Absence of perilipin results in leanness and reverses obesity in Lepr(db/db) mice

Obesity is a disorder of energy balance. Hormone-sensitive lipase (HSL) mediates the hydrolysis of triacylglycerol, the major form of stored energy in the body. Perilipin (encoded by the gene Plin), an adipocyte protein, has been postulated to modulate HSL activity. We show here that targeted disruption of Plin results in healthy mice that have constitutively activated fat-cell HSL. Plin -/- mice consume more food than control mice, but have normal body weight. They are much leaner and more muscular than controls, have 62% smaller white adipocytes, show elevated basal lipolysis that is resistant to beta-adrenergic agonist stimulation, and are cold-sensitive except when fed. They are also resistant to diet-induced obesity. Breeding the Plin -/- alleles into Leprdb/db mice reverses the obesity by ncreasing the metabolic rate of the mice. Our results demonstrate a role for perilipin in reining in basal HSL activity and regulating lipolysis and energy balance; thus, agents that inactivate perilipin may prove useful as anti-obesity medications.

Bicalutamide monotherapy compared with castration in patients with nonmetastatic locally advanced prostate cancer: 6.3 years of followup

PURPOSE

Nonsteroidal antiandrogen monotherapy may be a treatment option for some patients with advanced prostate cancer. We report a survival and safety update from an analysis of 2 studies in which patients with nonmetastatic (M0) locally advanced disease were treated with either 150 mg. bicalutamide monotherapy or castration.

MATERIALS AND METHODS

Data from 2 open label, multicenter studies of identical design were pooled according to protocol. Patients with stage T3/4 prostate cancer were randomized to receive 150 mg. bicalutamide daily or castration (orchiectomy or 3.6 mg. goserelin acetate every 28 days) in a 2:1 ratio.

RESULTS

A total of 480 patients with locally advanced prostate cancer were randomized to treatment. After a median followup of 6.3 years mortality was 56%. There was no statistically significant difference between the 2 groups in overall survival (hazard ratio 1.05, upper 1-sided 95% confidence limit 1.31, p = 0.70) or time to progression (1.20, 1.45, p = 0.11). There were statistically significant benefits in the bicalutamide monotherapy group in the 2 quality of life parameters of sexual interest (p = 0.029) and physical capacity (p = 0.046). The highest incidences of adverse events were the pharmacological side effects of hot flashes in the castration group, and breast pain and gynecomastia in the bicalutamide group. The incidences of other types of adverse events were low. Bicalutamide was well tolerated, with few drug related withdrawals from study, and no new safety issues were identified during this longer followup.

CONCLUSIONS

Monotherapy with 150 mg. bicalutamide is an attractive alternative to castration in patients with locally advanced prostate cancer for whom immediate hormone therapy is indicated.

Monte Carlo methods in electronic structures for large systems

Quantum Monte Carlo methods have recently made it possible to calculate the electronic structure of relatively large molecular systems with very high accuracy. These large systems range from positron complexes [NH(2),Ps] with approximately 10 electrons to C(20) isomers with 120 electrons, to silicon crystal structures of 250 atoms and 1000 valence electrons. The techniques for such calculations and a sampling of applications are reviewed.

A randomised comparison of 'Casodex' (bicalutamide) 150 mg monotherapy versus castration in the treatment of metastatic and locally advanced prostate cancer

OBJECTIVES

To evaluate the efficacy and tolerability of 'Casodex' monotherapy (150 mg daily) for metastatic and locally advanced prostate cancer.

METHODS

A total of 1,453 patients with either confirmed metastatic disease (M1), or T3/T4 non-metastatic disease with elevated prostate-specific antigen (M0) were recruited into one of two identical, multicentre, randomised studies to compare 'Casodex' 150 mg/day with castration. The protocols allowed for combined analysis.

RESULTS

At a median follow-up period of approximately 100 weeks for both studies, 'Casodex' 150 mg was found to be less effective than castration in patients with metastatic disease (M1) at entry (hazard ratio of 1.30 for time to death) with a difference in median survival of 6 weeks. In symptomatic M1 patients, 'Casodex' was associated with a statistically significant improvement in subjective response (70%) compared with castration (58%). Analysis of a validated quality-of-life questionnaire proved an advantage for 'Casodex' in sexual interest and physical capacity. 'Casodex' had a substantially lower incidence of hot flushes compared to castration (6-13% compared with 39-44%) and the most commonly reported adverse events were those expected for a potent antiandrogen. However, in patients with M0 disease at entry, the data are still immature with only 13% of M0 patients having died. An initial analysis of this immature data has suggested that the results in these patients may be different to those obtained in patients with M1 disease. A further survival analysis in patients with M0 disease is therefore planned when the data are more mature.

CONCLUSIONS

'Casodex' 150 mg is less effective than castration in patients with M1 disease. However, 'Casodex' has shown a benefit in terms of quality of life and subjective response when compared to castration and has an acceptable tolerability profile. Thus 'Casodex' 150 mg monotherapy is an option for patients with M1 prostate cancer for whom surgical or medical castration is not indicated or is not acceptable.

Follicular lymphoma can be distinguished from benign follicular hyperplasia by flow cytometry using simultaneous staining of cytoplasmic bcl-2 and cell surface CD20

The distinction between benign follicular hyperplasia (FH) and follicular lymphoma (FL) is sometimes problematic. We wanted to determine whether the expression of bcl-2 of FH was quantitatively different from that of FL, using surface CD20 expression as a discriminator of the various lymphoid compartments. Lymph node cell suspensions from 12 cases of FH and 17 cases of FL were analyzed by flow cytometry using a combined surface CD20 and intracellular bcl-2 staining. CD20- T cells in FH demonstrated the same bcl-2 expression as the CD20+ mantle cells, but the bright CD20+ germinal center cells showed near absence of bcl-2 expression. In contrast, the neoplastic cells of FL showed greater bcl-2 expression than the T cells of the same tumors and all cell populations of FH. This difference was particularly significant between the neoplastic B cells of FL and the germinal center cells of FH. The combined analysis of CD20 and bcl-2 should be useful for the differential diagnosis between FH and FL and particularly applicable to limited samples or when B-cell clonality is in question. Whether the quantitation of bcl-2 expression can be of further discriminatory value in malignant lymphomas remains to be determined.

Numerical studies of blood shear and washing in a continuous flow ventricular assist device

The third prototype of a continuous flow ventricular assist device (CF3) is being developed and tested for implantation in humans. The blood in the pump flows through a fully shrouded four bladed impeller (supported by magnetic bearings) and through small clearance regions on either side of the impeller. Computational fluid dynamics (CFD) solutions for this flow have been obtained by using TascFlow, a software package available from AEA Technology, UK. These flow solutions have been used to estimate the shear stresses on the blood in the pump and, hence, to minimize hemolysis. In addition, the solutions are informative for achieving a design that will provide good washing of the blood to minimize the possibility of stagnation points that can lead to thrombosis. This study presents numerical studies of these phenomena in the CF3. The calculated shear rate results are compared with values published in the open literature. The comparisons indicate that hemolysis will not be a problem with CF3, which is in agreement with preliminary experimental measurements. Flow studies are being conducted to determine the optimal size of the clearance regions.

Spontaneous subcapsular renal haemorrhage presenting with pleuritic chest pain

We present an unusual case of spontaneous renal subcapsular haematoma in a normal kidney presenting with pleuritic chest pain and mimicking pulmonary embolism. The literature suggests that the majority of these cases occur in association with renal tumours and that the diagnosis can best be made by computed tomographic scanning. Treatment is expectant but because of the high incidence of tumours, nephrectomy is usually necessary.

Computational flow study of the continuous flow ventricular assist device, prototype number 3 blood pump

A computational fluid dynamics study of blood flow in the continuous flow ventricular assist device, Prototype No. 3 (CFVAD3), which consists of a 4 blade shrouded impeller fully supported in magnetic bearings, was performed. This study focused on the regions within the pump where return flow occurs to the pump inlet, and where potentially damaging shear stresses and flow stagnation might occur: the impeller blade passages and the narrow gap clearance regions between the impeller-rotor and pump housing. Two separate geometry models define the spacing between the pump housing and the impeller's hub and shroud, and a third geometry model defines the pump's impeller and curved blades. The flow fields in these regions were calculated for various operating conditions of the pump. Pump performance curves were calculated, which compare well with experimentally obtained data. For all pump operating conditions, the flow rates within the gap regions were predicted to be toward the inlet of the pump, thus recirculating a portion of the impeller flow. Two smaller gap clearance regions were numerically examined to reduce the recirculation and to improve pump efficiency. The computational and geometry models will be used in future studies of a smaller pump to determine increased pump efficiency and the risk of hemolysis due to shear stress, and to insure the washing of blood through the clearance regions to prevent thrombosis.

Baclofen increases the soleus stretch reflex threshold in the early swing phase during walking in spastic multiple sclerosis patients

The effect of baclofen on walking performance was examined in nine spastic multiple sclerosis patients. In addition, nine healthy subjects were tested as controls. The modulation of the short latency soleus stretch reflex was closer to normal with baclofen compared to the recordings without baclofen, the modulation index being 74% (range: 60 - 100) with baclofen and 62% (range: 20 - 100) without baclofen, P=0.03. In healthy subjects the modulation index was 100% (range: 52 - 100). In the early swing phase the threshold of the soleus stretch reflex was significantly higher during baclofen medication being 139 deg/s (range: 63 - 302) compared with 93 deg/s (range: 37 - 187) without baclofen, P=0.004. The relation between the stretch velocity (input) and the amplitude of the stretch reflex (output) in early swing phase was unchanged being 0. 27 microVs/deg (range: 0.1 - 1.51) in patients with baclofen and 0. 24 microVs/deg (range: 0.08 - 0.79) without baclofen, P=0.25. Baclofen induced no change in input - output properties of the stretch reflex during walking compared with findings in a sitting position at matched EMG activity. There was a significant correlation between clinical spasticity score and stretch reflex threshold in the early swing phase (rho=-0.61, P=0.04) and between clinical spasticity score and the slope of the best linear fit in the early swing phase (rho=0.72, P=0.009).

Evolution of drug resistance in experimental populations of Candida albicans

Adaptation to inhibitory concentrations of the antifungal agent fluconazole was monitored in replicated experimental populations founded from a single, drug-sensitive cell of the yeast Candida albicans and reared over 330 generations. The concentration of fluconazole was maintained at twice the MIC in six populations; no fluconazole was added to another six populations. All six replicate populations grown with fluconazole adapted to the presence of drug as indicated by an increase in MIC; none of the six populations grown without fluconazole showed any change in MIC. In all populations evolved with drug, increased fluconazole resistance was accompanied by increased resistance to ketoconazole and itraconazole; these populations contained ergosterol in their cell membranes and were amphotericin sensitive. The increase in fluconazole MIC in the six populations evolved with drug followed different trajectories, and these populations achieved different levels of resistance, with distinct overexpression patterns of four genes involved in azole resistance: the ATP-binding cassette transporter genes, CDR1 and CDR2; the gene encoding the target enzyme of the azoles in the ergosterol biosynthetic pathway, ERG11; and the major facilitator gene, MDR1. Selective sweeps in these populations were accompanied by additional genomic changes with no known relationship to drug resistance: loss of heterozygosity in two of the five marker genes assayed and alterations in DNA fingerprints and electrophoretic karyotypes. These results show that chance, in the form of mutations that confer an adaptive advantage, is a determinant in the evolution of azole drug resistance in experimental populations of C. albicans.

The changing pattern of mortality and morbidity from radical cystectomy

OBJECTIVES

To examine the morbidity and mortality of radical cystectomy as currently practised, and to compare the findings with historical data.

PATIENTS AND METHODS

The operative mortality and early and late complications were recorded in 101 consecutive patients (median age 65 years, range 38-81; 33 aged >70 years) undergoing radical cystectomy between April 1992 and October 1997. Fifteen patients had relapsed after previous radical radiotherapy.

RESULTS

The median postoperative stay was 14 days (range 8-44). There were two deaths within 60 days of surgery (of patients aged 46 and 59 years) from respiratory failure and sepsis, respectively. The mortality in the elderly was not more than in other age groups. The early morbidity included two cases of lower limb insufficiency, both in the salvage cystectomy group, where the morbidity was significantly higher than in those undergoing primary cystectomy (chi-squared, P<0.01). Three patients underwent early re-exploration. There were four clinically significant episodes of deep vein thrombosis and two pulmonary emboli that were not fatal.

CONCLUSION

As currently practised, radical cystectomy is associated with a lower mortality (<2%) and morbidity than described previously. The added morbidity of salvage cystectomy and the acceptable mortality of primary cystectomy suggests that the treatment of choice for muscle-invasive disease is primary cystectomy, with external beam radiotherapy reserved for those patients unfit for major surgical intervention. Age alone should no longer be considered a contraindication to cystectomy.

Pharmacodynamics of a long acting depot preparation of avorelin in patients with prostate cancer. Avorelin Study Group

PURPOSE

We evaluate the pharmacodynamics, pharmacokinetics and tolerability of a sustained release depot formulation of avorelin, a new potent super agonist of luteinizing hormone-releasing hormone receptors, in patients with prostate cancer.

MATERIALS AND METHODS

A total of 60 patients were randomized to receive a 10 mg. (31) or 15 mg. (29) avorelin subcutaneous depot. Serum testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and plasma avorelin were measured regularly until depot exhaustion.

RESULTS

Of the 10 mg. group patients 3 withdrew from the study after 31 to 35 weeks due to disease progression. Of the 15 mg. group patients 1 did not complete the study for logistical reasons. After the expected flare in serum testosterone, LH and FSH during week 1, medical castration (testosterone concentration less than 1.735 nmol./l.) was achieved within 4 weeks of depot injection. Median duration of testosterone suppression was 40 weeks in the 10 mg. (95% confidence interval 35 to 42) and 39 in the 15 mg. (37 to 43) group. The reduction in serum LH was similar to that of testosterone, while that of FSH was less pronounced. Plasma avorelin was proportional to the dose and correlated with serum testosterone. Normalization of serum prostate specific (4 ng./ml. or less) at 6 months was achieved in 80 and 88% of the 10 and 15 mg. groups, respectively. During the (7 to 20-month) observation period 94 and 86% of the 10 and 15 mg. groups, respectively, complained of adverse events mainly related to androgen suppression (hot flushes, decreased libido and impotence) or the nature of the disease (skeletal pain). In each group 3 patients had serious adverse events requiring hospitalization for reasons unrelated to avorelin treatment. The depot was well tolerated locally.

CONCLUSIONS

Subcutaneous depot formulations of avorelin were well tolerated and had protracted inhibitory effects on pituitary gonadotropin secretion in patients with prostate cancer. Testosterone suppression was maintained for more than 6 months in all patients. Avorelin depots could be the first luteinizing hormone-releasing hormone agonist formulation to be administered at 6-month intervals.

Multilocus genotypes and DNA fingerprints Do not predict variation in azole resistance among clinical isolates of Candida albicans

If variation in azole resistance is due to inherent differences in strains of Candida albicans, as a predominantly clonal organism, then correlation between multilocus genotypes and drug resistance would be expected. A sample of 81 clinical isolates from patients infected with human immunodeficiency virus in Toronto, Canada, plus 3 reference isolates were genotyped at 16 loci, distributed on all linkage groups, by means of oligonucleotide hybridizations specific for each of the alleles at each locus. These multilocus genotypes were significantly correlated with DNA fingerprints obtained with the species-specific probe 27A, indicating widespread linkage disequilibrium in the genome. There were 64 multilocus diploid genotypes and 77 DNA fingerprint types delineated in this sample. Neither the multilocus genotyping nor DNA fingerprinting alone identified all of the 81 types identified by the combination of these two methods. Multilocus genotypes were not predictive of fluconazole resistance, suggesting that resistance is gained or lost too quickly to be predicted by linkage with neutral markers.

Early versus deferred hormone therapy

Although hormone therapy is widely used in the management of prostate cancer, the optimal timing of its initiation remains a matter of debate. Immediate hormone treatment has been compared with deferred treatment in randomized studies conducted by the Veterans Administration Cooperative Urological Research Group, the South Sweden Prostate Cancer Study Group and the Medical Research Council. Despite criticism of the design of these studies, the results indicate that early treatment may be associated with advantages in time to progression and survival. It is anticipated that ongoing studies, such as the European Organization for Research and Treatment of Cancer protocols 30846 and 30891, will provide further information on the optimal timing of endocrine treatment. Prognostic and quality of life factors also have an impact on the treatment decision. On the basis of available evidence, early hormone therapy is recommended for younger men with poorly differentiated tumours or advanced disease and for those who are seen infrequently by their physician. Deferred treatment using a strategy of watchful waiting is probably the best option for older men with well differentiated, low volume prostate cancer.

A pilot study for a randomized controlled trial comparing the efficacy, safety and cost-effectiveness of surgical treatments of the prostate

OBJECTIVE

To assess the numbers of men in outpatients and subsequently undergoing transurethral resection of the prostate (TURP) who were referred during 1993-94 and 1996-97, thereby assessing the feasibility of a subsequent study of treatment efficacy in men with bladder outlet obstruction secondary to benign prostatic hyperplasia, prospectively randomized to the surgical treatment options, i.e. TURP, laser ablation of the prostate, transurethral needle ablation and T3 thermotherapy, to investigate treatment outcome, cost-efficacy and cost-benefit.

PATIENTS AND METHODS

All patients considered and consenting for prostate surgery were reviewed prospectively with a view to inclusion in the proposed trial. The diagnosis was based on two estimates of flow rate from voids of >150 mL and from symptoms assessed using the International Prostate Symptom Score. All patients had TURP explained by a urological surgeon and nursing staff, and subsequently had further consultation with research staff.

RESULTS

Patients seen in clinic as new referrals increased by 11% between the periods assessed, although the numbers undergoing TURP decreased by 19%. Of the 383 patients screened, who were on the waiting list for TURP, only 13 elected to enter the trial. Of the 383 men, 267 (67%) ultimately had prostate surgery, with 39 (10%) electing to continue with watchful waiting and 34 (9%) continuing with pharmacotherapy.

CONCLUSION

Although more men with benign prostatic disease and lower urinary tract symptoms are being seen in clinics, the reduced proportion of patients continuing to surgical intervention will lead to increasing difficulty in carrying out randomized controlled clinical trials assessing surgical options. With ever more therapeutic options available, patients find it difficult to make decisions in both the clinical situation and when asked to enter a trial. Fully informed decisions by both the surgeon and the patient will only be possible when objective data are available from trials that investigate outcome, cost-efficacy and cost-benefit. This study suggests that when presented with more information and counselling, fewer men decide to undergo prostate surgery for symptomatic BPH.

Casodex (bicalutamide) 150-mg monotherapy compared with castration in patients with previously untreated nonmetastatic prostate cancer: results from two multicenter randomized trials at a median follow-up of 4 years

OBJECTIVES

To compare the efficacy, tolerability, and quality of life benefits of bicalutamide (Casodex) 150-mg/day monotherapy and castration in previously untreated nonmetastatic (M0) advanced prostate cancer.

METHODS

A total of 480 patients with Stage T3/T4 nonmetastatic disease randomly received oral bicalutamide 150 mg/day or castration (either bilateral orchiectomy or goserelin acetate [Zoladex] 3.6 mg every 28 days) in a 2:1 ratio in two open multicenter studies (studies 306 and 307). The design of these studies was similar to allow a pooled analysis.

RESULTS

In the combined survival analysis, at median follow-up of 202 and 205 weeks in studies 306 and 307, respectively, with 31% of the cases resulting in death, bicalutamide 150-mg monotherapy was statistically equivalent to castration; the risk of death from any cause was 7% less with bicalutamide than with castration (hazard ratio [HR] = 0.93). Data on time to treatment failure and objective progression could not be pooled, as results for these end points differed between the trials. In study 306, bicalutamide 150-mg monotherapy increased time to objective progression (HR = 0.58; P = 0.033) and treatment failure (HR = 0.66; P = 0.074), whereas in study 307, time to progression (HR = 1.35; P = 0.0471) and treatment failure (HR = 1.24; P = 0.097) favored castration. Bicalutamide therapy showed significant advantages over castration for both sexual interest (P = 0.029) and physical capacity (P = 0.046). Bicalutamide 150-mg monotherapy was well tolerated.

CONCLUSIONS

Bicalutamide 150-mg monotherapy provides a similar survival outcome to castration in previously untreated patients with nonmetastatic advanced prostate cancer and confers statistically significant benefits over castration with respect to sexual interest and physical capacity.

mtDNA recombination in a natural population

Variation in mtDNA has been used extensively to draw inferences in phylogenetics and population biology. In the majority of eukaryotes investigated, transmission of mtDNA is uniparental and clonal, with genotypic diversity arising from mutation alone. In other eukaryotes, the transmission of mtDNA is biparental or primarily uniparental with the possibility of "leakage" from the minority parent. In these cases, heteroplasmy carries the potential for recombination between mtDNAs of different descent. In fungi, such mtDNA recombination has long been documented but only in laboratory experiments and only under conditions in which heteroplasmy is ensured. Despite this experimental evidence, mtDNA recombination has not been to our knowledge documented in a natural population. Because evidence from natural populations is prerequisite to understanding the evolutionary impact of mtDNA recombination, we investigated the possibility of mtDNA recombination in an organism with the demonstrated potential for heteroplasmy in laboratory matings. Using nucleotide sequence data, we report here that the genotypic structure of mtDNA in a natural population of the basidiomycete fungus Armillaria gallica is inconsistent with purely clonal mtDNA evolution and is fully consistent with mtDNA recombination.

Human papillomavirus and bladder cancer

Bladder cancer remains an important cause of oncological morbidity and mortality in women. Known etiological agents include smoking and exposure to certain industrial chemical compounds, though the origin of the majority of cases remains unknown. Human papillomavirus infection is also common in women and has been closely linked to the development of carcinoma of the cervix. It has been suggested that infection with HPV may also be an important factor in the subsequent development of bladder cancer. A number of studies using various techniques of molecular biology have looked at the relationship between HPV infection and bladder cancer. Although the results are somewhat conflicting, the overall picture would suggest little involvement of HPV in the evolution of bladder cancer, except possibly in a small group of patients who are immunocompromised.

The aetiological significance of human papillomavirus in bladder cancer

OBJECTIVE

To determine the prevalence of human papillomavirus (HPV) DNA types 6, 11 and 16 in histological sections of human bladder cancer.

MATERIALS AND METHODS

Fifty-five formalin-fixed, paraffin-embedded bladder tumour specimens were analysed for the presence of HPV infection using Southern blotting DNA hybridization and radiolabelled probes for HPV DNA types 6/11 and 16.

RESULTS

Despite the detection of HPV DNA type 6, 11 and 16 in positive control samples and the successful detection of HPV DNA in anogenital cancer using the same technique, no HPV DNA was found in any of the bladder tumour specimens examined.

CONCLUSIONS

Using a technique with proven efficacy in the detection of HPV DNA from histological specimens, no HPV DNA was present in any of the bladder tumours examined. This finding is in agreement with most recently published studies suggesting that HPV has no significant role in the development of human bladder cancer.

Genetic exchange and recombination in populations of the root-infecting fungus Armillaria gallica

Genetic individuals, or genets, of Armillaria and other root-infecting basidiomycetes are usually found in discrete patches that often include the root systems of several adjacent trees. Each diploid individual is thought to arise in an unique mating event and then grow vegetatively in an expanding territory over a long period of time. Our objective in this study was to describe the population from which such genetic individuals are drawn. In a sample including 274 collections representing 121 genetic individuals of A. gallica (synonym A. bulbosa) from two sites in each of four regions of eastern North America, genotype frequencies at seven nuclear loci were not significantly different from Hardy-Weinberg expectations. Furthermore, allele frequencies at the seven loci were not significantly different between regions. Additional allelic data from four non-contiguous regions of mitochondrial DNA showed little or no population subdivision over the four regions. Analysis of the distribution of multilocus mtDNA haplotypes revealed some clonal transmission of mtDNAs between genets and nonrandom mating within sites. Despite the sharing of mtDNA types by some individuals, the overall sample contained a high level of genotypic diversity. The apparent linkage equilibrium between some pairs of loci and the high level of phylogenetic inconsistency among all four loci suggest the occurrence heteroplasmy and recombination among mtDNAs of A. gallica in nature. In laboratory matings of two haploid strains with different mtDNA types, a low frequency of recombination in mtDNA was detected.

Bladder and erectile dysfunction before and after rectal surgery for cancer

OBJECTIVE

To establish the incidence of bladder and erectile dysfunction after rectal surgery for cancer.

PATIENTS AND METHODS

Twenty patients (16 men and four women, median age 66 years, range 36-78) with carcinoma of the rectum were prospectively studied immediately before and 4 months after operation by clinical assessment, uroflowmetry and video-cystometrography. All patients were catheterized routinely at the time of surgery. Those experiencing voiding difficulties after catheter removal were managed by intermittent self-catheterization or an indwelling urethral catheter.

RESULTS

Before surgery, only six patients had completely normal bladder function and 13 of the 16 men were at least partially potent. Eight of the 19 patients who eventually had surgery developed identifiable bladder dysfunction, of whom three had urodynamic evidence of complete bladder denervation. Three men who were potent before became impotent after surgery.

CONCLUSIONS

Bladder and erectile dysfunction are recognized complications of radical rectal surgery, although there is significant variation in the reported risk; much of this variability is related to the retrospective nature of most previous studies. This study demonstrates the importance of prospective urodynamic evaluation and confirms that the small but significant risk of permanent bladder dysfunction is likely to be related to pelvic nerve injury at the time of surgery.