Publications by authors named "Thomas Behr"

Background: Salivary gland dysfunction with xerostomia is a major clinical problem without a causal therapy in most cases. The development of an animal model for scintigraphic assessment of salivary gland function has great clinical relevance for the investigation of promising new diagnostic and therapeutic strategies for chronic salivary gland diseases. This study reports the first experiences with scintigraphic analyses of salivary gland function in a rat model.

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This study describes the physicobiological characterization of PEI- and PEG-PEI polyplexes containing partially 2'-OMe modified 25/27mer dicer substrate siRNAs (DsiRNAs) and their in vivo behavior regarding biodistribution and systemic bioavailability after pulmonary application as well as their ability to knock down gene expression in the lung. Biophysical characterization included circular dichroism of siRNA in polyplexes, condensation efficiency of polymers and in vitro stability. After in vivo application, biodistribution and kinetics of radiolabeled polyplexes were quantified and recorded over time in three-dimensional SPECT images and by end point scintillation counting.

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Purpose: ReO(4)(-) has similar kinetics regarding the sodium iodide symporter (NIS) to I(-) and TcO(4)(-) in NIS-expressing tissue. We investigated the therapeutic potential of (186)ReO(4)(-) in NIS-transfected neuroendocrine tumour tissue.

Methods: For experiments, the stably NIS-transfected pancreatic neuroendocrine cancer cell line Bon1C was used.

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Objective: 99mTc-tetrofosmin single photon emission computed tomography (SPECT) is routinely used in the evaluation of coronary artery disease. A variety of different tumors, however, also demonstrate 99mTc-tetrofosmin uptake. We report six patients found with unexpected mediastinal and thoracic tumor uptake during Tc-tetrofosmin myocardial perfusion scintigraphy (MPS).

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Active as well as passive immunization against beta-amlyoid (Abeta) has been proposed as a treatment to lower cerebral amyloid burden and stabilize cognitive decline in Alzheimer's disease (AD). To clarify the mechanism of action underlying passive immunization, the in vivo distribution (and sites of degradation) of peripherally administered radiolabeled human and mouse anti-Abeta antibodies were analyzed in a transgenic mouse model of AD. In APP23 mice, a model in which mutated human amyloid precursor protein is overexpressed, the biodistribution of intravenously applicated (111)indium-conjugated affinity-purified human polyclonal autoantibodies (NAbs-Abeta) was compared to that of monoclonal anti-Abeta(1-17) (6E10), anti-Abeta(17-24) antibodies (4G8) and anti-CD-20 (Rituximab), a non-Abeta targeting control.

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Aim: The aim of this study was to determine the diagnostic value of fine-needle aspiration cytology (FNAC) before thyroidectomy in an endemic goiter region.

Methods: One hundred patients with preoperative FNAC of thyroid nodules who underwent thyroidectomy were recruited. FNAC were classified into five groups.

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Somatostatin receptor scintigraphy (SRS) is a valuable method for the detection of somatostatin receptor-positive lesions. Most gastrinomas (over-)express the somatostatin receptor subtype 2 which can be targeted by In-111 labeled Octreotide. Different studies show a high sensitivity of SRS for the localization and staging of gastrinomas.

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Purpose: There is growing interest in the human sodium/iodide symporter (NIS) gene both as a molecular imaging reporter gene and as a therapeutic gene. Here, we show the feasibility of radioisotope therapy of neuroendocrine tumors. As a separate application of NIS gene transfer, we image NIS-expressing tumors with pinhole SPECT in living subjects.

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Gastrin receptor scintigraphy (GRS) is a new imaging method primarily developed for the detection of metastases of medullary thyroid carcinoma (MTC). As gastrin-binding CCK(2) receptors are also expressed on a variety of other neuroendocrine tumours (NET), we compared GRS to somatostatin receptor scintigraphy (SRS) in patients with NET. SRS and GRS were performed within 21 days in a series of 60 consecutive patients with NET.

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Background: Cardiac allograft vasculopathy (CAV) represents a major prognostic factor in long-term survivors of heart transplantation (HTx). Reliable diagnosis of CAV late after HTx is important but remains the domain of invasive techniques such as coronary angiography.

Methods: To test alternative approaches, 54 consecutive HTx recipients (mean time since HTx: 52 months) were studied with intravascular ultrasound (IVUS), angiography, dobutamine stress echocardiography and immunofluorescence staining against anti-thrombin III (AT-III) in endomyocardial biopsies.

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Experimental Objectives: In vivo imaging of GLP-1 receptor-positive tissues may allow examination of physiologic and pathophysiologic processes. Based on the GLP-1 analog Exendin 4, we have developed a radiolabeled compound specifically targeting the GLP-1 receptor (DTPA-Lys40-Exendin 4). This work aims to detect GLP-1 receptor-positive tissues by biodistribution studies and in vivo small animal imaging studies.

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Purpose: Radiopeptide imaging is a valuable imaging method in the management of patients with neuroendocrine tumours (NET). To determine the clinical performance of gastrin receptor scintigraphy (GRS), it was compared with somatostatin receptor scintigraphy (SRS), computed tomography (CT) and (18)F-FDG positron emission tomography (PET) in patients with metastasised/recurrent medullary thyroid carcinoma (MTC).

Methods: Twenty-seven consecutive patients underwent imaging with GRS, SRS (19 patients), CT and PET (26 patients).

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Tens of millions of cataract surgeries are done every year and the number is increasing heavily. Posterior capsule opacification is the major postoperative complication with an incidence of 10 to 50% within 5 years, depending on the age of the patient. We present a novel approach for secondary cataract treatment in a noninvasive manner.

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Rationale And Objectives: Electronic learning (e-learning) may provide a means to enhance learning efficacy. However, introduction of e-learning often fails. We describe a strategy of how an e-learning curriculum was successfully implemented.

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Unlabelled: The aim of this study was to evaluate 3 new (99m)Tc-labeled minigastrin analogs modified with open chain tetraamines at the N-terminus for their suitability in the CCK-2/gastrin-R-targeted imaging of tumors (CCK-2/gastrin-R = cholecystokinin subtype 2/gastrin receptor).

Methods: The [(D)Glu(1)]minigastrin sequence was assembled on the solid support and the respective tetraamine precursors coupled at the N-terminus. Purified peptide conjugates were labeled with (99m)Tc under alkaline conditions.

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Purpose: Although complete resection (R0) of liver metastases (LM) remains the treatment of choice for colorectal cancer (CRC) patients amenable to curative therapy, only approximately one third survive for 5 years. The objective of this phase II study was to evaluate the safety and efficacy of radioimmunotherapy (RAIT) after salvage resection of LM.

Patients And Methods: Twenty-three patients who underwent surgery for LM of CRC received a dose of 40 to 60 mCi/m2 of 131I-labetuzumab, which is a humanized monoclonal antibody against carcinoembryonic antigen.

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Unlabelled: Uptake of radiolabeled peptides in the kidneys may obscure abdominal tumors in radiopeptide scintigraphy. This problem is much more pronounced in peptide receptor radionuclide therapy (i.e.

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For detection of most members of the Enterococcaceae, the specificity of a novel oligonucleotide microarray (ECC-PhyloChip) consisting of 41 hierarchically nested 16S or 23S rRNA gene-targeted probes was evaluated with 23 pure cultures (including 19 Enterococcus species). Target nucleic acids were prepared by PCR amplification of a 4.5-kb DNA fragment containing large parts of the 16S and 23S rRNA genes and were subsequently labeled fluorescently by random priming.

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Background: The majority of patients with head and neck squamous cell carcinoma (HNSCC) who have a clinical N0 neck undergo neck dissection (ND) even though no lymph node metastases may be detected. With this background, our investigation critically analyzes the value of sentinel lymphadenectomy.

Methods: Ninety patients with HNSCC, all staged with an N0 neck, underwent intraoperative 99mTc-radiolabeled detection of up to three hot nodes (SN1-3) during elective ND and primary site resection.

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Objective: The mitogen-activated protein (MAP) kinase system, especially the p38 MAP kinase, is activated in chronic heart failure (CHF). However, the role of vascular p38 MAP kinase in CHF has not been analyzed yet.

Methods And Results: In aortic rings from rats with CHF 10 weeks after myocardial infarction, acetylcholine-induced relaxation was attenuated (maximum relaxation, Rmax: 54+/-5%) compared to sham-operated animals (Rmax: 77+/-5%, p<0.

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A broad spectrum of radiolabeled peptides with high affinity for receptors expressed on tumor cells is currently under preclinical and clinical investigation for scintigraphic imaging and radionuclide therapy. The present paper evaluates two (99m)Tc-labeled forms of the C-terminal octapeptide of cholecystokinin (CCK8): sulfated (s)CCK8, with high affinity for CCK1 and CCK2 receptors, and nonsulfated (ns)CCK8, with high affinity for CCK2 receptors but low affinity for CCK1 receptors. Peptides were conjugated with the bifunctional chelator N-hydroxysuccinimidyl hydrazino niconitate (s-HYNIC).

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Aim: To determine the clinical potential of 2-[F]fluoro-2-deoxy-D-glucose positron emission tomography (F-FDG PET) in patients with medullary thyroid carcinoma (MTC), we compared it to computed tomography (CT), and somatostatin receptor scintigraphy (SRS).

Patients And Methods: Blinded evaluation of PET, CT and SRS images obtained from 26 patients with histologically proven metastatic MTC was done by nuclear medicine and radiology specialists. Sites of tumour involvement were classified as "sure" or "suspicious".

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Objective: The purpose of this investigation was to determine whether angiotensin II receptor (AII1R) antagonism interferes with cardiac monocyte chemoattractant protein-1 (MCP-1) expression in hypertrophic cardiomyopathy and failure.

Design: We studied the effects of the AII1R antagonist eprosartan on MCP-1 expression, and on the recruitment of macrophages into the myocardium in a model of cardiac hypertrophy and morbidity/mortality.

Methods: Stroke-prone spontaneously hypertensive rats fed a high-salt, high-fat diet (SFD) developed heart failure characterized by left ventricular (LV) hypertrophy/pathology and hypocontractility.

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The increasing interest in the so-called sentinel node concept, which has recently been adapted to squamous cell carcinomas of the upper aerodigestive tract, can be explained by encouraging results in other tumor entities. Although the publications on this topic do not yet allow a final judgment on the significance of sentinel lymphadenectomy in head and neck squamous cell carcinoma, early results emphasize the importance of this new diagnostic and therapeutic concept. The basic prerequisite is a detailed knowledge of the existing method-specific limitations in this anatomic region.

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There is a considerable discrepancy in the literature concerning the sensitivity of parathyroid scintigraphy (PS) with 99mTc-MIBI. We therefore analyzed our own data and compared them to the literature in a metaanalysis. All patients who received 99mTc -MIBI scintigraphy and subsequent surgery in our department for the detection of enlarged parathyroid glands in primary (pHPT) or secondary (sHPT) hyperparathyroidism between 1991 and 1999 were included in our retrospective analysis.

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