Relationship between stable cesium concentration and body size of Japanese flounder Paralichthys olivaceus and the effect of a size-dependent shift in diet.

To understand the relationship between the radioactive cesium (Cs) concentration in muscle of Japanese flounder Paralichthys olivaceus and the species' biological characteristics (size, sex, and age) under conditions of ecological equilibrium (i.e., distributed among ecosystem components over sufficient time, and with nearly constant ratios of Cs concentration in organisms to the concentration in water) as existed before the accident at the Fukushima Dai-ichi Nuclear Power Station (FDNPS), Japan, in 2011, we examined stable Cs, as it is thought to exist in equilibrium in the environment and behave similarly to radioactive Cs in aquatic animals. The concentration of stable Cs in 241 P. olivaceus (range 216-782 mm total length [TL]) collected in Sendai Bay, approximately 90 km north of the FDNPS, in June-July 2015 was expressed as an exponential function with size as an independent variable; the results show the concentration of stable Cs doubled with an increase in TL of 442 mm. Next, to evaluate the cause of the size-dependent change in stable Cs concentration, we examined 909 individuals (200-770 mm TL) collected in September 2013-July 2015 to determine their feeding habit based on size. Analysis of the frequency of occurrence of prey organisms in stomach contents showed that sand lance Ammodytes japonicus (55-180 mm standard length [SL]) was the most consistently consumed across size classes. Analysis on a wet-mass basis showed that A. japonicus and anchovy Engraulis japonicus (65-130 mm SL) were the main food of P. olivaceus sized 200-599 mm TL, whereas chub mackerel Scomber japonicus (120-230 mm SL) and two species of flatfishes (180-205 mm SL) were abundant in the diet of P. olivaceus sized ≥600 mm TL. All these prey items were presumed to have similar concentrations of stable Cs. Based on the above, the effect of diet on the relationship between stable Cs in muscle and fish size was considered negligible. That the diet of P. olivaceus largely did not change with size was also confirmed by C and N stable isotope ratios in P. olivaceus and their prey species. Therefore, the Cs-size relationship is probably determined by changes in the balance between the rate of Cs intake from food and seawater and the excretion rate during growth, both of which change as functions of body mass. Values of stable Cs concentrations among environmental components and animals appear to be a valid indicator for understanding the radioactive Cs distribution in the marine environment and aquatic animals under the equilibrium state, as existed before the 2011 nuclear accident.

[A Case of Venous Malformation that Occurred in the Retroperitoneum].

A 70-year-old man complaining of pain in his right leg presented to the Department of Orthopedics in our hospital. X-ray findings revealed calcifications around the left kidney. He was referred to our department for further examination. Computed tomography revealed a tumor 3 cm in diameter with calcifications and an obscure border that was located on the caudal side of the pancreas, anterior to the left iliopsoas muscle and at the left side of the aorta. Magnetic resonance imaging showed that the tumor had comparatively low intensity in diffusion-weighted images and the cell density was not high. The contrast of the tumor by enhanced computed tomography was weak, and we had difficulty judging whether the tumor was benign or malignant. Each tumor marker, immunity factor, and hormone-like catecholamine were within the normal range. We considered the retroperitoneal tumor with calcifications as Castleman disease or tumor of nerve origin. It is believed that most retroperitoneal tumors are malignant. We performed laparoscopic surgery to resect the retroperitoneal tumor. Histopathological diagnosis was a primary retroperitoneal venous malformation. Vascular malformation derived from the retroperitoneum is rare. Furthermore, very few cases of venous malformation in the retroperitoneum have been reported.

Development of a Complete En-Bloc Technique with Direct Bladder Neck Incision: A Newly Modified Approach for Holmium Laser Enucleation of the Prostate.

Introduction: The objectives of this study were to introduce a newly developed approach for holmium laser enucleation of the prostate (HoLEP) called the "complete en-bloc technique," and to compare the clinical outcomes of this approach with those of previously performed procedures. Methods: This study retrospectively assessed the perioperative findings from 548 patients with benign prostatic hyperplasia (BPH) undergoing HoLEP who were divided into the following groups according to the consecutive changes in surgical techniques: group A (n = 236), the three-lobe technique; group B (n = 137), the conventional en-bloc technique; and group C (n = 175), the complete en-bloc technique with direct bladder neck incision. Results: There were no significant differences in major clinical characteristics or urinary symptoms among groups A, B, and C. Although there was no significant difference in the resected prostate weight among the three groups, the enucleation time was significantly shorter and total laser energy was significantly lower in group C than in groups A and B. Therefore, the enucleation efficiency, calculated by dividing the resected prostate weight by the enucleation time, was significantly greater in group C than in groups A and B. Furthermore, no significant differences in the postoperative urinary symptoms, including the International Prostate Symptom Score (IPSS), quality of life, maximum flow rate, postvoid residual, and persistent stress urinary incontinence rate, were noted among the three groups, and there were no significant differences in the incidences of major perioperative complications, including the blood transfusion, bladder injury, urethral stricture, and bladder neck sclerosis among the three groups. Conclusions: These findings suggest that our complete en-bloc technique can improve the clinical outcomes of HoLEP in BPH patients, even in difficult cases, considering its markedly improved enucleation efficiency.

Oogenesis and reproductive investment of Atlantic herring are functions of not only present but long-ago environmental influences as well.

Following general life history theory, immediate reproductive investment (egg mass × fecundity/body mass) in oviparous teleosts is a consequence of both present and past environmental influences. This clarification questions the frequent use of season-independent (general) fecundity formulas in marine fish recruitment studies based on body metrics only. Here we test the underlying assumption of no lag effect on gametogenesis in the planktivorous, determinate-fecundity Atlantic herring (Clupea harengus) displaying large plasticity in egg mass and fecundity, examining Norwegian summer-autumn spawning herring (NASH), North Sea autumn-spawning herring (NSAH), and Norwegian spring-spawning herring (NSSH). No prior reproductive information existed for NASH. Compared with the 1960s, recent reproductive investment had dropped markedly, especially for NSAH, likely reflecting long-term changes in zooplankton biography and productivity. As egg mass was characteristically small for autumn spawners, although large for spring spawners (cf. different larval feeding conditions), fecundity was the most dynamic factor within reproductive investment. For the data-rich NSSH, we showed evidence that transient, major declines in zooplankton abundance resulted in low fecundity over several subsequent seasons, even if Fulton's condition factor (K) turned high. Temporal trends in Kslope (K on total length) were, however, informative. These results clarify that fecundity is defined by (i) dynamics of primary (standing stock) oocytes and (ii) down-regulation of secondary oocytes, both processes intimately linked to environmental conditions but operating at different timescales. Thus, general fecundity formulas typically understate interannual variability in actual fecundity. We therefore argue for the use of segmented fecundity formulas linked to dedicated monitoring programs.

Laparoscopic Pyeloplasty for Ureteropelvic Junction Obstruction in an Incompletely Duplicated Collecting System in a Patient with a Horseshoe Kidney.

We present a case of UPJO associated with an incompletely duplicated collecting system in a horseshoe kidney that was successfully treated by laparoscopic pyeloplasty with concomitant pyelolithotomy. A 53-year-old man had three urological anomalies and urolithiasis. We performed a pyeloplasty and pyelolithotomy using a fully intracorporeal technique. Clinical and radiographic evaluation confirmed complete resolution of the patient's condition. To our knowledge, there have been no reported cases of UPJO in an incompletely duplicated collecting system with a horseshoe kidney in the same patient. We also provide convincing evidence that laparoscopic pyeloplasty is feasible in complex cases of renal anatomic anomalies.

[AN ISOLATED INTERNAL ARTERY ANEURYSM WITH COMPLETE THROMBOTIC OCCLUSION FOR WHICH PREOPERATIVE DIAGNOSIS WAS DIFFICULT: A CASE REPORT].

A 74-year-old man was incidentally discovered during treatment of prostate cancer to have a pelvic tumor, measuring 8 cm in diameter. Enhanced abdominal computed tomography (CT) showed a roundish-shaped hypovascular solid tumor compressing the left internal iliac artery to the inner back side. Values on endocrinological examination were within normal ranges. The tumor was suspected to be chronic abscess, angiosarcoma, or gastrointestinal stromal tumor (GIST) or neurogenic tumor, but no definitive diagnosis was able to be established before operation. During laparotomy, given its location relative to the internal iliac artery wall, the tumor was extracted by sacrificing periphery of the artery. The pathological diagnosis was an internal artery aneurysm with complete thrombotic occlusion. Isolated internal iliac aneurysm is rare, and this is the first case which resulted in complete thrombotic occlusion.

Laparoscopic simultaneous bilateral adrenalectomy for testosterone-secreting bilateral adrenal tumors.

Laparoscopic adrenalectomy is widely accepted as a safe and minimally-invasive procedure. Although it is a standard procedure for the surgical treatment of adrenal tumors, its simultaneous use with bilateral adrenalectomy is relatively rare. A 21-year-old woman was referred to Hamamatsu University School of Medicine University Hospital complaining of a deepening voice, hirsutism and secondary amenorrhea. Abdominal computed tomography showed bilateral adrenal tumors, and hormonal examinations showed that the tumors secreted excessive testosterone, resulting in virilizing symptoms. Laparoscopic simultaneous bilateral adrenalectomy was carried out. Postoperatively, serum testosterone levels immediately recovered to within the normal range. Menstruation began the month after the operation, and the hirsutism gradually regressed. This is the third reported case of bilateral virilizing adrenal tumors, and the first to be successfully treated with laparoscopic simultaneous bilateral adrenalectomy.

[Surgery without blood transfusion for pheocromocytoma in a Jehovah's Witness patient: a case report].

A 59-year-old woman who identified as a Jehovah's Witness was diagnosed with pheochromocytoma in the left adrenal gland, measuring 11 cm in diameter, during treatment for hypertension. Given her desire to undergo transfusion-less surgery for religious reasons, we obtained fully informed consent and had the patient sign both a transfusion refusal and exemption-from-responsibility certificate and received consent to instead use plasma derivatives, preoperative diluted autologous transfusion and intraoperative salvaged autologous transfusion. To manage anemia and maintain total blood volume, we preoperatively administered erythropoiesis-stimulating agents and alpha 1 blocker, respectively. During the left adrenalectomy, the patient underwent a transfusion of 400 mL of preoperative diluted autologous blood, ultimately receiving no intraoperative salvaged autologous blood. The operation took 4 hours 42 minutes, and the total volume of blood lost was 335 mL. In conclusion, to complete transfusion-less surgery for pheochromocytoma, it is necessary to have the patient sign a generic refusal form for transfusion and exemption-from-responsibility certificate as well as outline via another consent form exactly what sort of transfusion is permitted on a more specific basis. And doctors should become skilled in perioperative management and operative technique for pheochromocytoma and make the best effort by all alternative medical treatment in order to build trust confidence with a patient.

[Long-term survival of metastatic clear cell adenocarcinoma of the female urethra by multidisciplinary treatment: a case report].

We report a case of clear cell adenocarcinoma of the female urethra. A 57-year-old woman presented with complaint of gross hematuria. Abdominal ultrasonography, cystourethroscopy, computed tomography (CT) and magnetic resonance imaging (MRI) revealed the urethral tumor was invasive to bladder neck. Clinical stage was determined as cT3N1M0, then anterior pelvic exenteration and ileal conduit formation were performed. The pathological diagnosis was clear cell adenocarcinoma of urethra and the stage was pT3N1. The patient received TS-1 and cisplatin for postoperative recurrence, but she died from multiple lung metastasis 54 months after the operation. Clear cell adenocarcinoma of the female urethra is rare case in the Japanese literatures. Pathogenesis and management of this rare condition are discussed.

Expression and functional role of ß3 -adrenoceptors in the human ureter.

OBJECTIVES: To investigate the presence of ß-adrenoceptor subtypes in the human ureter, and to examine whether ß(3) -adrenoceptors modulate relaxation of the human ureter. METHODS: Expression of messenger ribonucleic acid of ß-adrenoceptors in the human ureter was determined by reverse transcription polymerase chain reaction, and distribution of ß-adrenoceptors was examined by immunohistochemistry. In functional studies, the relaxant effects of isoproterenol, procaterol, TRK-380, salbutamol and BRL 37344 on KCl-induced contraction of the human ureter were evaluated, and the inhibitory effects of isoproterenol, procaterol and TRK-380 on electrical field stimulation-induced contractions were determined. RESULTS: Expression of ß(1) -, ß(2) - and ß(3) -adrenoceptor messenger ribonucleic acid in the human ureter was confirmed by reverse transcription polymerase chain reaction. Positive staining for ß(1) -, ß(2) - and ß(3) -adrenoceptor was identified not only in smooth muscle, but also in the urothelium of the human ureter. All ß-adrenoceptor agonists decreased the tone of KCl-induced contractions of the human ureter with a rank order of relaxant effects of isoproterenol > procaterol > TRK-380 > salbutamol > BRL 37344. Furthermore, isoproterenol, procaterol and TRK-380 significantly decreased the amplitude of electrical field stimulation-induced contractions with a rank order of inhibitory effects of isoproterenol > procaterol > TRK-380. CONCLUSIONS: Human ureteral relaxation is mediated by both ß(2) - and ß(3) -adrenoceptor stimulation. ß(3) -Adrenoceptor agonists have the potential to relax the human ureter, and their clinical application in the treatment of ureteral stones is expected.

Population subdivision of Japanese flounder Paralichthys olivaceus in the Pacific Coast of Tohoku Japan detected by means of mitochondrial phylogenetic information.

This study deals with mitochondrial phylogenetic information of Japanese flounder in the Pacific coast of Tohoku Japan to estimate the genetic population subdivision that was undetectable by conventional population statistics. We determined complete sequences of mitochondrial NADH dehydrogenase subunit-2 (ND2) and subunit-5 (ND5) genes for 151 individuals from northern (Aomori and Iwate prefectures, 40-41°N) and southern (Miyagi and Fukushima prefectures, 37-38°N) waters. Samples from both waters showed high genetic diversity, including 126 haplotypes. These haplotypes were located at mixed and nested positions on an inferred phylogenetic tree, and traditional F-statistics indicated no significant population divergence (φ(ST) = -0.00335, p > 0.05), corroborating our previous study. Three variable sites, however, showed significant base composition heterogeneity between samples from the northern and southern waters (Fisher's exact-test, p < 0.01). Nucleotide substitutions at the three sites converged on an apical clade, which consisted of the five southern individuals, whereas its sister clade consisted only of the three northern individuals. This phylogenetic information corroborates previous ecological studies indicating the presence of separate stocks in the northern and southern waters.

Expression of ß-Adrenoceptor Subtypes in Urothelium, Interstitial Cells and Detrusor of the Human Urinary Bladder.

OBJECTIVE: We examined whether interstitial cells (ICs) of the human urinary bladder expressed ß-adrenoceptor (AR) subtypes, and semiquantitatively compared the staining intensity among urothelium, ICs and detrusor muscles. METHODS: Paraffin sections of the human urinary bladder were obtained from histologically normal areas of formalin-fixed specimens removed for bladder carcinoma. Double-labeling immunohistochemical methods using antibodies against each ß-AR subtype and vimentin were performed to identify ICs of the human urinary bladder. The staining intensity of ß-ARs was semiquantitatively compared among urothelium, ICs and detrusor muscles. Further, gender-related difference or age-related correlation in the staining intensity of ß-ARs was compared in the same cell types. RESULTS: The expression of ß1 -, ß2 -, and ß3 -AR was observed in vimentin-positive ICs localized in suburothelium, between detrusor muscle bundles, and within these bundles of the human urinary bladder. The rank order of the staining intensity was urothelium > ICs = detrusor muscles in ß1 -AR, urothelium > ICs > detrusor muscles in ß2 -AR, whereas its order was ICs = detrusor muscles > urothelium in ß3 -AR. Except for urothelial ß1 -AR, there was no gender-related difference in the signal intensity of ß-ARs in the urothelium, ICs or detrusor muscles. Age negatively correlated with the signal intensity of all ß-AR subtypes. CONCLUSION: ß-ARs were expressed in vimentin-positive ICs of the human urinary bladder. As for ß2 - and ß3 -AR, there was no gender-related difference or age-related correlation in urothelium, ICs and detrusor muscles. In the human urinary bladder, ß-ARs expressed in ICs may play a role in bladder physiology.

Successful treatment for adrenocorticotropic hormone-independent macronodular adrenal hyperplasia with laparoscopic adrenalectomy: a case series.

INTRODUCTION: Adrenocorticotropic hormone-independent macronodular adrenal hyperplasia, characterized by bilateral macronodular adrenal hypertrophy and autonomous cortisol production, is a rare cause of Cushing's syndrome. Bilateral adrenalectomy is considered the standard treatment for adrenocorticotropic hormone-independent macronodular adrenal hyperplasia but obliges the patient to receive lifetime steroid replacement therapy subsequently, and may increase the patient's risk of adrenal insufficiency. These circumstances require surgeons to carefully consider operative strategies on an individual basis. CASE PRESENTATION: We performed successful laparoscopic adrenalectomy on four patients with adrenocorticotropic hormone-independent macronodular adrenal hyperplasia. Computed tomography scans showed bilateral adrenal enlargement in all patients. Case 1: a 56-year-old Japanese woman presented with obvious Cushing's symptoms during treatment for diabetes mellitus and hypertension. Case 2: a 37-year-old Japanese man also presented with Cushing's symptoms during treatment for diabetes mellitus and hypertension. These patients were diagnosed as Cushing's syndrome caused by adrenocorticotropic hormone-independent macronodular adrenal hyperplasia based on endocrinologic testing, and underwent bilateral laparoscopic adrenalectomy. Case 3: an 80-year-old Japanese woman was hospitalized due to unusual weight gain and heightened general fatigue, and was diagnosed as Cushing's syndrome caused by adrenocorticotropic hormone-independent macronodular adrenal hyperplasia. She underwent unilateral laparoscopic adrenalectomy due to high operative risk. Case 4: a 66-year-old Japanese man was discovered to have bilateral adrenal tumors on medical examination. He did not have Cushing's symptoms and was diagnosed as subclinical Cushing's syndrome due to suppressed adrenocorticotropic hormone serum levels and loss of cortisol circadian rhythm without abnormal levels of serum cortisol. He underwent unilateral laparoscopic adrenalectomy. During follow-up, serum cortisol levels were within the normal range in all cases, and serum adrenocorticotropic hormone levels were not suppressed. Further, cases with Cushing's syndrome experienced clinical improvement. CONCLUSIONS: We were able to effectively treat adrenocorticotropic hormone-independent macronodular adrenal hyperplasia in patients with obvious Cushing's symptoms by laparoscopic bilateral adrenalectomy, which promptly improved symptoms. Further, unilateral adrenalectomy was effective for treating an older patient at high operative risk and a patient with subclinical Cushing's syndrome.

[Rupture of renal artery aneurysm into the renal pelvis].

We report a case of ruptured renal artery aneurysm into the renal pelvis. A 48-year-old woman presented with complaints of gross hematuria and right back pain. Abdominal ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI) revealed the aneurysm, which was 5 x 5 cm in diameter. Enhansed CT revealed blood flow from the renal artery aneurysm into the renal pelvis. Radical nephrectomy was performed. Rupture of renal artery aneurysm into the renal pelvis is the 3rd case in the Japanese literatures. Pathogenesis and management of this rare condition are discussed.

[A clinical study of laparoscopic adrenalectomy for pheochromocytoma--analysis of clinical parameters influencing operative time and intraoperative systolic blood pressure].

PURPOSE: We retrospectively analyzed the preoperative clinical parameters which influence operative time and intraoperative maximum systolic blood pressure in patients undergoing laparoscopic adrenalectomy for pheochromocytoma. MATERIALS AND METHODS: Between January 1992 and September 2010, we performed 28 laparoscopic adrenalectomies for pheochromocytoma at Hamamatsu University School of Medicine. These 28 cases were characterized based on the following parameters: body mass index (BMI), tumor size, history of hypertension, preoperative blood pressure, serum concentration of catecholamine, and 24-h urinary excretion of catecholamine metabolite. We retrospectively analyzed whether or not these parameters influenced operative time or intraoperative maximum systolic blood pressure. RESULTS: All 28 cases of laparoscopic adrenalectomy were performed safely and without intraoperative complications and needed neither blood transfusion nor conversion to laparotomy. The median operative time was 203 minutes, and intraoperative hypertension (systolic blood pressure > 200 mmHg) occurred in 46% (13/28) of cases. Median day of discharge in all patients was post-operative day 5. Significant positive correlation was shown between tumor size and operative time and between intraoperative maximum systolic blood pressure and serum concentration of catecholamine or 24-h urinary excretion of catecholamine metabolite (p < 0.05). CONCLUSION: The lengthened operative time for large tumors and elevated intraoperative blood pressure for tumors with high preoperative catecholamine activity necessitate careful perioperative management in patients receiving laparoscopic adrenalectomy for pheochromocytoma.

[A case of ductal adenocarcinoma of the prostate treated with endocrine therapy and radiation therapy].

We report a case of ductal adenocarcinoma of the prostate. A 81-year-old man presented with a complaint of microhematuria. Serum prostate specific antigen (PSA) was 18. 44 ng/ml. A cystourethroscopic examination revealed a papillary tumor near the verumontanum. Transurethral resection of the tumor and transrectal prostatic needle biopsy was carried out. The pathological diagnosis was ductal adenocarcinoma and acinar adenocarcinoma of the prostate. The tumor responded to endocrine therapy and radiation therapy. At the follow up at 18 months, the PSA level was in the undetectable range (＜0.01 ng/ml), and no reccurence of the tumor was seen. Pathogenesis and management of this rare condition is discussed.

Application of ultrasonography and the resistive index for evaluating bladder outlet obstruction in patients with benign prostatic hyperplasia.

Benign prostatic hyperplasia (BPH) is an extremely common and chronic condition that can lead to bladder outlet obstruction (BOO) in elderly men. Although pressure-flow studies are considered the most reliable method for evaluating BOO, they are invasive and complicated. Transrectal ultrasonography (TRUS) is a promising alternative because of its minimal invasiveness. Recently, TRUS imaging has been shown capable of measuring the resistive index, a useful parameter for evaluating BOO and for determining proper medical intervention in patients suffering from BPH.

Combination therapy with sorafenib and S-1 for renal cell carcinoma producing granulocyte colony-stimulating factor.

We present the first case report of the use of sorafenib and S-1 for the treatment of renal cell carcinoma (RCC) producing granulocyte colony-stimulating factor (G-CSF). This entity is clinically rare and has a poor outcome. A 78-year-old Japanese man presented with macrohematuria, left flank pain, and a palpable mass. Laboratory data showed marked leukocytosis with increased serum and urinary G-CSF. The histopathological diagnosis was unclassified RCC. New combination therapy with sorafenib and S-1 exerted a therapeutic effect and apparently decreased serum and urinary G-CSF levels, although the patient died of gastrointestinal perforation. The use of combined sorafenib and S-1 may be worthy of consideration in the treatment of RCC producing G-CSF.

Arteriosclerosis related factors had no clinical significant correlation with resistive index in symptomatic benign prostatic hyperplasia.

OBJECTIVE: To investigate whether the resistive index (RI) in symptomatic benign prostatic hyperplasia (BPH) could be used as a surrogate index of the severity of lower urinary tract symptoms (LUTS) due to BPH, and whether arteriosclerosis-related factors were associated with the RI in LUTS due to BPH. METHODS: From January 2005 to April 2008, a total of 625 men with LUTS due to BPH were prospectively enrolled. Patients with heart failure, liver cirrhosis, prostatic cancer, neurogenic bladder, acute prostatitis, acute urinary retention, urethral stenosis, history of transurethral resection or any drug treatment for BPH, or currently under drug treatment for type 2 diabetes mellitus or dyslipidemia were excluded. Variables analyzed included estimated smoking status, blood pressure, body mass index (BMI), serum fasting glucose (FBS), lipid profile (low-density lipoprotein-cholesterol, high density lipoprotein-cholesterol and triglyceride), serum prostate-specific antigen, International Prostatic Symptom Score (IPSS), quality of life score, maximum urinary flow rate (Q(max.)), and postvoid residual urine volume (PVR). We also measured total prostate volume, transition zone (TZ) index, and RI using transrectal ultrasonography. Correlations among parameters were statistically examined. RESULTS: RI was significantly correlated with IPSS, Q(max.), and PVR, but not with blood pressure, BMI, or FBS. On multiple regression analysis, RI was a significant independent variable of IPSS, TZ index, and PVR. CONCLUSIONS: These findings suggest that RI might represent a surrogate index of the severity of LUTS due to BPH, and that RI might have no clinically significant relationship with arteriosclerosis-related factors.

Resistive index as risk factor for acute urinary retention in patients with benign prostatic hyperplasia.

OBJECTIVES: To examine the usefulness of several parameters obtained by transrectal ultrasonography in predicting acute urinary retention (AUR). METHODS: The present study consecutively enrolled 1962 men with a complaint of lower urinary tract symptoms. Of these men, 245 were found to have AUR on examination at our clinic. We assessed the International Prostate Symptom Score (IPSS), maximal urinary flow rate, and postvoid residual urine volume and measured the total prostate volume, transition zone index (TZI), and resistive index (RI) using transrectal ultrasonography. To compare the usefulness of these indexes for predicting AUR, we calculated the area under the receiver operating characteristic curve for each index and for age. RESULTS: In patients without AUR, age, prostate-specific antigen level, IPSS, maximal urinary flow rate, and postvoid residual urine volume were significantly correlated with both the TZI and the RI (P < .001). Multiple regression analysis demonstrated that age, maximal urinary flow rate, postvoid residual urine volume, and TZI were significant independent determinants of the RI (P < .001). Patients with AUR were, on average, older and had an elevated prostate-specific antigen level, increased IPSS, and greater TZI and RI than patients without AUR (P < .001). The area under the receiver operating characteristic curve was 0.640 (95% confidence interval [CI] 0.618-0.662) for age, 0.674 (95% CI 0.653-0.695) for prostate-specific antigen level, 0.787 (95% CI 0.768-0.805) for total prostate volume, 0.821 (95% CI 0.803-0.838) for IPSS, 0.860 (95% CI 0.844-0.875) for TZI, and 0.867 (95% CI 0.851-0.882) for RI. CONCLUSIONS: The RI and TZI obtained using transrectal ultrasonography correlated with the incidence of AUR and are useful predictors of AUR in patients with benign prostatic hyperplasia.