bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of Sustained Virological Response by Ribavirin Plasma Concentration at Week 4 of Therapy in Hepatitis C virus Genotype 1 Patients
Authors: Maynard Marianne , Pradat Pierre , Gagnieu Marie-Claude , Souvignet Claude , Trepo Christian 
Published: April 2022

Background Pegylated interferon/ribavirin combination is currently the standard treatment for chronic hepatitis C virus (HCV) infection. Body weight adjustment of ribavirin is crucial for response. However, previous studies found no relation between ingested dose and plasma concentration. The aim of this study was to define the ribavirin trough plasma concentration at week 4 (W4) associated with sustained virological response (SVR). Methods Thirty-one HCV genotype 1 patients (8 naive and 23 non-responders to a previous pegylated interferon/ribavirin therapy) were treated with pegylated interferon/ribavirin and assessed by HPLC for ribavirin plasma concentration at W4. Results Eleven patients (35%) achieved SVR, whereas 20 (65%) were non-responders. The median ribavirin plasma concentration at W4 (1.90 mg/l) varied from 1.62 mg/l in patients with subsequent non-response to 2.28 mg/l in sustained responders ( P=0.007). Receiver operating characteristic curve analysis indicated that the 2.01 mg/l threshold gave the best sensitivity and specificity (73% and 80%, respectively, area under the curve=0.80; P=0.007). Sixty-seven percent of patients with median ribavirin plasma concentration >2 mg/l achieved SVR versus only 16% below this level ( P=0.007). Multivariate regression analysis indicated that a ribavirin plasma concentration >2 mg/l at W4 was associated with SVR independent of gender, age, weight, baseline viral load and response to previous therapy. Conclusion These results, which remain to be confirmed in large clinical trials, highlight the potential relevance of ribavirin plasma level monitoring at an early stage of treatment. This monitoring could be of help in guiding antiviral therapy by offering dose adjustment in patients with ribavirin plasma level below the 2 mg/l threshold.
Comparison of DNA- and mRNA-Transfected Mouse Dendritic Cells as Potential Vaccines against the Human Papillomavirus Type 16 associated Oncoprotein E7
Authors: Dell Kerstin , Klein Corinna , Gissmann Lutz 
Published: April 2022

Background Dendritic cells (DCs) mediate the generation of strong cytotoxic T-lymphocyte (CTL) responses by functioning in antigen presentation and exerting adjuvant properties. We compared several activation markers and parameters of biological activity of DNA- and mRNA-transfected DCs in vitro and in vivo. Methods CpG-matured, bone marrow derived C57BL/6 mouse DCs were electroporated either with enhanced green fluorescence protein (EGFP) or human papillomavirus type 16 (HPV16) E7 expression plasmids or in vitro transcribed mRNAs encoding for the codon-optimized E7 or a shuffled version thereof. Activation marker expression and antigen presentation was analysed by fluorescence-activated cell sorting. The migratory behaviour of transfected DCs were investigated by in vitro chemotaxis experiments and cytokine expression by ELISA. CTL-priming capacity of transfected DCs were determined by vaccination of mice. Results mRNA transfection produced a two- to fourfold increase of the activation markers CD40, CD80, CD86 and MHC I and MHC II molecules. Predominately antigen-expressing DCs migrated after mRNA transfection. Furthermore, mRNA-transfected DCs were capable of inducing a chemokine gradient. After maturation, electroporation and activation with soluble CD40 ligand and interferon-γ, DCs displayed a T-helper cell type 2 cytokine expression pattern. Nevertheless, E7-transfected DCs were able to prime E7-specific CTL responses in vivo. The highest E7-specific CTL frequencies were found in mice immunized with mRNA-transfected DCs. The in vitro expanded CTLs exerted functional E7-specific cytotoxic activity. Conclusions Genetically modified DCs are suitable vehicles for the induction of E7-specific CTL responses in mice and hence could help to eradicate HPV-associated lesions in humans.
Very Early Viral Kinetics on Interferon Treatment in Chronic Hepatitis C virus Genotype 4 Infection
Authors: Jessner Wolfgang , Gschwantler Michael , Formann Elisabeth , Gurguta Calin , Watkins-Riedel Thomas , Wrba Friedrich , Ferenci Peter 
Published: April 2022

Background Interferon (IFN)-resistant hepatitis C virus strains limit efficacy of antiviral combination therapy in patients infected with genotypes 1 and 4. A single test dose of IFN was useful to identify non-responders to IFN-α2b/ribavirin (RBV) or likely non-responders to pegylated (PEG)-IFN-α2a/RBV therapy in genotype 1 patients. Our aim was to investigate this approach in genotype 4 patients. Methods Viral load was measured in 46 patients before and 24 h after 10 megaunits (MU) IFN-α2b, and before and during 2 weeks of daily 5 MU IFN-α2b administration. Thereafter, patients received 48 weeks combination therapy with either 180 μg PEG-IFN-α2a/week ( n=33), 1.5 μg/kg PEG-IFN-α2b/week ( n=7) or 5 MU IFN-α2b/2 days ( n=6), along with 1–1.2g RBV/day. For prediction analysis the largest group (PEG-IFN-α2a) was evaluated only. Results Median 24 h log10 change after 10 MU IFN-α2b was 1.15 (range 0.08–2.48) and after 5 MU IFN-α2b was 0.81 (-0.12–2.22; P<0.0001). Log10 changes after 2 weeks on 5 MU IFN-α2b daily and 24 h after 10 MU were the best predictors of early virological response (defined by negativity of a standard qualitative PCR) to PEG-IFN-α2a/RBV combination therapy (area under curve [AUC]=0.97; P<0.001, receiver operating characteristics), 24 h log10 change after 10 MU was the best predictor of sustained virological response (SVR; AUC=0.91, P=0.001). Conclusion As in genotype 1 patients, there is large variation in IFN responsiveness, including the presence of resistant strains, in genotype 4 patients. A 24 h log10 change after 10 MU IFN-α2b is an excellent predictor of SVR on PEG-IFNα2a/RBV combination therapy. This test may be useful to obtain homogeneous groups for clinical studies and could help in clinical decision making.
Prevalence and Risk Factors for Etravirine Resistance among Patients Failing on Non-Nucleoside Reverse Transcriptase Inhibitors
Authors: Lapadula Giuseppe , Calabresi Alessandra , Castelnuovo Filippo , Costarelli Silvia , Quiros-Roldan Eugenia , Paraninfo Giuseppe , Ceresoli Francesca , Gargiulo Franco , Manca Nino , Carosi Giampiero , Torti Carlo 
Published: April 2022

Background Prevalence and factors associated with etravirine (ETV) resistance mutations among patients failing on first-generation non-nucleoside reverse transcriptase inhibitors (NNRTI) merit investigation. Methods The study comprised an analysis of all sequential patients attending the Institute of Infectious Diseases (Brescia, northern Italy) who performed a genotypic resistance testing (GRT) after ≥3 months of a stable NNRTI-based regimen between 2001 and 2006. Multivariable ordinal logistic regression analysis was performed to assess predictors of ETV resistance mutations. Results Out of 248 strains, 153 (61.7%) harboured ≥1 ETV resistance mutations. In particular, 88 (35.5%), 53 (21.4%) and 12 (4.8%) harboured one, two and three mutations, respectively. The most frequent mutations were G190A (23%), Y181C (23%) and K101E (14.1%). Use of nevirapine (odds ratio [OR] 2.73; 95% confidence level [CI] 1.62–4.62; P<0.001) and a longer time frame between first HIV RNA >500 copies/ml and GRT (per month, OR 1.05; 95% CI 1.01–1.09; P=0.012) were associated with a greater number of ETV resistance mutations. Conversely, higher CD4+ T-cell counts at nadir (per 100 cells/mm3, OR 0.81; 95% CI 0.67–0.98; P=0.029) and use of lamivudine/emtricitabine (OR 0.57; 95% CI 0.37–0.87; P=0.009) were protective. Accumulation of ETV resistance-associated mutations was demonstrated by sequential GRT in 4/35 patients (all treated with nevirapine). Conclusions Mutations associated with ETV resistance were common among patients failing on NNRTI, but prevalence of viral strains harbouring three mutations was low. Use of efavirenz and co-administration of lamivudine reduced the risk of ETV resistance. The continued use of the current NNRTI in a failing regimen may select for additional resistant variants.
Mapping Natural Polymorphisms of Hepatitis C virus NS3/4A Protease and Antiviral Resistance to Inhibitors in Worldwide Isolates
Authors: López-Labrador F Xavier , Moya Andrés , Gonzàlez-Candelas Fernando 
Published: April 2022

Background Several inhibitors for the hepatitis C virus (HCV) NS3/4A protease are under development. Although previous studies identified viral resistance mutations, there is little information on the natural variability of proteases from the different viral subtypes. Here, we aimed to determine both the natural variability and presence of resistance or compensatory mutations to new protease inhibitors (PI) in NS3/4A proteases from worldwide HCV isolates. Methods A comprehensive analysis was performed in 380 HCV NS3 sequences (275 genotype 1; 105 other genotypes) from public HCV databases (EuHCVdb and Los Alamos). Amino acid polymorphism and signature patterns were deduced in the protease domain, including all sites associated with resistance to the PIs BILN-2061, Telaprevir (VX-950), Boceprevir (SCH-503034), SCH-6 and ITMN-191. Results Few of the residues in the catalytic triad or in substrate/metal-binding sites were polymorphic, and were identified in only 4/380 isolates. However, a relevant polymorphism was found in sites associated either with resistance to PI (V36, I170 and D168) or with compensatory mutations (I71, T72, Q86 and I153). Furthermore, some unique genotype-specific signature patterns associated with resistance to PI were also identified. Conclusions We describe for the first time the relevant natural polymorphisms of the HCV NS3/4A protease in worldwide isolates. Although the prevalence of major resistance mutations is very low, many compensatory sites are naturally polymorphic among proteases from several HCV subtypes. These data will help to determine whether HCV resistance is likely to be selected with new PIs and will aid the design of genotypic resistance testing.
Pharmacokinetic Interaction between Ethinyl Estradiol, Norethindrone and Darunavir with Low-Dose Ritonavir in Healthy Women
Authors: Sekar Vanitha J , Lefebvre Eric , Guzman Sabrina Spinosa , Felicione Elise , De Pauw Martine , Vangeneugden Tony , Hoetelmans Richard MW 
Published: April 2022

Background An open-label, randomized, crossover study was performed to investigate the effect of multiple doses of darunavir co-administered with low-dose ritonavir (DRV/r) on the steady-state pharmacokinetics of the oral contraceptives ethinyl estradiol (EE) and norethindrone (NE) (commercial name of the combined drug Ortho-Novum 1/35) in 19 HIV-negative healthy women. Methods In session 1, participants received 35 μg EE and 1.0 mg NE from days 1 to 21. In session 2, participants received the same oral contraceptive treatment as in session 1 on days 1 to 21 plus DRV/r (600 mg/100 mg twice daily) on days 1 to 14. Pharmacokinetic assessments were performed on day 14 for each session. Results Steady-state systemic exposure to EE and NE decreased when DRV/r was co-administered, based on the ratio of least square means of the minimum plasma concentration (Cmin), the maximum plasma concentration (Cmax), and the area under the curve (AUC24h) of EE (which decreased by 62%, 32% and 44%, respectively) and NE (which decreased by 30%, 10% and 14%, respectively) compared with administration of EE and NE alone. Five participants discontinued the study due to grade 2 cutaneous events, as required per protocol, during treatment with EE and NE in combination with DRV/r. There were no clinically relevant findings for laboratory and cardiovascular parameters. Conclusions The pharmacokinetic interaction observed here is considered to be clinically relevant as EE concentrations are considerably reduced when DRV/r is co-administered with EE and NE. Alternative or additional contraceptive measures should be used when oestrogen-based contraceptives are co-administered with DRV/r.
Putative Functional Domains of Human Cytomegalovirus pUL56 Involved in Dimerization and Benzimidazole D-Ribonucleoside Activity
Authors: Champier Gaël , Couvreux Anthony , Hantz Sébastien , Rametti Armelle , Mazeron Marie-Christine , Bouaziz Serge , Denis François , Alain Sophie 
Published: April 2022

Background Benzimidazole d-ribonucleosides inhibit DNA packaging during human cytomegalovirus (HCMV) replication. Although they have been shown to target pUL56 and pUL89 (the large and small subunits of the HCMV terminase, respectively) their mechanism of action is not yet fully understood. We aimed here to better understand HCMV DNA maturation and the mechanism of action of benzimidazole derivatives. Methods The HCMV pUL56 protein was studied by sequence analysis of the HCMV UL56 gene and herpesvirus counterparts combined with primary structure analysis of the corresponding amino acid sequences. Results The UL56 sequence analysis of 45 HCMV strains and counterparts among herpesviruses allowed the identification of 12 conserved regions. Moreover, comparison with the product of gene 49 (gp49) of bacteriophage T4 suggested that the pUL56 zinc finger is localized close to the dimerization site of pUL56, providing a spatial organization of the catalytic site that allows recognition and cleavage of DNA. Conclusions This study provides a basis to investigate the mechanism of concatemeric DNA cleavage and a biochemical basis for DNA packaging inhibition by benzimidazole derivatives.
Safety, tolerability and pharmacokinetics of enfuvirtide administered by a needle-free injection system compared with subcutaneous injection
Authors: Gottlieb Michael , Thommes James A ,   the WAND Study Team
Published: April 2022

Background Injection site reactions (ISRs) can present a challenge to patients when using enfuvirtide (ENF). This study compared ISRs associated with use of a needle-free injection device (NFID) with those associated with a standard 27-gauge half-inch needle/syringe (NS). Methods In this single-blind, crossover study, 58 ENF-naive participants were randomized to self-administer ENF with the NFID for 4 weeks (followed by 4 weeks using NS) or with the NS for 4 weeks (followed by 4 weeks using the NFID). A primary composite endpoint of painful ISR was defined as the combination of grade 1–3 ongoing pain plus either associated grade 3–4 (≥25 mm) induration or grade 2–4 nodules/cysts (>20 mm). An ISR summary score described ISR frequency/severity. Self-reported device preference was also evaluated at baseline and at study completion. Results Fewer participants using NFID experienced the primary composite endpoint of painful ISRs (10/28; 35.7%) compared with NS (20/28; 71.4%) ( P=0.004). There was a trend towards a reduced incidence/severity of ISR signs and symptoms with NFID, with significant reductions seen in pain/discomfort and pruritus ( P<0.05 and P<0.01, respectively). At the end of the study, most participants (22/25; 88%) expressed a preference for NFID. Haematoma was the sole NFID-related serious adverse event, but this did not lead to discontinuation. Conclusions Compared with a standard NS, use of an NFID to administer ENF was associated with a substantially lower incidence of painful ISRs, was generally safe and well-tolerated, and was preferred by most participants in the study.
A Pharmacokinetic and Pharmacogenetic Study of Efavirenz in Children: Dosing Guidelines can Result in Subtherapeutic Concentrations
Authors: Heine Robter , Scherpbier Henriette J , Crommentuyn Kristel ML , Bekker Vincent , Beijnen Jos H , Kuijpers Taco W , Huitema Alwin DR 
Published: April 2022

Background Our main objectives were to study the population pharmacokinetics of efavirenz and to explore the adequacy of dosing guidelines. Methods A total of 33 HIV-1-infected patients were recruited from the Emma Children's Hospital (Amsterdam, the Netherlands). Gender, age, drug formulation, the presence of the c.516G>T polymorphism in the CYP2B6 gene and the quantitation of liver enzymes alanine aminotransferase and aspartate aminotransferase at baseline were collected. A non-linear mixed effect pharmacokinetic model was developed. Results CYP2B6 genotype and drug formulation significantly influenced efavirenz pharmacokinetics. Clearance was 29.7% lower in children carrying the CYP2B6-516-G/T genotype compared with children carrying the G/G genotype. Relative bioavailiability of the oral liquid compared with tablets or capsules was 46.6%. Children carrying the CYP2B6-516-G/G genotype had a 50–70% probability of developing a subtherapeutic trough level of efavirenz and only 1–3% probability of developing a trough level >4 mg/l. To reduce the probability of developing a subtherapeutic trough concentration, we propose to give an adult efavirenz dose to children weighing ≥25 kg and to allometrically scale doses for other weight levels a priori. The dose of the oral solution should be twice the dose of capsules. Conclusions Population pharmacokinetics of efavirenz in children were adequately described. Current dosing guidelines can result in subtherapeutic concentrations in children carrying the CYP2B6-516-G/G genotype and with the liquid formulation. A priori dose adaptations in the paediatric population seem feasible and need prospective validation.
Inhibition of Human Metapneumovirus Replication by Small Interfering RNA
Authors: Deffrasnes Céline , Cavanagh Marie-Hélène , Goyette Nathalie , Cui Kunyuan , Ge Qing , Seth Shaguna , Templin Michael V , Quay Steven C , Johnson Paul H , Boivin Guy 
Published: April 2022

Background Human metapneumovirus (hMPV) is a major respiratory viral pathogen in young children, elderly individuals and immunocompromised patients. Despite its major effects related to bronchiolitis, pneumonia and its potential role in recurrent wheezing episodes, there is still no commercial treatment or vaccine available against this paramyxovirus. Methods We tested a therapeutic strategy for hMPV that was based on RNA interference. Results An hMPV genome-wide search for small interfering RNAs (siRNAs) by computational analysis revealed 200 potentially effective 21-mer siRNAs. Initial screening with a luciferase assay identified 57 siRNAs of interest. Further evaluation of their inhibitory potential against the four hMPV subgroups by quantitative real-time reverse transcriptase PCR and plaque immunoassay identified two highly potent siRNAs with 50% inhibitory concentration (IC50) values in the subnanomolar range. siRNA45 targets the nucleoprotein messenger RNA (mRNA) and had IC50 values <0.078 nM against representative strains from the four hMPV subgroups, whereas siRNA60, which targets the phosphoprotein mRNA, had IC50 values between 0.090– <0.078 nM against the same panel of hMPV strains. Longer 25/27-mer siRNAs known as Dicer substrates designed from the top two siRNA candidates were also evaluated and were at least as effective as their corresponding 21-mer siRNAs. Interestingly, the presence of one or two nucleotide mismatches in the target mRNA sequence of some hMPV subgroups did not always affect hMPV inhibition in vitro. Conclusions We successfully identified two highly efficient siRNAs against hMPV targeting essential components of the hMPV replication complex.
Highly Active Antiretroviral Therapy versus Zidovudine/Nevirapine Effects on Early Breast Milk HIV Type-1 RNA: A Phase II Randomized Clinical Trial
Authors: Chung Michael H , Kiarie James N , Richardson Barbra A , Lehman Dara A , Overbaugh Julie , Kinuthia John , Njiri Francis , John-Stewart Grace C 
Published: April 2022

Background Defining the effect of antiretroviral regimens on breast milk HIV type-1 (HIV-1) levels is useful to inform the rational design of strategies to decrease perinatal HIV-1 transmission. Methods Pregnant HIV-1 seropositive women (CD4+ T-cell count >250 and <500 cells/mm3) electing to breastfeed in Nairobi, Kenya were randomized to highly active anti-retroviral therapy (HAART; zidovudine [ZDV], lamivudine and nevirapine [NVP]) during pregnancy and 6 months post-partum or to short-course ZDV plus single-dose NVP (ZDV/NVP). Breast milk samples were collected two to three times per week in the first month post-partum. Results Between November 2003 and April 2006, 444 breast milk samples were collected from 58 randomized women during the first month after delivery. Between 3 and 14 days post-partum, women in the HAART and ZDV/NVP arms had a similar prevalence of undetectable breast milk HIV-1 RNA. From 15 to 28 days post-partum, women in the HAART arm had significantly lower levels of breast milk HIV-1 RNA than women randomized to ZDV/NVP (1.7 log10 copies/ml [limit of detection] versus >2.10 log10 copies/ml, P<0.001). In contrast to breast milk HIV-1 RNA, suppression of plasma HIV-1 RNA during the neonatal period was consistently several log10 greater in the HAART arm compared with the ZDV/NVP arm. Conclusions HAART resulted in lower breast milk HIV-1 RNA than ZDV/NVP; however, ZDV/NVP yielded comparable breast milk HIV-1 RNA levels in the first 2 weeks post-partum. Breast milk HIV-1 RNA remained suppressed in the ZDV/NVP arm despite increased plasma HIV-1 levels, which might reflect local drug effects or compartmentalization.
Pharmacokinetics of Atazanavir/Ritonavir Once Daily and Lopinavir/Ritonavir Twice and once Daily over 72 h following drug Cessation
Authors: Boffito Marta , Else Laura , Back David , Taylor Jessica , Khoo Saye , Sousa Marta , Pozniak Anton , Gazzard Brian , Moyle Graeme 
Published: April 2022

Background We investigated the pharmacokinetics of atazanavir/ritonavir once daily and lopinavir/ritonavir twice and once daily over 72 h following drug intake cessation. Methods This was an open-label, three-session, pharmacokinetic trial. Healthy volunteers received atazanavir/ritonavir 300/100 mg once daily and lopinavir/ ritonavir 400/100 mg twice daily and 800/200 mg once daily separately for 10 days. Pharmacokinetic profiles were assessed for each phase on day 10 over 72 h. Pharmacokinetic parameters were determined over 12 or 24 h and to the last measurable concentration by non-compartmental methods. Results Sixteen participants completed the study. Geometric mean terminal elimination half-life to 72 h of atazanavir was 8.35 h and not different from the 0–24 h half-life (9.91 h). Terminal elimination half-life of lopinavir was 2.33 h (twice daily) and 2.44 h (once daily). These values were lower compared with the half-life over the respective dosing intervals (7.15 and 4.88 h for 0–12 and 0–24 h, respectively). No participant on atazanavir had concentrations below the minimum effective concentration (MEC) of 150 ng/ml at 24 h. In total, 44% of the participants on lopinavir once daily had concentrations below the MEC of 1,000 ng/ml at 24 h. At 16 h and 20 h, 13% and 63% of participants were below target for twice daily lopinavir, respectively. At 36 h, all participants on lopinavir and 31% on atazanavir were below target. Ritonavir area under the plasma concentration–time curve was 30% lower and 26% higher when dosed at 100 mg or 200 mg with lopinavir versus atazanavir. Conclusions This study investigated the pharmacokinetic forgiveness of two boosted protease inhibitors. Whereas the decline in lopinavir concentrations occured rapidly as the boosting effect of ritonavir diminished, the rate of decline of atazanavir remained constant to 72 h.