Liver-Specific Expression of Transcriptionally Active SREBP-1c Is Associated with Fatty Liver and Increased Visceral Fat Mass

The pathogenesis of fatty liver is not understood in detail, but lipid overflow as well as de novo lipogenesis (DNL) seem to be the key points of hepatocyte accumulation of lipids. One key transcription factor in DNL is sterol regulatory element-binding protein (SREBP)-1c. We generated mice with liver-specific over-expression of mature human SREBP-1c under control of the albumin promoter and a liver-specific enhancer (alb-SREBP-1c) to analyze systemic perturbations caused by this distinct alteration. SREBP-1c targets specific genes and causes key enzymes in DNL and lipid metabolism to be up-regulated. The alb-SREBP-1c mice developed hepatic lipid accumulation featuring a fatty liver by the age of 24 weeks under normocaloric nutrition. On a molecular level, clinical parameters and lipid-profiles varied according to the fatty liver phenotype. The desaturation index was increased compared to wild type mice. In liver, fatty acids (FA) were increased by 50% (p<0.01) and lipid composition was shifted to mono unsaturated FA, whereas lipid profile in adipose tissue or serum was not altered. Serum analyses revealed a ∼2-fold (p<0.01) increase in triglycerides and free fatty acids, and a ∼3-fold (p<0.01) increase in insulin levels, indicating insulin resistance; however, no significant cytokine profile alterations have been determined. Interestingly and unexpectedly, mice also developed adipositas with considerably increased visceral adipose tissue, although calorie intake was not different compared to control mice. In conclusion, the alb-SREBP-1c mouse model allowed the elucidation of the systemic impact of SREBP-1c as a central regulator of lipid metabolism in vivo and also demonstrated that the liver is a more active player in metabolic diseases such as visceral obesity and insulin resistance

BIG KARL magnet spectrometer Operating System. User's manual

SIGLETIB: RN 5906 (363) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

t-dependence and production mechanisms of the ρ\rho, f and g resonances from ]pi−π+]pi^{-}\pi^{+}n at 17.2 GeV

The t-dependence of rho , f and g resonance production is compared using data from the CERN-Munich spectrometer. An amplitude analysis is performed, and the significance for various proposed models of the production mechanism discussed. The OPE term becomes increasingly adequate to describe the data as the resonant mass increases. (17 refs)

Peripheral pp‾\overline{p} production and decay angular distribution in the reaction \pi^{-}p\rightarrow\p\overline{p}n at 18.8 and 9.8 GeV

A total of 13920 pi /sup -/p to ppn events measured in a spark chamber experiment at 9.8 GeV incident pi /sup -/ momentum are compared with data recently published on the same reaction at 18.8 GeV. The s- dependence of the total cross section, the shape of d/sup 2/ sigma /d Mdt, and the pp decay angular distributions at both energies suggest that the production process is dominated by one-pion exchange. This is supported by comparison with new pi /sup +/p to pnp and pp to pi /sup +/ pi /sup -/ annihilation data. An interpretation of the angular distribution by partial waves is discussed, and results from a fit with a Breit-Wigner parametrization are presented. The cross section for the reaction pi /sup -/p to ppn in the range M/sub pp/<or=2.7 GeV and mod t/sub np/ mod <or=0.3 GeV/sup 2/ has been determined to be sigma =6.5+or-0.9 mu b at 9.8 GeV. (23 refs)

Construction and performance of large wire spark chambers with magnetostrictive read-out

Describes the construction and performance of wire spark chambers having an active area of 3.60*0.90 m/sup 2/, a gap of 10 mm, and a wire spacing of 1 mm. Magnetostrictive read-out from both planes gives two coordinate values per chamber. Chambers of this type, together with smaller ones of similar construction, have been part of a magnet spectrometer which performed reliably between May 1970 and May 1971; during this time they were pulsed approximately 10/sup 7/ times. (9 refs)

Isospin 2 ππ\pi\pi phase shifts from an experiment π+\pi^{+}p→π+π+\rightarrow\pi^{+}\pi^{+}n at at 12.5 GeV/c

The I=2 s- and d-wave pi pi phase shifts delta /sub s//sup 2/ and delta /sub d//sup 2/ have been determined in the pi pi mass region from 500-1500 MeV, using a sample of 17500 events pi /sup +/p to pi /sup +/ pi /sup +/ from a spark chamber experiment. For this purpose the moments of the pi pi angular distribution in the s-channel helicity frame have been written as bilinear expressions of OPE amplitudes modified by absorption and have been fitted to the measured values of the moments in four mass bins of width 0.25 GeV/c/sup 2/. The value of delta /sub s//sup 2/ in the rho -mass region ( delta /sub s//sup 2/ approximately=-15.5 degrees ) corresponds to an elastic cross-section of approximately=7.5 mb. The values of delta /sub d//sup 2/ are about a factor of 10 smaller than the corresponding values of delta /sub s//sup 2/ for the whole mass region considered. (5 refs)

A study of the ππ\pi\pi phase-shift solutions in the mass region 1.0 to 1.8 GeV from π−p→π−π+π\mathrm{\pi^−p \to \pi^−\pi^+\pi} at 17.2 GeV

The pi pi phase shifts from 1 to 1.8 GeV are presented. The method used was an essentially energy-independent parametrization of the amplitudes fitted simultaneously to the M/sub pi pi / and t-dependence of the moments of the dipion angular distribution from the reaction pi /sup -/p to pi /sup -/ pi /sup +/n at 17.2 GeV. The various ambiguous solutions are discussed. (19 refs)