Medicine
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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty
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Item Age-related changes in adaptation to severe anemia in childhood in developing countries(National Academy of Sciences, 2007) O Donnell, A.; Premawardhena, A.; Arambepola, M.; Allen, S.J.; Peto, T.E.; Fisher, C.A.; Rees, D.C.; Olivieri, N.F.; Weatherall, D.J.Severe forms of anemia in children in the developing countries may be characterized by different clinical manifestations at particular stages of development. Whether this reflects developmental changes in adaptation to anemia or other mechanisms is not clear. The pattern of adaptation to anemia has been assessed in 110 individuals with hemoglobin (Hb) E beta-thalassemia, one of the commonest forms of inherited anemia in Asia. It has been found that age and Hb levels are independent variables with respect to erythropoietin response and that there is a decline in the latter at a similar degree of anemia during development. To determine whether this finding is applicable to anemia due to other causes, a similar study has been carried out on 279 children with severe anemia due to Plasmodium falciparum malaria; the results were similar to those in the patients with thalassemia. These observations may have important implications both for the better understanding of the pathophysiology of profound anemia in early life and for its more logical and cost-effective management.Item Suppression of erythropoiesis in malarial anemia is associated with hemozoin in vitro and in vivo(American Society of Hematology, 2006) Casals-Pascual, C.; Kai, O.; Cheung, J.O.; Williams, S.; Lowe, B.; Nyanoti, M.; Williams, T.N.; Maitland, K.; Molyneux, M.; Newton, C.R.; Peshu, N.; Watt, S.M.; Roberts, D.J.Malarial anemia is a global public health problem and is characterized by a low reticulocyte response in the presence of life-threatening hemolysis. Although cytokines, in particular tumor necrosis factor-alpha (TNF-alpha), can suppress erythropoiesis, the grossly abnormal bone marrow morphology indicates that other factors may contribute to ineffective erythropoiesis. We hypothesized that the cytotoxic hemozoin (Hz) residues from digested hemoglobin (Hb) significantly contribute to abnormal erythropoiesis. Here, we show that not only isolated Hz, but also delipidated Hz, inhibits erythroid development in vitro in the absence of TNF-alpha. However, when added to cultures, TNF-alpha synergizes with Hz to inhibiterythropoiesis. Furthermore, we show that, in children with malarial anemia, the proportion of circulating monocytes containing Hz is associated withanemia (P < .001) and reticulocyte suppression (P = .009), and that this is independent of the level of circulating cytokines, including TNF-alpha. Plasma Hz is also associated with anemia (P < .001) and reticulocyte suppression (P = .02). Finally, histologic examination of the bone marrow of children who have died from malaria shows that pigmented erythroid and myeloid precursors are associated with the degree of abnormal erythroid development. Taken together, these observations provide compelling evidence for inhibition of erythropoiesis by Hz.Item The Clinical and epidemiological features of childhood malaria in a moderately endemic area of Sri Lanka(SEAMEO Regional Tropical Medicine and Public Health Project, 2002) Fernando, S.D.; Wickremasinghe, A.R.This study describes some clinical and epidemiological features of childhood malaria in a moderately endemic area of southern Sri Lanka. Six hundred and sixty-two children, who experienced 1,138 attacks of malaria, and 172 children, who experienced 202 attacks of acute non-malarial fever, were followed over a period of two years. Of the 1,138 malaria infections followed, 776 were due to P. vivax, 359 were due to P. falciparum, and 3 were mixed infections. The majority of children presented within the first three days of the onset of symptoms. Headache (96%), feeling cold (81%) and arthralgia (77%) were the commonest presenting symptoms. Two hundred and sixty-four children experienced more than one attack of malaria. The clinical and epidemiological features of childhood malaria that have important implications for the planning and targeting of preventive measures are discussed.Item Severe hepatic dysfunction associated with falciparum malaria(SEAMEO Regional Tropical Medicine and Public Health Project, 2001) Premaratna, R.; Gunatilake, A.K.E.; de Silva, N.R.; Tilakaratne, Y.; Fonseka, M.M.D.; de Silva, H.J.We describe severe hepatic dysfunction associated with an attack of falciparum malaria in six Sri Lankan patients. Clinicians working in areas endemic for malaria should be made aware of this unusual complication.Item Delayed cerebellar ataxia complication falciparum malaria - a clinical study of 74 patients(Springer-Verlag, 1994) Senanayake, N.; de Silva, H.J.We report the clinical features of 74 patients with delayed cerebellar ataxia (DCA) following falciparum malaria, who were prospectively followed up at two centres. This unusual complication has an acute onset, with signs suggesting a predominantly midline cerebellar lesion without any evidence of cerebral involvement. There was a delay of a median 13 days between the onset of fever and the onset of ataxia. DCA has a good prognosis, with spontaneous and complete recovery within 3 months. In our opinion, it is an example of a post-infective neurological syndrome possibly mediated via an immune mechanism.Item Urinary frequency in falciparum malaria(Oxford University Press, 1992) de Silva, H.J.; Herath, S.; de Silva, N.R.No Abstract AvailableItem Delayed cerebellar ataxia following falciparum malaria: lack of evidence for antibody mediation(Oxford University Press, 1992) de Silva, H.J.; de Silva, N.R.; Snook, J.A.No Abstract Available