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Results 201 - 250 of 1586
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Wu John Z - - 2006
Experimental evidence indicates that the biosynthetic activity of chondrocytes is associated with the mechanical environment. For example, excessive, repetitive loading has been found to induce cell death, morphological and cellular damage, as seen in degenerative joint disease, while cyclic, physiological-like loading has been found to trigger a partial recovery of ...
Jones Lynne C - - 2006
The aim of this study was to investigate whether cyclic loading can alter the response of osteoblasts to dexamethasone. Proliferation of osteoblast-like cells (MG-63) was assessed by determining uptake of 3H-thymidine. Three doses of dexamethasone were tested: 0.001 nM, .001 nM, or 0.1 nM. Exposure to increasing levels of dexamethasone ...
Jenal Urs - - 2006
Cyclic-di-GMP is a ubiquitous second messenger in bacteria. The recent discovery that c-di-GMP antagonistically controls motility and virulence of single, planktonic cells on one hand and cell adhesion and persistence of multicellular communities on the other has spurred interest in this regulatory compound. Cellular levels of c-di-GMP are controlled through ...
Loesberg W A - - 2005
Under the influence of mechanical stress, cultured fibroblasts have a tendency to orient themselves perpendicular to the stress direction. Similar cell alignment can be induced by guiding cells along topographical clues, like microgrooves. The aim of this study was to evaluate cell behavior on microgrooved substrates, exposed to cyclic stretching. ...
Kumar Bipin - - 2005
OBJECTIVE: High levels of wild-type alpha-synuclein are found in autopsied brain samples of idiopathic Parkinson's disease (PD), some familial PD, some Alzheimer's disease (AD) and Down's syndrome with dementia. Therefore, we have investigated whether overexpression of wild-type alpha-synuclein causes degeneration during adenosine, 3',5'-cyclic monophosphate (cAMP)-induced differentiation of murine neuroblastoma (NB) ...
Correa Silvana A A - - 2005
To assess the importance of the leucine residues in positions 262 and 265 of the angiotensin AT(1) receptor for signaling pathways and receptor expression and regulation, we compared the properties of CHO cells transfected with the wild type or the L262D or L265D receptor point mutants. It was found that ...
Basile Giovanna - - 2005
ADP-ribosyl cyclases are ubiquitous enzymes responsible for synthesis from NAD(+) of the intracellular calcium-releasing signal molecules cyclic ADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP(+)). Here, we show that cyclases from lower and higher Metazoa also synthesize three adenylic dinucleotides from cADPR and adenine: diadenosine diphosphate and two isomers ...
Belo A - - 2006
BACKGROUND AND AIMS: Nucleotides form the building blocks of DNA and are marketed as dietary supplements, alone or in combination with other ingredients, to promote general health. However, there has been only limited scientific study regarding the true biological activity of orally administered nucleotides. We therefore tested their efficacy in ...
Sato Kiminori - - 2005
PURPOSE: There are a few injectable biomaterials used in vocal-fold-augmentation surgery. In this study, liposuctioned autologous fat, used as the injection material, was investigated histologically. MATERIALS AND METHODS: Liposuctioned fat, which was harvested from 13 patients during injection laryngoplasty, was examined by light and electron microscopy. RESULTS: The cell membranes ...
Huang Chien-Ning - - 2005
It has been documented that arginine vasopressin (AVP) and prostaglandin E(2) (PGE(2)) regulate water reabsorption in renal tubular cells. The present study was attempted to delineate the downstream signaling of AVP and PGE(2) in a cortical collecting duct cell line (M-1 cell). Using RT-PCR, we detected mRNA for V2 and ...
Nguyen Bao T BT Department of Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, - - 2005
Relaxin stimulates cAMP production and activation of ERK and PI3K in THP-1 cells. Relaxin also stimulates protein kinase C zeta (PKCzeta) translocation to the plasma membrane in a PI3K-dependent manner in THP-1 and MCF-7 cells. However, relaxin did not increase cAMP production in MCF-7 cells. We overexpressed different adenylyl cyclase ...
Reigada David - - 2005
Stimulation of ATP or adenosine receptors causes important physiological changes in retinal pigment epithelial (RPE) cells that may influence their relationship to the adjacent photoreceptors. While RPE cells have been shown to release ATP, the regulation of extracellular ATP levels and the production of dephosphorylated purines is not clear. This ...
Smith N - - 2005
BACKGROUND: Antigen inhalation in atopic asthmatic patients results in an early asthmatic response (EAR), accompanied by a late asthmatic response (LAR) in 60% of patients. Inhaled 5'-adenosine monophosphate (5'-AMP) causes immediate bronchoconstriction in asthmatics but not in normal subjects. OBJECTIVES: The aims of this study were to investigate whether 5'-AMP ...
Wunder Frank - - 2005
We have established a rapid, homogeneous, cell-based, and highly sensitive assay for guanosine 3'-5'-cyclic monophosphate (cGMP) that is suitable for fully automated ultra-high-throughput screening. In this assay system, cGMP production is monitored in living cells via Ca2+ influx through the olfactory cyclic nucleotide-gated cation channel CNGA2, acting as the intracellular ...
Kajimoto Kazuaki - - 2005
1,2,3-Benzenetricarboxylate (BTA) and n-butylmalonate (BM), specific inhibitors of the mitochondrial tricarboxylate and dicarboxylate carrier, respectively, have been used to study the contribution of citrate export from mitochondria to the accumulation of fat in 3T3-L1 cells. Continuous treatment of the cells with BTA or BM for 5 days after the induction ...
Wolfe Alan J - - 2005
To succeed, many cells must alternate between life-styles that permit rapid growth in the presence of abundant nutrients and ones that enhance survival in the absence of those nutrients. One such change in life-style, the "acetate switch," occurs as cells deplete their environment of acetate-producing carbon sources and begin to ...
Budnik Lygia T - - 2005
Incubation of ovarian luteal cells with the bioactive lipid mediator lysophosphatidic acid (LPA) for 180 min abolishes gonadotropin-induced steroid production with no attenuation of the cyclic AMP accumulation. Treatment with the lysolipid also diminishes [14C]steroid production in cells preloaded with either [14C]cholesterol or [14C]acetate. Neither the expression of steroidogenic acute ...
Sun Wan-Chun - - 2005
AIM: To study the modulating effect of adenosine deaminase (ADA) on the adenosine A1 receptor (A1R) in HEK293 cells stably expressing the human A1R. METHODS: cDNA was amplified by RT-PCR using total RNA from human embryo brain tissue as the template. The PCR products were subcloned into the plasmid pcDNA3 ...
Arner Peter - - 2005
Testosterone is a potent regulator of lipolysis by influencing catecholamine signal transduction in fat cells. Major species differences exist as regards the testosterone effect. In rodents testosterone increases beta-adrenergic receptor mediated signals to lipolysis at multiple steps in the lipolytic cascade. The sex hormone also increases alpha2-adrenoceptor antilipolytic signalling in ...
Li Yunshan - - 2005
The hemolysin of Vibrio mimicus(VMH) is a pore-forming toxin with both enterotoxic and hemolytic activity. The hemolysis by VMH is induced by creation of pores in the membrane of erythrocyte; however, the mechanism for the enterotoxic action of VMH has remained unclear. In order to clarify the mechanism, we incubated ...
Mongillo Marco - - 2005
Cyclic adenosine monophosphate (cAMP) controls the physiological response to many diverse extracellular stimuli. To maintain signal specificity, cAMP-mediated signaling is finely tuned by means of a complex array of proteins that control the spatial and temporal dynamics of the second messenger within the cell. To unravel the way a cell ...
Ahlström Mikael - - 2005
The regulation of the secondary messengers, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), is crucial in the hormonal regulation of bone metabolism. Both cAMP and cGMP are inactivated by cyclic nucleotide phosphodiesterases (PDEs), a superfamily of enzymes divided into 11 families (PDE1-11). We compared the PDEs of cultured ...
Chang Ling-Wen - - 2005
The corpora allata synthesize and release juvenile hormone (JH) that in turn regulates insect growth, metamorphosis and reproduction. In the corpus allatum (CA) of the female adult cockroach Diploptera punctata, cyclic rise and decline in JH synthesis rates occur concurrently with cyclic growth and atrophy during an ovarian cycle. Here, ...
Chen Z Z Chien-Shiung Wu Laboratory, National Laboratory for Molecular and Bimolecular Electronics, Southeast University, Nanjing, 210096, P.R. - - 2005
Here, a filter with series of pools and dams structures was designed and fabricated, utilizing size difference between tumor and blood cells. The cell mixtures were successfully filtrated out by the filter, and separation efficiency was up to 99.9%. To evaluate the filter, physical models were made to describe the ...
Korićanac Lela B - - 2004
Novel antineoplastic agents, 8-chloroadenosine 3',5'-monophosphate (8-Cl-cAMP) and tiazofurin (TR), have been shown to be effective against different malignant cells. Through specific mechanisms of action they modulate the cellular signal transduction pathway, thereby causing growth inhibition, cell differentiation, and apoptosis. The aim of this work was the in vitro study of ...
Zivadinovic Dragoslava - - 2005
INTRODUCTION: 17beta-estradiol (E2) can rapidly induce cAMP production, but the conditions under which these cAMP levels are best measured and the signaling pathways responsible for the consequent proliferative effects on breast cancer cells are not fully understood. To help resolve these issues, we compared cAMP mechanistic responses in MCF-7 cell ...
Trbovich Alexander M AM Pediatric Surgical Research Laboratories/WRN 1024, Massachusetts General Hospital and Harvard Medical School, 32 Fruit Street, Boston, MA, - - 2004
In addition to causing Müllerian duct regression in fetal males, Müllerian inhibiting substance (MIS) inhibits the expression of the bifunctional cytochrome P450, C17 hydroxylase/C(17-20) lyase (Cyp17), the enzyme that catalyzes the committed step in sex steroid synthesis. To investigate the paracrine effects of MIS on steroidogenic activity, we have performed ...
Belibi Franck A - - 2004
BACKGROUND: Progressive cyst enlargement, the hallmark of autosomal-dominant polycystic kidney disease (ADPKD) and autosomal-recessive (ARPKD) polycystic kidney disease, precedes the eventual decline of function in these conditions. The expansion of individual cysts in ADPKD is determined to a major extent by mural epithelial cell proliferation and transepithelial fluid secretion. This ...
Johansson C Christian - - 2004
We examined the cAMP-mediated regulation of the epidermal growth factor-like growth factor amphiregulin (AR) in T cells and observed a strong cAMP-induced up-regulation of AR mRNA in a time- and concentration-dependent manner independent of T cell activation. This regulation may be mediated in part through activation of a cAMP-responsive element ...
Li Esther W Y - - 2004
The immunomodulatory effect of GMP and its derivates on the cell proliferative response of human macrophagelike cell, U937, and its effect on phagocytic activities via incorporation of fluorescence beads were studied. GMP was found to be a potent immunoenhancer at low concentrations, significantly enhancing the proliferation and phagocytic activities of ...
Kotoulas Othon B - - 2004
Glycogen autophagy, which includes the sequestration and degradation of cell glycogen in the autophagic vacuoles, is a selective process under conditions of demand for the massive hepatic production of glucose, as in the postnatal period. It represents a link between autophagy and glycogen metabolism. The formation of autophagic vacuoles in ...
Reichelt Wenche H - - 2004
BACKGROUND: We have proposed that the mitosis inhibiting peptide, pyroGlu-His-Gly (pEHG), a colon-specific negative feedback regulator of cell proliferation, works through a G protein-coupled receptor (GPCR), as do many other pyroglutamyl-peptides. MATERIALS AND METHODS: Non-tumorigenic YAMC (colon mucosa of Immorto mice), IMCE (Immorto-Min mouse hybrid) and human hepatoma (HepG2) cell ...
Paul Ralf - - 2004
Pole development is coordinated with the Caulobacter crescentus cell cycle by two-component signaling proteins. We show that an unusual response regulator, PleD, is required for polar differentiation and is sequestered to the cell pole only when it is activated by phosphorylation. Dynamic localization of PleD to the cell pole provides ...
Lee Ying-Hue - - 2004
Adipogenesis of preadipocytes in culture has been frequently used to study the molecular basis and effect of drugs on fat cell conversion. However, after adipogenic induction, cells respond to the inducing agent with various speeds of conversion and fat accumulation, which complicates direct molecular and biochemical analyses. Here we present ...
Tsai J A - - 2004
Extra-thyroidal thyrotropin (TSH) receptors (TSHRs) have been demonstrated in several tissues and cells, including human and rat osteosarcoma cell lines. We have explored whether human TSHR (hTSHRs) also are present in primary cultures of human osteoblast-like (hOB) cells. [(125) I]TSH binding was limited in hOB cells, but somewhat higher in ...
Korkmaz Yüksel - - 2004
The epithelial rests of Malassez (ERM) are derived from the disintegrating epithelial root sheath of Hertwig that guides root formation during tooth development. Low concentrations of nitric oxide (NO) produced by NO-synthase I (NOS I) and NOS III activate intracellular soluble guanylate cyclase (sGC) to produce intracellular cyclic guanosine 3':5'-monophosphate ...
Zhao Q - - 2004
The second messenger cyclic adenosine monophosphate (cAMP) plays an important role in cell proliferation, differentiation and apoptosis. In the present work, we evaluated the cAMP signaling in acute promyelocytic leukemia (APL) cells in the context of differentiation induced by all-trans retinoic acid (ATRA). There was a marked increase in the ...
Jacques-Silva Maria C - - 2004
Extracellular nucleotides and nucleosides induce proliferation in a set of human glioma cell lines. In this study we investigate the signal transduction pathways involved in ATP and adenosine-mediated proliferation in U138-MG human glioma cells. Cell proliferation was accessed through [(3)H]thymidine incorporation, cell counting and flow cytometry. Protein phosphorylation was detected ...
Khan Islam U - - 2004
Abnormal T-cell effector functions in systemic lupus erythematosus (SLE) are present and may be associated with disease immunopathogenesis. Our work has led to the characterization of a signaling defect, involving protein kinase A (PKA), leading to abnormal T-cell effector functions in SLE. PKA is a component of the adenylyl cyclase/cyclic ...
Winter L C - - 2003
The objective of this study was to quantify and compare stretch-mediated responses of primary rat osteoblast-like cells to uniform cyclic strain applied intermittently or continuously. Primary rat osteoblast-like cells were seeded and cultured in silicone rubber dishes for 2 days. They were then subjected to 1000 microstrains at 1 Hz ...
Adamec T - - 2003
The gene for mouse polyomavirus large tumor (LT) antigen, a potent oncoprotein, was expressed in Saccharomyces cerevisiae from the inducible GAL1 promoter. Substantial cell growth inhibition as well as colony and cell morphology changes dependent on cyclic adenosine monophosphate (cAMP) were observed. In contrast to cell and colony morphology alterations, ...
Prasad K N - - 2003
The mechanisms of carcinogenesis in nervous tissues are not well understood. It is now established that adenosine 3,',5'-cyclic monophosphate (cAMP)-pathway plays a crucial role in initiating differentiation in transformed and embryonic cells of neuronal and glial origin. Therefore, we propose that defects in the cAMP-pathway may initiate the first phase ...
Okamoto Hiroshi - - 2003
Poly(ADP-ribose) synthetase/polymerase (PARP) activation causes NAD+ depletion in pancreatic beta-cells, which results in necrotic cell death. On the other hand, ADP-ribosyl cyclase/cyclic ADP-ribose hydrolase (CD38) synthesizes cyclic ADP-ribose from NAD+, which acts as a second messenger, mobilizing intracellular Ca2+ for insulin secretion in response to glucose in beta-cells. PARP also ...
Hasegawa Go - - 2003
We have found that a 12-lipoxygenase metabolite of arachidonic acid, 12(S)-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid (12-HETE), induces cAMP production in human normal fibroblast TIG-1 cells. This phenomenon was not observed in other cells tested including human embryonic kidney HEK293 cells. We have speculated that this specific response might be influenced by the kinds ...
Masaki Eiji - - 2003
To examine effects of volatile anesthetics (VAs) on steroidogenesis, cell suspensions of isolated bovine adrenocortical cells were incubated with several steroidogenic agents in the presence or absence of halothane and sevoflurane. The adrenocortical cells were dispersed by trypsin digestion of bovine adrenal cortex. The cortisol level was measured fluorometrically. VAs ...
Morrone Fernanda B - - 2003
Extracellular purines (adenosine triphosphate (ATP), adenosine 5'-diphosphate (ADP) and adenosine) and pyrimidines (uridine 5'-triphosphate (UTP) and UDP) are important signaling molecules that mediate diverse biological effects via P1 and P2 purinergic receptors. The human glioma cell lines U87 MG, U251 MG and U138 MG were treated with purines and pyrimidines ...
Buckley K A - - 2003
Nucleotides, acting as agonists at P2 receptors, are important extracellular signaling molecules in many tissues. In bone they affect both bone-forming osteoblast and bone-resorbing osteoclast cell activity. The presence of nucleotides in the extracellular microenvironment is largely determined by their release from cells and metabolism by ecto-enzymes, both of which ...
Zheng Wenchao W Department of Pharmacology, Medical Science Center, University of Wisconsin, 1300, University Avenue, Madison, WI 53706, - - 2003
CYP1B1 is unique among P450 cytochromes in exhibiting inductive responses mediated by both the Ah receptor (AhR) and cAMP. cAMP induction was mediated either by a 189bp far upstream enhancer region (FUER, -5110 to -5298) or by a 230bp AhR-responsive enhancer region (AhER) (-797 to -1026). CYP1B1 luciferase reporters respond ...
Song Yao - - 2003
AIM: To investigate the characterization of cAMP response mediated by alpha1-adrenoceptor (alpha1-AR) subtypes in HEK293 cells. METHODS: (1) Full-length cDNA encoding three alpha1-AR subtypes were transfected into HEK293 cells by the calcium phosphate precipitation method, respectively. (2) The densities of alpha1-AR subtypes expressed in HEK293 cells were measured by radioligand ...
Kaulich Marko - - 2003
1. The metabolism of extracellular nucleotides in NG108-15 cells, a neuroblastoma x glioma hybrid cell line, was studied by means of capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MECC). 2. In NG108-15 cells ATP, ADP, AMP, UTP, UDP, and UMP were hydrolyzed to the nucleosides adenosine and uridine ...
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