Naohito Mikuma

VOIDING DYSFUNCTION IN ILEAL NEOBLADDER

PURPOSE We attempt to understand better the voiding mechanism and determine the causes of voiding dysfunction in ileal neobladder patients. MATERIALS AND METHODS The voiding condition in 12 bladder cancer patients who had undergone neobladder construction after radical cystectomy was examined by pressure-flow study and voiding cystourethrography. The patients were classified into 2 groups based on the maximum flow rate in a pressure-flow study: fine voiders (6), with a maximum flow rate of 15 ml. per second or more, and poor voiders (4), with a maximum flow rate of less than 15 ml. per second. RESULTS Maximum flow rate in the fine voiders was 26.2 +/- 8.7 ml. per second (mean plus or minus standard deviation) compared with 9.4 +/- 0.9 ml. per second in the poor voiders. The fine voiders strained 1.5 +/- 0.9 times to void 100 ml. of urine, whereas the poor voiders strained 7.0 +/- 6.3 times. The bladder capacity, vesical opening pressure and vesical pressure at the maximum flow rate were similar in both groups. Pelvic floor electrical activity was amplified when the neobladder was either full or close to its capacity, and it was relaxed in coordination with abdominal straining in all patients. Voiding cystourethrography revealed that, in fine voiders, the neobladder outlet was funnel-shaped when the bladder was full and opened wider when the patient strained to void. However, in poor voiders, the neobladder outlet did not funnel even on abdominal straining. CONCLUSIONS Neobladder patients void by abdominal straining and relaxing the pelvic floor musculature. To obtain smooth voiding in such patients, it is crucial to locate the neobladder opening at the most caudal portion and preserve neobladder outlet elasticity.

Magnetic resonance imaging of the male pelvic floor: The anatomical configuration and dynamic movement in healthy men

The male pelvic organs and the rhabdosphincter were visualized using magnetic resonance imaging (MRI) in five young male volunteers (mean age, 25.6 years). The prostate was crescent‐shaped in three subjects and doughnut‐shaped in two subjects. The external urethral sphincter (EUS) was located anterior to and lateral to the urethra but was rare on the rectal side. The membranous urethral length measured 28–35 mm (average, 31.0 mm). The pubourethral portion of the levator ani embraced the urinary bladder, the prostate, and the membranous urethra, and the most distal portion of the levator was thickened.

Ileal Neobladder for Bladder Substitution after Radical Cystectomy

Background: Studers ileal neobladder is technically simple, and favorable clinical results have been reported. However, there have been only a few follow‐up studies on this type of ileal neobladder. We reviewed the clinical outcomes of patients who received Studers ileal neobladder, with a minor modification, in our institution.

Ectopic Ureterocele with a Horseshoe Kidney in an Adult

A rare adult case of a left ectopic ureterocele associated with a duplex horseshoe kidney is reported. To the best of our knowledge, only one pediatric case of horseshoe kidney with an ectopic ureterocele has been reported. The present case was successfully treated by ureteropyelostomy, upper ureterectomy and unroofing of the ureterocele. The patient is currently followed with excretory urograms and renograms.

Morphological and Pharmacological Characterization of Guinea‐Pig Prostatic Smooth Muscle Cells in Vitro

Background Prostatic smooth muscle is thought to play a major role in the pathogenesis of bladder outlet obstruction in patients with benign prostatic hypertrophy. However, the physiology of prostatic smooth muscle cells remains largely unknown, in part due to the lack of a suitable model system. We therefore sought to establish an in vitro culture of guinea pig prostatic smooth muscle cells. Methods: Immature guinea pig prostate was treated by enzymatic digestion and the cells obtained were used to initiate the primary culture. After 3 to 4 passages, cultured smooth muscle cells were examined morphologically by immunocytochemistry and electron microscopy. The contractile properties of cultured smooth muscle cells were also examined.

Bilateral Deoxycorticosterone‐Secreting Adrenocortical Adenoma

A case of a 58‐year‐old man with bilateral deoxycorticosterone (DOC)‐secreting adrenocortical adenoma is reported. Before surgery, plasma levels of DOC and corticosterone were markedly elevated, but both adrenal hormone levels normalized after the surgical removal of the bilateral adrenal tumors. The histologic examination revealed bilateral adrenocortical adenoma, but curiously, the tissue concentrations of DOC and corticosterone were elevated only in the right adrenal gland.

Nocturnal luteinizing hormone secretion patterns at the onset of puberty measured using a highly sensitive immunofluorometric assay

Nocturnal LH pulse was analyzed in 4 prepubertal, 3 early pubertal and 2 midpubertal boys by measuring serum LH concentrations. Blood samples were taken every 30 minutes while awake, and every 20 minutes after subjects had gone to sleep. Serum LH was measured by using immunofluorometric assay (IFMA) with a lower detection limit of 0.02mIU/ml. Pulsatile LH secretion during sleep was detected in all subjects examined. LH pulse amplitude had the tendency to increase with the advance of pubertal stage. After the onset of puberty, LH pulse amplitude was significantly larger than before. The LH pulse was also detected while awake in 4 (1 prepubertal, 2 early pubertal and 1 mid-pubertal) boys. LH pulse frequency was almost the same in each pubertal stage. Serum testosterone levels gradually increased with the progress of pubertal stage. These results suggest that 1) LH is secreted in a pulsatile manner in the prepubertal subjects as well as in the pubertal subjects, 2) the increase of LH pulse amplitude plays an important role for the onset of puberty, and 3) LH pulse amplitude could be a biological marker that indicates the degree of maturation of the hypothalamo-pituitary unit in prepubertal children.