Low-dose heparin retention in temporary hemodialysis double-lumen catheter does not increase catheter occlusion and might reduce risk of bleeding.

BACKGROUND: The objective of this study was to assess the impact of heparin concentration retained in temporary double-lumen catheters on bleeding risk. METHODS: Activated partial thromboplastin time (aPTT) was measured in patients hemodialyzed via double-lumen catheters. Heparin solutions of 5,000 U/ml (group 1, n = 95) and 1,000 U/ml (group 2, n = 89) were randomly retained in catheters after placement and each hemodialysis (HD) session. Blood transfusion, bleeding episodes, and changes of hematocrit were recorded. RESULTS: The aPTT at the beginning of HD or 10 min after heparin lock was significantly prolonged, which was more prominent in the 5,000 U/ml group, whereas the aPTT declined to baseline values at the end of HD or before the next dialysis session in both groups. Infection and occlusion rates were similar in both groups. More patients suffered from major bleeding and prominent decline of hematocrit in the 5,000 U/ml group. CONCLUSIONS: Low-dose heparin (1,000 U/ml) retention in double-lumen catheters for temporary HD maintains comparable catheter patency and might reduce the bleeding risk.

Unusual cause of postrenal biopsy anuria in a renal transplant patient.

Arteriovenous fistula (AVF) is an uncommon but well-known complication of percutaneous renal biopsy. Most postbiopsy AVFs are asymptomatic and regress spontaneously; however, some AVFs result in hypertension, hematuria and renal insufficiency. Transplant renal artery stenosis (TRAS) is a potentially curable cause of posttransplant arterial hypertension, allograft dysfunction and graft loss. Whether postbiopsy AVF superimposed on TRAS also regresses spontaneously is unknown. The authors present a case of acute renal failure in a 56-year-old male renal allograft recipient with the combination of postbiopsy AVF and TRAS. At first, the authors performed percutaneous angioplasty with stent implantation for the TRAS, but the AVF gradually enlarged. Eighteen months later, the patient began to experience hypertension, and his serum creatinine level increased; he received transcatheter arterial embolization therapy for enlarged AVF, and his renal function returned to baseline level.

Intragraft pressures predict outcomes in hemodialysis patients with graft outflow lesions undergoing percutaneous transluminal angioplasty.

OBJECTIVES: This study is to introduce intragraft pressure (IGP) as intraprocedural parameter for outcome survey in hemodialysis patients with graft outflow lesions undergoing percutaneous transluminal angioplasty (PTA). BACKGROUND: The role of IGP on procedural endpoint and patency is unknown. METHODS: Seventy-five participants with graft outflow lesions receiving PTA were enrolled. Procedural data regarding IGP and angiographic findings were collected and the 1-year graft patency through collaboration with hemodialysis units. Analyses and comparisons among IGP, angiographic findings, and patency were conducted. Using the receiver operating characteristic (ROC) curve and Kaplan-Meier survival analysis, we intended to detect significance and the cut-off points of IGP for patency prediction, and difference in patency between the two groups divided by using the cut-off points. RESULTS: Pre-PTA and post-PTA IGP were significantly associated with 1-year patency (both significance <0.01) with 0.756 and 0.791 areas under the ROC curves, respectively. The cut-off points of pre-PTA and post-PTA IGP were closer to 106 and 47 mm Hg for prediction of 1-year patency (sensitivity = 0.76, specificity = 0.69; sensitivity = 0.79, specificity = 0.69, respectively; 95% CI). Significant reductions in 1-year patency were shown in the subjects with greater than the cut-off values, either pre-PTA or post-PTA IGP, compared with those with smaller than these values (both log rank test < 0.001). CONCLUSION: IGP might be useful to evaluate procedural endpoints and predict patency outcomes in hemodialysis patients with graft outflow lesions undergoing PTA. Patients with the greater pre-PTA or post-PTA IGP, to some level, seem to have the shorter patency.

Erythropoietin suppresses epithelial to mesenchymal transition and intercepts Smad signal transduction through a MEK-dependent mechanism in pig kidney (LLC-PK1) cell lines.

PURPOSE: Tumor growth factor-beta1 (TGF-beta1) plays a pivotal role in processes like kidney epithelial-mesenchymal transition (EMT) and interstitial fibrosis, which correlate well with progression of renal disease. Little is known about underlying mechanisms that regulate EMT. Based on the anatomical relationship between erythropoietin (EPO)-producing interstitial fibroblasts and adjacent tubular cells, we investigated the role of EPO in TGF-beta1-mediated EMT and fibrosis in kidney injury. METHODS: We examined apoptosis and EMT in TGF-beta1-treated LLC-PK1 cells in the presence or absence of EPO. We examined the effect of EPO on TGF-beta1-mediated Smad signaling. Apoptosis and cell proliferation were assessed with flow cytometry and hemocytometry. We used Western blotting and indirect immunofluorescence to evaluate expression levels of TGF-beta1 signal pathway proteins and EMT markers. RESULTS: We demonstrated that ZVAD-FMK (a caspase inhibitor) inhibited TGF-beta1-induced apoptosis but did not inhibit EMT. In contrast, EPO reversed TGF-beta1-mediated apoptosis and also partially inhibited TGF-beta1-mediated EMT. We showed that EPO treatment suppressed TGF-beta1-mediated signaling by inhibiting the phosphorylation and nuclear translocation of Smad 3. Inhibition of mitogen-activated protein kinase kinase 1 (MEK 1) either directly with PD98059 or with MEK 1 siRNA resulted in inhibition of EPO-mediated suppression of EMT and Smad signal transduction in TGF-beta1-treated cells. CONCLUSIONS: EPO inhibited apoptosis and EMT in TGF-beta1-treated LLC-PK1 cells. This effect of EPO was partially mediated by a mitogen-activated protein kinase-dependent inhibition of Smad signal transduction.

Clustering of unconventional cardiovascular risk factors among Taiwanese hemodialysis patients.

BACKGROUND: Cardiovascular disease (CAVD) is the most common cause of mortality for chronic hemodialysis (HD) patients, yet the risk factors for the events have not been well established. METHODS: We conducted a multicenter cross-sectional survey in 995 chronic HD patients recruited from 12 HD centers in Taiwan to investigate the prevalence of CAVD, including coronary heart disease (CHD), cerebrovascular disease (CVD), and peripheral vascular disease (PVD), and related them to 30 different parameters. RESULTS: The mean age of 995 patients (499 males/496 females) was 56.4 +/- 12.3 years, and average HD duration was 59.8 +/- 51.2 months. The prevalence rates of CHD, CVD, and PVD were 24.0, 6.0, and 5.3%, respectively. Results of our multivariate logistic regression analysis showed that out of the conventional CAVD risk factors, only old age and diabetes could be significantly associated with CAVD. Meanwhile, we found some novel clinical correlates, including low apolipoprotein A-I and creatinine for CHD, low uric acid for CVD, and low hematocrit and low diastolic blood pressure for PVD. Interestingly, left ventricular hypertrophy was found to be an independent correlate for all three: CHD, CVD, and PVD. CONCLUSIONS: Our study suggests that consideration of conventional cardiovascular risk factors as well as unconventional risk factors might better assess the risk for CAVD among HD patients.

Mechanisms of star fruit-induced acute renal failure.

We have previously discovered that star fruit can induce oliguric acute renal failure. To investigate the mechanisms of star fruit-associated acute oxalate nephropathy, the nephrotoxic effect of star fruit was examined in both cellular experiments and animal models. We evaluated renal function, pathological changes in kidney tissues and apoptotic effects using terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) assay in four groups of rats -- a control group (CG), fed with tap water (1); a star fruit group (SG), fed with star fruit juice naturally containing 0.2M oxalate (2); and oxalate groups (OxG), fed with 0.2M (3) or 0.4M (4) oxalate solution. The effects of both star fruit juice and oxalate on MDCK cells were also analyzed by flow cytometry. We found that the mean creatinine clearance was significantly lower in the SG, 0.2M OxG and 0.4M OxG. Dose-dependent apoptotic effects were evident from the TUNEL assay, and flow cytometry analysis of treated MDCK cells showed dose- and time-dependent effects. Our findings suggest that star fruit juice produces acute renal injury, not only through the obstructive effect of calcium oxalate crystals, but also by inducing apoptosis of renal epithelial cells, which may be caused by the levels of oxalate in the fruit.

Renal protection for coronary angiography in advanced renal failure patients by prophylactic hemodialysis. A randomized controlled trial.

OBJECTIVES: We performed a study to determine whether prophylactic hemodialysis reduces contrast nephropathy (CN) after coronary angiography in advanced renal failure patients. BACKGROUND: Pre-existing renal failure is the greatest risk factor for CN. Hemodialysis can effectively remove contrast media, but its effect upon preventing CN is still uncertain. METHODS: Eighty-two patients with chronic renal failure, referred for coronary angiography, were assigned randomly to receive either normal saline intravenously and prophylactic hemodialysis (dialysis group; n = 42) or fluid supplement only (control group; n = 40). RESULTS: Prophylactic hemodialysis lessened the decrease in creatinine clearance within 72 h in the dialysis group (0.4 +/- 0.9 ml/min/1.73 m(2) vs. 2.2 +/- 2.8 ml/min/1.73 m(2); p < 0.001). Compared with the dialysis group, the serum creatinine concentrations in the control group were significantly higher at day 4 (6.3 +/- 2.3 mg/dl vs. 5.1 +/- 1.3 mg/dl; p = 0.010) and at peak level (6.7 +/- 2.7 mg/dl vs. 5.3 +/- 1.5 mg/dl; p = 0.005). Temporary renal replacement therapy was required in 35% of the control patients and in 2% of the dialysis group (p < 0.001). Thirteen percent of the control patients, but none of the dialysis patients, required long-term dialysis after discharge (p = 0.018). For the patients not requiring chronic dialysis, 13 patients in the control group (37%) and 2 in the dialysis group (5%) had an increase in serum creatinine concentration at discharge of more than 1 mg/dl from baseline (p < 0.001). CONCLUSIONS: Prophylactic hemodialysis is effective in improving renal outcome in chronic renal failure patients undergoing coronary angiography.

Effects of folic acid and vitamin B complex on serum C-reactive protein and albumin levels in stable hemodialysis patients.

OBJECTIVE: Folic acid and vitamin B complex administration in uremic patients has been reported to lower plasma total homocysteine (tHcy) levels, but whether or not this has a beneficial effect on the inflammatory state is not clear. METHODS: We conducted a randomized open labeled study to determine the effects of folic acid (5 mg daily) and vitamin B complex administration on plasma tHcy levels as well as inflammatory (serum high-sensitivity C reactive protein, hs-CRP) and nutritional (serum albumin) markers in patients on maintenance hemodialysis. Treatment was given for 3 consecutive months to 61 patients on maintenance hemodialysis. Another 60 patients, all age-, sex-, hemodialysis duration-matched served as control group. MAIN OUTCOME MEASURES: Plasma tHcy, serum hs-CRP, albumin, creatinine (Cr), post-dialysis body weight (BW), and normalized protein catabolism rate (nPCR). RESULTS: After 3 months, levels of plasma tHcy and serum hs-CRP, Cr, and nPCR were significantly decreased while levels of serum albumin, vitamin B(12), folate, and BW were significantly increased. The dialytic dose (KT/V) and dietary intake remained unchanged. However, correlations between the magnitude of reduction of tHcy & hs-CRP, tHcy & Cr, and Cr & nPCR were statistically significant. CONCLUSIONS: Folic acid and vitamin B complex co-administration effectively lowers tHcy and hs-CRP levels and increases albumin levels in stable hemodialysis subjects, underscoring their potential benefit to attenuate the state of inflammation and possibly improve the nutritional status in patients on hemodialysis.

De novo malignancies after kidney transplantation.

OBJECTIVES: To investigate the occurrence and patterns of de novo malignancy in a series of kidney transplantation (KT) recipients in southern Taiwan. METHODS: A retrospective study of 108 KT recipients who underwent follow-up at our hospital from 1991 to 2004 was carried out. The occurrence and patterns of malignancy were assessed. RESULTS: Malignant growth was noted after transplantation in 9 patients (8.3%) and occurred 2 months to 7 years postoperatively, with an average of 4.1 years. There were 6 cases of urinary tract transitional cell carcinoma and 1 each of stomach, liver, and cervical cancer. The mean age at diagnosis of cancers was 54 years (range, 47 to 69 years); 1 patient with cancer was male, 8 were female. No skin cancer or lymphoma was detected in our transplant recipients. Compared with the KT patients without cancer, older age at KT, female recipient, and low educational status were the significant risk factors for the development of de novo cancers in our KT recipients (P <0.05). There were 3 deaths (50%) from urothelial carcinoma. CONCLUSIONS: Urinary tract transitional cell carcinoma was the main de novo cancer among KT recipients in southern Taiwan. Older age at KT, female recipient, and low educational status were the significant risk factors for the development of de novo cancers.

The role of oxalate in star fruit neurotoxicity of five-sixths nephrectomized rats.

To investigate the role of oxalate in star fruit neurotoxicity, rats were given star fruit or oxalate after a sham operation or modified five-sixths nephrectomy; namely, star fruit (SC) or oxalate (OxC) for sham-operated rats and star fruit (SNx), calcium gluconate treated star fruit juice (SCaNx), or oxalate (OxNx) for nephrectomized rats. After feedings, none of the rats in SC, OxC, and SCaNx groups developed movement disorders or died, while all rats in SNx group and OxNx group presented movement disorders and two rats in SNx group and four rats in OxNx group died within minute to hour after development of myoclonic jerk and/or tonic-clonic convulsion. The plasma oxalate levels rose significantly only in the SNx group and OxNx group that also presented clusters of generalized spike-waves in the electroencephalographic recordings. In conclusion, oxalate may play a key role in star fruit neurotoxicity in nephrectomized rats and probably in uremic patients.

Comparison of the diuretic effect of furosemide mixed with human albumin or fresh frozen plasma for patients with hypoalbuminemia in the intensive care unit.

BACKGROUND: Diuretics are commonly used in the intensive care unit (ICU) for patients with fluid over-loading. Hypoalbuminemia is a major cause of diuretic resistance. Albumin mixed with furosemide can promote diuresis and sodium excretion in patients with hypoalbuminemia. The purpose of this study is to compare the diuretic effect of furosemide (FU) mixed with human albumin (HA) or fresh frozen plasma (FFP) in ICU patients with hy-poalbuminemia. METHODS: Patients with fluid overloading and hypoalbuminemia who needed diuretic treatment were enrolled and were divided into 2 groups: the first group having clearance of creatinine (CCr) >20 ml/min, and the second group having CCr < or = 20 ml/min. FU (60 mg) mixed with HA (HA group), 60 mg FU mixed with FFP (FFP group) and water (placebo group) were given intravenously to these patients for 60 minutes in random order on the first, third and fifth day. After drug administration, 8-hour urine was collected, and urine amount and urinary sodium excretion were checked. RESULTS: Both the HA group and the FFP group had significantly higher urinary volume and sodium excretion than the placebo group in the patients with CCr >20 ml/min or CCr < or = 20 ml/min (p < 0.01). In the patients with CCr >20 ml/min, there was no difference in the amount of urine excretion and cumulative urinary sodium excretion between the HA group and FFP group. In the patients with CCr < or =ml;20 ml/min, the HA group had a significantly higher urine output and urinary sodium excretion than the FFP group (p < 0.05). CONCLUSIONS: In ICU patients, 60 mg FU mixed with HA or FFP has a similar diuretic effect in patients with CCr >20 ml/min. FFP is an effective alternative choice for improving diuresis for ICU patients with hypoalbuminemia. In patients with CCr < or = 20 ml/min, albumin mixed with 60 mg FU has a superior diuretic effect compared with FFP mixed with FU.

The clinical impact of bacteremia in complicated acute pyelonephritis.

BACKGROUND: Bacteremia has been considered as a surrogate marker of severe infection in several infectious diseases. However, it remains uncertain whether the presence of bacteremia correlates with severe infection in patients with complicated acute pyelonephritis (APN). METHODS: We performed a retrospective study to investigate the relationship between the presence of bacteremia and disease severity in complicated APN. To do this, we reviewed medical records from 128 patients diagnosed with complicated APN admitted to Kaohsiung Veterans General Hospital, Taiwan between January, 2003 and December, 2003. In our analysis, we compared clinical presentation, treatment response, and outcome in patients with and without bacteremia. RESULTS: Fifty-four of 128 patients (42%) were bacteremic. This group of patients presented more frequently with severe sepsis or septic shock (P < 0.001), compared with nonbacteremic patients. Other factors that correlated with the presence of bacteremia were older age, diabetes mellitus, more band forms in neutrophil cell counts, impaired renal function, and a lower level of serum albumin. Using a multivariate logistic regression analysis, we show that lower levels of serum albumin (odds ratio, 0.18; 95% CI, 0.05-0.65; P = 0.008) and presence of severe sepsis (odds ratio, 4.76; 95% CI, 1.43-15.84; P = 0.011) were independent factors associated with bacteremia. Following treatment, the bacteremic group took a longer time to become defervescent than the nonbacteremic group (5.1 +/- 2.3 vs. 4.2 +/- 1.6 days, P = 0.023). Also, the bacteremic group had a greater mean duration of intravenous antibiotics administration and longer hospital stays (P < 0.001). Multiple logistic regression analysis shows that non-Escherichia coli bacteremia, presence of urolithiasis or hydronephrosis, shorter duration of antibiotics administration, and being male were significantly associated with recurrence of urinary tract infection within 6 months. CONCLUSION: Bacteremia in cases of complicated APN indicates a severe disease, which is more likely to recur in patients with non-E coli bacteremia. Our study showed that bacteremia is indeed a useful clinical indicator of severe disease and, if found, should influence patient management. Therefore, we recommend that blood culture samples should be taken in all patients with complicated APN.

Metallic stent placement in hemodialysis graft patients after insufficient balloon dilation.

OBJECTIVE: We wanted to report our experience of metallic stent placement after insufficient balloon dilation in graft hemodialysis patients. MATERIALS AND METHODS: Twenty-three patients (13 loop grafts in the forearm and 10 straight grafts in the upper arm) underwent metallic stent placement due to insufficient flow after urokinase thrombolysis and balloon dilation. The indications for metallic stent deployment included 1) recoil and/or kinked venous stenosis in 21 patients (venous anastomosis: 17 patients, peripheral outflow vein: four patients); and 2) major vascular rupture in two patients. Metallic stents 8-10 mm in diameter and 40-80 mm in length were used. Of them, eight stents were deployed across the elbow crease. Access patency was determined by clinical follow-up and the overall rates were calculated by Kaplan-Meier survival analysis. RESULTS: No procedure-related complications (stent fracture or central migration) were encountered except for a delayed Wallstent shortening/migration at the venous anastomosis, which resulted in early access failure. The overall primary and secondary patency rates (+/-standard error) of all the vascular accesses in our 23 patients at 3, 6, 12 and 24 months were 69%+/-9 and 88%+/-6, 41%+/-10 and 88%+/-6, 30%+/-10 and 77%+/-10, and 12%+/-8 and 61%+/-13, respectively. For the forearm and upper-arm grafts, the primary and secondary patency rates were 51%+/-16 and 86%+/-13 vs 45%+/-15 and 73%+/-13 at 6 months, and 25%+/-15 and 71%+/-17 vs 23%+/-17 and 73%+/-13 at 12 months (p = .346 and .224), respectively. CONCLUSION: Metallic stent placement is a safe and effective means for treating peripheral venous lesions in dialysis graft patients after insufficient balloon dilation. No statistically difference in the patency rates between the forearm and upper-arm patient groups was seen.

Effect of anandamide on cytosolic Ca(2+) levels and proliferation in canine renal tubular cells.

The effect of the endogenous cannabinoid anandamide on cytosolic free Ca(2+) concentration ([Ca(2+)](i)) and proliferation is largely unknown. This study examined whether anandamide altered Ca(2+) levels and caused Ca(2+)-dependent cell death in Madin-Darby canine kidney (MDCK) cells. [Ca(2+)](i) and cell death were measured using the fluorescent dyes fura-2 and WST-1 respectively. Anandamide at concentrations above 5 muM increased [Ca(2+)](i) in a concentration-dependent manner. The Ca(2+) signal was reduced by 78% by removing extracellular Ca(2+). The anandamide-induced Ca(2+) influx was insensitive to L-type Ca(2+) channel blockers and the cannabinoid receptor antagonist AM 251, but was inhibited differently by aristolochic acid, WIN 55,212-2 (a cannabinoid receptor agonist), phorbol ester, GF 109203X and forskolin. After pretreatment with thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor), anandamide-induced Ca(2+) release was inhibited. Inhibition of phospholipase C with U73122 did not change anandamide-induced Ca(2+) release. At concentrations of 100 muM and 200 muM, anandamide killed 50% and 95% cells, respectively. The cytotoxic effect of 100 muM anandamide was completely reversed by pre-chelating cytosolic Ca(2+) with BAPTA. Collectively, in MDCK cells, anandamide induced [Ca(2+)](i) rises by causing Ca(2+) release from endoplasmic reticulum and Ca(2+) influx from extracellular space. Furthermore, anandamide can cause Ca(2+)-dependent cytotoxicity in a concentration-dependent manner.

Further evidence of the usefulness of Acute Physiology and Chronic Health Evaluation II scoring system in acute paraquat poisoning.

OBJECTIVE AND METHOD: We have previously successfully applied the Acute Physiology and Chronic Health Evaluation (APACHE) II system to assess the severity of patients with acute paraquat poisoning, and this article investigates further evidence of the usefulness of APACHE II system in predicting the in-hospital mortality of 64 patients with acute paraquat poisoning over a period of 12 years. The predictive factors including APACHE II score, plasma paraquat concentration, severity index of paraquat poisoning (SIPP), and estimated ingestion dosage of paraquat for evaluating the outcome in paraquat-poisoned patients were assessed. RESULTS: Overall mortality was 71.9%: 46 out of 64 patients died. Non-survivors (n = 46) had a higher APACHE II score (23.3 +/- 12.7) than survivors (n = 18) (6.1 +/- 4.2) (p < 0.001). The plasma paraquat concentration, SIPP, and estimated ingestion dosage of paraquat were significantly higher in non-survivors than in survivors (p < 0.05, in all comparisons). By multiple logistic regression analysis, only the APACHE II score and peak data of blood sugar in 24 h after admission were capable of predicting in-hospital mortality. By using the area under receiver operating characteristic curves (AURC), the APACHE II system yielded better discriminative power (AURC = 0.893) than SIPP (AURC = 0.674), plasma paraquat concentration (AURC = 0.676), and estimated ingestion dosage of paraquat (AURC = 0.673). An APACHE II score greater than 13 predicted in-hospital mortality with 67% sensitivity and 94% specificity. CONCLUSIONS: The APACHE II score is a simple, reproducible, and practical tool for evaluating the severity of acute paraquat poisoning.

Short report: persistent bradycardia caused by ciguatoxin poisoning after barracuda fish eggs ingestion in southern Taiwan.

We report an outbreak of ciguatoxin poisoning after barracuda fish ingestion in southern Taiwan. Three members of a family developed nausea, vomiting, watery diarrhea, and myalgias about 1 hour after eating three to ten eggs of a barracuda fish. Numbness of the lips and extremities followed the gastrointestinal symptoms about 2 hours after ingestion. Other manifestations included hyperthermia, hypotension, bradycardia, and hyperreflexia. Bradycardia persisted for several days, and one patient required a continuous infusion of intravenous atropine totaling 40 mg over 2 days. Further follow-up of the patients disclosed improvement of neurologic sequelae and bradycardia, but sensory abnormalities resolved several months later. In conclusion, ciguatoxin poisoning causes mainly gastrointestinal and neurologic effects of variable severity. In two patients with ciguatoxin poisoning after barracuda fish egg ingestion, persistent bradycardia required prolonged atropine infusion.

Single-session alcohol-retention sclerotherapy for simple renal cysts: comparison of 2- and 4-hr retention techniques.

OBJECTIVE: The objectives of our study were to evaluate the feasibility of ethanol sclerotherapy in treating simple renal cysts with prolonged ethanol retention and to compare the therapeutic results of 2- and 4-hr retention techniques. MATERIALS AND METHODS: We retrospectively reviewed 36 renal cysts in 33 patients treated by ethanol sclerotherapy with a single-session single-injection technique during the past 6 years. After complete aspiration of the cystic fluid, 95% ethanol was injected into the cyst and was retained for 4 hr in 14 cysts (group 1) and for 2 hr in 22 cysts (group 2). The average maximal diameter and aspirated volume of the cysts were 8.3 cm and 223 mL in group 1 patients and 7.9 cm and 167 mL in group 2, respectively. The ablated cysts were followed up regularly by sonography, CT, or both at 3- to 6-month intervals for at least 1 year. The nonparametric Mann-Whitney U test was used to compare differences in characteristics, treatment results, and laboratory data of the subjects in the two groups. The level of statistical significance was set at a p value of less than 0.05. RESULTS: Technically, all the patients tolerated the procedures. One patient had gross hematuria 10 days after the procedure. She underwent surgical deroofing treatment and was excluded in the later statistical analysis. After sclerotherapy, 14 cysts disappeared completely and 16 cysts showed marked regression with residual maximal diameter of less than 3 cm. The overall volume reduction rate was 97.6% in all 35 cysts. The mean residual longest diameters and average volume reduction rates of the treated cysts were 1.9 cm and 97.9% in group 1 patients and 1.1 cm and 97.3% in group 2 patients, respectively, which showed no statistical significance of volume reduction rate with a p value 0.149. CONCLUSION: The single-session prolonged ethanol-retention technique is safe and efficacious for the treatment of renal cysts. There is no statistical difference in therapeutic efficacy between 2- and 4-hr ethanol-retention techniques.

2-O-methyl PAF as a Ca2+ mobilizer in Madin Darby canine kidney cells.

In Madin-Darby canine kidney (MDCK) cells, the effect of 2-O-methyl PAF, an inactive analogue of platelet activating factor (PAF), on intracellular Ca2+ concentration ([Ca2+]i) was measured by using the Ca2+-sensitive fluorescent dye fura-2. 2-O-methyl PAF (> or = 15 microM) caused a rapid rise of [Ca2+]i in a concentration-dependent manner. 2-O-methyl PAF-induced [Ca2+]i rise was partly reduced by removal of extracellular Ca2+. 2-O-methyl PAF-induced extracellular Ca2+ influx was also suggested by Mn2+ influx-induced fura-2 fluorescence quench. The 2-O-methyl PAF-induced Ca2+ influx was blocked by nifedipine, verapamil and diltiazem. In Ca2+-free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca2+-ATPase, caused a monophasic [Ca2+]i rise, after which 2-O-methyl PAF failed to increase [Ca2+]i; also, pretreatment with 2-O-methyl PAF depleted thapsigargin-sensitive Ca2+ stores. U73122, an inhibitor of phospholipase C, abolished ATP (but not 2-O-methyl PAF)-induced [Ca2+]i rise. These findings suggest that 2-O-methyl PAF evokes a rapid increase in [Ca2+]i in renal tubular cells by stimulating both extracellular Ca2+ influx and intracellular Ca2+ release.