Chung-Wei Yang

Prospective cohort study comparing sequential organ failure assessment and acute physiology, age, chronic health evaluation III scoring systems for hospital mortality prediction in critically ill cirrhotic patients

The aim of the study was to evaluate the usefulness of sequential organ failure assessment (SOFA) and acute physiology, age, chronic health evaluation III (APACHE III) scoring systems obtained on the first day of intensive care unit (ICU) admission in predicting hospital mortality in critically ill cirrhotic patients. The study enrolled 102 cirrhotic patients consecutively admitted to ICU during a 1‐year period. Twenty‐five demographic, clinical and laboratory variables were analysed as predicators of survival. Information considered necessary to calculate the Child–Pugh, SOFA and APACHE III scores on the first day of ICU admission was also gathered. Overall hospital mortality was 68.6%. Multiple logistic regression analysis revealed that mean arterial pressure, SOFA and APACHE III scores were significantly related to prognosis. Goodness‐of‐fit was good for the SOFA and APACHE III models. Both predictive models displayed a similar degree of the best Youden index (0.68) and overall correctness (84%) of prediction. The SOFA and APACHE III models displayed good areas under the receiver–operating characteristic curve (0.917 ± 0.028 and 0.912 ± 0.029, respectively). Finally, a strong and significant positive correlation exists between SOFA and APACHE III scores for individual patients (r2 = 0.628, p < 0.001). This investigation confirms the grave prognosis for cirrhotic patients admitted to ICU. Both SOFA and APACHE III scores are excellent tools to predict the hospital mortality in critically ill cirrhotic patients. The overall predictive accuracy of SOFA and APACHE III is superior to that of Child–Pugh system. The role of these scoring systems in describing the dynamic aspects of clinical courses and allocating ICU resources needs to be clarified.

Peritoneal nitric oxide is a marker of peritonitis in patients on continuous ambulatory peritoneal dialysis

Nitric oxide plays an important role in mediating the inflammatory process. The aim of this study was to evaluate if nitric oxide production was increased during peritonitis in patients receiving continuous ambulatory peritoneal dialysis (CAPD), and the association with the prognosis. The study population comprised 21 patients with 22 episodes of peritonitis. Fifteen patients without peritonitis were controls. Nitrate was measured by HPLC and nitrite by the Griess method, to reflect nitric oxide production. Peritoneal dialysate effluent and plasma were collected from six patients during peritonitis and 1 week after treatment to study changes in dialysate:plasma ratio. In 15 patients, nitrite was measured during peritonitis and every 3 days for 2 weeks or until normalized for evolutional changes. The dialysate:plasma ratios of nitrate and nitrite during peritonitis were reduced 26% and 41.5%, respectively, after 1 week of treatment, indicating the peritoneal production of nitric oxide during peritonitis. In the evolutional study, a 5.1-fold increase of peak nitrite levels in bacterial peritonitis (n = 13) and a 2.5-fold increase in fungal peritonitis (n = 3) were observed compared to controls. Nitrite gradually declined to control levels (9.3 +/- 7.2 days) after effective antibiotic treatment, but took longer than to normalize leukocyte count in the peritoneal dialysate effluent (3.9 +/- 1.9 days). In four patients with refractory peritonitis (Candida infection in three, Acinetobacter infection in one), the nitrite levels remained elevated 2-fold despite treatment, and the catheters were removed. It is concluded that nitrite levels in peritoneal dialysate effluent may serve as a marker to assess treatment efficacy in CAPD patients with peritonitis.

Plasma ADMA Predicts Restenosis of Arteriovenous Fistula

Plasma levels of asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide production, correlate with endothelial dysfunction and the development of cardiovascular events in patients with uremia. It is not known whether endothelial dysfunction contributes to the dysfunction of arteriovenous fistulas (AVFs) in hemodialysis patients. Here, we studied the predictive value of baseline plasma ADMA for symptomatic restenosis of an AVF after percutaneous transluminal angioplasty in dialysis patients. We obtained baseline plasma ADMA levels before percutaneous transluminal angioplasty in 100 consecutive patients with dysfunctional AVFs. Patients were followed up clinically for up to 6 mo after angioplasty for recurrent dysfunction. During the 6 mo after angioplasty, 46 patients experienced recurrent dysfunction of their AVF; of these, follow-up fistulography showed restenosis at the same location in 41, new stenosis at different locations in two, and no significant stenosis in three patients. Up to 60% of the patients with high levels of ADMA (>0.910 microM) had target lesion restenosis compared with 25% of those with low levels (<0.910 microM; P < 0.001). In multivariate analysis, plasma ADMA independently nearly tripled the risk for recurrent symptomatic stenosis of an AVF after percutaneous transluminal angioplasty (hazard ratio 2.65; 95% confidence interval 1.33 to 5.28). These results suggest a role for ADMA in the progression of symptomatic restenoses of AVFs after percutaneous transluminal angioplasty and call for preventive strategies that target ADMA and/or endothelial dysfunction to decrease the risk for AVF restenosis.

Radial artery approach for endovascular salvage of occluded autogenous radial-cephalic fistulae

BACKGROUND The endovascular salvage of occluded autogenous radial-cephalic fistulae is a more challenging procedure than that for stenotic fistulae. To obtain an access to the fistula is one of the keys to success. Both retrograde venous approach and brachial artery approach have some disadvantages. The radial artery approach has been used in the endovascular therapy of fistula dysfunction, but few data focused on their feasibility and safety for the totally occluded fistulae. METHODS We retrospectively reviewed the patients with occluded autogenous radial-cephalic fistulae receiving endovascular salvage via the radial artery approach in our institution. From January 2004 to July 2007, 48 patients fulfilling the above criteria were enrolled. Balloon maceration was used for patients with small clots. Mechanical thrombectomy with an Arrow-Trerotola percutaneous thrombolytic device or an AngioJet rheolytic catheter was used for patients with large clot burden. Outcome variables included anatomic and clinical success, complications and primary and secondary patency. RESULTS All the transradial punctures were successful. Anatomic and clinical success was achieved in 96% of the cases. The post-interventional primary patency rates were 92%, 77%, 55% and 44% at 1, 3, 6 and 12 months, respectively. The post-interventional secondary patency rates were 96%, 93%, 89% and 89% at 1, 3, 6 and 12 months, respectively. The 12-month primary patency of the short-segment thrombus group was better than that of the long-segment thrombus group (57% versus 19%, P = 0.005). The complication rate was 4%. No puncture-site-related complications were noted, and all the radial arteries were palpable at follow-up. CONCLUSIONS An endovascular intervention through the radial artery approach is a safe and feasible strategy choice for restoring occluded autogenous radial-cephalic fistulae.

Gold nanoparticles conjugates-amplified aptamer immunosensing screen-printed carbon electrode strips for thrombin detection.

Thrombin plays the role in cardiovascular diseases and regulates many processes in inflammation and could be a feature of many pathological conditions, including the thromboembolic disease, cancer and neurodegenerative diseases. An ultrasensitive and amplified electrochemical sandwich assay using screen-printed carbon electrode (SPCE) strips for thrombin detection was established in this study. The conductivity and sensing performance of the carbon electrodes were enhanced by using gold nanoparticles (AuNPs). The aptamer addressed on the strips was used as a primary probe to capture thrombin in the detected samples. An amplifier was invented for recognizing thrombin captured on the SPCE, which is the multiple molecules of anti-thrombin antibody (Ab) and horseradish peroxidase (HRP) co-modified AuNPs (AuNPs/Ab-HRP). Hydrogen peroxide was used as the substrate for HRP and then the response current (RC) could be detected. The optimization of these AuNPs conjugates-amplified aptamer immunosensing SPCE strips was conducted for thrombin detection. The detection sensitivity showed a linear relation between RC and thrombin concentration in the range of 10 pM-100 nM, and limit of detection (LOD) was 1.5 pM. The fabricated AuNPs/Ab-HRP-amplified aptamer immunosensing SPCE strips were further used to detect thrombin in human serum with a linear range of 100 pM-100 nM. This study provided the promising SPCE strips with highly sensitive and rapid detection for thrombin by the electrochemical aptasensor combined with AuNPs conjugates for amplifying the detection signal.

Comparisons of Clinical Outcomes for Thrombectomy Devices with Different Mechanisms in Hemodialysis Arteriovenous Fistulas

To compare clinical outcomes between mechanical thrombectomy devices with hydrodynamic mechanism and rotational mechanism.

Cyclophilin A and Nuclear Factor of Activated T Cells Are Essential in Cyclosporine‐Mediated Suppression of Polyomavirus BK Replication

Immunosuppressants have impacts on the development of polyomavirus‐associated nephropathy. We previously demonstrated that cyclosporin A (CsA) suppressed polyomavirus BK (BKV) replication. The role of cyclophilin A (CypA) and nuclear factor of activated T cells (NFAT) in CsA‐imposed suppression of BKV replication was determined in this study. Results demonstrated that knockdown of CypA but not CypB significantly reduced BKV large T antigen (TAg) expression and BKV titer. Overexpression of CypA reversed CypA siRNA‐induced inhibition in BKV TAg expression. In addition, CypA overexpression attenuated the suppressive effect of CsA on TAg expression, suggesting CypA implicated in CsA‐mediated anti‐BKV effect. Knockdown of NFATc3 abrogated TAg expression, while overexpression of NFATc3 promoted TAg expression and augmented BKV promoter activity. NFATc3 binding to the BKV promoter was verified by chromatin immunoprecipitation assay and electrophoretic mobility shift assay. Renal histology also displayed an increase in NFATc3 expression in tubulointerstitium of BKV‐associated nephropathy. Furthermore, overexpression of NFATc3 rescued CsA‐mediated inhibition of BKV load and TAg expression. A CsA analog, NIM811, which cannot block NFAT functionality, failed to suppress TAg expression. In conclusion, CypA and NFAT are indispensable in BKV replication. CsA inhibits BKV replication through CypA and NFAT, which may be potential targets of anti‐BKV treatment.

Prognostic predictors of technique and patient survival in elderly Southeast Asian patients undergoing continuous ambulatory peritoneal dialysis.

The population of elderly patients entering chronic dialysis programmes is increasing. Elderly patients are susceptible to malnutrition and have multiple complicating disorders in addition to uraemia. Selecting appropriate dialysis modality is particularly critical in elderly patients. Continuous ambulatory peritoneal dialysis (CAPD) has many advantages to elderly patients; however, the clinical outcome varies for elderly CAPD patients. In comparison with Westerners, Southeast Asians have a small body mass index and may be more suited to CAPD therapy. To identify the prognostic predictors in elderly Southeast Asian patients, this historical cohort study analysed 144 patients aged ≥ 65 years at initiation of CAPD. A group of haemodialysis (HD) patients aged ≥ 65 years was utilised as the control group. Survival curves for patient and technique were derived from Kaplan–Meier analysis and were further analysed by Cox–Mantel log‐rank test. To elucidate the impact of individual factors on patient survival, various significant univariables were further subjected to multivariate analysis. No significant increase existed for relative risk of technique failure in elderly patients compared with younger patients. This analytical data indicates that CAPD was as good as HD for elderly uraemic patients regarding to the patient survival. Diabetes, dependent patients, low albumin levels and previous HD history were significant poor prognostic factors for survival of elderly CAPD patients. In conclusion, CAPD is an effective modality of renal replacement therapy for Southeast Asian elderly patients. The technique survival was not affected by patient age.

Proliferation of myofibroblasts in the stroma of renal oncocytoma

Objectives:  Myofibroblasts are a vital component of stroma of many malignant neoplasms, but it is not yet established whether stromal myofibroblasts also exist in benign tumours such as oncocytoma of the kidney.

Baseline plasma glycemic profiles but not inflammatory biomarkers predict symptomatic restenosis after angioplasty of arteriovenous fistulas in patients with hemodialysis

OBJECTIVE The aim of the study was to evaluate the role of atherosclerosis risk factors and baseline inflammatory status in the development of restenosis after successful percutaneous transluminal angioplasty (PTA) of hemodialysis arteriovenous (AV) fistulas. RESEARCH DESIGN AND METHODS We obtained baseline plasma biochemistry and inflammatory markers in 140 patients with dysfunctional AV fistulas before the PTA procedures. Patients were followed clinically for 6 months. RESULTS There was no significant difference in the baseline inflammatory markers between the restenosis and patency group. The Kaplan-Meier analysis showed that non-diabetic patients had higher patency rate than diabetic patients (69% vs. 48%, p=0.02) and diabetic patients with optimal glycemic control had higher patency rate than patients with suboptimal glycemic control (61% vs. 30%, p=0.01). CONCLUSIONS The presence of diabetes mellitus predicted restenosis of AV fistulas after PTA and optimal blood glucose control might be critical to the patency after PTA.