Search results for "Histochemistry"

Peripheral innervation of the heart

1987

The present immunohistochemical study demonstrates the multiplicity, histotopography and origin of peptidergic innervation in the mammalian heart. Neuropeptide Y (NPY) is the major representative of peptides in cardiac sympathetic efferents. Sympathetic afferents are characterized by the presence of tachykinins, calcitonin gene-related peptide and apparently also some opioid peptides. Predominant peptides of the vagal system are tachykinins. The intrinsic peptidergic system predominantly consists of vasoactive intestinal polypeptide/peptide histidine isoleucine. Paracrine systems are merely opioid-ergic. Target relations of extrinsic and intrinsic peptidergic nerves were found to be more di…

Diagnóstico diferencial inmunomorfológico de las lesiones quísticas maxilares con queratinización

2011

ResumenObjetivosLos quistes maxilares con queratinización son formas lesionales de carácter controvertido y de relevancia clínica, dada la implicación clínico-evolutiva del llamado tumor odontogénico queratoquístico (TOQ). En el presente estudio nos planteamos valorar la utilidad de las técnicas inmunohistoquímicas en la identificación de estas lesiones.Material y métodosSe analizan de forma retrospectiva las lesiones quísticas maxilares dotadas de fenómenos de queratinización interna, diagnosticadas en un mismo centro hospitalario, a lo largo de un periodo de 4 años, realizando un estudio inmunohistoquímico mediante la aplicación de un panel de cinco anticuerpos (Ki67, Bcl-2, p53, CK19, D2…

Immunohistochemical localization of nitric oxide synthases

1996

Orchestin, a calcium-binding phosphoprotein, is a matrix component of two successive transitory calcified biomineralizations cyclically elaborated by…

2003

Orchestia cavimana is a crustacean that cyclically replaces its calcified cuticle during molting cycles in order to grow. Its terrestrial way of life requires storage of calcium during each premolt period, as calcareous concretions, in tubular diverticula of the midgut. During the postmolt period the stored calcium is reabsorbed and is translocated through the storage organ epithelium as calcified small spherules. In a previous study, we sequenced and characterized a remarkable component of the organic matrix of the premolt storage structures, Orchestin, which is a calcium-binding phosphoprotein. In this paper, we analyzed the spatiotemporal expression of the orchestin gene by Northern blot…

Expression of hMLH1 and hMSH2 proteins in ameloblastomas and tooth germs

2017

Background Mismatch repair proteins (MMRPs) are a group of nuclear enzymes that participate in the repair of base mismatches that occur during DNA replication in all proliferating cells. The most studied MMRPs are hMSH2 and hMLH1, which are known to be highly expressed in normal tissues. A loss of MMRPs leads to the accumulation of DNA replication errors in proliferating cells. Ki-67 is a biomarker regarded to be the gold-standard tool for determining cell proliferation by immunohistochemical methods. The aim of this study was to investigate the immunohistochemical expression of hMLH1, hMSH2 and Ki-67 proteins in ameloblastomas and tooth germs, to contribute to the understanding of the deve…

OP0042 BLOCKING OF CD103+ TISSUE RESIDENT MEMORY T CELLS (TRM) AS A THERAPEUTIC STRATEGY IN SJOGREN’S SYNDROME

2021

Background:Tissue-resident memory T cells (TRM), are a recently identified T cells population featuring tissue localization and expression of markers of tissue homing, CD69 and CD103. Recently, the expansion of CD8+ TRMs and their involvement in the sialadenitis was described in a murine model of SS. However, CD4+ and CD8+ TRM’s functional relevance in pSS is still not fully understood, and the TRM therapeutic targeting unexplored.Objectives:The study aimed to address the role of CD4+ and CD8+ TRMs in the pathogenesis of pSS and to explore the therapeutic targeting of the tissue residency marker of TRM CD103.Methods:An animal model of experimental (ESS) obtained by immunization of female C5…

De novo CCND2 mutations leading to stabilization of cyclin D2 cause megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome

2014

Activating mutations in genes encoding phosphatidylinositol 3-kinase (PI3K)-AKT pathway components cause megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome (MPPH, OMIM 603387)(1-3). Here we report that individuals with MPPH lacking upstream PI3K-AKT pathway mutations carry de novo mutations in CCND2 (encoding cyclin D2) that are clustered around a residue that can be phosphorylated by glycogen synthase kinase 313 (GSK-3 beta)(4). Mutant CCND2 was resistant to proteasomal degradation in vitro compared to wild-type CCND2. The PI3K-AKT pathway modulates GSK-3 beta activity(4), and cells from individuals with PIK3CA, PIK3R2 or AKT3 mutations showed similar CCND2 accumulation. CCND…

Tumor de células de la granulosa extraovárico con mutación FOXL2. Diagnóstico diferencial morfológico e inmunohistoquímico

2020

Extraovarian granulosa cell tumor is a very uncommon tumor and the identification of a recurrent mutation in FOXL2 may be used as another diagnostic tool along with the classical morphological and immunohistochemical findings. Here, we report a new case of extraovarian granulosa cell tumor in a 57 years old female patient presented with a sub-hepatic mass and abdominal pain. Histopathological examination of the excised mass showed features of adult-type granulosa cell tumor with α-inhibin, calretinin, WT1, S100, CD99 and progesterone receptor immunoreactivity. A FOXL2 mutation was detected on molecular biology study. A final diagnosis was an extraovarian adult-type granulosa cell tumor. We …

Electron microscopic immunogold cytochemistry reveals chromogranin A confined to secretory granules of porcine Merkel cells

1990

By ultrastructural immunohistochemistry using the immunogold technique, immunoreactive (ir) Chromogranin A (CGA) was found to be confined to the secretory vesicles of porcine Merkel cells. CGA was present predominantly in the periphery of the electron-dense core and on the clear halo. These findings indicate that CGA is a regular constituent of Merkel cell secretory granules but probably not exclusively responsible for their electron opacity.

Chromogranin A in the Mammalian Merkel Cell: Cellular and Subcellular Distribution

1989

Chromogranin-A (CGA), which accounts for more than half the soluble matrix protein in secretory granules of various neuroendocrine cells, has a wide spectrum of potential biological roles and is considered an important marker of the diffuse neuroendocrine system (DNES). Light and electron microscopic immunohistochemistry of mammalian skin revealed that Merkel cells are exclusively CGA-immunoreactive (ir) and that the immunoreaction is localized in the secretory granules. This finding supports the classification of the Merkel cell as a member of the DNES. The CGA immunoreactivity was restricted to Merkel cells of pigs and humans. In human embryonic skin, CGA was expressed in Merkel cells as …