Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Seventy five patients with large spleens were investigated in order to establish the causes of splenomegaly in Northern Nigeria, to define further the diagnostic criteria of tropical splenomegaly syndrome (TSS), and to study its pathogenesis. Investigations included examination of liver biopsy, bone marrow cytology, lymphocyte response to phytohaemagglutinin (PHA), serum immunoglobulins and complement, and the presence of immunoglobulin and complement fixed in Kupffer cells. Thirty patients had TSS, five chronic lymphatic leukaemia (CLL), four a syndrome of gross lymphoid hyperplasia (GLH) distinct from TSS, CLL and the lymphomas, and twenty three miscellaneous conventional diseases. In thirteen cases no definite diagnosis could be established. TSS was found to be predominantly a disease of female Fulani cattle herders. Its essential characteristics were splenomegaly in the presence of acquired immunity to malaria, a grossly raised serum IgM, a lowered serum complement, and the presence of IgM fixed in Kupffer cells. There was lymphoid hyperplasia in bone marrow, hepatic sinusoids and often blood which may be indistinguishable from that in CLL. Lymphocytes undergo normal blastogenesis to PHA. There was clinical and haematological response to proguanil therapy. Reticuloendothelial phagocytosis of IgM, probably as a complex, seems to be the essential feature of the condition. As it was impossible to identify early cases of TSS it is unclear whether IgM overproduction or phagocytosis of IgM complexes is the first stage of the disease. The precise nature of the association with malaria remains obscure. The diagnosis of CLL demanded the demonstration of an abnormally low immunoglobulin level and impaired lymphocyte responsiveness to PHA by blast transformation or 3H-thymidine incorporation, in addition to the usual haematological findings. The syndrome GLH occurred in multiparous Hausa women. It was characterised by intense lymphocytosis with active, PHA-responsive cells, and normal immunoglobulin levels. Patients responded to proguanil therapy. It is suggested that these patients have a depressed immune response to malaria, perhaps through repeated pregnancies, and to a leukaemogenic agent, both of which stimulate lymphocytosis. Antimalarial treatment at this stage may prevent the development of frank leukaemia or lymphoma. The usefulness of the various investigative procedures and the problem of managing the large number of undiagnosed cases are discussed.
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PMID:Splenomegaly in Northern Nigeria. 1 54

Burkitt's lymphoma occurs mainly in parts of tropical Africa and has attracted the attention of experimental workers due to its epidemiological and clinical features, which indicate a viral etiology and a host immune response to the tumor. As a result of virological studies, Epstein-Barr virus (EBV) DNA has been demonstrated in almost all tested biopsies of African BL. This contrasts to the absence of EBV in all, or almost all, of the non-African Burkitt's lymphoma-like tumors, even though the number of tested tumors in this group is small, and to the lack of EBV in all other types of lymphoma or leukemia. Immunological studies have revealed the presence of antibodies to different EBV-associated antigens in all African patients with Burkitt's lymphoma. However the antibodies are not specific for Burkitt's lymphoma but are found in most adults all over the world, although at lower levels. They cannot therefore serve diagnostic purposes, but they can give prognostic information and occasionally give clues to the mechanisms behind late tumor recurrences, and possibly guide so-called immunotherapy. Burkitt's lymphoma patients contrast to appropriate control groups where some of the persons are anti-EBV seronegative, and this, together with the presence of EBV in Burkitt's lymphoma biopsies and the absence of EBV in other lymphomas, even though the cell type involved may be infectable by EBV in vitro and the tumor may arise in an EBV-carrying person, favors an etiological role in EBV in Burkitt's lymphoma and speaks against the "passenger" hypothesis, according to which EBV is picked up by the Burkitt's lymphoma cell which happens to be particularly suitable for EBV persistence. To explain the geographical distribution, a cofactor, such as certain forms of malaria, has been implied.
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PMID:Burkitt's lymphoma - a human tumor model system for immunological studies. 17 35

Compounds that compete with folic acid (folic acid antagonists [FAAs]) become limited in their usefulness in the treatment of leukemia, malaria, and bacterial infections by the rapid development of resistance. Assays of the plasma levels of certain of these FAAs led to the observation, in about 25% of the determinations, that a higher density of growth of Streptococcus faecium var. durans (ATCC 8043) was obtained at an FAA concentration just below the completely inhibitory level than at one-half this concentration. This and other considerations suggested that FAAs may act not only as selective agents for resistant organisms but also as mutagens. Seven FAAs including amethopterin, pyrimethamine, trimethoprim, chlorguanide triazine, an experimental quinazoline, WR-158,122, and two experimental triazines, WR-99,210 and WR-38,839, were tested for mutagenicity in the Salmonella reversion assay developed by Ames et al. (1975). All were found to be negative for strains TA1535, TA1537, TA1538, TA98, and TA100, both with and without microsomal activation. These compounds were then tested as mutagens for three traits in the folic acid-requiring S. faecium. FAAs were shown to cause mutations to folic acid independence, rifampin resistance, and FAA resistance. It is postulated that the FAAs induce mutations by causing thymine deprivation in the folic acid-requiring host.
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PMID:Mutagenic studies of folic acid antagonists. 32 58

Discovery of an enlarged spleen in a child requires steps to identify the etiology. One hundred and seventy-eight patients seen over a four-year period (1985-1988) at the Cocody Teaching Hospital were reviewed. The incidence of splenic enlargement among pediatric inpatients was 1.6%. Males (n = 106) were more often affected than females (n = 72). Slightly over half the children (54.49%) were 0 to 5 years of age. The main clinical presenting features were fever (90%), anemia (72%), a decline in general health (36.50%), enlargement of the liver (33.50%), jaundice (26.50%), and enlarged lymph nodes (7%). Type II of Hackett's classification accounted for most cases (61.80%), followed by Type III (14%). Main etiologies included malaria (53%), salmonella infections (15%), sickle cell anemia (14%), schistosomiasis (9%), AIDS (3%), and thalassemia (2%). Malignancies (leukemia, lymphoma) were relatively infrequent. More than one etiology was found in 13 cases. The distribution of etiologies by age group was determined and a strategy for investigating children with splenic enlargement in tropical countries was developed.
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PMID:[Etiology of splenomegaly in children in the tropics. 178 cases reviewed at the university hospital center of Abidjan-Cocody (Ivory Coast)]. 131 90

PCR was used to screen EBV-positive lymphomas from endemic and sporadic Burkitt's lymphoma patients, including EBV-positive lymphomas derived from patients with HIV infection. Only 10% of sporadic lymphomas from either North America (1/15) or South America (2/14) were associated with the type 2 EBV strain, whereas 50% (8/16) of lymphomas from equatorial Africa and 46% (10/22) of HIV-associated lymphomas were positive for the type 2 strain. These data, in conjunction with previous reports, suggest that the proportions of strain types in Burkitt's lymphoma reflect the proportions of strain types in peripheral lymphocytes, and not simply the prevailing regional strain. The increased association of the type 2 strain in lymphocytes and lymphomas from HIV-infected individuals and from Africa may be a result of intermittent (malaria) or continuous (HIU) compromise of immune function in these populations.
Leukemia 1992 Sep
PMID:Epstein-Barr virus genotypes in AIDS-associated lymphomas are similar to those in endemic Burkitt's lymphomas. 132 81

A free radical is any species capable of independent existence that contains one or more unpaired electrons. Free radical reactions have been implicated in the pathology of more than 50 human diseases. Radicals and other reactive oxygen species are formed constantly in the human body, both by deliberate synthesis (e.g. by activated phagocytes) and by chemical side-reactions. They are removed by enzymic and nonenzymic antioxidant defence systems. Oxidative stress, occurring when antioxidant defences are inadequate, can damage lipids, proteins, carbohydrates and DNA. A few clinical conditions are caused by oxidative stress, but more often the stress results from the disease. Sometimes it then makes a significant contribution to the disease pathology, and sometimes it does not. Several antioxidants are available for therapeutic use. They include molecules naturally present in the body [superoxide dismutase (SOD), alpha-tocopherol, glutathione and its precursors, ascorbic acid, adenosine, lactoferrin and carotenoids] as well as synthetic antioxidants [such as thiols, ebselen (PZ51), xanthine oxidase inhibitors, inhibitors of phagocyte function, iron ion chelators and probucol]. The therapeutic efficacy of SOD, alpha-tocopherol and ascorbic acid in the treatment of human disease is generally unimpressive to date although dietary deficiencies of the last two molecules should certainly be avoided. Xanthine oxidase inhibitors may be of limited relevance as antioxidants for human use. Exciting preliminary results with probucol (antiatherosclerosis), ebselen (anti-inflammatory), and iron ion chelators (in thalassaemia, leukaemia, malaria, stroke, traumatic brain injury and haemorrhagic shock) need to be confirmed by controlled clinical trials. Clinical testing of N-acetylcysteine in HIV-1-positive subjects may also be merited. A few drugs already in clinical use may have some antioxidant properties, but this ability is not widespread and drug-derived radicals may occasionally cause significant damage.
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PMID:Drug antioxidant effects. A basis for drug selection? 172 62

After 1940, the number of splenectomies performed in the United States and elsewhere increased rapidly. Splenectomy for Banti's disease and malaria decreased gradually into disrepute. Removal of the spleen for idiopathic thrombocytopenic purpura, congenital spherocytic anemia and acquired hemolytic anemia became accepted practice. However, debate still continues regarding the proper indications for splenectomy in Gaucher's disease, Felty's syndrome and leukemia.
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PMID:The spleen and splenectomy. 194 96

Epstein-Barr virus and HTLV-1 are both lymphotropic viruses, capable of immortalizing lymphocytes in vitro (Fig. 1). Both viruses have been sequenced and subjected to intense molecular biologic scrutiny, and in both cases genes believed to be important in lymphocyte immortalization have been identified. These viral genes are not homologues of cellular oncogenes, nor is there any evidence to suggest insertional mutagenesis. Rather, these genes alter the expression of a variety of cellular genes and, in so doing, alter the growth characteristics of the host cell. Infection with either virus is most likely to be asymptomatic, associated with a benign self-limited lymphoproliferation, or both, but in a small fraction of instances these benign lymphoproliferations give rise to a lymphoma or leukemia. In the case of the Epstein-Barr virus, a variety of cofactors have been identified that are important to the evolution of malignancy. These cofactors include immunosuppression in transplant recipients, cogenital immunodeficiency in the X-linked lymphoproliferative syndrome, human immunodeficiency virus infection in AIDS patients, and malaria in patients with endemic Burkitt's lymphoma. In the case of HTLV-1, cofactors have not been identified. Nonetheless, the importance of cofactors is suggested by the small fraction of the population infected by the virus who actually develop lymphoproliferative disease, and the long latency period between infection and the development of frank lymphoproliferative disease. In organ transplant recipients with lymphomas associated with Epstein-Barr virus infection, the EBV immortalizing/transforming genes are expressed in the malignant tissue. But in Burkitt's lymphoma and in adult T-cell leukemia/lymphoma, the EBV and HTLV-1 immortalizing/transforming genes are not detectably expressed. In Burkitt's lymphoma, it is suggested that the dysregulated myc gene renders the growth effects of Epstein-Barr virus latency genes superfluous. No comparable proto-oncogene translocation or activation has yet been identified in HTLV-1 lymphoma/leukemia.
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PMID:Human lymphotropic viruses associated with lymphoid malignancy: Epstein-Barr and HTLV-1. 217 3

One hundred and eighteen patients with chronic leukaemias were seen at the Lagos University Teaching Hospital, Nigeria, between 1964 and 1982. There were 75 patients with chronic granulocytic leukaemia (CGL) and 43 patients with chronic lymphocytic leukaemia (CLL). Although most of them presented with the familiar features of chronic leukaemias, a few features were remarkably different from those reported in some of the Caucasian series. CLL is less common than CGL in contrast to their relative incidence in Caucasians. Our patients generally presented with more massive splenomegaly and more severe anaemia, which could be attributed to late presentation, endemic malaria and possibly increased hypersplenism. The peak-age incidence in our patients with CGL was found in a younger age group (20-40 yr) than in the Caucasian series. When compared with a Caucasian series, our CGL patients on presentation had a significantly higher proportion of immature cells (blasts and promyelocytes) (P less than 0.05), probably reflecting their more delayed presentation. Follow up was generally poor as a result of a high default rate. Survival duration of both leukaemias was generally lower than in Caucasian series and for CGL patients there was a significant negative correlation between survival and spleen size at presentation, while for CLL patients there was a significant association between poor survival duration and high white cell count at presentation.
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PMID:Chronic leukaemia: an African experience. 261 22

Serum samples from 850 individuals from Venezuela were tested for the presence of antibodies to HTLV-III/LAV virus, the probable etiological agent of acquired immune deficiency syndrome (AIDS). At the time of the study, none of the individuals tested had symptoms indicative of AIDS or related disorders. Viral antibodies were assayed by indirect immunofluorescence (IF) assay, using a chronically infected, HTLV-III/LAV producer cell line CEM/LAV-NIT established in our laboratory. Twenty individuals (2.5%), 8 of them (40%) female, were seropositive by IF and by confirmatory Western blotting and radioimmunoprecipitation assays. The seropositivity rate ranged from 2.4% (11 of 465) in the general healthy population, 4% (2 of 50) among patients with Chagas' disease, and up to 29.2% (7 of 24) among patients with acute malaria infection. The titers of HTLV-III/LAV antibodies ranged from 1:40 to 1:640. In addition, 2 of 36 patients with hemophilia A (5.5%) also had antibodies to HTLV-III/LAV. Two of 7 patients with acute malaria had specific antibodies both to HTLV-III/LAV and HTLV-I, as determined by IF and Western blotting. None of over 169 randomly chosen, healthy blood donors from seven major Venezuelan cities, as well as none of 99 patients with leukemia/lymphoma, had antibodies to HTLV-III/LAV. The presence of specific antibodies among various Venezuelan populations indicates that HTLV-III/LAV, or a closely related cross-reactive virus, is indigenous in Latin American subjects as was previously indicated for tropical populations of central Africa. Isolation and characterization of this virus will help to understand the origin and etiology of AIDS.
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PMID:Antibodies to acquired immune deficiency syndrome (AIDS)-associated virus (HTLV-III/LAV) in Venezuelan populations. 301 23


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