220 research outputs found
Regulation of energy metabolism by interleukin-1 β, but not by interleukin-6, is mediated by nitric oxide in primary cultured rat hepatocytes
AbstractThe effects of inflammatory cytokines (interleukin-1 β, interleukin-6, and tumor necrosis factor-α) on energy metabolism were studied in primary cultured rat hepatocytes. Adenine nucleotide (ATP, ADP, and AMP) content, lactate production, the ketone body ratio (acetoacetate/β-hydroxybutyrate) reflecting the liver mitochondrial redox state (NAD+/NADH), and nitric oxide formation were measured. Insulin increased ATP content in hepatocytes and had a maximal effect after 8–12 h of culture. Both interleukin-1β and interleukin-6, but not tumor necrosis factor-α, significantly inhibited the ATP increase time- and dose-dependently. Interleukin-1β and interleukin-6 also stimulated lactate production. During the same period, interleukin-1 β but not interleukin-6 decreased the ketone body ratio. Furthermore, interleukin-1 β markedly stimulated nitric oxide formation in hepatocytes, and this increase was blocked by NG-monomethyl-L-arginine (a nitric oxide synthase inhibitor) and by interleukin-1 receptor antagonist. NG-monomethyl-l-arginine reversed inhibition of the ATP increase, decrease in the ketone body ratio, and increase in lactate production, which were induced by interleukin-lβ. Interleukin-1 receptor antagonist completely abolished all of the effects induced by interleukin-1 β. These results demonstrated that interleukin-1 β and interleukin-6 affect the insulin-induced energy metabolism in rat hepatocytes by different mechanisms. Specifically, interleukin-1 β inhibits ATP synthesis by causing the mitochondrial dysfunction, a process which may be mediated by nitric oxide
CHARACTERISTICS OF Y-BA-CU-O/NB AND BI-SR-CA-CU-O/NB TUNNEL-TYPE JOSEPHSON-JUNCTIONS
We have fabricated Y-Ba-Cu-O/Nb and Bi-Sr-Ca-Cu-O/Nb tunnel-type Junctions and observed the DC and AC Josephson effects. Gold thin films were deposited for an inter-layer to protect the reaction between the base electrode and the tunnel oxide before the tunnel barrier formation. In Y-Ba-Cu-O/Au/MgOx/Nb junctions, superconducting current, hysteresis of current-voltage characteristics and the rf-induced voltage steps at the voltage as high as 0.13 mV in the current-voltage characteristics were observed. Moreover, the superconducting current has been modulated by the magnetic field. In Bi-Sr-Ca-Cu-O/Au/MgO(x)/Nb junctions, superconducting current and the rf-induced voltage steps at the voltage as high as 0.15 mV were also observed
早期糖尿病性腎症での腎臓におけるα-Klotho 発現の低下とその尿中カルシウム排世に対する役割についての検討
Hypercalciuria is one of the early manifestations of diabetic nephropathy. We explored here the role of α-Klotho, a protein expressed predominantly in distal convoluted tubules that has a role in calcium reabsorption. We studied 31 patients with early diabetic nephropathy and compared them with 31 patients with IgA nephropathy and 7 with minimal change disease. Renal α-Klotho expression was significantly lower and urinary calcium excretion (UCa/UCr) significantly higher in diabetic nephropathy than in IgA nephropathy or minimal change disease. Multiple regression analyses indicated that α-Klotho mRNA was inversely correlated with calcium excretion. We next measured these parameters in a mouse model of streptozotocin (STZ)-induced diabetic nephropathy, characterized by glomerular hyperfiltration, as seen in early diabetic nephropathy. We also confirmed a reduction of renal α-Klotho mRNA down to almost 50% and enhanced calcium excretion in mice with STZ-induced diabetic nephropathy in comparison with nondiabetic mice. Hypercalciuria was exacerbated in heterozygous α-Klotho knockout mice in comparison with wild-type mice, each with STZ-induced diabetic nephropathy. Thus, α-Klotho expression was decreased in distal convoluted tubules in diabetic nephropathy in humans and mice. Renal loss of α-Klotho may affect urinary calcium excretion in early diabetic nephropathy.博士(医学)・乙第1293号・平成24年5月28日© 2012 International Society of Nephrolog
Transmission of survival signals through Delta-like 1 on activated CD4+ T cells
Notch expressed on CD4+ T cells transduces signals that mediate their effector functions and survival. Although Notch signaling is known to be cis-inhibited by Notch ligands expressed on the same cells, the role of Notch ligands on T cells remains unclear. In this report we demonstrate that the CD4+ T cell Notch ligand Dll1 transduces signals required for their survival. Co-transfer of CD4+ T cells from Dll1−/− and control mice into recipient mice followed by immunization revealed a rapid decline of CD4+ T cells from Dll1−/− mice compared with control cells. Dll1−/− mice exhibited lower clinical scores of experimental autoimmune encephalitis than control mice. The expression of Notch target genes in CD4+ T cells from Dll1−/− mice was not affected, suggesting that Dll1 deficiency in T cells does not affect cis Notch signaling. Overexpression of the intracellular domain of Dll1 in Dll1-deficient CD4+ T cells partially rescued impaired survival. Our data demonstrate that Dll1 is an independent regulator of Notch-signaling important for the survival of activated CD4+ T cells, and provide new insight into the physiological roles of Notch ligands as well as a regulatory mechanism important for maintaining adaptive immune responses
Measurement of low-energy antiproton detection efficiency in BESS below 1 GeV
An accelerator experiment was performed using a low-energy antiproton beam to
measure antiproton detection efficiency of BESS, a balloon-borne spectrometer
with a superconducting solenoid. Measured efficiencies showed good agreement
with calculated ones derived from the BESS Monte Carlo simulation based on
GEANT/GHEISHA. With detailed verification of the BESS simulation, the relative
systematic error of detection efficiency derived from the BESS simulation has
been determined to be 5%, compared with the previous estimation of
15% which was the dominant uncertainty for measurements of cosmic-ray
antiproton flux.Comment: 13 pages, 7 figure
Precise Measurement of Cosmic-Ray Proton and Helium Spectra with the BESS Spectrometer
We report cosmic-ray proton and helium spectra in energy ranges of 1 to 120
GeV and 1 to 54 GeV/nucleon, respectively, measured by a balloon flight of the
BESS spectrometer in 1998. The magnetic-rigidity of the cosmic-rays was
reliably determined by highly precise measurement of the circular track in a
uniform solenoidal magnetic field of 1 Tesla. Those spectra were determined
within overall uncertainties of +-5 % for protons and +- 10 % for helium nuclei
including statistical and systematic errors.Comment: 12 pages, 4 figure
Reference values for the locomotive syndrome risk test quantifying mobility of 8681 adults aged 20–89 years: A cross-sectional nationwide study in Japan
Background
The locomotive syndrome risk test was developed to quantify the decrease in mobility among adults, which could eventually lead to disability. The purpose of this study was to establish reference values for the locomotive syndrome risk test for adults and investigate the influence of age and sex.
Methods
We analyzed 8681 independent community dwellers (3607 men, 5074 women). Data pertaining to locomotive syndrome risk test (the two-step test, the stand-up test, and the 25-question geriatric locomotive function scale [GLFS-25]) scores were collected from seven administrative areas of Japan.
Results
The reference values of the three test scores were generated and all three test scores gradually decreased among young-to-middle-aged individuals and rapidly decreased in individuals aged over 60 years. The stand-up test score began decreasing significantly from the age of 30 years. The trajectories of decrease in the two-step test score with age was slightly different between men and women especially among the middle-aged individuals. The two physical test scores were more sensitive to aging than the self-reported test score.
Conclusion
The reference values generated in this study could be employed to determine whether an individual has mobility comparable to independent community dwellers of the same age and sex
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