Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Epstein-Barr virus (EBV) is an ubiquitous virus infecting nearly the entire adult human population. The EBV is closely associated with rhinopharyngeal cancer in Southern China and Northern Africa. Three geographic subtypes of EBV have been identified to date. They differ by their nuclear antigene EBNA2. The EBNA2 AC strains predominate in Asia; EBNA2 AD strains predominate in the United States; EBNA2 B strains have all been identified in black Africa. Burkitt's lymphoma is the most frequent tumor in children aged 5 to 9 years in equatorial Africa. A prospective study in 42,000 children in Ouganda demonstrated that children who develop Burkitt's lymphoma have severe EBV infection during the first months of life. Very early EBV infection observed in North or equatorial Africa increases the risk of Burkitt's lymphoma by 20-times that in Europe. Hyperendemic malaria observed in the equatorial zone increases the incidence of tumors by a factor of 20. An association between EBV and rhinopharyngeal cancer is a constant feature only in South China, in North and East Africa, as well as in arctic regions as cases of carcinoma not associated with EBV infection have been reported in Greece. Surveys in the Democratic Republic of China concerning several hundred thousand persons have shown that serum IgA/VCA allows early diagnosis of cancer. It is estimated that the risk of rhinopharyngeal cancer is 20% in Chinese with high levels of IgA/VCA.
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PMID:[Epstein-Barr virus and associated diseases. Course of Medical Virology, Institut Pasteur, 1995/1996]. 953 9

Burkitt's lymphoma has the highest incidence of any childhood cancer in equatorial Africa. Geographic distribution appears to be related to climatic conditions and coincides with areas of endemic malaria. These tumors are characterized by reciprocal translocation from chromosome 8 at or near the c-myc locus to either the immunoglobulin chain locus on chromosome 14 (80 p. 100 of cases) or one of the light chain loci on chromosome 2 or 22. As a result of this translocation, transcription of the protooncogene c-myc is activated. Deregulation of c-myc could play a major role in onset and development of the tumor. Study of Burkitt's lymphoma led to the discovery of the first association between viral infection and tumor development in humans. The Epstein-Barr virus is contained in all endemic Burkitt's lymphoma cells, thus implicating it as a likely etiologic factor. Viral expression is reduced essentially to small non-coding RNA, non-polyadenilates, and EBERs (10(6) copies per cell) and a nuclear protein EBNA1 which is indispensable for maintenance of the Epstein-Barr virus genome in infected cells. Expression of EBNA in transgenes leads to lymphoma in mice and could play a role in the expression of the c-myc gene involved in translocations.
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PMID:[Epstein-Barr virus and Burkitt's lymphoma]. 1090 54

The geographical and age distributions of endemic Burkitt's lymphoma (eBL), in Africa, parallel those of certain arboviruses, which include chikungunya fever. Increased incidences of antibodies to assorted arboviruses, including chikungunya, have been found in eBL sera compared to controls. An increased incidence and space-time case-clusters of eBL occurred during a chikungunya fever epidemic which were confirmed by serology and clinical observation. The present study, conducted in 1987-89, involved 108 eBL patients, and 97 local and 111 hospital controls. We examined, as hospital controls, patients with afebrile, non-malignant conditions admitted to Kamuzu Central Hospital, Malawi, during the eBL patients' first admission there. Analyses were for hospital controls and eBL patients at the end of their first admission and for local controls and eBL patients at the beginning of their third admission, about 8 weeks after the day of first admission, because of the local controls' temporal bias. Patients in case-clusters were among those seropositive for chikungunya virus, with a history compatible with arbovirus infection preceding the lymphoma, suggesting involvement of chikungunya virus in the case-clusters and a possible association between recent infection with this virus and development of the lymphoma. eBL patients were significantly more likely to be seropositive for chikungunya virus antibody (68x5%) than either hospital controls (46.8%) or local controls (50x5%) (P = 0x002 and 0x009, respectively), raising the possibility of an association between infection with an arbovirus and developing eBL in children already primed by holoendemic malaria and Epstein-Barr virus infection.
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PMID:Chikungunya fever as a risk factor for endemic Burkitt's lymphoma in Malawi. 1119 62

Burkitt's lymphoma is the most common malignant tumor encountered in children (age peak 3 to 8 years) living in areas with endemic malaria tropica. In the Hospital Central da Beira/Mozambique, two children with Burkitt's lymphoma were treated with cyclophosphamide. During the period covered by this report--August 1 to September 30, 2000--two of the required four treatment cycles were carried out, and both children experienced a remission.
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PMID:[A therapeutic approach in Burkitt's lymphoma. 2 case reports from the Hospital Central da Beira/Mozambique]. 1193 60

Burkitt's lymphoma is the commonest childhood malignancy in tropical Africa and the predisposing factors include malaria and infection with the Epstein-Barr virus. Recent studies suggest that the prevalence of this neoplasm is declining in this environment. The present study was undertaken to investigate whether there is a real decrease in the occurrence of Burkitt's lymphoma. We analysed 665 cases of childhood malignancies reported in the Ibadan Cancer Registry between 1991 and 1999. Burkitt's lymphoma and retinoblastoma remained the two commonest specific childhood malignancies, accounting for 19.4% and 17.9% of all childhood cancers, respectively. However, this represents a significant decline in the relative frequency of Burkitt's lymphoma when compared with similar surveys for the periods 1960 to 1972 and 1973 to 1990 when Burkitt's lymphoma accounted for 51.5% and 37.1%, respectively, of all childhood malignancies. In Ibadan, it seems that what appeared to be minor changes might actually be a real decline in the incidence of Burkitt's lymphoma and that it might be partly ascribed to improved living conditions and greater control of malaria.
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PMID:Decline in the frequency of Burkitt's lymphoma relative to other childhood malignancies in Ibadan, Nigeria. 1207 Sep 51

Forty-four children between 3 and 14 years of age with Burkitt's lymphoma were studied at the University of Nigeria Teaching Hospital, Enugu, Nigeria from November 1991 to March 1995. Mean age at presentation was 7.6 years with a male:female ratio of 2.7:1. Eighty-six per cent of the patients lived in a rural area. Of the 23 (52%) from Enugu State, 16 were living in contiguous local government areas with ten clustered round the middle of the year. All the children were of the lowest socio-economic class, 75% of them being in class V. The incidence of Burkitt's lymphoma was higher during the dry season and the period of high malaria transmission (p < 0.05). Abdominal tumour was the commonest mode of presentation (32% of patients). Thirty-six patients were treated with cyclophosphamide, Oncovin, methotrexate and predinisolone (COMP), five received cyclophosphamide alone and three had cyclophosphamide, methotrexate and prednisolone (CMP). Multi-drug regimens achieved better results which were significantly unrelated to the number of cycles of therapy received. Overall, 48% had complete and 35% partial remission, 23% relapsed and 16 (36%) patients died. The epidemiological characteristics of Burkitt's lymphoma in this study were similar to those in other tropical regions.
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PMID:Epidemiology of Burkitt's lymphoma in Enugu, Nigeria. 1253 Feb 87

Epstein-Barr virus (EBV) was discovered 40 years ago from examining electron micrographs of cells cultured from Burkitt's lymphoma, a childhood tumour that is common in sub-Saharan Africa, where its unusual geographical distribution - which matches that of holoendemic malaria -indicated a viral aetiology. However, far from showing a restricted distribution, EBV - a gamma-herpesvirus - was found to be widespread in all human populations and to persist in the vast majority of individuals as a lifelong, asymptomatic infection of the B-lymphocyte pool. Despite such ubiquity, the link between EBV and 'endemic' Burkitt's lymphoma proved consistent and became the first of an unexpectedly wide range of associations discovered between this virus and tumours.
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PMID:Epstein-Barr virus: 40 years on. 1551 Jan 57

Malaria and Epstein-Barr virus (EBV), recognised cofactors for endemic Burkitt's lymphoma, are ubiquitous within the lymphoma belt of Africa, and, unless other cofactors are involved, the tumour should be much more common than it is. Malaria and EBV alone cannot account for the occasional shifting foci and space-time case clusters of endemic Burkitt's lymphoma. Arboviruses and plant tumour promoters are other possible local cofactors that could explain such characteristics. The geographical and age distributions of endemic Burkitt's lymphoma parallel those of potentially oncogenic, mosquito-borne arboviruses. Arboviruses seem to be associated with case clusters of endemic Burkitt's lymphoma, and symptoms compatible with arbovirus infection have been seen immediately before the onset of the tumour. RNA and DNA viruses, including EBV, are promoted by extracts of a commonly used plant, Euphorbia tirucalli, the distribution of which coincides with the boundaries of the lymphoma belt. Extracts of E tirucalli are tumour promoters and can induce the characteristic 8;14 translocation of endemic Burkitt's lymphoma in EBV-infected cell-lines. They also activate latent EBV in infected cells, enhance EBV-mediated cell transformation, and modulate EBV-specific immunity.
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PMID:Is endemic Burkitt's lymphoma an alliance between three infections and a tumour promoter? 1558 45

Perennial and intense malaria transmission (holoendemic malaria) and Epstein-Barr virus (EBV) infection are 2 cofactors in the pathogenesis of endemic Burkitt lymphoma (eBL). In the present study, we compared EBV loads in children living in 2 regions of Kenya with differing malaria transmission intensities: Kisumu District, where malaria transmission is holoendemic, and Nandi District, where malaria transmission is sporadic. For comparison, blood samples were also obtained from US adults, Kenyan adults, and patients with eBL. Extraction of DNA from blood and quantification by polymerase chain reaction give an EBV load estimate that reflects the number of EBV-infected B cells. We observed a significant linear trend in mean EBV load, with the lowest EBV load detected in US adults and increasing EBV loads detected in Kenyan adults, Nandi children, Kisumu children, and patients with eBL, respectively. In addition, EBV loads were significantly higher in Kisumu children 1-4 years of age than in Nandi children of the same age. Our results support the hypothesis that repeated malaria infections in very young children modulate the persistence of EBV and increase the risk for the development of eBL.
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PMID:Exposure to holoendemic malaria results in elevated Epstein-Barr virus loads in children. 1577 68

Children living in malaria-endemic regions have high incidence of Burkitt's lymphoma (BL), the aetiology of which involves Plasmodium falciparum malaria and Epstein-Barr virus (EBV) infections. Acute malarial infection impairs the EBV-specific immune responses with the consequent increase in the number of EBV-carrying B cells in the circulation. To further understand the potential influence of malarial infection on the EBV persistence in children living in malaria-endemic areas, we studied the occurrence and quantified cell-free EBV-DNA in plasma from 73 Ghanaian children with and without acute malarial infection. Viral DNA was detected in 40% of the samples (47% in the malaria-infected and 34% in the nonmalaria group) but was absent in plasma from Ghanaian adults and healthy Italian children. These findings provide evidence that viral reactivation is common among children living in malaria-endemic areas, and may contribute to the increased risk for endemic BL. The data also suggest that the epidemiology of EBV infection and persistence varies in different areas of the world.
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PMID:Circulating epstein-barr virus in children living in malaria-endemic areas. 1588 38


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