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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A major question in the pathogenesis of AIDS encephalopathy and dementia is whether HIV-1 directly infects cells of the central nervous system (CNS). The propagation of HIV was attempted in six cell lines: three related and three unrelated to the nervous system. HIV was able to propagate in two human neuroblastoma cell lines and a lymphocytic cell line control but did not result in infections of African green monkey kidney cells, human cervix carcinoma cells, and one human brain astrocytoma cell line. Neuroblastoma cell lines infected with HIV showed peaks of reverse transcriptase activity at 10-14 days postinfection. After prolonged growth in cell cultures, one of the neuroblastoma cell lines showed multiphasic virus production, additional high peaks of reverse transcriptase activity, 20-fold greater than the first, lasting from 36 to 74 days and 110 to 140 days postinfection. The presence of HIV was confirmed by p24 antigen capture. The neuroblastoma cell lines had weak but detectable levels of CD4 immunoreactivity by immunoperoxidase and flow immunocytometric analysis. Although no T4-specific RNA sequences were detected by hybridization of Northern blots of total and poly A-selected RNA extracted from the two neuroblastoma cell lines by using a T4 specific complimentary DNA probe, monoclonal antibodies to the CD4 receptor blocked HIV infection in both neuroblastoma cell lines. Thus, the infection of neuroblastoma cells by HIV occurs in part by a CD4-dependent mechanism. Passaging the neuroblastoma cell lines weekly and bimonthly resulted in similar cell cycle-DNA content patterns for the more permissive cell line and with significant numbers of cells in the S phase. HIV-infected neuroblastoma cell lines provide an in vitro model for the evaluation of virus-host cell interactions and may be useful in addressing the issue of the persistence of HIV in the human CNS.
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PMID:HIV-1 propagates in human neuroblastoma cells. 170 60

Tryptophan (Trp) is an indispensable amino acid required for biosynthesis of proteins, serotonin and niacin. Indoleamine 2,3-dioxygenase (IDO) is induced by infections, viruses, lipopolysaccharides, or interferons (IFNs) and this results in significant catabolism of Trp along the kynurenine (Kyn) pathway. Intracellular growth of Toxoplasma gondii and Chlamydia psittaci in human fibroblasts in vitro is inhibited by IFN-gamma and this inhibition is negated by extra Trp in the medium. Similarly, growth of a number of human cell lines in vitro is inhibited by IFN-gamma and addition of extra Trp restores growth. Thus, in some in vitro systems, antiproliferative effects of IFN-gamma are mediated by induced depletion of Trp. We find that cancer patients given Type I or Type II IFNs can induce IDO which results in decreased serum Trp levels (20-50% of pretreatment) and increased urinary metabolites of the Kyn pathway (5 to 500 fold of pretreatment). We speculate that in vivo antineoplastic effects of IFNs and clinical side effects are mediated, at least in part, by a general or localized depletion of Trp. In view of reported increases of IFNs in autoimmune diseases and our earlier findings of elevated urinary Trp metabolites in autoimmune diseases, it seems likely that systemic or local depletion of Trp occurs in autoimmune diseases and may relate to degeneration, wasting and other symptoms in such diseases. We find high levels of IDO in cells isolated from synovia of arthritic joints. IFNs are also elevated in human immunodeficiency virus (HIV) patients and increasing IFN levels are associated with a worsening prognosis. We propose that IDO is induced chronically by HIV infection, is further increased by opportunistic infections, and that this chronic loss of Trp initiates mechanisms responsible for the cachexia, dementia, diarrhea and possibly immunosuppression of AIDS patients. In these symptoms, AIDS resembles classical pellagra due to dietary deficiency of Trp and niacin. In preliminary studies, others report low levels of Trp and serotonin, and elevated levels of Kyn and quinolinic acid in AIDS patients. The implications of these data in cancer, autoimmune diseases and AIDS are discussed.
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PMID:Implications of interferon-induced tryptophan catabolism in cancer, auto-immune diseases and AIDS. 172 46

Neuropathological investigations were carried out on 166 autopsies of HIV-seropositive patients, with and without AIDS. Opportunistic infections and lymphomas were present in about 50% of cases; 65 patients were bearers of HIV-encephalopathy. HIV core protein p24 was detected in few mono- and multinucleated macrophages (HIV-cells), only in cases with HIV-encephalopathy. In the CNS of HIV-positive, asymptomatic patients no histological or immunohistochemical abnormalities were seen. These findings let suppose that AIDS-Dementia is a result of a late infiltration of HIV-infected macrophages from the bloodstream into the brain and not due to an impairment of neuronal or glial cells infected by HIV in the early stages of the disease.
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PMID:[The CNS in AIDS and in asymptomatic HIV positive patients]. 172 27

Although the human immunodeficiency virus type 1 (HIV-1) is frequently isolated from the cerebrospinal fluid of infected patients, only a small percentage of patients are found to have clinical dementia or neuropathies (or both). The reasons for this remain unclear. In our study, serum neutralizing antibody titers against the human T cell leukemia virus-IIIB isolate of HIV-1 were tested in 10 patients with acquired immunodeficiency syndrome (AIDS) with neurologic complications and 20 patients with HIV infection without neurologic complications. Titers were significantly lower in the neuro-AIDS group, suggesting that impaired neutralizing antibody responses in this subpopulation of patients may be involved in the immunopathogenesis of AIDS encephalopathy.
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PMID:Neutralizing antibody responses in patients with AIDS with neurologic complications. 174 7

Whilst this conference presented no new or exciting breakthroughs in our understanding of the psychosocial or neuropsychological aspects of HIV disease, there were some useful contributions to our knowledge in these areas. Previous work suggesting that HIV seropositive individuals with HIV are no more likely to suffer poor psychosocial adjustment than matched HIV-controls. However, where psychiatric disorders are seen, the most common are adjustment disorders followed by drug and alcohol abuse. Mania, whilst quite rare, may be more commonly seen with HIV than should be expected. People with asymptomatic HIV infection appear to be no more likely to show a cognitive deficit than matched HIV-individuals and this appears to be equally true for gay men, intra-venous drug users and people with haemophilia. However, as the disease progresses, neuropsychological impairment, or even dementia, may be seen and when this occurs the pattern of decline appears to be precipitous rather than insidious.
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PMID:Neuroscience of HIV infection: basic and clinical frontiers. 178 84

Material of this study consists of data collected during treatment of HIV infected patients admitted to AIDS Clinic in Warsaw. This unit, as the first in Poland, hospitalized seropositive patients with various infectious problems. Psychiatric complication of HIV infection (which needed psychotropic medication) was already observed in the first patient, who died with AIDS diagnosis (in February, 1987). In this study data concerning patients in AIDS Clinic during 1990 are presented. In this time 89 HIV seropositive patients (11 of these were women) were admitted to the clinic. Fifty two patients (10 of them were women) were IV drug abusers. Other 33 patients were homosexual (among them 4 IV drug abusers). Eight patients were out of high risk groups for HIV infection. Twelve of 89 patients were newly AIDS diagnosed. Three of them were IV drug abusers. Nine of AIDS patients (one a drug abuser) died in 1990. In six of 12 patients with AIDS diagnosis (50%) neuropsychiatric disorders were stated: depressive syndromes (n = 2), dementia syndromes with severe neurological symptoms (n = 2), delirium syndromes (n = 2). Other 3 person were IV drug abusers. In this study all above mentioned cases and their treatment are described. Our data suggest that HIV seropositive patients with psychiatric disorders need very careful diagnosis and an individual therapeutic intervention.
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PMID:[Neuropsychological disorders in patients with symptomatic AIDS treated in 1990 at the Acquired Immunodeficiency Syndrome Clinic, Medical Academy, Warsaw]. 182 87

Quinolinic acid is an "excitotoxic" metabolite and an agonist of N-methyl-D-aspartate receptors. Of patients infected with human immunodeficiency virus type 1 (HIV-1) who were neurologically normal or exhibited only equivocal and subclinical signs of the acquired immunodeficiency syndrome (AIDS) dementia complex, concentrations of quinolinic acid in cerebrospinal fluid (CSF) were increased twofold in patients in the early stages of disease (Walter Reed stages 1 and 2) and averaged 3.8 times above normal in later-stage patients (Walter Reed stages 4 through 6). However, in patients with either clinically overt AIDS dementia complex, aseptic meningitis, opportunistic infections, or neoplasms, CSF levels were elevated over 20-fold and generally paralleled the severity of cognitive and motor dysfunction. CSF concentrations of quinolinic acid were significantly correlated to the severity of the neuropsychological deficits. After treatment of AIDS dementia complex with zidovudine and treatment of the opportunistic infections with specific antimicrobial therapies, CSF levels of quinolinic acid decreased in parallel with clinical neurological improvement. By analysis of the relationship between levels of quinolinic acid in the CSF and serum and integrity of the blood-brain barrier, as measured by the CSF:serum albumin ratio, it appears that CSF levels of quinolinic acid may be derived predominantly from intracerebral sources and perhaps from the serum. While quinolinic acid may be another "marker" of host- and virus-mediated events in the brain, the established excitotoxic effects of quinolinic acid and the magnitude of the increases in CSF levels of the acid raise the possibility that quinolinic acid plays a direct role in the pathogenesis of brain dysfunction associated with HIV-1 infection.
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PMID:Quinolinic acid in cerebrospinal fluid and serum in HIV-1 infection: relationship to clinical and neurological status. 182 18

Human immunodeficiency virus infection is frequently complicated by a syndrome of central nervous system dysfunction known as the acquired immunodeficiency syndrome dementia complex (ADC). The ADC is characterized by abnormalities in cognition, motor performance, and behavior, and it produces serious morbidity in a significant number of patients with acquired immunodeficiency syndrome. The pathogenesis of ADC is unclear, but appears to be caused by the human immunodeficiency virus itself, rather than by a secondary opportunistic process. Herein, we review the data regarding the pathogenesis of ADC and hypothesize a mechanism involving excitotoxicity and dopaminergic dysfunction. N-methyl-D-aspartate receptor antagonists may be of therapeutic benefit, as these agents may both limit glutamate-mediated neuronal dysfunction and improve dopaminergic neuronal function.
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PMID:Excitotoxicity and dopaminergic dysfunction in the acquired immunodeficiency syndrome dementia complex. Therapeutic implications. 184 34

The results of a study about psychiatric morbility in patients suffering from HIV infection treated in a psychiatric consulting department of a general hospital are presented. Out of one hundred of individuals studied, 93 showed a diagnosis in Axle I according to DSM-IIIR criteria for mental disorders classification. The diagnosis most frequently found was the one of disorders due to drugs dependence, in 41%; organic mental disorder in 29%; adaptation disorders in 15% and affective one in 5% of cases. In sixteen patients of the sample a follow-up was carried out finding ad evolution towards dementia. Diagnostic difficulties of this population and usefulness of carrying out a revision of diagnostic classifications usually employed are debated.
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PMID:[Neuropsychiatric aspects of HIV infection]. 185 24

The prevalence of neurosyphilis in human immunodeficiency virus type 1 (HIV-1)-seropositive (HIV+) persons was assessed during the course of a study of the neurological complications of HIV-1 infection. One hundred sixty-six asymptomatic HIV+ subjects, 63 neurologically symptomatic HIV+ subjects, and six at-risk HIV-1-seronegative (HIV-) control subjects underwent cerebrospinal fluid (CSF) analysis on entry into this longitudinal study. Three (1.8%) of the asymptomatic HIV+ subjects had both a reactive CSF VDRL test and a reactive CSF fluorescent treponemal antibody-absorption (FTA-ABS) test. Two of these three subjects had a history of appropriately treated early syphilis, and all had a reactive serum rapid plasma reagin test. Of the 63 neurologically symptomatic HIV+ subjects, one patient with dementia had both a reactive CSF VDRL test and a fluorescent treponemal antibody-absorption test. Subjective improvement in cognitive skills followed high-dose, intravenous penicillin therapy. Another subject had a penicillin-responsive myelopathy accompanied by a reactive CSF fluorescent treponemal antibody-absorption test result, but a nonreactive CSF VDRL. Unsuspected neurosyphilis is relatively common in our population of asymptomatic HIV+ subjects and may be responsible for neurological disease in a significant minority of neurologically symptomatic HIV+ persons. Cerebrospinal fluid examination should be performed in all HIV+ persons with a history of syphilis or serological evidence of syphilis, regardless of prior treatment. Additionally, neurosyphilis should be considered in the differential diagnosis of neurological disease in any HIV+ person.
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PMID:Neurosyphilis in human immunodeficiency virus type 1-seropositive individuals. A prospective study. 185 97


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