bluuebunny/crossref_metadata_2025_split huggingface dataset:
MITOCHONDRIA IN THE FLIGHT MUSCLES OF INSECTS
Authors: Watanabe Mary Ishimoto , Williams Carroll M. 
Published: May 2004

1. The "indirect" thoracic muscles of adult dipterous and hymenopterous insects consist of a unique type of muscle characterized by the presence of numerous spherical, intracytoplasmic bodies termed "sarcosomes."
2. When the muscle is teased or ground, the sarcosomes are liberated as a turbid suspension of bodies ranging from 1 to 4 µ in diameter. A method is described for the isolation of sarcosomes by a simple differential centrifugation.
3. The cytochemical, chemical, and enzymatic properties of sarcosomes were examined for the purpose of appraising their relation to the cytoplasmic bodies of other tissues.
4. Fresh sarcosomes are slowly but selectively stained by the mitochondrial reagents, Janus green B and pinacyanol. Fixed sarcosomes give a positive reaction with Regaud's mitochondrial stain.
5. Chemical analyses show that approximately 29 per cent of the dry weight of sarcosomes consists of lipids and 60 per cent of protein. Microbiological assay indicates the presence of about 1 gamma of riboflavin per milligram of nitrogen. These values resemble those reported for isolated mitochondria of vertebrate liver and kidney.
6. When examined spectroscopically the sarcosomes, like the vertebrate mitochondria, show a high titer of cytochromes a, b, and c.
7. The titer of cytochrome oxidase varies systematically with the adult age of the insect. A similar relation is observed for the enzyme catalase.
8. Isolated sarcosomes show significant titers of succinoxidase, α-glycerophosphate dehydrogenase, malic dehydrogenase, and pyruvic dehydrogenase. The following dehydrogenases could not be demonstrated: xanthine, phenylalanine, glycine, lactic, choline, glutamic, and alcohol. These results are compared with those previously reported for vertebrate mitochondria.
9. In view of their manifold points of biochemical similarity, it is concluded that the sarcosomes are the mitochondria of this highly specialized muscular tissue.
GROWTH AND PHAGE PRODUCTION OF LYSOGENIC B. MEGATHERIUM
Authors: Northrop John H. 
Published: May 2004

Cell multiplication and phage formation of lysogenic B. megatherium cultures have been determined under various conditions and in various culture media.
1. In general, the more rapid the growth of the culture, the more phage is produced. No conditions or culture media could be found which resulted in phage production without cell growth.
2. Cultures which produce phage grow normally, provided they are shaken. If they are allowed to stand, those which are producing phage undergo lysis. Less phage is produced by these cultures than by the ones which continue to grow.
3. Cells plated from such phage-producing cultures in liquid yeast extract medium grow normally on veal infusion broth agar or tryptose phosphate broth agar, which does not support phage formation, but will not grow on yeast extract agar.
4. Any amino acid except glycine, tyrosine, valine, leucine, and lysine can serve as a nitrogen source. Aspartic acid gives the most rapid cell growth.
5. The ribose nucleic acid content is higher in those cells which produce phage.
6. The organism requires higher concentrations of Mg, Ca, Sr, or Mn to produce phage than for growth.
7. The lysogenic culture can be grown indefinitely in media containing high phosphate concentrations. No phage is produced under these conditions, but the cells produce phage again in a short time after the addition of Mg. The potential ability to produce phage, therefore, is transmitted through cell division.
8. Colonies developed from spores which have been heated to 100°C. for 5 minutes produce phage and hence, infected cells must divide.
9. No phage can be detected after lysis of the cells by lysozyme.
LOSS AND RECOVERY OF EXCITABILITY BY NORMAL AND BY DEGENERATING NERVES DEPRIVED OF SODIUM
Authors: Gallego A. 
Published: May 2004

A study has been made of the loss of excitability in a sodium-free medium and of the recovery of excitability in Ringer's solution by A fibers of normal frog nerves and of nerves in advanced stages of Wallerian degeneration.
With normal nerves that are being kept in a sodium-free medium the number of conducting fibers does not undergo a readily detectable decrease in less than 1 to 2 hours; inexcitability of all the A fibers does not develop in less than 7 to 8 hours. During the development of inexcitability the speed of conduction of the still conducting fibers undergoes a progressive decrease; in advanced stages the speed of conduction is not more than one-fifth of the normal speed. The nerve fibers lose the ability to conduct rhythmic trains of impulses earlier than the ability to conduct single impulses.
The recovery of excitability in Ringer's solution duplicates in a reverse order the sequence of changes that have been previously observed during the development of inexcitability. The rate of the recovery of excitability in Ringer's solution is higher than the rate of the loss of excitability in the sodium-free medium.
With degenerating nerves the effect of the lack of sodium develops qualitatively in the same manner in which it develops with normal nerves. Degenerating nerve fibers, however, become inexcitable in a sodium-free medium earlier than normal fibers. The recovery of the excitability in Ringer's solution takes place in much the same manner in normal and in degenerating nerve fibers.
The loss of excitability during Wallerian degeneration is a process that develops simultaneously, or practically so, throughout the entire length of the fibers. The nerve fibers retain a great deal of functional ability throughout the several days which precede the onset of inexcitability and then suddenly become inexcitable.
THE METAMORPHOSIS OF HEMOGLOBIN IN THE BULLFROG
Authors: Riggs Austen 
Published: May 2004

1. Tadpole and adult hemoglobin do not differ significantly in molecular weight. The molecular weight of both is in the neighborhood of 68,000.
2. Heme-heme interaction as measured by the value of n in Hill's equation is virtually the same—about 2.8—in both tadpole and adult.
3. There appears to be no significant effect of pH upon the oxygen equilibrium of tadpole hemoglobin, in contrast to large Bohr and reverse Bohr effects in the adult. This is taken to mean that during metamorphosis acid groups of globin become sensitive to the oxygenation of heme by some change in the mode of linkage between heme and globin.
4. The oxygen affinity of tadpole hemoglobin is about seven times as great as that of the adult at pH 6 and twice as great at pH 9.
ON THE EXISTENCE OF A GRADIENT OF SENSITIVITY TO THE LACK OF SODIUM IN THE SPINAL ROOTS OF THE BULLFROG
Authors: Lorente de Nó R. 
Published: May 2004

The Et class of fibers includes fibers of Gasser's d.r. C group.
The fibers of the dorsal root are more sensitive to the effect of lack of sodium than are the fibers of the ventral root.
In the two roots there is a gradient of sensitivity to the lack of sodium, which is such that in all the root fibers the sensitivity decreases with increasing distance from the spinal cord. The gradient continues in the trunk up to about 10 to 12 mm. peripheral to the trunk-roots margin. No comparable gradient of sensitivity to the lack of sodium has been observed in the rest of the nerve trunk.
The gradient of sensitivity to the lack of sodium has no relationship to the anatomical distribution of the epineurium.
As a working hypothesis it is suggested that the gradient of sensitivity to the lack of sodium is one aspect of a transitional gradient that serves to establish a gradual change between the properties that the axons have inside the spinal cord and the properties that they have inside the nerve trunks.
Details are given of the temporal course of the loss of excitability by root fibers deprived of sodium. It is suggested that sodium is present in the nerve fibers, in 2 forms, loosely and tightly bound sodium and that loss of loosely bound sodium is sufficient to render the nerve fibers unable to conduct impulses. If the rate of loss of loosely bound sodium is decreased, conversion of tightly bound into loosely bound sodium may temporarily restore the excitability of the nerve fibers.
ON THE EFFECT OF AMMONIUM AND LITHIUM IONS UPON FROG NERVE DEPRIVED OF SODIUM
Authors: Gallego A. , Lorente de Nó R. 
Published: May 2004

An analysis has been made of the effect of ammonium and of lithium ions upon frog nerve deprived of sodium.
Ammonium ions cannot substitute for sodium ions and restore the excitability of the nerve fibers; nor can they increase the L fraction of the membrane potential and the efficiency of the nerve reaction. Certain observations, however, indicate that the presence of ammonium ions outside the nerve fibers may delay the development of inexcitability in a sodium-free medium of nerve fibers restored by a moderate amount of sodium ions.
Lithium ions can substitute for sodium and restore to nerve fibers of the A and C groups the ability to conduct impulses; the effect upon B fibers has not been investigated. Lithium cannot substitute for sodium in the role that sodium plays in the creation of the L fraction and in the establishment of the nerve reaction. In this respect lithium and sodium have opposite effects. This fact establishes an important difference between the two physiological responses that the nerve fibers can produce, the nerve impulse and the nerve reaction.
With untreated nerve the depolarization of nerve by lithium ions at high concentrations is preceded by a phase of hyperpolarization; with nerve deprived of sodium the depolarization begins without delay.
SEPARATION AND ASSAY OF LYSINS AND LYSIN-INHIBITOR COMPLEXES IN BLOOD AND TISSUES
Authors: Ponder Eric 
Published: May 2004

1. A process of extraction and assay, which combines the features of several existing methods, is described for the lytic materials which can be obtained from blood, plasma, serum, and tissues. At least two alcohol-soluble substances, one ether-soluble ("soap-like") and the other insoluble in ether in the cold ("lysolecithin-like"), can be obtained from preincubated blood, plasma, or serum. The hemolytic activity (or concentration) of the soap-like lysin obtained from blood is greater than that of the lysolecithin-like substance, but for plasma and serum the reverse is true, i.e. the red cells are involved in the production of the soap-like lysin, and probably supply some of it when acted upon by enzymes contained in plasma and serum. Preincubation of the blood or plasma increases the yield of lysin two- or threefold, and small quantities of both soap-like and lysolecithin-like lysins can be obtained from unpreincubated blood or plasma.
2. The soap-like lysins obtained from preincubated mouse liver are some 5 to 15 times as active as, or occur in some 5 to 15 times the concentration of, those obtained from blood or plasma. The lysolecithin-like lysins of preincubated liver are about twice as active as, or occur in about twice as great concentration of, those obtained from blood. Because of the shape of the time-dilution curve for these lysins, the relations between their activities, or concentrations, are often quite different from those which one would anticipate if one were to consider only the times required for the production of hemolysis.
3. Paper chromatography can be used to separate the soap-like and the lysolecithin-like lysins obtainable from small quantities of preincubated mouse liver homogenates or preincubated mouse blood. The presence of lysins is detected by their effect on the red cells of a suspension as it wets the paper. Various technical procedures for separating lytic components and for demonstrating that they move on the paper along with protein components are described.
4. Paper strip electrophoresis can be used to show that the supernatant fluid of a preincubated mouse liver homogenate contains at least two protein components and at least two lytic components, not very closely associated in their electrophoretic behavior.
5. Observations on the physical nature of the alcohol- and ether-soluble lysin point to its having a soap-like character. Its activity, as well as that of the lysolecithin-like lysin, is inhibited by cholesterol, by lecithin, and by various fractions of serum. Some of these effects have been studied quantitatively. The most inhibitory of the protein fractions are those which contain lipoproteins; i.e., II + III and IV + V.
THE CYTOCHROME C OXIDASE OF THE HOUSE FLY, MUSCA DOMESTICA L
Authors: Sacktor Bertram 
Published: May 2004

1. Insoluble and "soluble" forms of cytochrome c oxidase were prepared from house flies by methods described for mammalian tissue. A 4.5-fold purification was accomplished by preparing the enzyme in insoluble form (as compared with a crude water brei). The oxidase in "soluble" form was purified 20.0-fold.
2. The absorption spectrum of the "soluble" preparation from flies was similar to that from mammalian tissue, and indicated the presence of cytochromes a + a3 and b. In contrast with the corresponding mammalian enzymes these components were not separable by the existing techniques.
3. The Soret peak seen at 440 mµ and the alpha peak at 600 mµ were due. primarily to cytochromes a3 and a, respectively.
4. The oxidase activity of whole house flies was comparable with that of rat abdominal muscle. In both organisms, this activity was inhibited by cyanide to approximately the same extent.
5. The optimum buffer concentration for oxidase activity, as measured spectrophotometrically, was approximately 0.02 to 0.06 M. This is in agreement with results obtained for mammalian enzyme, as measured both manometrically and spectrophotometrically.
6. The present study has demonstrated the following components of the cytochrome system in house flies: b, c, a, and a3.
THE INTRACELLULAR GROWTH OF BACTERIOPHAGES
Authors: Anderson Thomas F. , Doermann A. H. 
Published: May 2004

The growth of the virus T3 has been followed by breaking up the complexes it forms with host cells at various stages in their development and then assaying the debris for active virus particles. Two independent methods for breaking up cells were used: sonic vibration and lysis by the T6-cyanide method previously used for the study of the growth of T4.
During the first half of the latent period both treatments, as well as cyanide alone, destroyed the capacity of the complexes for producing daughter virus particles. Furthermore, the infecting particles could not be recovered from them during the first half of the latent period.
After the complexes had had 12 minutes of incubation at 30°C. both methods freed daughter virus particles from them in numbers which increased steadily with time until, near the end of the rise period, the normal burst size was reached. In general the agreement between the two yields is so good that one may conclude that both methods liberate quantitatively the mature daughter T3 particles which exist in the complexes before normal lysis occurs.
PERMEABILITY PROPERTIES OF ERYTHROCYTE GHOSTS
Authors: Teorell Torsten 
Published: May 2004

1. Erythrocyte ghosts from human blood were produced by gentle water hemolysis. The ghost-containing hemolysate (about 20 mN) was added to media of different composition (KCl, NaCl, glucose, sucrose, etc.) and varying concentration ranging from 8 to 840 mN. The volume changes of the ghost cells were followed by a light absorption method. The potassium and sodium concentrations were also analyzed in some representative cases.
2. The ghosts shrank, or swelled, in two stages. An initial phase with a momentary expulsion, or uptake, of water leading to an osmotic equilibrium, was followed by a second phase in which a slow swelling or shrinking proceeded toward a final constant volume.
3. The ghosts were semipermeable in the sense that water always passed rapidly in either direction so as to maintain isotonicity with the external medium.
The relation between ghost cell volumes (V) and the total concentration (Ce) of the suspension medium can be expressed by a modified van't Hoff-Mariotte law: (Ce + a)(V – b) = constant. Here a is a term correcting for an internal pressure and b is the non-solvent volume of the ghost cells. This means that the ghosts behave as perfect osmometers.
4. On the other hand appreciable concentration differences of the K and Na ions could be maintained across the intact ghost cell membranes for long periods. Whether this phenomenon is due simply to very low cation permeability or to active transport processes cannot be decided, although the first assumption appears more probable.
5. When the ghosts were treated with small concentrations of a lytic substance like Na oleate, the alkali ion transfer was greatly increased. This seems to be a simple exchange diffusion process with simultaneous, continued maintenance of osmotic equilibrium (= the second phase).
A simplified theory is also given for the kinetics of the volume variations and ion exchange during the second phase (cf. the Appendix).
6. Miscellaneous observations on the effects of pH, and of some other substances are discussed. Some shape transformations of the ghost cells are also described.
THE EFFECT OF ELECTROLYTES ON THE CONTRACTILE ELEMENTS OF MUSCLE
Authors: Bozler Emil 
Published: May 2004

The effects of changes in electrolyte concentration on muscles which had been preserved in 50 per cent glycerol or washed in water were studied. The psoas preparation of Szent-Györgyi was generally used, but smooth and cardiac muscle gave the same results.
If the preparations are immersed in 0.16 molar NaCl or KCl and if the electrolyte subsequently is washed out with distilled water, tension rises. This effect is not obtained if solutions of CaCl2 or MgCl2 are used, but it is restored by brief immersion in NaCl or KCl solutions. Changes in pH have no effect. It is concluded that divalent cations are bound more firmly than monovalent ions, but that divalent exchange with monovalent ions.
After the application of ATP washing out electrolytes produces a much larger and more rapid rise in tension. This effect persists after ATP has been washed out and seems to be due to the removal of a substance which diminishes the dissociation of bound cations.
Washing out electrolytes also causes a large increase in transparency and swelling. These effects are also enhanced by previous application of ATP and are abolished or diminished by divalent cations.
The rise in tension and the swelling are explained as the result of an increase in the charge of the polar groups of the proteins. Because this mechanism produces only a small degree of shortening, it does not explain normal contraction, but it may be a part of this process. The significance of the phenomena described in relation to recent theories of the mechanism of muscular contraction is discussed. The observations show that increase in the charge of the contractile proteins causes contraction, not relaxation, as has been commonly assumed.
THE EFFECTS OF DIPHTHERIA TOXIN ON THE CECROPIA SILKWORM
Authors: Pappenheimer A. M. , Williams Carroll M. 
Published: May 2004

1. The metamorphosis of the Cecropia silkworm is accompanied by large and systematic changes in the insect's sensitivity to diphtheria toxin.
2. Injection of less than 1 gamma of toxin into mature caterpillars, prepupae, or developing adults causes cessation of development followed by delayed death 1 to 5 weeks later.
3. Dormant pupae, on the contrary, are resistant to 70 gamma of toxin and may survive even this enormous dose for over 4 weeks. One-hundredth of this dose, however, prevents pupae from initiating adult development.
4. Tetanus toxin, to which the insect is insensitive, failed to duplicate any of these effects.
5. Maximal sensitivity to diphtheria toxin is characteristic of those stages in the life history which depend on the presence and function of the cytochrome system. Resistance to the toxin, as in the case of the diapausing pupa, is correlated with the existence and utilization of metabolic pathways other than the usual cytochrome system.
6. This correlation persists within the individual insect. Thus, within the diapausing pupa, the toxin fails to affect the heart in which a normal cytochrome system is absent, but, within the same insect, causes a degeneration of the intersegmental muscles in which an intact cytochrome system is present.
7. These several lines of evidence are interpreted in support of the conclusion that diphtheria toxin acts by blocking the synthesis of one or more components in the cytochrome system.
PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES
Authors: Price Winston H. 
Published: May 2004

1. The synthesis of ribonucleic acid, desoxyribomicleic acid, and protein in S. muscae has been studied: (a) during the lag phase, (b) during the early log phase, and (c) while the cells are forming an adaptive enzyme for lactose utilization.
2. During the lag phase there may be a 60 per cent increase in ribonucleic acid and protein and a 50 per cent increase in dry weight without a change in cell count, as determined microscopically, or an increase in turbidity.
3. During this period, the increase in protein closely parallels the increase in ribonucleic acid, in contrast to desoxyribonucleic acid, which begins to be synthesized about 45 minutes after the protein and ribonucleic acid have begun to increase.
4. The RNA N/protein N ratio is proportional to the growth rate of all S. muscae strains studied.
5. While the RNA content per cell during the early log phase depends upon the growth rate, the DNA content per cell is fairly constant irrespective of the growth rate of the cell.
6. Resting cells of S. muscae have approximately the same RNA content per cell irrespective of their prospective growth rate.
7. While the cells are adapting to lactose, during which time there is little or no cellular division, there is never an increase of protein without a simultaneous increase in ribonucleic acid, the RNA N/protein N ratio during these intervals being approximately 0.15.
8. Lactose-adapting cells show a loss of ribonucleic acid. The purines-pyrimidines of the ribonucleic acid can be recovered in the cold 5 per cent trichloroacetic acid fraction, but the ribose component is completely lost from the system.
9. The significance of these results is discussed in relation to the importance of ribonucleic acid for protein synthesis.