Background. Elevated cardiac troponin (cTn) levels have been reported to predict adverse cardiovascular outcomes in asymptomatic ESRD patients. However, the prognostic value of elevated cTn levels ...associated with sepsis in ESRD patients is unknown. Therefore, this study aimed to elucidate the clinical implications of elevated cTnI levels in ESRD patients with sepsis. Methods. Of the 305 ESRD patients in whom cTnI was measured between January 2003 and December 2005, sepsis developed in 121 patients during follow-up. Based on cTnI levels at the onset of sepsis, patients were classified as elevated cTnI group (ET, n = 50, >0.2 ng/ml) and lower cTnI group (LT, n = 71, ≤0.2 ng/ml). Study endpoints were short- and long-term mortality. Short-term mortality was defined as death occurring within 90 days after sepsis, and patients who survived during this period were followed till death after 90 days. Results. Before sepsis, the median concentration of cTnI was 0.05 (0.01–3.59) ng/ml and it was significantly increased to 0.11 (0.01–22.0) ng/ml when sepsis supervened (P < 0.01). Compared to the LT group, the short-term mortality rate was significantly higher in the ET group (P < 0.05). After adjustment for age, diabetes, serum albumin and CRP levels, presence of shock and previous cardiovascular disease history, the ET group had a greater odds ratio of short-term mortality (OR 5.13, P < 0.01). In addition, the Kaplan–Meier plot for long-term survival revealed a significantly higher mortality rate in the ET group. In a multivariate Cox regression analysis, the elevation of cTnI levels was an independent determinant for long-term mortality (HR 5.90, P < 0.01). Conclusion. This study showed that elevated cTnI levels were significantly associated with short- and long-term mortality in ESRD patients with sepsis. Therefore, elevated cTnI levels in these patients should not be overlooked and be followed for adverse outcomes.
Angiotensin II (Ang-II) and vascular endothelial growth factor (VEGF) have an important role in the pathogenesis of diabetic nephropathy, but the signaling cascade of VEGF regulation in response to ...Ang-II in podocytes is largely unknown. In these experiments, we looked at the effect of Ang-II on the production of VEGF, and investigated whether VEGF production depends on the p38 mitogen activated protein kinase (MAPK) pathway in cultured mouse podocytes. Incubation of podocytes with Ang-II induced a rapid increase in VEGF mRNA expression and protein synthesis as well as its transcriptional activity in an Ang-II dose-dependent manner. To further define the role of angiotensin type 1 (AT1) and type 2 (AT2) receptors involved in Ang-II-mediated VEGF synthesis, the effects of selective AT1 and AT2 receptor antagonists were evaluated. Prior treatment with losartan significantly inhibited VEGF mRNA and protein synthesis induced by Ang-II, which suggests that the AT1 receptor is involved in Ang-II-mediated VEGF synthesis. Furthermore, stimulation of the cells with Ang-II increased both phosphorylation of p38 MAPK and MAP kinase kinase 3/6 (MKK3/6). Additionally, Ang-II enhanced the DNA binding activity to cAMP response element binding protein (CREB) and phosphorylation of CREB. In addition, to investigate the role of p38 MAPK in Ang-II-induced VEGF synthesis, podocytes were pretreated with or without the p38 MAPK inhibitor, SB203580 for 24 h to observe whether Ang-II-mediated VEGF synthesis was inhibited by blocking p38 MAPK. The addition of SB203580 led to a marked inhibition of the increased VEGF mRNA and protein production induced by Ang-II in a dose-dependent manner. Taken together, these results suggest that Ang-II stimulates the synthesis of VEGF in podocytes and the production of VEGF induced by Ang-II is mediated, in part, through the activation of the p38 MAPK pathway.
Carbon nanotube reinforced aluminum powders (Al-CNT) were fabricated by ball milling. The morphology observed by a scanning electron microscope showed impregnation of CNTs on the surface of aluminum ...flakes (Al-flakes). Polycarbonate (PC)/Al-CNT nanocomposites were prepared by a twin-screw extruder. The electrical resistivity of PC/Al-flake composites did not change with Al-flake content, while that of PC/CNT nanocomposites decreased with increasing CNT content, and the percolation threshold was obtained at 2 wt% CNT loading. The electrical resistivity of PC/Al-CNT nanocomposites showed a behavior similar to PC/CNT nanocomposites. The thermal conductivity of the composites increased with increasing filler contents. The PC/Al-CNT composites showed a viscosity trend that is similar to PC/CNT composites; however, it showed higher viscosities (G*, G") than PC/Al-flake composites in the low frequency range (up to ∼10 Hz) and lower viscosities in the higher frequency range (>10 Hz). The tensile modulus of PC/ Al-CNT composite increased while the strength decreased with increasing filler content. The modulus of PC/Al-CNT composite was higher than PC/CNT and PC/ Al-flake composites.
In patients with end-stage renal disease (ESRD), circulating adipokine levels are increased due to decreased renal clearance, irrespective of obesity. However, whether adipokines play a role in the ...development of insulin resistance (IR) in non-obese ESRD patients is unknown. We conducted a cross-sectional study to identify factors associated with IR in 62 non-obese patients on peritoneal dialysis (PD). Non-obesity was defined as body mass index (BMI) <25 kg/m². IR was determined using homeostatic model assessment-IR (HOMA-IR). We also measured serum concentrations of adiponectin, leptin, resistin, high-sensitivity C-reactive protein (hsCRP), and IL-6. The average BMI of the study patients was 21.6 kg/m². When patients were divided into two groups according to the median value of HOMA-IR, serum adiponectin levels were significantly lower in patients with HOMA-IR > 1.85 than in those with HOMA-IR ≤1.85, whereas serum concentrations of leptin and resistin did not differ between the two groups. In addition, log-transformed HOMA-IR was negatively correlated with adiponectin (γ = -0.464, P < 0.001) and log-transformed high-density lipoprotein cholesterol (γ = -0.250, P = 0.050) and positively correlated with age (γ = 0.334, P = 0.008) and triglyceride (γ = 0.392, P = 0.002). However, resistin, log-transformed leptin and log-transformed hsCRP were not associated with HOMA-IR. In a multiple linear regression model, adiponectin was independently associated with HOMA-IR (β = -0.023, P = 0.015). In conclusion, this study suggests that low circulating adiponectin levels might be involved in IR even in non-obese patients undergoing PD.
1 Department of Internal Medicine, The
Institute of Kidney Disease, Yonsei University College of Medicine,
Seoul ; 2 Department of Internal Medicine,
Kwandong University, Kyungki-do ; 3 Department
of ...Preventive Medicine, Yonsei University College of Medicine, Seoul,
Korea
Correspondence to: H.Y. Lee, Department of Internal Medicine, Yonsei
University College of Medicine, 134 Shinchondong, Seodaemun-gu, Seoul,
120-752,
Korea. hyl{at}yumc.yonsei.ac.kr
Background: Continuous ambulatory peritoneal dialysis
(CAPD) is an established treatment for end-stage renal disease (ESRD). We
investigated the outcome of CAPD over a period of 25 years at our
institution.
Methods: CAPD has been performed in 2301 patients in 25
years. After excluding patients with less than 3 months of follow-up and
missing data, we evaluated 1656 patients who started peritoneal dialysis
between November 1981 and December 2005. Data for sex, age, primary disease,
comorbidities, follow-up duration, cause of death, and cause of technique
failure were collected. We also examined data for urea kinetic modeling (UKM),
beginning in 1990, and peritonitis episodes, including causative organisms,
starting in 1992.
Results: Compared to incident patients from 1981-1992,
mean age and incidence of ESRD caused by diabetic nephropathy increased in
patients from 1993 to 2005. Technique survival after 5 and 10 years was 71.9%
and 48.1% respectively. Technique survival was significantly higher in
patients who started CAPD after 1992 than in those who started before 1992.
Peritonitis was the main reason for technique failure. Overall peritonitis
rate was 0.38 episodes per patient-year, with a significant downward trend to
0.29 per patient-year over 10 years, corresponding to a decrease in
gram-positive peritonitis. Patient survival after 5 and 10 years was 69.8% and
51.8% respectively. Patient survival improved significantly during 1992-2005
compared to 1981-1992 after adjustment for age, gender, diabetes, and
cardiovascular comorbidities hazard ratio (HR) 0.68, p < 0.01.
Subgroup analysis based on UKM revealed that dialysis adequacy did not affect
patient survival. However, diabetes (HR 2.78, p < 0.001), older
age (per 1 year: HR 1.06; p < 0.001), serum albumin level (per 1
g/dL: increase, HR 0.52; p < 0.05), and cardiovascular
comorbidities (HR 2.32, p < 0.01) were identified as significant
risk factors.
Conclusion: Technique survival has improved due partly to
a decrease in peritonitis, which was attributed to a decrease in gram-positive
peritonitis. Patient survival has also improved considering increases in aged
patients and ESRD caused by diabetes. The mortality rate of CAPD is still high
in older, diabetic, malnourished, and cardiovascular diseased patients. A more
careful management of higher risk groups will be needed to improve the outcome
of CAPD patients in the future.
KEY WORDS: CAPD; survival; peritonitis.
Received 14 August 2006;
accepted 15 December 2006.
Previous in vitro studies suggest that the p38 MAPK pathway may be involved in the pathogenesis of diabetic nephropathy, but the consequences of the inhibition of the p38 MAPK pathway have not been ...well elucidated in diabetic (DM) glomeruli. This study was undertaken to investigate the effect of p38 MAPK inhibitor, FR167653, on fibronectin expression and apoptosis in DM glomeruli and in high-glucose-stimulated mesangial cells (MC). In vivo, 32 Sprague-Dawley rats were injected with diluent (control, N = 16) or streptozotocin intraperitoneally (DM, N = 16). Eight rats from each group were treated with FR167653 for 3 mo. In vitro, rat MC were exposed to medium containing 5.6 mM glucose or 30 mM glucose high glucose (HG) with or without 10(-6) M FR167653 for 24 h. Fibronectin mRNA and protein expression were determined by real-time PCR and Western blot, respectively. Western blot for apoptosis-related molecules, terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling assay, and Hoechst 33342 staining were performed to determine apoptosis. FR167653 ameliorated the increases in fibronectin-to-GAPDH mRNA ratio and protein expression in DM glomeruli by 89 and 79% and in HG-stimulated MC by 70 and 91%, respectively (P < 0.05). Under diabetic conditions, Bcl-2 protein expression was decreased, whereas cleaved caspase-3 protein expression was increased (P < 0.05), and these changes were inhibited by FR167653 treatment. Apoptotic cells were also significantly increased in DM glomeruli and in HG-stimulated MC (P < 0.05), and FR167653 ameliorated these increases in apoptotic cells, both in vivo and in vitro. In conclusion, these findings suggest that the inhibition of the p38 MAPK pathway has a beneficial effect on the development of diabetic nephropathy by inhibiting the increase in fibronectin expression and apoptosis.
In this paper, four numerical formulas are introduced to calculate possible unbalanced magnetic forces (UMFs) during the assembly process in order to save calculation time and efforts. If the ...proposed formulas are used to calculate the UMFs according to the degree of rotor eccentricity every time the rotor position is changed relative to the stator position in the axial direction, a fully configured or partial 2-dimensional (2-D) model and 3-D periodic analysis model are used for magnetic field calculation instead of a fully configured 3-D analysis model. The reliance of the formulas is verified by comparing the results calculated by the formulas with each other. Then, the size and the number of guide bars as assembly jigs are selected considering the calculated UMFs.
The aim of this study is to establish a procedure for systematic design and performance evaluation of an offshore platform (FPSO; Floating, Production, Storage and Offloading) crane using a ...computational approach. Coupling analyses of the finite element and finite volume methods, which are applicable for ensuring robust design under the consideration of nonlinear environmental effects, were carried out. In order to investigate the effects of dynamic loading, the boundary conditions of an offshore platform crane having a lifting capacity of 100
tons were studied. In the finite volume method, a series of analyses were carried out using the computational fluid dynamics code, FLUENT. The crane's weight, maximum lifting load, calculated wind pressure and boundary conditions such as the inclination of the deck due to the extreme roll motion of FPSO were also considered in the finite element analyses using the commercial code, MSC/NASTRAN. Deformation, stress distribution, as well as fatigue life estimation were conducted under the unified computational environment. An advanced procedure for evaluating design concept validation was proposed for the application of FPSO design and construction.
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