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Biomedical subjects

R J Connor

Publications and source records attributed to R J Connor.

51 records · Page 3Linked to original sources
PubMed1980

Relationship of in vitro immune responses to Epstein-Barr herpesvirus and severity of infectious mononucleosis.

Immune responses to Epstein-Barr herpesvirus (EBV) and EBV-related antigens were studied serially in 18 patients with heterophil antibody-positive infectious mononucleosis and in 18 control subjects. Enhanced cellular immune responses to EBV particles and to EBV intracellular soluble antigens were found in the patients at convalescence, suggesting that the development of specific cellular immune responses was associated with apparent control of the virus infection. In addition, a correlation between severity of disease and specific cellular immune response was found. Patients with severe clinical signs were found to have a more active cellular immune response to EBV intracellular soluble antigens early in the infection compared with patients with mild disease. This suggests that an increased immune reactivity to intracellular antigens during the early part of the illness is related to the severity of clinical manifestations in infectious mononucleosis. Serum antibody to viral capsid antigen and early antigen was not related to the severity of clinical disease.

Antigens, Viral↗
PubMed1979

Skin cancer development in mice exposed chronically to immunosuppressive agents.

Inbred female C3Hf/HeN, murine mammary tumor virus-negative mice exposed to either UV light or benzo[a]pyrene (BP), were subjected to four different chronic immunosuppressive regimens to determine their effect on skin cancer development. The immunosuppressive agents were cyclophosphamide, methotrexate, cortisone, and heterologous antilymphocyte globulin. Because of an unexpectedly high morbidity and mortality of mice exposed to chronic immunosuppressive measures, the dosages were kept at a level that permitted them to survive but did not prolong allogeneic skin graft survival and lower antibody titers, nor did this level diminish proliferative responses of lymphocytes to mitogens or allogeneic lymphocytes. Nevertheless, the latency periods (time interval between beginning of medication and appearance of skin tumors) of tumors in mice exposed to immunosuppressant measures were significantly shortened in several groups of mice exposed to UV and subjected to cyclophosphamide, cortisone, or antilymphocyte globulin and mice exposed to BP and subjected to cortisone acetate. In 3 groups, spindle cell tumors (fibrosarcomas) shifted to squamous cell carcinomas. A suppressed immune function would not be regarded as the mechanism for the observed responses because immunosuppression was not detected in the experimental mice.

Animals↗
PubMed1978

Use of the leukocyte migration inhibition assay to evaluate antigenic differences in human breast cancers and melanomas.

The leukocyte migration inhibition assay was used to compare the antigenic reactivity of 3 M KCl extracts of human tumors. Many extracts demonstrated strong reactivity with patient leukocytes, whereas others demonstrated weak or no reactivity, Extracts prepared from primary tumors or local recurrent tumors were more antigenic than extracts from involved lymph nodes or pleural effusions. The least reactive preparations were extracts made from specimens of liver metastases obtained at autopsy. A large standard extract tested at a standard concentration was useful for the evaluation of antigenic reactivity of human tumor extracts. It served as a point of reference in simultaneous tests with one blood sample from each individual, thus eliminating the influence of patient variation on extract reactivity.

Antigens, Neoplasm↗
PubMed1978

Case-control study of antihypertensive and diuretic use by women with malignant and benign breast lesions detected in a mammography screening program.

A significant but low-level association (relative odds, 2.0; P less than 0.05) was observed between the occurrence of breast cancer and the use of rauwolfia derivatives for 5 or more years in the study of 481 breast cancer cases and 1,268 controls from a joint national mammography screening project of the National Cancer Institute and the American Cancer Society. This association was confined to women over age 50 years who were also heavier than average. No confounding effects could be held responsible for this association after adjustment was made for variables such as presence of hypertension, weight, age at first pregnancy, and other breast cancer risk factors. Other antihypertensive and diuretic drugs as well as multiple drug use also exhibited some suggestive associations with breast cancer. Another group of 421 women with benign lesions at breast biopsy were also compared to the 1,268 controls. They showed a significant association between benign lesions and use of thiazides for 5 or more years (relative odds, 2.4; P less than 0.001) whether employed to treat edema or hypertension. Other antihypertensive and diuretic agents also seemed to show this association, but most of them were being used together with thiazides.

Adult↗
PubMed1977

Proplast-coated high-strength magnets as potential denture stabilization devices.

This study was designed to determine if a samarium-cobalt magnet could be effectively sealed from the in vivo environment and be physically stablized in bone under similated functional stress. The following conclusions can be made from this study. (1) It is possible to effectively seal a samarium-cobalt magnet from the in vivo environment. Clinical observation, radiographs, and photomicrographs on all samples showed good healing and dense tissue over the surgical sites. The samples showed that connective tissue penetrated the Proplast, and clinically, the magnets appeared to be well stabilized in bone. (2) It follows that if magnets are properly coated and good surgical techniques are used, Proplast can be an effective sealant. Samarium or cobalt appeared in the surrounding tissues only where the coating was faulty. Further studies are being conducted which will cover a 2 year period as opposed to the original 5 month study. It is hoped that with specific tests, we will be able to demonstrate absolute fixation and no migration of the magnets.

Animals↗
PubMed1977

Leukocyte migration inhibition in patients with Ewing's sarcoma by 3-M potassium chloride extracts of fresh and tissue-cultured Ewing's sarcomas.

Leukocyte migration inhibition (LMI) assays were performed to detect cell-mediated immune reactions against tumor-associated antigens (TAA) of Ewing's sarcoma. With the use of crude antigen preparations obtained by 3M KCl extractions of fresh Ewing's sarcoma or of tissue culture cells derived from a pleural effusion of a Ewing's sarcoma patient, assays were performed with leukocytes from these patients, patients with other cancers, and normal donors. The results demonstrated approximately 60% or greater positive LMI reactivity in Ewing's sarcoma patients, as compared to less than 10% reactivity of normal donors, with the use of extracts of either fresh or tissue-cultured Ewing's sarcoma cells. A lower proportion of positive reactivity was observed in patients with breast and lung cancer. Further specificity tests indicated that a smaller proportion of patients with Ewing's sarcoma had LMI reactivity with KCl extracts of tissue-cultured cells derived from breast cancer of fresh lung cancer cells than did patients with the homologous disease. The results indicate that many patients with Ewing's sarcoma have cell-mediated immunity toward TAA on Ewing's sarcomas. Inasmuch as all the LMI assay were performed with allogeneic extracts, the data also suggested that different Ewing's sarcomas possess common antigens and that some breast and lung cancers may share some TAA with Ewing's sarcoma.

Antigens, Neoplasm↗
PubMed1977

Time of appearance and histology of tumors induced in the dorsal skin of C3Hf mice by ultraviolet radiation from a mercury arc lamp.

The time course of skin tumor induction was determined in hair-clipped inbred agouti C3Hf mice irradiated three times per week with a medium-pressure quartz-mercury lamp; 4 different UV doses were used. Although the ears were also exposed to the radiation, in the 3 groups given the highest doses no ear tumors were observed by the time each animal had developed at least 1 tumor on its back. No tumors were found in the animals receiving the lowest UV dose. In the group receiving the highest dose, males developed tumors earlier than did females; this trend continued in the lower dose groups. Many tumors that developed in the back skin were well-differentiated squamous cell carcinomas. Others were less well-differentiated squamous cell carcinomas. Others were less well defined so that the cell of origin was difficult to determine. In the group receiving the highest UV dose, the squamous cell carcinomas were few, whereas at the lower doses they predominated.

Animals↗
PubMed1976

Leukocyte migration inhibition by soluble extracts of MCF-7 tissue culture cell line derived from breast carcinoma.

Studies were conducted to determine whether MCF-7, a tissue culture cell line derived from a pleural effusion of a patient with breast carcinoma, could be used as a source of tumor-associated antigen for direct leukocyte migration-inhibition (LMI) assays. Of 32 patients with breast carcinoma, 27 (84.4%) gave positive migration-inhibition results on their initial tests with a 25-mug protein/ml concentration of a 3 M KCl extract of MCF-7; 1 of 24 (4.5%) normal donors reacted with MCF-7. An intermediate incidence of reactivity (7/16) was observed with the extract when leukocytes of patients with melanoma, lung carcinoma, and Ewing's sarcoma were used. In further specificity studies, leukocytes of patients with breast carcinoma gave a lower incidence of LMl reactivity than did those of patients with Ewing's sarcoma and lung carcinoma with KCl extracts of the appropriate histologic type of tumor. The results indicated that the MCF-7 cells possessed a tumor-associated antigen to which many patients with breast carcinoma are sensitized.

Antigens, Neoplasm↗