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Query: UMLS:C0085584 (encephalopathy)
 18,178 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Experimental intravenous challenge of five adult cats with the feline immunodeficiency virus Maryland isolate (FIV-MD) was investigated for its ability to induce neurologic abnormalities associated with the onset of immunodeficiency. Five 8-month-old cats were inoculated with 1000 median tissue culture infective dose of FIV-MD isolate, with five age-matched cats serving as uninfected controls. All FIV-MD-infected cats tested positive for serum antiviral antibodies and plasma viral DNA as detected by polymerase chain reaction at 2, 4, 10, and 16 months postinfection (PI). At 10 and 16 months PI, there was a significant reduction in the CD4/CD8 lymphocyte ratio, with all cats having a CD4/CD8 ratio of 1 or less. Total protein electrophoretic analysis of cerebrospinal fluid demonstrated a significantly increased albumin quotient at 4 and 16 months PI, representing a disrupted blood-brain barrier (BBB). At 16 months PI, all cats demonstrated a preferential increase in frontal cortical slow-wave activity compared with control cats. Serial evaluation of brainstem auditory evoked potential recordings revealed a prolongation of the interpeak latencies times over the study time. At least one abnormality was found over time in visual and somatosensory evoked potential testing in three and four infected cats, respectively. Comparing lymphocyte subtype ratios with neurologic testing revealed that every FIV-MD-infected cat exhibited an abnormality in at least one neurologic functional test with a concurrent CD4/CD8 count ratio of 1 or less. Overall, this study demonstrated that FIV-MD infection in adult cats results in a delayed-onset, progressive encephalopathy that parallels the decline in the CD4/CD8 lymphocyte ratio. Compared with prior information from pediatric FIV-MD-infected cats, these results indicate that age of infection influences the onset and severity of disease and may be associated with CD4 cell depletion in FIV-MD-infected cats, as seen in HIV-1-infected humans.
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PMID:Progressive encephalopathy associated with CD4/CD8 inversion in adult FIV-infected cats. 934 52

Less than half of the paediatric HIV infections recorded in Australia have resulted from perinatal transmission, but in recent years this has been the predominant mode of infection. There are 136 infants who are known to have been exposed perinatally to HIV in Australia: 49 of these are infected. Caesarean section is thought now not to reduce the risk of perinatal transmission (PNT); rather, the risk increases with duration of membrane rupture and rises rapidly after 4 h of membrane rupture. However, no data exist to show that interventions to expediate delivery after membrane rupture reduce the risk of PNT. Data such as these suggest that the majority of perinatal infections (probably about 60%) occur close to the time of delivery. While the overall risk of PNT for non-breast fed infants is approximately 20-25%, the risk of infection for the infant is considerably increased when there is evidence of increased maternal viral burden. Advanced maternal disease predicts that if the infant is infected there is more likely to be early progression of HIV than is the case for the less frequently infected infants of mothers who are asymptomatic. Bottle feeding may prevent infection of 10% of children exposed perinatally. Use of zidovudine by the mother in the third trimester and i.v. zidovudine during labour, followed by oral zidovudine for the infant for 6 weeks can reduce the PNT rate by two thirds, to about 8%. Approximately 3% of uninfected infants with perinatal HIV exposure may be found to be transiently virus positive but eventually become antibody negative and thus appear to have eliminated the virus. The risk of Pneumocystis carinii pneumonitis (PCP) cannot be predicted on the basis of CD4 count and it is recommended that all children of infected mothers commence PCP prophylaxis around the age of 6 weeks-2 months and continue that therapy until the age of 12 months or until it becomes clear that the infant is uninfected. The cumulative risk of AIDS increases rapidly during the first year of life to about 20%, then more slowly at a rate of about 2 or 3% a year. The shape of this curve reveals the bimodal progression of HIV disease in children. About 15-20% of children rapidly develop a severe immune deficiency, opportunistic infections and, in most cases, encephalopathy. There is a very high morbidity rate in this group of children, most of whom die before the age of 3 or 4 years. In contrast, 80-85% of children only become immunodeficient after a relatively long period, which is similar to or perhaps even longer than that in adults. Recent studies indicate that zidovudine antiviral monotherapy is no longer appropriate. While no clear alternative to monotherapy has emerged most would, wherever possible, commence antiretroviral therapy with a combination of two or three drugs including zidovudine plus didanosine or lamivudine. If a third drug is used it would probably be a protease inhibitor.
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PMID:Paediatric HIV update. 940 77

The chemokine receptors CCR5 and CXCR4 are co-receptors together with CD4 for human immunodeficiency virus (HIV)-1 entry into target cells. Macrophage-tropic HIV-1 viruses use CCR5 as a co-receptor, whereas T-cell-line tropic viruses use CXCR4. HIV-1 infects the brain and causes a progressive encephalopathy in 20 to 30% of infected children and adults. Most of the HIV-1-infected cells in the brain are macrophages and microglia. We examined expression of CCR5 and CXCR4 in brain tissue from 20 pediatric acquired immune deficiency syndrome (AIDS) patients in relation to neuropathological consequences of HIV-1 infection. The overall frequency of CCR5-positive perivascular mononuclear cells and macrophages was increased in the brains of children with severe HIV-1 encephalitis (HIVE) compared with children with mild HIVE or non-AIDS controls, whereas the frequency of CXCR4-positive perivascular cells did not correlate with disease severity. CCR5- and CXCR4-positive macrophages and microglia were detected in inflammatory lesions in the brain of children with severe HIVE. In addition, CXCR4 was detected in a subpopulation of neurons in autopsy brain tissue and primary human brain cultures. Similar findings were demonstrated in the brain of adult AIDS patients and controls. These findings suggest that CCR5-positive mononuclear cells, macrophages, and microglia contribute to disease progression in the central nervous system of children and adults with AIDS by serving as targets for virus replication.
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PMID:Localization of HIV-1 co-receptors CCR5 and CXCR4 in the brain of children with AIDS. 942 34

We investigated the impact of antiretroviral treatment on event-related potentials (ERP) as a possible marker of AIDS dementia. A total of 154 HIV-infected patients without central nervous system (CNS) neoplasm or opportunistic infection were examined and randomized to receive either zidovudine 500 mg/day or no antiretroviral treatment. The participants were prospectively examined by visually evoked ERP in a longitudinal design. Latencies and amplitudes of ERP were evaluated at the beginning of the study, after 1 year, and after 2 years. After 1 year, 98 patients could be analyzed, 47 of whom were taking zidovudine. In the treatment group, P3 latency was 419 +/- 55 msec at baseline and 424 +/- 52 msec at follow-up (not significant). In the patients without treatment, P3 latency was 437 +/- 42 msec at baseline and 462 +/- 53 msec at follow-up (p < .0001, Wilcoxon test). A significant inverse correlation existed between P3 latency and CD4 cell count in both groups. The increase of P3 latency in untreated patients and a stable P3 latency in treated patients could be confirmed in a subgroup analysis of 21 patients with a follow-up of three examinations in a 2-year period. Our data suggest that zidovudine has a positive impact on AIDS dementia as measured by ERP. This finding was observed in patients in different stages of HIV infection, thus suggesting that zidovudine is indicated in all stages of HIV infection to treat encephalopathy.
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PMID:Impact of antiretroviral treatment on AIDS dementia: a longitudinal prospective event-related potential study. 947 15

Electroencephalography (EEG) is a well-tolerated non-invasive method and is therefore well suited for repetitive examinations. We performed serial EEG's on 117 HIV patients without any clinical signs of secondary neuromanifestation in order to document electroencephalographic changes in the course of HIV infection. Clinical signs of HIV-associated encephalopathy presented 18 patients at the first examination and 23 at reexamination. EEGs were analyzed visually; there was a mean interval of 20.3 +/- 13.7 months between the first and the second examination. Significant slowing of background activity occurred in the course of the disease; the alpha rhythm decreased from 10.7 +/- 2.3 Hz to 10.0 +/- 2.4 Hz (P < 0.05) with an increase in amplitudes from 60.9 +/- 24.6 microV to 69.5 +/- 33.7 microV (p < 0.05). The percentage of spontaneous dysrhythmias also increased from 30.7% to 41.8% (P < 0.05); pathological findings provoked by hyperventilation increased from 13.6% to 18.2%. Foci occurred rarely and did not increase in frequency with time. CD4 cell counts decreased from 294.2 +/- 209.5/microliter to 188.7 +/- 208.3/microliter (P < 0.01). The results of this study indicate progressive CNS dysfunction with worsening of the immunostatus.
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PMID:[Routine electroencephalogram in follow-up of patients with HIV infections of different stages. A long-term study]. 967 71

The evolution of HIV infection acquired by vertical transmission is more rapid in children than in adults. Mean survival ranges from 75 to 90 months and only 70% of children reach the age of 6. The natural history has two different patterns. Approximately 15-20% of the children develop severe immunodeficiency with opportunist infections and encephalopathy in the first year of life and die within the first three years. In the remaining 80-85%, the progression of the disease is slower and they live for several years. It has been postulated that the first group is constituted by cases of intrauterine transmission, whereas transmission is closer to birth in the second group. Aside from the moment of transmission, other factors--maternal, infant, and viral--influence the evolution of the disease. There is a direct relation between the severity of maternal disease and the risk that the child will acquire opportunist infections or die in the early years of life. The evolution of the disease also depends on clinical manifestations. The development of opportunist infections, encephalopathy, and delayed height and weight gain are associated with rapid progression, whereas lymphoid interstitial pneumonia and parotitis are associated with a slower progression. Viral load probably is the factor that best predicts the course of infection, although the load values associated with slow or rapid progression have not been clearly defined. However, it is evident that the lower the viral load, the lower the risk of infection. Although the viral load may be undetectable at birth, it rapidly reaches very high values, higher than in adults. Moreover, the state of equilibrium may take several years to attain. In any case, a linear relation cannot be established between viral load and the risk of progression, so other markers must be evaluated, such as CD4.
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PMID:[Natural history of HIV infection in the child]. 967 96

A 2-year-old girl, who had prolonged thrush and spastic diplegia, was found to have a mother-to-child vertical transmission of human immunodeficiency virus type-1 (HIV). A brain computed tomography scan revealed a symmetrical calcification on the bilateral basal ganglia and periventricular white matter. She had an acquired immune deficiency syndrome (AIDS) encephalopathy of pure dominant pyramidal tract disorder without an intellectual deficit. Helper cell lymphocyte count (CD4) increased with the beginning of zidovudine (ZDV, also known as AZT) monotherapy but began to decrease after the 4th week to reach the baseline at 20th week. Zidovudine plus didanosine combination therapy was started at the 68th week, but because of intolerance, the combination was changed to ZDV plus lamivudine at the 98th week. By the 80th week, neither severe opportunistic infection nor deterioration of the neurological status was recognized, but chronic diarrhea appeared. The diarrhea advanced to the wasting syndrome at the age of 4 years and cytomegalovirus genome was confirmed in a biopsied specimen of the colon. Ganciclovir treatment was effective in stopping the diarrhea and increasing her bodyweight, but after the age of 5, resumption of diarrhea was followed by progressive emaciation and weakness. This work may provide some clues in treating children's AIDS.
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PMID:Encephalopathy and cytomegalovirus colitis in an AIDS child. 982 20

The first case of one of the most frequent intestinal microsporidians, Encephalitozoon intestinale, is reported from an AIDS patient in the Czech Republic. The patient experienced diarrhoea and was found to have microsporidia spores in stool. Species determination by electron microscopy confirmed the diagnosis of the microsporidian, E. intestinale. The CD4-count at the time of the diagnosis was 73 cells/mm3, IRI = 0.21. Only after symptomatic therapy and rehydration the patient stopped the complaining, and although he refused an antimicrosporidial therapy, the CD4-count one month later increased to 200 cells/mm3 and patient didn't suffered from diarrhoea. Six months after the first finding of microsporidia, the patient was admitted to the hospital care for progressive encephalopathy and developing wasting syndrome again with the intermittent diarrhoea. The patient was treated with albendazole at that time. Nevertheless, after 14 days of albendazole therapy, he still remained positive for E. intestinale spores in the stool (urine specimens remained negative for all the time). The patient died after a two-month hospitalisation and the apparent cause of death was purulent bronchopneumonia, wasting syndrome with microsporidiosis, and HIV encephalopathy. Generalised mycobacteriosis (MAC) was also found from the autopsy material.
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PMID:Encephalitozoon intestinale infection in an AIDS patient--a case report. 1008 22

Human immunodeficiency virus (HIV-1) infects the brain and causes a progressive encephalopathy in 20 to 30% of infected children and adults called AIDS dementia complex. Evidence from in vitro and in vivo studies suggests a role for the viral envelope glycoprotein gp120, as a mediator of neurotoxicity. However, the site of interaction of gp120 with neurons and astrocytes to mediate neuronal death is still unknown. Recently the chemokine receptors, CCR5 and CXCR4, have been identified as co-receptors together with CD4 for HIV-1 entry into the target cells, suggesting a possible role for these receptors in the pathogenesis of the HIV-1 infection in the brain. Here we report the expression of CCR5 and CXCR4 in many different rat brain areas. We also found both receptors in cultured type I astrocytes demonstrating that glial cells may represent an important target for chemokines in vivo. Indeed, the functional capacity of CXCR4 receptor in astrocytes was demonstrated showing that SDF 1 alpha induced an increase of intracellular calcium concentration.
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PMID:Expression of chemokine receptors in the rat brain. 1041 11

To describe the spectrum of epidemiological and major clinical manifestations of patients infected by human immunodeficiency virus type 1 (HIV-1) in a municipal hospital, a retrospective review was done of 53 HIV-1-infected patients who had been admitted to Taipei Municipal Jen-Ai Hospital between January 1990, and July 1996. The majority (94.3%) of the patients in the cohort were male. Peak incidence was found in the fourth decade (28.3%). Forty-four (83%) patients presented in the first hospital stay with acquired immunodeficiency syndrome (AIDS). The mean duration between establishment of diagnosis of HIV-1 infection and that of AIDS was 11.2 (0-84) months. Heterosexual transmission accounted for 54.7% of the infections in the study group, and bi-/homosexual men made up another 32%. Psychosis of new onset was noted in two patients. In all AIDS indicator conditions, Pneumocystis carinii pneumonia (PCP) was the leading opportunistic infection among AIDS patients. PCP was also on the top of initial manifestations of HIV-1 infection. One patient with Penicillium marneffei infection was diagnosed to have AIDS. The mean CD4 count at admission of AIDS patients was much lower than that of non-AIDS patients (32 vs. 297/microliter, p < 0.0005). During the follow-up period 24 of 53 patients died. Mean survival time of 23 expired patients after establishment of diagnosis of AIDS was 6.4 (0-29) months. The results indicated that males outnumbered females greatly in the number of cases. Sexual activity remained the most important route of infection. Psychosis of new onset may be an early manifestation of HIV-associated encephalopathy and requires more attention. In addition, the outcome was poor as most patients in this area did not become aware of risk of HIV-1 infection until they were seriously illed with full-blown AIDS that they would seek medical help. PCP was the most common incentive for medical consultation. Penicillium marneffei infection is endemic in southeast Asia, and should be classified as an AIDS indicator condition in Taiwan.
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PMID:Clinical experience of HIV/AIDS in a municipal hospital in Taiwan. 1059 14


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