Publications by authors named "Verheij M"

Purpose: The purpose of this study was to determine the value of (99m)Tc Hynic-rh-Annexin-V-Scintigraphy (TAVS), a non-invasive in vivo technique to demonstrate apoptosis in patients with head and neck squamous cell carcinoma.

Methods: TAVS were performed before and within 48 h after the first course of cisplatin-based chemoradiation. Radiation dose given to the tumour at the time of post-treatment TAVS was 6-8 Gy.

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We hypothesised that gastric cancer outcome could be improved with more effective and intensified postoperative chemoradiotherapy. This phase I/II study was performed to determine the maximal tolerated dose (MTD) and toxicity profile of postoperative radiotherapy with concurrent daily cisplatin and capecitabine. Patients were treated with capecitabine 1000 mg m(-2) twice a day (b.

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Perifosine is a member of the class of synthetic alkylphospholipids (APLs) and is being evaluated as anti-cancer agent in several clinical trials. These single-chain APLs accumulate in cellular membranes and disturb lipid-dependent signal transduction, ultimately causing apoptosis in a variety of tumor cells. The APL prototype edelfosine was previously found to be endocytosed by S49 mouse lymphoma cells via lipid rafts.

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Single-chain alkylphospholipids, unlike conventional chemotherapeutic drugs, act on cell membranes to induce apoptosis in tumor cells. We tested four different alkylphospholipids, i.e.

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Background: The Intergroup 0116 randomized study showed that postoperative 5-fluorouracil-based chemoradiotherapy improved locoregional control and overall survival in patients with gastric cancer. We hypothesized that these results could be improved further by using a more effective, intensified, and convenient chemotherapy schedule. Therefore, this Phase I-II dose-escalation study was performed to determine the maximal tolerated dose and toxicity profile of postoperative radiotherapy combined with concurrent capecitabine.

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In many tumor cell types, ionizing radiation (IR) or DNA-damaging anticancer drugs enhance sensitivity to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis, which is of great clinical interest. We have investigated the molecular mechanism underlying the response to combined modality treatment in p53-mutant Jurkat T leukemic cells overexpressing Bcl-2. These cells are largely resistant to individual treatment with TRAIL or IR, but sensitive to combined treatment, in vitro as well as in vivo.

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Purpose: In this study, the formation of cisplatin-DNA adducts after concurrent cisplatin-radiation and the relationship between adduct-formation in primary tumor tissue and normal tissue were investigated.

Methods: Three intravenous cisplatin-regimens, given concurrently with radiation, were studied: daily low-dose (6 mg/m(2)) cisplatin, weekly 40 mg/m(2), three-weekly 100 mg/m(2). A (32)P-postlabeling technique was used to quantify adducts in normal tissue [white blood cells (WBC) and buccal cells] and tumor.

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Purpose: The purpose of this study was to evaluate if sequential 99mTc Hynic-rh- annexin V scintigraphy (TAS) can predict outcome in patients with advanced lung cancer, shortly after the start of platinum-based chemotherapy.

Patients And Methods: In 16 consecutive chemotherapy-naive patients with advanced stage non-small-cell lung cancer scheduled for platinum-based chemotherapy, TAS was performed before and within 48 hours after the start of therapy. Chemotherapy-induced changes in tumor annexin V uptake, calculated as maximum count per pixel and expressed as percentage to baseline value, were compared with treatment response determined according to Response Evaluation Criteria in Solid Tumors.

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Very low-dose irradiation (2 x 2 Gy) is a new, effective, and safe local treatment for follicular lymphoma. To understand the biologic mechanisms of this extremely effective response, we compared by microarray the gene-expression profile of patients' biopsies taken before and after radiation. In all patients, a major and consistent induction of p53 target genes was seen.

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Concurrent treatment with radiotherapy and chemotherapy has emerged as an effective strategy to improve clinical outcome of cancer. In addition to combining radiation with classical anticancer agents, several new biological response modifiers are under investigation in pre-clinical and clinical studies. Synthetic alkylphospholipids are anticancer agents that in contrast to most anticancer drugs, do not target DNA, but insert in the plasma membrane and subsequently induce a broad range of biological effects, ultimately leading to cell death.

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Gastric cancer is the fourth most frequent cancer in the world. For curative treatment and local control of gastric cancer, surgery is essential. The extent of the lymph node dissection is still under debate.

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Purpose: Postoperative chemoradiotherapy in gastric cancer improves locoregional control and survival. Reports on late toxicity, however, have been scarce thus far. Because renal toxicity is one of the most serious late complications in upper abdominal radiotherapy, we prospectively analyzed kidney function in patients who underwent postoperative chemoradiotherapy for gastric cancer.

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The present study examined the effects of reserpine on the extracellular concentration of accumbal dopamine in high responders (HR) and low responders (LR) to novelty rats. Reserpine reduced the baseline concentration of extracellular accumbal dopamine more in HR than in LR, indicating that the dopamine release is more dependent on reserpine-sensitive storage vesicles in non-challenged HR than in non-challenged LR. In addition, reserpine reduced the novelty-induced increase of the extracellular concentration of accumbal dopamine in LR, but not in HR, indicating that the dopamine release in response to novelty depends on reserpine-sensitive storage vesicles only in LR, not in HR.

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The ALP (alkyl-lysophospholipid) edelfosine (1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine; Et-18-OCH3) induces apoptosis in S49 mouse lymphoma cells. To this end, ALP is internalized by lipid raft-dependent endocytosis and inhibits phosphatidylcholine synthesis. A variant cell-line, S49AR, which is resistant to ALP, was shown previously to be unable to internalize ALP via this lipid raft pathway.

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Background And Purpose: Resistance to apoptosis is a contributing factor in the response to radiotherapy. Aim of this study was to evaluate whether TRAIL--in a soluble isoleucine zippered form--enhances the cytotoxic effect of irradiation on tumour cells with a blockade in the mitochondrial apoptosis route and/or a dysfunctional p53 pathway.

Materials And Methods: The p53 mutant human T acute lymphoblastic leukemia line Jurkat transduced with the Bcl-2 gene was used as model system in vitro and in a subcutaneous transplant setting in immunodeficient mice.

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Purpose: Perifosine is an orally applicable, membrane-targeted alkylphosphocholine analogue with antitumour activity and radiosensitising properties in preclinical models. The purpose of this phase I study was to determine the feasibility and tolerability of concurrent daily perifosine and radiation in patients with advanced cancer.

Patients And Methods: Starting dose of perifosine was 50 mg/day; dose escalation was in steps of 50mg.

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G-protein coupled receptors encoded by viruses represent an unexplored class of potential drug targets. In this study, we describe the synthesis and pharmacological characterization of the first class of inverse agonists acting on the HCMV-encoded receptor US28. It is shown that replacement of the 4-hydroxy group of lead compound 1 with a methylamine group results in a significant 6-fold increase in affinity.

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Purpose: The purpose of this study was to map treatment-induced (99m)Tc-Hynic-rh-annexin V uptake in normal tissues using co-registration of SPECT and CT.

Methods: Nineteen patients (11 male, 8 female, mean age 57 years) with various malignant tumours (12 lymphomas, four non-small cell lung cancers and three head and neck squamous cell carcinomas) underwent (99m)Tc-Hynic-rh-annexin V scintigraphy and CT before and within 48 h after the start of anticancer therapy. SPECT and CT were performed separately, with the patient in a reproducible position.

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Behaviourally relevant novel stimuli are known to activate the mesocorticolimbic dopaminergic (DAergic) system. In this study we tested the reactivity of this system in response to distinct kinds of novelty processing. Using the in vivo microdialysis technique, we measured extracellular amounts of dopamine (DA) in different DAergic terminal regions during a social learning task in rats.

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The purpose of our study was to test the predictive value of cisplatin-DNA adduct levels in head and neck squamous cell carcinoma (HNSCC) patients treated with cisplatin-radiation. Patients with advanced-stage HNSCC were treated within a randomized trial, investigating the optimal route of cisplatin administration, concurrently with radiation. Cisplatin was administered intra-arterially (IA, 150 mg/m2, with systemic rescue by sodium thiosulfate) or intravenously (IV, 100 mg/m2).

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Purpose: Combined modality treatment has improved outcome in various solid tumors. Besides classic anticancer drugs, a new generation of biological response modifiers has emerged that increases the efficacy of radiation. Here, we have investigated whether perifosine, an orally applicable, membrane-targeted alkylphospholipid, enhances the antitumor effect of radiation in vitro and in vivo.

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Purpose: The International Atomic Energy Agency (IAEA) held a Technical Meeting of Consultants to (1) discuss a selection of relatively new agents, not those well-established in clinical practice, that operated through a variety of mechanisms to sensitize tumors to radiation and (2) to compare and contrast their tumor efficacy, normal tissue toxicity, and status of development regarding clinical application. The aim was to advise the IAEA as to which developing agent or class of agents would be worth promoting further, by supporting additional laboratory research or clinical trials, with the eventual goal of improving cancer control rates using radiotherapy, in developing countries in particular.

Results: The agents under discussion included a wide, but not complete, range of different types of drugs, and antibodies that interfered with molecules in cell signaling pathways.

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The anticancer agent doxorubicin is in certain cases administered as a long-circulating liposomal formulation. Due to angiogenesis-related structural abnormalities in the endothelial lining of many neoplasms, these complexes tend to extravasate and accumulate in the tumor stroma. However, delivery of doxorubicin is still not optimal since liposomes are not taken up directly by tumor cells.

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In this work, we have studied the response rates and duration of response after low-dose (4 Gy) involved field radiotherapy (LD-IF-RT) in relapsed or chemotherapy refractory indolent and aggressive lymphoma patients. 71 patients (177 symptomatic sites) received LD-IF-RT consisting of 39 males and 32 females with a median age of 69 years (range 43-93). Patients included were those with small lymphocytic lymphoma/chronic lymphocytic leukaemia (n=23), marginal zone lymphoma, nodal type (n=18), mantle cell lymphoma (n=17), and diffuse large B-cell lymphoma (n=13).

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Clinical use of anti-cancer alkylphospholipids is limited by gastrointestinal toxicity. However, new interest has emerged since it was shown that these drugs enhance the cytotoxic effect of conventional chemotherapy and radiotherapy in preclinical models. The aim of this study was to characterize the pharmacokinetic profile of perifosine, an oral analog of alkylphosphocholine (APC), and to compare in vitro drug uptake with in vivo drug accumulation in three human-derived squamous cell carcinomas (A431, HNXOE and KB).

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