Purification and Characterization of Alkaline Protease from Bacillus sp. HD292

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Proteolytic enzymes form a very significant group of enzymes which are used for a variety of purposes...     

Terminal ileal mucosal mast cells in irritable bowel syndrome

Terminal ileal biopsies were prospectively obtained and stained specifically for mast cells in 20 patients with irritable bowel syndrome (IBS) and 15 controls. The number of terminal ileal mast cells per high powered field (MC/HPF) (mean ±SEM) was 23.3±3.1 for, IBS and 6.8±1.1 for controls (P=0.0001). The diarrhea IBS subgroup had the greatest number of MC/HPF. No correlation was found between terminal ileal mucosal mast cell counts (MMCC) and the number of Manning criteria present or the functional bowel disease score (r=0.06 andr=?0.31, respectively). We conclude that terminal ileal MMCC are significantly elevated in a majority of patients with IBS. The mast cell may be responsible for the altered visceral perception found in the gastrointestinal tract in patients with IBS. The poor correlation of the MMCC to the clinical features of IBS may be the result of the dynamic state of the mast cell.     

Molecular epidemiology of Burkitt's lymphoma from South America: differences in breakpoint location and Epstein-Barr virus association from tumors in other world regions.

We have previously shown that the endemic (African) and sporadic (North American) forms of Burkitt's lymphoma (BL) differ at a molecular level. We have now extended our studies to the molecular epidemiology of BL in South America, specifically to two climatic regions: temperate (Argentina and Chile) and tropical (Brazil). We have examined the patterns of chromosomal breakpoint locations in 39 tumors with respect to geography and Epstein-Barr virus (EBV) association. The result of these analyses provide further support for the existence of pathogenetically distinct subtypes of BL in different world regions. The majority of breakpoints on chromosome 8 in South American BL (41%) occurred in the immediate flanking region of c-myc, ie, further 5' of the "typical" sporadic breakpoints, in the first exon/intron region, and further 3' of the "typical" endemic breakpoints, which are usually distant from c-myc. However, the distribution of breakpoints on chromosome 14 in tumors from the temperate and tropical regions of South America is similar to that observed in sporadic and endemic tumors. Interestingly, only one tumor with an unrearranged c-myc gene joined to the S mu region of chromosome 14 was observed. This combination was also rarely observed in our earlier series and presumably is either less readily generated by the mechanism that mediates 8;14 translocation or requires other, infrequent genetic changes to provide the necessary selective advantage for lymphomagenesis. The frequency of EBV association in South American BL (51%) is also intermediate with respect to tumors from the United States (30%) and Africa (100%). No correlation with the breakpoint location on chromosome 8 was discernable. Surprisingly, only 54% of tumors with breakpoint outside c-myc were EBV positive. This is in contrast to endemic tumors and suggests that any pathogenetic contribution of EBV is not dependent on breakpoint location, but is more likely to complement additional pathogenetic elements that differ in different world regions.     

Peak left ventricular pressure during percutaneous aortic balloon valvuloplasty: clinical and echocardiographic correlations

Peak left ventricular pressure during balloon inflation was measured in 20 patients who underwent balloon valvuloplasty for severe aortic stenosis to define the determinants of ventricular pressure development in response to increased loading conditions. The peak left ventricular pressure ranged from 150 +/- 5 to 386 +/- 22 mm Hg (mean +/- SD), was reproducible in each patient with each balloon inflation (mean coefficient of variation 7.8%) and correlated with concurrent echocardiographic measurements of ejection fraction (r = 0.89, p = 0.0001) and mass/volume ratio in systole (r = 0.91, p = 0.0001) or diastole (r = 0.88, p = 0.0001). Thirteen patients with class II or more severe congestive heart failure had lower values for peak left ventricular pressure than did those without failure (225 +/- 46 versus 305 +/- 45 mm Hg, p = 0.002), whereas no difference in rest left ventricular systolic pressure was seen between the two groups. The measurement of peak left ventricular pressure was inversely related to rest mean circumferential end-systolic wall stress (r = 0.52, p = 0.046). Thus, peak left ventricular systolic pressure measured during aortic valvuloplasty in humans correlates closely with traditional measures of left ventricular function. This measurement, which previously has been obtained only in experimental animal studies, is a simple and reproducible hemodynamic index that may provide new insights in studies of ventricular function and congestive heart failure in aortic stenosis.     

Cutting too deep? Assessing the impact of a shorter surgery clerkship on students' clinical skills and knowledge

Background

The aim of this study was to compare the performance of students completing an 8-week versus a 6-week surgery clerkship on an objective structured clinical examination (OSCE) and the National Board of Medical Examiners (NBME) clinical science surgery examination.

Methods

One hundred fifteen students from the 8-week clerkship and 99 from the 6-week clerkship were included. Performance on a summative OSCE was assessed using behaviorally anchored checklists. NBME exams were graded using the NBME's standard scaled scores. Results were compared using 2-tailed, independent-samples, unequal-variance t tests.

Results

Mean OSCE scores for the 8-week and 6-week curricula were not statistically different. Mean NBME scores also did not statistically differ. Six-week students performed significantly better in the specific OSCE subdomains of blood pressure, orthostatic blood pressure, rectal exam, and fecal occult blood test.

Conclusions

Overall OSCE and NBME exam performance did not differ between 8-week and 6-week surgery clerkship students.