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Biomedical subjects

J Soto

Publications and source records attributed to J Soto.

At least 163 records · Page 9Linked to original sources

Short- vs. long-term indoor radon measurements.

The major advantage of short-term vs. long-term indoor Rn measurements is that the information is available rapidly. A study of the results obtained for Rn measurements developed in Spain, employing grab samples and 3-mo alpha-track measurements, is discussed.

Air Pollutants, Radioactive↗

Effect of eosinophil-degranulating estrogens on spleen eosinophils and white pulp/red pulp ratio.

A role for eosinophils in the immune reaction has not been yet established. Considering that these leukocytes accumulate in lymphoid organs under glucocorticoid stimulation, we explored the possibility that they participate in the depression of immune reactions induced by these hormones and that they degranulate to exert this action. In this context, we investigated the dose effect of three estrogens on the number and degranulation of spleen red pulp eosinophils and on the percentage of spleen cross sectional area comprising white pulp. Estradiol-17 beta or 4 (OH) estradiol-17 beta increased red pulp eosinophils at low doses: 2 (OH) estradiol-17 beta increased them at a very high dose. The three estrogens degranulated the spleen eosinophils and decreased the lymphocyte containing spleen white pulp. We propose that the decrease in white pulp is a response mediated by agents released from degranulating eosinophils under the action of estrogen. Consequently, both estrogen-induced eosinophil degranulation and estrogen-induced increase in red pulp eosinophil numbers are conditions contributing to a decrease in white pulp volume. All above evidence supports the hypothesis that eosinophils are involved in immunoregulation by diminishing the number of lymphocytes contained in lymphoid organs.

Animals↗

Effect of ketotifen on the distribution and degranulation of uterine eosinophils in estrogen-treated rats.

Eosinophil leukocytes migrate from the blood to the uterus under estrogen stimulation, redistribute through uterine extravascular compartment, degranulate in the organ, and release agents that are involved in several parameters of estrogen action. Agents that induce blood eosinopenia, block their migration to the uterus, interfere with their redistribution within the organ or modify their degranulation, selectively interfere with eosinophil-mediated responses to estrogen. The present study investigated whether ketotifen, an antiallergic agent that inhibits allergen-induced eosinophil degranulation, interferes with estrogen-induced eosinophil migration to the uterus and their subsequent degranulation. Ketotifen does not interfere with estrogen-induced eosinophil accumulation in the uterus, but decreases the proportion of eosinophils located in endometrium and inhibits their degranulation. These results suggest that neither histamine, calcium or slow reacting substance of anaphilaxis are involved in eosinophil migration to the uterus. The inhibition by ketotifen of eosinophil degranulation may diminish eosinophil migration through extravascular compartment via a decrease in the release from degranulating eosinophils of enzymes required for this migration. It is possible that the inhibition by ketotifen of both, eosinophil degranulation and eosinophil motility through uterine extravascular compartment, interfere with eosinophil-mediated responses to estrogen or with other functions of these cells.

Animals↗

Natural radioactivity of some Spanish building materials.

The penetrating radiation from 226Ra, 232Th and 40K in conventional building materials has been measured by gamma spectrometry. A simple model is applied to the results to calculate the external radiation dose for people living in a typical Spanish house constructed with these materials. The radioactivity concentrations in the building materials were found to be similar to those reported for other countries. The average specific concentrations of 226Ra, 232Th and 40K for the total of 125 samples analyzed ranged from 5 to 421, 3 to 266 and 11 to 599 Bq kg-1, respectively. The results are examined in the light of standards for indoor exposure adopted by the Federal Republic of Germany and the criteria set up in the OECD/NEA Report, 1979.

Construction Materials↗

Density of epidermal Langerhans cells in psoriasis patients treated with an aromatic retinoid (RO 10-9359). An immunoperoxidase study using anti-T6 and anti-Ia monoclonal antibodies.

Immunocytochemical techniques using antibodies to the specific T6 and Ia (Major Histocompatibility Complex, class II, human HLA-Dr) antigens were used to determine the densities of epidermal Langerhans cells (LC) in psoriasis patients treated with the aromatic retinoid RO 10-9359. Fourteen patients were treated with the aromatic retinoid and were skin biopsied before, during and after therapy. Two psoriasis patients receiving PUVA (systemic 8-methoxypsoralen + UVA irradiation) were included in the study. The results showed an increase in LC numbers during aromatic retinoid administration, which coincided with an improvement in the clinical severity of the lesions. At the end of retinoid administration the LC numbers were similar to those found in the initial psoriatic plaques. The density of Ia+ LC, in comparison with T6+ LC in the epidermis of psoriatic plaques were significantly different. Dendritic and non-dendritic Ia+ cells were also observed in the dermis of the plaques. Unlike aromatic retinoid treated patients, PUVA treated patients showed a decrease of both T6+ and Ia+ epidermal LC by the middle of therapy, a total absence of immunoreaction by the end of therapy, and a return to normal skin values a few weeks after treatment. This immunocytochemical study helps in distinguishing between dendritic and other possible Ia-expressing cells from the infiltrate that may penetrate the epithelium. These results do not conclusively demonstrate the role of LC in the pathogenesis of psoriasis. Other factors, such as the interrelationship with other immune response cell types and alterations in the lymphokine cascade may be important.

Adult↗