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Biomedical subjects

D W Roberts

Publications and source records attributed to D W Roberts.

At least 181 records · Page 10Linked to original sources
PubMed1979

Modification of antibody response to type III pneumopolysaccharide by route of injection of pertussis vaccine.

Pertussis vaccine (PV) or diphtheria toxoid-PV-tetanus toxoid (DPT) altered the antibody response of BALB/c female mice to type III pneumococcal polysaccharide antigen (S3). The key factor affecting the magnitude of the response to S3 was the route of injection of PV or DPT, whereas the route of injection of S3 was not crucial. Subcutaneous injections of DPT augmented the antibody response to low, optimal, and tolerogenic (high) doses of S3 injected either subcutaneously or intraperitoneally. This enhancement was persistent and was observed both when S3 and DPT were mixed and injected subcutaneously and when S3 and DPT were injected concurrently at separate subcutaneous sites. When either PV or DPT was injected intraperitoneally, the antibody response to subcutaneously or intraperitoneally injected S3 was significantly decreased. These experiments demonstrate a dichotomy of effect dependent on the route of administration of PV. Most studies in mice utilizing PV employ the intraperitoneal injection route, and it is important to consider whether PV treatment by this route may have unique effects. Our data suggest that intraperitoneal injection of PV suppresses B cells, possibly by influencing regulatory cell function.

Animals↗
PubMed1979

T-cell immunity to malaria in the B-cell deficient mouse.

Some B-cell deficient mice drug-rescued with clindamycin HCl from otherwise lethal infections with Plasmodium yoelii resisted subsequent challenge with the same parasite despite the fact that they lacked detectable antibody to plasmodia. Parasitemias remained patent but at low levels (less than or equal to 5%) in these mice for prolonged periods of time, suggesting that some T-cell function independent of antibody formation can in part mediate immunity to malaria.

Animals↗
PubMed1978

Splenomegaly, enhanced phagocytosis, and anemia are thymus-dependent responses to malaria.

Immunologically competent mice and mice with defined immunological deficiencies were infected with Plasmodium yoelii. Splenomegaly, enhanced phagocytosis, and anemia were most marked in infected mice having intact thymic tissue. Whereas the spleens of infected nude mice increased minimally in size, the relative blood hemoglobin levels and the rates of carbon clearance in these mice were similar to those of noninfected, immunologically intact mice. Thymus-reconstituted nude mice and B-cell-deficient mice responded to infection in a manner similar to that of infected immunocompetent mice. These data demonstrate that the hallmarks of malaria, i.e., splenomegaly, enhanced phagocytosis, and anemia, are thymus-dependent responses to infection.

Anemia↗
PubMed1978

Dysmenorrhoea.

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Anti-Inflammatory Agents↗
PubMed1977

Prevention of recrudescent malaria in nude mice by thymic grafting or by treatment with hyperimmune serum.

Nude mice died when infected with the normally avirulent malarial parasite Plasmodium berghei yoelii. Furthermore, malaria recrudesced in Nu/Nu mice after the termination of acute disease by treatment with clindamycin. Recrudescence was not observed in Nu/Nu mice that had been grafted with thymic tissue or treated with hyperimmune serum. Mice mad B cell deficient by treatment with anti-mu-chain serum also died when infected with P. berghei yoelii. The data suggest that a crucial role of the thymus in preventing recrudescent malaria in this model system is to provide a helper function in the production of protective antibody.

Animals↗
PubMed1977

Molecular weight of DNA from four entomopoxviruses determined by electron microscopy.

DNA was isolated from entomopoxviruses infected Amsacta moorei and Euxoa auxiliaris (Lepidoptera), Goeldichironomus holoprasinus (Diptera), and Othnonius batesi (Coleoptera) and compared with vertebrate virus DNA (vaccinia). After incubation in Pronase, sodium lauryl sulfate, and deoxycholate, poxvirus preparations shadowed with platinum and palladium revealed subcore particles 45 to 60 nm in diameter. Continued incubation in Pronase resulted in the gradual release of DNA from the particles. Metal-shadowed DNA molecules were photographed in the electron microscope and measured, and the average molecular weights were calculated. Lepidopteran poxvirus DNA (135 X 10(6)) was approximately equal to vaccinia DNA (131.7 X 10(6)) in molecular weight. The molecular weight of dipteran and coleopteran poxvirus DNA (200 X 10(6) to 251 X 10(6)) was approximately 50% greater than vaccinia DNA. Based on the concentration of DNA and protein per virion, Amsacta entomopoxvirus contained 5.7 to 7.7% DNA.

Animals↗