PROTACs Targeting BRM (SMARCA2) Afford Selective In Vivo Degradation over BRG1 (SMARCA4) and Are Active in BRG1 Mutant Xenograft Tumor Models

The identification of VHL-binding proteolysis targeting chimeras (PROTACs) that potently degrade the BRM protein (also known as SMARCA2) in SW1573 cell-based experiments is described. These molecules exhibit between 10- and 100-fold degradation selectivity for BRM over the closely related paralog protein BRG1 (SMARCA4). They also selectively impair the proliferation of the H1944 "BRG1-mutant" NSCLC cell line, which lacks functional BRG1 protein and is thus highly dependent on BRM for growth, relative to the wild-type Calu6 line. In vivo experiments performed with a subset of compounds identified PROTACs that potently and selectively degraded BRM in the Calu6 and/or the HCC2302 BRG1 mutant NSCLC xenograft models and also afforded antitumor efficacy in the latter system. Subsequent PK/PD analysis established a need to achieve strong BRM degradation (>95%) in order to trigger meaningful antitumor activity in vivo. Intratumor quantitation of mRNA associated with two genes whose transcription was controlled by BRM (PLAU and KRT80) also supported this conclusion.

A comparison of surgical practice and operative outcomes between retroperitoneal and transperitoneal laparoscopic nephrectomies – 6 years of data from the BAUS Nephrectomy database

Objectives:

While the choice of surgical approach for laparoscopic nephrectomy is broadly split between transperitoneal and retroperitoneal options, the evidence for the impact of this decision on perioperative outcomes is built on relatively small volume data, with often inconsistent findings and conclusions. We aimed to assess the impact of operative approach on perioperative outcomes for laparoscopic radical, partial and simple nephrectomy and nephroureterectomy through analysis of the British Association of Urological Surgeons (BAUS) Nephrectomy database.

Patients and methods:

All patients added to the BAUS Nephrectomy database with laparoscopic surgery between 2012 and 2017 inclusively were included and subdivided by operation and surgical approach. Preoperative patient and tumour characteristics, as well as intraoperative and post-operative short-term outcomes, were assessed.

Results:

Overall, 26,682 operations were documented over the review window (81.6% transperitoneal). Small increases in blood loss ( p = 0.001), transfusion rate ( p = 0.02) and operative length ( p = 0.01) were seen for transperitoneal radical nephrectomies and longer hospital stays seen for retroperitoneal procedures (radical nephrectomy p = 0.00l; partial nephrectomy p = 0.04). Retroperitoneal procedures were associated with increased rates of conversion for simple nephrectomy ( p = 0.02), nephroureterectomy ( p = 0.03) and most notably partial nephrectomy (10.5% versus 4.4%; p = 0.001). No further variation in intraoperative complications, post-operative complications, tumour margin positivity rates, unintended ITU admission, or likelihood of death was identified related to surgical approach.

Conclusion:

Observed variations in perioperative outcomes were generally modest in nature, and little ground is seen to support a change in operative technique for those committed to one approach. A caveat to this exists with open conversion for retroperitoneal partial nephrectomies and requires careful consideration of patient selection by the individual surgeon.

Level of evidence:

4

SARS-CoV-2 Related Ischemic Colitis in an Adolescent With Trisomy 21: Diagnostic Pitfalls and Considerations

Millions of patients seek medical attention for diarrhea, vomiting, nausea, and abdominal pain. In the current environment, it is important to recognize that these symptoms may be the only manifestation or may precede more serious systemic complications of COVID-19. Herein, we describe the first case of ischemic colitis (IC) in a young adult who presented with diarrhea and highlight the laboratory pitfalls for patients with COVID-19 presenting with gastrointestinal (GI) symptoms.

Abstract 5687: Selective, chemically-induced degradation of BRM (SMARCA2) enables in vivo efficacy in BRG1 (SMARCA4)-deficient xenograft tumor models

The mammalian SWI/SNF complex catalyzes the remodeling of chromatin through the helicase activity of two mutually-exclusive, paralogous subunits, BRG1 and BRM. BRG1 is frequently mutated in cancer and its inactivation results in a cellular dependence on BRM. Despite the attractiveness of BRM as a synthetic lethal therapeutic target, the selective inhibition of BRM represents a considerable challenge due to the high degree of homology between BRM and BRG1. Furthermore, published data indicate that achieving such selectivity is likely essential to afford an acceptable therapeutic index. We sought to mimic the synthetic lethality observed in BRG1-mutant cancers by identifying proteolysis-targeting chimera (PROTAC®) molecules capable of selectively degrading BRM via trimeric complex formation with the von Hippel-Lindau (VHL) E3 ligase. In this disclosure, we report our initial discovery of potent and selective chimeric BRM-degrader molecules which exhibit BRM DC50 values <1 nM and BRG1/BRM DC50 ratios >25. Importantly, selective BRM degradation can be achieved in the absence of selective PROTAC® binding (BRG1/BRM Kd ratios <2). Global ubiquitin mapping and proteome profiling reveal no unexpected off-target activity of the selective BRM PROTAC® degraders. Treatment of a panel of NSCLC cell lines with a representative degrader molecule resulted in enhanced growth inhibition in BRG1-mutant relative to BRG1-wild-type cell lines. We also demonstrate that intermittent intravenous administration of an optimized BRM PROTAC® degrader exhibited strong in vivo modulation of pharmacodynamic biomarkers and afforded tumor growth inhibition in several BRG1-mutant xenograft models. Our study thus highlights the ability to transform a non-selective BRM-binding ligand into a selective and efficacious in vivo BRM PROTAC® degrader.

Citation Format: Michael Berlin, Jennifer Cantley, Jing Wang, Mark Bookbinder, Gregory Cadelina, Emily Chan, Huifen Chen, Xin Chen, Kim Davenport, Tharu Fernando, Debbie Gordon, Brian Hamman, Roy Haskell, Alexey Ishchenko, Donald S. Kirkpatrick, Jonathan Maher, Mark Merchant, John Moffat, Alicia Morgan, An Nguyen, Jennifer Pizzano, Connor Quinn, Christopher M. Rose, Emma Rousseau, Vijay Sethuraman, Leanna Staben, Catherine Wilson, Xiaofen Ye, Fabio Broccatelli, Robert Yauch, Peter S. Dragovich. Selective, chemically-induced degradation of BRM (SMARCA2) enables in vivo efficacy in BRG1 (SMARCA4)-deficient xenograft tumor models [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5687.

CALIBER: a phase II randomized feasibility trial of chemoablation with mitomycin-C vs surgical management in low-risk non-muscle-invasive bladder cancer

OBJECTIVES

To evaluate the activity of intravesical mitomycin-C (MMC) to ablate recurrent low-risk non-muscle-invasive bladder cancer (NMIBC) and assess whether it may enable patients to avoid surgical intervention for treatment of recurrence.

PATIENTS AND METHODS

CALIBER is a phase II feasibility study. Participants were randomized (2:1) to treatment with four once-weekly MMC 40-mg intravesical instillations (chemoablation arm) or to surgical management. The surgical group was included to assess the feasibility of randomization. The primary endpoint was complete response to intravesical MMC in the chemoablation arm at 3 months, reported with exact 95% confidence intervals (CIs). Secondary endpoints included time to subsequent recurrence, summarized by Kaplan-Meier methods.

RESULTS

Between February 2015 and August 2017, 82 patients with visual diagnosis of recurrent low-risk NMIBC were enrolled from 24 UK hospitals (chemoablation, n = 54; surgical management, n =28). The median follow-up was 24 months. Complete response at 3 months was 37.0% (20/54; 95% CI 24.3-51.3) with chemoablation and 80.8% (21/26; 95% CI 60.6-93.4) with surgical management. Amongst patients with complete response at 3 months, a similar proportion was recurrence-free by 12 months in both groups (84%). Amongst those with residual disease at 3 months, the 12-month recurrence-free proportion was lower in the surgical management group (40.0%) than in the chemoablation group (84%). Recruitment stopped early as chemoablation did not meet the prespecified threshold of 45% complete responses at 3 months.

CONCLUSION

Intravesical chemoablation in low-risk NMIBC is feasible and safe, but did not demonstrate sufficient response in the present trial. After chemoablation there may be a reduction in recurrence rate, even in non-responders, that is greater than with surgery alone. Further research is required to investigate the role and optimal schedule of neoadjuvant intravesical chemotherapy prior to surgery for NMIBC.

The effect of hypoglycaemia during hospital admission on health-related outcomes for people with diabetes: a systematic review and meta-analysis

AIM

To assess the health-related outcomes of hypoglycaemia for people with diabetes admitted to hospital; specifically, hospital length of stay and mortality.

METHODS

We conducted a systematic review and meta-analysis of studies relating to hypoglycaemia (< 4 mmol/l) for hospitalized adults (≥ 16 years) with diabetes reporting the primary outcomes of interest, hospital length of stay or mortality. Final papers for inclusion were reviewed in duplicate and the adjusted results of each were pooled, using a random effects model then undergoing further prespecified subgroup analysis.

RESULTS

In total, 15 studies were included in the meta-analysis. The pooled mean difference in length of stay for ward-based inpatients exposed to hypoglycaemia was 4.1 days longer [95% confidence interval (CI) 2.36 to 5.79; I² = 99%] compared with those without hypoglycaemia. This association remained robust across the pre-specified subgroup analyses. The pooled relative risk (RR) of in-hospital mortality was greater for those exposed to hypoglycaemia (RR 2.09, 95% CI 1.64 to 2.67; I² = 94%, n = 7 studies) but not in intensive care unit mortality (RR 0.75, 95% CI 0.49 to 1.16; I² =0%, n = 2 studies).

CONCLUSION

There is an association between inpatient hypoglycaemia and longer length of stay and greater in-hospital mortality. Studies examining this association were heterogenous in terms of both clinical populations and effect size, but the overall direction of the association was consistent. Therefore, glucose concentration should be considered a potential tool to aid the identification of inpatients at risk of poor health-related outcomes.

Does length of time spent on the waiting list for TURP influence the outcome?

With an ever increasing demand for operative procedures within the NHS but little increase in capacity, waiting lists are lengthening, particularly for benign procedures. We sought to determine whether increasing time on a waiting list influences the outcome from a transurethral resection of prostate (TURP), with a primary outcome measure of success at inpatient trial without catheter (TWOC) and pre-operative, peri-operative and post-operative secondary outcome measures.

Data was collected from four separate retrospective TURP audits performed between 2009-2015. A total of 379 TURP procedures were included with the time on the waiting list ranging from 8 to 384 days. In patients who were not catheterised pre-operatively success at in patient TWOC by 30 day intervals (in 30 day intervals from 1-30 days to over 151 days) was 79%, 83%, 88%, 87%, 100% and 83%; in those with a catheter, success was 46%, 71%, 75%, 100%, 50% and 86%. In conclusion waiting longer for a TURP does not adversely affect the outcome of inpatient TWOC.

Level of evidence: Not applicable – this is a single centre audit over multiple time points.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Post-operative use of Low Molecular Weight Heparin: Are patients doing their bit?

Introduction:

Current National Institute for Health and Care Excellence (NICE) guidelines recommend the use of Low Molecular Weight Heparin (LMWH) for one month post-operatively in abdominal and pelvic cancer surgery to reduce risk of venous thromboembolism. We audited the prescription of LMWH at discharge and the compliance of patients with LMWH post-operatively and instigated measures to improve compliance.

Materials and Methods:

All patients undergoing major urological surgery from November 2011 to April 2012 were audited, with data collected on evidence of post-operative prescription (from discharge summaries). Patients within this 3-month period were questioned regarding compliance following discharge. Following this, changes were instigated to improve compliance (earlier discussion of post-operative LMWH administration in clinic, improved patient and junior doctor education). All patients undergoing surgery from November 2012 to June 2013 were identified and a re-audit completed.

Results:

Post-operative prescription of LMWH improved overall from 73% to 88%. Patient compliance to complete LMWH course improved from 23% to 88%. At re-audit, 97% of patients felt that training was adequate, and 94% of patients understood the rationale for taking LMWH at re-audit.

Conclusion:

Education of junior doctors improved prescription of LMWH at discharge. Improved patient education improves community LMWH use compliance post-discharge.

Effectiveness of a multidisciplinary team approach to the prevention of readmission for acute glycaemic events

AIMS

To describe the effect of a combined diabetes specialist/mental health team approach to prevent readmissions for acute glycaemic events among patients with diabetes.

METHODS

Consecutive patients with diabetes, readmitted to a single hospital for an acute glycaemic condition, were offered one or more diabetes (including assessment, education, medication, technology use and intensive support) and mental health (including assessment, training and therapies) interventions. The pilot service took place over 11 months, with the preceding 24 months and subsequent 8 months serving as control periods.

RESULTS

Of the 58 patients admitted, 50 had Type 1 diabetes and were from within the hospital catchment area, and were discharged home. Of these, 32 (64%) had a pre-existing mental health issue and 14 (28%) had a complex social situation. In all, 96% of patients were met as an inpatient by a team member, and 94% accepted at least one intervention. The mean ±sd number of admissions per patient/month dropped from 0.12 ± 0.10 to 0.05 ± 0.10 (P < 0.001) during the intervention, increasing, once the intervention ended, to 0.16 ± 0.36 (P = 0.002). The mean ± sd length of stay similarly decreased and increased (0.6 ± 0.9 to 0.2 ± 0.7 days; P < 0.001 to 0.006) to 0.6 ± 1.4 days (P = 0.003) per patient/month) across the three periods, as did the mean ±sd tariff paid per patient/month (₤258.0 ± 374.0 vs ₤92.1 ± 245.0 vs ₤287.3 ± 563.8; P < 0.001 and P = 0.018, respectively). The mean ± sd HbA1c level dropped from 99 ± 22 to 92 ± 24 mmol/mol (11.2 ± 4.2% vs 10.6 ± 4.3%; P = 0.014) but did not increase after the intervention [89 ± 26 mmol/mol (10.4 ± 4.5%)].

CONCLUSIONS

The cost and long-term risks of hospitalization among patients with Type 1 diabetes and recurrent admissions can be reduced by a combined specialist diabetes/mental health team approach.

ATP-Bioluminescence as a method to evaluated microbiological quality of UHT milk

New approaches are needed to quickly indicate possible contamination of UHT milk, among them the technique of ATP-Bioluminescence. Therefore, the aim of this study was to compare the results of culture methods with the results of ATP-Bioluminescence technique of 102 UHT whole milk samples incubated at 48, 72, and 168 hours. UHT milk samples were analyzed for the presence of mesophilic and psychrotrophic aerobic microorganisms using Plate Count Agar (PCA), Brain-Heart Infusion (BHI) media and PetrifilmTM Aerobic Count (AC) plates. The ATP-Bioluminescence technique was applied through the Microbial Luminescent Screening (MLS) system. Significant correlations were found between counts of aerobic mesophilic microorganisms on PCA, PetrifilmTM AC, BHI and results of ATP bioluminescence technique (P≤0.05). The ATP-Bioluminescence technique had higher correlation with counting method in PCA than BHI media. At lower pass/fail limits of Relative Light Units (60, 50, 45 and 40 RLU), the number of samples identified as positive increased and statistically agreed with aerobic mesophilic microorganism counts (P>0.05). For the dairy industry, the ATP-Bioluminescence technique may become an important tool that assists the official methods to quickly monitor the microbiological quality of UHT milk though this will likely require a threshold below 150 RLU.

Reduced insulin requirements during participation in the DAFNE (dose adjustment for normal eating) structured education programme

Dose adjustment for normal eating (DAFNE) is a well-established structured education programme for patients with type 1 diabetes. We conducted a retrospective analysis of insulin dose changes associated with DAFNE training. Our results show significant reductions in total, quick acting and basal insulin doses in patients undergoing DAFNE training.

Suspected testicular torsion - urological or general surgical emergency?

INTRODUCTION

Suspected testicular torsion (TT) is a surgical emergency, usually requiring urgent scrotal exploration. Provision of urology on-call cover varies widely between hospitals and often falls under the remit of the general surgical team. The purpose of this study was to investigate whether the management of suspected TT differed between urology (UT) and surgical (ST) trainees in the Severn and South West Peninsula Deaneries.

SUBJECTS AND METHODS

An on-line questionnaire (SurveyMonkey. com) was sent to all UT and ST within the Deaneries. Questions covered training, on-call cover, intra-operative management and knowledge of complications following testicular fixation. Responses were analysed using an Excel spreadsheet and GraphPad statistical package.

RESULTS

Responses were received from 26/31 UT and 43/52 ST throughout 17 hospitals. Only three hospitals had separate middle-grade specialist urology cover. Scrotal exploration was taught by urologists to 72% of UT compared with 40% of ST (P = 0.012, Fisher's exact test). Variability in the number of operations performed, supervision and management of true TT was insignificant. However, ST were more likely to fix a normal testicle either in the absence of other pathology (53% vs 28%) or with a twisted appendix testis (42% vs 15%) than UT (P = 0.045 and P = 0.032, respectively). UT were more aware of evidence regarding chronic pain (47% vs 14%) and infertility (53% vs 18%) following testicular fixation than ST (P = 0.005 and P = 0.003, respectively). Medicolegally, 76% of UT would inform the on-call consultant prior to operation compared with 45% of ST (P = 0.012).

DISCUSSION

ST are significantly more likely to fix a normal testicle than UT (and then usually only on the affected side), contrary to best-practice. This variation may be due to the different sources of training received by the two groups. Knowledge of possible chronic pain and infertility following testicular fixation may also affect management.

CONCLUSIONS

Due to the variation, we suggest urology departments should draw up guidelines for management; trainees should be encouraged to discuss the case pre-operatively with the consultant; core surgical training should include a urology placement.

Audit of safety, efficacy, and cost-effectiveness of local anaesthetic cystodiathermy

INTRODUCTION

The aim of this study was to audit our experience of cystodiathermy under local anaesthetic (LA) at the time of flexible cystoscopy for recurrent superficial bladder transitional cell carcinoma (TCC).

PATIENTS AND METHODS

A total of 264 flexible cystoscopies were performed on patients with a past history of TCC. The number and site of recurrences were recorded and selected patients were offered cystodiathermy. Patient tolerability was noted. At follow-up, any recurrence was recorded.

RESULTS

Eighty patients (30%) had 91 procedures showing one or more recurrences. Fifty-one of the 80 patients (64%) were treated with cystodiathermy under LA. All completed treatment. Forty-five (88%) tolerated the procedure well. Forty-seven (92%) treatments were completed within 5 min. At a median follow-up of 15 weeks, 30 (59%) treated patients had no recurrence and three (6%) had recurrence at the site of treatment.

CONCLUSIONS

LA cystodiathermy is an effective and well-tolerated alternative to general anaesthetic cystodiathermy that enables treatment at the time of detection and may, thereby, reduce patient anxiety.

A comparative study of quality of life issues relating to open versus laparoscopic nephrectomy: a prospective pragmatic study

PURPOSE

We determined whether laparoscopic nephrectomy confers improved health related quality of life in the early postoperative period compared with open nephrectomy.

MATERIALS AND METHODS

Patients undergoing open or laparoscopic nephrectomy were prospectively recruited. Patients completed the Comorbidity Symptom Scale preoperatively as well as the SF-36(R) quality of life health survey and pain visual analog scale preoperatively, and 2 days and 1 month postoperatively.

RESULTS

A total of 100 patients were recruited, of whom 71 completed all questionnaires, including 38 in the laparoscopic group and 33 in the open group. In the 2 groups mean patient age was the same (56.8 years) and there was a similar sex distribution. The laparoscopic group had improved quality of life scores with significantly higher physical component scores 1 month postoperatively vs the open group (-5.7% vs -22.2%, p = 0.009). The laparoscopic group also had significantly higher mental component scores 2 days postoperatively vs the open group compared to baseline (6.0% vs -6.6%, p = 0.009). The laparoscopic group had significantly lower pain visual analog scale scores 1 month postoperatively compared to baseline. Patients with higher Comorbidity Symptom Scale scores were more likely to undergo a laparoscopic approach (p = 0.036). Despite this they had a significantly shorter hospital stay (4 vs 6 days, p <0.001).

CONCLUSIONS

Quality of life benefits of laparoscopic over open nephrectomy were found in the early postoperative period despite more comorbidities in the laparoscopic group. This provides further evidence of the benefits of the laparoscopic approach over open surgery.

Prospective study comparing the bladeless optical access trocar versus Hasson open trocar for the establishment of pneumoperitoneum in laparoscopic renal procedures

INTRODUCTION

To present a single centre prospective randomized study on the use of the bladeless Optiview system (Ethicon Endosurgery, Cincinnati, OH) to create the pneumoperitoneum in laparoscopic renal procedures reporting the results with regards safety, efficacy and complications and comparing it with the Hasson open technique.

PATIENTS AND METHODS

Sixty patients were randomly recruited, 27 to the open and 33 to the bladeless group at the Bristol Urological Institute, UK. Time to insertion, time to closure and any intraoperative and postoperative complication related to trocar insertion was recorded.

RESULTS

All procedures were performed for renal pathology. BMI values were similar in both groups. The mean time to insertion of the 12 mm Hasson and Bladeless trocars were 443 and 125 seconds, respectively (p < 0.0001). The incision in the bladeless group was only closed when the defect exceeded 12 mm (38%) or extended for specimen removal (23%), resulting in a mean time to closure of 203 seconds. In the Hasson group, entry into the abdominal cavity could not be confirmed in two patients (7.4%) due to multiple adhesions. In the Bladeless group, there was one failed placement (3%) requiring conversion to the Hasson technique and two injuries to intraabdominal structures (peritoneal minor bruising, liver injury requiring conversion to open procedure, 6%), There was one incidence of gas leakage (3%). There were no reports of port site herniation at a mean follow up of 9 months.

CONCLUSION

Direct placement of a bladeless trocar under direct vision in a desufflated abdomen can reduce port placement time when compared to the Hasson technique. The benefits are maximised by using the bladeless trocar for procedures not requiring intact specimen removal. However, despite visualisation of tissue layers, this port cannot prevent serious intra abdominal injuries that can occur in a higher percentage of cases in comparison to the Hasson technique.

Effect of smooth muscle relaxant drugs on proximal human ureteric activity in vivo: a pilot study

Drugs are increasingly being used to promote stone passage in renal colic. Diclofenac, nifedipine and tamsulosin cause ureteric smooth muscle relaxation in vitro; however, in clinical trials nifedipine and tamsulosin promote stone passage whereas diclofenac has no apparent benefit. We adapted a ureteric pressure transducer catheter in an attempt to compare the human ureteric response to these drugs in vivo. The catheter was inserted into the contralateral ureter following ureteroscopy for stone disease. Contraction frequency, pressure and velocity measurements were recorded at 24 h. Each patient was randomly allocated to receive oral diclofenac, nifedipine or tamsulosin. Measurements were taken following drug administration. Eighteen patients (mean age 50 years) were recruited. Two patients were excluded intraoperatively and three required early removal of the catheter. Prior to drug administration, the mean number of contractions recorded was 0-4.1/min and the peak contraction pressure ranged from 11 to 35 mmHg. Conduction velocity ranged from 1.5 to 2.6 cm/s. Ureteric peristalsis persisted in all patients despite these drugs. Diclofenac and nifedipine produced inconsistent ureteric pressure responses but had little effect on contraction frequency. Tamsulosin significantly reduced ureteric pressure but had no effect on contraction frequency. There are many limitations associated with the use of ureteric catheters, however, they may provide some useful information when used to record the response to an intervention in the same patient. These preliminary results suggest a reduction in pressure generation may be the essential factor in the promotion of stone passage. More work is required but these drugs may work by preventing the increased, uncoordinated muscular activity seen in renal colic whilst maintaining peristalsis, thereby promoting stone passage.

Does rate matter? The results of a randomized controlled trial of 60 versus 120 shocks per minute for shock wave lithotripsy of renal calculi

PURPOSE

In this study we prospectively compared 2 rates of shock wave delivery, 60 and 120 shock waves per minute, to determine whether rate affects outcome with the Dornier Lithotripter S, a lithotriptor with an electromagnetic shock wave source, for renal calculi.

MATERIALS AND METHODS

A total of 104 patients with uncomplicated single renal calculus were randomized and treated. Following a single treatment patients were reviewed at 3 months to determine outcome. A plain abdominal x-ray was performed and the size of any residual fragments was noted. Four patients were lost to followup, 1 in the 60 shock waves per minute group and 3 in the 120 shock waves per minute group.

RESULTS

Of the 100 patients with complete followup 49 were treated at 60 shock waves per minute and 51 at 120 shock waves per minute. There was no statistically significant difference between mean stone area treated (p = 0.32) or additional analgesic use in the form of patient controlled alfentanil (p = 0.82). A successful outcome was defined by fragments smaller than 4 mm or stone-free status. At 60 shock waves per minute 59% of patients had a successful outcome compared with 61% at 120 shock waves per minute (p = 0.87) following a single treatment. Post-treatment complications were similar in both groups at 8% for 120 shock waves per minute and 10% for 60 shock waves per minute (p = 0.68).

CONCLUSIONS

There was no significant difference in patient controlled analgesia use, complications or outcome between rates 60 and 120. Contrary to previous studies these results suggest that a slower rate of shock wave delivery during extracorporeal shock wave lithotripsy for renal calculi does not improve treatment efficacy with the Dornier Lithotripter S.

A comparative in vitro study to determine the beneficial effect of calcium-channel and alpha(1)-adrenoceptor antagonism on human ureteric activity

OBJECTIVE

To compare the in vitro human ureteric muscle response to calcium-channel and alpha-adrenoceptor antagonists, to determine the promoting factor for stone passage. Clinical trials suggest that stone passage in renal colic can be promoted by ureteric relaxation using these agents, however nonsteroidal anti-inflammatory drugs appear to reduce ureteric activity in vitro but do not promote stone passage when used in clinical trials.

MATERIALS AND METHODS

Human ureteric muscle strips were used to record the effect that each drug had on muscle tone in vitro. The ureter was obtained at open nephrectomy or cystectomy. Potassium-enriched Krebs' solution was used to evoke maximal muscle tone, followed by adding each drug in increasing concentrations to determine the percentage reduction in tone. The drugs used to represent each group were nifedipine, 5-methylurapidil (5-MU) and diclofenac. In all, 201 ureteric strips were obtained from 39 patients.

RESULTS

At all drug concentrations, the in vitro relaxant effect of nifedipine and 5-MU was greater than that of diclofenac. At 10(-5) M the median reduction in proximal and distal ureteric tone to diclofenac, nifedipine and 5-MU were 18%, 5% and 47%, vs 57%, 33% and 65%, respectively.

CONCLUSION

Nifedipine and 5-MU produced greater ureteric relaxation in vitro than diclofenac; they predominantly relax distal ureter. This suggests that a reduction in ureteric muscle tone, as opposed to complete ablation of activity, might be the promoting factor for stone passage.

A reminder of the association between Clostridium septicum and colonic adenocarcinoma

We present the case of a patient, with previously unknown liver metastases, presenting with a liver abscess and Clostridium septicum septicaemia. C. septicum is known to be associated with both malignancy and immunosuppression and therefore in patients where this organism is isolated, efforts must be made to exclude an occult underlying malignancy or haematological disorder.

Antegrade versus Retrograde Endopyelotomy for Pelvi-Ureteric Junction (PUJ) Obstruction

OBJECTIVES

To compare complication and success rates of antegrade and retrograde endopyelotomy performed over 10 years and to define possible risk factors associated with treatment failure.

METHODS

From 1994 to 2004, 61 patients underwent a total of 68 endoscopic treatments: 19 antegrade and 49 retrograde endopyelotomy procedures. Antegrade endopyelotomy was always performed using diathermy. In the first 18 procedures retrograde endopyelotomy was performed using diathermy. In the most recent 30 procedures the incision was made using holmium laser. Endoluminal ultrasound was used in 78% of retrograde endopyelotomy and in 5% of antegrade endopyelotomy.

RESULTS

The retrograde endopyelotomy patients demonstrated significantly lower complication rates (12.5% vs. 42%) and shorter hospital stay (1.5 vs. 7 days) than the antegrade endopyelotomy patients. The mean follow up of the patients who remained free from disease recurrence during the study period was 46 and 24 months for the antegrade and retrograde endopyelotomy group, respectively. The overall success rate (mean time to failure) of antegrade and retrograde endopyelotomy was 56% (31 months) and 70% (17 months), respectively. There was no statistically significant increase in the overall success rate of retrograde endopyelotomy using endoluminal ultrasound per se. Stratifying retrograde endopyelotomy by the type of energy used for the incision, the overall success rate (mean time to failure) was 80% (10 months) and 53% (21 months) for Holmium laser and diathermy, respectively (p = 0.0626).

CONCLUSIONS

The overall success of antegrade and retrograde endopyelotomy in this series appears to be largely a factor of lead-time bias and is similar enough to recommend retrograde endopyelotomy with holmium laser on the basis of its relative safety and shorter hospital stay.

Evidence for the use of silver-alloy-coated urethral catheters

Catheter-associated urinary tract infections (CAUTIs) are a common occurrence and are associated with increased patient morbidity and mortality. In addition, they delay patient discharge from hospital, substantially increase hospital costs and promote the emergence of resistant organisms. Any intervention resulting in a decrease in the incidence of CAUTIs would have a significant impact on patient quality of life and hospital costs. By reviewing the current literature, it can be seen that the use of silver-alloy-coated hydrogel catheters can reduce CAUTIs by up to 45%. Despite reducing CAUTIs in most hospital situations, the greatest reduction is seen in postoperative patients, intensive care unit patients and burns patients.

A 3-year review of The British Association of Urological Surgeons Section of Endourology Laparoscopic Nephrectomy Audit

OBJECTIVE

To report and compare the data obtained from the BAUS UK national laparoscopic nephrectomy audit over the past 3 years.

METHODS

Each year, consultants performing laparoscopic nephrectomy are invited to submit prospectively collected data on all patients so treated at their centres. The data from each centre is entered into a nationally established database using a standard data-collection sheet. The indications for surgery, and data during and after surgery are collected. Since 2001, data were reported on 1294 laparoscopic nephrectomies.

RESULTS

Over the 3 years, the number of centres returning data has increased from 25 to 48. In 2002, data on 263 nephrectomies were returned; by 2004, this had increased to 598. In all three audits, most cases were for nonfunctioning kidneys and renal cell carcinoma, with transitional cell carcinoma and stones forming a smaller proportion. Over the 3 years, the mean (range) operative duration has reduced from 173 (89-335) to 166 (42-395) min. The median postoperative stay remained at 4-5 days, with a wide range reflecting other than clinical reasons for delayed discharge. The mortality rate remained low, at 0.7% and 0.2%, respectively, for 2002 and 2004. The mean conversion rate remained at 6-8% and the mean complication rate at 17-2%, but the proportion of major complications reduced from 10% to 4%. The transfusion rate also reduced from 10% to 7%. The operative duration, transfusion and conversion rates were higher in those centres performing fewer than 12 cases/year than in those performing at least one case per month.

CONCLUSION

The BAUS laparoscopic nephrectomy audit is an effective method for ensuring both the safe and widespread implementation of this relatively new technique to the UK, and compliance with internationally accepted standards. This audit has shown differences in clinical outcomes in favour of high-volume centres, which may help to inform decisions about the centralization of urological laparoscopy services.

Our Experience with Retroperitoneal and Transperitoneal Laparoscopic Pyeloplasty for Pelvi-Ureteric Junction Obstruction

OBJECTIVE

Laparoscopic dismembered pyeloplasty has been quoted to have equivalent success rates to the traditional open procedure in the treatment of pelvi-ureteric junction obstruction (PUJO). The aim of this study was to report our experience with laparoscopic pyeloplasty.

PATIENTS AND METHODS

All patients with PUJO are entered into a database to record patient, operative and post-operative details. Over an eleven-year period, 176 procedures were performed. Eighty-three procedures were dismembered laparoscopic pyeloplasties, of which two retroperitoneal procedures were converted to open. The first 17 procedures were performed via the retroperitoneal approach and the following 66 via the transperitoneal route. Thirty-one procedures were open pyeloplasty.

RESULTS

The retroperitoneal group had a mean follow up of 35 (16-66) months. Five patients (33%) developed recurrent symptoms with evidence of obstruction seen on the renogram within 4 months and required further surgery. The transperitoneal group had a mean follow up of 15 (3-38) months. Five patients were classified as failures (mean time to failure 4.6 months) resulting in a success rate of 92% for the transperitoneal route. Both groups had a mean post-operative hospital stay of 3.6 days. Open pyeloplasty at our institution has a success rate of 88% at a mean follow up of 85 months (range 3-260 months) and a mean length of post-operative stay of 6 days.

CONCLUSION

Overall our success rate following laparoscopic pyeloplasty is 88%. However, our preferred approach is transperitoneal, which is associated with a success rate of 92%. This is equivalent, if not better than that seen following open pyeloplasty with the additional benefits of reduced hospital stay and time to recovery. There are many possible explanations for this difference in success rates between approaches, however equivalent results are reported in the literature and therefore the learning curve is likely to be the major factor in this series.

MAP kinase pathways in the yeast Saccharomyces cerevisiae

A cascade of three protein kinases known as a mitogen-activated protein kinase (MAPK) cascade is commonly found as part of the signaling pathways in eukaryotic cells. Almost two decades of genetic and biochemical experimentation plus the recently completed DNA sequence of the Saccharomyces cerevisiae genome have revealed just five functionally distinct MAPK cascades in this yeast. Sexual conjugation, cell growth, and adaptation to stress, for example, all require MAPK-mediated cellular responses. A primary function of these cascades appears to be the regulation of gene expression in response to extracellular signals or as part of specific developmental processes. In addition, the MAPK cascades often appear to regulate the cell cycle and vice versa. Despite the success of the gene hunter era in revealing these pathways, there are still many significant gaps in our knowledge of the molecular mechanisms for activation of these cascades and how the cascades regulate cell function. For example, comparison of different yeast signaling pathways reveals a surprising variety of different types of upstream signaling proteins that function to activate a MAPK cascade, yet how the upstream proteins actually activate the cascade remains unclear. We also know that the yeast MAPK pathways regulate each other and interact with other signaling pathways to produce a coordinated pattern of gene expression, but the molecular mechanisms of this cross talk are poorly understood. This review is therefore an attempt to present the current knowledge of MAPK pathways in yeast and some directions for future research in this area.

Propylene glycol-induced proximal renal tubular cell injury

Propylene glycol is a solvent that is used in many oral, injectable, and topical medications. Although uncommon, acute renal failure has been attributed to propylene glycol. The mechanism of propylene glycol-mediated renal injury is unknown. We report a case of acute renal failure in a 16-year-old boy given large doses of pentobarbital and phenobarbital, both of which are solubilized with propylene glycol. A renal biopsy showed proximal renal tubular cell swelling and vacuole formation. The data from this case suggest that the reversible acute renal failure caused by propylene glycol is attributable to proximal renal tubular cell injury.

The treatment of idiopathic and diabetic gastroparesis with acute intravenous and chronic oral erythromycin

The objective of this study was to investigate the effects of intravenous erythromycin and chronic oral dosing of erythromycin on gastric emptying in patients with idiopathic or diabetic gastroparesis. Symptoms were assessed on oral dosing and during long-term follow-up in an ambulatory setting at a University referral center. Fourteen patients (10 idiopathic and four diabetic gastroparesis) were studied. Four patients left during the 4-wk study; two due to rash, one with cramps and vomiting on erythromycin, and one due to other medical problems. Ten patients completed the 4-wk study and commenced long-term therapy. Five of these patients experienced enough symptomatic relief to continue oral erythromycin long-term, being followed for an average period of 8.4 months. After initial documentation of delayed gastric emptying, patients received 6 mg/kg intravenous erythromycin lactobionate before a second gastric emptying study. Erythromycin base was then given orally at a dose of 500 mg tid-ac and qhs, with a final gastric emptying study performed after 4 wk. During long-term follow-up, erythromycin dosage was adjusted to minimize symptoms. Radionuclide-labeled gastric emptying of a solid meal was studied at baseline, following intravenous erythromycin, and after 4 wk of oral treatment with erythromycin. Symptom scores were assessed at baseline, at 4 wk, and then at 8-wk intervals. The percentage of the solid meal retained in the stomach at 2 h decreased from 85% +/- 11% (SD) at baseline to 20% +/- 29% following intravenous erythromycin (p < 0.001), and to 48% +/- 21% after 4 wk of oral therapy (p < 0.01 vs. baseline). There was a reduction in total symptom scores and a significant reduction in global assessment scores (p = 0.03). We conclude that erythromycin has a strong gastric prokinetic effect in both idiopathic and diabetic gastroparesis, and may represent a useful new therapeutic approach to this problem.

The laser Doppler analysis of posturally induced changes in skin blood flow at elevated temperatures

Recently, it has become possible to use laser Doppler techniques to separately quantitate the two components of blood flow, microvascular volume and red blood cell velocity. We used these techniques in 21 normal volunteers to quantitate the effect of postural changes in skin blood flow and its components at 35 degrees C and at 44 degrees C. Postural skin blood flow changes have ben studied extensively at basal skin temperature, but not at elevated temperatures. We contrasted changes at sites with arteriovenous anastomotic (AVA) blood flow (toe and finger pulps) with changes at sites with primarily nutritive flow (elbow and knee). Skin blood flow increased markedly with increasing temperature. The increases at the elbow and knee were the products of equivalent increases in both microvascular volume and velocity. In contrast, the increases on the finger and toe pulps were mainly due to increases in velocity. Elevation of both upper and lower extremities brought about a decrease in skin blood flow. Dependency increased blood flow. The magnitudes of observed changes were greater on the lower extremity than on the upper extremity and greater at 44 degrees C than at 35 degrees C. Once again, with postural change, the nutritive areas exhibited similar changes in volume and velocity while the AVA areas primarily showed velocity alterations. The correlation of systolic pulse pressures with blood flow was greater at the AVA areas than at nutritive areas and greater at 44 degrees C than at 35 degrees C. This correlation was with the velocity rather than with the volume component.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of acutely infected arthroplasty with local antibiotics

The authors have identified 22 patients with acutely infected total joint arthroplasties, 9 hips, and 13 knees. Following organism identification and assessment of the patients' general medical condition, the patients were treated with an implantable antibiotic pump. This allowed the delivery of a high concentration of antibiotic solution to a localized area. Systemic levels of antibiotic were kept to a minimum, thereby eliminating potential serious side effects of antibiotic treatment. Local concentrations were extremely high, exceeding the minimal inhibitory concentration (MIC) in all cases by 8-10-fold. Twenty patients have been followed for 30 months, and of these, 17 patients are considered to be infection free. There were three failures. The organisms that have been treated have been gram negatives, gram positives, and some mixed infections. Results are encouraging with this form of treatment, and additional patients are continually being added to the study.

Extrathoracic and transthoracic management of vascular disease of the aortic arch branches: a 16-year experience

To determine factors influencing results of operation for proximal brachiocephalic arterial disease, a 16-year review of 74 consecutive patients was undertaken. A total of 62 subclavian, 14 common carotid, 6 innominate, and 2 vertebral arteries were revascularized during 79 procedures. The approach was transthoracic in 12 operations and extrathoracic in 67. Mean follow-up was 57 +/- 45 months. Two patients (2.5%) died of stroke after extrathoracic revascularization of the common carotid artery. Cumulative 5-year and 10-year freedom from neurological events was 81% and 75%, respectively. The best results were obtained with transthoracic procedures, with revascularization of the subclavian artery rather than the common carotid artery, and in operations performed in patients without associated distal carotid disease. In view of the recent progress in operative techniques and postoperative surgical care, the choice between the transthoracic approach and the extrathoracic approach should not be biased; rather, they should remain equal and viable alternatives based on anatomical and clinical features of the individual patients.

Operative treatment of displaced intra-articular fractures of the calcaneus

Thirty-five patients with 41 calcaneus fractures, seen at Cook County Hospital over a 3 1/2-year period, underwent an open reduction and internal fixation of their fractures through a sinus tarsi incision. Bohler's angle averaged 6 degrees preoperatively and 26 degrees postoperatively. An additional measurement, the critical angle, was defined. This angle is a measurement of the congruency of the posterior facet. It facilitated the selection of patients for an open reduction as well as allowed a determination of the adequacy of restoration of the joint surfaces postoperatively. In this series the critical angle averaged 26 degrees preoperatively and 1 degree postoperatively. Followup was possible in 73% of the patients. Almost all of the patients exhibited some degree of limitation of motion of the subtalar joint, but the reduction of the fracture fragments was maintained in all cases and secondary deformity and complaints did not develop.

Local delivery of antibiotics via an implantable pump in the treatment of osteomyelitis

Twenty-one patients with osteomyelitis were treated with surgical debridement and local antibiotic therapy. Amikacin (19 patients) or netilmicin (2 patients) was delivered locally via a pump implanted subcutaneously. The outflow catheters were led from the pump subcutaneously to the infected area and placed in the defect created by the surgical debridement. The pump was refilled at intervals, on an outpatient basis. The pump was surgically removed at the conclusion of therapy. Follow-up evaluation was for 12-27 months. The duration of hospitalization was five to 52 days (mean, 23 days). The infusions were sustained for 32-140 days (mean, 63 days). Systemic levels of antibiotics were always below acceptable trough levels. Levels in the wound drainage of the 11 patients who drained after operation were always greater than the upper limit of the assay. Nephrotoxicity and ototoxicity were determined using pre- and posttherapy creatinine clearances and audiograms. Two patients exhibited minimal nephrotoxicity (creatinine clearance of 66 ml/minute and 55 ml/minute; normal, 70 ml/minute). There were no other adverse effects of the antibiotics. Sixteen patients have not drained since removal of the pumps.