Prevalence and risk factors for vascular calcification in Chinese patients receiving dialysis: baseline results from a prospective cohort study.

OBJECTIVE: With limited data available on calcification prevalence in chronic kidney disease (CKD) patients on dialysis, the China Dialysis Calcification Study (CDCS) determined the prevalence of vascular/valvular calcification (VC) and association of risk factors in Chinese patients with prevalent hemodialysis (HD) or peritoneal dialysis (PD). METHODS: CKD patients undergoing HD/PD for ≥6 months were enrolled. Prevalence data for calcification and medical history were documented at baseline. Coronary artery calcification (CAC) was assessed by electron beam or multi-slice computed tomography (EBCT/MSCT), abdominal aortic calcification (AAC) by lateral lumbar radiography, and cardiac valvular calcification (ValvC) by echocardiography. Serum phosphorus, calcium, intact parathyroid hormone (iPTH), and 25-hydroxyvitamin D and FGF-23 were evaluated. A logistic regression model was used to evaluate the association between risk factors and VC. RESULTS: Of 1,497 patients, 1,493 (78.3% HD, 21.7% PD) had ≥1 baseline calcification image (final analysis cohort, FAC) and 1,423 (78.8% HD, 21.2% PD) had baseline calcification data complete (BCDC). Prevalence of VC was 77.4% in FAC (80.8% HD, 65.1% PD, p < .001) and 77.5% in BCDC (80.7% HD, 65.8% PD). The proportion of BCDC patients with single-site calcification were 20% for CAC, 4.3% for AAC, and 4.3% for cardiac valvular calcification (ValvC), respectively. Double site calcifications were 23.4% for CAC and AAC, 6.5% for CAC and ValvC, and 1.1% for AAC and ValvC, respectively. In total, 17.9% patients had calcification at all three sites. CONCLUSIONS: High prevalence of total VC in Chinese CKD patients will supplement current knowledge, which is mostly limited, contributing in creating awareness and optimizing VC management.

Abnormal ankle-brachial index and risk of cardiovascular or all-cause mortality in patients with chronic kidney disease: a meta-analysis.

Prognostic role of ankle-brachial index (ABI) in patients with chronic kidney disease (CKD) is controversial. We aimed to evaluate whether abnormal ABI was an independent predictor of cardiovascular or all-cause mortality in CKD patients with or without hemodialysis by conducting a meta-analysis. We systematically searched Pubmed and Embase databases for prospective observational studies that investigated baseline abnormal ABI and subsequent cardiovascular or all-cause mortality risk in CKD patients with or without hemodialysis. An ABI value of 0.9 to 1.3 was defined as normal. Pooled hazard risk (HR) with 95% confidence interval (CI) was calculated for the abnormal vs. normal ABI category. Six studies enrolling 5820 patients were identified and analyzed. Overall, abnormal ABI was associated with an increased risk of all-cause mortality (HR 2.26; 95% CI 1.60-3.18) and cardiovascular mortality (HR 3.58; 95% CI 2.53-5.06). Subgroup analysis indicated that patients with abnormally low ABI increased by 2.45-fold all-cause mortality and 5.18-fold cardiovascular mortality. Similarly, an abnormally high ABI increased by 1.94-fold all-cause mortality and 4.04-fold cardiovascular mortality. In addition, the effect of abnormal ABI on all-cause mortality was more pronounced among hemodialysis patients (HR 3.06; 95% CI 2.30-4.07) but not in CKD patients (HR 1.42; 95% CI 0.98-2.05). Abnormally low and high ABI are independently associated with cardiovascular or all-cause mortality risk in maintenance hemodialysis patients. This meta-analysis highlighted an U-shaped relationship between ABI and mortality risk in CKD patients undergoing hemodialysis. However, findings of this meta-analysis were undermined by the small number of included studies.

Fibrin sheath formation and intimal thickening after catheter placement in dog model: role of hemodynamic wall shear stress.

PURPOSE: To investigate the role of wall shear stress in aspects of the formation of fibrin sheath and intimal thickening in a dog model. METHODS: Tunneled silicone 14.5-F catheters were inserted into the left internal jugular vein in eight dogs. The dogs were separated into two groups according to catheter indwelling time of 14 and 28 days. All dogs underwent extracorporeal circulation three times a week. Multidetector computed tomography venography (MDCTV) examination was used to examine the catheter tip thrombus. After the animals were sacrificed, histological and immunohistochemistry evaluations were performed to confirm specific cell populations. We used computer modeling to generate wall shear stress profiles for the blood flow through the catheter. RESULTS: Catheter-related sheaths were identified in all catheter specimens, but there was no fibrin sheath around the catheter tip. There were also differences in wall shear stress between the different venous wall sites. Differences in vein wall thickening at different sites have been found at both 14 days (intima to media (I/M) ratio S1 vs S2: p = 0.01, S3 vs S4: p<0.01) and 28 days (I/M ratio S1 vs S2: p<0.01, S3 vs S4: p<0.05). CONCLUSIONS: After catheter placement, fibrin sheath formation partially covered the catheter. Meanwhile, focal areas of intimal thickening were also seen in the venous wall adjacent to the sites of high wall shear stress. These findings indicate an important role of wall shear stress profiles in fibrin sheath formation and intimal thickening.

[Qualitative Determination of Organic Vapour Using Violet and Visible Spectrum].

Vapours of organic matters were determined qualitatively employed with ultraviolet-visible absorption spectroscopy. Vapours of organic matters were detected using ultraviolet-visible spectrophotometer employing polyethylene film as medium, the ultraviolet and visible absorption spectra of vegetable oil vapours of soybean oil, sunflower seed oil, peanut oil, rapeseed oil, sesame oil, cotton seed oil, tung tree seed oil, and organic compound vapours of acetone, ethyl acetate, 95% ethanol, glacial acetic acid were obtained. Experimental results showed that spectra of the vegetable oil vapour and the organic compound vapour could be obtained commendably, since ultra violet and visible spectrum of polyethylene film could be deducted by spectrograph zero setting. Different kinds of vegetable oils could been distinguished commendably in the spectra since the λ(max), λ(min), number of absorption peak, position, inflection point in the ultra violet and visible spectra obtained from the vapours of the vegetable oils were all inconsistent, and the vapours of organic compounds were also determined perfectly. The method had a good reproducibility, the ultraviolet and visible absorption spectra of the vapours of sunflower seed oil in 10 times determination were absolutely the same. The experimental result indicated that polyethylene film as a kind of medium could be used for qualitative analysis of ultraviolet and visible absorption spectroscopy. The method for determination of the vapours of the vegetable oils and organic compounds had the peculiarities of fast speed analysis, well reproducibility, accuracy and reliability and low cost, and so on. Ultraviolet and visible absorption spectrum of organic vapour could provide feature information of material vapour and structural information of organic compound, and provide a novel test method for identifying vapour of compound and organic matter.

Physiological energetics of the ascidian Styela clava in relation to body size and temperature.

The ascidian Styela clava is widely distributed in northern China and is thought to be important in the functioning of estuarine systems. This ascidian may experience highly variable physiological conditions, and its physiological responses to these are of interest considering its ecological role. This study presents data on the physiological parameters in relation to body size and temperature (12-28 degrees C) of S. clava. Respiration, excretion, feces, ingestion and absorption energy were positive related to size and its mass exponents (b-values) varied from 0.2930 to 0.7488. Respiration energy increased with increasing, but critical values were found at 20 degrees C for energy of ingestion and absorption, while 24 degrees C for energy in feces and excretion. At the range of 16-24 degrees C, the scope for growth, gross and net growth efficiencies of ascidians increased with increasing temperature. The energy budget equations of different sized ascidians were obtained at different temperatures. Excretion energy shared a minimal fraction in ingestion energy (1.30-2.47%), the ratios of feces energy and respiration energy to ingestion energy were 46.53-64.27% and 10.26-80.75%, respectively. The physiological data obtained in the present study indicated that S. clava could adjust its energy budget according to the environment and its physiological conditions to meet their nutritional and energetic demands. In the range of experimental temperature (12-28 degrees C), 16-20 degrees C was suitable for the rearing of S. clava to achieve optimum development, while deficient metabolic adjustment induced a negative scope for growth of S. clava at 28 degrees C.