bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDIES ON THE METABOLISM OF AUTOTROPHIC BACTERIA
Authors: Vogler K. G.
Published: May 2004

In a study of chemosynthesis (the fixation of CO2 by autotrophic bacteria in the dark) in Thiobacillus thiooxidans, the data obtained support the following conclusions:

1. CO2 can be fixed by "resting cells" of Thiobacillus thiooxidans; the fixation is not "growth bound."

2. The physiological condition of the cell is of considerable importance in determining CO2 fixation.

3. CO2 fixation can occur in the absence of oxidizable sulfur in "young" cells. The extent of this fixation appears to be dependent upon the pCO2.

4. CO2 fixation can also occur under anaerobic conditions and the presence of sulfur does not influence such fixation.

5. However, in the CO2 fixation by cells in the absence of sulfur, only a limited amount of CO2 can be fixed. This amount is approximately 40 µl. CO2 per 100 micrograms bacterial nitrogen. After a culture has utilized this amount of CO2 it no longer has the ability to fix CO2 but releases it during its respiration.

6. Relatively short periods of sulfur oxidation can restore the ability of cells to fix CO2 under conditions where sulfur oxidation is prevented.

7. It is possible to oxidize sulfur in the absence of CO2 and to store the energy thus formed within the cell. It is then possible to use this energy at a later time for the fixation of CO2 in the entire absence of sulfur oxidation.

8. Cultures of Thiobacillus thiooxidans respiring on sulfur utilize CO2 in a reaction which proceeds to a zero concentration of CO2 in the atmosphere.

9. CO2 may act as an oxidizing agent for sulfur.

10. Hydrogen is not utilized by the organism.

11. It is possible to selectively inhibit sulfur oxidation and CO2 fixation.
THE ANTIGENICITY OF d-RIBONUCLEASE; THE INHIBITION OF THE ENZYME BY ITS HOMOLOGOUS IMMUNE SERUM
Authors: Smolens J. , Sevag M. G.
Published: May 2004

The enzyme d-ribonuclease is antigenic. Antisera, prepared by three different methods, reacted against antigen dilutions up to one million.

Apparently the homologous antiserum, when combined with the d-ribonuclease inhibited the activity of the enzyme from 10 to 30 per cent.
HUMORAL RHEOLOGY
Authors: Copley Alfred L. , Krchma Ludwig C. , Whitney Mary E.
Published: May 2004

1. A modified falling ball viscometer (rolling ball viscometer) for blood and other humors is presented. It is capable of easily measuring flow properties at several stresses, as is required to define satisfactorily the properties of anomalous flow systems. At high shearing stresses, apparent specific viscosity values of 2.5 + are observed, corresponding to 2.2 ±0.2 reported as possible with the biological viscometer of Whittaker and Winton.

2. Previous references to the anomalous flow properties of blood were verified. It was demonstrated that these systems conform to the Bingham concept of anomalous flow. To define completely the flow properties of such systems it is necessary to make determinations at at least two shearing stresses, preferably more. Data are reported for the pseudoviscosity and yield value, the latter being possibly the most specific property of the three bloods studied.

3. Heparin in increasing amounts tended to decrease the apparent viscosity, pseudoviscosity, and yield value of blood. Similar increases of heparin also reduced the viscosites of the serum and plasma.

4. The ratio of the apparent viscosity of blood and its plasma was found to be reasonably constant as reported by Trevan. However, as the apparent viscosity is a function of the shearing stress, it is believed that the relationship for the calculations of corpuscular concentrations, such as the Whittaker and Winton modification of the Hatschek formula, is specific for the instrument and conditions of tests by which it was determined.

5. Heparinized blood was found to exhibit thixotropy, dilatancy, and age-hardening phenomena.
ALLOCATION OF ELECTRICAL RESPONSES FROM THE COMPOUND EYE OF GRASSHOPPERS
Authors: Jahn Theodore Louis , Wulff Verner John
Published: May 2004

1. The effect of extirpation of the optic ganglion on the ERG and on electrical oscillations recorded from the compound eye was determined.

2. Extirpation of the optic ganglion prevents the occurrence of oscillations, and it is concluded that they originate in the ganglion.

3. Extirpation of the optic ganglion changes the wave form of the ERG. The sharpness of the b-wave is decreased, the relative magnitude of the c-wave is increased, and the d-wave is obliterated. These changes can be explained by assuming that the ERG is the algebraic sum of two potential changes, one in the compound eye, and another, of opposite sign in the ganglion. This assumption is supported by data from a number of experiments in which the electrode positions were varied.

4. The explanation of the present data (which indicates two sites of origin of the ERG) is similar to the three-component theory which accounts for the complex wave form of the vertebrate ERG.
STUDIES ON THE METABOLISM OF AUTOTROPHIC BACTERIA
Authors: Vogler K. G. , LePage G. A. , Umbreit W. W.
Published: May 2004

The data of this paper indicate that:

1. The "energy of activation" (µ) of sulfur oxidation by the autotrophic bacterium, Thiobacillus thiooxidans, is similar to that of other respirations.

2. The pH of the menstruum does not influence the respiration on sulfur between the limits of pH 2 to 4.8 once contact between the bacterial cell and the sulfur particle has been established but it does influence the rate at which such contact occurs.

3. The pO2 has little effect upon the respiration of this organism.

4. Most organic materials have no detectable effect upon the respiration of Thiobacillus thiooxidans, but the organic acids of terminal respiration seem to stimulate the respiration in the absence of oxidizable sulfur and certain of them inhibit sulfur oxidation.

5. In so far as inhibitor studies on intact cells are trustworthy, sulfur oxidation goes through iron-containing systems similar to cytochrome. It is possible that the oxygen contained in the sulfuric acid formed during sulfur oxidation is derived from the oxygen of the water.
THE pH STABILITY OF PROTYROSINASE AND TYROSINASE
Authors: Allen Thomas Hunter , Otis Arthur B. , Bodine Joseph Hall
Published: May 2004

1. pH stability diagrams for protyrosinase and for tyrosinase were constructed.

2. Above pH 7.30 protyrosinase is unstable. Between pH 7.30 and pH 9.30 there is a partial destruction. Beyond pH 9.30 it changes irreversibly into tyrosinase which in turn is destroyed beyond pH 10.12.

3. Through the lower ranges of pH protyrosinase is less stable than tyrosinase The former is destroyed below pH 4.80, while the latter is unaffected until the pH drops below 4.10.

4. The tyrosinase produced at high pH values resembles that produced by other methods.
STUDIES ON THE METABOLISM OF THE AUTOTROPHIC BACTERIA
Authors: Vogler K. G. , Umbreit W. W.
Published: May 2004

In the autotrophic bacterium, Thiobacillus thiooxidans, the oxidation of sulfur is coupled to transfers of phosphate from the medium to the cells. CO2 fixation is coupled to transfers of inorganic phosphate from the cells to the medium and is dependent, in the absence of concomitant sulfur oxidation, upon the amount of phosphate previously taken up during sulfur oxidation. The energy reservoir, which is formed by sulfur oxidation in the absence of CO2 and which can be released for the fixation of CO2 under conditions which do not permit sulfur oxidation, is a phosphorylated compound and the data suggest that the energy is stored in the cell as phosphate bond energy. It is possible to oxidize sulfur at a constant rate for hours in the absence of CO2. The phosphate energy formed during this process is probably released by cell phosphotases. It is possible to inhibit these phosphotases by means of inorganic phosphate and thus to inhibit sulfur oxidation in the absence of CO2. In the presence of CO2, where alternative uses for the phosphate energy are available, the inhibition is relieved. Sulfur oxidation (energy input) is coupled, not to CO2 fixation, but to phosphate esterification. CO2 fixation (energy utilization) is coupled with phosphate release.
THE USE OF A MEASURABLE CAUSE OF DEATH (HEMORRHAGE) FOR THE EVALUATION OF AGING
Authors: Simms Henry S.
Published: May 2004

1. There has been need for a reliable experimental standard for the process of aging. Chronological age is a poor standard owing to irrelevant changes and individual variability. Longevity does not indicate the rate of aging because it depends not only upon aging but also upon intrinsic death rate, individual variability, and the selective effect of experimental treatment upon resistance to specific diseases.

2. The use of a known measurable cause of death (hemorrhage) on healthy animals of various ages reproduces the known mortality curve for rats, and differentiates this measure of the aging process from individual variation.

3. The possibilities for the use of this method in determining the nature of the aging process are pointed out.
THE EFFECT OF SPECIFIC POISONS UPON THE PHOTO-REDUCTION WITH HYDROGEN IN GREEN ALGAE
Authors: Gaffron Hans
Published: May 2004

1. The effect of poisons upon the photoreduction with hydrogen in Scenedesmus and similar algae has been studied. The poisons used were cyanide, hydroxylamine, dinitrophenol, and carbon monoxide, substances known to inhibit more or less specifically certain enzymatic reactions.

2. It was found that quite generally one has to distinguish between the action of poisons upon the photoreduction in the stationary state, once this type of metabolism has been well established in the cells, and their effects on transition phenomena, on the "adaptation" and its reversal, the "turnback" from photoreduction to photosynthesis.

3. Cyanide inhibits photoreduction more strongly than it inhibits photosynthesis in the same algae. It is concluded that the mechanism of oxygen liberation, which is idle in photoreduction, is not very sensitive to cyanide.

4. Hydroxylamine in low concentrations is a powerful inhibitor of photosynthesis but has practically no influence on the rate of photoreduction. Consequently, it is assumed that it acts in photosynthesis mainly by inhibiting the evolution of oxygen. Greater concentrations of hydroxylamine clearly inhibit photoreduction, but diminish the rate to about one-half only. A greater degree of inhibition is obtained only by prolonged incubation.

5. Dinitrophenol was found to inhibit strongly the reduction of carbon dioxide, under aerobic as well as under anaerobic conditions. A stimulating effect of dinitrophenol can be demonstrated only with respiration or fermentation, not with photosynthesis.

6. Carbon monoxide interferes with all phases of the hydrogen metabolism in algae. It is supposed therefore to be a specific inhibitor for the hydrogenase system.

7. The "adaptation" to the hydrogen metabolism, which takes place if the algae are incubated anaerobically in hydrogen for several hours, is inhibited completely by very small amounts of cyanide. The adaptation reaction is more sensitive to cyanide than most of the other metabolic processes in the same cell. Correspondingly cyanide enhances the return to aerobic conditions, the "turnback," which occurs under the influence of light of high intensities.

8. Hydroxylamine, applied aerobically, inhibits the adaptation reaction to about the same degree as it inhibits photosynthesis. Photoreduction proceeds after the adaptation in presence of hydroxylamine only at a fraction of the rate that it would have if the poison were added later.

9. Hydroxylamine in concentrations of 10–3 M protects the anaerobic metabolism against the return to aerobic photosynthesis which normally occurs under the influence of light of too high intensity. The protection is only relative and the higher the light intensity the more hydroxylamine is needed to keep photoreduction going. Once a "turnback" occurs in presence of much hydroxylamine all photochemical gas exchange comes to an end.
ACTION OF INHIBITORS ON HYDROGENASE IN AZOTOBACTER
Authors: Wilson J. B. , Wilson P. W.
Published: May 2004

The inhibitors usually associated with the activity of the cytochrome oxidase system—cyanide and carbon monoxide—are also effective in reducing the oxidation of H2 by intact cells of Azotobacter vinelandii. The hydrogenase system is more sensitive to CO than is the respiratory system.

Oxidation of a carbon source and of hydrogen by Azotobacter cells is inhibited in a quantitatively different manner by the following compounds: sodium azide, hydroxylamine, sodium iodoacetate, and sodium fluoride. In every case, a concentration range which is definitely inhibitory for respiration has little or no effect on the hydrogenase activity.

The differential inhibition by hydroxylamine explains certain observations in the literature which have been erroneously interpreted as demonstrating a specific inhibition by NH2OH of biological nitrogen fixation. This supposed demonstration has been offered as support for the hypothesis that NH2OH is an intermediate in the fixation reaction.

The differential inhibitors can be used for detection of hydrogenase in cultures possessing a high endogenous respiration. The method is illustrated by an experiment with root nodule bacteria from pea and cowpea nodules. No hydrogenase was found in either.
THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR
Authors: Sollner Karl , Carr Charles W.
Published: May 2004

1. Experiments were carried out to decide whether or not the electromotive properties of dried collodion membranes depend upon their thickness.

2. A number of dried collodion membranes of varying thickness, 3–160 µ, were prepared from collodion preparations of different electrochemical activity. The characteristic concentration potentials across them were measured and the means of these values determined for each thickness.

3. The characteristic concentration potentials across dried collodion membranes are a function of their thickness. The thinnest membranes yield in all cases the lowest concentration potentials; increasingly thicker membranes give increasingly higher potential values, until a constant value is reached which is characteristic of the particular collodion preparation used. With electrochemically active collodion, characteristic concentration potentials approaching the thermodynamically possible maximum are obtained with membranes of only 10 µ thickness, thinner membranes giving appreciably lower values. With two rather inactive commercial collodion preparations the characteristic concentration potential increases from about 30 mv. for membranes 3 µ thick to about 42 mv. for 20 µ membranes; still thicker membranes do not show a significant increase in the potential values. With a highly purified collodion preparation the constant maximum value was found to be about 32 mv., 4 µ thick membranes giving only about 22 mv.

4. These results do not support the homogeneous phase theory as applied to the dried collodion membrane. They are readily compatible with the micellar-structural theory. Several special possible cases of the latter as applied to the dried collodion membrane are discussed.
THE TURNOVER RATE OF PHOSPHOLIPIDS IN THE PLASMA OF THE DOG AS MEASURED WITH RADIOACTIVE PHOSPHORUS
Authors: Zilversmit D. B. , Entenman C. , Fishler M. C. , Chaikoff I. L.
Published: May 2004

1. A method for the determination of turnover time and turnover rate of plasma phospholipid is presented.

2. During the postabsorptive state 5.2 to 8.0 mg. of phospholipid phosphorus are turned over per hour in the plasma of dogs weighing 6–9 kilos.

3. The amount of phospholipid in an organ that is supplied by plasma phospholipid per hour is calculated.
STUDIES ON THE MECHANISM OF HYDROGEN TRANSPORT IN ANIMAL TISSUES
Authors: Potter V. R. , DuBois K. P.
Published: May 2004

1. The mechanism of succinic dehydrogenase action was studied by means of inhibitors.

2. The enzyme is inhibited by a large number of diverse compounds whose only common denominator appears to be their ability to react with SH groups. These compounds include quinonoid structures, sulfhydryl reagents, sulfhydryl compounds, copper, zinc, selenite, and arsenite.

3. In contrast to the above inhibitors, the action of malonate does not appear to involve sulfhydryl groups and is explained on the basis of its affinity for the enzyme groups which react with the carboxyl groups of succinate.

4. The action of malonate and the sulfhydryl reactants is mutually exclusive, and this fact suggests the conclusion that the sulfhydryl group of the enzyme is located between the carboxyl affinity points.

5. On the basis of the deduced structure of the succinate-activating center of the enzyme, it is suggested that the enzyme may function by oscillating between the EnSH and EnS· forms, rather than by a thiol-disulfide equilibrium.
PACEMAKERS IN NITELLA
Authors: Osterhout W. J. V.
Published: May 2004

An electrical impulse traveling along a Nitella cell may produce a complete or a partial response. The two kinds of response may occur in regular alternation.

The partial response varies greatly and may be so far reduced as to appear as a local thickening in the upstroke of the action curve, usually accompanied by a more or less pronounced hump. In consequence a considerable variety of action curves is produced.

The observations show that different regions of the cell may react differently.
NATIVE AND REGENERATED BOVINE ALBUMIN
Authors: Martin Donald S. , Erickson John O. , Putnam Frank W. , Neurath Hans
Published: May 2004

1. The effects of regeneration of whole bovine albumin on antigenic activity and serological specificity were determined by precipitin measurements on rabbit antisera to (1) native whole albumin, (2) albumin regenerated from 8 M urea, and (3) albumin regenerated from 8 M guanidine hydrochloride.

2. While numerically the mean antibody response to these three antigens was found to decrease in the order named, only the difference in antigenic activity between native and guanidine hydrochloride-regenerated albumin was statistically significant. Native, crystalline, carbohydrate-free albumin (crystalbumin) was considerably less antigenic than native whole bovine albumin, its activity being comparable to, if not less than, that observed for guanidine hydrochloride-regenerated whole albumin.

3. All four antigens were immunologically equivalent.

4. The antigenic activity of these proteins is discussed in terms of protein structure and carbohydrate content.
THEORY AND MEASUREMENT OF VISUAL MECHANISMS
Authors: Crozier W. J. , Wolf Ernst
Published: May 2004

Flicker response contours (F vs. log Im) for a square image subtending 0.602° on a side, located in the fovea, are simplex probability integrals for a "white" and for four (five) spectral regions filtered from this white, and with different light-time fractions in the flash cycle. The subjective phenomena (the appearance of the field, the intensity threshold for color, and others) at the fusion points along these contours parallel in a variety of ways those obtained on duplex flicker contours resulting from the use of larger or eccentrically placed flickered images. These phenomena therefore cannot be held to indicate involvements of "rod" excitation.

The scatter of the index of variation of I1 is such as to demonstrate the full participation of all the potentially excitable neural units at all levels of flash frequency, for each kind of light. The magnitude of this scatter, a measure of neural integration in visual performance, is a function of the number of these units (with Fmax. nearly constant); the two quantities vary together when wave-length composition of light is altered.

The properties of the contours for a white light and for the spectral regions filtered from it show that, for the image within the fovea, different numbers of units are excitable in flicker recognition according to the wave-length band used, and different mean frequencies of elements of effect under fixed conditions. The changes in the mean intensity for activation of these units as a function of the light-time fraction in the flash cycle are correlated with the numbers of these units; when this is corrected for, it is pointed out that despite the differences in shape of F vs. log I it cannot be concluded that the mechanism of excitation differs for different wave-lengths. It is indicated that "white" must be regarded as a synthesis, not a mere summation, of effects due to different spectral regions. Certain differences are pointed to as between foveal and more peripheral regions tested, and as between observers differing in the degree of the "yellow spot effect," with regard to the relative effects of wave-length and of image area. A general consequence is the outlining of conditions required for the precise comparison of excitabilities as a function of wave-length in the multivariate visual system.
STUDIES ON THE ANOMALOUS VISCOSITY AND FLOW-BIREFRINGENCE OF PROTEIN SOLUTIONS
Authors: Lawrence A. S. C. , Needham Joseph , Shen Shih-Chang
Published: May 2004

1. A coaxial viscosimeter which permits the simultaneous determination of relative and anomalous viscosity and of flow-birefringence is described. Flow-anomaly and flow-birefringence are regarded as characteristic of elongated micelles and molecules.

2. Such methods have been applied to dilute solutions of proteins. The conditions under which the coaxial (Couette) viscosimeter measures the viscosity of the bulk phase and the surface film phase respectively have been investigated and are described.

3. The general behaviour of protein solutions subjected to shear is summarised.
STUDIES ON THE ANOMALOUS VISCOSITY AND FLOW-BIREFRINGENCE OF PROTEIN SOLUTIONS
Authors: Lawrence A. S. C. , Miall Margaret , Needham Joseph , Shen Shih-Chang
Published: May 2004

1. An extensive investigation has been made of protein particle shape using the methods of flow-birefringence and anomalous viscosity measurement in the coaxial cell.

2. As a result of investigations on a number of proteins, it is concluded that they may be divided into four groups.

Group A consists of those which show flow-anomaly both in the bulk phase and in the surface film. These also show flow-birefringence in the bulk phase. Examples: tobacco mosaic disease virus nucleoprotein; myosin. Though corpuscular proteins, they have elongated particles before denaturation.

Group B consists of those which show flow-anomaly only (in the first instance) in the surface film, and no flow-birefringence in the bulk phase. They are probably close to spherical in shape in solution, but form elongated particles as they denature in the surface film. After this process has been completed, they may show flow-anomaly also in the bulk phase. Some proteins show flow-anomaly in the surface film immediately it forms, others only show it after a certain time has elapsed for the building up of the film. We designate the former as group B1 and the latter as group B2.

Group B1, immediate surface film flow-anomaly. Examples: serum euglobulin, amphibian embryo euglobulin b.

Group B2, slowly appearing surface film flow-anomaly. After the film has once been fully formed and then dispersed by shaking, the solution may have the properties of that of a protein in group B1; i.e., anomalous flow in the film may occur immediately on testing in the viscosimeter. Examples: avian ovalbumin, amphibian embryo pseudoglobulin.

Group C consists of those proteins which show flow-anomaly neither in the bulk phase nor in the surface film, under the conditions used by us. They are probably close to spherical in shape. Examples: insulin, methaemoglobin, amphibian embryo euglobulin c, mucoproteins.

3. The theoretical significance of protein fibre molecules, whether native or formed by denaturation in the living cell, is discussed, especially in relation to experimental morphology and cytology.
THE EFFECT OF CARBON DIOXIDE TENSION ON THE METABOLISM OF CEREBRAL CORTEX AND MEDULLA OBLONGATA
Authors: Craig Francis N.
Published: May 2004

Manometric measurements were made of oxygen uptake (QOO2) and aerobic lactic acid output (QG) by slices of cerebral cortex and medulla oblongata of the cat in the presence of mixtures of 1, 5, and 20 volumes per cent of carbon dioxide in oxygen. The concentrations of NaHCO3 and NaCl in the medium were varied to maintain constant pH and sodium ion concentrations. The calcium ion concentration was 0.0002 M.

At pH 7.5 under these conditions, an increase in carbon dioxide from 1 per cent to 5 per cent doubled the QG of both tissues but did not alter QOO2; an increase from 5 per cent to 20 per cent carbon dioxide had no further effect on QG in either tissue or QOO2 of cortex, but did depress the QOO2 of medulla.

At pH 8.1, an increase in carbon dioxide from 1 per cent to 5 per cent raised the QOO2 and QG of cortex by about 60 per cent.

Measurements at low oxygen tension carried out previously in phosphate medium were repeated in bicarbonate medium to obtain data for the combined output of lactic acid and carbon dioxide (QA). When the oxygen in the gas phase was decreased from 95 to 3 volumes per cent, the lactic acid output as measured colorimetrically increased by 114 mg./gm. in cortex and by 8 mg./gm. in medulla; QA increased from 12.3 to 13.5 in cortex and decreased from 5.1 to 3.8 in medulla.
DIFFERING RATES OF DEATH AT INNER AND OUTER SURFACES OF THE PROTOPLASM
Authors: Osterhout W. J. V.
Published: May 2004

When protoplasm dies it becomes completely and irreversibly permeable and this may be used as a criterion of death. On this basis we may say that when 0.2 M formaldehyde plus 0.001 M NaCl is applied to Nitella death arrives sooner at the inner protoplasmic surface than at the outer.

If, however, we apply 0.17 M formaldehyde plus 0.01 M KCl death arrives sooner at the outer protoplasmic surface.

The difference appears to be due largely to the conditions at the two surfaces. With 0.2 M formaldehyde plus 0.001 M NaCl the inner surface is subject to a greater electrical pressure than the outer and is in contact with a higher concentration of KCl. In the other case these conditions are more nearly equal so that the layer first reached by the reagent is the first to become permeable.

The outer protoplasmic surface has the ability to distinguish electrically between K+ and Na+ (potassium effect). Under the influence of formaldehyde this ability is lost. This is chiefly due to a falling off in the partition coefficient of KCl in the outer protoplasmic surface.

At about the same time the inner protoplasmic surface becomes completely permeable. But the outer protoplasmic surface retains its ability to distinguish electrically between different concentrations of the same salt, showing that it has not become completely permeable.

After the potential has disappeared the turgidity (hydrostatic pressure inside the cell) persists for some time, probably because the outer protoplasmic surface has not become completely permeable.
THE PENETRATION OF AMMONIA INTO FROG MUSCLE
Authors: Fenn Wallace O. , Haege Lorraine F. , Sheridan Eugenia , Flick John B.
Published: May 2004

1. A study was made of the electrolyte changes which occur when frog muscles are immersed in a Ringer solution with 1/5 of the Na replaced by NH4Cl. Analyses were made in the solution and in the muscles for K and NH3, and the muscles were also analyzed for Cl, HCO3, and Na. Control muscles were immersed in normal Ringer's solution and similarly analyzed.

2. The amount of ammonia taken up was about equal to the K and Na lost. There was also a small increase in chloride content. The bicarbonate content was the same in both experimental and control muscles, indicating no change in the muscle pH due to the NH3 which penetrated. An increased loss of K due to the penetration of NH3 was also demonstrated by the use of radioactive K.

3. After 5 hours, the concentration of ammonia per gram of muscle is about the same as the concentration in the solution. After 4 or 5 days, the concentration in the muscle is about 1.5 times that in the solution. The inside to outside NH3 ratio is about equal to the corresponding H ion ratio, but is much less than the K ratio.

4. The rate of penetration of the NH3 is increased by a rise of temperature, by stirring the solution, and by decrease in the concentration of Na, K, Ca, or Mg in the solution; it is decreased by increasing the size of the muscles or by killing them with chloroform or boiling.

5. Liver, smooth muscle, skin, and kidney, in a few experiments, behaved much like muscle except that there was a formation of urea in the case of liver.

6. The injection of NH4Cl into anesthetized cats causes an increase in the level of K in the blood plasma.
THE RHEOLOGY OF THE BLOOD. III
Authors: Bingham Eugene C. , Roepke Raymond R.
Published: May 2004

The authors have confirmed the fact that blood serum and plasma behave rheologically like a true viscous liquid. It is true for whole blood only to a first approximation, but with this reservation they have studied the available data and extended the equation of Bingham and Durham to cover protein solutions of various concentrations and at various temperatures as well as mixtures of proteins and corpuscles present in whole blood. If Φ is the fluidity of whole blood, Φ1 is the fluidity of water and ΔΦ = Φ – Φ1, then

ΔΦ = ß1b1 + ß2b2 + ß3b3 + ···

where ß1, ß2, ß3, etc., are constants for the fluidity lowering of the salts, albumin, globulin, fibrinogen, and the corpuscles, etc., present in the whole blood.

The conclusions from the data referred to are intended to buttress this simple equation (6).
CULTURE CONDITIONS AND THE DEVELOPMENT OF THE PHOTOSYNTHETIC MECHANISM
Authors: Myers Jack , Clark L. B.
Published: May 2004

1. An apparatus has been developed which maintains a constant density of population of Chlorella by automatic dilution of the growing culture with fresh medium.

2. Cells harvested from the apparatus in daily samples are highly uniform in rate of growth and rate of photosynthesis measured under arbitrarily chosen conditions.
THE RHEOLOGY OF THE BLOOD
Authors: Bingham Eugene C. , Roepke Raymond R.
Published: May 2004

In the preceding paper (1b) a formula was developed for the lowering of the fluidity of a medium by a mixture of proteins, given the volume concentration of each and its fluidity-lowering constant. Whole blood is now shown to follow an essentially similar formula, except that the hemoglobin content is taken from the literature as the best available measure of the volume of the blood cells Δ Φ = 0.24H, assuming the fluidity of the medium to be 53 rhes. Age, sex, diet, barometric pressure affect the hemoglobin content of the blood, but the formula may apply to any healthy human blood to about 3 per cent. The shape, number, and size of the blood cells, if known, might help to explain discrepancies as well as the state of oxidation of the blood. In disease the discrepancy becomes much greater, suggesting the possible use of rheology in diagnosis.
THE STRUCTURE OF THE COLLODION MEMBRANE AND ITS ELECTRICAL BEHAVIOR
Authors: Carr Charles W. , Gregor Harry P. , Sollner Karl
Published: May 2004

The technique of Abrams and Sollner for the preparation of electropositive dried protamine collodion membranes has been improved. Porous collodion membranes cast on the outside of rotating tubes are treated for 48 hours with a solution of 2 per cent protamine sulfate buffered at pH 11. After being washed thoroughly the membranes are dried in air for several hours, soaked in water for several hours, and removed from the tubes. Further drying in air but without support shrinks the membranes slightly. The resulting membranes are designated "permselective" or "megapermselective" protamine collodion membranes. These membranes regularly give characteristic concentration potentials of –52 to –53 mv. and (in 0.1 M KCl) resistance of 0.5 to 15 ohms per membrane of 50 cm.2 area. This resistance is several orders of magnitude smaller than that of the conventional dyestuff- and alkaloid-impregnated positive membranes. The megapermselective protamine collodion membranes can be kept either dry or in water for prolonged periods without detectable deterioration. They are quite smooth, have a regular shape, and stand considerable handling without breakage.

The megapermselective protamine collodion membranes are the electropositive analogues of the electronegative megapermselective collodion membranes described by Carr and Sollner.
ELECTRIC TISSUE
Authors: Cox R. T. , Coates C. W. , Brown M. Vertner
Published: May 2004

In the main electric organs of the electric eel, the cross-sectional area, the thickness of the electroplaxes, and certain electrical characteristics of the tissue vary widely between the anterior and posterior ends. However, a transverse layer of the organs one electroplax thick has certain characteristics which are roughly uniform along the organs. These are its volume, its maximum voltage, its maximum current per unit area, and the resistance of unit area at the peak of the discharge.

Measurements of the voltage developed by a segment of the organs across different external resistances at different instants during the discharge are all rather well described by representing the segment, with the adjacent non-electric tissue, as a simple combination of E.M.F. and ohmic resistance. The internal resistance of the tissue varies during the discharge. Its E.M.F. appears to be practically constant, at least during the greater part of the discharge.

Estimates made of the total electric energy show it about equal to the energy supplied by the decrease of phosphocreatine and the formation of lactic acid.
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.
SOME EFFECTS OF DERIVATIVES OF VITAMIN K ON THE METABOLISM OF UNICELLULAR ALGAE
Authors: Gaffron H.
Published: May 2004

Vitamin K1, 2-methyl-3-phytyl-1,4-naphthoquinone, is a substance found in all plant chloroplasts. It is, therefore, interesting to know whether it has any influence upon the metabolism of plants. Experiments made with the phytol-free derivatives like 2-methyl-1,4-naphthoquinone or the corresponding 3-oxy compound, phthiocol, gave the following results. These substances accelerate the respiration of Chlorella or Scenedesmus in a way similar to the action of the dinitrophenols. They inhibit photosynthesis and the compensation of respiration in the light strongly like hydroxylamine. In Scenedesmus they hinder the adaptation to the anaerobic utilization of hydrogen. If given after adaptation in amounts sufficient to stop photosynthesis they do not prevent photoreduction but rather stabilize this reaction against reversion. Their presence destroys the coupling between the reduction of carbon dioxide in the dark and the oxyhydrogen reaction in adapted algae. One can expect, therefore, that the natural vitamin K present in plants in concentrations of about 10–3 M takes part in some metabolic reaction as a catalyst or regulator.
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.