3,527 research outputs found
Postnatal regulation of myosin heavy chain isoform expression and metabolic enzyme activity by nutrition
No full textDevelopment of muscle is critically dependent on several hormones which in turn are regulated by nutritional status. We therefore determined the impact of mild postnatal undernutrition on key markers of myofibre function: type I slow myosin heavy chain (MyHC) isoform, myosin ATPase, succinate dehydrogenase and α-glycerophosphate dehydrogenase. In situ hybridization, immunocytochemistry and enzyme histochemistry were used to assess functionally distinct muscles from 6-week-old pigs which had been fed an optimal (6 % (60 g food/kg body weight per d)) or low (2 % (20 g food/kg per d)) intake for 3 weeks, and kept at 26°C. Nutritional status had striking muscle-specific influences on contractile and metabolic properties of myofibres, and especially on myosin isoform expression. A low food intake upregulated slow MyHC mRNA and protein levels in rhomboideus by 53 % (P < 0·01) and 18 % (P < 0·05) respectively; effects in longissimus dorsi, soleus and diaphragm were not significant. The oxidative capacity of all muscles increased on the low intake, albeit to varying extents: longissimus dorsi (55 %), rhomboideus (30 %), soleus (21 %), diaphragm (7 %). Proportions of slow oxidative fibres increased at the expense of fast glycolytic fibres. These novel findings suggest a critical role for postnatal nutrition in regulating myosin gene expression and muscle phenotype. They have important implications for optimal development of human infants: on a low intake, energetic efficiency will increase and the integrated response to many metabolic and growth hormones will alter, since both are dependent on myofibre type. Mechanisms underlying these changes probably involve complex interactions between hormones acting as nutritional signals and differential effects on their cell membrane receptors or nuclear receptors
Growth hormone receptor gene expression in porcine skeletal and cardiac muscles is selectively regulated by postnatal undernutrition
No full textDuring mild postnatal undernutrition, growth hormone receptor (GHR) mRNA abundance decreases in liver but increases in longissimus dorsi muscle. We tested the following hypotheses: 1) GHR gene expression is related to the metabolic and contractile characteristics of different muscles, and 2) the GHR response to nutrition depends on muscle type. Eight pairs of littermate pigs were weaned at 3 wk and given an optimal [60 g/(kg·d)] or low [(20 g/(kg·d)] food intake for the next 3 wk. All pigs grew, but at a slower rate in the low food intake group (P 0.10). Compared with the high intake pigs, hepatic GHR mRNA was downregulated in the low intake pigs by 59% (P 0.4); soleus, 65% (P < 0.05); cardiac, 51% (P < 0.05). Moreover, the proportion of skeletal muscle fibers with high oxidative capacity was also greater in the low intake group (P < 0.05). We conclude that postnatal GHR gene expression and its regulation by mild undernutrition are related to the metabolic, contractile and specific functional properties of different muscles
Growth hormone receptor gene expression is related to metabolic and contractile properties of muscle
No full textApplicazione di biotecnologie nello studio delle interazioni fra stato nutrizionale ed accrescimento
No full textMeasurements of the decays B-0 -> (D)over-bar(0) p(p)over-bar, B0 -> (D)over-bar*(0) p(p)over-bar, B-0 -> D- p(p)over-bar pi(+), and B-0 -> D*(-) p(p)over-bar pi(+)
No full textWe present measurements of branching fractions of B-0 decays to multibody final states containing protons, based on 232x10(6) Upsilon(4S)-> B (B) over bar decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. We measure the branching fractions B(B-0 ->(D) over bar (0)p (p) over bar)=(1.13 +/- 0.06 +/- 0.08)x10(-4), B(B-0 ->(D) over bar (*0)p (p) over bar)=(1.01 +/- 0.10 +/- 0.09)x10(-4), B(B-0 -> D(-)p (p) over bar pi(+))=(3.38 +/- 0.14 +/- 0.29)x10(-4), and B(B-0 -> D(*-)p (p) over bar pi(+))=(4.81 +/- 0.22 +/- 0.44)x10(-4) where the first error is statistical and the second systematic. We present a search for the charmed pentaquark state, Theta(c)(3100) observed by H1 and put limits on the branching fraction B(B-0 ->Theta(c)(p) over bar pi(+))xB(Theta(c)-> D(*-)p)Theta(c)(p) over bar pi(+))xB(Theta(c)-> D(-)p)< 9x10(-6). Upon investigation of the decay structure of the above four B-0 decay modes, we see an enhancement at low p (p) over bar mass and deviations from phase-space in the (D) over bar(p) over bar and (D) over bar invariant mass spectra
Measurement of the mass of the D[superscript 0] meson
No full textWe report a measurement of the D[superscript 0] meson mass using the decay chain D[superscript *](2010)[superscript +] → D[superscript 0]π[superscript +] with D[superscript 0] → K[superscript −]K[superscript −]K[superscript +]π[superscript +]. The data were recorded with the BABAR detector at center-of-mass energies at and near the Υ(4S) resonance, and correspond to an integrated luminosity of approximately 477 fb[superscript −1]. We obtain m(D[superscript 0]) = (1864.841 ± 0.048 ± 0.063) MeV, where the quoted errors are statistical and systematic, respectively. The uncertainty of this measurement is half that of the best previous measurement.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
Measurement of the D[superscript *](2010)[superscript +] natural linewidth and the D[superscript *](2010)[superscript +] - D[superscript 0] mass difference
No full textWe measure the mass difference, Δm[subscript 0], between the D[superscript *](2010)[superscript +] and the D[superscript 0] and the natural linewidth, Γ, of the transition D[superscript *](2010)[superscript +] → D[superscript 0]π[superscript +]. The data were recorded with the BABAR detector at center-of-mass energies at and near the Υ(4S) resonance, and correspond to an integrated luminosity of approximately 477 fb[superscript −1]. The D[superscript 0] is reconstructed in the decay modes D[superscript 0] → K[superscript −]π[superscript +] and D[superscript 0] → K[superscript −]π[superscript +]π[superscript −]π[superscript +]. For the decay mode D[superscript 0] → K[superscript −]π[superscript +] we obtain Γ = (83.4 ± 1.7 ± 1.5) keV and Δm[subscript 0] = (145425.6 ± 0.6 ± 1.8) keV, where the quoted errors are statistical and systematic, respectively. For the D[superscript 0] → K[superscript −]π[superscript +]π[superscript −]π[superscript +] mode we obtain Γ = (83.2 ± 1.5 ± 2.6) keV and Δm[subscript 0] = (145426.6 ± 0.5 ± 2.0) keV. The combined measurements yield Γ = (83.3 ± 1.2 ± 1.4) keV and Δm[subscript 0] = (145425.9 ± 0.4 ± 1.7) keV; the width is a factor of approximately 12 times more precise than the previous value, while the mass difference is a factor of approximately 6 times more precise.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
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