Genome-wide association study in an F2 Duroc x Pietrain resource population for economically important meat quality and carcass traits.

Meat quality is essential for consumer acceptance, it ultimately impacts pork production profitability and it is subject to genetic control. The objective of this study was to map genomic regions associated with economically important meat quality and carcass traits. We performed a genome-wide association (GWA) analysis to map regions associated with 38 meat quality and carcass traits recorded for 948 F2 pigs from the Michigan State University Duroc × Pietrain resource population. The F0, F1, and 336 F2 pigs were genotyped with the Illumina Porcine SNP60 BeadChip, while the remaining F2 pigs were genotyped with the GeneSeek Genomic Profiler for Porcine Low Desnisty (LD) chip, and imputed with high accuracy ( = 0.97). Altogether the genomic dataset comprised 1,019 animals and 44,911 SNP. A Gaussian linear mixed model was fitted to estimate the breeding values and the variance components. A linear transformation was performed to estimate the marker effects and variances. Type I error rate was controlled at a False Discovery Rate of 5%. Seven putative QTL found in this study were previously reported in other studies. Two novel QTL associated with tenderness (TEN) were located on SSC3 [135.6:137.5Mb; False Discovery rate (FDR) < 0.03] and SSC5 (67.3:69.1Mb; FDR < 0.02). The QTL region identified on SSC15 includes Protein Kinase AMP-activated É£ 3-subunit gene (), which has been associated with 24-h pH (pH24), drip loss (DL) and cook yield (CY). Also, novel candidate genes were identified for TEN in the region on SSC5 [A Kinase (PRKA) Anchor Protein 3 (], and for tenth rib backfat thickness (BF10) [Carnitine O-Acetyltransferase ()] on SSC1. The association of gene polymorphisms with pork quality traits has been reported for several pig populations. However, there are no SNP for this gene on the chip used, thus we genotyped the animals for 2 non-synonymous variants ( and ). We then performed a GWA conditioning on the genotype of both SNP and was associated with pH24, DL, protein content (PRO) and CY ( < 0.004) and T30N with Juiciness, TEN, shear force, pH24, PRO, and CY < 0.04). Finally, we performed a GWA conditioning on the genotype of the SNP peak detected in this study, and T30N remained associated only with PRO ( < 0.02). Therefore, in this study we identified 2 novel QTL regions, suggest 2 novel candidate genes, and conclude that other SNP in PRKAG3 or nearby gene(s) explain the observed associations on SSC15 in this population.

In vitro study and in vivo application of a reusable double-channel sphincterotome.

BACKGROUND AND STUDY AIMS: Therapeutic endoscopic retrograde cholangiopancreatography (ERCP) has been deemed to be a "cost-prohibitive" procedure, based upon the cumulative costs of one-time-use accessories and current reimbursement plans. One-time-use sphincterotomes comprise a significant component of that cost and, accordingly, we evaluated the disability and clinical usefulness of a recently introduced reusable double-channel sphincterotome. MATERIALS AND METHODS: We studied a reusable 6-Fr sphincterotome at baseline and following contamination with 10(6) Bacillus stearothermophilus. Reprocessing included a unique 30-minute ultrasonic cleaning step in lieu of manual cleaning, followed by steam sterilization. Parameters evaluated included sphincterotome function, electrical integrity, and our ability to sterilize the devices for three in vitro trials. In vivo studies included patient demographics and outcomes, procedural findings, and success rates, and the mean number of times the sphincterotome was used, functional grading at time of use, and reasons for sphincterotome malfunction. RESULTS: Ten out of ten sphincterotomes maintained form, function, and electrical integrity in vitro, and all cultures were negative after sterilization. In the initial in vivo study, ten sphincterotomes were used in 50 patients (mean, 5 uses) with a 94% success rate. Reasons for sphincterotome failure included leak or breakage of the accessory port in 70%, wire fracture in 10%, incorrect wire bow in 10%, and clogged injection port in 10%. Following reconfiguration of the insertion-port polymer, an additional ten sphincterotomes were used in 110 patients (mean, 11 uses). Mechanical failure occurred primarily at the wire-insertion port, resulting in progressive friction with reuse. There were neither electrical nor infectious complications associated with reuse. CONCLUSIONS: A reusable double-channel sphincterotome is available which can theoretically be reprocessed and sterilized without the manual cleaning step of the reprocessing process. Contingent upon both provider and patient, multiple reuse can be anticipated, and contingent upon purchase price and reprocessing costs, the potential for procedural cost savings is significant.

In vitro and in vivo evaluation of a reusable double-channel sphincterotome.

BACKGROUND: To date, one reusable, double-channel sphincterotome has been approved by the Food and Drug Administration in the United States. Whether this device can be reprocessed easily and whether it is more durable than currently manufactured disposable sphincterotomes are uncertain. METHODS: Thirty double-channel, 20 mm, braided-wire sphincterotomes approved for multiple uses were studied in vitro/in vivo with regard to durability and sterilization. A cost analysis of reusable, disposable, and reprocessed disposable sphincterotomes was also carried out. RESULTS: Three of 10 sphincterotomes evaluated in vitro broke after 3, 4, and 8 uses. Electrical integrity was preserved after 10 uses in the remaining sphincterotomes. Nine sphincterotomes remained functional for at least 3 uses, five for 6 uses, and one for 10 uses. Culture results after inoculation demonstrated contamination with surviving organisms after manual cleaning and no growth after ethylene oxide sterilization. Sixty-one procedures were performed in vivo using 20 sphincterotomes (mean number of uses 3.1). No evidence of procedurally related infection occurred with reuse. Cost per use of this reusable sphincterotome was calculated to be $62.98; it became cost effective after 2.2 and 7.9 uses when compared with disposable and reprocessed, disposable sphincterotomes, respectively. CONCLUSIONS: This reusable sphincterotome proved to be safe, easily sterilized, and electrically intact after repeated use. In vivo, however, a progressive loss of function limited the mean number of uses to 3.1. In settings that preclude reuse of reprocessed disposable accessories, this reusable sphincterotome may provide a means to decrease costs associated with endoscopic retrograde cholangiopancreatography.

In vitro evaluation of wire integrity and ability to reprocess single-use sphincterotomes.

BACKGROUND: Sphincterotomes are currently marketed as one-time-use items and constitute considerable cumulative expense in a busy endoscopy unit. It is uncertain whether these accessories can be safely reprocessed without loss of form and function. METHODS: We studied disposable sphincterotomes (five 5F, five 6F) in vitro as to their durability, electrical integrity, and ability to be adequately cleaned both manually and with ethylene oxide after contamination with 10(5) to 10(6) Mycobacterium chelonei. RESULTS: Seven of the 10 sphincterotomes withstood the rigors of reuse; three 6F sphincterotomes developed wire fracture between four and eight uses. Electrical integrity, as measured by an electrosurgical analyzer, remained intact up to time of breakage in all sphincterotomes. Manual cleaning followed by glutaraldehyde soak resulted in residual mycobacterial colonies in five 6F sphincterotomes and a single 5F sphincterotome. No instrument had residual organisms cultured following manual cleaning and ethylene oxide sterilization. CONCLUSIONS: The authors conclude that one-time-use sphincterotomes have the potential for safe reuse.

An analysis of extradural dead space after fronto-orbital surgery.

This study was undertaken to evaluate several concerns regarding the extradural space resulting from elective fronto-orbital advancement or frontal sinus cranialization techniques. The questions are (1) Do infants undergoing these techniques have the potential to obliterate this space at an accelerated rate, e.g., within 1 or 2 days? (2) Do adults have any potential to obliterate the space? (3) Do children obliterate the space like infants or like adults? (4) What is the specific time sequence for dead-space obliteration? Twenty patients ranging in age from 6 months to 35 years were studied before and after fronto-orbital advancement. The patients were divided into three groups: (1) infants (up to 15 months), (2) children (up to 9 years), and (3) adults (9 years and beyond). Postoperative intracranial dead space was assessed by serial CT scans. Ten patients had CT scans more than 14 days after surgery. These data demonstrate that intracranial dead space in infants is obliterated in a delayed fashion. Children tend to obliterate intracranial dead space in a manner similar to that of infants. Adults are able to obliterate the space over a longer, but finite, period of time as compared with infants and children. Part of the mechanism responsible for obliteration of the postoperative space may be enlargement of the ventricular system.

A coaxial gas delivery system for laser bronchoscopy.

This paper discusses the development and implementation of a prototype coaxial gas delivery system for laser bronchoscopy. The design of the system is presented including a detailed description of the device's theory of operation and construction. The system's medical application in laser bronchoscopy is described.