Targeting human respiratory syncytial virus transcription anti-termination factor M2-1 to inhibit in vivo viral replication.

Human respiratory syncytial virus (hRSV) is a leading cause of acute lower respiratory tract infection in infants, elderly and immunocompromised individuals. To date, no specific antiviral drug is available to treat or prevent this disease. Here, we report that the Smoothened receptor (Smo) antagonist cyclopamine acts as a potent and selective inhibitor of in vitro and in vivo hRSV replication. Cyclopamine inhibits hRSV through a novel, Smo-independent mechanism. It specifically impairs the function of the hRSV RNA-dependent RNA polymerase complex notably by reducing expression levels of the viral anti-termination factor M2-1. The relevance of these findings is corroborated by the demonstration that a single R151K mutation in M2-1 is sufficient to confer virus resistance to cyclopamine in vitro and that cyclopamine is able to reduce virus titers in a mouse model of hRSV infection. The results of our study open a novel avenue for the development of future therapies against hRSV infection.

Cutaneous adverse drug reactions in Indian population: A systematic review.

BACKGROUND: Epidemiological data is limited for cutaneous adverse drug reactions (CADRs) in India. Most of the Indian studies have small sample size and are of limited duration. AIMS: The aim of this study is to analyze CADRs with reference to the causative drugs and their clinical characteristics in Indian population. MATERIALS AND METHODS: As per selection criteria, electronic databases were searched for publications describing CADRs from January-1995 to April-2013 by two independent investigators. Data of the causative drugs and clinical characteristics were extracted and summarized by absolute numbers, percentages, ranges, and means as presented by the authors. The subgroup analysis of causative drugs was performed for causality assessment, severe or nonsevere reactions and occurrence of common CADRs. Studies showing "definite" and "probable" categories of causality analysis were labeled as "definite and probable causality (DPC) studies". The other included studies were labeled as "non-DPC studies". RESULTS: Of 8337 retrieved references, 18 prospective studies were selected for analysis. The pooled incidence was 9.22/1000 total among outpatient and inpatient cases. Commonly observed reactions were maculopapular rash (32.39%), fixed drug eruptions (FDEs) (20.13%), urticaria (17.49%) and Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) (6.84%). The major causative drug groups were antimicrobials (45.46%), nonsteroidal anti-inflammatory drugs (NSAIDs) (20.87%) and anti-epileptic drugs (14.57%). Commonly implicated drugs were sulfa (13.32%), ß-lactams (8.96%) and carbamazepine (6.65%). High frequency of CADRs is observed with anti-epileptic drugs in DPC studies only. Carbamazepine, phenytoin and fluoroquinolones had higher severe to nonsevere cutaneous reaction ratio than other drugs. Antimicrobials were the main causative drugs for maculopapular rash, FDEs and SJS/TEN, and NSAIDs for the urticaria. The mortality for overall CADRs, SJS/TEN, and exfoliative dermatitis were 1.71%, 16.39%, and 3.57%, respectively. "Definitely preventable", "probably preventable" and "not preventable" categories CADRs were 15.64%, 63.14%, and 34.64%, respectively. CONCLUSION: Antimicrobials, NSAIDs and antiepileptic are common causative agents of CADRs in India. Antiepileptic agents show high rates of severe cutaneous reactions.