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J FONG

Publications and source records attributed to J FONG.

At least 19 recordsLinked to original sources
PubMed1964

STUDIES OF TUBERCLE BACILLUS-HISTIOCYTE RELATIONSHIPS. 8. COMPARATIVE STUDY OF CELLULAR RESISTANCE INDUCED BY BRUCELLA AND MYCOBACTERIA.

Comparison of the Brucella-immune and the BCG-immune histiocyte, each of which is resistant to necrotization by either Brucella or mycobacteria, has revealed a number of dissimilarities in their behavior. The Brucella-immune histiocyte was found to be incapable of transferring its resistance to the cells of normal animals; it was also unable to achieve attenuation of virulent tubercle bacilli. In contrast, the BCG-immune histiocyte and certain of its subcellular components (ribosomes and ribosomal RNA) were effective in inducing cellular resistance in normal animals against both Brucella and mycobacteria. When RNA was used, only immune ribosomal RNA was effective; when intact ribosomes were used, both immune and recipient ribosomes proved active. These investigations have also shown that the resistance of the BCG-immune histiocyte against Brucella and mycobacteria was of long duration and not readily dissociable.

Animals↗
PubMed1963

STUDIES OF TUBERCLE BACILLUS-HISTIOCYTE RELATIONSHIPS. VII. HOMOLOGOUS AND HETEROLOGOUS TRANSFER OF CELLULAR RESISTANCE.

Immunization of mice or guinea pigs with BCG rendered all or most of the histiocytes of these animals resistant to necrotization by virulent H37Rv; this cellular resistance was mediated by immune serum. Immune mouse histiocytes (from BCG-immunized animals) were able to induce cellular resistance in normal homologous and heterologous (rabbit) animal species; mouse histiocytic ribosomes were also tested in the homologous species and found to be active. Immune guinea pig histiocytes (from BCG-immunized guinea pigs) were ineffective in transferring cellular resistance to either homologous or heterologous (mouse and rabbit) animal species. Immune rabbit histiocytes were capable of inducing cellular resistance in mice and guinea pigs; rabbit histiocytic ribosomes were also tested in normal mice and found to be active in induction of cellular resistance. Recipient guinea pig histiocytes (from guinea pigs inoculated with immune rabbit histiocytes) were capable of inducing cellular resistance in normal guinea pigs and rabbits. Cultivation of lysed immune histiocytes of all three animal species on glycerol-blood agar medium failed to reveal any viable BCG; this provided one additional bit of evidence against the idea that induction of cellular resistance is due to viable bacilli.

Animals↗
PubMed1963

STUDIES OF TUBERCLE BACILLUS-HISTIOCYTE RELATIONSHIPS. VI. INDUCTION OF CELLULAR RESISTANCE BY RIBOSOMES AND RIBOSOMAL RNA.

The various cellular components of immune rabbit histiocytes have been analyzed for their ability to induce cellular resistance in normal animals. The results of these investigations have shown that the nuclear and mitochondrial fractions were inactive and that the microsomal and ribosomal fractions were active. The importance of ribonucleic acid in induction of cellular resistance was established by isolation of an active ribosomal RNA and by demonstration of inactivation of this material with ribonuclease but not with deoxyribonuclease or trypsin. The possibility that viable bacilli were present in immune ribosomes was tested; the absence of complement-fixing antibodies and of skin reactivity to tuberculin in animals inoculated with ribosomes was considered as partial evidence of absence of living bacilli.

Animals↗
PubMed1962

Studies on tubercle bacillus-histiocyte relationship. V. Passive transfer of cellular resistance.

Studies of passive transfer of cellular resistance, as manifested by refractoriness to necrotization with virulent tubercle bacilli, have shown that immune histiocytes or immune lymphocytes were effective transferring agents; immune polymorphonuclear leucocytes and immune serum as well as comparable cells from normal animals lacked this capacity. Comparisons of immune histiocytes and immune lymphocytes showed that the former cells were more efficient; this was indicated by (a) the smaller numbers of immune histiocytes needed for passive transfer, (b) the longer duration of cellular resistance in recipients given histiocytes than in those given lymphocytes, (c) the greater capacity of histiocytes to effect serial passive transfer, and (d) the ability of histiocytic but not lymphocytic lysates to transfer cellular resistance. Experiments to establish the mechanism of passive transfer of cellular resistance showed that there was no active induction of resistance in recipients through transfer of bacillary antigens contained in immune histiocytes; in fact, the results of serial passive transfers with immune histiocytes suggested an active replication of the "cell resistance factor."

Animals↗
PubMed1961

Studies on tubercle bacillusmonocyte relationship. IV. Effects of passage in normal and immune systems upon virulent bacilli.

Passage of the virulent H37Rv strain of tubercle bacillus in normal or immune systems (normal or immune monocytes suspended in the corresponding serum) resulted in decreased virulence of the bacilli; this was evidenced by the very low mortality rates in mice inoculated intravenously with passaged bacilli. Passaged bacilli when cultivated directly in tween-albumin medium or when grown on glycerol-blood agar plates after recovery from infected mouse tissues proved as virulent as unpassaged bacilli. The decreased virulence of passaged H37Rv was accompanied by loss of ability to bind neutral red. Passaged H37Rv was more sensitive than unpassaged bacilli to inactivation by sodium oleate and by normal monocyte lysate; however, passaged H37Rv was more resistant than unpassaged bacilli to inhibition by streptomycin.

Administration, Intravenous↗
PubMed1959

Studies on tubercle bacillus-monocyte relationship. III. Conditions affecting the action of serum and cells; modification of bacilli in an immune system.

Studies of the relationship of protective serum factor to cellular resistance and to tuberculin skin sensitivity have demonstrated that protective serum factor may exist independently of a high level of cellular resistance, and that both protective factor and cellular resistance may be demonstrable without a concomitant hypersensitivity of the delayed type. The experiments with absorbed sera and the globulin fraction of immune serum indicated no specific association of protective serum factor with antibody globulin. The protective factor in immune serum was found to be thermostable and non-dialyzable. In vitro exposure of virulent tubercle bacilli to the immune serum from BCG-immunized animals failed to alter the bacterial capacity for destruction of monocytes and for intracellular proliferation. In vitro cultivation of normal and immune monocytes in normal or immune serum was not effective in changing the native susceptibility or resistance of these cells. Effective manifestation of resistance to virulent tubercle bacilli by immune monocytes was found to require the continuous presence of immune serum. The intracellular passage of virulent tubercle bacilli in an immune system (immune monocytes cultivated in immune serum) resulted in a decreased bacterial potential for destruction of normal monocytes when these were cultivated in the presence of immune serum.

Animals↗
PubMed1957

Cross-immunity between Brucella melitensis and Mycobacterium tuberculosis; intracellular behavior of Brucella melitensis in monocytes from vaccinated animals.

A non-specific element has been demonstrated in the resistance of monocytes derived from immunized rabbits. Vaccination by BCG or by an effective anti-brucellosis reagent induces protection in either case against both Mycobacterium tuberculosis and Brucella melitensis when studied by the monocyte culture method. The activity of the antiserum required to demonstrate the resistance of the monocyte is not affected when the agglutinating action of the anti-Brucella rabbit serum is removed by absorption. The ability of the monocytes from specifically immunized rabbits to retard the growth of virulent Brucella was demonstrated, not as an all-or-none phenomenon, but in the light of the unrestricted bacterial multiplication which occurs in monocytes from normal animals.

Animals↗
PubMed1957

Studies on tubercle bacillus-monocyte relationship. II. Induction of monocyte degeneration by bacteria and culture filtrate: specificity of serum and monocyte effects on resistance to degeneration.

Studies of virulent, attenuated, and avirulent strains of tubercle bacilli have demonstrated the proficiency of virulent strains to effect degeneration of normal monocytes cultivated in the presence of normal serum. Attenuated strains were less active in this respect, and avirulent bacilli failed to induce monocytic degeneration. Comparison of the effects of virulent H37Rv with O.T., P.P.D., and a culture filtrate of H37Rv revealed a similarity in action of H37Rv and its filtrate. The action of O.T. and P.P.D. differed from that of H37Rv in that the greatest effect of H37Rv was upon normal cells as opposed to the effect of O.T. and P.P.D. upon immune cells. Additionally, it was demonstrated that immune serum (anti-BCG) protected immune cells against H37Rv but not against O.T. or P.P.D. The protection of immune cells by heterologous antisera (anti-Salmonella and anti-ovalbumin) as well as by homologous antiserum (anti-BCG) against the degenerative effects of H37Rv indicated a non-specificity in action of serum factors. The ability of the monocytes of animals immunized with BCG and the failure of monocytes of animals immunized with Salmonella rutgers to withstand parasitization with H37Rv, when both types of monocytes were cultivated in immune (anti-BCG) serum, indicated a specificity of cellular resistance.

Animals↗
PubMed1956

Studies on tubercle bacillus-monocyte relationship. I. Quantitative analysis of effect of serum of animals vaccinated with BCG upon bacterium-monocyte system.

Studies of the conditions necessary for maintenance of constant cell populations in vitro in the Mackaness type of culture chamber have indicated the importance of preliminary trypsinization of cells and the beneficial effect of 40 per cent rabbit serum in Tyrode's solution. Under these optimal conditions, uninfected suspensions of monocytes exhibited little change in cell numbers over a period of 40 to 72 hours. Infection of monocytes with the virulent H37Rv strain of tubercle bacillus resulted in an early degeneration of a certain proportion of the cells cultivated in the presence of normal rabbit serum. This degeneration was apparent not only for cells of tuberculin-negative animals but also for those derived from tuberculin-positive animals. The serum of animals vaccinated with BCG exerted a favorable effect upon the survival of monocytes infected with virulent tubercle bacilli. Treatment with this serum caused a delay in degeneration of infected normal cells (cells of tuberculin-negative rabbits) and a complete inhibition of degeneration of infected immune cells (cells of rabbits vaccinated with BCG).

Bacillus↗