Morphology of corneal nerves in soft contact lens wear. A comparative study using confocal microscopy

The aim of this study was to evaluate corneal innervation in soft contact lens wearers using the Tomey Confoscan confocal microscope (40x/0.75 objective lens). Three distinct age- and sex-matched subject groups were involved, including extended soft (hydrogel and silicone-hydrogel) contact lens wearers, overnight soft (hydrogel) contact lens wearers, and non contact lens wearers. A number of variables were objectively measured, subjectively evaluated, or graded in order to investigate the distribution and morphology of corneal nerves. For most of the evaluated parameters, no statistically significant differences were found. However, qualitative observations showed noticeable differences in corneal nerve appearance among the different subject groups; the degree of corneal oedema was suggested as the main causative factor. In conclusion, neither the short-term (overnight wear) nor the long-term (12-month extended wear) soft contact lens wear appeared to affect the morphology and/or distribution of corneal nerves as viewed with confocal microscopy.     

A high fidelity tissue-based cardiac surgical simulator.

OBJECTIVE: Issues concerning the training and certification of surgical specialists have taken on great significance in the last decade. A realistic computer-assisted, tissue-based simulator developed for use in the training of cardiac surgical residents in the conduct of a variety of cardiac surgical procedures in a low-volume cardiothoracic surgery unit of a typical developing country is described. The simulator can also be used to demonstrate the function of technology specific to cardiac surgical procedures in a way that previously has only been possible via the conduct of a procedure on a live animal or human being. METHODS: A porcine heart in a novel simulated operating theatre environment with real-time simulated haemodynamic monitoring and coronary blood flow, in arrested and beating-heart modes, is used as a training tool for surgical residents. RESULTS: Standard and beating-heart coronary arterial bypass, aortic valve replacement, aortic homograft replacement and pulmonary autograft procedures can be simulated with high degrees of realism and with the superimposition of adverse clinical scenarios requiring valid decision making and clinical judgments to be made by the trainees. CONCLUSIONS: The cardiac surgical simulation preparation described here would appear to be able to contribute positively to the training of residents in low-volume centres, as well as having the potential for application in other settings as a training tool or clinical skills assessment or accreditation device. Collaboration with larger centres is recommended in order to accurately assess the utility of this preparation as an adjunctive cardiothoracic surgical training aid.     

Acute and chronic effects of cisplatinum upon testicular function in the rat

One of the side effects of cisplatinum-based chemotherapy is the impairment of spermatogenic function. In order to understand the mechanisms responsible for this side effect, the present study examined the short- and long-term effects of five daily injections of 2 mg/kg cisplatinum upon the functional normality of Leydig cells and Sertoli cells in intact adult rats, and their relationship with the status of spermatogenesis. Results of the present study demonstrate that cisplatinum treatment resulted in a progressive but reversible loss of germ cells from the seminiferous epithelium. Although testicular testosterone contents reduced transiently after the adminisration of cisplatinum, these testosterone levels are otherwise sufficient to support complete spermatogenesis. Thus, the cisplatinum-induced germinal regression cannot be accounted for by hypoandrogenism. The testicular ABP contents of the drug-treated rats remained unchanged during the treatment period, decreased transiently 30 days after the treatment, and returned to normal 120 days after treatment. A decrease in epididymal ABP content was also noted 10 and 30 days after the drug treatment. These observations suggest that Sertoli cell functions were affected by cisplatinum treatment. The effects of cisplatinum upon Sertoli cells were further demonstrated by the dose-dependent suppression of the production of ABP, lactate, and estradiol in cultured Sertoli cells. In addition, cisplatinum administration resulted in a reversible decrease in pituitary weights and an irreversible decrease in seminal vesicle weights. These results further demonstrate the toxic effects of cisplatinum upon various aspects of the male reproductive system.     

Thirty cases of Irukandji envenomation from far north Queensland

The Irukandji jelly fish (Carukia barnesi) is responsible for a significant number of envenomations in northern Australia during the summer. Emergency physicians in these coastal areas frequently manage patients who have been envenomed by this potentially serious marine creature. The jelly fish is small (its bell is up to 2.5cm across) but the tentacles may be up to half a metre in length. It is rarely seen before envenomating. The sting usually initially causes localised pain followed by systemic symptoms known as the ‘Irukandji syndrome’, which include potentially life threatening pulmonary oedema. This article discusses Irukandji envenomation and its treatment, and reviews our experience in treating 30 patients who presented to the Emergency Department of Cairns Base Hospital in December of 1996 having been stung by the Irukandji. Of these cases, 27 (90%) patients developed systemic symptoms (the Irukandji syndrome) and 19 (63%) required admission. Twelve (40%) patients required more than 100mg of titrated, intravenous pethidine to relieve the pain. There were no cases of pulmonary oedema. All patients were discharged home well within 24 hours.     

Posterior Cervical-Thoracic Thermograms: Pattern Persistence and Correlation with Chronic Headache Syndromes

SYNOPSIS
These experiments investigate thermographic patterns in the posterior cervical/thoracic (PCT) region of 530headache patients and 30 headache/injury-free volunteers. The study examines: The longitudinal persistence ofProximal and Distal patterns; three distinct midline patterns (PCT I, II, and III); and their correlation with diagnosis,injury, and pain.
Twenty-four (80%) of 30 randomly selected subjects displayed unchanged Proximal patterns at the meanobservation period of 5.5 months. PCT pattern fluctuations occurred in 13/30 (43.3%) subjects. The distinctivenessof each subject's Proximal and Distal patterns was verified by blind calling of thermogram pairs. Patternpersistence was validated with alcohol spray-Patterns were identical regardless of using a 0.5°C or 1.0°Ctemperature setting. Temperature settings of 1.0°C yielded more distinct Proximal and Distal patterns.
Chi square analysis determined that there was no significant difference in the number of PCT III patterns in theexperimental or control groups.
In conclusion, it appears that Proximal and Distal Patterns may be consistent over time and individually unique,but that PCT patterns fluctuate and, therefore, do not correlate with chronic headaches.     

Augmentation by calcium channel antagonists of general anaesthetic potency in mice.

The effects of three kinds of calcium channel antagonists on the anaesthetic potencies of ethanol, pentobarbitone and argon were examined in mice. Ethanol and pentobarbitone anaesthetic potencies in mice were significantly increased by verapamil 10 mg kg-1, flunarizine 40 mg kg-1 and nitrendipine 100 mg kg-1. Argon anaesthetic potency was significantly increased by nitrendipine 50 mg kg-1 and 100 mg kg-1 in a dose-related fashion. Even at very high doses the calcium channel antagonists did not produce anaesthesia by themselves. At the doses used the calcium channel antagonists did not affect the blood concentrations of ethanol, 2 h, or pentobarbitone, 15 min, after anaesthetic administration.