bluuebunny/crossref_metadata_2025 huggingface dataset:
PHOTOOXIDATIONS IN PIGMENTED BLEPHARISMA
Authors: Giese Arthur C. , Zeuthen Erik
Published: May 2004

1. Blepharisma undulans, a protozoan with a reddish pigment, shows increased oxygen consumption under the influence of light.

2. If the light intensity is high, the animals are killed during a burst of oxygen consumption.

3. If the blepharismas are first bleached by exposure to light of low intensity they show only slightly increased oxygen consumption under the influence of light and they are not killed.

4. A preparation in which the animals are killed by heat still shows the increase in oxygen consumption on illumination with brilliant light. The supernatant solution does so as well, as does an alcohol extract of the dye.

5. The conclusion is drawn that the blepharismas are killed during photooxidation of the pigment, but the mechanism of action is not clear. Several possibilities are considered in the discussion.
PEPTIDASE INCREASE ACCOMPANYING GROWTH OF THE LARVAL SALIVARY GLAND OF DROSOPHILA MELANOGASTER
Authors: Patterson Elizabeth K. , Dackerman Marjorie E. , Schultz Jack
Published: May 2004

1. The larval salivary gland of Drosophila melanogaster offers an opportunity to study growth in a tissue in which no cell division occurs but in which the cells increase in size.

2. Measurements of alanylglycine (AG)-peptidase content have been made in three stocks of Drosophila melanogaster at different growth stages of the larval salivary gland, and have been correlated with its total nitrogen and volume.

3. During the prepupal instar, the AG-peptidase content of the gland increases parallel with total nitrogen but decreases when histolysis of the gland begins. Conversely, a benzoyl-l-arginineamide-hydrolyzing endopeptidase is not measurable until histolysis sets in.

4. In the final larval growth period of a giant mutant, there is a concomitant increase in peptidase, total nitrogen, and volume of the gland.

5. A similar association of peptidase content and total nitrogen is found in comparing glands of different sizes from the giant stock, at the time of maximal peptidase content in the prepupa.

6. The data are interpreted as evidence for an association of AG-peptidase with growth of the cells in the gland. This agrees with the earlier interpretation by Linderstrøm-Lang and Holter of data obtained from study of more complex tissues.

7. A survey of the available measurements of peptidase content in other organisms shows that wherever an increase of cell substance occurs, peptidase content increases. Conversely, peptidase remains constant where cell division is unaccompanied by an increase of cell substances.

8. The joint association of peptidases and pentosenucleic acids with protein synthesis is pointed out.

9. The possiblity is considered that peptidases may be essential parts of a unit in which coupled reactions necessary for protein synthesis occur. The rôle of the peptidases in this system is discussed. They may act either synthetically to form new peptide linkages (problematic), or hydrolytically to mobilize the necessary specific amino acids.
METHYL GREEN-PYRONIN
Authors: Kurnick N. B.
Published: May 2004

1. Methyl green stains selectively highly polymerized desoxyribonucleic acid, and fails to stain, to any significant extent, depolymerized desoxyribonucleic acid and ribonucleic acid.

2. Pyronin stains preferentially low polymers of nucleic acid.

3. Triphenylmethane dyes with two amino groups appear to share the selectivity of methyl green. Those with three amino groups are not selective.

4. A stereochemical hypothesis is offered to account for these observations.
CARBOHYDRATE METABOLISM OF SCHISTOSOMA MANSONI
Authors: Bueding Ernest
Published: May 2004

1. Schistosoma mansoni utilizes in 1 hour an amount of glucose equivalent to one-sixth to one-fifth of its dry weight. Over 80 per cent of the metabolized glucose is converted to lactic acid by this organism.

2. The rates of glucose utilization and of lactic acid production by S. mansoni are the same under aerobic and under anaerobic conditions.

3. A high rate of lactic acid production and the absence of a postanaerobic increase in the oxygen uptake differentiate S. mansoni from most other parasitic helminths whose metabolism has been studied.

4. Arsenite and p-chloromercuric benzoate inhibit in low concentrations the oxygen uptake and the rate of glycolysis of S. mansoni. This inhibition is not prevented or reversed by an excess of glutathione or of thioglycollate.

5. Fluoride inhibits the removal of glucose and the production of lactic acid by S. mansoni to the same degree.

6. Low concentrations of quinacrine (atabrine) do not affect the respiration or the carbohydrate metabolism of the schistosomes.

7. The inhibitory effect of aldehydes on the metabolism of S. mansoni has been measured. Among this group of compounds dl-glyceraldehyde and o-nitrobenzaldehyde are the most effective inhibitors of glycolysis.

8. In a concentration of 2.6 x 10–6 M (1:1,000,000) a cyanine dye inhibits almost completely the respiration of the schistosomes, but has no effect on their rate of glycolysis. The oxygen uptake of the worms is inhibited by fuadin to a greater degree than their rate of glycolysis. 2-methyl-1,4-napthoquinone is a much more effective inhibitor of glycolysis than of the respiration of S. mansoni. The latter compound interacts with plasma albumin and, therefore, its inhibitory action on the metabolism of the schistosomes is greatly reduced in human serum or plasma.

9. Evidence is discussed which indicates that, in contrast to glycolysis, respiratory metabolism is not essential for the survival of S. mansoni.
STUDIES ON CELL ENZYME SYSTEMS
Authors: Chase Aurin M.
Published: May 2004

Solutions of the enzyme luciferase, extracted from Cypridina, were subjected at pH 6.8 to temperatures from 40–55°C. for times up to 24 hours. After the desired exposures samples were cooled rapidly to room temperature, mixed with luciferin, and the first order velocity constants (representing luciferase activity) of the resulting luminescent reactions were determined by a photo electric method.

The form of the curve relating luciferase activity to time of exposure to a temperature in the above range is compound in nature. If the exposure to the high temperature is not too long, about two-thirds of the lost activity is slowly regained on standing at room temperature.

The data were described by an equation which represents the following mechanism:

See PDF for Equation

A plot of the logarithm of the rate constant, k1, against the reciprocal of the absolute temperature yielded an experimental activation energy for this reaction of about 57,000 calories, typical of protein denaturation processes. Log k2 plotted against 1/T was described by either a curve or two straight lines, high activation energies resulting in either case, again indicating protein denaturation. The plot of log k3: vs. 1/T showed no apparent dependence upon temperature, k3 being practically constant over the range studied. This may indicate that the underlying mechanism is not actually as simple as pictured. Two other mechanisms that were also considered were discarded because of lack of experimental support.

Measurements of the decrease of luciferase activity at 48°C. and at pH 6.7, pH 5.5, and pH 7.9 showed that inactivation of the enzyme at this temperature was much more rapid at pH 7.9 than at pH 6.7 and was even faster at pH 5.5.

These results from the Cypridina luminescent system were compared with those of other investigators on other systems.
AGEING AND THE INFLUX OF WATER INTO RADISH ROOT-HAIR CELLS
Authors: Rosene Hilda F.
Published: May 2004

A micropotometric device previously described by the writer was used to determine quantitatively the velocity of water influx in cubic microns per square micron of hair surface per minute of comparatively older and younger root hairs of radish seedlings in a humid atmosphere at 29° ± 1°C. when the micropotometers were filled with Hoagland solution at pH 6.8. In each experiment, measurements were made on two hairs of different length and different age on a given root and the hairs were inserted into the micropotometers a sufficient distance so that the area of immersion, 13,200µ2, was the same in each instance.

The range of velocities of water influx through the immersed surface was 4.46 to 1.16µ3/µ2/min. for the younger and shorter hairs which varied in length from 280 to 460 microns. The range of velocities of water influx through the immersed surface of the older hairs which varied from 661 to 2300 microns in length was 1.94 to 0.47µ3/µ2/min. The data indicate that water entry slows down in older hairs independent of root length.

Estimations were made of the times to replace hair volumes based upon the mean velocities of water entry of the immersed areas. It was found that the time for the hairs to absorb an amount of water equivalent to their own volumes under the conditions specified was a matter of minutes or less; the range was 0.90 to 8.51 minutes.
THE INFLUENCE OF INSULIN ON THE RATE OF GLUCOSE OXIDATION BY PASTEURELLA PESTIS
Authors: Levine H. B.
Published: May 2004

The rate of oxidation of glucose by freshly harvested resting cells of P. pestis strain A-1122 was accelerated by 20 to 41 per cent in the presence of insulin. The stimulatory action was not noted when cell-free enzyme preparations were employed and was less marked after storage of cells for 3 days. Although insulin was not oxidized by the organism, the amount of oxygen consumed during the dissimilation of a unit weight of glucose was increased in the presence of the hormone.
ADSORPTION STUDIES IN A SYNTHETIC RUBBER LATEX-OVALBUMIN SYSTEM
Authors: Williams H. B. , Choppin A. R.
Published: May 2004

1. Adsorption of ovalbumin on the latex surface was in excess of the quantity required to produce coverage of the surface over most of the protein concentrations range which was investigated.

2. "S" shaped isothermals which probably indicated multilayer adsorption were obtained.

3. The quantity of ovalbumin required to produce a constant surface charge density on the latex particle surface was a function of the pH, and a theory of active centers on the latex particles has been suggested.

4. A shift in the isoelectric point from that of native ovalbumin has been observed for the protein when adsorbed on a synthetic latex.
PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES
Authors: Price Winston H.
Published: May 2004

1. A strain of S. muscae which requires a substance present in certain acid-hydrolyzed proteins (AHPF) for virus liberation when singly infected in Fildes' synthetic medium no longer needs this substance when multiply infected.

2. In the absence of the AHPF under conditions of multiple infection the amount of phage released is approximately equal to the number of infecting particles between two to ten. Over ten particles per cell has no further effect on the yield of virus.

3. The experimental evidence indicates that it is the phage particle and not some other component in the lysate which can replace the AHPF.

4. The minimum latent period and rise period of cells singly infected in the presence of the AHPF and multiply infected in the absence of the AHPF are the same.

5. The desoxynucleic acid synthesis of cells, infected with a very few virus particles in the presence of excess AHPF and multiply infected with ten particles in the absence of the AHPF, occurs at approximately the same rate, with both infected samples synthesizing about the same amount of desoxynucleic acid and liberating the same yields of virus.

6. A strain of S. muscae which requires aspartic acid for virus synthesis when singly infected does not need this substance when multiply infected, the burst size under the latter conditions depending upon the multiplicity of infection between 3 to 12 particles per cell.

7. The data indicate that the virus released from multiply infected cells in the absence of added AHPF or aspartic acid is newly synthesized virus and not the original infecting particles.

8. The phage particle contains the AHPF and aspartic acid.

9. As a tentative working hypothesis, it is assumed that the AHPF and aspartic acid for phage formation under conditions of multiple infection, in the absence of added AHPF, or of aspartic acid, are contributed by the original infecting particles.

10. Ultraviolet-inactivated phage is adsorbed to the host cell and kills the cell although little virus is released under the experimental conditions.

11. Ultraviolet-inactivated phage particles, if added before the active particle is adsorbed, will greatly inhibit the liberation of new virus particles; but does not do so if added a few minutes after the active particle has been adsorbed.

12. Under the experimental conditions, reactivation of phage when present in multiply infected cells does not occur; and such ultraviolet-inactivated phage cannot serve as a source of the AHPF or aspartic acid, although the AHPF can be liberated from such inactivated particles by acid hydrolysis.

13. The results are discussed in relation to Luria's experiments with ultraviolet-treated phage and to his "gene pool" hypothesis of phage formation.
RATE OF EXCRETION OF N15 AFTER FEEDING N15-LABELED l-ASPARTIC ACID IN MAN
Authors: Wu Hsien , Snyderman Selma E.
Published: May 2004

1. l-Aspartic acid labeled with N15 was fed to one human adult and six infants, and the total N and N15 were determined in the urine from time to time.

2. The N15 concentration (or isotopic ratio) of urinary N reached its maximum in the adult about 2 hours and in the infants about 4 hours after feeding, then fell off logarithmically.

3. Assuming that the N of aspartic acid readily entered into equilibrium with other N compounds in the pool, the rate of turnover of the N pool was calculated from the rate of fall of the isotopic ratio of urinary N. This rate of turnover of N was about 4 per cent per hour in the adult and 6 to 12 per cent per hour in the infants.

4. The rate of protein synthesis calculated from the rate of turnover of N was 10 mg. N per kilo per hour in the adult and 18 to 27 mg. N per kilo per hour in the infants, with one exception which showed a higher rate of 52 mg. N per kilo per hour. The size of the metabolic pool of N per kilo in non-growing infants was about the same as that in the adult (0.4 to 0.5 gm.) but it was somewhat larger in growing infants (0.5 to 0.8 gm.).
THE DESOXYRIBONUCLEIC ACID CONTENT OF ANIMAL CELLS AND ITS EVOLUTIONARY SIGNIFICANCE
Authors: Mirsky A. E. , Ris Hans
Published: May 2004

1. Evidence is summarized for the constancy of DNA content for each set of chromosomes in the various cells of an organism.

2. The DNA contents of the egg and sperm nuclei are the same.

3. A brief survey is given of DNA contents per cell in invertebrates and vertebrates.

(a) In invertebrates there is some slight evidence that when primitive and higher forms are compared the amount of DNA per cell is increased in the latter.

(b) In fishes there is a tendency for the amount of DNA per cell to remain constant within the different species of a family.

(c) The values of DNA per cell in lung fishes, amphibians, reptiles, and birds suggest that in the evolution of these vertebrates there has been a decline in DNA content per cell.

4. Concerning the significance of quantity of DNA per cell in vertebrates:

(a) It appears not to be in proportion to the number of different genes in a cell.

(b) It may be related to the number of strands in the chromosomes.

(c) In homologous cells of different animals it is directly related to the mass of the cell.
SOME EFFECTS OF 2537 Å ON GREEN ALGAE AND CHLOROPLAST PREPARATIONS
Authors: Holt A. S. , Brooks I. A. , Arnold W. A.
Published: May 2004

1. The kinetics of the inactivation of photosynthesis by 2537 Å in Chlorella pyrenoidosa and Scenedesmus D1 indicate that, while the destruction process is largely a first order effect, higher order effects also occur, which become evident at low exposures. In agreement with previous observations, endogenous respiration is insensitive to exposures which inactivate photosynthesis.

2. In Scenedesmus D1 a solid dose of ultraviolet has no more effect on the photosynthetic apparatus than a dose of equal total duration interrupted by periods of photosynthesis. Nor is any difference noted if the cells are in a different buffer, e.g. 0.05 M KH2PO4, or carbonate-bicarbonate buffer 9.

3. In C. pyrenoidosa, a solid dose and an interrupted dose cause equal effects on photosynthesis when neutral phosphate buffer is used. If the ultraviolet exposure schedules are identical, equal effects are also noted in cells suspended in buffer 9, and in 0.05 M phosphate (pH 6.2). Solid exposures are, however, much more effective than interrupted exposures, when buffer 9 is used.

4. Oxygen evolution (Hill reaction), photosynthesis, and photoreduction in Scenedesmus D1 are equally sensitive to a given dose of ultraviolet. The mechanism responsible for adaptation to hydrogen metabolism is not more sensitive to ultraviolet than is the photosynthetic mechanism. The O2/H2/CO2 reaction in darkness is less sensitive to ultraviolet than any of the above reactions.

5. Glucose oxidation by C. pyrenoidosa, and colony formation in Scenedesmus D1 are far more sensitive to a given dose of ultraviolet than photosynthesis in these organisms.

6. The photosynthetic apparatus of C. pyrenoidosa is more sensitive to ultraviolet than that of Scenedesmus D1.

7. The Hill reaction in chloroplast fragments is also inactivated by 2537 Å by a first order process. Exposures which inactivate this reaction completely have no effect on polyphenol oxidase, cytochrome oxidase, or catalase in the same chloroplast preparation.

8. After irradiation, the survival of photosynthesis in Scenedesmus D1 and of the Hill reaction in chloroplast fragments are independent of the light intensity used to measure these processes.

9. No significant changes occur in the ultraviolet absorption of chloroplasts after an exposure to 2537 Å, which completely inactivates the Hill reaction.
ACTION OF INHIBITORS AT THE MYONEURAL JUNCTION
Authors: Kirschner L. B. , Stone W. E.
Published: May 2004

1. A study is presented of the actions of certain inhibitors on the frog rectus abdominis muscle stimulated by acetylcholine.

2. A type of analysis has been developed which provides a reliable criterion for judging whether an inhibitor is competing with acetylcholine for receptors at the myoneural junction or whether acting by a different mechanism.

3. The "curares" are shown to act by competitive inhibition at the myoneural junction, confirming earlier work of others on the mode of action of curare.

4. Atropine acts as an inhibitor at the myoneural junction. The inhibition may be non-competitive or it may be complicated by an additional effect at some point other than the myoneural junction.

5. A possible mechanism for anomalous inhibitor effects is the action of a single compound at more than one locus in the Ach mechanism. Eserine exerts such a dual effect at the end-plate.

6. Some of the available electrical and chemical data have been correlated to make possible a partial explanation of the role of Ach in transmission at the myoneural junction.
THE OXYGEN EQUILIBRIUM OF THE HEMOGLOBIN OF THE EEL, ANGUILLA ROSTRATA
Authors: Riggs Austen
Published: May 2004

Kawamoto had reported that eel hemoglobin has a hyperbolic oxygen equilibrium function, with n in the Hill equation equal to 1. On the basis of Kawamoto's data and with new measurements, it is shown that the equilibrium function is in fact S-shaped, as in most other vertebrates, and n in Hill's equation equals 1.8.
SOLUBILITY CHANGES OF PROTEINS IN SEA URCHIN EGGS UPON FERTILIZATION
Authors: Monroy Alberto , Oddo Anna Monroy
Published: May 2004

The results presented in this paper give evidence of changes in solubility occurring in a protein fraction of the eggs of Arbacia lixula upon fertilization. The electrophoretic analysis indicates that it is only one part of one of the components of the KCl fraction that undergoes the change. However, under some experimental conditions (freezing and thawing of the KCl fraction or extraction of the whole eggs with water at room temperature) a larger portion of the KCl fraction, namely the whole group of components a and b, may be involved and undergoes coagulation. Therefore assuming that the results obtained on the extracts of frozen-dried fertilized eggs do reflect what actually occurs under natural conditions, we must also assume the existence of mechanisms controlling the extent of this change in the living eggs. The fact that in many cases one part or the whole of the sensitive fraction has been found to undergo an increase in solubility may suggest that the process of coagulation discovered by Mirsky is a two-step process. In the first step the sensitive fraction undergoes a change that makes it more soluble and then, when certain conditions are fulfilled, coagulation occurs. An alternative explanation could also be that the coagulated or coagulating fraction is attacked by the proteolytic enzyme that, as shown by Lundblad (1949, 1950), is activated on fertilization. This, however, seems to be less probable, as extraction was always carried out at 0° C. and in as short a time as possible.

However, further experiments are needed to decide whether the coagulation of the sensitive fraction is an actual occurrence under natural conditions. The results obtained with the eggs of Arbacia punctulata may cast some doubt on this assumption.
RESTORATION INDUCED BY CATALASE IN IRRADIATED MICROORGANISMS
Authors: Latarjet Raymond , Caldas Luis Renato ,   With the Technical Assistance of Pierre Morenne and Liliane Chamaillard
Published: May 2004

1. E. coli, strain K-12, and B. megatherium 899, irradiated in strict but still undefined physiological conditions with certain heavy doses of ultraviolet light, are efficiently restored by catalase, which acts on or fixes itself upon the bacteria in a few minutes. This restoration (C. R.), different from photorestoration, is aided by a little visible light.

2. At 37° the restorability lasts for about 2 hours after UV irradiation; the restored cells begin to divide at the same time as the normal survivors.

3. C. R. is not produced after x-irradiation.

4. B. megatherium Mox and E. coli, strain B/r show little C. R.; E. coli strain B shows none. None of these three strains is lysogenic, whereas the two preceding catalase-restorable strains are.

5. Phage production in the system "K-12 infected with T2 phage" is restored by catalase after UV irradiation, whereas phage production in the system "infected B" is not.

6. With K-12, catalase does not prevent the growth of phage and the lysis induced by UV irradiation (Lwoff's phenomenon).

7. Hypotheses are discussed concerning: (a) the chemical nature of this action of catalase; (b) a possible relation between C. R. and lysogenicity of the sensitive bacteria; (c) the consequences of such chemical restorations on the general problem of cell radiosensitivity.
CHANGES IN NON-PROTEIN NITROGEN METABOLISM DURING TOBACCO MOSAIC VIRUS BIOSYNTHESIS
Authors: Commoner Barry , Dietz Phyllis M.
Published: May 2004

1. Discs cut from tobacco leaf tissue infected with tobacco mosaic virus and cultured in water contain less non-protein nitrogen than comparable uninfected discs during the time at which TMV is formed. This deficiency disappears when virus formation ceases. Discs cultured in nutrient solution form about twice as much TMV as discs cultured in water. The maximum non-protein nitrogen deficiency is comparable in magnitude to the amount of virus synthesized.

2. The largest difference between injected and uninfected tissue occurs in the ammonia content. Smaller, but significant differences in amide content are found. Infected discs cultured in water show no significant differences from control discs in free amino acid content; infected discs cultured in nutrient solution develop a small deficiency in amino acid nitrogen.

3. The general patterns of change in composition of the pool of soluble nitrogen are similar in both infected and uninfected discs.

4. The data indicate that the bulk of the nitrogen incorporated into virus protein is withdrawn from the leaf's pool of soluble nitrogen; virus is formed de novo from ammonia nitrogen and non-nitrogenous carbon sources. The effect of virus infection on host nitrogen metabolism appears to be due to the formation of virus rather than to its presence.
SULFHYDRYL GROUPS AND THE INTERACTION BETWEEN THE HEMES IN HEMOGLOBIN
Authors: Riggs Austen F.
Published: May 2004

1. Dialysis of a hemoglobin solution against slightly alkaline buffer (pH 8.68) causes a decrease in heme-heme interaction. The value of n in Hill's equation drops from 2.9 to 2.0, while the oxygen affinity increases slightly. Addition of glutathione largely reverses the effects of dialysis (n rises from 2.0 to 2.5 to 2.6).

2. Addition of the sulfhydryl reagent, p-chloromercuribenzoate (1.8 x 10–3 M), results in a large though not complete blocking of heme-heme interaction. The value of n drops from 2.9 to 1.4. This effect is largely reversed with glutathione (n rises to 2.6).
CHARACTERISTICS OF COLLODION MEMBRANES FOR ULTRAFILTRATION
Authors: Bugher John C.
Published: May 2004

An apparatus for the production of graded collodion membranes is described. The theoretical considerations of calibration are discussed in relation to the demonstrable structure and statistical characteristics of the membranes. A new definition of an "end-point" is suggested.
RESPIRATION AND INTENSITY DEPENDENCE OF PHOTOSYNTHESIS IN CHLORELLA
Authors: Brackett Frederick S. , Olson Rodney A. , Crickard Robert G.
Published: May 2004

1. Respiration changes as a result of illumination.

2. In the absence of glucose or other supply of substrate, respiration decays in the dark showing at least two types—a fast decay in a few minutes and a slow decay lasting hours.

3. Respiratory response to illumination is delayed.

4. Intermittent illumination (in the absence of glucose, etc.) produces a periodic variation in respiration with a delay or phase lag.

5. Periodic variation of respiration may produce a higher average value in the dark than in the light due to the lag and depending upon the period of intermittent illumination.

6. Based upon average respiration values our data confirm the Kok effect.

7. Interpolated values of respiration, however, result in photosynthetic rates which are linearly dependent upon intensity of illumination.

8. Thus the quantum efficiency is found to be independent of intensity, over the wide range of intensities investigated.
METABOLIC FACTORS INFLUENCING THE SODIUM AND POTASSIUM DISTRIBUTION IN ULVA LACTUCA
Authors: Scott George T. , Hayward Hugh R.
Published: May 2004

1. Methods for the use of the marine green alga, Ulva lactuca, in studies on electrolyte metabolism are described.

2. The effect of illumination and iodoacetate on the potassium and sodium content, as well as the influence of light and running sea water on the iodoacetate effect was investigated. The rate of exchange of cellular potassium ion for K42 under conditions of light and dark at 20 and 30°C. was studied.

3. Ulva maintained in the dark for long periods loses some potassium and gains sodium, both effects being reversed upon illumination. The presence of 0.001 M iodoacetate in the dark causes a marked progressive loss of potassium and gain of sodium, phenomena which do not occur when the alga is illuminated. Evidence for the penetration of the inhibitor into the cell in the presence of light is presented. The iodoacetate effect on potassium and sodium content, once established, can be "washed out" of the alga when the plant is placed in light and running sea water without the inhibitor. Illumination and increased temperature each favor a more rapid exchange of tissue for environmental potassium ion.

4. In the interpretation of these findings it is emphasized that metabolic work, perhaps in the form of ion transports, must be done by the cell to compensate for the continual flow of potassium ion and sodium ion with their respective concentration gradients and thus maintain homeostasis within the cell. Evidence is presented which indicates separate mechanisms for the distribution of sodium and potassium in this organism. It is further suggested that the degradation of phosphoglyceric acid, an important glycolytic and photosynthetic intermediate, or one of the products of its metabolism supplied the energy for these ion transports(s). The role of permeability per se is considered.
AXOPLASMIC PROTEINS OF THE SQUID GIANT NERVE FIBER WITH PARTICULAR REFERENCE TO THE FIBROUS PROTEIN
Authors: Maxfield Myles
Published: May 2004

1. Axoplasm of squid giant nerve fibers is examined with the ultracentrifuge and electrophoresis apparatus and several distinct components demonstrated.

2. One of these components, a protein called axon filaments, is isolated by fractional extraction followed by differential ultracentrifugation and redissolving in glycine solution. Axon filaments are monodisperse by ultracentrifugation. Their physical chemical properties have been studied.

3. The existence of a reversible transformation of axon filaments into a particle of lower molecular weight and lower asymmetry has been demonstrated.
A STUDY OF THE ACTION OF PHAGOLESSIN A58 ON THE T PHAGES
Authors: Hall Elizabeth A. , Asheshov Igor N.
Published: May 2004

Phagolessin A58, an antibiotic substance active against a number of bacterial viruses, was studied for activity against the seven T phages. Only three of the seven phages—T1, T3, and T7—proved to be sensitive to the antibiotic. The antibiotic caused a direct, apparently irreversible inactivation of free phage particles.

A study of the properties of the inactivated phage particles showed that the particles retained the ability to kill host cells and to exert mutual exclusion against an unrelated phage after infectivity was lost. There was a progressive loss in these two properties when higher concentrations of antibiotic were used to inactivate the phage. Results with inactivated T3 and T7 revealed that these two properties—the ability to kill host cells and to exclude an unrelated phage—were lost at a different rate. They were, therefore, presumed to be different properties of these particular phage particles.

The inactivation of phage by phagolessin A58 was inhibited by desoxyribose nucleic acid and to a lesser extent by ribose nucleic add. Cytosine, thymine, adenine, guanine, and cysteine failed to inhibit the reaction.
TISSUE CULTURE STUDIES
Authors: Rosenberg Sheldon , Kirk Paul L.
Published: May 2004

Some of the compounds in the active fraction of ultrafiltrates of chick embryo extract have been identified as taurine, serine, glutamic acid, xanthine, uracil, glucose-6-phosphate, glucose, ferrous iron, and inorganic phosphate.

Based on the identity of these compounds a synthetic replacement for the ultrafilterable portion of chick embryo extract has been devised. There is an additional nutritional requirement that can be met by vitamin B12. Folic acid appears to be beneficial to the system though the requirements of this or any of the above compounds except vitamin B12 remain for future research. The low nitrogen content of the isolated fraction and the synthetic mixture suggests that the main nutrition of chick cells in roller tube cultures is derived from the non-dialyzable portion of the medium.
A COMPARISON OF FIVE EFFECTS OF ULTRAVIOLET LIGHT ON THE ARBACIA EGG
Authors: Blum Harold F. , Cook John S. , Loos Gordon M.
Published: May 2004

The demonstration of five different effects of ultraviolet radiation on the sea urchin's egg indicates that more than one basic photochemical process goes on there. Photorecovery is observed in only one of these. The need for caution in interpreting such effects is obvious.

Evidence for a different mechanism for the timing of cleavage in eggs activated by ultraviolet radiation as compared to normally fertilized eggs is presented.

The bearing of these studies on survival curves for microorganisms is discussed.
EARLY EFFECTS OF HIGH INTENSITY X-RADIATION ON SKELETAL MUSCLE
Authors: Gerstner Herbert B. , Lewis Robert B. , Richey Everett O.
Published: May 2004

Comparative studies of x-radiation effects on both isolated cold blooded (frog) and intact warm blooded (rabbit) muscles were performed. Frog muscles irradiated with doses above 50 kr showed early fatigue, contracture, prolongation of relaxation time, decreased contraction amplitude for heavy loads, and histologic changes noticeable 8 hours after exposure. Rabbit muscles exposed to 72 kr exhibited a gradually progressing impairment of function. Complete abolishment of function was reached within 24 hours following irradiation and was accompanied by severe histologic alterations.
AN ENZYMATIC LOCUS PARTICIPATING IN CELLULAR DIVISION OF A YEAST
Authors: Nickerson Walter J.
Published: May 2004

Growing cells of a filamentous mutant of a yeast, Candida albicans, were found to accumulate and reduce tetrazolium dyes whereas cells of the parent strain, growing as a normally budding yeast, accumulated the dye but did not reduce it. In older cultures, in which rapidly metabolizable carbohydrate has been depleted, the parent strain characteristically produces filaments. These cells, growing in the absence of cellular division, also exhibit tetrazolium reduction. The filamentous mutant synthesizes cell mass at a rate almost equal to that of the parent strain and is not distinguished therefrom in fermentation ability, nutritional requirements for growth, rate of endogenous respiration, or polysaccharide composition. These facts, in conjunction with the striking differences in tetrazolium reduction, lead to the conclusion that the morphological mutant has an impairment to a cellular oxidation mechanism at a flavoprotein locus. This locus is, then, the site at which a reaction essential for cellular division, is coupled via an oxidation-reduction to cellular metabolism. Preliminary evidence is presented providing good indication that uncoupling of cellular division (by genetic block) in the mutant or in the parent (by substrate exhaustion) results from impairment to a dissociable metal chelate mechanism which normally couples a reaction essential to cellular division to flavoprotein oxidation.
THE IDENTITY OF THE FLUORESCENT AND DELAYED LIGHT EMISSION SPECTRA IN CHLORELLA
Authors: Arnold William , Davidson J. B.
Published: May 2004

1. The delayed light emission of Chlorella pyrenoidosa over the wave length range 400 to 950 mµ has been investigated.

2. Emission of delayed light is confined to the range 600 to 800 mµ.

3. To the precision with which the low light intensities involved can be measured with the apparatus in these experiments, the emission spectrum of the delayed light is the same as the spectrum of the fluorescent light.

4. Thus the delayed light must come from excited chlorophyll.
THE ISOLATION OF A STAPHYLOCOCCAL PHAGE VARIANT SUSCEPTIBLE TO AN UNUSUAL HOST CONTROL
Authors: Ralston D. J. , Krueger A. P.
Published: May 2004

A series of phage P1 variants was isolated from plaques developing on S. aureus WF 145. One in particular, phage 14, was studied in detail because its host range appeared to be dependent on the previous host of production; i.e., it was subject to a host control. When this phage was produced on host K1 its lysate assayed equally well on both 145 and K1 cells. When produced on host 145, however, it assayed manyfold higher on 145 than on host K1. All its particles adsorbed on K1 cells, but only a small percentage were able to produce plaques. No differences could be found in adsorption rates, latent periods, or burst sizes of the phage on the two hosts. No extracellular inactivating substances could be detected which could account for such changes, nor could the results be explained readily on a mutational basis, since distinct phage strains could not be isolated. The change in virus properties was found to occur in the first burst of singly infected host 145 cells, regardless of the previous host or its prior lytic abilities.

Heat inactivation destroyed activity for K1 cells more rapidly than for 145 cells. This was found to be a property of both the stock phage P1 and phage 14. Phage 14 could be heated until there remained particles which could multiply only on strain 145. When the plaques of such survivors were examined they were found to contain phage which could multiply on both hosts in a ratio characteristic of the original unheated preparation.

The data suggest that the observed changes were caused by a host control over the formation of a phage material(s) necessary for successful infection of host K1. Such a substance theoretically could be related to the labile material destroyed by heat and required for plaque formation on host K1.
STUDIES IN CELL PERMEABILITY
Authors: Foulkes E. C.
Published: May 2004

The uptake of pyruvate by yeast was studied under a variety of conditions of temperature, extracellular concentration, O2 pressure, and pH. It was shown that physical diffusion adequately explains the permeation of undissociated pyruvic acid into the outer and inner regions of the cell. The entrance of pyruvate ion into the outer region appears to take place by the same process. The passage of pyruvate ion across the membrane separating the outer from the inner region was found to occur only under conditions under which pyruvate is metabolized. The mechanism of the active process involved in the uptake of pyruvate is not known.
GLUCOSE-6-PHOSPHATE AND 6-PHOSPHOGLUCONATE DEHYDROGENASES FROM EGGS OF THE SEA URCHIN, ARBACIA PUNCTULATA
Authors: Krahl M. E. , Keltch A. K. , Walters C. P. , Clowes G. H. A.
Published: May 2004

1. Glucose-6-phosphate and 6-phosphogluconate dehydrogenases have been found in homogenates of Arbacia eggs; 95 per cent of the activity toward each substrate is recovered in the supernatant fraction after centrifuging at 20,000 g for 30 minutes.

2. With glucose-6-phosphate as substrate) the rate of TPN reduction by the supernatant fraction from 1 gm. wet weight unfertilized or fertilized eggs was 1.8 to 3.0 micromoles per minute; this rate is sufficient to support a rate of oxygen consumption 24 times that observed for unfertilized, and 6 times that for fertilized, eggs. Pentose was formed from glucose-6-phosphate at a rate 0.3 to 0.5 that of TPN reduction, when both rates were expressed as micromoles per minute.

3. The concentrations of glucose-6-phosphate and 6-phosphogluconate for half maximal activity were each approximately 0.00004 M for the respective enzymes in the supernatant fraction. Maximal activity toward 6-phosphogluconate was 50 to 60 per cent of that toward glucose-6-phosphate. Glucose-6-phosphate dehydrogenase activity was 50 per cent inhibited in presence of 0.00006 M 2,4,5-trichlorophenol.

4. Reduction of DPN by the supernatant fraction in presence of fructose-1,6-diphosphate and ADP was 0.1 to 0.2 micromoles per minute per gm. wet eggs, indicating that the glycolytic pathway can metabolize glucose-6-phosphate at about 5 per cent the rate at which it can be oxidized by the TPN system from unfertilized or fertilized Arbacia eggs.

5. Phosphoglucomutase, hexose isomerase, and a phosphatase for fructose-1,6-diphosphate also appear to be present in Arbacia eggs.
THE NON-VIRUS PROTEINS ASSOCIATED WITH TOBACCO MOSAIC VIRUS
Authors: Commoner Barry , Yamada Mas
Published: May 2004

1. Exhaustive fractionation of leaves from tobacco plants systemically infected with TMV has led to the isolation of two non-virus proteins, B3 and B6, and the detection of a third, A4, which do not occur in comparable uninfected plants.

2. Components B3 and B6 have been found consistently in a series of ten extracts from plants grown over an 18 month period in all seasons of the year. It is concluded that these components are as characteristic of the infected plant as TMV itself.

3. As they occur in the initial extracts, the non-virus proteins are of low molecular weight (S20 ca. 3). On treatment, each component tends to form a high molecular weight polymer with an electrophoretic mobility considerably greater than that of the starting material. The high molecular weight derivatives of A4, B3, and B6 have been designated A8, B8, and B7 respectively. There is no evidence that these high molecular weight components occur as such in the infected leaf.

4. The non-virus proteins are free of nucleic acid and are not infectious. They cross-react immunochemically with TMV.

5. Compared with TMV content, the amounts of the non-virus proteins found in infected leaf are relatively small, falling in the range of 10 to 150 micrograms per gm. of tissue.
RELATIONSHIPS BETWEEN TOBACCO MOSAIC VIRUS AND THE NON-VIRUS PROTEINS
Authors: Commoner Barry , Rodenberg Sidney D.
Published: May 2004

1. The non-virus proteins, A4, B3, and B6, characteristically found in tobacco leaf infected with TMV exhibit specific immunochemical cross-reactions with serum prepared against the virus. The close immunochemical relations which occur among these proteins do not extend to any normal tobacco leaf proteins.

2. The rate of appearance of the non-virus proteins in newly infected cultured leaf tissue at various times after inoculation has been determined by immunochemical techniques and by direct isolation of the proteins. Both methods give comparable results. The non-virus proteins appear abruptly at about 220 hours after inoculation, when the TMV content is about one-third its final value. The amount of A4 rises rapidly and then levels off. The B6 content rises rapidly and continuously over the course of the experiment. B3 appears last, and increases in amount considerably more slowly than A4 and B6.

3. The isotope contents of TMV, B3, and B6 which appear in given intervals after inoculation in newly infected leaf cultured in nutrient containing N15H4 have been compared. The isotope levels of concurrent TMV, B3, and B6 are identical within the experimental error. The isotope conditions employed in this experiment lead to the conclusion that this coincidence of N15 levels means that the virus and non-virus proteins are probably synthesized at about the same time from the same non-protein source of nitrogen.

4. Possible interpretations of the available data on the non-virus proteins are discussed. It is likely that one or more of these proteins represents small protein units which occur in the TMV nucleoprotein.As they exist in the infected leaf, the non-virus proteins are probably no longer available to the biochemical processes which lead to TMV synthesis. They are probably not precursors of TMV protein in a temporal sense.
ACCUMULATION OF SULFATE LABELLED WITH S35 BY RAT TISSUE IN VITRO
Authors: Deyrup Ingrith J. , Ussing Hans H.
Published: May 2004

Rat kidney slices incubated in vitro may show, in parallel with other shifts in electrolyte content, a striking capacity for accumulating sulfate ion (sulfate labelled with S35). The uptake is reversed or reduced by CN-, cooling to room temperature, and by interference with adequate oxygenation. Under the conditions of the experiment, the presence in the medium of sodium acetate and glucose as substrates was found to be without measurable effect on the accumulation. The extent of sulfate uptake is related to the ionic composition of the medium in which the tissue is incubated, for the uptake occurs optimally only in the presence of a K+ level of about 0.04 M, and is decreased as the concentration of Na+ rises. Likewise, when Ca++, Mg++, or choline is present in the medium, sulfate accumulation may be depressed. In addition to renal cortex, kidney medulla and liver showed capacity for sulfate accumulation, whereas no convincing evidence for significant uptake was obtained with strips of aorta, colon, or diaphragm.
AN APPLICATION OF AUTOCORRELATION METHODS TO THE INTERPRETATION OF INTESTINAL MOTILITY RECORDS
Authors: Small Melvin D. , Brean John W. , Farrar John T.
Published: May 2004

The application of statistical communication techniques to the analysis of intestinal motility records has made available certain information that has heretofore been obscure. This information is:

1. A measure of total activity expressed in square millimeters of Hg.

2. The frequency and amplitude of segmental activity.

3. A measure of the random variations in the amplitude of the "segmental" waves.

4. A measure of random activity and the range and relative amplitudes of the frequencies making up this component.
POST-TETANIC POTENTIATION OF POLYSYNAPTIC REFLEXES OF THE SPINAL CORD
Authors: Wilson Victor J.
Published: May 2004

The phenomenon of post-tetanic potentiation has been studied in the cat spinal cord with particular reference to polysynaptic responses. Following tetanization of dorsal roots, these reflexes show an increased response, as measured in terms of their voltage-time area, with a predominant change in the earlier reflex pathways. Both of these changes in the reflex discharge have a time course of 15 to 25 seconds.

Post-tetanic potentiation is also observed in response to stimulation of a dorsal rootlet following tetanization of another rootlet in the same or in a neighboring segment. This effect can be explained by post-tetanic changes in the terminals of secondary, and possibly higher order, internuncial cells, essentially similar to those changes in the primary afferent terminals which give rise to potentiation of the monosynaptic reflex.
OLFACTORY NERVE FIBERS
Authors: Gasser Herbert S. ,   With the Collaboration of G. E. Palade
Published: May 2004

Cross sections of olfactory nerves present a unique appearance. They indicate the presence of large numbers of very small nerve fibers, with a modal diameter of about 0.2 µ and a narrow range for their size variation. From one side of the nasal septum of a pig the yield of fibers was estimated at 6,000,000; the number arising from the turbinates would be considerably larger. The fibers are attached to the membranes of the Schwann sheaths in large bundles through mesaxons longer and more branched than those that have been seen in other nerves.

Continuity of the axons between the nerves and the bipolar cells was traced in an examination of the olfactory mucous membrane; and the indication of a one-to-one relationship between cells and axons was reinforced by a comparative count. After the axons leave the bipolar cells they become incased in the central projections of the sustentacular cells. Where the latter come into contact with the basal cells the axons emerge to push back the plasma membranes of the basal cells in the first step in acquiring their nerve sheaths. Later steps are described. When the axons are delivered by the basal cells to the collecting Schwann tubes, they are already aggregated into small bundles with sheaths fundamentally the same as those they will possess until they are delivered to the glia in the olfactory bulb.

Some of the aspects of the cytology of the bipolar cells and adjoining sustentacular cells are described.

A survey of the physiological properties of olfactory nerve fibers was made in some experiments on the olfactory nerve of the pike. Almost all of the action potential is encompassed within a single elevation, manifesting at its front a conduction velocity of 0.2 m./sec. For a comparison, the last elevation in the C action potential in the sciatic nerve of the frog is cited as an example of conduction at the same velocity.

Though expressed through long time constants, the properties of the pike olfactory fibers conform to the generalized schema for properties of vertebrate nerve fibers. This conformity signalizes that they differ from the exceptional properties of the unmedullated fibers of dorsal root origin.

An afferent function for unmedullated nerve fibers does not imply that the fibers concerned are alike in their physiological properties.