[Ga-68-PSMA PET/CT for prostate cancer].

Prostate-specific membrane antigen (PSMA) is expressed as a cell surface protein physiologically in the prostate and can be found in all stages of prostate cancer. Even in castration-resistant prostate cancers, this overexpression of PSMA occurs. Due to the enzymatic activity of PSMA it was possible develop specific inhibitors from which "small molecule" radiopharmaceuticals were derived.

The impact of simulated and real microgravity on bone cells and mesenchymal stem cells.

How microgravity affects the biology of human cells and the formation of 3D cell cultures in real and simulated microgravity (r- and s-µg) is currently a hot topic in biomedicine. In r- and s-µg, various cell types were found to form 3D structures. This review will focus on the current knowledge of tissue engineering in space and on Earth using systems such as the random positioning machine (RPM), the 2D-clinostat, or the NASA-developed rotating wall vessel bioreactor (RWV) to create tissue from bone, tumor, and mesenchymal stem cells.

Mechanisms of apoptosis in irradiated and sunitinib-treated follicular thyroid cancer cells.

The multikinase inhibitor sunitinib (S) seems to have promising potential in the treatment of thyroid cancer. We focused on the impact of S and/or irradiation (R) on mechanisms of apoptosis in follicular thyroid cancer cells. The effects of R, S and their combination were evaluated 2 and 4 days after treatment, using the human thyroid cancer cell line CGTH W-1.

Impact of sunitinib on human thyroid cancer cells.

Background/aims: Thyroid cancer accounts for about 1% of all cancer cases. Multikinase inhibitors like sunitinib (S) have a promising potential in thyroid cancer therapy. Therefore, the principal aim of this study was to investigate the impact of sunitinib on the secretion of cytokines of follicular thyroid cancer cells.

Interaction of proteins identified in human thyroid cells.

Influence of gravity forces on the regulation of protein expression by healthy and malignant thyroid cells was studied with the aim to identify protein interactions. Western blot analyses of a limited number of proteins suggested a time-dependent regulation of protein expression by simulated microgravity. After applying free flow isoelectric focusing and mass spectrometry to search for differently expressed proteins by thyroid cells exposed to simulated microgravity for three days, a considerable number of candidates for gravi-sensitive proteins were detected.

Gravity-sensitive signaling drives 3-dimensional formation of multicellular thyroid cancer spheroids.

This study focused on the effects induced by a random positioning machine (RPM) on FTC-133 thyroid cancer cells and evaluated signaling elements involved in 3-dimensional multicellular tumor spheroid (MCTS) formation. The cells were cultured on the RPM, a device developed to simulate microgravity, and under static 1-g conditions. After 24 h on the RPM, MCTSs swimming in culture supernatants were found, in addition to growth of adherent (AD) cells.

Cell separation by countercurrent centrifugal elutriation: recent developments.

Countercurrent centrifugal elutriation (CCE) is a cell separation technique that separates particles predominantly according to their size, and to some degree according to their specific density, without a need for antibodies or ligands tagging cell surfaces. The principles of this technique have been known for half a century. Still, numerous recent publications confirmed that CCE is a valuable supplement to current cell separation technology.

Short-term weightlessness produced by parabolic flight maneuvers altered gene expression patterns in human endothelial cells.

This study focused on the effects of short-term microgravity (22 s) on the gene expression and morphology of endothelial cells (ECs) and evaluated gravisensitive signaling elements. ECs were investigated during four German Space Agency (Deutsches Zentrum für Luft- und Raumfahrt) parabolic flight campaigns. Hoechst 33342 and acridine orange/ethidium bromide staining showed no signs of cell death in ECs after 31 parabolas (P31).

Diagnostic and therapeutic use of membrane proteins in cancer cells.

As proteomics technologies develop, increasing number of membrane-associated proteins specific for cancer cells are being discovered. These proteins are of great interest, particularly because they are rich in targets for antibodies. Amongst them candidate biomarkers for early tumor diagnosis, prognosis and treatment have been detected.

18F-FET-PET-based dose painting by numbers with protons.

Purpose: To investigate the potential of (18)F-fluoroethyltyrosine-positron emission tomography-((18)F-FET-PET-)based dose painting by numbers with protons.

Material And Methods: Due to its high specificity to brain tumor cells, FET has a high potential to serve as a target for dose painting by numbers. Biological image-based dose painting might lead to an inhomogeneous dose prescription.

Changes of apoptosis, p53, and bcl-2 by irradiation in poorly differentiated thyroid carcinoma cell lines: a prognostic marker for the prospect of therapeutic success?

Background: Poorly differentiated thyroid carcinoma (PDTC) has an unfavorable prognosis. Surgical management is the principal treatment approach. In addition, radioiodine treatment and external beam radiotherapy (EBRT) are given to reduce the risk of local relapse.

Staged surgery with neoadjuvant 90Y-DOTATOC therapy for down-sizing synchronous bilobular hepatic metastases from a neuroendocrine pancreatic tumor.

Purpose: Treatment with DOTA-d-Phe(1)-Tyr(3)-octreotide (DOTATOC), labeled with beta-emitting radioisotope yttrium-90 ((90)Y-DOTATOC), has successfully been used for the palliative treatment of patients with advanced somatostatin receptor-expressing neuroendocrine tumors (NETs). However, controversy persists as to whether patients with metastatic NETs of the pancreas should undergo radical (salvage) surgery or receive palliative therapy. We proposed that (90)Y-DOTATOC could be used in a neoadjuvant intention for improving therapy of hepatic NET metastases.

Radiolabeled annexin V for imaging apoptosis in radiated human follicular thyroid carcinomas--is an individualized protocol necessary?

Introduction: Induction of apoptosis is a widely used strategy for cancer therapy, but evaluating the degree and success of this therapy still poses a problem. Radiolabeled annexin V has been proposed to be a promising candidate for detecting apoptotic cells in tumors following chemotherapy in vivo. In order to see whether radiolabeled annexin V could be a suitable substance for the noninvasive in vivo detection of apoptosis in thyroid tissue and to establish an optimized study protocol, we investigated two poorly differentiated thyroid carcinoma cell lines: ML-1 and FTC-133.

A biologically adapted dose-escalation approach, demonstrated for 18F-FET-PET in brain tumors.

Purpose: To demonstrate the feasibility of a biologically adapted dose-escalation approach to brain tumors.

Material And Methods: Due to the specific accumulation of fluoroethyltyrosine (FET) in brain tumors, (18)F-FET-PET imaging is used to derive a voxel-by-voxel dose distribution. Although the kinetics of (18)F-FET are not completely understood, the authors regard regions with high tracer uptake as vital and aggressive tumor and use a linear dose-escalation function between SUV (standard uptake value) 3 and SUV 5.

Significance of scintigraphy for the localisation of obscure gastrointestinal bleedings.

Aim: To determine the role of scintigraphy in patients with gastrointestinal (GI) bleeding of unknown localisation.

Methods: We performed retrospective analyses on 92 patients receiving scintigraphies from 1993 to 2000 in the University of Regensburg hospital, which were done for localisation of GI bleeding as a diagnostic step after an unsuccessful endoscopy. In addition to the scintigraphies, further diagnostic steps such as endoscopy, angiography or operations were performed.

Innovative strategies in in vivo apoptosis imaging.

Apoptosis (programmed cell death) plays a key role in the pathogenesis of many disorders including cerebral and myocardial ischemia, autoimmune and neurodegenerative diseases, infections, organ and bone marrow transplant rejection, and tumor response to chemotherapy and/or radiotherapy. Apoptosis in itself represents a complex mechanism where numerous (pro-apoptotic and anti-apoptotic) molecules interact in an elaborate manner. Since the original description by Kerr et al.

Papillary microcarcinoma and papillary cancer of the thyroid

Aims: Major controversies exist regarding the treatment of papillary microcarcinoma of the thyroid (PMC). Prior to 2003 PMC was defined by the WHO as a papillary carcinoma of 1 cm or less in diameter. In 2004 that definition changed, with the new classification requiring that the tumour also must be found incidentally.

Clinical value of planar and tomographic dual-isotope scintigraphy using 99mTc-methylene diphosphonate and 131I in patients with thyroid cancer.

Purpose: (131)I whole-body scintigraphy is a highly sensitive method for the detection of differentiated thyroid tumours and metastases. However, a lack of anatomical landmarks and the physiological excretion of the tracer complicates the evaluation of the images. Therefore, we determined whether additional bone scintigraphy in combination with (131)I scintigraphy, simultaneously acquired via planar and tomographic techniques, positively contributes to the treatment plan in patients with non-conclusive (131)I images.

Mechanisms of regional wall motion abnormalities in contrast-enhanced dobutamine stress echocardiography.

Background: In the diagnosis of coronary artery disease (CAD) with Dobutamine Stress Echocardiography (DSE), regional wall motion abnormalities (RWMA) are assumed to indicate a perfusion deficit.

Methods And Results: For a more particular examination of RWMAs, we compared simultaneous echo-contrast (Optisone)-enhanced DSE (0-40 microg/kg Dobutamine, 16-segment- model) and MiBi-SPECT in a prospective double-blinded study design in 69 non-selected consecutive patients (44 male, 25 female, age 64+/-12 years). Additionally, all patients were examined by coronary-angiography.

[Integration of PACS and HIS into the workflow of a nuclear medicine department. Experience in Regensburg].

Aim: The development of new diagnostic techniques and the implementation of a modern quality control management system requires the continuous adaptation of existing data processing tools to the nuclear medicine diagnostic workflow. Furthermore, PACS connected to HIS facilitates and enhances the transfer of data and pictures, and satisfies the legal requirements for data retention as regulated by law. Therefore, the aim of this work is to present the architecture, structure and results of such a system newly installed in a department of nuclear medicine.

Vasculitis of the aortic arch and cardiac valves as the cause of relapsing fever of unknown origin in an elderly, white man.

Here, we report the case of fever of unknown origin (FUO) in a 77-year-old white man. The patient presented with a 3-week history of fever (between 38.5 and 39 degrees C) and general malaise.

Retinoid- and sodium-butyrate-induced decrease in heat shock protein 70 membrane-positive tumor cells is associated with reduced sensitivity to natural killer cell lysis, growth delay, and altered growth morphology.

Human tumors frequently present heat shock protein 70 (Hsp70) on their cell membranes, whereas corresponding normal tissues fail to do so. Therefore, an Hsp70 membrane-positive phenotype provided a tumor-specific marker. Moreover, membrane-bound Hsp70 provides a target structure for the cytolytic attack mediated by natural killer (NK) cells.

Evaluation of the clinical value of bone metabolic parameters for the screening of osseous metastases compared to bone scintigraphy.

BACKGROUND: Bone metastases are common in many types of cancer. As screening methods different imaging modalities are available. A new approach for the screening of osseous metastases represents the measurement of bone metabolic markers.

Effects of PTK787/ZK222584, a tyrosine kinase inhibitor, on the growth of a poorly differentiated thyroid carcinoma: an animal study.

The process of neoangiogenesis is induced by several mediators. Vascular endothelial growth factor (VEGF) plays a key role in tumor angiogenesis including thyroid carcinomas. The principal aim of this study was to test the hypothesis that inhibition of VEGF activity by PTK787/ZK222584 (PTK/ZK), a specific blocker of both VEGF-receptor tyrosine kinases, could inhibit the growth of a poorly differentiated thyroid cancer.