阴茎勃起神经再生模型和机制的研究

探明神经性勃起功能障碍(NED)的分子生物学机制以期对该类疾病进行神经调控干预,是男科学研究的当务之急。本文回顾了急性神经损伤、前列腺癌、糖尿病和帕金森病所致的NED的研究进展。通过利用大鼠阴茎勃起神经的盆腔大神经节(MPG),在体外构建一个三维培养体系来研究各种生长因子和细胞信号通路对神经再生的影响。体外结果表明脑源性神经生长因子(BDNF)通过JAK/STAT信号通路可显著促进NED的恢复,并在体内证实了该效应。因此,通过调控JAK/STAT信号通路来达到神经调控干预措施预防治疗神经性勃起功能障碍成为可能。     

Effect of extended-term estrogen on voiding in a postpartum ovariectomized rat model

Introduction

We tested the hypothesis that extended-term (5-week) estrogen therapy would negatively impact voiding function in a postpartum, ovariectomized rat model.

Methods

Immediately after delivery, 30 primiparous Sprague–Dawley rats underwent intravaginal balloon dilation, followed by ovariectomy 1 week later. Cystometry at postpartum week 2 determined normal or abnormal voiding patterns. After randomization, one-half the normal and abnormal voiding rats received 5 weeks of estrogen therapy, while the remainder received placebo. Estrogen effect was determined by repeat cystometry and immunohistochemical analysis of the urethra and vagina.

Results

Abnormal voiding increased from 60.0% to 73.3% in the estrogen- treated group and declined from 60% to 33% for the placebo group. Rats were then divided into 4 groups for comparison: normal voiding versus placebo (group 1), abnormal voiding versus placebo (group 2), normal voiding versus estrogen (group 3) and abnormal voiding versus estrogen (group 4). Bladder capacity, leak point pressure and maximum voiding pressure were most depressed in group 4. Estrogen treatment was associated with a significant downregulation of α_1A and α_1D-adrenoceptors in the urethral submucosa but an upregulation of nNOS in the urethral smooth muscle.

Conclusion

Extended-term estrogen therapy in a rat model of simulated birth trauma and ovariectomy resulted in a higher rate of incontinence. Immunohistochemical examination demonstrated significant downregulation of urethral α_1A- and α_1D-adrenoceptors and upregulation of neuronal nitric oxide synthase (nNOS) in the urethra of estrogen-treated groups. These studies question the use of hormone replacement therapy in the treatment of postmenopausal incontinence.     

Detailed anatomy of penile neurovascular structures: surgical significance

In 10 formalin-preserved adult male cadavers, dissection of the penile veins, arteries and nerves revealed information of clinical importance. The main venous drainage of the corpora cavernosa is via the cavernous veins, with additional drainage through the circumflex, deep dorsal, and crural veins. The arterial supply of the cavernous bodies varied remarkably, and the incidence of an accessory internal pudendal artery was high. The cavernous nerves, previously believed to be microscopic structures, were in fact identifiable grossly, and we were able to follow them from the region of the hilum of the penis to the prostate. The nature of these nerves was then confirmed by serial histologic sectioning. This detailed knowledge of the venous drainage and arterial and nervous supply of the penis, as well as of the relationships among the cavernous structures in the hilum of the penis, can elucidate the cause of erectile dysfunction and provide a valuable guide for surgical correction of vasculogenic and neurogenic impotence.     

Spinal anesthesia and electroerection in dogs and monkeys

We studied the penile erectile response to cavernous nerve electrostimulation in five monkeys and eight dogs before and during spinal anesthesia. Anesthesia was obtained by intradural injection (at L4-L5 level) of either xylocaine (two mg./kg. body weight) or tetracaine (0.2 mg./kg.). In monkeys, systolic blood pressure reduction (average 17.2%), slight elongation and tumescence of the penis, and increase of intracavernous pressure were noted after spinal anesthesia. Electrostimulation of the cavernous nerves resulted in longer erection and detumescence phases than obtained before anesthesia. In dogs, a similar blood pressure decrease (16.6% average) was noted after anesthesia. The response during anesthesia to electrostimulation of the erectile nerves was, however, variable. Changing the animal's position abolished the erectile response in three of four dogs while no change of erectile response due to anesthesia could be demonstrated in the remaining four dogs. We conclude that spinal anesthesia seems to enhance simian, but not canine, erectile response to electrostimulation of the erectile nerves, possibly via interference of the autonomic regulatory mechanism.     

Vestibular evoked myogenic potentials are heavily dependent on type I hair cell activity of the saccular macula in guinea pigs

This study applied the vestibular evoked myogenic potential (VEMP) test to guinea pigs coupled with electronic microscopic examination to determine whether VEMPs are dependent on type I or II hair cell activity of the saccular macula. An amount of 0.05 ml of gentamicin (40 mg/ml) was injected directly overlaying, but not through, the round window membrane of the left ear in guinea pigs.One week after surgery, auditory brainstem response test revealed normal responses in 12 animals (80%), and elevated thresholds in 3 animals (20%). The VEMP test using click stimulation showed absent responses in all 15 animals (100%). Another 6 gentamicin-treated animals underwent the VEMP test using galvanic stimulation and all 6 also displayed absent responses. Ultrathin sections of the saccular macula in the gentamicin-treated ears displayed morphologic alterations in type I or II hair cells, including shrinkage and/or vacuolization in the cytoplasm, increased electron density of the cytoplasm and nuclear chromatin, and cellular lucency. However, extrusion degeneration was rare and only present in type II hair cells. Quantitative analysis demonstrated that the histological density of intact type I hair cells was 1.1 +/- 1.2/4000 microm(2) in the gentamicin-treated ears, showing significantly less than that in control ears (4.5 +/- 1.8/4000 microm(2)). However, no significant difference was observed in the densities of intact type II hair cells and supporting cells between treated and control ears. Furthermore, the calyx terminals surrounding the damaged type I hair cells were swollen and disrupted, while the button afferents contacting the damaged type II hair cells were not obviously deformed. Based on the above results, we therefore conclude that VEMPs are heavily dependent on type I hair cell activity of the saccular macula in guinea pigs.     

β-阻滞剂塞利洛尔的合成

报道了β－阻滞剂塞利洛尔的简便制备方法，即以对乙氧基苯胺为原料，经酰胺化，傅克反应，以环氧氯丙烷取代，最后用叔丁胺直接与环氧基反应开环等４步反应制得。比文献五步反应缩短了一步，产物经元素分析、红外光谱、核磁共振谱、质谱等分析确定结构。     

The diagnosis of venogenic impotence: dynamic or pharmacologic cavernosometry?

In an attempt to refine the diagnosis of venogenic impotence, we evaluated different techniques of cavernosometry in 10 dogs. Saline was perfused intracavernously in five dogs to induce erection. Regardless of the amount required for induction, a mean flow rate of 23.4 ml./min. was necessary to maintain an intracavernous pressure level of 110 cm. H2O. In seven dogs, a leak was created by intracavernous insertion of a 19-gauge needle. When erection was induced by either cavernous nerve stimulation or a combination of papaverine injection and saline perfusion, the mean flow through the needle was significantly less than when erection was induced by saline perfusion alone (1.73, 1.78, and 8.77 ml./min., respectively). Sympathetic trunk stimulation at the level of L5 could reduce the intracavernous pressure by 90% in erections induced by neural stimulation or papaverine plus perfusion but had no effect on erection induced by saline perfusion alone. Our findings show that cavernosometry after intracavernous injection of papaverine will provide more valuable information in patients in whom venogenic impotence is suspected.     

军事航空医学专业数字图书馆建设

介绍军事航空医学专业数字图书馆现状,详细阐述军事航空医学专业数字图书馆建设对策,包括回溯建库资源数字化、软硬件设施建设保障化、专业数据库重点化等。