家兔高位输精管结扎后其近端结构变化的观察

家兔高位输精管结扎后其近端结构出现明显变化。光镜和电镜观察显示，管的近端管径增粗，管腔扩张，腔内充满精子。柱状上皮细胞顶部胞膜内陷增多，胞质内含有较丰富的有衣小泡、多泡体、溶酶体和线粒体等。出现变化的时间是术后的第３个月。中位输精管结扎后其近端结构的变化基本相似于高位结扎。低位输精管结扎后无变化。本研究结果提示，家兔输精管不单纯是输送精子的管道，还有较强的摄取某些物质的作用。     

Expression of epithelial markers in sarcomatoid carcinoma: an immunohistochemical study

Thirty-four cases of sarcomatoid carcinoma with minimal epithelial components (SC) and six cases of sarcomatous tumour without any epithelial component (ST) in various organs were studied by the immunoperoxidase technique for the expression of epithelial markers, cytokeratins and epithelial membrane antigen (EMA). Employing antibodies against both high and low molecular weight cytokeratins, sarcomatoid components in 30 examples of SC were stained positively. Epithelial membrane antigen was demonstrated in 19 out of 34 SC. The positive cells for epithelial markers within sarcomatoid components in some cases of SC, which were regarded as originating from squamous cell carcinoma, tended to be seen less frequently than in the tumours derived from adenocarcinoma or transitional cell carcinoma. In six cases of ST, stain for EMA was negative and stain for cytokeratins was positive in three examples. The immunohistochemical examination of epithelial markers in the tumours of these types may be of value in differentiating these tumours from true sarcomas.     

Vasitis nodosa and associated clinical findings.

To establish the prevalence of vasitis nodosa in patients who had undergone vasectomy segments of vas deferens resected from 40 patients at the time of vasectomy reversal were examined histologically and immunohistochemically. The findings were correlated with clinical history and postoperative outcome. Controls comprised segments of normal vas deferens excised at vasectomy. Twenty of the 40 vasovasostomy specimens showed vasitis nodosa; in 13 this was associated with sperm granulomas and in two with spermatocoeles. The vasitis nodosa was characterised by multiple small ductules extending from the central lumen of the vas into the muscle layers and adventitia. In 14 cases there was mucinous metaplasia of the epithelium lining the ductules. The number of nerve fibres in the submucosa and muscle layers was reduced after vasectomy. In patients with vasitis, however, hyperplasia of nerve fibres in the adventitia (16 of 20 cases) and formation of neuromas were seen. Nerve fibre hyperplasia was seen in only one, and sperm granulomas and spermatocoeles in none of the 20 specimens without vasitis nodosa. The development of vasitis nodosa was independent of the patients' age or the interval between vasectomy and reversal. The restoration of fertility did not seem to be affected by previous vasitis nodosa.     

Pregnancy after vasovasostomy for vasectomy reversal: a study of factors affecting long-term return of fertility in 282 patients followed for 10 years

The aim of this study was to determine the eventual fertilityof those patients following vasectomy reversal who have no pressure-inducedsecondary epididymal blockage. These patients underwent simplevasovasostomy because at the time of the reversla surgery therewere sperm present in large numbers in the vas fluid. It waspossible to obtain long-term follow-up on 326 early patientswho underwent vasectomy reversal 8–10 years age. Two hundredand eighty-two of those patients had sperm in the vas fluid.These patients, were studied for pregnancy rate and post-operativesemen parameters in relation tio presence or absence of spermin the vas fluid at the time of vasectomy reversal, durationof time since vasectomy, pre-operative serum antisperm antibodytiters, the influence of varicocoele and quantitative evaluationof testicular biopsy. All of the 44 patients with no sperm inthe vas fluid remained azoospermic following vasovasostomy.Of the 282 patients with sperm in the vas fluid, 228 (81% )eventually impregnated their wives. Twenty-four patients withsperm in the vas fluid (9%) were azoospermic and did not impregnatetheir wives. Of the 258 patients who had sperm patency, thepregnancy rate was 88%. The number of mature spermatids pertubule in the testis correlated closely with the post-operativesperm count in patent cases. Quantitative evaluation of thetesticular biopsy revealed normal spermtogenesis, even in patientswith azoospermia or severe oligospermia post-operatively. Technicalfailures were due to blockage either at the vasovasostomy site,or epididymal blockage unrecognized at the time of vasovasostomy.Sperm count had a minimal impact on the likelihood of pregnancyso long as there was patency, and there was no discrepancy betweensperm count and actual testicular sperm production as determinedby testicular biopsy. Pregancy was not related to the presenceor absence of a varicocoele, pre-oprative serum sperm antibodylevels, or testicular biopsy findings     

Regional variations in endoplasmic reticulum in the vas deferens of normal and vasectomized rats

The fine structure of the epithelium of different parts of the rat vas deferens was studied in normal rats and at intervals of up to nine months after vasectomy. The cytology of the columnar epithelial cells showed regional variations particularly in the type and extent of endoplasmic reticulum. Cells of the proximal part of the vas deferens were characterized by basal and perinuclear granular endoplasmic reticulum, a large Golgi apparatus, and numerous apical microvilli, vesicles, and vacuoles. In contrast, the columnar cells of the distal portion of the vas deferens contained large amounts of smooth endoplasmic reticulum, much of which assumed the form of large whorls of smooth membranes. In the distal segment the number of microvilli, vesicles, and vacuoles was less but mitochondria were more numerous than in the proximal part. Cells in the middle portion of the vas deferens showed some features of both proximal and distal parts. These structural characteristics, along with previous experiments, suggest that in the proximal portion of the vas deferens absorption of material from the lumen is an important function, while the cells of the distal part may synthesize steroids. Thus, these regional differences in ultrastructure probably reflect regional differences in function along the length of the vas deferens. After vasectomy the regional specializations were retained and did not appear to be altered. The possibility that this structural and functional sequence is significant for normal fertility and its relation to attempts to reconnect the vas deferens after vasectomy are considered.     

家兔附睾管尾段吸收功能的研究

家兔输精管低位结扎后附睾管尾段结构出现明显变化，外形和光电镜观察显示其管径增大，管腔扩张，腔内精子密集。附睾的平均重量增加。主细胞顶部胞膜向胞质内凹陷增多，并形成施工吞饮小泡，核上区出现许多与吸收作用有关的小泡、大泡、多泡体、溶酶体和线粒体等超微结构。出现上述变化的时间是术后的第３个月。输精管中位结扎组的变化情况基本相似于低位结扎组。输精高位结扎后因不能排出的睾网液可在附睾的近段被大部吸收，少量的     

Quantitative (stereological) study of the effects of vasectomy on spermatogenesis in rabbits

Using stereological methods, especially the optical disector for unbiased estimation of nuclear number, our recent study demonstrated that long-term (6 or 12 months) vasectomy in the rhesus monkey had no significant effects on spermatogenesis (Peng et al. Reproduction 2002, 124, 847-856). This study aimed to determine the scenario in the rabbit using the same morphometric methodology. Three groups of normal male Japanese white rabbits (aged 4-5 months) were subjected to unilateral vasectomy; 10 days, 6 months and 12 months later both testes and epididymides were removed. Testicular and epididymal methacrylate-embedded sections were obtained for stereology. Vasectomy-induced damage to spermatogenesis was observed, primarily sloughing of spermatogenic cells with a greater reduction in the number of advanced (adluminal) cells. The damage was most severe at 10 days, occurring in all the testes on the vasectomized side and involving sloughing of even type A spermatogonia, the number of which returned to normal at 6 and 12 months. Damage was less severe at 6 and 12 months, being found in half of the testes of the vasectomy side, in which the total numbers of later germ cell types were 24.0-59.1% (spermatocytes) and 0.3-11.6% (spermatids) of control at 6 months, and 20.1-22.1% (spermatocytes) and 0.4-12.0% (spermatids) of control at 12 months. By contrast, Sertoli cell number per testis was unchanged following vasectomy in any group. Epididymis on the vasectomy side, especially at 10 days and 6 months, appeared larger than on the contralateral side, but this difference was not statistically significant, and no sperm granuloma was seen in the epididymis.     

Effect of long‐term vasectomy on seminiferous tubules in the guinea pig

The little previous work on the influence of vasectomy on the guinea pig testis has given controversial results. One group reports that the guinea pig suffers autoimmune orchitis while others claim damage may be mechanical. To clarify the issue, this study compares the morphology of seminiferous tubules 3 years after left unilateral vasectomy (8 guinea pigs) and control sham operation (6 animals). Grossly, left and right testes following left‐sided vasectomy were similar to controls and not significantly different in weight. On histology, left and right experimental testes and the control material showed various degrees of seminiferous tubular degeneration, including intraepithelial vesicle formation, loss of germ cells and intraluminal macrophages. Although vesicle formation was striking in most testes, quantitative analysis indicated that it was more frequent in the ipsilateral testis following unilateral vasectomy. It seems that vasectomy had exacerbated an age‐related phenomenon. Lymphocytic infiltration was seen in five of the left testes following vasectomy, in two of the corresponding right testes, but in none of the controls. Two vasectomized left testes, however, showed atrophic changes but no lymphocytic invasion. The results suggest that autoimmune orchitis follows vasectomy but that it may not be the primary cause of degeneration. Attempts to gain positive evidence for mechanical damage, however, were inconclusive. Clin. Anat. 12:250–263, 1999. © 1999 Wiley‐Liss, Inc.     

Effect of vasectomy on the seminiferous tubule boundary zone in the Albino Swiss rat

The boundary zone of a seminiferous tubule consists of the basement membrane of the seminiferous epithelium, its myoid cells, and their basal laminae. This study examines the boundary zones of seminiferous tubules in healthy and degenerated testes following long-term, left-sided vasectomy in the rat and compares them to those of sham-operated controls and adult rats exposed in utero to the antiandrogen, flutamide. Degenerated tubular profiles showed similar changes, irrespective of whether the degeneration was ipsilateral or bilateral. In transverse tubular profiles, the basal laminae of the seminiferous epithelium and the myoid cells became more undulating, that of seminiferous epithelium showing complex folding. The collagen layer of the boundary zone, which lies between the basal laminae of the seminiferous epithelium and the myoid cells, thickened and its fibers became irregularly orientated. Rather than being flattened as in controls, the region of the myoid cell near the nucleus and the nucleus itself developed triangular profiles in the transversely sectioned tubules. Similar features were also seen in the degenerated tubules of rats exposed to flutamide. The changes in the boundary zone are not specific for vasectomy and probably reflect reduction in the cross-sectional area of tubular profiles and possibly in their length. We also noted occasional leukocytes infiltrating the boundary zone; they may have increased in number in those tubules that showed degeneration following vasectomy.     

Seminiferous epithelium damage after short period of busulphan treatment in adult rats and vitamin B12 efficacy in the recovery of spermatogonial germ cells

Several different strategies have been adopted in attempt to recover from chemotherapy‐damaged spermatogenesis that is often seen in oncologic patients. In this study, we have evaluated the impact of short period of exposure to busulphan on the haemogram and seminiferous epithelium of adult rats, focusing on spermatogonial depletion and Sertoli cell (SC) integrity. We then examined whether vitamin B₁₂ supplementation improves the haematological parameters and spermatogonia number. The animals received 10 mg/kg of busulphan (BuG) or busulfan+vitamin B₁₂ (Bu/B₁₂G) on the first and fourth days of treatment. In H.E.‐stained testicular sections, the areas of the seminiferous tubule (ST) and seminiferous epithelium were measured. The number of spermatogonia in H.E‐stained and PCNA‐immunolabelled testicular sections was quantified. The frequency of tubules with abnormal SC nuclei or TUNEL‐positive SC was evaluated. Vimentin immunofluorescence in ST was also evaluated. In BuG and Bu/B₁₂G, the animals showed leukopenia and thrombocytopenia, but the body weight reduced only in BuG. The areas of ST and seminiferous epithelium decreased in Bu/B₁₂G and BuG. In BuG, the number of H.E.‐stained and PCNA‐immunolabelled spermatogonia reduced significantly. The frequency of tubules containing abnormal SC nuclei and TUNEL‐positive SC increased and the vimentin immunoexpression pattern changed. In Bu/B₁₂G, the number of H.E.‐stained or PCNA‐immunolabelled spermatogonia increased fourfold in comparison with BuG. The structural changes in ST after 6 days of busulphan exposure may be associated with the potential effect of this anti‐neoplastic agent on SC. The increased number of spermatogonia in the busulphan‐treated animals receiving vitamin B₁₂ indicates that this vitamin can be an adjuvant therapy to improve the fertility in male cancer patients.     

Vasitis nodosa-a site of arrest of malignant germ cells

A 40-year-old man, with a history of vasectomy 11 years previously, presented with a tumour in his right testis. At orchidectomy a seminoma was found, together with a nodule on the vas deferens. Histological examination of this area in the vas identified the lesion of vasitis nodosa and also showed it to be the site of proliferating germ cells. The pathogenesis of this lesion is discussed.     

Benign neural invasion in vasitis nodosa

Three instances of invasion of nerves of the spermatic cord by benign proliferative ductules of the vas deferens following vasectomy are reported. This phenomenon occurred in association with the histopathological features of vasitis nodosa and was noted in tissue removed during vasovasostomy in two cases and from a painful lower inguinal nodule at the site of vasectomy in a third example. Such neural invasion deserves attention because, especially in association with a proliferative ductular pattern, it may be mistaken for adenocarcinoma. The lesion is also of intrinsic interest in the light of benign neural invasion at other sites.     

Effect of nicotine on secretory component synthesis by secretory epithelial cells.

Previously, we reported that secretory component (SC), lactoferrin (LF), and lysozyme (LY) levels were significantly lower in saliva from smokeless tobacco (ST) users than in saliva from control non-tobacco users. However, the levels of salivary immunoglobulin A were significantly higher, albeit with an altered attachment of SC, in ST users than in control subjects. SC, LF, and LY are synthesized by secretory epithelial cells at mucosal sites adjacent to lymphocyte regions. In the present report, HT-29 human epithelial cells, cultured with various concentrations of an ST aqueous extract or pure nicotine (0 to 1 mg/ml) or cotinine (0 to 5 mg/ml), exhibited significantly lower levels of cell-associated cell lysate (CL) and secreted culture supernatant (CS) SC, LF, and LY than cells cultured without ST components. Nicotine significantly decreased (P < or = 0.05) the synthesis of SC by 20 to 100%, LF by 20 to 60%, and LY by 5 to 75% of CL and CS control values. Studies also indicated significant decreases (P < or = 0.05) in SC, LF, and LY levels in both CL and CS of cells cultured with ST aqueous extract or cotinine. Total cell numbers and metabolic activity significantly decreased primarily when cells were incubated with higher concentrations of ST extract, nicotine, or cotinine. The addition of human recombinant interleukin-4 or gamma interferon diminished the effects ST had on HT-29 cell synthesis of SC, LF, and LY. Our data indicate that nicotine, cotinine, and ST have an adverse effect on synthesis and secretion of SC, LF, and LY. These effects were below ST concentrations found to be cytotoxic for secretory epithelial cells. Furthermore, addition of interleukin-4 or gamma interferon reduced the suppressive effect of ST on synthesis or secretion of SC, LF, or LY.     

Satellite Cells of Sensory Neurons after Various Types of Sciatic Nerve Trauma in the Rat

Sciatic nerve crushing, transection, and ligation models were used in rats to study the reactions of and changes in the numbers of satellite cells (SC) in spinal dorsal root ganglia in the lumbar segment. Nerve transection was followed by the appearance of neurons surrounded by two layers of SC. The thickness of SC processes and the areas of contacts with neurons increased as a result of invaginations into neuron perikarya. After nerve ligation, SC and their processes were located around parts of large and intermediate neurons in several tightly appressed layers; the area of contact between SC and neuron perikarya showed increased development of invaginations such that lamellar structures appeared in the SC cytoplasm, along with contacts with SC processes surrounding neighboring neurons. The greatest increases in SC numbers were seen after ligation of the nerve. Transection was followed by increases in the numbers of small and intermediate neurons surrounded by vimentin-positive SC. The number of large neurons surrounded by these cells decreased. At all time points following ligation of the nerve, all neurons in the study ganglia were surrounded by vimentin-positive SC. Post-traumatic changes in structure and numbers differed in SC associated with sensory neurons of individual size populations and depended on the type of trauma applied to efferent conductors.     

Presence of synaptonemal complex protein 1 transversal filament-like protein in human primary spermatocytes

The synaptonemal complex (SC) is involved in the pairing of chromosomes during meiosis. We found that antibodies raised against a protein component (P1) of the mouse synaptonemal complex, mouse SCP1, also identified the SC in human primary spermatocytes. Biopsies from 18 men presented with infertility were evaluated by light-field microscopy and grouped into five categories: normal spermatogenesis, Sertoli cell-only syndrome, meiotic disturbances, spermiogenic (i.e. differentiation) disturbances, and other combined disturbances. In all the normal subjects the SCP1 antibody distinctly stained the synaptonemal complexes of primary spermatocytes, whereas Sertoli cells, spermatogonia or spermatids were never stained. In three of the groups, which had germ cells but showed spermatogenic disturbances, the staining was similar to that seen in normal subjects. In sharp contrast to this, in sections from men with Sertoli cell-only syndrome no specific staining was seen. This study demonstrates that a SCP1-related protein is also conserved in the synaptonemal complex in meiotic cells from man. Further studies will reveal to what extent the absence or the non-functionality of SCP1 contributes to male infertility.      

Testicular cytology in azoospermia

Two hundred-seventy-five azoospermic mates were subjected to fine-needle aspiration (FNA) cytologic study of testis with the aim of determining the cause of azoospermia; 534 aspirates from these patients were classified as follows: normal spermatogenesis (162), hypospermatogenesis (mild, moderate, or severe, 226), absence of spermatogenesis (130), maturation arrest (36), Sertoli-cell-only syndrome (14), and Leydig-cell hyperplasia (3). The morphology of cells was excellent in the cytologic preparations and various spermatogenic cells and Sertoli cells were easily recognized. Leydig cells were uncommonly seen, except in cases of Leydig-cell hyperplasia. Degenerative changes, possibly due to obstruction, were seen in 104 cases. The procedure was well tolerated by the patients. We conclude that FNA cytology is a useful investigative modality in the evaluation of azoospermic males.     

Effects on the efferent ducts in Macaca mulatta.

Immunopathologic findings in efferent ducts of 36 rhesus macaques vasectomized as many as 12 years earlier and of 11 age-matched control animals were compared. Electron-microscopic observation of these ducts revealed changes after vasectomy. The epithelium shortened from a prevasectomy height of 25 mu to 14 mu as the ducts stretched after vasectomy. The number of sperm and macrophages in the lumen increased. The basement membrane was 300-700 A wide in nonvasectomized animals but several times that in animals vasectomized 6 or more years before; the mean width significantly increased with time after vasectomy. Numerous electron-dense immune complexes were found within the thickened lamina in 33% of vasectomized animals and in none of the controls. The mean size of the electron-dense areas varied from 0.01 sq mu in a monkey vasectomized 3 years earlier to 0.18 sq mu in an animal vasectomized 7 years earlier; the mean area significantly increased with time after vasectomy. Frozen sections of testis and epididymis were evaluated through the use of fluorescein-conjugated antibodies. Of the nonvasectomized controls, 18% showed immune deposits. Of the vasectomized animals, 53% revealed C3 deposition in the basement membrane surrounding the efferent ducts. The presence of electron-dense deposits plus the finding of putative immune complexes as revealed by immunofluorescence suggested that vasectomy enhances leakage of sperm antigens, particularly in the region of the efferent duct.     

Male contraception: hormonal, mechanical and other

Methods of male contraception that have been developed so farhave mainly focused on the inhibition of spermatogenesis throughsuppression of the hypothalamo- pituitary secretion of gonodotrophins,and simultaneous supplementation with androgens. These methodsinclude the use of combinations of progestogens or luteinizinghormone-releasing hormone antagonists and testosterone derivatives,or high dose testosterone. Though effective contraception canbe obtained, side-effects and/or the high cost of treatmentlimit the widespread use of these approaches. Inhibition ofsperm maturation in the epididymis, or direct interference withspermatogenic cells or the cells of Sertoli by e.g. gossypolhave been abandoned because of toxic side-effects. Voluntarysterilization by vasectomy is the most commonly used methodof male contraception, but its surgical nature, problematicreversibility and suspected link with subsequent prostate cancerrender the method far from ideal. Non-surgical vas occlusionmay overcome some of these problems, but data on long-term side-effectsand reversibility are lacking. New contraceptive developmentsshould focus on interfering with highly specific aspects ofspermatogenesis such as unique enzymatic processes and intercellularcommunication through cytokines, or application of antibodiesagainst antigens of the epididymis or the spermatozoa. Onlythrough better understanding of normal and pathological spermatogenesiswill it be possible to develop an acceptable male contraceptive.     

The effect of unilateral vasectomy on testosterone and testicular parameters in the adult male African giant rat (Cricetomys gambianus)

Background

The effects of vasectomy on spermatogenesis and reproductive parameters are recognized to be specie-dependent with marked differences in levels of perturbations observed.

Objectives

To assess the impact of unilateral vasectomy on testosterone level and other testicular parameters in the male African giant rat (AGR) (Cricetomys gambianus).

Methods

Sixteen adult male AGRs weighing 500–1300 g were recruited for the experiment. Animals were randomly divided into three experimental groups (1–3) and one control (sham operated) group with four rats per group. Experimental vasectomy was done by carefully ligating the vas deferens of the right testis of all the experimental groups (1, 2, and 3) and animals were allowed either 8, 6 and 2 weeks respectively before sacrifice. Sham-operated animals served as the control. Blood samples were collected and assayed for testosterone while testicular tissue was further processed for seminal fluid and histo-pathological analyses.

Results

Spermatogenic parameters indicate a pattern of decline in sperm count and motility between the experimental groups and the control and azoospermia in the eight-week group. Histological alterations were marked by atrophy of seminiferous tubules which was proportional to the duration of vasectomy. Serum testosterone levels were significantly reduced at eight weeks. There was no statistically significant difference between sperm counts of right and left testes except for group 3. Results suggest that unilateral vasectomy of the AGR may have negative impact on the contralateral testis in the male African giant rat.

Conclusion

These preliminary results reveal that unilateral vasectomy in the AGR may result in perturbations of the histo-architecture of the testes with possible decline in function.