Preclinical Characterization of PC786, an Inhaled Small-Molecule Respiratory Syncytial Virus L Protein Polymerase Inhibitor.

Although respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infection in infants and young children, attempts to develop an effective therapy have so far proved unsuccessful. Here we report the preclinical profiles of PC786, a potent nonnucleoside RSV L protein polymerase inhibitor, designed for inhalation treatment of RSV infection. PC786 demonstrated a potent and selective antiviral activity against laboratory-adapted or clinical isolates of RSV-A (50% inhibitory concentration [IC50], <0.09 to 0.71 nM) and RSV-B (IC50, 1.3 to 50.6 nM), which were determined by inhibition of cytopathic effects in HEp-2 cells without causing detectable cytotoxicity. The underlying inhibition of virus replication was confirmed by PCR analysis. The effects of PC786 were largely unaffected by the multiplicity of infection (MOI) and were retained in the face of established RSV replication in a time-of-addition study. Persistent anti-RSV effects of PC786 were also demonstrated in human bronchial epithelial cells. In vivo intranasal once daily dosing with PC786 was able to reduce the virus load to undetectable levels in lung homogenates from RSV-infected mice and cotton rats. Treatment with escalating concentrations identified a dominant mutation in the L protein (Y1631H) in vitro In addition, PC786 potently inhibited RSV RNA-dependent RNA polymerase (RdRp) activity in a cell-free enzyme assay and minigenome assay in HEp-2 cells (IC50, 2.1 and 0.5 nM, respectively). Thus, PC786 was shown to be a potent anti-RSV agent via inhibition of RdRp activity, making topical treatment with this compound a novel potential therapy for the treatment of human RSV infections.

Discovery of novel benzothienoazepine derivatives as potent inhibitors of respiratory syncytial virus.

The development of novel non-nucleoside inhibitors of the RSV polymerase complex is of significant clinical interest. Compounds derived from the benzothienoazepine core, such as AZ-27, are potent inhibitors of RSV viruses of the A-subgroup, but are only moderately active against the B serotype and as yet have not demonstrated activity in vivo. Herein we report the discovery of several novel families of C-2 arylated benzothienoazepine derivatives that are highly potent RSV polymerase inhibitors and reveal an exemplary structure, compound 4a, which shows low nanomolar activity against both RSV A and B viral subtypes. Furthermore, this compound is effective at suppressing viral replication, when administered intranasally, in a rodent model of RSV infection. These results suggest that compounds belonging to this chemotypes have the potential to provide superior anti-RSV agents than those currently available for clinical use.

Evaluation of fluoropyruvate as nucleophile in reactions catalysed by N-acetyl neuraminic acid lyase variants: scope, limitations and stereoselectivity.

The catalysis of reactions involving fluoropyruvate as donor by N-acetyl neuraminic acid lyase (NAL) variants was investigated. Under kinetic control, the wild-type enzyme catalysed the reaction between fluoropyruvate and N-acetyl mannosamine to give a 90 : 10 ratio of the (3R,4R)- and (3S,4R)-configured products; after extended reaction times, equilibration occurred to give a 30 : 70 mixture of these products. The efficiency and stereoselectivity of reactions of a range of substrates catalysed by the E192N, E192N/T167V/S208V and E192N/T167G NAL variants were also studied. Using fluoropyruvate and (2R,3S)- or (2S,3R)-2,3-dihydroxy-4-oxo-N,N-dipropylbutanamide as substrates, it was possible to obtain three of the four possible diastereomeric products; for each product, the ratio of anomeric and pyranose/furanose forms was determined. The crystal structure of S. aureus NAL in complex with fluoropyruvate was determined, assisting rationalisation of the stereochemical outcome of C-C bond formation.

Survey of high school students' perceptions about their iPod use, knowledge of hearing health, and need for education.

PURPOSE: High school students' knowledge about hearing health and their perceptions of how they use personal listening devices (PLDs) including iPods were surveyed to determine the need, content, and preferred format for educational outreach to them. METHOD: This study was a descriptive convenience survey of students at a California high school. An 83-item questionnaire was administered in December 2009 to assess students' demographics, knowledge of hearing health, perceived iPod use, and risk activities. RESULTS: The response rate was 56%. Most of the students perceived that they used iPods safely. However, responses indicated that many of the respondents could be at risk of injury to themselves or others if they became unaware of their surroundings while listening to iPods. Some students were knowledgeable about hearing health and safe iPod use, but most needed information about hearing loss and hearing conservation. CONCLUSION: Most of the students needed education (e.g., via health classes or the Internet) about hearing health, the warning signs of hearing loss, and how to prevent hearing loss. Resources for educational audiologists are provided.

National survey of pediatricians' opinions about and practices for acute otitis media and xylitol use.

BACKGROUND: Acute otitis media (AOM) is the main reason for physician visits and antibiotic prescriptions in children. Pediatricians (Peds) are gatekeepers for services and sources of information for families. The 2004 American Academy of Pediatrics/American Academy of Family Physicians (AAP/AAFP) Clinical Practice Guideline: Diagnosis and Management of Acute Otitis Media recommended preventative and management measures for Peds' practice. Treatments for AOM (antimicrobial therapy and surgery) sometimes have questionable effectiveness, risks, and high costs. Thus, Peds should consider using prophylactics for AOM that are easy to administer, cost-effective, and have minimal side effects. Xylitol, a naturally occurring sugar alcohol, is widely used to prevent AOM and for other health conditions in Europe, and as a dental caries prophylaxis in the United States. It would be helpful to know Peds' attitudes and practices to identify barriers to xylitol's use as a prophylaxis for AOM in the United States. PURPOSE: To conduct a national survey of Peds in the United States to evaluate how closely they adhered to the AAP/AAFP guideline, and their knowledge and opinions about xylitol use. RESEARCH DESIGN: A randomized, national postal survey. METHOD: A 48-item questionnaire developed for this study was mailed to a random sample of 506 Peds within the United States during spring 2009. It assessed Peds' demographics, adherence to the guideline, and knowledge and opinions about and use of xylitol as a prophylaxis for AOM in children. RESULTS: The questionnaire response rate was 22% (98 useable/506 mailed - 63 returned undeliverable). Participants were about equal for gender, and almost all were in private practice for over 10 yr. Most had pediatric patients with at least one bout of AOM annually. The majority adhered to the guideline (e.g., almost all routinely assessed and managed patients' pain for AOM and encouraged prevention by recommending that families reduce risk factors). Most used and were comfortable with otoscopy for diagnosing AOM, but not tympanometry. Almost all believed that conductive hearing loss could hinder speech-language and academic development, and AOM could reduce quality of life of children. They also believed that those under 6 mo of age with AOM should receive antibacterial therapy beginning with amoxicillin but did not use complementary and alternative medicine (CAM). Only about half knew about medical uses for xylitol, but of those, most were aware of its use in chewing gum to prevent AOM but had not used it with patients. They were not sure of xylitol's effectiveness or appropriate dosages but cited stomach cramping and diarrhea as possible side effects. Most would use xylitol if evidence supported it and wanted information about it via reprints or electronically. Few agreed that audiologists are important in diagnosing/managing AOM. CONCLUSIONS: Most of these Peds adhered to the AAP/AAFP guideline. They were not using CAMs like xylitol for preventing AOM in children. Future research should focus on prevention and the use of xylitol as a possible prophylaxis regimen for AOM in patients.