PubMed Health⌕ Search

Biomedical subjects

G R Pearson

Publications and source records attributed to G R Pearson.

At least 181 records · Page 10Linked to original sources
PubMed1976

Reovirus-like agent (rotavirus) from lambs.

Rotavirus particles were demonstrated by electron microscopy in the feces of lambs with diarrhea. Rotavirus antigen was synthesized in cell cultures infected with filtrates of the diarrheic feces, but the virus was not adapted to grow serially in cell cultures. An antigenic relationship between rotaviruses from lambs, pigs, and calves was demonstrated by immunofluorescence. Colostrum-deprived lambs were infected with the lamb rotavirus, and the virus was passaged in lambs. Viral replication occurred in the villous epithelial cells of the small intestine, and the virus was excreted in the feces up to 78 h postinfection. Diarrhea was not observed in the experimentally infected lambs.

Animals↗
PubMed1976

Immune response of monkeys to lymphotrophic herpesvirus antigens.

Herpesvirus saimiri induces leukemia and/or malignant lymphoma when inoculated into different species of nonhuman primates including marmosets and owl monkeys. No malignant disease, however, has been recognized in the natural host for this virus, the squirrel monkey, although a high percentage of these monkeys are chronically infected with H. saimiri. Furthermore, one species of marmosets, as well as capuchin and some owl monkeys, fail to develop lymphoma following experimental virus infection but developed a chronic infection similar to that noted in the natural host. The availability of susceptible and resistant species made it possible to attempt to delineate those humoral and cellular immune parameters that might correlate both with tumor induction and resistance. The findings from these investigations are reviewed and discussed in relation to vaccine studies in this system as a model for a human herpesvirus vaccine.

Animals↗
PubMed1975

Augmentation of lymphocyte cytotoxicity by antibody to herpesvirus saimiri associated antigens.

Sera from owl monkeys infected with Herpesvirus saimiri (HVS) mediated antibody-dependent lymphocyte cytotoxicity (ADLC) against virus-infected owl monkey kidney cells. Peripheral blood lymphocytes from rhesus monkeys served as effector cells in this cytotoxic assay. ADLC titers increased along with membrane immunofluorescence (MF) titers but among some sera, the ADLC titers were much higher than expected from the MF titers, suggesting that multiple serum factors were involved in mediating ADLC in this system. Absorption of both low and high titered sera with HVS-infected owl monkey kidney cells removed all ADLC activity. Preliminary results from serial serum samples from two infected monkeys that developed leukemia and/or lymphoma demonstrated that ADLC but not MF titers increased to high titers with progression of disease and followed essentially a different kinetic pattern than that noted by MF. The possible significance of these findings in relation to malignant disease induced by this virus is discussed.

Animals↗
PubMed1975

Enhancement of Moloney sarcoma virus-induced tumor growth by concanavalin A.

Adult mice injected intraperitoneally with concanavalin A (con-A) commencing with the onset of 6mm. Moloney sarcoma virus (MSV)-induced tumors showed a marked enhancement of tumor growth compared to untreated control mice; whereas, treatment with con-A beginning on day 0 relative to MSV inoculation had no effect. Antibody production as measured by indirect membrane fluorescence was not affected by con-A. Since in vivo administered con-A has a specific suppressive effect on T-lymphocytes it is suggested that the primary immunologic response to MSV antigens is a function of T-cells.

Animals↗
PubMed1975

Spontaneous lymphoma associated with Herpesvirus saimiri in owl monkeys.

Two cases of lymphoma and one case of lymphoproliferative disease were found in a group of 7 owl monkeys imported into our colony as a single group. Herpesvirus saimiri (HVS) was isolated from the tumor cells of 1 lymphoma by cocultivation and from kidney cell cultures from the monkey with lymphoproliferative disease. Antibody to HVS was found in serum samples from 2 monkeys positive for HVS but not in the sera from the 4 clinically normal monkeys. Antibody to Epstein-Barr virus-infected cells was also found in the serum from the animal with lymphoma.

Animals↗
PubMed1975

Infection of capuchin monkeys (Cebus albifrons) with Herpesvirus saimiri.

Herpesvirus saimiri (HVS) induced persistent, clinically inapparent infections of long-term duration in capuchin monkeys (Cebus albifrons). The infections were characterized by development of antibody to HVS-associated antigens and recovery of low levels of virus-genome-carrying lymphocytes in the peripheral blood. Peripheral lymphocyte counts remained in low-normal to normal ranges and no physical signs of lymphoma were evident. Prednisolone treatment caused immunosuppression in one monkey; this was accompanied by a progressive loss of humoral antibody to HVS-associated antigens, but neoplastic disease did not develop.

Animals↗
PubMed1974

Letter: Tumours.

Explore the source record for details and available documents.

Animals↗