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Background and Purpose: The expression of voltage-dependent K(+) channels (K(v) ) 1.5 is regulated by members of the heat shock protein (Hsp) family. We examined whether the heat shock transcription factor 1 (HSF-1) and its inducer geranylgeranylacetone (GGA) could affect the expression of K(v) 1.5 channels and its anchoring protein, synapse associated protein 97 (SAP97).Experimental Approach: Transfected mouse atrial cardiomyocytes (HL-1 cells) and COS7 cells were subjected to luciferase reporter gene assay and whole-cell patch clamp. Protein and mRNA extracts were subjected to Western blot and quantitative real-time polymerase chain reaction.Key Results: Heat shock of HL-1 cells induced expression of Hsp70, HSF-1, SAP97 and K(v) 1.5 proteins. These effects were reproduced by wild-type HSF-1. Both heat shock and expression of HSF-1, but not the R71G mutant, increased the SAP97 mRNA level. Small interfering RNA (siRNA) against SAP97 abolished HSF-1-induced increase of K(v) 1.5 and SAP97 proteins. A luciferase reporter gene assay revealed that the SAP97 promoter region (from -919 to -740) that contains heat shock elements (HSEs) was required for this induction. Suppression of SIRT1 function either by nicotinamide or siRNA decreased the level of SAP97 mRNA. SIRT1 activation by resveratrol had opposing effects. A treatment of the cells with GGA increased the level of SAP97 mRNA, K(v) 1.5 proteins and I(Kur) current, which could be modified with either resveratrol or nicotinamide.Conclusions and Implications: HSF-1 induced transcription of SAP97 through SIRT1-dependent interaction with HSEs; the increase in SAP97 resulted in stabilization of K(v)1.5 channels. These effects were mimicked by GGA. [ABSTRACT FROM AUTHOR]

We developed Lu0 .4 Gd1 .6 SiO5 (LGSO) crystal as a new scintillator for medical imaging applications. The size of the LGSO ingot obtained for this investigation was approximately 60 mm in diameter and 170 mm in length. The as-grown crystal was yellow in color. To eliminate the tint, the crystal was annealed in pure N2 atmosphere after the growth. As a result, the LGSO became colorless with uniform and large light output which is about 2.0 times that of GSO. [ABSTRACT FROM AUTHOR]

The emission spectra for X-ray and UV excitation, decay curve for emission above 460 nm under γ-ray excitation, and energy spectrum by using avalanche photodiode (APD) for excitation with 137Cs γ-rays have been measured for Lu0.4Gd1.6SiO5 having 2.0 mol% Ce. The emission spectrum under X-ray excitation showed two peaks around 430 and 495 nm. The excitation-emission spectrum under UV excitation also had two peaks at 425 and 510 nm for excitation wavelength of 285 and 385 nm, respectively. There was no significant difference in decay constants of emission between the longer and shorter wavelength components. Energy resolution by using an APD was 8.0% for 137Cs γ-ray excitation. [ABSTRACT FROM AUTHOR]

Abstract: We exposed crystalline Si (C-Si) substrates to a NH3 plasma by the method of plasma enhanced chemical vapor deposition (PECVD) and the Si substrates were nitrided at a nitridation temperature, T n, between 300 and 600°C. The nitrided layers were grown directly on n-type C-Si substrates with high resistivity for measurements of electron resonance (ESR) and Fourier transform infrared (FTIR) absorption. The intensity of the N–H IR bending band increased with increasing T n up to 450°C, and then decreased again with a further increasing in T n. We found a strong correlation between the change in the ESR spin density, N s, and that in the N–H bending intensity, which was obtained from the spectral intensity at around 1200cm−1. Furthermore, incorporation of N atoms in amorphous Si x N y layers may improve the structural property at T n =450°C for various insulating applications. In addition, we found that the atomic densities and/or composition of a-Si x N y may decrease the BHF etch rate. [Copyright &y& Elsevier]

Circulating immune complexes (CIC) were frequently observed in patients with idiopathic thrombocytopenic purpura (ITP). To analyse the pathogenic role of CIC, we studied the correlation between the disease activity and the CIC level, and whether platelet antigens were involved in CIC from ITP sera. Elevated CIC levels, measured by C1q. anti-C3 and spermatozoa micro-enzyme-linked immunosorbent assay, were found in 37%, 54% and 52% of the patients, respectively. However, there were no significant correlations (r = -011, -003 and -0.04, respectively) between the platelet count and the CIC level. Platelet antigens in CIC were detected with rabbit anti-human platelet serum. The CIC from 18%, 25% and 25%, respectively, of ITP sera contained platelet antigens, but the CIC from only 3%. 9% and 6% of SLE sera and from 3%, 2% and 5% of the sera of alloimmunized patients, respectively, contained these antigens. There were significant correlations (r = 0.51, 0.80 and 0.65, respectively) between the amount of platelet antigens and the CIC level in ITP sera. However, there were no correlations (r = -0.26, -0.29 and 0-08, respectively) between the platelet count and the amount of platelet antigens in the CIC. We detected platelet antigens in CIC from ITP sera, but surmise that these CIC perhaps do not play an important role in platelet destruction. [ABSTRACT FROM AUTHOR]

Electrophysiological effects of ethanol on rabbit sino-atrial node were studied by means of the double-microelectrode voltage clamp method. In spontaneously beating preparations, ethanol (above 1%) decreased the maximum rate of depolarization of the action potential. Furthermore, 3% ethanol produced a significant decrease in the action potential amplitude, the action potential duration at 50% repolarization and the rate of the diastolic depolarization. Of the current systems, voltage clamp studies showed that ethanol reduced the slow inward current, the time-dependent potassium outward current and the hyperpolarization activated inward current. These observations indicate that ethanol does not have an effect on a single current system, but directly modifies the spontaneous discharge of sino-atrial node pacemaker cells due to a reduction of the time-dependent current systems. [ABSTRACT FROM AUTHOR]

Peripheral blood T cells from 40 patients with idiopathic thrombocytopenic purpura (ITP) were analysed for the presence of surface la antigens using monoclonal antibodies by indirect immunofluorescence. The percentage of la-positive (Ia &plus;) T cells was significantly increased in patients with ITP (6.8±2.9%. P<0.005) as compared with normal controls (2.3 ± 0.9%), There was an inverse correlation between the percentages of Ia+ T cells and platelet counts (r = 0.58, P<0.005)and a positive correlation between the percentage of these cells and platelet-associated IgG (PAIgG) values (r = 0.55, P<0.01), The percentage of la+ T cells was found to decrease within two weeks during therapy with high dose γ - globulin or corticosteroid. We have previously reported the presence of T cells bearing both helper/inducer (H/I) and suppressor/cytotoxic (S/C) phenotypes (double labelled cells. DI.C) in patients with ITP and an inverse correlation between the percentages of DLC and their platelet counts. In the present study, we showed that a major part of Ia+ T cells had both H/I and S/C phenotypes. We also examined the correlation between Ia+ T cells and autologous mixed lyniphocyle reaction (AMLR). A defective AMLR was demonstrated in patients with ITP. Furthermore, an inverse correlation was found between the percentages of la+ T cells and the proliferative responses to AMLR (r= --0.49, P< 0.01). These results suggest that increased circulating Ia+ T cells play a role in the abnormalities of the immunoregulatory system of ITP. especially in the regulation of autoantibody production. [ABSTRACT FROM AUTHOR]

We investigated whether thrombocytopenia in patients with chronic hepatitis C is due to anti-platelet autoantibodies. Platelet-associated IgG (PAIgG) and platelet-associated IgM (PAIgM) were measured by direct immunofluorescent flow cytometric analysis. Elevation of PAIgM level was detected in 70% of chronic hepatitis C patients, while only a mild elevation of PAIgG level was detected in 32% of the cases. The elevation of PAIgM values in these patients was comparable to that in patients with chronic immune thrombocytopenic purpura (ITP). However, elevated PAIgM was also found in both patients with and without thrombocytopenia, and no correlation was found between PAIgM and platelet count. Eluted PAIgM did not react with normal platelets in all cases with a positive PAIgM value, indicating that eluted PAIgM contained no detectable anti-platelet antibodies. During alpha-interferon therapy, the level of PAIgM increased in association with the decrease in platelet counts in 75% of the cases; however, eluted PAIgM at any day point never reacted with platelets from normal donors. PAIgM was elevated in patients with chronic hepatitis C, but contained no detectable anti-platelet autoantibodies. Thrombocytopenia in these patients is not due to anti-platelet autoantibodies. [ABSTRACT FROM AUTHOR]

Castanospermine (CSP) inhibits α-glucusidase, which is involved in the initial step N-linked oligosaccharide processing of secretory and membrane glycoproteins. In Staphylococcus aureus Cowan I (SAC)-stimulated human lymphocyte culture, CSP at a dose of 20 μg/ml caused a twofold increase in immunoglobulin G (IgG) release after 7 days. An initial 48-h exposure to CSP sufficed for this enhancing effect. Plaque-forming cell assays on the seventh day disclosed that CSP caused an increase in the number of IgG-, IgA- and IgM-secreting cells. In cross-culture experiments, only a mixture of B cells pretreated with CSP and untreated T cells showed an increase in IgG production. Tritiated thymidine incorporation studies revealed that CSP enhanced B-cell responses to T cell-derived soluble factor (TSF). When incubated with CSP for 18 h, B cells showed an increased surface binding on [3H]concanavalin A (Con A). These results indicate that the alteration in B-cell membrane oligosaccharides enhances the response to TSF at an early stage of SAC culture, leading loan increase in Ig-secreting cell number at later stages. The present study provides evidence that cell-surface oligosaccharides of B cells play an important role in the responses of B cells to lymphokines. [ABSTRACT FROM AUTHOR]

Analyzes the causes of cracks in single-crystal gadolinium-silicon oxide (GSO), and studies the growth conditions of GSO. Scintillation properties of GSO crystals; History of single-crystal cerium GSO; Observations made of the GSO crystal boule; Possible causes of the cracks; How the causes of the cracks were eliminated.