Morphologic findings of the ischemic myocardium.

This study assesses the relation between qualitative and quantitative findings of myocytes and interstitial connective tissue in the ischemic heart disease. Qualitative and quantitative changes of myocytes and interstitial connective tissue were studied on the serial cross myocardial sections from 20 autopsied hearts with ischemic lesions, stained by immunohistochemistry using a monoclonal antibody (von Willebrand factor) and with hematoxylin-eosin method. Myocardial sections included proximal and distal part of occlusion and area of occlusion of coronary vessels. The volume densities (V V) of the cardiac myocytes and interstitial fibrosis in the group with coronary occlusion were examined stereologically and compared with control group. The findings showed a significant reduction in the volume density of myocytes and an increase in the volume density of interstitial fibrosis in patients with coronary occlusion compared with control group. Significant reduction in the volume density of myocytes and an increase in volume density of interstitial fibrosis were greater in the distal part of occlusion and area of occlusion, than in the proximal part of the occlusion. Our stereological results give useful quantitative information's of changes in myocardium parts during coronary occlusion as well as in normal conditions, and represent objective proof of significant changes in ischemic myocardium described by qualitative analyses.

Evaluation of Seldinger technique emergency cricothyroidotomy versus standard surgical cricothyroidotomy in 200 cadavers.

BACKGROUND: Percutaneous cricothyroidotomy is a lifesaving procedure for airway obstruction in trauma victims who need airway establishment and cannot be intubated or in whom intubation has failed. METHODS: The purpose of this study was to examine whether there is a training effect using Seldinger technique emergency cricothyroidotomy (group 1; Arndt Emergency Cricothyroidotomy Catheter Set; Cook Critical Care, Bloomington, IN) versus standard surgical cricothyroidotomy (group 2). Twenty emergency physicians performed five cricothyroidotomies with each method in a total of 200 human cadavers, comparing efficacy and safety (speed, success rate, and injuries). RESULTS: Seven attempts in group 1 and six in group 2 had to be aborted. Time intervals from the start of the procedure to location of the cricothyroid membrane were not significantly different between the groups. However, time to tracheal puncture (P < 0.01) and time to first ventilation (P < 0.001) were significantly longer in group 2. No time effect could be observed in both groups. The airway was accurately placed into the trachea through the cricothyroid membrane in 88.2% (82 of 93) of the cadavers in group 1 and in 84.0% (79 of 94) in group 2 (not significant). No injuries were observed in group 1, whereas there were six punctures of the thyroid vessels in group 2 (P < 0.05). CONCLUSIONS: With respect to time needed for the procedure, the participants performed Seldinger technique emergency cricothyroidotomy significantly faster as compared with standard surgical cricothyroidotomy. Even if no training effect had been observed, the authors believe that it is important to train residents in different methods of cricothyroidotomy in cadavers in addition to training in mannequins to achieve a higher level of efficacy in real-life situations. The shorter time to first ventilation and the fact that no injuries could be observed favor the Seldinger technique.

Expression of gap junction proteins (connexin 26, 30, 32, 43) in normal mucosa, hyperkeratosis and carcinoma of the human larynx.

INTRODUCTION: Gap junction proteins (connexins = Cx) form transmembrane channels and mediate the transfer of small molecules and ions between the cytoplasm of adjacent cells. Most tissues express several Cx isoforms. The precise combination might play an important role in the maintenance of cell differentiation. Human carcinogenesis is accompanied by aberrant expression and function of Cx. While the larynx is a target organ for many tumor promoters, no data on Cx expression in laryngeal mucosa are available. The goal of the study was to observe the expression of different Cx (Cx26, -30, -32 and -43) in the normal mucosa, hyperkeratoses and carcinomas of the human larynx. METHOD: The immunofluorescence method was performed in normal (n = 7) and dysplastic (n = 6) laryngeal mucosa and in squamous cell carcinoma (n = 7) using affinity-purified polyclonal rabbit antibodies against the 4 Cx isoforms and FITC-conjugated secondary antibodies. RESULTS: The immunofluorescence staining of the normal human vocal fold's epithelium showed the expression of Cx26 and Cx30 in the parabasal and intermediate layers, whereas Cx43 was localized in the basal, parabasal and lower intermediate layers. Cx epitopes could not be found in the upper layers. The precanceroses showed a similar expression of the Cx compared to normal laryngeal epithelium. Due to the higher degree of staining observed in dysplastic specimens, a hyperexpression of Cx26, -30 and -43 could be assumed. The squamous cell carcinomas were characterized by inhomogeneous staining for Cx26, -30 and -43. Regions of intensive expression alternated with regions of no expression. Cx32 could not be observed by immunofluorescence staining in laryngeal tissue. CONCLUSION: In immunohistochemical terms, there was no alteration of the expression of Cx isoforms during carcinogenesis in the laryngeal epithelium. These results do not exclude a loss of functional intercellular gap junction communication by posttranslational modifications of Cx isoforms or disturbed Cx integration into the gap junction channel. Further studies should investigate potential defective gap junctional intercellular communication in cancer cells based on molecular studies.