Biomedical subjects

Simone Heiss

Publications and source records attributed to Simone Heiss.

4 recordsLinked to original sources

PubMed2006

Angiogenesis in nodal B cell lymphomas: a high throughput study.

AIM: To assess the biological significance of vascular endothelial growth factor (VEGF) A, VEGF receptor (Flk-1) and cyclooxygenase 2 (COX2) expression with respect to microvessel density (MVD), proliferative activity (Ki-67), expression of p53 and clinical presentation in a large cohort of nodal B cell lymphomas. METHODS: An immunohistochemical and morphometric study was performed on a validated tissue microarray containing 271 B cell lymphoma specimens, 197 of which included follow-up data. Statistical assessment was done by Pearson's chi(2) test, Spearman's rank correlation coefficient, analysis of variance and survival analysis. RESULTS: 266 (98%) cases were evaluable. Strong VEGF expression was observed in only 20 diffuse large B cell lymphomas (DLBCLs). Flk-1 and COX2 were expressed in 53 and 21 cases, respectively, mainly in DLBCLs, follicular lymphoma (FL) grade 3 and mantle cell lymphomas (MCLs), in a low proportion of cells. MVD decreased in the following order: DLBCLs, FLs, MCLs and small lymphocytic lymphomas/chronic lymphocytic leukaemia (SLL/CLLs). VEGF expression correlated with Ki-67, p53 and COX2 expression in the whole cohort and in DLBCLs. Flk-1 expression correlated with Ki-67 in the cohort and in SLL/CLL and FL grade 1 and 2. COX2 expression correlated with Ki-67 and p53. The analysed angiogenesis parameters did not correlate with clinical parameters or survival. CONCLUSIONS: Angiogenesis plays a differential role in various B cell lymphomas. Aggressive lymphomas express the potential molecular therapeutic targets VEGF and COX2, and have higher MVD. In a few low proliferation-fraction lymphomas, Flk-1 might have a role in proliferative advantage. Therapeutic strategies aimed at angiogenesis should take into account lymphoma heterogeneity.

Aged↗

PubMed2006

Perivascular treatment with azathioprine reduces neointimal hyperplasia in experimental vein grafts.

BACKGROUND: Azathioprine is an immunosuppressive and anti-inflammatory drug, and it has been shown to induce apoptosis in human T-lymphocytes. We investigated whether local treatment with azathioprine can inhibit neointimal hyperplasia in experimental vein grafts. METHODS: C57BL/6J mice underwent interposition of the inferior vena cava from isogenic donor mice into the common carotid artery using a cuff technique. In the treatment group azathioprine was perivascularly applied. The control group did not receive local treatment. Vein grafts were harvested at 1 and 2 weeks postoperatively and underwent morphometric analysis as well as immunohistochemical analysis for apoptosis (TUNEL). RESULTS: In grafted veins without treatment (controls), neointimal thickness was 10 microm (range, 6-29 microm), and 12 microm (range, 8-40 microm) at 1 and 2 weeks postoperatively, respectively. In azathioprine-treated grafts, the neointimal thickness was 2 microm (range, 1-5 microm) and 4 microm (range, 3-11 microm) at 1 and 2 weeks postoperatively, respectively. This reduction of neointimal thickness was significant at 1 week (P = .001) and 2 weeks (P = .016) postoperatively. Azathioprine-treated vein grafts showed an increased rate of apoptosis in the vascular wall as compared with controls (593 [range, 26-783] versus 45 [range, 0-106] apoptotic cells/mm(2) at 1 week, P = .063; and 656 [range, 327-1270] versus 19 [range, 0-79] apoptotic cells/mm(2) at 2 weeks, P = .016). CONCLUSION: We conclude that treatment of experimental vein grafts with azathioprine is associated with a reduction of neointimal hyperplasia and an increased apoptosis rate in the vascular wall. These results suggest that azathioprine may be useful for the prevention of vein graft disease after coronary artery bypass grafting.

Animals↗

PubMed2005

Myelodysplastic/myeloproliferative disease with erythropoietic hyperplasia (erythroid preleukemia) and the unique translocation (8;9)(p23;p24): first description of a case.

We report on a patient fulfilling the diagnostic criteria of unclassifiable myelodysplastic/myeloproliferative diseases with prominent erythropoietic hyperplasia/dysplasia (erythroid preleukemia) and the unique translocation (8;9)(p23;p24). The patient presented with B-symptoms, erythroblastemia, thrombopenia, marked eosinophilia, presence of myeloid precursors in the peripheral blood, and decreased erythropoietin level. Nodular peritrabecular polymorphous blasts, dysplastic megakaryocytes, and a diffuse argyrophilic fibrosis were detected in the trephine bone marrow biopsy. Immunohistochemically, the blasts stained positively for glycophorin C and hemoglobin A; the proliferation fraction was nearly 90% in the Ki-67 stain. Expression of the phosphorylated Janus kinase 2 was detected in almost all megakaryocytes and in isolated erythroblast islets, suggesting a probable activation of Janus kinase 2, the jak-2 gene being mapped on 9p24. Ten months after initial diagnosis, the disease progressed to frank acute erythroid leukemia. We report for the first time a myelodysplastic/myeloproliferative disease (erythroid preleukemia) accompanied by the specific chromosomal aberration t(8;9)(p23;p24), distinct histopathology, and clinical and laboratory symptoms, and progress to acute erythroid leukemia.

Biopsy↗

PubMed2005

Over-expression of tumor necrosis factor-alpha in bone marrow biopsies from patients with myelodysplastic syndromes: relationship to anemia and prognosis.

OBJECTIVES: An excessive intramedullar progenitor cell apoptosis, to which elevated expression of tumor necrosis factor-alpha (TNF-alpha) might contribute, is considered the main cause of inefficient hematopoiesis in myelodysplastic syndromes (MDS). Enhanced bone marrow (BM) angiogenesis is regarded as an essential cofactor in the progression of MDS to acute myelogenous leukemia (AML) and microvessel formation may be induced by TNF-alpha as well. To investigate TNF-alpha signaling and neoangiogenesis as potential molecular pathways for therapeutic intervention in MDS with respect to the various MDS subtypes, we performed a morphological and clinico-pathological study on a large series of paraffin-embedded trephine BM biopsies. METHODS: TNF-alpha expression and BM vessels were immunohistochemically analyzed on 89 paraffin-embedded BM biopsies from patients with MDS and secondary AML, including 12 control samples. Data were correlated with clinico-pathological and laboratory parameters and analyzed for their prognostic significance considering overall survival. RESULTS: TNF-alpha was over-expressed in MDS patients, especially in those with refractory anemia and its expression correlated with BM cellularity and with magnitude of anemia as well as with microvessel density (MVD). TNF-alpha over-expression was associated with premature deaths. MVD was increased in MDS and secondary AML and correlated with marrow cellularity and expression of TNF-alpha, but was not of prognostic significance. CONCLUSIONS: TNF-alpha expression and MVD are elevated in MDS and secondary AML. TNF-alpha expression in BM progenitor cells appears to negatively impact erythropoiesis and overall survival in MDS, and may serve as a potential therapeutic target in patients with hypercellular MDS with marked anemia.

Adult↗