Publications by authors named "Hach A"

Aim: Thyroid scintigraphy enables the depiction of the functional status of thyroid nodules (TNs) with both, Tc-pertechnetate and Iodine. The functional status is relevant for diagnostic procedures for the differentiation of benign and malignant TNs. The aim of this study was to examine the current frequencies of hyper-, hypo- and isofunctioning TNs in Germany and to estimate the risk of malignancy with regard to functional status.

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Despite the reduced life expectancy and staggering financial burden of medical treatment associated with tobacco smoking, the molecular, cellular, and ensemble adaptations associated with chronic nicotine consumption remain poorly understood. Complex circuitry interconnecting dopaminergic and cholinergic regions of the midbrain and mesopontine tegmentum are critical for nicotine associated reward. Yet our knowledge of the nicotine activation of these regions is incomplete, in part due to their cell type diversity.

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Background: Reported results for thyroid nodule fine-needle aspiration (FNA) cytology mainly originate from tertiary centers. However, thyroid nodule FNA cytology is mainly performed in primary care settings for which the distribution of FNA Bethesda categories and their respective malignancy rates are largely unknown. Therefore, this study investigated FNA cytology malignancy rates of a large primary care setting to determine to what extent current evidence-based strategies for the malignancy risk stratification of thyroid nodules are applied and applicable in such primary care settings.

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Background: Major differences with respect to the diagnostic performance of a "ruling in" approach in the presurgical diagnosis of indeterminate thyroid fine-needle aspirations (FNAs) have been reported. Therefore, the aim of this prospective multicenter study was to investigate the specific diagnostic impact of mutation testing using a seven-gene panel in a routine primary referral setting analyzing FNAs from endocrinology and nuclear medicine practices in Germany.

Methods: RNA and DNA was extracted from 564 routine air-dried FNA smears obtained from 64 physicians and cytologically graded by one experienced cytopathologist.

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Low-density wood fiber insulation boards are traditionally manufactured in a wet process using a closed water circuit (process water). The water of these industrial processes contains natural phenolic extractives, aside from small amounts of admixtures (e.g.

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Background And Objective: Results for the detection of point mutations and rearrangements have thus far been obtained by fresh material of fine needle aspiration cytology (FNAC). After a first retrospective study we report on the diagnostic detection in routinely obtained, consecutive air-dried FNAC smears.

Methods: RNA and DNA was extracted from 154 consecutive routine air-dried FNAC smears: 80 with microfollicular proliferation (MFP), 45 with follicular neoplasia (FN), 26 with the cytological diagnosis of papillary carcinomas (PTC) and 3 which were suspicious for malignancy.

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Aim: In recent years, various professional societies published guidelines for diagnostic evaluation of thyroid nodules, in which the indication for scintigraphy is restricted to patients with subnormal TSH values. It is seen controversial whether such recommendations should be transferred to Germany, partly because of lower iodine intake in this country and the consequent higher percentage of autonomous thyroid nodules, which are not accompanied by a measurable dysfunction. Since reliable data to this topic are scarce, we analyzed multicentrically the spectrum of scintigraphically "hot" and "warm" nodules under the current epidemiological conditions.

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Current models evoke the plasma membrane (PM) as the exclusive platform from which Ras regulates signalling. We developed a fluorescent probe that reports where and when Ras is activated in living cells. We show that oncogenic H-Ras and N-Ras engage Raf-1 on the Golgi and that endogenous Ras and unpalmitoylated H-Ras are activated in response to mitogens on the Golgi and endoplasmic reticulum (ER), respectively.

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In Saccharomyces cerevisiae, heme directly mediates the effects of oxygen on transcription through the heme activator protein Hap1. In the absence of heme, Hap1 is bound by at least four cellular proteins, including Hsp90 and Ydj1, forming a higher-order complex, termed HMC, and its activity is repressed. Here we purified the HMC and showed by mass spectrometry that two previously unidentified major components of the HMC are the Ssa-type Hsp70 molecular chaperone and Sro9 proteins.

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Heme is a key molecule in mediating the effects of oxygen on various molecular and cellular processes in many living organisms. In the yeast Saccharomyces cerevisiae, heme serves as a secondary signal for oxygen; intracellular heme synthesis directly correlates with oxygen tension in the environment. In yeast, oxygen sensing and heme signaling are primarily mediated by the heme activator protein Hap1, which, in response to heme, activates the transcription of genes required for respiration and for controlling oxidative damage.

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Heme regulation of the activity of diverse proteins was thought to be mediated by heme-responsive motifs (HRMs). The yeast transcriptional activator Hap1 contains seven HRMs: HRM1-7. Three copies of a 17-amino-acid repeat are also located in the region encompassing HRM1 to -6.

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The heme activator protein Hap1 is a member of the yeast Gal4 family, which consists of transcription factors with a conserved Zn(2)Cys(6) cluster that recognizes a CGG triplet. Many members of the Gal4 family contain a coiled coil dimerization element and bind symmetrically to DNA as homodimers. However, Hap1 possesses two unique properties.

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In the absence of heme, Hap1 is associated with molecular chaperones such as Hsp90 and Ydj1 and forms a higher order complex termed HMC. Heme disrupts this complex and permits Hap1 to bind to DNA with high affinity, thereby activating transcription. Heme regulation of Hap1 activity is analogous to the regulation of steroid receptors by steroids, which involves molecular chaperones.

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Heme plays key regulatory roles in numerous molecular and cellular processes for systems that sense or use oxygen. In the yeast Saccharomyces cerevisiae, oxygen sensing and heme signaling are mediated by heme activator protein 1 (Hap1). Hap1 contains seven heme-responsive motifs (HRMs): six are clustered in the heme domain, and a seventh is near the activation domain.

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Apart from serving as a prosthetic group in globins and enzymes, heme is a key regulator controlling a wide range of molecular and cellular processes involved in oxygen sensing and utilization. To gain insights into molecular mechanisms of heme signaling and oxygen sensing in eukaryotes, we investigated the yeast heme-responsive transcriptional activator HAP1. HAP1 activity is regulated precisely and tightly by heme.

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Light and electron microscopic immunolocalization of taurine, a sulfur-containing free amino acid, was investigated in the photoneuroendocrine pineal organ and the retinal photoreceptor and pigment epithelial layer of the ayu Plecoglossus altivelis, an anadromous fish. Intense immunostaining was found in the outer segments of pineal photoreceptors and retinal cone-like cells. Moderate but definite immunostaining was found in the cytoplasmic processes of pineal supporting cells, the outer segments of retinal rod-like cells, and the apical processes of pigment epithelial cells.

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Multicopy single-stranded DNA (msDNA) molecules consist of single-stranded DNA covalently linked to RNA. In Escherichia coli, such molecules are encoded by genetic elements called retrons. The DNA moieties of msDNAs have characteristic stem-loop structures, and most of these structures contain mismatched base pairs.

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Taurine-like immunoreactivity (TLI) is found in the pigeon retina at high levels within cones, in select cells of the inner nuclear layer and in sublaminae of the inner plexiform layer. At the ultrastructural level a high density of immuno-gold particles in visualized in the ellipsoid, but not in the paraboloid area of the inner segment. It is present in perikarya and the presynaptic endings of cones, but not in postsynaptic cell processes.

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Nuclear medical examinations of children have to be performed with special regard to the problems of radiation protection because of the high radiation sensitivity esp. of infants and young children. The present contribution describes how any unnecessary radiation exposure can be avoided by the correct choice and planning of a nuclear medical study, by using the appropriate radiopharmaceutical as well as by the exact calculation of the amount of activity applied, depending on body surface resp.

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Bone scintigraphy with 99mtechnetium-labelled polyphosphonates is the most sensitive test for early detection of skeletal metastases. Bone metastases are a major factor in prognosis and have a considerable influence on the therapy selected. In patients with prostate cancer, we recommend routine bone scintigraphy in the initial staging.

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Nuclear medicine examinations hold an important position in the diagnosis of diseases of the spine. During the last decade, decisive progress has been made in the field of instrumentation and radiopharmaceutical techniques: the use of high resolution collimators and the introduction of emission computer tomography as examples of improved instrumentation as well as 99m-Technetium red blood cell labelling as a new radiopharmaceutical technique. These present some of the developments responsible for the growing importance of scintigraphical diagnosis.

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The clinical usefulness of immunoscintigraphy with the monoclonal anti-CEA (carcinoembryonic antigen) antibody BW431/26, directly labelled with 99m-Technetium in targeting colorectal carcinomas was investigated in 43 patients. In addition, tumour cell grading and CEA-expression were examined immunohistochemically. Best imaging results were obtained in pelvic tumour lesions (sensitivity 80%).

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Concerning malignant tumours of the oral cavity, pharynx and larynx, bone metastases are in general rarely seen. For the specification to which patients the whole body bone scintigraphy as detection method should be applied, the findings of 370 patients were analysed retrospectively. In respect of primary staging, bone metastases could be found by scintigraphy in only 1.

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