Publications by authors named "Anton Sadjak"

Medullary thyroid carcinoma (MTC) originates from the C‑cells of the thyroid and is not sensitive to radiation or chemotherapy. Therefore, surgical removal of the tumor tissue in its entirety is the only curative treatment for MTC. The present study aimed to examine the potential mechanisms of action of extracts of Trailliaedoxa gracilis (TG; WW Smith & Forrest), a plant from the province of Sichuan, China, and of ursolic acid (UA), a pentacyclic triterpen present in TG, on the MTC‑SK MTC cell line.

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Background/aim: Medullary thyroid carcinoma (MTC) is a tumor associated with poor prognosis since it exhibits high resistance against conventional cancer therapy. Recent studies have shown that quinazolines exhibit a pro-apoptotic effect on malignant cells. The aim of the present study was to elucidate whether MTC cells are affected by quinazolines, in particular prazosin.

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Neuroendocrine tumors are relatively insensitive to radiation therapy, as well as chemotherapy. Thus, new approaches for alternative therapies are needed. We found that glutamate receptor antagonists are capable of suppressing tumor growth and cell activity of different peripheral malignancies.

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Neuroendocrine tumors respond poorly to radiation and conventional chemotherapy, hence surgical removal of the neoplastic tissue is still the most effective way of treatment. In an attempt to find new therapeutic plant extracts of Christia vespertilionis (CV) their antitumor potential in human medullary thyroid carcinoma (MTC) and human small intestinal neuroendocrine tumor (SI-NET) cell lines were tested. Proliferation and viability were analyzed using cell counting and WST-1 assay.

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MSCs (mesenchymal stem cells) are planned foruse in regenerative medicine to offset age-dependent alterations. However, MSCs are affected by replicative senescence associated with decreasing proliferation potential, telomere shortening and DNA damage during in vitro propagation. To monitor in vitro senescence, we have assessed the integrity of DNA by the alkaline comet assay.

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Even though the erythroleukemia cell lines K562 and HEL do not express α1-adrenoceptors, some α1-adrenergic drugs influence both survival and differentiation of these cell lines. Since Ca2+ is closely related to cellular homeostasis, we examined the capacity of α1-adrenergic drugs to modulate the intracellular Ca2+ content in K562 cells. Because of morphological alterations of mitochondria following α1-adrenergic agonist treatment, we also scrutinized mitochondrial functions.

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Preliminary data showed that α1-adrenergic antagonists induce apoptosis and a switch towards megakaryocytic differentiation in human erythroleukemia cells. To test the hypothesis whether survival and differentiation of erythroleukemia cells are under control of α1-adrenergic signalling, we examined α1-adrenoceptor expression of erythroleukemia cells and compared the in vitro effects of α-adrenergic antagonists with those of agonists. We discovered that α1-adrenergic agonists suppress both erythroid differentiation and growth of erythroleukemia cells concomitant with lipofuscin accumulation, autophagy and necrotic cell death.

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The major excitatory neurotransmitter glutamate is also found in the periphery in an increasing number of nonexcitable cells. In line with this it became apparent that glutamate can regulate a broad array of peripheral biological responses, as well. Of particular interest is the discovery that glutamate receptor reactive reagents can influence tumor biology.

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The erythroleukemia cell lines K562 and human erythroleukemia (HEL) are established models to study erythroid and megakaryocytic differentiation in vitro. In this study, we show that the alpha1-adrenergic antagonists, benoxathian and prazosin, inhibit the proliferation and induce apoptosis in K562 and HEL cells. Furthermore, both tested substances induced the expression of the megakaryocytic marker CD41a, whereas the expression of the erythroid marker glycophorin-a was decreased or unchanged.

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Although maternal-fetal cholesterol transfer may serve to compensate for insufficient fetal cholesterol biosynthesis under pathological conditions, it may have detrimental consequences under conditions of maternal hypercholesterolemia leading to preatherosclerotic lesion development in fetal aortas. Maternal cholesterol may enter fetal circulation by traversing syncytiotrophoblast and endothelial layers of the placenta. We hypothesized that endothelial cells (ECs) of the fetoplacental vasculature display a high and tightly regulated capacity for cholesterol release.

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In order to assess possible renal mechanisms causing the as yet unexplained side-effects of peripheral edema, weight gain and swollen limbs seen during the chronic administration of opioids in patients, a rat study was designed, mimicking a constant infusion (24 h) of morphine (CAS 57-27-2) using subcutaneous drug delivery device systems. Subcutaneous (s.c.

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Patients with moderate to severe pain were treated with buprenorphine patches in one of 3 concentrations: 35 micrograms/h, 52.5 micrograms/h and 70 micrograms/h (= 0.8 mg/d, 1.

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Clonidine ((2-[2,6-dichlorophenyl]amino)-2-imidazoline) preferentially stimulates central alpha(2)-adrenoceptors, which leads to inhibition of sympathetic tone, resulting in a lowering of arterial pressure and of heart rate. Additionally, many other desirable and undesirable effects are described, including analgesia, sedation and withdrawal reactions, which consist of a sudden rise in arterial pressure, nervousness, agitation and increased heart rate. The present study has the goal to develop a simple and effective method for the analysis of trace amounts of clonidine in human blood serum.

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