Identification and characterization of a drug-sensitive strain enables puromycin-based translational assays in Saccharomyces cerevisiae.

Puromycin is an aminonucleoside antibiotic with structural similarity to aminoacyl tRNA. This structure allows the drug to bind the ribosomal A site and incorporate into nascent polypeptides, causing chain termination, ribosomal subunit dissociation and widespread translational arrest at high concentrations. In contrast, at sufficiently low concentrations, puromycin incorporates primarily at the C-terminus of proteins. While a number of techniques utilize puromycin incorporation as a tool for probing translational activity in vivo, these methods cannot be applied in yeasts that are insensitive to puromycin. Here, we describe a mutant strain of the yeast Saccharomyces cerevisiae that is sensitive to puromycin and characterize the cellular response to the drug. Puromycin inhibits the growth of yeast cells mutant for erg6∆, pdr1∆ and pdr3∆ (EPP) on both solid and liquid media. Puromycin also induces the aggregation of the cytoplasmic processing body component Edc3 in the mutant strain. We establish that puromycin is rapidly incorporated into yeast proteins and test the effects of puromycin on translation in vivo. This study establishes the EPP strain as a valuable tool for implementing puromycin-based assays in yeast, which will enable new avenues of inquiry into protein production and maturation.

The Effect of Temperament on Outcomes of Opioid and Non-Opioid Pediatric Dental Sedation.

Purpose: To assess oral sedation success using midazolam and hydroxyzine with and without meperidine, and to assess the relationship between child temperament and sedation outcomes. Methods: This study recruited children between the ages of 36 and 95 months who were randomly assigned to receive dental treatment with an oral sedation regimen of midazolam (0.5 mg/kg) and hydroxyzine (1.0 mg/kg) with or without meperidine (1.5 mg/kg). Data were collected from the treatment log and electronic health records. Parents completed the Child Behavior Questionnaire Short Form (CBQ-SF) to assess temperament. Results: The study included 37 participants. The overall treatment success rate was 54 percent. There were no significant differences in sedation outcome with age, sex, insurance status, sedation regimen, isolation method or duration of procedure. Children with high pre-operative Frankl behavioral ratings were more likely to have a successful sedation outcome (P <0.01). Children who displayed high soothability experienced higher rates of success (P =0.04), which was more pronounced in the non-opioid group (P <0.01). Conclusion: The study showed low rates of success for a relatively small sample size. There was no difference in sedation success between the opioid group and non-opioid group. However, pre-procedure behavior and temperament characteristic of sooth- ability may warrant more exploration as predictors of sedation success.

Evaluation and integration of disparate classification systems for clefts of the lip.

Orofacial clefting is a common birth defect with wide phenotypic variability. Many systems have been developed to classify cleft patterns to facilitate diagnosis, management, surgical treatment, and research. In this review, we examine the rationale for different existing classification schemes and determine their inter-relationships, as well as strengths and deficiencies for subclassification of clefts of the lip. The various systems differ in how they describe and define attributes of cleft lip (CL) phenotypes. Application and analysis of the CL classifications reveal discrepancies that may result in errors when comparing studies that use different systems. These inconsistencies in terminology, variable levels of subclassification, and ambiguity in some descriptions may confound analyses and impede further research aimed at understanding the genetics and etiology of clefts, development of effective treatment options for patients, as well as cross-institutional comparisons of outcome measures. Identification and reconciliation of discrepancies among existing systems is the first step toward creating a common standard to allow for a more explicit interpretation that will ultimately lead to a better understanding of the causes and manifestations of phenotypic variations in clefting.