The role of endothelin-1 and endothelin receptor antagonists in allergic rhinitis inflammation: ovalbumin-induced rat model

OBJECTIVE

Desloratadine is a biologically active metabolite of loratadine which is indicated for the treatment of allergic rhinitis. Bosentan is a dual endothelin receptor antagonist used to treatment of pulmonary artery hypertension (PAH). In this study, we aimed to determine the role of endothelins in allergic rhinitis (AR) and the effects of endothelin receptor antagonists in AR rat models through comparison with desloratadine.

METHODS

In total, 20 adult Sprague-Dawley rats were used in this study. An ovalbumin-induced allergic rhinitis model was formed in three study groups except for the control group. Bosentan (100 mg/kg/day) was given to the bosentan-treated group for 7 days and desloratadine (10 mg/kg/day) was administered to the antihistaminic-treated group for 7 days. Nasal symptom scorings and histopathological examinations of the nasal tissues were carried out. Serum IgE levels and ET-1 and TNF-alpha mRNA expression levels were analysed. Between group comparisons for nasal symptoms, histopathological analysis, and molecular analyses were performed with a one-way ANOVA and Duncans multiple comparison tests. Significance was accepted at p smaller than 0.05.

RESULTS

Bosentan inhibited nasal symptom more significantly than desloratadine. The IgE level, ET-1 and TNF-alpha mRNA expression levels statistically increased in the allergic rhinitis group when compared to other groups. Conversely, the bosentan-treatment group showed a significant recovery from the same parameters. The deterioration in histopathological parameters reached the highest levels in the allergic rhinitis group. The histopathological findings were close to those of the control group in the bosentan and antihistaminic-treated group.

CONCLUSIONS

ET-1 is one of the mediators that impact AR development and ET-1 antagonists can be useful for symptom control and for decreasing allergic inflammation in AR patients.

The lung endothelin system: a potent therapeutic target with bosentan for the amelioration of lung alterations in a rat model of diabetes mellitus

PURPOSE

The aim of this study is to show the effect of a new mechanism on endothelin (ET) receptors in the physiopathology of diabetes-related pulmonary injury. We tested the hypothesis that dual ET-1 receptor antagonism via bosentan can reverse diabetes-induced lung injury.

METHODS

The rats (24 male) were separated into four groups: group 1 (HEALTHY): Control group; group 2 (DM): Streptozotocin 60 mg/kg (i.p.); group 3 (DM + BOS-1): Diabetes + bosentan 50 mg/kg per-os; group 4 (DM + BOS-2): Diabetes + bosentan 100 mg/kg per-os. The bosentan treatment was initiated immediately after the onset of STZ-induced diabetes and continued for 6 weeks.

RESULTS

In the treatment group, SOD activity was significantly increased, although GSH and MDA levels and TNF-α and TGF-β gene expression were decreased. Bosentan 50 mg/kg and bosentan 100 mg/kg showed a significantly down-regulatory effect on ET-1, ET-A, and ET-B mRNA expression.

CONCLUSIONS

In conclusion, increased endothelin levels in the lung associated with diabetes may be one cause of endothelial dysfunction, cytokine increase, and oxidant/antioxidant imbalance in the pathogenesis of complications that may develop during diabetes. With its multiple effects, bosentan therapy may be an effective option against complications that may develop in association with diabetes.

Palliative stoma creation: comparison of laparoscopic vs conventional procedures

BACKGROUND

The creation of a stoma is an established therapeutic concept for the palliation of non-resectable rectal carcinomas and advanced tumours infiltrating the pelvis.

MATERIALS AND METHODS

In two prospective country-wide multicentre studies, each conducted over a similar period of time, the peri-operative course and postoperative short-term outcomes of laparoscopic vs laparotomy-based stoma construction were compared.

RESULTS

A total of 90 patients underwent palliative laparoscopic construction; 550 patients received a stoma via a laparotomy. The intra-operative complication rate was lower after open surgery than after laparoscopic surgery (2.7 vs 5.6%; p = 0.15), although the difference was not significant. With regard to general (30.9 vs 15.6%; p = 0.003) and also specific postoperative complications (13.8 vs 5.6%; p = 0.029), however, a significant advantage of the laparoscopic approach was seen. Furthermore, mortality in the laparoscopic group was also significantly lower (4.4 vs 14.0%; p = 0.011).

CONCLUSION

Palliative stoma done via laparoscopy had significantly better outcomes in terms of postoperative morbidity and mortality in comparison with the open surgical procedure.

Food-borne botulism cases in Van region in eastern Turkey: importance of electromyography in the diagnosis

OBJECTIVES

Food-borne botulism is an acute form of poisoning that results from ingestion of a toxin produced by Clostridium botulinum. Botulism toxin causes its major effect by blocking neuromuscular transmission in autonomic and motor nerve terminals.

METHODS

In this study, we present the features of eleven cases of food-borne botulism admitted to our hospital in 2001. All of the cases were caused by home-prepared foods; green beans. In these cases, the main symptoms and signs were generalized muscular weakness, dry mouth, dysphagia, disponea and diplopia. Electrophysiological studies were performed on four patients.

RESULTS

Motor conduction studies showed that compound muscle action potentials were decreased with normal latencies and conduction velocities. The needle electromyography showed signs of denervation potentials like fibrillation and positive waves in four patients. Repetitive nerve stimulation with high frequency (20 Hz) induced an increment close to 100% in the amplitudes in 2 of 4 patients.

CONCLUSION

Although toxin could not be detected in the patients, the electromyographic findings supported our diagnosis. We concluded that electromyography has an important role in diagnosis of botulism, especially in the condition that serologic tests are negative or cannot be performed.