Evaluation of Efficacy of Microwave Irradiation in Disinfecting Dental Gypsum Casts: An Ex Vivo Study

The aim of this study is to assess the efficacy of microwave irradiation in disinfecting gypsum casts and also to compare its efficacy with validated method of chemical disinfection. The present study is an ex vivo study conducted on a sample of five irreversible hydrocolloid impressions in vitro and on ten patients gypsum casts in vivo following standard impression techniques to check the efficacy of microwave oven irradiation and compare its efficacy with standard chemical method of disinfection. Results were analysed using Mann–Whitney test and Wilcoxon signed rank test. Untreated gypsum casts showed cfu/ml counts with a median log value of 6, while microwave-irradiated ones had median cfu/ml counts of 0. Casts poured from chemically disinfected impressions demonstrated cfu/ml counts with a median log value of 5. Microwave irradiation was found to be effective in disinfecting gypsum casts when compared to chemical disinfectant in disinfecting dental impressions.     

Challenges in Patient Enrollment and Retention in Clinical Studies for Alcoholic Hepatitis: Experience of the TREAT Consortium

The TREAT Consortium has carried out clinical studies on alcoholic hepatitis (AH) for over 4 years. We encountered problems with participant recruitment, retention, and eligibility for specific protocols. To improve our ability to carry out such trials, we reviewed recruitment screening logs, end of study logs, and surveyed study coordinators to learn the reasons for missing patients, why patients declined enrollment, and the number of patients eligible for treatment trials. Associations of the recruited subjects’ demographics with their adherence to follow‐up appointments were examined. Three hundred eight‐seven patients (AH and heavy drinking controls) were enrolled in the observational study, and 55 AH patients were recruited into treatment trials. About half of patients identified with AH could not be recruited; no specific reason could be determined for about two‐thirds of these. Among the patients who gave a reason for not participating, the most common reasons were feeling too sick to participate, desire to concentrate on abstinence, and lack of interest in research. Approximately a quarter of the AH patients met eligibility criteria for treatment trials for moderate or severe AH and we were able to recruit half to two‐thirds of those eligible. Approximately 35% of participants in the observational study returned for both 6‐ and 12‐month follow‐up visits. We did not identify biopsychosocial or demographic correlates of retention in the study. This analysis revealed that attempts at recruitment into trials for AH miss some subjects because of structural issues surrounding their hospital admission, and encounter a high rate of patient refusal to participate. Nonetheless, more than half of the patients who met the eligibility criteria for moderate or severe AH were entered into clinical trials. Retention rates for the observational study are relatively low. These findings need to be accounted for in clinical trial design and power analysis.     

New observations on the pathogenesis of multiple intestinal atresias

It has been suggested that multiple intestinal atresias result from multiple ischemic infarctions of the intestinal tract. We have studied surgical material from 59 neonates with intestinal atresias seen at our hospital between 1975 and 1986. Forty (68%) patients had single intestinal atresias and 19 (32%) had multiple atresias. There were seven cases of hereditary multiple atresias seen in three families and 12 cases of nonhereditary multiple atresias. All hereditary cases had numerous type I or type II gastrointestinal atresias but none had type IIIa atresia. Six of the seven hereditary cases had multiple atresias in the small as well as large bowel. The 12 patients with nonhereditary atresias had various types of atresias but mesenteric or intestinal interruption was observed in only two patients. All patients with hereditary multiple intestinal atresias showed identical microscopic appearances in the small and large intestine, consisting of sieve-like multiple lumina, each surrounded by its own mucosa and muscularis mucosae but sharing a common muscle coat. There was no evidence of lanugo, bile pigments, or squames within the lumen distal to atretic segments in any of these patients. Six nonhereditary cases who had multiple septal atresias affecting only the small bowel demonstrated essentially similar lesions on microscopic examination as seen in hereditary cases. There was no evidence of arterial occlusion in the mesentery and lanugo, bile pigments, and squames could not be found distally in the intestinal contents in any of these cases. These pathologic findings suggest that all cases of hereditary multiple intestinal atresias and some cases of nonhereditary multiple intestinal atresias are a consequence of a malformative process of the gastrointestinal tract rather than an ischemic process.     

Comparison of magnetic resonance cholangiography and percutaneous transhepatic cholangiography in the evaluation of bile duct strictures after cholecystectomy

BACKGROUND: Percutaneous transhepatic cholangiography (PTC) has been the preferred investigation to delineate the anatomy of the biliary tract in a patient with a bile duct stricture after cholecystectomy. Recently magnetic resonance cholangiography (MRC) has been described to evaluate the obstructed biliary tract. This paper reports a comparison of MRC with PTC in evaluating patients with an iatrogenic bile duct stricture. METHODS: This was a prospective study of 26 patients who had surgery for a bile duct stricture after cholecystectomy. Before operation all patients underwent both MRC and PTC, the results of which were compared with the intraoperative findings. RESULTS: Both PTC and MRC were comparable with regard to image quality, detection of intrahepatic bile duct dilatation, assessment of the level of injury and detection of abnormalities such as intraduct calculi, cholangitic liver abscesses and atrophy of liver lobes. MRC provided additional information in four patients, including detection of associated fluid collections (n = 3) and portal hypertension (n = 1). In eight patients more than one puncture had to be performed during PTC to delineate the complete anatomy. CONCLUSION: MRC is an accurate and non-invasive imaging procedure for preoperative evaluation of patients with a bile duct injury after cholecystectomy, and is capable of providing additional information which may not be available with PTC.