Biomedical subjects

H Folch

Publications and source records attributed to H Folch.

41 records · Page 3Linked to original sources

PubMedDate not supplied

Radiation induced loss of anti-Ig binding ability of lymphocytes.

The effect of irradiation on the anti Ig binding ability of lymphocytes after irradiation was studied. Normal control and irradiated lymphoid cells were treated with rabbit anti mouse IgG fluorescein conjugated serum and the fluorescein positive cells compared. A reduction in the proportion of stained cells in the irradiated lymphocytes was found. It depends on the dose and on the incubation time at 37 degrees C after irradiation. The maximum effect was detected after 10 minutes of incubation, longer incubation is associated with a partial recovery of the stainability of the IgG receptors.

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PubMedDate not supplied

Radiation-induced apoptosis in thymocytes: pH sensitization.

Thymocytes were used as a model system to study the effect of microenvironmental pH changes on the radiation-induced apoptosis. We found that the sensitivity of thymocytes toward radiation induced apoptosis is increased by increasing the pH of the incubation medium. The major sensitivity change occurs between pH 7 and 8. In a given cell suspension the results obtained where similar when the apoptosis evaluation was carried out either by counting the picnotic nuclei, or monitoring the fraction of apoptotic nuclei by flow cytometry; both methods show a radiosensitization when the pH value of incubation media rises from 7 to 8. These results may be important when "in vitro" experiments are performed with lymphoid cells, since changes in pH of the media may determine important changes in the results.

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PubMedDate not supplied

Dose rate dependence of radiation induced IgG membrane receptor alteration [1].

Mouse lymph node lymphocytes are irradiated at different dose rates and the B-cell receptors to anti IgG are tested. The expression of receptors is inhibited by irradiation. It is shown that the effectivity of irradiation increases with decreasing dose rate suggesting that membrane damage may be important for situations of chronic irradiation or implant radiotherapy.

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PubMedDate not supplied

T gamma cell levels in mammary and cervical uterine cancer patients before and after local irradiation treatment.

Total T and T gamma cell populations were studied in patients suffering from mammary of cervical uterine cancer. The results show that for both groups of patients there were no changes in the total T cell counts when compared with controls: but T gamma subpopulation values were greatly increased in the cancer patient groups, irrespective of in the mammary cancer group, whether the tumor mass was present at the moment of evaluation or surgically removed. The percentage of T mu cells returned to normal level after local irradiation treatment in all cases studied. We speculate about the possible changes in lymphocyte migration as a consequence of irradiation which may affect cells in the blood stream.

Breast Neoplasms↗

PubMedDate not supplied

Proliferation and apoptosis in infection with infectious bursal disease virus: a flow cytometric study.

Programmed cell death, or apoptosis, is involved in the normal physiology of many immunocompetent organs, including lymphocytes of the bursa of Fabricius in chickens. Involvement of apoptosis has also been described in some viral diseases such as AIDS. The purpose of this work was to study the potential role of apoptosis in the pathogenesis of Gumboro disease in the bursa of Fabricius. Our results show that 1-3 days after infection of young chickens with infectious bursal disease virus, the number of apoptotic cells increases and cellularity and proliferation decrease. Because of the dynamic nature of bursal lymphocyte populations and the involvement of apoptosis in lymphocyte cell physiology, the increased level of cells undergoing apoptosis may be due to an impairment in the withdrawal of apoptotic cells. A concomitant increase in macrophages in infected bursae and a dramatic decrease in cellularity suggest that an increase in apoptosis may be an important cause of cell depletion.

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