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Updated immunization strategies are needed to address multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. Here we report interim results from an ongoing, open-label phase 2/3 trial evaluating the safety and immunogenicity of the bivalent Coronavirus Disease 2019 (COVID-19) vaccine candidate mRNA-1273.211, which contains equal mRNA amounts encoding the ancestral SARS-CoV-2 and Beta variant spike proteins, as 50-µg (n = 300) and 100-µg (n = 595) first booster doses administered approximately 8.7–9.7 months after the mRNA-1273 primary vaccine series (NCT04927065). The primary objectives were to evaluate the safety and reactogenicity of mRNA-1273.211 and to demonstrate non-inferior antibody responses compared to the mRNA-1273 100-µg primary series. Additionally, a pre-specified immunogenicity objective was to demonstrate superior antibody responses compared to the previously authorized mRNA-1273 50-µg booster. The mRNA-1273.211 booster doses (50-µg or 100-µg) 28 days after immunization elicited higher neutralizing antibody responses against the ancestral SARS-CoV-2 and Beta variant than those elicited 28 days after the second mRNA‑1273 dose of the primary series (NCT04470427). Antibody responses 28 days and 180 days after the 50-µg mRNA-1273.211 booster dose were also higher than those after a 50-µg mRNA-1273 booster dose (NCT04405076) against the ancestral SARS-CoV-2 and Beta, Omicron BA.1 and Delta variants, and all pre-specified immunogenicity objectives were met. The safety and reactogenicity profile of the bivalent mRNA-1273.211 booster (50-µg) was similar to the booster dose of mRNA-1273 (50-µg). Immunization with the primary series does not set a ceiling to the neutralizing antibody response, and a booster dose of the bivalent vaccine elicits a robust response with titers that are likely to be protective against COVID-19. These results indicate that bivalent booster vaccines can induce potent, durable and broad antibody responses against multiple variants, providing a new tool in response to emerging variants.

Rising breakthrough infections of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in previously immunized individuals have raised concerns for the need for a booster vaccine dose to combat waning antibody levels and new variants. Here we report the results of the open-label, non-randomized part B of a phase 2 trial in which we evaluated the safety and immunogenicity of a booster injection of 50 µg of the coronavirus disease 2019 (COVID-19) vaccine mRNA-1273 in 344 adult participants immunized 6–8 months earlier with a primary series of two doses of 50 µg or 100 µg of mRNA-1273 (NCT04405076). Neutralizing antibody (nAb) titers against wild-type SARS-CoV-2 at 1 month after the booster were 1.7-fold (95% confidence interval (CI): 1.5, 1.9) higher than those at 28 days after the second injection of the primary series, which met the pre-specified non-inferiority criterion (primary immunogenicity objective) and might indicate a memory B cell response. The nAb titers against the Delta variant (B.1.617.2) (exploratory objective) at 1 month after the booster were 2.1-fold (95% CI: 1.8, 2.4) higher than those at 28 days after the second injection of the primary series. The seroresponse rate (95% CI (four-fold rise from baseline)) was 100% (98.7, 100.0) at 28 days after the booster compared to 98.3% (96.0, 99.4) after the primary series. The higher antibody titers at 28 days after the booster dose compared to 28 days after the second dose in the phase 3 COVE study were also observed in two assays for anti-spike IgG antibody measured by ELISA and by Meso Scale Discovery (MSD) Multiplex. The frequency of solicited local and systemic adverse reactions after the booster dose was similar to that after the second dose in the primary two-dose series of mRNA-1273 (50 µg or 100 µg); no new signals were observed in the unsolicited adverse events; and no serious adverse events were reported in the 1-month follow-up period. These results show that a booster injection of mRNA-1273 more than 6 months after completing the primary two-dose series is safe and elicited nAb titers that were statistically significantly higher than the peak titers detected after the primary vaccination series, suggesting that a booster dose of mRNA-1273 might result in increased vaccine effectiveness against infection and disease caused by SARS-CoV-2.

Background Primary spontaneous pneumothorax is a common disorder occurring in young adults without underlying lung disease. Although tobacco smoking is a well-documented risk factor for spontaneous pneumothorax, an association between electronic cigarette use (that is, vaping) and spontaneous pneumothorax has not been noted. We report a case of spontaneous pneumothoraces correlated with vaping. Case presentation An 18-year-old Caucasian man presented twice with recurrent right-sided spontaneous pneumothoraces within 2 weeks. He reported a history of vaping just prior to both episodes. Diagnostic testing was notable for a right-sided spontaneous pneumothorax on chest X-ray and computed tomography scan. His symptoms improved following insertion of a chest tube and drainage of air on each occasion. In the 2-week follow-up visit for the recurrent episode, he was asymptomatic and reported that he was no longer using electronic cigarettes. Conclusions Providers and patients should be aware of the potential risk of spontaneous pneumothorax associated with electronic cigarettes.

Aim - comparison of biological hermeticity, mechanical strength and differences in morphological characteristics of one-row and two-row colon anastomoses. 20 animals were used in the experiment. Rabbits of both sexes aged from 8 months to 1.5 years and weighing from 1.5 to 2.6 kg were used as experimental animals. The animals were divided into experimental and control groups. In the experimental group we used the developed technique of one-row colon anastomosis (CA) formation, in the control group - the traditional two-row CA. Assessment of mechanical strength was performed by using the original method of pneumopression of colon segment with the anastomosis. The biological hermeticity was assessed by culturing flushing water from the anastomosis line to growth medium. The morphological picture was evaluated by microscopy of histological samples from the anastomosis line. The mechanical strength of the one-row anastomosis, compared with the traditional two-row, was higher at each stage of the study, on the first day by 66.3%, the third - 87.6%, the fifth - 76.1%, the seventh - 85.4%. The formation of a one-row CA allowed to achieve biological hermeticity of the anastomosis area in all periods of the early postoperative period, and when using a double-row suture, the anastomosis area became sterile only from 5 day. Morphologically, the picture was characterized by inflammatory processes in the anastomosis area when using the original technique, which were stopped in 3-5 days, and in the control group they persisted for up to 7 days, accompanied by vascular paresis of the intestinal wall, blood stasis and blood clots, with zones of mucosal necrosis at 3 and 5 day of observation.

The combination of protein and polysaccharides with magnetic materials has been implemented in biomedical applications for decades. Proteins such as silk, collagen, and elastin and polysaccharides such as chitosan, cellulose, and alginate have been heavily used in composite biomaterials. The wide diversity in the structure of the materials including their primary monomer/amino acid sequences allow for tunable properties. Various types of these composites are highly regarded due to their biocompatible, thermal, and mechanical properties while retaining their biological characteristics. This review provides information on protein and polysaccharide materials combined with magnetic elements in the biomedical space showcasing the materials used, fabrication methods, and their subsequent applications in biomedical research.

Background There is a need for hepatitis C virus (HCV) therapies with excellent efficacy across genotypes and in diverse populations. Part A of the C-CREST-1 and C-CREST-2 trials led to the selection of a three-drug regimen of grazoprevir (MK-5172; an HCV NS3/4A protease inhibitor; 100 mg/day) plus ruzasvir (MK-8408; an NS5A inhibitor; 60 mg/day) plus uprifosbuvir (MK-3682; an HCV NS5B polymerase inhibitor; 450 mg/day). Part B of the studies tested this combination as a single formulation in different treatment durations in a broader population. Methods Part B of these randomised, phase 2, open-label clinical trials enrolled individuals from 15 countries who were chronically infected with HCV genotypes 1–6 (HCV RNA ≥10 000 IU/mL) with or without compensated cirrhosis. Those with genotype 1, genotype 2, genotype 4, or genotype 6 were treatment-naive; those with genotype 3 could be treatment-naive or treatment-experienced with pegylated interferon and ribavirin. Randomisation occurred centrally using an interactive voice response system and integrated web response system. Participants were randomly assigned to receive treatment for 8, 12, or 16 weeks with a fixed-dose combination of grazoprevir, ruzasvir, and uprifosbuvir with or without ribavirin. The primary endpoint was the proportion of participants achieving sustained virological response 12 weeks after the end of all study therapy (SVR12), defined as HCV RNA less than the lower limit of quantification (either target detected unquantifiable or target not detected [

Tetraspanins are a family of proteins possessing four transmembrane domains that help in lateral organization of plasma membrane proteins. These proteins interact with each other as well as other receptors and signaling proteins, resulting in functional complexes called “tetraspanin microdomains.” Tetraspanins, including CD82, play an essential role in the pathogenesis of fungal infections. Dectin-1, a receptor for the fungal cell wall carbohydrate β-1,3-glucan, is vital to host defense against fungal infections. The current study identifies a novel association between tetraspanin CD82 and Dectin-1 on the plasma membrane of Candida albicans–containing phagosomes independent of phagocytic ability. Deletion of CD82 in mice resulted in diminished fungicidal activity, increased C. albicans viability within macrophages, and decreased cytokine production (TNF-α, IL-1β) at both mRNA and protein level in macrophages. Additionally, CD82 organized Dectin-1 clustering in the phagocytic cup. Deletion of CD82 modulates Dectin-1 signaling, resulting in a reduction of Src and Syk phosphorylation and reactive oxygen species production. CD82 knockout mice were more susceptible to C. albicans as compared with wild-type mice. Furthermore, patient C. albicans–induced cytokine production was influenced by two human CD82 single nucleotide polymorphisms, whereas an additional CD82 single nucleotide polymorphism increased the risk for candidemia independent of cytokine production. Together, these data demonstrate that CD82 organizes the proper assembly of Dectin-1 signaling machinery in response to C. albicans.

Background Glioblastoma (GBM) is the most common primary brain malignancy in adults, yet survival outcomes remain poor. First line treatment is well established, however disease invariably recurs and improving prognosis is challenging. With the aim of personalizing therapy at recurrence, we have established a high content screening (HCS) platform to analyze the sensitivity profile of seven patient-derived cancer stem cell lines to 83 FDA-approved chemotherapy drugs, with and without irradiation. Methods Seven cancer stem cell lines were derived from patients with GBM and, along with the established cell line U87-MG, each patient-derived line was cultured in tandem in serum-free conditions as adherent monolayers and three-dimensional neurospheres. Chemotherapeutics were screened at multiple concentrations and cells double-stained to observe their effect on both cell death and proliferation. Sensitivity was classified using high-throughput algorithmic image analysis. Results Cell line specific drug responses were observed across the seven patient-derived cell lines. Few agents were seen to have radio-sensitizing effects, yet some drug classes showed a marked difference in efficacy between monolayers and neurospheres. In vivo validation of six drugs suggested that cell death readout in a three-dimensional culture scenario is a more physiologically relevant screening model and could be used effectively to assess the chemosensitivity of patient-derived GBM lines. Conclusion The study puts forward a number of non-standard chemotherapeutics that could be useful in the treatment of recurrent GBM, namely mitoxantrone, bortezomib and actinomycin D, whilst demonstrating the potential of HCS to be used for personalized treatment based on the chemosensitivity profile of patient tumor cells.

Aims and objectives This study aimed to determine the interobserver reliability between bedside nurses and attending physicians for a paediatric respiratory score as part of an asthma Integrated Care Pathway implementation. Background An Integrated Care Pathway is one approach to improving quality of care for children hospitalised with asthma. Prior to implementation of the integrated care pathway, it was necessary to train nursing staff on the use of a respiratory assessment tool and to evaluate the interobserver reliability use of this tool. Design Prospective study using a convenience sample of children hospitalised for a respiratory illness in an academic medical centre. Methods The respiratory assessment used was the Paediatric Asthma Score. Bedside nurse-attending physician (27 different RNs and three attending paediatric hospitalists) pairs performed 71 simultaneous patient assessments on 20 patients. Intraclass correlation coefficient and kappa statistics were used to assess interobserver reliability. Results The overall intraclass correlation coefficient was nearly perfect where κ = 0·95, 95% CI (0·92, 0·97) and overall kappa for reliability based on clinically relevant score breakpoints was also high with κ = 0·82, 95% CI (0·75, 0·90). The majority of subgroup analyses revealed substantial to almost perfect agreement across a variety of diagnoses, age ranges, and individual score components. Conclusions Bedside nurses, with support and training from attending physicians, can perform respiratory assessments that agree almost perfectly with those of attending physicians. Relevance to clinical practice The use of an Integrated Care Pathway allows for optimal interprofessional collaboration between bedside nurses and attending physicians.

Background Hepatitis C virus (HCV) infection is common in persons who inject drugs (PWID). Objective To evaluate elbasvir-grazoprevir in treating HCV infection in PWID. Design Randomized, placebo-controlled, double-blind trial. (ClinicalTrials.gov: NCT02105688). Setting Australia, Canada, France, Germany, Israel, the Netherlands, New Zealand, Norway, Spain, Taiwan, the United Kingdom, and the United States. Patients 301 treatment-naive patients with chronic HCV genotype 1, 4, or 6 infection who were at least 80% adherent to visits for opioid agonist therapy (OAT). Intervention The immediate-treatment group (ITG) received elbasvir-grazoprevir for 12 weeks; the deferred-treatment group (DTG) received placebo for 12 weeks, no treatment for 4 weeks, then open-label elbasvir-grazoprevir for 12 weeks. Measurements The primary outcome was sustained virologic response at 12 weeks (SVR12), evaluated separately in the ITG and DTG. Other outcomes included SVR24, viral recurrence or reinfection, and adverse events. Results The SVR12 was 91.5% (95% CI, 86.8% to 95.0%) in the ITG and 89.5% (95% CI, 81.5% to 94.8%) in the active phase of the DTG. Drug use at baseline and during treatment did not affect SVR12 or adherence to HCV therapy. Among 18 patients with posttreatment viral recurrence through 24-week follow-up, 6 had probable reinfection. If the probable reinfections were assumed to be responses, SVR12 was 94.0% (CI, 89.8% to 96.9%) in the ITG. One patient in the ITG (1 of 201) and 1 in the placebo-phase DTG (1 of 100) discontinued treatment because of an adverse event. Limitation These findings may not be generalizable to PWID who are not receiving OAT, nor do they apply to persons with genotype 3 infection, a common strain in PWID. Conclusion Patients with HCV infection who were receiving OAT and treated with elbasvir-grazoprevir had high rates of SVR12, regardless of ongoing drug use. These results support the removal of drug use as a barrier to interferon-free HCV treatment for patients receiving OAT. Primary funding source Merck & Co.

Direct-acting antiviral agents (DAAs) represent the standard of care for patients with hepatitis C virus (HCV) infection. Combining DAAs with different mechanisms may allow for shorter treatment durations that are effective across multiple genotypes. The aim of the C-SWIFT study was to identify the minimum effective treatment duration across multiple genotypes. C-SWIFT was an open-label, single-center trial in treatment-naive patients with chronic HCV genotype (GT)1 or 3 infection. All patients received elbasvir (EBR) 50 mg/grazoprevir (GZR) 100 mg with sofosbuvir (SOF) 400 mg for 4-12 weeks. Patients with GT1 infection who failed therapy were eligible for retreatment with EBR/GZR+SOF and ribavirin for 12 weeks. The primary efficacy endpoint was sustained virological response [SVR]12 (SVR of HCV RNA

Patients infected with hepatitis C virus (HCV) genotype 1, 4, or 6, with or without cirrhosis, previously treated with peg-interferon and ribavirin, are a challenge to treat. We performed a phase 3 randomized controlled open-label trial to assess the effects of 12 or 16 weeks of treatment with once-daily elbasvir (an HCV NS5A inhibitor, 50 mg) and grazoprevir (an HCV NS3/4A protease inhibitor, 100 mg), in a fixed-dose combination tablet, with or without twice-daily ribavirin, in this patient population.We analyzed data from 420 patients (35% with cirrhosis, 64% with a null or partial response to peg-interferon and ribavirin) who were randomly assigned (1:1:1:1) to groups given elbasvir and grazoprevir once daily, with or without twice-daily ribavirin, for 12 or 16 weeks, at 65 study centers in 15 countries in Europe, Asia, and Central and North America. Randomization was stratified by cirrhosis status and type of peg-interferon and ribavirin treatment failure. HCV RNA was measured using COBAS TaqMan v2.0. The primary end point was HCV RNA15 IU/mL, 12 weeks after completion of treatment (SVR12). We aimed to determine whether the proportion of patients achieving an SVR12 in any group was greater than the reference rate (58%).With 12 weeks of treatment, an SVR12 was achieved by 92.4% of patients given elbasvir and grazoprevir and 94.2% of patients given elbasvir and grazoprevir with ribavirin. With 16 weeks of treatment, an SVR12 was achieved by 92.4% of patients given elbasvir and grazoprevir and 98.1% of patients given elbasvir and grazoprevir with ribavirin. Among patients treated for 12 weeks without ribavirin, virologic failure occurred in 6.8%, 0%, and 12.5% of patients with HCV genotype 1a, 1b, or 4 infection, respectively. Among patients given elbasvir and grazoprevir for 12 weeks, virologic failure occurred in 0% of patients infected with HCV genotypes 1 and 4 who relapsed after completing peg-interferon and ribavirin, and 7.5% infected with HCV genotypes 1 and 4, respectively, with a null or partial response to peg-interferon and ribavirin. Among patients treated for 16 weeks who received ribavirin, there were no incidences of virologic failure. Common adverse events were fatigue (23.1%), headache (19.8%), and nausea (11.0%).The combination tablet of elbasvir and grazoprevir, with or without ribavirin, was highly efficacious in inducing an SVR12 in patients with HCV genotype 1, 4, or 6 infection failed by previous treatment with peg-interferon and ribavirin, including patients with cirrhosis and/or a prior null response. The treatment was generally well tolerated. ClinicalTrials.gov Number: NCT02105701.

Ecdysteroids coordinate essential biological processes in Drosophila through a complex of two nuclear receptors, the ecdysteroid receptor (EcR) and the ultraspiracle protein (Usp). Biochemical experiments have shown that, in contrast to Usp, the EcR molecule is characterized by high intramolecular plasticity. To investigate whether this plasticity is sufficient to form EcR complexes with nuclear receptors other than Usp, we studied the interaction of EcR with the DHR38 nuclear receptor. Previous in vitro experiments suggested that DHR38 can form complexes with Usp and thus disrupt Usp-EcR interaction with the specific hsp27pal response element. This article provides the experimental evidence that EcR is able to form complexes with DHR38 as well. The recombinant DNA-binding domains (DBDs) of EcR and DHR38 interact specifically on hsp27pal. However, the interaction between the receptors is not restricted to their isolated DBDs. We pre\xadsent data that indicate that the full-length EcR and DHR38 can also form specific complexes within the nuclei of living cells. This interaction is mediated by the hinge region of EcR, which was recently classified as an intrinsically disordered region. Our results indicate that DHR38 might modulate the activity of the Usp-EcR heterodimer by forming complexes with both of its components.

Orai1 and STIM1 have been identified as the main determinants of the store-operated Ca2+ entry (SOCE). Their specific roles in SOCE and their molecular interactions have been studied extensively following heterologous overexpression or molecular knockdown and extrapolated to the endogenous processes in naive cells. Using molecular and imaging techniques, we found that variation of expression levels of Orai1 or STIM1 can significantly alter expression and role of some endogenous regulators of SOCE. Although functional inhibition of Ca2+-independent phospholipase A2 β (iPLA2β or PLA2g6A), or depletion of plasma membrane cholesterol caused a dramatic loss of endogenous SOCE in HEK293 cells, these effects were attenuated significantly when either Orai1 or STIM1 were overexpressed. Molecular knockdown of iPLA2β impaired SOCE in both control cells and cells overexpressing STIM1. We also discovered important cross-talk between expression of Orai1 and a specific plasma membrane variant of iPLA2β but not STIM1. These data confirm the role of iPLA2β as an essential mediator of endogenous SOCE and demonstrate that its physiological role can be obscured by Orai1 and STIM1 overexpression. Background: Store-operated Ca2+ entry (SOCE) is essential for cell function. Results: We discovered cross-talk between expression of molecules that determine SOCE and demonstrated that the role of endogenous mediators may be altered in overexpressed system. Conclusion: iPLA2β is an important regulator of endogenous SOCE, but its role can be obscured by Orai1 and STIM1 overexpression. Significance: Mediators of endogenous SOCE are important for Ca2+ homeostasis in health and disease.

Purpose Elbasvir (MK-8742) and grazoprevir (MK-5172; Merck & Co, Inc, Kenilworth, New Jersey) are hepatitis C virus (HCV)-specific inhibitors of the nonstructural protein 5A phosphoprotein and the nonstructural protein 3/4A protease, respectively. The aims of these studies were to evaluate the antiviral activity and safety of different doses of elbasvir or grazoprevir each administered as monotherapy to participants infected with either HCV genotype (GT) 1 or GT3. Methods These 2 double-blind, randomized, placebo-controlled, sequential-panel, multiple ascending dose studies were conducted to assess the safety and pharmacodynamics of 5 days of once-daily elbasvir or 7 days of once-daily grazoprevir in adult male participants chronically infected with either HCV GT1 or GT3. Findings Oral administration of elbasvir or grazoprevir once daily exhibited potent antiviral activity in participants with chronic GT1 or GT3 HCV infections. HCV RNA levels declined rapidly (within 1 day for elbasvir and 2 days for grazoprevir). At 50 mg of elbasvir once daily, the mean maximum reductions in HCV RNA from baseline were 5.21, 4.17, and 3.12 log10 IU/mL for GT1b-, GT1a-, and GT3-infected participants, respectively. At 100 mg of grazoprevir once daily, the mean maximum reductions in HCV RNA from baseline were 4.74 and 2.64 log10 IU/mL for GT1- and GT3-infected participants. Implications The results in the elbasvir monotherapy study showed that 10 to 50 mg of elbasvir was associated with a rapid decline in HCV viral load; the results in the grazoprevir monotherapy study suggest that doses of 50 mg of grazoprevir and higher are on the maximum response plateau of the dose–response curve for GT1-infected participants. The results of these proof-of-concept studies provided preliminary data for the selection of the dosages of elbasvir and grazoprevir to test in Phase II and III clinical studies. ClinicalTrials.gov identifiers: NCT00998985 (Protocol 5172-004) and NCT01532973 (Protocol 8742-002).

BACKGROUND The American Academy of Pediatrics (AAP) published expanded safe sleep guidelines in 2011. OBJECTIVE The purpose of this quality improvement project was to promote the AAP safe sleep recommendations and provide appropriate role modeling of these recommendations for hemodynamically stable infants throughout their hospital stay. DESIGN AND INTERVENTION A safe sleep educational initiative for parents and hospital staff included an observation of infant sleep practice before and after the initiative and a pre- and posteducation questionnaire of nurses' knowledge, attitudes, and opinions. SETTING AND PARTICIPANTS A Magnet-designated urban hospital that included 72 pediatric beds, a 60-bed NICU, and 41 mother-baby beds; and 658 pediatric and obstetric nurses. RESULTS One-hundred percent of nurses received the educational intervention. Observations noted an improvement from 70% to 90% (p< 0.01) of infants in a safe sleep position when comparing pre- and postintervention results. There were some improvements in knowledge of and agreement with the AAP guidelines after the educational intervention, but not as much as expected. CONCLUSIONS There was inconsistency between nursing knowledge and practice about safe infant sleep. Nurses were aware of the AAP recommendations, but it took time to achieve close to full compliance in changing clinical practice. Observation was an important part of this initiative to reinforce knowledge and role model best practice for parents.

Comment in New kids on the block--step by step to an ideal HCV therapy. [Lancet. 2015]; International audience; There is a high medical need for an interferon-free, all-oral, short-duration therapy for hepatitis C virus (HCV) that is highly effective across diverse patient populations, including patients with cirrhosis or previous null response to pegylated interferon (peginterferon) plus ribavirin (PR-null responders). We aimed to assess the efficacy, safety, and effective treatment duration of grazoprevir (an HCV NS3/4A protease inhibitor) combined with elbasvir (an HCV NS5A inhibitor) with or without ribavirin in patients with HCV genotype 1 infection with baseline characteristics of poor response. The C-WORTHY trial is a randomised, open-label phase 2 trial of grazoprevir plus elbasvir with or without ribavirin; here we report findings for two cohorts of previously untreated patients with cirrhosis (cohort 1) and those with previous PR-null response with or without cirrhosis (cohort 2) enrolled in part B of the study. Eligible patients were adults aged 18 years or older with chronic HCV genotype 1 infection and HCV RNA concentrations of 10 000 IU/mL or higher in peripheral blood. We randomly assigned patients to receive grazoprevir (100 mg daily) and elbasvir (50 mg daily) with or without ribavirin for 12 or 18 weeks. Randomisation was done centrally with an interactive voice response system; patients and study investigators were masked to treatment duration up to week 12 but not to treatment allocation. The primary endpoint was the proportion of patients achieving HCV RNA less than 25 IU/mL at 12 weeks after end of treatment (SVR12), assessed by COBAS TaqMan version 2.0. This study is registered with ClinicalTrials.gov, number NCT01717326. We describe findings for 253 patients enrolled in cohort 1 (n=123) or cohort 2 (n=130). In cohort 1, we randomly assigned 60 patients to the 12-week regimen (31 with ribavirin and 29 with no ribavirin) and 63 to the 18-week regimen (32 with ribavirin and 31 with no ribavirin); in cohort 2, we randomly assigned 65 patients to the 12-week regimen (32 with ribavirin and 33 with no ribavirin) and 65 to the 18-week regimen (33 with ribavirin and 32 with no ribavirin. High SVR12 rates were achieved irrespective of the use of ribavirin or extension of the treatment duration from 12 to 18 weeks; SVR12 rates ranged from 90% (95% CI 74-98; 28/31; cohort 1, 12 weeks, ribavirin-containing) to 100% (95% CI 89-100; 33/33; cohort 2, 18 weeks, ribavirin-containing). Among patients treated for 12 weeks with grazoprevir plus elbasvir without ribavirin, 97% (95% CI 82-100, 28/29) of patients in cohort 1 and 91% (76-98, 30/33) of patients in cohort 2 achieved SVR12. Adverse events reported in more than 10% of patients were fatigue (66 patients, 26% [95% CI 21-32]), headache (58 patients, 23% [95% CI 18-29]), and asthenia (35 patients, 14% [95% CI 10-19]). Treatment with grazoprevir plus elbasvir, both with and without ribavirin and for both 12 and 18 weeks' treatment duration, showed high rates of efficacy in previously untreated patients with cirrhosis and previous PR-null responders with and without cirrhosis. These results support the phase 3 development of grazoprevir plus elbasvir.

SummaryThe mammalian APOBEC3 family of cytidine deaminases includes several members that possess potent antiretroviral activity. Human APOBEC3F and APOBEC3G are specifically incorporated into human immunodeficiency virus type 1 (HIV-1) progeny virions in the absence of virion infectivity factor (Vif), where they deaminate deoxycytidine to deoxyuridine on the minus strand of nascent reverse transcripts. Editing of the HIV-1 cDNA leads to its degradation or to G to A hypermutation of the integrated provirus [1–8]. Here, we show that APOBEC3 proteins also restrict the activity of a distantly related long terminal repeat (LTR) retrotransposon. When expressed in the yeast Saccharomyces cerevisiae, human APOBEC3C, APOBEC3F, or APOBEC3G or mouse APOBEC3 potently inhibit replication of the Ty1 LTR retrotransposon. APOBEC3G interacts with Ty1 Gag and is packaged into Ty1 virus-like particles (VLPs) by a mechanism that closely resembles the one it uses to enter HIV-1 virions. Expression of APOBEC3G results in a reduced level of Ty1 cDNA integration and G to A editing of integrated Ty1 cDNA. Our findings indicate that APOBEC3G restricts Ty1 and HIV-1 by similar mechanisms and suggest that the APOBEC3 proteins target a substantially broader spectrum of retroelements than previously appreciated.

The exosome, an evolutionarily conserved complex of multiple 3'--5' exoribonucleases, is responsible for a variety of RNA processing and degradation events in eukaryotes. In this report Arabidopsis thaliana AtRrp4p is shown to be an active 3'--5' exonuclease that requires a free 3'-hydroxyl and degrades RNA hydrolytically and distributively, releasing nucleoside 5'-monophosphate products. AtRrp4p behaves as an approximately 500 kDa species during sedimentation through a 10-30% glycerol gradient, co-migrating with AtRrp41p, another exosome subunit, and it interacts in vitro with AtRrp41p, suggesting that it is also present in the plant cell as a subunit of the exosome. We found that, in addition to a previously reported S1-type RNA-binding domain, members of the Rrp4p family of proteins contain a KH-type RNA-binding domain in the C-terminal half and show that either domain alone can bind RNA. However, only the full-length protein is capable of degrading RNA and interacting with AtRrp41p.

International audience; BACKGROUND & AIMS:HCV-infected cirrhotics may urgently need therapy but are often under-represented in clinical trials resulting in limited data to guide their management. We performed a meta-analysis of well-compensated cirrhotic patients from five Phase 3 trials.METHODS:Patients received P/R (peginterferon/ribavirin; 4 weeks) followed by BOC (boceprevir)/P/R or P/R for 24, 32, or 44 weeks. Sustained virologic response (SVR) rates were calculated by Metavir score. Multivariate logistic regression (MLR) models identified baseline and on-treatment predictors of SVR. Safety was evaluated by adverse-event (AE) reporting and laboratory monitoring.RESULTS:Pooled meta-estimates for SVR rates (95% confidence interval) in 212 F4 (cirrhotic) patients were 55% (43, 66) with BOC/P/R vs.17% (0, 41) with P/R. MLR identified 4 predictors of SVR in F3/F4 patients: undetectable HCV-RNA at treatment week (TW) 8; ⩾ 1 log10 decline in HCV-RNA from baseline at TW4; male; and baseline HCV-RNA ⩽ 800,000 IU/ml. SVR rate was 89% (65/73) in F4 patients who were HCV-RNA undetectable at TW8. No F3 (0/5) or F4 (0/17) patients with

Background & Aims MK-5172 is an inhibitor of the hepatitis C virus (HCV) nonstructural protein 3/4A protease; MK-5172 is taken once daily and has a higher potency and barrier to resistance than licensed protease inhibitors. We investigated the efficacy and tolerability of MK-5172 with peginterferon and ribavirin (PR) in treatment-naive patients with chronic HCV genotype 1 infection without cirrhosis. Methods We performed a multicenter, double-blind, randomized, active-controlled, dose-ranging, response-guided therapy study. A total of 332 patients received MK-5172 (100, 200, 400, or 800 mg) once daily for 12 weeks in combination with PR. Patients in the MK-5172 groups received PR for an additional 12 or 36 weeks, based on response at week 4. Patients in the control group (n = 66) received a combination of boceprevir and PR, dosed in accordance with boceprevir's US product circular. Results At 24 weeks after the end of therapy, sustained virologic responses were achieved in 89%, 93%, 91%, and 86% of the patients in the groups given the combination of PR and MK-5172 (100, 200, 400, or 800 mg), respectively, vs 61% of controls. In the MK-5172 group receiving 100 mg, 91% of patients had undetectable levels of HCV RNA at week 4 and qualified for the short duration of therapy. The combination of MK-5172 and PR generally was well tolerated. Transient increases in transaminase levels were noted in the MK-5172 groups given 400 and 800 mg, at higher frequencies than in the MK-5172 groups given 100 or 200 mg, or control groups. Conclusions Once-daily MK-5172 (100 mg) with PR for 24 or 48 weeks was highly effective and well tolerated among treatment-naive patients with HCV genotype 1 infection without cirrhosis. Studies are underway to evaluate interferon-free MK-5172–based regimens. ClinicalTrials.gov number: NCT01353911.

International audience; Background & AimsTreatment of hepatitis C virus (HCV) infection with boceprevir, peginterferon, and ribavirin can lead to anemia, which has been managed by reducing ribavirin dose and/or erythropoietin therapy. We assessed the effects of these anemia management strategies on rates of sustained virologic response (SVR) and safety.MethodsPatients (n = 687) received 4 weeks of peginterferon and ribavirin followed by 24 or 44 weeks of boceprevir (800 mg, 3 times each day) plus peginterferon and ribavirin. Patients who became anemic (levels of hemoglobin approximately ≤10 g/dL) during the study treatment period (n = 500) were assigned to groups that were managed by ribavirin dosage reduction (n = 249) or erythropoietin therapy (n = 251).ResultsRates of SVR were comparable between patients whose anemia was managed by ribavirin dosage reduction (71.5%) vs erythropoietin therapy (70.9%), regardless of the timing of the first intervention to manage anemia or the magnitude of ribavirin dosage reduction. There was a threshold for the effect on rate of SVR: patients who received

International audience; BACKGROUND:Adherence to therapeutic regimens affects the efficacy of peginterferon alfa (P) and ribavirin (R) therapy in patients with chronic hepatitis C virus genotype 1.AIM:To determine if medication adherence impacts efficacy [sustained virological response (SVR)] with triple therapy that includes boceprevir (BOC) plus P/R.METHODS:Adherence was determined in two Phase 3 clinical studies with BOC: SPRINT-2 (previously untreated patients) and RESPOND-2 (patients who failed previous therapy with P/R). Adherence to the assigned duration of the dosing regimen and adherence to the three times a day (t.d.s.) dosing interval of 7-9 h for BOC were assessed by the recording of data from patients' dosing diaries and by the amount of study drug dispensed and returned.RESULTS:Most patients (63-71%) adhered to ≥80% of their assigned treatment duration and achieved SVR rates of 86-90%. In contrast, patients who adhered to 80%) to the t.d.s. dosing interval (7-9 h) with BOC did not influence the SVR rates (SVR = 60-83%) with the exception of patients who failed previous treatment and adhered to 60% of t.d.s. dosing with boceprevir is important in patients who failed previous therapy.

Bacterial beta-galactosidase is one of several reporter enzymes used in studying the transcriptional activity of eukaryotic promoters. Although it is one of the easiest and least expensive enzymes to assay, its use has been limited because of its low sensitivity, which is due in part to endogenous levels of beta-galactosidase in many eukaryotic cells. In this study, we compared the pH and salt requirements, as well as the heat stability, of bacterial and eukaryotic beta-galactosidase in order to identify conditions which would inhibit the beta-galactosidase enzyme endogenous to eukaryotic cells without adversely affecting the activity of either purified bacterial beta-galactosidase or reporter beta-galactosidase produced after transfection of expression vectors into eukaryotic cells. Heat treatment at 50 degrees C for 1 h inactivated the beta-galactosidase activity endogenous to several eukaryotic cell lines by as much as 40-fold without adversely affecting the activity of bacterial beta-galactosidase. This treatment increased the sensitivity of this reporter enzyme and allowed the development of a rapid and quantifiable screening assay for HIV-1 tat inhibitors.

Background : Rhinoviruses and the homologous polioviruses have hydrophobic pockets below their receptor-binding sites, which often contain unidentified electron density (‘pocket factors'). Certain antiviral compounds also bind in the pocket, displacing the pocket factor and inhibiting uncoating. However, human rhinovirus (HRV)14, which belongs to the major group of rhinoviruses that use intercellular adhesion molecule-1 (ICAM-1) as a receptor, has an empty pocket. When antiviral compounds bind into the empty pocket of HRV14, the roof of the pocket, which is also the floor of the receptor binding site (the canyon), is deformed, preventing receptor attachment. The role of the pocket in viral infectivity is not known. Results : We have determined the structure of HRV16, another major receptor group rhinovirus serotype, to atomic resolution. Unlike HRV14, the pockets contain electron density resembling a fatty acid, eight or more carbon atoms long. Binding of the antiviral compound WIN 56291 does not cause deformation of the pocket, although it does prevent receptor attachment. Conclusions : We conjecture that the binding of the receptor to HRV16 can occur only when the pocket is temporarily empty, when it is possible for the canyon floor to be deformed downwards into the pocket. We further porpose that the role of the pocket factor is to stabilize virus in transit from one host cell to the next, and that binding of ICAM-1 traps the pocket in the empty state, destabilizing the virus as required for uncoating.

A multiplexed human papillomavirus (HPV) immunoassay has been developed for the detection of human IgG antibodies to HPV type 6, 11, 16, 18, 31, 33, 45, 52, and 58 virus-like particle (VLP) types in serum following natural infection or immunization with VLP-based vaccines. The VLP antigens were covalently conjugated to carboxyl Luminex microspheres (MS) using a carbodiimide chemistry. Antibody (Ab) titers were determined in a direct binding format, in which an IgG1- to -4-specific, phycoerythrin (PE)-labeled monoclonal antibody (MAb) (HP6043) binds to human serum IgG antibodies. Pooled serum samples from rhesus macaques immunized with a 9-valent VLP-based vaccine served as the reference standard. The overall specificity of the assay was >99%, and the linearity (parallelism) of the assay was

The genomic RNA of retroviruses and retrovirus-like transposons must be sequestered from the cellular translational machinery so that it can be packaged into viral particles. Eukaryotic mRNA processing bodies (P bodies) play a central role in segregating cellular mRNAs from the translational machinery for storage or decay. In this work, we provide evidence that the RNA of the Saccharomyces cerevisiae Ty1 retrotransposon is packaged into virus-like particles (VLPs) in P bodies. Ty1 RNA is translationally repressed, and Ty1 Gag, the capsid and RNA binding protein, accumulates in discrete cytoplasmic foci, a subset of which localize to P bodies. Human APOBEC3G, a potent Ty1 restriction factor that is packaged into Ty1 VLPs via an interaction with Gag, also localizes to P bodies. The association of APOBEC3G with P bodies does not require Ty1 element expression, suggesting that P-body localization of APOBEC3G and Ty1 Gag precedes VLP assembly. Additionally, we report that two P-body-associated 5′ to 3′ mRNA decay pathways, deadenylation-dependent mRNA decay (DDD) and nonsense-mediated decay (NMD), stimulate Ty1 retrotransposition. The additive contributions of DDD and NMD explain the strong requirement for general 5′ to 3′ mRNA degradation factors Dcp1, Dcp2, and Xrn1 in Ty1 retromobility. 5′ to 3′ decay factors act at a posttranslational step in retrotransposition, and Ty1 RNA packaging into VLPs is abolished in the absence of the 5′ to 3′ exonuclease Xrn1. Together, the results suggest that VLPs assemble in P bodies and that 5′ to 3′ mRNA decay is essential for the packaging of Ty1 RNA in VLPs.

A CoMFA analysis of eight compounds related to disoxaril whose X-ray structures bound to HRV-14 had been determined resulted in a strong positive correlation of activity with steric effects of the compounds, particularly toward the pore end of the compound binding site, and no correlation with electrostatic effects. These results confirm what had been previously found, that the activity of these compounds was highly dependent upon their hydrophobic nature as expressed by log p. The CoMFA study also confirmed the results from the comparison of a series of active and inactive compounds using volume maps which showed that bulk at the pore end of the molecule was conducive to high levels of antiviral activity while excessive bulk around the ring led to poor activity.

The binding affinities (Kds) and the rates of association and dissociation of members of a chemical class of antiviral compounds at their active sites in human rhinovirus type 14 (HRV-14) were determined. On the basis of analysis by LIGAND, a nonlinear curve-fitting program, of saturation binding experiments with HRV-14, the Kds for Win 52084, Win 56590, disoxaril (Win 51711), and Win 54954 were found to be 0.02, 0.02, 0.08, and 0.22 microM, respectively. The independently determined kinetic rates of association and dissociation resulted in calculated Kd values which were in agreement with the Kd values determined in saturation binding experiments. Scatchard plots of each of four compounds for the binding data indicated that approximately 40 to 60 molecules were bound per HRV-14 virion. Hill plots showed no evidence of cooperativity in binding. Furthermore, the antiviral activities (MICs in plaque reduction assays with HRV-14) for this limited series of compounds (n = 4) correlated well (r = 0.997) with the observed Kds. Likewise, the absence of detectable binding of Win 54954 to the drug-resistant mutant HRV-14 (Leu-1188) corresponded to a lack of antiviral activity. The positive relationship between the antiviral activities and the Kds that were determined may have implications for the molecular design of capsid-binding antirhinovirus drugs.

Stromal interaction molecule 1 (STIM1) and Orai1 have been identified as crucial elements of the store-operated Ca2+ entry (SOCE) pathway, but the mechanism of their functional interaction remains controversial. It is now well established that, upon depletion of the stores, both molecules can accumulate and colocalize in specific areas (puncta) where the endoplasmic reticulum comes in close proximity to the plasma membrane. Some models propose a direct interaction between STIM1 and Orai1 as the most straightforward mechanism for signal transduction from the stores to the plasma membrane. To test some of the predictions of a conformational coupling model, we assessed how tight the relationships are between STIM1 and Orai1 expression, puncta formation, and SOCE activation. Here we present evidence that STIM1 accumulates in puncta equally well in the presence or absence of Orai1 expression, that STIM1 accumulation is not sufficient for Orai1 accumulation in the same areas, and that normal Ca2+ release-activated Ca2+ current ( ICRAC) can be activated in STIM1-deficient cells. These data challenge the idea of direct conformational coupling between STIM1 and Orai1 as a viable mechanism of puncta formation and SOCE activation and uncover greater complexity in their relationship, which may require additional intermediate elements.

The heterodimer of the ecdysone receptor (EcR) and ultraspiracle (Usp), members of the nuclear receptor superfamily, is considered to be functional receptor for the ecdysteroids that coordinate essential biological processes in insects. In this work we have applied a bimolecular fluorescence complementation (BiFC) method to directly analyze the formation of the EcR/Usp complex. The BiFC experiments were carried out in mammalian cells which are routinely used for heterologous studies of the EcR/Usp complex, including experiments on EcR-based artificial molecular gene switches. BiFC analysis, supported by flow cytometry, revealed that EcR-Usp interaction is nuclei-restricted. If expressed separately, Usp and EcR are able to form nuclear complexes in the absence of the cognate dimerization partner. We have observed that Muristerone A that is widely used for the induction of ecdysteroid-dependent transcription in mammalian cells, does not significantly change the number of EcR/Usp and EcR/EcR complexes, and it does not influence their subcellular localization.

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Ecdysteroids coordinate development, reproduction and other essential biological processes in insects and other arthropods through the receptor which is a heterodimer of two members of the nuclear receptors superfamily, the ecdysteroid receptor (EcR) and the Ultraspiracle (Usp). Although the transcriptionally active EcR/Usp heterocomplex is believed to be the only functional form of the receptor, there are data indicating that EcR may be involved in the mediation of the non-genomic effects outside of the nucleus. Since the nucleocytoplasmic shuttling could be a key element determining participation of the single nuclear receptor molecule both in the genomic and non-genomic functions we have analyzed nuclear import and export properties of the EcR and Usp from Drosophila melanogaster. We show for the first time that both receptors exhibit differential distribution of the nuclear localization and nuclear export signals (NLSs and NESs). In particular, the Usp which exhibits exclusively nuclear localization in all cell types analyzed, contains apparently only NLS activity within the DNA-binding domain. In contrast, the three known EcR isoforms (A, B1 and B2) are mosaics of elements which can potentially mediate their nucleocytoplasmic shuttling. We have found two active NESs in ligand binding domain and NLS activity within the DNA-binding domain of all isoforms. Simultaneously we demonstrate that B1 and A isoforms possess an additional NLS activity localized in AB regions. We speculate that this characteristic, along with the previously reported structural pliability of the EcR molecule, allows the single receptor to evoke many different genomic as well as non-genomic ecdysteroid-dependent responses.

The heterodimer consisting of ecdysteroid receptor (EcR) and ultraspiracle (USP), both of which are members of the nuclear receptor superfamily, is considered to be the functional ecdysteroid receptor. Here we analyzed the subcellular distribution of EcR and USP fused to fluorescent proteins. The experiments were carried out in mammalian COS-7, CHO-K1 and HeLa cells to facilitate investigation of the subcellular trafficking of EcR and USP in the absence of endogenous expression of these two receptors. The distribution of USP tagged with a yellow fluorescent protein (YFP-USP) was almost exclusively nuclear in all cell types analyzed. The nuclear localization remained constant for at least 1 day after the first visible signs of expression. In contrast, the intracellular distribution of EcR tagged with a yellow fluorescent protein (YFP-EcR) varied and was dependent on time and cell type, although YFP-EcR alone was also able to partially translocate into the nuclear compartment. Coexpression of YFP-EcR with USP tagged with a cyan fluorescent protein (CFP-USP) resulted in exclusively nuclear localization of both proteins in all cell types analyzed. The USP-induced nuclear localization of YFP-EcR was stable for at least 20 hours. These experiments suggest that USP has a profound effect on the subcellular distribution of EcR.

Deadenylation of mRNA is often the first and rate-limiting step in mRNA decay. PARN, a poly(A)-specific 3′ →5′ ribonuclease which is conserved in many eukaryotes, has been proposed to be primarily responsible for such a reaction, yet the importance of the PARN function at the whole-organism level has not been demonstrated in any species. Here, we show that mRNA deadenylation by PARN is essential for viability in higher plants (Arabidopsis thaliana). Yet, this essential requirement for the PARN function is not universal across the phylogenetic spectrum, because PARN is dispensable in Fungi (Schizosaccharomyces pombe), and can be at least severely downregulated without any obvious consequences in Metazoa (Caenorhabditis elegans). Development of the Arabidopsis embryos lacking PARN (AtPARN), as well as of those expressing an enzymatically inactive protein, was markedly retarded, and ultimately culminated in an arrest at the bent-cotyledon stage. Importantly, only some, rather than all, embryo-specific transcripts were hyperadenylated in the mutant embryos, suggesting that preferential deadenylation of a specific select subset of mRNAs, rather than a general deadenylation of the whole mRNA population, by AtPARN is indispensable for embryogenesis in Arabidopsis. These findings indicate a unique, nonredundant role of AtPARN among the multiple plant deadenylases.

The purpose of this study was to compare arterial heat balance ear temperature measurements to rectal temperatures in infants and children and to determine the ability of the ear thermometer being tested to detect fever. From 12/95 to 2/96, 1,175 pairs of ear and rectal temperature measurements were prospectively obtained from 140 infants and toddlers. The mean rectal temperature was 37.58 degrees C (sd = 0.68) and the mean ear temperature was 37.60 degrees C (sd = 0.85). However, at the low end of the rectal temperature scale, ear temperatures tended to be higher, and at the high end of the rectal temperature scale, ear temperatures tended to be lower. There were 292 readings with a rectal temperature > or = 38.0 degrees C and in 204 (70%) the ear temperature was also > or = 38.0 degrees C. A retrospective analysis of 53 children who became febrile in hospital (ear or rectal temperature > or = 38.0 degrees C) showed that fever was detected first by rectal measurement in seven, by ear measurement in 31 (59%), and by both in 15 (28%). These data indicate that, on the average, rectal and ear temperature measurements are not different. Fever that developed in children after hospitalization was more likely to be first detected by ear than by rectal measurement.

Novel antiherpetic 3-quinolinecarboxamides were discovered as part of a drug discovery program at Sterling Winthrop Inc. A major goal of this research was to identify novel non-nucleoside agents possessing activity against acyclovir resistant herpes simplex virus. From screening compound libraries in an HSV-2 plaque reduction assay, 1-ethyl-1,4-dihydro-4-oxo-7-(4-pyridinyl)-3-quinolinecarboxamide (1) emerged as an attractive lead structure. By modifying the quinoline ring at the 1-, 2-, 3-, 4-, and 7-positions, analogues were identified that have up to 5-fold increased in vitro potency relative to acyclovir. In a single dose mouse model of infection the 1-(4-FC6H4) analogue 17, one of the most potent derivatives in vitro, displayed comparable oral antiherpetic efficacy to acyclovir at 1/16 the dose; in a multiple dose regimen, however, it was 2-fold less potent. Mechanism of action studies indicate that these new compounds interact with a different, as yet undefined, molecular target than acyclovir.

Background: Group B coxsackieviruses (CVBs) are etiologic agents of a number of human diseases that range in severity from asymptomatic to lethal infections. They are small, single-stranded RNA icosahedral viruses that belong to the enterovirus genus of the picornavirus family. Structural studies were initiated in light of the information available on the cellular receptors for this virus and to assist in the design of antiviral capsid-binding compounds for the CVBs. Results The structure of coxsackievirus B3 (CVB3) has been solved to a resolution of 3.5 a. The β -sandwich structure of the viral capsid proteins VP1, VP2 and VP3 is conserved between CVB3 and other picornaviruses. Structural differences between CVB3 and other enteroviruses and rhinoviruses are located primarily on the viral surface. The hydrophobic pocket of the VP1 β -sandwich is occupied by a pocket factor, modeled as a C 16 fatty acid. An additional study has shown that the pocket factor can be displaced by an antiviral compound. Myristate was observed covalently linked to the N terminus of VP4. Density consistent with the presence of ions was observed on the icosahedral threefold and fivefold axes. Conclusion The canyon and twofold depression, major surface depressions, are predicted to be the primary and secondary receptor-binding sites on CVB3, respectively. Neutralizing immunogenic sites are predicted to lie on the extreme surfaces of the capsid at sites that lack amino acid sequence conservation among the CVBs. The ions located on the icosahedral threefold and fivefold axes together with the pocket factor may contribute to the pH stability of the coxsackieviruses.

A series of 1,2,4-oxadiazoles has been prepared as ester bioisosteres and tested against 15 human rhinovirus serotypes, and the MIC80, the concentration which inhibits 80% or 12 of the serotypes tested, was determined. Homologation of the alkyl group attached to the oxadiazole ring resulted in a reduction in activity with increased chain length. Introduction of hydrophilic groups in this position rendered the compounds inactive. Increasing the length of the side chain attached to the isoxazole ring resulted in an increase in activity. Replacement of the methyl with alkoxyalkyl substituents retained activity; however, introduction of a hydroxyl group on to the side chain reduced activity. Compound 8a, where both the isoxazole and oxadiazole rings were substituted with methyl groups, was one of the most active compounds in the series. A comparison was made between 8a and the two isomeric oxadiazoles 41 and 46, and an attempt was made to explain the difference in activity by examining electrostatic potential maps and by an energy profiling study. No conclusive results were obtained from these studies.

On the grounds of clinical and experimental data on hepatobiliary system obtained by hepatobiliscintigraphy (HBSG) and morphological study of hepatic parenchyma deterioration of hepatocytes and suppression of concentrating abilities of gallbladder were found in 68 patients with colorectal cancer and no clinical and laboratory manifestation. Any antitumor treatment, especially combined with chemotherapy, aggravates the disorders. Surgical intervention provokes transient ciliary dyskinesia. Unspecific reactive hepatitis associated with intrahepatic cholestasis and aggravated by antitumor therapy should be considered as a morphological ground for the functional changes. HBSG is recommended to be performed from time to time during post-operative rehabilitation of patients who underwent radical surgery for colorectal cancer. Correction of revealed disorders should be carried out in gastroenterological departments.

The efficacy of oral WIN 54954 for the prevention of rhinovirus infection and illness was tested in two randomized, double-blinded, placebo-controlled volunteer challenge studies. Volunteers were inoculated with rhinovirus type 39 (MIC of WIN 54954, 0.17 microgram/ml) or rhinovirus type 23 (MIC, 0.016 microgram/ml). The volunteers received two doses of drug (600 mg per dose) or placebo on the first day; this was followed by three doses on each of the subsequent 5 days. All volunteers were challenged with virus after the third dose of study drug. No significant antiviral or clinical effect was detected in either study. Pharmacokinetic studies revealed that on the last day of drug administration, 38 of 39 (97%) volunteers had trough levels of WIN 54954 in plasma greater than the MIC for the respective virus. Nasal wash specimens collected on the same day revealed a detectable level in only 6 of 24 (25%) volunteers at the peak (range, 6 to 24 ng/ml) and in only 2 of 14 (14%) volunteers at the trough (range, 6 and 7 ng/ml). These results suggest that the lack of efficacy of WIN 54954 against rhinovirus may be related to an inability to deliver sufficient drug to the site of viral infection.

A series of conformationally restricted analogs of disoxaril has been synthesized and evaluated against human rhinovirus types (HRV) 14 and 1A. The sensitivity of these serotypes to this series varied and was dependent upon the length of the molecule as well as upon the flexibility of the aliphatic chain. Minimum energy conformations of these compounds were overlaid with the X-ray structure of a closely related analog 9 bound to the capsid protein of both HRV-14 and -1A and then modeled in the compound-binding site of both serotypes. A comparative sweep volume of these compounds about the isoxazole ring revealed an inaccessible region of space for the cis-olefin 8b, which is not the case for either the trans-olefin 8a or the acetylene 5. This region may be important to the binding of the compounds to the HRV-14 site particularly during entry into the pocket.

Spontaneous mutants of human rhinovirus 14 resistant to WIN 52084, an antiviral compound that inhibits attachment to cells, were isolated by selecting plaques that developed when wild-type virus was plated in the presence of high (2 micrograms/ml) or low (0.1 to 0.4 micrograms/ml) concentrations of the compound. Two classes of drug resistance were observed: a high-resistance (HR) class with a frequency of about 4 x 10(-5), and a low-resistance (LR) class with a 10- to 30-fold-higher frequency. The RNA genomes of 56 HR mutants and 13 LR mutants were sequenced in regions encoding the drug-binding site. The HR mutations mapped to only 2 of the 16 amino acid residues that form the walls of the drug-binding pocket. The side chains of these two residues point directly into the pocket and were invariably replaced by bulkier groups. These findings, and patterns of resistance to related WIN compounds, support the concept that HR mutations may hinder the entry or seating of drug within the binding pocket. In contrast, all of the LR mutations mapped to portions of the polypeptide chain near the canyon floor that move when the drug is inserted. Because several LR mutations partially reverse the attachment-inhibiting effect of WIN compounds, these mutants provide useful tools for studying the regions of the capsid structure involved in attachment. This paper shows that the method of escape mutant analysis, previously used to identify antibody binding sites on human rhinovirus 14, is also applicable to analysis of antiviral drug activity.

Mutants of human rhinovirus 14 were isolated and characterized by searching for resistance to compounds that inhibit viral uncoating. The portions of the RNA that code for amino acids that surround the antiviral compound binding site were sequenced. X-ray analysis of two of these mutants, 1188 Val → Leu and 1199 Cys → Tyr, shows that these were single-site substitutions which would sterically hinder drug binding. Differences in the resistance of mutant viruses to various antiviral compounds may be rationalized in terms of the three-dimensional structures of these mutants. Predictions of the structures of mutant rhinovirus 14 with the substitutions 1188 Val → Leu, 1199 Cys → Tyr and 1199 Cys → Trp in VP1 were made using a molecular dynamics technique. The predicted structure of the 1199 Cys → Tyr mutant was consistent with the electron density map, while the 1188 Val → Leu prediction was not. Large (up to 1.4 A) conformational differences between native rhinovirus 14 and the 1199 Cys → Tyr mutant occurred in main-chain atoms near the mutation site. These changes, as well as the orientation of the 1199 tyrosine side-chain, were correctly predicted by the molecular dynamics calculation. The structure of the predicted 1199 Cys → Trp mutation is consistent with the drug-resistant properties of this virus.

The structure of human rhinovirus 1A (HRV1A) has been determined to 3.2 A resolution using phase refinement and extension by symmetry averaging starting with phases at 5 A resolution calculated from the known human rhinovirus 14 (HRV14) structure. The polypeptide backbone structures of HRV1A and HRV14 are similar, but the exposed surfaces are rather different. Differential charge distribution of amino acid residues in the “canyon”, the putative receptor binding site, provides a possible explanation for the difference in minor versus major receptor group specificities, represented by HRV1A and HRV14, respectively. The hydrophobic pocket in VP1, into which antiviral compounds bind, is in an “open” conformation similar to that observed in drug-bound HRV14. Drug binding in HRV1A does not induce extensive conformational changes, in contrast to the case of HRV14.