143 research outputs found

    Plasma brain natriuretic peptide and the evaluation of volume overload in infants and children with congenital heart disease.

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    This study was designed to explore whether it was possible to evaluate the severity of VSD, PDA, and ASD by measuring brain natriuretic peptide (BNP) levels. We also investigated normal BNP levels in children to provide a baseline for our study. We measured BNP levels in 253 normal children, including 11 normal neonates, and in 91 VSD patients, 29 PDA patients, and 34 ASD patients. BNP levels showed no age-related differences in normal children (the mean value: 5.3 +/- 3.8 pg/ml). In the healthy neonates, BNP levels rose from 10.4 +/- 11.9 pg/ml in cord blood to 118.8 +/- 83.2 pg/ml on day 0, then fell to 15.3 +/- 7.8 pg/ml by day 7. In VSD and PDA patients, BNP levels correlated significantly with Qp/Qs, LVEDV, and peak RVP/LVP. In ASD patients, BNP levels correlated with Qp/Qs and RVEDV. Especially, in VSD patients, as an index corresponding to 1.5-2.0 of the Qp/Qs ratio, BNP levels of 20-35 pg/ml were found to be best with regard to both sensitivity and specificity. In the healthy neonates, BNP levels changed rapidly after birth. In VSD, PDA, and ASD patients, BNP levels were well-correlated with the severity of the disease. Especially, in VSD patients, it that appears BNP levels may be useful in evaluating surgical indications, with 20-35 pg/ml levels being the appropriate cut-off value.</p

    Phosphatidic acid-dependent localization and basal de-phosphorylation of RA-GEFs regulate lymphocyte trafficking

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    Background: Lymphocytes circulate between peripheral lymphoid tissues via blood and lymphatic systems, and chemokine-induced migration is important in trafficking lymphocytes to distant sites. The small GTPase Rap1 is important in mediating lymphocyte motility, and Rap1-GEFs are involved in chemokine-mediated Rap1 activation. Here, we describe the roles and mechanisms of Rap1-GEFs in lymphocyte trafficking. Results: In this study, we show that RA-GEF-1 and 2 (also known as Rapgef2 and 6) are key guanine nucleotide exchange factors (GEF) for Rap1 in lymphocyte trafficking. Mice harboring T cell-specific knockouts of Rapgef2/6 demonstrate defective homing and egress of T cells. Sphingosine-1-phosphate (S1P) as well as chemokines activates Rap1 in a RA-GEF-1/2-dependent manner, and their deficiency in T cells impairs Mst1 phosphorylation, cell polarization, and chemotaxis toward S1P gradient. On the other hand, B cell-specific knockouts of Rapgef2/6 impair chemokine-dependent retention of B cells in the bone marrow and passively facilitate egress. Phospholipase D2-dependent production of phosphatidic acid by these chemotactic factors determines spatial distribution of Rap1-GTP subsequent to membrane localization of RA-GEFs and induces the development of front membrane. On the other hand, basal de-phosphorylation of RA-GEFs is necessary for chemotactic factor-dependent increase in GEF activity for Rap1. Conclusions: We demonstrate here that subcellular distribution and activation of RA-GEFs are key factors for a directional movement of lymphocytes and that phosphatidic acid is critical for membrane translocation of RA-GEFs with chemokine stimulation

    Multiple roles of phosphoinositide-specific phospholipase C isozymes

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    Phosphoinositide-specific phospholipase C is an effector molecule in the signal transduction process. It generates two second messengers, inositol-1,4,5-trisphosphate and diacylglycerol from phosphatidylinositol 4,5-bisphosphate. Currently, thirteen mammal PLC isozymes have been identified, and they are divided into six groups: PLC-beta, -gamma, -delta, -epsilon, -zeta and -eta. Sequence analysis studies demonstrated that each isozyme has more than one alternative splicing variant. PLC isozymes contain the X and Y domains that are responsible for catalytic activity. Several other domains including the PH domain, the C2 domain and EF hand motifs are involved in various biological functions of PLC isozymes as signaling proteins. The distribution of PLC isozymes is tissue and organ specific. Recent studies on isolated cells and knockout mice depleted of PLC isozymes have revealed their distinct phenotypes. Given the specificity in distribution and cellular localization, it is clear that each PLC isozyme bears a unique function in the modulation of physiological responses. In this review, we discuss the structural organization, enzymatic properties and molecular diversity of PLC splicing variants and study functional and physiological roles of each isozyme.open19320

    Alveolar lymphocyte proliferation induced by Propionibacterium acnes in sarcoidosis patients.

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    The proliferation of lymphocytes induced by Propionibacterium acnes (P. acnes) was measured by the in vitro incorporation of 3H-thymidine. The mean response rate of alveolar lymphocytes obtained by bronchoalveolar lavage was 2.23 +/- 0.89 in nine untreated sarcoidosis patients, 0.85 +/- 0.17 in five sarcoidosis patients given corticosteroids and 0.78 +/- 0.29 in 11 controls. The proliferation was significantly enhanced in the untreated patients compared to both the treated patients (p less than 0.01) and controls (p less than 0.001), but there was no significant difference in response rates between the treated patients and controls. The response rate of alveolar lymphocytes was significantly higher in four active patients (3.05 +/- 0.61) than in four inactive patients (1.77 +/- 0.44) (p less than 0.05) and in the controls (p less than 0.001). In sarcoidosis patients, the response rates showed a good correlation with activities of serum lysozyme (r = 0.695, p less than 0.01), and with percentages of lymphocytes in bronchoalveolar lavage fluid (r = 0.591, p less than 0.05). There was a low correlation between angiotensin-converting enzyme activities and the response rates (r = 0.508, p less than 0.1). Neither peripheral blood lymphocytes in sarcoidosis patients nor in controls showed any response to P. acnes, but alveolar lymphocytes of the untreated active sarcoidosis patients were sensitive to P. acnes. The lymphocytes activated by P. acnes may play a central role in the induction of alveolitis in sarcoidosis patients.</p

    The Suzaku Observation of the Nucleus of the Radio-Loud Active Galaxy Centaurus A: Constraints on Abundances of the Accreting Material

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    A Suzaku observation of the nucleus of the radio-loud AGN Centaurus A in 2005 has yielded a broadband spectrum spanning 0.3 to 250 keV. The net exposure times after screening were: 70 ks per X-ray Imaging Spectrometer (XIS) camera, 60.8 ks for the Hard X-ray Detector (HXD) PIN, and 17.1 ks for the HXD-GSO. The hard X-rays are fit by two power-laws of the same slope, absorbed by columns of 1.5 and 7 * 10^{23} cm^{-2} respectively. The spectrum is consistent with previous suggestions that the power-law components are X-ray emission from the sub-pc VLBI jet and from Bondi accretion at the core, but it is also consistent with a partial covering interpretation. The soft band is dominated by thermal emission from the diffuse plasma and is fit well by a two-temperature VAPEC model, plus a third power-law component to account for scattered nuclear emission, jet emission, and emission from X-ray Binaries and other point sources. Narrow fluorescent emission lines from Fe, Si, S, Ar, Ca and Ni are detected. The Fe K alpha line width yields a 200 light-day lower limit on the distance from the black hole to the line-emitting gas. Fe, Ca, and S K-shell absorption edges are detected. Elemental abundances are constrained via absorption edge depths and strengths of the fluorescent and diffuse plasma emission lines. The high metallicity ([Fe/H]=+0.1) of the circumnuclear material suggests that it could not have originated in the relatively metal-poor outer halo unless enrichment by local star formation has occurred. Relative abundances are consistent with enrichment from Type II and Ia supernovae.Comment: Accepted for publication to ApJ. 22 pages, 11 figures (3 color). Uses emulateapj5.sty. Grammatical errors corrected; some references update

    Clinical features of 125 patients with sarcoidosis: Okayama University Hospital review of a recent 10-year period.

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    Clinical features were studied in 125 patients with sarcoidosis (72 females and 53 males) diagnosed at Okayama University Hospital during a recent 10-year period. The age distribution had two peaks in patients in their 20s and the 50s. Over half of the patients were detected at health screening check and were asymptomatic, while the remaining were symptomatic. Twelve patients were in stage 0, 41 were in stage I, 54 were in stage II, 16 were in stage III, and 2 were in stage IV according to the chest x-ray findings. Serum angiotensin converting enzyme levels and serum lysozyme levels were elevated in 60% and 76% of the patients, respectively. The bronchoalveolar lavage fluid showed lymphocytosis, especially of helper T-cells. The clinical features of sarcoidosis appear to depend on the duration of the disease.</p

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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