Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pathogenesis of neuropsychological abnormalities in patients with human immunodeficiency virus type 1 (HIV-1) encephalitis is obscure because neurons are not the target of infection and severe neuronal loss occurs only late during the disease. Moreover, there is evidence indicating that HIV dementia is not a homogeneous entity and could partially reverse after treatment with zidovudine. The finding that impaired axonal flow, evidenced by beta-amyloid precursor protein immunoreactivity, could contribute to the neuropsychological deficits prompted the present study. Brains of patients with full-blown acquired immunodeficiency syndrome (AIDS) were studied and findings compared with those of normal and abnormal control subjects. The presence of HIV-1 DNA was investigated by nested polymerase chain reaction; axonal abnormalities were detected by beta-amyloid precursor protein, ubiquitin immunohistochemistry, and silver staining. Accumulation of beta-amyloid precursor protein was observed in all the HIV encephalitis brains studied; the appearance of the immunostaining varied from globular structures to bundles of parallel formations. In 2 AIDS brains without pathological abnormalities, only the latter pattern was detected. The brains with trauma were strongly reactive with beta-amyloid precursor protein antibody and the different reactivity within them correlated with posttrauma survival, only globular structures being detected in the older cases. No correlation was found between the different pattern of beta-amyloid precursor protein reactivity and dementia in AIDS patients. These results show that widespread axonal injury is a constant feature in AIDS brains and suggest that it could play a role in the pathogenesis of the neuropsychological abnormalities of these patients.
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PMID:Accumulation of beta-amyloid precursor protein in HIV encephalitis: relationship with neuropsychological abnormalities. 922 83

The authors examined the possibility of replacing immunoperoxidase conjugates with silver sol (mean diameter of particles 9 nm) adsorption-bound to antispecies IgG in solid-phase enzyme immunoassay in microtitration plates. Experiments with commercial test systems Antigen and Recombitest-antiHIV-1,2 manufactured by the Vektor State Research Center of Virology and Biotechnology, Ministry of Health and Medical Industry of the Russian Federation, showed that the sensitivity of detecting anti-HIV with silver immunosols and boosting of the signal with physical development was no less sensitive than standard EIA with immunoperoxidase conjugate. Preparation of silver immunosols is simple, easily reproducible, and is based on sparing and economic use of immunoreagents.
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PMID:[Use of silver immunosalts for detecting HIV antibodies in microtiter plates]. 929 41

The presence of neuropsychological disturbances in HIV-positive, pre-symptomatic individuals is a controversial issue. Neuroimaging studies have not shown brain atrophy or hyperintensity in the white matter, whereas proton magnetic resonance spectroscopy has revealed some abnormality of cerebral biochemistry. Using an antibody to beta-amyloid precursor protein (beta-APP), we previously demonstrated frequent and widespread axonal changes in the brains of AIDS patients. In this study, we extended the use of beta-APP to asymptomatic patients in order to establish a possible morphological correlation with neuropsychological disorders. Brain samples from 29 patients were examined. Results showed bundles of beta-APP-positive axons in 8/29 cases (27%). The changes, seen in both superficial and deep white matter, were either focal or diffuse, could not be visualized by silver or ubiquitin stains, and did not coexist with any change in distribution or morphology of astrocytes and microglial cells. We conclude that in HIV-positive asymptomatic individuals, axonal changes: (a) may be related to the state of immune activation with consequent presence of toxic substances, including cytokines, observed in these patients; (b) may represent mild changes that could undergo repair, unless other pathological events, such as the supervening of the AIDS stage and the specific encephalitis, make them permanent.
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PMID:Axonal damage revealed by accumulation of beta-APP in HIV-positive individuals without AIDS. 937 Feb 37

A nested polymerase chain reaction (PCR) assay was investigated for detection of Pneumocystis carinii in 96 respiratory tract specimens from 82 children, of whom 28 were immunocompetent but with chronic lung disorders (CLD), eight had AIDS and P. carinii pneumonia (PCP), 16 had AIDS but no respiratory symptoms, and 30 were healthy immunocompetent children. Gomori methenamine silver stain (GMS) and indirect immunofluorescence assay (IFA) were performed in parallel. Of 36 specimens from children with CLD, 12 were P. carinii PCR-positive compared to 10 positive by GMS-IFA. Of eight specimens from children with AIDS and PCP, seven were P. carinii-positive by PCR and six by GMS-IFA, and of 22 specimens from HIV-positive children without respiratory symptoms, two were positive by PCR and none by GMS-IFA. P. carinii DNA was also detected by PCR in blood samples from four children with P. carinii-positive nasopharyngeal aspirates. Specimens from healthy children were negative for P. carinii by both PCR and GMS-IFA. Of the seven children with CLD, who were P. carinii-positive, two had clinical and microbiological improvement with co-trimoxazole treatment, two improved initially but relapsed, and one had P. carinii cysts persistently in follow-up specimens despite co-trimoxazole treatment. These results suggest an association between P. carinii and exacerbations of CLD in childhood, in the absence of HIV infection or other immunodeficiency syndromes.
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PMID:Detection of Pneumocystis carinii among children with chronic respiratory disorders in the absence of HIV infection and immunodeficiency. 956 99

Among the wall-less mycoplasmas only a few species have been identified with a capsule at their cell surface. Mycoplasma penetrans is a recently identified mycoplasma with unique morphology, isolated from HIV-infected patients. Using transmission electron microscopy, it was found that M. penetrans is surrounded by capsular material 11 nm (strain GTU-54-6A1) to 30 nm (strain HF-2) thick, which can be stained with ruthenium red and labelled with cationized ferritin. The polysaccharide composition of this capsule was indicated by its staining with periodic acid-thiocarbohydrazide silver proteinate and the abolition of ruthenium red staining of the cell surface by neuraminidase treatment. In addition, proteinase K treatment of the M. penetrans cells resulted in removal of the capsule, suggesting that polypeptides may contribute in anchoring it to the membrane or in its stability. Two different types of glycosylated material were detected in mycoplasma extracts by SDS-PAGE and periodic acid-Schiff staining. The first component was a high-molecular-mass material, which was heat- and proteinase-K-labile and which probably constitutes the capsular polymer. The other component was a low-molecular-mass glycolipid fraction, which was proteinase-K-, heat- and EDTA-resistant. The identification of a capsule at the M. penetrans cell surface is of particular interest for a mycoplasma which has been shown to adhere to various host cells and to penetrate into their intracellular compartments. The capsule may have significance in the pathogenesis of disease associated with infection by this organism.
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PMID:Identification of two glycosylated components of Mycoplasma penetrans: a surface-exposed capsular polysaccharide and a glycolipid fraction. 961 99

Renal specimens were obtained from 179 autopsies of persons autopsied in the Institute of Forensic Medicine, University of Bonn, from 1987 to 1997. All persons were known as intravenous drug addicts. All renal specimens were examined with hematoxylin-eosin, PAS, Siriusred and Gomori (methenamine silver trichrome stain) and investigated with primary antibody against LCA (leucocyte common antigen), CD 68, IgG and IgM. 105 specimens (61.7%) showed a mono-lymphocytic membranoproliferative glomerulonephritis (MPGN), 48 specimens (45.7%) deposits of IgM. No case with focal segmental glomerulosclerosis (FSGS) as reported in male African-American intravenous drug addicts was found. In 37 out of 54 cases, hepatitis antibodies were detected in serum and three out of these 54 cases were HIV-positive. Chronic hepatitis B and C are known to be associated with glomerulonephritis. We found some cases without detection of hepatitis antibodies but with severe glomerulonephritis. In contrast to African-American drug addicts, European drug addicts do not develop a FSGS but a MPGN, partly due to heroin or other adulterants and apparently independent from hepatitis infection.
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PMID:Heroin associated nephropathy--a post-mortem study. 972 75

Detection of P. carinii has increased with the use of polymerase chain reaction (PCR), particularly in sputum samples. In this study, sputum samples obtained from 30 immunosuppressed patients with respiratory symptoms (12 HIV-infected) were tested by standard cytochemical staining (Giemsa and methenamine silver), immunofluorescence (IF) staining and PCR for detection of P. carinii and the results were compared. Pneumocystis carinii was detected in 4, 8 and 13 sputum samples by cytological staining, IF test and PCR, respectively. Specific amplification bands were obtained in all sputum samples that were positive by both other tests. All tests gave negative results in sputum samples obtained from 5 HIV-infected asymptomatic patients and 22 non-immunosuppressed tuberculosis patients. Our observations suggest that PCR results were well correlated with P. carinii pneumonia (PCP), especially in non-HIV-infected patients. However, PCR positivity obtained in HIV-infected patients could be misleading in the diagnosis of PCP without careful clinical evaluation. Positive results obtained by Giemsa staining or IF test confirm diagnosis of PCP authoritatively. As a result, we suggest testing sputum samples by both PCR and IF techniques for detection of P. carinii.
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PMID:Comparison of cytochemical staining, immunofluorescence and PCR for diagnosis of pneumocystis carinii on sputum samples. 973 Feb 96

The use of systems to detect the presence of 24kd protein as well as the levels of antibodies to it, is very useful in the follow-up of HIV-1 infected individuals. To develop these systems it is necessary to have this protein purified. The present paper describes the purification of p24 starting from the semipurified viral flattening on saocaharose gradient, using immunoaffinity chromatography with monoclonal antibodies coupled to Sepharosa 4B activated with cyanogen bromide. For the characterization of the purified product it was used polyacrylamide gel electrophoresis with silver staining and immunoelectrotransference. As a result, it was obtained p24 which can be used for the development of diagnostic tools and monoclonal antibodies.
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PMID:[Purification of the natural 24kd (P24) of the type-1 human immunodeficiency virus (HIV-1) using immunoaffinity]. 976 78

Isoforms of aspartyl proteinase (Sap), which are encoded by at least nine related SAP genes, have been implicated to be a major virulence factor of the opportunistic yeast Candida albicans in experimental infections. Although it is generally assumed that proteinases are important for infections, detailed information on the pathogenetic role of Saps is still lacking. The same applies to the question whether the genes and corresponding isoforms of the enzyme are expressed during oral infection. For in vivo investigations, parts of the lesional oral epithelium were collected from three HIV-infected patients with oropharyngeal candidiasis. Immunoelectron microscopy was performed (pre- and post-embedding gold labeling with silver enhancement) using an anti-Sap murine monoclonal antibody directed against the gene products Sap1-3. It was possible to demonstrate expression of Sap antigens in each of the three samples of human oral candidiasis. This suggests that at least one of the genes SAP1-3 was expressed at the time of sample collection. Furthermore, a possible role of the enzymes during the interaction of yeast cells and mucosal cells is suggested: the majority of Sap antigens is secreted by those C. albicans cells that adhere directly to the epithelial surface. Sap immunoreactivity can be detected in particular at the site of close contact between C. albicans and epithelial cells, suggesting a pathogenetic role of the Saps in host-fungal interaction. Thus, inhibition of the enzyme might prove to be an important alternative in the prevention and treatment of candidiasis.
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PMID:In vivo expression and localization of Candida albicans secreted aspartyl proteinases during oral candidiasis in HIV-infected patients. 1008 19

The effect of 44 different metal ions (Ag+, Al3+, As(O-)2, Au3+, Ba2+, Be2+, Bi3+, Cd2+, Ce3+, CO2+, Cr(O2-)4, Cr3+, Cs+, Cu2+, Fe3+, Fe2+, Ga3+, Ge4+, Hg2+, Ir4+, La3+, Li+, Mn2+, MO6+, Ni2+, OS4+, Pb2+, Pt4+, Rb+, Rh3+, Sb5+, Se(O2-)4, Se(O2-)3, Sn2+, Sr2+, Th4+, T1+, U(O2+)2, V(O-)3, VO2+, W(O2-)4, Y3+, Zn2+, and Zr4+) on the activity of the reverse transcriptase (RT) of the human immunodeficiency virus (HIV-1) was investigated in vitro. For this study, the RT activity assay was carried out by means of an enzyme-linked immunosorbent assay (ELISA) kit, using the template/primer hybrid poly(A) oligo(dT)15, which required some modifications: (1) possible interfering metal chelators (such as EDTA) in the original lysis buffer were avoided, and a new buffer (50 mM Tris-NO3, pH 7.8) was used throughout; (2) an amount of 2 ng of RT per well was considered to be optimal after checking the linearity of the reaction with increasing amounts of enzyme; (3) an incubation temperature of 37 degrees C and an incubation time of 1 h were chosen after preliminary studies in a wide range of temperature and time. At an incubation temperature > or = 40 degrees C, there was a dramatic loss of enzymatic activity. In addition, when RT alone was preincubated for 1 h at 5 degrees C, 25 degrees C, and 37 degrees C, there was a large (83%) loss of activity at 37 C as compared to that at 5 degrees C. These results are indicative of enzyme thermolability, which is higher in the absence of substrates. The effect of metal ions on RT activity was tested using two different metal salt concentrations (10(-4) M and 10(-5) M). Under such experimental conditions, the presence of five metal ions (Pt4+, Ag+, Rh3+, Zn2+, and Hg2+) decreased the RT activity in a dose-response fashion. The observed order of effectiveness with respect to inhibition was Pt4+ > Ag+ > Rh3+ > Zn2+ = Hg2+. Estimated mean inhibitory concentrations (IC50) were 7.8 microM for (NH4)2PtCl6, 14.1 microM for AgNO3, 46.8 microM for RhCl3, 53.7 microM for Zn(SO)4, and 56.2 microM for Hg(NO3)2. Because these data are of the same order of magnitude as the corresponding values related to other RT inhibitors used in anti-AIDS therapy, metal compounds or their derivatives could give an interesting contribution in the development of new RT inhibitors for clinical use.
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PMID:Effects of trace metal compounds on HIV-1 reverse transcriptase: an in vitro study. 1032 22


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