Die Lamina propria der Hodenkanälchen von Wirbeltieren: Eine vergleichende licht- und elektronenmikroskopische Untersuchung: The lamina propria of vertebrate seminiferous tubules: A comparative light and electron microscopic investigation

The lamina propria of the seminiferous tubules was compared by means of light and electron microscopy in specimens obtained from the following vertebrates: Mute swan, northern mallard, blackbird, grey short-tailed opossum, north american opossum, european rabbit, mouse, rat, golden hamster, mini pig, bull, llama, roebuck, horse, coati, cat, dog, java monkey, orang utan. The lamina propria consists of basal lamina, ground substance, collagen fibers, fibroblasts and myofibroblasts. Myofibroblasts are characterized by myofilaments, dense patches and a basal lamina covering their plasmalemma. The layers of myofibroblasts always lie adjacent to the germinal epithelium, while the surrounding fibroblast layers are located peripherally.     

Lamina propria: The connective tissue of rat urinary bladder mucosa

To describe and illustrate the structure of the propria, the bladder of adult rats was fixed in controlled conditions of distension and examined by light and electron microscopy. The lamina propria, ~50 µm thick in the distended bladder, consists of a superficial part (the cellular component), adjacent to the urothelium, rich in nerves, capillaries, fibroblasts and thin bundles of collagen, and a deep, thicker part (the fibrous component), adjacent to the detrusor, rich in large collagen fibres and with few fibroblasts. In the cellular part there is an extensive plexus of afferent nerve fibers and a dense capillary network (with numerous pericytes), lying close to the urothelium, that is unique to the bladder. The main resident cells are fibroblasts, adhering to each other at the end of laminar extensions without forming specialized junctions. The deep part of the lamina propria is made of thick collagen fibers, interwoven and crisscrossing each other, with a few fibroblasts in the interstitial spaces between them. In summary, the superficial part of the lamina propria has most of the bladder afferent nerves, contains many fibroblasts and has a network of suburothelial capillaries. The deep part as a whole forms an ovoid balloon of woven fibrous material that is acted upon by the detrusor musculature attached to its outer surface. The lamina propria is a strong fibrous barrier between urothelium and musculature. The abundance of collagen points to the main role for its fibroblasts, that is, the production of collagen fibrils, assisting the mechanical role of the lamina propria.     

Quantitative and ultrastructural alterations in the lamina propria and Sertoli cells in human cryptorchid testes

A quantitative and ultrastructural study was performed on biopsies of human cryptorchid testes to investigate lesions in the lamina propria and Sertoli cells. Prepubertal cryptorchid testes (1-9 years of age) were classified into four groups: Type 1, testes with minimal lesions; Type II, testes with a moderate decrease in tubule diameter and spermatogonal number; Type III, testes with Sertoli cell hypoplasia and a marked reduction in tubule diameter and spermatogonal number; and Type IV, testes with Sertoli cell hyperplasia and a variable reduction in spermatogonal number. An increase in thickness of the lamina propria was found in Type II and III testes from 5 years of age onwards. These testes also showed a decrease in both the average number of peritubular cells per cross-sectioned tubule and in the average nuclear volume of these cells. Most of the postpubertal cryptorchid testes from 13- to 18-year-old youths presented a prepubertal pattern suggestive of delayed testicular maturation. Postpubertal testes from 19- to 27-year-old men were classified into three types: Type A testes showed complete spermatogenesis, mature Sertoli cells and no lesions in the lamina propria; Type B testes showed isolated spermatogonia, mature Sertoli cells, and a marked thickening of the lamina propria; and Type C testes showed isolated spermatogonia, hyperplasia of immature Sertoli cells, and a slightly thickened lamina propria. Maturation of the lamina propria was always associated with maturation of the Sertoli cells. Thickening of the lamina propria was associated with peritubular cell alterations consisting of decreases in the nuclear volume (average and total per testis) of peritubular cells and increases in the number of these cells per cross-sectioned tubule. The three types of adult cryptorchid testes appear to be the postpubertal transformation of Type 1 testes (Type A), Type II and Type III testes (Type B), and Type IV testes (Type C).     

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.     

Electron microscopic evidence for deep invaginations of the lamina propria towards the seminiferous tubule lumen in a patient with varicocele

Ultrastructural studies on biopsy tissue from the right testis of a 39-year old patient with varicocele revealed 2.5-5 microns thick invaginations of the lamina propria towards the lumen of the seminiferous tubules. These invaginations were of various lengths. The presence of invaginations was confirmed through examination of serial semi-thin sections. In some seminiferous tubules two neighbouring deep invaginations were joined together thus completely encircling and thereby separating the basal compartment, and in some cases even the adluminal compartment, of the seminiferous tubule. The invaginations were surrounded continuously by the basement membrane and contained collagen fibres, cell processes of myoid cells and in some cases also their nuclei.     

Distribution of elastic fiber types in the epiphyseal region

Three types of elastic fibers have been described: mature elastic fibers, elaunin fibers, and oxytalan fibers. To our knowledge, their location in the immature epiphysis has never been previously reported. The aim of the present study was to use histochemistry, immunohistochemistry, and electron microscopy to demonstrate the distribution of each type of elastic fiber in the epiphyseal region of growing humans and rabbits. Histological samples were collected from the knees of 10 immature New Zealand White rabbits and four children of various ages. The Weigert resorcin-fuchsin, Gomori aldehyde-fuchsin, Verhoeff iron haematoxylin, and Fullmer-Lillie methods were used for histochemistry; anti-elastin monoclonal antibodies, for immunohistochemistry; and tannic acid, uranyl acetate, and lead citrate stain, for transmission electron microscopy analysis. Elastic fibers were detected in the perichondrium, the epiphyseal vessels, and the outer and middle zones of Ranvier's groove. Their orientation was longitudinal in the outer zone and circumferential in the middle zone of the groove. Oxytalan fibrils (i.e., bundles of filaments of 10–12 nm in diameter that do not contain elastin) and elaunin fibers (i.e., filaments that cross discontinuous aggregates of elastin) were more plentiful in the middle zone and decreased with age, whereas mature fibers were more numerous in the outer zone and increased with age. This organization of elastic fibers seems to indicate an age-related process of maturation of the elastic network. The contribution of these fibers to the mechanical properties of the epiphyseal plate and to the growth process remains to be determined.     

阳萎患者阴茎海绵体平滑肌细胞超微结构的研究

阴茎海绵体平滑肌细胞超微结构的改变对阴茎勃起功能具有重要的意义。以阳萎患者与对照组对比研究的方法，观察了阳萎患者阴茎海绵体组织细胞超微结构改变。结果表明，阳萎阴茎海绵体平滑肌细胞超微结构有明显的病理改变，以线粒体退变、微丝减少或消失、内质网损害扩张、糖原缺乏等为主，也可见到微血管腔闭塞的现象，提示局部有微循环障碍的问题。引起这种病理损害的原因可能与局部组织缺血缺氧有关。认为海绵体组织的这种病理改变可能是引起阳萎的直接因素之一。     

Ultrastructural analysis of human penile corpus cavernosum Its significance in tumescence and detumescence

The erectile tissue from 15 normal and impotent male patients was studied by electron microscopy to determine if any ultrastructural features could contribute to the basic understanding of the physiology of penile erection and detumescence. It was found that the endothelium lining the cavernous lacunae contained both contractile elements and Weibel-Palade bodies which have a possible role in vasoconstriction. Within the trabeculae of the cavernous body there was an abundance of elastin as well as oxytalan and elaunin fibers around bundles of smooth muscle. With these elements affording an anchorage system for contraction of smooth muscles within the trabeculae, an alternate contraction of smooth muscles and endothelium could account for the erectile and detumescent states.     

主动脉夹层患者升主动脉中层弹性蛋白与弹力纤维的变化

目的:探讨Stanford A型主动脉夹层(AD)升主动脉中层弹性蛋白和弹力纤维变化。方法:收集10例Stanford A型AD患者术中获取的升主动脉管壁组织标本与10例脑死亡捐献手术中或冠状动脉旁路移植术中获取的正常升主动脉管壁组织标本,用Westernblot法检测两组标本中膜层弹性蛋白表达;用EVG弹力纤维染色分析两组升主动脉中膜层弹力纤维形态及含量。结果:Westernblot结果显示,AD升主动脉中膜层弹性蛋白含量较正常升主动脉明显降低[(0.32±0.07)vs.(1.12±0.17),t=6.722,P=0.003]。EVG染色结果显示,AD升主动脉中膜层弹力纤维形态和排列紊乱,弹力板层断裂、丢失,而正常升主动脉中膜弹力纤维排列紧密、有序,弹力板结构完整,层次分明;AD升主动脉中膜层弹力纤维含量较正常升主动脉明显降低[(85762.8±106.2)vs.(164482.8±161.4),t=5.902,P0.001]。弹性蛋白与弹力纤维含量在AD与正常升主动脉中膜层均呈明显正相关(r=0.953、0.973,均P0.001)。结论:StanfordA型AD患者升主动脉中层弹性蛋白和弹力纤维含量下降,弹力纤维形态和结构紊乱,该改变可能在AD的发生中起了重要作用。     

The fine structure of intraepithelial free nerve endings in the canine vocal cord mucosa

Innervation of the epithelium on the undersurface of the canine vocal cords was investigated by transmission electron microscopy. In the subepithelial lamina propria, nerve bundles containing unmyelinated fibers were observed. The nerve bundles, encircled by basal lamina, were enclosed by a thin connective tissue layer and by flattened fibroblast-like cells. With nerve bundles approaching the epithelium, the axons divided repeatedly and entered the epithelial layer. In the epithelial cells, nerve axons formed knob-like swellings that contained a small number of large granular vesicles and a large number of small agranular vesicles. A sensory function responsive to irritant chemical stimuli and to mechanical stimuli is presumed for these vesicle-containing nerve processes.     

3D‐electron microscopic characterization of interstitial cells in the human bladder upper lamina propria

Aims

To explore the ultrastructure of interstitial cells in the upper lamina propria of the human bladder, to describe the spatial relationships and to investigate cell‐cell contacts.

Methods

Focused ion beam scanning electron microscopy (FIB‐SEM), 3‐View SEM and confocal laser scanning microscopy were used to analyze the 3D ultrastructure of the upper lamina propria in male and female human bladders.

Results

3View‐SEM image stacks as large as 59 × 59 × 17 μm³ (xyz) at a resolution of 16 × 16 × 50 nm³ and high resolution (5 × 5 × 10 nm³) FIB‐SEM stacks could be analyzed. Interstitial cells with myoid differentiation (mIC) and fibroblast like interstitial cells (fIC) were the major cell types in the upper lamina propria. The flat, sheet‐like ICs were oriented strictly parallel to the urothelium. No spindle shaped cells were present. We furthermore identified one branched cell (bIC) with several processes contacting urothelial cells by penetrating the basal membrane. This cell did not make any contacts to other ICs within the upper lamina propria. We found no evidence for the occurrence of telocytes in the upper lamina propria.

Conclusions

Comprehensive 3D‐ultrastructural analysis of the human bladder confirmed distinct subtypes of interstitial cells. We provide evidence for a foremost unknown direct connection between a branched interstitial cell and urothelial cells of which the functional role has still to be elucidated. 3D‐ultrastructure analyses at high resolution are needed to further define the subpopulations of lamina propria cells and cell‐cell interactions.     

Changes in elastin density in different locations of the vaginal wall in women with pelvic organ prolapse

Introduction and hypothesis

The purpose of this study was to analyze the histomorphometric properties of the vaginal wall in women with pelvic organ prolapse (POP).

Methods

In 15 women undergoing surgery for POP, full-thickness biopsies were collected at two different sites of location from the anterior and/or posterior vaginal wall. Properties of the precervical area (POP-Q point C/D) were compared with the most distal portion of the vaginal wall (POP-Q point Ba/Bp) using histological staining and immunohistochemistry. The densities of total collagen fibers, elastic fibers, smooth muscle cells, and blood vessels were determined by combining high-resolution virtual imaging and computer-assisted digital image analysis.

Results

The mean elastin density was significantly decreased in the lamina propria and muscularis layer of the vaginal wall from the most distal portion of the prolapsed vaginal wall compared with the precervical area. This difference was statistically significant in the lamina propria for both anterior (8.4?±?1.2 and 12.1?±?2.0, p?=?0.048) and posterior (6.8?±?0.5 and 10.1?±?1.4, p?=?0.040) locations, and in the muscularis for the anterior (5.2?±?0.4 and 8.4?±?1.2, p?=?0.009) vaginal wall. There were no statistically significant differences in the mean densities of collagen fibers, smooth muscle cells or blood vessels between the two locations.

Conclusions

In this study, we observed changes in elastin density in two different locations of the vaginal wall from women with POP. The histomorphometric properties of the vaginal wall can be variable from one place to another in the same patient. This result supports the existence of most vulnerable locations within the vaginal wall and the potential benefit of site-specific prolapse surgery.     

Collagen and elastic fibers in the penis of human fetuses at 28 weeks postconception.

OBJECTIVES: The extracellular matrix is a key element in penile function and pathology, yet little is known of its development. Herein we investigated the morphological organization of collagen and elastin in the corpora cavernosa and tunica albuginea of human fetuses. MATERIAL AND METHODS: The penises from 5 fresh human fetuses at 28 weeks postconception (WPC) were routinely fixed and embedded, and all staining procedures were carried out on paraffin sections. Collagen was evidenced by staining with: (1) Gomori's trichrome; (2) sirius red, followed by observation under polarized light, and (3) an antihuman collagen type-III antibody. Elastin and the whole elastic system were revealed using an antihuman elastin antibody and Weigert's resorcin fucsin, respectively. RESULTS: At this stage of fetal development, the albuginea is formed predominantly by dense bundles of collagen. Near the corpora cavernosa, the presence of type-III collagen was also observed. Weigert staining showed numerous fibers of the elastic system in the albuginea. Type-III collagen was found to be strongly positive in the cavernous trabeculae and in the connective sheath surrounding the central artery. Using Weigert staining and an immunolabeling method with primary antibody against human elastin, we found an important quantity of elastic system fibers in the trabeculae of the corpora cavernosa. CONCLUSION: In fetuses at 28 WPC the albuginea is formed predominantly by dense bundles of collagen. The trabecular structures of the corpora cavernosa present a significant quantity of type-III collagen and elastic system fibers.     

Elastic fibers in tunica propria of undescended and contralateral scrotal testes from cryptorchid patients

Elastic fibers in the tunica propria of the testes from cryptorchid patients and normal fertile adults were examined by light (Weigert resorcin-fuchsin stain) and electron microscopic techniques. In the testes from normal fertile adults, elastic fibers were proved to exist in the tunica propria by light and electron microscopy, and were located in the fibrous and cellular layers of the tunica propria. In the undescended testes from the cryptorchid patients, during prepubertal and pubertal periods, elastic fibers could not be visualized in the tunica propria, but were found after puberty. The positive Weigert reaction of the tunica propria in the undescended testes from postpubertal cryptorchid patients, however, was markedly weaker than that in normal control patients, suggesting diminution of elastic fibers. This diminution of elastic fibers in the undescended testes from postpubertal cryptorchid patients was also substantiated by electron microscopy. However, in the contralateral scrotal testes, elastic fibers appeared during puberty and were observed after puberty in the same manner as in normal testes. Thus, the present study suggested retarded appearance of elastic fibers in puberty and impaired development of those fibers after puberty, in the undescended testes of cryptorchid patients.     

Kit-positive interstitial cells in the rabbit urethra: structural relationships with nerves and smooth muscle

OBJECTIVE: To identify interstitial cells (ICs) in the wall of the rabbit urethra using antibodies to the Kit receptor, and to examine their location, morphology and relationship with nerves and smooth muscle cells (SMCs), as studies of enzymatically isolated cells from the rabbit urethra have established that there are specialized cells that show spontaneous electrical activity and have morphological properties of ICs. MATERIALS AND METHODS: Urethral tissues from rabbits were fixed, labelled with antibodies and examined with confocal microscopy. Some specimens were embedded in paraffin wax and processed for histology. Histological sections from the most proximal third and mid-third region of rabbit urethra were stained with Masson's Trichrome to show their cellular arrangement. RESULTS: Sections from both regions had outer longitudinal and inner circular layers of SM, and a lamina propria containing connective tissue and blood vessels; the lumen was lined with urothelial cells. The mid-third region had a more developed circular SM layer than the most-proximal samples, and had extensive inner longitudinal SM bundles in the lamina propria. Labelling with anti-Kit revealed immunopositive cells within the wall of the rabbit urethra, in the circular and longitudinal layers of the muscularis. Double-labelling with an antibody to SM myosin showed Kit-positive cells on the boundary of the SM bundles, orientated parallel to the axis of the bundles. Others were in spaces between the bundles and often made contact with each other. Kit-positive cells were either elongated, with several lateral branches, or stellate with branches coming from a central soma. Similar cells could be labelled with vimentin antibodies. Their relationship with intramural nerves was examined by double immunostaining with an anti-neurofilament antibody. There were frequent points of contact between Kit-positive cells and nerves, with similar findings in specimens double-immunostained with anti-neuronal nitric oxide synthase (nNOS). CONCLUSION: Kit-positive ICs were found within the SM layers of the rabbit urethra, in association with nerves, on the edge of SM bundles and in the interbundle spaces. The contact with nNOS-containing neurones might imply participation in the nitrergic inhibitory neurotransmission of the urethra.     

Immunohistochemical analysis of the human bladder

An immunohistochemical profile of cells in the mucosa and lamina propria of adult human bladders is described. Urothelial cells were HLA-DR-ve, ACP + ve and ATPase-ve. All lymphocytes in this layer were of the suppressor/cytotoxic T subgroup and dendritic cells with an identical phenotype to Langerhans cells were seen. In the lamina propria most lymphocytes were of the suppressor/cytotoxic type with some helper/inducer cells. An occasional natural killer cell and Langerhans cell was identified and large macrophage cells with a common phenotype to antigen presenting interdigitating (ID) cells were noted. Fibronectin staining was dense in the vicinity of basement membranes merging to form fine interconnecting latticework-like structures elsewhere in the lamina propria.     

Steroid metabolism and morphologic features of the human testis

Serum FSH, LH, and testosterone were studied in 114 infertile men with poor sperm production. Testicular biopsies were taken and classified morphologically. In 90 specimens, the pattern of conversion of progesterone was determined in vitro and expressed as the ratio of 20 alpha-hydroxy-4-pregnene-3-one to 17 alpha-hydroxyprogesterone. An excess of the former metabolite indicates a prepubertal type of steroid metabolism. The normal limit of this ratio is given. The collected data indicate that the prepubertal type of steroid metabolic pattern is related to the thickness of the lamina propria of the seminiferous tubules only, and not to peripheral hormone levels. In particular, the presence of hyaline deposits in the lamina propria seems to determine the metabolic pattern. It is suggested that the character of the lamina propria separating the tubular and interstitial compartments of the testis is of crucial importance for the functional interrelationship between these compartments. This supports the concept of an intratesticular regulatory mechanism of both steroid metabolism and spermatogenesis.     

Pulse granuloma of urinary bladder associated with interstitial cystitis

Pulse granulomas are uncommon, benign foreign body inflammatory reactions that typically occur in the oral cavity. They are exceedingly rare elsewhere. Here we describe a 35-year-old woman who presented with interstitial cystitis and was found to have an incidental bladder mass. Histological examination of the biopsy revealed a pulse granuloma. The salient histopathologic features include corrugated hyaline rings and amorphous hyaline conglomerations within the connective tissue stroma of the lamina propria, admixed with chronic inflammatory cells with multinucleated foreign-body type giant cells. To our knowledge this is the first reported case of a pulse granuloma in the urinary bladder.     

Ultrastructure of the human interspinous ligament and ligamentum flavum. A preliminary study

The ultrastructure of ligamenta flava (LF) and interspinous ligaments (ISL) obtained from four patients who underwent surgery for vertebral fracture (control group) and five patients operated for disc herniation was studied. The fine structure of LF was composed of elastic and elaunin fibers. Small diameter collagen fibrils were found between the elastic system fibers. The ISL was constituted predominantly of collagen fibrils. Elastic fibers were seen in the most ventral part of the ligament. In ISL and LF of the control group, the cells were fibroblastic-like cells. Chondrocytes were present only near their attachment sites. The proteoglycans were demonstrated between the collagen fibrils, and they appeared to form a regular interfibrillar linking. In ligaments obtained from patients with disc herniation, several modifications were found. The fibroblasts transformed into chondrocytic cells, which were surrounded by a pericellular matrix rich in proteoglycan filaments. A few cells that had suffered necrosis were found. Alterations in the collagen-proteoglycans arrangement also were evidenced. The proteoglycan filaments were randomly oriented to the collagen fibrils.     

The role of the human bladder lamina propria myofibroblast

OBJECTIVES: To describe the ultrastructure and relationship to nerves of the myofibroblast in the human bladder lamina propria, and discuss its possible role in bladder function, including sensing stretch, as the response of the bladder to stretch has been thoroughly investigated by afferent nerve recordings, but specialized stretch sensing organs have yet to be identified. MATERIALS AND METHODS: Flexible cystoscopic bladder biopsies were obtained from patients with detrusor hyper-reflexia and from controls. Systematic electron micrographs were obtained throughout the lamina propria, and the presence and location of cells with ultrastructural characteristics of myofibroblasts noted, together with their relation to surrounding nerves. RESULTS: Within the lamina propria there was a layer of cells with the cytological characteristics of both fibroblasts and smooth muscle cells, that included bundles of fine cytoplasmic filaments, dense bodies, linear arrays of subsurface vacuoles, and the presence of an interrupted basal lamina. This combination of features is characteristic of the myofibroblast. These cells had close contacts with unmyelinated axonal varicosities containing a mixture of clear and large dense-cored vesicles, or clear vesicles alone. CONCLUSIONS: There is a layer of cells with the ultrastructural characteristics of myofibroblasts within the human bladder lamina propria. Their close contacts with nerves containing both small clear, and small clear with dense-cored, vesicles implies they have both an efferent and an afferent nerve supply, possibly functioning as a bladder stretch receptor. Furthermore, because of their similarities with the interstitial cells of Cajal in the gut, which are claimed to modulate small intestinal function, we discuss other possible roles for bladder lamina propria myofibroblasts.