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1.
Summary The epithelial lining of the anal canal is of colo-rectal type in the upper part and squamous in the lower part, while the middle zone is called the anal transitional zone (ATZ). This zone is characterized by an epithelium which bears a resemblance to that of the anal glands and shows little mucus secretion. The histochemical properties of the mucins in the epithelium of 39 anal canals, resected for ano-rectal adenocarcinoma, basaloid carcinoma, squamous carcinoma and malignant melanoma were investigated. The study reveals that (1) the mucin composition of the ATZ epithelium corresponds to that of the anal glands, being characterized by a mixture of sulpho- and sialomucins with scarcity or absence ofO-acylated sialic acids; and (2) cases with carcinomas located near the dentate line show changes in the mucin composition of the adjoining anal canal epithelium, regardless of tumour type. In colo-rectal type mucosa, these mucins consist of increasing amounts of sialomucins with a predominance ofN-acyl derivatives, and in the anal could be detected in the ATZ epithelium. It is concluded that rectal and anal glands in the anal canal are exposed to stimuli which alter the normal process of glycoprotein synthesis and secretion. The changes seem to be secondary to tumour growth and independent of the histological type of tumour.  相似文献   

2.
Summary The comparative distribution and coexistence of chromogranin A (CGA)-, serotonin (5-hydroxytryptamine; 5-HT)- and pancreastatin (PST)-like immunoreactivity in endocrine-like cells of the human anal canal was investigated by light-microscopic immunocytochemistry. The largest population of colorectal endocrine-like cells consisted of CGA-immunoreactive (ir) cells, followed by the 5-HT-ir and PST-ir cell population. In the anal transitional zone (ATZ), CGA-and 5-HT-immunoreactivity was equally distributed; ir-PST was confined to a smaller endocrine-like cell population. In the squamous zone and the perianal skin, Merkel cells in the basal layer of the epidermis and hair follicles exhibited ir-CGA and ir-PST but no ir-5-HT. Double immunofluorescence on identical sections revealed distinct coexistence patterns. In the colorectal zone, about 2/3 of the CGA-ir endocrine-like cells also stained for 5-HT, whereas in the ATZ epithelium, CGA- and 5-HT-immunoreactivity completely overlapped. No 5-HT-immunoreactivity could be detected in CGA-ir Merkel cells of the squamous zone of the anal canal and the perianal skin. PST-immunoreactivity was present in about 1/3 of the CGA-ir colorectal and anal transitional endocrine-like cells and in about 1/4 of the Merkel-cell population staining for CGA. These chemically heterogeneous phenotypes of the anal endocrine-like and Merkel cells may reflect a specific regulatory role of these cells in the various epithelial linings of the human anal canal and the perianal skin.  相似文献   

3.
In certain regions of the body, transition zones exist where stratified squamous epithelia directly abut against other types of epithelia. Certain transition zones are especially prone to tumorigenesis an example being the anorectal junction, although the reason for this is not known. One possibility is that the abrupt transition of the simple columnar epithelium of the colon to the stratified squamous epithelium of the proximal portion of the anal canal may contain a unique stem cell niche. We investigated whether the anorectal region contained cells with stem cell properties relative to the adjacent epithelium. We utilized a tetracycline-regulatable histone H2B-GFP transgenic mice model, previously used to identify hair follicle stem cells, to fluorescently label slow-cycling anal epithelial cells (e.g., prospective stem cells) in combination with a panel of putative stem cell markers. We identified a population of long-term GFP label-retaining cells concentrated at the junction between the anal canal and the rectum. These cells are BrdU-retaining cells and expressed the stem cell marker CD34. Moreover, tracking the fate of the anal label-retaining cells in vivo revealed that the slow-cycling cells only gave rise to progeny of the anal epithelium. In conclusion, we identified a unique population of cells at the anorectal junction which can be separated from the other basal anal epithelial cells based upon the expression of the stem cell marker CD34 and integrin α6, and thus represent a putative anal stem cell population.Key words: stem cells, transitional epithelium, keratinocyte, slow-cycling, label retaining cell  相似文献   

4.
Three-dimensional analysis demonstrated the presence of cytoplasmic vela extending from exocrine cells into the space between endocrine cells and basal lamina in the gastrointestinal epithelium of the rabbit; these structures were also observed in various other mammals. The following techniques were used to determine the morphologic characteristics of these vela and to study their significance: preparation of semiserial thin sections, three-dimensional reconstruction in plexiglass and lanthanum staining of pericellular spaces. It was found that these fine vela, devoid of major differentiated cell-constituents, sometimes form a pseudocircular crown at the base of endocrine cells. If the zone of basal apposition of the plasma membrane is referred to as ZBA and the zones of lateral apposition as ZLA, the presence of this velum makes it possible to distinguish a zone of immediate apposition without interposition (ZIA) and a mediate zone of apposition with interposition (ZMA) within the ZBA. Exocrine cell processes can also penetrate within endocrine cells in invaginations, and the depth of these invaginations can be demonstrated by lanthanum staining. Adjacent to the membrane zones defined above, other cytoplasmic microdomains-M(ZLA) and M(ZBA), as well as M(ZIA) and M(ZMA) of different morphofunctional significance may also be envisaged.  相似文献   

5.
In embryological terms the anal papillae are the product of eversion of the hindgut tissues. The rectum and the anal papillae have the same origin and have a marked structural similarity. The insect hindgut is very labile being able to produce salt transporting or ‘chloride cells’ from any of the tissues of which it is composed.The hindgut consists of four distinct regions: the ileum and part of the anal canal have a mechanical function, the rectum and the posterior anal canal contain transporting cells. Two new cell types, ‘interstitial’ and ‘tertiary’ are reported in the rectum.The structure of the anal papillae changes with increased salinity. Changes in the plasma membranes alter the surface area for transport. Changes in the number of mitochondria are not accompanied by changes in oxygen consumption. If mitochondria are the site of oxidative metabolism then their number docs not control the level of oxygen consumption.In Aedes aegypti the papillary epithelium appears to be a syncytium. Across the lumen of the papillae there are cellular sheets supporting the tracheoles. At the base of the papillae there is a cellular transition zone; circular muscles in this region may be used to occlude the papillae. The control of salt transport may be hormonal.  相似文献   

6.
In certain regions of the body, transition zones exist where stratified squamous epithelia directly abut against other types of epithelia. Certain transition zones are especially prone to tumorigenesis an example being the anorectal junction, although the reason for this is not known. One possibility is that the abrupt transition of the simple columnar epithelium of the colon to the stratified squamous epithelium of the proximal portion of the anal canal may contain a unique stem cell niche. We investigated whether the anorectal region contained cells with stem cell properties relative to the adjacent epithelium. We utilized a tetracycline-regulatable histone H2B-GFP transgenic mice model, previously used to identify hair follicle stem cells, to fluorescently label slow-cycling anal epithelial cells (e.g. prospective stem cells) in combination with a panel of putative stem cell markers. We identified a population of long-term GFP label-retaining cells concentrated at the junction between the anal canal and the rectum. These cells are BrdU-retaining cells and expressed the stem cell marker CD34. Moreover, tracking the fate of the anal label-retaining cells in vivo revealed that the slow-cycling cells only gave rise to progeny of the anal epithelium. In conclusion, we identified a unique population of cells at the anorectal junction which can be separated from the other basal anal epithelial cells based upon the expression of the stem cell marker CD34 and integrin a6, and thus represent a putative anal stem cell population.  相似文献   

7.
The topographical distribution of endocrine cells in the crypt and villus epithelium along the length of the mouse intestine was studied. Argyrophil reactivity using the Grimelius stain was used to estimate the total endocrine population of the intestine. Comparisons were then made with the fraction of endocrine cells containing glucagon like material, stained immunocytochemically using rabbit anti-glucagon antisera. A highly significant reduction in the incidence of endocrine cells (argyrophil reactive) from the proximal to distal end of the intestine was noted. However, only 10-30% of these cells contained glucagon like material in the crypts of the duodenum, jejunum and ileum, compared to 30-60% in the crypts of the colon and rectum. The distribution of endocrine cells (argyrophil reactive) was maximal in the lower regions of the proliferative zone of the crypts but showed no significant variation along the length of the villi. Cells containing glucagon like material were also most frequent in the lower regions of the proliferative zone of the crypts, but were not generally found above the bottom third of the villi. Each crypt in the small intestine contains between 3 and 5 endocrine cells one of which contained glucagon like immunoreactive material. In the colon and rectum each crypt contains about 6-8 endocrine cells, of which 3-4 contained glucagon like immunoreactive material. These results indicate that a sub-set of cells containing glucagon like material, differentiate early in the lineage of endocrine cells within the proliferative zone of the intestinal crypts.  相似文献   

8.
T Rettig  Z Halata 《Acta anatomica》1990,137(3):189-201
The sensory innervation of the anal canal of the pig was investigated by light and electron microscopy. The distribution of the different types of sensory nerve endings correlates with the histology of different zones: (1) After the rectal mucosa there was a zone lined with nonkeratinized stratified squamous epithelium. (2) A middle zone was lined with keratinized stratified squamous epithelium. Here the dermis already showed a papillary and reticular layer. (3) The last zone showed hairy skin with a high hair density. The following nerve endings were found: Free nerve endings reached the stratum superficiale in nonkeratinized squamous epithelium and the stratum granulosum in the keratinized squamous epithelium. Dermal free nerve endings were found in all zones near the epithelium and two different types were identified as those derived from C-fibers and those from A-delta-fibers. Merkel nerve endings showed different features depending on their location. Few Merkel-like cells were found in the epithelium of the anal crypts. Typical Merkel Tastscheiben were located at the base of epithelial ridges or pegs in zones 2 and 3. The number of Merkel cells varied up to 200. The myelinated afferent fiber supplied 10-15 Merkel cells. Merkel cells were also found regularly in the outermost layer of the external rooth sheath of hair follicles at about the same level as perifollicular nerve endings. Lamellated corpuscles were found in the dermis of all zones except the cranial part of zone 1, where the anal crypts are located. Generally they consisted of a central nerve terminal which may be branched. Each terminal was surrounded by an inner core of concentrically arranged lamellae of the terminal Schwann cell and one or several inner cores were included in a capsule of perineural cells. The size of the corpuscle, the regularity of the inner core and the number of capsular layers depended on the location of the corpuscle.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

9.
The topographical distribution of endocrine cells in the crypt and villus epithelium along the length of the mouse intestine was studied. Argyrophil reactivity using the Grimelius stain was used to estimate the total endocrine population of the intestine. Comparisons were then made with the fraction of endocrine cells containing glucagon like material, stained immunocytochemically using rabbit anti-glucagon antisera. A highly significant reduction in the incidence of endocrine cells (argyrophil reactive) from the proximal to distal end of the intestine was noted. However, only 10-30% of these cells contained glucagon like material in the crypts of the duodenum, jejunum and ileum, compared to 30–60% in the crypts of the colon and rectum. The distribution of endocrine cells (argyrophil reactive) was maximal in the lower regions of the proliferative zone of the crypts but showed no significant variation along the length of the villi. Cells containing glucagon like material were also most frequent in the lower regions of the proliferative zone of the crypts, but were not generally found above the botom third of the villi. Each crypt in the small intestine contains between 3 and 5 endocrine cells one of which contained glucagon like immunoreactive material. In the colon and rectum each crypt contains about 6-8 endocrine cells, of which 3–4 contained glucagon like immunoreactive material. These results indicate that a sub-set of cells containing glucagon like material, differentiate early in the lineage of endocrine cells within the proliferative zone of the intestinal crypts.  相似文献   

10.
Endocrine cells were investigated in human Bartholin's glands by use of histochemical, immunohistochemical and ultrastructural methods. Endocrine cells represent normal constituents of these glands, being mainly distributed throughout the transitional epithelium of the major excretory duct; however, single elements are dispersed among the acinar lobules. Serotonin-, calcitonin-, katacalcin-, bombesin- and alpha-hCG-immunoreactive cells were recognized, with serotonin-immunoreactive cells predominating. Co-expression of calcitonin, katacalcin or alpha-hCG with serotonin was observed in single endocrine cells. At the ultrastructural level, these cells are richly granulated and show typical neuroendocrine features. Bartholin's glands display an endocrine profile quite similar to that of other cloacal-derived tissues.  相似文献   

11.
We describe the ultrastructural organization of the anal organs of Craterostigmus tasmanianus, which are located on the ventral side of the bivalvular anal capsule. Each part of the capsule bears four pore fields with several anal pores. The pores lead into a pore canal, which is surrounded by the single-layered epithelium of the anal organs. Each anal organ is composed of four different cell types: transporting cells of the main epithelium, junctional cells, isolated epidermal glands, and the cells forming the pore canal. The transporting cells exhibit infoldings of the outer cell membranes, forming a basal labyrinth and a poorly developed apical complex. The cells are covered by a specialized cuticle with a widened subcuticular layer. Only the cuticle of the main epithelium is covered by a mucous layer, secreted by the epidermal glands. The ultrastructural organization of the anal organ is comparable to the coxal and anal organs of other pleurostigmophoran Chilopoda. It is likely that the coxal and anal organs of the Pleurostigmophora are homologous, due to their identical ultrastructural organization. Differences concerning the location on the trunk of Pleurostigmophora are not sufficient to reject a hypothesis of homology. Anal organs are found not only in Craterostigmomorpha, but also in most adult Geophilomorpha, and in larvae and most adults of Lithobiomorpha. The anal organs of C. tasmanianus are thought to play an important role in the uptake of atmospheric water. J. Morphol.  相似文献   

12.
The expression and function of thrombomodulin (TM), an endothelial cofactor protein for thrombin-mediated protein C activation, in the epithelium are not fully characterized. This report describes the distribution and localization of TM in the various types of epithelia in the rat by light and electron microscopic immunocytochemistry. TM showed a limited distribution and was expressed by the keratinizing stratified epithelia of the skin, tongue, and esophagus, but was not present on the non-keratinizing epithelia of the vagina, ureter, trachea, stomach, or gut. An identical pattern of TM expression was seen in mucocutaneous junctions, transitional zones from a non-keratinizing stratified epithelium to a keratinizing epithelium at the edge of the eyelid and in the anal canal. As the keratinization of the stratified epithelia proceeded, the staining intensity increased in the transitional zones. Within the keratinizing stratified epithelia, TM staining was limited to the keratinocytes of the spinous layer, the spinous cells. The subcellular localization of TM on the spinous cells was restricted to the plasma membrane facing the intercellular spaces. TM was not detectable on the desmosomes or the two membranes making up the junction, presumably the nexus. The functional significance of TM in keratinizing epithelia is discussed. Accepted: 14 October 1999  相似文献   

13.
The squirrel monkey uterine cervix was studied macroscopically and microscopically in intact and ovariectomized monkeys. The effect in ovariectomized monkeys of estradiol dipropionate or progesterone of both given after estrogen priming was studied by PAS staining. The lower portion of the cervix was dilated to form a vestibule into which projected fibromuscular colliculi which arose from the isthmic end of the cervix. The stratified squamous epithelium of the vagina was continuous through the external os with a similar epithelium lining the vestibule and covering the external surfaces of the colliculi. The transitional zone between the stratified epithelium and columnar cells was variable. The colliculi were covered internally with mucosal folds of columnar epithelium continuous with those of the endocervical canal. Glycogen concentration in the smooth muscle did not fluctuate markedly, irrespective of the hormones used. Glycogen granules were more numerous in the stratified squamous epithelium. Malt-diastase-resistant material appeared to be more abundant in the columnar epithelium and glandular lumina when the monkeys received both hormones than when they received solely estrogen or progesterone.  相似文献   

14.
The highest expression level of a 70-kDa heat shock protein family member Hspa2 is detected specifically in meiotic and post-meiotic male germ cells, which is reflected by original name of this protein, i.e., testis-specific Hsp70. However, this chaperon protein could be also detected in certain somatic tissues. Here, the extra-testicular expression pattern of mouse Hspa2 was analyzed. We found expression of Hspa2 in various epithelial cells including lining of bronchioles and oviduct, columnar epithelium of endometrium, epithelial reticular cells of thymus, transitional epithelium of the urinary bladder, or ependymal cells covering walls of the ventricular system of the brain. Surprisingly, Hspa2 was a putative secretory protein in intestine, endometrial glands and subcommissural organ. Hspa2 was detected in central and peripheral nervous system: in neuron’s bodies and fiber tracts, in the subventricular zone of the lateral ventricles, in the dentate gyrus of the hippocampus, in enteric ganglia of the gastrointestinal tract. Hspa2 was also expressed in smooth muscles and at low level in immune system (in germinal centers associated with B-lymphocyte production). In addition to somatic tissues listed above, Hspa2 was detected in oocytes arrested at diplotene of the first meiotic division. N. Vydra and B. Winiarski contributed equally to the work.  相似文献   

15.
The regional distribution and relative occurrence of phthalates were studied immunohistochemically by confocal laser scanning microscopy in the alimentary tract of the green frog, Rana esculenta, using an antibody against o-phthalate esters. Many positive sites indicating the basal presence of phthalate esters were identified. The immunoreactive cells were located in the gastric glands of the stomach and in the intestinal epithelium regions with variable frequencies. The regional distribution of phathalate-accumulating cells resembled that of fish and demonstrated that these endocrine disruptors not only enter via the alimentary canal, but also bioaccumulate inside cells specialized in secretion as well as absorption functions.  相似文献   

16.

Purpose

The aim of the study is to identify the risk factors of synchronous ILN metastasis for lower rectal cancer involving the anal canal.

Methods

Patients with lower rectal cancer who underwent radical resection at the Fudan University Shanghai Cancer Center were retrospectively analyzed. The synchronous ILN metastasis was defined as the metastasis occurring within 6 months after the diagnosis of rectal cancer. Patients’ gender, age, tumor diameter, dentate line invasion, differentiation level, histological type, depth of invasion, perirectal LN metastasis, lymphovascular invasion or perineural invasion were analyzed in the study. The correlation between synchronous ILN involvement and clinicopathological features were analyzed with Chi-square test/fisher’s exact test. Variables with p<0.05 in univariate analysis were then analyzed in a multivariate logistic model. Odds ratio (OR) along with 95% confidence intervals (95% CI) were calculated.

Results

A total of 325 patients (182 men and 143 women) with lower rectal cancer met the criteria and were enrolled in the study. Among them, 20 patients (6.2%) had synchronous ILN metastasis. Both univariate and multivariate analysis showed the invasion of the dentate line had a strong correlation with synchronous ILN metastasis with the odds ratio (OR) of 23.558 [95% confidence interval (CI) 6.380–86.982] (p<0.001). The presence of lymphovascular invasion also showed a significant correlation synchronous ILN metastasis with odds ratio (OR) of 5.260 [95% confidence interval (CI) 1.818–15.212] (p = 0.002).

Conclusions

The invasion of dentate line and lymphovascular invasion are two independent risk factors of inguinal lymph node metastasis for lower rectal cancer involving the anal canal.  相似文献   

17.
Summary After gentle trypsinization, the pseudostratified columnar Müllerian epithelium that lines the uterine cervix of newborn mice could be separated from the enclosing stromal tissue. Pure epithelial tubes explanted in vitro and were allowed to grow in a standard medium for 3–4 days forming a confluent colony of rather closely-fitting cells. The cell sheet was studied by a preparatory technique that allows examination of a large number of cells with preserved intercellular spatial orientation. Attempts were made to identify cultured cells according to the morphology of cell types in the cervicovaginal epithelium in vivo.Electron micrographs revealed that, close to the explant, the cultured cell sheet exhibited several features similar to the Müllerian epithelium in vivo. Outside these central areas of the colony was a broad transitional zone consisting of thin platelike cells distinguished by an abundance of microfilaments. At the periphery of the colonies, bulky cells possessing microvilli and a vacuolated cytoplasm tended to overlap adjoining platelike cells. These bulky cells had a morphology resembling that of the superficial cells seen in the upper vagina and common cervical canal of immature and diestrous animals. The epithelial development in the cultures apparently simulated the transformation in vivo from a pseudostratified Müllerian epithelium in the newborn to a stratified epithelium resembling that of the uppermost vagina and common cervical canal of immature animals. Judged by morphological and cytochemical criteria, the Müllerian cells in the outgrowth obviously had many changed features. It thus seems questionable whether the cells grown in vitro are comparable with the corresponding cells in vivo when used for experiments requiring the controlled conditions of the culture environment.Supported by grants from the Norwegian Research Council for Science and the Humanities and from the Norwegian Cancer Society  相似文献   

18.
In colonic neoplasms, endocrine differentiation is encountered not only in carcinoid tumors but also in adenocarcinomas, where endocrine cells may represent a distinct line of differentiation in the tumor. The significance of endocrine differentiation in colorectal cancer is not well established, partly because of the paucity of tumor cell lines which can serve as a model for studying endocrine differentiation. In this report we describe the properties of NCI-H716 cells, a cell line derived from a poorly differentiated adenocarcinoma of the caecum, under various in vitro conditions and as xenografts in athymic mice. Phenotypical properties were immunohistochemically assessed using a panel of differentiation related antibodies, and also by Northern blot analysis and by electron microscopy. Receptors for biogenic amines and peptide hormones were analyzed by ligand binding assay. These studies show that: 1. NCI-H716 cells can be undifferentiated, or show endocrine, mucin-producing or "amphicrine" properties. 2. Endocrine differentiation of NCI-H716 cells preferentially occurs in xenografts in athymic mice, which suggests that mesenchymal elements induce endocrine differentiation. 3. NCI-H716 cells express large amounts of high affinity receptors for gastrin, serotonin and somatostatin and these substances can regulate growth. Thus, NCI-H716 cells form a suitable model for the study of endocrine differentiation in intestinal epithelium and of auto- or paracrine growth regulation in intestinal neoplasia.  相似文献   

19.
Electron-microscopic examinations of the sturgeon gut were performed. Oesophageal goblet cells were abundant in the stratified epithelium. The ultrastructural features of the secretory granules of the oesophageal and intestinal goblet cells were quite similar to those of other vertebrates. Lobules of multilocular adipose tissue were observed in the deep tunica propriasubmucosa of the oesophagus, in close association with vasculature and large fibre bundles of myelinated and unmyelinated axons. Similarly composed nerve fibre bundles were observed in the cardiac stomach, too. The presence of myelinated axons is an unusual feature in the vertebrate enteric nervous system. Cardiac and fundic zones of the stomach showed an epithelium with columnar ciliated and non-ciliated cells, the latter equipped with fuzzy microvilli. Cells lining the tubular gastric proper glands were markedly granulated. Intestinal superficial epithelium was columnar and contained ciliated, as well as non-ciliated and goblet cells. In the tunica propria all over the intestine, the presence and ultrastructure of granulated cells was in addition described. Intraepithelial granulated leukocytes were seen throughout the alimentary canal. Various types of endocrine cells were seen both in the stomach and in the intestine, the size of their granules was measured and their ultrastructure described and compared to that of mammalian cell types.  相似文献   

20.
An operation has been developed that permits total removal of all disease-prone mucosa in ulcerative colitis but avoids the need for a permanent ileostomy. The colon and upper half of the rectum are excised and the remaining inflamed mucosa is stripped from the rectal stump down to the dentate line of the anal canal. A pouch is fashioned from a triplicated loop of terminal ileum. This is drawn down through the denuded rectum and an anastomosis created, via the per-anal approach, between the ileum just distal to the pouch and the mid-anal canal. A temporary ileostomy is made. Out of eight patients so treated, five were available for assessment, and four of them were highly satisfied with the result in improved health and function. The remaining three were awaiting closure of their ileostomies.  相似文献   

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