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Biomedical subjects

R T Prehn

Publications and source records attributed to R T Prehn.

At least 37 records · Page 2Linked to original sources
PubMed1983

Splenic variations affecting sarcomagenesis among mice of an inbred strain.

Among overtly identical mice of an inbred strain, some are relatively susceptible and some relatively resistant to sarcomagenesis by large concentrations of 3-methylcholanthrene (MCA) (Prehn, 1975 a). Spleen cells from mice, subsequently shown to be relatively susceptible, conveyed a relative resistance to oncogenesis when transferred to irradiated recipients; spleen cells from mice, subsequently shown to be relatively resistant, conveyed to secondary hosts a relative susceptibility.

Animals↗
PubMed1982

Influence of immune status of host on immunogenicity of tumors induced with two doses of methylcholanthrene.

Previous studies by Prehn demonstrated a direct correlation between the dose of carcinogen used for tumor induction and the immunogenicity of the resulting tumors. The purpose of the present study was to determine the role of the host's immune response and the influence of the carcinogen on immune function in this relationship. For that reason, a comparison was made of the immunogenicities of tumors induced with two doses of carcinogen in immunologically normal mice and in mice immunodepressed by adult thymectomy and irradiation. If the direct relationship between dose and immunogenicity demonstrated in normal mice was due to the degree of immunosuppression produced by the carcinogen, this correlation should not be apparent in mice already immunosuppressed. Although there was some increase in the immunogenicity of tumors induced in the immunosuppressed mice, the same relationship between carcinogen dose and immunogenicity was observed in both groups of mice. These results indicate that the degree of immunogenicity of tumors induced with both high and low doses of carcinogen was influenced by immunoselection, but in addition another, non-immunologic factor was significant in the relationship between carcinogen dose and immunogenicity.

Animals↗
PubMed1981

Genetic susceptibility to post-thymectomy autoimmune diseases in mice.

The strain distribution pattern of five different post-thymectomy autoimmune diseases was determined in 21 inbred and two congenic, resistant strains of mice. The results indicated that susceptibility genes outside the H-2 complex may be involved in the development of localized autoimmune diseases in neonatally thymectomized mice. Studies of recombinant inbred strains also showed that susceptibility to gastritis was not associated with the H-2 haplotype but appeared to be influenced by a minor histocompatibility locus. Possible linkage to the H-2 complex was suggested only in the development of coagulating gland adenitis. Although one experiment showed that susceptibility to orchitis and coagulating gland adenitis was inherited as a recessive trait, further studies are required to determine the exact mode of inheritance in each disease system.

Animals↗
PubMed1979

Differential susceptibility of the axilla and groin of the mouse to chemical oncogenesis.

INCIDENTAL to investigations of chemical oncogenesis, we have observed that 3-methylcholanthrene (3-MC)-induced subcutaneous sarcogenesis occurred more rapidly in the axillary than in the inguinal region of the mouse. Recently Auerbach et al. have described what may be a similar phenomenon-a marked tendency for tumour transplants to grow better cephalically(1,2).

Journal Article↗
PubMed1978

Stimulatory effect of immunization on tumor induction by Moloney murine sarcoma virus.

Adult mice were immunized with varying doses of inactivated Moloney murine leukemia virus (M-MuLV). Eight weeks after immunization, mice were challenged with a dose of Moloney murine sarcoma virus (M-MuSV) that could induce tumors in approximately 50% of normal animals. Mice immunized with high doses of M-MuLV (10(10) particles) had significantly decreased tumor incidences, whereas mice immunized with low doses of M-MuLV (10(2) particles) had significnatly increased tumor incidences compared to those in nonimmunized controls. The stimulatory effect could be abrogated by the irradiation of mice with 450 rads 24 hours prior to M-MuSV challenge, whereas the inhibitory effect was resistant to this irradiation procedure. The results suggested that immunization with virus can either stimulate or inhibit virus-induced tumorigenesis, depending on the dose of virus used for immunization.

Animals↗
PubMed1978

Are tumor-associated transplantation antigens of chemically induced sarcomas related to alien histocompatibility antigens?

The hypothesis tested was that tumor-specific transplantation antigens of chemically induced tumors cross-react with allogeneic histocompatibility antigens. This hypothesis makes several predictions that can be tested experimentally. First, tumors should grow better and be less immunogenic in certain F1 hybrids than in their syngeneic parents, owing to the hypothecated cross-reactivity of the tumor-specific transplantation antigens with F1 antigens. This is in contrast to the more common observation that parental strain tumors grow worse in the F1 hybrids than they do in the parent. Also certain allogeneic skin grafts might immunize the parental strain mice against their syngeneic tumors, and, finally, immunizing parental mice with syngeneic tumor might cause accelerated rejection of certain skin allografts. The results show that certain tumors grew better in the F1 mice than they did in the parents but that the tumors were not less immunogenic in the F1 hybrids. Mice immunized against alloantigens showed a dose-dependent enhancement of syngeneic tumor growth. Finally, mice immunized with syngeneic tumors demonstrated an apparent prolongation of certain skin allografts. The discussion considers possible alternatives explaining these results.

Animals↗