Publications by authors named "Verhofstad A"

Purpose: Experimental studies indicate that perioperative hypoperfusion impairs anastomotic healing. In bowel surgery, the part of bowel that will be anastomosed is often pedicled, leaving the blood supply dependent on the marginal artery only. Little is known about the blood supply in such a segment, and whether anastomotic strength is affected when flow would be reduced.

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Background: Phaeochromocytomas and paragangliomas are neuro-endocrine tumours that occur sporadically and in several hereditary tumour syndromes, including the phaeochromocytoma-paraganglioma syndrome. This syndrome is caused by germline mutations in succinate dehydrogenase B (SDHB), C (SDHC), or D (SDHD) genes. Clinically, the phaeochromocytoma-paraganglioma syndrome is often unrecognised, although 10-30% of apparently sporadic phaeochromocytomas and paragangliomas harbour germline SDH-gene mutations.

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Pheochromocytomas (PCC) are catecholamine-producing tumors arising from the adrenal medulla that occur either sporadically or in the context of hereditary cancer syndromes, such as multiple endocrine neoplasia type 2 (MEN2), von Hippel-Lindau disease (VHL), neurofibromatosis type 1, and the PCC-paraganglioma syndrome. Conventional comparative genomic hybridization studies have shown loss of 1p and 3q in the majority of sporadic and MEN2-related PCC, and 3p and 11p loss in VHL-related PCC. The development of a submegabase tiling resolution array enabled us to perform a genome-wide high-resolution analysis of 36 sporadic benign PCC.

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Objectives: Histopathology of prostate needle biopsies (PNBs) is an important part in the diagnosis, prognosis and treatment evaluation of prostate cancer. The determination of metabolite levels in the same biopsies may have additional clinical value. Here, we demonstrate the use of non-destructive high resolution magic angle spinning (HRMAS) proton NMR Spectroscopy for the assessment of metabolic profiles of prostate tissue in PNBs as commonly obtained in standard clinical practice.

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The treatment of choice for non-metastatic pheochromocytoma is surgical resection. Its goals are to abolish catecholamine hypersecretion, normalize blood pressure, and prevent further tumor growth or progression to metastatic disease. Data on long-term mortality and morbidity after pheochromocytoma surgery are limited.

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The clinical behavior of endocrine pancreatic tumors (EPTs) is difficult to predict in the absence of metastases or invasion to adjacent organs. Several markers have been indicated as potential predictors of metastatic disease, such as tumor size > or =2 cm, Ki67 proliferative index > or =2%, cytokeratin (CK) 19 status, and recently in insulinomas, chromosomal instability (CIN). The goal of this study was to evaluate the value of these markers, and in particular of the CIN, to predict tumor recurrence or progression and tumor-specific death, using a series of 47 insulinomas and 24 non-insulinoma EPTs.

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Pheochromocytomas (PCCs) are rare tumors that arise from chromaffin tissue in the adrenal medulla, but can also occur in the abdomen outside the adrenals and are then called sympathetic paragangliomas (sPGLs). According to the literature, between 15 and 25% of apparently sporadic adrenal PCC and sPGL are caused by germline mutations in RET, von Hippel-Lindau disease (VHL), succinate dehydrogenase subunit B (SDHB), or subunit D SDHD. However, few studies have addressed the mutationfrequency of these candidate genes in selected subgroups of PCC andsPGL, such as bilateral adrenal PCC or extra-adrenal sPGL, and none have looked at somatic mutations by analyzing tumor tissue.

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Both polyamine metabolism and DNA methylation play an important role in normal and malignant growth. Specific enzyme inhibitors or drugs that interfere with these metabolic pathways have proven to be potential anticancer agents. Since DNA methylation and polyamine metabolism depend on a common substrate, i.

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Objective: Pheochromocytomas are uncommon tumours arising from chromaffin cells of the adrenal medulla and related paraganglia. So far, one of the few reported markers to discriminate malignant from benign tumours is the betaB-subunit of inhibin and activin, members of the transforming growth factor (TGF)-beta superfamily of growth and differentiation factors.

Design: We investigated the expression of the mRNAs coding for activin and inhibin subunits, their receptors and binding proteins by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and studied the presence of the inhibin betaB-subunit in human pheochromocytomas by immunohistochemistry.

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Introduction: Gemcitabine has been shown to exert a radiosensitizing effect in various epithelial cancers. The aim of the present studies was to investigate whether the efficacy of radioimmunotherapy (RIT) using the (131)I-labeled anti-CEA monoclonal antibody (MAb) MN-14 could be enhanced by coadministration of gemcitabine in nude mice with small (1-3 mm) peritoneal metastases of colonic origin.

Materials And Methods: Firstly, the maximum tolerated dose (MTD) of gemcitabine was determined, when administered intraperitoneally at two different dosing schedules (0.

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Pheochromocytomas (PCCs) are neuroendocrine tumors of chromaffin tissue that produce catecholamines. They are usually located in the adrenal medulla, although in about 10% the tumors arise from extra-adrenal chromaffin tissue. The majority of PCCs arise sporadically, but PCCs occur also in the context of hereditary cancer syndromes.

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Brain-derived neurotrophic factor (BDNF) belongs to the neurotrophin family of neuronal cell survival and differentiation factors but is thought to be involved in neuronal cell proliferation and myelination as well. To explore the role of BDNF in vivo, we employed the intermediate pituitary melanotrope cells of the amphibian Xenopus laevis as a model system. These cells mediate background adaptation of the animal by producing high levels of the prohormone proopiomelanocortin (POMC) when the animal is black adapted.

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Background: Multiple factors contribute to the process of prosthetic graft failure. Some of them are specifically related to the biological behavior of the used materials. To pursue the ideal substitute for the autologous vein graft, many materials have been taken into consideration.

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Pheochromocytomas (PCC) are relatively rare neuroendocrine tumors, mainly of the adrenal medulla. They arise sporadically or occur secondary to inherited cancer syndromes, such as multiple endocrine neoplasia type II (MEN2), von Hippel-Lindau disease (VHL), or neurofibromatosis type I (NF1). Loss of 1p is the most frequently encountered genetic alteration, especially in MEN2-related and sporadic PCC.

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Endocrine pancreatic tumors (EPTs) comprise a highly heterogeneous group of tumors with different clinical behavior and genetic makeup. Insulinomas represent the predominant syndromic subtype of EPTs. The metastatic potential of insulinomas can frequently not be predicted using histopathological criteria, and also molecular markers indicating malignant progression are unreliable because of the small number of cases per subtype studied so far.

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Background: Inhibition of the COX-2 enzyme has been shown to have a radiosensitizing effect in epithelial cancers. The aim of this study was to investigate whether the efficacy of radioimmunotherapy (RIT) using 131I-labeled anti-CEA monoclonal antibody MN-14 could be enhanced by co-administration of the selective COX-2 inhibitor Parecoxib in mice with small volume (1-3 mm) peritoneal carcinomatosis of colonic origin.

Methods: First, the efficacy of 14 daily injections of Parecoxib monotherapy (0-0.

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Purpose: We examined the value of SDHD mutation screening in patients presenting with apparently sporadic and familial pheochromocytoma for the identification of SDHD-related pheochromocytomas.

Patients And Methods: This retrospective study involved 126 patients with adrenal or extra-adrenal pheochromocytomas, including 24 patients with a family history of multiple endocrine neoplasia 2, von Hippel-Lindau disease, neurofibromatosis type 1, or paraganglioma (PGL). Conformation-dependent gel electrophoresis and sequence determination analysis of germline and tumor DNA were used to identify SDHD alterations.

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The enzyme ornithine decarboxylase (ODC) and its regulatory protein antizyme-1 (AZ1) are key regulators in the homeostasis of polyamines. To gain more insight into the exact intracellular distribution of ODC and AZ1, we performed immunocytochemical and Green Fluorescent Protein-fluorocytochemical studies in cultured human cervix carcinoma and human prostatic carcinoma (PC-346C) cells. ODC localization patterns varied from predominantly cytoplasmic to both cytoplasmic and nuclear staining, whereas AZ1 was mostly found in the nucleus.

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Purpose: To differentiate prostate carcinoma from healthy peripheral zone and central gland using quantitative dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging and two-dimensional (1)H MR spectroscopic imaging (MRSI) combined into one clinical protocol.

Materials And Methods: Twenty-three prostate cancer patients were studied with a combined DCE-MRI and MRSI protocol. Cancer regions were localized by histopathology of whole mount sections after radical prostatectomy.

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Matrix metalloproteinases (MMPs) have been implicated as mediators of tissue damage in several inflammatory diseases. Since the multiple organ dysfunction syndrome (MODS) is thought to result from systemic inflammation, overactivation of MMPs could contribute to the organ damage observed. The expression and activity of several MMPs were studied in a murine model for MODS.

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Unlabelled: Therapeutic efficacy in radioimmunotherapy depends, among other things, on the choice of the radionuclide. The aim of the present study was to determine the most suitable radionuclide for radioimmunotherapy with monoclonal antibody MN-14 to carcinoembryonic antigen in an experimental model of small peritoneal metastases of colorectal origin.

Methods: In nude mice with intraperitoneal LS174T tumors (diameter, 1-3 mm), the biodistributions of MN-14 labeled with (131)I ((131)I-MN-14), (186)Re-mercaptoacetyltriglycine ((186)Re-MN-14), and (88)Y-diethylenetriaminepentaacetic acid (DTPA) ((88)Y-MN-14) after intravenous and intraperitoneal administration were determined.

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A hallmark of Type 2 diabetes mellitus (T2DM) is chronic hyperglycemia, which is thought to play a role in pancreatic beta-cell failure. Here we investigated whether treatment of Zucker diabetic fatty (ZDF) rats, an animal model for T2DM, with the renal glucose transport inhibitor phlorizin could prevent alterations in the pancreatic islets. ZDF rats were treated with phlorizin or vehicle for 13 weeks starting with 6-week-old rats and before the onset of hyperglycemia.

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Background: The strength of intestinal anastomoses is relatively low in the first days after operation, possibly as a result of localized degradation of the supporting matrix by enzymes from the matrix metalloproteinase (MMP) family. The aim of this study was to examine whether doxycycline, a drug known to inhibit MMP activity, could enhance anastomotic strength.

Methods: Male Wistar rats received anastomoses in both ileum and colon.

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The importance of polyamines in prostatic growth and differentiation has prompted studies to evaluate the clinical relevance of the ornithine decarboxylase/polyamine system in prostatic cancer. These studies show that differences in biological behaviour of prostatic (cancer) cells are associated with changes in polyamine levels and/or the activity of their metabolic enzymes. Faulty antizyme regulation of polyamine homoeostasis may play an important role in the growth and progression of prostatic carcinoma.

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