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Biomedical subjects

S J Ismael

Publications and source records attributed to S J Ismael.

9 recordsLinked to original sources
PubMed1998

Increased dexamethasone-induced apoptosis of thymocytes from mice exposed to long-term extremely low frequency magnetic fields.

To address the effect of extremely low frequency electromagnetic fields on programmed cell death we assessed both the spontaneous and dexamethasone (Dex)-induced apoptosis of thymocytes and spleen cells from mice submitted to a long-term continuous exposure of a 0.4-1.0 microT 60 Hz magnetic field or an 8-20 microT direct current (DC) magnetic field. Dex-induced apoptosis but not spontaneous apoptosis was substantially increased in thymocytes from 0.4 to 1.0 microT 60 Hz field-exposed animals. Spontaneous apoptosis and Dex-induced apoptosis of spleen cells were not affected by the 0.4-1.0 microT 60 Hz field exposure. In addition, spontaneous apoptosis and Dex-induced apoptosis of thymocytes and spleen cells from mice exposed to an 8-20 microT DC field were similar to the controls. These findings represent the first demonstration that thymocytes from mice exposed to a long-term 0.4-1.0 microT 60 Hz field may show abnormal response to Dex apoptotic stimuli.

Animals↗
PubMed1987

Leu 7+, Leu 11a- acute T-lymphoblastic leukemia having low K cell activity and no NK cell activity.

The phenotypic and functional features of the leukemic blasts from a child with T-acute lymphoblastic leukemia (T-ALL) were studied. The leukemic cells lacked the usual markers of T-cell lineage (T3-, T11-, E-sheep-) although they displayed some T-lymphocyte markers (T6+, T8+, T9+, T10+) and were T gamma-. Furthermore, these cells had a strong reaction with anti-Leu 7 but were negative to anti-Leu 11a antibody and exhibited low K cell activity, no NK activity, and showed virtually no response to PHA. These leukemic cells probably represented the leukemic counterpart of the Leu 7+, Leu 11a- subset that has been demonstrated in the peripheral blood of normal individuals.

Antibodies, Monoclonal↗
PubMed1987

Absence of OKT4 antigen epitope: report of a case in a Brazilian population.

During the study of 162 normal subjects we found an 8 month-old black girl without previous illnesses, especially infections, whose lymphocytes did not react with OKT4 monoclonal antibody. However the CD4 subset was present, since the number of lymphocytes which reacted with Leu 3a and T4 was normal. In addition the percentage of Fc mu+ lymphocytes, K cell activity and PHA response were normal. The proportion of the other lymphocyte subsets did not differ from normal controls. Four first degree relatives of this child had a normal proportion of OKT4+ lymphocytes. The absence of OKT4 epitope was previously reported as a rare genetic variant which was detected only in Japanese and in subjects of black African ancestry.

Antigens, Surface↗
PubMed1987

Age-associated changes of T lymphocyte subsets.

The percentage and the absolute number of T3, T4, T6, T8, and T10 lymphocytes of the peripheral blood were determined in 100 children (3 days to 10 years), 29 adults (18 to 59 years), and 30 elderly individuals (60 to 98 years). The percentage of the various T lymphocyte subsets and T4/T8 lymphocyte ratio for the children and elderly did not differ statistically from adults, except for the proportion of T4 lymphocytes which was higher in the subgroup with 3 days of age. The absolute number of total lymphocytes, T3 and T8 lymphocytes was increased in children up to the age of 6 years while the number of T4 lymphocytes was increased up to the age of 2 years. Increased numbers of T6 lymphocytes were detected in children from 1 to 2 years of age while the number of T10 lymphocytes was increased in children up to the age of 2 years. Finally there was no difference between the results observed in elderly individuals and adults.

Adolescent↗
PubMed1987

Splenic function in haemophilia.

Studies of splenic function were carried out on 17 haemophilic patients over 9 years of age, and 20 control patients. The clearance of autologous heat-damaged 99mTc-labelled erythrocytes from circulation and into the spleen was measured: the spleen area by scintillation scanning, and the enumeration of pitted erythrocytes by direct interference microscopy. Splenic enlargement was observed in 10 patients (59%). On the basis of the clearance half-time, splenic function was normal in 3/13 (23%) and hyperactive in 9/13 (69%) patients. One heavily transfused patient had a hypoactive spleen with long clearance half-time, slow splenic uptake of radioactivity and high pit counts. These results demonstrate that the spleen of haemophiliacs is usually enlarged and functionally abnormal.

Adolescent↗
PubMed1986

Cell-mediated immunity in Brazilian hemophilia patients.

The purpose of this study was to correlate the immunological features of healthy hemophiliac A patients treated with commercial cryoprecipitates with those who received factor VIII concentrates associated or not with cryoprecipitates. The absolute number of total lymphocytes, T3, T4 and B lymphocytes did not differ for either group of patients or the controls. The number of T8 lymphocytes was higher in the group treated only with cryoprecipitates than for the controls. The T4/T8 lymphocyte ratios for both groups of patients were significantly lower than in the controls. This was due to a decrease in the percentage of T4 and increase of T8 lymphocytes. K cell activity was lower in both groups of patients than the controls. These results indicate that both cryoprecipitates and commercial factor VIII concentrate replacements had similar effects on the development of lymphocyte abnormalities.

Adolescent↗
PubMed1984

Treatment of sickle cell diseases with aspirin.

The effects of long-term aspirin for the treatment of sickle cell disease were compared with placebo in a double-blind trial completed by 29 patients. Each patient was submitted to a 5-month period of treatment with aspirin (median dose 31 mg/kg/day) and an equivalent period with placebo. No clinical or laboratory differences were observed between the two phases, including the frequency of painful crises and infectious episodes, hemoglobin concentration, PCV, reticulocytes, Hb F, bilirubin, irreversibly sickled cells, filterability of red cell, sickling in vitro and hypoxia-induced potassium loss.

Adolescent↗