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Biomedical subjects

A Abbas

Publications and source records attributed to A Abbas.

10 recordsLinked to original sources
PubMed1992

High expression of transforming growth factor-beta long cell cycle times and a unique clustering of S-phase cells in patients with acute promyelocytic leukemia.

Expression of transforming growth factor-beta (TGF-beta), which inhibits the proliferation of hematopoietic progenitors, was investigated simultaneously with cell cycle characteristics in 63 bone marrow biopsies from 23 cases with acute promyelocytic leukemia (APL). Bromodeoxyuridine (BrdU) was administered to every patient (17 newly diagnosed) for determination of the labeling index (LI) and the durations of S-phase (Ts) and the cell cycle (Tc) of leukemic promyelocytes. APL cases had lower LI both in the bone marrow aspirate (6.1% v 11.4%, P = .008) and biopsy (21.1% v 28.0%, P = .001) and longer Tc (93.6 hours v 56.0 hours, P = .002) when compared with other French-American-British subtypes. TGF-beta expression (detected by a monoclonal anti-TGF-beta 2/beta 3 antibody) was dramatically high, especially in interstitial areas of the biopsies. S-phase cells were found as geographically restricted islands of proliferation (GRIPs) in 20 of 22 cases. Weekly biopsies showed an increment in TGF-beta on day 7 of therapy in 13 of 17 cases, while in vivo differentiation was noted in 9 of 15. We conclude that the presence of high TGF-beta expression may explain the biologic basis for the slowly cycling nature of leukemic promyelocytes in APL as well as the unique clustering of S-phase cells observed in GRIPs.

Adult↗
PubMed1992

Fetal plasma erythropoietin concentration in red blood cell-isoimmunized pregnancies.

OBJECTIVE: The aim of this study was to investigate the relationship between fetal anemia, plasma erythropoietin concentration, and erythroblastosis in red blood cell-isoimmunized pregnancies. STUDY DESIGN: Fetal plasma erythropoietin concentration in umbilical venous blood samples from 68 red blood cell-isoimmunized pregnancies at 18 to 35 weeks' gestation was measured. Measurements were compared with the appropriate reference range with gestation, and associations with blood pH, erythroblast count, and hemoglobin concentration were examined. RESULTS: The mean fetal plasma erythropoietin concentration and erythroblast count in red blood cell-isoimmunized pregnancies were significantly increased only in severe fetal anemia (hemoglobin deficit > 7 gm/dl). Furthermore, some severely anemic fetuses were hydropic and acidemic. The degree of increase in plasma erythropoietin was significantly associated with both fetal acidemia and, more strongly, fetal erythroblastosis. CONCLUSION: These findings suggest that in fetuses from red blood cell-isoimmunized pregnancies the ability to prevent tissue hypoxia is present until anemia becomes severe, presumably by an increase in cardiac output and tissue perfusion. In severe anemia tissue hypoxia occurs, and the data indicate that fetuses respond by increasing erythropoietin production from at least 20 weeks' gestation. Furthermore, more accurate assessment of tissue oxygenation may be obtained by measuring the erythroblast count rather than the blood pH.

Anemia↗
PubMed1992

Fetal renal defects: associated malformations and chromosomal defects.

During a 6-year period (1985-1990) blood karyotyping was performed in 682 fetuses with renal defects. There were: 276 fetuses with mild hydronephrosis; 206 with moderate/severe hydronephrosis; 173 with multicystic dysplasia, and 27 with renal agenesis. The overall incidence of chromosomal abnormalities was 12% (trisomies, n = 63; deletions, n = 9; triploidies, n = 5, and sex chromosome aneuploidies, n = 8). There were more than twice as many males than females, but the incidence of chromosomal defects in females was almost double (18%) than in males (10%). Furthermore, compared to the overall maternal age-related risk, the risk for fetal chromosomal abnormalities was three times higher when there was an isolated renal defect and thirty times higher when there were additional malformations. The risk of chromosomal abnormalities was similar for fetuses with unilateral or bilateral involvement, different types of renal defects, urethral or ureteric obstruction, and oligohydramnios or normal/reduced amniotic fluid volume. Nevertheless, the patterns of chromosomal abnormalities, and consequently that of associated malformations, were related to the different types of renal defects.

Abnormalities, Multiple↗
PubMed1992

Fetal and maternal erythropoietin levels in normal pregnancy.

In a cross-sectional study of 120 pregnancies undergoing cordocentesis for prenatal diagnosis (n = 90) or elective caesarean section (n = 30), the umbilical cord and maternal venous plasma erythropoietin (Epo) concentrations were measured. Fetal Epo levels increased from a mean of 4 mU/ml at 16 weeks to 13 mU/ml at 40 weeks' gestation. There were no significant associations between fetal plasma Epo concentration and fetal blood gases, haemoglobin concentration, oxygen content or erythroblast count. The maternal plasma Epo concentration (mean = 14 mU/ml, range 1-77 mU/ml) did not change with gestation but was significantly higher than levels in non-pregnant females (mean = 6.6 mU/ml, range 1-25 mU/ml).

Erythroblasts↗
PubMed1992

Distribution of relaxin between human maternal and fetal circulations and amniotic fluid.

Relaxin was measured in maternal blood and amniotic fluid samples at 9-40 weeks and in fetal blood samples at 19-41 weeks of pregnancy. In amniotic fluid, concentrations of relaxin rose from 58 ng/l (geometric mean) at 10 weeks to 142 ng/l at 14 weeks and declined subsequently to 55 ng/l at 22 weeks. In maternal blood, mean relaxin concentrations were ten times greater than in amniotic fluid, and concentrations decreased with gestation. Since there was no significant association between the relaxin concentrations in the two compartments, relaxin in the amniotic fluid may be derived from the decidualized endometrium rather than the maternal circulation, alternatively its metabolism may be different in the two compartments. The absence of detectable concentrations of relaxin in any of the fetal blood samples demonstrates that there is no significant placental transfer or fetal synthesis of this peptide.

Amniotic Fluid↗
PubMed1989

Headache.

Headache is one of the commonest problems to face the family doctor and hospital practitioners. Though migraine and tension headaches are the most common, other types could reflect serious underlying structural causes. Accurate diagnosis can usually be made from a complete history and examination. However, referral of some patients to a specialist clinic is inevitable.

Acupuncture Analgesia↗
PubMed1989

Latent iron deficiency anaemia in schistosomiasis.

This study was carried on 60 male patients, 20 have simple intestinal mansoniasis, 20 have simple urinary bilharziasis and 20 have hepatosplenic mansoniasis. Latent iron deficiency anaemia, defined as those having normal Hb content (greater than 13 g/dl) and low serum ferritin (less than 15 ng/mL). Such latent anaemia was found in 35% of cases with simple mansoniasis, 20% of cases with simple urinary bilharziasis but not in any case with hepatosplenic mansoniasis. Also it was associated with mild intensity of infection.

Adolescent↗