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)

CD26 or dipeptidyl peptidase IV (DPP-IV) is a cell surface protease involved in T cell activation. Monoclonal antibodies (mAbs) directed against the CD26 molecule are able to stimulate CD26-expressing T cells. Although many different CD26-specific mAbs exist which are able to provide a triggering signal in T cells, little is known about their specific epitopes on the CD26 molecule. Whereas some mAbs were shown to compete with each other and to inhibit the association of adenosine deaminase (ADA) and human immunodeficiency virus 1 (HIV-1)-derived Tat protein with CD26, other CD26-specific mAbs obviously bind to distinct regions on DPP-IV. In the present study we have generated truncated versions of the human CD26 molecule and expressed them in COS-1 cells to study the binding pattern of a panel of 14 CD26-specific mAbs in confocal microscopy and, thus, correlated the CD26-specific mAbs epitopes with the binding region of ADA. We show that the majority of anti-CD26 mAbs is directed against the glycosylation-rich region of the molecule whereas the ADA-binding site could be located in the cysteine-rich region of DPP-IV. In contrast to binding experiments with purified ADA, which revealed a specific association with CD26 on CD26-positive Jurkat cells, HIV-derived Tat protein did not interact specifically with CD26 on transfected Jurkat cells, nor could Tat binding be competed by anti-CD26-specific mAbs.
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PMID:The adenosine deaminase-binding region is distinct from major anti-CD26 mAb epitopes on the human dipeptidyl peptidase IV(CD26) molecule. 1006 44

In the Winter 1989 issue, Anastos and Marte wrote about the neglect of women in defining and treating AIDS. Women in the AIDS epidemic, they wrote, are considered mainly as vectors of transmission to men or children, not as people who are themselves HIV-infected and victims of transmission. They are predominantly women of color who, by the dictates of poverty and racism, live in communities at high risk for HIV infection. They are subjected to demeaning attitudes, poor health care services, and tragically late diagnosis in many cases. In this article the authors examine the issues of reproductive rights and HIV testing in women hospitalized for childbirth. Wendy Chavkin continues the discussion on p. 19, focusing on the efforts of AIDS prevention programs to target women solely because of their reproductive function and on the lack of services available for women who are tested.
Health PAC Bull 1990
PMID:Women--the missing persons in the AIDS epidemic. Part II. 1010 16

Though at times tumultuous, the 6th International Conference on AIDS, hosted by in San Francisco, avoided the polarization of previous conferences and achieved a political success. Conference participants vehemently objected to the Immigration and Naturalization Service's policy of barring homosexuals and HIV carriers from entering the country, a practice that remained unchanged for the conference. Over 80 organizations boycotted the conference. Displeasure with US government policies was also evident when AIDS activists drowned out the speech by Secretary of Health and Human Services Louis Sullivan. While paper presentations by notable researchers appeared to be mostly a formality, since most of the information had already been published, useful exchanges did occur when scientists were, for a day, allowed to display abstracts on their latest research. But perhaps the most popular printed item on the conference was ACT UP's Research Agenda, a handout prepared by the AIDS activist group listing a series of drugs that should be tested and treatments that should be tried. Participants heard the disturbing news of the spread of the epidemic, of how 3.5 million Africans are infected, and of how Brazilian teenagers are at great risk of infection. Furthermore, participants discussed the high cost of AIDS care in the US (estimated at $85,000/patient) and the reluctance of insurance companies to cover AIDS-stricken patients. Aside from the exchange of information, the conference's real success came in the political arena, establishing itself as policymaker and champion of the affected.
Health PAC Bull 1990
PMID:AIDS at the beginning of the second decade. 1018 28

We evaluated a flow cytometric (FCM) two-color immunophenotyping of CD3+/CD4+ T-helper and CD3+/CD8+ T-suppressor lymphocytes in whole blood samples from HIV-infected individuals using monoclonal antibody reagents from three different manufacturers. Lymphocytes were firstly determined using CD45/CD14 in association with a forward scatter/side scatter gating strategy. CD3+/CD4+ and CD3+/CD8+ were then determined and compared. Reagents from all manufacturers showed good separation of lymphocytes, monocytes and granulocytes with high purity and recovery. There was a good correlation of the percentage of CD3+/CD4+ and CD3+/CD8+ lymphocytes amongst each of the manufacturer's reagents, but the fluorescent intensities of positive cells were not the same. This difference can result in poor discrimination of positive and negative non CD3 cells leading to erroneous results.
Asian Pac J Allergy Immunol 1998 Dec
PMID:Evaluation of monoclonal antibody reagents from three different manufacturers using flow cytometric two-color immunophenotyping. 1021

A new field-based similarity forcing procedure for matching conformationally-flexible molecules is presented. The method extends earlier work on similarity matching of molecules based upon the program MIMIC, by directly coupling a similarity function to a molecular mechanics force field. In this way conformational energetics are fully accounted for in the similarity matching process. Simultaneous similarity/conformational searches can then be undertaken within a Monte Carlo or molecular dynamics framework. Here, a Monte Carlo approach is used to provide a simple example of two HIV-1 reverse transcriptase inhibitors, nevirapine and alpha APA, that illustrates the basic characteristics of the method and suggests areas for further investigation.
Pac Symp Biocomput 1999
PMID:Field-based similarity forcing in energy minimization and molecular matching. 1038 Feb 15

To determine if the immunopathologic alterations of HIV-infected lymph nodes have any correlation with clinical stages in the northern Thai patients, we conducted a comparative analysis of immunopathologic features of lymph nodes between 25 HIV-infected patients from various clinical categories and 25 non-HIV individuals of reactive hyperplasia morphology of lymph node biopsies. The risk factors for HIV infection were all heterosexual. The majority of patients in clinical category A (PGL) showed a histopathologic pattern of explosive follicular hyperplasia, while category C (AIDS) patients demonstrated follicular involution and lymphocyte depletion on lymph node sections. Interestingly, weak reactivity for HIV p24 gag protein was detected within the germinal centers and scattering interfollicular lymphocytes in only 20% of the HIV-infected cases. Morphologically, the presence of MGCs was specific for HIV-infected lymph nodes. MGCs (hematoxylin & eosin stain) were found in 64% of the HIV-infected cases, which was significantly different from 4% found in control cases (p = 0.00002). By S-100 immunostaining, MGCs were demonstrated in all HIV-infected lymph node sections, while they were found in 32% of the control lymph nodes. Immunostaining with S-100 protein also revealed the appearance of syncytial ballooning and countable numbers of MGCs. High numbers of MGCs seemed to correlate with histologic and clinical changes. In conclusion, the HIV-infected patients had high numbers of MGCs or syncytia on lymph node sections in early stage and pre-AIDS conditions, which has never been reported before.
Asian Pac J Allergy Immunol 1999 Jun
PMID:Clinico-immunopathological alterations of lymph nodes from human immunodeficiency virus-infected patients in northern Thailand. 1046 43

We show that protein flexibility can be characterized using graph theory, from a single protein conformation. Covalent and hydrogen bonds are modeled by distance and angular constraints, and a map is constructed of the regions in this network that are flexible or rigid, based on whether their dihedral bonds remain rotatable or are locked by other interactions in the network. This analysis takes only a second on a typical PC, and interatomic potentials; the most time-consuming aspect of molecular dynamics calculations, are not required. Our preliminary work has shown that this approach identifies the experimentally observed, biologically important flexible regions in HIV protease and lysine-arginine-ornithine binding protein. Here we analyze three evolutionarily distant cytochromes c, and find strong similarity between their flexible regions, despite having only 39% sequence identity. Furthermore, we show how the structural flexibility increases as the weaker hydrogen bonds are removed, as would happen under thermal denaturation of the protein. This approach identifies the critical hydrogen bonds that cross-link the tertiary structure.
Pac Symp Biocomput 2000
PMID:Flexibility and critical hydrogen bonds in cytochrome c. 1090 68

CCR5, a chemokine receptor, is the principal coreceptor for macrophage-tropic HIV-1 which is the most important variant for viral transmission. It has been demonstrated that a homozygous genotype of a 32-bp deletion in CCR5 gene (delta32CCR5) shows a high degree of resistance to HIV-1 infection. To demonstrate that delta32CCR5 does exist in Thai natives, the CCR5 genotypes and allelic frequencies in 860 Thai injecting drug users (IDUs) were determined by PCR and DNA sequencing. Of these, six (0.7%) were CCR5/delta32CCR5 heterozygotes and no homozygote was found. The overall delta32CCR5 allelic frequency was 0.0035 and in HIV-1 seronegative (n = 490) and seropositive (n = 370) IDUs were 0.0051 and 0.0004, respectively, which were not significantly different (p = 0.3776). Here we report that the delta32CCR5 does exist in Thai IDUs as it is present in other human races. Such low allelic frequency may indicate that this mutation does not attribute a significant role in HIV-1 transmission in Thai IDUs.
Asian Pac J Allergy Immunol 2000 Jun
PMID:The first report of CCR5 delta 32 mutant in Thai injecting drug users. 1092 21

Every functional protein appears to have some conserved amino acids which are critically important to the basic structure and function of the protein and thus under purifying selection. Some proteins also have variable amino acids which, when changed, offer a selective advantage, and thus undergo adaptive evolution. These amino acids are also important to the structure and function of the protein, although in a different way. It seems that the selective pressure in every protein varies among sites. Maximum likelihood models developed recently for comparison of silent and replacement nucleotide substitution rates allow for variable selective pressures among amino acid sites, and provide a powerful approach to studying the evolutionary process of protein-coding genes. This paper applies the likelihood models to analyze a data set of 186 HIV-1 gp120 env gene sequences for comparison with a previous analysis of the same data set. The maximum likelihood analysis identified a number of sites under positive selection, some in the conserved regions of the protein.
Pac Symp Biocomput 2001
PMID:Maximum likelihood analysis of adaptive evolution in HIV-1 gp120 env gene. 1126 43

A new algorithm for inferring the evolution of within-host viral sequences is presented. A sequential-linking approach is developed so that a longitudinal phylogenetic tree can be reconstructed from sequential molecular data that are obtained at different time points from the same host. The algorithm employs a codon-based model, which uses a Markov process to describe substitutions between codons, to calculate nonsynonymous and synonymous substitution rates and to distinguish positive selection and neutral evolution. The algorithm is applied to a data set of the V3 region of the HIV-1 envelope genes sequenced at different years after the infection of a single patient. The results suggest that this algorithm may provide a more realistic description of viral evolution than traditional evolutionary models, because it accounts for both neutral and adaptive evolution, and reconstructs a longitudinal phylogenetic tree that describes the dynamic process of viral evolution.
Pac Symp Biocomput 2001
PMID:A new algorithm for analysis of within-host HIV-1 evolution. 1126 76


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