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Biomedical subjects

O Sezer

Publications and source records attributed to O Sezer.

At least 55 records · Page 3Linked to original sources
PubMed2000

Patients with malignant lymphomas experience a higher rate of documented infections than patients with breast cancer after high-dose chemotherapy with autologous peripheral stem cell transplantation.

The influence of underlying disease on documented infections has rarely been addressed in patients treated with high-dose chemotherapy (HDCT) and subsequent autologous peripheral blood stem cell transplantation (PBSCT). Because autografting has been used most frequently for malignant lymphomas and breast cancer, we analyzed in a retrospective study the data of 100 consecutive adult patients with either malignant lymphomas (group A, n = 50) or breast cancer (group B, n = 50) treated with HDCT at a single institution. The number of autografted CD34+ cells was not statistically different in either group. In this paper, we show for the first time that there is a significant difference in clinically or microbiologically documented infections in these groups of patients: documented infections occurred in 30% of malignant lymphoma patients but only in 4% of breast cancer patients (P=0.001). Of all isolated microorganisms, 78% were gram-positive. Because most of the documented infections were due to staphylococci, further studies should prospectively evaluate preventive measures to reduce the high incidence of these infections. This is especially important for lymphoma patients, who can be regarded as a high-risk group concerning gram-positive bacteremia.

Adult↗
PubMed2000

Bone marrow microvessel density is a prognostic factor for survival in patients with multiple myeloma.

The importance of neoangiogenesis for the progressive growth and viability of solid tumors is well established. Recently, there has been growing evidence that angiogenesis might also be important in hematological malignancies, but only few data are available. In this report, we have studied the impact of bone marrow microvessel density and survival in patients with multiple myeloma (MM). Immunohistochemical CD34 stained paraffin-embedded bone marrow biopsies of 44 patients with newly diagnosed MM were studied. Microvessels were counted in 400 x magnification and the mean number of vessels per area in each sample was noted as the microvessel density (MVD). The median MVD was 48 vessels/mm2, the range was 0-125 vessels/mm2. Using a cut-off value of the median MVD in the Kaplan-Meier analysis, the median survival was 22.2 months in the group with the higher MVD and was not reached in the group with the lower MVD (P< 0.01). In a multivariate Cox regression analysis, using previously identified prognostic factors beta2-microglobulin, C-reactive protein (CRP), and age, MVD remained significant as a prognostic factor (P< 0.03).

Adult↗
PubMed2000

New therapeutic approaches in primary systemic AL amyloidosis.

Primary systemic AL (amyloid light-chain) amyloidosis is a plasma cell disorder in which depositions of amyloid light-chain protein cause progressive organ failure. The prognosis of primary amyloidosis is generally poor, with a median survival of 1-2 years. There is no available treatment which improves impaired organ function by induction of amyloid mobilization. Since amyloidosis is a dynamic process, measures that reduce the supply of the amyloid fibril precursor protein can result in a major regression of the deposits. Conventional-dose melphalan can prolong the median duration of survival from 8.5 to 18 months, but the clinical response rates with improvement of impaired organ function are low and the response is slow. Preliminary data suggest that VAD is effective in AL amyloidosis. Up-front high-dose chemotherapy with autologous peripheral blood stem cell transplantation can result in an improvement of the patient's clinical condition, but the treatment-related toxicity can be high, owing to impaired organ function. The use of VAD followed by high-dose chemotherapy is the concept of a German trial. The improvement of the patient's condition prior to high-dose chemotherapy by induction of a remission with VAD might reduce the transplantation-related morbidity and mortality in amyloidosis.

Amyloid↗
PubMed2000

Detection of HMGI-C in the peripheral blood of breast cancer patients.

The human high mobility group (HMG) protein (HMGI-C) belongs to the HMG family of architectural transcription factors which are expressed only during embryonic development, and not in normal adult tissues. Considerable interest has recently been shown in HMGI-C and its expression in a variety of neoplastic tissues, whereas no expression could be found in normal tissue adjacent to the tumour. So far, no data is available on the expression of HMGI-C in the peripheral blood of patients with solid tumours. In this study we analysed the expression of HMGI-C in peripheral blood samples of 61 patients with breast cancer and 35 healthy donors using a haemi-nested reverse transcriptase-polymerase chain reaction (RT-PCR) technique. No HMGI-C could be detected in any of the healthy donors' samples. In the three prognostic groups according to the Nottingham Prognostic Score, the proportion of patients expressing HMGI-C differed significantly (P=0.001). The worse the prognosis was, the more patients expressed HMGI-C. This is the first report on the expression of HMGI-C in the peripheral blood of patients with breast cancer and our data suggest that this expression is correlated with a poor prognosis.

Adult↗
PubMed2000

Proteasome inhibitors induced caspase-dependent apoptosis and accumulation of p21WAF1/Cip1 in human immature leukemic cells.

The 26S proteasome is a non-lysosomal multicatalytic protease complex for degrading intracellular proteins by ATP/ubiquitin-dependent proteolysis. Tightly ordered proteasomal degradation of proteins critical for cell cycle control implies a role of the proteasome in maintaining cell proliferation and cell survival. In this study, we demonstrate that cell-permeable proteasome inhibitors, lactacystin, benzyloxycarbonyl(Z)-leucyl-leucyl-leucinal (ZLLLal; MG-132) and 4-hydroxy-5-iodo-3-nitrophenylacetyl-leucyl-leucyl-leucine vinyl sulfone (NLVS), induce apoptosis abundantly in p53-defective leukemic cell lines CCRF-CEM, U937 and K562 as well as in myelogenic and lymphatic leukemic cells obtained from adult individuals with relapsed acute leukemias. Leukemic cell apoptosis induced by the proteasome inhibitors was dependent on activation of caspase-3 and related caspase family proteases, because caspase-3 inhibitor N-acetyl-L-aspartyl-L-glutamyl-L-valyl-L-aspartal (Ac-DEVD-cho) and, more effectively, the general caspase-inhibitor N-benzyloxycarbonyl-L-valyl-L-alanyl-L-aspartate fluoromethylketone (Z-VAD-fmk) were capable of blocking apoptosis induced by lactacystin, ZLLLal or NLVS. Induction of apoptosis by lactacystin or ZLLLal was accompanied by cell cycle arrest at G2/M phase and by accumulation and stabilization of cyclin-dependent kinase inhibitor p21WAF1/Cip and tumor suppressor protein p53. A role of p53 in mediating apoptosis or induction of p21WAF1/Cip1 was ruled out since CCRF-CEM and U937 cells express non-functional mutant p53, and K562 cells lack expression of p53. Viability and hematopoietic outgrowth of human CD34+ progenitor cells treated with lactacystin were slightly reduced, whereas treatment of CD34 + cells with ZLLLal or the cytostatic drugs doxorubicin and gemcitabine resulted in markedly reduced viability and hematopoietic outgrowth. These results demonstrate a basic role of the proteasome in maintaining survival of human leukemic cells, and may define cell-permeable proteasome inhibitors as potently anti-leukemic agents which exhibit a moderate hematopoietic toxicity in vitro.

Acetylcysteine↗
PubMed2000

Novel approaches to the treatment of primary amyloidosis.

Primary (AL, amyloid light-chain) amyloidosis is a plasma cell disorder in which deposits of amyloid light-chain protein cause progressive organ failure. It is important to recognise that amyloidosis is a dynamic process and chemotherapy-induced reduction of the activity of the plasma cell clone reduces the supply of the amyloid precursor protein and can result in a major regression of the deposits. The most common target organ is the kidney and renal amyloidosis manifests as proteinuria or nephrotic syndrome. Proteinuria is seen in three quarters of patients. Amyloid related nephrotic syndrome and renal failure are potentially reversible. Fatigue, congestive heart failure, hepatomegaly, peripheral neuropathy, orthostatic hypotension, carpal tunnel syndrome and macroglossia are other common features. The median survival is one to two years. Conventional-dose melphalan as standard treatment can prolong the median duration of survival by about ten months, but the clinical response rates with improvement of impaired organ function are low. Up-front high-dose chemotherapy with autologous peripheral blood stem cell transplantation is much more effective and can result in a major improvement in the clinical condition of patients. However, the toxicity related to this treatment can be relevant due to impaired organ function. Conventional-dose chemotherapy consisting of vincristine, doxorubicin and dexamethasone or high-dose dexamethasone or interferon-alpha are other possible approaches to treatment. The improvement of patient condition with an effective conventional-dose chemotherapy may increase the tolerability of high-dose chemotherapy and reduce transplantation related problems.

Amyloidosis↗
PubMed2000

Diagnosis and treatment of AL amyloidosis.

AL (amyloid light-chain) amyloidosis is a plasma cell disorder in which depositions of amyloid light-chain protein cause progressive organ failure. Virtually all patients with AL amyloidosis have a monoclonal protein in the serum or urine or a monoclonal population of plasma cells in the bone marrow. The most common target organ is the kidney and renal amyloidosis manifests as proteinuria or nephrotic syndrome in 3/4 of the patients. The median survival is one to two years. It is important to recognize that the amyloidosis is a dynamic process, and chemotherapy induced reduction of the activity of the plasma cell clone reduces the supply of the amyloid precursor protein and can result in a major regression of the deposits. Amyloid-related nephrotic syndrome and renal failure are potentially reversible. Conventional-dose melphalan as standard treatment can prolong the median duration of survival about 10 months, but the clinical response rates with improvement of impaired organ function are low with a slow response. Upfront high-dose chemotherapy with autologous peripheral blood stem cell transplantation is much more effective and can result in a major improvement of the patient's clinical condition, but the treatment-related toxicity can be relevant due to impaired organ function. The initial use of a conventional-dose chemotherapy consisting of vincristine, doxorubicin and dexamethasone (VAD) to achieve a remission and subsequent high-dose chemotherapy is the concept of a German trial. The improvement of the condition of the patient by this approach may increase the tolerability of high-dose chemotherapy and reduce transplantation-related problems.

Amyloid↗
PubMed1999

Tumor necrosis factor-alpha and interferon-gamma induce expression of functional Fas ligand on HT29 and MCF7 adenocarcinoma cells.

Tumor cells develop diverse mechanisms to escape from immune surveillance, including expression of Fas ligand (FasL), a 40-kDa type II transmembrane protein that mediates apoptosis by binding to its cognate receptor Fas (APO-1/CD95). Upon activation, T lymphocytes and natural killer (NK) cells express Fas and thus become sensitive to FasL-mediated apoptosis. Here we show that tumor necrosis factor-alpha (TNF-alpha) in addition to interferon-gamma (IFN-gamma) induces cell surface expression of functional FasL in human HT29 colon and MCF7 breast adenocarcinoma cells that constitutively lack cell surface expression of FasL. These cells, expressing FasL, are capable of inducing apoptosis in Fas-positive Jurkat T cells mediated by plasma membrane-bound FasL and soluble forms of FasL. By contrast, mutational deletion of Fas cell surface expression as well as inhibition of caspase family proteases involved in Fas signaling and monoclonal antibodies neutralizing FasL protect Jurkat T cells from apoptosis caused by the FasL-expressing HT29 or MCF7 cells. These results demonstrate that TNF-alpha and IFN-gamma induce expression of functional FasL in adenocarcinoma cells which thereby can kill T lymphocytes by the FasL/Fas pathway.

Adenocarcinoma↗
PubMed1999

Increased levels of vascular endothelial growth factor in bronchoalveolar lavage of patients with bronchial carcinoma effect of tumour activity and oxidative stress due to radio-chemotherapy?

BACKGROUND: Vascular endothelial growth factor (VEGF) plays a crucial role in physiological and neoplastic angiogenesis. Moreover, VEGF has been found to be upregulated by conditions associated with the generation of free radicals and reactive oxygen intermediates. In patients with cancer, studies to evaluate VEGF as a measure of tumour activity were carried out. We tested the hypothesis that VEGF is additionally affected by oxidative stress due to anticancer therapy. Moreover, the suitability of epidermal growth factor (EGF) to estimate tumour activity was studied. PATIENTS AND METHODS: 60 patients with non-small cell lung cancer (NSCLC) covering different therapy progress and modalities underwent bronchoalveolar lavage. VEGF-, EGF-, albumin- and total protein-concentrations in bronchoalveolar lavage fluid (BALF) and VEGF-levels in blood plasma were studied. RESULTS: BALF VEGF-levels were increased in patients with advanced NSCLC before and in anticancer therapy. In patients who had received radiotherapy to the lung prior to chemotherapy, VEGF concentrations were noticeably higher than under sole chemotherapy. Pulmonary endothelial hyperpermeability was found in patients with recently diagnosed tumours and patients undergoing anti-cancer therapy. Evaluation of EGF-levels in BALF revealed no significant influence of tumour activity or cancer therapy on this parameter. CONCLUSION: BALF-levels of VEGF are affected by tumour activity and oxidative stress due to anticancer therapy.

Adult↗
PubMed1999

Oxidant-induced lung injury in anticancer therapy.

Lung injury is one of the most frequent side effects in anticancer therapy. Especially simultaneous application of high doses of ionising radiation and radiosensitising cytotoxic drugs is considered to cause deleterious pneumonitis and pulmonary fibrosis. Growing evidence indicates that reactive oxygen species (ROS) play a key role in the development of these disorders. They are capable of causing cell component alterations and changing cellular protein expression. Observing these disease mechanisms reveals an impressive self-amplifying cascade of secondary ROS generation. Through intricate interactions between cells, cytokines and growth factors, fibroblasts are activated and thus pulmonary matrix content is massively increased. - As clinical appearance is uniform and unspecific, an early, reliable diagnosis of therapy-associated lung damage is not possible so far. However, improving this situation could enable us to take advantage of new multimodal therapeutic facilities. This review discusses mechanisms of ROS generation during radio-chemotherapy in the lung, antioxidant defense strategies and responses to oxidants, thereby assessing current diagnostic tools.

Animals↗
PubMed1999

Eosinophilia during fludarabine treatment of chronic lymphocytic leukemia.

Although eosinophilia has been reported as a side effect of purine analogues, there is no report on fludarabine-induced eosinophilia in chronic lymphocytic leukemia (CLL). During chemotherapy with fludarabine and cyclophosphamide, we observed two cases of significant eosinophilia. A 67-year-old patient with CLL developed bone marrow and peripheral blood eosinophilia up to 7.9x10(9)/l, the highest eosinophil count ever reported during treatment with a purine analogue. The eosinophilia persisted for 33 days. Another patient developed bone marrow eosinophilia without eosinophilia in the peripheral blood. These are the first documented cases of fludarabine-induced eosinophilia in CLL, and this side effect may conceivably be more common than previously recognized.

Aged↗
PubMed1999

Rapid reversal of nephrotic syndrome due to primary systemic AL amyloidosis after VAD and subsequent high-dose chemotherapy with autologous stem cell support.

In a patient with nephrotic syndrome, renal biopsy revealed AL amyloid deposits. Monoclonal lambda light chains were identified in serum and urine. A low percentage of monoclonal plasma cells was detected in the bone marrow. The patient received four cycles of VAD and subsequent high-dose chemotherapy (HDCT) with melphalan (200 mg/m2) followed by autologous peripheral blood stem cell transplantation. Proteinuria rapidly diminished during chemotherapy. Three months after HDCT, the patient has no edema, and no signs of plasma cell dyscrasia are currently detectable. Using VAD before starting HDCT may improve the condition of patients with amyloidosis and reduce transplantation-related morbidity and mortality.

Amyloidosis↗
PubMed1999

Development of an EORTC questionnaire module to be used in health-related quality-of-life assessment for patients with multiple myeloma. European Organization for Research and Treatment of Cancer Study Group on Quality of Life.

A multiple myeloma-specific quality-of-life questionnaire module has been designed in collaboration with the EORTC Quality-of-Life Study Group to be used in clinical trials with the EORTC QLQ-C30, a general cancer questionnaire. Strict methodology was employed to ensure thorough and appropriate development of the module. An extensive literature review was performed to identify health-related quality-of-life issues relevant to patients with multiple myeloma. Semi-structured interviews were then carried out in several European countries with health-care providers experienced in the treatment of patients with multiple myeloma, and with a group of patients with multiple myeloma, to identify the issues which were most important to patients. A questionnaire was devised from the list of issues, using a 1-week time-frame and response categories consistent with the EORTC QLQ-C30. The provisional questionnaire and the EORTC QLQ-C30 were administered to patients with multiple myeloma in each participating country with further semi-structured interviews to refine the content and design of the questionnaire. A review of the results obtained in each stage of development resulted in a 24-item myeloma-specific module, the EORTC QLQ-MY24, which assesses disease-specific symptoms and their impact on everyday life, treatment side-effects, social support, and future perspective. The module is currently undergoing further international field-testing to assess its psychometric properties.

Adult↗
PubMed1999

Prolonged infusion of gemcitabine in stage IV breast cancer: a phase I study.

Gemcitabine is an effective agent in the treatment of metastatic breast cancer. The phosphorylation of gemcitabine into the active gemcitabine triphosphate (dFdCTP) is catalyzed by deoxycytidine kinase. This enzyme is saturated at plasma concentrations achieved after an infusion over 30 min. Therefore accumulation of higher intracellular dFdCTP concentrations, which may result in an enhanced antineoplastic activity, cannot be achieved by higher dosage, but only by prolonged infusion time. The objectives of this phase I trial were to determine the dose-limiting toxicities (DLT) and the maximum tolerated dose (MTD) of gemcitabine given as a 6 h i.v. infusion. Patients with metastatic breast cancer were treated with gemcitabine as a 6 h infusion on days 1, 8 and 15 every 4 weeks. The starting dose was 200 mg/m2 with an interindividual escalation in 50 mg/m2 increments. Sixteen patients received 196 doses through three dose levels. All patients were assessable for toxicity, 13 assessable for response. The MTD was 250 mg/m2. DLT was observed at 300 mg/m2 consisting of a reversible elevation of transaminases WHO grade 3 in two patients and cutaneous toxicity grade 3 in one patient. Most common non-hematologic toxicities were mild to moderate and rapidly reversible elevation of liver enzymes in all patients, nausea and vomiting (four patients grade 2, five patients grade 3), and mild alopecia. Hematologic toxicity was mild with neutropenia WHO grade 3 and 4 in only one patient each, and no grade 3 thrombocytopenia. One patient achieved a complete remission and another patient a partial response, for an overall response rate of 15% (two of 13). In addition, seven patients (54%) had stable disease and four (31%) failed to respond to the treatment. We conclude gemcitabine 250 mg/m2 days 1, 8 and 15 every 4 weeks can be safely administered as 6 h infusion. Toxicity, especially myelosuppression, is surprisingly mild. Based on this result a phase II study with 250 mg/m2 administered over 6 h was initiated to determine the efficacy.

Adolescent↗
PubMed1999

Phase II trial of gemcitabine as prolonged infusion in metastatic breast cancer.

Gemcitabine is an active agent in the treatment of metastatic breast cancer. The phosphorylation of gemcitabine into the active gemcitabine triphosphate (dFdCTP) is catalyzed by deoxycytidine kinase. This enzyme is saturated at plasma concentrations achieved after an infusion over 30 min. Therefore accumulation of higher intracellular dFdCTP concentrations, which may result in an enhanced antineoplastic activity, cannot be achieved by higher dosage, but only by prolonged infusion time. In a previous phase I trial the maximum tolerated dose of gemcitabine given as a 6 h i.v. infusion was 250 mg/m2. The objective of this phase II trial was to determine the efficacy and safety of gemcitabine as prolonged infusion in patients with metastatic breast cancer. Twenty patients [median age 50.4 years, range 35-63 years; performance status EORTC 0 (17 patients), 1 (two patients), 2 (one patient)] with metastatic breast cancer were treated with 250 mg/m2 gemcitabine as infusion over 6 h on days 1, 8 and 15 q3 weeks for up to six courses (median 3.9 courses). Treatment was first line for four patients, second line for five patients and third line or higher for 11 patients. Metastatic sites were liver in 14 patients, bone in 12 patients, lung in eight patients and lymph nodes in nine patients. Nine patients presented two metastatic sites, three patients three and five patients four. All patients were evaluable for response and toxicity. One patient (5%) achieved a complete remission (CR) and four patients (20%) a partial remission (PR) (one patient with CR of visceral metastases but stable bone metastases), for an overall response rate of 25% (five of 20). In addition, six patients (30%) had stable disease and nine (45%) failed to respond to the treatment. Time to progression ranged from 2 to 23 months with a median of 6.3 months. Hematologic toxicity was mild with leukopenia grade 3 in only three patients (15%) and no grade 3 thrombocytopenia. Moderate elevations of liver enzymes (three patients grade 3), nausea and vomiting (two patients grade 2), and mild alopecia were observed, but only one patient had to be withdrawn due to toxicity. In conclusion gemcitabine as prolonged infusion is an effective treatment in metastatic breast cancer. Toxicity, especially myelosuppression, is surprisingly mild. Therefore, gemcitabine seems to be ideal for combination therapies.

Adult↗
PubMed1999

CD99 positivity and EWS-FLI1 gene rearrangement identify a breast tumor in a 60-year-old patient with attributes of the Ewing family of neoplasms.

Rearrangements of the EWS gene with ETS transcription factor genes as a result of chromosomal translocation and high expression levels of CD99MIC2 characterize the Ewing family of tumors (EFT). This group of rather undifferentiated neoplasms affects bone and soft tissue in children and young adults mostly between 5 and 30 years of age (median, 15 years). This study reports a case of a CD99MIC2 positive small round cell tumor in the breast of a 60-year-old woman in whom a t(11;22)(q24;q12) chromosomal aberration was identified by cytogenetic analysis. Reverse transcriptase (RT)-polymerase chain reaction (PCR) followed by sequence analysis revealed expression of a chimera transcript in which EWS exon 10 was fused to FLI1 exon 6. Previously, this gene fusion has been reported to occur in approximately 3% of EFT. The specific gene rearrangement of EWS intron 10 was confirmed on Southern blot of genomic DNA. This study further contributes to the growing list of unusual neoplasms in adults that carry genotypic and phenotypic traits of the EFT.

12E7 Antigen↗