Sensitivity and specificity of stroboscopy in preoperative differentiation of dysplasia from early invasive glottic carcinoma.

Leukoplakia is a descriptive clinical term designating a white patch or plaque of the mucosa and must be complemented by histology, which can range from simple totally benign keratosis with or without atypia up to invasive carcinoma. The aim of this study is to evaluate the accuracy of videostroboscopy in preoperative differentiation of early invasive glottic carcinoma from intraepithelial atypia and dysplasia. 46 patients with a total of 60 leukoplakia lesions on the vocal folds were included in the study. Videostroboscopy was used to divide them into two groups based on preservation of the mucosal wave and this was correlated with the final pathology after treatment. The sensitivity and specificity of videostroboscopy in predicting invasive nature of the lesions based on absence or reduction of the mucosal wave were 96.8 and 92.8 %, respectively, with an overall accuracy of 95 %. We suggest that routine application of videostroboscopy can be an important, simple, non-invasive tool, to achieve, in a single procedure, proper and accurate evaluation of glottic leukoplakia.

Ursodeoxycholic acid therapy for intractable total parenteral nutrition-associated cholestasis in surgical very low birth weight infants.

INTRODUCTION: Cholestasis associated with long-term total parenteral nutrition (TPN) occurs commonly in very low birth weight (VLBW) infants. Indeed, the majority of infants with TPN-associated cholestasis (TPNAC) respond very well to TPN withdrawal and full enteral feeding, yet some of them do not respond and have the potential for development of intractable cholestasis. It has been demonstrated that ursodeoxycholic acid (UDCA) has beneficial effects in treating TPNAC in various age groups. Nevertheless, the clinical data of UDCA use in VLBW infants, the most vulnerable group, are limited. We report the results of administration of UDCA therapy to VLBW infants with intractable TPNAC. METHODS: Medical records of VLBW infants who were treated with oral UDCA, at dose of 15-20 mg/kg/day, for intractable TPNAC were reviewed from 1999-2001. Treatment effectiveness was evaluated by monitoring the biochemical hepatic markers, including total bilirubin, direct bilirubin, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT). RESULTS: A total of 13 infants were identified with the diagnosis of intractable TPNAC and they were treated with UDCA therapy. There was a significant reduction in serum levels of direct bilirubin, total bilirubin (p-value equals 0.0001) and AST (p-value equals 0.001). However, the serum levels of ALP, ALT and GGT showed a trend of improvement, yet none of them was statistically significant. Serum direct bilirubin was noted as the first marker to respond to UDCA therapy. It declined steadily during the course of therapy except in two intervals at the sixth and twelfth week of therapy that apparently associated with severe sepsis. There were no serious side effects noted. CONCLUSION: Our series data suggest that UDCA is safe and may be a potential treatment for intractable TPNAC if used within two weeks after TPN withdrawal and full enteral feeding. Sepsis may alter the effectiveness of UDCA therapy.

Penetration of household insecticides through different types of textile fabrics.

Six different types of fabrics were compared for their ability to protect against human exposure to three different commercial household aerosol insecticides. Fabrics used in this investigation were, 100% cotton, cotton-polyester thermal underwear, cotton-polyester blend (twill), 100% acrylic, 100% wool and artificial silk (rayon). The household insecticides were, Black Flag (Ant and Roach Killer), Raid (Ant and Roach Killer) and Hot Shot (Wasp and Hornet Killer) containing propoxur, permethrin/pyrethrins and chlorpyrifos/allethrins as their active ingredients respectively. A fluorescent tracer, 4-methyl-7-diethyl amino coumarin was mixed with the aerosol (or equivalent aliquot) and sprayed onto cloth squares fitted on Whatman paper patches. The percentage of penetration through the cloth was quantified by the intensity of the fluorescence spectrum of each patch extract and the amount of the tracer recovered was calculated. The extract was concentrated to 1/10th of the volume to measure the content of each of the insecticides by supercritical fluid chromatography (SFC) using electron capture (ECD) and diode array detectors. Scanning electron microscope (SEM) images of the fabrics showed the geometry of the yarn. The results obtained from the fluorescence spectra, SFC and SEM showed that cotton-polyester (twill), cotton, wool and cotton thermal underwear were the least penetrable materials for the aerosols. On the other hand, acrylic and artificial silk (rayon) were the most penetrable cloth types.

Subtilopeptidase A produced by Bacillus subtilis PR-70. II. Kinetic behaviour of immobilized enzyme.

The kinetic behaviour of immobilized subtilopeptidase A was investigated. The enzyme was obtained from a local isolate of B. subtilis PR-70. Using different inorganic supports, Amberlite CG-50 was superior in this respect. It gave 97.8% adsorption, followed by silica gel GC. The values of K and K2 for the rate of enzyme catalyzed being 8.75 and 2.06, respectively. The behaviour of v against Et is the same as v against St. Michaelis' constant was determined using different methods. The average of Km value and Vmax were 0.0094 and 0.95, respectively. Studying how v behaves when St is varied while Et is constant, two active site per enzyme molecule and auto-inhibition of enzyme by its own substrate were observed. Comparing kinetic parameters of a soluble and insoluble subtilopeptidase A showed that Km decreased from 0.016 to 0.0094, while Vmax increased from 0.71 to 0.95, respectively. This indicated that when subtilopeptidase was bound to Amb. GC-50, a case of partially non-competitive inhibition occurred. The recovery of enzymatic activity in the water insoluble subtilopeptidase A is 12.8 per cent.