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Biomedical subjects

R B Whitney

Publications and source records attributed to R B Whitney.

29 records · Page 2Linked to original sources

Mode of action of immunosuppressive substances in sera of tumor-bearing mice.

Sera from mice with transplanted 3-methylcholanthrene (MCA)-induced tumors inhibited the proliferative response of normal mouse lymphocytes to mitogens and allogeneic cells. The sera were not toxic to these cells and did not inhibit mitogen responses by an increased binding of mitogen to serum components. The sera could have prevented the initiation of the proliferative response or could have inhibited cells already proliferating. The uptake of 3H-uridine, an event preceding DNA synthesis, was also suppressed. The sera had no effect on proliferation of a normal tissue culture line or an allogeneic tumor cell line induced by MCA. However, sera from tumor-bearing mice slowed growth of the autochthonous tumor cells and allogeneic lymphoma cells but did not completely block their proliferation. Exposure of lymphoid cells to the sera for a period as brief as 1 hour markedly decreased the ability of cells to respond subsequently to mitogens, and washing of the cells did not restore that ability. The inhibitory activity of the sera was only partially removed by absorption with lymphoid cells or cell lines.

Animals↗

Effects of sera from tumor-bearing mice on mitogen and allogeneic cell stimulation of normal lymphoid cells.

The mitogens concanavalin A (Con A) and bacterial lipopolysaccharide (LPS) stimulated normal spleen cells of DBA/2J, CBA/J, and BALB/c mice about equally in the presence of either isologous or homologous serum. This system revealed that sera from mice with five different methylcholanthrene-induced rhabdomyosarcomas inhibited mitogen stimulation of normal spleen cells. Sera from mice with a mammaryadenocarcinoma and spontaneous rhabdomyosarcoma were similarly suppressive. In contrast, sera from mice with melanoma were not inhibitory and often enhanced stimulation. Sera from tumor-bearing animals had the same effects both qualitatively and quantitatively on cells from the strain carrying the tumor and on cells from the other two strains. The mixed lymphocyte response of CBA/J times BALB/c spleen cells was affected exactly as were the responses to mitogen by the various sera. Stimulation by mitogen of mouse lymph-node cells and spleen cells with macrophages removed, as well as that of guinea pig spleen cells, was also inhibited by sera from mice with rhabdomyosarcoma and mammary adenocarcinoma.

Adenocarcinoma↗

The relationship of immune status to the efficacy of immunotherapy in preventing tumour recurrence in mice.

The immunotherapeutic value of tumour extracts or B.C.G. in preventing either the occurrence of primary tumours or the recurrence of tumours in surgically resected animals has been examined. A transplantable methylcholanthrene induced tumour in DBA/2J mice was used. Neither tumour extract nor chemically modified extract was effective in preventing tumour growth in immunized animals, even though the mice demonstrated measurable levels of cell mediated tumour immunity at the time of tumour challenge. The frequency of tumour recurrence after resection of small tumours (about 1·0 g) was significantly lowered by treatment of the mice with a combination of B.C.G. and either modified or unmodified tumour extract. The frequency of recurrence after resection of large tumours (about 2·5 g) was not affected by any form of immunotherapy although the survival time of treated animals was significantly prolonged. The immunological status of animals with small and large tumours was examined and it was shown that mice with 1·0 g tumours have unimpaired mitogen responsiveness and measurable tumour specific immunity, whereas mice bearing large tumours (2·5 g) have a markedly impaired immune system.

Animals↗

Identification of alcoholism in young adults by blood chemistries.

A stepwise linear discriminant analysis was conducted between young adult alcoholics in an alcoholism treatment center and non-alcoholic college students. Analysis of 31 commonly ordered clinical laboratory tests yielded three significant variables (urea nitrogen, potassium and MCV) which correctly classify 89% of alcoholics and 92% of non-alcoholics.

Adolescent↗