Scaling up numbers and competency of graduating medical and dental students in Nigeria: Need to improve medical trainers' competency in teaching

Background

With the increasing medical brain drain in Nigeria, there is a need to train and graduate more doctors to fill in the gaps created to mitigate the effects. To meet this goal, the trainers need to evolve and have the competency to deliver quality training for many more enrollees in medical schools.

Aim

This study aimed to gather information about the perception of medical teachers' need to obtain certification in medical education and what this will achieve in scaling up the competency and number of graduating medical doctors.

Subjects and Methods

Medical teachers in Nigeria participated in this mixed (quantitative and qualitative) study. Four hundred medical consultants and teachers were randomly selected and sent a semi-structured pre-validated questionnaire; also, a panel discussion was conducted with six medical teachers with other special assignments in universities and postgraduate colleges. Quantitative data were analyzed using Statistical Package for the Social Sciences (SPSS) 24, differences in proportions were calculated using the Chi-square test, and P values <0.05 were considered significant.

Results

Two hundred and thirty-eight (59.5%) participants completed the form, 63 (26.5%) had practiced for <5 years, and 114 (47.9%) had >10 years of practice experience. A majority of 168 (70.6%) were physician lecturers in federal or state universities, and 15.5% had obtained certifications of any kind in medical education. Over 80% perceived that medical education training should not be a prerequisite to teach, but a similar percentage believed that faculty medical education training can help scale up the training competency and the number of graduating medical doctors.

Conclusion

To scale up the number and competency of graduating medical doctors, medical teachers need to acquire core teaching competency. The respondents and discussants believe that when these core teaching competencies have been fully developed, it will be easier to increase the number of medical students' enrollees, teach them their curriculum through innovations, and graduate them with improved competencies.

Protective role of Allium cepa Linn (onion) juice on maternal dexamethasone induced alterations in reproductive functions of female offspring of Wistar rats

Maternal treatment with dexamethasone induces oxidative stress in the reproductive structures of offspring. Consumption of Allium cepa Linn improves antioxidant status. This study was designed to evaluate the protective role of Allium cepa Linn juice on maternal dexamethasone induced alterations in reproductive functions of the female offspring of Wistar rats. Twenty lactating dams (180-200 ​g) were randomly assigned into four groups (n ​= ​5) on the day of parturition and treated as follows during lactation for 21 days: Control (5 ​ml/kg BW distilled water); Dexamethasone (60 ​μg/kg BW); Allium cepa (5 ​ml/kg BW); Dexamethasone ​+ ​Allium cepa (60 ​μg/kg BW ​+ ​5 ​ml/kg BW). The female offspring were separated at birth. Days of vaginal opening and first oestrus cycle, length and frequency of estrous cycle as well as serum hormonal profiles were assessed as measure of reproductive functions. Ovarian superoxide dismutase (SOD) activity, catalase activity and malondialdehyde (MDA) level were measured as indices of oxidative stress. Oestrous cycle length, frequencies of diestrus as well as the Ovarian MDA were significantly increased (p ​< ​0.05) in dexamethasone (DEX) group relative to control group. Serum 17β-oestradiol and corticosterone level in addition to SOD and catalase activities were significantly reduced (p ​< ​0.05) in DEX group relative to control. Co-administration of Dex with Allium cepa Linn juice reduced the oestrous length, frequency of diestrous as well as ovarian MDA. There was also a significant increase in serum 17β-oestradiol, ovarian SOD and catalase activity. The results suggest that Allium cepa could protect against alterations in reproductive functions of offspring induced by maternal treatment with dexamethasone during lactation in Wistar rats. The flavonoid constituent of onion may also help in reducing oxidative stress in the offspring.

Allium cepa Linn juice protect against alterations in reproductive functions induced by maternal dexamethsone treatment during lactation in male offspring of Wistar rats

Treatment with dams with dexamethasone during lactation has been reported to induce oxidative stress in the testis of the offspring. Allium cepa L (Red Onion) is known to be a potent free radical scavenger. The protective role of Allium cepa against oxidative stress induced in testis following treatment with dexamehasone during lactation in Wistar rats was assessed. Twenty female rats were assigned into four groups (n = 5) during lactation and they were treated as follows: Group 1 serve as Control (distilled water), Group 2, 3, and four were admistered dexamethasone (60 μg/kg), Allium cepa (5 ml/kg) and dexamethasone + Allium cepa respectively. Testicular descent, pubertal age, sperm quality indices, and serum hormonal profile were assessed as indices of reproductive function. Testicular malondialdehyde (MDA) reduced glutathione (GSH) as well as superoxide dismutase (SOD) and catalase activities were assessed as measures of oxidative stress. Results obtained showed that dexamethasone caused significant (P < 0.05) reduction in testes weights, indices of sperm quality, serum testosterone, FSH, LH levels and testicular antioxidant enzyme activities. There was significant delay (P < 0.05) in days of testes descent, preputial separation and increase in testicular MDA. However, maternal treatment with Allium cepa Linn juice significantly (P < 0.05) improved both indices of reproductive function and testicular antioxidant enzymes. These findings suggest that Allium cepa Linn has a protective effect against testicular oxidative stress and reproductive dysfunction following treatment of dams with dexamethasone during lactation.

Coconut Water Prevents Renal and Hepatic Changes in Offspring of Monosodium Glutamate-Treated Wistar Rat Dams

Monosodium glutamate (MSG) is a widely-consumed taste enhancer which has been implicated in the aetiology of renal and hepatic dysfunction in adults and their offspring. There is increasing evidence on the therapeutic properties of Coconut Water (CW) in kidney and liver disorders. This study investigated the effects of CW on renal and hepatic functions in offspring of MSG-fed dams. Twelve female Wistar rats (120 - 140 g) were grouped into four as follows; Control (10 ml/Kg distilled water), MSG (0.08 mg/Kg), CW (10 ml/Kg) and MSG+CW. Treatments were given orally daily commencing two weeks prior to mating, throughout mating and gestation until parturition. All dams received standard rodent diet and drinking water ad libitum throughout the study. After weaning on Post-Natal Day (PND) 28, serum was obtained from offspring for assay of liver and renal function. Histological analysis of the livers and kidneys were performed on both dams and offspring. There was no significant difference in liver enzymes, urea, creatinine and albumin levels amongst the offspring on PND 28. However, liver and kidney sections from MSG dams and their offspring showed early degenerative changes which were not evident in renal and hepatic tissues from CW and MSG+CW dams and offspring. These observations suggest that coconut water protects against monosodium glutamate-induced renal and hepatic dysfunction in dams and offspring.

Ethical and legal issues in renal transplantation in Nigeria

With the increasing number of patients being offered kidney transplantation by many centers in the developing world, it is not unexpected that there would be attendant ethical and legal issues even when the selection process for transplantation seems medically justified. Because of the inadequate infrastructure for hemodialysis and peritoneal dialysis, coupled with the challenges of logistics for maintenance dialysis, transplantation would seem to be the best option for patients with end-stage renal failure, even in developed economies where these can easily be tackled. The main issues here revolve around incentives for donors, organ trade and trafficking and the economics of eliminating the waiting list and the criminal activities of organ trans-plantation. In the developing world, with the current level of corruption and poverty, there is a need to redouble efforts to monitor transplant activities. Professional bodies should take the lead in this regard. Furthermore, there is a need for governments to engage in public consultation and community awareness concerning organ donation in living and deceased persons.

Maternal treatment with dexamethasone during lactation delays male puberty and disrupts reproductive functions via hypothalamic-pituitary-gonadal axis alterations

The effects of maternal treatment with dexamethasone during lactation on pubertal timing, serum hormonal profile and sperm indices in the male offspring were assessed. Twenty lactating dams were divided into 4 groups (n=5). Group 1 was administered subcutaneously 0.02ml/100g/day normal saline at lactation days 1-21. Groups 2-4 were administered subcutaneously 100μg/kg/day dexamethasone (Dex) at lactation days 1-7, 1-14, and 1-21 respectively. Results showed that there was significant reduction in serum testosterone in the DexLD 1-7 (p<0.05), DexLD 1-14 (p<0.01) and DexLD 1-21 (p<0.001) relative to control. In addition there was a significant reduction in serum FSH and LH in the DexLD 1-7 (p<0.01), DexLD 1-14 (p<0.001) and DexLD 1-21 (p<0.001) when compared with the control. Treatment with dexamethasone during lactation significantly increased the days of preputial separation in the DexLD 1-7 (p<0.05), DexLD 1-14 (p<0.05) and DexLD 1-21 (p<0.001) relative to control. Maternal treatment with dexamethasone throughout lactation period also significantly reduced sperm counts (p<0.001), motility (p<0.01) and increased percentage abnormal sperm (p<0.001) in the offspring when compared with the control. In conclusion, maternal treatment with dexamethasone during lactation may induce delayed puberty and disrupt reproductive functions by altering activities at hypothalamic-pituitary-gonadal axis in the male offspring.

Effects of Oral Maternal Administration of Caffeine on Reproductive Functions of Male Offspring of Wistar Rats

Caffeine was investigated for its possible fetal programming effects on reproductive function of male offspring. Sixty-five pregnant Wistar rats were grouped into four. Group 1 was control and received distilled water. Groups 2, 3 and 4 were treated orally with 1.14, 3.42 and 5.70 mg/kg body weight of caffeine respectively. Each group was subdivided into four based on gestation days (GD) 1-7, 8-14, 15-21 and 1-21. The day of parturition was taken as postnatal day zero (0). Male offspring were sacrificed on postnatal day 70. Parameters determined were: weight at birth, body weight at postnatal day 21 and 70, anogenital distance (AGD) index, sperm parameters, reproductive organ weight, histology and hormonal profile (testosterone, FSH and LH). Data were analyzed using Analysis of Variance. Level of significance was taken at P<0.05. Male offspring belonging to caffeine treated dams showed dose dependent significant decreases in birth weight. Male offspring from dams treated with caffeine during GD 1-7 and GD 1-21 had a significant increase in their AGD index. Also, male offspring from dams treated with 1.14 and 5.70 mg/kg body weight of caffeine during GD 8-14 had a significant increase in AGD index. Dams treated with 3.42 mg/kg body weight of caffeine during GD 15-21, had a significant increase in the AGD index of their male offspring. The sperm motility of offspring from dams treated with 5.70 mg/kg body weight of caffeine during GD 1-7 and GD 1-21 were significantly increased. Offspring of GD 8-14 and GD 15-21 dams treated with 3.42 and 5.70 mg/kg body weight of caffeine respectively, showed significantly reduced serum testosterone level. There was a significant decrease in the weight of testes of offspring from dams treated with caffeine during GD 8-14. Histological sections of testes of offspring from caffeine treated dams showed interstitial congestions, edema, reduced germinal epithelial height and detached basal membrane. Maternal caffeine exposure during different gestational periods adversely affected birth weight and some reproductive indices in male offspring of Wistar rats.

Effects of methotrexate on serum testosterone level in sleep deprived male Wistar rats

BACKGROUND

Sleep deprivation has been reported to decrease testosterone levels but the mechanism remains unclear. Studies have shown that sleep deprivation increases interleukin 1 beta (IL-1β), a pro-inflammatory cytokine and that increased IL-1β levels cause reductions in Leydig cell production of testosterone. This study was therefore designed to determine the effects of methotrexate, an IL-1β blocker on serum testosterone levels in sleep deprived male Wistar rats.

METHODS

Twenty male Wistar rats were randomly assigned into four groups (n = 5); group I (Control) received the vehicle (1% tween 80 solution); group II (methotrexate) received 0.5 mg/kg body weight methotrexate; group III (SD) was sleep deprived and received the vehicle; group IV (SD+Methotrexate) was sleep deprived and received 0.5 mg/kg body weight methotrexate. Sleep deprivation was induced using the modified multiple platform technique for 14 days. Treatments were administered twice weekly by oral gavage for 14 days. Blood was collected on day 14 and serum was obtained for analyses of testosterone, LH and FSH levels. IL-1β level and histology of the testis were also determined. Data were expressed as Mean ± SEM and analysed using ANOVA. p < 0.05 was considered significant.

RESULTS

Serum testosterone levels were significantly decreased while testicular IL-1β was increased in SD and SD+Methotrexate compared with Control. FSH and LH levels were not significantly different among the groups.

CONCLUSION

Results of this study suggest that reduction in serum testosterone level in sleep deprived rats is not dependent on increased level of IL-1β.

Coconut water alters maternal high fat diet induced changes in hormones and pup morphometry of Wistar rats

BACKGROUND

Maternal high fat diet (HFD) during gestation adversely programmes foetal metabolism and cardiovascular function for the development of obesity and its related cardiovascular diseases in adult life. The hypolipidemic actions of coconut water (CW) in the presence of HFD have been reported. This study examined the effects of oral administration of CW on lipid panel, hormone profile, pup and placental morphometry of dams fed HFD during gestation.

METHODS

Twenty-four pregnant Wistar rats were assigned to four groups (n = 6) and treated daily from gestation day (GD) 1 to 21 as follows; Group 1: 1 ml/100g b.wt. distilled water; Group 2: 1ml/100g b.wt. CW; Group 3: HFD (70% standard rat feed plus 30% butter); Group 4: HFD + 1 ml/100g b.wt. CW. Animals were sacrificed on GD 21. Random blood glucose was measured using tail blood. Caesarean section was performed to remove the pups and their placentas which were immediately measured. Oxidative stress status of the placentas; serum lipid and hormone profiles of dams were assessed.

RESULTS

HFD+CW resulted in significant (P < 0.05) reductions in pup weight and morphometric indices when compared with pups from HFD. These changes were accompanied by significant improvements in maternal serum lipid profile, alterations in hormone levels and higher placental lipid peroxidation.

CONCLUSION

These results suggest that coconut water is protective against maternal high fat diet-induced changes. Further studies are on-going to determine the actions of coconut water of maternal high fat diet induced foetal programming of adult health.

N (G)-nitro-L-arginine Methyl Ester Protects Against Hormonal Imbalances Associated with Nicotine Administration in Male Rats

Background:

The administration of nicotine is associated with altered hormonal imbalances and increased serum and testicular nitric oxide (NO) level.

Aim:

This study sought to investigate the effects of NO inhibition with N^G-nitro-L-arginine methyl ester (L-NAME) on altered hormonal imbalance in adult male albinorats.

Materials and Methods:

Rats were administered with 0.5 mg/kg body weight (BW) and 1.0 mg/kg BW nicotine and were treated with L-NAME in the drinking water or drinking water alone for 30 days. Serum was analyzed for testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), and prolactin using radioimmunoassay.

Results:

Nicotine administration significantly decreased (P < 0.05) testosterone in the low and high dose treated groups and FSH in the high dose treated group when compared with the control group. There was a significant increase (P < 0.05) in mean LH and prolactin level in the high dose treated group when compared with the control. Concomitant treatment with nicotine and L-NAME produced significant increases in testosterone and FSH, and a decrease in prolactin in 1.0 mg/kg BW. L-NAME alone did not lead to a significant increase in testosterone when compared with control.

Conclusion:

These data demonstrate that the suppressive effects of nicotine on testosterone level of the adult male rat can be prevented by NOS blockade with L-NAME. It appears that these beneficial effects are mediated primarily within the gonad; however, the involvement of the pituitary cannot be totally ruled out.

Effects of vitamin E and melatonin on serum testosterone level in sleep deprived Wistar rats

BACKGROUND

Sleep deprivation affects a significant proportion of the global population. It has been reported to induce oxidative stress in the testes and reduce serum testosterone levels. Exogenous anti-oxidants have been known to prevent damages and diseases associated with oxidative stress but there is dearth of knowledge on their effectiveness during sleep deprivation.

AIM

This study was designed to investigate the effects of two anti-oxidants; melatonin and vitamin E on serum testosterone concentration in sleep deprived male Wistar rats.

METHODS

Thirty (30) male Wistar rats were used for this study. Animals were divided into six (6) groups (n = 5). Group 1 was the control, group 2 rats were sleep deprived, group 3 received vitamin E (200 mg/ kg bwt) only, group 4 rats received vitamin E and were sleep deprived, group 5 received melatonin only (10 mg/kg bwt), and group 6 rats received melatonin (10 mg/kg bwt) and were sleep deprived. Sleep deprivation was induced using the modified multiple platform technique. Body weights were taken on days 7, 14 and 21. Blood was collected at sacrifice and serum was obtained for analyses of testosterone, corticosterone and melatonin. Testicular malondialdehyde, superoxide dismutase and catalase levels were determined by the methods of Adam-Vizi and Seregi (1982), Misra and Fridovich (1972), and Sinha, (1972) respectively. Data obtained were analyzed using one way ANOVA and p < 0.05 was considered significant.

RESULTS

Serum testosterone (nmol/l) of the sleep deprived animals (0.6 ± 0.3) reduced significantly (p < 0.05) compared with control group (3.3 ± 0.04), sleep deprived+vitamin E group (2.8 ± 0.5) and sleep deprived+melatonin group (2.0 ± 0.3). Also, melatonin+sleep deprived group had reduced testosterone compared with control. There were no significant changes in the serum corticosterone (nmol/l) and melatonin levels in all the groups compared with the sleep deprived group. However, corticosterone was increased in the sleep deprived+Vitamin E group (51.6 ± 20.5) compared with control (6.3 ± 0.6) Sleep deprived group had increased testicular malondialdehyde (MDA) (1.6 ± 0.1 unit/mg), superoxide dismutase (SOD) (3.2 ± 0.2 unit/mg), and catalasel evels (44.3 ± 1.1 unit/ mg) compared with control (0.9 ± 0.0 μmg). MDA, and catalase were significantly reduced in sleep deprived+vitamin E (1.1 ± 0.2, 2.4 ± 0.3, 39 ± 1.0 unit/ mg) compared with sleep deprived while melatonin alone had increased MDA. level (1.7 ± 0.2unit/mg) compared with control. SOD in the sleep deprived+melatonin group (2.7 ± 0.2 μ/mg) as compared with control increased (p < 0.05) while MDA and catalase levels as compared with control and sleep deprived groups showed no difference. Histological findings showed that the pathology in the testes of sleep deprived rats was ameliorated by vitamin E.

CONCLUSION

Vitamin E had a more potent effect than melatonin in maintaining testosterone level in sleep deprived Wistar rat.

Cocos nucifera L. water improves reproductive indices in Wistar Rats

BACKGROUND

This study explored the effects of Cocos nucifera L. water (CW) on the hypothalamo-pituitary-gonadal axis (HPG) and fertility in Wistar rats.

METHODS

Adult male and female Wistar rats were treated orally as follows; Study 1: Group 1: control (distilled water), group 2: 20 ml/kg corn oil (danazol vehicle), group 3: 20 ml/kg CW, group 4: 40 ml/kg CW, group 5: danazol, group 6: danazol + 20 ml/kg CW and group 7: danazol + 40 ml/kg CW. 200 mg/ kg danazol was administered. Serum levels of LH, FSH, estradiol and testosterone; gonadal weights and sperm indices were assessed. Study 2: Group 1: control (distilled water), group 2: 20 ml/kg CW, group 3: 40 ml/kg CW for 6 and 2 weeks prior to mating in male and female rats respectively.

RESULTS

Significant (p < 0.05) increases in estradiol concentration were observed in groups 3, 4, 6 and 7. Significant reductions in LH, FSH, estradiol and testosterone levels were observed in group 5 which were ameliorated in groups 6 and 7. Males showed significant increases in sperm count and motility in groups 3, 4, 6 and 7, and reductions in these variables along with viability in group 5. CW pre-treatment increased fecundity index and proportion of female pups from dams, while the pups from sires showed higher birth weights.

CONCLUSIONS

CW acts on the HPG to positively influence reproductive function in both males and females and may aid in maternal preconception sex selection of female offspring.

Antioxidant profile changes in reproductive tissues of rats treated with nicotine

OBJECTIVES:

Nicotine intake has been associated with reduced fertility, although the mechanisms responsible are still unclear. However, oxidative stress has been repeatedly implicated as the leading cause of male infertility. This study was therefore designed to investigate the effects of nicotine administration on testicular oxidant and antioxidant system in male albino rats.

MATERIALS AND METHODS:

Forty male rats weighing between 150 and 180 g were divided into five groups and treated orally for 30 days. Group I, which served as the control received 0.2 ml/kg normal saline, Groups II and III received 0.5 mg/kg and 1.0 mg/kg body weight (BW) of nicotine respectively. The fourth and fifth groups were administered with 0.5 mg/kg and 1.0 mg/kg BW of nicotine, but were left untreated for another 30 days. Homogenate of testis and epididymis were assayed for lipid peroxidation and anti-oxidant enzyme.

RESULTS:

The results show a significant decrease (P < 0.05) in testicular glutathione peroxidase, glutathione reductase, catalase and superoxide dismutase while a significant increase (P < 0.05) was observed in testicular lipid peroxidation and nitric oxide level in both groups when compared with the control.

CONCLUSION:

This experiment established that nicotine administration is associated with decreased testicular antioxidant and increase testicular lipid peroxidation, which might be a mechanism by which nicotine induce infertility.

Localized 3D analysis of cartilage composition and morphology in small animal models of joint degeneration

OBJECTIVE

Current histological scoring methods to evaluate efficacy of potential therapeutics for slowing or preventing joint degeneration are time-consuming and semi-quantitative in nature. Hence, there is a need to develop and standardize quantitative outcome measures to define sensitive metrics for studying potential therapeutics. The objectives of this study were to use equilibrium partitioning of an ionic contrast agent via Equilibrium Partitioning of an Ionic Contrast-Microcomputed tomography (EPIC-μCT) to quantitatively characterize morphological and compositional changes in the tibial articular cartilage in two distinct models of joint degeneration and define localized regions of interest to detect degenerative cartilage changes.

MATERIALS AND METHODS

The monosodium iodoacetate (MIA) and medial meniscal transection (MMT) rat models were used in this study. Three weeks post-surgery, tibiae were analyzed using EPIC-μCT and histology. EPIC-μCT allowed measurement of 3D morphological changes in cartilage thickness, volume and composition.

RESULTS

Extensive cartilage degeneration was observed throughout the joint in the MIA model after 3 weeks. In contrast, the MMT model showed more localized degeneration with regional thickening of the medial tibial plateau and a decrease in attenuation consistent with proteoglycan (PG) depletion. Focal lesions were also observed and 3D volume calculated as an additional outcome metric.

CONCLUSIONS

EPIC-μCT was used to quantitatively assess joint degeneration in two distinct preclinical models. The MMT model showed similar features to human Osteoarthritis (OA), including localized lesion formation and PG loss, while the MIA model displayed extensive cartilage degeneration throughout the joint. EPIC-μCT imaging provides a rapid and quantitative screening tool for preclinical evaluation of OA therapeutics.

Preliminary study on the effects of Buchholzia coriacea seed extract on male reproductive parameters in rats

The effects of methanol extract of Buchholzia coriacea seed was studied on male reproductive system of albino rats. Administration of 200mg/kg b.w.(p.o.) of the extract for 6 weeks resulted in significant reduction (P˂0.05) in the weight of the epididymis and seminal vesicle, but not the testes and prostate gland. Also the weight of the visceral organs- lungs, liver, heart and kidney were unaffected. A marked decrease (P<0.05) in sperm motility and volume was also observed in sperm collected from the caudal epididymis of the treated animals. Sperm count and morphology were not significantly affected (P<0.05). Total tissue protein of the epididymis and testes of the treated rats was significantly increased (P<0.05) and fertility was zero in the treated rats. Histological section showed that the epididymal ducts were mostly empty, though the epithelial lining appeared normal. There were fewer spermatozoa and late stage spermatids in the testes, with normal testicular epithelium. The results suggest that the extract of Buchholzia coriacea may have antifertility effects in male rats, the site of action most probably the epididymis.

Influence of prolonged exposure to Nigerian Bonny light crude oil on fertility indices in rats

The effect of Bony Light Crude Oil (BLCO) on some sperm functions during short term exposure has been reported. The present study investigated the effect of long term ingestion of BLCO on fertility indices in male and female albino rats. Adult male rats in groups of five were exposed daily to 0, 200, 400 and 800 mg/kg BLCO (orally, p.o) dissolved in olive oil which served as the control, for six weeks. The male rats were cohabited with untreated adult female rats (for mating) during the last 6th week of treatment. Similarly, adult female rats in groups of five were exposed daily to 0, 200, 400 and 800 mg/kg BLCO (p.o) for 6 weeks. The rats were mated with untreated male rats during the last 6th week of treatment. Body weights of the treated rats remain unaffected. However, a significant decrease in the weight of the testis, epididymis, cauda epididymal sperm count, motility, viability and normal morphology of the spermatozoa was observed. There was 100% mating success as all untreated female rats with a significant decrease in number, birth weight and survival rate of offspring delivered. BLCO treated female rats had irregular oestrous cycle with increased frequency of oestrous and metestrous phases and a decrease in the diestrous phase. A dose-dependent reduction in fertility success, number and birth weight of offspring of the BLCO treated females mated with normal males was recorded. Histological study of the epididymis and testis showed BLCO treatment-related lesions. The results suggest that, Bonny light crude oil reduced fertility indices of male and female rats.

Gastro-protective effect of methanol extract of Ficus asperifolia bark on indomethacin-induced gastric ulcer in rats

The gastro-protective and antioxidant effects of methanol extract of Ficus asperifolia bark on indomethacin induced gastric ulcer were investigated in male rats. Thirty two male rats divided into 4 equal groups and were treated as follows: group1 (control), 0.5ml of 5% tween 80 (vehicle for the extract), groups 2 and 3, 100 and 500mg/kg of Ficus asperifolia extract respectively and group 4, cimetidine (100mg/kg). After two weeks of daily oral administration of vehicle, extract or cimetidine, gastric ulcer was induced in all rats with indomethacin (40 mg/kg, p.o). Gastric juice pH, gastric acid concentration, gastric ulcer score, percentage gastric ulcer inhibition, activity levels of superoxide dismutase (SOD), catalase and malondiadehyde (MDA) were determined. Ficus asperifolia extract significantly increased gastric pH (p<0.05) but decreased (p<0.01) gastric acid secretion in dose dependent manner when compared with the control. Inhibition of gastric ulcer in extract and cimetidine treated rats was similar. Activities of SOD and catalase were significantly increased (p<0.05) while MDA was significantly decreased (p< 0.05) in extract treated rats when compared with the control. The results suggest that Ficus asperifolia possesses gastro-protective and antioxidant properties against gastric ulcer induced by indomethacin.

Quinolizidine alkaloids: the bioactive principles in Cnestis ferruginea (de Candolle) with male antifertility activities

OBJECTIVES

The reproductive activities of purified fractions from the root extract of Cnestis ferruginea was evaluated in rats. Phytochemical screening of the extract revealed the presence of alkaloids, tannins and anthraquinones.

MATERIALS AND METHODS

Column chromatography produced 20 fractions which were reduced to 6 by thin layer chromatography. Nuclear magnetic resonance spectroscopy revealed quinolizidine alkaloids (fractions 3 and 4) as the active principles in the extract of Cnestis ferruginea. Each fraction of Cnestis ferruginea (0.1, 1 and 2 mgkg(-1)bw) was administered to rats by gavages for 60 days.

RESULTS

All fractions caused significant reduction (p<0.05) in sperm counts, motility, viability, morphology and plasma levels of testosterone, luteinizing hormone and follicle stimulating hormone. Fractions 3 and 4 caused the highest reduction (p<0.001) in fertility, FSH and LH levels comparable to those of quinine sulphate. There was recovery after 60 days of withdrawal from the extracts.

CONCLUSION

The results suggest that Cnestis ferruginea possesses reversible male antifertility effects. The active principles with these activities appear to be quinolizidine alkaloids.

Effects of oral administration of nicotine on organ weight, serum testosterone level and testicular histology in adult male rats

This study investigated the effects of oral administration of nicotine on body and reproductive organ weight, serum testosterone level and testicular histology in adult male rats. Forty male rats divided into five groups and treated for a period of 30 days with 0.5mg/kg (low dose) and 1.0 mg/kg (high dose) body weight of nicotine while the control rats received 0.2 ml/kg normal saline. The fourth and fifth groups were gavaged with 0.5mg/kg and 1.0mg/kg body weight of nicotine but were left untreated for another 30 days. These groups served as the recovery groups.&nbsp; At the end of each experimental period, the animals were scarified and their reproductive organs were removed and weighed immediately. There was no significant change in the body weight. There was a significant decrease (p <0.05) in the testicular and epididymal weight of rats for both treatments while the decrease in the seminal vesicle weight for both treatment groups was not significant. The prostate weight was not significantly increased in both groups. The recovery groups showed appreciable recovery in their organ weight. Serum level of testosterone of both groups was significantly decreased in a dose dependent manner when compared with those of the control rats. The histological section showed testicular degeneration and disorganization in the cytoarchitecture, as the observed changes were pronounced in the high dose group than the low dose group. However, there were both regeneration of the germinal epithelium and restructuring of the interstitum towards normal in the recovery groups. No lesion was observed in the epididymis of the rats. The results suggest that nicotine has deleterious effect on the male reproductive organ of albino rats ameliorated by nicotine cessation.

Implication of reproductive endocrine malfunction in male antifertility efficacy of Azadirachta indica extract in rats

The effects of the ethanol extract of Azadirachta indica stem bark on body and organ weights, sperm morphology, counts and viability, serum levels of testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH) were studied in albino rats. Intraperitoneal administration (i.p) of the extract for ten weeks caused significant dose-dependent decreases in weights of the testis, epididymis and seminal vesicles but an increase in that of the adrenal gland. Sperm counts, morphology and viability were adversely affected in the extract treated rats. Rats that received 150 mgkg(-1) b.w. Azadirachta extract were unable to impregnate female rats throughout the duration of the study. However, these female rats conceived and sired physically normal litters about four weeks after cohabitation with untreated male rats. Azadirachta indica produced dose-dependent reduction in serum testosterone and LH but no change in FSH levels. Most of the changes produced in this study were restored in recovery experiments.

A comparative study of students' performance in preclinical physiology assessed by multiple choice and short essay questions

This study was designed to compare the performance of medical students in physiology when assessed by multiple choice questions (MCQs) and short essay questions (SEQs). The study also examined the influence of factors such as age, sex, O/level grades and JAMB scores on performance in the MCQs and SEQs. A structured questionnaire was administered to 264 medical students' four months before the Part I MBBS examination. Apart from personal data of each student, the questionnaire sought information on the JAMB scores and GCE O' Level grades of each student in English Language, Biology, Chemistry, Physics and Mathematics. The physiology syllabus was divided into five parts and the students were administered separate examinations (tests) on each part. Each test consisted of MCQs and SEQs. The performance in MCQs and SEQs were compared. Also, the effects of JAMB scores and GCE O/level grades on the performance in both the MCQs and SEQs were assessed. The results showed that the students performed better in all MCQ tests than in the SEQs. JAMB scores and O' level English Language grade had no significant effect on students' performance in MCQs and SEQs. However O' level grades in Biology, Chemistry, Physics and Mathematics had significant effects on performance in MCQs and SEQs. Inadequate knowledge of physiology and inability to present information in a logical sequence are believed to be major factors contributing to the poorer performance in the SEQs compared with MCQs. In view of the finding of significant association between performance in MCQs and SEQs and GCE O/level grades in science subjects and mathematics, it was recommended that both JAMB results and the GCE results in the four O/level subjects above may be considered when selecting candidates for admission into the medical schools.

Antiulcerogenic effects of Tylophora conspicua in male rats

Studies were undertaken on the effect of a crude (TC) and an alkaloid fraction (TA) of the leaf extracts of Tylophora conspicua on indomethacin-induced gastric ulceration and gastric acid secretion in male albino rats. Both the TC and TA produced a dose-dependent inhibition of gastric ulceration. At a dose level of 40 mg/kg TC and TA were more effective (TA being more potent) than propranolol in inhibiting gastric ulceration. The highest dose of the extracts used (80 mg/kg) completely inhibited gastric ulceration. Intravenous administration of the TC and TA significantly decreased acid output at low dose (20 mg/kg), medium dose (40 mg/kg) and high dose (80 mg/kg) from the peak basal of 0.54 +/- 0.02 mEq/L/min to 0. 49 +/- 0.02 mEq/L/min, 0.35 +/- 0.01 mEq/L/min and 0.21 +/- 0.02 Meq/L/min respectively. 80 mg/kg of TC and TA significantly reduced the histamine (1 mg/kg) induced gastric acid secretion. The results suggest that the antiulcer activity of Tylophora conspicua might be produced by gastric acid inhibition.

Distribution of ABO and RH genes in Nigeria

Phenotype and gene frequencies of ABO and RH (D) systems were studied in 37,846 random blood donors in five zone of Nigeria (South West) (Yoruba)--Zone A, North West (Hausa-Fulani)--Zone B, Plateau (Birom)--Zone C, South East (Igbo)--Zone D and North East (Kanuri)--Zone E). We assessed the micro differences of genetic markers of ABO and RH blood groups between the ethnic groups in the ABO and RH blood group systems. Gene frequencies were ABO *O = 0.7068, ABO *A = 0.1490, ABO *B = 0.1443, RH *D = 0.8150 and results are similar to those earlier reported. Phenotype frequencies of the blood groups were in agreement with Hardy-Weinberg equilibrium expectations, except in two zones B and C where deviation was thought to be due to a high frequency of blood group AB.

Antifertility activity of Quassia amara in male rats - in vivo study

The crude methanol extract of the stem wood of Quassia amara. L. (A-1) significantly caused a reduction in the weight of the testis, epididymis and seminal vesicle, but an increase in that of the anterior pituitary gland. Epididymal sperm counts, serum levels of testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) were significantly reduced when the rats were treated with the extract. Furthermore the basal and LH-stimulated testosterone secretion of Leydig cells isolated from rats pretreated with the extract was inhibited. These changes seemed to be restored eight weeks after the withdrawal from extract treatments. Two compounds - quassin and 2-methoxycanthin-6-one were isolated after fractionation of A-1. Quassin produced similar biological actions as the crude extract while the effects of 2-methoxycanthin-6-one did not seem to differ from those of the control. Quassin appears to be the antifertility principle of Quassia amara.

Antifertility activity of Quassia amara: quassin inhibits the steroidogenesis in rat Leydig cells in vitro

The crude methanol extract of the stem wood of Quassia amara L. inhibited both the basal and LH-stimulated testosterone secretion of rat Leydig cells in a dose-dependent fashion. Fractionation of the extract by chromatography gave quassin (1) and 2-methoxycanthin-6-one (2); compound 1 proved to be the bioactive agent.

Methyl angolensate: the antiulcer agent of the stem bark of Entandrophragma angolense

Methyl angolensate (1), the major compound isolated from the methanol extract of the stem bark of Entandrophragma angolense produced a dose-related inhibition of gastric ulceration, 40 mg/kg body weight (B.W.) being more effective than 40 mg/kg B.W. of propranolol. The highest dose used (80 mg/kg B.W.) completely inhibited gastric ulceration and significantly reduced gastric acidity (P < 0.05). Furthermore, 1 (40 mg/kg B.W.) significantly reduced gastric acid secretion induced by histamine (1.0 mg/kg B.W.) and carbachol (1.0 mg/kg B.W.). These results suggest that 1 produces its antiulcer activity by inhibition of gastric acid secretion.