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

Recombinant reverse transcriptase (RT) of HIV-1 was conjugated to beta-D-galactosidase from Escherichia coli in three different ways. Maleimide groups were introduced into beta-D-galactosidase molecules using N,N'-o-phenylenedimaleimide in the absence (method I) or presence (method II) of N-ethylmaleimide or into beta-D-galactosidase molecules, which had been treated with excess of 4,4'-dithiodipyridine to block thiol groups, using N-succinimidyl-6-maleimidohexanoate (method III). Subsequently, the maleimide groups were reacted with thiol groups introduced into recombinant RT molecules using N-succinimidyl-S-acetylmercaptoacetate. The conjugates were tested by a sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay). The immune complex consisting of 2,4-dinitrophenyl-bovine serum albumin-recombinant RT conjugate, anti-HIV-1 IgG and recombinant RT-beta-D-galactosidase conjugate was captured by polystyrene beads coated with (anti-2,4-dinitrophenyl group) IgG, eluted with N epsilon-2,4-dinitrophenyl-L-lysine and transferred to polystyrene beads with (anti-human IgG gamma chain) IgG. The conjugate prepared by method III, which showed the least polymerization, the least loss of the specific enzyme activity and the lowest nonspecific binding, improved the sensitivity of the enzyme immunoassay for anti-HIV-1 IgG approximately 30-fold compared with RT-horseradish peroxidase conjugate.
 ...
PMID:Conjugation of recombinant reverse transcriptase of HIV-1 to beta-D-galactosidase from Escherichia coli for ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) of anti-HIV-1 IgG. 751 83

Anti-HIV-1 IgG in urine was detected by an ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant reverse transcriptase (RT), p17 and p24 as antigens, and beta-D-galactosidase from Escherichia coli as label. Anti-HIV-1 IgG in urine was reacted simultaneously with 2,4-dinitrophenyl-bovine serum albumin-recombinant protein conjugate and recombinant protein-beta-D-galactosidase conjugate. The immune complex formed, consisting of the three components, was trapped onto polystyrene balls coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG. After washing, the immune complex was eluted from the polystyrene balls with excess of epsilon N-2,4-dinitrophenyl-L-lysine and transferred to clean polystyrene balls coated with affinity-purified (anti-human IgG gamma-chain) IgG. Finally, the enzyme activity bound to the last solid phase was assayed by fluorometry. Using recombinant RT as antigen, the sensitivity and specificity for 83 seropositives and 100 seronegatives were both 100%, and the lowest signal for 60 asymptomatic carriers was 8.2-fold higher than the highest signal for the seronegatives. The positivity with recombinant RT as antigen could be confirmed by using recombinant p17 and p24 as antigens. The sensitivity could be improved by a longer assay of bound beta-D-galactosidase activity by using concentrated urine samples and by the combined use of recombinant RT, p17, and p24. Thus, reliable diagnosis of HIV-1 infection was possible for asymptomatic carriers.
 ...
PMID:Diagnosis of HIV-1 infection by detection of antibody IgG to HIV-1 in urine with ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant proteins as antigens. 752 37

The fundamental role played by reverse transcriptase (RT) in the replication of retroviruses has made this enzyme a key target in the chemotherapy of HIV infection. Since the replicative cycle of HIV is interrupted by RT inhibitors, the inhibition of HIV RT is currently considered as a useful approach in the prophylaxis and intervention of AIDS. The MeOH and water extracts of 41 medicinal plants used in Egyptian folk medicine were evaluated for their HIV-1 RT inhibitory effects, and inhibitory substances were identified from the fruit of Phyllanthus emblica that showed a potent inhibitory activity to HIV-1-RT. The enzyme activity was determined by the amount of tritium labeled-substrate incorporation into a polymer fraction in the presence of a template-primer. Of the plant materials tested, the fruits of Phyllanthus emblica L. (MeOH extract), Quercus pedunculata (MeOH and water extracts), Rumex cyprius (MeOH and water extracts), Terminalia bellerica (MeOH and water extracts), Terminalia chebula (MeOH and water extracts), and Terminalia horrida (MeOH extract) showed significant inhibitory activity with IC50 of 2-49 mcg/ml. However, in the presence of bovine serum albumin (BSA), the inhibitory potency of most of the extracts, except for P. emblica (MeOH extract) and T. chebula (water extract), was appreciably reduced by nonspecific binding of their ingredients with BSA. Through a bioassay guided-fractionation of the methanol extract of the fruit of P. emblica, putranjivain A (1) was isolated as a potent inhibitory substance with IC50 = 3.9 mcM, together with 1,6-di-O-galloyl-beta-D-glucose (2), 1-O-galloyl-beta-D-glucose (3), kaempferol-3-O-beta-D-glucoside (4), quercetin-3-O-beta-D-glucoside (5), and digallic acid (6). The inhibitory mode of action by 1, 2, and 6 was noncompetitive with respect to the substrate but competitive with respect to a template-primer. Furthermore, the stereochemistry of 1 was established in this paper by nuclear magnetic resonance spectroscopy.
 ...
PMID:Inhibitory effects of Egyptian folk medicines on human immunodeficiency virus (HIV) reverse transcriptase. 754 17

HIV-1 Rev protein directs nuclear export of pre-mRNAs and mRNAs containing its binding site, the Rev response element (RRE). To define how Rev acts, we used conjugates between bovine serum albumin (BSA) and peptides comprising the Rev activation domain (BSA-R). BSA-R inhibited Rev-mediated nuclear RNA export, whereas a mutant activation domain peptide conjugate did not. BSA-R did not affect the export of mRNA, tRNA, or ribosomal subunits, but did inhibit export of 5S rRNA and spliceosomal U snRNAs. BSA-R was itself exported from the nucleus in an active, saturable manner. Thus, the Rev activation domain constitutes a nuclear export signal that redirects RRE-containing viral RNAs to a non-mRNA export pathway.
 ...
PMID:The HIV-1 Rev activation domain is a nuclear export signal that accesses an export pathway used by specific cellular RNAs. 754 68

Infection of mice with the murine leukemia virus (LP-BM5) was evaluated as a model for the thrombocytopenia of HIV/AIDS. Percent 35S incorporation into platelets, platelet size, platelet count, platelet-associated immunoglobulins (PAIgG), and megakaryocyte size and number were evaluated over a period of 3-9 weeks postinfection (PI). Thrombopoietin from human embryonic kidney cells was administered to mice 9 weeks PI, and similar indices of platelet production were measured 2, 3, and 4 days after treatment with a biological preparation of thrombopoietin (thrombocytopoiesis-stimulating factor, or TSF). Platelet counts decreased in a time-dependent fashion (p = 0.0006) following infection, reaching a nadir at 8 weeks PI (82% of control values). Percent 35S incorporation into platelets also decreased over the 9-week period (p = 0.0001), falling to 63% of control values by week 9. Additionally, platelet volume increased in a linear fashion (p = 0.01), rising to 105% of control values by week 9. No changes in PAIgG were noted over the 9-week period. Megakaryocyte numbers in the femoral marrow were decreased at 8 weeks PI (p = 0.02, 78% of control values), while increased mean megakaryocyte size (p = 0.007, 116% of controls) was noted in the same animals. Increased numbers of naked megakaryocyte nuclei were observed at 3 weeks PI (p < 0.05, 208% of control values). Administration of 2 U/mouse of a highly purified preparation of TSF to virus-infected, thrombocytopenic mice resulted in increased thrombocytopoiesis, as compared to human serum albumin-treated, virus-infected controls.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Evaluation of murine leukemia virus infection as a model for thrombocytopenia of HIV/AIDS: mechanism of thrombocytopenia and modulation of thrombocytopenia by thrombopoietin. 754 11

Concern about false negative serology tests for infectious diseases in hemodiluted cadaver donors resulted in issuance of new regulations and guidelines from the FDA and CDC. Bone or tissue from donors receiving > or = 4 units of blood, blood products, colloids or crystalloids within 48 h of sampling must be quarantined unless: (a) a pretransfusion serum is available; or (b) an adequate algorithm is employed to ensure hemodilution is insufficient to alter test results, i.e. cause false negatives. Left undefined in these regulations is, what is an adequate algorithm and what amount of hemodilution would cause false negatives. A pretransfusion sample was not available for about 20% of our donors and many had incomplete infusion histories. We used the unambiguous quantitation of serum albumin and total protein to define hemodilution and, if present, hemoconcentration of sera by ultrafiltration to normal protein levels prior to serology testing. Control experiments showed excellent correlation between serum dilution and protein concentration (r > 0.99) and a quantitative recovery of 96.9 +/- 1.4% upon hemoconcentration. Known positive sera (CMV-Ab; HTLV-1Ab; HIV-1,2Ab; HBsAb; HCV-Ab; HBsAg) were spiked into normal sera and diluted up to 1:2000, well beyond detectable levels. A qualitative recovery of 100% and a quantitative recovery of 97.6 +/- 7.5% of antibody or antigen reactivity was achieved upon hemoconcentration and retesting. In two studies, 14% (30/210) and 43% (23/54) of cadaver donors had serum proteins below normal limits and their sera was hemoconcentrated.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Hemoconcentration prior to serology testing in hemodiluted cadaver bone and tissue donors. 757 36

1,1'-Dideoxygossypol (DDG), 1,1'-dideoxygossylic acid (DDGA), 8-deoxyhemigossypol (DHG), and 8-deoxyhemigossylic acid (DHGA) were synthesized and tested for their ability to inhibit the replication of HIV in vitro. The EC50 for DDGA was < 1 microM, and its threshold cytotoxicity was approximately 20 microM. DDG was less effective than DDGA against HIV and showed considerable toxicity at 5 microM. DHGA was ineffective against HIV and had very low cytotoxicity. DHG showed some anti-HIV activity, but the threshold cytotoxicity was 5 microM. The dissociation constants for the binding of the four compounds to human serum albumin were determined by fluorescence quenching titrations, and all four were found to have much lower affinities for albumin than the parent compound gossypol.
 ...
PMID:Synthesis and anti-HIV activity of 1,1'-dideoxygossypol and related compounds. 760 7

To investigate the mechanism of action of the 22-amino-acid HIV fusion peptide on HIV infection, we studied its influence on virus adsorption and HIV-induced syncytium formation. The effect of the peptide preparations on the synthesis of viral antigens in HIV-infected cell cultures was determined by antigen capture assay, and the inhibition of proviral DNA synthesis was detected by hybridization with a HIV-specific oligonucleotide probe after PCR amplification. Fusion peptides inhibited HIV-induced syncytium formation and antigen production in lytic infected cells, and this effect was increased in conjugation with bovine serum albumin or with synthetic net-charged polymer by its C-terminus. The association of peptide with carrier by N-terminus, or with positive-charged polymer or gelatin completely abolished its effect on HIV infection. No peptide preparations influenced HIV-1 chronically infected cells. Because peptide preparations blocked the HIV-specific DNA synthesis 2 hr after infection without influencing virus adsorption and reverse transcription, we concluded that the block of infection occurred during the penetration of virions through the cell membrane. On the basis of results obtained we propose that our peptide preparations could be used for anti-HIV chemotherapy. The possibility of the existence of receptors for gp41 N-terminal region on target cell membrane is discussed.
 ...
PMID:Inhibition of human immunodeficiency virus type 1 (HIV-1) penetration into target cells by synthetic peptides mimicking the N-terminus of the HIV-1 transmembrane glycoprotein. 768 57

Recent genetic experiments have suggested that tat transactivation of the human immunodeficiency virus type 1 (HIV-1) long terminal repeat requires functional upstream enhancer sequences--Sp1 sites, in particular. In these experiments, HeLa cell nuclear extracts were passed over affinity matrices containing chemically synthesized or bacterially expressed HIV-1 Tat. Assay of material that bound to and eluted from the Tat matrices revealed the presence of the Sp1 transcription factor. Other transcription factors (Oct and NF-kappa B) also bound to Tat matrices but with less efficiency--in parallel with the lower capacities of these binding motifs to confer Tat responsiveness on a basal HIV-1 promoter compared with Sp1 sites. Passage of nuclear extracts over matrices containing other neutral proteins, including bovine serum albumin, ovalbumin, and lysozyme, revealed no or reduced binding. Cross-linking experiments indicated that the purified Sp1 and Tat proteins can form multimeric complexes in the absence of other proteins. The region of Tat responsible for Sp1 binding was localized to a region encompassing residues 30 to 62. Immunoprecipitation experiments with HIV-1-infected T lymphocytes indicated coimmunoprecipitation of Tat and Sp1. These experiments extend previous genetic experiments and suggest a direct interaction between Tat and Sp1 during transactivation.
 ...
PMID:In vitro and in vivo binding of human immunodeficiency virus type 1 Tat protein and Sp1 transcription factor. 769 Apr 21

The enormous progress made in biotechnology and purification of plasma proteins (pp) and the demands to avoid risks of transmitting HIV, hepatitis and other virus infections by these have resulted in the development of numerous recombinant human (rh) pp, which are now about to be used as replacement therapy in transfusion medicine. Human rh albumin has been used in clinical trials last year, a competition to serum albumin can be expected in the next time. During the last decade, the genes or cDNA have been cloned and characterized for all relevant pp involved in blood coagulation. Beside the rh factor VIII (rh FVIII) which has been introduced clinically in 1991, the rh FVIIa is under investigation in patients with hemophilia A and inhibitors. After establishing of rhFIX in triple transgenic mice, the industrial potential will be evaluated in terms of scale up culturing and production. The valuation of advantages and drawbacks of the current rh pp in comparison to conventional pp will have to be determined in the last decade of our century.
 ...
PMID:[Recombinant plasma proteins for therapeutic use--status and developmental trends]. 769 61


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