华蟾蜍毒素对离体豚鼠输精管的作用

华蟾蜍毒素(华蟾素)使离体豚鼠输精管产生剂量依赖性收缩反应,利血平化豚鼠输精管及冷藏输精管对华蟾素反应减弱。给酚妥拉明、维拉帕米后,输精管对华蟾素反应均受抑制,溴苄胺可使反应潜伏期缩短。结果提示华蟾素收缩输精管反应可能与其促进肾上腺素能神经末稍NA释放有关。     

Perfluorochemicals as US contrast agents for tumor imaging and hepatosplenography: preliminary clinical results

In animals, perfluorochemicals (PFCs) are effective ultrasound (US) contrast agents that produce hepatic, splenic, and tumor enhancement. The use of Fluosol-DA 20%, an emulsion of perfluorodecalin and perfluorotripropylamine, was studied in nine non-critically ill patients with cancer who had liver lesions. US studies without Fluosol were compared with studies obtained 24, 48, and 72 hours after Fluosol infusion. Vital signs and extensive laboratory analyses are performed before and after Fluosol infusion. Liver metastases from colonic, pancreatic, and gastric carcinoma exhibited rim or diffuse enhancement after a Fluosol dose of 1.6 g/kg or greater. Fluosol produced echogenic enhancement of the liver and spleen relative to kidney at a dose of 2.4 g/kg, allowing the detection of nonenhancing lesions. In addition, Fluosol at a dose of 1.6 g/kg or greater allowed detection of lesions not seen before contrast medium was administered in three of the seven patients studied. There was a mild increase in the level of serum glutamic oxaloacetic transaminase in two patients, one given 2.4 and the other 3.2 g/kg of Fluosol. Mild and transient allergic reactions without change in vital signs were experienced by two patients.     

A temporary nontoxic lubricant for a synthetic absorbable suture

Synthetic absorbable sutures have been coated with lubricants to improve their handling characteristics. A unique surfactant, poloxamer 188, has been used to coat the surface of the polyglycolic acid sutures. This lubricant was chosen because it does not damage the tissues defenses of the host and invite infection. Since poloxamer 188 is readily soluble in aqueous solutions, it is rapidly absorbed in the tissue environment resulting in an uncoated suture that displays increased knot security. The coating of polyglactin 910 is also minimally reactive in tissues and does not damage tissue defense. In contrast with the coated polyglycolic acid sutures, the knot security of the coated polyglactin 910 sutures is not altered by exposure to an aqueous environment or implantation. The increased knot security of the coated polyglycolic acid suture after implantation is considered to be a distinct clinical advantage over that of the coated polyglactin 910 sutures.     

Considerations in the choice of sutures for wound closure of the genitourinary tract

The ideal suture for use within the urinary tract should maintain its tensile strength until wound repair is satisfactory and then it should undergo rapid total absorption without promoting stone formation. The bladder has a great potential for repair, attaining 100 per cent of the strength of the unwounded tissue in 14 to 21 days. Braided synthetic absorbable sutures appear to be suited ideally for closure of incised wounds of a urinary conduit. They maintain their tensile strength for approximately 21 days, during which time the healing tissues regain strength rapidly. Because sutures are foreign bodies and have access to urine, they may serve as a nidus for stone formation. Several factors that have been identified as important determinants of foreign body urolithiasis include the presence of urine, urine volume and pH, infection, physical and chemical configuration of the foreign body, and animal species. The incidence of suture urolithiasis is related directly to the duration in which the sutures are present in the urinary tract. Consequently, absorbable sutures are preferred over nonabsorbable sutures for closure of wounds of the urinary conduit. In the absence of infection braided synthetic absorbable sutures have distinct advantages over gut sutures for closure of urinary tract wounds. They are absorbed by nonenzymatic hydrolysis in a predictable manner with limited inflammatory response. In contrast, gut sutures have an unpredictable absorption rate by enzymatic degradation and elicit an exaggerated inflammatory response. Because infected urine, especially Proteus species, accelerates the degradation of absorbable synthetic sutures to a greater degree than gut sutures, wound closure in the presence of infection should be accomplished with the absorbable natural fiber suture. Nonabsorbable sutures or staples should not be used in the urinary tract because they predictably promote urolithiasis.     

Surgical sperm retrieval and intracytoplasmic sperm injection as treatment of obstructive azoospermia

Male genital tract obstructions may result from infections, previous inguinal and scrotal surgery (vasectomy) and congenital bilateral absence of the vas deferens (CBAVD). Microsurgery can sometimes be successful in treating the obstruction. In other cases and in cases of failed surgical intervention, the patient can be treated by microsurgical or percutaneous epididymal sperm aspiration (MESA, PESA) or testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI). We present the results of 39 ICSI procedures for obstructive azoospermia in 24 couples. The aetiology of the obstruction was failed microsurgery in 11 patients, CBAVD in nine and genital infections in four. Sperm retrieval was accomplished via MESA in four cases, PESA in 18 cases and via TESE in 11 cases. TESE was only applied when PESA failed to produce enough spermatozoa for simultaneous ICSI. In six patients, the ICSI procedure was performed with cryopreserved spermatozoa after an initial PESA procedure. Fertilization occurred in 47% of the metaphase II oocytes; embryo transfer was performed in 92% of procedures and resulted in a clinical pregnancy in 13/39 procedures. Ongoing pregnancy was achieved in 10/39 procedures. One pregnancy was terminated early after prenatal investigation showed a cytogenetic abnormality (47,XX+18, Edwards syndrome). The other nine pregnancies resulted in the live birth of 10 children, without any congenital abnormalities. Epididymal and testicular retrieved spermatozoa were successfully used for ICSI to treat obstructive azoospermia, and resulted in an ongoing pregnancy in 10 of 24 couples (41.6%) after 39 ICSI procedures, a success rate of 25.6% per treatment cycle and of 27.7% per embryo transfer.