Limb immobilization alters functional electrophysiological parameters of sciatic nerve

Immobilization, used in clinical practice to treat traumatologic problems, causes changes in muscle, but it is not known whether changes also occur in nerves. We investigated the effects of immobilization on excitability and compound action potential (CAP) and the ultrastructure of the rat sciatic nerve. Fourteen days after immobilization of the right leg of adult male Wistar rats (n=34), animals were killed and the right sciatic nerve was dissected and mounted in a moist chamber. Nerves were stimulated at a baseline frequency of 0.2 Hz and tested for 2 min at 20, 50, and 100 Hz. Immobilization altered nerve excitability. Rheobase and chronaxy changed from 3.13±0.05 V and 52.31±1.95 µs (control group, n=13) to 2.84±0.06 V and 59.71±2.79 µs (immobilized group, n=15), respectively. Immobilization altered the amplitude of CAP waves and decreased the conduction velocity of the first CAP wave (from 93.63±7.49 to 79.14±5.59 m/s) but not of the second wave. Transmission electron microscopy showed fragmentation of the myelin sheath of the sciatic nerve of immobilized limbs and degeneration of the axon. In conclusion, we demonstrated that long-lasting leg immobilization can induce alterations in nerve function.

One-week triple therapy with omeprazole plus azithromycin and secnidazole is ineffective in eradicating "helicobacter pylori"

Background: There is not yet consensus on the most effective treatment for the helicobacter pylori infection, particularly in most developing countries. Azithromycin is a new macrolide and relatively novel agent for H. pylori eradication with an in vitro MIC90 lower than 1 mg/ml.Secnidazole, a nitromidazole that causes fewer side effects than metronidazole, was recenty reported to be used, for the firt time, in the treatment of H. pylori infection. Aim: To evaluate, in a prospective, randomized, single-center study, the association of twodifferent doses of omeprazole, azithromycin and secnidazole in H. pylori eradication. Patients and methods: After informed consent, 55 patients (36m,19F) with duodenal ulcer associated with H. pylori infection were randomized to receive omeprazole 20mg uid (Group A) or 20mg bid (Group B) for sevem days plus azithromycin 500mg uid for six days and secnidazole 2,000mg uid in the first, fourth and seventh day. The H. pylori status was assessed before and 60-90 days posttreatment using urease test, histology and 13C-urea breath test. Statistical analysis was performed by X² test. Results: The two groups had similar demographic characteristics. Fifty-five patients (36M, 19F) were enrolled. Six patients did not show-up for the second visit posttreatment. So, of the 49 evaluable patients, 25por cento (6/24) in Group A and 44por cento(11/25) in Group B wereeradicated, in a per protocol (PP) analysis. Intetion-to-treat (ITT) eradication rates were 21,4por cento (6/28) in Group A and 40.7por cento (11/27) im Group B. The differences betweem ITT and PP analysis from the two groups were not statistically significant. Conclusions: This study shows a very low eradication rate with the two regimens comprising of omeprazole, azithromycin and secnidazole and therefore, should not be recommended for thetreatment of H. pylori infection