Kazumichi Matsushita

Inhibition of c-Jun N-terminal kinase ameliorates apoptosis induced by hydrogen peroxide in the kidney tubule epithelial cells (NRK-52E).

Background: Hydrogen peroxide (H₂O₂)-induced apoptosis has been shown to be involved in ischemic and toxic tubular damage. Recent studies have revealed that oxidative stress can activate c-Jun N-terminal kinase (JNK), and the oxidative stress-JNK pathway is an important apoptotic pathway of cells exposed to various stresses. The present study was designed to investigate JNK activation and the effects of the JNK pathway inhibition during H₂O₂-induced apoptosis in kidney epithelial tubule cells (NRK-52E). Materials and Methods: NRK-52E cells were treated with 0–500 µM H₂O₂ and/or 100 µM quercetin (an inhibitor of the JNK pathway). Apoptosis was assessed by flow cytometry analysis and DNA ladder. JNK activity was assessed by the GST-c-Jun (1-169) binding/protein kinase assay. Results: H₂O₂ induced apoptosis in NRK-52E cells in a concentration-dependent manner, which was demonstrated by the reduced DNA PI staining, externalization of phosphatidylserine and DNA ladder. Apoptosis induced by H₂O₂was accompanied by JNK activation and up-regulated JNK activity. Quercetin treatment suppressed the JNK activity and ameliorated apoptosis induced by H₂O₂. Conclusions: H₂O₂ induced apoptosis in NRK-52E cells, which was associated with activation and up-regulation of JNK. Quercetin treatment could decrease JNK activity and ameliorate H₂O₂-induced apoptosis.

Self-reversed parallel wire balloon technique for dilating unyielding strictures in native dialysis fistulas.

Editor: For patients undergoing hemodialysis treatment who have a rigid stricture of an arteriovenous fistula, it is extremely difficult to achieve sufficient dilation even if a highpressure resistant balloon catheter is used. In such cases, the parallel wire technique (1,2) has been a better alternative to achieve arteriovenous fistula dilation. The effectiveness of the parallel wire technique has been explained as being a result of the guide wire indwelling between the balloon and the stricture causing a cracked or cut intima, by which the vessel is extended. In other words, the cutting balloon’s blade is replaced with the guide wire. Eventually, the intimal injury is limited to the cracked area. It is speculated that the recurrence of strictures at these points will be less frequent. In the parallel wire technique, there are three alternative ways to indwell the guide wire, as shown in Figure 1: the conventional method passes another wire through the sheath of larger size (Fig 1a); the wire can also be passed through another puncture (Fig 1b); and finally, the selfreversed parallel wire technique, described herein, can be used (Fig 1c). Disadvantages of the conventional technique are that the sheath is required to be thicker than the optimum size and that blood is lost from the point at which the sheath is applied (2). It was reported that 200 mL of blood is generally lost with this method, and use of a Y-shaped connector was recommended (2). The disadvantage of the second method is that a new vein puncture is required and another guide wire is needed. To improve upon these techniques, we chose the method illustrated in Figure 1c: the self-reversed parallel wire technique. In this method, only one guide wire is passed through the sheath, so a sheath of appropriate size is sufficient and a connector preventing blood loss will not be needed. In our hospital, initial implementation of this method used two wires for conventional parallel wire technique (1,2), but this method presented problems such as blood loss from the sheath and required the use of an oversized sheath. Self-reversed parallel wire technique is a simple modification of the conventional one. Details of its implementation and effectiveness are reported herein. Between January 1999 and September 2001, blood access intervention therapy was carried out in 163 patients undergoing hemodialysis treatment. All these patients also had native arteriovenous fistulae. For these cases, we usually used noncompliant balloon catheters (balloon diameter: 4–6 mm) with a rated burst pressure of 15 atm and inflation times of 2 minutes for each dilation. Ultra-short braidedtype sheaths were used (5 F, 3 cm long; Medikit, Tokyo, Japan). In our experience, insufficient dilation was achieved in 22 cases (13%) in which only the high-pressure resistant balloon was used. The self-reversed parallel wire technique was applied in these cases. Figure 2 shows the self-reversed parallel wire technique procedure. A sheath of the required size (5 F) was inserted, through which a flexible-tipped guide-wire with an angleshaped tip (Radifocus; Terumo, Tokyo, Japan) was passed. The tip was then turned in a 180° curve by pushing the tip Figure 1. There are three alternative parallel wire techniques. (a) The conventional method requires an oversized sheath; (b) another puncture can be made to insert the guide wire; or (c) the self-reversed parallel wire technique can be employed.

INTRAPERITONEAL RUPTURE OF GIANT HYDRONEPHROSIS DUE TO URETERAL CANCER ACCOMPANIED BY RENAL CELL CARCINOMA

Intraperitoneal rupture of hydronephrosis is rare. We report a case of hydronephrosis caused by ureteral cancer accompanied by ipsilateral renal cell carcinoma. CASE REPORT A 72-year-old man complaining of general weakness and a tumor in the left upper abdomen without tenderness presented at our hospital. Abdominal ultrasonography and computerized tomography (CT) revealed a giant renal cystic mass and a solid mass at the lower end of the ureter (fig. 1, a to d). Diagnosis was tumor of the left ureteral stump, and a series of operations was scheduled. However, the patient complained of sudden reduction of the mass and resolution of the sensation of abdominal fullness. CT revealed a marked decrease in hydronephrosis and a large amount of ascites in the peritoneal cavity (fig. 1, e and f). Intraperitoneal rupture of left hydronephrosis was diagnosed, and an emergency procedure was performed. When the intraperitoneal cavity was entered through a midline incision there was approximately 1,000 ml. of dark brown ascites and an approximately 5 mm. foramen, from which bloody liquid was excreted into the descending colonic mesentery. Total nephroureterectomy was performed. Extirpated weight was 2,900 g. (including 1,900 ml. of dark fluid). There was a large amount of clotted blood within the renal pelvis, which revealed marked wall thickening. Papillary tumors were noted along the entire ureter. Cytological evaluation of the ascites and renal pelvic urine revealed class IV. Pathological diagnosis regarding the ureter was transitional cell carcinoma, grade 2 greater than 1, pT1, interferon-, pR0, pN0. An induration 3.5 cm. in diameter (fig. 2, a) was noted in the totally destroyed renal tissue (fig. 2, b). Pathological diagnosis was renal cell carcinoma, clear cell subtype, grade 2, interferon- ,V (), pT1a, pN0. Also, the ruptured portion of the kidney comprised necrotic