cent inhibition depends on the concentration of inhibitor.
5. Finely dispersed mitochondrial particles have much greater ATPase activity than intact mitochondria. The possible relationship of this observation to latent ATPase is considered.
6. A magnesium-activated adenylate kinase is present in these mitochondria. The liberated orthophosphate, derived from ADP, is the result of the activity of adenylate kinase followed by the specific ATPase.
7. ATP can be dephosphorylated by enzymes found in the muscle fibrils, and in a "soluble" fraction, as well as in mitochondria. The fibrillar ATPase is Ca++-activated. The "soluble" fraction, however, like the mitochondria, is Mg++-activated. The "soluble" ATP dephosphorylation mechanism is distinguished from the mitochondrial ATPase in that it is inhibited by fluoride.
8. The "soluble" fraction also contains a magnesium-activated inorganic pyrophosphatase. Fluoride completely inhibits this enzymatic reaction.
9. The possible mechanism of ATP dephosphorylation in the "soluble" fraction is discussed.
THE RELATIONSHIP OF SODIUM UPTAKE, POTASSIUM REJECTION, AND SKIN POTENTIAL IN ISOLATED FROG SKIN
Authors: Huf Ernst G. , Wills Joyce 
Published: May 2004

1. Isolated surviving frog skin, when bathed with the same kind of diluted Ringer's solution on both sides, shows a negative correlation between net active salt uptake by the epithelium and spontaneous skin potential. Average values of 0.15 to 0.86 µeq. x hr.–1 x cm.–2 were measured and correlated with average skin potentials ranging from 107 to 25 mv.
2. Sodium uptake exceeded chloride uptake by about the same amount, irrespective of the height of the skin potential.
3. The same skins which exhibited a negative correlation between net uptake of sodium chloride and skin potential showed a positive correlation between net potassium rejection from the epithelium and skin potential, for voltages above 30 to 40 mv. In skins of voltages lower than this, potassium ions were taken up rather than rejected. Average values for rejection of +11.8 to –0.8 centi-µeq. x hr.–1 x cm.–2 were measured.
4. Net fluid uptake, associated with active uptake of sodium chloride, was small and occurred in the direction of the salt uptake. No dependence of net fluid uptake upon skin potential was observed.
5. Skins of winter frogs, pretreated with a commercial purified ACTH preparation, were less active than their respective controls with regard to uptake of sodium chloride. Rejection of potassium was the same in treated and untreated skins. Posterior pituitary factors, as possible contaminants, did not account for the effect of the ACTH preparation.
6. DOCA, DOC, and cortisone did not alter the normal correlation referred to under (1) and (3).
7. In interpreting the experimental results on theoretical grounds, it is suggested (a) that in normal skin, it is the variation in the electric conductance in skin of chloride ions which essentially, although not exclusively, determines the rate of net uptake of sodium chloride, (b) that a factor in the ACTH preparation used, possibly ACTH itself, may have lowered the electric conductance in skin of sodium ions either truly or apparently, (c) that potassium ions are treated by the skin primarily as passive ions. There is some indication that potassium ions are also actively taken up by the epithelium of skin.