Calcium and potassium channels are involved in curcumin relaxant effect on tracheal smooth muscles.

Context: Curcumin, the active component of Curcuma longa L. (Zingiberaceae), exhibits a wide variety of biological activities including vasodilation and anti-inflammation.Objective: The relaxant effect of curcumin in tracheal smooth muscle (TSM) was not examined so far, thus, this study was designed to assess the relaxant effect of curcumin on rat TSM and examine the underlying mechanism(s) responsible for this effect.Materials and methods: TSM was contracted by KCl (60 mM) or methacholine (10 µM), and cumulative concentrations of curcumin (12.5, 25, 50, and 100 mg/mL) or theophylline (0.2, 0.4, 0.6, and 0.8 mM, as positive control) were added to organ bath. The relaxant effect of curcumin was examined in non-incubated or incubated tissues with atropine (1 µM), chlorpheniramine (1 µM), indomethacin (1 µM), and papaverine (100 µM).Results: In non-incubated TSM, curcumin showed significant relaxant effects on KCl-induced contraction in a concentration-dependent manner (p < 0.001 for all concentrations). The relaxant effects of curcumin 12.5, 25, and 50 mg/mL were significantly lower in atropine-incubated tissue compared to non-incubated TSM (p < 0.05 to p < 0.001). A significant difference was observed in EC50 between atropine-incubated (48.10 ± 2.55) and non-incubated (41.65 ± 1.81) tissues (p < 0.05). Theophylline showed a significant relaxant effect on both KCl and methacholine-induced contraction in a concentration-dependent manner (p < 0.001 for all cases).Conclusions: The results indicated a relatively potent relaxant effect of curcumin on TSM, which was less marked than the effect of theophylline. Calcium channel blocking and/or potassium channel opening properties of curcumin may be responsible for TSM relaxation.

Thymectomy for Nonthymomatous Myasthenia Gravis: Comparison of Video-Assisted Thoracoscopic and Transsternal Thymectomy.

OBJECTIVE: Thymectomy considered as a standard procedure in treatment of all the steps of myasthenia gravis. Video-assisted thoracoscopic surgery (VATS) thymectomy is one of the minimally invasive procedures that because of the short duration of hospitalization, less postoperative pain, and scar after surgery, nowadays it is replaced the traditional methods of surgery for patients with myasthenia gravis, but there are still differences and concerns. The aim of this study was to compare outcomes of two different techniques of surgery, VATS versus transsternal (TS) in the treatment of myasthenia gravis. METHODS: In this pilot study, 42 patients with myasthenia gravis and without a thymus tumor were evaluated based on Myasthenia Gravis Foundation of America classification and drug consumption. Then, they randomly underwent two different techniques of surgery: VATS versus TS. Patients were evaluated based on preoperative and postoperative variables. RESULTS: Duration of intensive care unit stay and hospitalization has been reduced in patients who underwent VATS thymectomy operation technique. In addition, duration of surgical procedure has been reduced significantly in these patients. These patients have less blood loss during surgery compared with TS group. The Myasthenia Gravis Foundation of America postoperative status in VATS thymectomy revealed that the number of patients with complete stable remission was higher and number of persons remained unchanged was lower in this group. CONCLUSIONS: VATS thymectomy is a safe and appropriate approach comparing with traditional methods such as TS thymectomy for patients with myasthenia gravis. This method has better results after surgery and can be used as a minimally invasive alternative method instead of TS thymectomy.

Effect of Diaphragm Plication in Thymoma Patients with and without Myasthenia Gravis.

BACKGROUND: Thymoma is the most common tumor of the anterior mediastinum that has the most effective treatment, as it can be completely resected. In patients with advanced stage, phrenic nerve involvement can be seen and suggested treatment for these patients is unilateral phrenic excision and diaphragm plication. However in patients with myasthenia gravis, there are concerns in relation to this method of treatment. The aim of this study is to evaluate the effects of plication of the diaphragm on complications of phrenic nerve excision in thymoma patients with and without myasthenia gravis involving the phrenic nerve. MATERIALS AND METHODS: A retrospective cohort study was performed on 26 patients with thymoma; half of the patients had myasthenia gravis and the other half did not have myasthenia gravis. We performed diaphragm plication in 7 patients in each group with excision of phrenic nerve. Patients were evaluated based on preoperative and postoperative variables. RESULTS: The patients' age (P=0.943), sex (P=0.999), blood loss during surgery (P=0.919), need for transfusion during surgery (P=0.999), short term complications (P=0.186), need for tracheostomy (P=0.27) and mortality (P=0.09) differences were not significant. However, the average duration of ICU stay (P=0.001) and intubation in ICU (P=0.001) in patients who had myasthenia gravis was more than patients without myasthenia gravis. These values were less in patients with myasthenia gravis and diaphragm plication than patients with myasthenia gravis and no diaphragm plication. CONCLUSION: Excision of the phrenic nerve in patients with myasthenia gravis associated with thymoma and phrenic nerve involvement is appropriate.