مجله پزشکی کوثر
سال ششم شماره 3 (پیاپی 21، پاییز 1380)

Several studies have suggested that cholestasis (bile-duct resection, obstructive jaundice) causes renal damage. In fact, renal failure is the most significant cause of morbidity and mortality in the cholestatic patients. In this study, the antioxidant drug, allopurinol as a xanthine oxidase inhibitor was used (1 mg/ml in drinking water and 20 mg/kg i.p. one day before surgery) to evaluate the OFR involvement in cholestasis-induced renal damage. Three groups of rats, control (n=6); cholestatic with (n=10) and without (n=10) treatment were studied by light microscopy for renal histological changes. In this study the renal tubules in cholestatic rats, were highly damaged ten days after cholestasis. Necrosis was seen and tubular cast formation was frequent in the lumen of tubules. In the treated kidneys, there was some trend to improvement in renal morphology, namely less cellular vacuolation and tubular damage and less luminal debris. Since allopurinol improved histological changes in rat kidney, this study suggests OFR involvement in renal damage was induced by cholestasis.

The main purpose of this study was to investigate the effects of electrical nerve stimulation on alpha motoneuron excitability. The electrophysiological parameters of H-reflex and F-wave were assessed. The experiment was performed on ten non-athletic healthy men without neurologic disorders with a mean age 6.52 × 4.4 years and three spastic hemiplegic patients with a mean age 65.33 × 6.32 years. In the experimental protocol electrical simulation (TENS) applied on common peroneal nerves with a frequency of 99 Hz and pulse width (duration) 250 of 30 minutes. H-reflex and F-wave of the soleus muscle were recorded in three stages sequenced immediately, 5 minutes and 10 minutes later. The parameters such as amplitudes and latencies of H-reflex and F-wave were compared with the data before stimulation. Finally, after 30 minutes application of TENS the following results were obtained: 1- The mean peak to peak amplitude of H-reflexes and F-waves were significantly decreased after application of TENS in normal subjects. (P>0.05) 2- H/M ratios and F/M ratios were significantly decreased after application of TENS in normal subjects. (P>0.05) 3- The mean latency of H-reflexes and F-waves were significantly increased after application of TENS in normal subjects. (P>0.05) 4- In spastic patients, the mean peak to peak amplitude of H-reflexes and F-waves, and the H/M and F/M ratios were significantly decreased and the mean latencies of H-reflexes and F-waves were significantly increased after application of TENS. The reduction of amplitude of H-reflexes and F-waves, H/M and F/M ratios demonstrated reduction of spasticity in the patients group. The above-mentioned parameters are parts of electrophysiological indicators of spasticity.

The purpose of this study was to investigate the iontophoretic effect of epinephrine on the compound muscle action potential (CMAP) and physiological aspects of nerves and muscle, to increase the function of physical therapy. Twenty healthy men ranging 20 -30 years were divided in two groups (iontophorsis and direct current). Epinephrine solution (1 mg/ml) was used for iontophoresis and normal saline for direct current. After recording CMAP, iontophoresis and direct current were applied for each group.(50 mA. Min) by placing an active electrode on CMAPs were examined at 1, 5, 10 and 15 minutes after the iontophoresis and direct current stimulation and then compared with an average of 5 recordings before application of iontophpresis and direct current. The results of this study show that iontophoresis of epinephrine increases after amplitude 5, 10, and 15 minutes (p>0.05) and increases positive peak, duration and rising time after 1,5,10, and 15 minutes (p>0.05). Increased repolarization in the first minute after iontophoresis was significant (P>0.05). Direct current increases the duration, rising time, propagation of depolarization and repolarization time at 1, 5, 10 and 15 minutes (P>0.05). The slope of propagation after iotophoresis increase at 10 minutes (P>0.05) where as direct current reduces the slopes of rising, propagation, and repolarization of CMAPs at 1,5,10 and 15 minutes (P>0.05). These findings indicate that iontophoresis of epinephrine effect the neuromuscular junction to increase muscle fibers involvement where as direct current stimulation with hyperpolarization reduce suitable activities of muscle fibers.

Adenosine and adenine nucleotides,(adenosine 5-triphosphate (ATP) and adenosine 5- diphosphate (ADP)) play an important role in the regulation of many biological processes including the control of vascular tone and homeostasis by interaction with specific receptors on the cell surface. The aims of this study were: I) investigation of responses of rat isolated pulmonary artery rings (main and branches) to these drugs; II) Possible involvement of nitric oxide L-arginine (No/L-Arg) pathway induced relaxant responses. The effects of adenosine (AD), adenosine diphosphate (ADP) and adenosine triphosphate (ATP) were studied on artery rings precontracted with 100 nanomole phenylephrine (EC75). AD, ADP and ATP induced slowly developing endothelium -independent relaxations in these artery rings. Relaxant responses to AD were antagonised by the P1-receptor antagonist, theophylline. Pretreatment of arety rings with L-NAME did not affect relaxant responses to AD. Also mechanical removal of endothelium depressed only relaxant responses to 3 micromole AD. Relaxant responses to ADP and ATP were depressed in denuded endothelium artery rings or when they were pretreated with 200 micromole Nw nitro L-arginine methyl ester (L-NAME). In some experiments, L-NAME reversed relaxant responses to ADP and ATP; and these effects were inhibited by l milimole of L-arginine (L-Arg). Pretreatment of artery rings with glibenclamide (ATP-sensitive potassium channel blocker), theophylline (Purinergic receptor antagonist), indomethacin (prostacycline inhibitor) and propranolol (beta-adrenoceptor blocker) was not effective in relaxant responses to ADP or ATP. The results of this study showed that relaxant responses of rat pulmonary artery rings to AD were endothelium-independent and the NO/L-Arg pathway was not involved in relaxant responses. Also relaxant responses to AD were mediated by stimulation with purinergic P1 and Theophylline (purinergic-receptor antagonist) inhibited relaxant responses to ADP and ATP. This was endothelium-depented and the NO/L-Arg pathway was involved in relaxant responses. It is possible that relaxant responses to ATP or ADP were induced via P2-receptors.

The restrictions of serological assessment in ocular toxoplasmosis are well recognized, thus we must pay attention to the role of aqueous humor analysis as a diagnostic tool in these patients. In a retrospective study eight patients with cataracts, as controls, and eight patients with ocular toxoplasmosis surveyed. The cataract patients tested did not show a positive Goldmann - Witmer coefficient (Less than 0.006). The four cases with clinically diagnosed toxoplasmic chorioretinitis had Goldman - Witmer coefficients greater than four. In the four patients diagnosed as toxoplasmic uveitis, this factor was less than 0.4 (P>0.05).

Addition of dexamethasone to drugs used in epidural anesthesia reduces the spread of post-operative backache. In this double-blind clinical trial, the effect of dexamethasone addition to epidural anesthesia was studied. In this regard 59 surgical (other than obsteric and cesarianvsection) patients were randomly divided into two groups. The first group of 30 patients recieved 300 mg 1.5% Lidocaine with 1/200,000 epinephrine in 1 cc normal saline and the second group of 29 patients received 300mg 1.5% Lidocaine pulse 1,200,000 epinephrine with 4 mg Dexamethasone in epidural anesthesia. Patients were visited 12, 24, and 48 hours after operation and according to VAS Score and the degree of post epidural backache was recorded and results were compared. In the first group (without dexamethasone) the number of patients with moderate and severe backache were to and in the second group (with dexamethosone) one patient had backache. This study showed that the second group had less backache. It can then be concluded that dexamethasone is able to reduce postepidural backache.

Chronic sensorymotor polyneuropathy is the most common neurological complication of chronic renal failure. Rarely, patients recieving peritoneal dialysis develop a rapidly evolving polyneuropathy simulating the Guillain-Barre syndrome.We report two patients with subacute demyelinating polyneuropathy 2-8 weeks after onset of continuous ambulatory peritoneal dialysis (CAPD).One patient had complete improvement after renal transplantation and the other had considerable improvement with plasmapheresis. Because of coincidetal occurence of neuropathy with the onset of CAPD, a causal relationship between them is suspected.