Search results for "keratin"
showing 10 items of 303 documents
The identification and localization of two intermediate filament proteins in the tunic of Styela plicata (Tunicata, Styelidae).
2009
The intermediate filament (IF) proteins Styela C and Styela D from the tunicate Styela (Urochordata) are co-expressed in all epidermal cells and they are thought to behave as type I and type II keratins. These two IF proteins, Styela C and Styela D, were identified in immunoblots of proteins isolated from the tunic of Styela plicata. The occurrence and distribution of these proteins within the tunic of this ascidian was examined by means of immunofluorescence and immunoperoxidase techniques, using anti-Styela C and anti-Styela D antibodies. In addition, immuno-electron microscopy of the tunic showed that the two proteins are located in the cuticle layer and in the tunic matrix. These result…
Adenosine A2A and A2B Receptors Differentially Modulate Keratinocyte Proliferation: Possible Deregulation in Psoriatic Epidermis
2017
Adenosine is a potent regulator of inflammation and immunity, but the role of adenosine receptors in keratinocytes remains controversial. We determined that in addition to A2B receptors, human epidermal keratinocytes also express A2A receptors, although to a lower extent. Through the use of selective adenosine receptor agonists and antagonists, we showed that physiological concentrations of adenosine activate A2B receptors in normal human keratinocytes, inducing cell cycle arrest through the increase of intracellular calcium but not through cAMP signaling. In contrast, the selective activation of A2A receptors by CGS-21680 induces keratinocyte proliferation via p38–mitogen-activated protein…
Mammalian Epidermis: A Compendium of Lipid Functionality
2022
Mammalian epidermis is a striking example of the role of lipids in tissue biology. In this stratified epithelium, highly specialized structures are formed that leverage the hydrophobic properties of lipids to form an impermeable barrier and protect the humid internal environment of the body from the dry outside. This is achieved through tightly regulated lipid synthesis that generates the molecular species unique to the tissue. Beyond their fundamental structural role, lipids are involved in the active protection of the body from external insults. Lipid species present on the surface of the body possess antimicrobial activity and directly contribute to shaping the commensal microbiota. Lipi…
Control of murine hair follicle regression (catagen) by TGF‐β1in vivo
2000
The regression phase of the hair cycle (catagen) is an apoptosis-driven process accompanied by terminal differentiation, proteolysis, and matrix remodeling. As an inhibitor of keratinocyte proliferation and inductor of keratinocyte apoptosis, transforming growth factor beta1 (TGF-beta1) has been proposed to play an important role in catagen regulation. This is suggested, for example, by maximal expression of TGF-beta1 and its receptors during late anagen and the onset of catagen of the hair cycle. We examined the potential involvement of TGF-beta1 in catagen control. We compared the first spontaneous entry of hair follicles into catagen between TGF-beta1 null mice and age-matched wild-type …
Immunology of dermatophytosis
1983
By causing experimental lesions of dermatophytosis in rabbits inoculated and reinoculated with T. mentagrophytes var. granulosum and T. rubrum a study was carried out of the state of cellular immunity response, during infection, and also of the antigens responsible for the sensitization. Cellular immunity response was detected using the leucocyte migration test (L.M.T.) in the presence of antigenic compounds of the 'Keratinase' of Eleuterio et al.
Isolation and colture of beta-like cells from porcine Wirsung duct
2009
We sought to develop a protocol to isolate and culture porcine Wirsung duct cells in order to determine their potency to differentiate into insulin-expressing beta-like cells. The porcine Wirsung duct isolated by a surgical microdissection was digested with collagenase P and trypsin to dissociate ductal cells. These elements were cultured in serum-free supplemented media: for 2 weeks. Thereafter the cells were exposed to varying concentrations of glucose (0, 5.6, 17.8, and 25 mmol/L) to induce a beta-like phenotype, as identified by immunohistochemical staining. Cell growth proceeded slowly for the first 2 weeks of culture. After glucose induction for 2 weeks, they formed pancreatic islet-l…
Clinical evaluation of subepithelial connective tissue graft and guided tissue regeneration for treatment of Miller's class 1 gingival recession: com…
2013
Objectives: The present study aims to clinically compare and evaluate subepithelial connective tissue graft and the GTR based root coverage in treatment of Miller’s Class I gingival recession. Study Design: 30 patients with at least one pair of Miller’s Class I gingival recession were treated either with Subepithelial connective tissue graft (Group A) or Guided tissue regeneration (Group B). Clinical parameters monitored included recession RD, width of keratinized gingiva (KG), probing depth (PD), clinical attachment level (CAL), attached gingiva (AG), residual probing depth (RPD) and % of Root coverage(%RC). Measurements were taken at baseline, three months and six months. A standard surgi…
Expression of Cytokeratin 7 and 20 in Pathological Conditions of the Bile Tract
2003
Expression of cytokeratin 7 (CK7) and cytokeratin 20 (CK20) helps to establish the origin of biliary and metastatic carcinomas. We investigated the expression of CK7 and CK20 in inflammatory, metaplastic and neoplastic conditions of the bile ducts, and evaluated possible relationships between the CK expression pattern and extrahepatic bile duct/gallbladder carcinomas (EBDCs) or intrahepatic bile duct carcinomas (IBDCs). We used immunohistochemistry for the investigation of 48 formalin-fixed, paraffin-embedded specimens grouped as: A) lithiasic or inflamed surgically resected extrahepatic bile ducts/gallbladders: all were CK7+/CK20+; B) percutaneous liver biopsies from patients with chronic …
Facial cystic lesions and onychodystrophy.
2018
Chromophobe Renal Cell Carcinoma
1996
SUMMARY A case ofchromophobe renal cell carcinoma is reported in a 73 year-old man. Light microscopically, the tumor was composed of polygonal cells with a slightly eosinophilic and a fine reticular pattern, and a reaction of the cytoplasm with Hale's acid iron colloid. Ultrastructural analysis showed membranous microuesicles within the tumor cells, with degenerated mitochondria. Immunohistochemical profile against intermediate filaments was positive to cytokeratin 18 and negative against uimentin. Flow cytometry and cytogenetics revealed a predominant bypertriploid population. Few cases have been published with flow cytometry and cytogenetic findings. We report a new case.