Endogenous hydrogen sulfide is the third gaseous signal molecule after nitric oxide and carbon monoxide;it is synthesized through cystathionine-?-synthase and cystathionine-?-cleavage pathway.Hydrogen sulfide can directly react with the KATP channel,reduce extracellular Ca2+ influx,and work together with testosterone,nitric oxide,carbon monoxide,relaxing corpus cavernosum smooth muscle and improving diastolic function of blood vessels.It can also inhibit vascular smooth muscle cell proliferation,promote apoptosis,and improve vascular remodeling.Therefore,in-depth study of H2S in the regulating penile erection can provide a new way for the treatment of erectile dysfunction.

Objective To study the clinical CT manifestations of infective ovarian cysts so as to improve diagnostic ability.Methods All the cases were evaluated on plane scan and enhancement scan.Their manifestations on CT were analysed.Results The cysts lying in the left ovary account for 14 cases, in the right ovary 4 cases. The size of cysts varied from 11 cm?10 cm?11 cm to 4 cm?3 cm?4 cm. The cyst walls thickened to some extent. 15 cases thickened “gradually”. 3 cases thickened “comparatively evenly”. The thickness of the cyst walls was over 1 cm, the thickest being 2 cm. The length of the thickened wall was more than one half circumference of the cyst, with smooth inner side.The cyst wall showed the density of soft tissues and it was mildly intensified after being enhanced.Conclusion The clinical CT manifestations of infective ovarian cysts have certain characteristics.