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Biomedical subjects

I T Manyonda

Publications and source records attributed to I T Manyonda.

29 records · Page 2Linked to original sources
PubMed1992

Effect of 17 beta-oestradiol on lymphocyte subpopulations, delayed cutaneous hypersensitivity responses and mixed lymphocyte reactions in post-menopausal women.

High-dose steroids are known to be potent modulators of the immune response. We accordingly investigated the effect of therapeutic doses of 17 beta-oestradiol (E2) on cellular immune responses in post-menopausal women. Fifteen (15) healthy women who had undergone a natural menopause were treated with E2 in the form of 100 mg estraderm patches applied twice weekly for 3 out of every 4 weeks over a 3-month period, followed by combined oestrogen and progestogen formulations as long-term therapy. Blood samples were taken on two occasions prior to treatment and at weeks 1, 3, 4, 7, 9, 12 and 24 after commencing therapy. Lymphocyte subsets (CD2, CD4, CD8, CD19, HLA-DR and NK) were studied in each blood sample using a monoclonal antibody kit and a two-colour fluorescence flow-cytometer. One-way mixed lymphocyte reactions (MLRs) were performed using the same stimulator throughout. Delayed hypersensitivity skin tests (DHTs) were carried out twice before treatment and at weeks 3, 4, 12 and 24 using Multitest 7-antigen kits (Institut Mérieux). Lymphocyte subsets did not change significantly with treatment, but both the MLRs and the DHTs were significantly depressed, maximally so by the third week of treatment. We conclude that therapeutic doses of E2 modulate certain immune responses. The significance of this is discussed in the light of the increasing use of long-term oestrogen replacement therapy.

Estradiol↗
PubMed1991

Massive obstetric hemorrhage due to placenta previa/accreta with prior cesarean section.

There is a high association between anterior placenta previa, placenta accreta and previous cesarean section. We report three cases which illustrate the particular danger of massive hemorrhage posed by placenta previa/accreta in a scarred uterus. As the incidence of cesarean section continues to rise worldwide, the problem of placenta previa/accreta is likely to become more common. We emphasize the need for each obstetric unit to have a protocol for dealing with massive hemorrhage.

Adult↗
PubMed1990

The influence of suture material on vaginal vault granulations following abdominal hysterectomy.

A questionnaire was circulated to 1147 members (consultant status) and fellows of the Royal College of Obstetricians and Gynaecologists to survey the current management of the vaginal vault following abdominal hysterectomy. Of the 56% who responded, the majority (87%) routinely close the vault. An interrupted mattress suture is used by 60%, a continuous suture by 43% and the Lembert suture by 2%. Chromic catgut is favoured by 60%, a synthetic polymer by 33% and plain catgut by 6%. We then organized a prospective, randomized trial involving 114 women who underwent total abdominal hysterectomy for benign indications. No. 1 polygalactide (Vicryl) was used in 58 women, and No. 1 chromic catgut in 56. Overall, 37 (32%) had vault granulations 6 weeks post-operatively. Chromic catgut had been used in 25 (68%) and polygalactide in the remaining 12 (32%) (P = 0.01). Only 2 (5%) of these women denied any symptoms, while the rest complained of vaginal discharge, bleeding or both. Neither the patients' age, weight or parity, nor the status of the surgeon influenced the occurrence of granulations. We conclude that the widespread use of chromic catgut revealed by our survey is unacceptable: polygalactide, a synthetic polymer, is associated with fewer vaginal vault granulations than chromic catgut.

Adult↗
PubMed1990

The effect of delayed pushing in the second stage of labor with continuous lumbar epidural analgesia.

We studied primigravid women in spontaneous labor at term and given epidural analgesia. Two hundred such women giving birth in 1983 were compared with similar groups who gave birth in 1985 and 1987 after the introduction of 'delayed pushing' into our labor ward protocol. Four hundred controls were obtained in 1983 and 1985 by selecting from the labor ward register the next normal primigravid woman in spontaneous labor without epidural analgesia. The assisted delivery rate was significantly higher in all three epidural groups than in the controls (p less than 0.001). Among epidural labors, there was no significant difference between 1983 and 1987 in the incidence of rotational or non-rotational forceps, or of cesarean section. In each epidural group, women who waited more than 60 min were less likely to experience a normal spontaneous delivery than were those who did not (p less than 0.001 in 1983; p = 0.006 in 1985 p = 0.035 in 1987). We conclude that to delay pushing beyond 60 min confers no benefit regarding mode of delivery.

Adult↗
PubMed1989

Obstructive uropathy from endometriosis after hysterectomy and oophorectomy; two case reports.

Two patients with obstructive uropathy as a result of post menopausal endometriosis are reported. They both illustrate the potential problems of hormone replacement therapy after bilateral salpingo-oophorectomy and hysterectomy in patients who have had extensive endometriosis. It is suggested that in such patients the potential of reactivation of the disease with hormone-replacement therapy should be recognised and ureteric involvement be excluded by intravenous urography or renograms.

Adult↗
PubMedDate not supplied

Collagen phagocytosis by human extravillous trophoblast: potential role in trophoblastic invasion.

OBJECTIVES: To study collagen phagocytosis by human extravillous trophoblast. METHODS: First-trimester extravillous trophoblastic cell lines and primary trophoblast cell preparations were cultured in vitro with collagen-coated fluorescent latex beads and fluorescent-labeled collagen. Confocal microscopy was used to demonstrate internalization of collagen and beads. The effect of cytochalasin B, temperature, metabolic inhibitors, and cytokines was studied by culturing trophoblast cells with tritiated collagen. Acridine orange was used to stain for lysosomal compartments, and histochemical methods were used to demonstrate acid phosphatase in trophoblast cells. RESULTS: Both cell lines and primary culture cells internalize collagen and beads. Confocal microscopy unequivocally localized the phagocytosed material to the intracellular compartment. Inhibition by cytochalasin B and culture at 4C of uptake of [3H] collagen suggested that the process was phagocytosis. Cytokines and growth factors did not affect phagocytosis. Lysosomal compartments and acid phosphatase appear to colocalize. CONCLUSIONS: The continuous remodeling and turnover of collagen which occur in a wide variety of tissues under both physiologic and pathologic conditions are thought to be mediated by two pathways: one external (involving release of proteolytic enzymes), and the other internal (involving phagocytosis). Similar remodeling events are likely to occur during trophoblast invasion. Although current views emphasize the importance of the extracellular pathway, we postulate, on the basis of our findings, that both pathways are used, with the internal pathway probably being dominant. We hypothesize that the proteolytic enzymes (extracellular pathway) disrupt collagen matrices, thereby facilitating phagocytosis. It is teleologically sound to conceive of a dominant intracellular pathway, as it allows for more precise control of the process of invasion and is economical, as the products of collagen degradation can be used as energy sources or building blocks.

2,2'-Dipyridyl↗