Browsing by Author "Okafor, C. M. F."

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Cellular responses to modified Plasmodium falciparum MSP 119 antigens in individuals previously exposed to natural malaria infection
(Springer, 2009) Okafor, C. M. F.; Anumudu, C. I.; Omosun, Y. O.; Uthaipibull, C.; Ayede, I.; Awobode, H. O.; Odaibo, A. B.; Langhorne, J.; Holder, A. A.; Nwuba, R. I.; Troye-Blomberg, M.
Background: MSP1 processing-inhibitory antibodies bind to epitopes on the 19 kDa C-terminal region of the Plasmodium falciparum merozoite surface protein 1 (MSP119), inhibiting erythrocyte invasion. Blocking antibodies also bind to this antigen but prevent inhibitory antibodies binding, allowing invasion to proceed. Recombinant MSP119 had been modified previously to allow inhibitory but not blocking antibodies to continue to bind. Immunization with these modified proteins, therefore, has the potential to induce more effective protective antibodies. However, it was unclear whether the modification of MSP119 would affect critical T-cell responses to epitopes in this antigen. Methods: The cellular responses to wild-type MSP119 and a panel of modified MSP119 antigens were measured using an in-vitro assay for two groups of individuals: the first were malaria-naïve and the second had been naturally exposed to Plasmodium falciparum infection. The cellular responses to the modified proteins were examined using cells from malaria-exposed infants and adults. Results: Interestingly, stimulation indices (SI) for responses induced by some of the modified proteins were at least two-fold higher than those elicited by the wild-type MSP119. A protein with four amino acid substitutions (Glu27→Tyr, Leu31→Arg, Tyr34→Ser and Glu43→Leu) had the highest stimulation index (SI up to 360) and induced large responses in 64% of the samples that had significant cellular responses to the modified proteins.
Clinical manifestations and immune response to MSP 119 in severe paediatric malaria in Adeoyo state maternity hospital, Ibadan
(College of Medicine, University of Ibadan and the University College Hospital, 2004) Anumudu, C. I.; Okafor, C. M. F.; Ngwumohaike, V.; Afolabi, K. A.; Nwuba, R. I.; Nwagwu, M.
A 10-week cross-sectional study was carried out at the Adeoyo State Maternity Hospital (Beere, Ibadan), Southwestern Nigeria in order to determine (a) the prevalence of severe malaria, (b) identify the predominant clinical presentations that characterise the disease in children below 5 years and the pattern of antibody responses to MSP 119 elicited in severe malaria complications. Three thousand, one hundred and thirty-one cases reported to the Out Patients' Department; of these, 372 (11.8%) subjects were recruited on the basis of doctors' diagnosis of severe malaria, malaria and other complications. Six per cent (188/3131) of the patients were admitted. Serum samples for 320 of the 372 subjects were analysed for antibodies specific to MSP 119 by ELISA. The highest antibody responses occurred in the age group 2-5 years. Parasite prevalence was 77.9% (290 of 372 subjects) and parasite density ranged from 80 to >100000 parasites/uL blood. Fever (an average temperature of 38.6 ±0.4°C and peak at 41°C) and severe malaria were the major clinical manifestations of rnalaria amongst the study population. Severe malaria was found to be associated with other features such as cough, vomiting and diarrhoea.
Epidemiological factors that promote the development of severe malaria anaemia in children in Ibadan
(Faculty of Medicine, Makerere University, 2007) Anumudu, C. I.; Okafor, C. M. F.; Ngwumohaike, V.; Afolabi, K. A.; Nwuba, R. I.; Nwagwu, M.
Background: Effective control and management of severe malaria cases depends on a clear understanding of the local epidemiological factors and specific clinical manifestations of the disease in the different endemic regions. Objectives: To determine the prevalence of severe malaria and epidemiological factors that affect the development of malaria anaemia. Methods: A cross-sectional survey was carried out among children below 5 years of age, at the Adeoyo State Maternity Hospital, Ibadan, Nigeria. Questionnaires and case histories were taken from patients clinically diagnosed of malaria. Thus, 372 volunteers were recruited into the study from the 3131 paediatric cases that reported over the10-week period to the out-patient department (OPD) of the hospital. 229 (61.6%) of the recruited volunteers presented with fever (>37.5 oC) at consultation. These had malaria parasite and PCV tests done. Results: Clinical diagnosis was confirmed microscopically in 78% (290/372) for Plasmodium infection using thick film slides. Anaemia (PCV <28%) prevalence was 28.2%. Factors that contributed to the rapid progression of uncomplicated malaria to severe status included: age of the child, level of parasitaemia, careless response and attitude of parents or guardians to fever in the children; parents’ preoccupation with their jobs or other healthy children and unwillingness to use available health facilities. Conclusion: The study underscores the need for community involved partnership for malaria control especially through health education for the home management of malaria, especially among those experiencing some form of inequity in access to healthcare.
Serum ferritin levels in children with malaria anaemia in Ibadan
(Nigerian Society for Experimental Biology, 2006) Anumudu, C. I.; Molehin., A. J.; Oladiti, S. O.; Okafor, C. M. F.
This study assessed the serum ferritin levels in plasma samples from children (4 – 74 months old) admitted for malaria at the Adeoyo Maternity Hospital (Beere) Ibadan, Oyo State, using a sandwich-ELISA. These values were compared with malaria parasitemia, MSP-1 antibody titre and packed cell volume values previously obtained through standard methods. Statistical analyses were carried out using SPSS, Excel and Epi-Calc software. Results showed that the serum ferritin level in the population ranged in from 363ng/ml to 1000ng/ml, with a mean value of 630ng/ml. There was a negative correlation between serum ferritin levels and the packed cell volume, and malaria parasitemia in the children; while the serum ferritin levels increased with increasing malaria antibodies. There was no significant difference in the mean levels of ferritin in anaemic and non-anaemic children. Serum ferritin concentration decreased with increasing age in children with malaria. Gender was found to have no significant association with serum ferritin levels in children with malaria anaemia.