bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Modern Pacing Algorithms on Generator Longevity:
Authors: GELVAN DAN , CRYSTAL EUGENE , DOKUMACI BARBAROS , GOLDSHMID YUVAL , OVSYSHCHER I. ELI
Published: August 2003

Pulse generator (PG) longevity is of major importance to the quality of care of pacemaker patients. A series of automatic algorithms affect PG longevity. This study investigated the individual and combined effects of three algorithms incorporated in the Medtronic Kappa 700 pacemaker series: Capture Management periodically measures the stimulation threshold and adjusts the PG output, Sinus Preference allows the sinus rate to prevail in a specified range below the sensor rate, and Search AV allows an extension of the AV interval if spontaneous conduction is observed. The effects of Capture Management, Sinus Preference, and Search AV on device longevity were studied in 21 consecutive patients treated in the VDD and DDDR modes. Patients were followed for 1 year. The data were analyzed using an equation provided by the manufacturer. Capture Management was activated in 20 patients. For 11 PGs at the basic settings, longevity was extended by 5.2%, whereas reprogrammed PGs had no gain. Sinus Preference was active in four DDDR patients, who gained

12.0 ± 5.3%

atrial sensing from it, with a resultant longevity gain of

1.4 ± 0.45 months

(NS). Search AV was active in 19 patients and 8 responders gained

7.8 ± 4.4 months

PG longevity. The overall longevity in this study was

106.3 ± 8.4 months

with all features as programmed, whereas the longevity without Capture Management and Search AV algorithms would be

98.2 ± 4.9 months

, saving

8.1 ± 5.8 months

(range 0–18) of battery life. Thus, two algorithms: Capture Management and Search AV, have clinical relevance in the extension of PG longevity. (PACE 2003; 26:1796–1802)
Clinical Predictors and Time Course of Arrhythmia Recurrence in Patients with Early Reinitiation of Atrial Fibrillation After Successful Internal Cardioversion
Authors: TSE HUNG‐FAT , LAU CHU PAK
Published: August 2003

Early reinitiation of atrial fibrillation (ERAF) was commonly observed after successful electrical cardioversion, however, the effect of ERAF on the subsequent time course of arrhythmia recurrence remains unclear. The aim of this study was to evaluate the clinical predictors and time course of AF recurrence with respect to the occurrence of ERAF after successful cardioversion. The clinical predictors and time course of AF recurrence were prospectively evaluated in 124 patients (94 men, 30 women; mean age

65 ± 9 years

) with persistent AF (mean AF duration

36 ± 40 months

), who underwent internal cardioversion. After cardioversion, all patients received treatment with sotalol and were monitored for AF recurrence. Successful restoration of sinus rhythm was achieved in 104 (84%) of 124 patients. ERAF was observed in 28 (27%) of 104 patients in whom 26 of them were successfully treated acutely with intravenous sotalol and repeated cardioversion. After a mean follow‐up of 26 months, 29 (28%) of 104 patients remained in sinus rhythm. Kaplan‐Meier analysis revealed a significantly poorer outcome with regard to the recurrence of AF in patients with ERAF (hazard ratio 1.7,

P = 0.03

) and in those with AF for more than 3 years (hazard ratio 1.6,

P = 0.03

). Despite treatment with sotalol, patients with ERAF had a significantly higher AF recurrence rate within the first day (13/26 [50%] vs 12/76 [16%],

P < 0.01

), but not during long‐term follow‐up (21/26 [81%] vs 52/76 [68%],

P = 0.3

). In contrast, patients with AF for more than 3 years had a similar AF recurrence rate within the first day (7/29 [24%] vs 18/73 [25%],

P = 1.0

), but a significantly higher recurrence rate during long‐term follow‐up (27/29 [93%] vs 46/73 [37%],

P < 0.01

). In conclusion, the occurrence of ERAF and long AF duration were independent predictors for AF recurrence after successful internal cardioversion. The difference in the time course of AF recurrence in patients with ERAF from those with long AF duration suggests distinct arrhythmogenic mechanisms. (PACE 2003; 26:1809–1814)
Adaptive Pacing During Ventricular Fibrillation
Authors: JOHNSON PHILIP L. , NEWTON JONATHAN C. , ROLLINS DENNIS L. , SMITH WILLIAM M. , IDEKER RAYMOND E.
Published: August 2003

While it has been shown that pacing during ventricular fibrillation (VF) can capture a portion of the epicardium, little is known about the characteristics of the area captured or about whether adaptively changing the pacing rate during VF will increase the area captured. In six open‐chested pigs, pacing during VF was performed from the center of a plaque containing 504 electrodes 2 mm apart in a

21 × 24

array on the anterior right ventricle. Simultaneous recordings from the 504 electrodes were used to construct activation maps from which the area of epicardium captured by pacing was determined. Four pacing algorithms were examined: (1) fixed rate pacing at 95% of the median VF activation rate, (2 and 3) adaptive pacing in which the pacing timing and/or rate is reset in real time if capture is not obtained, and (4) pacing at a slowly increasing rate after initial capture. Regional capture, defined as control of the myocardium under at least 10 plaque electrodes, was achieved in 71% (92/129) of pacing episodes. The incidence of capture was not significantly different for pacing algorithms 1–3. The maximum area captured for each pacing episode with algorithms 1–3 was

3.8 ± 2.0  cm2

(mean ± SD). Within each animal, the pattern of capture was similar among all pacing episodes, no matter which algorithm was used

r = 0.85 ± 0.25

). The region of greatest capture extended away from the pacing site along the long axis of the myocardial fibers. However, the area of captured epicardium toward the right ventricular side of the pacing electrode was 9.7 times greater than toward the left ventricular side. This principal direction toward the right ventricular side of the pacing electrode was the same direction traveled by the majority of VF activation fronts before capture occurred. The absence of recorded activations at the pacing site for 20 consecutive stimuli predicted 83% of the time that regional capture was present. With algorithm 4, the pacing rate could be increased

7.1%± 4.3%

while maintaining capture; however, the area of capture progressively decreased as the pacing rate increased. While pacing from the anterior right ventricular epicardium during VF, the area of capture is repeatable and is markedly asymmetrical with almost 10 times as much epicardium captured on the side of the pacing electrode closest to the acute margin of the right ventricle as on the opposite side. This marked asymmetry is associated both with myofiber orientation and with the direction of spread of activation and hence the direction of dispersion of refractoriness during VF just before pacing is initiated. It is possible to perform adaptive pacing algorithms in real time during VF; however, the two adaptive algorithms tested did not capture significantly more epicardium than a simple fixed‐rate pacing algorithm. Although it is possible to maintain capture while increasing the pacing rate during VF, the area of capture decreases. (PACE 2003; 26:1824–1836)
Diagnostic Yield of External Electrocardiographic Loop Recorders in Patients with Recurrent Syncope and Negative Tilt Table Test
Authors: SCHUCHERT ANDREAS , MAAS RENKE , KRETZSCHMAR CHRISTINA , BEHRENS GINA , KRATZMANN INGRID , MEINERTZ THOMAS
Published: August 2003

External electrocardiographic loop recording permits extended cardiac rhythm monitoring and ECG storage before and after device activation. The purpose of the study was to assess the diagnostic yield of external loop recorders in patients with more than two syncopal events within the last 6 months and a negative tilt table test. Twenty‐four consecutive patients (51 ± 14 years, male n = 9) were enrolled with 3 ± 4 recurrent syncopal events within the last 6 months and no overt structural heart disease. The loop recorder CardioCall continuously records a two‐channel ECG via skin electrodes. When activated, up to 4.5 minutes of the ECG preceding activation is stored. The time between tilt table testing and monitoring was 5 ± 4 weeks. The average monitoring period covered 50 ± 22 days. Recording was either unsuccessful or terminated prematurely in 5 patients. The reasons were skin irritation secondary to the electrodes in two patients, cable damage in one patient, and two patients inadvertently erased the stored data when replacing the batteries. Fourteen patients activated the loop recorder at least once. Symptoms leading to device activation were syncope (n = 1), dizziness (n = 11), feeling unwell (n = 7), palpitations (n = 5), headaches (n = 1), and chest pain (n = 1). The loop recorder documented sinus tachycardia during the syncopal event. Sinus tachycardia was also observed in 7 other patients, and atrial flutter in two patients. Eight patients had recurrent syncope with two patients experiencing syncope prior to the monitoring period, one syncope occurred in a patient who inadvertently erased the stored data, one event coincided with sinus tachycardia, and 4 (17%) patients had syncope during 15 ± 10 months after termination of loop monitoring. The external loop recorder was not very useful for arrhythmia detection in patients with syncopal events, no overt heart disease, and a negative tilt table test because the cardiac rhythm was stored in only 1 of 8 (13%) patients with recurrent syncope. Reasons for the low diagnostic yield of external loop recorders were infrequent syncopal events after the baseline evaluation, with rare events during the limited monitoring period in particular, and premature termination or unsuccessful recording in 21% of patients. (PACE 2003; 26:1837–1840)
Effect of Right Atrial Overdrive Pacing in the Prevention of Symptomatic Paroxysmal Atrial Fibrillation:
Authors: WIBERG STEFAN , LÖNNERHOLM STEFAN , JENSEN STEEN M. , BLOMSTRÖM PER , RINGQVIST IVAR , BLOMSTRÖM‐LUNDQVIST CARINA
Published: August 2003

The aim of this study was to assess if right atrial overdrive pacing can suppress symptomatic episodes of paroxysmal atrial fibrillation (PAF) in patients without bradyarrhythmias. Forty‐two patients with frequent and symptomatic PAF without other pacing indication had a pacemaker implanted after a 4‐week run‐in period, during which the frequency of symptomatic PAF episodes and the mean heart rate were objectively documented. Depending on the mean heart rate recorded during run‐in, the pacemaker was programmed in random order to right atrial AAI pacing at 10–19 beats/min > mean heart rate (medium overdrive [MO]), at 20–29 beats/min > mean heart rate (high overdrive [HO]) and to no pacing (OAO mode) for 4–12 weeks each using a crossover design. In the 35 patients who completed the protocol, the number of symptomatic episodes of PAF (>30‐second duration) per week was significantly lower during MO pacing (median 0.88, P = 0.001, n = 35) and during HO pacing (median 0.75, P = 0.002, n = 20) than during OAO (median 2.02 and 2.04, respectively). There was no difference between MO and HO pacing in the 20 patients paced at both rates (0.97 vs 0.75, P = 0.33). Seven patients did not complete the protocol due to persistent atrial fibrillation (n = 4), angina pectoris requiring surgery (n = 1), and unwillingness to continue the study due to improvement (n = 1) or worsening (n = 1) of symptoms during the study periods. Right atrial overdrive pacing can reduce the number of symptomatic PAF episodes in patients with frequent and drug refractory PAF but without bradyarrhythmias. (PACE 2003; 26:1841–1848)
Atrioventricular Nodal Reentry Tachycardia with Multiple AH Jumps:
Authors: KUO CHI‐TAI , LUQMAN NAZAR , LIN KUO‐HUNG , CHENG NYE‐JAN , HSU TSU‐SHIU , LEE YING‐SHIUNG
Published: August 2003

This article describes the additional use of incremental atrial burst pacing (A1A1) and double atrial extrastimulation with a predefined fast pathway conducted A2 (A1A2A3), rather than single atrial extrastimulation (A1A2) only, to characterize typical atrioventricular nodal reentrant tachycardia (AVNRT). The authors noted an additional 32% of patients had multiple anterograde AV nodal physiology demonstrated when A1A1 or A1A2A3 protocols were deployed compared to more conventional A1A2 protocols. The A2H2max (449 ± 147 vs 339 ± 94 ms) and A3H3max (481 ± 120 vs 389 ± 85 ms) were higher in 31 patients where multiple jumps in the AV nodal conduction curve were obtained (group 1) compared to 192 patients where only single jump was obtained (group 2) (both P < 0.01). Postablation, the degree of reduction of A2H2max (49%) and A3H3max (50%) in group 1 was greater than in group 2 (38% and 42%, respectively, P < 0.05). In seven of group 1 patients in whom A1A2A3 stimulation was required to reveal multiple jumps, the A2H2max remained unchanged after ablation (237 ± 89 vs 214 ± 59, P  > 0.05). A3H3max was the only parameter that shortened significantly after ablation. Generally, successful ablation resulted in loss of multiple discontinuities in A1A1/A1H1 or A2A3/A3H3 curves. In conclusion, a combination of A1A2, A1A1, and A1A2A3 are required to fully elucidate AVNRT. Significant shortening of AHmax or loss of multiple jumps after ablation indicates successful elimination of AVNRT in these patients. (PACE 2003; 26:1849–1855)
Atrial Electrogram Amplitude and Efficacy of Cavotricuspid Isthmus Ablation for Atrial Flutter
Authors: OZAYDIN MEHMET , TADA HIROSHI , CHUGH AMAN , SCHARF CHRISTOPH , LAI STEVE W.K. , PELOSI FRANK , KNIGHT BRADLEY P. , MORADY FRED , ORAL HAKAN
Published: August 2003

Large atrial electrogram amplitudes recorded in the cavotricuspid isthmus (CTI) may reflect thick atrial musculature. For this reason, in patients with atrial flutter, the efficacy of an application of conventional radiofrequency energy may be related to the amplitude of the local atrial electrogram. In 100 consecutive patients (mean age 59 ± 13 years) with atrial flutter, contiguous applications of radiofrequency energy were delivered in the CTI. The criterion for complete CTI block was the presence of widely split double potentials (>110 ms) along the entire ablation line during pacing from the coronary sinus and posterolateral right atrium. The atrial electrogram amplitude was measured before and after applications of radiofrequency energy at sites of gaps in the ablation line. Complete CTI block was achieved in 90 (90%) of the 100 patients. The mean atrial electrogram amplitudes at gap sites where an application of radiofrequency energy did and did not result in complete block were 0.36 ± 0.42 and 0.67 ± 0.62 mV, respectively (P < 0.01). The positive and negative predictive values (for complete block) of a ≥50% decrease in electrogram amplitude after an application of radiofrequency energy were 100% and 35%, respectively. The mean atrial electrogram amplitude is larger at CTI sites where complete isthmus block cannot be achieved with conventional radiofrequency energy. The efficacy of conventional radiofrequency ablation may be improved by identifying areas in the CTI where the voltage is relatively low. (PACE 2003; 26:1859–1863)
Effective Long‐Term Left Atrial Pacing Using Regular Screw‐In Leads Implanted Within the Coronary Sinus
Authors: OUALI SANA , ANSELME FRÉDÉRIC , HIDDEN FRANÇOISE , SAVOURÉ ARNAUD , CRIBIER ALAIN , SAOUDI NADIR , FRANK ROBERT
Published: August 2003

Passive‐fixation leads positioned inside the coronary sinus (CS) have been found to be effective in LA pacing and sensing, but their use is limited by a high incidence of early and late dislodgment. Since anatomic studies have shown that the proximal part of the CS is surrounded by a relatively thick musculature, the feasibility, safety, and efficacy of acute and chronic coronary sinus pacing via regular screw‐in leads positioned within the first centimeters of the CS were evaluated as compared to passive‐fixation leads. Thirty‐three patients (21 men, age 62 ± 10 years) underwent dual chamber pacemaker implantation with LA pacing obtained via passive‐fixation leads (7 patients) or regular screw‐in leads (26 patients). The former approach was prematurely abandoned because of a high rate of acute and late lead dislodgment (42%). The chronic pacing threshold was 1.7 ± 1.0 V at 0.67‐ms pulse width and 1.47 ± 1.3 V at 0.5‐ms pulse width for passive‐ and active‐fixation leads, respectively. In the CS active‐fixation lead group, no postoperative pericardial effusion, CS lead dislodgment, nor diaphragmatic stimulation were observed. In this last group, steroid eluting leads (14 patients) have a statistically lower pacing threshold than noneluting steroid leads (12 patients) (0.88 ± 0.23 vs 2.29 ± 1.68 V, P = 0.011) at long‐term follow‐up. The use of regular screw‐in leads implanted within the CS allows effective and safe long‐term LA pacing without risk of dislodgment. (PACE 2003; 26:1873–1877)
Fever and phenotype: transgenerational effect of disease on desert locust phase state
Authors: Elliot Sam L. , Blanford Simon , Horton Charlotte M. , Thomas Matthew B.
Published: August 2003

Natural enemy attack can cause transgenerational shifts in phenotype such that offspring are less vulnerable to future attack. Desert locusts (Schistocerca gregaria) show density‐dependent variation in their resistance to pathogens, such that they are less vulnerable to pathogens when in the high‐density gregarious phase state (when they would probably be more exposed to pathogens) than when in the solitarious phase state. We therefore hypothesized that infected gregarious parents would maintain this phenotype in their offspring. We infected gregarious desert locust nymphs with the fungal pathogen Metarhizium anisopliae var. acridum, and allowed them to survive to reproduction by means of behavioural fever. The phase state of the locust offspring was assessed by their colouration and behavioural assays. Contrary to our hypothesis, we found an increase in solitarization in the infected population (14.6% solitarious offspring from infected parents, vs. <2% from uninfected counterparts at equivalent density). In a second experiment, we simulated behavioural fever temperatures and obtained a similar result (13.6% solitarious offspring vs. 4.4% from controls), implying that the phenomenon is probably a side‐effect of the hosts’ fever response. Identification of this novel environmental factor affecting locust phase state could have important implications for the biological control of these major pests.
Keeping the herds healthy and alert: implications of predator control for infectious disease
Authors: Packer Craig , Holt Robert D. , Hudson Peter J. , Lafferty Kevin D. , Dobson Andrew P.
Published: August 2003

Predator control programmes are generally implemented in an attempt to increase prey population sizes. However, predator removal could prove harmful to prey populations that are regulated primarily by parasitic infections rather than by predation. We develop models for microparasitic and macroparasitic infection that specify the conditions where predator removal will (a) increase the incidence of parasitic infection, (b) reduce the number of healthy individuals in the prey population and (c) decrease the overall size of the prey population. In general, predator removal is more likely to be harmful when the parasite is highly virulent, macroparasites are highly aggregated in their prey, hosts are long‐lived and the predators select infected prey.
Present patterns and future prospects for biodiversity in the Western Hemisphere
Authors: Andelman Sandy J. , Willig Michael R.
Published: August 2003

Creating networks of nature reserves to protect areas rich in biodiversity from the adverse impacts of anthropogenic change is a critical and urgent task. We illustrate the skewed geographical and size distributions of protected areas in the Western Hemisphere. For instance, 811 of 1413 reserves in the Western Hemisphere are smaller than 10 km2, and 35% of the total area of these reserves is in Alaska. We compile ranges for all bats in the continental Western Hemisphere and find that 82% of threatened and small‐range species are not protected adequately. Many of the most vulnerable species occur in the areas of highest human density. We provide maps delineating areas where conservation investments may have the greatest impact in preventing biodiversity losses.
Reverse latitudinal trends in species richness of pitcher‐plant food webs
Authors: Buckley Hannah L. , Miller Thomas E. , Ellison Aaron M. , Gotelli Nicholas J.
Published: August 2003

Latitudinal patterns in species richness have been well documented for guilds and individual trophic groups, but comparable patterns for entire, multitrophic communities have not been described. We studied the entire food web that inhabits the water‐filled leaves of the pitcher plantSarracenia purpureaacross North America at two spatial scales: among sites and among leaves within sites. Contrary to the expectation, total species richness at both scales increased with latitude, because of increasing species richness at the lower trophic levels. This latitudinal pattern may be driven by a top‐down effect. The abundance of the mosquitoWyeomyia smithii, a ubiquitous top predator in this system, decreases from south to north and may permit greater species richness of prey trophic levels at higher latitudes.
Biodiversity and biocontrol: emergent impacts of a multi‐enemy assemblage on pest suppression and crop yield in an agroecosystem
Authors: Cardinale Bradley J. , Harvey Chad T. , Gross Kevin , Ives Anthony R.
Published: August 2003

The suppression of agricultural pests has often been proposed as an important service of natural enemy diversity, but few experiments have tested this assertion. In this study we present empirical evidence that increasing the richness of a particular guild of natural enemies can reduce the density of a widespread group of herbivorous pests and, in turn, increase the yield of an economically important crop. We performed an experiment in large field enclosures where we manipulated the presence/absence of three of the most important natural enemies (the coccinellid beetle Harmonia axyridis, the damsel bug Nabis sp., and the parasitic wasp Aphidius ervi) of pea aphids (Acyrthosiphon pisum) that feed on alfalfa (Medicago sativa). When all three enemy species were together, the population density of the pea aphid was suppressed more than could be predicted from the summed impact of each enemy species alone. As crop yield was negatively related to pea aphid density, there was a concomitant non‐additive increase in the production of alfalfa in enclosures containing the more diverse enemy guild. This trophic cascade appeared to be influenced by an indirect interaction involving a second herbivore inhabiting the system – the cowpea aphid, Aphis craccivora. Data suggest that high relative densities of cowpea aphids inhibited parasitism of pea aphids by the specialist parasitoid, A. ervi. Therefore, when natural enemies were together and densities of cowpea aphids were reduced by generalist predators, parasitism of pea aphids increased. This interaction modification is similar to other types of indirect interactions among enemy species (e.g. predator–predator facilitation) that can enhance the suppression of agricultural pests. Results of our study, and those of others performed in agroecosystems, complement the broader debate over how biodiversity influences ecosystem functioning by specifically focusing on systems that produce goods of immediate relevance to human society.
The evolutionary ecology ofPlasmodium
Authors: Paul R. E. L. , Ariey F. , Robert V.
Published: August 2003

Plasmodium, the aetiological agent of malaria, imposes a substantial public health burden on human society and one that is likely to deteriorate. Hitherto, the recent Darwinian medicine movement has promoted the important role evolutionary biology can play in issues of public health. Recasting the malaria parasite two‐host life cycle within an evolutionary framework has generated considerable insight into how the parasite has adapted to life within both vertebrate and insect hosts. Coupled with the rapid advances in the molecular basis to host–parasite interactions, exploration of the evolutionary ecology ofPlasmodiumwill enable identification of key steps in the life cycle and highlight fruitful avenues of research for developing malaria control strategies. In addition, elucidating the extent to whichPlasmodiumcan respond to short‐ and long‐term changes in selection pressures, i.e. its adaptive capacity, is even more crucial in predicting how the burden of malaria will alter with our rapidly evolving ecology.
Invasional ‘meltdown’ on an oceanic island
Authors: O'Dowd Dennis J. , Green Peter T. , Lake P. S.
Published: August 2003

Islands can serve as model systems for understanding how biological invasions affect community structure and ecosystem function. Here we show invasion by the alien crazy ant Anoplolepis gracilipes causes a rapid, catastrophic shift in the rain forest ecosystem of a tropical oceanic island, affecting at least three trophic levels. In invaded areas, crazy ants extirpate the red land crab, the dominant endemic consumer on the forest floor. In doing so, crazy ants indirectly release seedling recruitment, enhance species richness of seedlings, and slow litter breakdown. In the forest canopy, new associations between this invasive ant and honeydew‐secreting scale insects accelerate and diversify impacts. Sustained high densities of foraging ants on canopy trees result in high population densities of host‐generalist scale insects and growth of sooty moulds, leading to canopy dieback and even deaths of canopy trees. The indirect fallout from the displacement of a native ‘keystone’ species by an ant invader, itself abetted by introduced/cryptogenic mutualists, produces synergism in impacts to precipitate invasional ‘meltdown’ in this system.
The scaling of reproductive variability in trees
Authors: Kerkhoff Andrew J. , Ballantyne Ford
Published: August 2003

Seed output in perennial plant populations is temporally variable and often synchronous over large regions. The similarly complex spatiotemporal dynamics of animal populations have been characterized by the power‐law scaling of the variance in population numbers with mean abundance. Here we show that a large compilation of published reproductive time series exhibits largely invariant mean–variance scaling properties across both angiosperm and conifer tree species. A simple model of seed production in tree stands shows that observed values of the scaling exponent reflect very general aspects of plant ecology and life history as well as the temporal dynamics of seed production. Together, these results suggest that the continuum of reproductive variability and synchrony observed in trees may reflect the influence of a common set of ecological processes.
Cyclooxygenase‐2 promotes angiogenesis in pTa/T1 urothelial bladder carcinoma but does not predict recurrence
Authors: Friedrich M.G. , Toma M.I. , Petri S. , Huland H.
Published: August 2003

OBJECTIVE

To investigate the effect of cyclooxygenase‐2 (COX‐2) on microvessel density (MVD) and on the clinical prognosis in patients with non‐muscle invasive urothelial carcinoma of the bladder, as COX‐2 expression is significantly greater in epithelial tumours and there is increasing evidence that COX‐2 might contribute to tumour neovascularization.

PATIENTS AND METHODS

We assessed tumour samples from 110 patients undergoing transurethral resection for primary pTa/pT1 bladder carcinoma (pTa, 84; pT1, 26; grade 1, 22; grade 2, 81; grade 3, seven). Paraffin sections were assessed immunohistochemically using antibodies against COX‐2, CD34 (endothelial cells) and CD105 (proliferating vessels). COX‐2 expression was quantified by the number of stained cells (negative, +, ++) and the MVD calculated as vessels per field.

RESULTS

Of the 110 tumours, 45 (41%) had no immunostaining for COX‐2, 40 had faint staining with at least isolated positive cells (+) and 25 stained ++. COX‐2 positive tumours had significantly greater vascularization for proliferating vessels. In COX‐2 negative tumours the MVD was 22.1, identified by CD34 immunostaining, and 3.4 for proliferating vessels (CD105), whereas COX‐2 positive tumours had a MVD of 18.3 (CD34), and of 5.8, respectively (CD105). Complete follow‐up data were available in 91 patients; after a mean follow‐up of 25 months, 18 (20%) had tumour recurrences. There was no significant difference in the recurrence rates or disease‐free survival between COX‐2‐positive (19%, 25.6 months) or ‐negative patients (21%, 25.2 months).

CONCLUSION

These results confirm the involvement of COX‐2 in angiogenesis in bladder cancer, as COX‐2 promoted blood vessel proliferation in the tumour zone, and indicate the usefulness of COX‐2‐inhibiting drugs in preventing and treating superficial bladder cancer.
Beneficial effects of continuous overnight catheter drainage in children with polyuric renal failure
Authors: Montané B. , Abitbol C. , Seeherunvong W. , Chandar J. , Strauss J. , González R. , Zilleruelo G.
Published: August 2003

The authors from Miami discuss the problems affecting children with dysfunctional bladder syndrome. If there is progressive renal disease polyuria may overwhelm bladder capacity. They set out to determine whether overnight catheter drainage in such patients might have a beneficial effect. They found that this technique in patients with progressive polyuric renal failure may have the potential to preserve renal function in selected patients. They also state that it should not be seen as a replacement for surgical augmentation of the bladder or intermittent catheterization.

OBJECTIVE

To determine the possible beneficial effect of providing decompression of the collecting system by continuous overnight catheter drainage (COCD) in children with progressive renal disease and dysfunctional bladder syndrome, commonly associated with polyuria which may overwhelm bladder capacity.

PATIENTS AND METHODS

COCD was used in seven patients (four boys) with progressive polyuric kidney failure associated with dysfunctional bladders (current age 18.7 years, sd 5; age at COCD 12 years, sd 6). Five children had surgical bladder augmentation and all were prescribed daytime intermittent catheterization (IC) for a mean (sd) of 4.7 (3.4) years before COCD. All had significant polyuria, with a mean (sd) urine output of 2370 (971) mL/m2 per day.

RESULTS

The mean (sd) glomerular filtration rate at the start of COCD was 48 (21) mL/min/1.73 m2, which is currently stable in the five patients continuing treatment. The mean (sd) duration of COCD was 4.9 (2) years. One patient showed no improvement and had a pre‐emptive transplant within 1.2 years; another was transplanted after 5.5 years. Six patients showed evidence of benefit from COCD, with significant attenuation in the slope of renal functional decay (P = 0.02) and a mean (sd) prolongation of the predicted time to end‐stage renal disease of 12.2 (5.6) years (P < 0.002). Hospitalization for febrile urinary tract infections was decreased from a mean (sd) of 1.7 (1.4) to 0.4 (0.7) times (P = 0.03) in the first year of COCD and eliminated by the second year (P < 0.01).

CONCLUSION

COCD of the dysfunctional bladder in patients with progressive polyuric renal failure appears to offer the potential for preserving kidney function in selected patients. It does not replace surgical bladder augmentation or daytime IC in the core management.
Triple incision to treat phimosis in children: an alternative to circumcision?
Authors: Fischer‐Klein Ch. , Rauchenwald M.
Published: August 2003

OBJECTIVE

To evaluate the functional and cosmetic results and patient satisfaction after triple incision plasty for phimosis in children.

PATIENTS AND METHODS

The study included 197 boys who had a triple incision for phimosis (mean age 5.8 years, range 0.25–18). The indications for preputial surgery were recurrent balanoposthitis, ballooning during micturition and severe phimotic stenosis. The results after surgery were assessed using a questionnaire about the child’s/parent's satisfaction, and an outpatient follow‐up examination for functional and cosmetic preputial appearance.

RESULTS

Of 128 parents/children responding, 108 (84%) were satisfied with the function and 102 (80%) reported a good cosmetic outcome. Triple incision as preputioplasty would be recommended to other parents by 119 (93%) respondents. Ninety‐one (71%) of the parents feared disadvantages in their son's later life if the child had been circumcised. The outpatient examination showed an excellent functional and cosmetic outcome in 71 (77%) of the children.

CONCLUSION

Triple incision is a simple, fast and safe technique for preputial relief, with good functional and cosmetic results, and was well accepted by the patients.
Partner's influence on patient preference for treatment in early prostate cancer
Authors: Srirangam S.J. , Pearson E. , Grose C. , Brown S.C.W. , Collins G.N. , O'Reilly P.H.
Published: August 2003

OBJECTIVE

To determine the partner's influence on the patient's choice of treatment for early prostate cancer, and whether partner characteristics and biases predict the preference.

PATIENTS, SUBJECTS AND METHODS

Questionnaires for partners to complete retrospectively were sent to consecutive patients recruited in a study comparing treatment options for early prostate cancer. The partners’ perceptions about prostate cancer were explored and the partners asked to comment on the suitability of each treatment option. Partners recorded their influence on the patient's choice using a 10‐point visual linear analogue scale.

RESULTS

Questionnaires were sent to 116 eligible patients and 82 were returned for analysis (mean partner age 63 years). When asked to recall the treatment options initially discussed, all partners recalled radiotherapy (EBRT), all but one radical prostatectomy (RP), 51% brachytherapy, but only 29% watchful waiting (WW); 41% of partners stated RP as their chosen option, 37% EBRT, 12% brachytherapy and 10% no clear favourite. None preferred WW. Employment and education status were not significant predictors of partners’ preference but retired partners and those aged > 65 years were 3 times more likely to prefer EBRT than were their employed and younger counterparts, respectively. The partners’ mean (median, sd) self‐assessed influence factor was 4.8 (5, 3.4). Of the partners, 88% reported active involvement throughout the process, identifying information‐gathering and emotional support as their primary roles. Most deliberately chose not to influence the patient's final decision.

CONCLUSION

Partner preference is influenced by pre‐existing conceptions about cancer and its treatment. While undoubtedly influential throughout the decision‐making process, partners deliberately left the final decision to the patient.
Trazodone for erectile dysfunction: a systematic review and meta‐analysis
Authors: Fink H.A. , MacDonald R. , Rutks I.R. , Wilt T.J.
Published: August 2003

Evidence‐based medicine is an important way of allowing the reader to judge clearly whether a treatment has a place in a particular condition, and to see what faults were present in the various trials of its efficacy. It is often rather unsettling to read in a meta‐analysis or in a systematic literature review how poorly constructed many trials are. The authors from Minneapolis have carried out such a study into the use of trazodone in male erectile dysfunction. They draw attention to the poor quality of many of the trials and give their reasons for this observation. They suggest that trazodone may be helpful in men with this condition, possibly at higher doses and in men with psychogenic erectile dysfunction.

OBJECTIVE

To determine the efficacy and safety of trazodone in the treatment of erectile dysfunction (ED) in a meta‐analysis.

METHODS

The data sources used were Medline and the Cochrane Library databases (January 1966 to May 2002), bibliographies of retrieved articles and review articles, and conference proceedings and abstracts. Trials were eligible for inclusion in the review if they included men with ED, compared trazodone with a control, were randomized, of ≥ 7 days’ duration and assessed clinically relevant outcomes. Two reviewers independently evaluated study quality and extracted data in a standardized fashion.

RESULTS

Six trials (comprising 396 men) met the inclusion criteria; they consisted of heterogeneous populations, were small, brief and in some cases methodologically weak. Three of the six trials showed an apparently clinically meaningful benefit of trazodone for ED compared with placebo, the differences being statistically significant in two. In pooled results, trazodone monotherapy appeared more likely than placebo to lead to a ‘positive treatment response’, although this difference was not statistically significant (37% vs 20%; relative benefit increase, 1.6; 95% confidence interval, CI, 0.8–3.3). Subgroup analyses suggested that men with psychogenic ED might be more likely to benefit from trazodone than those with mixed or physiological ED. The efficacy of trazodone also appeared greater at higher doses (150–200 vs 50 mg/day). Men randomized to trazodone were not significantly more likely than those receiving placebo to withdraw for any reason or for an adverse event, or to have specific adverse events, but wide CIs could not exclude a greater risk of these adverse outcomes with trazodone. Specific adverse events with trazodone included dry mouth (19%), sedation (16%), dizziness (16%) and fatigue (15%).

CONCLUSION

Trazodone may be helpful in men with ED, possibly more so at higher doses, and in men with psychogenic ED. Future high‐quality trials should compare trazodone with placebo and other therapies in men with depression and psychogenic ED.
Quantitative evaluation of bone metastases in patients with advanced prostate cancer during systemic treatment
Authors: Yahara J. , Noguchi M. , Noda S.
Published: August 2003

OBJECTIVE

To assess the clinical usefulness of quantifying the extent of disease on bone scans in monitoring treatment response in patients with advanced prostate cancer, using computer‐assisted image analysis.

PATIENTS AND METHODS

The percentage of the positive area on the bone scan (%PABS) was quantified automatically using a personal computer with an image‐analysis program. Serial measurements of %PABS in 42 patients with bone metastasis from prostate cancer followed for a mean (range) of 33 (4–72) months with hormonal therapy were compared with those of the extent of disease (EOD) grades in bone lesions and serum prostate specific antigen (PSA) levels according to treatment response.

RESULTS

Serial values of EOD grades and %PABS decreased during treatment in 11 patients with a partial response and in 12 with progressive disease who had no bone metastasis progression. However, EOD grades and %PABS increased in the remaining 19 patients with progressive disease who had bone metastatic progression. Estimated survival curves showed that %PABS was a useful prognostic indicator, in that patients with a > 25% decline in %PABS survived longer than those with a < 25% decline after treatment (P = 0.0207).

CONCLUSIONS

The %PABS is a simple and reproducible estimate of the proportion of the skeleton involving tumours in patients with advanced prostate cancer, and serial measurements of %PABS can assist in monitoring the treatment response in patients with bone metastatic prostate cancer.
Tolterodine is equally effective in patients with mixed incontinence and those with urge incontinence alone
Authors: Kreder K.J. , Brubaker L. , Mainprize T.
Published: August 2003

OBJECTIVE

To examine the efficacy of tolterodine, an antimuscarinic agent with a bladder‐selective profile, in patients with mixed incontinence (MI, stress and urge) compared with patients with urge incontinence (UI) alone.

PATIENTS AND METHODS

The study included 239 patients with MI (urge predominating) and 755 with urge incontinence alone from a single‐blind, multicentre trial of 1380 patients (80% female) with an overactive bladder. Those completing the trial were analysed ‘per‐protocol’. After a 7‐day washout and a 3‐day run‐in to collect baseline information, patients were treated with tolterodine twice daily for 16 weeks. The two groups were compared for incontinence episodes/24 h, voiding frequency, nocturia episodes and pad usage after 16 weeks of treatment.

RESULTS

After 16 weeks the median changes from baseline for all voiding variables were statistically significant for the MI and the UI groups (P < 0.001), with no apparent significant between‐group differences. The median percentage reduction in incontinence episodes from baseline was 67% for the MI and 75% for the UI groups (P = 0.39). ‘Dry’ rates for the MI and UI groups at the end of the study were 39% (66/171) and 44% (243/552), respectively, whilst 24% of patients in each group (MI 40/170; UI 130/551) achieved a voiding pattern of < 8 voids/24 h. ‘Cure’ rates for nocturia and the reduction in the number of patients not using pads used were also similar between the groups.

CONCLUSION

Tolterodine is as effective in reducing leakage and other symptoms of an overactive bladder in patients with MI as it is in patients with UI alone.
A comparison of lycopene and orchidectomy vs orchidectomy alone in the management of advanced prostate cancer
Authors: Ansari M.S. , Gupta N.P.
Published: August 2003

OBJECTIVE

To compare the efficacy of lycopene plus orchidectomy with orchidectomy alone in the management of advanced prostate cancer.

PATIENTS AND METHODS

Fifty‐four patients with histologically confirmed metastatic prostatic cancer (M1b or D2) and a performance status of 0–2 (World Health Organization) were entered into the trial between March 2000 and June 2002. The trial comprised two treatment arms, i.e. patients were randomized to orchidectomy alone or orchidectomy plus lycopene (OL), each of 27 patients. Lycopene was started on the day of orchidectomy at 2 mg twice daily. Patients were evaluated clinically before and every 3 months after the intervention, with measurements of prostate‐specific antigen (PSA), a bone scan and uroflowmetry, with the clinical response assessed as the change in these variables.

RESULTS

At 6 months there was a significant reduction in PSA level in both treatments, but more marked in the OL group (mean 9.1 and 26.4 ng/mL, P = 0.9). After 2 years these changes were more consistent in the OL group (mean 3.01 and 9.02 ng/mL; P < 0.001). Eleven (40%) patients in orchidectomy and 21 (78%) in the OL group had a complete PSA response (P < 0.05), with a partial response in nine (33%) and four (15%), and progression in seven (25%) and two (7%), respectively (P < 0.05). Bone scans showed that in the orchidectomy arm only four (15%) patients had a complete response, vs eight (30%) in the OL group (P < 0.02), with a partial response in 19 (70%) and 17 (63%), and progression in four (15%) and two (7%), respectively (P < 0.02). There was a significant improvement in peak flow rate in the OL group, with a mean difference of +1.17 mL/s (P < 0.04). Of the 54 patients who entered the trial, 19 (35%) died, 12 (22%) in orchidectomy and seven (13%) in OL group (P < 0.001).

CONCLUSION

Adding lycopene to orchidectomy produced a more reliable and consistent decrease in serum PSA level; it not only shrinks the primary tumour but also diminishes the secondary tumours, providing better relief from bone pain and lower urinary tract symptoms, and improving survival compared with orchidectomy alone.
The ageing male and erectile dysfunction
Authors: Montorsi F. , Briganti A. , Salonia A. , Deho’ F. , Zanni G. , Cestari A. , Guazzoni G. , Rigatti P. , Stief C.
Published: August 2003

Erectile dysfunction is common in the ageing man and reliable therapies are needed. The pathophysiology of erectile dysfunction in this group mainly includes chronic ischaemia, which triggers the deterioration of cavernosal smooth muscle and the development of corporeal fibrosis. Assessing the ageing man with erectile dysfunction who seeks medical treatment should comprise a thorough medical and sexual history, a systemic and focused physical examination and selected blood tests. Oral drug therapy represents a safe and effective option for most ageing men.
Anterior urethral strictures
Authors: Barbagli G. , Palminteri E. , Lazzeri M. , Guazzoni G.
Published: August 2003

The surgical treatment of adult anterior urethral strictures has developed continuously. Recently considerable changes have been introduced, involving the cause of the urethral disease and surgical techniques. The criteria for selecting the reconstructive surgical technique are presented according to the cause and a new classification of urethral strictures. The main surgical procedures are presented and fully illustrated, with an updated and comprehensive review of recent publications.
Anterior urethral valves and diverticula
Authors: Paulhac P. , Fourcade L. , Lesaux N. , Alain J.L. , Colombeau P.
Published: August 2003

Obstructive lesions of the anterior urethra (valves, diverticula) are rare and can be difficult to diagnose. One recent case led us to review existing international reports; there are case histories for 260 patients over a 20‐year period. The anatomical interpretation of these lesions is far from being unequivocal but many authors clearly distinguish between valves and diverticula, the basic difference being in the contiguity between the anomaly and the corpus spongiosum. Where the clinical presentation depends on age, the diagnosis depends essentially on voiding cysto‐urethrography, which must image the whole urethra. Generally, the treatment for valves is simple, consisting of endoscopic resection. For diverticula it is not always necessary or desirable to remove the diverticulum; if there is a well‐formed distal obstructing lip, removing it may be enough to cure the obstruction.
Predicting the impacts of climate change on the distribution of species: are bioclimate envelope models useful?
Authors: Pearson Richard G. , Dawson Terence P.
Published: August 2003

Modelling strategies for predicting the potential impacts of climate change on the natural distribution of species have often focused on the characterization of a species’ bioclimate envelope. A number of recent critiques have questioned the validity of this approach by pointing to the many factors other than climate that play an important part in determining species distributions and the dynamics of distribution changes. Such factors include biotic interactions, evolutionary change and dispersal ability. This paper reviews and evaluates criticisms of bioclimate envelope models and discusses the implications of these criticisms for the different modelling strategies employed. It is proposed that, although the complexity of the natural system presents fundamental limits to predictive modelling, the bioclimate envelope approach can provide a useful first approximation as to the potentially dramatic impact of climate change on biodiversity. However, it is stressed that the spatial scale at which these models are applied is of fundamental importance, and that model results should not be interpreted without due consideration of the limitations involved. A hierarchical modelling framework is proposed through which some of these limitations can be addressed within a broader, scale‐dependent context.