Role of thrombospondin-1 in high-salt-induced mesenteric artery endothelial impairment in rats.

The matrix glycoprotein thrombospondin-1 (THBS1) modulates nitric oxide (NO) signaling in endothelial cells. A high-salt diet induces deficiencies of NO production and bioavailability, thereby leading to endothelial dysfunction. In this study we investigated the changes of THBS1 expression and its pathological role in the dysfunction of mesenteric artery endothelial cells (MAECs) induced by a high-salt diet. Wild-type rats, and wild-type and Thbs1-/- mice were fed chow containing 8% w/w NaCl for 4 weeks. We showed that a high salt diet significantly increased THBS1 expression and secretion in plasma and MAECs, and damaged endothelium-dependent vasodilation of mesenteric resistance arteries in wild-type animals, but not in Thbs1-/- mice. In rat MAECs, we demonstrated that a high salt environment (10-40 mM) dose-dependently increased THBS1 expression accompanied by suppressed endothelial nitric oxide synthase (eNOS) and phospho-eNOS S1177 production as well as NO release. Blockade of transforming growth factor-ß1 (TGF-ß1) activity by a TGF-ß1 inhibitor SB 431542 reversed THBS1 up-regulation, rescued the eNOS decrease, enhanced phospho-eNOS S1177 expression, and inhibited Smad4 translocation to the nucleus. By conducting dual-luciferase reporter experiments in HEK293T cells, we demonstrated that Smad4, a transcription promoter, upregulated Thbs1 transcription. We conclude that THBS1 contributes to endothelial dysfunction in a high-salt environment and may be a potential target for treatment of high-salt-induced endothelium dysfunction.

[Oil content of Pyracantha seeds and its relations to soil nutrients in northwestern Hunan Province].

Pyracantha seeds were collected from five habitats in the Karst region of northwestern Hunan Province, and the oil content and its components were determined, with their relations to soil nutrients studied. The results showed that soil total P had positive correlation with the linolic acid in P. fortuneana seed oil, while other soil nutrients had no correlations with the fat acids in the oil. The vitamin E in seed oil had significant positive correlations with soil total Ca and total Mg. The P. fortuneana seeds in test region had the maximum oil content of 5.9%, and the average vitamin E content of 9.9 g x kg(-1). The relative contents of linolic acid, oleic acid and palmic acid were 63.7%, 20.8% and 13.2%, respectively.

Using rare earth element tracers and neutron activation analysis to study rill erosion process.

Spatially averaged soil erosion data provide little information on the process of rill erosion. The dynamically varied data on the temporal and spatial distributions in the rill erosion process are needed to better understand the erosion process and reveal its innate characteristics. The objectives of this study were to examine the feasibility and effectiveness of rare earth element (REE) tracers and the neutron activation analysis (NAA) method on the study of the rill erosion process and to reveal quantitatively the relationships and characteristics of temporal and spatial distributions of sediment yield in rill erosion. Four REEs were used to study the changeable process of rill erosion at 4 slope positions. Four water inflow rates were applied to a 0.3 x 5 m soil bed at 3 slopes of 10.5%, 15.8% and 21.2% in scouring experiments. All of the runoff was collected in the experiment. Each sample was air-dried and well mixed. Then 20 g of each sample was sieved through 100-mesh and about a 50 mg sample was weighed for analysis of the four elemental compositions by NAA. Results indicate that the REE tracers and NAA method can be used to not only quantitatively determine soil erosion amounts on different slope segments, but also to reveal the changeable process of rill erosion amount. All of the relative errors of the experimental results were less than 25%, which is considered satisfactory on the study of rill erosion process.

[Single-stage arterial switch operation for transposition of the great arteries and Taussig-Bing with aortic arch obstruction].

OBJECTIVE: To evaluate one-stage arterial Switch operation for transposition of the great arteries (TGA) and Taussig-Bing with aortic arch obstruction. METHODS: From January 2001 to June 2004, 8 patients had aortic arch obstruction, 3 with TGA and 5 with Taussig-Bing. Except one patient was 8 months old, all of others were 5 days to 3 months old, the mean operation age was (40 +/- 36) d and the mean weight was (4.3 +/- 0.5) kg. All patients were repaired by one-stage operation. The aortic arch obstruction was repaired in deep hypothermia circulatory arrest, and arterial switch procedure was performed in deep hypothermia and low flow perfusion. RESULTS: There had 1 death who was 8 months old and had low cardiac output, complete artrioventricular block (AVB) and severe pulmonary hypertension postoperation. One patient was 3 months old who had asphyxia at 5 days postoperatively. Six patients followed up from 5 months to 2 years. One Taussig-Bing with interrupted aortic arch had residual obstruction at the anastomosis of aorta. Two had trivial aortic valve regurgitation, and one had mild pulmonary valve regurgitation. CONCLUSIONS: One-stage repair for TGA and Taussig-Bing with aortic obstruction achieves excellent results. The reasons for the death were pulmonary hypertension and abnormal coronary artery. The operative procedure should be performed as early as possible for the better result.