bluuebunny/crossref_metadata_2025_split huggingface dataset:
MIXING RATE OF PHOSPHATE BETWEEN PLASMA AND INTERSTITIAL BODY FLUID OF COWS
Authors: Kleiber Max , Smith Arthur H. , Ralston N. P. 
Published: May 2004

Radiophosphate was injected into the left jugular vein of dairy cows. Blood samples were taken frequently from the right jugular vein during the first hour after injection. Between 20 minutes and 1 hour after injection, the decrease in plasma radioactivity could be formulated as a first order process, designated as "process 3," with a turnover time of 50 minutes. From 5 to 20 minutes after injection the decrease in plasma activity could be interpreted as the result of mixing plasma phosphate with another phosphate pool, designated as the second pool. The capacity of this second pool was derived as a constant in a kinetic equation, so chosen that the resulting mixing rates were independent of time.
For two cows the capacity of the second pool was 5 and 8 times, respectively. the phosphate content of the plasma. This result led to the working hypothesis that the major part of the second pool was the phosphate in the interstitial tissue fluid.
The turnover time of the plasma phosphate in the mixing process with the second pool amounted to an average of 14 minutes for 5 lactating cows, and an average of 21 minutes for 2 dry cows. This result was obtained under the assumption that the slow first order process 3 is parallel to the mixing process. The assumption that the slower first order process is in series with the mixing process reduces the resulting mixing time to about four-fifths of that reported above. The calculation of process 2 which deviates from first order may be applicable to numerous turnover processes in which both exchange pools have a limited capacity.
EFFECT OF NEUROTOMY ON THE INORGANIC CATION CONTENT OF SKELETAL MUSCLE
Authors: Humoller Fred L. , Griswold Barbara , McIntyre A. R. ,   With the Technical Assistance of Jean Allison
Published: May 2004

1. A study of the effect of denervation on the inorganic cation content of muscle has been carried out. In this study 69 rats were employed.
2. By using the flame photometer for the estimation of sodium and potassium and increasing the sensitivity of previous methods for the estimation of calcium and magnesium, it has been possible to carry out analyses for all these ions on as little as 0.5 gm. of tissue.
3. It was observed that following neurotomy the concentration of sodium and calcium in the whole muscle increased significantly while at the same time the potassium content decreased. The magnesium content remained unchanged during the period studied.
4. The significance of these results has been discussed.
THE ELECTRICAL RESPONSE OF THE LATERAL LINE SYSTEM OF FISH TO TONE AND OTHER STIMULI
Authors: Suckling E. E. , Suckling J. A. 
Published: May 2004

1. The lateral line of Fundulus heteroclitus and Fundulus majalis is shown to react to tone at an intensity level of 20 dynes per sq. cm. at frequencies up to 200 or 300 cycles per second.
2. Evidence is given that the nerve can reproduce the stimulating tone frequency up to at least 180 cycles per second.
3. The response of the lateral line to the swimming movements of nearby fish is demonstrated.
4. Fundulus and several other species are shown to give strong spontaneous activity of the lateral line nerve.
EXCITATION CHARACTERISTICS OF THE SQUID GIANT AXON: A TEST OF EXCITATION THEORY IN A CASE OF RAPID ACCOMMODATION
Authors: LeFevre Paul G. ,   With the Technical Assistance of Marian E. LeFevre
Published: May 2004

1. The characteristics of the threshold excitation behavior of the squid giant axon were investigated with condenser discharges, exponentially blunted D. c. shocks, sinusoidal currents, and brief condenser-discharge test shocks superimposed at either electrode at controlled brief intervals following the closing of a constant current.
2. Data obtained by the use of condenser discharges and exponentially blunted currents followed theoretical patterns separately, but could not be mutually reconciled, under the system of the two-factor theories of excitation, since the accommodation was so rapid that the apparent ratio between the two time factors was incompatible with certain previously neglected theoretical limitations.
3. Data obtained with the other procedures indicated similarly rapid accommodation, but usually showed an imaginary component in the values of the time constants, associated with a capacity of the threshold to exhibit damped oscillatory behavior.
4. The anodal threshold behavior did not parallel that at the cathode, showing neither oscillation nor accommodation at ordinary current intensities.
5. The digressions from predictions of the two-factor theories of excitation are partly analyzed and compared with other reported deviations.
TISSUE CULTURE STUDIES
Authors: Hull Wayne , Kirk Paul L. 
Published: May 2004

The effect of horse serum alone, and of embryo extract alone, was compared with that of "complete medium" on the content and synthesis of ribo- and desoxyribonucleic acids and uptake of tracer P32 by chick heart cultures in vitro.
The factors mentioned are influenced by embryo extract in a manner similar to the effect in complete medium. Horse serum produced little synthesis of nucleic acids or uptake of tracer, giving only slightly more effect than Tyrode's solution alone.
Cutting the tissue into smaller pieces caused considerably greater synthetic effects, and retarded necrosis of the implant.
PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES
Authors: Price Winston H. 
Published: May 2004

1. A substance is present in autolyzed pepsin solutions which stimulates the release of phage by some strains of S. muscae when added to Fildes' synthetic medium.
2. The substance is assayed by determining the quantity necessary to increase the phage yield to one-half the maximum value, using the one-step growth curve technique.
3. The substance has been concentrated and partially purified (500-fold) by heavy metal precipitation, butyl alcohol extraction, and absorption on norit.
4. No known amino acid or accessory growth substance tested could replace this substance.
PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES
Authors: Price Winston H. 
Published: May 2004

1. Four strains of Staphylococcus muscae have been isolated which differ in their growth rates and phage syntheses in Fildes' synthetic medium.
2. Two of the strains when singly infected cannot release phage in Fildes' synthetic medium unless a substance present in certain acid-hydrolyzed proteins is added to the medium. One of these strains also requires other substance(s) present in acid-hydrolyzed proteins in order to grow in Fildes' medium.
3. The two strains which do not require the addition of the phage-stimulating factor have been found either to synthesize this substance, or one similar to it. One of these strains will not grow in Fildes' medium unless substance(s) present in acid-hydrolyzed proteins is added to the medium.
4. The purified acid-hydrolyzed protein factor necessary for virus liberation does not affect the multiplication rate of uninfected S. muscae cells in Fildes' synthetic medium.
5. The substance is not needed for the adsorption or the invasion of the host cell by the virus. In the absence of the factor, the virus is adsorbed to the cell and "kills" it.
6. An analysis carried out by means of the one-step growth curve technique has indicated that the substance is not concerned simply with the mechanism of virus release, but is necessary for some initial stage in virus synthesis.
7. With one bacterial strain not requiring the AHPF, aspartic acid had to be present at least during the minimum latent period for the cell to form virus.
8. In the absence of aspartic acid, the virus was adsorbed to the cell and killed it, but no virus was released from singly infected bacteria.
9. If the cells were grown in a medium containing aspartic acid and then resuspended in the medium minus aspartic acid, no virus was released, although such cells contained at least two times the amount of aspartic acid necessary for the burst size in the complete medium.
10. Aspartic acid, a constituent of the virus particle, appears from an analysis of one-step growth curves to take part in the initial phase of phage synthesis.
11. The effect of amino acids on virus formation is discussed in relation to the time sequence of virus protein and desoxyribonucleic acid synthesis.
A RAPID SLIDE PLAQUE TECHNIC FOR BACTERIOPHAGE ASSAY
Authors: Jones D. , Krueger A. P. 
Published: May 2004

1. A modified rapid plaque-counting procedure is described, whereby staphylococcal phage host-cell suspensions in agar are spread over constant areas on glass slides and are incubated in moist chambers.
2. Statistical analysis indicated a precision of ±8.2 for means of sets of eight slides incubated at 37°C. and ±7.6 for means of sets of eight incubated at 28°C.
3. With the staphylococcus system, a temperature of 28°C. yielded significantly higher counts than at 37°C.
4. Counts made after 4 hours may be used as an estimate of the final plaque count bearing in mind the fact that the yield at this time is significantly less than at 24 hours.
5. The data presented compared favorably with the results obtained by the plate method used by Hershey, and suggest that a greater precision may be obtained by this method—at least for the staph. K phage system.
ANOMALOUS FEATURES OF THE LOSS OF K FROM HUMAN RED CELLS: RESULTS OF EXTENDED OBSERVATIONS
Authors: Ponder Eric 
Published: May 2004

1. The anomalous course of the curves relating K loss to time in systems containing human red cells in isotonic NaCl, and particularly the high positions of the asymptotes to which the curves apparently proceed, are due to the population of red cells consisting of at least two components, one of which loses K more readily than the other.
2. Since large K-Na exchanges can occur between red cells and an isotonic suspension medium without there being large volume changes, a restatement of the "dual mechanism of hemolysis" hypothesis, which takes account of the cell's being slowly permeable to cations, is required. If some approximations of minor consequence are allowed, the hypothesis can be restated in a quantitatively satisfactory way.
3. The general features of K-Na exchanges, including prolytic exchanges are summarized.
THE AMINO ACID COMPOSITION AND SOME PROPERTIES OF HISTONES
Authors: Daly Marie M. , Mirsky A. E. , Ris Hans 
Published: May 2004

Some of the properties and the amino acid compositions of the histones of calf thymus, calf liver, fowl erythrocytes, and of a protamine-like material isolated from rooster sperm were described.
The amino acid compositions of the histones were rather similar except that no methionine was found in the fowl erythrocyte histone.
In the fowl, histones are found in the somatic chromosomes and protamines are found in the sperm chromosomes. This shows that great variations in chromosome composition can exist in an organism.
Histone is digested by pepsin both when isolated and when in the chromosome.
FREQUENCY OF SEEING FUNCTIONS FOR INTENSITY DISCRIMINATION AT VARIOUS LEVELS OF ADAPTING INTENSITY
Authors: Mueller Conrad G. 
Published: May 2004

1. The percentage of times a human subject detects an increment (ΔI) in intensity was determined as a function of the magnitude of the increment and the magnitude of the stimulus (I) to which the increment is added.
2. Foveal stimulation was used, and five frequency of seeing curves were obtained at each of nine values of adapting intensity covering the range from –1.45 to 4.45 log photons. Each frequency of seeing curve shows the percentage of times an increment in intensity is detected as a function of the logarithm of the increment.
3. The slope of the frequency of seeing curve increases slightly with an increase in I and finally becomes independent of I at medium to high intensities.
4. The implications of the results for quantum theories of visual excitation are considered.
ACTIVE TRANSPORT INTO THE HUMAN ERYTHROCYTE: EVIDENCE FROM COMPARATIVE KINETICS AND COMPETITION AMONG MONOSACCHARIDES
Authors: LeFevre Paul G. , Davies Robert I. 
Published: May 2004

1. Applicability of the previously postulated active transport system for conveying glucose into the human red cell was tested in connection with a number of related substances, comprising 6-carbon aldoses and ketoses, 5-carbon aldoses, and 5- or 6-carbon polyhydric alcohols.
2. The alcohols did not perceptibly penetrate the cells; all the sugars penetrated, the rates differing, but all of the same order of magnitude.
3. All the aldoses penetrated according to the pattern previously reported for glucose, in that the rate of penetration was not directly related to the gradient, but subject to some limiting factor.
4. The ketoses penetrated approximately according to the pattern of passive diffusion.
5. When present in equal concentrations, any aldose prevented or greatly delayed the entrance of a ketose, while the ketose did not perceptibly alter the rate of aldose uptake. Within each class, similar inhibitory relations were observed.
6. Penetration of all the sugars showed a high temperature coefficient and was inhibited by the mercuric ion or p-chloromercuribenzoate; certain of the sugars showed a residual degree of penetration not thus inhibitable.
7. Penetration of the ketoses was selectively inhibited by barbital.
8. These observations are interpreted in terms of simple equilibria between the various sugars and a hypothetical carrier molecule in the membrane, with which the sugars form a complex during their passage through the membrane. Comparisons between the sugars in relation to their reactions with the carrier system are indicated.
TISSUE HEMOLYSINS AS LYSIN-INHIBITOR COMPLEXES
Authors: Ponder Eric 
Published: May 2004

1. Lytic substances are enzymatically produced at 37°C. from tissue slices or homogenates (mouse liver, kidney, etc.) and appear in the medium in which the tissue fragments are suspended. Their concentration increases with the time during which the tissue is kept at 37°C. (preincubation), and is accompanied by pH changes, so that the lytic activity as finally measured is a function of both the time of preincubation and of the pH. The optimum pH for lysin production is above 7.0, but the lysins, once produced, hemolyze red cells more rapidly at low pH's than at high ones. The enzyme system which produces the lysins is inactivated by heating to 100°C. for 5 minutes. Sodium iodoacetate and fluoride interfere with lysin production principally by reducing the concomitant pH shift; KCN accelerates the production of lytic material in mouse liver homogenates.
2. Comparison of the lytic activity of the supernatant fluid of a preincubated homogenate with the much greater lytic activity of the substances which can be extracted from the same supernatant fluid by alcohol and ether points to these extractable substances existing in the supernatant fluid as lysin-inhibitor complexes of relatively low lytic activity. These complexes are formed enzymatically during preincubation from non-lytic complexes in the tissue. The latter may be lipoproteins, and the highly lytic ether-extractable substances may be fatty acids or their soaps.
3. The diffusibility of the lysin-inhibitor complexes is small.
4. Lytic substances which are ether-insoluble can be extracted with alcohol from tissues as well as from serum. These "lysolecithin-like" substances exist in the supernatant fluids of homogenates as lysin-inhibitor complexes.
5. Lysis of mouse red cells by substances contained in mouse tissue (liver and kidney) is often accompanied by the formation of methemoglobin and choleglobin. Mouse red cells containing choleglobin are abnormally fragile both osmotically and mechanically, and it is possible that a process involving the production of choleglobin, accompanied or followed by globin denaturation, is one which contributes towards the hemolysis which occurs in systems containing tissue slices or homogenates.
SULFHYDRYL GROUPS IN RELATION TO THE METABOLISM AND MOTILITY OF HUMAN SPERMATOZOA
Authors: MacLeod John 
Published: May 2004

1. The motility and metabolism of human spermatozoa are inhibited by substances which have an affinity for sulfhydryl groups.
2. These inhibitions can be prevented, and in part, reversed, by the addition to the cell + inhibitor system of sulfhydryl compounds such as cysteine or glutathione.
3. Cysteine and glutathione, under aerobic conditions or in a system in which these substances can be oxidized, show widely different effects on the motility of the spermatozoa. Cysteine destroys the motility of the spermatozoa, whereas glutathione has no effect upon it.
4. Possible mechanisms of these effects are discussed.
UPTAKE AND RETENTION OF FIXED CARBON IN ADULT MICE
Authors: Buchanan Donald L. ,   With the Technical Assistance of Alberta DiVittorio and Akira Nakao
Published: May 2004

1. Mice were continuously exposed to air containing C14O2. The specific radioactivities of urea carbon, total fecal carbon, and numerous components of tissue carbon were compared as a function of the duration of exposure with the radioactivity of the air CO2.
2. The data indicate that the total CO2 fixed from the air is proportional to its concentration in the air.
3. When the CO2 concentration in the air is normal (0.03 per cent) about 0.34 per cent of the carbon of urea originates from air CO2. A lesser proportion of the non-urea carbon of urine has its origin from air CO2.
4. Only about 0.0054 per cent of the total fecal carbon is derived from air when the CO2 concentration is 0.03 per cent. The constituents, which are extractable with alcohol and water, contain considerably higher proportions of fixed carbon than either the insoluble residue or the ether-extractable material.
5. The rates of uptake at the beginning of the exposure and the rates of loss at the termination of the exposure differed strikingly among the tissues studied.
6. However, the ultimate ratio of fixed air CO2 carbon to total carbon in these tissues seemed to be approaching limiting values which would not vary by more than a factor of 3 from one another. It appears that of the total organic carbon in an adult mouse approximately 0.01 per cent may originate directly from the CO2 of the air when the animal respires in air having a CO2 concentration of 0.03 per cent, and that 1.8 per cent or more of the total carbon may originate from CO2 within the animal.
7. Data are presented which indicate the life span of the mouse erythrocyte to be 49 days.
8. Calculations made on the basis of these experimental data and the accepted standard for permissible radiation in the human would allow mice to be continuously exposed to air containing 31 µc. per c.m. without ever exceeding the accepted permissible level for humans.
POTASSIUM MOVEMENT IN RELATION TO NERVE ACTIVITY
Authors: Shanes Abraham M. 
Published: May 2004

The depolarization of crab nerve during repetitive stimulation is unaffected by the presence of glucose or by an increase in the calcium content of the medium. It is increased in both amplitude and rate by veratrine; in the presence of this alkaloid mixture the rate but not the magnitude of the depolarization is increased by an elevation in the calcium concentration. Repolarization following stimulation is unaltered by glucose and accelerated by a greater calcium concentration. Veratrine increases both the amplitude and the time constant of repolarization; its effect on the time constant is counteracted by an elevation of the calcium in the medium.
Potassium released during stimulation and its reabsorption following activity have been observed by analyses of small volumes of sea water in contact with crab nerve. Under the conditions employed 3 x 10–8 µM potassium is liberated per impulse per gm. wet weight of nerve. This loss is increased by low concentrations of veratrine, which also increase the amount reabsorbed during recovery. The depletion of potassium from the medium is appreciably less if the potassium previously released during activity has not been removed.
Inexcitability resulting from anoxia can be washed away with oxygen-free solution—rapidly and completely in the case of the squid axon, slowly and incompletely in crab nerve.
The potassium shifts are in the proper direction and of the correct order of magnitude to account for the negative and positive after-potentials in terms of potassium accumulation or depletion in the extracellular space.
THE HEMOGLOBIN OF THE SEA LAMPREY, PETROMYZON MARINUS
Authors: Wald George , Riggs Austen 
Published: May 2004

The blood hemoglobin of the sea lamprey presents a curious mixture of primitive and highly specialized properties. Like muscle hemoglobin, it has a molecular weight of about 17,000, and apparently contains a single heme. Its isoelectric point is like that of a typical invertebrate hemoglobin. Its amino acid composition is partly characteristic of invertebrate) partly of vertebrate hemoglobins (Pedersen; Roche and Fontaine).
In the present experiments, the oxygen equilibrium curve of this pigment was measured at several pH's. As expected, it is a rectangular hyperbola, the first such function to be observed in a vertebrate blood hemoglobin.
Other hemoglobins known to possess this type of oxygen dissociation curve—those of vertebrate muscle, the worm Nippostrongylus, and the bot-fly larva—appear to serve primarily the function of oxygen storage rather than transport. Lamprey hemoglobin on the contrary is an efficient oxygen-transporting agent. It achieves this status by having, unlike muscle hemoglobin, a relatively low oxygen affinity, and a very large Bohr effect. In these properties it rivals the most effective vertebrate blood hemoglobins.
FRACTIONATION OF PLASMA GLOBULIN FOR PROTHROMBIN, THROMBOKINASE, AND ACCESSORY THROMBOPLASTIN
Authors: Milstone J. H. 
Published: May 2004

1. Crude globulin from more than 1,000 liters of citrated bovine plasma has been used in developing a procedure for moderately large scale separation of clotting factors. Fraction A, prothrombin, kinase, and thrombin fractions were prepared. Fraction A contained both kinase and accessory thromboplastin, the latter predominating when fraction A was diluted.
2. When prothrombin was activated by kinase, the rate of thrombin production was enhanced by the addition of platelets, or brain lipid, or dilute fraction A. These accessory thromboplastins caused this acceleration only when calcium chloride was added. Even with calcium, they were not effective unless kinase was present.
3. In contrast, the action of kinase was not entirely dependent on either ionic calcium or accessory thromboplastin. The concentrated kinase fraction activated prothrombin in the presence of excess oxalate. Although kinase often contaminates highly purified thrombins, it is probably distinct from thrombin. The ratio of kinase to thrombin was 100 times as great in the kinase fraction as in the thrombin fraction.
4. The kinase fraction, diluted 45,000-fold, to protein-nitrogen concentrations as low as 0.02 microgram per ml., accelerated the conversion of crude prokinase in three-stage tests.
5. The findings are consistent with the following concept of the basic enzymatic mechanism:
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It is now added that calcium and accessory thromboplastin exert their effects by impinging on the basic mechanism, in a chemically secondary or indirect manner.