Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0001175 (AIDS)
 120,706 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the hope of finding a treatable condition, the need for rapid diagnosis in HIV-seropositive patients with brain lesions is apparent. In order to evaluate the efficacy of stereotactic brain biopsy in AIDS patients, we retrospectively studied 25 HIV-infected patients undergoing stereotactic biopsy. Brain lesions were identified with gadolinium-enhanced MRI and/or contrast CT. Brain biopsy was performed using the system of Riechert. From 8 up to 15 small tissue samples from one or two targets were obtained in every patient. The biopsy material was examined cytologically, histologically (including electron microscopy), immunohistochemically and, in part, by animal test and polymerase chain reaction (PCR). A definite diagnosis was achieved in 92%. Diagnosis included primary central nervous system lymphoma (PCNSL) (10), toxoplasmosis (10), progressive multifocal leukoencephalopathy (2) and one case of co-existing toxoplasmosis and cytomegalovirus infection. Two biopsies were non-diagnostic. All PCNSLs showed polymorphic B-cell populations of high malignancy; accurate classification according to the Kiel classification was not possible. In 3 lymphomas Epstein-Barr nuclear antigen (EBNA) 2-mRNA could be detected by PCR and confirmed immunohistochemically by EBNA 2 expression. In 6 cases autopsy confirmed the biopsy diagnosis. Conventional histology was not sufficiently decisive for toxoplasmosis and progressive multifocal leukoencephalopathy, so that immunohistochemistry and animal tests became very important for a final diagnosis. With the help of different morphological and molecular biological techniques stereotactic brain biopsy appears to be an effective method in the diagnosis of HIV-associated brain lesions. In view of the marked radio- and chemosensitivity of PCNSLs it is mandatory to establish an early and accurate histological diagnosis for adequate treatment.
 ...
PMID:Stereotactic brain biopsy in AIDS. 132 43

To determine the prognostic value of CT and MRI in AIDS we studied the survival of patients with neurological involvement, in relation to the initial imaging results. Twenty-six initial CT and 15 MRI examinations of 41 patients were reviewed for the presence of cerebral atrophy and/or focal lesions. The mean survival time of patients with initially normal imaging was longer (700 +/- 89 days) than that of patients with isolated cerebral atrophy (326 +/- 65) or isolated focal lesions (202 +/- 97). The shortest survival (78 +/- 44 days) was found in patients with both cerebral atrophy and focal lesions. The risk of death in patients with atrophy alone was 3.6 times higher, that in patients with focal lesions alone 6.4 times higher, and in patients with both changes 19.3 times higher than in patients with initially normal imaging. Cerebral imaging with CT and/or MRI thus allows identification of AIDS-related cerebral changes and may contribute to assessment of prognosis.
 ...
PMID:CT and MRI: prognostic tools in patients with AIDS and neurological deficits. 133 69

Nervous system opportunistic infections are seen in about one fifth of AIDS cases and account for over 40% of the patients with neurological manifestations. Serious infections are seen in severely immunosuppressed patients, usually with CD4 counts of 200 ml-1 or less. The commonest is CMV, which can produce acute encephalitis, sometimes with focal hemisphere or brain-stem signs, dementia, retinitis, optic neuritis and an ascending radiculomyeloencephalitis. Cryptococcal meningitis is the most frequent fungal disease; a high degree of clinical suspicion is required in patients with fever, malaise, headache or seizures. Only CSF cultures are always positive; both serum and CSF cryptococcal antigen tests are highly sensitive and specific. Treatment with amphotericin B and flucytosine is successful in at least 70% of first episodes but side-effects are common. Without maintenance therapy 50% of patients relapse; fluconazole is recommended. Cerebral toxoplasmosis can present with focal cerebral or spinal cord signs but also as a diffuse encephalopathy; negative T. gondii serology is exceptional but positive serum titres are usually unhelpful. Treatment with sulfadiazine, pyrimethamine and folinic acid achieves good results in 90% of the first episodes, but side-effects are common. Appearances on CT scan or MRI may take several weeks to improve. The value of an empirical approach to treatment is well-established; an initial cerebral biopsy is difficult to justify. Without maintenance therapy a relapse rate of 50% can be expected; therapy with sulfadiazine and pyrimethamine may also prevent pneumocystosis. HIV disease appears to increase the likelihood of neurosyphilis, and the risk of relapse after conventional penicillin doses, in patients with syphilis; at least 3-4 weeks of appropriate therapy are recommended. A number of other diseases caused by viruses, fungi, bacteria and parasites are less common; these include progressive multifocal leukoencephalopathy, herpes simplex and zoster infections and tuberculosis.
 ...
PMID:Central nervous system opportunistic infections in HIV disease: clinical aspects. 134 47

Toxoplasma gondii is the cause of the most common opportunistic infection of the brain in AIDS but is extremely rare as the cause of a solitary lesion of the spinal cord. Symptoms are weakness of the lower limbs followed closely by paralysis unless diagnosed and treated early. We present such a case in an intravenous drug abuser with AIDS and emphasize that MRI is the diagnostic tool of choice and that the index of suspicion should be high in immunosuppressed patients.
 ...
PMID:Spinal cord toxoplasma lesion in AIDS: MR findings. 152 78

Increased concentrations of the excitotoxin quinolinic acid (QUIN) have been implicated in the neurologic deficits and brain atrophy that may accompany infection with the human immunodeficiency virus type-1. Key neuropathologic features of the AIDS encephalitis are replicated in some macaques following infection with the simian immunodeficiency virus (SIV). In the present studies, cerebrospinal fluid (CSF) QUIN concentrations increased within 2 weeks following infection of 11 rhesus macaques (Macaca mulatta) with a neurotropic sooty mangabey isolate of the simian immunodeficiency virus (SIVsm) and were sustained to greater than 2 standard deviations above uninfected control macaques. Highest CSF QUIN concentrations (up to 400-fold above pre-inoculation levels) were observed in 6 SIVsm-infected macaques with motor and behavioral abnormalities during life, brain atrophy on MRI scan and inflammatory lesions within the brain and meninges. Four of the 6 neurologic macaques deteriorated rapidly within 12 weeks after inoculation and had substantially larger increases in CSF QUIN levels than 2 other neurologic macaques and 5 macaques without neurologic signs which survived for longer than 37 weeks. Increases in serum QUIN and CSF kynurenic acid also occurred but generally to a lesser degree than the increases in CSF QUIN. In some animals, increases in serum L-kynurenine concentrations and reductions in CSF and serum L-tryptophan occurred and were consistent with activation of indoleamine-2, 3-dioxygenase, the first enzyme of the kynurenine pathway in extrahepatic tissues. CSF QUIN exceeded serum QUIN in 8.8% of samples from macaques with neurologic signs, supporting increased QUIN synthesis within the central nervous system. Production of [13C6]QUIN was demonstrated in one SIVsm-infected macaque and one uninfected control macaque following an intracisternal injection of [13C6]L-tryptophan and suggests that L-tryptophan is a substrate for QUIN synthesis within the nervous system or meninges, although the cellular localization of QUIN synthesis remain to be determined. We conclude that increases in kynurenine pathway metabolism occur in SIV-infected macaques and are most prominent in macaques with neurologic signs. Macaques infected with SIV offer a model to investigate the relationship between the metabolism of neuroactive kynurenines and neurologic disturbances associated with retroviral infection.
 ...
PMID:Relationship of neurologic status in macaques infected with the simian immunodeficiency virus to cerebrospinal fluid quinolinic acid and kynurenic acid. 153 32

This study was carried out to determine clinical features, abnormalities on CT scan and MRI, and course in patients with HIV-I-related progressive multifocal leukoencephalopathy (PML). There were 14 patients with a presumptive diagnosis of PML among 500 HIV-I infected patients with neurological complaints, examined between September 1982 and May 1991 in the University Medical Centre in Amsterdam by a neurologist. In these 14 patients clinical features, imaging abnormalities and course of the disease were analysed retrospectively. All patients presented with progressive focal neurological abnormalities. Cerebrospinal fluid analysis revealed aspecific abnormalities in 5/13 patients. CT scanning of the brain showed hypodense areas in the white matter, without mass effect and with contrast enhancing in only one patient. MR Imaging of the brain showed high signal intensity areas in white matter and in gray matter (10/13), without mass effect, and with contrast enhancement in two. Specimens for neuropathological examination were obtained from 7 patients; in all these cases the diagnosis of PML was confirmed. In patients with AIDS a presumptive diagnosis of PML can be based on clinical features, brain imaging abnormalities and course. However neuropathological confirmation remains the gold standard. Usually the course in these patients was steadily progressive. Most patients died within one year.
 ...
PMID:[Progressive multifocal leukoencephalopathy in AIDS]. 155 55

CT and MRI findings in 35 patients with the acquired immune deficiency syndrome (AIDS) and proven intracranial tuberculosis (TB) are presented. Over 90% of the patients were intravenous drug abusers and in two-thirds TB was the first manifestation of AIDS. CT was normal in one quarter, the most frequent findings being hydrocephalus (51%) and meningeal enhancement (41%), commonly seen together (31.5%). Meningeal enhancement was seen in 48% of the CT studies with intravenous contrast medium and in 3 cases studied with MRI and i.v. gadolinium DTPA, in 2 of which CT was negative. Parenchymal involvement was found in 37% of cases; MRI was more sensitive than CT for its detection. One quarter of the patients had ischaemic lesions, mainly in the basal ganglia. We confirm the usefulness of CT and the superiority of MRI in the diagnosis of intracranial TB and in differential diagnosis from other conditions likely to be found in these patients.
 ...
PMID:Intracranial tuberculosis in AIDS: CT and MRI findings. 155 31

In a prospective study to determine the incidence of clinical dementia in patients with AIDS and ARC, 29 men and 3 women, 19 with ARC and 13 with AIDS, were examined neurologically and neuropsychologically every 6 months for 2 years during a placebo-controlled zidovudine (AZT) licensing trial. Most received two MRI brain scans. Although no patient was clinically demented at baseline, 9 (28%) developed dementia during the 2 years. Progression to dementia was associated with neuropsychological deterioration and with worsening on MRI during a preceding 6-month period, but not with baseline treatment group assignment. The results suggest that patients at CDC Stage IV who do not receive antiretroviral treatment earlier in their illness may develop clinical dementia at an annual rate of about 14%.
 ...
PMID:Incidence of AIDS dementia in a two-year follow-up of AIDS and ARC patients on an initial phase II AZT placebo-controlled study: San Diego cohort. 162 57

Previous studies of the frequency of high-signal lesions in human immunodeficiency virus (HIV) infection have had methodological weaknesses regarding lack of control groups, differing machine strengths, and biased subject selection. To obtain a more accurate estimate of prevalence, MRI scans were performed on 243 HIV-positive and HIV-negative homosexual or bisexual men with no history of intravenous drug use. Axial T2-weighted (long TR/TE, spin-echo) MRI scans were rated blindly for presence of focal white matter high-signal lesions. Incidence of hyperintensities was low in all groups, although slightly higher in patients with AIDS, and was not associated with neuropsychological performance. The lower incidence of hyperintensities appears to relate to elimination of methodological problems in previous studies.
 ...
PMID:Magnetic resonance imaging of white matter lesions in HIV infection. 162 78

One hundred and one persons infected with human immunodeficiency virus (HIV-1), in whom other central nervous system infections or diseases were excluded, underwent brain CT and/or MRI at various stages of HIV-1 infection: 29 were asymptomatic (ASX), 35 had lymphadenopathy syndrome (LAS), 17 had AIDS-related complex (ARC), and 20 had AIDS. A control group of 32 HIV-1-seronegative healthy persons underwent brain MRI. The most common finding was brain atrophy, found in 9% of controls, and 31% of ASX cases, 29% of LAS, 59% of ARC and 70% of AIDS. Even the difference between the ASX or LAS groups and controls was significant. The changes were bilateral and symmetrical, and they were more severe at later stages of infection. Infratentorial atrophy was seen in the early stages; supratentorial atrophy became more pronounced at ARC, and generalized atrophy was typical of AIDS. Non-specific small hyperintense foci were found on MRI in 13% of controls and 6-15% of the infected groups. Larger, diffuse, bilateral white matter infiltrates were detected in 4 demented patients with AIDS. Four patients with AIDS and 1 with LAS had focal hyperintense lesions in the internal capsules, lentiform nuclei or thalamus, often bilateral on MRI. One patient with AIDS, examined with CT only, had low density in the lentiform nucleus. Loss of brain parenchyma can occur at an early stage of HIV-1 infection, and the atrophic process becomes more intense at later stages (ARC and AIDS). Parenchymal infiltration, seen as hyperintense areas on MRI, is most often associated with severe clinical symptoms, in the later stages of the disease.
 ...
PMID:Radiological study of the brain at various stages of human immunodeficiency virus infection: early development of brain atrophy. 163 Jun 7


1 2 3 4 5 6 7 8 9 10 Next >>