bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE BEHAVIOR OF VIRULENT AND AVIRULENT STAPHYLOCOCCI IN THE TISSUES OF NORMAL MICE
Authors: Smith J. Maclean , Dubos René J. 
Published: June 2004

The fate of hemolytic staphylococci injected intravenousiy into albino mice was followed by determining quantitatively the numbers of living organisms present in the various tissues at different intervals of time after infection.
Irrespective of the strain of staphylococcus used, most of the organisms disappeared rapidly from the blood, liver, spleen, and kidneys. This was true even when the infective dose consisted of large numbers of virulent, coagulase-positive staphylococci, capable of producing a fatal disease in a high percentage of the infected mice. The initial rate of removal or destruction of staphylococci was particularly high in the lungs and kidneys. In all cases on the other hand, a few living staphylococci persisted in the various organs for several weeks after infection, even when the organisms were non-virulent and coagulase-negative.
Although virulent as well as avirulent staphylococci were eliminated extremely rapidly and efficiently from the kidneys during the initial stage of infection, the microorganisms soon began to multiply in this organ, causing abscesses first detected in the cortex. Death of the animals infected with virulent cultures appeared to be due to the destruction of renal tissue by these abscesses. The abscesses caused by the avirulent strains eventually became sterile, and healed.
No convincing difference could be recognized amongst seven strains in their resistance to the bactericidal power of the mouse tissues during the initial phase of the infection. In contrast, marked quantitative differences came to light in their subsequent behavior in the kidneys. The multiplication of the coagulase-negative staphylococci in this organ soon came to an end in all animals and never proceeded far enough to result in fatal disease. The staphylococci of a weakly coagulase-positive strain multiplied somewhat more extensively in the kidneys than did the coagulase-negative, but never sufficiently to cause the death of any animal within the period of observation of 1 month. The three coagulase-positive strains tested yielded the largest bacterial population in the kidneys and caused the death of many of the infected animals. These three virulent strains differed quantitatively amongst themselves with regard to both the rapidity and extent of their multiplication in the kidneys and the lethal power of a given infective dose.
Taken together, the findings indicate that the hemolytic strains of staphylococci can be arranged in a continuous spectrum according to their ability to cause disease in albino mice. Although virulence for these animals appeared to be correlated with the production of coagulase, it did not seem to depend upon the ability of this substance to interfere with the bactericidal mechanisms of the mouse organs during the early phase of the infection. Virulence manifested itself chiefly by the production in the kidneys of progressive abscesses originating from the few staphylococci which were not destroyed during the initial bactericidal reaction.
NUTRITION OF THE HOST AND NATURAL RESISTANCE TO INFECTION
Authors: Schneider Howard A. , Zinder Norton D. 
Published: June 2004

The double strain inoculation test as used for the assay of nutritional factors capable of enhancing survivorship in mouse salmonellosis has been modified and improved. The modification has been based on the use of genetically marked strains of S. typhimurium, and substitutes for survivorship a bacteriological datum, a certain minimum population size of the virulent salmonellae in the mouse spleen at a certain time. The analysis permitting this substitution and the economies achieved by the modification has been presented.
In the course of development of the new assay evidence was obtained that the nutrient entity or entities responsible for enhanced survivorship, as measured by the bacteriological correlate, are not stored in the mouse. A deficiency state was achieved 24 hours after supplying the basal synthetic diet. Similarly, positive effect of active nutrients was evident as soon as 24 hours after feeding.
STUDIES ON THE O ANTIGEN OF SALMONELLA TYPHOSA
Authors: Johnson Arthur G. , Gaines Sidney , Landy Maurice 
Published: June 2004

Quantitative studies have demonstrated that a purified lipopolysaccharide (endotoxin) derived from the O-901 strain of Salmonella typhosa markedly enhanced the antibody response of rabbits when given separately or in conjunction with protein antigens. The augmentation of antibody levels varied from 2- to 40-fold with the number of injections, the dosage of antigen and endotoxin, and the route of administration. This antibody-enhancing property was found to be common to a broad group of endotoxins from Gram-negative bacilli and was not restricted to the lipopolysaccharide derived from S. typhosa.
Factors affecting this enhancement were investigated, and data are presented which indicate that host susceptibility to endotoxin is a prerequisite for elevation of antibody levels; the intact lipopolysaccharide, as isolated, might not be essential for this activity; and the rate of clearance of antigen from the circulation of rabbits was accelerated when endotoxin was given in conjunction with protein.
The data obtained are discussed in relation to postulated mechanisms on the antibody-enhancing action of endotoxin.
ON THE NATURE OF PARABIOSIS INTOXICATION: SHOCK AS THE PRECIPITATING CAUSE
Authors: Hall C. E. , Hall O. 
Published: June 2004

Spinal transection of one of a parabiotic pair of rats is immediately followed by a state indistinguishable in visual and hematologic characteristics from spontaneous "parabiosis intoxication." The transected rat develops erythremia, hyperhemoglobinemia, and an increased hematocrit count; whereas the twin concurrently shows anemia characterized by a decrease in hemoglobin, erythrocyte count, and hematocrit reading, and often also lipemia.
These findings are ascribed to whole blood transfusion of one rat by the other followed by adjustments compensatory to the resulting distortion in the respective blood volumes. It is suggested that parabiosis intoxication is a manifestation of this same process and is not due, as has been contended, to an immune response.
THE PREPARATION AND FUNCTION OF THE HYPERTENSIN-CONVERTING ENZYME
Authors: Skeggs Leonard T. , Kahn Joseph R. , Shumway Norman P. 
Published: June 2004

It has been shown by use of isolated, perfused rat kidneys that hypertensin II is a potent vasoconstrictor substance while hypertensin I is not. Hence it would appear that in intact animals the pressor activity of hypertensin I results from its rapid conversion to hypertensin II.
An enzyme which effects this conversion has been procured from horse plasma in a semipurified form by means of ammonium sulfate fractionation and isoelectric precipitation. A method is described for estimating the activity of the enzyme. An example of the use of the preparation in converting purified hypertensin I to hypertensin II has been described.
ANTIGENIC VARIANTS OF INFLUENZA A VIRUS (PR8 STRAIN)
Authors: Gerber Paul , Hamre Dorothy , Loosli Clayton G. 
Published: June 2004

Four successive generations of antigenic variants of influenza PR8-S virus, each derived from the previous one by serial passage in the lungs of mice immunized with the homologous agent, were compared with the original parent PR8-S virus with respect to their serological and immunological character. It was demonstrated by means of H.I., complement-fixation and in ovo-neutralization tests that the variants exhibited a progressively decreasing reactivity with the parent PR8-S antiserum while retaining the ability to elicit antibody to PR8-S influenza virus and to their respective predecessors. Accompanying these changes was a progressive reduction in antigenicity without any significant changes in pathogenicity for mice. Experimental evidence was presented which indicates that the serological changes observed with the variants are not related to the P-Q phenomenon.
Antibody absorption tests showed that the variants share antigens with PR8-S virus but differ from it by the presence of specific antigenic components; these increase in quantity with each successive variant while the amount of related antigens shows a progressive decrease.
The importance of evaluating the significance of antigenic changes of influenza viruses with active immunity tests was emphasized by the fact that PR8-S vaccine protected mice against fatal infection with lethal doses of the variant strains although the latter had a progressively decreasing serological reactivity with PR8-S antiserum.
The inheritable character of the new antigenic properties of the variant strains was demonstrated by their persistence in the absence of thea selective environment following 18 to 24 serial intranasal passages with large inocula in normal mice and following limiting dilution passage in fertile eggs.
THE RELATION OF ANGIOTONIN AND L-NOREPINEPHRINE TO ESSENTIAL HYPERTENSION AS DETERMINED BY THE REACTION OF THE NAILFOLD CAPILLARY BED
Authors: Greisman Sheldon E. 
Published: June 2004

Further evidence has been obtained that L-norepinephrine infusions markedly decreases cutaneous capillary blood flow in the nailfold. Sustained ischemia of the capillary bed occurred prior to the attainment of hypertensive diastolic arterial blood pressure levels. Corroborative evidence of this nailfold capillary ischemia was obtained from the capillary reactive hyperemia that followed the abrupt discontinuance of the L-norepinephrine infusions.
The infusion of angiotonin into persons with normal blood pressure did not induce sustained ischemia of the nailfold capillary vessels, even after definite hypertensive diastolic arterial blood pressure levels were attained. Corroboration of the adequacy of nailfold capillary blood flow was obtained by noting the absence of capillary reactive hyperemia following the abrupt cessation of the angiotonin infusions.
The nailfold capillary bed in persons with angiotonin-induced hypertension could not be distinguished from that of persons with essential hypertension by direct microscopic examination.
During the infusion of angiotonin into subjects with normal cardiovascular systems, the reactivity of the nailfold capillary bed to circulating L-norepinephrine was significantly increased, approaching the levels found in persons with essential hypertension.
From the standpoint of its effects upon the nailfold capillary bed, angiotonin, unlike L-norepinephrine, is one substance which possesses the properties required of the hypothetical humoral pressor substance of essential hypertension.
STUDIES OF THE BACTERICIDAL ACTION OF PHAGOCYTIN
Authors: Hirsch James G. 
Published: June 2004

The bactericidal activity of phagocytin on Gram-negative enteric bacilli is influenced by the reaction of the medium; the more acid the environment, the more marked is the activity.
Phagocytin exerts approximately the same action whether citrate, acetate, or phosphate salts are used as buffer, and the addition of glucose, casein hydrolysate, or cation binding agents does not produce notable change. Although proteins in general have but little effect, the inclusion in the medium of a high concentration of bovine plasma albumin neutralizes the lethal action of phagocytin on enteric bacilli. Very high concentrations of magnesium or calcium ions antagonize but do not completely block the bactericidal effect.
The bactericidal activity of phagocytin is essentially independent of the numbers of bacteria exposed; a 100-fold increase m the numbers of enteric bacilli results in approximately a 2-fold increase in the concentration of phagocytin required to kill 90 per cent of them.
When susceptible microorganisms are exposed to phagocytin at 0°C., practically no killing takes place. At higher temperatures the bactericidal action is rapid, being well advanced in 5 minutes and complete within 30 minutes.
ACTION OF X-RAYS ON MAMMALIAN CELLS
Authors: Puck Theodore T. , Marcus Philip I. 
Published: June 2004

The effects of x-irradiation have been quantitatively studied on single cells of a human cervical carcinoma (HeLa) under conditions such that 100 per cent of the unirradiated cells reproduce in isolation to form macroscopic colonies. This technique eliminates complexities due to interactions of members of large cell populations.
Survival of single cells (defined as the ability to form a macroscopic colony within 15 days) yields a typical 2 hit curve when plotted against x-ray dose. The initial shoulder extends to about 75 r, after which a linear logarithmic survival rate is obtained, in which the dose needed to reduce survivors to 37 per cent is 96 r. This radiation sensitivity is tens to hundreds of times greater than that of any microorganism for which the equivalent function bas been studied.
Evidence, though not proof, is presented that the lethal effect is due to a radiation-induced genetic defect which, however, cannot be a simple single gene inactivation. The locus of the action could be chromosomal.
Beginning at doses of 100 r, or possibly earlier, growth-delaying effects of radiation are visible.
Cells in which the ability to reproduce has been destroyed by doses below 800 r, can still multiply several times. At higher doses even a single cell division is precluded.
A large proportion of the cells killed by radiation at any dose gives rise to one or more giant cells. These metabolize actively, grow to huge proportions but never reproduce under the experimental conditions employed. Methods of preparing large populations of giant cells are described. These giants are particularly susceptible to virus action.
Some of the irradiated cells disappear from the plate, presumably by disintegration. This action of radiation is by far the least efficient, since even after 10,000 r, 5 to 10 per cent of the original cell inoculum is recoverable as giants.
THE LOCALIZATION OF SKIN-SENSITIZING ANTIBODY IN THE SERA OF RAGWEED-SENSITIVE INDIVIDUALS BY ELECTROPHORESIS
Authors: Sehon Alec H. , Harter John G. , Rose Bram ,   With the Technical Assistance of P. L. Rojowski
Published: June 2004

Starch electrophoresis was used to separate allergic sera into electrophoretically distinct albumin, α-, ß-, and γ-globulin fractions. The identity of the various fractions was established by free and paper electrophoresis. The γ-globulin fractions were also characterized by ultracentrifugation.
The serum skin-sensitizing antibody to ragweed pollen was shown to be associated with the γ-globulins in fourteen allergic sera by means of passive transfer technique. The mobility of the skin-sensitizing antibody corresponded to that of γ–1 and/or γ–2 globulins. All the other serum fractions were devoid of reaginic activity.
Reaginic activity per se was not directly related to protein concentration.
The discrepancies between these results, and those obtained by others and ourselves previously are discussed.
STUDIES ON COPPER METABOLISM. XIX
Authors: Bush J. A. , Jensen W. N. , Athens J. W. , Ashenbrucker Helen , Cartwright G. E. , Wintrobe M. M. 
Published: June 2004

Ferrokinetic studies were performed in three copper-deficient swine and the results have been compared with similar studies in 18 normal pigs. The mean value for the plasma iron turnover rate in the deficient swine was 1.76 mg./kg. day; for the red cell iron incorporation rate, 1.24 mg./kg. day; for the red cell iron turnover rate, 1.18 mg./kg. day; for the red cell life span, 13 days. Corresponding figures in the normal swine were 1.11 mg./kg. day, 1.01 mg./kg. day, 0.59 mg./kg. day and 63 days, respectively.
The red cell life span was measured by the use of radioactive chromium in a total of 26 pigs. The mean erythrocyte half-life of normal cells transfused into normal pigs was 17 days. The mean half-life of erythrocytes from copperdeficient swine transfused into copper-deficient swine was 9 days. The mean half-life of red cells from control animals transfused into copper-deficient swine was 16 days while that of erythrocytes from copper-deficient swine transfused into normal pigs, was 13 days. The mean half-life of cells from iron-deficient pigs transfused into iron-deficient pigs was 19 days.
It is concluded that copper deficiency anemia results from both a shortened erythrocyte survival time and limited capacity of the bone marrow to produce red cells. It is suggested that copper is an essential component of erythrocytes in swine.
STUDIES ON BACTERIEMIA
Authors: Rogers David E. 
Published: June 2004

During the course of studies on the characteristics of experimental bacteriemia, staphylococci were swiftly cleared from the blood stream of rabbits during the initial 10 to 15 minutes following intravenous injection of microorganisms. A subsequent abrupt decline in the rate of clearance ensued, resulting in a low grade bacteriemia which was demonstrable for many hours.
The experiments reported have indicated that this strain of staphylococcus is rapidly phagocyted within the vascular system of rabbits, and that viable staphylococci circulate within the cytoplasm of polymorphonuclear leukocytes.
The removal mechanisms contained within the liver and spleen appear to preferentially trap circulating extracellular staphylococci. When most of the circulating staphylococci are contained within leukocytes, splanchnic removal declines or virtually ceases.
These observations suggest that viable, intracellular microorganisms are responsible for the persistence of staphylococcal bacteriemia in rabbits following the phase of rapid removal from the blood stream.
AN ASCITES TUMOR APPEARING DURING THE PASSAGE OF EPERYTHROZOON COCCOIDES IN MICE
Authors: Nelson John B. 
Published: June 2004

A strain of Eperythrozoon coccoides was maintained in a pure state for 16 months in unsplenectomized Princeton mice by the intraperitoneal injection of parasitized blood, at intervals of 1 to 3 weeks. In the 39th passage three out of five mice developed marked ascites with innumerable neoplastic cells in the peritoneal fluid. By passage of this fluid the tumor cells and the eperythrozoon were transferred together, with the rapid development of ascites and early death of the animals. On continued passage of ascitic fluid and blood from the mice of the 39th successive group both the tumor and the eperythrozoon were ultimately obtained in a pure state. Development of the passaged tumor was uninfluenced by the eperythrozoon but growth of the latter appeared enhanced in the presence of the neoplastic cells. Throughout 50 passages in mice the ascites tumor has not altered in character.
The intraperitoneal injection of ascitic fluid was irregularly followed by the appearance of tumor cells in the blood, the rate of the carriage being 26 per cent in sixty-five animals. The subcutaneous and intramuscular injection of the fluid resulted in solid, highly invasive, local growths which did not metastasize. The solid growths proved transferable in series yet after 20 passages still produced the ascites tumor on intraperitoneal injection of their cells.
STUDIES ON HOST-VIRUS INTERACTIONS IN THE CHICK EMBRYO-INFLUENZA VIRUS SYSTEM
Authors: Liu Oscar C. , Paucker Kurt , Henle Werner 
Published: June 2004

Certain aspects of the formation of non-infectious hemagglutinins (NIHA) in the chick embryo infected with influenza virus have been analyzed.
It was shown by the use of combined in ovo-deembryonation technics that little or no NIHA is released following infection with small doses of standard virus during the most active and constant growth periods of the virus extending to about the 36th hour of incubation in spite of the fact that multiple infection of cells must have taken place in the latter half of that period. A slight decrease in the ID50/HA ratios of the yields obtained after the 36th hour, coinciding with the falling off of virus production and release may possibly be explained in terms of inactivation of completed virus or leakage of as yet incompleted virus from damaged cells.
Exposure of the entodermal cells of the allantois of eggs deembryonated shortiy after injection of saturation or near saturation inocula of standard seed to large quantities of infectious virus added to the media at various times after infection and not extending over more than 2 hours resulted in a decrease of the ID50/HA ratios of the progenies only during the first 2 or possibly 4 hours after the primary inoculation. Later addition did not influence the yields. As discussed, such sudden and heavy exposures of cells are not expected to occur during the infectious process induced by small inocula of standard seed.
The possible role of destruction of cell receptors in NIHA production has been analyzed in several ways. The addition of receptor-destroying enzyme (RDE) to the media of deembryonated eggs after near saturation inocula of standard seeds, if anything, increased the ID50/HA ratios of the progenies, and that only when added during the first few hours following infection, presumably by reducing the changes for high multiplicity of infection of cells. In contrast, ultraviolet-inactivated virus, which retains its enzymatic activity, lowered, if anything, the ID50/HA ratios of the progenies, when present in the media of deembryonated eggs from the 2nd to 4th or possibly 6th hour after infection. Excessive amounts of irradiated virus may still cause some degree of interference under these conditions. Later addition of irradiated viruses were without effect with respect to NIHA production or interference. In attempts to alter the cell receptors prior to infection by potassium periodate (KIO4), it was noted that the addition of glycerol led to the appearance and partial retention for at least 24 hours of substances in the allantoic fluids which were capable of inactivating considerable proportions of standard virus. These data indicate that destruction of external cell receptors plays little if any role in NIHA production.
The implications of these findings are discussed.
THE PATHOGENESIS OF HYPERLIPEMIA INDUCED BY MEANS OF SURFACE-ACTIVE AGENTS
Authors: Hirsch Robert L. , Kellner Aaron 
Published: June 2004

Rabbits subjected to subtotal hepatectomy failed to develop increased serum cholesterol levels following parenteral injection of triton WR 1339, the finding indicating that the liver is essential for the establishment of the hypercholesterolemia induced by surface-active agents.
The cholesterol content of the livers of rabbits rendered hyperlipemic by means of triton remained unchanged both during the rapid rise of the serum cholesterol levels and during the return to normal values. By contrast, the cholesterol content of the livers of rabbits fed cholesterol rose progressively over a period of 5 weeks, concommittant with the increase in serum cholesterol levels. The findings provide support for the hypothesis that surface-active agents bring about hyperlipemia by altering the circulating lipoproteins in some manner so that they are retained in the circulating body fluids.