Role of chloride transport proteins in the vasorelaxant action of nitroprusside in isolated rat aorta

Chloride ions play a key role in smooth muscle contraction, but little is known concerning their role in smooth muscle relaxation. Here we investigated the effect of chloride transport inhibitors on the vasorelaxant responses to nitroprusside in isolated and endothelium-denuded rat aorta, precontracted with phenylephrine 1 muM. Incubation of aortic rings in NO(3)(-) media strongly potentiated the vasorelaxant responses to nitroprusside. Bumetanide, DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid) and acetazolamide strongly potentiated the vasorelaxant responses to nitroprusside (by 70-100%). EC(50) were 2.3+/-0.5 microM for bumetanide, 26+/-15 microM for DIDS and 510+/-118 microM for acetazolamide (n=6 for condition). Niflumic acid, a selective inhibitor of ClCa (calcium-activated chloride channels), potentiated nitroprusside relaxation to a similar extent as chloride transport inhibitors, in a non-additive manner. Zinc and nickel ions, both modestly potentiated nitroprusside vasorelaxation (by 20-30%). Cobaltum had negligible effect on nitroprusside vasorelaxation. CPA (p-chlorophenoxy-acetic acid), an inhibitor of volume-sensitive chloride channels (ClC), slightly potentiated nitroprusside vasorelaxation (by 15%), and the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel inhibitors CFTR(inh)172 (5-[(4-Carboxyphenyl)methylene]-2-thioxo-3-[(3-trifluoromethyl)phenyl-4-thiazolidinone), DPC (diphenylamine-2,2'-dicarboxylic acid) and glibenclamide were without significant effect. In conclusion, inhibition of chloride transport proteins strongly potentiates the vasorelaxant responses to nitroprusside in isolated rat aorta. This effect seems mediated by chloride depletion and inhibition of a chloride channel activated by both, calcium and cyclic GMP (cGMP).     

POLYMORPHOUS LIGHT ERUPTION: TREATMENT WITH THALIDOMIDE*

Epidemiological, clinical, aetiological and therapeutic aspects of polymorphous light eruption, a very common disease in Mexico, are reviewed. Twenty-five patients with this disease were treated with thalidomide over a period of 45 to 150 days with a dose depending on age: 100 to 200 mg a day. The results were satisfactory in 88% of the cases without any important side-effect. The teratogenic action of the drug is stressed and the authors think that although the action mechanism of the drug remains unknown, it may shed new light on the understanding and treatment of this disease.     

Pro-ejaculatory effect of the aqueous crude extract of cihuapatli (Montanoa tomentosa) in spinal male rats

In the present study, the pro-sexual effect of the cihuapatli (Montanoa tomentosa) and its possible pro-ejaculatory properties in spinal male rats were examined. Systemic administration of the aqueous crude extracts of Montanoa tomentosa exerted a pro-ejaculatory effect and produced an increase in the number of discharges in the ejaculatory motor patterns in the spinal rats. The cihuapatli-induced ejaculatory responses included the expression of penile erections and penile movements and the potent expulsion of urethral contents and in some cases the expulsion of seminal plugs. The cihuapatli-induced ejaculatory motor patterns were similar to that obtained after systemic oxytocin. Cihuapatli- and oxytocin-induced ejaculatory motor responses and the penile erections and movements were abolished by the pre-treatment with hexamethonium, a selective oxytocin antagonist. Present data show that the cihuapatli extract acts directly at the spinal system in charge of the expression of the ejaculatory motor patterns and suggest that the aqueous crude extract exerts its aphrodisiacs properties by increasing sexual potency acting as an oxytocic agent.     

Haematogenous dissemination of Leishmania (Viannia) braziliensis in human American tegumentary leishmaniasis

One of the potential dangers of American tegumentary leishmaniasis (ATL) caused by Leishmania (Viannia) braziliensis is the development of mucosal lesions. Haematogenous dissemination of the parasite is the most likely mechanism to explain this occurrence, but most attempts to isolate the parasite from blood have so far been unsuccessful. The presence of Leishmania in peripheral blood was therefore evaluated by PCR using DNA samples isolated from patients presenting active cutaneous or mucosal disease, and from individuals cured by antimonial treatment as well as individuals without a past history of leishmaniasis but with a positive Montenegro skin test, all living in L. (V.) braziliensis-endemic areas. Leishmania DNA was found not only in those patients presenting active cutaneous (24.8%) or mucosal (35%) lesions, but also in samples isolated from healed individuals (27.3%) as well as in asymptomatic skin-test-positive residents of endemic areas (37.5%). Overall, PCR showed the presence of parasite DNA in the blood of 26.2% of the 225 examined samples. These data suggest that persistence of parasites within the host may last for many years and, rather than being a risk factor, might be important in maintaining the protective response in those living in endemic areas.     

Laparoscopic partial cystectomy in the management of bladder endometriosis: report of two cases

Endometriosis is the proliferation of endometrial tissue outside the normal confines of the myometrium or uterine cavity. Endometriosis involving the urinary tract occurs in approximately 1% to 2% of cases. The bladder is affected in 80% of these patients. The diagnosis of vesical endometriosis is difficult, and it should be confirmed by cystoscopy with biopsy. Laparoscopic examination represents the gold standard for the diagnosis of pelvic endometriosis. Urinary bladder endometriosis may be treated surgically or medically with hormone-suppressive therapy. However, medical treatments usually are only palliative, and symptoms generally recur on discontinuation. We report our experience in two patients with vesical endometriosis who were managed successfully with cystoscopy-assisted laparoscopic partial cystectomy.