LATENT VIRAL INFECTION OF CELLS IN TISSUE CULTUREMorgan, Herbert R.
doi: 10.1084/jem.103.1.37pmid: 13278453
Chick embryo tissues maintained for from 11 to 28 days in Hank's balanced salt solution lost their capacity to support the multiplication of psittacosis virus. The virus however infected such cells, as active multiplication of the virus occurred on the addition of beef embryo extract to this nutritionally poor medium at any period up to 28 days of cultivation in balanced salt solution. The virus remained in a state of latency for as long as 15 days in these starved cells in a non-infectious phase. These results obtained in this in vitro model system for the investigation of latent infections of cells with psittacosis virus suggest that cell nutrition as well as an alteration in the immunological defenses of the host may prove to be an important factor in the activation of latent viral infections. Footnotes Submitted: 22 September 1955
ANTIGENICITY OF RAT COLLAGENRothbard, Sidney; Watson, Robert F.
doi: 10.1084/jem.103.1.57pmid: 13278455
Reverse anaphylactic shock was induced in rats by intravenous injection of serum containing complement-fixing antibodies, obtamed by immunization of rabbits with purified preparations of rat tail collagen. Normal rabbit serum or serum containing antibodies to collagen from tunica of carp swim bladder was without effect. The clinical and pathological findings resembled those described by previous workers studying direct and reverse anaphylactic reactions induced in the rat with other antigens. Thrombocytopenia, leukopenia with rebound leukocytosis, delayed blood coagulability, lowering of serum complement and the development of a refractory state to the antibody after the initial shock—all compatible with anaphylaxis—were demonstrated. The reacting substance was found to be in the gamma globulin fraction of the serum, and the antibody titer appeared to be correlated with the degree of shock and vascular injury. Collagen injury in rats dying from acute shock or in those injected with repeated sublethal doses was not demonstrated by the methods employed; techniques by which lesions of collagen might be induced are discussed. Absorption experiments indicated that anti-rat collagen rabbit serum is specifically directed to a substance, apparently collagen, in the rat; it is likely that the combination of the antibody and collagen induces anaphylactic shock. These studies, made in vivo , provide further evidence of antigenic and immunological differences between acid-soluble rat and fish collagens. Footnotes Submitted: 13 September 1955
ANTITUBERCULOUS IMMUNITY INDUCED BY METHANOL EXTRACTS OF TUBERCLE BACILLI—ITS ENHANCEMENT BY ADJUVANTSWeiss, David W.; Dubos, René J.
doi: 10.1084/jem.103.1.73pmid: 13278456
It is possible to prepare from tubercle bacilli a fraction soluble in methanol which is capable of eliciting in mice a marked degree of resistance against virulent tuberculous infection. The immunity was evident whether the infective dose was large and caused a disease with a rapid course, or was very small and caused a disease of many months duration. Active material has been obtained by extraction with methanol at 55°C. of bacterial cells killed with 2 per cent phenol, and washed with acetone. The methanol extracts used in the present study have been prepared from the phenol-killed cells of a culture of BCG, and of the avirulent culture H37Ra. Vaccination of mice bas been carried out by the intraperitoneal route, and the challenge infection (with a highly virulent bovine culture), by the intravenous route. Weight for weight, the protective activity of the methanol extract is smaller than that of the bacterial cells from which it is extracted, but its primary toxicity for mice is also considerably lower. The protective activity can be increased, and the immunity prolonged, by using certain adjuvants as vehicle for injection of the vaccine. An oil adjuvant mixture, and small amounts of a highly purified preparation of the somatic antigen of typhoid bacilli, have been found capable of enhancing and prolonging the antituberculous immunity induced by the methanol extract. Under appropriate conditions the resistance resulting from intraperitoneal injection of the methanol extract is of the same order as that which follows vaccination with whole killed tubercle bacilli or with living BCG. Footnotes Submitted: 2 October 1955
THE BEHAVIOR OF VIRULENT AND AVIRULENT STAPHYLOCOCCI IN THE TISSUES OF NORMAL MICESmith, J. Maclean; Dubos, René J.
doi: 10.1084/jem.103.1.87pmid: 13278457
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. Footnotes Submitted: 2 October 1955
THE EFFECT OF NUTRITIONAL DISTURBANCES ON THE SUSCEPTIBILITY OF MICE TO STAPHYLOCOCCAL INFECTIONSSmiths, J. Maclean; Dubos, René J.
doi: 10.1084/jem.103.1.109pmid: 13278458
The susceptibility of mice to intravenous injection of coagulase-positive hemolytic staphylococci was estimated by ( a ) observing the extent and time of mortality of infected animals; ( b ) determining the number of colonies of cocci that could be recovered from the liver and spleen at various intervals of time after infection. Complete deprival of food for 36 to 48 hours immediately before infection was found to increase susceptibility. This infection-enhancing effect was further increased by allowing the animals to drink a 5 per cent glucose solution instead of water or saline during the fasting period. In contrast, sodium lactate partially corrected the effect of fasting. The infection-enhancing effect of fasting was reversible. Mice prevented from gaining weight for several weeks either by restricting their daily food intake, or by feeding them ad lib . an inadequate diet, appeared just as resistant to staphylococcal infection as did mice that gained weight rapidly on an unrestricted, complete diet. Footnotes Submitted: 2 October 1955
THE EFFECT OF DINITROPHENOL AND THYROXIN ON THE SUSCEPTIBILITY OF MICE TO STAPHYLOCOCCAL INFECTIONSSmiths, J. Maclean; Dubos, René J.
doi: 10.1084/jem.103.1.119pmid: 13278459
Mice were given daily per os amounts of dinitrophenol or of thyroid extract sufficient to prevent or retard the normal weight gain of uninfected animals, but not large enough to cause their death. When mice maintained on these regimens for 1 or 2 weeks were infected with staphylococci, most of them died within 12 days—much more rapidly than did mice fed a normal diet. Deaths occurred even when the organism injected was a non-virulent staphylococcus, unable to cause fatal disease in mice fed a normal diet. There was some suggestion that thyroid treatment interfered with the bactericidal mechanism in the liver, spleen, and kidneys of mice during the initial phase of infection. In contrast there was no clear evidence at any time thereafter that either thyroid extract or dinitrophenol caused the staphylococci to multiply more rapidly in the various organs. Footnotes Submitted: 2 October 1955
GLOMERULAR LESIONS AND THE NEPHROTIC SYNDROME IN RABBITS GIVEN SACCHARATED IRON OXIDE INTRAVENOUSLYEllis, John T.
doi: 10.1084/jem.103.1.127pmid: 13278460
Intravascular precipitates, comprised at least in part of iron, formed regularly in rabbits given one or more injections of a saccharated iron oxide preparation intravenously, and these lodged in numerous capillaries throughout the body, particularly those of the lungs and kidneys. Large numbers of the brownish precipitates remained in the capillaries of the renal glomeruli during the first few days following injection of the iron, but most of them disappeared after 5 to 7 days, with only moderate amounts of brown pigment remaining in the endothelial cells of the renal glomeruli. Signs of acute injury of the glomerular tufts—namely) pyknosis of some of the endothelial cells, margination of leukocytes within the glomerular capillaries, and slight proliferation of the epithelial cells—also developed some 5 to 7 days following injection of the iron, along with marked proteinuria, which proved transitory if no further injections were given. When the iron preparation was given repeatedly over prolonged intervals, however, the proteinuria persisted and became extreme, and hypoproteinemia developed, often with hypercholesterolemia and transitory edema as well. Histological studies of the kidneys of rabbits manifesting the nephrotic syndrome, as just described, disclosed that virtually all the renal glomeruli were greatly altered, mainly owing to proliferation of the epithelial cells, together with some fibrosis and atrophy. Some of the rabbits having marked proteinuria and other functional changes eventually developed azotemia following repeated injections of the iron, and several of them lost weight and died; the renal glomeruli of these animals showed changes like those just described, but the alterations were more extensive. Considered together, the findings provide evidence that the intravascular precipitates first occluded the glomerular capillaries for a period of several days following injection of the iron and then largely disappeared from them just prior to the development of morphologic signs of glomerular injury and proteinuria. Hence the possibility was considered that the intracapillary precipitates might have produced acute injury to the walls of the glomerular capllaries through the agency of anoxia. But it is plain that the findings of the present study do not disclose the essential nature of the anatomical change responsible for the proteinuria, or the means whereby this was produced. The findings as a whole were briefly considered in relation to the pathogenesis of the nephrotic syndrome as it occurs naturally in human beings. Footnotes Submitted: 5 September 1955