Browsing by Author "Kumar, P. L."

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Allelopathic potential of some biocontrol agents for the control of fungal rot of yellow yam (Dioscorea cayenensis Lam)
(2015) Dania, V. O; Fadina, O.O; Ayodele, M..; Kumar, P. L.
The adverse effects of synthetic pesticides on human health and natural ecosystem necessitate the need to explore natural mechanisms of disease control in plants. This study evaluated the allelopathic potential of five biocontrol agents: Trichoderma longibrachiatum, Trichoderma asperellum, Bacillus subtilis, Bacillus cereus and Pseudomonas fluorescens in the control of six fungal pathogens associated with tuber rot of Dioscorea cayenensis. Rotten tuber samples were randomly collected across three agro-ecological zones (AEZs): humid rainforest (HF), derived savanna (DS), and southern Guinea savanna (SGS) in Nigeria. Biocontrol agents were isolated from the yam rhizosphere using the serial dilution method; the agar paring method was used for the in vivo trials. The destruction sampling method was used to evaluate rot control by the antagonists in vivo. Aspergillus niger had the highest incidence of 64.71% across the HF, 52.08% across the DS, and 41.98% across the SGS. B. subtilis had the highest inhibitory zone of 16.7+0.05% when paired with A. niger, 15.4+ 0.01% with Lasiodiplodia theobromate, 14.0 + 0.33% with Penicillium oxalicum, 7.1 + 0.14% when paired with Rhizoctonia solani: 17.1 + 0.11% with Sclerotium rolfisii, and 10.3 + 0.94% with Fusarium oxysporum. All biocontrol agents significantly (P=0.05) reduced rot development of the test pathogens relative to the control in the in vivo experiment. The establishment of a distant zone of inhibition, especially by the bacterial antagonist attests to the fact that they produced allelochemical substances. Therefore, further research is recommended to evaluate the biochemical composition of these microbial metabolites, their level of toxicity, and fate in the environment
Insertion/deletion polymorphism of the angiotensin-converting enzyme gene and the risk of hypertension among residents of two cities, South-South Nigeria
(Medknow Publications, 2014) Kooffreh, M. E.; Anumudu, C. I.; Kumar, P. L.
Background: Hypertension is a public health challenge due to its high prevalence, and is a major risk factor for cardiovascular diseases. This study was designed to determine the frequency of the I/D polymorphism of the angiotensin-converting enzyme gene and its association with hypertension in a sample population of Calabar and Uyo, South-South Nigeria. Materials and Methods: A population-based case control design consisting of total of 1224 participants, 612 each of patients and controls, were randomly recruited from hypertension clinics and the general population. The I/D polymorphism was investigated using polymerase chain reaction. Multiple regression and odds ratio (OR) was applied to test whether the ID genotypes were predictors of hypertension. Results: The I/D genotype frequencies were 73(12%), 262(43%) and 277(45%); 74(12%), 303(50%) and 235(38%) for the II, ID, DD genotype in patient and control groups, respectively. A higher frequency of the ID genotype was observed in controls of which 208(61%) were females. By multiple regression analysis, age was a predictor for SBP in patients, r = 0.596, and DBP in controls, r = 0.555. Gender, Body mass index, I/D genotypes were not significant predictors for hypertension but the I/D polymorpism was associated with an increased risk for hypertension with an OR of 1.15 95%CI (0.924-1.456). Conclusion: The I/D polymorphism of the angiotensin-converting enzyme gene was a risk factor for hypertension in the sample population of Calabar and Uyo. This research will form baseline information for subsequent molecular studies in this population.
A study of the M235T variant of the angiotensinogen gene and hypertension in a sample population of Calabar and Uyo, Nigeria
(Elsevier, 2013) Kooffreh, M. E.; Anumudu, C. I.; Akpan, E. E.; Ikpeme, E. V.; Kumar, P. L.
A common molecular variant of the angiotensinogen gene had been reported to predispose some ethnic groups to hypertension. This case-control study was designed to determine the frequency and association of the angiotensinogen M235T al1ele with hypertension in residents of Calabar and Uyo cities, south-south Nigeria. The study involved 1308 subjects, 612 patients and 696 controls. The M235T variant was investigated using an allele specific polymerase chain reaction and enzymatic digestion to determine al1ele frequencies. Hypertensinogenic factors such as dietary habits, physical activity, smoking and drinking habits were assessed using questionnaires. Descriptive statistics, chi-square and multiple regression analysis were used to analyze the data obtained. The M235T al1ele frequency was high (0.94 for hypertensives and 0.96 for controls) though it was not associated with hypertension status. The odds ratio for hypertension was 0.64 (95% confidence interval: 0.39-1.06) there were no significant differences between the genotype frequency of hypertensives and controls. By multiple regression, hypertension was observed to be associated with age and was a predictor for systolic blood pressure in both patient r2 = 0.359; p < 0.05 and control groups r2 = 0.26.