Triiodothyronine increases myocardial function and pyruvate entry into the citric acid cycle after reperfusion in a model of infant cardiopulmonary bypass

Triiodothyronine (T3) supplementation improves clinical outcomes in infants after cardiac surgery using cardiopulmonary bypass by unknown mechanisms. We utilized a translational model of infant cardiopulmonary bypass to test the hypothesis that T3 modulates pyruvate entry into the citric acid cycle (CAC), thereby providing the energy support for improved cardiac function after ischemia-reperfusion (I/R). Neonatal piglets received intracoronary [2-(13)Carbon((13)C)]pyruvate for 40 min (8 mM) during control aerobic conditions (control) or immediately after reperfusion (I/R) from global hypothermic ischemia. A third group (I/R-Tr) received T3 (1.2 μg/kg) during reperfusion. We assessed absolute CAC intermediate levels and flux parameters into the CAC through oxidative pyruvate decarboxylation (PDC) and anaplerotic carboxylation (PC) using [2-(13)C]pyruvate and isotopomer analysis by gas and liquid chromatography-mass spectrometry and (13)C-nuclear magnetic resonance spectroscopy. When compared with I/R, T3 (group I/R-Tr) increased cardiac power and oxygen consumption after I/R while elevating flux of both PDC and PC (～4-fold). Although neither I/R nor I/R-Tr modified absolute CAC levels, T3 inhibited I/R-induced reductions in their molar percent enrichment. Furthermore, (13)C-labeling of CAC intermediates suggests that T3 may decrease entry of unlabeled carbons at the level of oxaloacetate through anaplerosis or exchange reaction with asparate. T3 markedly enhances PC and PDC fluxes, thereby providing potential substrate for elevated cardiac function after reperfusion. This T3-induced increase in pyruvate fluxes occurs with preservation of the CAC intermediate pool. Our labeling data raise the possibility that T3 reduces reliance on amino acids for anaplerosis after reperfusion.     

Differential protein expression in the corpus callosum (body) of human alcoholic brain

Neuroimage analysis in alcoholic corpus callosum (CC) suggests that microstructural abnormalities are higher in the genu followed by the body and the splenium. Molecular mechanisms underlying these dysmorphologys are still unclear. Protein expression was performed using the CC body samples [(nine controls, seven uncomplicated, and six complicated (with liver cirrhosis) alcoholics] through proteomics approach. Thirty-nine protein spots in uncomplicated and 60 in complicated alcoholics were differentially altered compared with the control ( p  < 0.05). Comparison between alcoholic groups revealed that 40% more protein showed altered expression in complicated compared with uncomplicated. This result suggests that alcohol-related liver dysfunction has synergetic effects on brain protein expression. Subregional expression profiles indicate that the highest numbers of region-specific proteins were in the genus followed by the CC body and the splenium. Interestingly, abnormal thiamine cascade was strongly suggested in the genu, and to a lesser extent in the CC body, but no such cascade was observed in the splenium. Therefore, alcohol-induced microstructural damage detected by image analysis in the CC, possibly involves multiple biochemical mechanisms.     

Effects of glycerol and fructose on purine synthesis de novo and on PP-ribose-P availability in rat liver cells

Incubation of freshly isolated rat liver cells with glycerol resulted in an initial decrease, followed by an increase in purine synthesis de novo and in PP-ribose-P availability. The magnitude of these effects was dependent on the concentration of glycerol; as it increased, the initial period of latency or inhibition was prolonged, and the extent of the subsequent stimulation was greater. The intracellular Pi concentration and the [14C]ATP/[14C]ADP ratio were also initially decreased in these cells, and they too returned subsequently to normal values. All these changes were similar to those induced by fructose under the same conditions. The increase in PP-ribose-P availability always preceded that in purine synthesis de novo, indicating that, under most circumstances, PP-ribose-P availability is limiting for purine synthesis de novo. Finally, PP-ribose-P synthesis in these cells varied in parallel with the intracellular Pi concentration and with the ATP/ADP and ATP/AMP ratios.     

Determination of citrulline in human plasma, red blood cells and urine by electron impact (EI) ionization gas chromatography-mass spectrometry

A method was developed by using gas chromatography-mass spectrometry in the electron impact ionization mode to quantify citrulline in plasma, red blood cells (RBC) and urine. For all three fluids, citrulline was extracted on ion exchange resins, before derivatization to its propyl-heptaflorobutyryl-ester. Assay precision (coefficient of variation, CV) was <5%, recovery% was >90% and the within- and between-day CV were <10% on 200 microL of plasma and RBC, and 400 microL of urine. The current method allows for the detection of 20 pmol of natural citrulline in aqueous standards, and small volumes (<100 microL) of biological fluids.     

Gène CFTR et infertilité masculine en 2001 Conseil génétique, diagnostic prénatal, diagnostic pré-implantatoire

As the vas deferens is also absent in the majority of CF (cystic fibrosis) males, it has been proposed that CBAVD (Congenital Bilateral Absence of Vas Deferens) males may present an incomplete or mild form of CF. Many studies using more extensive mutation analysis have confirmed the role of CFTR gene defects: 80% of CBAVD patients carry one or two mutations. Each patient with a diagnosis of CBAVD should also be examined for pulmonary and pancreatic signs, and sweat tests should be performed. In couples with CBAVD linked to CFTR mutations, the risk of having children with CF or infertility is increased if the female is also a carrier. The woman should be screened for the most frequent CFTR mutations according to her ethnic background. After screening for 80% of the mutations responsible for CF, the residual risk of being a carrier with negative screening is: Z=h(1?a)/(1?ah)=1/120 considering a carrier frequency of 1/25 in the general population. In the case of positive screening, antenatal diagnosis by chorionic villus sampling may be proposed. However, in some situations it is difficult to predict the phenotypic consequences for the child, particularly when a severe transmutation of a variable allele is identified. As these couples require medically-assisted reproduction techniques, pre-implantation genetic diagnosis appears to be more appropriate than antenatal diagnosis. Only embryos that inherit the non-mutated maternal CFTR allele are replaced in the uterus. Examination of childre born to couples with CBAVD is mandatory: immunoreactive trypsinogen assay at 3 days of age, sweat test at 3 months and clinical examination, especially looking for signs of CF. Identification of CFTR mutations in a CBAVD patient has important consequences for his family. Each sibling has a 50% risk of being a carrier and a 25% risk of inheriting the same genotype. The genetic counsellor must inform these siblings about the possible risk of having CF children if they carry CFTR mutations and if their partner is also a carrier.     

Signature Lipids and Stable Carbon Isotope Analyses of Octopus Spring Hyperthermophilic Communities Compared with Those of Aquificales Representatives

The molecular and isotopic compositions of lipid biomarkers of cultured Aquificales genera have been used to study the community and trophic structure of the hyperthermophilic pink streamers and vent biofilm from Octopus Spring. Thermocrinis ruber, Thermocrinis sp. strain HI 11/12, Hydrogenobacter thermophilus TK-6, Aquifex pyrophilus, and Aquifex aeolicus all contained glycerol-ether phospholipids as well as acyl glycerides. The n-C_20:1 and cy-C₂₁ fatty acids dominated all of the Aquificales, while the alkyl glycerol ethers were mainly C_18:0. These Aquificales biomarkers were major constituents of the lipid extracts of two Octopus Spring samples, a biofilm associated with the siliceous vent walls, and the well-known pink streamer community (PSC). Both the biofilm and the PSC contained mono- and dialkyl glycerol ethers in which C₁₈ and C₂₀ alkyl groups were prevalent. Phospholipid fatty acids included both the Aquificales n-C_20:1 and cy-C₂₁, plus a series of iso-branched fatty acids (i-C_15:0 to i-C_21:0), indicating an additional bacterial component. Biomass and lipids from the PSC were depleted in ¹³C relative to source water CO₂ by 10.9 and 17.2‰, respectively. The C_20–21 fatty acids of the PSC were less depleted than the iso-branched fatty acids, 18.4 and 22.6‰, respectively. The biomass of T. ruber grown on CO₂ was depleted in ¹³C by only 3.3‰ relative to C source. In contrast, biomass was depleted by 19.7‰ when formate was the C source. Independent of carbon source, T. ruber lipids were heavier than biomass (+1.3‰). The depletion in the C_20–21 fatty acids from the PSC indicates that Thermocrinis biomass must be similarly depleted and too light to be explained by growth on CO₂. Accordingly, Thermocrinis in the PSC is likely to have utilized formate, presumably generated in the spring source region.