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Methods for the Morphological Study of Tracheal and Bronchial Glands
Published in Joan Gil, Models of Lung Disease, 2020
In the human respiratory tract the submucosa consists of glands and cartilage, the two occurring together, with the gland mainly internal to the cartilage lying between it and the epithelium but also between the plates of cartilage. Glands are most numerous in the trachea, progressively decreasing distally, along with the cartilage. They are absent from airways smaller than 1 mm in diameter (i.e., bronchiolus).
Imaging in IBD
Published in Peter Sagar, Andrew G. Hill, Charles H. Knowles, Stefan Post, Willem A. Bemelman, Patricia L. Roberts, Susan Galandiuk, John R.T. Monson, Michael R.B. Keighley, Norman S. Williams, Keighley & Williams’ Surgery of the Anus, Rectum and Colon, 2019
Small amounts of pericolonic free fluid may be seen in severe UC, a finding that indicates focal serosal involvement.56 Loss of haustration and luminal narrowing are common findings in longstanding inactive UC found at endoscopy and MRC. Although it is understandable why the colon wall becomes thickened in a transmural inflammatory disease, such as CD, the mechanisms leading to this pathological finding in UC, which predominantly involves the mucosa, remain unclear. For unknown reasons in long-standing UC, there is a characteristic hypertrophy of the muscularis mucosa, which produces a typical tubular shape of the lumen. Also, the submucosa may have fatty infiltration that contributes to segmental narrowing of some portions of the colon. Fatty proliferation in UC is typically limited to the perirectal space, producing an enlarged presacral space. Less frequently, fatty proliferation is seen in the sigmoid colon and other colonic segments.57
Introduction
Published in Shayne C. Gad, Toxicology of the Gastrointestinal Tract, 2018
The mucosa of the esophagus consists of nonkeratinized stratified squamous epithelium, lamina propria (areolar connective tissue), and a muscularis muscosae (smooth muscle). Near the stomach, the mucosa of the esophagus also contains mucous glands. The stratified squamous epithelium associated with the lips, mouth, tongue, oropharynx, laryngopharynx, and esophagus affords considerable protection against abrasion and wear-and-tear from food particles that are chewed, mixed with secretions, and swallowed. The submucosa contains areolar connective tissue, blood vessels, and mucous glands. The muscularis of the superior third of the esophagus is skeletal muscle; the intermediate third is skeletal and smooth muscle. and the inferior third is smooth muscle. The superficial layer is known as the adventitia, rather than the serosa, because the areolar connective tissue of this layer is not covered by mesothelium and because the connective tissue merges with the connective tissue of surrounding structures of the mediastinum, through which it passes. The adventitia attaches the esophagus to surrounding structures.
Current status and advances in esophageal drug delivery technology: influence of physiological, pathophysiological and pharmaceutical factors
Published in Drug Delivery, 2023
Ai Wei Lim, Nicholas J. Talley, Marjorie M. Walker, Gert Storm, Susan Hua
The average thickness of the esophageal wall is approximately 1.87 to 2.70 mm in the dilated state and 4.05 to 5.68 mm in the contracted state (Xia et al., 2009). The thickness of the esophageal wall has also been reported to be slightly larger in males (5.26 mm) compared to females (4.34 mm) (Xia et al., 2009). The wall of the esophagus is comprised of the mucosa, submucosa, and muscularis propria (Figure 1). In healthy individuals, the mucosa is composed of three layers – non-keratinized, stratified squamous epithelium; lamina propria (composed of connective tissue); and muscularis mucosa (Scott-Brown et al., 2008; Orlando, 2010; Standring, 2020). The muscularis mucosa is composed primarily of smooth muscle, with a combination of striated muscles at the upper part of the esophagus. The submucosa layer consists of predominantly blood vessels, lymphatic vessels, minor salivary glands, connective tissues, and autonomic nerve plexus (i.e. submucosal plexus). The muscularis propria is formed by a mixture of striated and smooth muscles and is responsible for motor functions of the esophagus.
Factors associated with non-lifting of colorectal mucosal lesions
Published in Scandinavian Journal of Gastroenterology, 2023
Jiang-Ping Yu, Shao-Peng Yang, Rong-Wei Ruan, Sheng-Sen Chen, Yan-Dong Li, Hai-Bin Lou, Shi Wang
Previous studies have shown that non-lifting signs were often associated with recurrent or residual adenoma, and other forms of inflammatory bowel diseases and prior manipulation, which are known to induce submucosal fibrosis [5]. Interestingly, our study found that MMPA may be another histological characteristic of non-lifting signs. During dissection of submucosa, we observed muscle fiber-like tissue from deeper layer extend into the mucous layer and submucosa. The results of immunohistochemical staining showed that muscle fibers from the muscularis propria stained by desmin are distributed in the muscularis mucosa and submucosa, which may indicate extension of muscularis propria into mucous layer. Of the 29 cases with non-lifting lesions included, 9 were identified as MMPA through H&E staining and desmin immunohistochemical staining (Figure 3). Further analysis found that MMPA usually occurs in adenomas with diameters larger than 3 cm, and most of these lesions are type 2B in JNET classification or type IV and V-I in Pit Pattern classification. We believe that the muscle fibers of the muscularis propria pulling on the muscularis mucosae may be another reason for the non-lifting sign. This phenomenon may be caused by neoplastic cells secreting some factors to stimulate muscle fiber hyperplasia. This is closely related to the development of tumors, and its mechanism needs to be further studied.
Endoscopic and clinicopathologic features of early gastric signet ring cell carcinoma ≤20 mm: a retrospective observational study
Published in Scandinavian Journal of Gastroenterology, 2023
Jianing Xu, Jingyi Zhu, Lanhui Lin, Zhiyu Li, Feng Gu, Fangning Wang, Huihong Zhai
Histological changes of GSRCC initially occur in the glandular neck, that is, the proliferative zone [25]. Nonetheless, it was also hypothesized that GSRCC might not be exocrine differentiated due to the lack of mucin in gastric cancer cells [26]. Previous report showed that GSRCC originated from oxyntic mucosa, some of which were derived from neuroendocrine cells [27], making it possible to coexist with a neuroendocrine tumor [28]. We did find the existence of chromogranin A/synaptophysin staining positive in a small proportion of patients by immunohistochemistry in our study (data not shown), indicating GSRCC might stem from neuroendocrine cells. Our results indicated that endoscopists should be vigilant against the occurrence of GSRCC on the atrophic mucosa as well as non-atrophic mucosa. The risk of submucosal invasion and lymphovascular invasion increased as the lesion size augmented, resulting in a greater proportion of patients not meeting the requirements of absolute or expanded indications. In this study, all patients with lesions invading submucosa were eventually treated with surgery, which was concordant with the 2021 JGES guideline recommendation [8].