6,664 research outputs found
HL-1 cells express an inwardly rectifying K+ current activated via muscarinic receptors comparable to that in mouse atrial myocytes
No full textAn inwardly rectifying K^+ current is present in atrial cardiac myocytes that is activated by acetylcholine (I_{KACh}). Physiologically, activation of the current in the SA node is important in slowing the heart rate with increased parasympathetic tone. It is a paradigm for the direct regulation of signaling effectors by the Gβγ G-protein subunit. Many questions have been addressed in heterologous expression systems with less focus on the behaviour in native myocytes partly because of the technical difficulties in undertaking comparable studies in native cells. In this study, we characterise a potassium current in the atrial-derived cell line HL-1. Using an electrophysiological approach, we compare the characteristics of the potassium current with those in native atrial cells and in a HEK cell line expressing the cloned Kir3.1/3.4 channel. The potassium current recorded in HL-1 is inwardly rectifying and activated by the muscarinic agonist carbachol. Carbachol-activated currents were inhibited by pertussis toxin and tertiapin-Q. The basal current was time-dependently increased when GTP was substituted in the patch-clamp pipette by the non-hydrolysable analogue GTPγS. We compared the kinetics of current modulation in HL-1 with those of freshly isolated atrial mouse cardiomyocytes. The current activation and deactivation kinetics in HL-1 cells are comparable to those measured in atrial cardiomyocytes. Using immunofluorescence, we found GIRK4 at the membrane in HL-1 cells. Real-time RT-PCR confirms the presence of mRNA for the main G-protein subunits, as well as for M2 muscarinic and A1 adenosine receptors. The data suggest HL-1 cells are a good model to study IKAch
Role of hypolipidemic drug clofibrate in altering iron regulatory proteins IRP1 and IRP2 activities and hepatic iron metabolism in rats fed a low iron diet.
No full textRNA interference-mediated control of hepatitis B virus and emergence of resistant mutant
No full textAssociation between symptoms/diagnosis of attention-deficit/hyperactivity disorders and sleep problems/disorders-focus on Taiwan’s studies
No full textOn the relocation problem with a second working crew for resource recycling
No full text[[abstract]]In this paper, we introduce a variant of the relocation problem, which was formulated from a public house redevelopment project in Boston. In the problem of interest, given some initial resources in a common pool there is a set of jobs to be processed on a two-machine flowshop. Each job acquires a specific number of resources to start its processing and will return a number of resources to the pool at its completion. The resource consumption and resource recycle processes are performed on machine one and machine two, respectively, in a two-machine flowshop style. Abiding by the resource constraints, the problem seeks to find a feasible schedule whose makespan is minimized. In this paper, we first present NP-hardness proofs for some special cases. Three heuristic algorithms are designed to compose approximate schedules. Two lower bounds are developed and then used to test the performance of our proposed heuristics. Numerical results from computational experiments suggest that the proposed heuristics can produce quality solutions in a reasonable time.[[note]]SC
Role of protein kinase C in phosphorylation of vinculin in adriamycin-resistant HL-60 leukemia cells
No full textIn response to phorbol esters such as 12-O-tetradecanoylphorbol-13-acetate (TPA), HL-60 cells differentiate to macrophage-like cells and exhibit the ability to phosphorylate vinculin in vitro. Adriamycin-resistant HL-60 (HL-60/ADR) cells similarly demonstrate this characteristic without prior treatment with TPA. Since protein kinase C (PK-C) is a cellular TPA receptor, we have examined the role of this enzyme in the inherent ability of HL-60/ADR cells to phosphorylate vinculin. DEAE-cellulose chromatography of cell extracts revealed that HL-60/ADR cells contained 2-fold more PK-C than did the parental cell line. All PK-C activity was found in the cytosol of wild type HL-60 cells, whereas 85% of PK-C activity was cytosolic and 15% was membrane-bound in HL-60/ADR cells. After a 2-day treatment with 10 nM TPA, PK-C activity was reduced 80-90% in both cell lines regardless of its intracellular distribution. Immunoblotting of cell extracts from HL-60/ADR cells or HL-60 cells following treatment with TPA revealed increased levels of a 52-kDa species of similar mass to M-kinase. Coincident with these changes after TPA treatment was a reduction in Ca2+ and phospholipid-independent phosphorylation of vinculin in vitro in extracts from HL-60/ADR cells, whereas HL-60 cells exhibited an elevation of this phosphoprotein. The phosphorylation of vinculin in TPA-treated HL-60 cells or untreated HL-60/ADR cells was blocked by antibodies to protein kinase C. These results suggest that it is not the absolute level of protein kinase C but rather the proteolytic activation of PK-C to a Ca2+ and phospholipid-independent form which is associated with the utilization of vinculin as an endogenous substrate
Case report: Management of canine pulmonary thromboembolism after adulticide administration in a heartworm-infected dog
No full text
Transfer of a foreign gene to Japanese abalone (Haliotis diversicolor supertexta) by direct testis-injection.
No full text
- …
