Dynamic transurethral sonography and 3-dimensional reconstruction of the rhabdosphincter and urethra: initial experience in continent and incontinent women.

OBJECTIVE: The purpose of this study was to evaluate the female urethra and the striated urinary sphincter, the rhabdosphincter (RS), by means of dynamic transurethral sonography and sonographic 3-dimensional (3D) reconstructions. METHODS: In 15 female patients with urinary stress incontinence (mean age, 67.5 years) and 5 continent women (mean age, 48.3 years), morphologic characteristics and function of the RS and urethra were examined with a 10-MHz transurethral ultrasound transducer. With the help of a mechanical pullback system, the transducer was slowly retracted to scan the whole urethra and the RS from the bladder neck to the urethral orifice. Subsequently, 3D reconstructions of the urethra using an integrated computer system were performed. The RS as well as the length of the urethra were investigated under contracted and noncontracted conditions to measure contractility of the RS and dynamic changes of the lower urinary tract. RESULTS: Partial or complete loss of RS function was detected in patients with stress incontinence. The findings on sonography were found to correlate well with the grade of incontinence. Furthermore, under contraction of the RS, a median increase in urethral length was observed. In incontinent patients, the increase in the urethral length was statistically significantly less (P = .04), which was related to the reduced contractility of the RS. CONCLUSIONS: Dynamic transurethral sonography with subsequent 3D reconstructions allows for assessment of function and morphologic characteristics of the RS and urethra. Normal contraction of the RS results in an elongation of the urethra.     

Blockade of swelling-induced chloride channels by phenol derivatives.

1. In NIH3T3 fibroblasts, the chloride channel involved in regulatory volume decrease (RVD) was identified as ICln, a protein isolated from a cDNA library derived from Madin Darby canine Kidney (MDCK) cells. ICln expressed in Xenopus laevis oocytes gives rise to an outwardly rectifying chloride current, sensitive to the extracellular addition of nucleotides and the known chloride channel blockers, DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid) and NPPB (5-nitro-2-(3-phenylpropylamino)-benzoic acid). We set out to study whether substances structurally similar to NPPB are able to interfere with RVD. 2. RVD in NIH3T3 fibroblasts and MDCK cells is temperature-dependent. 3. RVD, the swelling-dependent chloride current and the depolarization seen after reducing extracellular osmolarity can be blocked by gossypol and NDGA (nordihydroguaiaretic acid), both structurally related to NPPB. 4. The cyclic AMP-dependent chloride current elicited in CaCo cells is less sensitive to the two substances tested while the calcium-activated chloride current in fibroblasts is insensitive. 5. The binding site for the two phenol derivatives onto ICln seems to be distinct but closely related to the nucleotide binding site identified as G x G x G, a glycine repeat located at the predicted outer mouth of the ICln channel protein.     

Plain abdominal radiography with transabdominal native tissue harmonic imaging ultrasonography vs unenhanced computed tomography in renal colic

OBJECTIVE: To compare plain film kidney, ureter and bladder radiography (KUB) with transabdominal native tissue harmonic imaging ultrasonography (NTHI-US) vs unenhanced computed tomography (CT) for the diagnosis of urinary calculi in patients with acute flank pain. PATIENTS AND METHODS: In all, 112 patients who presented to the urological department with clinical suspicion of ureteric calculi were included. These patients had KUB with NTHI-US and unenhanced CT. Of the 112 patients, 14 were lost to follow-up and therefore excluded. For the remaining 98 patients (53 men, 45 women; mean age 43.3 years, range: 19-74) the KUB with NTHI-US findings were compared with the CT findings, which served as the 'gold standard'. RESULTS: In all, 75 patients were confirmed to have ureteric calculi. KUB with transabdominal NTHI-US detected 72 of the 75 patients with calculi (sensitivity 96%, specificity 91%, and accuracy 95%). Unenhanced CT detected urolithiasis in all 75 patients (sensitivity, specificity and accuracy of 100%). Both techniques showed further extra-urinary pathologies. CONCLUSION: This prospective study shows that CT is the most accurate technique for detecting urolithiasis. However, KUB with transabdominal NTHI-US is an alternative to unenhanced CT with comparable results.     

Real-time elastography for detecting prostate cancer: preliminary experience

OBJECTIVE: To assess the use of real-time elastography (RTE) for detecting prostate cancer in patients scheduled for radical prostatectomy (RP), as most solid tumours differ in their consistency from the deriving tissue, and RTE might offer a new tool for cancer detection. PATIENTS AND METHODS: We examined 15 patients (mean age 56 years, sd 6.2, range 46-71) with RTE, using an ultrasonography (US) system with a 7.5-MHz transrectal probe as a transducer. RTE is capable of visualizing displacements between pairs of US images of tissues when placed under axial compression. The stiffness of the lesion was displayed from blue (soft) to black (hard). Hard lesions with a diameter of > or = 5 mm were considered as malignant. All patients had the diagnosis of prostate cancer confirmed by biopsy and had a mean (range) prostate specific antigen (PSA) level of 4.6 (1.4-16.1) ng/mL; all were scheduled for RP. US was performed by two investigators and interpreted by consensus. Cancer location and size was determined in the RTE mode only. One pathologist classified tumour location, grade and stage. The RTE findings were compared with the pathological findings. RESULTS: There were no major complications during RP in any patient; all had a pT2 tumour on histopathological examination, the Gleason score was 5-9 and the mean (range) tumour size 1.1 (0.6-2.5) cm. Thirty-five foci of prostate cancer were present at the pathological evaluation; multiple foci were found in 11 of the 15 glands. RTE detected 28 of 35 cancer foci (sensitivity 80%). The per-patient analysis showed that RTE detected at least one cancer area in each of the 15 patients. Only four sites with false-positive findings on RTE and no histopathological correlation were detected; these findings were obtained in the first five patients (period of learning). CONCLUSIONS: RTE can be used to visualize differences in tissue elasticity. Our results show that RTE allows the detection of prostate cancer and estimation of tumour location and size. RTE of the prostate is a new imaging method with great potential for detecting prostate cancer.     

What are the supportive structures of the female urethra?

AIMS: Female stress urinary incontinence is thought to result from impairment of the connective tissue "ligaments" of the urethra. Surgical repair of female incontinence mainly involves fixation of the urethra to the pubic bone or other surrounding structures. In the present anatomical-radiological study, the anatomy of the connective tissue structures around the female urethra was investigated to determine the anatomical structures that support the urethra and the rhabdosphincter. MATERIALS AND METHODS: The topography of the anterior compartment of the female pelvis was studied in serial sections and one anatomical preparation of 30 female fetuses and of six adult females. The pelves of 29 female fetuses were processed according to plastination histology technique. The pelves of the six adult specimens were processed according to sheet plastination technique. In addition, the anatomical findings were compared with MR images of 41 adult female volunteers. RESULTS: The ventro-lateral aspect of the urethra remains free of fixating ligaments throughout its pelvic course. Ventro-laterally the urethra is enclosed by the ventral parts of the levator ani, its fasciae and a ventral urethral connective tissue bridge connecting both sides. Dorsally, the urethra is intimately connected to the wall of the vagina. CONCLUSIONS: The female urethra has no direct ligamentous fixation to the pubic bone. Urethral continence after pregnancy and childbirth may be explained by a widening of the hiatus of the levator ani or the anterior vaginal wall, resulting in overstretching of the ventral urethral connective tissue bridge or the disruption of the fixation between urethra and vagina.     

Urinary acetonitrile concentrations correlate with recent smoking behaviour

OBJECTIVES: To assess the concentration of acetonitrile (a saturated aliphatic nitrile) in the urine of habitual cigarette smokers and non-smokers, as exposure to smoke can be measured by monitoring ambient air or by in vivo tests, but acetonitrile measured in exhaled breath is reportedly a quantitative marker of recent smoking behaviour. SUBJECTS AND METHODS: The study included 101 volunteers (57 men and 44 women, mean age 49 years). An absence of urinary tract infection on urine analysis or clinical history was mandatory. The subjects were classified into five groups, i.e. a control group of non-smokers and four groups according to the number of cigarettes smoked daily. Urine samples were stored at 8 degrees C until acetonitrile was measured, within 24 h of collection, using proton-transfer reaction mass spectrometry (PTR-MS). Each measurement was repeated at least 10 times, and the mean used for statistical analysis. RESULTS: The mean (sd) acetonitrile level in the urine of 46 non-smokers was 3.74 (1.78) parts per billion volatile (ppbv). The concentration of acetonitrile increased with the number of cigarettes smoked daily, the highest concentration being in the subgroup of 13 very heavy smokers (>30 cigarettes/day) with means up to 28.04 (5.38) ppbv. CONCLUSION: PTR-MS is a quick, noninvasive online method for determining urinary acetonitrile levels, a marker for recent active and passive smoking behaviour, and thus for checking compliance. As smoking has been shown to affect the genesis of bladder cancer, further studies are required to determine the association of acetonitrile with bladder cancer.     

Power Doppler ultrasound imaging for quantification of urinary bladder neck blood flow changes

This study was designed to evaluate power Doppler imaging for assessment of urinary bladder neck blood flow in comparison with laser Doppler flowmetry (LDF) in an animal model. Transrectal power Doppler ultrasound (US) and LDF of the urinary bladder neck were performed in three anesthetized pigs during comparative cystometry. Normal saline (NaCl) was used for the first run, followed by a second run with 0.2 mol/L potassium chloride (KCl). Standardized sonographic equipment settings (Acuson Sequoia 512); MountainView, CA) were used for power Doppler imaging. Computer-assisted calculation of color pixel density (CPD) of power Doppler images was performed using Scion Image) software image analysis. Tissue perfusion units (TPU) were measured using a BLF21 laser Doppler flowmeter (Transonic Systems Inc., Ithaca, NY, USA). The power Doppler results were compared with the findings obtained by LDF. NaCl filling resulted in a mean CPD increase at the bladder neck from 18.65 (+/- 1.78) at empty bladder to 37.8 (+/- 1.84) at 100 mL and to 88.32 (+/- 1.35) at full bladder capacity (C(max)) of 270 mL, respectively. With KCl filling, a mean CPD increase from 18.65 (+/- 1.78) to 59.63 (+/- 0.5) at 100 mL and 110.82 (+/- 2.98) at full bladder capacity (270 mL) was observed. The CPD increase was significantly higher for KCl than with NaCl (p < 0.001). With NaCl filling, bladder neck blood flow increased from 22 TPU (empty) to 46 TPU (100 mL) and 62.5 TPU at C(max), compared to 22 TPU, 50 TPU and 102.5 TPU with KCl. CPD and TPU measurements showed a strong correlation at p = 0.01. In conclusion, transrectal power Doppler US image quantification is a feasible and accurate method for assessing blood flow changes in the urinary bladder neck.