1,721,040 research outputs found
Cell proliferation and apoptosis in the pathogenesis of oesophagogastric lesions in pigs
No full textRecent studies have stressed the importance of epithelial hyperproliferation in the pathogenesis of early lesions (parakeratotic hyperkeratosis) of the porcine gastric pars oesophagea (PO). In this study, immunohistochemical staining with Ki67 (clone MIB 1) and AgNOR proteins silver staining were used to evaluate, by means of image analysis, cell proliferation in normal and parakeratotic (parakeratotic hyperkeratosis) epithelia of the PO. Apoptotic activity was also assessed with the TUNEL assay and compared with cell proliferative parameters. Early lesions of the PO were characterised by a significant increase in epithelial proliferative activity while there was no difference in the apoptotic activity between normal and parakeratotic epithelia. Our data confirm the hyperproliferative nature of epithelial changes preceding degeneration and erosion/ulcer of the PO and suggest that an underlying feature of gastric ulcers in pigs is an imbalance between cell proliferation and programmed cell death. © 2000 Harcourt Publishers Ltd
IDENTIFICATION OF CELL TYPES PRESENT IN BOVINE HAEMOLYMPH NODES AND LYMPH NODES BY IMMUNOSTAINING
No full textMediastinal haemolymph nodes (HN) and lymph nodes (LN) of 15 healthy calves and ten healthy steers and 53 steers with respiratory diseases (pneumonias) were studied using monoclonal antibodies (Mabs) specific to bovine B and T lymphocytes: BAQ155A (B), CH128A (BoCD2), CACT138A (BoCD4), CACT80 (BoCD8), BAQ4A (Null cells). Topographical distribution of the HN T and B cell subset appears similar to the distributions in the LN. The germinal centres contained B+, BoCD2+ and BoCD4+ cells, whereas no staining of lymphocytes could be seen in the mantle zone. BoCD2+, BoCD4+ and BoCD8+ lymphocytes were located in the parafollicular lymphatic tissue, whereas B and Null lymphocytes were scattered. The same pattern was observed in the hyperplastic haemolymphadenitis of steers with respiratory diseases with an increased positive staining for BoCD4 and BoCD8. A similar pattern was observed for HN and LN Immunoglobulin Containing Cells (ICC). Furthermore, in the calf HN, IgM positive ICC were the most frequent class (44% in HN vs. 33% in LN). It is likely that they could contribute to produce a particularly efficient primary immune response. This is the first study of the distribution of different lymphocyte phenotypes in mammalian haemolymph nodes. © 1993
Assessment of proliferative activity by anti-PCNA monoclonal antibodies in formalin-fixed, paraffin-embedded samples and correlation with mitotic index
No full textn the present study, the employment of clone PClO inveterinary oncology has been investigated, with regard toimmunoreactivity in dogs and cats and reproducibility of themethod on samples with known and unknown time of fix-ation as often happens in stored material for retrospectiveinvestigations. The percentage of labeled nuclei (PCNA in-dex) was evaluated by computerized image analysis. Twodifferent values of PCNA index were considered: one count-ing as positive only the strongly labeled nuclei (SP-PCNAindex) and the other counting as positive all the labeled nuclei(TP-PCNA index). Both values of PCNA index were com-pared with mitotic index (number of mitoses per 1,000 cells
Detection of proliferating cell nuclear antigen (PCNA) in canine and feline mammary tumours
No full textQuantitation of immunohistochemical staining of the proliferating cell nuclear antigen (PCNA, clone PC10) by image analysis was performed on benign and malignant mammary tumours of dogs and cats. Scoring of the slides was carried out by image analysis to assess the percentage of labelled nuclei (expressed as a ratio of areas). Either the strongly labelled nuclei (SP-PCNA index), or all of the stained nuclei (TP-PCNA index) were counted as positive to determine the growth fraction and its correlation with the histopathological classification and nuclear grade (degree of nuclear differentiation, considered a morphological correlate of tumour aggressiveness). A significant difference in the values of PCNA indices was seen between benign and malignant growths (P<0·0001, dog; P<0·05, cat). Neither of the PCNA indices showed correlation with nuclear grade in dogs (P=0·14 for SP-PCNA index and P=0·31 for TP-PCNA index) or cats (P=0·09 for SP-PCNA index and P=0·07 for TP-PCNA index). A significant difference in the number of mitoses, expressed as mitotic index, was seen between benign and malignant growths in the dog (P<0·01) but not in the cat (P=0·078). Good correlation of mitotic index with nuclear grade was revealed in canine malignant growths (P<0·05), but in feline malignant tumours such correlation ({itP<0·05) was shown only when the values of intermediate plus typical forms were compared with the data for atypical forms. It is concluded that quantitation of PCNA-positive nuclear area by image analysis provides an objective method for assessing proliferative activity in benign and malignant mammary tumours of dogs and cats. © 1995 Academic Press Limited
Laminin expression in testicular tumours of the dog
No full textThe expression of laminin was studied to determine the distribution pattern of basement membranes (BMs) in normal testes and in a series of 40 canine testicular tumours (seminomas, Leydig and Sertoli cell tumours). BM was always present around seminiferous tubules and blood vessels in normal testes and in seminomas and Sertoli cell tumours of the intratubular type without invasion. BM changes (fragmentation or loss, or both) were usually found in invasive neoplasms which retained their tubular structure; disruption or absence was observed in tumours with a diffuse pattern. The BM was never expressed in Leydig cell tumours, except around vessels, irrespective of their histological growth pattern (cystic-vascular, pseudoadenomatous, diffuse). An attempt was made to relate the degree of BM modification to proliferative activity as assessed by PCNA (proliferating cell nuclear antigen) and Ki67 monoclonal antibodies and mitotic index. In parallel with the progressive loss of BM an increase in proliferative activity occurred, indicating that BM changes are additional useful prognostic indicators in testicular tumours of the dog. © 1995 Academic Press Limited
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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