Search results for "FORS"
showing 10 items of 285 documents
Inhibition of ovarian steroidogenesis by cyclic-GMP in a fly
2003
1479-6805 0022-0795; Previous investigations in the female blowfly Phormia regina have shown that 3-isobutyl-1-methylxanthine (IBMX), a broad spectrum inhibitor of phosphodiesterases (PDEs), fails to mimic the steroidogenic effects of cAMP on ovaries, although it efficiently increases the concentrations of this second messenger. In this study, experiments carried out to clear up this contradiction demonstrated that IBMX, besides its effect on cAMP, also increased cGMP concentrations in blowfly ovary and that these two cyclic nucleotides controlled ovarian steroidogenesis antagonistically. In particular, a selective inhibitor of cGMP-specific PDEs, unlike IBMX, had a very strong negative eff…
Detection of periodontal pathogens in mothers of preterm birth and/or low weight
2019
Background The present study aims to estimate the possible relationship between periodontal pathogens in the oral cavity and the birth of Preterm Birth (PTB) and/or Low Birth Weight (LBW). Material and Methods It’s a case- control study with the subgengival biofilm samples were collected from four sites up deeper until 48 hours postpartum and were processes by Polymerase Chain Reaction (PCR) for presence the periodontal pathogens Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Treponema denticola (Td), Tannerella forsythia (Tf) e Aggregatibacter actinomycetemcomitans (Aa). The mothers were divided into case grup (babies weighing < 2500g and/or gesta…
Tannerella forsythia is associated with increased levels of atherogenic low density lipoprotein and total cholesterol in chronic periodontitis
2015
Background: Accumulating evidence suggests that acute and chronic infections with periodontopathogens are associated with an increased risk of cardiovascular disease. The objective of this study was to assess whether Tannerella forsythia and Porphyromonas gingivalis are associated with increased levels of atherogenic low-density lipoprotein (LDL), high-density lipoprotein, total cholesterol (TC), triglycerides and body mass index (BMI) in chronic periodontitis patients. Material and Methods: Medical history and clinical and radiographic examination were conducted in 80 chronic periodontitis patients and 28 healthy individuals. Fasting blood samples were drawn for the measurement of the para…
Release of non-neuronal acetylcholine from the human placenta: difference to neuronal acetylcholine
2001
The synthesis and release of non-neuronal acetylcholine, a widely expressed signaling molecule, were investigated in the human placenta. This tissue is free of cholinergic neurons, i.e. a contamination of neuronal acetylcholine can be excluded. The villus showed a choline acetyltransferase (ChAT) activity of 0.65 nmol/mg protein per h and contained 500 nmol acetylcholine/g dry weight. In the absence of cholinesterase inhibitors the release of acetylcholine from isolated villus pieces amounted to 1.3 nmol/g wet weight per 10 min corresponding to a fractional release rate of 0.13% per min. The following substances did not significantly modify the release of acetylcholine: oxotremorine (1 micr…
Isoprenaline and forskolin increase evoked vasopressin release from rat pituitary
1982
Isolated neurointermediate lobes of rat pituitaries were incubated in Krebs solution. The vasopressin release evoked by electrical stimulation (0.2 ms, 80 V, 15 Hz, 10 s trains at 10 s intervals for a total of 10 min) was completely inhibited by tetrodotoxin. Isoprenaline increased the evoked vasopressin release to a maximum of 60% (EC50 10 nM) and this effect was antagonized surmountably by propranolol. Forskolin increased the vasopressin release by 98%. These results suggest the presence within the neurohypophysis of a beta-adrenoceptor-linked adenylate cyclase facilitating vasopressin secretion.
Calcium inhibits ovarian steroidogenesis in the blowfly Phormia regina.
2002
1479-6805 0022-0795; Calcium is frequently involved in the stimulation of steroidogenesis in gonads and endocrine glands, generally in association with cAMP. However, our present observations show that it has the opposite effect in the ovary of the blowfly Phormia regina. Our in vitro experiments first showed that extracellular calcium does not play a role during the stimulation of steroidogenesis in fly ovaries; indeed steroidogenesis was activated in vitro as efficiently in a medium with or without calcium, either by pharmacological compounds mimicking cAMP signaling or by active brain extracts. When calcium was experimentally introduced into biosynthetic cells by ionophores or liberated …
Role of the cyclic AMP-dependent pathway in free radical-induced cholesterol accumulation in vascular smooth muscle cells.
2000
We have previously reported that free radical-treated vascular smooth muscle cells (SMC) lead to cholesterol accumulation in vitro. In the current study, we investigated the effects of oxidative stress on cyclic AMP concentration and cAMP-dependent enzymes involved in cholesterol homeostasis in A7r5 cells. Under our conditions of a mild oxidative stress, namely with no change in cell viability, we found that free radicals, initiated using azobis-amidinopropane dihydrochloride (AAPH), resulted in a dose-dependent decrease in cellular cAMP which was opposed by vitamin E preincubation. Although the addition of adenylate cyclase activators (carbacyclin and forskolin) increased cAMP levels it di…
Induction of dendritic cell maturation and modulation of dendritic cell-induced immune responses by prostaglandins
2000
Dendritic cells (DC) are the most potent antigen-presenting cells of the immune system. In this study we investigated the effects of various prostaglandins (PG) on the stimulatory capacity of DC. DC were generated from peripheral progenitor cells in the presence of IL-4 and GM-CSF and stimulated with IL-1, IL-6 and TNF-alpha on day 7. Simultaneously, PG (PGD(2), PGE(1), PGE(2), PGF(2 alpha), PGI(2)) were added at various concentrations (10(-5) to 10(-9) M) on day 7. In all experiments, PGE(2) had the most potent influence on the maturation of the DC, followed by other PG in the order PGE(1) > PGD(2) > PGF(2 alpha) > PGI(2). In addition, the expression of the surface molecules CD40, CD54, CD…
Interleukin-6 production in "normal" and HTLV-1 tax-expressing brain-specific endothelial cells.
1993
Abnormal cytokine production can contribute in many instances to the development of pathology. Our study focuses on the regulation of interleukin (IL)-6 production in vitro in brain-specific endothelial cells (BEC) under physiological conditions and in a model of human T leukemia virus-1 (HTLV-1) infection. IL-6 production was strongly up-regulated in a dose-dependent mode upon exposure to recombinant IL-1 beta, although nearly not detectable in unstimulated BEC. This induction of IL-6 production could be achieved by reagents known to increase intracellular levels of cAMP, such as forskolin, prostaglandin E or pentoxifylline. Furthermore, transcription and production of IL-6 was inducible b…
Qualitative Forschung in Deutsch als Fremdsprache
2009
Qualitative Forschung ist heute ein fester Bestandteil der aktualempirischen Sozial- und Erziehungswissenschaft. Mit ihrem Anspruch, die Sicht der Beforschten zur Grundlage von wissenschaftlichen Untersuchungen werden zu lassen, stellt sie derzeit in der Fremdsprachenerwerbsforschung den favorisierten Forschungsansatz dar. Im vorliegenden Band werden schwerpunktmäßig empirische Forschungsprojekte vorgestellt, aber auch methodologische Fragestellungen auf theoretischer Ebene diskutiert und konkrete Verfahren zur Datenerhebung, -aufbereitung und -analyse erörtert. Die Beiträge sind das Ergebnis eines fachwissenschaftlichen Austauschs, der im Rahmen der 3. Tagung der Deutschen Sprachwissenscha…