Faculty of Basic Medical Sciences

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    Bacterial Degradation of Carbazole and Microbial Diversity of Hydrocarbon-Contaminated Soils in a Tropical Environment.
    (2014) Salam, L.B
    Carbazole, an N-heterocyclic aromatic hydrocarbon is of environmental concern due to its persistence, recalcitrance, mutagenic and toxic activities. Degradation of carbazole has been reported since early 1990s, to lead to production of dead-end metabolites and hydroxylated carbazoles, which are released into the environment. However, angular dioxygenation of carbazole reported in very few bacteria genera, with hydroxylation at C1 and C9a carbons produces anthranilic acid and catechol as major metabolites, which are completely mineralized. Four bacterial strains with extensive degradation abilities on carbazole were isolated from three hydrocarbon-contaminated soils (Abandoned Coal Power Plant, ACPP; Mechanic Workshop, MWO and NEPA Substation, UNILAG, NESU) in Lagos, Nigeria. Physicochemical analyses of the soil samples indicate gross pollution of the soils with a high hydrocarbon content (157 g/kg) and presence of heavy metals (lead, nickel, cadmium). Phylogenetic analysis of the four strains indicated that they were Achromobacter sp. strain SL1 (AB646575.2), Pseudomonas sp. strain SL4 (AB646578.2), Microbacterium esteraromaticum strain SL6 (AB646579.2) and Stenotrophomonas maltophilia strain BA (AB646574). The rate of degradation of carbazole by the four isolates, after 30 days of incubation, were 0.057, 0.062, 0.036 and 0.050 mg l-1 h-1 for strains SL1, SL4, SL6 and BA, respectively. Gas chromatographic analyses of residual carbazole, after 30 days of incubation, revealed that 81.3%, 85%, 64.4% and 76% of 50 ppm carbazole were degraded by strains SLI, SL4, SL6 and BA, respectively. GC-MS and HPLC analyses of the extracts from the growing and resting cells of strains SL1, SL4 and SL6 cultured on carbazole revealed anthranilic acid and catechol, which were not detected in strain BA under the same conditions. The three strains (SL1, SL4, SL6) degrade catechol via the ortho pathway producing cis cis muconic acid as established by UV-Vis spectroscopy. Microcosm experiments with sterile and native soils amended with 100 ppm carbazole indicated carbazole removal rates of 66.96%-82.16% in sterile soils and 19.19%-91.64% in native soils by the test organisms. All four strains utilized a wide range of polycyclic and heterocyclic aromatic hydrocarbons. Clone library analysis of 16S rRNA recovered four hundred and thirty seven clones from MWO soil that cut across thirteen different bacterial phyla as revealed by RDP-II and NCBI. The representative bacteria phyla identified from MWO soil, using clone library analysis, were Proteobacteria, Bacteroidetes, Chloroflexi, Acidobacteria, Firmicutes, Actinobacteria, Verrucomicrobia, Planctomycetes, Chlorobi, Spirochaetes, Chlamydiae, TM7 and OD1. The clone library coverage indicates 42% of the library is covered at the species delineation with Shannon index of 5.59. This study has established carbazole angular dioxygenation and mineralization by isolates from a tropical environment. It also revealed the presence of novel bacterial genera contributing to natural attenuation of hydrocarbon pollutants in soil through clone library analysis
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    Biochemical Studies Of Secondary Metabolite Of Penicillium Chrysogenum Grown On Selected Agro-Wastes
    (School of Postgraduate Studies University of Lagos, 2012) ONYEGEME-OKERENTA, B.M.
    Selected agro-wastes found in Lagos, Nigeria (cassava peels, corncob, sawdust, and sugarcane pulp) were compared with glucose and lactose as microbial substrates for cultivating P. chrysogenum (wild strain). This study was designed to give added value to agro waste as substrates to cultivate P. chrysogenum and subsequent production of secondary metabolite with antibiotic and anticoagulant properties. In the growth studies, corn cob and cassava peels significantly (p < 0.05) produced the highest amount of mycelia weight. Corn cob yielded a mycelia weight of 0.15 ± 0.02 and 0.92 ± 0.04mg/ml on the third and ninth day respectively while cassava peels yielded a mycelia weight of 0.13 ± 0.07 and 0.12 ± 0.02mg/ml on the third and twelfth day respectively. Mycelia weight of the organism, in media containing glucose, sugar cane and lactose was 0.12 ± 0.02, 0.068 ± 0.05 and 0.055 ± 0.03mg/ml respectively, was highest on the ninth day. Sawdust gave the least growth with a mycelia weight of 0.07 ± 0.01mg/ml on the third day. Cassava media has the highest carbohydrate content. Changes in extracellular protein secreted into the different media (every 3days for 21days) shows that culture media containing cassava peels gave the highest protein peak of 0.38 ± 0.08 mg/ml on the sixth day, while corncob gave an early peak of 0.30 ± 0.03mg/ml on the third day. Sawdust gave two protein peaks, 0.15 ± 0.03 on the third day and 0.25 ± 0.01mg/ml on the twelfth day. A total protein yield of 0.2 ± 0.05, 0.08 ± 0.02, 0.06 ± 0.02 mg/ml respectively was obtained with glucose, sugarcane pulp and lactose containing media on the third day. The results suggest that cassava peels, corncob and sugarcane pulp could serve as cheap fermentation substrates for the growth of the fungus. Optimum pH and temperature of growth and antibiotic production was 6.5 and 25OC respectively. elected agro-wastes found in Lagos, Nigeria (cassava peels, corncob, sawdust, and sugarcane pulp) were compared with glucose and lactose as microbial substrates for cultivating P. chrysogenum (wild strain). This study was designed to give added value to agro waste as substrates to cultivate P. chrysogenum and subsequent production of secondary metabolite with antibiotic and anticoagulant properties. In the growth studies, corn cob and cassava peels significantly (p < 0.05) produced the highest amount of mycelia weight. Corn cob yielded a mycelia weight of 0.15 ± 0.02 and 0.92 ± 0.04mg/ml on the third and ninth day respectively while cassava peels yielded a mycelia weight of 0.13 ± 0.07 and 0.12 ± 0.02mg/ml on the third and twelfth day respectively. Mycelia weight of the organism, in media containing glucose, sugar cane and lactose was 0.12 ± 0.02, 0.068 ± 0.05 and 0.055 ± 0.03mg/ml respectively, was highest on the ninth day. Sawdust gave the least growth with a mycelia weight of 0.07 ± 0.01mg/ml on the third day. Cassava media has the highest carbohydrate content. Changes in extracellular protein secreted into the different media (every 3days for 21days) shows that culture media containing cassava peels gave the highest protein peak of 0.38 ± 0.08 mg/ml on the sixth day, while corncob gave an early peak of 0.30 ± 0.03mg/ml on the third day. Sawdust gave two protein peaks, 0.15 ± 0.03 on the third day and 0.25 ± 0.01mg/ml on the twelfth day. A total protein yield of 0.2 ± 0.05, 0.08 ± 0.02, 0.06 ± 0.02 mg/ml respectively was obtained with glucose, sugarcane pulp and lactose containing media on the third day. The results suggest that cassava peels, corncob and sugarcane pulp could serve as cheap fermentation substrates for the growth of the fungus. Optimum pH and temperature of growth and antibiotic production was 6.5 and 25OC respectively. UV xxx modification of parent strain produced two mutant strains with 70% increase in penicillin production. In vitro antibacterial activity of the culture extracts was tested against some clinical bacterial isolates, namely, B. subtilis, E. coli, P. mirabilis and P. aeruginosa. Commercial Benzyl Penicillin was used as reference drug. The culture extracts and standard drug inhibited the growth of B. subtilis and E. coli. Zone of inhibition varied with the carbon source. Culture extracts and reference drug were not effective against the isolates of P. aeruginosa and P. mirabilis because they produce β-lactamase enzymes which hydrolyse the β-lactam present in the extract and reference drug. Antibacterial activity of extracts from cultures containing cassava peels and sugarcane pulp compared positively with that of the standard drug. The Minimum inhibitory concentration (MIC) of the reference drug against the susceptible organisms was 0.2 - 0.4mg/ml. For the culture extracts, the MIC ranged from 0.4 to 2.0mg/ml. It was 0.4 - 0.8mg/ml for cassava peels and sugarcane pulp, 0.6 - 0.8mg/ml for glucose and lactose, 0.8 - 1.0mg/ml for corncob and 1.0 - 2.0mg/ml for sawdust. Toxicity study showed that the extract is safe for use as there were no visible changes or recorded deaths 48 - 72hours after administration of the extracts. Haematological evaluation showed a significant decrease (p<0.05) in platelet count for both the extract and reference drug in the sub acute toxicity study as well as in infection and inflammatory conditions. The extract was shown to have a potent antithrombic and anticoagulant activities against thrombin and whole blood respectively. Higher concentrations of the extract and reference drug caused an increase in whole blood clotting time. At 6mg/ml of the extract and 5mg/ml of the reference drug, clot formation was not observed. There was complete inhibition of thrombin coagulation at concentrations above 10 and 20mg/ml of the reference drug and extract respectively
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    Biological and Serological Studies on Toxoplasma Gondii in Lagos, Nigeria.
    (University of Lagos, 1987-03) Mensah, E.B
    Sera from 775 persons in 10 age-groups, living in Lagos metropolis, were titrated for Toxoplasma antibodies, using the haemagglutination test. The overall percentage positive was 63.2%. The highest (78.4%) was found amongst the age group ranging from 36-40 years, whilst the lowest (48.2%) was recorded in the age group 11-15 years. The risk of nonimmune persons acquiring infection was calculated in the different age group using Van Der Veen's equation. Venous blood samples, cord blood, as well as placental tissue were also collected from a total of 452 pregnant women who attended some antenatal clinics in Lagos. Of the 452 samples studied 60.18% were positive for Toxoplasma antibodies. 70.7% the cord blood specimen collected were also positive. Transmission pattern of toxoplasmosis employing cats was studied, as faecal samples of cats collected randomly from different areas of Lagos were analysed, using the Formol-Ether Concentration technique after Ritchie (1948) to detect the presence of oocysts. The cats were also bled for serological tests. Those found to be negative were fed acutely-ill mouse, and the course of development of the parasite was observed.The effect of Toxoplasma infection on pregnancy was observed using mice models, and it was found that when pregnant mice were experimentally infected, intraperitoneally within the different thirds of their gestation period, death occurred, beginning from the 11th to the 29th day, and not earlier. Toxoplasma gondii trophozoites were maintained in vitro in different fluid media, with pH values ranging from 6.3 to 7.3. The length in days before the death of the infected mice was recorded and it was related to the viability and number of surviving organisms in the suspension. A graph in survival time against preservation time (both in days) was then drawn. The maximum length of survival at 40C was in whole human blood, as well as in foetal Bovine Serum, for up to 56 days. The molecular weight of the proteins present in the RH strain of Toxoplasma gondii laboratory prepared antigen (after Voller et at., 1976) was determined by gel filtration onSephadex G200 chromatography column. The absorbance of the 3 fractions derived were read at 280 nanometers, and the molecular weights were determined by extrapolation from a standard curve of ve/vo against the molecular weights of 4 standard proteins. The molecular weights ranged from 12,445 to 186,209 daltons.
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    Changes in Cardiovascular Functions Haematologic and Metabolic Enzyme Activities in Sprague Dawley Rats Exposed to Petroleum Products.
    (2014) Azeez, O.M
    Increased blood pressure has been associated with exposure to petroleum products by inhalation or administration of contaminated water. The mechanism of action has however not been elucidated. This study was undertaken to investigate the effect of petroleum products on cardiovascular functions using three different routes of administration and the possible involvement of oxidative stress in the mechanism of action. Sprague Dawley rats were divided into four main groups; control, diesel (automotive gas oil), kerosene (dual purpose kerosene) and petrol (premium motor spirit). Each of the groups except control was subdivided into three; ingestion, inhalation and water contaminated groups; with 10 rats in each group and sub-group. The control was not exposed to any treatment. The diesel, kerosene and petrol sub-groups, were exposed to their corresponding contaminants via ingestion, inhalation and water contamination respectively. Each administration and exposure lasted eight weeks. The results showed that blood pressure and heart rate were significantly increased (p<0.05) in the treated groups when compared with control. However, there was insignificant reduced blood pressure in petrol ingestion group. The significant increase in the blood pressure and heart rate persisted one week after stoppage of exposure in all the groups; suggesting that exposure to petroleum products could cause hypertension; the effect could be as a result of the ability of petroleum products to cause sensitization of the vascular smooth muscle to catecholamines, elicited by impaired endothelium-dependent and -independent vasomotor function. Baroreflex response was significantly (p<0.05) increased in diesel and kerosene groups compared with control, however the increase in the petrol was only significant for a while and returned to the control level by 25 seconds. This suggests that with exposure to petrol the baroreceptors still reset the blood pressure to a new higher than normal value as though normal. The activities of baroreceptors have been altered by diesel and kerosene such that they could no longer reset the arterial blood pressure. Exposure to diesel was most deleterious in all except in the inhalation group. There was reduced body weight gain (p<0.05) in all exposed rats, which was most severe in the diesel group, when compared with control as well as kerosene and petrol groups. Exposure to petroleum products dissolved fat and lipid in the body causing degeneration of fat store. The reduced weight gain might also be associated with decreased food intake seen in the study especially the diesel group. Anaemia was implicated as there were significant (p<0.05) reductions in RBC, PCV, and Hb. Platelets and lymphocyte reduced significantly in diesel and petrol groups but not significant in kerosene groups. A significant increase in WBC was recorded in diesel, kerosene and petrol groups. Liver damage as a result of increased reactive oxygen species was more severe in the diesel ingestion group as Alanine amino transferase (ALT), Aspartate amino transferase (AST) and Alkaline phosphatase (ALP) increased significantly p<0.05) in all the groups. The results also showed significant increase in lipid peroxidation, as concentration of MDA increased significantly (p<0.01) in all the treated groups. Catalase (CAT), Glutathione reductase (GSH) and superoxide dismutase (SOD) activities were (p<0.05) reduced significantly in serum and tissue homogenate at varying proportions in the different groups. In the urine samples there was significant reduction in creatinine and urea value compared with control, while creatinine and urea in serum increased significantly suggesting renal function impairment. In conclusion, exposure to petroleum products resulted in increased blood pressure and heart rate; the baroreceptors were impaired by diesel and kerosene; caused anaemia, reduced platelets and lymphocytes and caused renal dysfunction. The severity of the effects was most severe in the diesel groups. This study suggests that afore-mentioned observations are partly caused by oxidative stress by altering the levels of CAT, GSH, SOD and MDA.
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    The Charactrization Antibiotic Susceptibility and Plasmid Profiles of Coagulase - Negative Staphylococci in Lagos
    (1999) Onubogu, C.C
    A total of 745 gram-positive, catalase-positive clustering cocci were obtained from various clinical specimens which included wound, blood, urine, catheter tips, high vaginal and endocervical swabs, urethral swabs, seminal fluids, bone secretions, eye and ear swabs. Thes isolates were obtained over an 18-month period from the Lagos University Teaching Hospital (LUTH), Idi-Araba, and General Hpspital, Ikeja. Swab samples were also obtained from skin, hands, axilla and nose of an apparently normal population and compared wtih isolated from clinical specimens. Isolation, and identification of coagulase-negative staphylococci (CoNS)were carried out using conventional methods. Characterisaction to species level was done using both conventional method and the APL rapid Commercial kit (ID 32 STAPH). The strains were tested for slime and beta-lactamase production. Other extracellular products tested for included DNase, lipase, protease, and gelatinase activities. Susceptibility to a range of antibiotics was tested and minimum inhibitory concentrations of some these antibiotics were determined. Some of these coagulase-negative staphylococci were screened for the presence of plasmids. A total of 244 isolates of coagulase-negative staphylococci were obtained, of which 241 were characterised to species level while 3 were unclassified. Staphylococcus epidermidis (109) was the most commonly isolated species from all the specimens. Comparing the conventional methods with the rapid commercial API kit (ID 32 STAPH), there was 98.8% specificity for the former and 95.9% specificity for the latter. A total of 40.50% were slime producers. Over one quarter (28.69%) of CoNS species showed lipase activity with greatest activity being shown by S. haemolyticus (54.17%). About 11.81% and 11% showed DNase and gelatinase activity respectively while 8.86% proteolytic activity. Betalactamase was detected in 69.5% of coagulase-negative staphylococci isolates. Majority of the isolates were multidrug-resistant to commonly used antibiotics. Some of the isolates harboured plasmids with molecuar weight ranging between 0.76 to 13.5 kilobase. Various findings reported in this study suggest that, coagulase-negative staphylococci can no longer be regarded as contaminants, but play a signirficant role in some infections in Lagos.
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    Contraceptive and Morphometric Effects of the Aqueous Extract of Carica Papaya Bark on Male Sprague Dawley Rats.
    (School of Postgraduate Studies University of Lagos., 2008) Kusemiju, T.O
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    Effects of Androgens in the Onset and Magnitude of Salt- Induced Hypertension in Male Sprague-Dawley Rats
    (2010-10) Oloyo, A.K
    Blood pressure is consistently higher in males compared with females from puberty onwards and men show an increased risk for hypertension compared to women. The gender disparity in cardiovascular functions and diseases has been linked to the effect of sex hormones on vascular reactivity. Although previous studies have suggested that the effect of chronic exposure to testosterone is an increase in vascular tone, it therefore implies that lack of testosterone should elicit vasorelaxation. Salt-sensitive hypertension in humans is associated with higher morbidity and mortality which may also be gender related. The role of gender in salt-sensitivity is not clear and the long-term effects of androgens on vascular reactivity especially in salt-induced hypertension have not been studied experimentally. Therefore experiments were designed to assess the effects of androgens on the development of salt-induced hypertension in male Sprague-Dawley rats by assessing vascular relaxation response to agonist as well as vascular smooth muscle histomorphology in orchidectomy-induced androgen deficient rats placed on a normal or high salt diet with or without testosterone supplementation. Weanling male Sprague-Dawley rats aged 8 weeks were divided into 8 groups of 16 rats each. They were either bilaterally orchidectomised or sham-operated under anaesthesia, with or without testosterone replacement (10mg/kg sustanon 250® i.m once in 3 weeks). They were placed on normal (0.3%) or high (8%) NaCl diet for 6 weeks. Arterial blood pressure was determined in conscious rats before and weekly throughout the experimental period using non-invasive tail cuff method. Terminal arterial blood pressure was also determined via femoral artery cannulation. Serum concentration of testosterone was determined using enzyme immunoassay (EIA) technique at the end of the feeding period. Thoracic aorta was isolated and 3mm aortic rings were suspended in organ baths and relaxation responses to acetylcholine (ACh), sodium nitroprusside (SNP) forskolin, diazoxide, testosterone and DHEA in the presence or absence of L- nitro-Arginine methyl ester (L-NAME), indomethacin, barium chloride, flutamide and Aminogluthetemide in noradrenaline pre-contracted rings were studied. Lipid peroxidation was studied in the heart and kidney homogenates using the TBARs method. The serum activity of super oxide dismutase (SOD) was also determined. Histological examination of thoracic aorta and mesenteric artery were carried out with specific dyes using haematoxylin and eosin stain for the cytoplasm and nucleus and Verhoeff – Van Geison and Picro-sirius red stains for elastin and collagen content estimation respectively. Histomorphometric analysis was determined using a programmed software IMAGE-PRO 3DS 6.1. The results indicate a significant increase (P < 0.001) in the mean arterial blood pressure (MABP) of rats placed on high salt diet (HSD), when compared with control or orchidectomised rats. Orchidectomy elicited a reduction in MABP while testosterone replacement normalized MABP to values seen in intact rats placed on high salt diet. High salt diet reduced relaxation response to ACh both in the presence and absence of eNOS inhibition with L-NAME. There was a significant decrease (P < 0.05) in the relaxation response to forskolin in rats placed on high salt diet when compared with controls. High salt diet reduced the relaxation response to diazoxide but not in orchidectomised rats while testosterone supplementation re-established the blunted diazoxide relaxation. The results also show a significant increase (P < 0.001) in lipid peroxidation of HSD groups compared with controls. Orchidectomy elicited a reduction in lipid peroxidation while testosterone supplementation returned it to the level observed in the intact groups. On the other hand there was a significant decrease (P < 0.01) in the serum level of SOD of the HSD groups when compared with controls, while orchidectomy increased the SOD activity, testosterone supplementation restored it to the level observed in the intact groups. Tunica media thickness and cross sectional area, elastin and collagen contents were all significantly elevated in the rats placed on high salt diet while orchidectomy significantly reduced the values of the parameters in high salt group but concomitant administration of testosterone restored them to the levels observed in intact rats. Both aromatase inhibition and androgen receptor blockade did not prevent the relaxing effect of testosterone on rings from rat aorta. There was also no significant difference between testosterone relaxation response in the presence or absence of L-NAME and indomethacin. However, 3µM BaCl2 almost completely abolished the aortic ring relaxation response to testosterone while 1 µM nifedipine potentiated the vasorelaxing effect of testosterone. The results indicate that in male Sprague-Dawley rats, endogenous testosterone promotes blood pressure-elevating effect of a HSD such that bilateral orchidectomy reduced the blood pressure and attenuated the impaired endothelial function induced by HSD. However ,this was reversed by concomitant administration of testosterone, suggesting a role for androgens in enhancing long term vascular smooth muscle tone and hence the maintenance of arterial blood pressure. Endogenous testosterone enhanced ROS-generating and promoted vascular hypertrophic effect of a HSD in the rats. On the other hand, exogenous testosterone relaxes rat aorta directly via a non-genomic pathway which is independent of endothelial derived vasoactive substances.
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    The Effects of Aqueous Leaf Extracts of Hybanthus Enneaspermus and Parquetina Nigrescens on Female Reproduction and Pregnancy Outcome in Sprague-Dawley Rats
    (2010-12) Awobajo, F.O
    There is dearth of scientific information on the effects of Hybanthus enneaspermus (HE) and Parquetina nigrescens (PN) on female reproduction, pregnancy and its outcome. Yet, these two medicinal plants remain the first line of medicinal plants commonly used by Traditional Birth Attendants in care of women before, during and after pregnancy in South-west Nigeria. The effect of aqueous leaf extract of Hybanthus enneaspermus (HEaq) and Parquetina nigrescens (PNaq) on female reproduction and pregnancy outcome were investigated using Sprague-Dawley rats. The acute oral lethal doses (LD50) for the two extracts were determined in Swiss albino mice, using moving average method and probit analysis. Extract administration was orally at a dose of 2g/kg body weight for four weeks for non-pregnant rats and for the duration of pregnancy in gravid rats. The effects of the two medicinal plants were separately examined on gravid and non-gravid female reproductive parameters. Parameters examined in non-pregnant rats include; oestrus cycle pattern and length, ovulation, female hormonal profile (follicle stimulating hormone (FSH), luteinizing hormone (LH), estrogen and progesterone), reproductive and other organ weight (uterus, pituitary gland, ovary, liver and kidney) , organ histology and body weight changes. The effects of the two extracts were also examined on the following parameters in pregnant-rats; maternal body weight, uterine muscle contraction, blastocyst implantation, placenta weight, haematological profile, fasting blood glucose, lipid and electrolyte profile, blood pressure, gestation length, litter size, weight at birth, and the presence of any birth defect. The LD50 value of 8.23 ± 0.35 gram/kg body weight for HEaq and 13.93 ± 0.10 gram/kg body weight for PNaq was calculated using probit analysis. Oestrous cycle was studied prior to and after extract administration by daily examination of the vagina smears under the microscope. xx Blood samples were collected after 12 hours fasting, at the different phases of the oestrous cycle via retro-orbital sinus or via cardiac puncture after cervical dislocation for haematological, lipid, electrolyte and hormonal study. Ovulation study was carried out at estrus by flushing the oviduct with normal saline and counting the ovum in the effluent under the microscope. Certified pregnant rats grouped into the HEaq and PNaq extract treated groups were gavaged the corresponding extracts from day one till the day 19 of pregnancy for implantation/ resorption study or a day prior to delivery day. Laparotomy was carried out on day 19 of pregnancy after cervical dislocation, and the uterus examined for implantation sites and resorption sites that are vascularised areas without implantation. Dose-response of the two extracts at graded concentrations was examined on fasting blood glucose level in non-pregnant rats to determine their effective hypoglycaemic doses (EHD). The effective hypoglycaemic doses were subjected to oral glucose tolerance test and compared with standard known hypoglycaemic agent (Glibenclamide). Further studies on the hypoglycaemic effects of the two extracts at a dose of 2g/kg body weight were also tested in pregnant rats. The LD50 for the two extracts was determined using probit after oral injection of doses ranging between 2.5 - 20 gram/kg body weight for PNaq extract and 4 – 32gram/kg body weight for HEaq extract. The two extracts were found to have a wide LD50 margin producing no significant disruption of the liver tissue architecture thoug the weights were increased. However, an amorphous deposit was noticed in the glomerulus. The two extracts significantly increased (p<0.05) the estrogen and FSH level at all phases of the oestrous cycle. The two extracts also increased the length of the fertile period (proestrus and estrous). This was because of the reduced LH level recorded at the proestrus and estrus phases of the cycle. The reduced LH also resulted in reduction in the number of ovum released at ovulation with resultant increase in number of atretic follicles as revealed by the histological study of the ovaries. Contrary to their use in folkloric medicine, the two extracts had no significant effect on maternal red blood cell count. However, Hybanthus enneaspermus increased while Parquetina nigrescens reduced the white blood cell count. Both extracts increased significantly (p < 0.05) the spontaneous isometric contraction of the myometrial tissue. There was a significant reduction (p < 0.05) in the number of implants in extract treated rats while the placenta weights, weights and size of the litter at 19th day and at birth were also significantly reduced in all extract treated groups. The two extract have no effect on maternal weight gain during pregnancy but the wet weight of important organ such as pituitary responsible for secretion of gonadotrophins was significantly reduced after extract administration. The two extracts had hypoglycaemic activities and hypotensive effect in pregnant rats. Although, the mechanism of action of aqueous leaf extract of Hybanthus enneaspermus and Parquetina nigrescens on female reproduction and pregnancy is not fully known, it can however be concluded that the extracts possess anti-fertility effect in female rats. This anti-fertility effect was expressed via the down regulation of the luteinizing hormone released. The two extract also possessed hypoglycaemic and hypotensive activities that can justify their use in correcting some pregnancy associated diseases such as preeclampsia and foetal macrosomia. In addition, both extracts increased the contraction of the myometrial strips from pregnant rats justifying their possible use in inducing labour when given to pregnant women towards term.
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    Effects of Diarrhoea on intestinal brush burder enzymes and protein nutritional status of the Rat
    (School of Postgraduate Studies of the University of Lagos, Akoka, 1993-02-02) Elemo, B.O
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    Effects of Exercise Training on Walking Function and Selected Cardiovascular Parameters of Adult Patients with Stroke
    (School of Postgraduate Studies, 2009-04) Olawale, O.A
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    Effects of Severe Burn Injury on Testicular Histology and Function in Sprague-Dawley Rats
    (2012-02) Jewo, P.I
    Burns are a common form of trauma, and have a high incidence in many countries. Though the majority of burns are mild, and are treated on an out-patient basis, a significant mortality and morbidity occur from burns. A WHO survey predicting burn mortality up to the year 2020 estimated a global annual death burden of almost 250,000. A full 95% of that number was expected to come from low and medium income countries (LMIC). However, over the past several years, mass burns with devastating consequences have occurred repeatedly from petroleum-related fires in Nigeria, an oil producing country. Thermal injuries elicit a systemic response involving several body systems especially the cardio-vascular, immune, and endocrine systems. Although the initial response involves haemo-vascular deficits and shock, a multifaceted response follows which involves changing endocrine priorities and alterations in the serum levels of a wide range of cytokines. Suppression of the hypothalamo-pituitary- organ axes is a key finding in the endocrine response to severe burns. There are also changes in several of the body’s physiologic parameters. An increasing number of studies have shown that severe burns can damage the mammalian testis and reduce spermatogenesis. Detailed characterization of histologic changes induced in the testis by severe burns is lacking. The mechanisms underlying observed testicular damage are still poorly understood, and in the reviewed literature no strategies for combating it have been put forward. The problem is largely due to the difficulty of getting testicular tissue from living victims of burns. Consequently, most published studies of the effect of severe burn on the testes have been carried out on tissues obtained at autopsy. This challenge was approached by investigating changes in epididymal semen parameters, anti-oxidant status and the histology of the testis. An animal model of Sprague-Dawley rats was used for the study. They were exposed to thermal injury across a broad range of burn severity including cases with chronic wounds with delayed healing. The effects of a variety of potential therapies were determined, namely: a balanced FSH/LH preparation, testosterone (T) alone and a combination of FSH/LH and testosterone. Studies of the potential benefits of ascorbic acid (AA), a broad spectrum free radical scavenger on burn-induced changes in testicular histology and function were also carried out. Burn injury caused a significant reduction in sperm density, motility and proportion of morphologically normal spermatozoa (P<0.01). Less dramatic changes occurred in hormone levels though in animals where there was chronic skin wound T level was significantly reduced even at 16 weeks (P<0.05). FSH and LH levels were reduced at 8 weeks. However in cases where the animals were kept for up to 16 weeks their levels were almost normal. Histopathological changes consisted of severe germ cell loss in seminiferous tubules of animals with severe burns. Sloughing of germ cells was also significantly higher in the groups with severe burns. In the case of animals with chronic skin wounds, many tubules had near complete destruction of germ cells leaving only basal cells intact. Burn injury caused severe seminiferous tubular damage, especially germ cell loss (p<0.05). This was matched by significant reduction in sperm density and percentage of histologically intact tubules (p<0.05). Burn injury also increased oxidative stress, with elevated malondialdehyde (MDA) levels (p<0.01) and caused changes in catalase and superoxide dismutase enzyme levels. Treatment with FSH, LH and T did not mitigate the anti-fertility effects of severe burns, whereas ascorbic acid treatment improved sperm parameters and significantly reduced histological evidence of testicular damage. It normalised MDA levels and attenuated changes in the levels of catalase and superoxide dismutase. Ascorbic acid treatment also significantly reduced histological damage to seminiferous tubules.
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    An enzyme linked immunosorbent assay (ELISA) for thyriglobulin antibodies
    (School of Postgraduate Studies of the University of Lagos, Akoka, 1992) Adedara, T.A
    An enzyme-linked immunosorbent essay (ELISA) has been developed for the quantitative analysis of thyroglobulin antibodies. The method is based on the detection of antibodies using enzyme-labelled antiglobulin.
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    Evaluation of HIV Testing Methods and Development of HIV Testing Algorithms in Lagos, Nigeria
    (School of Postgraduate Studies University of Lagos, 2007) Badaru, S.O
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    Experimental Infections of Biomphalaria Glabrata, B. Pfeifferi and B. Sudanica with Schistosoma Mansoni
    (University of Lagos, 1989) Wey, I.O
    A laboratory study was carried out to determine quantitatively the degree of compatibility between biomohalaria glabrata, B. pfeifferi and B. sudanica and Schistosoma mansoni. The effect of host diet and mode of exposure to miracidia, continuous darkness, origin of host species and parasite strains, miracidial dosage level, age and intensity of primary infection in dual infections were examined by measuring snail survival, growth, fecundity, prepatent period, infection rate and cercarial production. The results of experiments on host diet and exposure technique showed that individual exposure of B. glabrata snails to mircidia resulted in injection rates varying from 31% - 85% compared with a range of 6% - 22% obtained in mass exposed snails. Lettuce plus Tetramin and lettuce plus rabbit pellets were found to be superior diets to lettuce alone. Light-deprivation did not significantly reduce the survivorship, growth, fecundity and cercarial production of B. glabrata. The compatibility of large (1479.1mh), medium (493.5mg) and small 101.5mg) B. glabrata with S. mansoni was tested. Medium-sized snails were found to produce the highest average cercarial yield of 628 cercariae per snail per day compared to 377 cercariae produced by small and large snails respectively. This trend was confirmed in a subsequent modified replicate. An investigation of the compatibility between Sudanese B. pfeifferi, Ethiopian B. sudanica and Brazilain B. glabrata to Kenya and Brazilian strains of S. mansoni strain from Kenya. The highest infection rate (60%) and the highest cercarial yield (2792 cercariae per snail) were produced by this host-parasite combination. Exposure of B. glabrata to varying doses of miracidia ranging from 1 to 50 resulted in decreased cercarial production at miracidial densities above fifteen. Four different types of shell deformations were observed in addition to polyembryony and the production of eggmasses which were completely devoid of eggs and embryos.Superimposition of homologous miracidia on pre-existing S. mansoni infections was easily achieved in B. glabrata. However, the effect of superinfection on snail survival, growth, fecundity and cercarial production depended on the sequence of infection and the interval between infections. A challenge infection of five miracidia within an interval of one week, was found to enhance cercarial production and inhibit ovipository activity to a high degree (P < 0.001). On the contrary, snails which received a challenge infection of fifteen miracidia three weeks after a primary dose of five miracidia showed less evidence of ovipository inhibition and had a significantly reduced mean cercarial production (P < 0.05). The significance of the age of the primary infection is discussed.
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    Open Access
    Factors Associated with Pathogenicity and Antibiotic Resistance of Local Strains of Lancefield Groups A, C and G Streptococci
    (University of Lagos, 1989-11-07) Lawal, F.S
    Four thousand, three hundred and ninety five throat, 4,395 nasal and 58 skin lesion swabspecimens were examined bacteriologically out of which 401 (9.12%) were positive for betahaemolytic streptococci (BHS) and 11 (0.25%) for non-haemolytic streptococci (NHS). On the basis of Lancefield group polysaccharide antigens, the isolates were classified into groups A, C, D, G and non-groupable BHS strains. On the basis of bacitracin sensitivity and biochemical analysis, these groups and ungroupable HBS strains were classified into Strept pyogenes Strept. equisimilis, Strept. canis and Strept. milleri. Six members of group A, 68 of group C and 117 of group G BHS isolates were O (SLO), deoxyribonuclease B (DNase B), hyaluronidase, M-associated protein (MAP), serum opacity factor (SOF), proteinase, M,T and R protein antigens. These antigenic components were observed in varying percentages of the isolates: all (100.0%) the six members of group A were positive for SLO and MAP, five (83.3%) for DNase B and hyaluronidase, three (50.0%) for SOF and four (66.6%) for proteinase activity; 41 (60.29%) of group C for SLO and MAP, 52 (76.47%) for DNase B, 56 (82.35%) for hyaluronidase, and nil (0.0%) for both SOF and proteinase while 68 (58.11%) of group G produced SLO, 94 (80.34%) DNase B 56 (47.86%) hyaluronidase, 104 (88.88%) MAP and nil (0.0%) for SOF and proteinase. The ultimately established group C serotype CI and group G serotypes GI - VIII examined for both indigenous and group A - cross - reacting T4 or T25 - antigen showed evidence of these antigens as follows: both serotypes CI and GI showed their indigenous T-antigen and group A cross-reacting T25 and T4 respectively, while serotypes GII - VIII showed indigenous Tantigens only. Varying proportions of those BHS strains (8: 68 for group C and 68: 117 for group G) that produced high ( > 1:80) titres of MAP were studied further. Six members of group C and 19 of group G were ultimately selected as vaccine strains for antisera production in rabbit. Five of the six members of group C and 17 out of 19 of group G successfully produced corresponding type antibodies. Distinct type antisera, one for group C and eight for group Gcorresponding respectively to group C (serotype CI) and group G (serotypes GI - VIII) eventually emerged after absorption with appropriate group C or group G heterologous strains. Other type antisera and their corresponding typeable vaccine strains turned out to be homologous to other group C or group G types. These group C and group G antisera were initially used in parallel with group A type 12 (G 12) and group G strain 51/755 antisera (controls) to screen Lancefield's extracts of 86 group C isolates and 152 group G isolates respectively for evidence of M or R like type antigen. Twelve (13.65%) of the 86 group C and 75 (50.33) of 149 group G isolates could be M-serotyped while none (0.0) showed evidence of R-like antigen/antibody activity. The remaining 76 (86.36%) group C and 74 (49.66%) group G isolates could not be serotyped with the available antisera. Twenty (Co5T'S'). The three patterns occurred in varying percentages of 63.48 (353/556), 33.27 (185/556) and 3.25 (18/556) respectively. Representative strains of the three antibiotic susceptibility patterns, Co5 S' T', Co5 S' T5, and Co' S' T' were observed further to show varying (80 - 0.62 ug/ml) rages of minimum inhibitory concentrations (MIC) of chloramphenicol co-trimoxazole, erythromycin, penicillin G, streptomycin and tetracycline for the three antibiotic - susceptibility patterns, which in the case of chloraphenicol, co-trimoxazole, erythromycin and penicillin G correlated with in vitro susceptibility and in the case of streptomycin and tetracycline correlated with in vitro resistance of the BHS isolates tested against the six antibiotics. The three representative patterns were further screened for evidence of antibiotic - resistance factors, plasmid deoxyribonucleic acid and beta-lactamase for which none of the isolates was positive.