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Biomedical subjects

L Savas

Publications and source records attributed to L Savas.

23 records · Page 2Linked to original sources
PubMed1995

Expression of p53 antigen in inflamed and regenerated mucosa in ulcerative colitis and Crohn's disease.

Physiologic overexpression of p53 protein may occur in the G1 stage of the cell cycle to slow down the cell cycle and allow DNA repair in stressed or injured cells. We questioned whether there is increased expression of p53 protein in acutely inflamed mucosa (AI) and regenerated mucosa (RM) in ulcerative colitis (UC) and Crohn's disease (CD). Formalin-fixed paraffin-embedded sections of resected bowels from eight patients with UC and 20 with CD were reviewed, and blocks were selected having areas defined as follows: AI = two high-power fields (HPFs) at the edge of an ulcer, or one HPF with an inflamed crypt in the center; RM = branched or irregular glands with only mild chronic inflammation. Blocks with normal mucosa were available in 20 cases. One case of CD also had dysplasia, adenoma, and invasive carcinoma. p53 was identified with PAb1801 antibody using a labeled avidin-biotin immunoperoxidase technique. In each defined area, the positive nuclei were counted and expressed as the number of positive nuclei per 10 HPFs. Data were analyzed statistically for comparisons within and between the diseases. In normal mucosa, only rare cells expressed p53 in two cases of CD. The mean frequency of positive nuclei was 2.24/10 HPFs in AI and 0.30/10 HPFs in RM in CD, and 7.63/10 HPFs in AI and 1.14/10 HPFs in RM in UC. Differences between the means for AI and RM were statistically significant in both UC and CD. Although not significant, the frequency of positive staining in both AI and RM was greater in UC as compared with CD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Simultaneous chronic lymphocytic leukemia and chronic myelogenous leukemia. Evidence of a separate stem cell origin.

The authors studied a patient with the simultaneous occurrence of chronic lymphocytic leukemia (CLL) and chronic myelogenous leukemia (CML). The coexistence of these two hematologic malignancies leads to questions about their cell of origin. Through analysis of this patient's DNA, the authors studied the derivation of the two malignancies. They separated the blood into a myeloid-rich fraction and a fraction containing the malignant lymphocytes. JH and bcr probes were used to study these loci in the myeloid and lymphoid fractions and in unfractionated white blood cells. The authors found that the unfractionated leukocytes contained the bcr and JH rearrangements. Conversely, the lymphoid fraction contained only the JH rearrangement, and the myeloid fraction contained only the bcr rearrangement, suggesting that these malignancies arose from separate stem cells. This is the first reported patient with simultaneously occurring CML and CLL definitively shown to arise from distinct progenitors, and this report raises questions about the origin of these two cell lines.

Aged↗
PubMed1993

Characterization of the inflammatory cell populations in normal colon and colonic carcinomas.

UNLABELLED: Little is known about the nature of the mucosa-associated immune system within the normal colon, or about the immune response to colon carcinoma. In this study inflammatory cells (ICs) in 14 normal colons and 14 carcinomas were characterized. Overall inflammation, lymphocytes, plasma cells, neutrophils, and eosinophils were graded in routine H & E sections. Frozen sections were stained by an immunoperoxidase technique using antibodies to the T cell associated antigens CD2, CD7, CD4, CD8, and T cell receptors alpha beta and gamma delta. B cells were identified with CD20, macrophages with CD68, and Class II antigen with anti-HLA DR. Each cell type was semiquantitatively graded in 10 high power fields (HPFs) in the lumenal half (LH) or basal half (BH) of the normal mucosae, and in epithelium or stroma of the carcinomas. In normal colons, ICs were more frequent in LH than in BH. Plasma cells, lymphocytes and monocytes predominated. Subtyping of lymphocytes showed that CD4+ TCR alpha beta + T lymphocytes were most numerous in the lamina propria. Lymphocytes within the epithelium were CD8+ T cells. Around carcinomas the overall grade of ICs was 1+ in the majority of cases. Plasma cells, CD4+ and CD8+ cells with the TCR alpha beta receptor, and macrophages were most frequent. Lymphoid aggregates of both T and B cells were frequent. CONCLUSIONS: 1. Normal colon contains a diffuse luminally oriented population of TCR alpha beta+ CD4+ T cells, plasma cells, macrophages and class II antigen-expressing cells in the lamina propria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMedDate not supplied

Expression of adhesion molecules in the host response to colon carcinoma.

Expression of the adhesion molecules LFA-1, ICAM-1, and VCAM-1 was studied in five resected colon carcinomas, one villous adenoma, and normal colon mucosa to determine whether expression of these markers is increased in response to tumor. Frozen tissue samples were stained by a labeled avidin-biotin technique using primary antibodies to LFA-1 (CD11a), CD2, CD4, CD8, CD20, CD68, HLA-DR, ICAM-1 (CD54), and VCAM-1. For each marker, the number of positive mononuclear cells was graded semiquantitatively, and stromal and endothelial cells were scored as either positive or negative. Overall grade of inflammation was increased in tumor compared with normal mucosa in five cases. Cells positive for LFA-1, CD2, CD4, CD8, and CD20 were increased in the tumors in the same cases. ICAM-1 was expressed in vessels, inflammatory cells, and stromal cells in normal mucosa. It was markedly increased in tumor stroma in all six cases. VCAM-1 was negative in normal mucosa, and focally expressed in tumor vessels and stroma. We conclude that increased expression of adhesion molecules occurs around colon neoplasms, particularly in stromal cells, and may be a mechanism for the recruitment of activated leukocytes as part of the inflammatory response to colon carcinomas.

Adenoma, Villous↗