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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 21-year-old black man with sickle cell disease who has received blood transfusions for 11 years because of recurrent stroke has had a decline in numbers of circulating lymphocytes and T4 cells over the past four years. Two and a half years ago persistent generalized lymphadenopathy developed, associated with a positive test for human immunodeficiency virus (HIV) antibody. For the past seven months he has had a pruritic maculopapular rash, primarily on the extensor surfaces of the extremities. Multiple skin biopsies revealed only nonspecific perivascular infiltrates of mononuclear cells. This rash appears to be an unusual manifestation of HIV infection, and may be an indicator of impending AIDS.
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PMID:Unusual chronic maculopapular rash associated with human immunodeficiency virus infection. 292 31

Approximately a third of adults and half of children with acquired immunodeficiency syndrome (AIDS) eventually suffer from neurological manifestations, including dysfunction of cognition, movement, and sensation. Among the various pathologies reported in the brain of patients with AIDS is neuronal injury and loss. A paradox arises, however, because neurons themselves are for all intents and purposes not infected by human immunodeficiency virus type 1 (HIV-1). This paper reviews evidence suggesting that at least part of the neuronal injury observed in the brain of AIDS patients is related to excessive influx of Ca2+. There is growing support for the existence of HIV- or immune-related toxins that lead indirectly to the injury or death of neurons via a potentially complex web of interactions between macrophages (or microglia), astrocytes, and neurons. Human immunodeficiency virus-infected monocytoid cells (macrophages, microglia, or monocytes), especially after interacting with astrocytes, secrete substances that potentially contribute to neurotoxicity. Not all of these substances are yet known, but they may include eicosanoids, that is, arachidonic acid and its metabolites, as well as platelet-activating factor. Macrophages activated by HIV-1 envelope protein gp120 also appear to release arachidonic acid and its metabolites. These factors can lead to increased glutamate release or decreased glutamate reuptake. In addition, gamma interferon (IFN-gamma) stimulation of macrophages induce release of the glutamate-like agonist quinolinate. Human immunodeficiency virus-infected or gp120-stimulated macrophages also produce cytokines, including tumor necrosis factor-alpha and interleukin-1 beta, which contribute to astrogliosis. A final common pathway for neuronal susceptibility appears to be operative, similar to that observed in stroke, trauma, epilepsy, neuropathic pain, and several neurodegenerative diseases, possibly including Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis. This mechanism involves the activation of voltage-dependent Ca2+ channels and N-methyl-D-aspartate (NMDA) receptor-operated channels, and therefore offers hope for future pharmacological intervention. This review focuses on clinically tolerated calcium channel antagonists and NMDA antagonists with the potential for trials in humans with AIDS dementia in the near future.
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PMID:AIDS-related dementia and calcium homeostasis. 784 72

Perhaps as many as 25-50% of adult patients and children with acquired immunodeficiency syndrome (AIDS) eventually suffer from neurological manifestations, including dysfunction of cognition, movement, and sensation. How can human immunodeficiency virus type 1 (HIV-1) result in neuronal damage if neurons themselves are for all intents and purposes not infected by the virus? This article reviews a series of experiments leading to a hypothesis that accounts at least in part for the neurotoxicity observed in the brains of AIDS patients. There is growing support for the existence of HIV- or immune-related toxins that lead indirectly to the injury or demise of neurons via a potentially complex web of interactions among macrophages (or microglia), astrocytes, and neurons. HIV-infected monocytoid cells (macrophages, microglia, or monocytes), after interacting with astrocytes, secrete eicosanoids, i.e., arachidonic acid and its metabolites, including platelet-activating factor. Macrophages activated by HIV-1 envelope protein gp120 also appear to release arachidonic acid and its metabolites. In addition, interferon-gamma (IFN-gamma) stimulation of macrophages induces release of the glutamate-like agonist, quinolinate. Furthermore, HIV-infected macrophage production of cytokines, including TNF-alpha and IL1-beta, contributes to astrogliosis. A final common pathway for neuronal susceptibility appears to be operative, similar to that observed in stroke, trauma, epilepsy, neuropathic pain, and several neurodegenerative diseases, possibly including Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis. This mechanism involves the activation of voltage-dependent Ca2+ channels and N-methyl-D-aspartate (NMDA) receptor-operated channels, and, therefore, offers hope for future pharmacological intervention. This article focuses on clinically tolerated calcium channel antagonists and NMDA antagonists with the potential for trials in humans with AIDS dementia in the near future.
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PMID:HIV-related neuronal injury. Potential therapeutic intervention with calcium channel antagonists and NMDA antagonists. 799 15

To characterize the factors affecting the decision to withdraw from dialysis, the authors compared patients withdrawing from dialysis (n=62) with patients dying from all other causes (n=242) over 21 years (1976-1996) in a single dialysis unit. Compared with those who died from other causes, patients who withdrew were older (67+/-11 vs 61+/-11 years); were more likely to have severe physical impairment (87% vs 62%) and severe restriction of activities of daily living (77% vs 46%); and had higher frequencies of congestive heart failure (81 % vs 62%), myocardial infarction (60% vs 42%), peripheral vascular disease (71 % vs 40%), and diabetes mellitus (66% vs 36%) (p < or = 0.014). Dialysis modality; duration of dialysis; the degree of family support; index of disease severity; the use of tobacco, alcohol, or illicit drugs; and the frequency of ischemic heart disease, dysrhythmia, pericarditis, cardiac arrest, cerebrovascular accident, hypertension, obstructive lung disease, cancer, and human immunodeficiency virus did not differ between the two groups. Stepwise logistic regression showed that dialysis during 1990-1996, severe limitation of activities of daily living, and diabetes mellitus were independent risk factors for withdrawal. During 1990-1996, 44% of the deaths were caused by withdrawal from treatment. In addition to other factors, dialysis in the 1990s is a strong predictor of withdrawal from dialysis. The reasons for the increased rate of withdrawal from dialysis in recent years, and the effect of this increased rate of withdrawal on mortality, need further evaluation.
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PMID:Twenty-one year mortality in a dialysis unit: changing effect of withdrawal from dialysis. 961 51

Very high mortality rates have been reported in large inner-city areas such as the South Bronx and Harlem in New York City, but also may occur in smaller US urban areas. Using published death rates for the South Bronx as the standard, the standardized mortality ratio was slightly lower than 1.00 for Hartford, Connecticut (population 139,739 in 1990), but more than 1.00 for three impoverished Hartford census tracts that contained public housing projects. Compared with the South Bronx, death rates in Hartford were lower for human immunodeficiency virus (HIV), injury-homicide, and alcohol-drugs, but higher for hypertension-stroke (in all three tracts) and cancer (in two of the three tracts). Variations in patterns of causes of death among impoverished US urban areas have implications for planning epidemiologic studies and targeting interventions.
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PMID:Mortality in Hartford, Connecticut: a comparison with the South Bronx, New York. 976 49

Programmed cell death contributes to the morbidity and mortality of several neurological disorders including stroke, Alzheimer's disease and human immunodeficiency virus (HIV)-associated dementia. Patients with HIV dementia show evidence of programmed cell death in brain. In vitro data demonstrates several neurotoxic products of macrophage infection that cause neural cell death, including tumor necrosis factor alpha (TNFalpha) and platelet activating factor (PAF). We treated human brain aggregate cultures with these cytokines and determined their effect on the mRNA and protein levels for Bcl-2, Bcl(x) and Bax alpha. TNFalpha and PAF differentially regulate the Bcl-2 family of proteins at a post-transcriptional level. Following TNFalpha treatment, Bcl-2 protein is significantly decreased, and at least one additional Bax isomer emerges. Bcl(xL) protein is slightly increased after treatment with either cytokine. We demonstrated that overexpression of Bcl-2 in brain aggregate cultures protects cells from TNFalpha-induced damage but has no effect on cell damage induced by PAF. We conclude that Bcl-2 and Bax alpha proteins play significant roles in modulating neural cell death from TNFalpha- but not from PAF-induced cell damage.
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PMID:Differential modulation of cell death proteins in human brain cells by tumor necrosis factor alpha and platelet activating factor. 982 63

Cases of herpes zoster ophtalmicus (HZO) with delayed contralateral hemiparesis caused by hemispheric stroke secondary to granulomatous angiitis have been reported and are a well-recognized complication of herpes zoster. Similar cases have been reported more recently during infection with human immunodeficiency virus (HIV). We describe two HIV+ patients without any clinical history of zoster dermatitis who developed a sudden hemiparesis followed 2 weeks later for one by an acute retinal necrosis. Computerized tomography (CT) scan, magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), and digital subtraction angiography (DSA) were performed and showed a hemispheric stroke with evidence of a segmental arteritis of the carotid syphon. Varicella zoster virus (VZV) was found in the cerebro spinal fluid (CSF) in the two patients and after puncture of the vitreous fluid of the patient with the acute retinal necrosis. These two cases exemplify the difficulty of diagnosis of stroke in HIV+ patients, which seems to be more frequent than in similarly aged non-infected patients and demonstrates that VZV needs to be taken in consideration and identified even without any past history of zoster dermatitis.
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PMID:Cerebral infarction associated with vasculitis due to varicella zoster virus in patients infected with the human immunodeficiency virus. 986 4

Glutamic acid is the principal excitatory neurotransmitter in the mammalian central nervous system. Glutamic acid binds to a variety of excitatory amino acid receptors, which are ligand-gated ion channels. It is activation of these receptors that leads to depolarisation and neuronal excitation. In normal synaptic functioning, activation of excitatory amino acid receptors is transitory. However, if, for any reason, receptor activation becomes excessive or prolonged, the target neurones become damaged and eventually die. This process of neuronal death is called excitotoxicity and appears to involve sustained elevations of intracellular calcium levels. Impairment of neuronal energy metabolism may sensitise neurones to excitotoxic cell death. The principle of excitotoxicity has been well-established experimentally, both in in vitro systems and in vivo, following administration of excitatory amino acids into the nervous system. A role for excitotoxicity in the aetiology or progression of several human neurodegenerative diseases has been proposed, which has stimulated much research recently. This has led to the hope that compounds that interfere with glutamatergic neurotransmission may be of clinical benefit in treating such diseases. However, except in the case of a few very rare conditions, direct evidence for a pathogenic role for excitotoxicity in neurological disease is missing. Much attention has been directed at obtaining evidence for a role for excitotoxicity in the neurological sequelae of stroke, and there now seems to be little doubt that such a process is indeed a determining factor in the extent of the lesions observed. Several clinical trials have evaluated the potential of antiglutamate drugs to improve outcome following acute ischaemic stroke, but to date, the results of these have been disappointing. In amyotrophic lateral sclerosis, neurolathyrism, and human immunodeficiency virus dementia complex, several lines of circumstantial evidence suggest that excitotoxicity may contribute to the pathogenic process. An antiglutamate drug, riluzole, recently has been shown to provide some therapeutic benefit in the treatment of amyotrophic lateral sclerosis. Parkinson's disease and Huntington's disease are examples of neurodegenerative diseases where mitochondrial dysfunction may sensitise specific populations of neurones to excitotoxicity from synaptic glutamic acid. The first clinical trials aimed at providing neuroprotection with antiglutamate drugs are currently in progress for these two diseases.
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PMID:The role of excitotoxicity in neurodegenerative disease: implications for therapy. 1033 61

Beta 2-glycoprotein I (beta2-GPI) is an antigenic target recognised by antiphospholipid antibodies found in association with the antiphospholipid syndrome (APS). In this study, the prevalence of Immunoglobulin M (IgM) and IgA anti-beta2-GPI antibodies was examined in APS patients and compared with IgG antibodies. In addition the value of measuring antibody isotypes and IgG subclass was investigated in the laboratory diagnosis of APS. A solid phase enzyme linked immunosorbent assay was established to measure IgG, IgM and IgA and IgG subclass antibodies to beta2-GPI in patients with APS and a variety of other thrombotic and non-thrombotic disorders. Raised levels of IgM anti-beta2-GPI antibodies were observed in 65% of patients with APS, 21% with systemic lupus erythematosus (SLE), 23% with rheumatoid factor, 4% with stroke, 5% carotid artery stenosis (CAS), 17% with a biological false positive serology for syphilis, 43% with infectious mononucleosis (IM) and 27% with human immunodeficiency virus (HIV). The median value for IgM antibodies to beta2-GPI for all these groups ranged from 2 to 7 arbitrary units (AU). Elevated levels of IgA antibodies to beta2-GPI were found in patients with APS (47%), SLE (13%), rheumatoid factor (26%), CAS (48%), stroke (25%), VDRL false positive serology for syphilis (33%), IM (47%) and HIV (7%). The median value of IgA antibodies to beta2-GPI in all of these groups ranged from 2 to 4 AU. Conversely the median value for IgG anti-beta2-GPI in APS patients was 112 AU compared to 1-4 AU in the other conditions examined. The presence of IgM and IgA antibodies to beta2-GPI was much less specific and sensitive for APS than IgG, with raised levels of these isotypes seen in a variety of thrombotic and non-thrombotic disorders. Elevated levels of IgG1, IgG2, IgG3 and IgG4 antibodies to beta2-GPI were detected in APS patients. While all four IgG anti-beta2-GPI antibody subclasses were represented in APS patients there appeared to be a significant overall skewing towards to the IgG2 subclass.
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PMID:Anti-Beta 2-glycoprotein I antibody isotype and IgG subclass in antiphospholipid syndrome patients. 1068 Jul 49

The objective of this study was to elucidate the mechanisms of an ischemic stroke in a human immunodeficiency virus, type 1 (HIV)-infected population. Several clinical and autopsy studies have suggested an increased incidence of strokes in HIV-infected persons. These studies have been performed on diverse populations with numerous confounds for strokes, including, drug abuse and coexistent opportunistic infection. Because of these confounding factors, it has been difficult to assess whether a unique stroke propensity exists among HIV-infected persons. A retrospective case-controlled study was carried out of patients registered in the Durban Stroke Data Bank (DSDB) (n=1298) located in KwaZulu Natal province of South Africa. Sixteen per cent of all strokes in young (<50 year old) black Africans living in KwaZulu Natal province on the east coast of South Africa reported to the DSDB occurred in association with HIV infection. This HIV-infected population was free of drug abuse and relatively devoid of opportunistic infections. The incidence rate of HIV in this stroke population paralleled that of the young black population at large, suggesting no significant overall increased rate of stroke in association with HIV. However, when compared to strokes occurring in an age- and sex-matched, HIV-seronegative control population, the cryptogenic stroke was more common in the HIV-infected population. Although the incidence of rate of stroke appeared to be no higher among HIV-infected young black Africans in the KwaZulu province than among HIV-seronegative controls, the increased incidence of a large vessel cryptogenic stroke in the former suggests the presence of a co-existent prothromobotic state.
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PMID:Cerebrovascular disease in young, HIV-infected, black Africans in the KwaZulu Natal province of South Africa. 1087 12


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