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Biomedical subjects

G C Onyemelukwe

Publications and source records attributed to G C Onyemelukwe.

At least 19 recordsLinked to original sources
PubMed2003

Sildenafil citrate (Viagra) for the treatment of erectile dysfunction in Nigerian men.

Fifty-eight Nigerian outpatients with documented erectile dysfunction (ED) received open-label sildenafil citrate (Viagra) for 8 weeks. The 50-mg starting dose could be adjusted to 100 or 25 mg based on response and tolerability. The International Index of Erectile Function (IIEF) Questionnaire, a global efficacy question, and intercourse data recorded in a patient event log were used to assess efficacy. Frequency of penetration and maintained erection were both significantly enhanced (P<0.0001); 95% of patients reported improved erections and 81% of all attempts at intercourse were successful. Orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction also improved significantly (P&<0.0001). The most frequent adverse events (all-cause) were headache (17%) and myalgia (3%); only one patient discontinued treatment because of headache, which was considered unrelated to sildenafil. Oral sildenafil significantly improved erectile function and was well tolerated in this trial of Nigerian men suffering from ED. Our results are consistent with reports from other countries.

Adult↗
PubMed2002

CD4+ and CD8+ lymphocytes and clinical features of HIV seropositive Nigerians on presentation.

Eighty of 200 HIV seropositive patients admitted in the medical wards of Ahmadu Bello University Teaching Hospital, Zaria from year 1995 to 1997 were studied on presentation and compared to 40 age and sex matched controls. The main clinical features observed included weight loss, pyrexia, diarrhoea, lymphadenopathy, anaemia and pruritic dermatosis. Sixty-two of the 80 patients (73.2%) presented at stages 3 and 4 of WHO Clinical and Laboratory staging. Thirty (30) percent of these patients died between a period of one to four months after presentation. The main diseases complicating HIV infection at presentation of the 80 patients were Mycobacterium tuberculosis infection (30%), acute bacterial infections (with Salmonella typhi, Streptococcus pneumoniae and Staphylococcus aureus) (24%), candidiasis (14%) and Kaposi sarcoma (2%). Seropositivity for HIV types was found to be HIV-I alone in 43.5% of cases; HIV-II alone in 14% and both HIV-I and II in 42% of cases. Risk factors associated with HIV infection were multiple sexual partners (73%), sexually transmitted disease (70%), and unscreened blood transfusion (1%). HIV positive patients had a mean CD4+ T-cells of 0.24 x 10(9) +/- 0.17 which was significantly lower than the mean of 0.6 +/- 0. 17 x 10(9)/L for controls (P < 0.05 students t-test). Thirty (35%) of the patients had CD4+ counts of less than 0.2 x 10(9)/L (200 cells/microl) at presentation. The mean CD3+ lymphocytes count was 0.51 +/- 0.24 x 10(9)/L for patients and 1.04 +/- 0.71 x 10(9)/L for controls. The mean CD8+ lymphocyte count in patients was 0.29 +/- 0.19 x 10(9)/L and 0.44 x 10(9)/L for controls. Both CD3+ and CD8+ lymphocyte populations were statistically lower in patients than controls (P < 0.05).

AIDS-Related Opportunistic Infections↗
PubMed2001

T-lymphocyte subsets in patients with hookworm infection in Zaria, Nigeria.

Peripheral lymphocyte subsets CD3, CD4, CD8 were studied using monoclonal antibodies to determine the mechanism of immunosuppression observed in an earlier study with total T-cells using the sheep erythrocyte rosetting technique. The study was carried out in 37 Nigerian patients with hookworm infection (Necator americanus and Ancylostoma duodenale and 17 healthy Nigerians as controls. The leucocyte migration inhibition (LMI) test was also carried out to assess the functional integrity of the lymphocytes, while the hookworm status of the patients was assessed by the Stoll technique for measuring egg counts. The results of the T-cell studied showed that CD3 and CD4 cell percentages were significantly depressed in hookworm patients compared to controls (P<0.05). The difference between mean CD8 percentages and absolutes in hookworms patients and controls were not significant. Absolute CD3 and CD4 numbers were not significantly lowered compared to controls in the study and CD4/CD8 ratios were insignificantly reduced. Patients with polyparasitism including hookworm infection showed significant reduction in CD3 and CD4 cells when compared with controls and with patients with hookworm infection alone. The leucocyte migration inhibition response to purified protein derivative of M. tuberculosis (PPD) was significantly decreased in hookworm patients compared to controls, confirming that functionally cell mediated immunity is depressed in hookworm infection.

Adolescent↗
PubMed2001

Snake bite in Nigeria.

Four families of venomous snakes are found in Nigeria--Viperidae, Elapidae, Colubridae and Actraspididae but three species carpet viper (Echis ocellatus), black-necked spitting cobra (Naja nigricollis) and puff adder (Bitis arietans), belonging to the first two families, are the most important snakes associated with envenoming in Nigeria. The incidence of bites has been reported as 497 per 100,000 population per year with a 12 percent natural mortality, with Echis ocellatus accounting for at least 66 percent in certain foci. Bites occur more often while victims were farming, herding or walking although the spitting cobra may bite victims who roll upon it in their sleep. Carpet viper venom contains a prothrombin activating procoagulant, haemorrhagin and cytolytic fractions which cause haemorrhage, incoagulable blood, shock and local reactions/ necrosis. The spitting cobra bite manifests with local tissue reaction and occassionally with bleeding from the site of bite, but no classic neurotoxic feature has been observed except following Egyptian cobra (N. haje) bites. Cardiotoxicity and renal failure may occassionally occur following bites by the carpet viper and the puff adder. In the laboratory, haematological and other features are noted and immunodiagnosis has a role in species identification. Immobilisation of the bitten limb is probably the single most important first aid measure. Antivenom should be used cautiously when indicated. As only 8.5 percent of snake bite victims attend hospitals in Nigeria, health education should be the main preventive measure, mean-while, the study of immunisation of occupationally predisposed individuals in endemic areas should be intensified. A new Fab fragment antivenom specific to Nigerian Echis ocellatus was investigated clinically, just as the local herbs-Aristolochia spp, Guiera spp and Schummaniophyton spp are investigated experimentally.

Animals↗
PubMed2000

Secretory IgA and complement levels in patients with hookworm infection in Zaria.

As a continuing investigation into the immunological reactions involved in hookworm infection the levels of secretory IgA (sIgA). IgM, IgA, complement C3 and C4 were studied in 57 Nigerians with hookworm infection and compared with those of 28 healthy, normal controls. The hookworm patients were divided into three groups based on the degree of anaemia (Hb1-7 and hypochromia +++). Group II had moderate anaemia (Hb8-11, hypochromia ++ and Group III had no signs of anaemia despite the underlying hookworm infection. The patients also comprised those in whom hookworm was the sole infection and those with hookworm associated with other parasites. Significant differences in the results between each patient subgroup and the controls were analysed using the student t-test. IgA was significantly elevated in patients with anaemia of mild to moderate severity and in patients with hookworm only (P < 0.05) while sIgA was significantly elevated in all subgroups compared to controls (P < 0.05). IgM was significantly elevated in-patients with marked anaemia, in-patients without anaemia and in those with hookworm infection associated with other parasites (P < 0.05). The difference in IgG levels between patients and controls was not significant (P 0.1). C4 was significantly elevated in patients with marked moderate anaemia and those with hookworm only (P < 0.05) while C3 levels were not significantly different in the subgroups compared with controls. These results suggest the possibility of polyclonal B-cell activation by T-independent antigens such as the polysaccharide cuticular antigens of the hookworms and the stimulation of the classical pathway of the complement system.

Adolescent↗
PubMed1995

Pregnancy associated alpha-glycoprotein (SP-III) in Nigerian pregnant women.

Pregnancy associated protein (SP-III) was measured by rocket electroimmunoassay in the sera of Nigerian women with normal and abnormal singleton pregnancy. A tendency to increases of SP-III levels with advancing gestational age was observed. SP-III may contribute to immunosuppression in preventing anti-allograft responsiveness and levels may also reflect the effect of infections since SP-III is also leucocyte derived. Values in PET and anaemia in pregnancy were similar to values in normal pregnant women.

Adolescent↗
PubMed1994

Immunosuppression in Nigerians with hookworm infection.

T rosette cells results in patients with (Necator americanus and Ancylostoma duodenale) hookworm infection, divided into groups on the basis of the degree of anaemia (Group I had marked anaemia Hb 1-7, hypochromia ), Group II had moderate anaemia (Hb 8-11, hypochromia ++) and Group III had no signs of anaemia despite the underlying hookworm infection), were compared with results in 28 healthy controls who had no signs of other infection and excreting no ova of hookworm or other parasites. The level of sheep erythrocyte rosette-forming T-lymphocytes (SE-TL) in the patients (Group I:42 +/- 8%; Group II:45 +/- 11%; Group III:47 +/- 6%) was markedly reduced compared to controls (58 +/- 13%) (P < 0.001). The leucocyte migratory responses to purified protein derivative (P.P.D); were significantly (P < 0.05) reduced in all the subgroups as compared with the controls. The results support the hypothesis of the existence of immunosuppression in patients with hookworm infection.

Adolescent↗
PubMed1992

Anti-thrombin III deficiency in Nigerian children with sickle cell disease. Possible role in the cerebral syndrome.

A prospective study of Nigerian children with sickle cell disease was undertaken to determine serum levels of antithrombin III (AT-III) and compare these with normal controls. Mean serum AT-III was significantly lower in patients than in controls (14.51 +/- 4.84 mg/dl and 17.75 +/- 5.92 mg/dl) respectively. Seven of the 49 sickle cell patients had AT-III levels below 50% of normal values. Mean platelet counts were significantly higher in sicklers than in normal controls. AT-III deficiency may predispose to thrombotic complications in children with sickle cell disease.

Acute Disease↗
PubMed1991

Population variation in molecular polymorphisms of the short arm of the human X chromosome.

Five DNA probes (RC8, 754, XJ 1-1, pert 87.8, and L1.28) from the short arm of the human X chromosome were investigated in samples from five populations (English, Nigerian, Chinese, Muslim, and Hindu from India). The variation in the allele frequencies of several probes between different groups was significant. The average heterozygosity in females of the five populations ranged from 32% to 51%. The genetic distance between the five groups was compatible with that using traditional polymorphic systems. There is an interesting suggestion of longitudinal cline for allele *2 (9 kb) detected with probe L1.28. The X-linked RFLPs are useful genetic markers for anthropological studies.

Alleles↗
PubMed1991

Renal function in non-insulin dependent--diabetes mellitus.

Creatinine clearance, urinary specific gravity after water deprivation and fractional excretion of sodium, potassium and phosphate were measured in 28 patients with uncomplicated non-insulin dependent diabetes mellitus. Defective concentrating capacity was found in 46pc of the patients and 21pc had decreased glomerular filtration rate. Renal handling of sodium was normal in the patients but they showed a tendency for renal retention of potassium. Glycosuric patients showed marked phosphaturia.

Diabetes Mellitus, Type 2↗
PubMed1990

The effect of short-term malaria chemoprophylaxis on the immune response of semi-immune adult volunteers.

In 17 semi-immune adult volunteers, chemoprophylaxis with 300 mg chloroquine base weekly for six months was found to be effective in suppressing malaria. However, following 3 months of chemoprophylaxis, a significant reduction of IFA titres was seen lasting up to 2 months after chloroquine withdrawal. There was resurgence of malaria in the post-intervention phase. 2 months after drug withdrawal, serum concentrations of IgG and factor B were significantly reduced. 3 months after initiation of chloroquine prophylaxis, a temporary but significant decrease of IgG and IgM serum concentrations was found with a corresponding decline in the number of B-lymphocytes and regulatory T-cells. These returned to normal at 6 months of chemoprophylaxis. Our findings suggest that short-term malaria chemoprophylaxis may significantly interfere with humoral and cell-mediated immunity in areas of intensive P. falciparum transmission.

Adult↗
PubMed1990

Properdin factor B allotypes in diabetic Nigerians. A preliminary report on chromosome 6 markers.

Properdin factor B(Bf) allotypes were determined in patients with insulin dependent (type 1) diabetes mellitus (n = 15); in patients with non-insulin dependent diabetes mellitus n = 15); and in healthy Nigerians (n = 252) from various tribal groups. In all three groups only commonly reported Bf allotypes namely BfF, F1, S and S1 were observed. More important, BfF1 allele was significantly increased in patients with insulin dependent (type 1) diabetes mellitus (expected 1/15, observed 5/15), X2 = P less than 0.005). It is suggested that this allele is probably the same as that reported in caucasoids and is part of a supratype or ancestral haplotype defined by HLA-B18, C4A3, C4A3, BQo, BfF1, DR3 marking type 1 (insulin dependent) diabetes mellitus.

Adolescent↗
PubMed1989

Antithrombin III in Echis carinatus envenomation in northern Nigeria.

Antithrombin III was evaluated in 21 patients admitted with Echis carinatus envenomation. Although there was evidence of incoagulability in all patients and elevated fibrin degradation products, mean antithrombin III levels were found to be significantly greater than in controls. This result suggests that Echis carinatus venom (echarin) may bypass the consumption of antithrombin III molecules.

Adult↗
PubMed1989

Alpha-1-antitrypsin, immunoglobulins and radiological type in Nigerians with pulmonary tuberculosis.

Tuberculin skin test tended to be more intensely reactive in the caseonodular and other groups than the military group. Serum IgA, IgG and IgM and alpha-I-antitrypsin levels were higher in Northern Nigerians with pulmonary tuberculosis than in controls. IgA and IgG levels were higher in miliary tuberculosis than caseonodular and cavitating tuberculosis. The cavitatory lesions in tuberculosis may not result from autodigestion by inflammatory proteases since alpha-I-antitrypsin-the major inhibitor of proteases was not deficient in cavitatory tuberculosis. While an unqualified immunological spectrum of tuberculous disease in our patients has not clearly been demonstrated due to limited facilities, our results show a tendency to this spectrum.

Adolescent↗
PubMed1989

Complement components in Nigerians with bronchial asthma.

Serum complement components C1q, C3, C4, factor B, and C3d breakdown products were measured in asthmatic Nigerians and in age-matched and sex-matched controls. C3 mean level was higher than in controls while C1q and C4 mean levels were lower than in controls. High levels of C3d in asthmatic patients suggest the possible role of C3a and C5a anaphylatoxins in the etiopathogenesis of perennial asthma in Nigerian patients in a tropical environment with ubiquitous airborne allergens and infective agents. The significantly elevated levels of IgM and IgG may suggest recurrent respiratory challenge of perennial antigens in our environment.

Adult↗