Research Interests

Current research interests include:

1. Robotics in Urology and its scientific evaluation: Given the precision of robotic technology it is expected that prospective evaluation of every procedure performed over a five year period by collecting data on operative parameters and HRQoL will show advantages over conventional surgery. The above are being compared with laparoscopic and open urological counterparts; specifically the BOLERO trial of robotic versus open and laparoscopic cystectomy for bladder cancer is planned. A “robotic steering group” oversees the health sciences evaluation of this project. It is expected that evaluation of 3D and 2D vision will demonstrate the advantage of
stereoscopic vision and increased degrees of freedom. A unique evaluation of humanrobot performance in collaboration with the Jet Propulsion Lab, California using
mathematical primitives derived from space robotics has been conducted. A new mechatronic sensor is being developed in collaboration with Prof Lakmal Seneviratne at
the KCL strand campus and is supported by the EPSRC. Ergonomics by digitised video assessment of surgical posture during robotic, laparoscopic and open surgery is likely to show an advantage in favour of robotic surgery. Augmented reality and 3D planning of the operative scene within the Da Vinci system is being tested in collaboration with Prof Dave Hawkes of UCL and Dr Graeme Penny of KCL.

2. Stem cells and cell targeted therapies in prostate and bladder cancer: This is a collaborative project with Professor John Masters from UCL and the new MRC Transplantation Centre at Guys. The ultimate aim is to study the possibility of developing regenerated bladders and ileal conduits from stem cells in samples removed during robotic surgery and an immunological appraisal of the technique.

3. Bladder physiology particularly receptors such as the vanilloid receptor TRPV1, P2X3, SNAP25, SV2. New methods of assessing receptor structure and function based on high throughput methods derived from the Human Genome Project (HGP). We are investigating in the role of myofibroblasts and their relationship with connexin 42. We are using a combination of micro-array technology, real time PCR and immunohistochemistry in human tissues and a rat model. My group is collaborating with Prof Steve MacMahon at Guy’s and Prof Clare Fowler at Queen Square to answer these questions.

4. Membrane tagged technology to enhance the action of Botulinum toxin in overactive bladders in collaboration with Dr Richard Smith in our Protein Chemistry Lab in the MRC Transplant Centre. This technology has already been used to reduce complement mediated transplant injury.

Dasgupta Theses

1. The effect of intravesical capsaicin on nerve densities in the urinary bladder in patients with detrusor hyperreflexia: MSc Urol -University of London and the Chisholm Medal, 1996
2. Towards an understanding of the role of intravesical capsaicin in detrusor hyperreflexia: MD thesis -University of London, 2000-1

Summary of Theses

1. Capsaicin is the pungent extract of red-hot chilli peppers. Chillies were grown as early as 5000 BC in Mexico and have been used medicinally, for thousands of years. Animal experiments have demonstrated that capsaicin blocks a C-fibre mediated micturition reflex in spinal cats. The aim of our MRC-funded study was to investigate its role in the treatment of detrusor hyperreflexia due to spinal cord disease. Intravesical instillations of 1-2 mmol/l of capsaicin, dissolved as a powder in 30% alcohol in saline, were effective in 70% of patients with refractory detrusor hyperreflexia. Capsaicin caused an increase in the maximum cystometric capacity and decrease in the amplitude of hyperreflexic detrusor contractions. Even after repeated instillations over 5 years there was no evidence of premalignant or malignant changes in biopsies from bladders thus treated. Suprapubic discomfort during instillations was reduced by the prior use of intravesical lignocaine (40ml of 2% for 20 mins) or by anaesthetising the bladder with iontophoresis of intravesical lignocaine (electromotive drug administration) before capsaicin.

2. Cryostat sections of flexible cystoscopic biopsies before and 6 weeks after capsaicin treatment were stained with the neuronal markers S 100 and PGP 9.5. By using
computerised image analysis of lamina propria nerve densities it was found that intravesical capsaicin caused a reduction in densities of the presumptive sensory suburothelial nerves. Early data using electron microscopy seemed to show a reduction in the densities of clear and dense cored vesicles after capsaicin treatment.

3. Intravesical capsaicin is a significant advance in Uro-Neurology and has led to lead to the introduction of other neourotoxins to treat the overactive bladder, in particular Botulinum toxin.

Supervised Theses

PhD
1. XMRI in bracytherapy for prostate cancer – P Acher (examination 2009)
2. Image guided robotic prostatectomy for localised prostate cancer – S Thompson
3. Botulinum toxin in idiopathic detrusor overactivity – A Sahai (examination 2009)
4. SV2 and NOS expression and the effect of BTX-A – C Dowson

MD

1. Cell free DNA in prostate cancer – J Boddy – degree awarded
2. Botulinum toxin in detrusor overactivity – M Kalsi
3. The urothelium in urinary tract infections – R Kucheria
4. Ergonomics of Robotic, Laparoscopic and Open surgery – O Elhage

MS
1. Transatlantic telementoring and telerobotics – B Challacombe – degree awarded
2. Co-morbidity assessment in prostate cancer – R Singh (examination 2009)
3. Photodynamic cystoscopy in bladder cancer – E Ray (examination 2009)

MSc
1. Effect of flexible uretero-renoscopy on renal function – M Bultitude – degree awarded
2. Botulinum toxin in neurogenic detrusor overactivity – R Popat - degree awarded
3. Botulinum toxin in overactive bladders – P Sangster - degree awarded along with the Chisholm Gold Medal
4. Virtual Reality Laparoscopic nephrectomy – T Nedas – degree awarded along with the Chisholm Gold Medal
5. Validation of a VR Laparoscopic Nephrectomy Simulator – James Brewin
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