Protection with thymoquinone against formaldehyde-induced neurotoxicity in the rats.

INTRODUCTION: This study aimed to investigate the neurotoxic damage of formaldehyde (FA), which is commonly used in medicine and industrial fields, for the hippocampus of rats and the protective role of thymoquinone (TQ) against this neurotoxicity. METHODS: There were five groups with eight rats in each. Two control groups were formed, in one of them physiological saline was applied and in the other one corn oil was applied. FA was injected in Group 3. Group 4 was exposed to FA and TQ simultaneously. Group 5 received TQ only. At the end of the experiment animals were sacrificed and brain tissues were removed for biochemical and histopathological investigation. RESULTS: catalase (CAT), glutathione peroxidase (GSH-px) and superoxide dismutase (SOD), all known as enzymes with antioxidant activities, were increased in FA and TQ simultaneously administered group. FA caused prominent subarachnoidal hemorrhage and vacuolization. Vacuolization was not observed but occasional subarachnoidal hemorrhage was detected in the FA+TQ group. CONCLUSION: Neurotoxic damage in hippocampus induced by FA was reverted by administration of TQ (Tab. 1, Fig. 1, Ref. 26).

The mechanical properties of intact and traumatized epidural catheters.

UNLABELLED: Comparative data on the mechanical properties of epidural catheters used clinically are not available. We performed a controlled laboratory investigation to assess the mechanical performance of three different intact or traumatized catheter types (Polyurethane, clear nylon, and radiopaque nylon catheters, designed for 18-gauge Tuohy needles). We studied a control (intact) and two trauma groups (needle bevel and surgical blade). Catheters were loaded to their breaking points by using a Lloyd LS500 material testing machine (Lloyd, Southampton, UK). Maximal load and extension values before breakage were measured, and modulus of elasticity and toughness values were calculated. Intact polyurethane catheters did not break within the limits of the experimental study (extension up to 3 times the original length of a specimen). The toughness values obtained from polyurethane and clear nylon catheters were significantly higher than those for the radiopaque catheters in intact specimens (P < 0.05). In the traumatized groups, polyurethane catheters had the highest toughness values (P < 0.05). Modulus of elasticity values were higher in both control and trauma groups of the radiopaque catheters when compared with the polyurethane and clear nylon catheters, which indicates a higher stiffness to elastic deformation (P < 0.05). In conclusion, polyurethane catheters are the most durable catheter type to tensile loading, either intact or traumatized. Mechanical properties can be used to predict complications related to the clinical use of these catheters. IMPLICATIONS: Using a computer-assisted material testing machine, we studied the mechanical properties of three different types of epidural catheters, either intact or traumatized, in a blinded, controlled study. This information may be vital to clinicians who implant epidural catheters by helping them choose a catheter that has the lowest probability of failure.

A novel method of evaluation of three heat-moisture exchangers in six different ventilator settings.

OBJECTIVE: The purpose of this study was to assess and compare the humidification, heating, and resistance properties of three commercially available heat-moisture exchangers (HMEs). To mimic clinical conditions, a previously validated, new, realistic experimental set-up and measurement protocol was used. DESIGN: Prospective, comparative experimental study. SETTING: Surgical Intensive Care Unit, University Hospital of Rotterdam. MATERIALS: An experimental set-up consisting of a patient model, measurement systems, and ventilator and three different HME types. INTERVENTIONS: The air flow, pressure in the ventilation circuit, pressure difference over the HME, and partial water vapour pressure and temperature at each side of the HMEs were measured. Measurements were repeated every 30 min during the first 2 h and every hour up to 24 h for each HME at six different ventilator settings. The mean inspiratory and maximum expiratory resistance, flow-weighted mean absolute humidity and temperature outputs, and humidification and heating efficiencies of HMEs were calculated. MEASUREMENTS AND RESULTS: The Dar Hygroster had the highest humidity output, temperature output, humidification efficiency, and heating efficiency values throughout the study (32.8 +/- 21. mg/l, 32.2 +/- 0.8 degrees C, 86.3 +/- 2.3%, and 0.9 +/- 0.01%, respectively) in comparison to the Humid-Vent Filter (25.3 +/- 3.2 mg/l, 31.9 +/- 0.8 degrees C, 72.2 +/- 5.3%, 0.9 +/- 0.02%, respectively) and the Pall Ultipor BB100 breathing circuit filter (23.4 +/- 3 mg/l, 28.3 +/- 0.7 degrees C, 68.8 +/- 5.9%, 0.8 +/- 0.02%, respectively). The inspiratory and expiratory resistance of the HMEs remained below clinically acceptable maximum values (2.60 +/- 0.04 and 2.45 +/- 0.05 cmH2O/l per s, respectively). CONCLUSION: The Dar Hygroster filter was found to have the highest humidity and temperature output of all three HMEs, the Humid-Vent filter had a satisfactory humidity output only at low tidal volume flow rate and minute volume settings, whereas the Pall Ultipore BB 100 never achieved a sufficient humidity and temperature output.

An experimental set-up to test heat-moisture exchangers.

OBJECTIVES: The purpose of this study was to build an experimental set-up to assess continuously the humidification, heating and resistance properties of heat-moisture exchangers (HMEs) under clinical conditions. DESIGN: The experimental set-up consists of a patient model, measurement systems and a ventilator. SETTING: Surgical ICU, University Hospital of Rotterdam. MATERIALS: A clinically used HME. MEASUREMENTS AND RESULTS: The air flow, pressure in the ventilation circuit, pressure difference over the HME, and partial water vapour pressure and temperature at each side of the HME were measured. The resistance, absolute humidity, humidification efficiency and temperature difference at the patient side of the HME were calculated. Measurements were performed during 24 h. The temperature output, humidity output and lung mechanics of the patient model were similar to values found in mechanically ventilated patients. The measurement system was in agreement with the ISO draft standard and was capable of measuring dynamic variation of water and heat exchange over the range of a clinically used ventilator setting. CONCLUSION: The experimental set-up described is reliable for evaluating HMEs and can also be used for future clinical evaluation of HMEs. The main advantages of this set-up over those described previously are: (i) measurements of dynamic variations of water and heat exchange; (ii) on-line measurements of expiratory, as well as inspiratory resistance.

The place of acupuncture in the management of psychogenic impotence.

Successful sexual functioning is a complex process involving psychological and social responses as well as neurological, biochemical and vascular processes. Today it is believed that more than 50% of the sexual dysfunction cases have an organic etiology. Reflecting the controversy over the management of psychogenic impotence, there are several different methods which are currently in clinical use. In this prospective study we aimed to evaluate the curative effects of acupuncture therapy in men with purely psychogenic impotence. Of the 29 patients treated with this procedure 20 patients demonstrated successful erections following a varying number of acupuncture sessions. In the light of our findings we may conclude that acupuncture may be an effective alternative in the management of purely psychogenic impotence.

A case of acute poisoning due to organophosphate insecticide.

A case of acute severe organophosphate poisoning by deliberate self administration is reported. The patient required intensive therapy for 30 days. Unusual features of the case were the avoidance of atropine, because of the high risk of ventricular fibrillation, and the ineffectiveness of pralidoxime.