Search

Introduction: Air bubbles in the dialysis circuit are rarely visible after automatic priming; however, they are often visible after the needles are manually connected to the circuit. To prevent this issue, we thought to prime needles with a circuit at automatic priming by the hemodialysis machine. In order to achieve this idea, we designed and manufactured a novel capped needle to connect the needles to the extracorporeal circuit before the automatic priming of the hemodialysis machine. This study investigated the effectiveness of this novel capped needle and compared it with the conventional method for preventing air bubble contamination. Methods: We tested novel capped needles ten times to evaluate whether the dialysis machine works appropriately and removes air bubbles even with the attached capped needle. Next, we performed 25 trials using the conventional method, in which skilled nurses manually connect the needle. In both methods, we thoroughly counted the air bubbles with our naked eyes. We predicted that the capped needle would leave few bubbles in the circuit. In order to evaluate fewer bubbles, we conducted an additional experiment using a microparticle counter to measure the size and number of the bubbles. Results: We thoroughly searched for air bubbles during each of the ten tests but could not find any bubbles visible to the naked eye. In the conventional method, bubbles were visible in 29 out of 50 cases. The bubble count was significantly lower in the capped-needle method than in the conventional method (p < 0.0001, Pearson's χ2 test). In the additional experiments using the microparticle counter, the average remaining air volume in the extracorporeal circuit was 0.0999 ± 0.2438 nL when the priming was performed using the novel capped needles. Conclusion: The novel capped needle eliminated all visible bubbles efficiently and effectively; therefore, it could be a valuable device for hemodialysis treatment. The reduction of air from the dialysis circuit may improve patient prognosis. [ABSTRACT FROM AUTHOR]

Backgrounds/Aims: It has been reported that urinary oxidative stress markers are higher in diabetic patients with proteinuria. We performed the present study to elucidate the relationship between urinary excretion of oxidative stress markers, albumin excretion, and histological changes, and to confirm the potential utility of oxidative stress markers for clinical treatment. Methods: Diabetic db/db mice or nondiabetic db/m mice were administered candesartan (10 mg/kg/day) or hydralazine (50 mg/kg/day) for 18 weeks. Results: Thirty-week-old male db/db mice treated with control vehicle revealed elevated urinary excretion and immunohistological levels of 8-hydroxydeoxyguanosine in glomeruli when compared to db/m mice. Treatment with candesartan, but not hydralazine, reduced these values to levels in db/m mice. Increased mesangial expansion, urinary excretion of albumin and 8-isoprostane, and glomerular immunohistological levels of nitrotyrosine in db/db mice were also decreased markedly by candesartan but not hydralazine. Interestingly, correlations between levels of albumin and oxidative stress markers in urine were very high, even when groups undergoing long-term (44 weeks) treatment were included (correlation coefficient 0.767 with respect to 8-hydroxydeoxyguanosine, 0.888 with respect to 8-isoprostane). Conclusion: It is anticipated that urinary concentrations of oxidative stress markers will be direct barometers of glomerulus-derived oxidative stress and glomerular injury in diabetic nephropathy. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Aims: The present study was designed to examine the role of the renin-angiotensin system in the regulation of macula densa cyclooxygenase-2 (COX-2) during altered dietary salt intake. Methods: We investigated COX-2 expression in the macula densa of angiotensinogen gene-knockout (Atg–/–) mice. COX-2 expression in the renal cortex was determined by real-time quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. Results: The renal cortical expression of COX-2 mRNA increased 24.7 times in Atg–/– mice compared with Atg+/+ mice. When Atg--/– mice were fed a high-salt diet (4% NaCl) for 10 days, the levels of COX-2 expression were markedly suppressed. The macula densa COX-2 immunoreactivity was correlated with the mRNA expression. The selective inhibition of neuronal isoform of nitric oxide synthase (N-NOS) activity by 7-nitroindazole significantly reduced the levels of COX-2 mRNA in Atg–/– mice by 54.1%. Conclusion: These results suggest that (1) COX-2 activity in the macula densa can be regulated by salt intake through a mechanism independent of the renin-angiotensin system, and (2) COX-2 expression is functionally linked to renal cortical N-NOS activity in Atg–/– mice. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]