A study on budding protrusions of human seminiferous tubules

In order to elucidate the morphogenesis of seminiferous tubular protrusions, histometric, microscopic and electron microscopic studies were performed on the testes of 202 Japanese men, including 117 sudden deaths, 75 hospital deaths and 10 prostatic cancer cases. Protrusions usually occurred at outer convexes of multi-bending tubular portions and were divided into dome, sessile, pedunculated and multi-branched types. Aggregated Sertoli cells were present in dome-type protrusions as a major component, and spermatogenesis associated with active mitoses of spermatogonia was induced with development of protrusions. Protruding walls consisted of inner compact and outer loose layers. Distribution of lipid droplets in Sertoli cell cytoplasm in protrusions was different from those in the original tubules. The incidence of protrusions peaked in the forties and sixties, respectively, in the case of hospital and sudden death cases with underlying tubular atrophy. The findings suggest that tubular protrusions take place as a compensatory reaction for declining spermatogenesis, and therefore, probably represent a regenerative phenomenon in hypospermatogenic testes.     

Obstruction of the tubuli recti and ductuli efferentes by dilated veins in the testes of men with varicocele and its possible role in causing atrophy of the seminiferous tubules

Hormone measurements, spermiograms and testicular biopsies studies were performed in young with varicocele. In addition, the testes and epididymides of 27 adults with varicocele were obtained from autopsies. Light and electron microscopic examination of biopsy and autopsy specimens revealed two types of lesions in testes with varicocele: 1) a diffuse lesion consisting of abnormal spermatozoa and spermatid morphology and sloughing of immature spermatozoa and spermatid; 2) focal lesion, distributed irregularly throughout the testicular parenchyma, affecting several small groups of seminiferous tubules. Each of these groups corresponded to a testicular lobule and showed different degrees of tubular atrophy, so that the focal lesions were distributed in a mosaic pattern. The testicular interstitium showed dilated veins and venules, and progressive collagenization. Some testes showed dilated veins in the rete testis, which compressed several tubuli recti and caused tubular atrophy in the seminiferous tubules opening into these tubuli recti. Other testes showed dilated young veins among the ductuli efferentes, and the rete testis channels appeared to be dilated. Among the different etiological mechanisms which have been suggested to for testicular lesions in varicocele, tubular obstruction at the level of either the tubuli recti or the ductuli efferentes might be responsible for lesions leading to testicular atrophy.     

Early morphological changes in the abdominal testes in immature unilaterally cryptorchid rats

Testicular descent was prevented unilaterally in newborn rats by cutting the gubernaculum testis. Morphological changes due to non-descent of the testes were studied in 16-, 20-, and 24-day-old rats. Scrotal and abdominal temperatures were measured in control rats, and a difference was noted from 16 days and onwards. At 16 days of age the abdominal testes showed an abnormal accumulation of lipid droplets in the Sertoli cells at certain stages of spermatogenesis, and the number of tubules which had developed a lumen was slightly greater than in the scrotal testes. At 20 days of age, some spermatocytes were degenerating in the abdominal testes, especially in the tubular segments where lipid accumulation had been seen earlier. Lipid accumulation was noted in the Sertoli cells in all stages of spermatogenesis and additional ultrastructural signs of Sertoli cell malfunction such as dilatation of the SER and dilatation of the intercellular space between adjacent Sertoli cells was observed. Also the number of tubules containing a lumen was slightly larger in the abdominal testes. At 24 days of age, the number of spermatocytes was reduced in abdominal testes and the morphological changes seen earlier in the Sertoli cells were more pronounced. The function of the blood-testis barrier was investigated by the ability of the tubules to exclude lanthanum, and no differences were found between scrotal and abdominal testes at 16 and 20 days of age. The present study suggests that the earliest morphological changes in experimentally primary abdominal testes may occur in the Sertoli cells.     

Die Bedeutung des Tubulusdurchmessers im Hodenbiopsiematerial bei Oligozoospermie

This publication deals with the question how the tubular diameter in testicular biopsy gives conclusion to spermatogenic activity in patients with oligozoospermia. Therefore a collective of 50 patients with oligozoospermia between 0.3-20.7 mill. spermatozoa/ml was examined. 30 patients with occlusion azoospermia were the normal control group. In all patients a rice grain-sized testicular biopsy were performed of both testes. One part of the tissue was prepared for paraffin sections, the other one for semithin sections. The mean tubular diameter measured in all patients (that means in oligozoospermia of different severity as well as in occlusion azoospermia) was about 160 micrometers in paraffin sections and about 200 micrometers in semithin sections. But the fixation must be taken into consideration: the diameter of tubules in paraffin sections is smaller (about 20%) than in semithin sections.     

Morphological evidence for two types of idiopathic ''Sertoli-cell-only'' syndrome

Biopsies of testicular specimens taken from 41 patients that were diagnosed as having idiopathic Sertoli-cell-only syndrome were classified into two types, A and B, on the basis of histological and immunohistochemical findings. Thirty eight specimens that were classified as type A exhibited seminiferous tubules of small diameter and with tubular wall hyalinization, but containing normal adult type Sertoli cells. The other three specimens that were classified as type B showed no seminiferous tubular wall hyalinization, and their Sertoli cells had vimentin distribution localized in the subnuclear cytoplasm and had a pseudostratified lining, features resembling the appearance of fetal Sertoli cells. In one patient with a seminoma, a comparative study of the same testis prior to and post-irradiation was undertaken. Judging from this, postpubertal depletion of the germ cell population was considered to be responsible for the tubular atrophy observed in type A. Type B testes, though small in number, were characterized by a morphology distinct from the type A, but their pathogenesis remains unknown.     

Use of laparoscopy in children with impalpable testes

Our experience in Manchester using laparoscopy in children with impalpable testes is detailed. Eighty-seven testes were investigated in 77 patients. Of these, 36% had no testes, although in 28% evidence of a vas was found. In those testes which were found, surgery was performed, either orchidopexy or, if positioned high, microsurgery. Orchidectomy was rarely carried out (5 testes only).     

Laminin, type IV collagen, and fibronectin in normal and cryptorchid human testes. An immunohistochemical study

An immunohistochemical study of laminin, type IV collagen, and fibronectin was carried out in the testes of normal men and in the cryptorchid and contralateral scrotal testes of cryptorchid men from 2 to 40 years of age. The integrated optical density (IOD) per unit area of the lamina propria was measured in the immunostained sections. Fibronectin was found throughout the thickness of the lamina propria of the seminiferous tubules and in the interstitial connective tissue. No differences between normal and cryptorchid testes were found. Laminin was observed in the innermost part of the lamina propria of the seminiferous tubules and surrounding the endothelium of blood capillaries from infancy. No differences were found between normal and cryptorchid testes in the prepubertal period. In adult cryptorchid testes, laminin formed more numerous and deeper invaginations towards the seminiferous epithelium than in normal adult testes. Type IV collagen appeared throughout the thickness of the lamina propria of normal testes as well as in the wall of interstitial blood vessels. From infancy, the lamina propria of seminiferous tubules, but not blood vessel walls, showed lesser immunostaining for type IV collagen and a lower IOD of this component than did control tests from men of the same age. No differences between unilateral and bilateral cryptorchidism were found. The contralateral scrotal testes of cryptorchid males showed intermediate immunostaining for type IV collagen between that of normal control testes and that of cryptorchid testes. These findings suggest that the lamina propria of seminiferous tubules is lesioned at an early age in both cryptorchid and contralateral scrotal testes of cryptorchid men.     

Testicular focal atrophy – tubular blockade as partial degeneration of the tubule

This study investigated whether focal atrophy is a degenerative process of a whole tubule or tubular blockade as partial intratesticular degeneration. Serial section analyses of testicular tissue from 19 men with different andrologic diseases were examined. From every fifth section of any series, defined areas were viewed under a light microscope, and tubule sections were drawn. Three-dimensional reconstructions were made from these materials. Reconstructions of the seminiferous tubules showed tubular blockade as partial degeneration of the tubules. Transition from an intact portion to a blockade was accompanied by an increase in the thickness of the lamina propria. The blockade was a cell cord that contained Sertoli cells and, at most, spermatogonia, or it was a completely atrophied tubule, a so-called tubular scar. In a given tubule, defined areas of atrophy and areas of spermatogenic activity were both found. Occurrence of tubular blockade increased with age. Serial section analyses of testicular tissue showed tubular blockade as the partial degeneration of seminiferous tubules. In focal atrophy, a given tubule can have defined areas of atrophy and areas of spermatogenic activity. Received: 25 August 1999 / Accepted: 21 April 2000     

Local regulation of Leydig cells by the seminiferous tubules. Effect of short-term cryptorchidism

Unilateral cryptorchism was induced in adult rats for 24 h, and its effect on testicular morphology and intratesticular testosterone concentration after hCG-stimulation were studied. In seminiferous, tubules from abdominal testes an increased number of degenerating germ cells was noted in stages XIV-III of the spermatogenic cycle and Sertoli cells contained an increased amount of lipid droplets in stages XIV-VIII. However, germ cells and Sertoli cells from tubules at other stages of the cycle appeared unaffected. In scrotal testes the size of peritubular Leydig cells varied in phase with the spermatogenic cycle. The largest cells were found adjacent to stage VII-VIII and the smallest adjacent to stage XI-XII. In abdominal testes no stage-dependent variation in the size of peritubular Leydig cells was seen. Perivascular Leydig cells were of equal size in abdominal and scrotal testes. The testicular testosterone concentration following stimulation with a low dose of hCG was significantly lower in abdominal testes. It is suggested that the seminiferous tubules locally modulate Leydig cell function and that the stage specific stimulatory influence from stage VII-VIII is rapidly lost during experimental cryptorchidism.     

神经肽Y在大鼠睾丸内的表达及其意义

目的 :分析神经肽Y(NPY)在大鼠睾丸中的表达 ,探讨NPY在雄激素生成和精子发生中的作用。　方法 :用RT PCR半定量法分析SD雄性大鼠睾丸中的NPYmRNA的表达 ,以β actin为内参照。用免疫组化法观察NPY在组织和细胞内的分布。　结果 :NPY基因在大鼠睾丸中有相当水平的表达 ,在PCR产物电泳图谱中见到明显的基因扩增产物条带 ;免疫组化显示 ,NPY在睾丸间质区、睾丸小血管周围及其精曲小管周围阳性表达 ,而在精曲小管内未见表达。　结论 :睾丸内表达的NPY可能直接参与了睾丸功能的调节。     

Two cases of 46,XX male with chief complaint of infertility

We report two cases of XX male with chief complaints of infertility. Physical examination of both patients aged 42 and 29 demonstrated normal male habitus except for small testes. Semen analyses demonstrated no spermatozoa. Endocrinological examinations showed hypergonadotrophic hypogonadism. Vesiculograms demonstrated normal seminal tracts. Histological examination of their testes did not reveal germ cells; one case lacked seminiferous tubules and there was hyalinization in the seminiferous tubule in another case. Chromosomal analyses of peripheral blood demonstrated 46,XX. The sex-determining region Y gene was positive and DAZ (deleted in azoospermia) gene was negative in both cases.     

Laminin and type IV collagen in the human testis

Specimens of normal human testis and biopsies from testes with Sertoli-cell-only syndrome in which the seminiferous tubules had a remarkably thickened lamina propria, were investigated immunohistochemically using specific antibodies against human laminin and human type IV collagen. In the normal testis, both laminin and type IV collagen were localized to the epithelial basement membranes and the peritubular cell layers. In addition, laminin was found in the Sertoli cells. In the pathological testis, structures representing invaginations of the tubular basement membrane were positive for both laminin and type IV collagen. The presence of laminin and type IV collagen in the myoid cell layers, and laminin in the Sertoli cells from both normal and pathological testis and its indication for the secretion of these substances by the myoid and Sertoli cells is discussed.     

Pattern of Sertoli cell degeneration in cryptorchid prepubertal tests

Seventy-three testicular biopsies from 54 children (aged 2 months-14 years) with undescended testes were examined by light and electron microscopy. The biopsies included abdominal, inguinally fixed, inguinally moveable, and retractile testes. Alterations in Sertoli cell morphology were found in all biopsies. The alterations included dilated elements of rough endoplasmic reticulum, vacuolization of the cytoplasm, mitochondria with poorly preserved cristae, increase in electron density of the matrix, elongation of the nuclei, and irregularities of the nuclear membrane. According to the numerical appearance of these cells and to the extent of lesions in single Sertoli cells, seven phases in the continuous process of tubular alteration were distinguished. The most severe tubular damaged (phase VII) occurred when the seminiferous epithelium consisted exclusively of necrotic cells. All phases of tubular alterations were seen regularly in each of the biopsies investigated. Germ cells occurred only in phases I-IV and were never observed in tubules in phases V-VII. Significant differences became evident between inguinal and retractile testes by morphometric evaluation. It was demonstrated that the number of germ cells per cross-sectioned tubule (S/T value) correlated negatively with the percentage of tubules in phases V-VII. In contrast to inguinal testes, a complete absence of Sertoli cells and an S/T value less than 0.1 were never found in retractile testes and the percentage of tubules in phases V-VII was reduced significantly compared with inguinal testes. Our findings indicate that (i) maldescended testis in patients between 1 and 15 years-of-age is associated with a special pattern of Sertoli cell degeneration; (ii) Sertoli cell degeneration is a continuous process, which can lead eventually to complete dissolution of the seminiferous epithelium; (iii) total degeneration is not related to age but is dependent on testicular position; (iv) a defined phase of degeneration excludes germ cell development, and therefore enhanced Sertoli cell degeneration in cryptorchid testes must also account for the reduction in germ cell number.     

Ultrastructural studies of tubules, analogous to skeletal cell T-tubules, in alveolar soft part sarcoma

Tumor tissues from six patients with alveolar soft part sarcoma (ASPS) were investigated ultrastructurally to determine the presence of smooth tubules associated with plasmalemmal invaginations. Two different types of smooth tubular structures were identified: an aggregated and a dispersed type. The aggregated type (found in one of the six ASPSs) showed marked aggregation of many elongated smooth tubules without ribosomes associated with the plasmalemma. In the dispersed type (observed in the remaining five ASPSs), there was a conspicious appearance of a few smooth tubules scattered throughout the cytoplasm. Smooth tubules were the main component in both types, suggesting that both types appeared to have the same origin, although there were some differences in number, appearance, and distribution of the tubules between the two types. The smooth tubules in both types were classified into three different subtypes on the basis of materials in the tubular lumen. Ultrastructual observation and a plasmalemmal tracer-method, showed smooth tubules in continuity with the plasmalemma in three of the six cases, indicating that the tubules originated from the plasmalemma. Since the tubular structures were found in the tumor tissues of all six patients, they are probably one of the characteristic features of ASPS. Received for publication on Aug. 21, 1997; accepted on Dec. 4, 1997     

Mast cells and fibrosis on testicular biopsies in male infertility

Testicular dysfunction correlates with increased testicular mast cells. Mast cells can activate fibroblasts and promote collagen synthesis. The aim of the study was to examine testicular mast cells containing tryptase, and the relationship between mast cells and different fibrosis stages of interstitium and peritubular region of testes. Testicular biopsies obtained from 33 infertile men were assigned to 2 groups: normal spermatogenesis (n = 10) and defective spermatogenesis (n = 23). Total, interstitial, and peritubular mast cells were examined immunohistochemically using antihuman tryptase. The fibrosis stage was evaluated using vimentin and alpha-smooth muscle actin. The ratio of tubules with sclerosis to total tubules was also calculated. In all cases, mast cells were mainly localized in the interstitium. The number of total mast cells was significantly higher in defective spermatogenesis than in normal spermatogenesis (p = .048). In both groups, interstitial mast cells were higher than peritubular mast cells. However, the increase in peritubular region was much higher than the increase in interstitium. Total, peritubular, and interstitial mast cell counts were not different from each other, according to the changing fibrosis stages. Total and interstitial mast cells were significantly higher in the cases with sclerosing seminiferous tubules than in the cases with no sclerosis (p = .04 and p = .024, respectively). The mast cells and the mast cell product tryptase could be involved in the etiology of defective spermatogenesis, especially whenever the last stage (tubular hyalinization and sclerosis) takes place.     

Quantification of germ cells and seminiferous tubules by stereological examination of testicles from 50 boys who suffered from sudden death

A stereological study of the development of testicular volume, the germ cell population and the seminiferous tubules was carried out on testes from 50 boys between 0 and 18 years of age who had suffered from sudden unexpected death. Semi-thin sections (0.5 μm) of testicular tissue were prepared and examined by point and profile counting using a projection microscope. Testicular weight was recorded in 48 of the cases. Median volume of pairs of testes increased from 1.1 (range 0.3–1.9) to 3.0 cm³ (range 2.8–3.4) during the 0–10 year period, while the median of the total number of germ ceils per boy was augmented from 13 times 10⁶ (range 4.4–36 times 10⁶) to 83 times 10⁶ (range 32–122 times 10⁶) during the same period. The median length of the seminiferous tubules per boy was 181 m (range 27–361) in the 0–1 year period and 411 m (range 277–660) in the group 5–10 years. Mean tubular diameter was unchanged during the first 10 years of life, whereas the mean nuclear diameter of the germ cells showed significant negative correlation to age in boys less than 10 years. After the age of 10 years a more marked growth of testicular volume, an increase in the number of germ cells and the diameter as well as the length of the seminiferous tubules were observed. Thus, the study showed that testicular size, the number of germ cells and the total length of the seminiferous tubules per boy increased not only in puberty but also during the first ten years of life.     

肾小管坏死后修复与胚胎发育过程中细胞极性形成的比较

目的:细胞极性是肾小管上皮细胞发挥生理功能的结构基础。本研究的目的是明确成体大鼠肾小管坏死后修复过程中与胚胎大鼠肾小管发育过程中细胞极性形成过程的一致性。方法:通过皮下注射硫酸庆大霉素制作出生后8周雄性Wistar大鼠急性肾小管坏死后自然修复的动物模型,分别在注射庆大霉素后第7天(用药5d,停药2d)、第14天和第28天采集肾脏标本;另外采集妊娠20d大鼠的胚胎肾脏标本。观察成体大鼠肾小管坏死后修复再生过程中与胚胎大鼠肾小管发育过程中肾小管的形态学变化;以Na+-K+-ATP酶作为细胞极性的标志物,采用免疫荧光染色技术对比观察成体大鼠肾小管坏死后修复再生过程中与胚胎大鼠肾小管发育过程中细胞极性形成的过程。结果:(1)成体大鼠注射庆大霉素后第7天,肾小管上皮细胞坏死、脱落,肾小管基底膜裸露,管腔内有大量脱落的上皮细胞碎片;第14天,肾小管基底膜出现新再生的肾小管上皮细胞;第28天,大多数肾小管结构基本恢复正常。(2)成体大鼠注射庆大霉素后第7天,裸露的肾小管基底膜没有Na+-K+-ATP酶的表达;第14天,新再生的肾小管上皮细胞有Na+-K+-ATP酶的表达,但此时Na+-K+-ATP酶没有明显的极性分布,胞膜和胞浆均有表达;第28天,Na+-K+-ATP酶呈极性分布,主要表达在肾小管上皮细胞的侧基底膜。(3)胚胎大鼠肾小管发育过程是从S形体发育成为不成熟的肾小管,再发育成为成熟的肾小管。(4)胚胎大鼠肾小管发育过程中,Na+-K+-ATP酶的表达从没有极性到有极性分布,即Na+-K+-ATP酶从肾小管上皮细胞的胞膜和胞浆均有表达到只局限在侧基底膜表达。结论:成体大鼠肾小管坏死后修复过程中细胞极性形成的过程与胚胎大鼠肾小管发育过程中细胞极性形成的过程是一致的,提示大鼠肾小管坏死后修复再生的过程类似肾小管胚胎发育的过程。     

Changes in the volume and histology of retractile testes in prepubertal boys

Testicular development was studied in prepubertal boys with retractile testes. Testicular volume, the diameter of the seminiferous tubules and the number of spermatogonia in the tubules were decreased in cases of unilateral retractile testis, when compared with values for the contralateral normally descended testis. On the other hand, in patients with a unilateral retractile testis and contralateral inguinal testis, there was no difference in the developmental parameters between the two testes. These results suggest that the retractile testis has developmental failures characteristic of a cryptorchid testis and therefore requires orchiopexy.     

Histological and Morphometric Studies in Undescended Testes

The histological pattern, volumetric fractions (VF) of tubular and interstitial tissue and the germinal cells, and the mean tubular diameter (MTD) were studied in 175 biopsies from 134 boys aged 3.5–16.9 years with unilateral or bilateral undescended testes. The findings were compared to those obtained in autopsy material from 67 normal boys aged 0.3–20.6 years. In both groups, the qualitative histological pattern was similar to the findings in other reports. In the normal material, VF of spermatogonia A was relatively stable whereas VF of the total spermatogenesis increased sharply after 10 years of age. In the patients, the mean values of both these variables were markedly decreased in all age groups. VF of tubular tissue and the ratio VF tubular/VF interstitial tissue were relatively stable in childhood and increased after 10 years of age both in the patients and in the normal group. In patients aged 3.5–7.9 years, the testicular volume and the volume of tubular tissue per testis were decreased. The MTD of undescended testes was decreased in patients aged 3.5–5.9 years and over 10 years of age. None of the variables investigated showed significant differences between cases with high (intraabdominal and canalicular) and low retention. The results indicated that impairment of the germinal and Sertoli cell lines were usually present in retained testes after 3.5 years of age. The normal maturational changes of tubular and interstital tissues were retarded or absent in pubertal cryptorchids.     

A morphological study of the testes in patients with idiopathic male infertility--immunohistochemical analysis of collagens and laminin in human testes

In the human testis, the distribution of extracellular components, such as types I, III, IV and V collagens and laminin, was investigated immunohistochemically by light microscopy. Specimens were obtained by testicular biopsy from 40 patients with idiopathic male infertility and 14 normal adult males. In the normal testes, the basement membrane was positive for types I, III, IV and V collagens and laminin. However, the distribution patterns of these components were different. Furthermore, a reactivity for types I and III collagens was found in the interstitial connective tissue matrix. Immunoreactivity for types I and III collagens was markedly positive in the limiting membranes around the Leydig cells. In the pathological testes, all the layers of the basement membrane of both thickened and obstructed tubules were positive for types I and III collagens. On the other hand, reaction products of type IV collagen were localized in the inner layer of the basement membrane and the peritubular cell (myoid cell) layer, and those of laminin were only found in the inner layer. Type V collagen-reactivity was observed in the basement membrane of thickened tubules. Positive reactions for types IV and V collagens and laminin were seldom recognized in the obstructed tubules. In the interstitial space, the connective tissues were significantly increased as compared with normal testes, which included extracellular components that reacted for types I and III collagens. Histological findings in normal adult testes and pathological testes were compared. Quantitative analysis of mean thickness of the basement membrane (W), mean seminiferous tubular diameter (T), T/W ratio and Leydig cell index demonstrated significant differences between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)