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)

Tumour Necrosis Factor (TNF) is produced at the initiation of malaria infections (pre-erythrocytic phase), as demonstrated by the release of bioactive TNF by peripheral blood mononuclear cells from individuals residing in endemic areas after stimulation with stage specific sporozoite antigens. During the erythrocytic phase, TNF production is greatly augmented by parasite antigens at the time of schizont rupture and merozoite release from infected erythrocytes. Some of the strongest inducers of TNF synthesis and release are malaria toxins, e.g. glycosylphosphatidylinositol moieties and malaria pigment. Because of TNF's well-known cytotoxic activity it was originally hypothesized that it alone was responsible for killing parasites directly or within host cells. Though earlier reports of the capability of serum containing TNF to kill plasmodia supported this idea, later experiments with recombinant TNF showed a lack of significant parasiticidal activity. Recent studies investigating related factors showed that they were involved with TNF in the control of infection. These factors included -ther cytokines, such as interleukin (IL)-1, IL-6, IL-12, interferon-gamma (IFN gamma) as well as nitric oxide intermediates (NOI) and reactive oxygen intermediates (ROI). This positioned TNF as a key regulator of the immune response against the malaria parasite. However, it must be noted that TNF and its associated factors are also responsible for the fever, aches and pains of acute illness, as well as the hypoglycemia, shock, bleeding and reversible coma of severe malaria seen in approximately 1 percent of individuals with malaria. Therein lies the rub; factors important in the control of malaria also appear to have detrimental properties. Research presented in this review characterizes TNF and associated cytokines' importance in the immune response to malaria.
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PMID:Tumour necrosis factor and associated cytokines in the host's response to malaria. 939 95

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

Risk testing for HIV serostatus is unlikely to detect more than 20% of HIV-positive pregnant women. Of the 11 pregnant women discovered to be HIV-infected at Port Moresby General Hospital in Papua New Guinea in 1994-95, only four had more than two sexual partners since 1992 and none was an intravenous drug user. The deleterious effect of pregnancy on HIV disease progression appears to be small but variable, with more serious effects in the later stages of disease. The risk of vertical transmission increases when viral loads are high, the general maternal condition is poor, and delivery is preterm. In developing countries, where HIV-infected pregnant women are likely to be malnourished and to have concomitant infections such as malaria and tuberculosis, the risks of preterm labor, small-for-gestational age infants, and chorioamnionitis are increased. HIV-related gynecologic conditions such as pelvic inflammatory disease, vulvovaginal candidiasis, and cervical neoplasia may be resistant to treatment and tend to recur. Pregnancy prevention through effective contraceptive methods such as Depo-Provera and tubal ligation may be more important to HIV-infected women than prevention of viral transmission, especially when both partners are seropositive.
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PMID:HIV infections in obstetrics and gynaecology. 979 61

Artemisinin derivatives are endoperoxide antimalarials widely used to treat falciparum malaria in areas where drug resistance is common. In Plasmodium falciparum-infected erythrocytes, radiolabeled artemisinin derivatives have been shown to react with malarial proteins, one of which is the Translationally Controlled Tumor Protein (TCTP). The P. falciparum TCTP was found by immunofluorescence to be located in both the cytoplasm and food vacuoles. Immunoelectron microscopy shows that it is present in the parasite cytoplasm as well as in its food vacuolar and limiting membranes. Like other TCTPs, the P. falciparum protein binds to calcium. Further studies on the physiological role of TCTP may aid in understanding the mechanism of action of endoperoxide antimalarials.
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PMID:The Plasmodium falciparum translationally controlled tumor protein: subcellular localization and calcium binding. 1053 9

The immune mechanisms whereby malaria parasites are eliminated by the human host or how they may avoid the immune response are poorly understood. Individuals living in malaria-endemic areas gradually acquire immunity. It is well established that this immunity involves both cell-mediated and humoral mechanisms and that T cells are the major regulators in both these events. The existence of functionally distinct P. falciparum-specific CD4+ T-cell subsets in humans has been shown in several studies. However, in contrast to what is the case in murine models there is no definitive link between the activation of various T cells and the course of human P. falciparum blood-stage infection. In the present paper we will review recent findings which illustrate how the balance between functionally different T-cell subsets affects the development of malaria immunity but also may contribute to its pathogenicity. An example of the latter is the deposition of IgE-containing immune complexes in small vessels, probably leading to local overproduction of tumor-necrosis factor (TNF), a pathogenic factor in malaria.
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PMID:Immune regulation of protection and pathogenesis in Plasmodium falciparum malaria. 1069 45

Primary angiosarcoma of the spleen is a rare entity, but it is the most common primary splenic malignancy. These tumors demonstrate an aggressive growth pattern and can be single or multiple. The diagnosis should be suspected in a patient who presents with splenomegaly but without evidence of lymphoma, malaria, leukemia, or portal hypertension. The tumor may also present with acute abdominal symptoms secondary to spontaneous splenic rupture. We describe two cases of primary angiosarcoma of the spleen with computed tomographic, magnetic resonance, and sonographic features.
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PMID:Primary angiosarcoma of the spleen--CT, MR, and sonographic characteristics: report of two cases. 1082 52

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

On 1 October 1997 Ocean Road Hospital in Daressalam commemorated one hundred years of its existence. As early as 1888 a provisional hospital had been set up in Zanzibar by the German Lutheran Church to serve the needs of the Germans living and working on the East African coast. But when the British established their protectorate over Zanzibar in 1890, the hospital was moved to Dar es Salaam. As cooperation between Mission hospital and Government authorities proved difficult, the German colonial administration was determined to build an hospital of its own. Lack of funds delayed the construction of the building which had to be built on a more modest scale than originally planned. But when the hospital was inaugurated in October 1897, people were impressed both by its functional usefulness and aesthetic attraction. The history of the German Government Hospital reflects the political context of the time as well as the progress of medicine in combatting endemic diseases. While patients were often segregated by race--the Government Hospital in Daressalam almost exclusively reserved for Europeans--all were benefitting from the results of medical science. For Robert Koch the hospital (and its laboratory) served as basis for his research in the field of malaria, black water fever, sleeping sickness, and relapsing fever. It was from Africa that the embarked on his journey to Stockholm to receive the Nobel Prize in December 1905. During the First World War Ocean Road Hospital, as it was called from now on, was taken over by the British. Since independence, the Tanzanians are in charge. It is presently the only tumor hospital of the country, closely cooperating with the German Cancer Research Center (DKFZ) in Heidelberg. Restoration of Ocean Road Hospital, completed at the beginning of this year, was made possible by a grant of the Federal Republic of Germany.
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PMID:[Early days of the Ocean Road Hospital in Dar es Salaam: from mission hospital to government hospital]. 1106 15

We have characterized brain cytokine expression profiles in the Plasmodium coatneyi/rhesus (Macaque mulatta) malaria model. Eight rhesus monkeys were included in the study; four were infected with P. coatneyi, and four were used as uninfected controls. All inoculated animals became infected. Eleven days after parasite inoculation, the rhesus monkeys were killed and tissue samples from 4 regions of the brain (cortex and white matter of the cerebrum, cerebellum, and midbrain) were collected for quantitation of mRNA expression of cytokines, adhesion molecules, and inducible nitric oxide synthetase (iNOS) by reverse transcriptase-polymerase chain reaction (RT-PCR). The expression levels of tumor necrosis actor-alpha (TNF-alpha), gamma interferon (IFN-gamma), interleukin-1-beta (IL-1beta), intercellular adhesion molecule-1 (ICAM-1) and inducible nitric oxide synethetase (iNOS) were highest in the cerebellum of infected animals, correlating well with pathologic observations of sequestration of parasitized erythrocytes in this region of the brain. Infected animals also had higher TNF-alpha expression levels in the cortex and IL-1beta expression levels in the cortex, white matter, and midbrain. Thus, the expression of pro-inflammatory and T helper-1 (TH-1) cytokines, adhesion molecules, and iNOS appears to predominate in the cerebellum of infected rhesus monkeys.
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PMID:Expression of proinflammatory cytokines in four regions of the brain in Macaque mulatta (rhesus) monkeys infected with Plasmodium coatneyi. 1122 Jul 73

Artesunate (ART) is a semi-synthetic derivative of artemisinin, the active principle of the Chinese herb Artemisia annua. ART reveals remarkable activity against otherwise multidrug-resistant Plasmodium falciparum and P. vivax malaria. ART has now been analyzed for its anti-cancer activity against 55 cell lines of the Developmental Therapeutics Program of the National Cancer Institute, USA. ART was most active against leukemia and colon cancer cell lines (mean GI50 values: 1.11+/-0.56 microM and 2.13+/-0.74 microM , respectively). Non-small cell lung cancer cell lines showed the highest mean GI50 value (25.62+/-14.95 microM) indicating the lowest sensitivity towards ART in this test panel. Intermediate GI50 values were obtained for melanomas, breast, ovarian, prostate, CNS, and renal cancer cell lines. Importantly, a comparison of ART's cytotoxicity with those of other standard cytostatic drugs showed that ART was active in molar ranges comparable to those of established anti-tumor drugs. Furthermore, we tested CEM leukemia sub-lines resistant to either doxorubicin, vincristine, methotrexate, or hydroxyurea which do not belong to the N.C.I. screening panel. None of these drug-resistant cell lines showed cross resistance to ART. To gain insight into the molecular mechanisms of ART's cytotoxicity, we used a panel of isogenic Saccaromyces cerevisiae strains with defined genetic mutations in DNA repair, DNA checkpoint and cell proliferation genes. A yeast strain with a defective mitosis regulating BUB3 gene showed increased ART sensitivity and another strain with a defective proliferation-regulating CLN2 gene showed increased ART resistance over the wild-type strain, wt644. None of the other DNA repair or DNA check-point deficient isogenic strains were different from the wild-type. These results and the known low toxicity of ART are clues that ART may be a promising novel candidate for cancer chemotherapy.
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PMID:The anti-malarial artesunate is also active against cancer. 1125 Nov 72


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