Scholarly works
Permanent URI for this collectionhttps://repository.ui.edu.ng/handle/123456789/424
Browse
2 results
Search Results
Item GENETIC POLYMORPHISMS ASSOCIATED WITH HYPERTENSION IN THE ETHNIC POPULATIONS OF CALABAR AND UYO, NIGERIA(2012-08) KOOFFREH, M.E.Hypertension is a public health challenge due to its high prevalence, and is a major risk factor for cardiovascular diseases. Hypertension is a complex disease resulting from an interaction of genes and environmental factors. Inconsistent association between polymorphisms of the renin angiotensin aldosterone, the atrial natriuretic peptide systems and hypertension has been reported among various ethnic groups, but not for the Efiks and Ibibios in south-south Nigeria. This study was designed to determine the frequency of gene polymorphisms of these two systems and their association with hypertension in Calabar and Uyo, Nigeria. A population-based case control design was used. A total of 1224 participants, 612 each of patients and controls were randomly recruited from hypertension clinics and the general population. Genotyping of the M235T allele of the angiotensinogen, Insertion/Deletion allele (I/D) of the angiotensinogen converting enzyme, A1166C allele of the angiotensin II type I receptor and C664G allele of the atrial natriuretic peptide genes to identify variants was performed using polymerase chain reaction and restriction enzyme digestion. The Hardy-Weinberg equation was used to calculate the allele and genotype frequencies. Plasma angiotensinogen levels were measured by Enzyme Linked Immunosorbent Assay. Hypertensinogenic factors such as age, familial history, physical exercise and drinking were assessed using questionnaires. Descriptive statistics, chi-square, multiple regression analysis and odds ratio were used to analyze the data. The frequency of the genotypes M235M, M235T, T235T of the M235T allele for the Efiks were 0.4, 7.7, 92 % in patients and 0, 6, 94 % in controls; for the Ibibios were 0.5, 1.2, 87 % in patients and 0, 7, 93 % in controls. The I/D genotypes II, ID, DD frequencies for the Efiks were 11, 44, 46 % in patients and 16, 45, 39 % in controls; for the Ibibios were 11, 40, 49 % in patients and 13, 49, 38 % in controls. The frequency of the A1166C carriers was 1 % while 99 % of the study population had the wild type A1166A genotype for the A1166C allele. Only the CC genotype was observed for the C664G allele. These frequencies did not conform to the Hardy-Weinberg assumptions. There were no significant differences between the genotype frequencies of patients and controls. Plasma angiotensinogen values were significantly higher in the patients with M235T allele than in the controls. Age was a positive predictor for systolic blood pressure (SBP, r = 0.60) in patients and diastolic blood pressure (DBP, r = 0.56) in controls. Other hypertensinogenic variables were not predictors for SBP and DBP in the population (p < 0.05). The Insertion/Deletion allele was a risk factor for hypertension, (O.R = 1.15). A high frequency was observed for the M235T allele and the Insertion/Deletion allele, which was associated with an increased risk for hypertension. The lack of association between the alleles of the M235T, A1166C and the C664G and hypertension suggests that other loci or environmental factors are involved in the disease outcome.Item INSECTICIDE RESISTANCE ASSOCIATED WITH 2La INVERSION AND MICROSATELLITE LOCI POLYMORPHISM IN Anopheles gambiae s.s. POPULATIONS FROM LAGOS AND OYO STATES, NIGERIA(2016-04) ADEOGUN, A. O.Dichlorodiphenyltrichloroethane (DDT) and deltamethrin are insecticides frequently used in malaria vector control interventions in Africa. Resistance to these insecticides has emerged in the malaria vector, Anopheles. However, the assortment of two genetic mechanisms, 2La inversion and the polymorphism of microsatellite loci, have also been associated with insecticide resistance in Anopheles populations in several countries with limited studies on these resistance mechanisms in Nigeria. This study was therefore designed to determine DDT and deltamethrin insecticide resistance, associated with 2La inversion and microsatellite loci polymorphism in Anopheles gambiae s.s. populations from Lagos and Oyo States. Larval samples of Anopheles were collected from six localities each in Lagos and Oyo States and were morphologically identified using standard methods. Emerged adult females (Lagos: n = 1,822, Oyo: n = 1,810) were exposed to 4% DDT and 0.05% Deltamethrin insecticide s separately for one hour, according to WHO insecticide susceptibility criteria . The mosquitoes were characterised using PCR and restriction enzyme digestion (for M and S forms). Resistant mosquitoes to DDT were further subjected to 2La inversion and microsatellite loci characterisation. Genotyping of DDT resistant mosquitoes to 2La inversion was performed on 30 selected Anopheles gambiae s.s. (M molecular form) from each locality using PCR. Ten microsatellite loci, selected close to documented insecticide resistance genes within and outside 2La, were examined for polymorphic alleles using standard methods. Lagos and Oyo resistant Anopheles populations were compared using descriptive statistics. The 2La inversion data for the two states were analysed using Wright F-statistic, Chi-square and Hardy-Weinberg equation. Microsatellite data were subjected to linkage disequilibrium and one-way ANOVA at α=0.05 . Mosquitoes from Lagos were more resistant to DDT and deltamethrin with 0.0-34.5 and 50.0-92.7% mortalities, respectively compared to those from Oyo with 13.3–84.0 and 80.0–100% mortalities, respectively. Significant difference in resistance profile between Lagos and Oyo Anopheles population was recorded only for DDT with deltamethrin showing insignificant values between populations. Anopheles gambiae s.s. was the only species found in all the localities surveyed in Lagos and all belonged to the M molecular form. Oyo State populations contained more Anopheles arabiensis (58.0%) than the Anopheles gambiae s.s. (42.0%) with sympatric occurrence of the M and S molecular forms. The DDT resistance profile patterned the 2La inversion karyotype (Lagos:FST=0.104; Oyo:FST=0.043) with the Chi square values falling within Hardy-Weinberg estimates (χ2=0.001-3.81, p=0.096 - 0.999) in all populations. Microsatellite genotypic linkage disequilibrium occurred in 24.0% of the loci (χ2=10.6 - 25.0, p=0.00005-0.032) between Lagos and Oyo populations. Six out of ten polymorphic alleles had significantly high genetic differentiation values, AG2H26 (FST=0.2938), AG2H175 (FST=0.0595), AG2H590 (FST=0.0519), for Lagos and Oyo populations; three of which AG2H637 (FST=0.1134), AG2H772 (FST=0.3246), AG2H143 (FST=0.0817) , were located within inversion 2La. Resistance to dichlorodiphenyltrichloroethane and deltamethrin in Anopheles population was established in Lagos and Oyo States. The resistance profile associated with 2La inversion karyotypes, and polymorphism of six microsatellite loci may be used as genetic markers in malaria vector control interventions in Lagos and Oyo States, Nigeria.