Embedded Tissue (embedded + tissue)

Distribution by Scientific Domains

Kinds of Embedded Tissue

  • paraffin embedded tissue

  • Selected Abstracts

    Myocardial lipofuscin-laden lysosomes contain the apoptosis marker caspase-cleaved cytokeratin-18

    A. Soleiman
    ABSTRACT Background Acute coronary syndrome is related to increased circulatory concentration of soluble apoptosis specific caspase-cleaved cytokeratin-18 (ccCK-18). Potential cardiac sources of this intermediate filament derivative have not been investigated to date. Materials and methods Paraffin embedded tissue of normal myocardium, and chronically damaged samples of ischaemic, congestive and hypertrophic cardiomyopathy were analysed by histology and by CK-8, CK-18, ccCK-18 immunohistochemistry (each group, n = 15). Antibody specificity of the ccCK-18 antibody M30 was checked by immunoblotting on lysed myocardium and enriched myocardial lysosomes. Results ccCK-18 and CK-18 but not CK-8 were present in all forms of cardiomyopathy, most prominently in ischaemic cardiomyopathy while only traces were detectable immunohistochemically in normal myocardium. Weak CK-18 and strong ccCK-18 staining co-localized to lysosomes with cardiac age pigment lipofuscin. Weak staining of CK-18 was detected in the cytoplasm of coronary endothelia. Conclusion Our study reveals that cardiac lipofuscin-laden lysosomes contain ccCK-18, a marker of apoptosis and its precursor CK-18. This ccCK-18 pool might contribute to increased systemic levels of ccCK-18 in acute coronary syndrome thus monitoring myocardial damage. [source]

    A new technique, which clearly distinguishes fibre types in fixed muscle tissue

    W. M. H. Behan
    Aims:, A method of distinguishing between type 1 and 2 skeletal muscle fibres in wax-embedded tissue is needed. The ATPase method is the basis for fibre identification on frozen tissue and a new method should not give significantly different results. Isoforms of myosin and myofibrillar ATPase are known to correlate. Materials and methods:, We devised an immunohistochemical double-labelling (IHC) protocol using monoclonal antibodies to fast and slow myosin. We compared results in the two methods by morphometric analysis of frozen muscle and then applied the method to paraffin-embedded tissue. Results:, On frozen sections there were no significant differences (P = 0.57) in the percentages of type 1 (46% IHC method vs. 48% ATPase) or type 2 fibres (54% vs. 52%) and 2a and 2b subtypes were distinguished easily. Cross-sectional area (in Ám2), diameter (Ám) and form factor were all similar. Various diagnostic samples of wax embedded tissue were then examined. These gave excellent results with clear colour contrast: type 1 fibres, black and type 2 fibres, red (see examples). Conclusion:, An IHC method based on the fast and slow isoforms of myosin gives similar results to the ATPase method while providing an important advantage in its applicability to wax-embedded muscle. [source]

    Glycoproteins of drusen and drusen-like lesions

    Purpose: Drusen are a marker of age-related macular degeneration. Lesions similar to drusen, both in histology and their clinical appearance are also seen in choroidal tumours, chronic inflammatory and degenerative conditions of the eye, and in mesangiocapillary glomerulonephritis type II (MCGN-II). This study aims to compare the saccharide composition of these drusen-like lesions in the various ocular pathological groups and in MCGN-II. Methods: Formalin fixed and paraffin wax embedded tissue from 21 eyes was studied. The histological diagnoses included AMD, retinal detachment, malignant melanoma, long-standing uveitis, glaucoma and MCGN II. Glycosylation was examined using a panel of twenty biotinylated lectins and an avidin-peroxidase-DAB-cobalt revealing system, with and without neuraminidase pre-treatment. Results: High mannose, bi/tri-nonbisected and bisected complex N-glycan, N-acetyl glucosaminyl, galactosyl and sialyl residues were found to be expressed by drusen, while treatment with neuraminidase exposed subterminal N-acetyl galactosamine and galactosyl residues. Similar binding patterns were found in the various pathological groups studied. Conclusions: As there was no significant difference in the lectin-binding pattern in drusen in different pathologies, a common pathogenesis or at least a final common pathway for the elaboration of carbohydrate components of drusen is suggested. [source]

    Cytomegalovirus infection in the brain of liver transplant recipients: Do pathologically occult infections matter clinically?

    Raymund R. Razonable MD
    Cytomegalovirus (CMV) infection remains a highly prevalent systemic complication following orthotopic liver transplantation (LT), accounting for a significant increase in morbidity and affiliated costs. However, unlike other immunosuppressed groups of population, CMV infection of the central nervous system in LT is rarely diagnosed, either clinically or postmortem. Furthermore, in 20% of the LT patients who develop preterminal neurological complications, the etiology remains undetermined. With the hypothesis that at least some of these cases could be related to an occult CMV infection, we examined brain tissue from 83 unselected autopsies of LT patients by morphological, immunohistochemical (IHC), in situ hybridization (ISH), and nested polymerase chain reaction (nested PCR) techniques. Microglial nodules were observed in 17 brains of the LT group (20.4%) but in none of the 36 controls. Isolated positive cells by either IHC, ISH, or both techniques, were identified in 11 LT patients (13.2%) and in 2 controls (5.5%). CMV DNA amplification was obtained from paraffin embedded tissues in 41 of 81 LT cases (50.6%), and in 5 controls (13.8%) (P=0.00017). Viral inclusion bodies, inflammatory infiltrates, or necrotizing changes were not identified in any case. Our findings indicate an increased susceptibility of the brain of LT patients to occult infection by CMV and suggest that a latent or low-grade infection of the central nervous system could operate as a reservoir of the CMV and play a role in some of the unexplained neurological symptoms that appear in the postoperative period. [source]

    OLIG-1 and 2 gene expression and oligodendroglial tumours

    K. Hoang-Xuan
    OLIG 1/2 genes encode basic helix-loop-helix transcription factors that play a critical role in motor neurone and oligodendrocyte fate specification during development. Two recent studies in which OLIG transcripts were detected by in situ hybridization have reported a high expression of the OLIG genes in oligodendrogliomas. This suggests that the detection of these lineage markers could become an adjunct to the classic morphological diagnosis of these tumours. There are problems in the diagnosis of oligodendroglioma. To date, all other known oligodendrocyte lineage markers have failed to label specifically neoplastic oligodendrocytes. Deletions on chromosome 1p and 19q are much more frequent in oligodendrogliomas than in astrocytomas but these molecular alterations are not constant. For the future, when routinely available, immunohistochemical techniques using anti-OLIG antibodies on paraffin embedded tissues will allow a systematic study of a large series of tumours so that we will know the specificity and sensitivity of this investigation in diagnosis. At another level, it is possible that expression of OLIG in neoplastic oligodendrocyte might participate in the oncogenesis of oligodendrogliomas. Initial work suggests that this is probably not the case. However further in vitro and in vivo studies analysing the functional consequence of OLIG overexpression in terms of proliferation and tumour progression are needed. [source]

    Variability in serotonin and enterochromaffin cells in patients with colonic inertia and idiopathic diarrhoea as compared to normal controls

    COLORECTAL DISEASE, Issue 5 2002
    M. K. Baig
    Abstract Aim To evaluate differences in distribution, density and staining intensity of enterochromaffin cells (EC) and serotonin cells (SC) in the colonic mucosa of patients with colonic inertia (CI), idiopathic diarrhoea (ID) and a control group. Methods Three groups were studied: 19 patients' colons after subtotal colectomy for CI, and 17 patients' biopsies for diarrhoea (>3 bowel movements/day) with histological findings of normal mucosa (excluding microscopic, eosinophillic and collagenous colitis). The third group included 15 patients who underwent colonoscopy and biopsy for indications other than constipation, inflammatory bowel disease, diarrhoea or neoplasm (control group). Specimen blocks were obtained in each case from the right and left colon. Immunohistochemical staining for EC and SC were done on 4 Ám sections from Hollandes fixed, paraffin embedded tissues with primary rabbit antibody against chromagranin A or serotonin, and biotynylated secondary antibody and enzyme labelled streptavidin. Results The number of EC in the mucosa of the left colon in patients with CI (16.8 ▒ 10.2) and ID (19.9 ▒ 9.7) were significantly higher than they were on the right side (CI: 9.4 ▒ 6.0, ID: 12.1 ▒ 5.3). However, there were no significant differences between the left and right sides in the control group (L: 10.3 ▒ 5.3; R: 13.4 ▒ 7.6). Although the quantity of EC in the left colon in both patients with CI (P < 0.05) and ID (P < 0.01) were significantly higher than in the controls, there was no significant difference between CI and ID. In both the right and left colon, the percentage of EC with low positive density was significantly higher (P < 0.01) while those cells with moderate or low staining intensity were significantly lower in patients with CI than in either patients with ID or control group. In patients with CI, the quantity of SC in the mucosa of the left colon (12.1 ▒ 6.4) was higher than in the right (CI: 7.9 ▒ 3.6; control 4.6 ▒ 3.3; ID 4.6 ▒ 2.9) (P = 0.0057). In contrast there was no significant difference in SC in either the ID or control groups. The quantity of SC in both sides of the colon was significantly higher both in patients with CI as compared to the control group (P < 0.01) and patients with CI vs. patients with ID (L = P < 0.01; R = P < 0.05). There was a significantly positive correlation between the numbers of EC and SC in patients with CI (L: r = 0.5425, P < 0.05; R: r = 0.745, P < 0.01). Conclusion In patients with CI, EC increases possibly due to an increase in SC. Conversely, in patients with ID, the EC increase results from peptides other than SC. Our results suggest that different aetiological factors contribute to ID and CI. [source]