715 research outputs found
Cyclic AMP-associated shape change in mesangial cells and its reversal by prostaglandin E2
Cyclic AMP-associated shape change in mesangial cells and its reversal by prostaglandin E2. The mesangial cell is a glomerular cell type with smooth muscle-like (contractile) properties. The responses evoked in cultured mesangial cells by catecholamines were examined in the presence or absence of prostaglandin E2 (PGE2) with or without a phosphodiesterase inhibitor. Exposure to 10-4M norepinephrine, epinephrine, or isoproterenol elevated intracellular cyclic AMP (cAMP) levels in mesangial cells (25th to 30th passages) nearly threefold. If isobutylmethylxanthine (MIX) was also included, the hormones caused marked further increases in cAMP (after a 20-min incubation, control with MIX, 64.2 ± 5.2 pmoles/mg protein; 10-4M norepinephrine, 4266 ± 284 pmoles/mg protein; 10-4M epinephrine, 5812 ± 173 pmoles/mg protein; and 10-4M isoproterenol, 3136 ± 114 pmoles/mg protein). Under both of these circumstances (that is, catecholamines with or without MIX) greater than 50% of the cells underwent a change in shape (that is, had a round cell body with long, thin tapered processes). The cAMP and shape change response was independent of extracellular calcium ions and appeared to be due to β-adrenergic stimulation. Isoproterenol with MIX stimulated an alteration in morphology and cAMP production at concentrations of 10-4M to 10-9M. Within 10 min following β-adrenergic stimulation (10-4M isoproterenol plus MIX) cAMP was maximum; at this time a shape change was first evident. Eighty-five to one hundred percent of the cells had undergone a shape change by 40 min. Dibutyryl cAMP (10-3M) also induced a shape change in cultured mesangial cells. The addition of PGE2 to either morphologically altered cells or to the isoproterenol incubation medium (with or without MIX) prior to treating the cells, resulted in complete restoration to the normal flat appearance of mesangial cells or no shape change, respectively. PGE2 attenuated but did not abolish hormone-induced elevations in intracellular cAMP. Thus, catecholamines caused mesangial cells to change their shape in association with elevations of intracellular cAMP. PGE2 markedly inhibited the shape change as well as markedly attenuated cAMP generation.La modification de la forme associé l'PAMP cyclique dans les cellules mésangiales et sa interversion par prostaglandine E2. La cellule mésangiale est un type cellulaire glomérulaire ayant despropriétés voisines du muscle lisse (contractile). Les réponses évoquées dans des cellules mésangiales en culture par les catécholamines ont été examinées en présence ou en l'absence de prostaglandine E2 (PGE2) avec ou sans un inhibiteur des phosphodiestérases. L'exposition à 10-4M de noradrénaline, d'adrénaline, ou d'isoprotérénol a élevé les niveaux d'AMP cyclique intracellulaires (cAMP) dans les cellules mésangiales (25ème à 30ème passages) de presque troisfois. Si de l'isobutylméthylxanthine (MIX) était également inclue, les hormones entraînaient des augmentations plus fortes de cAMP (après 20 min d'incubation, contrôles avec MIX, 64,2 ± 5,2 pmoles/mg protéines; 10-4M noradrénaline, 4266 ± 284 pmoles/g protéines; 10-4M adrénaline, 5812 ± 173 pmoles/mg protéines; et 10-4M isoprotérénol, 3136 ± 114 pmoles/mg protéines). Dans chacune de ces circontances (c'est-à-dire catécholamines avec ou sans MIX), plus de 50% cellules subissaient une modification de forme (c'est-à-dire avaient un corps cellulaire rond, avec des expansions rubannées longues et fines). Les réponses cAMP et de modification de forme étaient indépendantes des ions calcium extracellulaires, et paraîssaient être dues à la stimulation β-adrénergique. L'isoprotérénol avec MIX stimulait une altération de la morphologie et de la production de cAMP pour des concentrations de 10-4M à 10-9M. En 10 min, après stimulation β-adrénergique (10-4M d'isoprotérénol plus MIX), cAMP était maximum; à ce moment, la modification de forme était évidente. Quatre-vingt-cinq à cent pour cent des cellules avaient subi une modification de forme en 40 min. Le dibutyryl cAMP (10-3M) induisait également une modification de forme dans les cellules mésangiales en culture. L'addition de PGE2 soit à des cellules morphologiquement altérées, soit au milieu d'incubation de l'isoprotérénol (avec ou sans MIX), avant de traiter les cellules, entraînait une restauration complète de l'apparence normale, plate, des cellules mésangiales, ou l'absence de modification, respectivement. PGE2 a atténué, mais n'a pas aboli les élévations induites par les hormones du cAMP intracellulaire. Ainsi, les catécholamines faisaient changer de forme les cellules mésangiales en association avec des élévations du cAMP intracellulaire. La PGE2 inhibait de façon marquée la modification de changement, et atténuait sensiblement la génération de cAMP
Availability and Utilization of Malaria Prevention Strategies in Pregnancy in Eastern India
BACKGROUND. Malaria in pregnancy in India, as elsewhere, is responsible for maternal anemia and adverse pregnancy outcomes such as low birth weight and preterm birth. It is not known whether prevention and treatment strategies for malaria in pregnancy (case management, insecticide-treated bednets, intermittent preventive therapy) are widely utilized in India. METHODS. This cross-sectional study was conducted during 2006-2008 in two states of India, Jharkhand and Chhattisgarh, at 7 facilities representing a range of rural and urban populations and areas of more versus less stable malaria transmission. 280 antenatal visits (40/site) were observed by study personnel coupled with exit interviews of pregnant women to assess emphasis upon, availability and utilization of malaria prevention practices by health workers and pregnant women. The facilities were assessed for the availability of antimalarials, lab supplies and bednets. RESULTS. All participating facilities were equipped to perform malaria blood smears; none used rapid diagnostic tests. Chloroquine, endorsed for chemoprophylaxis during pregnancy by the government at the time of the study, was stocked regularly at all facilities although the quantity stocked varied. Availability of alternative antimalarials for use in pregnancy was less consistent. In Jharkhand, no health worker recommended bednet use during the antenatal visit yet over 90% of pregnant women had bednets in their household. In Chhattisgarh, bednets were available at all facilities but only 14.4% of health workers recommended their use. 40% of the pregnant women interviewed had bednets in their household. Only 1.4% of all households owned an insecticide-treated bednet; yet 40% of all women reported their households had been sprayed with insecticide. Antimalarial chemoprophylaxis with chloroquine was prescribed in only 2 (0.7%) and intermittent preventive therapy prescribed in only one (0.4%) of the 280 observed visits. CONCLUSIONS. A disconnect remains between routine antenatal practices in India and known strategies to prevent and treat malaria in pregnancy. Prevention strategies, in particular the use of insecticide-treated bednets, are underutilized. Gaps highlighted by this study combined with recent estimates of the prevalence of malaria during pregnancy in these areas should be used to revise governmental policy and target increased educational efforts among health care workers and pregnant women.United States Agency for International Development/India mission (cooperative agreement GHS-A-00-03-00020-00); National Institute of Allergy and Infectious Disease (R03 HD52167-01); Indian National Institute of Malaria Research; Indo-US Program for Contraception and Reproductive Health Researc
Local Charge of the nu=5/2 Fractional Quantum Hall State
Electrons in two dimensions and strong magnetic fields effectively lose their
kinetic energy and display exotic behavior dominated by Coulomb forces. When
the ratio of electrons to magnetic flux quanta in the system is near 5/2, the
unique correlated phase that emerges is predicted to be gapped with
fractionally charged quasiparticles and a ground state degeneracy that grows
exponentially as these quasiparticles are introduced. Interestingly, the only
way to transform between the many ground states would be to braid the
fractional excitations around each other, a property with applications in
quantum information processing. Here we present the first observation of
localized quasiparticles at nu=5/2, confined to puddles by disorder. Using a
local electrometer to compare how quasiparticles at nu=5/2 and nu=7/3 charge
these puddles, we are able to extract the ratio of local charges for these
states. Averaged over several disorder configurations and samples, we find the
ratio to be 4/3, suggesting that the local charges are e/3 at seven thirds and
e/4 at five halves, in agreement with theoretical predictions. This
confirmation of localized e/4 quasiparticles is necessary for proposed
interferometry experiments to test statistics and computational ability of the
state at nu=5/2.Comment: 6 pages, 4 figures corrected titl
GRACEFUL CHROMATIC NUMBER OF SOME CARTESIAN PRODUCT GRAPHS
A graph is a system consisting of a finite non empty set of vertices and a set of edges . A (proper) vertex colouring of is a function for some positive integer such that for every edge . Moreover, if for every adjacent edges , then the function is called graceful colouring for . The minimum number such that is a graceful colouring for is called the graceful chromatic number of . The purpose of this research is to determine graceful chromatic number of Cartesian product graphs for integers and , and for integers . Here, and are cycle and path with vertices, respectively. We found some exact values and bounds for graceful chromatic number of these mentioned Cartesian product graphs
Acetabular fractures following rugby tackles: a case series
<p>Abstract</p> <p>Introduction</p> <p>Rugby is the third most popular team contact sport in the world and is increasing in popularity. In 1995, rugby in Europe turned professional, and with this has come an increased rate of injury.</p> <p>Case presentation</p> <p>In a six-month period from July to December, two open reduction and internal fixations of acetabular fractures were performed in young Caucasian men (16 and 24 years old) who sustained their injuries after rugby tackles. Both of these cases are described as well as the biomechanical factors contributing to the fracture and the recovery. Acetabular fractures of the hip during sport are rare occurrences.</p> <p>Conclusion</p> <p>Our recent experience of two cases over a six-month period creates concern that these high-energy injuries may become more frequent as rugby continues to adopt advanced training regimens. Protective equipment is unlikely to reduce the forces imparted across the hip joint; however, limiting 'the tackle' to only two players may well reduce the likelihood of this life-altering injury.</p
MSH3 polymorphisms and protein levels affect CAG repeat instability in huntington's disease mice
Expansions of trinucleotide CAG/CTG repeats in somatic tissues are thought to contribute to ongoing disease progression through an affected individual's life with Huntington's disease or myotonic dystrophy. Broad ranges of repeat instability arise between individuals with expanded repeats, suggesting the existence of modifiers of repeat instability. Mice with expanded CAG/CTG repeats show variable levels of instability depending upon mouse strain. However, to date the genetic modifiers underlying these differences have not been identified. We show that in liver and striatum the R6/1 Huntington's disease (HD) (CAG)~100 transgene, when present in a congenic C57BL/6J (B6) background, incurred expansion-biased repeat mutations, whereas the repeat was stable in a congenic BALB/cByJ (CBy) background. Reciprocal congenic mice revealed the Msh3 gene as the determinant for the differences in repeat instability. Expansion bias was observed in congenic mice homozygous for the B6 Msh3 gene on a CBy background, while the CAG tract was stabilized in congenics homozygous for the CBy Msh3 gene on a B6 background. The CAG stabilization was as dramatic as genetic deficiency of Msh2. The B6 and CBy Msh3 genes had identical promoters but differed in coding regions and showed strikingly different protein levels. B6 MSH3 variant protein is highly expressed and associated with CAG expansions, while the CBy MSH3 variant protein is expressed at barely detectable levels, associating with CAG stability. The DHFR protein, which is divergently transcribed from a promoter shared by the Msh3 gene, did not show varied levels between mouse strains. Thus, naturally occurring MSH3 protein polymorphisms are modifiers of CAG repeat instability, likely through variable MSH3 protein stability. Since evidence supports that somatic CAG instability is a modifier and predictor of disease, our data are consistent with the hypothesis that variable levels of CAG instability associated with polymorphisms of DNA repair genes may have prognostic implications for various repeat-associated diseases
Evaluation of three PCR-based diagnostic assays for detecting mixed Plasmodium infection
<p>Abstract</p> <p>Background</p> <p>One of the most commonly used molecular test for malaria diagnosis is the polymerase chain reaction (PCR)-based amplification of the 18S ribosomal DNA (rDNA) gene. Published diagnostic assays based on the 18S gene include the "gold standard" nested assay, semi-nested multiplex assay, and one tube multiplex assay. To our knowledge, no one has reported whether the two multiplex methods are better at detecting mixed <it>Plasmodium </it>infections compared to the nested assay using known quantities of DNA in experimentally mixed cocktails.</p> <p>Findings</p> <p>Here we evaluated three PCR assays (nested, semi-nested multiplex, and one-tube multiplex) for the simultaneous detection of human malaria parasites using experimentally mixed cocktails of known quantities of laboratory derived DNA. All three assays detected individual species with high sensitivity and specificity when DNA was from any one single species; however, experimentally mixed DNA cocktails with all four species present were correctly identified most consistently with the nested method. The other two methods failed to consistently identify all four species correctly, especially at lower concentrations of DNA -subclinical levels of malaria (DNA equivalent to or less than 10 parasites per microliter).</p> <p>Conclusions</p> <p>The nested PCR method remains the method of choice for the detection of mixed malaria infections and especially of sub-clinical infections. Further optimization and/or new molecular gene targets may improve the success rate of detecting multiple parasite species simultaneously using traditional PCR assays.</p
p63 heterozygous mutant mice are not prone to spontaneous or chemically induced tumors
Homology between p63 and p53 has suggested that these proteins might function similarly. However, the majority of data from human tumors have not supported a similar role for p63 in tumor suppression. To investigate this issue, we studied spontaneous tumorigenesis in p63+/- mice in both WT and p53-compromised backgrounds. We found that p63+/- mice were not tumor prone and mice heterozygous for both p63 and p53 had fewer tumors than p53+/- mice. The rare tumors that developed in mice with compromised p63 were also distinct from those of p53+/- mice. Furthermore, p63+/- mice were not prone to chemically induced tumorigenesis, and p63 expression was maintained in carcinomas. These findings demonstrate that, in agreement with data from human tumors, p63 plays a markedly different biological role in cancer than p53
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A Blind Comparative Study of Focused Wave Interactions with a Fixed FPSO-like Structure (CCP-WSI Blind Test Series 1)
Results from Blind Test Series 1, part of the Collaborative ComputationalProject in Wave Structure Interaction (CCP-WSI), are presented. Partici-pants, with a range of numerical methods, simulate blindly the interactionbetween a fixed structure and focused waves ranging in steepness and di-rection. Numerical results are compared against corresponding physicaldata. The predictive capability of each method is assessed based on pres-sure and run-up measurements. In general, all methods perform well inthe cases considered, however, there is notable variation in the results(even between similar methods). Recommendations are made for appro-priate considerations and analysis in future comparative studies
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