Endo/sarcoplasmic reticulum (ER) Ca2+-pumps are important for cell survival and communication but they are inactivated by reactive oxygen species (ROS). We have previously reported that the Ca2+-pump isoform SERCA3a is more resistant than SERCA2b to damage by peroxide. Since peroxide and superoxide differ in their redox potentials, we now report the effects of superoxide on the two Ca2+-pump isoforms.
View Article and Find Full Text PDFEndothelium from rat aorta expresses sarco/endoplasmic reticulum Ca2+(SERCA) pump gene SERCA3 where as the smooth muscle expresses SERCA2. This has led to the postulate that vascular endothelium expresses SERCA3. To test this postulate, we examined the SERCA2 and SERCA3 mRNA expression in endothelium and smooth muscle dissected from coronary artery, coronary vein, aorta and vena cava of pig.
View Article and Find Full Text PDFElevated levels of B lymphocytes with a unique surface alloantigen have been reported to be characteristic of patients with acute rheumatic fever or rheumatic heart disease. Mouse monoclonal antibodies (mAbs) to this alloantigen have been proposed as being useful in identifying individuals at risk for the development of these sequelae of group A streptococcal infection. However, previous studies have suggested that the discriminating ability of the mAbs was highest when the mAbs were made by using lymphocytes from the same ethnic population.
View Article and Find Full Text PDFMol Cell Biochem
December 1999
Endothelins (ETs) contract de-endothelialized rings from left descending coronary artery via ET(A) or ET(B) receptors. Here we test the hypothesis that the actions of EA(A) and ET(B) receptors are similar in their sensitivities to damage by hydrogen peroxide. In Ca2+-containing Krebs' solution, 100 nM of the ET(B) agonist IRL1620 produced contractions with significantly smaller force (17.
View Article and Find Full Text PDFThe conformational analysis of an immunomodulating tetrapeptide rigin (H-Gly-Gln-Pro-Arg-OH), shown to possess diverse immunological activity, has been investigated both theoretically and experimentally for its conformational preferences. Unrestrained molecular dynamics simulation studies in implicit dimethylsulfoxide provide strong support for the existence of a significant population of ordered reverse turn structures for the major trans isomer. Of the three different energy minimized families, generated from computer molecular modelling, only one could be complemented by most of the 1D and 2D 1H NMR parameters obtained in dimethylsulfoxide-d6.
View Article and Find Full Text PDFNerve growth factor (NGF) treatment converts rapidly dividing PC12 cells into a neuronal phenotype. To understand the Ca2+ sequestration mechanisms accompanying this differentiation, we examined the endoplasmic reticulum Ca2+ (SERCA) pump levels using two different assays: ATP-dependent azide insensitive oxalate stimulated 45Ca2+ uptake by PC12 cells permeabilized with saponin, and Western blots using a monoclonal antibody which reacts with all the SERCA isoforms. We also examined the reaction to an antibody against the plasma membrane Ca2+ (PMCA) pump.
View Article and Find Full Text PDFEur J Pharmacol
January 2000
Cyclopiazonic acid contracts pig coronary artery de-endothelialized rings, and pretreating the rings with hydrogen peroxide (H(2)O(2)) inhibits this contraction (IC(50)=0.097+/-0.013 mM).
View Article and Find Full Text PDFMol Cell Biochem
November 1999
Pig left descending coronary artery (main artery) and its next branch (branch arteries) differ in many properties. Here we report on the receptor types and the Ca2+ pools utilized for endothelin (ET) contraction in 3 mm long de-endothelialized rings of the main (weight 7.38 +/- 0.
View Article and Find Full Text PDFObjective: In this study, clinical practice guidelines were developed by a multidisciplinary team for patients with infections admitted to a surgical intensive care unit (ICU).
Design: A 51-day baseline audit period (Phase I) in a 20-bed (private rooms) surgical ICU was compared with a 34-day period in the same unit after implementation of the guidelines (Phase II).
Patients: Phase I included 182 patients (670 patient days), and Phase II included 139 patients (427 patient days).
Eur J Cancer Care (Engl)
June 1999
A rare case of granulocytic sarcoma of orbit preceding the onset of acute meyloblastic leukaemia is presented. A 7-year-old boy presented with proptosis and no other systemic complaints. The appearance of an enlarged muscle in initial tomographic imaging with a normal peripheral blood picture caused a diagnostic problem.
View Article and Find Full Text PDFMobilization of endoplasmic reticulum Ca2+ is pivotal to the ability of a cell to send or respond to stimuli. Ca(2+)-Mg(2+)-ATPases, termed SERCA pumps, sequester Ca2+ into the sarco/endoplasmic reticulum. There are several SERCA protein isoforms encoded by three genes.
View Article and Find Full Text PDFToxicol Appl Pharmacol
August 1999
Silver has been shown to be extremely toxic to freshwater teleosts, acting to inhibit Na(+) uptake at the gills, due to the inactivation of branchial Na(+)/K(+)-ATPase activity. However, the gills are also a route by which silver may enter the fish. Therefore, this study focuses on the mechanism of transport of this nonessential metal across the basolateral membrane of the gill cell, using basolateral membrane vesicles (BLMV) prepared from the gills of freshwater rainbow trout.
View Article and Find Full Text PDFSplice-site and missense mutations have been identified in tau associated with frontotemporal dementia with parkinsonism linked to chromosome 17. In this study we assessed the genetic contribution of tau mutations to three patient series with non-Alzheimer's (non-AD) degenerative dementia. The groups included (1) a community-based dementia series from Minnesota, MN; (2) a referral series with clinicopathological tauopathy; and (3) a pathologically confirmed familial frontotemporal dementia series from Manchester, UK.
View Article and Find Full Text PDFReactive oxygen species (ROS, free radicals) produced during cardiac ischemia and reperfusion can damage the contractile functions of arteries. The sarcoplasmic reticulum (SR) Ca2+ pump in coronary artery smooth muscle is very sensitive to ROS. Here we show that contractions of de-endothelialized rings from porcine left coronary artery produced by the hormone Angiotensin II and by the SR Ca2+ pump inhibitors cyclopiazonic acid and thapsigargin correlate negatively with the tissue weight.
View Article and Find Full Text PDFThe yeast two-hybrid system, immunofluorescence and co-immunoprecipitation techniques were used to identify a novel candidate protein with which presenilin-1 (PS-1) interacts. This interacting protein, the gene of which is encoded on chromosome 16, contains two tetratricopeptide repeats (TPR) that are known to mediate interactions between proteins, appears to be primarily localized to the cytoplasm of transfected HEK293 cells, and is expressed in brain. Preliminary yeast two-hybrid data suggests this candidate may interact with both heat shock protein-90 and heat shock protein-70 and thus may be a novel member of TPR-containing proteins which interact with this complex.
View Article and Find Full Text PDFObjectives: To study the outcome of pregnancy in women with artificial heart valves and to compare the maternal and perinatal outcome in mechanical and bioprosthetic valves.
Method: Retrospective analysis of 34 pregnancies in 29 women who conceived after cardiac valve replacement was carried out.
Results: The majority of women (76.
Missense and splice site mutations in the microtubule-associated protein tau gene were recently found associated with fronto-temporal dementia and parkinsonism linked to chromosome 17 (Poorkaj et al. (1998) Ann. Neurol.
View Article and Find Full Text PDFCD4+ and CD8+ T cells from healthy donors, acute rheumatic fever (ARF) and chronic rheumatic heart disease (CRHD) patients responded variably to a superantigen from Streptococcus pyogenes--Streptococcal pyrogenic erythrogenic toxin A (SPE-A). In vitro culture of CD4+ T cells from ARF patients (CD4-ARF) with SPE-A exhibited a Th1 type of response as they produced high levels of IL-2, while CD4+ T cells from CRHD patients (CD4-RHD) secreted IL-4 and IL-10 in large amounts, i.e.
View Article and Find Full Text PDFForty-eight patients with double-chambered right ventricle (DCRV) were prospectively studied over a 3-year period. Clinical, echocardiographic, hemodynamic, and angiographic studies were done in all. Three patients were studied postoperatively also.
View Article and Find Full Text PDFPurpose: To evaluate the efficacy of albendazole in the management of orbital myocysticercosis.
Method: Twenty-one consecutive patients diagnosed as having orbital myocysticercosis by ultrasonography, supported by computed tomography (CT)/magnetic resonance imaging (MRI), were included in the study. All patients received oral albendazole at a dosage of 30 mg/kg for 15 days with a low-dose steroid cover (5-10 mg per day).
Cardiac muscle expresses sarcoplasmic/endoplasmic-reticulum Ca2+ pump isoform SERCA2a; stomach smooth muscle expresses SERCA2b. In 2-day-old rabbits, cardiac muscle contained levels of SERCA2 protein that were 100-200-fold those in the stomach smooth muscle. In nuclear run-on assays, the rate of SERCA2 gene transcription in heart nuclei was not significantly higher than in the stomach smooth-muscle nuclei.
View Article and Find Full Text PDFAust N Z J Obstet Gynaecol
August 1998
Two hundred and seventy five pregnancies in patients with congenital heart disease during 1980-1996 were analyzed retrospectively. Maternal and perinatal outcome was compared in 251 pregnancies of women with acyanotic and 24 pregnancies of women with cyanotic heart disease. Congenital heart disease was diagnosed during the index pregnancy in 26.
View Article and Find Full Text PDFA 104 kDa protein (SAP 104) accumulates in rice seedlings in response to several abiotic stress conditions and immunological homologues of rice SAP 104 have been detected in several monocot and dicot species, as also Neurospora crassa, a fungus. In this report, we show that the amino acid sequence of a tryptic peptide generated from purified SAP 104 bears significant homology with an ATP-binding domain of the HSP 100 family proteins of Arabidopsis thaliana and Glycine max. It is further shown that differential uninduced and induced (by high-temperature stress) levels of this protein are accumulated in various organs of the mature rice plant grown under field conditions.
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