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K Nonomura

Publications and source records attributed to K Nonomura.

At least 19 recordsLinked to original sources
PubMed1999

Changes in renal blood flow in response to sympathomimetics in the rat transplanted and denervated kidney.

BACKGROUND: Renal denervation and re-innervation may affect vascular responses to sympathomimetics, which may play a role in the maintainance of renal blood flow (RBF) following renal transplantation. The purpose of the present study was to elucidate pharmacological alteration of the renal sympathetic response following kidney transplantation. Using the rat kidney transplantation model, we focused on responses to various sympathomimetics in order to investigate the effects of sympathetic denervation and functional remodulation mechanisms in the transplanted kidney. METHODS: Male isogenic rats underwent unilateral kidney denervation or kidney transplantation accompanied by unilateral native nephrectomy. Renal blood flow was evaluated using a laser Doppler flow meter following bolus injection of 50 microg/kg dopamine and continuous infusion of 60 microg/min phenylephrine (PE) at 0, 30, 60, 90 and 240 days after transplantation as well as at 30 days after denervation. RESULTS: Bolus injection of dopamine (50 microg/kg) induced an initial reduction in RBF (that of alpha-adrenoceptors) followed by a long-lasting increase in RBF (that of beta-adrenoceptors) in the native kidney. In grafted or denervated kidneys, the dopamine-induced decrease in RBF mediated by alpha-adrenoceptors was markedly enhanced while the increase in RBF mediated by an action of dopamine on beta-adrenoceptors was blunted. The effects of the post-transplant period on vascular responses to dopamine were significant, but not completely synchronized with the native kidney, even at 240 days. Continuous infusion of PE (60 microg/min) produced a gradual increase in RBF in the native kidney, whereas a sudden reduction (i.e. breakthrough in autoregulation) was observed in the denervated and transplanted kidney. CONCLUSIONS: The responses to sympathomimetics in the grafted kidney were shifted towards flow reduction (i.e. enhanced vasoconstriction via stimulation of alpha-adrenoceptors and blunted vasodilatation via stimulation of beta-adrenoceptors. This functional impairment was recovered in a time-dependent manner. In addition, the hemodynamic autoregulation system in the kidney deteriorated following transplantation or denervation.

Animals↗
PubMed1999

Impact of congenital narrowing of the bulbar urethra (Cobb's collar) and its transurethral incision in children.

OBJECTIVES: We described the clinical manifestation and outcome after transurethral incision (TUI) of a congenital narrowing of the bulbar urethra (Cobb's collar). MATERIALS AND METHODS: Over a period of 11 years a total of 74 boys, from 3 months to 16 years old with a mean age of 5 years, were subjected to TUI. A febrile urinary tract infection (UTI) was the most common symptom in 40 cases, enuresis in 15, urinary incontinence in 11, hematuria in 9, antenatally diagnosed dilated urinary tract in 4 and others in 9. Concurrent bladder instability was detected by cystometry in 27/31 boys older than 3 years with suspicious bladder urgency. When the bulbar narrowing was detected by cystourethroscopy under 8 Fr, the lesion was simultaneously incised by using an infantile resectoscope (Olympus 10 Fr with a knife electrode or Storz 10 F with a cold knife). RESULTS: Vesicoureteral refluxes (VURs) occurred in 39 cases (53%) and it was diminished in 11 and improved in 25 after TUI. Of the 40 cases, 38 (95%) were free from UTI after TUI. For enuresis and urinary incontinence, 14/15 and all 11, respectively, thrived after TUI and the anticholinergic supplement. Although 61 cases were primarily cured with no complications, insufficient cutting and recurrence of the stricture required an additional TUI in 13 cases for whom the knife electrode was mostly used. Overall clinical improvement was obtained in 71/74 (93%) cases after TUI. CONCLUSION: Meticulous cystourethroscopy is indispensable for detecting a clinically significant bulbar narrowing. TUI of the lesion is useful as a primary treatment in the majority of cases even with concurrent VUR and unstable bladder. A cold knife is preferable to electrocautery in incising this fine anterior urethral lesion.

Adolescent↗
PubMed1998

Experience with kidney transplantation in children and adolescents.

BACKGROUND: Paediatric kidney transplantation has different aspects in adults in terms of underlying primary renal disease, surgical technique, perioperative care and graft prognosis. Significant urological problems are present in a high percentage of paediatric recipients. This study was undertaken to characterize paediatric kidney transplantation as performed at our institutes. METHODS: Twenty-eight patients (age range 4-17 years, 10 girls, 18 boys) were included in this study. We analyzed (1) urologic procedures performed prior to or simultaneously with transplantation, (2) intraoperative changes in haemodynamics, (3) postoperative complications and (4) acute allograft rejection and graft prognosis. RESULTS: Of 4 patients with lower urinary tract abnormalities (neurogenic bladder in 3, posterior urethral valve in 1), 2 underwent augmentation ileocystoplasty prior to transplantation. The Mitrofanoff procedure as a diversion for neourethra was also performed in 2 of the 4 patients. All these 4 patients were managed with clean intermittent catheterization. Central venous pressure changes before and after graft vessel declamping were much greater in patients with body weight below 25 kg than in those above 25 kg. Five surgical complications and 6 infections were encountered postoperatively and hypertension was lasting in 6. Thirteen patients experienced 19 periods of acute allograft rejection. All of the 24 patients in the cyclosporin era (1986-) overcame rejections and they are all alive with good graft function. CONCLUSIONS: As long as proper pretransplant patient evaluation and management, and intensive perioperative care are undertaken, good prognosis of renal allograft can be achieved in young patients.

Adolescent↗
PubMed1998

Kidney transplantation in patients with neurovesical dysfunction.

BACKGROUND: Five renal recipients with neurovesical dysfunction (NVD) were retrospectively reviewed focusing on anatomical and urodynamic abnormalities of the lower urinary tract and their management prior to kidney transplantation. METHODS: The underlying anomalies in these 5 patients were a posterior urethral valve (1 with an imperforate anus; n = 2), meningomyelocele (n = 2) and a congenital short urethra with an imperforate anus (n = 1). Their urinary tracts were evaluated prior to transplantation with voiding cystourethrography, urethrocystoscopy, cystometrography and electromyography of the external urethral sphincter to identify a possible focus of urinary tract infection, urine storage and voiding function. RESULTS: All 5 patients had NVD proven by urodynamic studies or by documentation of urinary retention in the absence of mechanical outlet obstruction. Bilateral high grade vesicoureteral reflux was noted in all patients, requiring ureteroneocystostomy. Clean intermittent catheterization (CIC) was ultimately employed for bladder emptying in all patients. Two patients with poor bladder compliance underwent augmentation cystoplasty before transplantation. The Mitrofanoff procedure was used in 2 patients with structural urethral abnormalities to access the bladder for catheterization. After eradication of possible sources of infection and establishment of a low-pressure urine storage system with bladder emptying by CIC, kidney transplantation was performed. Following kidney transplantation, all of the recipients were asymptomatic for urinary tract infections using CIC. Although 1 patient lost his graft due to chronic rejection, the other 4 other patients have good renal function. CONCLUSION: Kidney transplantation in patients with NVD can be performed provided that their urinary tract problems are properly resolved.

Adolescent↗
PubMed1998

Clinical features of vesicoureteral reflux in infants and outcome of conservative therapeutic approach.

OBJECTIVES: We evaluated the clinical features of vesicoureteral reflux (VUR) detected in infants and the outcome of a conservative therapeutic approach. METHODS: Consecutively 67 infants with VUR (55 boys and 12 girls) were enrolled in this study. Of the 67 patients, 34 had primary and 33 had secondary VUR. Underlying abnormalities in secondary VUR were: posterior urethral valve (PUV) in 7; bulbar urethral stenosis (Cobb's collar) in 16; neurovesical dysfunction (NVD) in 8, and others in 2. Transurethral incision was performed in patients with PUV or Cobb's collar. NVD was managed with intermittent catheterization. All patients were followed with antibiotic prophylaxis. RESULTS: No significant difference was found in VUR grades between primary and secondary VUR. Spontaneous resolution of VUR was noted in 31% of primary and 54% of secondary VUR (p<0.02). VUR downgrading including VUR resolution was also noted more often in secondary than in primary VUR (80 vs. 48%; p<0.01). CONCLUSIONS: The distribution of primary and secondary VUR in infants was almost equal in our study. Resolution of reflux is seen more often in secondary than in primary cases. Thus, early detection and proper management of underlying lower urinary tract abnormalities, either structural or functional, are crucial in the treatment of VUR in infants.

Female↗
PubMed1998

Surgical repair of anterior hypospadias with fish-mouth meatus and intact prepuce based on anatomical characteristics.

PURPOSE: A variant form of anterior hypospadias, called a megameatus and intact prepuce (MIP), is thought to be less amenable to conventional distal hypospadias repair. The feasibility of using the standard technique with a parameatal-based foreskin flap is described herein. MATERIALS AND METHODS: Nine children with the MIP variant underwent repair. A foreskin flap for urethroplasty was harvested from either the ventral (Mathiew) or unilateral site. The glans was split along with the cleft glanular groove to create the glans wings. The flap was laid on the urethral plate to form a neourethra, and glanulomeatoplasty was completed by approximation of the glans wings. Sleeve reapproximation of the penile foreskin was performed for uncircumcised skin closure. RESULTS: The functional and cosmetic results of the procedure were excellent in 8 cases including 1 with temporary postoperative edema of redundant foreskin. The last case underwent excision of the ventral excess foreskin for cosmetic reasons. CONCLUSIONS: Although the etiology of the MIP variant remains obscure, the urethral plate distal to the meatus is uniformly pliable and healthy in this variant. Furthermore, the ventral portion just proximal to the meatus is well developed and not atretic so that the parameatal ventral foreskin is safely harvested for onlay urethroplasty.

Child, Preschool↗
PubMed1998

Kidney transplantation in a child with posterior urethral valve from a hepatitis B virus-carrier mother. Report of a case with special reference to urinary tract reconstruction for dysfunctionalized uropathies and seroimmunological preparation against viral transmission.

The case of a 7-year-old boy with posterior urethral valve (PUV) who underwent successful kidney transplantation for progressive renal failure is reported. He required complex reconstructive surgery for PUV-related disorders, and also specific serological preparation for hepatitis B (HB) as his living donor mother was a proven carrier. By carefully executing the principles of reconstructive surgery and with well-planned seroimmunological preparation, we have demonstrated that successful kidney transplantation can be done from an HB Ag-positive mother to an HB Ag- and HB Ab-negative son, even when his urinary tract is severely dysfunctional due to PUV.

Carrier State↗
PubMed1998

[Application and limitation of neoadjuvant hormonal therapy for prostate cancer].

Of 156 patients, 111 (clinical stage T1a-b; 21, T1c; 17, T2a-b; 36, T2c; 27, T3; 10) immediately underwent radical prostatectomy (surgery group), and 45 (clinical stage T1a-b; 8, T1c; 4, T2a-b; 10, T2c; 9, T3; 14) received neoadjuvant hormonal therapy (NHT group). NHT offered probability of increasing organ-confined cancer(OCC; pathological stage pT2 or lower N0M0) in the following group, which contains (a) patients who had moderately differentiated adenocarcinoma in the biopsy specimen and T2b or lower diseases, and (b) those who had well differentiated adenocarcinoma, T2c diseases and PSA levels of 10 ng/ml or higher, referred to as "OCC suitable criteria". Of 156 patients, 51 (33%) met OCC suitable criteria. In those cases, the proportion of OCC in NHT group was significantly higher than that in surgery group (11/12 (92%) vs. 16/39 (41%), p = 0.002). NHT is useful for increasing OCC in patients who meet OCC suitable criteria.

Adenocarcinoma↗
PubMed1997

Normal perfusion pressure breakthrough syndrome in giant arteriovenous malformations.

The treatment of large, high-flow cerebral arteriovenous malformations is one of the most difficult operations which neurosurgeons encounter because of the complex surgery and the post-operative effects on the brain. We have evaluated 10 patients with large, high-flow AVMs who underwent surgical resection. Patients were investigated with contrast-enhanced computed tomography and magnetic resonance imaging, 1231-IMP single photon emission computed tomography (SPECT) studies of cerebral flow and cerebral vasodilatory function, intraoperative Laser Doppler flowmetry (4 or 10 patients), and conventional angiography. The volume of the arteriovenous malformation nidi ranged from 32.8 to 210.5 cc. SPECT imaging performed on the first post-operative day showed marked hyperperfusion in the brain tissue surrounding the resected nidus, and these regions were normal on images on the 7th post-operative day. Laser Doppler flowmetry showed sudden, and marked increase in CBF immediately following placement of temporary clips on the main feeding artery. Angiograms done on 7-14 days following surgery showed a stagnating artery, fragile vessel, and a prolonged circulation time. Our results indicate that pre- and post-operative SPECT study, especially a dynamic SPECT study done on the first post-operative day, was the most useful examination for ascertaining the post-operative normal perfusion pressure breakthrough.

Adolescent↗
PubMed1997

Feasibility of urodynamic study (combined cystometry and electromyography of the external urethral sphincter) under general anesthesia in children.

BACKGROUND: To assess the feasibility of urodynamic study under general anesthesia (GA) we performed electromyography of the external urethral sphincter (EUS-EMG) on 73 children and cystometry (CM) alone on 10 children. METHODS: Subjects were divided into 3 groups. Those in groups I and II were suspected of having voiding dysfunction with (group I) or without (group II) overt neurospinal defects, while those in group III were thought to be functionally normal. EUS-EMG was performed under light anesthesia following cystourethroscopy to examine structural abnormalities. Atropine sulfate premedication was not used for the anesthetic procedure; muscle relaxants were used only for tracheal intubation. RESULTS: Voiding was observed in 83% of the patients. Among patients who voided, detrusor-external sphincter dyssynergia (DSD) was noted in 7 (38%) group I patients and 6 (19%) group II patients; in group III, voiding was synergic in all patients. In 10 cases, CM alone was carried out both under anesthesia and in the waking state; anesthesia suppressed detrusor hyperreflexia (DH) in all 9 patients but produced no change in bladder compliance. CONCLUSIONS: In children with urinary disorders, urodynamic study under GA following cystourethroscopy is a feasible method for assessing EUS function and documenting DSD; DH is not evaluable, however. Stratifying urinary management on the basis of these examinations resulted in satisfactory clinical outcomes.

Adolescent↗
PubMed1997

Kidney-alone transplantation in diabetic patients with end-stage renal disease.

From January 1989 to December 1995, 5 diabetic patients with end-stage renal disease (1 woman, 4 men) underwent kidney-alone transplantation. The mean age of the recipients at the time of transplantation was 37.4 years (range, 32 to 43). Craft function and glucose tolerance was evaluated for 5 to 72 months after surgery. Postoperative complications were seen in 2 patients; nonspecific subcutaneous infections and an asymptomatic partial allograft infarction. All renal allografts were functioning 1 year after transplantation, with a mean serum creatinine level of 1.10 mg/dL (range, 0.8 to 1.8 mg/dL), and a mean urinary protein level of 17.8 mg/dL (range, 5 to 27 mg/dL). The postoperative daily dose of insulin was higher than the preoperative dose, while the level of glycated hemoglobin (HbA1C) increased after surgery and peaked 6 months after transplantation; 1 year after transplantation it had reverted to the preoperative level. As long as the diabetic complications of the renal allograft recipients are not severe, the short-term survival and the renal function of diabetic patients with end-stage renal disease improves after kidney-alone transplantation, which is still the standard method of treatment in Japan.

Adult↗
PubMed1997

Early experience with real-time CT-fluoroscopy for an intracranial lesion.

We have developed a real-time CT-fluoroscopy (CTF) system of which the initial trial was reported in 1993. This paper deals with the early clinical experience with this system. A third-generation scanner equipped with a slip-ring (Toshiba) was used. Images were reconstructed and displayed at a rate of 6/s with a 0.83-second delay time using a newly designed array processor. CTF was carried out in 12 cases (10 brain hemorrhages, 2 tumors). Good-quality fluoroscopic images were obtained in all cases. Real-time monitoring with CTF of needle placement and advancement was useful for accurate puncture needle biopsy and evacuation of the lesions. No serious complication was experienced in this series.

Biopsy, Needle↗
PubMed1997

[Clinical evaluation of donor renal artery reconstruction in kidney transplantation].

UNLABELLED: This retrospective study describes the experience of arterial reconstruction of donor kidney in our institute since 1982. MATERIALS AND METHODS: Of total 56 living related kidney transplantations 15 required renal arterial reconstruction or ligation of donor kidneys. Renal arterial reconstruction was employed for 11 cases (end to side anastomosis [4 cases], conjoined anastomosis [3], hypogastric artery graft interposition [3], other [1], while simple ligation was employed for 4. Bench surgery with microsurgical techniques was employed for the repair. Elective surgery was done for preoperatively defined multiple renal arteries [10] and aneurysm [1], while imperative surgery for intraoperatively detected accessory arteries [2] and surgical injuries [2]. Postoperative patency of arteries and renal function (GFR) and evaluated by 99mTc-DTPA renoscintigraphy. RESULTS: The mean total ischemic time of reconstructed cases was 135 min., while that of ligated ones was 67 min. None of them required hemodialysis due to acute tubular necrosis. Postoperative graft arterial patency was impaired in 2 of 11 reconstructed cases (18%), while it was impaired in 3 of 4 ligated cases (75%). Two failure attempts of arterial reconstruction cases were all imperative ones. Postoperative GFR of the graft was well preserved in all cases. CONCLUSION: We conclude that (1) Ligation and imperative surgery tend to be associated with renal infarction, although it does not affect GFR. (2) Renal artery reconstruction was highly successful in preserving renal mass (or normal cortical image), albeit longer ischemic time than simple ligation. (3) Considering importance of preserved nephron mass in clinical renal transplantation every attempt should be made to repair the donor arterial anomalies when expected (elective) or found (imperative). (4) Thorough preoperative evaluation of donor renal arteries is mandatory.

Adult↗
PubMed1997

[One-stage-bilateral adrenalectomy by thoracoabdominal approach for bilateral large pheochromocytomas in men type IIa. A case report].

We experienced a case of MEN type 2a with bilateral and large pheochromocytomas. A 39-year-old man was admitted to the previous hospital with complaints of paroxysmal headache. hypertension and diabetes mellitus. Radiographic imagings showed thyroid tumors in both lobes and bilateral adrenal tumors. Thyroid tumors were histologically proved to be medullary thyroid carcinoma by needle biopsy and systemic investigations revealed an excessive secretion of plasma and urinary cathecholamines which suggested the presence of pheochromocytoma. The patient was diagnosed as MEN type 2a. He was admitted to our hospital for the treatment of bilateral adrenal tumors for which we performed one-stage bilateral adrenalectomy by thoracoabdmonal approach. Both adrenal tumors were histologically confirmed as pheochromocytoma. The patient's postoperative course was uneventful. He underwent uneventful total thyroidectomy approximately 2 months after bilateral adrenalectomy. Even in bilateral and large pheochromocytomas, one-stage bilateral adrenarectomyenables safe postoperative managements. We concluded that the thoracoabdominal approach is feasible in the patients with huge and cranially spreading adrenal tumor, which gives us a wide operative field for easy vascular control.

Adrenal Gland Neoplasms↗
PubMed1997

Structural changes of collagen components and diminution of nerves in congenital ureteropelvic junction obstruction.

PURPOSE: Three-dimensional arrangements of smooth muscle cells, collagenous component and peripheral nerves of congenital ureteropelvic junction (UPJ) obstruction were studied in order to clarify the pathogenetic mechanism of interaction among these neuro-myo-stromal components. MATERIALS AND METHODS: The UPJ and upper ureters were obtained from 14 patients with congenital hydronephrosis (7 intrinsic and 4 extrinsic obstruction) and 7 normal controls. Three-dimensional arrangement of each structural component was observed by scanning electron microscopy, and the nerve distribution was analyzed with immunohistochemistry for protein gene product 9.5. RESULTS: The UPJ of intrinsic obstruction had structural features as follows. Muscle fascicles were sparse and thin. Each muscle cell was thin in diameter. Intercellular spaces were six to seven times wider than controls. Collagen fibrillar sheaths of smooth muscle cells (pericellular collagen fibrils attached to the basement membrane) were interwoven to form a dense felt-like structure against thin lace-like sheaths in controls. Interstitial collagenous component showed dense and compact structure against loose network of wavy collagen bundles in controls. In the muscular layer, nerve distribution was decreased to about one-third of controls. In contrast, non-stenotic portion of intrinsic UPJ obstruction as well as materials from extrinsic UPJ obstruction showed no structural difference as compared with controls. CONCLUSIONS: In the intrinsic obstruction, nerve fibers were depleted in the muscular layers in the ureteric walls, resulting in dysfunction and atrophy of muscle fibers and an increase of collagen fibers in the muscle layers with abnormal accumulation of intercellular and interstitial collagen. These changes may disrupt the mobility of UPJ and lead to both mechanical and functional obstruction.

Adult↗