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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The southwestern region of Japan is known as a very high endemic area of human T-cell lymphotropic virus type 1 (HTLV-1), the etiologic agent for adult T-cell leukemia (ATL) and probable causative agent for tropical spastic paraparesis and its Japanese version, HTLV-1-associated myelopathy (HAM). Hemodialysis (HD) patients seem to be at high risk for HTLV-1 infection even in other regions of Japan because they sometimes receive multiple blood transfusions. We examined antibody against ATL-associated antigen (ATLA-Ab) in 1,132 HD patients, including 1,066 patients in nonendemic areas (Chubu and Tokyo) and 66 in a highly endemic area (Okinawa). The HD patients in Okinawa showed the highest prevalence, 21.2% (14/66), while those in the Chubu area showed the lowest, 1.1% (10/846), and those in the Tokyo area an intermediate value, 2.7% (6/220). The prevalence of HD patients in each area was significantly higher than that of local blood donors, reflecting an increased prevalence roughly corresponding to the respective endemic rate. The average prevalence of ATLA-Ab among the HD patients was 2.7% (30/1,132), which was similar to that of HBs antigen (3.2%). In the nonendemic areas, 15 of 16 patients with ATLA-Ab had a history of blood transfusions, showing a significant correlation to the presence of ATLA-Ab (P less than 0.01), although four had family histories related to the endemic area. The relative risk of the presence of ATLA-Ab for HD patients with a history of blood transfusions was calculated as 10.3. In the endemic area of Okinawa, the relationship to blood transfusion was not so close, probably masked by the high background prevalence.
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PMID:Prevalence of HTLV-1 antibodies in hemodialysis patients in Japan. 290 Dec 22

We report the immunological studies of 50 cases with a chronic progressive myelopathy associated with elevated antibodies to human T-cell lymphotropic virus type I (HTLV-I) and adult T-cell leukemia-like cells (HAM). These are as follows: (1) T-cell activation; (2) increase of the OKT4/OKT8 ratio, due mostly to increased inducer/helper T cells and/or decreased suppressor/cytotoxic T cells; (3) decrease of natural killer cell numbers and activity; and (4) increase of immunoglobulins (IgG, IgA). Our results provide evidence that autoimmune events may participate in the pathogenesis of HAM and may be relevant in the hypothesis of common immune mechanisms between HAM and HTLV-I positive tropical spastic paraparesis.
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PMID:Immunological studies of HTLV-I associated myelopathy. 297 11

Human T lymphotropic virus type 1 (HTLV-I) is a retrovirus which is prevalent in southern Japan, the Caribbean Basin, and Africa. Recent seroprevalence studies in the United States suggest that there are about 50,000 infected individuals. The identification of 5 individuals with HTLV-I-associated leukemia/lymphoma referred to our center with relatively limited screening methods suggests that these disorders are more common than currently appreciated. Though 99% of infected individuals remain asymptomatic, this virus may cause immunosuppression, lymphomas, or myelopathy. The lymphomas have been classified as acute or chronic forms of adult T cell leukemia-lymphoma (ATLL). Acute ATLL is a T cell form of non-Hodgkin's lymphoma in an HTLV-I-infected individual with leukemia, skin infiltration, or hypercalcemia. This disorder is poorly responsive to chemotherapy and all patients should be referred for experimental protocols. Chronic ATLL is an insidious disease characterized by lymphadenopathy, skin infiltration of less than 10% of the body surface, and/or atypical lymphocytes with highly convoluted nuclei which include 1 to 10% of the nucleated cells in the peripheral blood, but no visceral involvement or hypercalcemia. The prognosis of these patients is not clearly defined. All individuals with mature T lymphocytic malignancies should be evaluated with HTLV-I-specific assays. The most sensitive and specific assays available include the enzyme linked immunoadsorbent antibody assay (ELISA) and the polymerase chain DNA amplification reaction assay. With improved laboratory techniques and greater awareness of the characteristics of this disease by clinicians, it is likely that the natural history of HTLV-I infection will be better defined, and improvements in therapeutic management will be developed.
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PMID:Leukemias associated with human T-cell lymphotropic virus type I in a non-endemic region. 305 20

A number of viruses, parasites and bacteria can be transmitted by blood. Blood seronegative for cytomegalovirus (CMV), effectively prevents CMV infection in seronegative bone marrow recipients. Such blood is available at larger blood transfusion services. Immune anti-CMV globulin can also be helpful in protection of transplant recipients. Human T-lymphotropic virus, type 1 (HTLV-1) causing leukemia and myelopathy can also be transmitted by blood. Blood banks are considering donor screening in areas where the prevalence of this virus is significant. Parvoviruses that may cause crises in haemolytic anaemias present a potential hazard of transfusion. Malaria and syphilis are currently not very important infectious complications of transfusion, whereas prolonged storage of platelets has reemphasised the risk of bacterial growth in blood products.
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PMID:Transfusion transmitted infectious agents, excluding hepatitis and human immunodeficiency viruses. 306 85

Transient or permanent paraplegia after the use of intrathecal (IT) methotrexate (MTX) or cytosine arabinoside (Ara-C) for treatment or prophylaxis of patients with meningeal leukemia is an unusual complication, with an incidence of less than 3% among such patients. Only 15 cases involving IT MTX have been documented and even fewer with IT Ara-C. Three patients were studied who developed permanent or ascending myelopathy from treatment of their leukemia or rhabdomyosarcoma with IT chemotherapy. The patients' ages ranged from 7 to 62 years. Two of the three patients had electromyographic examinations. These revealed a primary motor neuron degeneration or a polyradiculopathy, superimposed on a mild axonal peripheral neuropathy associated with vincristine therapy. This is consistent with other electromyographic studies. Two of the patients showed an elevation of the cerebral spinal fluid (CSF) protein before development of paraplegia; one also showed a rise in myelin basic protein associated with his myelopathy. Neuropathologic findings suggest demyelination as the primary process leading to myelopathy. Increasing evidence has shown that total CSF protein, or more specifically, the myelin basic protein, may be elevated before development of paraplegia. Routine serial testing of the CSF for total protein could be used as a screening test during therapy.
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PMID:Paraplegia and quadriplegia after intrathecal chemotherapy. 321 64

T lymphocytes of patients with human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy (HAM) were cultured. After cultivating for several months, HAM-derived cell lines were tested for the presence of HTLV-1 proviral genome. We have found two major subgroups, the SacI type and the PstI type, of HTLV-1 by the restriction map analysis. They were almost equally distributed among HAM patients. We have also found two types of the provirus in DNA derived from fresh peripheral blood lymphocytes (PBL) or lymph node cells of adult T-cell leukemia/lymphoma (ATL) patients. The PstI type proviruses were predominant in ATL patients. It was concluded that two major subgroups of HTLV-1 exist in Japan and both types have an ability to cause either of two diseases, ATL or HAM.
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PMID:Two major subgroups of human T-cell leukemia virus-1 in Japan. 326 21

We describe a patient with progressive, irreversible, necrotizing myelopathy associated with myelomonocytic leukemia. The neuropathologic lesions consisted of diffuse necrosis, most pronounced in the cervical cord and affecting both the gray and white matter. These areas corresponded to areas of increased T2 on magnetic resonance imaging scans of the patient. We felt that there was no causal relationship of these lesions to any single antileukemic agent the patient received, and no other local or systemic causes were found to explain the lesions at necropsy. It is suggested that our case is an example of paraneoplastic necrotizing myelopathy. To our knowledge, this is the third case of necrotizing myelopathy associated with leukemia reported in the English medical literature, and the first one demonstrating usefulness of magnetic resonance imaging in diagnosis of necrotizing myelopathy.
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PMID:Progressive necrotizing myelopathy associated with leukemia: clinical, pathologic, and MRI correlation. 347 69

A transient cerebral disturbance characterized by somnolence of varying degree is described in children after cranial irradiation given as part of central nervous system (C.N.S.) prophylaxis for acute lymphoblastic leukaemia in remission.Out of 28 such children receiving cranial irradiation as part of the Medical Research Council protocol for C.N.S. prophylaxis 11 (39%) developed pronounced symptoms of somnolence, anorexia, and lethargy some six weeks after the completion of cranial irradiation, and a further 11 (39%) developed these features in mild form. In all cases the symptoms were transient, no focal neurological abnormality was detected, and all children made a spontaneous and complete recovery. E.E.G. studies on five somnolent children showed similar abnormal activity of diffuse and patchy distribution over both hemispheres. Indirect evidence is presented to support the concept that this syndrome represents a transient radiation encephalopathy, analogous to acute transient radiation myelopathy, caused by temporary disturbance of myelin synthesis.
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PMID:Somnolence after prophylactic cranial irradiation in children with acute lymphoblastic leukaemia. 451 11

A number of neurological disturbances occur during the treatment of childhood malignancies with cytotoxic drugs like vincristine, methotrexate, cytosine-arabinoside, cyclophosphamide, asparaginase and others. Neurological complications range from peripheral neuropathy, myopathy, myelopathy to encephalopathy with methotrexate induced encephalopathy leading to permanent brain damage or death in most cases. Irradiation of the brain can produce transient or permanent brain damage by a direct effect on nervous tissue and by altering the blood brain barrier or the blood circulation. The many conflicting reports concerning the quality of life of long-term survivors of childhood leukaemia do not give sufficient data for final conclusions. The experiences we have encountered over the past ten years seem to confirm the optimistic echo from others. There is, however, an urgent need for a prospective study to answer the all important question: will a child suffering from leukemia emerge physically and mentally unharmed after long and aggressive treatment?
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PMID:Therapy of acute lymphoblastic leukaemia in childhood: effects on the nervous system. 625 7

Eventually, gene therapy may be a valid option for chronic viral infections, including retroviral infections. Human retroviral diseases fit two categories: (1) those that result from a monoclonal outgrowth of a human T-cell leukemia virus type I (HTLV-I)-infected cell, as in the case of adult T cell leukemia (ATL); and (2) those that appear to result directly from virus load rather than monoclonal outgrowth--such as tropical spastic paraparesis/HTLV-I associated myelopathy (TSP/HAM) and human immunodeficiency virus (HIV)-associated acquired immune deficiency syndrome (AIDS). For ATL gene therapy, corrective mechanisms directed at regulatory sequences rather than viral sequences may be most important, though perhaps anti-tax therapy would be useful. For TSP/HAM and AIDS, gene therapy directed to control virus replication may be most useful. For anti-retroviral therapy, one may use dominant negative mutants and a variety of other approaches that direct toxins or compete out viral regulatory gene signal sequences. For maximum benefit, such therapy should be directed to different essential genes (eg gag, pol, env, tat or rev) involved in the virus replication cycle and utilize different toxic approaches. A major impediment to the use of gene therapy for AIDS is our inability to transfect a significant fraction of target cells in vivo. Except for reconstituted mice, retroviral systems of animals have been under-utilized as models for gene therapy. Naturally occurring retroviral diseases of cats, goats, horses, and other species provide models for future development.
Leukemia 1995 Oct
PMID:Gene therapy against retroviral diseases. 747 20


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