Biomedical subjects

C G Stief

Publications and source records attributed to C G Stief.

165 records · Page 10Linked to original sources

PubMed1986

[Preliminary results of the treatment of erectile impotence by intracavernous self administration of vasoactive substances].

From a group of 120 patients with erectile deficiency, 43 cases with arterial disorders with or without associated nervous, psychologic or venous causes were selected for treatment. Mean age of group was 44.5 years. A preliminary series of test was performed during hospital stay, consisting of injection of phentolamine and papaverine into corpus cavernosum. This allowed determination of the minimal effective dose for maintaining erection, and 41 patients accepted to continue treatment at home by auto-injection of products. Regular review showed that all had erections, considered to be complete in 95%. The initially determined dose was usually reduced, probably due to sexual stimulation. The erections appeared earlier (8 min) and lasted longer (140 min), ejaculation provoking only minimal detumescence. Patients responding poorly had venous losses. During initial tests, 2 patients had abnormally prolonged erections requiring puncture of corpus cavernosum. Incidents or habit-forming did not develop and patients and partners did not present psychological problems.

Adult↗

PubMedDate not supplied

Phosphodiesterase inhibitors in the treatment of erectile dysfunction.

Based on knowledge of intracellular signal propagation in cavernous smooth muscle tone regulation and the development of new and selective pharmacological agents, selective phosphodiesterase (PDE) inhibitors were recently introduced in the treatment of erectile dysfunction. The presence of mRNAs specific for 13 different human phosphodiesterase isoenzymes and isoforms in human cavernous tissue was shown by RT-PCR. We detected an expression of the following genes encoding for both cAMP and cGMP hydrolyzing PDEs: all three isogenes of PDE I and PDE IIa, which do hydrolyze cAMP as well as cGMP; the specific cAMP hydrolyzing PDEs PDE IIIa, the four isogenes of PDE IV, PDE VIIa and PDE VIIIa and the cGMP-specific PDEs PDE Va and PDE IXa. By protein chemical methods, PDE-isoenzymes III, IV and V were characterized in the human cavernous smooth muscles. In functional organ bath studies using precontracted human cavernous tissue strips, PDE III and V inhibitors showed the most pronounced relaxant responses. In clinical studies, the use of the orally active PDE V inhibitor sildenafil induced a pronounced and significant erectogenic effect in patients both with predominantly psychogenic and organogenic etiology of erectile dysfunction. The first promising clinical data of the use of an orally active PDE inhibitor for the treatment of erectile dysfunction are well supported by consistent basic scientific findings. Further research will possibly allow to identify diagnostic tools for erectile dysfunction and for even more selective drugs in its therapy.

Journal Article↗

PubMedDate not supplied

General anesthesia for ureteral measurements in the rabbit.

Literature search and in vitro studies on ureteral function in humans and rabbits have proven that the rabbit is a suitable animal model for the investigation of the effect of smooth muscle relaxing substances on the ureter. One of the main problems encountered was to find an appropriate anesthetic protocol for this animal model. Application of barbiturates as a monotherapy proved to be unsuitable to allow painfree preparation of the abdomen. Intravenous (iv) anesthesia consisting of ketamine-HCl/xylazine-HCl could not be considered due to interference with ureteral smooth muscle tone. Intravenous administration of ketamine-HCl induced immediate ureteral contractions with increased frequency of ureteral activity. Xylazine-hydrochloride, a mixed alpha 2-, alpha 1-adrenoceptor agonist inhibits the increase in synthesis of 3'5'-cAMP. Since the test substances used are phosphodiesterase-IV-inhibitors (rolipram and its two enantiomers), which increase 3'5'-cAMP, this type of anesthesia would interfere with the pharmacological effect to be investigated. General anesthesia using a combination of nitrous oxide (2 l/min) and oxygen (1 l/min) and a very small amount (2 mg/kg b.w.) of pentobarbital i.v. every 30 minutes, was found to be the most suitable form of anesthesia. It resulted in much more stable circulatory conditions, sufficient depth of anesthesia and the possibility to test muscle relaxing substances (PDE-IV-inhibitor) without any influence from anesthesia on their efficacy.

Anesthesia, General↗