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Biomedical subjects

T Yagisawa

Publications and source records attributed to T Yagisawa.

At least 19 recordsLinked to original sources
PubMed2005

Retroperitoneoscopic living donor nephrectomy: a safe and minimally invasive procedure for the donor.

A living kidney donor surgery must be safe and minimally invasive. In addition the removed kidney must be in good condition. Retroperitoneoscopic nephrectomy has the advantage that it does not risk intra-abdominal organ injuries and provides direct access to the renal artery/vein despite the small working space. An abdominal wall-lifting method combined with the pneumoretroperitoneum provides sufficient space to use a hand skillfully in retroperitoneoscopic surgery. Introduction of hand-assisted retroperitoneoscopic living donor nephrectomy with the abdominal wall-lifting method yielded safer and easier operations as well as shorter warm ischemia (mean: 3 minutes; 7 seconds) and operative times (mean: 3 hours; 28 minutes) in the current 10 cases. The procedure is a useful alternative to procure a kidney graft.

Adult↗
PubMed2001

Contributory metabolic factors in the development of nephrolithiasis in patients with medullary sponge kidney.

Whether specific metabolic abnormalities are related to nephrolithiasis in patients with medullary sponge kidney (MSK) remains a debated issue. The purpose of this study is to determine metabolic disorders in patients with MSK and nephrolithiasis compared with idiopathic calcium-stone-forming patients. One hundred eighty-four patients with recurrent calcium-stone formations were investigated with regard to metabolic abnormalities. Of these, 22 patients (11.9%; 13 men, 9 women) showed MSK by radiological examination. MSK was defined as a kidney that presented at least three linear or round papillary opacities in the affected papilla on urography. Multiple stones (more than five) existed in both kidneys in all patients with MSK. The remaining 162 patients (109 men, 53 women) were idiopathic calcium-stone formers. Frequencies of low urine volume (urine < 1,500 mL/24 h) and hyperoxaluria (oxalate > 40 mg/24 h) were similar between the groups. Hypercalciuria (men, calcium > 300 mg/24 h; women, calcium of 250 mg/24 h) was found less frequently in the MSK group. The frequency of hypocitraturia (citrate < 300 mg/24 h) was significantly greater in the MSK group than the idiopathic group (77.3% versus 33.9%, respectively). Mean 24-hour urinary excretions of calcium, citrate, uric acid, and magnesium were significantly less in the MSK group. No differences were found in serum calcium, phosphate, and parathyroid hormone levels between the groups. Low urinary excretions of citrate and magnesium are the most typical metabolic disorders that distinguish MSK stone patients from idiopathic calcium-stone-forming patients. In addition to such anatomic abnormalities as ectatic collecting ducts, low levels of urinary inhibitors of stones seem to contribute to the pathogenesis of nephrolithiasis in patients with MSK.

Calcium↗
PubMed2001

Benefits of ureteroscopic pneumatic lithotripsy for the treatment of impacted ureteral stones.

PURPOSE: Although new forms of lithotripsy, such as new-generation shockwave and laser lithotripsies, have recently been developed, the optimal treatment for impacted ureteral stones (IUS) remains controversial. We investigated, retrospectively, the outcome of IUS treated with ureteroscopic pneumatic lithotripsy. PATIENTS AND METHODS: Twenty-two IUS cases were treated using ureteroscopic pneumatic lithotripsy. Of 22 stones, 8 (36%) were treated by ureteroscopic pneumatic lithotripsy as initial treatment and 14 (64%) with pneumatic lithotripsy as an auxiliary treatment after SWL. The stone sizes ranged from 7 to 16 mm with 14 located in the proximal, 3 in the middle, and 5 in the distal ureter. RESULTS: Twenty stones (91%) were effectively fragmented by ureteroscopic pneumatic lithotripsy and eliminated within 1 month after treatment. One stone could not be observed with the ureteroscope secondary to the kinking and stricture of the ureter under the stone, and the stone moved into the kidney during the procedure. The stone was subsequently treated successfully with SWL. One other stone was first fragmented into two pieces; and one big piece, which migrated into the kidney, was treated successfully with SWL. Complications such as bleeding, ureteral injury, and perforation did not occur. Although a few small fragments migrated into the kidney during the procedure in three cases, the overall stone-free rate at 1 month after a one-session treatment with pneumatic lithotripsy was 91%. CONCLUSION: Impacted ureteral stones can be treated effectively with ureteroscopic pneumatic lithotripsy in both the short and the long term.

Adult↗
PubMed2001

Retroperitoneoscopic unroofing of a renal cyst under epidural anesthesia.

Laparoscopic surgery has routinely been performed under general anesthesia. Our first case of a large renal cyst treated successfully with retroperitoneoscopic unroofing under epidural anesthesia is presented here. Epidural anesthesia can be used for retroperitoneoscopic surgery if necessary.

Anesthesia, Epidural↗
PubMed2001

The influence of sex hormones on renal osteopontin expression and urinary constituents in experimental urolithiasis.

PURPOSE: To our knowledge the influence of sex hormones on urinary stone formation remains undetermined. We investigated the effect of castration on urinary lithogenic factors and renal osteopontin expression in rats previously treated with ethylene glycol. MATERIALS AND METHODS: Sprague-Dawley rats were divided normal males, castrated males, males with 2 weeks of 0.75% ethylene glycol treatment, castrated males with 2 weeks of 0.75% ethylene glycol treatment, normal females, castrated females, females with 2 weeks of 0.75% ethylene glycol treatment and castrated females with 2 weeks of 0.75% ethylene glycol treatment. We analyzed 24-hour urine samples for urinary constituents, such as calcium, oxalate, citrate, uric acid, phosphate, magnesium, sodium, potassium and creatinine. The kidneys were examined for osteopontin expression by Northern blot analysis and for crystal deposition by histological examination. RESULTS: In intact male rats calcium and citrate excretion decreased and oxalate excretion increased significantly after ethylene glycol treatment. Castrated male rats with ethylene glycol had greater calcium and less oxalate excretion than male intact rats with ethylene glycol. In intact female rats uric acid excretion decreased and only calcium excretion increased significantly after ethylene glycol treatment. Castrated female rats with ethylene glycol excreted significantly more oxalate and less calcium than intact female rats with ethylene glycol. Renal osteopontin expression was the same in male intact and castrated rats, and in female intact and castrated rats. In males with ethylene glycol expression was stronger in castrated than in intact rats. In females with ethylene glycol expression was weaker in castrated than in intact rats. No crystal deposits were found in the kidneys in any group. CONCLUSIONS: Testosterone appears to promote stone formation by suppressing osteopontin expression in the kidneys and increasing urinary oxalate excretion. Estrogen appears to inhibit stone formation by increasing osteopontin expression in the kidneys and decreasing urinary oxalate excretion.

Animals↗