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Biomedical subjects

J G Bekesi

Publications and source records attributed to J G Bekesi.

At least 109 records · Page 6Linked to original sources

Lymphocyte function of Michigan dairy farmers exposed to polybrominated biphenyls.

Michigan dairy farm residents ate farm products containing polybrominated biphenyls (PBB's) after the accidential contamination of animal feed with the chemical in that state in 1973. The circulating blood lymphocytes of these residents show significant changes. Abnormalities include decreases in the numbers and percentages of peripheral blood lymphocytes that form rosettes with either sheep erythrocytes alone or with sheep erythrocytes sensitized with antibody and complement, increases in lymphocytes with no detectable surface markers ("null" cells), and altered responses to tests designed to evaluate functional integrity of the cells. There appears to be no consistent correlation between the concentration of PBB's in the plasma and the altered lymphocytes. Studies showed that in Wisconsin dairy farm residents and healthy individuals in the New York area who were not exposed to PBB's there were no such abnormalities.

Adult↗

Unexpected longevity of a patient with malignant pleural mesothelioma: report of a case.

A 53-year-old male with untreated malignant pleural mesothelioma and with seven years survival time since the appearance of clinical symptoms is reported. Histopathological and immunological findings were at variance with those usually seen with mesothelioma. Both lymphocyte surface markers and lymphocyte function values were found to be within normal range; in contrast, in eleven mesothelioma patients who progressed and died, both numerical and functional defects in T and B lymphocytes were seen. There was potential for neighborhood asbestos exposure.

B-Lymphocytes↗

Specific immunotherapy with neuraminidase-modified leukemic cells: experimental and clinical trials.

The data presented establish the therapeutic effectiveness of immunotherapy with neuraminidase-treated allogeneic myeloblasts in combination with sustaining chemotherapy in patients with acute myelocytic leukemia. The in vivo and in vitro immunologic tests indicate normal immunocompetence in patients receiving immunotherapy versus control patients treated with chemotherapy alone. These findings correlate well with the improved duration of remission as the direct result of the immunotherapy.

Animals↗

Effects of methanol extraction residue of Bacillus calmette-Guérin in humans.

Forty patients with histologically confirmed neoplastic diseases were treated with the methanol extraction residue of Bacillus Calmette-Guérin (MER). Thirty-six received concomitant chemotherapy. MER was initially given intradermally twice a month, 1 week apart, at a dose of 200 mug into each of five sites draining different lymph node-bearing areas on the anterior body surface. Thirty-seven patients developed local ulcerations at least 0.5 cm in diameter at MER injection sites. Typical lesion evolution was characterized by erythema and induration followed by vesicle formation and central necrosis. Either granulation tissue or a thick nonulcerated eschar preceded healing, leaving a linear, flat scar. Systemic toxicity consisted of malaise, fever, and myalgias on the day of MER administration. No hematological or biochemical changes directly attributable to MER were observed. Dose titrations in decreasing 10-fold dilutions in a linear array in a single anatomical region were carried out on 35 occasions. All patients but three developed at least a 5-mm induration to the 1-mug dose within 2 weeks of titration. Dose reductions were necessary in 19 instances. The minimal dose that produced a 1-cm inflammatory lesion with central necrosis was 0.01 mug. Serial biopsies were performed. These indicated a time-related series of changes from a nonspecific inflammatory lesion to an acute inflammatory response with microabscesses, followed by noncaseating granulomata and ultimately fibrosis. MER is a quantifiable nonviable immunostimulant that obeys dose-response relationships in its cutaneous lesions.

Antineoplastic Agents↗

Therapeutic effectiveness of neuraminidase-treated tumor cells as an immunogen in man and experimental animals with leukemia.

The immunogenicity of leukemia L1210 in DBA/2 Ha and 6C3HED lymphosarcoma tumor cells in C3H/f mice was significantly increased after treatment with V. cholerae neuraminidase. DBA/2 Ha and C3H/f mice repeatedly immunized with neuraminidase-treated tumor cells rejected subsequent challenge of 10(7) or 10(6) untreated tumor cells, respectively. Based on the 51Cr microcytotoxicity assay, both strains of mice showed strong complement-dependent antibody titers and cell-mediated immunity. Sera and splenic lymphocytes from immunized C3H/f mice neutralized the tumorigenicity of 6C3HED lymphosarcoma and protected the recipient C3H/f mice against the disease. Immune lymphocytes pretreated with anti-theta sera lost their ability to neutralize the tumorigenicity of lymphosarcoma, and they failed to be stimulated by T-cell mitogens. We studied the effectiveness of chemoimmunotherapy in DBA/2 Ha mice with leukemia L1210. A single near optimal dose of BCNU 2 days after implantation of 10(6) tumor cells increased the survival time. A single immunization with 2 X 10(7) neuraminidase-treated L1210 tumor cells 4 days after cytoreductive therapy increased survival and resulted in cures for 50% of animals. Immunization of mice with neuraminidase-treated tumor cells and MER produced indefinite survival in a larger percentage of mice than did either treatment alone. AKR mice with spontaneous leukemia treated with combination chemotherapy sustained an 180% increase in life-span. Combination chemotherapy plus immunization with neuraminidase-treated syngeneic or allogeneic (Gross virus-induced) E2G leukemia cells were highly effective in prolonging the life-span of the immunized leukemic AKR mice. The experimental data led to clinical trials in acute myelocytic leukemia with neuraminidase-treated a-logeneic myeloblasts. Patients with acute myelocytic leukemia were randomized into two groups after remission induction. The median remission duration of patients on sustaining chemotherapy alone was 19 weeks (8 patients), whereas six of nine patients who received neuraminidase-treated allogeneic myeloblasts remain in remission 79-132 weeks. Statistical analysis of the remission duration and survival of patients who received chemoimmunotherapy versus the control group shows highly significant differences.

AKR murine leukemia virus↗

Treatment of spontaneous leukemia in AKR mice with chemotherapy, immunotherapy, or interferon.

AKR mice are genetically destined to develop Gross (RNA) virus-induced lymphatic leukemia. Leukemic AKR mice treated with combination vincristine, cyclophosphamide (Cytoxan), and 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea sustained a 180% increase of life-span. Combination chemotherapy plus immunization with neuraminidase-treated allogeneic (Gross virus-induced) G2G leukemic cells intradermally resulted in 35% of animals surviving beyond 150 days without evidence of the disease. It is significant that allogeneic E2G leukemic cells as immunogen were as effective in prolonging the life-span of the immunized leukemic AKR mice as were syngeneic leukemic thymocytes. Virazole (1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide), an antiviral compound, alone showed no apparent antitumor effect. However, in experiments in which the clinically diagnosed leukemic AKR mice received a combination of cytoreductive therapy [vincristine plus prednisone or, more effectively, vincristine, Cytoxan plus 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea, followed by Virazole], there was a noticeable reduction of the viral titer, a delay in the reappearance of viable clonogenic cells, and an increase in the survival time for the leukemic AKR mice as compared to those receiving cytoreductive therapy alone. The effectiveness of purified mouse interferon in AKR mice was also examined. The decrease in the viral titer of animals that received interferon treatment was markedly greater than of those receiving a combination of cytoreductive therapy with Virazole or immunotherapy. The administration of mouse interferon had a direct effect on the appearance of the spontaneous leukemia in AKR mice. The median life-span of the control animals was 36 weeks, whereas 45% of the AKR mice treated with five doses of 5 X 10(4) units of interferon are still alive at 54 weeks of age. Thus, interferon not only reduces the Gross murine leukemia virus titer in the chronically infected AKR mice but also significantly delays the appearance of the primary lymphoma.

AKR murine leukemia virus↗