The Journal of Experimental Medicine

Miller, Elizabeth M.; Goebel, Walther F.

doi: 10.1084/jem.100.6.525pmid: 13211912

1. By complement-fixation tests it has been shown that the lysogenic and sensitive strains of B. megatherium share one or more antigenic components which are serologically related but not identical. 2. Bacilli of the lysogenic strain of B. megatherium , when grown under conditions such that little extracellular phage is produced, fail to evoke antibodies in rabbits which react either in complement-fixation or neutralization tests with purified megatherium T phage. From this it must be concluded either that prophage is not antigenic or that any antibody which it might elicit does not react with the antigens of the mature virus. The observations reported in this communication accord with the hypothesis that prophage is a genetic structure. Footnotes Submitted: 16 July 1954

Tamm, Igor; Tyrrell, David A. J.

doi: 10.1084/jem.100.6.541pmid: 13211913

A procedure is described for kinetic studies on the multiplication of Lee virus in the chorioallantoic membrane in vitro employing the hemagglutination technique for measurement of virus concentration. A linear relationship was found between the logarithm of virus adsorbed and the amount of membrane used. Of the virus adsorbed less than 10 per cent could be recovered from the membrane. Of the recoverable virus 90 per cent was eliminated by specific immune serum. Lee virus was adsorbed by the allantoic and chorionic layers of the membrane to a similar degree. Multiplication occurred in both layers and to a similar extent. When 10 7.66 EID 50 of Lee virus was inoculated per 2.9 cm. 2 of chorioallantoic membrane, the ratio of infectivity to hemagglutination titer in the yield was low, although the rate of appearance of virus particles was not diminished despite the large inocula. Virus produced in membranes was liberated rapidly and continually into the medium. 5,6-Dichloro-1-ß- D -ribofuranosylbenzimidazole (DRB), 0.000055 M , prolonged the latent period by more than 100 per cent. The rate of increase during the period of rapid rise was similar in the presence or absence of DRB, but the yield was markedly reduced at the end of this period in the presence of DRB. The amount of the virus in the membranes continued to rise in the presence of DRB and eventually approached the maximal levels reached much earlier in the controls. Measurement of the amount of virus in the media indicated a greater degree of inhibition than did measurement in the membranes. Comparative studies with two benzimidazole derivatives on the dependence of the inhibitory effect on the time of addition of the compound showed that processes which could be inhibited by DRB were of shorter duration than those inhibited by 2,5-dimethylbenzimidazole (MB). With MB the relationship between the time of addition and the inhibitory effect was similar both for virus and for soluble complement-fixing antigen; with DRB the inhibitable processes were of shorter duration for the complement-fixing antigen than for virus particles. DRB was not only 35 times more active on a molar basis but also was more selective in its action than MB. DRB interfered with processes which preceded the emergence of either soluble complement-fixing antigen or virus particles. Some of the implications of these findings are discussed in relation to the mechanism of inhibition of influenza virus multiplication by benzimidazole derivatives. Footnotes Submitted: 29 July 1954

Teodoru, Constantin V.; Shwartzman, Gregory

doi: 10.1084/jem.100.6.563pmid: 13211914

Alterations in susceptibility of the Syrian hamster to poliomyelitis virus (MEF1) inoculated intracerebrally appeared closely related to seasonal changes and experimental disturbances in the adreno-testes equilibrium. Enhanced susceptibility coincided with seasonal enlargement of adrenals, followed cortisone and DOCA treatment and appeared during the initial postorchiectomy period. Increased resistance occurred incidentally to adrenalectomy, seasonal diminution in adrenal weight, testosterone overdosage, and testicular hypertrophy induced by treatment with GTH or chorionic gonadotrophin. The effect of certain hormonal interactions, the interference of conditioning factors and the role of compensatory reactions are discussed. Footnotes Submitted: 29 July 1954

Gaylord, William H.

doi: 10.1084/jem.100.6.575pmid: 13211915

Electron micrographs of intracellular memngopneumonitis virus have shown several types of particles which are presumably representative of different stages of a life cycle. They are: ( a ) Elementary bodies—dense particles 250 to 300 mµ in diameter with very dense central granules. ( b ) Intermediate forms—less dense than elementary bodies and larger. They are 300 to 400 mµ in diameter, contain a very dense central granule, and often have two or three limiting zones, ( c ) Circles 400 to 500 mµ in diameter—homogeneous structures with single membranes and no internal granules. They are often elongated and constricted at the center in the manner of budding yeast cells, ( d ) Circles 500 to 600 mµ in diameter with single membranes.mdash;One, two, and three dense granules may be present in some of these structures, ( e ) "Larger" structures, circular to elliptical, often with discontinuities or ruptures in their membranes. They sometimes seem to have internal septa. It has been inferred from these observations that the virus can multiply by binary fission or by multiple endosporulation and that elementary bodies are a spore-like stage. Footnotes Submitted: 28 March 1954

Ginsberg, Harold S.

doi: 10.1084/jem.100.6.581pmid: 13211916

Formation of non-infectious virus—particles which hemagglutinate red blood cells and react with antibody to fix complement but do not infect the chick embryo or mouse—occurred when large quantities of certain strains of influenza viruses were inoculated intranasally into mice. Dependent upon the agent employed, 10 6.5 to 10 8.5 E.I.D. was essential to elicit this phenomenon. To accomplish this unusual multiplication it was essential to use a strain of virus which effected extensive pulmonary consolidation; strains of virus which did not produce marked lung lesions, even when as much as 10 8.5 E.I.D. was inoculated, did not form non-infectious virus. The development of this viral form was directly dependent upon the extent of cell damage obtained: consolidation of more than 50 per cent of the lung volume was required. The majority of non-infectious particles developed during the initial cycle of viral multiplication, and concurrently with the formation of non-infectious virus there was a corresponding decrease in the number of infectious viral particles. Non-infectious virus could not be propagated on serial passage in mouse lungs: on second lung passage only fully infectious virus was detectable. The formation of the non-infectious viral form was not the result of interference with synthesis of infectious virus by inactivated virus in the inoculum; for inoculation of heated infected allantoic fluid which contained more than 99 per cent of non-infectious virus did not result in the development of new non-infectious virus. Although inoculation of a large quantity of virus resulted in infection which yielded a relatively low titer of infectious and high titer of non-infectious virus, inoculation of a small quantity of the agent resulted in a high yield of infectious virus and no non-infectious that was detectable. In both instances the total quantity of antigenic viral material synthesized in the mouse lungs was the same. These data do not support the hypothesis that the non-infectious virus formed consisted of immature or incomplete viral particles, but suggest instead that non-infectious virus is inactivated virus or some aberrant form of the agent. Footnotes Submitted: 6 August 1954

Klatskin, Gerald; Krehl, Willard A.; Conn, Harold O.

doi: 10.1084/jem.100.6.605pmid: 13211917

Rats maintained for a period of 7 months on a fluid intake of 15 per cent alcohol and a diet marginal in lipotropic activity developed fatty infiltration and mild fibrosis of the liver. Similar changes were observed in pair-fed controls given an isocaloric equivalent of sucrose instead of alcohol, but not in pair-fed controls receiving neither alcohol nor sucrose supplements. To exclude the possibility that the alcohol effect was related to an augmentation of the caloric intake, a third group of controls was given the same amount of alcohol, but a limited number of calories. This was accomplished by subtracting from the basal diet an amount of sucrose equivalent in calories to the alcohol consumed. Under these conditions the hepatic changes following alcohol ingestion appeared to be enhanced. Choline or methionine, on the other hand, abolished the effects of both alcohol and sucrose supplements. There was no increase in fecal nitrogen excretion following alcohol ingestion, and no histological changes were observed in the pancreas. These results are consistent with the hypothesis that alcohol increases the choline requirement of the rat, but do not support the contention that this effect is the consequence of an augmented caloric intake. Further studies are needed to establish conclusively the relationship between alcohol ingestion and the choline requirement, and to elucidate the mechanisms involved. Footnotes Submitted: 27 July 1954

Klatskin, Gerald; Krehl, Willard A.

doi: 10.1084/jem.100.6.615pmid: 13211918

The effect of alcohol on the choline requirement was assayed in weanling rats maintained on a basal diet of relatively low lipotropic activity containing the equivalent of 0.089 per cent choline. Alcohol was administered as a 15 per cent solution in lieu of drinking water. The incidence of renal cortical necrosis, the increase in kidney weight, and the mortality rate at the end of 14 days served as indices of choline deficiency. Under these conditions alcohol-fed animals developed more severe signs of choline deficiency than either pair-fed controls or pair-fed isocaloric controls receiving a sucrose supplement instead of alcohol. The addition of as little as 0.08 per cent of choline to the basal diet abolished these differences. It was concluded that ( a ) alcohol increases the choline requirement, and may, thus, induce a state of relative deficiency when the diet is marginal in lipotropic activity, and ( b ) this effect is independent of the caloric intake. The possible significance of these observations in relation to chronic alcoholism in the pathogenesis of Laennec's cirrhosis has been discussed. Footnotes Submitted: 27 July 1954

Krumwiede, Elma

doi: 10.1084/jem.100.6.629pmid: 13211919

The opalescence produced in serum by group A streptococci has been investigated. The development of opalescence is shown to be initiated by an enzyme attached to the bacterial cell which acts upon the α 1 -lipoprotein fraction of serum liberating the lipids from the protein. This enzyme has been termed a lipoproteinase. Evidence is presented which suggests that the degree of opalescence which develops following lipoproteinase activity is influenced not only by factors attached to the bacterial cell but also by substances present in serum. The lipoproteinase is antigenic and many human sera contain specific antibodies which inhibit the action of the enzyme. Footnotes Submitted: 18 August 1954

Palade, George E.; Porter, Keith R.

doi: 10.1084/jem.100.6.641pmid: 13211920

A series of representative cell types including avian fibroblasts, and macrophages; rabbit mesothelia, endothelia, and nephron epithelia; and rat glandular epithelia (parotid) were studied comparatively in vitro and in situ with the electron microscope. Cells in vitro were examined in whole mounts and in sections whereas cells in situ were observed exclusively in sections. It was found that an endoplasmic reticulum similar to that previously described in cultured material is present in situ in all cell types examined. Modifications in its appearance introduced by the sectioning technique were discussed and explained. The observations showed in addition that the endoplasmic reticulum is a network of cavities which may enlarge into relatively vast, flattened vesicles here described as cisternae. Footnotes Submitted: 26 July 1954

Murphy, James S.

doi: 10.1084/jem.100.6.657pmid: 13211921

The rate at which cultures of B. megatherium 899a produce certain mutants of its phage T (wild type) has been investigated in two media; one (peptone) in which reinfection of sensitive cells, if present, is virtually certain, and one (asparagine) in which reinfection is extremely unlikely. Little difference either in the number or types of mutants produced has been detected. It is concluded that phage mutants are produced directly by B. megatherium 899a and that no intermediate passage through a sensitive cell is necessary for the mutation. 396 individual mutant plaques have been isolated and classified into at least 18 types of plaque-forming mutants of B. megatherium 899a. The over-all mutant ratio found was in the order of 1:2000 while individual mutants appeared with rates between 1:7000 and less than 1:100,000. Footnotes Submitted: 30 July 1954