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)

7C8 is a mouse monoclonal antibody that is specific for the third hypervariable loop (V3 loop) of the human immunodeficiency virus type 2 (HIV-2) associated protein gp125. Fab fragments of 7C8 effectively neutralize HIV-2. 7C8 was expressed and purified from a hybridoma cell line in order to establish the molecular basis underlying the specificity of the 7C8 antibody for the V3 loop as well as the specific role of the elongated third complementarity-determining region of the heavy chain (CDRH3). The antibody was digested with papain and Fab fragments were purified using size-exclusion chromatography. Hanging-drop vapour-diffusion crystallization techniques were employed and the protein was crystallized in 50 mM ammonium sulfate, 100 mM Tris-HCl pH 8.5, 25%(w/v) PEG 8000 and 2.5%(w/v) PEG 400 at 275 K. The analysed crystals belonged to the rhombohedral space group P3(2)21, with unit-cell parameters a = b = 100.1, c = 196.8 A, and diffracted to 2.7 A resolution.
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PMID:Production, purification, crystallization and preliminary X-ray diffraction analysis of the HIV-2-neutralizing V3 loop-specific Fab fragment 7C8. 1957 45

Chronic hepatitis C is frequent and aggressive in HIV-positive patients. Identification of early predictors of response to anti-HCV therapy is needed for a lower rate of response and higher discontinuations, compared to HCV mono-infected subjects. The aim of our study was to evaluate the predictive value of virological response (VR) at week 4-8-12 of Pegylated interferon alpha-2b (PEG-IFN) plus ribavirin (RBV) on sustained virological response (SVR) in HIV-HCV co-infected patients. 100 patients were treated with PEG-IFN (1.5 mcg/Kg/w) plus RBV (> or =10.6 mg/kg/d) and randomized for 24-48 or 48-72 weeks, respectively for genotype 2-3 and 1-4, in case of response (HCV-RNA PCR negativity) at the end of standard therapy (24 weeks for genotype 2-3, 48 weeks for genotype 1-4). Transcription-Mediated Amplification (TMA) assay for HCV-RNA was also applied. 27 patients reached end-of-treatment response (9 genotype 1-4, 18 genotype 2-3), 21 achieved SVR (8 genotype 1-4, 13 genotype 2-3). 35 patients dropped, 15 due to side-effects. SVR was statistically related to lower baseline HCV-RNA and to VR at week 4-8-12, with PPV 64%, 53% and 58%, and NPV 81%, 96% and 88%, respectively. In 27 patients, TMA was performed and confirmed standard PCR, except in two cases of relapse, who were PCR negative but TMA positive at week-12. In conclusion, VR at week 8 showed the highest NPV on SVR (96%). The study of viral kinetics requires further investigations in HIV-positive patients to guarantee a cost-effective therapy and to guide individually the duration of treatment. In this setting, TMA might be useful.
Curr HIV Res 2009 Jul
PMID:Predictability of sustained virological response to pegylated interferon alpha-2b Plus ribavirin therapy by week-8 viral response in HIV-positive patients with chronic hepatitis C virus infection. 1960 82

An amphiphilic prodrug of anti-HIV nucleoside analogue, cholesteryl-phosphonyl zidovudine (CPNZ) was synthesized. An aqueous suspension containing CPNZ self-assemblies was obtained through injecting the ethanol solution of CPNZ and cholesteryl succinyl poly(ethylene glycol) 1500 (20:1, mol/mol) into water under agitation. Hydrophobic interaction may be the driving force of molecular self-assembly. The self-assemblies were nanoscale with approximately 100nm in size, and remained stable for a long time. Degradation of CPNZ self-assemblies was investigated in various environments including buffered solutions, plasma and rabbit tissue homogenates. CPNZ was degraded very slowly in neutral solutions but rapidly in various plasma with the half-lives (t(1/2)) of less than 20h. Tissue homogenates degraded CPNZ with varied rates depending on enzyme activity. CPNZ self-assemblies showed potent anti-HIV activity on MT4 cell model, the anti-HIV 50% effective concentration (EC(50)) of which was 1nM, only equal to 1/5 of AZT EC(50). CPNZ was rapidly eliminated from circulation and distributed into the mononuclear phagocyte system (MPS) including liver, spleen and lung after bolus intravenous administration of CPNZ self-assemblies followed slowly elimination. The possible products include AZT-5'-H-phosphonate, AZT and their derivatives. The MPS-targeted effect and high anti-HIV activity of CPNZ self-assemblies make them become a promising self-assembled drug delivery system (SADDS).
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PMID:Self-assembled drug delivery systems. Part 4. In vitro/in vivo studies of the self-assemblies of cholesteryl-phosphonyl zidovudine. 1964 18

The objective of this study was to synthesize derivatives of the anti-HIV drug stavudine (d4T) with more favourable physicochemical properties for transdermal delivery in an effort to increase transdermal penetration of stavudine and thus reduce the severe side effects associated with the dose-dependent oral therapy. The synthesis, hydrolytic stability, and in vitro human skin permeation flux of a series of novel methoxypoly(ethylene glycol) (MPEG) carbonates of stavudine are reported. The carbonates were synthesized in a two-step process by coupling the MPEG promoiety of various chain lengths to C-5' of d4T. In kinetic studies the carbonates proved to be markedly stable in weakly acidic phosphate medium (pH 5.0) with half-lives ranging from 16 to 58 days. The aqueous solubility increased as the ethylene oxide chain lengthened. However, there was no significant increase in the estimated solubility in octanol. In vitro in the phosphate buffer (200 mM; pH 5.0) almost all carbonates permeate the human skin. However, the most effective penetrant, the derivative with 3 ethylene oxide units in the side chain, exhibited a flux of 26.1 nmol/cm(2)/h as compared to 59.15 nmol/cm(2)/h of the parent drug stavudine. Thus, no permeation enhancement was observed during this study.
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PMID:Synthesis and in vitro transdermal penetration of methoxypoly(ethylene glycol) carbonate derivatives of stavudine. 1967 96

A method for studying steady-state kinetics of nucleotide analogues incorporation into DNA strand by non-gel CE (NGCE) with LIF was developed. Nucleoside analogue is a kind of antiviral agent used to inhibit viral replication in infected cells, especially HIV. Steady-state parameter K(m) for nucleotide analogues is determined to imply the relationship between nucleoside analogues and the enzyme in the DNA chain elongation and predict the antiviral efficacy in vivo. Samples were prepared by single nucleotide incorporation assays catalyzed by Taq DNA polymerase at 58 degrees C and HIV reverse transcriptase (RT) at 37 degrees C, and then were separated using NGCE under optimized conditions: 25 mmol/L Tris-boric-EDTA buffer (pH 8.0) with 7 mmol/L urea in the presence of 20% w/v PEG 35000 at 30 degrees C and -20 kV. K(m(dTTP)), K(m(d4TTP)) and K(m(AZTTP)) were measured by NGCE for the first time and their values for Taq DNA polymerase were 0.29+/-0.04, 32.1+/-3.3 and 74.5+/-6.6 micromol/L, respectively. For HIV RT, the values were 0.15+/-0.05, 0.31+/-0.03 and 0.17+/-0.03 micromol/L, respectively. The trend of data for HIV RT measured by NGCE was consistent with that measured by PAGE. The reported method by NGCE for the K(m) determination was powerful, sensitive and fast, and required less amounts of reagents compared with PAGE. It be employed as a reliable alternative method and further applied in other relative studies of nucleoside analogue substrates and DNA polymerases or RTs.
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PMID:Study on steady-state kinetics of nucleotide analogues incorporation by non-gel CE. 2011 62

A systematic review was conducted of the full economic evaluations of the cost-effectiveness of peginterferon alfa-2b (PEG-IFN alfa-2b) plus ribavirin (RBV) in the treatment of chronic hepatitis C (CHC). A total of 439 references were screened and 11 studies were included. The studies employed decision analytic Markov models in which hypothetical cohorts of patients progressed through a series of health states characteristic of the natural history of CHC. The studies analyzed various regimens of PEG-IFN alfa-2b plus RBV including stopping rules for different genotypes, and fixed or weight-based dosing of RBV. In all studies, PEG-IFN alfa-2b plus RBV was associated with favorable incremental cost-effectiveness ratios (ICERs) when compared with IFN plus RBV. Tailored treatment according to bodyweight dosing and circumscribed treatment for different genotypes improves ICERs further. Further cost-effectiveness analyses should consider the impact of antiviral treatment in subgroups of patients including those co-infected with HIV, hemophiliacs and patients who are retreated following previous treatment failure, where data are available.
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PMID:A systematic review of the cost-effectiveness of peginterferon alfa-2b in the treatment of chronic hepatitis C. 2052 20

Four double-drug HIV NRTI/NNRTI inhibitors 15a-d of the type [d4U]-spacer-[HI-236] in which the spacer is varied as 1-butynyl (15a), propargyl-1-PEG (15b), propargyl-2-PEG (15c) and propargyl-4-PEG (15d) have been synthesized and biologically evaluated as RT inhibitors against HIV-1. The key step in their synthesis involved a Sonogashira coupling of 5-iodo d4U's benzoate with an alkynylated tethered HI-236 precursor followed by introduction of the HI-236 thiourea functionality. Biological evaluation in both cell-culture (MT-2 cells) as well as using an in vitro RT assay revealed 15a-c to be all more active than d4T. However, overall the results indicate the derivatives are acting as chain-extended NNRTIs in which for 15b-d the nucleoside component is likely situated outside of the pocket but with no evidence for any synergistic double binding between the NRTI and NNRTI sites. This is attributed, in part, to the lack of phosphorylation of the nucleoside component of the double-drug as a result of kinase recognition failure, which is not improved upon with the phosphoramidate of 15d incorporating a 4-PEG spacer.
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PMID:[d4U]-spacer-[HI-236] double-drug inhibitors of HIV-1 reverse-transcriptase. 2060 72

NC-1 is a murine monoclonal antibody that specifically recognizes the six-helix bundle core of the human immunodeficiency virus type 1 (HIV-1) gp41. As such, it is a useful tool for probing gp41 conformations in HIV-1 membrane fusion. To establish the structural basis underlying the NC-1 specificity, X-ray crystallography was employed to solve its three-dimensional structure. To accomplish this, hybridoma-produced NC-1 antibody was first purified and digested with papain. Its Fab fragment was then purified using size-exclusion chromatography following Fc depletion using a Protein A affinity column. Finally, crystallization of NC-1 Fab was performed by the hanging-drop vapour-diffusion method and the protein was crystallized at pH 8.0 using PEG 6000 as precipitant. The results showed that the NC-1 Fab crystals belonged to the trigonal space group P3(2)21, with unit-cell parameters a = b = 118.7, c = 106.0 A. There is one Fab molecule in the asymmetric unit, with 67.5% solvent content. An X-ray diffraction data set was collected at 3.2 A resolution and a clear molecular-replacement solution was obtained for solution of the structure.
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PMID:Fab crystallization and preliminary X-ray analysis of NC-1, an anti-HIV-1 antibody that recognizes the six-helix bundle core of gp41. 2060 91

Tuberculosis (TB) is the second most deadly infectious disease behind the Human Immunodeficiency Virus (HIV). An effective pharmacotherapy has been available for more than 5 decades. However, the length of the treatment and the pill burden result in low patient compliance and adherence to the regimens. Nanotechnologies can overcome these basic technological drawbacks. The present work explored the molecular implications governing the encapsulation and water solubilization of RIF within flower-like micelles of poly(epsilon-caprolactone)-b-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCL-PEG-PCL) block copolymers. Ten derivatives of different molecular weight and hydrophobic/hydrophilic caprolactone/ethylene oxide ratio (CL/EO) were synthesized by a fast and high-yield Microwave-Assisted Polymer Synthesis (MAPS) technique; CL/EO values are determined by taking the ratios of the number of repeating units in the PCL and the PEG segments. The aggregation behavior of the copolymers was thoroughly investigated by means of surface tension (critical micellar concentration), dynamic light scattering (size, size distribution and zeta potential) and transmission electron microscopy (morphology). In general, the greater the central PEG segment, the larger the micelles formed. The physical stability was intimately associated with the molecular weight and the composition. Then, the encapsulation of RIF in the different copolymer families was evaluated, and the physical stability of the drug-loaded aggregates characterized. The micellar size appears as the most crucial property, this phenomenon being primarily controlled by the molecular weight of the PEG central block. Having expressed this, sufficiently high CL/EO ratios (and long PCL segments) are also demanded to attain stable micellar systems with cores that are large enough to host the bulky RIF molecule.
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PMID:Molecular implications in the nanoencapsulation of the anti-tuberculosis drug rifampicin within flower-like polymeric micelles. 2062 65

The combination of pegylated interferons (PEG-IFNs) and ribavirin represents the standard of care for the treatment of chronic HCV-infected patients, yet with a success rate around 50% in genotypes 1 and 4, high costs and side effects. Therefore, early prediction of sustained virological response (SVR) is a relevant issue for HCV-patients. We evaluated the association between SVR and decline of HCV-RNA at 48h in a prospective cohort of 145 HCV-patients treated with PEG-IFNs and ribavirin (males=69.1%; genotypes 1/4=51.0%; HIV-1 coinfected=6.7%). SVR was obtained in 65.5% of patients, while 16.6% experienced relapse and 17.9% no response. The first-phase of HCV-RNA decline clearly differentiated patients with SVR from relapsers and non-responders, independently of genotype (P<0.001). In univariate and multivariate analyses, different infralogaritmic thresholds of HCV-RNA decay at 48h were tested, observing the highest predictive potential at 0.5log: decays above this threshold showed a 76.2% negative predictive value for SVR, whereas decays >0.5log indicated a 6.8 odds ratio (95% C.I.: 2.0-23.2) for SVR after controlling for genotype, baseline viremia, adherence to therapy and HIV coinfection. Decays beyond the 0.5log threshold were also strongly associated with and highly predictive of early virological response (95.0% positive predictive value, P<0.001).
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PMID:Rapid prediction of sustained virological response in patients chronically infected with HCV by evaluation of RNA decay 48h after the start of treatment with pegylated interferon and ribavirin. 2070 36


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