Morphological analysis of the relation between immunoglobulin A production in the small intestine and the enteric nervous system

To investigate the relation between the enteric nervous system and immunocytes, fecal immunoglobulin (Ig) A and the distribution of IgA-positive cells close to nerve fibers in the lamina propria around the crypts of the small intestine were examined after intraperitoneal injection of lipopolysaccharides (LPS). In mice, IgA in the feces 1 h (LPS1) and 6 h (LPS6) after LPS injection increased compared to that in the control group. In the ileum lamina propria of the LPS1 group, the number of IgA-positive cells close to the epithelial basement membrane was increased. In the LPS6 group, on the other hand, there was a significant increase in the number of IgA-positive cells close to both the basement membrane and the nerve fibers. Our data suggest that LPS induced an increase in the number of IgA-positive cells migrating to the nerve fibers, and that migration to the nerve fibers is as important as migration to the basement membrane for IgA production.     

Basal lamina fenestrations in the human colon: transmission and scanning electron microscope study

Basal lamina at the interface between colonic epithelial cells and the lamina propria was exposed by incubating colonic specimens in 1% boric acid solutions. Examination of this epithelial-stromal interface by scanning electron microscopy (SEM) showed a smooth, slightly undulating basal lamina covering crypts and luminal surfaces. The basal lamina on the luminal surfaces had numerous round or ovoid fenestrations, most measuring 2.5-4.0 microns. These were continuous with channels in the collagen fiber network of the lamina propria. Except very near the surface, no fenestrations were found in the basal lamina lining the crypts. Transmission electron microscopy (TEM) of serial thin sections of colonic mucosa without the epithelial cells removed showed only a few actual basal lamina fenestrations. Rarely, epithelial cell processes extended into the lamina propria through the basal lamina. Most of the fenestrations seen by SEM appeared to correspond spatially by TEM to foci of close contact between the basal lamina and underlying fibroblastic cell processes. At these sites the basal lamina and fibroblastic cell process might be removed along with the overlying epithelial cells during processing with boric acid. These data support functional differences in epithelial-stromal interaction between cell populations lining the luminal surface and those making up the crypt lining and pericryptal fibroblast sheath. The TEM findings demonstrate that the human colonic basal lamina is not absolutely continuous and that the development of basal lamina fenestrations and epithelial cell processes extending into the lamina propria is not pathognomonic of neoplastic transformation and stromal invasion.     

The variable fine structure of elastin visualized with verhoeff's iron hematoxylin

Verhoeff's iron hematoxylin (VIH) followed by lead citrate (LC) applied to epoxy thin sections stained the dense component of elastic fibers heavily and the peripheral microfibrillar component lightly in guinea pig trachea and mouse testis fixed with a glutaraldehyde-osmium tetroxide sequence. This method stained large fimbriated fibers beneath tracheal epithelium, small fibers and stacked aggregates thereof in the deep lamina propria, cartilage and adventitia of the trachea and large stacked fibers in the fibroelastic band of the trachea. Fibers of the fetus differed from those of the adult, especially in the subepithelial elastic lamina of the trachea. Elastic fibers were intimately associated with fibroblasts and particularly slender fibroblast processes in tracheal stroma and with chondrocytes in tracheal cartilage. Fibroblasts associated with elastic fibers in the tracheal subepithelial lamina propria were often closely bordered by eosinophils, mast cells, or monocytes. Occasional mast cells extended slender processes around elastic fibers in the subepithelial lamina propria. In mouse testis and in many regions of the trachea, small elastic fibers were identified which were below the limits of resolution for the light microscope and were not apparent at the ultrastructural level in routinely stained thin sections.     

The variable fine structure of elastin visualized with Verhoeff's iron hematoxylin.

Verhoeff's iron hematoxylin (VIH) followed by lead citrate (LC) applied to epoxy thin sections stained the dense component of elastic fibers heavily and the peripheral microfibrillar component lightly in guinea pig trachea and mouse testis fixed with a glutaraldehyde-osmium tetroxide sequence. This method stained large fimbriated fibers beneath tracheal epithelium, small fibers and stacked aggregates thereof in the deep lamina propria, cartilage and adventitia of the trachea and large stacked fibers in the fibroelastic band of the trachea. Fibers of the fetus differed from those of the adult, especially in the subepithelial elastic lamina of the trachea. Elastic fibers were intimately associated with fibroblasts and particularly slender fibroblast processes in tracheal stroma and with chondrocytes in tracheal cartilage. Fibroblasts associated with elastic fibers in the tracheal subepithelial lamina propria were often closely bordered by eosinophils, mast cells, or monocytes. Occasional mast cells extended slender processes around elastic fibers in the subepithelial lamina propria. In mouse testis and in many regions of the trachea, small elastic fibers were identified which were below the limits of resolution for the light microscope and were not apparent at the ultrastructural level in routinely stained thin sections.     

人空肠NPY能神经分布的研究

本文用免疫组织化学ABC法,对神经肽Y(NPY)能神经纤维和神经元在人空肠壁内的分布进行了研究.结果:NPY能神经纤维和神经元呈棕褐色;NPY能神经纤维遍布肠壁各层,位于粘膜固有层内的神经纤维在小肠腺周围交织或疏网状.NPY能神经元见于肌间及粘膜下神经丛,尤以后者为多.粘膜内也可见NPY能神经元,它们分布于小肠腺下方,紧靠粘膜肌,或位于粘膜肌内.     

大鼠舌组织中肥大细胞与肽能神经纤维的分布

目的探讨舌组织内肥大细胞与肽能神经的关系及其功能意义。方法采用甲苯胺蓝染色和免疫组织化学ABC染色法对10只Wistar大鼠舌组织进行SP、VIP和NPY染色。结果经与甲苯胺蓝邻片对比观察,舌组织内肥大细胞分别呈SP、VIP和NPY免疫反应性;在舌组织固有层及肌间结缔组织中还分布有丰富的SP、VIP和NPY免疫反应阳性纤维;在肽能神经纤维附近或周围可见有免疫反应阳性的肥大细胞,这些肥大细胞与神经纤维紧密相靠或接触。结论 大鼠舌组织内肥大细胞和神经纤维分别呈SP、VIP和NPY免疫反应性,提示肥大细胞与周围神经无论是在形态还是在功能上有着密切的联系。     

Regional differences in the distribution of nerve fibers showing substance P- and calcitonin gene-related peptide-like immunoreactivity in the rat larynx

Summary The distribution of substance P (SP) — and calcitonin gene-related peptide (CGRP) — containing nerve fibers in the rat larynx was studied using immunohistochemistry. Double-labeling studies revealed a high degree of co-existence of SP- and CGRP-like immunoreactivity (LI) in the nerve fibers in the larynx. There was a considerable regional difference in the number of immunoreactive nerve fibers in the epithelium and lamina propria. Richly supplied sites were the laryngeal side of the epiglottis and the ventral recess, whilst there was no evidence of nerve fibers in the squamous epithelium of the vocal cords. However, where the squamous epithelium of the vocal cords changed into a cuboidal epithelium, a moderate number of nerve fibers was present, and a large number of fibers was seen where the squamous epithelium of the cords was in close contact with cartilage. Nerve fibers showing SP- and CGRP-LI were also observed close to the acini and ducts of the glands, in the blood vessel walls, close to the perichondrium of all the cartilages, and outside the cricothyroid and cricoarytenoid joints. CGRP-LI was detected in epithelial cells facing the lumen of the airway and in cells in the acini and ducts of glands in the subglottic region and trachea. Unilateral sympathectomy did not affect the pattern of SP- and CGRP-innervation in the larynx, whereas after vagotomy, the SP- and CGRP-innervation almost disappeared ipsilaterally in the upper parts of the epiglottis and aryepiglottic folds.     

The comparative pathology of the primate colon.

This survey has revealed further close similarities between the pathology of certain colonic diseases in humans and primates. The changes taking place in acute inflammations of varying severity confined to the lamina propria are virtually identical as are those seen in the healing process. In primates chronic inflammatory processes caused by protozoa resemble those in humans very closely. Microherniation of mucosal glands through the muscularis mucosae were found in a wide range of species. Evidence pointed to such herniations playing an important role in the spread of inflammatory diseases from the lamina propria into the submucosa by affording the aetiological agent access through the muscularis mucosae. No case of adenocarcinoma was found in this survey and the cause for the striking difference in incidence of this disease in human and primate colons is discussed.     

Microstructure of the vocal fold in elderly humans

Significant changes in the voice occur after the age of 50 years. Changes in the structure of the vocal fold (VF) can interfere with the voice. The aim of this study is to investigate the structure of the VF of elderly people that may contribute to the tendency of the human voice to deteriorate. Larynges were obtained from eight embalmed cadavers aged 72-98 years. The middle portion of each vocal fold was removed and placed in 4% buffered formalin. Tissue blocks were then processed and embedded in wax. Four to six micron coronal sections were cut and stained with Haematoxylin and Eosin (H&E), Masson's Trichrome (MTS), Elastin van Gieson (EVG), Herovici (HERO), picrosirius and CD31 immunohistochemical marker in order to study the collagen fibers, elastic fibers and microvasculature of the VF. The maturity of collagen fibers within the VF were noted to increase from the superficial to the deep layer of the lamina propria (LP). Contrary to current literature, the amount of elastic fibers was sparse in the superficial layer of the LP in the vocal tissue of elderly cadavers. Numerous cross-sectioned blood vessels were seen in the lamina propria near the free edge, and near the superior and inferior surfaces of the VF. The presence of lymphatic vessels was confirmed in the VF of elderly subjects. This study revealed that the collagenous component of the deep layer of the VF LP was made up of mature fibers whilst immature collagen fibers made up the superficial layer of the LP. There was a notable scarcity of elastic fibers in the superficial layer of the LP. Lymphatics were seen and were orientated differently in the geriatric vocal folds.     

Morphological analysis of the acute effects of overdistension on the extracellular matrix of the rat urinary bladder wall.

PURPOSE: To investigate the morphological effects of acute overdistension in the structure of the extracellular matrix of the bladder wall in rats. MATERIALS AND METHODS: The bladders of a group of 6 male Wistar rats were transurethrally overdistended for 3 hours. Another identical group (the control group) was only submitted to a sham operation. Specimens from the bladder dome were analyzed with light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). RESULTS: LM--The control group bladders had a 4 to 5 layer urothelium, a lamina propria, and a smooth muscle layer with longitudinal and transversal fibers. The overdistended bladders presented an intense interstitial infiltrate in the lamina propria, and a less intense infiltrate among the smooth muscle fibers. TEM--The cells of the overdistended bladders had a significant amount of vacuoles, unlike the control bladders, where such vacuoles were scarce or absent. SEM--A delicate three-dimensional mesh of collagen fibrils was observed in the lamina propria of the bladder walls from the control group. Whilst for the control group this mesh consisted of distinct geometric structures, with mostly circular cellular spaces surrounded by the fibrils, the overdistended group showed evidence of distortion of the mesh, with flattened and elongated cellular spaces. CONCLUSIONS: Acute bladder overdistension induces structural modifications, altering the arrangement and interaction of collagen fibrils, as well as incipient tissue damage as edema in the lamina propria and smooth muscle layers.     

Innervation of the Epithelium and Lamina Propria of the Urethra of the Female Rat

The aim of this study was to characterize the number, type and distribution of immunochemically identified nerves in epithelium and lamina propria of the female rat urethra. Urethras from female Sprague–Dawley rats (n = 12) were fixed, frozen and sectioned (8 μm). Standard immunohistochemical techniques were used to identify putative nerves using the following antibodies: calcitonin gene related peptide (cgrp), neuronal nitric oxide synthase (nNos), tyrosine hydroxylase (TH) and vesicular acetylcholine transporter (vacht). The number, distribution and characteristics of all immunoreactive (IR) structures adjacent to the urethral epithelium and in the lamina propria was assessed. In the bladder, few cgrp-IR and vacht-IR fibers were associated with the urothelium or suburothelium of the lateral wall. In contrast, large numbers of vacht-IR, nNos-IR and cgrp-IR fibers were found close to the epithelium and subepithelium of the bladder neck and throughout the urethra. The number of cgrp-IR fibers was significantly higher in the urethra in comparison with the bladder neck. A population of undescribed cgrp-IR cells associated with the bladder neck and proximal urethra has been characterized. Each of these cells appears to be associated with a nerve fiber. In the distal urethra, the number of peptidergic fibers penetrating the epithelium was significantly higher than the rest of the urethra. Clearly, this study has revealed a highly complex and heterogeneous network of putative afferent nerves fibers along the length of the urethra. These structural specializations need to be taken into account when probing the different functions of the urethra. Anat Rec, 302:201–214, 2019. © 2018 Wiley Periodicals, Inc.     

Tenascin expression in inflammatory,dysplastic and neoplastic lesions of the human stomach

Wie studied the expression of tenascin (Tn) in human stomach. In the normal mucosa of the antrum and body, Tn reaction was only seen in the muscularis mucosae, in the region of the pyloric sphincter and in the duodenum, a Tn-immunoreactive rim was seen underlying surface epithelial cells. Antral gastritis, irrespective of the degree of inflammation, showed a rim-like Tn expression under the surface epithelial cells but no Tn reaction was seen in mild chronic gastritis of the body. In some moderate and severe examples of chronic gastritis a delicate Tn-reactive line was seen to underline the surface epithelium focally and the neck regions of gastric pits. Discontinuous Tn immunoreactivity was sometimes seen beneath hyperplastic epithelium in both parts of the stomach. A Tn-immunoreactive line was seldom seen surrounding glands showing intestinal metaplasia. In both benign and malignant ulcers prominent Tn immunoreaction was seen at the base of ulcers extending deep into the underlying muscularis. Only severely dysplastic lesions displayed Tn in the lamina propria, in close association with capillaries. In early forms of diffuse gastric cancer (DGCA) raggedly increased Tn staining was seen in the lamina propria underlying affected surface epithelial cells. In advanced forms of DGCA consistent Tn expression was seen in the tumour stroma. A distinct Tn reaction was seen surrounding invasive tumour cell nests of intestinal type gastric cancer (IGCA) in the submucosa, whereas in early forms of the tumour enhanced Tn reaction was noted predominantly in the upper part of the lamina propria in the vicinity of dysplastic elements. Notably, while most invading DGCA tumour cell nests showed no Tn in the submucosa and muscle cell layer, invading IGCA islets showed prominent expression of Tn. The most conspicuous Tn enhancement in the stomach is seen in invasive tumours and in ulcers suggesting that Tn is an important stromal component in malignant growth and in lesions undergoing active repair and remodelling.     

Lamina propria of the human vocal fold: histomorphometric study of collagen fibers

Background  

Since the seminal work of M. Hirano, which defined the three-layered lamina propria of the human vocal fold, there has been confusion in the labeling of each layer. Recent studies described the composition of fibers and interstitial molecules within the lamina propria leading to various biomechanical properties. However, collagen fibers appear as the most important structure component.     

胆碱能神经在正常人胃壁的分布

为了给临床病理状态下胃溃疡神经分布提供参照，更好地为溃疡病的防治提供形态学依据，本文采用Ｋａｒｎｏｖｓｋｙ－Ｒｏｏｔｓ法，观察了４例正常人胃壁胆碱能神经纤维分布特点。结果：胃壁各层均有乙酰胆碱酯酶（ＡＣｈＥ）阳性纤维，但上皮和固有层上部未见ＡＣｈＥ阳性纤维；ＡＣｈＥ阳性纤维有４种形态：终末纤维、终末前纤维、神经束、神经干，胃壁各层细小动脉壁也存在神经末梢分布，在含非特异胆碱酸酶反应中，可见胃粘膜上皮下固有膜内，存在分支的神经末梢交互联成网状，可能是传入性质，对其功能意义做了讨论     

Gonadotropin-releasing hormone agonist binding in tiger salamander nasal cavity

Binding of the iodinated gonadotropin-releasing hormone (GnRH) agonist, buserelin, was examined in the nasal cavities of tiger salamanders using in vitro autoradiography. Binding of [¹²⁵I]buserelin was seen within the chemosensory epithelium of the main nasal cavity and Jacobson's (vomeronasal) organ. Highest levels of binding were observed over the chemosensory neuron dendrites. Given the apparent lack of GnRH-immunoreactive fibers within the chemosensory epithelium as we have observed in a previous study, these observations suggest that GnRH may diffuse from fibers in the lamina propria of the chemosensory mucosa into the sensory epithelium to modulate chemosensory reception.     

Visceral target organs in systemic St. Louis encephalitis virus infection of hamsters

Ultrastructural aspects of St. Louis encephalitis virus infection of the major extraneutral organs and tissues of suckling hamsters were examined. In the pancreas, both the exocrine and endocrine portions were equally affected by the virus. A feature apparently unique to flaviviruses was the accumulation of virus particles in all types of secretory granules in this organ. Virus particles were seen within myocardial fibers and within the smooth muscle cells and endothelial cells of small blood vessels of the heart. In the intestines, the lamina propria was the most severely infected, with virus particles accumulated in all cell types.     

Sensory nerve endings in the hard palate and papilla incisiva of the rhesus monkey

 The sensory innervation of the hard palate of the rhesus monkey was studied by light and electron microscopy. The mucosa of the hard palate is subject to a particularly heavy mechanical load requiring functional specialisation of the horny epithelium in the form of thickenings – the papilla incisiva and eight pairs of rugae palatinae. A thin layer of firm connective tissue (lamina propria) attaches the mucosa to the periost of the hard palate. Sensory nerve fibres were found most abundantly in the papilla incisiva and first rugae palatinae. Their number decreases in an aboral direction. Five types of sensory nerve endings were found. Free nerve endings were ubiquitous in the epithelium and lamina propria. Merkel nerve endings were found in the basal layer of the epithelium of the papilla incisiva and rugae palatinae. Meissner corpuscles were located in the connective tissue between epithelial pegs, while lamellated corpuscles were seen below the epithelial pegs. Ruffini corpuscles were found in the deeper layer of the lamina propria. Thus, a variety of sensory nerve endings were found in the hard palate, especially in those areas that are in close contact with the tongue during chewing of food. This rich innervation suggests an important role in monitoring the mechanical properties of food and the position of the tongue. Accepted: 30 September 1998     

Proliferation of D2-40-expressing intestinal lymphatic vessels in the lamina propria in inflammatory bowel disease

Lymphatic vessels in the colon are normally distributed beneath the muscularis mucosae with rare branches reaching through the muscularis mucosae to the most basal aspect of the colonic crypts. In chronic inflammatory bowel disease demonstrating acute inflammation and architectural disarray, lymph vessel proliferation is seen within the lamina propria and within the submucosa. We analyzed the number and distribution of lymphatic vessels within the lamina propria and submucosa in chronic active and treated ulcerative colitis with restoration of architecture by immunostaining with D2-40, a specific monoclonal antibody against lymphatic vessels. We found significantly increased numbers of lymph vessels in chronic active ulcerative colitis both within the lamina propria and the submucosa as compared to normal mucosa. Numbers of lymph vessels in lamina propria were highest in severe chronic active ulcerative colitis and less in moderate and minimal residual disease with minimal architectural disarray (p<0.05). Lymph vessels in the submucosa were increased significantly above normal values in both severe, moderate and minimal residual disease. We conclude that lymph vessel distribution in chronic active ulcerative colitis extends into the lamina propria. With restoration of architectural morphology, the integrity of the lamina propria in regards to the distribution of lymph vessels is restored.     

Ultrastructural evaluation of apoptosis induced by Helicobacter pylori infection in human gastric mucosa: novel remarks on lamina propria mucosae

It has been considered that Helicobacter pylori (H. pylori) infection is a major cause of human gastritis and gastroduodenal ulcers (G-DU). Many investigations of the relationship between H. pylori and apoptosis have been reported recently. However, these studies focused mostly on epithelium, using the TUNEL method. In the present study, we evaluated by electron microscopy the occurrence of apoptosis in the mesenchymal cells of lamina propria mucosae infected with H. pylori. Gastric biopsy specimens from 37 H. pylori-infected G-DU patients and 8 noninfected volunteers were examined with both light and electron microscopy and analyzed by the TUNEL method. The TUNEL method showed no significant difference between H. pylori-infected and noninfected cases. In contrast, electron microscopy revealed significant numbers of apototic fibroblasts and smooth muscle cells in H. pylori-infected lamina propria mucosae, with a diminished number of collagen fibers in surrounding areas. These areas showed edematous changes histopathologically. These results indicated that H. pylori infection induces apoptosis of fibroblasts and smooth muscle cells in lamina propria, with decrease in the numbers of collagen fibers, suggesting that these alterations may be affected by exaggerate acid secretion, decrease mucus protecting factors, and result in ulcer formation.     

Histological score for cells with irregular nuclear contours for the diagnosis of reflux esophagitis in children

Histological criteria for the diagnosis of reflux esophagitis include basal zone hyperplasia, stromal papillae elongation, and inflammatory infiltrate. However, endoscopic esophageal biopsy specimens may include little or no lamina propria. Intraepithelial T lymphocytes, seen in hematoxylin and eosin-stained sections as cells with irregular nuclear contours (CINC), may have a higher density in children with esophagitis. We evaluated the diagnostic accuracy of a numerical score built up by grading the "classical" parameters and its correlation with CINC density in grasp biopsy specimens obtained from children undergoing esophagogastroduodenoscopy with and without esophagitis. We analyzed esophageal biopsy specimens from 349 children (median age, 5 years) subdivided in 4 groups according to the previous routine histology report: group 1, 144 children with esophagitis; group 2, 65 controls; group 3, 51 children with dubious esophagitis; and group 4, 75 children with esophagitis on endoscopy but a normal histology report. A numerical value was assigned to each parameter; the sum of these values represented the histological score. We also evaluated intraepithelial CINC density (ie, number of CINC per high-power field). We separately analyzed histological sections with and without lamina propria. For both total score and for CINC density, we calculated a cutoff using a receiver operating characteristic curve. Cutoffs of 6 for score and of 4 for CINC density provided the best sensitivity and specificity. Sensitivity of the histological score was better in biopsy specimens containing lamina propria (94%) than in those without lamina propria (4%). Sensitivity of CINC density was satisfactory in both specimens with (78%) and without (75%) lamina propria. Specificity was satisfactory for both parameters. In conclusion, when lamina propria was present in sections of endoscopic esophageal biopsy specimens, histological score provided a better diagnostic accuracy for the diagnosis of esophagitis. However, when no lamina propria was present, as was the case in 67% of our children, CINC density had better sensitivity. In addition, this latter parameter showed esophageal mucosa damage in 34% of previously dubious cases or cases with esophagitis at endoscopy but a previous routine histology report of normal mucosa.