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Biomedical subjects

O A Dada

Publications and source records attributed to O A Dada.

At least 19 recordsLinked to original sources
PubMed2005

The establishment of sperm morphology satellite training laboratories in Africa.

Summary Discrepancies in the results of semen analysis can be caused by a variety of factors, for example, a microscope for semen analysis can be situated in the practice of an urologist, cytologist or microbiologist, or even in a health care office in the countryside in a developing country. The study aimed to evaluate the (i) sperm morphology assessment skills of the participants who attended WHO seminology workshops and (ii) to appraise the possibility of using trained technologists to set up satellite training facilities in their own area. The Centre for Research in Reproductive Health, Ogun State University Teaching Hospital (Nigeria) initiated training sessions in their area. Subsequently, 16 technologists were trained in three sessions. Papanicolaou-stained slides, supplied by Tygerberg were used as test material. Pre- and post-training results were used to calculate the mean percentage of normal cells as well as the percentage deviation from the reference laboratory. The mean percentage normal spermatozoa recorded by the Nigerian trainees during pre-training evaluations differed by 38% from the reference value, compared with a post-training difference of 16% (P < 0.001). Tertiary academic hospitals can play an important educational role in the region. The present results underline the power of long distance educational programmes. Similar laboratories are currently being set up in Kenya and Zambia.

Humans↗
PubMed2002

Investigation of hormonal male contraception in African men: suppression of spermatogenesis by oral desogestrel with depot testosterone.

BACKGROUND: Suppression of spermatogenesis to azoospermia is required for effective hormonal male contraception, but the degree of suppression varies between ethnic groups. We here report the first study of hormonal suppression of spermatogenesis in two African centres using a regimen of oral progestogen with depot testosterone. METHODS A total of 31 healthy men (21 black) were recruited in Cape Town and 21 men in Sagamu, Nigeria. Subjects were randomized to take either 150 or 300 micro g desogestrel daily p.o. with testosterone pellets. In Cape Town, desogestrel was administered for 24 weeks with 400 mg testosterone re-administered 12 weekly. In Sagamu, desogestrel was administered for 52 weeks with 200 mg testosterone (later increased to 400 mg) re-administered 12-weekly. RESULTS: In Cape Town, 22 men completed at least 20 weeks treatment. Azoospermia was achieved in 8/10 and 8/12 men in the 150 micro g and 300 micro g desogestrel groups. Four men in Sagamu withdrew. Azoospermia was achieved in all 17 men in the two groups. There were no significant changes in lipoprotein or haemoglobin concentrations in any group. CONCLUSION: These data demonstrate that the combination of oral desogestrel with depot testosterone is an effective regimen for suppression of spermatogenesis in African as in Caucasian and Chinese men, with azoospermia achieved in a total of 83/98 (85%) men.

Administration, Oral↗
PubMed2002

Infant feeding and lactational amenorrhea in Sagamu, Nigeria.

Five hundred and twenty educated, breastfeeding women in Sagamu, Nigeria, were observed prospectively in order to describe their infant feeding practices and to determine whether any predictors of the return of menses could be identified. The women remained amenorrheic for seven months. Compared with similarly selected women in other countries, they regularly fed their infants with supplements from a very early age, yet breastfeeding frequency and duration did not decline dramatically. Semi-solid food was introduced at about four months and such supplementation, as well as earlier supplementation with milk/milk-based feedings, was associated with the return of menses. The median duration of abstinence was about four months but the mean may have been much longer. No woman became pregnant until her infant was weaned.

Adult↗
PubMed1991

Glycosylated haemoglobin levels in children with protein-energy malnutrition.

Fasting blood glucose, serum protein and glycosylated haemoglobin level (HbA1c) were determined in 50 children (aged 1-5 years) suffering from protein-energy malnutrition and in 25 healthy and nutritionally normal children of the same age group. It was observed that HbA1c correlated well with the blood glucose values of the children. It was also observed that they had significantly higher values of HbA1c than the controls, indicating the existence in them of glucose intolerance. Long-term monitoring of the glycaemic status is therefore suggested as a means of assessing any relationship between glycosylated haemoglobin and impaired pancreatic function in such patients.

Blood Glucose↗
PubMed1991

Comparative study of glycosylated haemoglobin and serum fructosamine values in children with protein-energy malnutrition.

Serum fructosamine, glycosylated haemoglobin (HbAic), fasting blood glucose and serum proteins were determined in 50 malnourished children aged 1-5 years and in 25 healthy and nutritionally normal children of the same age group. It was observed that both HbAic and fructosamine values correlated well with the blood glucose values of the patients. It was also observed that the patients had significantly elevated values of HbAic, indicating the existence of glucose intolerance in them. In contrast, the fructosamine values were significantly reduced in the patients and this was attributed to the hypoproteinaemia in such patients. It was concluded that while both HbAic frustosamine correlate well with blood glucose values, HbAic gives a better reflection of the glycaemic status of malnourished children because its level is not significantly altered by hypoproteinaemia. HbAic measurement may, therefore, be a more reliable indicator of glucose status than serum fructosamine in children with protein-energy malnutrition.

Blood Glucose↗
PubMed1984

17 Beta-estradiol, progesterone and testosterone in the normal menstrual cycle of Nigerians.

Circulating blood levels of estradiol, progesterone and testosterone are reported in 17 normally menstruating Nigerian women. The pattern of secretion and the range of levels of estradiol and progesterone are similar to those reported in other ethnic groups. Testosterone levels were, in general, higher than corresponding values in Caucasian or Asian women, but were of the same order of magnitude as previously reported in Zambian African women.

Adult↗
PubMed1984

Effect of acute chloroquine treatment on prostaglandin- and gonadotropin-stimulated testosterone secretion of rat testis.

The effect of chloroquine injection to rats on in vitro-testosterone secretion stimulated by human chorionic gonadotropin (hCG) and prostaglandin E1 (PGE1) was studied. Rats were injected for 5 days with chloroquine phosphate. Testosterone secretion was stimulated by hCG or PGE1 for 3 h in the removed testis and was measured by radioimmunoassay. Chloroquine treatment in vivo does not seem to have any demonstrable effect on testosterone secretion stimulated by hCG or PGE 1 in prepubertal as well as in the postpubertal rats. However, in pubertal rats chloroquine treatment inhibited testosterone secretion in hCG-stimulated testis.

Aging↗
PubMed1984

Chloroquine phosphate and the intestinal transport of estrogens.

The effect of the antimalaria drug, chloroquine phosphate, on the transport of [3H]estradiol and [3H]estrone sulphate was studied in isolated sacs of rat duodenum. Net transport of the two estrogens from the mucosal to the serosal sides of the intestinal segment was significantly stimulated at chloroquine concentration of 1.0 mM or higher. However, the transformation of estradiol to estrone glucuronide and of estrone sulphate to estrone, which is normally associated with the transport of these estrogens, was significantly inhibited in the presence of the drug.

Animals↗
PubMed1983

Drug effects on the intestinal absorption of estrogens.

It is now recognized that intestinal metabolism is one of the major factors affecting the bioavailability of orally administered, natural and synthetic estrogens. Other drugs and dietary constituents taken concomitantly may modify the intestinal metabolism and enterohepatic circulation of these steroids. Various antibiotics, phenobarbitone and large doses of ascorbic acid have been reported to modify the clinical efficacy of steroidal oral contraceptives. Experimental and other evidence indicate that antibiotics, by modifying the intestinal microflora, affect the intestinal metabolism and enterohepatic circulation of estrogens. Phenobarbitone and ascorbic acid on the other hand probably influence intestinal metabolism through an effect on intestinal mucosal enzymes. Further experimental evidence in rats suggest that such commonly used drugs as analgesic acetylsalicylic acid, antimalarial chloroquine phosphate and alcohol also alter the intestinal mucosal metabolism of estradiol and estrone sulphate and may thus alter the bioavailability of these estrogens. Further studies are necessary to evaluate the clinical significance of these observations.

Analgesics↗
PubMed1983

Biochemical hypothyroidism in Nigerian children with nephrotic syndrome.

The nephrotic syndrome in Nigerian children is known to be largely associated with the endemicity of quartan malaria. Routine thyroid function studies were carried out on 24 children with clinical and biochemical evidence of the nephrotic syndrome. The children, aged four to 14 years, were all in the active phase of their disease, presenting with facial and pedal oedema and ascites. There was severe hypoalbuninaemia [mean (S.E.); 19.2 (1.1) g/l], hypercholesterolaemia; 10.5 (1.0) mmol/l and severe albuminuria ranging from 1 to 10 g/l. There was no clinical evidence of thyroid disease. The results of thyroid function tests in these children were compared with those of 181 apparently healthy children of the same age range. The mean total serum thyroxine levels (S.E.) were 118.3 (2.6) and 50.0 (6.4) nmol/l in controls and patients, respectively; T3 resin uptake values were 29.8 (0.2)% and 33.1 (1.2)%; the free thyroxine index (FTI) was 34.7 (0.8) and 16.7 (1.9) while thyrotropin (TSH) levels were 4.8 (0.2) and 10.6 (1.0) mU/l (IRP. MRC 68/38), respectively. The findings of low levels of thyroxine and FTI in association with high levels of TSH suggest that a state of primary hypothyroidism exists in these nephrotic children.

Adolescent↗
PubMed1983

Thyroid hormones and the reactivities of genetic variants of human erythrocytic glucose-6-phosphate dehydrogenase.

Thyroid hormones, throxine (T4) and triiodothyronine (T3) which are known to activate glucose-6-phosphate dehydrogenase (G6PD) activity in vivo act as substrate inhibitors of G6PD in vitro. T4 competitively inhibits NADP in human erythrocyte G6PD variants G6PDA, G6PDB and G6PDA- with inhibition constants of 2.40 +/- 0.90 X 10(-6), 3.44 +/- 0.63 X 10(-6) and 6.53 +/- 0.60 X 10(-6) mol/l, respectively. The inhibition is, however, noncompetitive with respect to G6P in the three variants. T3 also has similar inhibition pattern to T4 with inhibition constants for NADP of 1.9 +/- 0.08 X 10(-5) and 1.28 +/- 0.17 X 10(-5) mol/l for G6PDB and G6PDA-, respectively. cAMP on the other hand inhibits G6P competitively with inhibition constants 1.50 +/- 0.22 X 10(-4), 1.06 +/- 0.24 X 10(-4) and 1.76 +/- 0.14 X 10(-4) mol/l for G6PDB, G6PDA and G6PDA-, respectively. There are significant differences in the inhibition effects of T4 and cAMP with respect to NADP as substrates for the normal enzyme G6PDA or G6PDB and the deficient enzyme G6PDA- when NADP is the substrate, the latter being much more inhibited. The activation effect of thyroid hormones in vivo may therefore not be a direct result of thyroid hormone binding to the G6PD enzyme nor mediated through the action of cAMP but plausibly be through complexation of inhibitory trace metal ions by the thyroid hormones T4 and T3.

Cyclic AMP↗
PubMed1983

The effect of chloroquine on the uptake of 3H-oestradiol by the uterus and other tissues of the rat.

Adult virgin albino rats were ovariectomized for 10 days and were thereafter administered a daily dose of chloroquine diphosphate (12 mg/kg rat weight) in aqueous solution. This 'chronic dose' produced a significant enhancement of 3H-oestradiol uptake by the uterus and an inhibition of uptake by the liver of the rats. These effects were not observed when the chloroquine was administered only on 1 day ('acute dose') which corresponded to the last day of the 8-day treated rats. Chloroquine, in either regimen, was found to have no significant effect on oestradiol uptake by the kidney or gastrocnemius muscle. These results suggest that chronic chloroquine treatment may lead to an alteration of oestradiol binding and action in its target organs.

Animals↗