A semi-quantitative RT-PCR method to measure the in vivo effect of dietary conjugated linoleic acid on porcine muscle PPAR gene expression

Conjugated linoleic acid (CLA) can activate (in vitro) the nuclear transcription factors known as the peroxisome proliferators activated receptors (PPAR). CLA was fed at 11 g CLA/kg of feed for 45d to castrated male pigs (barrows) to better understand long term effects of PPAR activation in vivo. The barrows fed CLA had lean muscle increased by 3.5% and overall fat reduced by 9.2% but intramuscular fat (IMF %) was increased by 14% (P < 0.05). To measure the effect of long term feeding of CLA on porcine muscle gene expression, a semi-quantitative RT-PCR method was developed using cDNA normalized against the housekeeping genes cyclophilin and β-actin. This method does not require radioactivity or expensive PCR instruments with real-time fluorescent detection. PPARγ and the PPAR responsive gene AFABP but not PPARα were significantly increased (P < 0.05) in the CLA fed pig’s muscle. PPARα and PPARγ were also quantitatively tested for large differences in gene expression by western blot analysis but no significant difference was detected at this level. Although large differences in gene expression of the PPAR transcriptional factors could not be confirmed by western blotting techniques. The increased expression of AFABP gene, which is responsive to PPAR transcriptional factors, confirmed that dietary CLA can induce a detectable increase in basal PPAR transcriptional activity in the live animal

Enhancement of Josephson photoresponse of granular high‐Tc superconductor thin films by deoxygenation

The dependence of the far infrared Josephson photoresponse of current biased granular high‐Tc superconductor thin films on deoxygenation is presented. Bi2Sr2CaCu2O8 and TlBa2Ca2Cu3O9 thin films were heated in vacuum to temperatures of between 200 and 500 °C. The resulting deoxygenation weakens the intergrain coupling, thereby reducing the critical current and enhancing the photoresponse. In this way the optimum temperature for the fast Josephson response may be tuned to lie outside the temperature region of the slow bolometric signal

The effect of N-acetylcysteine supplementation on serum homocysteine levels and hepatic and renal oxidative stress in homocysteine thiolactone-treated rats

The effect of N-acetylcysteine (NAC) (1g/kg body weight/day) on serum homocysteine (Hcy) levels, insulin resistance (IR), and hepatic and renal prooxidant-antioxidant balance was evaluated in rats treated with homocysteine thiolactone (HcyT) (500mg/kg body weight/day for 6 weeks). Reactive oxygen species (ROS), malondialdehyde (MDA), glutathione, ferric reducing antioxidant power, and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were determined in the liver and kidney. HcyT elevated serum Hcy levels and caused IR, but liver and kidney function tests remained unchanged. HcyT increased ROS and MDA without any change in hepatic antioxidants, but it elevated renal SOD and GSH-Px activities. NAC decreased serum Hcy, hepatic and renal ROS and MDA levels, and renal SOD and GSH-Px activities in rats with high Hcy levels. However, it did not ameliorate IR. Our results indicate that NAC supplementation may be effective in decreasing Hcy levels and Hcy-induced hepatic and renal oxidative stress

Molecular bases of copper and iron deficiency-associated dyslipidemia: a microarray analysis of the rat intestinal transcriptome

As essential cofactor in many proteins and redox enzymes, copper and iron are involved in a wide range of biological processes. Mild dietary deficiency of metals represents an underestimated problem for human health, because it does not cause clear signs and clinical symptoms, but it is associated to long-term deleterious effects in cardiovascular system and alterations in lipid metabolism. The aim of this work was to study the biological processes significantly affected by mild dietary deficiency of both metals in rat intestine, in order to better understand the molecular bases of the systemic metabolic alterations, as hypercholesterolemia and hypertriglyceridemia observed in copper-deficient rats. A gene-microarray differential analysis was carried out on the intestinal transcriptome of copper- and iron-deficient rats, thus highlighting the biological processes significantly modulated by the dietary restrictions. The gene array analysis showed a down-regulation of genes involved in mitochondrial and peroxisomal fatty acids beta-oxidation and an up-regulation of genes involved in plasmatic cholesterol transport (apoprotein E and lecithin:cholesterol acyltransferase) in copper deficiency. Furthermore, a severe down-regulation of ApoH was pointed out in iron-deficient animals