Neobladder reconstruction following radical cystoprostatectomy for invasive bladder cancer.

A survey on neobladder reconstruction after radical cystectomy due to invasive bladder cancer is presented. Stress is laid on the selection patients, factors affecting the choice of urinary diversion, contraindications for neobladder, oncological factors influencing selection of neobladder, continence, complications and other factors which may affect a favourable outcome.

Perception and neuronal coding of subjective contours in the owl.

Robust form perception and underlying neuronal mechanisms require generalized representation of object boundaries, independent of how they are defined. One visual ability essential for form perception is reconstruction of contours absent from the retinal image. Here we show that barn owls perceive subjective contours defined by grating gaps and phase-shifted abutting gratings. Moreover, single-neuron recordings from visual forebrain (visual Wulst) of awake, behaving birds revealed a high proportion of neurons signaling such subjective contours, independent of local stimulus attributes. These data suggest that the visual Wulst is important in contour-based form perception and exhibits a functional complexity analogous to mammalian extrastriate cortex.

Presentation and outcome following radical cystectomy in Hispanics with bladder cancer.

OBJECTIVE: Significant racial and ethnic differences in the epidemiology of bladder cancer (BC) exist. Studies have shown African Americans to have lower incidence of bladder cancer than Caucasians, but higher incidence of invasive BC. Hispanics are the largest minority group in the United States. However, no reported studies on bladder cancer among Hispanics are available to date. As our center is in a unique position to study BC in Hispanic patients we were prompted to assess presentation and outcome of patients undergoing radical cystectomy (RC) for BC. MATERIALS AND METHODS: Between January 1992 and May 2006, 448 RC were performed. All relevant data were collected and entered into a database. Patients were categorized by ethnicity as Hispanic and non-Hispanic White. African-American and other minority groups were excluded because of the small number. Comparative analysis of Hispanic and non-Hispanic White patients was performed. RESULTS: 67 (17%) patients were Hispanic. Mean follow-up period was 41 (SD +/- 40) months. Clinical and pathological data between these two groups were compared. Pre-cystectomy T stage was not significantly different between both groups. However, after RC incidence of < or = T1 disease in Hispanics was lower (22%) than Caucasians (37%). This difference, statistically significant (P = 0.024) indicates that Hispanics who undergo RC present with higher stage disease. Kaplan-Meier log rank test indicated a difference in disease free survival and disease specific survival between the two groups but however it did not reach statistical significance (Log Rank P = 0.082, P = 0.063). No significant difference in overall survival was observed (P = 0.465). CONCLUSIONS: Hispanic patients managed with RC for bladder carcinoma present with higher stage disease.

Hemospermia following transrectal ultrasound-guided prostate biopsy: a prospective study.

Hemospermia is known to be associated with transrectal ultrasound-guided prostate biopsy (TRUS-PB). The true incidence of hemospermia, its duration and implications are not well established. We performed a prospective observational study involving patients undergoing TRUS-PB for suspected prostate cancer at our institution. Sixty-three eligible men were included in the study. Most men (84%) undergoing TRUS-PB, who were able to ejaculate, experienced hemospermia, which was associated with some degree of anxiety. The mean duration of hemospermia was 3.5 (+/-1.7) weeks. The number of ejaculations before the complete resolution of hemospermia was 8 (+/-6.7). None of the clinical and pathological factors was a significant predictor of the duration of hemospermia. Patients should be adequately counseled before TRUS-PB to avoid undue anxiety and alterations in sexual activity.

A random-matrix theory of the number sense.

Number sense, a spontaneous ability to process approximate numbers, has been documented in human adults, infants and newborns, and many other animals. Species as distant as monkeys and crows exhibit very similar neurons tuned to specific numerosities. How number sense can emerge in the absence of learning or fine tuning is currently unknown. We introduce a random-matrix theory of self-organized neural states where numbers are coded by vectors of activation across multiple units, and where the vector codes for successive integers are obtained through multiplication by a fixed but random matrix. This cortical implementation of the 'von Mises' algorithm explains many otherwise disconnected observations ranging from neural tuning curves in monkeys to looking times in neonates and cortical numerotopy in adults. The theory clarifies the origin of Weber-Fechner's Law and yields a novel and empirically validated prediction of multi-peak number neurons. Random matrices constitute a novel mechanism for the emergence of brain states coding for quantity.This article is part of a discussion meeting issue 'The origins of numerical abilities'.

Hierarchical processing of horizontal disparity information in the visual forebrain of behaving owls.

According to their restricted receptive fields and input-filter characteristics, disparity-sensitive neurons at early processing levels of the visual system perform rather ambiguous computations; they respond vigorously to disparity in false-matched images and show multiple response peaks in their disparity-tuning profiles. On the other hand, the perception of depth from binocular disparity is reliable, thus raising the question as to where and how in the brain additional processing is accomplished leading toward behaviorally relevant disparity detection. To address this issue, tuning data during stimulation with correlated and anticorrelated random-dot stereograms (a-RDS) were obtained from 52 disparity-sensitive visual Wulst neurons in three behaving owls. From the disparity-tuning curves, several quantitative measures were derived that allowed to determine the response ambiguity of a cell. A systematic decline of response ambiguities with increasing response latencies was observed. An increase in response latencies of neurons was correlated with a decrease of the strength of responses to a-RDS. Declining responses to a-RDS are expected for global detectors, because an owl was not able to discriminate depth in psychophysical tests with a-RDS. In addition, suppression of response side peaks was increased and disparity tuning was enhanced with growing response latencies. These results suggest a functional hierarchy of disparity processing in the owl's forebrain, leading from spatial filters to more global disparity detectors that may be able to solve the correspondence problem. Nonlinear threshold operations and inhibition are proposed as candidate mechanisms to resolve coding ambiguities.

A sensorineural progressive autosomal recessive form of isolated deafness, DFNB13, maps to chromosome 7q34-q36.

Deafness is the most frequent sensorineural defect in children. The vast majority of the prelingual forms of isolated deafness are highly genetically heterogeneous with an autosomal recessive mode of inheritance. Using linkage analysis, we have mapped the gene responsible for a severe progressive sensorineural hearing loss, DFNB13, segregating in a large consanguineous family living in an isolated region in northern Lebanon. A maximum lod score of 4.5 was detected for markers D7S661-D7S498. Recombination events and homozygosity mapping by descent define a 17 cM gene interval in the chromosome region 7q34-q36, between the markers D7S2468/D7S2505, on the proximal side, and D7S2439, on the distal side.

Release from masking in fluctuating background noise in a songbird's auditory forebrain.

Fluctuations in the ubiquitous masking background noise can be exploited by the vertebrate auditory system to considerably improve signal detection. Here we demonstrate neuronal masking release in amplitude-modulated background noise on the level of the European starling's auditory forebrain, an area that is the analogue of the mammalian primary auditory cortex. Tone-evoked responses in the presence of modulated and unmodulated maskers were recorded in unrestrained birds via radiotelemetry. Based on a rate code, the average amount of neuronal masking release was similar to that observed in a psychoacoustic study on the starling with stimuli confined to a single auditory filter. The results suggest that the neurons exploited predominantly temporal features of the acoustic background to improve signal detection.

Miniature stereo radio transmitter for simultaneous recording of multiple single-neuron signals from behaving owls.

Wireless radiotelemetric transmission of neuronal activity is an elegant technique to study brain-behavior interaction in unrestrained animals. In the current study, a miniature FM-stereo radio transmitter is described that permitted simultaneous recordings from two microelectrodes in behaving barn owls. Input from two independent channels is multiplexed to form a stereo composite signal that modulates a radio frequency carrier. The high quality of broadcasted extracellular signals enabled separation of single units based on differences in spike waveforms. Recording several single cells from different electrodes allows the possibility of investigating correlations between small, distributed neuronal ensembles. Multi-channel radiotelemetry that meets the demands of modern electrophysiology might open a new perspective for combined behavioral/neurophysiological approaches in freely-behaving animals.

Effect of terazosin on prostatism in men with normal and abnormal peak urinary flow rates.

OBJECTIVES: To determine if men with normal peak urinary flow rates (PFR) and prostatism respond to terazosin. METHODS: Forty-one men over the age of 50 years with an American Urological Association (AUA) symptom score greater than 8, postvoid residual urine volume (PVR) less than 300 mL, and no clinical or biochemical evidence of prostate cancer were treated with terazosin independent of the baseline PFR. The effect of terazosin on the AUA symptom score and PFR were compared for subjects with a PFR of 15 mL/s or less (group I) and those with a PFR greater than 15 mL/s (group II). RESULTS: The baseline age, AUA symptom score, prostate volume, and PVR were not significantly different between the two groups. The mean changes in AUA symptom score were -45.0% and -49.5% for groups I and II, respectively. The mean changes in PFR were 7.0% and -26.6% for groups I and II, respectively. CONCLUSIONS: The effect of terazosin on AUA symptom score is independent of baseline PFR, indicating that the mechanism of action of terazosin is not exclusively mediated by reduction of bladder outlet obstruction. Randomized controlled studies are required to confirm this provocative observation.

Adjustable frequency selectivity of auditory forebrain neurons recorded in a freely moving songbird via radiotelemetry.

One of the hearing system's basic properties that determines the detection of signals is its frequency selectivity. In the natural environment, a songbird may achieve an improved detection ability if the neuronal filters of its auditory system could be sharpened to adapt to the spectrum of the background noise. To address this issue, we studied 35 multi-unit clusters in the input layer of the primary auditory forebrain of nine European starlings (Sturnus vulgaris). Microelectrodes were chronically implanted in this songbird's cortex analogue and the neuronal activity was transmitted from unrestrained birds via a miniature FM transmitter. Frequency tuning curves (FTCs) and inhibitory sidebands were determined by presenting a matrix of frequency-level combinations of pure tones. From each FTC, the characteristic frequency (CF) and several parameters describing the neurons' filter characteristics were derived and compared to the same recording site's filter function while simultaneously stimulating with a continuous CF tone 20 dB above the response threshold. Our results show a significant improvement of frequency selectivity during two-tone stimulation, indicating that spectral filtering in the starling's auditory forebrain depends on the acoustic background in which a signal is presented. Moreover, frequency selectivity was found to be a function of the time over which the stimulus persisted, since FTCs were much sharper and inhibitory sidebands were largely expanded several milliseconds after response onset. Neuronal filter bandwidths during two-tone stimulation in the auditory forebrain are in good agreement with psychoacoustically measured critical bandwidths in the same species. Radiotelemetry proved to be a powerful tool in studying neuronal activity in freely behaving birds.

Modified Pfannenstiel approach for radical retropubic prostatectomy: a 3-year experience.

A modified Pfannenstiel approach for radical retropubic prostatectomy (RRP) has been described previously. We present our experience with this approach for performing a RRP over the past 3 years. Between January 2003 and July 2006, 544 consecutive RRPs by modified Pfannenstiel approach between January 2003 and July 2006 were performed. We analyzed blood loss, transfusions, use of drain, pain score, analgesia and hospital stay. Patients were followed up at 6 weeks, three monthly for a year and six monthly thereafter. All clinical and operative variables were entered into a database and analyzed. A total of 544 men underwent RRP with median follow-up of 11 (s.d.+/-10.5) months. The mean age was 60 (s.d.+/-7) years. About 83, 91 and 95% of patients had nerve sparing, bladder neck preservation and a lymph node dissection, respectively. Fifty-three patients had a concurrent inguinal hernia repair through the same incision. Mean estimated blood loss was 431 (s.d.+/-267) ml. The pathological staging distribution was T2, 82%; T3a, 9%; and T3b, 9%. The mean pain score at days 1 and 7 were 3.7 (s.d.+/-2.5) and 3.3 (s.d.+/-3), respectively. The median hospital stay was 36 h (s.d.+/-24). About 5.5% have had biochemical recurrence. At 12 months 97% were continent and 46% potent. RRP using a modified Pfannenstiel approach offers safety and efficacy. It facilitates repair of associated inguinal hernia through the same incision.

Seeing more than meets the eye: processing of illusory contours in animals.

This review article illustrates that mammals, birds and insects are able to perceive illusory contours. Illusory contours lack a physical counterpart, but monkeys, cats, owls and bees perceive them as if they were real borders. In all of these species, a neural correlate for such perceptual completion phenomena has been described. The robustness of neuronal responses and the abundance of cells argue that such neurons might indeed represent a neural correlate for illusory contour perception. The internal state of an animal subject (i.e., alert and behaving) seems to be an important factor when correlating neural activity with perceptual phenomena. The fact that the neural network necessary for illusory contour perception has been found in relatively early visual brain areas in all tested animals suggests that bottom-up processing is largely sufficient to explain such perceptual abilities. However, recent findings in monkeys indicate that feedback loops within the visual system may provide additional modulation. The detection of illusory contours by independently evolved visual systems argues that processing of edges in the absence of contrast gradients reflects fundamental visual constraints and not just an artifact of visual processing.

Horizontal-disparity tuning of neurons in the visual forebrain of the behaving barn owl.

Stereovision plays a major role in depth perception of animals having frontally-oriented eyes, most notably primates, cats, and owls. Neuronal mechanisms of disparity sensitivity have only been investigated in anesthetized owls so far. In the current study, responses of 160 visual Wulst neurons to static random-dot stereograms (RDS) were recorded via radiotelemetry in awake, fixating barn owls. The majority of neurons (76%) discharged significantly as a function of horizontal disparity in RDS. The distribution of preferred disparities mirrored the behaviorally relevant range of horizontal disparities that owls can exploit for depth vision. Most tuning profiles displayed periodic modulation and could well be fitted with a Gabor function as expected if disparity detectors were implemented according to the disparity energy model. Corresponding to this observation, a continuum of tuning profiles was observed rather than discrete categories. To assess a possible clustering of neurons with similar disparity-tuning properties, single units, and multi-unit activity recorded at individual recording sites were compared. Only a minority of neurons were clustered according to their disparity-tuning properties, suggesting that neurons in the visual Wulst are not organized into columns by preferred disparity. To assess whether variable vergence eye movements influenced tuning data, we correlated tuning peak positions on a trial-by-trial basis for units that were recorded simultaneously. The general lack of significant correlation between single-trial peak positions of simultaneously recorded units indicated that vergence, if at all, had only a minor influence on the data. Our study emphasizes the significance of visual Wulst neurons in analyzing stereoscopic depth information and introduces the barn owl as a second model system to study stereopsis in awake, behaving animals.

Encoding of both vertical and horizontal disparity in random-dot stereograms by Wulst neurons of awake barn owls.

In binocular vision, the lateral displacement of the eyes gives rise to both horizontal and vertical disparities between the images projected onto the left and right retinae. While it is well known that horizontal disparity is exploited by the binocular visual system of birds and mammals to enable depth perception, the role of vertical disparity is still largely unclear. In this study, neuronal activity in the visual forebrain (visual Wulst) of behaving barn owls to vertical disparity was investigated. Single-unit responses to global random-dot stereograms (RDS) were recorded with chronically implanted electrodes and transmitted via radiotelemetry. Nearly half of the cells investigated (44%, 16/36) varied the discharge as a function of vertical disparity. Like horizontal-disparity tuning profiles, vertical-disparity tuning curves typically exhibited periodic modulation with side peaks flanking a prominent main peak, and thus, could be fitted well with a Gabor function. This indicates that tuning to vertical disparity was not caused by disrupting horizontal-disparity tuning via vertical stimulus offset, but by classical disparity detectors whose orientation tuning was tilted. When tested with horizontal in addition to vertical disparity, almost all cells investigated (92%, 12/13) were tuned to both kinds of disparity. The emergence of disparity detectors sensitive in two dimensions (horizontal and vertical) is discussed within the framework of the disparity energy model.

Signal detection in amplitude-modulated maskers. II. Processing in the songbird's auditory forebrain.

In the natural environment, acoustic signals have to be detected in ubiquitous background noise. Temporal fluctuations of background noise can be exploited by the auditory system to enhance signal detection, especially if spectral masking components are coherently amplitude modulated across several auditory channels (a phenomenon called 'comodulation masking release'). In this study of neuronal mechanisms of masking release in the primary auditory forebrain (field L) of awake European starlings (Sturnus vulgaris), we determined and compared neural detection thresholds for 20-ms probe tones presented in a background of sinusoidally amplitude modulated (10-Hz) noise maskers. Responses of a total of 34 multiunit clusters were recorded via radiotelemetry with chronically implanted microelectrodes from unrestrained birds. For maskers consisting of a single noise band centred around the recording site's characteristic frequency, a substantial reduction in detection threshold (21 dB on average) was found when probe tones were presented during envelope dips rather than during envelope peaks. Such effects could also explain results obtained for masking protocols where the on-frequency noise band was presented together with excitatory or inhibitory flanking bands that were either coherently modulated (in-phase) or incoherently modulated (phase-shifted). Generally, masking release for probe tones in maskers with flanking bands extending beyond the frequency range of a cell cluster's excitatory tuning curve was not substantially improved. Only some of the neurophysiological results are in agreement with behavioural data from the same species if only the average population response is considered. A subsample of individual neurons, however, could account for behavioural thresholds.

Time course of simultaneous masking in the starling's auditory forebrain.

Simultaneous masking of pure tones was studied in the primary auditory forebrain of a songbird species, the European starling (Sturnus vulgaris). The responses of 32 multi-unit clusters in the input layer of the auditory neostriatum (field L2a) were recorded via radiotelemetry from freely moving birds. The probe was a 10-ms tone burst at the units' characteristic-frequency (CF) presented 20 dB above the threshold. The masker was an 80-ms tone burst presented either at the units' CF (excitatory masker) or at a frequency located in inhibitory side-bands (inhibitory masker) of the units' tuning curves. The probe was presented either 3 ms or 63 ms after masker onset. Probes presented at a 3-ms delay were influenced at significantly lower levels of an excitatory masker than probes presented at a 63-ms delay. The mean difference in masker level at the detection thresholds for both probe delays was 8 dB. No difference in masker level was observed for inhibitory-frequency maskers. The observed neural masking effects may be explained by at least four mechanisms: (1) swamping of the probe response by the response to the masker, (2) a reduction of the probe response during neural adaptation of the response to the masker, (3) a reduction of the probe response during side-band inhibition in the central nervous system, and (4) suppression originating in the cochlea.

Intraoperative and postoperative complications of radical retropubic prostatectomy in a consecutive series of 1,000 cases.

PURPOSE: We critically examined the intraoperative and postoperative complications associated with radical retropubic prostatectomy in the modern era. MATERIALS AND METHODS: Between April 18, 1994 and July 13, 2000, 1,000 men underwent radical retropubic prostatectomy performed by a single surgeon. The whole inpatient hospital medical record of 909 patients, the outpatient charts of 955 and a self-administered patient survey completed by 679 were reviewed by 2 data managers not involved in surgical management or followup care. In all 1,000 cases at least 1 of the 3 data sources was reviewed. RESULTS: Mean patient age was 60.3 years. In 73%, 99.8% and 95.7% of cases serum prostate specific antigen was 10 ng./ml. or less, disease was clinical stage T1 or T2 and Gleason score was 7 or less, respectively, while 19.9% of pathological specimens showed positive margins. There were 8 intraoperative complications (0.8%). All 5 rectal injuries and the single ureteral injury were detected during the initial surgical procedure and repaired without sequelae. Only 14 men (1.4%) had any other complications during hospitalization. Until postoperative day 30, 4 pulmonary emboli (0.4%) with or without deep vein thrombosis and 5 myocardial infarctions (0.5%) developed. There were no intraoperative or in-hospital postoperative deaths and only 1 postoperative death secondary to myocardial infarction during the initial 30 days. Reexploration was done for hemorrhage and a disrupted anastomosis in 3 and 2 cases, respectively. Mean hospitalization was 2.3 days, 9.7% of patients required allogenic blood transfusion and 15 (1.5%) were rehospitalized. CONCLUSIONS: Our series represents a rigorous assessment of the complications associated with radical retropubic prostatectomy. It shows that in the hands of an experienced urological surgeon, this procedure is associated with minimal intraoperative and postoperative morbidity. Of the patients 98% had no intraoperative or postoperative complications. Our series enables appropriate contemporary comparisons to be made with laparoscopic prostatectomy and radiation therapy. This outcomes analysis implies that radical retropubic prostatectomy cannot be assumed to have greater morbidity than radiation therapy and it sets a high standard for those advocating laparoscopic radical prostatectomy.

Comparison of two different doses of preoperative recombinant erythropoietin in men undergoing radical retropubic prostatectomy.

OBJECTIVES: To determine whether the response to recombinant erythropoietin is dose dependent in men undergoing radical prostatectomy and to elucidate the relative cost-effectiveness of two dosing regimens. METHODS: A prospective, open-label study comparing the effectiveness, cost, and safety of two different doses of recombinant erythropoietin was performed in men undergoing radical retropubic prostatectomy. The first 100 men received 600 IU/kg (high dose) of epoetin alfa. A second group of 100 men received 300 IU/kg (low dose). All men received two doses of erythropoietin on preoperative days 14 and 7, provided their baseline hematocrit levels were less than 48%. Hematocrit levels were measured at baseline (more than 14 days before surgery), at the time of anesthesia induction, in the recovery room postoperatively, on the first postoperative day, and on the morning of discharge. RESULTS: The mean increase in hematocrit from baseline to induction for the high and low-dose groups was 4.50 and 4.69, respectively (P = 0.7225). Six men (6%) in the high-dose group and seven (7%) in the low-dose group required allogenic blood transfusions. The mean cost of high and low-dose epoetin alfa was $1218 and $656, respectively. The cost per percentage point increase in hematocrit in the low-dose group was significantly less than in the high-dose group. No thromboembolic events occurred in the high or low-dose group. CONCLUSIONS: In men undergoing radical retropubic prostatectomy, the administration of epoetin alfa on preoperative days 14 and 7 was a safe and effective treatment strategy for reducing the risk of allogenic blood transfusions. The 300 IU/kg dosing regimen was significantly more cost effective than the 600 IU/kg dosing regimen.

Early removal of urinary catheter after radical retropubic prostatectomy is both feasible and desirable.

OBJECTIVES: To determine the feasibility and desirability of removing the urinary catheter 7 days after radical retropubic prostatectomy. METHODS: Between February 28, 2000 and October 5, 2000, 184 men underwent radical retropubic prostatectomy by a single surgeon. Of these men, 97% underwent gravity cystography under fluoroscopic control on postoperative day (POD) 7. The indwelling urinary catheter was removed on POD 7 if no evidence of extravasation was observed on cystography. Patients completed a self-administered questionnaire at the time of catheter removal to capture the degree of bother from incisional pain and the indwelling urinary catheter during the recovery period. The level of urinary continence was determined at 3 months after radical retropubic prostatectomy. RESULTS: One hundred thirty-five of the cystograms (75%) had no evidence of extravasation. The indwelling catheters were removed in 130 (97%) of 135 cases. The body weight, surgical specimen weight, presence or absence of intraoperative anastomotic extravasation, volume of pelvic drainage recorded from the Hemovac drain, and creatinine level of the pelvic drainage fluids did not predict the finding of extravasation on the POD 7 cystogram. Fifteen percent of the men whose catheters were removed on POD 7 developed acute urinary retention. At 3 months, 72% of men required no or a single protective pad, and 87% indicated they experienced no or slight bother from incontinence. These continence outcomes are comparable with a historical control group by the same surgeon who underwent catheter removal on POD 14. Forty-five percent of the men reported the catheter caused moderate to severe bother, compared with only 19% of men who indicated moderate to severe bother from incisional pain. In retrospect, 95.6% of men indicated willingness to undergo cystography on POD 7 with the intent of early catheter removal. CONCLUSIONS: The results of our study suggest that most men will have no extravasation on a cystogram performed on POD 7 and that removing the catheter at this time in these cases does not increase the risk of complications or compromise overall urinary continence. The urinary catheter is a significant bother and limits physical activity during the postoperative period. Cystography and early removal of the catheter is both feasible and desirable and should be offered to men after radical retropubic prostatectomy.