Search results for "Nucleoside"
showing 10 items of 166 documents
Patterns of transmitted HIV drug resistance in Europe vary by risk group
2014
BACKGROUND: In Europe, a continuous programme (SPREAD) has been in place for ten years to study transmission of drug resistant HIV. We analysed time trends of transmitted drug resistance mutations (TDRM) in relation to the risk behaviour reported. METHODS: HIV-1 patients newly diagnosed in 27 countries from 2002 through 2007 were included. Inclusion was representative for risk group and geographical distribution in the participating countries in Europe. Trends over time were calculated by logistic regression. RESULTS: From the 4317 patients included, the majority was men-having-sex-with-men -MSM (2084, 48%), followed by heterosexuals (1501, 35%) and injection drug users (IDU) (355, 8%). MSM…
Transmission of drug-resistant HIV-1 in Europe remains limited to single classes
2008
BACKGROUND: The spread of drug-resistant HIV-1 might compromise the future success of current first-line regimens. OBJECTIVE: To analyse the extent and impact of transmission of drug-resistant HIV-1 variants in Europe. DESIGN AND METHODS: The European prospective programme (SPREAD) collected demographic, clinical and virological data from 1245 HIV-1-infected individuals in 17 countries diagnosed in 2002-2003. The potential impact of transmitted drug resistance mutations (TDRMs) on therapy response was determined by using genotypic interpretation algorithms. RESULTS: The overall prevalence of viruses with drug-resistance mutations was 9.1% [96/1050; 95% confidence interval: 7.5-11.1]. The ma…
Add-on peginterferon alfa-2a to nucleos(t)ide analogue therapy for Caucasian patients with hepatitis B ‘e’ antigen-negative chronic hepatitis B genot…
2019
Nucleos(t)ide analogues (NAs) and peginterferon have complementary effects in chronic hepatitis B, but it is unclear whether combination therapy improves responses in genotype D-infected patients. We conducted an open-label study of peginterferon alfa-2a 180 μg/week added to ongoing NA therapy in hepatitis B e antigen (HBeAg)-negative, genotype D-infected patients with HBV DNA <20 IU/mL. The primary endpoint was proportion of patients with ≥50% decline in serum HBsAg by the end of the 48-week add-on phase. Seventy patients received treatment, 11 were withdrawn at week 24 for no decrease in HBsAg, and 14 withdrew for other reasons. Response rate (per-protocol population) was 67.4% (29/43) at…
No pol mutation is associated independently with the lack of immune recovery in patients infected with HIV and failing antiretroviral therapy
2011
An investigation was undertaken to determine whether specific pol mutations hinder long-term immune recovery regardless of virological response. In total, 826 patients with >50 HIV RNA copies/ml, who underwent genotypic resistance testing between 1 January 2000 and 31 December 2003 after >3 years of antiretroviral treatment, and were followed up for >3 years after genotypic resistance testing, were analyzed retrospectively. The outcome of the study was the lack of immune recovery after >3 years of follow-up, defined as a slope by linear regression 50 copies/ml divided by the number of HIV RNA measurements during follow-up. Logistic regression was used for univariable and multivariable analy…
Modulation of the nuclear-envelope nucleoside triphosphatase by poly(A)-rich mRNA and by microtubule protein.
1982
Nuclear envelopes contain a nucleoside triphosphatase which is thought to be involved in the supply of energy for nucleo-cytoplasmic RNA transport. This enzyme is stimulated most efficiently by poly(A) and to a lesser extent by poly(G) and poly(dT). Half-maximal stimulation of the enzyme from rat liver nuclei, which was associated with the poly(A)-specific endoribonuclease IV and was free from poly(A) polymerase and endoribonuclease V activity, was determined to occur at a concentration of 1.1 × 106 poly(A) molecules/nuclear ghost. Double-reciprocal plot analyses revealed a 2.8-fold stimulation of the enzyme by poly(A). Poly(A) in the hybrid form had no influence on the activity of the nucl…
Differential effect of insulin and epidermal growth factor on the mRNA translocation system and transport of specific poly(A+) mRNA and poly(A-) mRNA…
1990
The efficiency of efflux of rapidly labeled poly(A)-containing mRNA from isolated rat liver nuclei was found to be modulated by insulin and epidermal growth factor (EGF) in a biphasic but opposite way. At physiological concentrations (10 pM insulin and 1 pM EGF), maximal stimulation of the transport rate by insulin (to 137%) and maximal inhibition by EGF (to 69%) were obtained; at higher concentrations (greater than 100 pM and greater than 10 pM, respectively), the amount of poly(A)-containing mRNA released into the postnuclear supernatant was nearly identical with the level found in untreated nuclei (= 100%). Using mRNA entrapped into closed nuclear envelope (NE) vesicles as a model system…
Proteins from rat liver cytosol which stimulate mRNA transport. Purification and interactions with the nuclear envelope mRNA translocation system.
1986
Two polysome-associated proteins with particular affinities for poly(A) have been purified from rat liver. These proteins stimulate the efflux of mRNA from isolated nuclei in conditions under which such efflux closely stimulates mRNA transport in vivo, and they are therefore considered as mRNA-transport-stimulatory proteins. Their interaction with the mRNA-translocation system in isolated nuclear envelopes has been studied. The results are generally consistent with the most recently proposed kinetic model of mRNA translocation. One protein, P58, has not been described previously. It inhibits the protein kinase that down-regulates the NTPase, it enhances the NTPase activity in both the prese…
Modeling interactions between Human Equilibrative Nucleoside Transporter-1 and other factors involved in the response to gemcitabine treatment to pre…
2014
Background Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy, characterized by largely unsatisfactory responses to the currently available therapeutic strategies. In this study we evaluated the expression of genes involved in gemcitabine uptake in a selected cohort of patients with PDAC, with well-defined clinical-pathological features. Methods mRNA levels of hENT1, CHOP, MRP1 and DCK were evaluated by means of qRT-PCR in matched pairs of tumor and adjacent normal tissue samples collected from PDAC patients treated with gemcitabine after surgical tumor resection. To detect possible interaction between gene expression levels and to identify subgroups of patients a…
Role of Kras Status in Patients with Metastatic Colorectal Cancer Receiving First-Line Chemotherapy plus Bevacizumab: A TTD Group Cooperative Study
2012
Background: In the MACRO study, patients with metastatic colorectal cancer (mCRC) were randomised to first-line treatment with 6 cycles of capecitabine and oxaliplatin (XELOX) plus bevacizumab followed by either single-agent bevacizumab or XELOX plus bevacizumab until disease progression. An additional retrospective analysis was performed to define the prognostic value of tumour KRAS status on progression-free survival (PFS), overall survival (OS) and response rates. Methodology/Principal Findings: KRAS data (tumour KRAS status and type of mutation) were collected by questionnaire from participating centres that performed KRAS analyses. These data were then cross-referenced with efficacy da…
Binding of benzo(a)pyrene metabolites to cellular DNA in perfused rat lungs
1978
The influence of pretreatment with monooxygenase inducers on total irreversible binding of metabolically activated [3H]-benzo(a)pyrene to cellular DNA and the formation of benzo(a)pyrene metabolite-deoxyribonucleoside adducts after cytochrome P-448 induction was studied in perfused rat lungs. Pretreatment with the cytochrome P-448 inducer beta-naphthoflavone increasing binding by a factor of 23. In lungs of induced animals, 0.45 pmoles of benzo(a)pyrene equivalents were bound per mg DNA. Binding to RNA and to protein was also considerably induced by beta-naphthoflavone. Phenobarbital treatment did not significantly increase binding to cellular macromolecules of rat lung. Analysis of hydroly…