bluuebunny/crossref_metadata_2025 huggingface dataset:
MULTIPLICATION AND SURVIVAL OF TUBERCLE BACILLI IN THE ORGANS OF MICE
Authors: Pierce Cynthia H. , Dubos René J. , Schaefer Werner B.
Published: June 2004

Cultures of tubercle bacilli (typical bovine and human strains) known to differ in the severity of the lesions they induce in experimental animals, were injected in various doses into the cerebrum, peritoneal cavity, or blood stream of mice. Quantitative determinations of the numbers of living bacilli present in the tissues at different intervals of time after infection led to the following classification of the cultures tested:—

(a) Certain well known variant forms of tubercle bacilli were found to be unable to multiply in vivo, although they could survive for many weeks in the tissues of mice. These organisms proved to be truly avirulent.

(b) Other variant forms underwent multiplication in vivo, even when extremely small infective doses were used, but could not give rise to progressive disease. It is proposed to designate these strains, which produce only abortive infections, as "attenuated." Different levels of attenuation could be detected. The maximum numbers of living bacilli that were recovered from the tissues corresponded directly to the severity and duration of the abortive lesions that could be produced by the strain in guinea pigs or in mice and were characteristic for each strain tested. The two BCG substrains tested were found to differ markedly in their level of attenuation.

(c) The cultures virulent for guinea pigs were also capable of establishing a progressive infection in mice even when small infective doses were used.

In the case of the attenuated and virulent strains, the population of living bacilli present in the lungs was at first much lower than that in the spleen, but it continued to increase in the former organs throughout the period of observation. This was notably true in the case of the virulent cultures. In contrast, the numbers of living bacilli in the spleen rapidly reached a maximum in the case of all cultures and then decreased progressively. For a given infective dose, and a given interval of time after inoculation, the maximum levels of living bacterial population attained in the spleen and in the lungs proved to be a direct expression of the virulence of the strain.
ANTITUBERCULOUS IMMUNITY INDUCED IN MICE BY VACCINATION WITH LIVING CULTURES OF ATTENUATED TUBERCLE BACILLI
Authors: Dubos René J. , Pierce Cynthia H. , Schaefer Werner B.
Published: June 2004

The immunity induced in mice by vaccination with living attenuated cultures of tubercle bacilli was measured by two criteria.

(a) Increase in survival time of the vaccinated animals after infection with a dose of virulent bacilli sufficient to kill all the unvaccinated controls within 10 to 20 days.

(b) Difference in the number of living bacilli recovered from the spleen and lungs of vaccinated and normal animals infected with a small dose of virulent bacilli.

The level of immunity induced was found to depend upon the extent of multiplication in vivo of the bacilli used for vaccination. This in turn was conditioned by the degree of attenuation characteristic of the bacterial strain used in the preparation of the vaccine, the amount of vaccine injected, the route of vaccination, and the time interval between vaccination and challenge infection. It was possible to prevent or retard the development of immunity by treating the mice in course of immunization with a drug, isoniazid, capable of interrupting the multiplication in vivo of the bacilli used as vaccine.

Although immunity regularly developed and lasted for many weeks when the proper conditions of vaccination were used, the immune response was never sufficient to protect the animals against ultimate death from infection with virulent tubercle bacilli. The prolongation of life in the vaccinated mice was not consequent on a direct bactericidal effect but rather on a retarded or interrupted multiplication of the virulent bacilli in vivo.

The quantitative bacteriological techniques used in the present study would appear to be of value for the analysis of certain problems of immunity, and for the appraisal of vaccines and techniques of vaccination.
A COMPARATIVE HISTOLOGIC AND IMMUNOLOGIC STUDY IN RABBITS OF INDUCED HYPERSENSITIVITY OF THE SERUM SICKNESS TYPE
Authors: Germuth Frederick G.
Published: June 2004

A histologic and quantitative immunologic study was made on a large group of rabbits injected intravenously with a single dose of crystallized bovine albumin and bled and sacrificed at various intervals after injection. Both cardiovascular and renal lesions were encountered in high incidence. The various stages in the development of these lesions were observed from their first appearance until their complete regression. The cardiac, vascular, and renal alterations were morphologically similar to those of rheumatic fever, polyarteritis nodosa, and acute glomerulonephritis, respectively, in man.

In addition to those tissue changes ordinarily attributed to hypersensitivity, peculiar granulomatous lesions consisting of epithelioid and foreign body giant cells were encountered in the follicles of the spleen and in the lymph nodes of a large proportion of the animals receiving the antigen. Similar granulomas in the spleen and lymph nodes as well as in other tissues have been described in polyarteritis nodosa. The present experimental demonstration that an epithelioid and giant cell reaction may result from hypersensitivity provides evidence for the allergic origin of those cases of polyarteritis nodosa of unknown etiology containing this type of lesion.

In the present study the time of development of the cardiovascular, renal, and granulomatous lesions was determined in relation to the blood clearance of antigen and the time of appearance of circulating antibody. All the tissue lesions developed during the "immune" phase of antigen elimination and regressed after the antigen had been completely eliminated and free antibody had appeared in the circulation. These temporal relationships indicate that the tissue lesions which occur after the intravenous administration of foreign protein are the result of antigen-antibody combination.
AN ANTIVIRAL SUBSTANCE FROM PENICILLIUM FUNICULOSUM
Authors: Shope Richard E.
Published: June 2004

A culture of P. funiculosum isolated on Guam proved capable of elaborating a substance which exerted a favorable therapeutic effect against swine influenza virus infections in white mice. The culture was extremely variable and irregular in its production of the antiviral substance, and during maintenance in the laboratory for several years gradually lost this property. Efforts to restore it were unsuccessful.

Subsequently it was found that the mold elaborated a substance, now designated helenine, which is therapeutically effective against Columbia SK encephalomyelitis virus infections in mice. Helenine appears to differ from the substance earlier procured from the mold, which was active against swine influenza virus infections in mice. It is frequently present in greater or lesser amount in the fluid portions of stationary cultures of P. funiculosum but is more regularly obtained and in larger amount, from the cellular components of the pellicles. When liberated from these latter by mechanical bruising and fracturing, it goes into solution in the culture fluids. It is precipitable from aqueous solution by 50 per cent acetone.

Infected mice injected with helenine in amounts less than the amount which produces a maximal therapeutic effect exhibit a dosage response. Increasing the dose above the optimum fails to increase the therapeutic effect.

Helenine exerts its maximum effect when given within the first 10 hours after viral infection but its influence is apparent even when treatment is delayed for up to 24 hours. It is not effective against massive amounts of virus and gives the best therapeutic results when used in the treatment of animals infected with from 10 to 1000 fatal doses of virus. Treatment of infected mice with helenine delays the entrance of virus into their brains for from 24 to 48 hours.

The mechanism by which helenine exerts its therapeutic effect against SK virus is not known but the findings presented suggest either that it causes an inhibition or interruption of multiplication of the virus, slowing down the whole process of infection and spread to the central nervous system, or that in some way it interferes temporarily with the neuroinvasiveness of the virus.
THE STAGES IN CALCIFICATION OF THE RAT KIDNEY AFTER THE ADMINISTRATION OF URANIUM NITRATE
Authors: Dahl Lewis K.
Published: June 2004

The anatomical and histochemical alterations in rat kidneys after the parenteral administration of uranium nitrate [UO2(NO3)2·6H2O] have been studied. The histological effects produced by this agent over a wide range of dose levels were nearly identical in character and differed principally in their speed of evolution. The deposition of calcium always began at foci in the cytoplasm of the cells of the proximal convoluted tubules of the inner cortex. It remained intracellular until the cell boundaries were destroyed.

Deposits of calcium could be found before any other cellular damage could be demonstrated by histological examination. Later, when degeneration and necrosis were present, the foci of calcification were imperfectly related to them in location or degree. In contrast, the amount of calcification was correlated with the dose of uranium nitrate, being greatest in the kidneys of rats that received 20 mg./kg., next greatest in the 30 mg./kg. rats, less in the 10 mg./kg. rats, and slight in those that received 2 mg./kg.

Histochemical stains for ferric and ferrous iron, chondroitinsulfate, and polysaccharides gave results that were negative or unrelated to the deposits of calcium, thus making it unlikely that these substances held any appreciable amount of calcium in the tissue. Yet it is clear that some anion other than phosphate must be combined with part of the calcium; the results with the alizarin and von Kóssa stains confirmed an earlier result (1) in showing that the first deposits of calcium are formed without comparable accumulations of phosphate.
OBSERVATIONS ON A SUBMICROSCOPIC BASOPHILIC COMPONENT OF CYTOPLASM
Authors: Porter Keith R.
Published: June 2004

The cytoplasmic ground substance of animal tissue cells grown in vitro has been found by electron microscopy to contain, as a part of its submicroscopic structure, a complex reticulum of strands, to be referred to as the endoplasmic reticulum. It has been found in all types of cells extensively studied.

The components of this reticular system vary considerably in size and form, apparently in some relation to physiological changes in the cell. Thus in one cell of a culture colony it may be finely divided into strands or canaliculi, 50 to 100 mµ in diameter, whereas in an adjacent cell of the same type the components of the reticulum may be relatively coarse, 600 mµ in diameter, and vesiculated. The membrane, which can be shown to limit the system and separate it from the rest of the ground substance, is similar in thickness to the plasma membrane surrounding the cell.

Photomicrographs of living cells taken by phase contrast and dark field microscopy define a structure of similar form and indicate that the reticulum of the electron microscope image has its equivalent in the living unit. Where its component units are sufficiently large, a structure of identical form can be resolved by light microscopy in cells stained with hematoxylin or with toluidine blue. This indicated that the endoplasmic reticulum is to be identified with the basophilic or chromophilic component (the ergastoplasm) of the cytoplasm and that such properties of this component as have been determined by cytochemical methods, such as a high RNA content, may be assigned to this "submicroscopic" system.
NEUTRALIZATION OF VIRUSES BY HOMOLOGOUS IMMUNE SERUM
Authors: Tyrrell David A. J. , Horsfall Frank L.
Published: June 2004

Neutralization experiments with Newcastle disease, influenza A, or bacterial virus, T3, reveal, under all conditions studied, a linear relationship between the logarithm of the serum dilution end point and that of the quantity of virus used. With Newcastle disease and influenza A, the slope of the neutralization line varies markedly with the host-cell system used and in the chick embryo is strikingly affected by the route of inoculation. The other variables examined have no definite effect upon the slope. Reactivation of neutralized influenza virus is demonstrable in the chick embryo on dilution of the mixture.

There appears to be an inverse relationship between the degree of susceptibility of a host to infection with influenza A virus and the neutralizing titer of a serum as measured in that host. With the T3-serum system, comparable results are obtained when the number of unneutralized virus particles chosen as the end point is varied widely.
STUDIES ON THE GENERALIZED SHWARTZMAN REACTION
Authors: Good Robert A. , Thomas Lewis
Published: June 2004

In order to explore the hypothesis that the occurrence of thrombosis of small blood vessels is an essential stage in the development of the local and generalized Shwartzman reactions, the effect of heparin was studied.

Aqueous heparin, administered intravenously, and "depot" heparin, injected subcutaneously, prevented completely the occurrence of the local and generalized Shwartzman phenomena. The amounts of heparin required for protection were similar to the amounts required to produce sustained incoagulability of the blood of rabbits for a period of at least 4 hours.

The local and generalized Shwartzman reactions were prevented when heparin was given at the time of provocation, but not when heparin was administered during the period of preparation.

Heparin prevented the development of bilateral cortical necrosis of the kidneys following a single intravenous injection of meningococcal toxin in rabbits previously treated with cortisone or thorotrast.

Hemorrhagic necrosis of the skin which follows an intradermal injection of toxin in thorotrast-treated rabbits was also prevented by heparin.

Provocation of the dermal Shwartzman reaction with glycogen, saline suspension of rabbit liver, and human serum was prevented by treatment with heparin.

Heparin itself, in the preparations and dosages used, had no consistent effect on either white blood cell or platelet counts. Heparin had no effect on the occurrence of polymorphonuclear leukopenia which follows an intravenous injection of meningococcal toxin.

Treatment with heparin did not interfere with the lethal effect of single, large doses of meningococcus toxin.

In animals in which bilateral cortical necrosis of the kidneys was prevented by heparin, occlusion of the glomerular capillaries by "fibrinoid" material did not occur.

These observations support the concept that vascular occlusion plays an essential role in the development of the local and generalized Shwartzman reactions.
A HISTOLOGICAL STUDY OF INFECTIOUS CANINE HEPATITIS BY MEANS OF FLUORESCENT ANTIBODY
Authors: Coffin David L. , Coons Albert H. , Cabasso Victor J.
Published: June 2004

A study of experimental infectious canine hepatitis in dogs by means of specific fluorescent antibody indicates that the intranuclear inclusions of this disease contain high concentrations of viral antigen.

The increase in virus in the nuclei, as indicated by the accumulation of specific antigenic material, begins on the nuclear membrane and spreads from there to the interior of the nucleus, with the gradual formation of larger granules. Subsequently there appear the homogeneous inclusion bodies characteristic of this infection.
THE RELATIONSHIP BETWEEN CYTOCHONDRIA AND MYOFIBRILS IN PIGEON SKELETAL MUSCLE
Authors: Harman John W. , Osborne Ursula H.
Published: June 2004

In pigeon breast muscle the mitochondria are the principal site of oxidative metabolism, whereas the myofibrils are incapable of oxidizing intermediates of the Krebs cycle. The mitochondria contain the oxidative enzymes, and the sarcosomes are associated with a factor which accelerates the mitochondrial oxidative rate. The maintenance of myofibrillar contractility and structure is closely correlated with preservation of mitochondrial oxidative capacity and structure. By use of fluoride and dinitrophenol the connection between mitochondrial metabolism and myofibrillar behavior is shown to occur through the process of oxidative phosphorylation.
OBSERVATIONS CONCERNING THE PRODUCTION AND EXCRETION OF CHOLESTEROL IN MAMMALS
Authors: Friedman Meyer , Byers Sanford O. , Shibata Eichi
Published: June 2004

The absorption of oral cholesterol by rats was followed directly by analyses of the thoracic lymph and indirectly by calculating the deficit of fecal cholesterol under the amount fed. The two methods checked within about 20 per cent, with fecal analyses indicating the greater absorption. The absorbed cholesterol was found to be deposited in the liver, only very minor quantities being found in other organs or plasma.

Bile is necessary for normal absorption of cholesterol, although very small amounts are absorbed even in its absence. Excess oral cholic acid increases the absorption of cholesterol by otherwise normal animals. The rat absorbs about 47 per cent of a single 50 mg. dose of cholesterol and about 34 per cent of a 100 mg. dose.
VARIATION IN THE FUNCTIONAL POWER OF HUMAN SWEAT GLANDS
Authors: Dole Vincent P. , Thaysen Jørn Hess
Published: June 2004

A method has been worked out for the measurement of the volume of sweat produced by individual glands. A special paper, impregnated with iodine, absorbs water in a uniform way and shows the area of wetting by a sharply defined blue dot. Indirect calibrations showed that 1 cm.3 of water would form a spot of 700 cm.2 area, and that this relation of volume to area was a constant one over a wide range. The actual volumes encountered in prints of the sweat glands were from 5 x 10–9 to 4 x 10–6 cm.3.

The relative activity of glands at any instant of time can be expressed by the statistical distribution of log diameter of the dots on the print. This distribution, which might at first sight seem rather artificial, has the advantage of being unaffected by a proportionate change in the output of water from each gland. Thus it is independent of the duration of contact between print paper and skin, and of changes in the average flow from the field as a whole. It is sensitive only to changes in the activity of glands relative to each other.

The methods of printing and statistical analysis were used to study the relative activity of glands in a field of 22 mm. diameter. Glands of the forearm and back were studied both under direct stimulation with mecholyl and under the reflex stimulation of environmental heat, similar results being obtained with the two kinds of stimuli. Glands of the abdomen and leg, stimulated with mecholyl, were studied in one experiment.

Detailed comparison of the dots in consecutive prints showed that the large dots remained large and the small dots continued to be small. These persistent differences in the outflow of water from adjacent glands were interpreted as being due to differences in the functional power of the glands.

Repeated prints of the glands during a period of 75 minutes, in which the sweat flow was declining, showed that the relative activity of the glands remained constant. This meant that the set of glands, although differing greatly in power, varied together as a functional unit.

Different regions of the body show not only the variation of glandular power within each small area, but also marked differences in the average power of glands belonging to the different regions. Glands of the back, for instance, show a much greater outflow than glands of the forearm when stimulated equally with a local injection of mecholyl. Equal rates of outflow, therefore, do not mean equal states of functional activity, unless the regions being compared are of equal functional power.
THE SUBMICROSCOPIC ORGANIZATION OF AXON MATERIAL ISOLATED FROM MYELIN NERVE FIBERS
Authors: De Robertis E. , Franchi C. M.
Published: June 2004

A technique has been developed for the extrusion of axon material from myelinated nerve fibers. This material is then compressed and prepared for observation with the electron microscope. All the stages of preparation and purification of the axon material can be checked microscopically and in the present paper they are illustrated with phase contrast photomicrographs.

Observation with the electron microscope of the compressed axons showed the presence of the following components: granules, fibrils, and a membranous material. Only the larger granules could be seen with the ordinary microscope. A considerable number of dense granules were observed. Of these the largest resemble typical mitochondria of 250 mµ by 900 mµ. In addition rows or small clusters of dense granules ranging in diameter from 250 to 90 mµ were present. In several specimens fragments of a membrane 120 to 140 A thick and intimately connected with the axon were found. The entire axon appeared to be constituted of a large bundle of parallel tightly packed fibrils among which the granules are interspersed. The fibrils are of indefinite length and generally smooth. They are rather labile structures, less resistant in the rat than in the toad nerve. They varied between 100 and 400 A in diameter and in some cases disintegrated into very fine filaments (less than 100 A thick).

The significance is discussed of the submicroscopic structures revealed by electron microscopy of the material prepared in the way described.
STUDIES OF THE EFFECT OF BACTERIAL ENDOTOXINS ON RABBIT LEUCOCYTES
Authors: Cluff Leighton E.
Published: June 2004

Bacterial endotoxin injected intravenously into rabbits inhibited the migration of leucocytes from the buffy coat of centrifuged blood (4). Repeated daily injections of endotoxin resulted in the rabbits becoming resistant to the fever-inducing action of the toxin, and migration of leucocytes from centrifuged blood was no longer inhibited by injection of the toxin. Leucocyte migration from the buffy coat of centrifuged blood after injection of toxin into the rabbits appeared gradually over the first few days of repeated injections, and disappeared during the 10 to 15 days after cessation of daily injections of toxin. The resistance to endotoxin, demonstrated by leucocyte migration and pyrogen tolerance, could not be passively transferred with serum from resistant animals, and was non-specific, in that resistance to one endotoxin conferred some resistance to toxin from an organism of a different species. No relationship could be demonstrated between precipitin titer and resistance. Thorotrast abolished resistance to the fever-inducing activity of endotoxin, but its effect on leucocyte resistance was not clear, since when injected alone it inhibited migration of leucocytes from the buffy coat of centrifuged blood.

The suggestion is made that the failure of toxin to inhibit the migration of leucocytes from resistant rabbits is due either to the presence of leucocytes which have become adapted to the toxin by repeated exposure, or to rapid removal of the toxin by the reticulo-endothelial system. It is unlikely that leucocyte resistance participates in the development of tolerance to the fever-inducing action of endotoxin. However, in view of the participation of the leucocyte in the pathogenesis of the Shwartzman reaction, the presence of leucocytes resistant to endotoxin may be responsible in part for the development of resistance to the Shwartzman phenomenon.
THE INACTIVATION OF HERPES SIMPLEX VIRUS BY PHOSPHATASE ENZYMES
Authors: Amos Harold
Published: June 2004

Tissue phosphatases which are present in virus suspensions were found to contribute in considerable measure to the inactivation of herpes simplex virus.

Phosphatase inhibitors and phosphatase substrates have been found to prolong the survival of the virus.

Exogenous phosphatases, both acid and alkaline, have been demonstrated to bring about the loss of infectivity of suspensions of this virus.
STUDIES ON THE CHEMISTRY OF THE TRANSFORMING ACTIVITY
Authors: Zamenhof Stephen , Alexander Hattie E. , Leidy Grace
Published: June 2004

The transforming principles of Hemophilus influenzae have been purified by a new method including fractional extraction. The active molecule behaves in these extractions like the bulk of the DNA preparation. The minimal amount of DNA necessary for transformation appeared to be of the same order of magnitude as the amount of DNA in a single cell.

Quantitative study has been made of the resistance of transforming activity to various agents. When subjected to heat, the temperature at which the activity starts to decrease corresponds rather closely to the temperature at which the viscosity of the bulk of the DNA preparations starts to decrease. Similar correspondence was found when the transforming principle was subjected to pH changes. This is further evidence that the behavior of the active molecules is similar to the behavior of the average DNA molecule of the preparation. The activity is reduced by exposure to low ionic strength and by dehydration. Desoxyribonuclease in concentrations less than 10–4 γ/cc. is able to destroy the activity; a lag period during which the activity but not the viscosity decreases has been observed. NaNO2 at pH 5.3, HCHO and 10–5 M Fe++ reduce or destroy the activity; the importance of intact amino groups in the DNA molecule for the activity is discussed. Several protein-denaturing, sterilizing, and mutagenic agents have been found to have no effect on the transforming activity.
AN ABSOLUTE METHOD FOR ASSAY OF VIRUS HEMAGGLUTININS
Authors: Levine Seymour , Puck Theodore T. , Sagik Bernard P.
Published: June 2004

A rapid and precise method is described for determination of absolute numbers of hemagglutinating particles present in virus suspensions. The method involves spectrophotometric measurement of the number of red cells dimerized by the virus under conditions in which formation of larger aggregates is precluded.

Results of this procedure are compared with those of titrations based on egg infectivity and the polystyrene microsphere electron micrography for influenza virus; and with plaque count titrations on chick embryo cell monolayers in the case of the virus of Newcastle disease. The agreement is well within the limits expected in view of the different quantities which the various procedures measure.

The conversion factor for transforming titre in hemagglutinating units based on the pattern procedure into absolute number of agglutinating particles is the same for influenza and Newcastle disease virus.

The precipitation of red blood cells by Newcastle disease virus at 23°C. is optimal at pH's between 6.2 and 5.8.
THE EFFECT OF TUBERCULIN AND CORTISONE SINGLY AND IN COMBINATION ON EXPLANTED TISSUES OF GUINEA PIGS, MICE, AND RABBITS
Authors: Holden Margaret , Seegal Beatrice Carrier , Adams Lillian B.
Published: June 2004

Tuberculin (P.P.D.) and cortisone acetate, singly and in combination, were added to explanted splenic tissue derived from guinea pigs, mice, and rabbits, and buffy coats obtained from rabbits. These tissues came from normal animals or from animals which had been infected with the tubercle bacillus or immunized with killed tubercle bacilli.

5 µg./ml. of tuberculin or 0.5 µg./ml. of cortisone was the largest concentration of the respective reagents which was tolerated by cultured cells from normal animals.

From the results with all tissues studied it would appear that P.P.D. selectively damaged only the growing cells of splenic tissues from sensitive guinea pigs and to a lesser degree the migrating cells of buffy coats obtained from sensitive rabbits.

Cortisone appeared to have increased toxicity for only explanted splenic cells from tuberculin-sensitive guinea pigs.

The specific effect of P.P.D. on tissues from tuberculin-sensitive animals was not modified by cortisone under the conditions of these experiments. Thus these data furnished no evidence that cortisone had any direct effect on the response of the sensitive cells to P.P.D.
THE ANTIMYCOBACTERIAL ACTIVITY OF A PEPTIDE PREPARATION DERIVED FROM CALF THYMUS
Authors: Dubos René J. , Hirsch James G.
Published: June 2004

A stable, water-soluble substance which possesses potent antimycobacterial activity under certain conditions in vitro has been prepared from calf thymus. This substance has been tentatively named thymus peptide. In final concentrations of 1 to 10 µg. per ml. of an albumin medium it inhibits the growth of various strains of mammalian mycobacteria, but manifests only little or no inhibitory activity against a variety of other microbial species.

The ability of thymus peptide to inhibit the multiplication of tubercle bacilli diminishes when the inoculum is large, or when the medium is acidic. It is also markedly antagonized by addition of enzymatic hydrolysate of casein or beef heart infusion broth to the culture medium.

Thymus peptide does not exert a rapid bactericidal action on tubercle bacilli, but organisms exposed to this compound for longer than 2 weeks could not be made to multiply in ordinary culture media.

Substances similar or identical to the thymus peptide preparation could be extracted from calf spleen, sheep thymus, beef lymph nodes, and calf pancreas, but not from calf lung or calf liver.
CHEMICAL STUDIES ON A BASIC PEPTIDE PREPARATION DERIVED FROM CALF THYMUS
Authors: Hirsch James G. , Dubos René J.
Published: June 2004

A substance possessing antimycobacterial activity under certain conditions in vitro has been prepared from aqueous extracts of calf thymus. Chemical studies have demonstrated that the activity of this substance is due to a basic peptide or a mixture of basic peptides. Although this thymus fraction has been shown to be essentially free of compounds other than peptides, it has not been obtained in a homogeneous state.

The thymus peptide preparation is soluble in water and in the lower alcohols. Its solubility is minimal between pH 10 and 11, suggesting that its isoelectric point may be in this vicinity. The microbiological activity of thymus peptide is destroyed by acid or alkaline hydrolysis and also by trypsin digestion, but is unaffected by pepsin digestion. Cellulose membranes are permeable to thymus peptide.

The most noteworthy finding concerning the amino acid composition of thymus peptide is the preponderance of the basic amino acids lysine and arginine, which together account for about 40 per cent of the weight of this substance. No cystine, and only trace amounts of other amino acids containing sulfur, are present in the thymus peptide preparation.
THE MECHANISM OF ALLOXAN PROTECTION IN EXPERIMENTAL ATHEROSCLEROSIS
Authors: Cook D. L. , Mills Lois M. , Green D. M.
Published: June 2004

Experiments were performed to compare the effects of cholesterol feeding in (a) control rabbits, (b) alloxan-diabetic rabbits, and (c) rabbits injected with alloxan while the pancreas was temporarily occluded from the circulation.

The alloxan-diabetic rabbits consumed significantly higher quantities of cholesterol and food and had serum cholesterol and lipoprotein (Sf 5–9 and Sf 16–30) concentrations significantly increased over the control levels. They failed to show a commensurate increase in the degree of atherosclerosis.

Rabbits in which the diabetogenic action of alloxan was prevented by temporary occlusion of the pancreas from the circulation during its administration developed grades of hypercholesterolemia, hyperlipoproteinemia, and atherosclerosis not significantly different from the controls.

The results are interpreted as indicating that the effects of alloxan on tissues other than the pancreas do not protect against experimental atherosclerosis produced by cholesterol feeding.
ELECTRON MICROSCOPE STUDIES ON ULTRATHIN SECTIONS OF MUSCLE
Authors: Hodge Alan J. , Huxley Hugh E. , Spiro David
Published: June 2004

Thin sections of striated muscle from frog (sartorius), rabbit (psoas), rat (heart), and fly (flight muscle), and of smooth muscle from clam (adductor) have been obtained using a new microtome. Electron micrographs of them are presented. The sections are sufficiently thin to achieve a resolution of 30 to 40 A. In fly flight muscle, the myofibrils are distinct and well separated morphological units. In frog and rabbit muscle the myofibrils appear to be so closely packed under normal conditions that their identity as separate units is almost lost. In all types of striated muscle examined, it was found that the filaments are arranged within the myofibrils in a continuous and highly regular hexagonal array. The diameter of the filaments in embedded, sectioned muscle appears to be significantly less than that observed in dried shadowed material. The 400 A axial period, observed in frog and rabbit muscle, and in rat heart muscle, was found to extend across the interstitial material between the filaments.

The significance of these findings is discussed.
QUANTITATIVE ASPECTS OF THE SPONTANEOUS ELUTION OF INFLUENZA VIRUS FROM RED CELLS
Authors: Sagik Bernard , Puck Theodore , Levine Seymour
Published: June 2004

Each chick and human red cell contains approximately 300 sites capable of attaching influenza virus particles. These correspond to an area representing approximately 2 per cent of the red cell surface.

Although the rate of attachment of PR8 to red cells is not diffusion-limited, when calculated on the basis of the total cell area, it does approach the theoretical maximum for interaction between the virus and the fraction of the cell area known to contain attachment sites.

It is demonstrated that the virus attachment can initiate a spreading disturbance on the red cell membrane which extends over an area far exceeding that covered by the attached virus and which leads to the destruction of receptor sites. This process does not involve cyclic virus attachment, elution from the cell, and reattachment to another site.

Practically all the receptor sites on a cell are destroyed before any virus is liberated into the medium.

The spontaneous elution of virus from red cells within 24 hours at 37° C. requires a threshold value of at least 3 and less than 5 virus particles per cell.

Parallelisms between the spontaneous elution reaction and the phenomenon of lysis-from-without in the bacteriophage system are demonstrated.
THE EXISTENCE OF TWO FORMS OF HYPERTENSIN
Authors: Skeggs Leonard T. , Marsh Walton H. , Kahn Joseph R. , Shumway Norman P.
Published: June 2004

Two types of hypertensin have been demonstrated by means of counter-current distribution. The first type is the product of the action of the enzyme, renin, upon its substrate and has been designated hypertensin I. It can be rapidly converted to a second approximately equally pressor compound, hypertensin II, apparently through the action of an enzyme in the plasma which requires halide or nitrate for activation.

A highly purified preparation containing horse hypertensins I and II caused an elevation of blood pressure when injected into human beings.
EFFECT OF AGE ON SOME ASPECTS OF SULFATE METABOLISM IN THE RAT
Authors: Dziewiatkowski Dominic D.
Published: June 2004

S35-labelled sodium sulfate was administered to rats 10, 30, and 300 days old in an intraperitoneal dose of 0.3 µc. per gm. of body weight. Representative animals of each age were sacrificed 12, 24, 48, and 96 hours after injection.

The concentration of sulfur-35 in the pooled sera of the 10-day-old rats was found to be strikingly higher than the level in the sera of the 30-day-old and the 300-day-old rats, while the levels of sulfur-35 in the sera of rats in the latter two age groups were similar. The difference was not explained by the differences in binding of sulfate by serum proteins. Although no binding could be detected when sulfate was added to serum in vitro, a substantial fraction, up to 80 per cent by the 96th hour, was observed to be bound after injection into the living rat. The 10-day-old rats differed from the older ones in having lower levels of serum proteins and lesser amounts of bound sulfate. The non-dialyzable sulfur-35 was associated to the largest extent with the albumin component in the sera.

The age of the rats found expression in the specific activities of the sulfate-sulfur of mucopolysaccharides isolated from the skeletons, pelts, and viscera. The highest specific activities were observed in the mucopolysaccharides isolated from the tissues of the youngest rats; the lowest in those from the oldest rats. Though the maximum concentration was rapidly attained in the mucopolysaccharides from the various tissues in each of the age groups, the subsequent decreases in concentration were slow.

Radiochemical analyses for sulfur-35 in ends and shafts of femurs and radioautographs of humeri supported the assumption that the labelled sulfate had been incorporated into the chondroitin sulfate of growing cartilage.
DISRUPTION OF INFLUENZA VIRUS
Authors: Tyrrell David A. J. , Horsfall Frank L.
Published: June 2004

1. The hemagglutinating capacity, enzymic activity, and infectivity of several influenza viruses were destroyed by repeated freezing and thawing of dialyzed allantoic fluids containing them.

2. Influenza virus degraded by freezing and thawing, by treatment with 5 M urea, or by heating at 65°C. still combined with homologous antibody and was demonstrable by blocking of the hemagglutination-inhibition and virus neutralization reactions.

3. After 50 cycles of freezing and thawing, much of the blocking antigen activity was not sedimented by centrifugation at 120,000 g for 2 hours, and electron microscopy showed complete disruption of the virus particles. So called soluble blocking antigen was obtained from four strains of influenza A, the Lee strain of influenza B, mumps, and Newcastle disease viruses.

4. Soluble blocking antigens from influenza A viruses were highly strain-specific; gave little or no reaction in complement-fixation tests; stimulated but little antibody production in rabbits and did not induce immunity in mice; caused reactivation of infective virus in neutral mixtures of homologous virus and immune serum.

5. Repeatedly frozen and thawed influenza virus preparations did not interfere with the propagation of infective virus in the allantoic sac. The blocking antigen activity they contained was precipitated by half saturated ammonium sulfate, destroyed by trypsin, chymotrypsin, or heating at 56°C. for 30 minutes, but was unaffected by desoxyribonuclease or ribonuclease.

6. These findings are in accord with the view that soluble blocking antigen obtained from influenza virus particles on disruption by repeated freezing and thawing is protein in nature and represents the essential antigenic material of the intact virus.
STUDIES ON SUSCEPTIBILITY TO INFECTION FOLLOWING IONIZING RADIATION
Authors: Hammond Carolyn W. , Tompkins Marianne , Miller C. Phillip
Published: June 2004

Daily cultures of blood obtained from the tail were made on mice from the 7th day to the 17th or 22nd days after exposure to 550 r total body x-irradiation. Seven mice with negative blood cultures survived to the 27th day when they were sacrificed and found to have negative heart's blood cultures. Every mouse with bacteremia died. Heart's blood cultures post mortem always confirmed the bacteriological findings in the serial cultures. Most of the bacteremias occurred between the 7th and 15th days.

The duration of the bacteremia varied with the microorganism which caused it. Pseudomonas bacteremia was always rapidly fatal. Those caused by Proteus and E. coli continued for a maximum of 72 and 48 hours. Of longest duration was bacteremia caused by Paracolobactrum which was tolerated for as long as 5 days.
HEMAGGLUTINATION WITH ARTHROPOD-BORNE VIRUSES
Authors: Casals Jordi , Brown Lenora V.
Published: June 2004

Through the use of acetone and ether extraction of brain tissue from newborn mice infected with certain arthropod-borne viruses, it has been possible to demonstrate hemagglutinins for chick erythrocytes associated with the following viruses: dengue Type 1, dengue Type 2, Eastern equine encephalitis, Ilhéus, Japanese B, Ntaya, St. Louis, Sindbis, Uganda S, Venezuelan equine encephalitis, West Nile (Egypt 101 strain), Western equine encephalitis, and yellow fever (viscerotropic and neurotropic strains).

On the basis of the temperature and pH required for reaction, the viruses can be assembled in two groups: A—those that require 37°C. and a pH of about 6.4, comprising Eastern, Venezuelan, and Western equine encephalitis and Sindbis viruses; and B—those that require either 4° or 22°C. and a pH of about 7.0, comprising dengue Types 1 and 2, Ilhéus, Japanese B, Ntaya, St. Louis, Uganda S, West Nile, and yellow fever viruses.

A method of eliminating non-specific inhibitory substances present in sera was developed. The method consists essentially of filtration through Seitz pads.

Extensive serological crossings were found among viruses of each group, while antisera of one group failed consistently to cross-react with antigens of the other.

Antisera deriving from animals immunized with certain viruses for which no hemagglutinins could be developed by the present method, reacted with members of either one or the other group. Thus Semliki Forest virus would appear to belong to Group A, and Russian Far Eastern and louping ill viruses to Group B.
FACTORS RELATED TO THE GROWTH OF PSITTACOSIS VIRUS (STRAIN 6BC)
Authors: Morgan Herbert R. ,   With the Technical Assistance of John P. Bader
Published: June 2004

The analogues of amino acids, ß-2-thienylalanine, ethionine, and 6-methyltryptophane, inhibited the growth of psittacosis virus (6BC) in tissue culture without evidence of serious toxicity for the host cells.

Of a number of vitamin analogues tested, only salicyl-ß-alanide inhibited viral multiplication in the absence of toxic effects on the host cells. 6,7-Diethylriboflavin, desoxypyridoxine, and oxythiamine reduced viral growth in concentrations that possessed some toxicity for host tissue. In tolerated amounts, 3-acetylpyridine, pyridine-3-sulfonic acid, pantoyl sulfanilamide, and desthiobiotin did not effect viral multiplication.

Sodium malonate inhibited psittacosis virus growth in non-toxic amounts, whereas sodium monofluoroacetate was ineffective.

Colchicine suppressed multiplication of virus only after a prolonged period of exposure and subsequent delay before producing inhibition, suggesting that the effect was secondary to its antimitotic action which suppressed multiplication of the host cells.
STUDIES ON THE NATURE OF HEMOPHILUS INFLUENZAE CELLS SUSCEPTIBLE TO HERITABLE CHANGES BY DESOXYRIBONUCLEIC ACIDS
Authors: Alexander Hattie E. , Leidy Grace , Hahn Eros
Published: June 2004

In E. influenzae the highly specific desoxyribonucleic acids (DNA's) which play the role of heredity determinants of type specificity and SM resistance, have induced these traits in only a small proportion of the population exposed to their action. The evidence suggests that this small proportion, "the susceptible cells" possess a property or substance needed by the DNA in order to induce an heritable change.

The size of the small proportion of susceptible cells can be influenced significantly by a number of factors; when all the factors now to be listed are operating the frequency has not exceeded 1:1000.

The Type of Origin of Recipient Cells.—Type a exhibits the lowest frequency, about 1:10,000,000, and type d the highest, approximately 1 per 1000 cells exposed. This type-specific property which controls the frequency of susceptible cells is an inherited trait; repeated change to a heterologous type shows no influence on the incidence of these cells.

Concentration of DNA.—Within certain limits increase in the concentration of DNA controlling streptomycin resistance can increase the size of the proportion of cells in which streptomycin resistance can be induced. However, increases in concentrations greater than 10–1 µg. per ml. have not induced streptomycin resistance in a higher proportion of cells.

Phase of Growth Cycle.—Predictable fluctuations in frequency of induced heritable changes have been demonstrated in both Rb and Rd populations during growth. There is no evidence that susceptible cells reproduce their kind; they emerge in all experiments when the population reaches the end of the logarithmic period and a density of 2 to 4 x 108 cells per ml. In the early logarithmic phase it is difficult to demonstrate the presence of susceptible cells. The peak frequency of susceptible cells occurs in the early stationary phase of the growth cycle. Thereafter, the decline in frequency is a gradual one.

The data suggest that in a given population the same cells are susceptible to a number of different type-specific DNA's and the DNA controlling SM resistance.

Comparison of Frequency of Cells Susceptible to Different DNA's.—In a given population the frequency of cells susceptible to different type-specific DNA's and the DNA controlling streptomycin resistance is not significantly different.

Competition between Type-Specific DNA's—The data suggest that DNA's of types a, b, and c compete for the same cells in Rd populations. When Rd populations are exposed simultaneously to 2 of these 3 DNA's in different concentrations the proportion which each type contributes to the total type-specific cells induced is closely correlated with the concentration of the corresponding DNA.

Exclusion of DNA's.—Induction of one type specificity or streptomycin resistance can be completely prevented in a population containing susceptible cells by previous exposure for 15 minutes to a 1000-fold higher concentration of another type-specific DNA.
IMMUNOCHEMICAL STUDIES OF ANTITOXIN PRODUCED IN NORMAL AND ALLERGIC INDIVIDUALS HYPERIMMUNIZED WITH DIPHTHERIA TOXOID
Authors: Kuhns William J.
Published: June 2004

Electrophoresis on a starch-supporting medium was used to fractionate sera containing human diphtheria antitoxin of the following varieties (a) precipitating antitoxin, (b) non-precipitating skin-sensitizing antitoxin, and (c) mixtures containing precipitating and skin-sensitizing antitoxins. Aliquots of the protein fractions thus separated were tested for activity using the rabbit toxin neutralization test, precipitin techniques, and passive transfer tests in human skin.

Non-precipitating, skin-sensitizing diphtheria antitoxin migrated largely as a fast moving gamma (γ1) globulin. Passive transfer studies of isolated antitoxic fractions showed that they were as potent as whole serum in the ability to cause immediate wheal reactions. These fractions were not precipitable using appropriate quantities of purified toxoid.

Precipitating diphtheria antitoxin migrated largely as a slow moving gamma (γ2) globulin. Isolated antitoxic fractions of appropriate strength obtained from representative sera were precipitable by toxin and were unable to cause immediate wheal reactions upon toxoid challenge in human recipients.

Mixtures of skin-sensitizing and precipitating antitoxins were separable by the technique of starch electrophoresis. The individual components removed from mixtures by this method retained the properties by which they could be characterized in whole serum.
CELLULAR MECHANISMS OF PROTEIN METABOLISM IN THE NEPHRON
Authors: Oliver Jean , Moses Montrose J. , MacDowell Muriel C. , Lee Yin Chen
Published: June 2004

Histochemical methods show not only the presence of absorbed protein in the cellular droplet, but also the general identity of its constituent substances with those of the mitochondrial rodlets. Both contain considerable amounts of phospholipid and probably some PNA. The reactivity of the cytoplasmic constituents in droplet and in rodlet are different, however, since in the droplet these substances stain more intensely. As judged by variations observed in this intensity during the evolution of the droplet, these constituents and the absorbed protein vary in their proportions and amount. The droplet would appear to be a highly active center of protein metabolism.