Biomedical subjects

C R Mehta

Publications and source records attributed to C R Mehta.

23 records · Page 2Linked to original sources

PubMed1979

Cancer mortality among beekeepers.

Carcinogenic effects of bee venom were evaluated in a mortality study of 580 occupationally exposed beekeepers. The subjects were identified through obituary notices published between 1949 and 1978 in three journals of the U.S. beekeeping industry. Death certificates of beekeepers were examined for causes of mortality, and proportionate mortality ratios were compared with those for the general U.S. population. Beekeepers had a slightly lower than expected fraction of deaths from cancer. The deficit of lung cancers in male beekeepers was significant (p less than 0.05) and may indicate that fewer beekeepers were cigarette smokers. The frequencies of other cancers did not differ significantly from expectation. Non-Hodgkin lymphoma developed in four persons, and was expected in two. Mortality from diseases other than cancer showed no unusual patterns. At least two persons died from accidents directly related to the care of beehives. Analysis of a subgroup of 377 males with major roles in the beekeeping industry showed no substantial differences in distribution of causes of death. This study of beekeepers reveals neither adverse nor beneficial effects of intense exposure to bee stings.

Bee Venoms↗

PubMed1979

The genetics of PLT response. II. HLA-DRw is a major PLT-stimulating determinant.

PLT response is restricted by the HLA-D region. The present study was undertaken to help define the role of HLA-DRw in PLT restimulation. Haplotype-primed intrafamily PLT cells were made against specificities HLA-DRw1, HLA-DRw3, and HLA-DRw7; each PLT was then restimulated with cells from a 35-member unrelated panel. Restimulation values for each PLT were subjected to bimodal clustering analysis. In addition, blocking experiments were performed with other intrafamily and homozygous typing cell PLT after preincubation with B cell alloantisera. The results show a high correlation (0.881 less than or equal to r less than or equal to 1.00) between the HLA-DRw specificity of the priming haplotype and the HLA-DRw specificity of unrelated panel cells that restimulate in PLT. When stimulating cells were absorbed with the corresponding DRw alloantisera or p29,34 heteroantiserum (against B cell specific antigens), PLT restimulation was significantly blocked. However, the PLT cells treated with antisera showed no effect. The results strongly suggest that HLA-DRw is the principal PLT-stimulating determinant.

Binding, Competitive↗

PubMedDate not supplied

Results of a phase II protocol for evaluation of new chemotherapeutic regimens in patients with inoperable non-small cell lung carcinoma (EST-2575, generation I).

Two hundred and eighty-four patients with inoperable non-small cell lung carcinoma were randomized by the Eastern Cooperative Oncology Group to receive one of seven primary chemotherapy regimens: cyclophosphamide and methotrexate; Baker's antifol; vincristine, bleomycin, and methotrexate; melphalan; cyclophosphamide and CCNU (control arm); 5-FU procarbazine; and hexamethylmelamine, doxorubicin, and methotrexate (HAM). Patients with disease progression were eligible for treatment with VM-26 or ascorbic acid. HAM resulted in higher response rates than cyclophosphamide and CCNU in patients with adenocarcinoma (32%) and large cell carcinoma (23%). It was not tested in patients with squamous cell carcinoma. In terms of survival, HAM was significantly better than cyclophosphamide and CCNU in patients with limited disease. Its toxicity was predominantly hematologic and gastrointestinal. This regimen is being further evaluated by the Eastern Cooperative Oncology Group in patients with inoperable non-small cell lung carcinoma. Crossover therapy with VM-26 or ascorbic acid had no therapeutic benefit.

Adenocarcinoma↗

PubMedDate not supplied

Chemotherapy for metastatic non-small cell bronchogenic carcinoma: EST 2575, generation III, HAM versus CAMP.

Between September 1978 and March 1979 the Eastern Cooperative Oncology Group compared the CAMP (cyclophosphamide, doxorubicin, methotrexate, and procarbazine) and HAM (hexamethylmelamine, doxorubicin, and methotrexate) regimens in 154 patients with metastatic non-small cell bronchogenic carcinoma. Most patients were ambulatory (77%) and had not received prior radiotherapy (59%). HAM produced two complete responses (CR) and eight partial responses (PR) (n = 77; 2.5% CR, 10.4% PR, 13% overall response) whereas CAMP resulted in five CR and 12 PR (n = 77; 6.5% CR, 15.6% PR, 22% overall response). This difference was not statistically significant (P = 0.14 with Fisher's exact 2-sided test) nor was the difference in overall median survival (HAM, 22.1 weeks and CAMP, 19.3 weeks). Responders had a significantly improved median survival (32.5 weeks) compared to nonresponders (17.9 weeks, P = 0.018). Ambulatory performance status and lack of prior radiotherapy were positive predictors for prolonged survival.

Aged↗

PubMedDate not supplied

Chemotherapy for inoperable, non-small cell bronchogenic carcinoma: EST 2575, generation II.

Between 1976 and 1978 the Eastern Cooperative Oncology Group tested ten regimens in 415 patients with histologically documented, inoperable non-small cell bronchogenic carcinoma. Most patients were ambulatory (69%) and had extensive disease (69%). Patients were stratified by cell type: squamous cell carcinoma (SQ), large cell anaplastic carcinoma (LC), or adenocarcinoma (AD). Ineffective single agents (including cell types tested and percent complete and partial responses) were dactinomycin (SQ, 6%), dianhydrogalactitol (SQ, 0), ftorafur (AD and LC, 3%), and piperazinedione (AD and LC, 7%), Ineffective combination regimens included the contemporary standard regimen cyclophosphamide (CYT) plus CCNU (SQ, AD, and LC, 9%), methotrexate plus doxorubicin (ADR) plus CYT plus CCNU (MAC) (SQ and AD, 12%), and mitolactol plus ADR (AD and LC, 8%). When compared to CYT plus CCNU the following regimens demonstrated significant activity: CYT plus bleomycin plus cisplatin (SQ, 23%; P = 0.02) and ADR plus 5-FU plus cisplatin (AD and LC, 24%; P = 0.006). Mitomycin demonstrated marginal activity in squamous cell cancer (19%, P = 0.06). Neither "active" regimen improved survival although responders to any regimen had a significant prolongation of median survival (31.6 vs 15.7 weeks, P = 0.002). The MACC regimen, piperazinedione, and mitomycin were substantially more toxic than the two effective regimens, which were adequately tolerated. Ambulatory performance status, limited disease, and prior surgery were significant positive prognostic variables whereas prior radiation and pretreatment weight loss adversely affected response or survival.

Adenocarcinoma↗