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Mucous Granules (mucous + granule)

Distribution by Scientific Domains

Life Sciences	66%
Medical Sciences	33%

Selected Abstracts

Structure of adhesive organ of the mountain-stream catfish, Pseudocheneis sulcatus (Teleostei: Sisoridae)

ACTA ZOOLOGICA, Issue 4 2005
Debasish Das
Abstract The structure and ultrastructure of the adhesive organ (AO) in the catfish, Pseudocheneis sulcatus (Sisoridae), an inhabitant of the sub-Himalayan streams of India, is described. The surface of the AO is thrown into folds, the ridges of which bear curved spines. The AO epidermis consists of 10,12 tiers of filament-rich cells, of which the outer tier cells project spines lined with a thick plasma membrane and bear bundles of tonofilaments (TF). Their cytoplasm contains TF and large mucus-like granules, but no obvious organelles. A second tier of living cells with spines is present beneath the outer tier and seems to replace the latter when its spines are damaged or shed. The outer tier cells react positively with antibody to cytokeratin. Actin labelling is clearly absent from the outer tier, indicating that keratinization of the outer tier occurs in the absence of actin filaments. In the cells of the third to fifth tiers, the cytoplasm possesses abundant small mucous granules (0.1,0.3 µm), and fewer TF compared to the cytoplasm in the spines. The cells of the innermost tiers and the basal layer possess few TF bundles, but no mucous granules. The potential of AO filament cells to produce both mucous granules and keratin filaments is noteworthy. The observations provide evidence that specific regions of fish epidermis can actually undergo a true process of keratinization. [source]

Ultrastructural localization of salivary mucins MUC5B and MUC7 in human labial glands

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2010
Monica Piras
Piras M, Hand AR, Tore G, Ledda GP, Piludu M. Ultrastructural localization of salivary mucins MUC5B and MUC7 in human labial glands. Eur J Oral Sci 2010; 118: 14,18. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci As a result of their presence throughout the mouth in the submucosa or between muscle fibers, minor salivary glands secrete directly and continuously into the oral cavity, providing mucosal surfaces with highly glycosylated proteins that are active in bacterial aggregation and in oral tissue lubrication. In this study, we investigated the ultrastructural localization of the MUC5B and MUC7 mucins in human labial glands by means of a postembedding immunogold technique. Thin sections of normal human labial glands, obtained during surgery, were incubated with polyclonal antibodies to human salivary mucins MUC5B and MUC7, and then with gold-labeled secondary antibodies. Specific MUC5B reactivity was found in the secretory granules of mucous cells of all glands examined, and was associated with the luminal membrane of duct cells. MUC7 labeling was observed in the granules of both mucous and seromucous secretory cells of the glandular parenchyma. Quantitative analyses demonstrated that seromucous granules have higher immunogold labeling densities for MUC7 than mucous granules. Our immunohistochemical data extend the results of previous light microscopic studies of MUC5B and MUC7 localizations, pointing out the significant contribution of human labial glands in the secretion process of these two mucins. [source]

Apocrine carcinoma of the vulva in a band-like arrangement with inflammatory and telangiectatic metastasis via local lymphatic channels

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 1 2003
Takahiro Kiyohara MD
Background Primary adenocarcinomas of the vulva have been classified as sweat gland carcinomas, extramammary Paget's disease, and primary breast carcinomas of the vulva. They share some common histopathologic features. Methods We describe a 72-year-old Japanese woman with apocrine carcinoma of the vulva and local lymphatic metastasis. Results The patient presented with a bruise on her inguinal area. Physical examination revealed a 4 cm × 7 cm, dark-red, irregularly elevated tumor on the left labium majora. Dome-shaped, flesh-colored, small papulovesicles were scattered on the abdomen, accompanied by erythema and induration. The lesion showed a band-like arrangement. General examination revealed multiple bone metastases, particularly in the spine. Microscopic examination revealed a moderately differentiated adenocarcinoma with signet ring cells. A few pagetoid clear cells were present in the hypertrophic epidermis. The peripheral papulovesicles demonstrated the same histopathologic view as in inflammatory and telangiectatic, metastatic breast carcinoma. Tumor cells were positive for various ductal and glandular markers. Estrogen and progesterone receptors were not expressed. Ultrastructural findings suggested differentiation towards apocrine or mammary glands because of the presence of an apocrine process and electron-dense mucous granules. The patient died in spite of combination chemotherapy and irradiation therapy. Conclusions We report a rare case of apocrine carcinoma of the vulva in a band-like arrangement with local lymphatic metastasis which showed the clinical and histopathologic characteristics of inflammatory and telangiectatic carcinoma. [source]

Observations on the histochemistry and ultrastructure of regenerating caudal epidermis of the tuatara Sphenodon punctatus (Sphenodontida, Lepidosauria, Reptilia)

JOURNAL OF MORPHOLOGY, Issue 2 2003
Lorenzo Alibardi
Abstract Study of the histology, histochemistry, and fine structure of caudal epidermal regeneration in Sphenodon punctatus through restoration of a scaled form reveals that the processes involved resemble those known in lizards. Following establishment of a wound epithelium (WE), subjacent scale neogenesis involves epidermal downgrowths into the dermis. Although the process is extremely slow, and most new scales do not overlap, their epidermal coverings reestablish epidermal generation (EG) formation. As in lizards, the flat, ,-keratogenic, WE cells contain lipids as revealed by their affinity for Sudan III. A few mucous cells that store large PAS-positive mucus-like granules also occur in WE. During differentiation of WE cells, among the bundles of 70-nm tonofilaments are many lamellar bodies (LBs) and mucous granules (MGs) that discharge their contents into the cytoplasm and extracellular spaces producing a strongly PAS-positive keratinized tissue. Richness of epidermal lipids coexistent with mucus is a primitive characteristic for amniote vertebrates, probably related to functions as a barrier to cutaneous water loss (CWL). As scale neogenesis begins, beneath the superficial WE appear 3,5 layers of irregularly shaped cells. These contain tonofilament bundles surrounded by small, round keratohyalin-like granules (KHLGs) and a keratinized matrix with ,-keratin packets and a 3,5-nm thick keratin granulation. This mixture of ,- and ,-keratogenic capacities resembles that seen in the innermost cells of a normal tuatara epidermal generation. As in the latter, but in contrast to both normal and regenerating lizard epidermis, no definable shedding complex with interdigitating clear layer and oberhautchen cells occurs (Alibardi and Maderson, 2003). The tortuous boundaries, and merging ,-keratin packets, identify subjacent keratinizing cells as precursors of the typical stratified, squamous ,-layer seen in long-term regenerated caudal skin wherein the entire vertical sequence of epidermal layers resembles that of normal scales. The sequence of events in caudal epidermal regeneration in S. punctatus resembles that documented for lizards. Observed differences between posttrauma scale neogenesis and scale embryogenesis are responses to functional problems involved in, respectively, restoring, or forming, a barrier to CWL while accommodating rapid somatic growth. J. Morphol. 256:134,145, 2003. © 2003 Wiley-Liss, Inc. [source]

The Mucosa of the Digestive Tract in Micropogonias furnieri: A Light and Electron Microscope Approach

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2008
A. O. Diaz
Summary The histomorphological aspects as well as the histochemical content and distribution of glycoproteins (GPs) in the mucosa of the digestive tract of the white croaker Micropogonias furnieri were studied. The buccopharyngeal cavity and the esophagous showed a squamous stratified epithelium with mucous cells. The stomach presented three portions: cardias, fundus and pylorus. Tubular glands formed by a single type of gland cell were located along the cardias and fundus. Histochemical tests showed that the buccopharyngeal cavity and the esophagous presented the largest amount of the different types of mucosubstances. Both organs showed abundant secretory mucous cells that synthesize large quantities of neutral, sulphated and sialylated GPs. The surface epithelium in the cardias and fundus synthesized and secreted scarce sialylated and neutral GPs whereas the secretions of the apical surface were abundant. The pylorus secreted large amounts of neutral as well as sulphated and sialylated GPs. Gland cells secreted neutral GPs. The ultrastructural features of the gut cells were quite similar to those of other teleosts. The buccopharyngeal cavity and the esophagous surface epithelial cells, identified by their superficial localization, were characterized by cytoplasmic vesicles of different size. Abundant goblet cells with secretory mucous granules were also present. Gastric glands in the stomach contained just one form of cell with a fine structure similar to cells that secrete pepsinogen. [source]