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Biomedical subjects

M S Michel

Publications and source records attributed to M S Michel.

At least 19 recordsLinked to original sources

[Hematogenous contact dermatitis after intravesicular instillation of mitomycin C].

Mitomycin C is an alkylating chemotherapeutic agent which is instilled intravesically to prevent recurrence of superficial bladder carcinomas. After several cycles of mitomycin C, our patient developed a pruritic genital dermatitis and palmar desquamation. Following exclusion of a fungal infection, we performed patch tests using the standard series, the major basic ointment ingredients, disinfectants, and mitomycin C in concentrations of 0.001 to 0.1%; the resulting diagnosis was allergic contact dermatitis due to delayed-type hypersensitivity to mitomycin C. The skin rash rapidly resolved with application of topical steroids, and the intravesical chemotherapy was changed to doxorubicin. Eczematous skin reactions are quite common side effects after intravesical instillation of mitomycin C. In the majority of cases, they are caused by delayed-type hypersensitivity reactions, presumably elicited by hematogenous spread of the allergen, and not by irritation. The sensitization most likely occurs via the bladder mucosa. In order to differentiate between allergic and toxic contact dermatitis, patch tests with the above-mentioned mitomycin C concentrations are useful. In cases of mild allergic contact dermatitis the intravesical chemotherapy might be continued with concomitant topical steroids.

Administration, Intravesical↗

Shock wave lithotripsy versus ureteroscopy for distal ureteral calculi: a prospective study.

We performed a prospective, non-randomised study to determine the appropriate first-line treatment modality for distal ureteral stones. Between 2003 and 2004, a total of 124 patients with distal ureteral calculi were entered into the study (mean age 48 years, 35 women and 99 men). Sixty-two patients were treated with shock wave lithotripsy (SWL) and 62 patients with ureteroscopy (URS). The average stone size was 6.9 mm (3-33 mm) for SWL and 7.2 mm (3-30 mm) for URS. The treatment decision depended on the patients' preference and clinical parameters (i.e. contraindications for anaesthesia). URS was performed under general anaesthesia, using semirigid 8 Fr instruments. SWL was performed under analgo-sedation using a Modulith SLX. Of patients treated with SWL, 84% had a treatment success within 7 days, 98% after URS. These results show a significant success (P=0.005) in favour of URS. The average in-patient stay after SWL was 3 days and for URS 4 days (not significant). The results show a high efficacy and a low complication rate for both modalities. The attained stone-free rate shows a significant advantage for primary URS.

Adult↗

[Further development of urology in the tension field of surgical and molecular medicine].

Methods based on molecular biology and molecular medicine now have important practical applications in many areas of theoretical and clinical medicine, and it is no longer possible to imagine life without them. This means that in a largely surgical discipline, such as urology, completely new challenges are coming to the fore, which urology, as an academic and clinical discipline, now has to face up to, and to a much greater degree than hitherto. However, there is less and less freedom of action in any university department of urology, as a result not only of intensified legal outline conditions in the healthcare sector and tight public budgets, but also of faculty- and hospital-specific blocks to innovation. There is an urgent need for the creation of appropriate outline conditions and innovative structures that will allow efficient surgical care and also an efficient way of working scientifically.

Academies and Institutes↗

Protein profiling of bladder cancer using the 2D-PAGE and SELDI-TOF-MS technique.

Protein profiling is a promising tool for tumor characterization and the detection of tumor markers in bladder cancer. Techniques for 2-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and surface-enhanced laser desorption/ionization with time-of-flight mass spectrometry (SELDI-TOF-MS) have improved; both were evaluated using bladder tumor tissue. Normal urothelium and pTa G2, pT1 G3, and >or=pT3 G3 tissues were obtained from the operating room and, after macrodissection, subjected to 2D-PAGE and to SELDI-TOF-MS ProteinChip. 2D-PAGE gels expressed significantly different protein patterns for pTa G2 and pT3 G3 tumors. pT1 G3 tumors showed expression profiles similar to those of the invasive tumors, with upregulation of galectin 3, gelsolin, villin 2, moesin, and annexin 6. Similarly, distinct protein peaks were detected for superficial and muscle-invasive urothelial cancers by SELDI-TOF-MS. Six of seven superficial pTa G2 tumors showed an intense peak at 6.7 and 10.1 kD, while invasive carcinomas showed an intense peak near 9.5 kD. No disturbing influence of surrounding tissue on the results was detected. It was shown that both techniques (2D-PAGE and ProteinChip) work well, and especially ProteinChip analysis seems promising for clinical application.

Biomarkers, Tumor↗

[Foreign body in the urinary bladder after vascular surgery].

INTRODUCTION: We are presenting a rare complication after femorofemoral bypass surgery. CASE REPORT: In a 61-year-old male patient, a femorofemoral crossover bypass graft was inadvertently placed through the urinary bladder. Postoperatively, the patient developed macrohematuria, which cleared spontaneously. The diagnosis of an intravesical graft was made 3 months after surgery by cystoscopy performed because of dysuria. The patient underwent open bladder surgery 7 months later as he refused earlier intervention. The misplaced graft, which was not infected and showed good function and perfusion, was extravesically relocated. At a 16-month follow-up examination, the patient is free of urological symptoms and the bypass functions well. CONCLUSIONS: In case of dysuria or macrohematuria after vascular surgery in the vicinity of the urinary bladder, a misplaced bypass should be excluded.

Anastomosis, Surgical↗

Relaxant effects of beta-adrenergic agonists on porcine and human detrusor muscle.

AIM: Relaxant effects of different beta-adrenoceptor agonists on porcine and human detrusor were examined. Thus, the beta-adrenoceptor subtype mainly responsible for relaxation in the detrusor muscle of pigs was characterized. Additionally, different effects of several beta-agonists in both species were shown. METHODS: Experiments were performed on muscle strips of porcine and human detrusor suspended in a tissue bath. The relaxant effects of the non-selective beta-agonist isoprenaline, the selective beta2-agonists procaterol, salbutamol and the selective beta3-agonists BRL 37344, CL 316 243 and CGP 12177 on potassium-induced contraction were investigated. The inhibitory effect of different substances on the maximum contraction and the rank order of potency for endogenous catecholamines was determined in pigs. Furthermore, concentration-relaxation curves were performed for pigs and humans. RESULTS: Pigs: In the pre-treatment experiments isoprenaline and procaterol showed similar effects. The concentration-response experiments showed that the maximum relaxation induced by procaterol and salbutamol was more than 90%, not significantly different from isoprenaline, whereas the maximum relaxations of CL 316 243, BRL 37344 and CGP 12177 amounted to 68, 70 or 30%, respectively. Rank order of potencies was isoprenaline > or = adrenaline > noradrenaline. Humans: Isoprenaline, procaterol, salbutamol and CL 316 243 showed a maximum relaxation of 80, 41, 24 and 35% and pD2 values of 6.24, 5.65, 5.48 and 5.55, respectively. CONCLUSION: Beta2-receptors play a main functional role in mediating relaxation of porcine detrusor. Selective beta2- and beta3-agonists similarly relax the human detrusor. Effects were smaller compared with the pig.

Adrenergic beta-Agonists↗

[Chemoprevention of prostate cancer].

Despite advances in the detection and management of prostate cancer, this disease remains a major cause of morbidity and mortality in men. Increasing attention has focused on the role of chemoprevention for prostate cancer, i.e., the administration of agents that inhibit one or more steps in the natural course of prostate carcinogenesis. We review prostate cancer chemoprevention studies in Europe. Published studies were identified in a search of MEDLINE. Information about ongoing studies was provided by author access to protocols. A variety of chemoprevention studies have focused on the role of dietary factors, vitamins, and trace elements in prostate cancer. Some of these studies have been prospective, randomized, and double-blinded, while others have used retrospective or epidemiological approaches. Large-scale randomized studies are also evaluating the role of 5alpha-reductase inhibitors, which inhibit the conversion of testosterone to the more potent androgen dihydrotestosterone. Robust evidence is lacking for the value of chemopreventive agents in prostate cancer. Current evidence does suggest that vitamin E and selenium may have a role in prostate cancer chemoprevention. Data from two studies, one examining the type 1 5alpha-reductase selective inhibitor finasteride and the other using the dual 5a-reductase inhibitor dutasteride, will determine the benefits of androgen inhibition strategies for prostate cancer chemoprevention.

Anticarcinogenic Agents↗

[Early instillation in superficial bladder carcinoma. Current status].

The high recurrence rate in superficial bladder cancer (>70%) is caused by the adhesion of free floating tumor cells during transurethral treatment, by incomplete resections, and by overlooked and new tumors. Frequent follow-ups and reoperations are necessary. A single immediate instillation after TUR shows positive effects in reducing recurrence rates and is therefore recommended in the European Guidelines from 2001. The amount, concentration, instillation time, and substances have not yet been standardized. By analyzing the literature we found many different techniques of early instillation therapy. Different substances, concentrations, varying instillation times, and application times make a comparison of these studies very difficult. Further studies are needed to standardize early postoperative instillation therapy.

Administration, Intravesical↗

[Urodynamic findings in patients with infantile cerebral palsy].

OBJECTIVE: Aim of study was to evaluate the urodynamic findings in patients with infantile cerebral palsy. MATERIAL AND METHODS: In 29 patients (aged 3-53), a videourodynamic investigation was performed after evaluation of urological anamnesis, clinical assessment and sonographic determination of residual urine. The patients were divided into group 1 (23 symptomatic patients aged 5 years and older with recurrent urinary tract infection, pollakiuria or urinary incontinence) and group 2 (6 asymptomatic patients). RESULTS: In group 1, 21/23 patients (91%) had reduced compliance (0.6 - 16.4 ml/cmH(2)O) and 16/23 patients (70%) increased leak point pressure (> 40 cmH(2)O). In all 23 patients, detrusor instability and detrusor sphincter dyssynergia (during voiding) was found. Fluoroscopy showed bladder trabeculation or diverticula in 14 patients (61%) and 2nd-3rd degree vesicoureterorenal reflux in 2 patients (9%). In group 2, 2/6 patients (33%) had reduced compliance (0.7 and 5.8 ml/cmH(2)O) and 4/6 (67%) increased leak point pressure (> 40 cmH(2)O). In 5/6 patients (83%), detrusor instability and detrusor sphincter dyssynergia was seen. Fluoroscopy showed bladder trabeculation in 3 patients (50%), whereas no reflux was observed. Only one of the 29 patients (3 %) showed no pathological videourodynamic or anamnestic findings. CONCLUSIONS: We conclude that videourodynamic assessment should be performed in all patients with infantile cerebral palsy. The decision should not be based on clinical symptoms such as pollakiuria, recurrent urinary tract infection or urinary incontinence.

Adolescent↗

[Established and new urological therapeutic options in the management of prostate carcinoma].

The surgical and medical management of carcinoma of the prostate is a central issue in urology. Radical prostatectomy is the standard procedure in the curative therapy of locally confined carcinoma of the prostate. Recently, alternative minimally invasive options such as brachytherapy and the still experimental focused ultrasound and cryotherapy have gained in interest. Further palliative schemes such as hormonal ablation and chemotherapy have become established in the management of locally advanced and generalized carcinoma or elderly patients. It was our objective to give an account of these established and new urological therapy options in the management of carcinoma of the prostate.

Aged↗

[Detection of prostate carcinomas with T1-weighted dynamic contrast-enhanced MRI. Value of two-compartment model].

AIM: The suitability of dynamic parameters of the two-compartment model for detecting prostate carcinomas and its correlation with tumor microvascular density were evaluated. METHODS: The study included 43 patients with biopsy-proven prostate carcinoma: 28 were examined by 1.0-T MRI (Turbo-FLASH) and 15 by 1.5-T MRI (FLASH) with infusion of 0.1 mmol/kg Gd-DTPA. Signal time curves were parametrized with an open two-compartment model in amplitude and exchange rate constants (k(ep)). The microvascular density of resected prostate carcinomas was determined. RESULTS: The microvascular density in the tumors was significantly higher than in the adjacent healthy prostate tissue and correlated in both sequences with k(ep). Prostate carcinomas of the peripheral zone were demarcated by amplitude and k(ep). In the Turbo-FLASH sequence there was a significant difference between the tumor tissue and healthy peripheral zone in terms of k(ep) and in the FLASH sequence in terms of amplitude. CONCLUSION: Prostate carcinomas can be visualized with dynamic T1-weighted MR sequences using a two-compartment model. Moreover, the parameter k(ep) reveals the microvascular density in the tumor and can thus provide valuable clinical information for characterizing the tumors.

Biopsy↗

[Urologic interventional therapy of kidney calculi (II)--Endoscopic methods: ureterorenoscopy and percutaneous nephrolitholapaxy].

Although ESWL allows for the treatment of most urinary stones, there are remaining situations, in which satisfying results cannot be achieved, e.g. large kidney stones or specific anatomy. In such cases endoscopic procedure like ureterorenoscopy (URS) or percutaneous nephrolithotomy (PCNL), alone or in combination with ESWL, allow minimally-invasive removal of these stones. Primarily, the development of modern intracorporeal lithotripter probes and extraction instruments along with a reduction of instruments' diameter could improve efficacy and reduce mortality. This article will provide an overview of techniques, application and results of endoscopic urinary stone treatment.

Combined Modality Therapy↗

[Urologic interventional therapy of kidney calculi (I)--extracorporeal shockwave lithotripsy].

With a prevalence of around 5% in western countries, urolithiasis is a frequently occurring disease but with a poorly understood pathogenesis. Effective prevention is not possible for most stone types, in particular for calcium-containing stones, which occur most frequently. Additionally, after occurrence, patient compliance is often inadequate. Interventional therapy becomes necessary after stone manifestation within the urinary tract. Not all stone compositions respond to a drug treatment. Whereas in the seventies, stone treatment meant open surgery newly developed minimally-invasive procedures have displaced this treatment. The clinical introduction of extracorporal shock wave lithotripsy (ESWL) has played a crucial role in this process. Today, more than 80% of all urinary stones can be treated by modern lithotripters. Combination with other minimally-invasive procedures further improve stone free rate. This article provides an overview of technique, application and results of ESWL treatment.

Humans↗

Gene delivery into prostate cancer cells by holmium laser application.

New approaches to treat prostate cancer (PCA) are utilizing gene therapy and aim to correct the disease at the genetic level. Getting a gene efficiently into the target cell is the subject of much interest. We used a holmium laser for transfecting rat PCA cells with the reporter gene pEGFP. By FACS analysis and fluorescence microscopy, we could demonstrate that cellular delivery of plasmid DNA was possible with high efficiencies up to 41.3%. Therefore, transfection of PCA cells by holmium laser might offer a promising new gene transfer strategy to PCA with minimal invasiveness.

Adenocarcinoma↗

Prostate cancer transfection by acoustic energy using pEGFP-N1 as reporter gene in the solid Dunning R-3327-MatLu tumor.

BACKGROUND: Gene therapy is expected to play a major role in medical treatment in the future. Several different methods for DNA transfection exist. We evaluated the efficacy and effects of transfection by acoustic energy in a standardized prostate cancer model. METHODS: Subcutaneous implantation of Dunning tumors was followed by injection of pEGFP-DNA plasmid. Tumors were treated by acoustic energy with different parameter settings and the transfection rate was assessed by FACScan. RESULTS: Standardized experimental conditions resulted in minor intragroup deviations. Intratumoral injection resulted in a transfection rate of 0.3% (control group). The statistically significant increase of 4.6% in cell transfection rate was gained by applying acoustic energy. CONCLUSIONS: DNA transfection of solid tumors can be mediated by the application of acoustic energy. Achieved transfection rates are encouraging and imply therapeutical levels. Prodrug activation or suicide gene therapy are possible fields of investigation in the treatment of prostate cancer.

Acoustics↗

Rotoresect for bloodless transurethral resection of the prostate: a 4-year follow-up.

OBJECTIVE: To report the results and long-term follow-up of transurethral resection of the prostate (TURP) with a new resection device, the Rotoresect (Karl Storz, Tuttlingen, Germany). PATIENTS AND METHODS: Most endoscopic resection techniques for benign prostatic tissue aim for high ablation rates and minimal bleeding. Available resection electrodes are effective, but cause high blood loss (loop electrode), or less bleeding but poorer ablation rates (electrovaporization). To resolve these conflicts the Rotoresect was developed in 1995; it consists of a specially designed rotating resection electrode, driven by a micromotor, and a high-frequency current to enable simultaneous coagulation, vaporization and mechanical tissue removal during resection. To date, 84 patients with benign prostatic hyperplasia have had their prostate resected with this device (mean prostate size 46.0, sd 18.4 mL) and have been assessed for up to 4 years. RESULTS: During resection there was very little bleeding, with no significant changes in haemoglobin or sodium levels. The mean (sd) duration of catheterization was 1.4 (1.1) days; the urinary peak flow rate was improved from 9.7 (3.2) to 24.2 (8.23) mL/s and the residual urine volume reduced from 187.3 (109.6) to 22.7 (19.5) mL. The International Prostate Symptom Score and quality-of-life index were both improved, from 24.0 (7.5) to 4.1 (2.7), and 4.2 (3.2) to 0.8 (0.9), respectively. Overall the results were stable during the 4 years of follow-up. CONCLUSION: The Rotoresect combines the advantages of standard resection (high ablation rate) by actively rotating the resection electrode, and the haemostatic effect of electrovaporization (minimal blood loss) by simultaneous tissue coagulation and vaporization.

Aged↗