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Biomedical subjects

C L Larson

Publications and source records attributed to C L Larson.

At least 37 records · Page 2Linked to original sources
PubMed1977

Effect of treatment with BCG on the course of visceral leishmaniasis in BALB/c mice.

Intravenous inoculation of BCG was found to be both prophylactic and therapeutic in BALB/c mice against challenge with amastigotes of Leishmania donovani. Spleens and livers of mice inoculated with BCG maintained total parasite burdens at significantly lower levels when compared to controls. BCG administered intravenously 14 days prior to and on the same day of protozoan challenge was more protective than vaccine given 30 and 14 days prior to challenge. A level of 10(7) viable units of BCG provided more protection against challenge with parasites than did 10(6) viable units. BCG given the same route as the challenge dose of amastigotes provided more protection than if administered via some other route. BCG given to mice with an already established infection was shown to significantly reduce their parasite burdens.

Animals↗
PubMed1974

Resistance of female mice to vaginal infection induced by Herpesvirus hominis type 2: effects of immunization with Mycobacterium bovis, intravenous injection of specific Herpesvirus hominis type 2 antiserum, and a combination of these procedures.

The susceptibility of 4- to 6-week-old female white Swiss mice to intravaginal inoculation with Herpesvirus hominis type 2 (HVH2) and the effect of prior intravenous immunization with Mycobacterium bovis (BCG) and/or treatment with specific HVH2 antiserum (SAS) were investigated. Mice inoculated intravaginally developed vaginitis, posterior paralysis, encephalitis, and death. Prior immunization with BCG either had no effect or appeared in some cases to enhance the course of the disease, whereas a single 0.5-ml intravenous injection of SAS provided significant protection. However, synergistic interaction of BCG immunization and treatment with SAS produced the greatest degree of protection in mice challenged intravaginally with HVH2.

Age Factors↗
PubMed1974

Delayed hypersensitivity reactions provoked by ribosomes from acid-fast bacilli: physical characteristics and immunological aspects of core ribosomal proteins from Mycobacterium smegmatis.

Ribosomal subunits from Mycobacterium smegmatis were analyzed by using sedimentation velocity, sedimentation equilibrium, and acrylamide gel electrophoresis experiments. These s(20.w) values for the subunits are 48.7S and 28.1S. The molecular weight of the 49S subunit is about 1.65 x 10(6), and that of the 28S subunit is 7.8 x 10(5). Both subunits contain about 37% protein and 63% ribonucleic acid. A protein-deficient particle having an s(20.w) value of 15.7S contains about 11% protein and 89% ribonucleic acid. Skin tests showed all subunits and proteins to be active as agents in provoking delayed hypersensitivity, but the 16S protein-deficient particle, as well as the proteins derived from it, was more specific than the subunits themselves.

Animals↗
PubMed1973

Ribosomes of acid-fast bacilli: immunogenicity, serology, and in vitro correlates of delayed hypersensitivity.

Ribosomal fractions obtained from Mycobacterium bovis (BCG) and M. smegmatis (strain butyricum) were studied to determine their antigenicity, their ability to stimulate the production of soluble mediators of delayed hypersensitivity (in vitro correlates) by sensitized peritoneal exudate cells, and the antigenic relations of ribosomal antigens of BCG to BCG protoplasm and H37Rv culture filtrates. The crude ribosomes and the 50-30S ribosomal subunit pool obtained from each of the organisms induced both delayed and immediate hypersensitivity when injected in incomplete Freund adjuvant into rabbits, and skin reactions could be elicited in sensitized rabbits with those antigens. The crude ribosomes and 50-30S ribosomal subunit pool of M. smegmatis stimulated lymphocytes of guinea pigs sensitized with viable organisms to produce macrophage migration inhibition factor. Comparable ribosomal fractions from BCG bacilli caused lymphocytes of guinea pigs sensitized with viable M. bovis (BCG) to produce skin reactive factor. Immunoelectrophoretic studies showed that H37Rv culture filtrate, protoplasm, crude ribosomes, and 50-30S ribosomal subunits of BCG contain multiple precipitinogens and that many of these were shared between the different antigen systems. Comparative electrophoresis revealed that BCG protoplasm and H37Rv culture filtrate shared a major portion of their components with each other and relatively few with ribosomal systems. The ribosomal systems shared the major portion of their components with each other and relatively few with the other antigen systems.

Animals↗
PubMed1973

Resistance of mice to infection with Friend disease virus after subcutaneous injection of Friend virus and Friend spleen cells.

Swiss mice injected subcutaneously with suspensions of spleen cells or an extract of spleens from mice infected with Friend virus develop resistance to subsequent intravenous inoculation of Friend virus. A single injection of either Friend virus or Friend cells induces resistance. Immunized mice display resistance when challenged 6 months after immunization and survive for at least 20 weeks after infection. Neutralization tests indicate that serum, but not lymphoid cells of resistant animals, can neutralize Friend virus. In vitro neutralization tests indicate that residence of virus within the peritoneal cavity of immune mice for 1 h sharply reduces the infective titer of the virus.

Animals↗
PubMed1972

Infection-immunity in tularemia: specificity of cellular immunity.

The relationship between hypersensitivity and cellular resistance to infection with facultative intracellular parasites was studied in mice by using infection-immunity in tularemia as a model system. Delayed hypersensitivity to antigenic fractions of Francisella tularensis was first detected 6 to 7 days after immunization with viable F. tularensis vaccine, at which time immunity against challenge infection developed. Both immunity and delayed-type sensitivity reached maximal levels by 9 to 10 days. Immediate hypersensitivity occurred after immunization with both viable and nonviable tularemia vaccines but could not be correlated with resistance since nonviable antigens were not protective. Attempts to relate resistance to F. tularensis with nonspecific immunity factors were unsuccessful. Immunization of mice with BCG vaccine stimulated protection against infection with F. novicida and Salmonella typhimurium but provided no protection against infection with F. tularensis. Moreover, viable tularemia vaccine, while inducing marked protection against challenge with specific organisms, afforded no protection against infection with S. typhimurium or S. enteritidis. It is concluded that cellular immunity in tularemia involves an immunologically specific component.

Animals↗
PubMed1972

Delayed hypersensitivity reactions provoked by ribosomes from acid-fast bacilli. I. Ribosomal isolation, characterization, delayed hypersensitivity, and specificity.

Ribosomes and ribosomal subunits of Mycobacterium bovis (strain BCG) and M. smegmatis have been isolated and employed as skin test antigens in guinea pigs sensitized with homologous or heterologous organisms. Ribosomes and ribosomal subunits were found to be potent antigens for skin test purposes, and the 30S subunits were found to be more specific and active than the 50S subunits.

Animals↗
PubMed1972

Herpesvirus hominis type 2 infections in rabbits: effect of prior immunization with attenuated Mycobacterium bovis (BCG) cells.

Angora, New Zealand, and Dutch-belted rabbits were tested for their susceptibility to graded doses of Herpesvirus hominis type 2 administered by vaginal instillation, intracorneal injection, and scarification of the cornea. Central nervous system involvement and death occurred after infection by the various routes employed. Prior immunization of Dutch-belted and New Zealand rabbits with viable Mycobacterium bovis (BCG) cells injected intravenously provided protection against subsequent infections with type 2 virus.

Animals↗