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Articles by R.A. Umar
Total Records ( 12 ) for R.A. Umar
  R.A. Umar , S.W. Hassan , M.J. Ladan , I.K. Matazu , B. Shehu , R.A. Shehu , L.G. Muhammed and F.I. Molabo
  We studied the effects of acute and sub-chronic oral administration of nevirapine, lamivudine and stavudine on liver function in albino rats. Acute administration of nevirapine resulted in significant (p<0.05) increases in activities of Aspartate amino transferase (AST) and Alanine amino transferase (ALT). Total proteins, albumin and globulin were significantly lowered. Upon sub-chronic administration of nevirapine, only AST and ALT activities were significantly raised. Acute administration of lamivudine was associated with significantly (p<0.05) lower albumin and globulin and higher total bilirubin and conjugated bilirubin levels. There were no significant differences (p>0.05) in liver function profiles associated with sub-chronic administration of the drug. However, acute and sub-chronic administrations of stavudine were not associated with significant (p>0.05) changes in liver function profiles. We conclude that while the use of stavudine is safe, acute and sub-chronic oral administration of nevirapine and lamivudine are associated with hepatotoxicity and hepatoprotective agents should be incorporated in the treatment regimens employing these drugs to avert life-threatening complications.
  S.W. Hassan , M. Lawal , B.Y. Muhammad , R.A. Umar , L.S. Bilbis and Y. Saidu
  The anthraquinone glycosides composition and toxicity studies of isolated anthraquinone glycosides and aqueous ethanol stem bark extracts of Ficus sycomorus on rat liver and kidney functions were conducted. The yield of anthraquinone glycosides in 40 g powdered stem bark extract was 16.0% (w/v). Liver and renal indices were significantly (p<0.05) changed at higher doses of 617.86, 988.57 (anthraqiunone glycosides), 767.80 and 1228.60 mg kg-1 body weight (aqueous ethanol extract). Dose dependant decrease in weight (p<0.05) was observed in the rats administered higher doses of the aqueous ethanol and anthraquinone glycosides extracts. The results suggest that extracts of Ficus sycomorus cause adverse effects to liver and kidney at higher doses.
  R.A. Umar , M.J. Ladan , S.W. Hassan , Y. Sa`id , A.Y. Abbas and I.B. Oduolisaeme
  The sub-Saharan African region is home to the greatest burden of Human Immunodeficiency Virus infection and Acquired Immunodeficiency Syndrome (HIV/AIDS). Appropriate management of infectious diseases is the most cost effective intervention to reduce the burden of disease. Highly Active Anti Retroviral Therapy (HAART) is the mainstay for inhibiting the multiplication of the causative agent and improving quality of life of the victims. There is some doubt in the region regarding the safety of the drugs in the anti AIDS pharmacy. Local studies on the safety of these agents are few. We studied the effects of acute and sub-acute oral administration of Lamivudine, Nevirapine and Stavudine on haematological profiles in albino rats. The rats were administered acute and sub-acute doses of Lamivudine, Nevirapine and Stavudine. Packed Cell Volume (PCV), total white blood cell count and differentials were determined by standard haematological methods. There were no significant differences (p<0.05) in the parametres except in PCV, eosinophils, neutrophils and leucocyte count associated with nevirapine and leucocytes and eosinophils associated with lamivudine. We conclude that acute and sub-acute oral administration of these drugs is associated with few haematological abnormalities and is therefore safe.
  M.J. Ladan , R.A. Umar , S.W. Hassan and B. Shehu
  Diabetes is a clinical syndrome characterized by hyperglycemia due to absolute or relative deficiency of insulin. The hyperglycemia is associated with various forms of dyslipidemia, all of which are established risk factors for cardiovascular disease. Recent studies indicate that tight glycemic control and administration of cholesterol lowering agents among others are beneficial to diabetic patients. Data are lacking on the impact of treatment on glycemic status and lipid profiles of Nigerian diabetics. We studied the levels of fasting blood glucose, total cholesterol, High-Density Lipoproteins (HDL), Low-Density Lipoproteins (LDL) and triglycerides in 46 diabetics (on treatment) and ten treatment naive diabetics. Eighty apparently healthy individuals, matched for age, formed the controls. Serum glucose was determined by glucose oxidase kit method, total cholesterol by Trinder’s method, HDL and LDL by quantitative precipitation with phosphotungstate in the presence of Mg2+ ions and triglycerides by enzymatic method. Glucose and total cholesterol levels were 14.5±9.8 and 11.5±3.5 mmol L-1, 214.4±40 and 166.8±36 mg dL-1 for treatment naive and diabetics on treatment, respectively. Both were significantly higher (p<0.05) than in the controls. LDL and triglycerides levels were significantly higher (p<0.05) in the diabetics than in the controls. There was no significant difference (p>0.05) in the mean HDL levels between the diabetics and the controls. All the parameters were significantly higher (p<0.05) in the treatment naive diabetics. The results suggest that treatment has profound positive effect on the indices of diabetes and that strict glycemic and lipidemic control have not been achieved in the patients we studied.
  S.W. Hassan , R.A. Umar , I.K. Matazu , H.M. Maishanu , A.Y. Abbas and A.A. Sani
  The effect of sun, oven and solar drying on the nutrients and non-nutrients composition of leaves of Leptadenia hastata was investigated. All the drying methods were found to significantly decrease (p<0.05) magnesium content in sun (1.49±0.49 mg 100 g-1), followed by oven (1.27±0.06 mg 100 g-1) and the lowest in solar dried (0.93±0.07 mg 100 g-1) leaves compared to fresh sample. Drying methods with exception of oven drying did not significantly (p>0.05) lower lipids content. The drying processes employed significantly (p<0.05) decreased carbohydrate, crude protein, magnesium and moisture content. Potassium, ash and crude fibre were significantly (p<0.05) increased. Oven drying significantly reduced acid value (2.82±0.41%), followed by sun (2.12±0.65%) and solar drying (1.76±0.21%) in decreasing order. Tannins, saponins, volatile oils, saponin glycosides and alkaloids were detected in fresh and dried samples. These compounds with exception of saponins and saponin glycosides (sun and oven dried) decreased in trace amounts upon drying. The results reinforce the growing awareness that the leaves of Leptadenia hastata can contribute useful amounts of nutrients to human diets and reduction of toxic non-nutrients compounds upon drying.
  R.A. Umar , S.W. Hassan , M.J. Ladan , M. Nma Jiya , M.K. Abubakar and U. Nata`ala
  The aim of this study was to evaluate the association of K76T mutation in Pfcrt gene and chloroquine treatment failure following reports that the efficacy of chloroquine in the treatment of uncomplicated falciparum malaria in Africa is seriously compromised by high levels of drug resistance. The occurrence of mutation on codon 76 of Plasmodium falciparum chloroquine resistance transporter (Pfcrt) gene has been associated with development of resistance to chloroquine. We investigated the association of K76T mutation in Pfcrt gene in malaria-infected blood samples from a cohort of Nigerian children with uncomplicated falciparum malaria treated with chloroquine and its association with clinical (in vivo) resistance. The Pfcrt T76 allele was very significantly associated with resistance to chloroquine (Fischer exact test: p = 0.0001). We conclude that K76T mutation in Pfcrt gene is significantly associated with chloroquine resistance and that it could be used as a population marker for chloroquine resistance in this part of the country.
  S.W. Hassan , M. Lawal , B.Y. Muhammad , R.A. Umar , L.S. Bilbis , A.A. Ebbo and Y.U. Dabai
  The column chromatographic fractions of chloroform (CHL1, CHL2 and CHL3) root extracts of Boscia angustifolia were screened for antibacterial activity and phytochemical properties. CHL1 fraction was significantly active (p<0.05) at 5 to 60 mg L-1 on Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Streptococcus pneumoniae with Minimum Inhibitory Concentration (MIC) of 0.63 to 1.25 mg L-1. The active fraction (CHL1) revealed the presence of only alkaloids with Retention factor (Rf) value of 0.36. The active antibacterial agent in the most potent fraction (CHL1) was isolated and identified by thin layer chromatography (TLC) and phytochemistry. The CHL2 and CHL3 fractions did not show inhibitory activity at 5 to 60 mg L-1. The antibacterial activity of root extract of Boscia angustifolia is due to a chloroform-extractable compound. The results support the ethnomedicinal use of root of Boscia angustifolia for the treatment of bacterial diseases.
  S.W. Hassan , R.A. Umar , Y.U. Dabai , A.A. Ebbo and U.Z. Faruk
  The aqueous and organic solvent leaves extracts of Pteridium aquilinum were screened for antibacterial activity by hole-in-plate bioassay procedure. The effect of aqueous leaves extract of the plant on hepatorenal functions in rabbits was also studied. Hexane (HX) fraction at 10 to 120 mg mL-1 did not show activity against Escherichia coli and Pseudomonas aeruginosa. However, it was significantly (p<0.05) active against Staphylococcus aureus at 90 and 120 mg mL-1. The chloroform (CHL) extract fraction at concentrations of 50-120 mg mL-1 was significantly (p<0.05) active on all the bacterial species. Petroleum ether (PE) at 10-120 mg mL-1 showed significant (p<0.05) inhibition of S. aureus and E. coli. Aqueous (W) extract exhibited significant inhibitory activity at 50-120 mg mL-1 on S. aureus and P. aeruginosa. Tannins, anthraquinone glycosides, cardiac glycosides, cyanogenic glycosides and volatile oils were detected in the extracts. The lethal dose (LD50) of the aqueous leaves extracts was found to be greater than 3000 mg kg-1 (p.o.) in rabbits. Non significant (p>0.05) and significant (p<0.05) changes in renal and liver indices, respectively were observed. Aqueous leaves extract of Pteridium aquilinum is toxic to the liver of rabbits only at 1500-3000 mg kg-1. These results have provided scientific evidence to justify the indigenous use of the plant against infectious diseases.
  S.W. Hassan , M.G. Abubakar , R.A. Umar , A.S. Yakubu , H.M. Maishanu and G. Ayeni
  Leaf extracts of Kingelia africana were evaluated for wound healing, antibacterial, toxicological and chemical properties. Antibacterial activity was done using hole-in-plate bioassay, wound healing by circular incision, toxicological and chemical properties were evaluated using standard methods. The results show a more rapid wound healing at all the hydromethanolic concentrations employed than 90 mg mL-1 of procaine penicillin on the 4, 7, 10, 13, 16 and 19th day. Exudation was more prominent in control and antibiotic treated groups compared to other groups on day 2 of wounding. Clinical features revealed redness, exudation, scab formation and other changes. The aqueous and organic solvent leaf extracts exhibited significant (p<0.05) antibacterial activity against Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli at concentrations ranging from 30 to 120 mg mL-1. Most of the hepatorenal indices were significantly (p<0.05) increased at doses of 2000 to 4000 mg kg-1 indicating compromised functions of these organs. The lethal dose (LD50) of the leaf extract was greater than 3000 mg kg-1. Alkaloids (9.80±0.20), tannins (22.80±0.05), saponins (8.85±0.50), flavonoids (7.80±1.00% w/v), glycosides, saponin glycosides, steroids and anthraquinones were detected. Low values of sodium (6.5±0.01) potassium (3.1±0.01), magnesium (0.126±0.03), phosphorus (2.04±0.04) and calcium (0.108±0.01 mg%) were observed. The results show that leaves extracts of K. africana could be cautiously used and also provide support for the traditional use of the plant in treating bacterial diseases and wound healing due to its chemical constituents.
  S.W. Hassan , M. Lawal , B.Y. Muhammad , R.A. Umar , L.S. Bilbis , U.Z. Faruk and A.A. Ebbo
  The in vitro antifungal activity and phytochemical properties of column chromatography fractions of Hexane (HX), Petroleum Ether (PE) and Chloroform (CHL) of stem bark of Ficus sycomorus were studied. The bioactive agent in the most potent fraction with antifungal properties was isolated and identified by preparative Thin Layer Chromatography (TLC) and phytochemical analysis. The hexane fractions (HX2 and HX3) were significantly active (p<0.05) at 0.31 to 5.63 mg mL-1 on Microsporum gypseum, Aspergillus niger, Aspergillus flavus and Candida albicans. The fractions revealed the presence of Steroids (STR), Condensed Tannins (CDT), Cardiac Glycosides (CG) and Saponins (SAP). The HX4 fraction was the most potent, exhibiting complete inhibitory activity against all the fungal isolates tested. The fraction contained Anthraquinone Glycosides (ATG) with Retention factor (Rf) value of 0.87. All the PE fractions (PE1, PE2 and PE3) did not exhibit significant activity on the fungal isolates at 0.31 to 3.75 mg mL-1. The CHL fractions (CHL1 and CHL2) showed very high inhibitory activity on only Trichophyton mentagrophytes and Trichophyton rubrum. The phytochemical analysis of these fractions revealed the presence of CG, SAP, CDT and STR. The results of the present study add credence to the ethnomedicinal uses of Ficus sycomorus for the treatment of fungal diseases.
  R.A. Umar , S.W. Hassan , M.J. Ladan , M. Nma Jiya , I.K. Matazu , M.K. Abubakar , U. Nata`ala and K. Abdullahi
  In a prospective cross sectional study, the therapeutic efficacy of chloroquine was assessed in children under the age of five years with uncomplicated P. falciparum malaria in Sokoto, Nigeria, using the in vivo 14 day World Health Organization`s protocol (with some modifications). One hundred and twenty six children aged 2 to 59 months were enrolled, out of which 108 completed the study. Clinical, parasitological and haematological data at study start and end were obtained by standard methods. Children were treated with 25 mg kg-1 body weight over 3 days. Adequate clinical and parasitological response was 72.2%, clinical failure was 23.27 and total treatment failure 27.8%. Because of unacceptably high rate of treatment failures due to diminishing efficacy, chloroquine cannot remain the recommended first line drug for the treatment of P. falciparum malaria in pre-school children in Nigeria and the antimalarial treatment policy change from chloroquine to Artemisin-based combination was necessary and justified. Challenges to the success of the policy for control of malaria morbidity and mortality were discussed.
  R.A. Umar , N.M. Jiya , M.J. Ladan , M.K. Abubakar , S.W. Hassan and U. Nata`ala
  We surveyed for the prevalence of anaemia, by packed cell volume and haemoglobin determinations, in a cohort of 36 pre-school children with uncomplicated Falciparum malaria in Sokoto, Nigeria. By packed cell volume, 5 (3.9%) of the children were mildly anaemic, 3 (8.3%) were moderately anaemic and 28 (77.8%) were normal. As indicated by haemoglobin levels, 6.0 (16.67%) of the study children have moderate anaemia while the remaining 30 (83.3%) were normal. There was no incidence of severe anemia in the study cohort. Comparison of Hb with PCV methods for anaemia detection indicates that the latter is more efficient in detecting prevalence of anaemia in our study subjects. Peak incidence of mild anaemia occurred in the age groups 0-12 and 49-60 months, with the lowest incidence occurring in age group 37-48 months. Peak and lowest incidence of moderate anaemia occurred in the age group 13-24 and 0-12 months, respectively. Haemoglobin levels did not vary significantly among the age groups (ANOVA, F = 1.006, p = 0.4194). Although all children less than five years of age in this setting are at risk for anaemia, the age group 13-24 months should be especially monitored for anti-anaemia interventions.
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