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J Rassweiler

Publications and source records attributed to J Rassweiler.

At least 37 records · Page 2Linked to original sources
PubMed1999

Cisplatin-resistant bladder carcinoma cells: enhanced expression of metallothioneins.

Cisplatin is one of the most potent cytotoxic drugs and in chemotherapy has ameliorated numerous tumors. Nevertheless, resistance to cisplatin is a problem that is encountered in the chemotherapy of urologic tumors, especially transitional cell carcinomas. In order to improve definition of the mechanisms of cisplatin-resistance we established a series of cisplatin-resistant sublines from the cell line RT 112 in increasing concentrations of cisplatin. The most resistant subline CP3 is approximately 10 times more resistant than the parental line and shows a 10-fold cross-resistance against methotrexate, whereas vinblastine and doxorubicin are equally effective in the parental and sublines. Combined treatment of CP3 cells with cisplatin and buthionine sulfoximine (BSO) does not result in enhanced cell kill, thereby ruling out glutathione as a resistance mechanism. However, in comparison with parental cells, CP3 cells are about 1.5 times more resistant against cadmium. On the protein level, the cisplatin-resistant cells reveal an enhanced expression of metallothionein II (MTII), but not MTI, suggesting that the cisplatin resistance we observed in these sublines is at least partly mediated by MTII. These sublines will in the future serve as valuable tools for the analysis of cisplatin resistance, especially in view of metallothionein-mediated resistance mechanisms.

Antineoplastic Agents↗
PubMed1999

Geometry of laparoscopic suturing and knotting techniques.

BACKGROUND: Spatial limitation, together with a fixed trocar position, restricted handling, and movement of the instruments, is inevitably associated with reconstructive laparoscopy and retroperitoneoscopy. This problem includes not only suturing technique and instruments but also geometric factors of endoscopic reconstruction, such as optimal distances between the working trocars, length of instruments, and angles between the instruments and the object. We present an experimental access to determine the specific impact of these factors on reconstructive laparoscopy. MATERIALS AND METHODS: In an in vitro model, end-to-end anastomoses of porcine intestine were performed using a standardized intracorporeal suturing technique. Suturing was performed without and after training in reconstructive surgery with variation of the following geometric factors: (1) the distance between the working trocars (between 6 and 12 cm); (2) the position of the object (lateral right, medially, lateral left); (3) the camera position (medially, lateral right, lateral left); (4) the angle between the instruments and a horizontal line (15 degrees , 55 degrees, 90 degrees); (5) the intracorporeal length of instruments (between 10 and 25 cm); and (6) narrowed space available for the instruments (between 4 and 25 cm). RESULTS: Continual training decreased the time required for suturing between 30% to 50%. Training decreased the time required for nonsuturing activities between 50% and 70% but the time required for suturing activities only between 20% and 45%. If the space between instruments and camera was limited, shifting the camera into a lateral position simplified the procedure of intracorporeal suturing. Angles of <55 degrees between instruments and the horizontal line simplified laparoscopic suturing, as did angles of <45 degrees between the instruments. In cases of maximally narrowed space (diameter of 4 cm), a suture filament length of <10 cm decreased the time required by 30%. CONCLUSION: We suggest an isosceles triangle between the instruments with an angle between 25 degrees and 45 degrees and an angle of <55 degrees between the instruments and the horizontal line as the optimal geometry for intracorporeal suturing. These data should be considered when planning a reconstructive laparoscopic procedure (i.e., alignment of trocars, table position). However, further studies are required to confirm these preliminary results.

Anastomosis, Surgical↗
PubMed1999

Treatment of Peyronie's disease by extracorporeal shockwave therapy: evaluation of our preliminary results.

BACKGROUND: Peyronie's disease is an idiopathic disorder of the penis that produces erectile dysfunction. It affects mainly the tunica albuginea. We describe our preliminary results with extracorporal shockwave therapy (ESWT) as a new noninvasive modality for the treatment of Peyronie's disease. PATIENTS AND METHODS: In this study, 24 patients aged 36 to 67 years were treated with ESWT on the Lithostar overhead-module (Siemens). All our patients had unsuccessful medical treatment before ESWT. The average plaque was 7x15 mm. The number of shockwaves ranged from 15,000 to 25,000 (18-21 kV) delivered in four to ten sessions. Most patients needed local anesthesia before therapy. RESULTS: Four patients (17%) showed marked improvement and complete remission of the penile deviation. Six patients (25%) showed partial remission with painless erections after treatment. Four patients had painless erections after treatment but still had some penile deviation. In 10 patients (41%), ESWT failed, necessitating subsequent penile surgery. CONCLUSIONS: Our preliminary results with a response rate of 59% with ESWT for Peyronie's disease, including a 17% complete remission rate, is encouraging. However, further multicenter studies will have to prove if ESWT is a real therapeutic option for this disease.

Adult↗
PubMed1999

Complications of laparoscopic procedures in urology: experience with 2,407 procedures at 4 German centers.

PURPOSE: The 4 most active centers of the laparoscopy working group of the German Urologic Association collected data about the complications associated with laparoscopic surgery in urology. MATERIALS AND METHODS: At 4 centers 2,407 laparoscopies or retroperitoneoscopies were performed as of May 1998, including 776 for varicocelectomy, 259 for cryptorchidism, 481 for pelvic lymph node dissection, 351 for nephrectomy/heminephrectomy renal pathology, 139 for renal cyst resection, 58 for ureteral procedures, 44 for adrenalectomy, 41 for nephropexy, 41 for lymphocele fenestration, 40 for retroperitoneal para-aortic lymphadenectomy and 187 for other operations. The complications were evaluated, listed according to the anatomical specificity and grouped with respect to the surgical step during laparoscopy. RESULTS: A total of 107 complications (4.4%) occurred. The re-intervention rate was 0.8% and the mortality rate was 0.08%. The complication rate depended on the difficulty of the procedure and averaged 1.0, 3.9 and 9.2%, respectively, for easy, difficult and very difficult operations. The majority were vascular injuries (1.7%) and visceral lesions (1.1%) followed by complications of healing and infection (0.8%). Only 0.2% of complications was associated with the access technique (trocar insertion), whereas most occurred during dissection (2.9%). The complication rate was 13.3% for the first 100 procedures and subsequently averaged 3.6%. CONCLUSIONS: Critical documentation of experience from several institutions, especially for an analysis of complications of urological laparoscopy, is important for the development of this surgical technique. The overall complication rate is comparable to other specialties. Future technical developments in trocar insertion, tissue dissection and control of bleeding with our improved training program will further reduce the complication rate.

Germany↗
PubMed1999

Treatment of renal stones by extracorporeal shock wave lithotripsy.

Based on an extensive review of the literature and our own clinical experience, this article attempts to present clear guidelines for the management of various kidney stones that will be acceptable to clinical urologists and their patients. Regarding our own patients, we compared different studies and discussed the results concerning the anatomical kidney situation, stone size, stone localization and observation time. Stone-free rates of patients with calyceal diverticula calculi range from 4 to 58%, with an increase after longer follow-up periods. According to the importance of residual fragments following extracorporeal shock wave lithotripsy (ESWL), we have to distinguish between clinical insignificant residual fragments and clinical significant residual fragments. 24 months following ESWL, stone passage occurs as a continuous process, and if there are no clinical symptoms, any endoscopic procedure should be considered as over-treatment. Newer ESWL technology has increased the percentage of clinically insignificant residual fragments. We consider percutaneous nephrolithotripsy in most of the patients with renal calculi smaller than 30 mm in diameter only as second-line therapy.

Humans↗
PubMed1998

Laparoscopic nephrectomy: the experience of the laparoscopy working group of the German Urologic Association.

PURPOSE: The centers of the laparoscopy working group of the German Urologic Association collected data to prove the efficacy, safety and reproducibility of laparoscopic nephrectomy. MATERIALS AND METHODS: At 14 centers 482 laparoscopic nephrectomies have been performed until December 1996 via a transperitoneal approach in 344 (71%) and a retroperitoneal approach in 138 (29%). All 482 laparoscopic nephrectomies were performed by a total of 20 surgeons with an average of 24 procedures per surgeon (range 4 to 105). The indications for nephrectomy were benign renal pathology in 444 patients (92%), including renovascular disease in 28%, hydronephrosis in 20%, reflux nephropathy in 15%, chronic pyelonephritis in 12%, end stage nephrolithiasis in 11%, renal dysplasia in 4% and renal tuberculosis in 1%. Of the remaining 38 patients (8%) laparoscopic radical nephrectomy was performed for renal cell carcinoma in 5% and for upper tract transitional cell carcinoma in 3%. RESULTS: Operating time depended mainly on the pathology of the kidney (that is small dysplastic organ versus large hydronephrosis) and the learning curve of the surgeon. However, the average operating time did not vary significantly among the different centers (maximum 277.6 and minimum 81.9 minutes). Intraoperative or perioperative complications were noted in 29 patients (6.0%), including bleeding in 22 (4.6%), bowel injury in 3, hypercarbia in 2 and pleura lesion in 1 and pulmonary embolism in 1. The conversion rate was 10.3% (bleeding, bowel injury, difficult dissection), including 4 patients with renal tuberculosis, 2 with xanthogranulomatous nephritis, and 1 each following renal trauma and embolization. The re-intervention rate was 3.4% due to bleeding in 6 cases, abscess formation in 3, intestinal stenosis in 2 and a pancreatic fistula and port hernia in 1. Mean hospital stay was 5.4 days. CONCLUSIONS: Laparoscopic nephrectomy has become a well established procedure in those urology departments focusing on laparoscopy. The indications and results are reproducible at these centers. However, for patients with severe perinephritis (that is renal tuberculosis, xanthogranulomatous nephritis, posttraumatic atrophy) a higher likelihood of open conversion must be considered.

Adolescent↗
PubMed1998

Liarozole--a novel treatment approach for advanced prostate cancer: results of a large randomized trial versus cyproterone acetate. Liarozole Study Group.

OBJECTIVES: To compare the efficacy of oral liarozole, the first retinoic acid metabolism-blocking agent (RAMBA) to be developed as differentiation therapy for human solid tumors, with that of cyproterone acetate (CPA), an antiandrogen for the treatment of metastatic prostate cancer. Liarozole promotes differentiation of cancer cells by increasing the intratumoral levels of retinoic acid. METHODS: A total of 321 patients with metastatic prostate cancer in relapse after first-line endocrine therapy entered a Phase III international multicenter study (recruitment from February 1992 to August 1994) comparing liarozole (300 mg two times daily) with CPA (100 mg two times daily). RESULTS: Accounting for differences in baseline prognostic factors, the adjusted hazard ratio for survival was 0.74 in favor of liarozole (P = 0.039), indicating a 26% lower risk of death than in patients treated with CPA. Median crude (unadjusted) survival time was the same in the liarozole group as in the CPA group (10.3 months). More patients showed a PSA response (at least 50% reduction in PSA from baseline) when treated with liarozole (20%) than with CPA (4%) (P < 0.001). Prostate-specific antigen (PSA) responders had a median survival benefit of 10 months over nonresponders, irrespective of treatment (hazard ratio 0.43; P = 0.0018). PSA response was apparent within 3 months in approximately 90% of patients who responded. Pain improved more in the liarozole group than in the CPA group (P = 0.03). PSA responders had lower median pain scores than nonresponders (1.7 versus 2.5) and better quality of life (median Functional Living Index-Cancer score 108 versus 98) at end point, ie, treatment discontinuation, as well as throughout the treatment period. Among the most frequently occurring adverse events in the liarozole group were dry skin (51% of patients), pruritus (25%), rash (16%), nail disorders (16%), and hair loss (15%). These adverse events were generally mild to moderate in severity and did not affect the overall quality of life score. There were no detectable effects of either treatment on vital signs such as blood pressure, heart rate, electrocardiogram, and body weight. CONCLUSIONS: Liarozole is superior to CPA in terms of PSA response, PSA progression, and survival, and is capable of maintaining patients' quality of life. The observed adverse events were mild to moderate in nature. These results show that liarozole is a possible treatment option after first-line endocrine therapy has failed.

Aged↗
PubMed1998

Organ retrieval systems for endoscopic nephrectomy: a comparative study.

Laparoscopic or retroperitoneoscopic interventions such as nephrectomy or tumor nephrectomy call for the removal of large quantities of tissue, which can no longer be extracted via the relatively confined lumen of a cannula. For this purpose, a variety of organ retrieval systems have been designed and are commercially available with the aim of safe tissue retrieval. This paper summarizes the results of an experimental and clinical comparison of the most important organ entrapment systems suitable for endoscopic nephrectomy. The LapSacs was the first organ bag especially designed for laparoscopic nephrectomy. Despite various new modifications of this entrapment system, it still represents one of the best alternatives and has been used worldwide with success. However, because of its simplicity, it requires a certain laparoscopic expertise and involves a learning curve. Newly developed retrieval systems (i.e., LapBag, Extraction Bag, Endo-Catch) offer some advantages regarding the handling of the bag, which may be particularly useful during retroperitoneoscopic nephrectomy with a restricted working space. Retrieval systems (i.e., Endobag, Endopouch) with low resistance to tearing forces or permeability to tumor cells or bacteria (i.e., Espiner Bag) cannot be recommended for endoscopic nephrectomy.

Animals↗
PubMed1998

Laser endopyelotomy: minimally invasive therapy of ureteropelvic junction stenosis.

Endoscopic pyelotomy is a minimally invasive procedure that is increasingly used for the management of ureteropelvic junction (UPJ) obstruction. We report the results and advantages in the management of UPJ obstruction using a ureteroscopic retrograde laser-assisted approach (laser endopyelotomy; LEP). Thirty-four patients were treated between December 1994 and June 1997 by this new technique. Twenty-seven obstructions were primary. The mean time of follow-up is 18 months. An indwelling ureteral catheter was placed 3 weeks prior to treatment. Intraoperatively, after the removal of the stent, a guidewire was passed across the stenosis, and the ureter was entered with a semirigid ureteroscope. The LEP was then performed under visual control using a contact laser fiber until all obstructive fibers had been cut. Follow-up examinations included sonography, intravenous urography, and, in unclear cases, a radionuclide renal scan with furosemide application after 3 months. The success rate was 85%. The most important factor influencing the outcome was the grade of hydronephrosis. Postoperative side effects have been minimal, and minor complications occurred in only 5 patients (15%). Laser endopyelotomy is a minimally invasive procedure with less morbidity for the treatment of UPJ obstruction. Only patients with a severe extrinsic cause of obstruction should be excluded from this technique. These cases can be approached laparoscopically.

Adolescent↗
PubMed1998

Nephrectomy: A comparative study between the transperitoneal and retroperitoneal laparoscopic versus the open approach.

OBJECTIVES: Different techniques have been introduced to perform laparoscopic nephrectomy using either the transperitoneal or the retroperitoneal route. However, to date only few data exist comparing the results and morbidity of these procedures as well as with the standard technique of open nephrectomy. MATERIAL AND METHODS: This paper compares the clinical results of 18 transperitoneal laparoscopic nephrectomies (TLN) for benign renal disease with 17 retroperitoneal laparoscopic nephrectomies (RLN) and 19 consecutive open nephrectomies (Nx). All groups were comparable in terms of indication. The analysis of clinical data included operative time, morbidity, length of analgesic use and postoperative hospital stay. RESULTS: The mean operative time for benign disease was 206.5 for TLN, 211.2 for RLN and 117 min for open nephrectomy. Analgesic medication requirement per patient was 2 days for TLN, 1 day for RLN and 4 days for Nx while the postoperative hospital stay averaged 7 days for TLN, 6 days for RLN and 10 days for Nx. The time of convalescence was 21 days after RLN, 24 days after TLN versus 40 days after open nephrectomy. CONCLUSIONS: Our results demonstrate an overall clear advantage of a laparoscopic approach when compared to open surgery and also reveals distinct benefits of a retroperitoneal approach.

Adolescent↗
PubMed1997

Laparoscopy-assisted penile revascularization: a new method.

Analysis of more than 100 penile revascularizations using the Mannheim modification showed a success rate as high as 82% in properly selected patients. However, the dissection of the epigastric artery requires a relatively large incision, with the risk of postoperative bleeding, pain, and hernia formation. Therefore, we designed a laparoscopic approach for dissection of the epigastric vessels. From January 1995 to October 1996, we performed laparoscopy-assisted penile revascularization in 15 pharmacotesting nonresponders with erectile dysfunction. The first step is dissection of the penile vessels to minimize the occlusion time of the epigastric arteries. Thereafter, the extraperitoneal cavity is exposed using a balloon-trocar system inserted via a 15-mm suprapubic incision. A pneumoextraperitoneum is established, and two further cannulas are inserted (10 mm subumbilical, 5 mm in the lower abdomen contralateral to the desired epigastric artery). The dissection of the epigastric vessels starts caudally at the origin from the external iliac vessels and continues to the periumbilical area. All branches are dissected between clips, keeping the artery and vein together. For extraction of the artery, we insert another 5-mm port through the incision at the penile base. After desufflation of the extraperitoneal space and closure of the trocar wounds, microsurgical penile revascularization is performed using the previously described modification of the Hauri procedure. The mean operating time for laparoscopic dissection of epigastric artery was 120 minutes. No intraoperative complication occurred. One patient suffered from an inguinal hematoma. After a median follow-up of 12 month, 53% of patients showed spontaneous erections, and another 27% achieved a full erection with the aid of additional pharmacotherapy. Laparoscopic dissection of the epigastric arteries proved to be feasible, resulting in a considerable reduction of overall morbidity of penile revascularization without reducing the efficacy of the procedure.

Adult↗
PubMed1997

Successful treatment of stage-IIIB seminoma with single-agent carboplatin therapy.

Single-agent carboplatin chemotherapy has recently been introduced into the therapy of limited seminoma. Because of poor compliance due to Down's syndrome we successfully treated a 32-year-old man with relapsed stage-IIIB seminoma with a dose-modified carboplatin monotherapy schedule leading to complete remission even after a follow-up of 4 years.

Adult↗
PubMed1996

Color-coded Doppler sonography in the diagnosis of abdominal masses.

A man in his forties was operated on for testicular cancer on the right-side with subsequent radiotherapy. Two years later, another tumor was found on the opposite side and surgically removed, followed by polychemotherapy. In the follow-up period, CT scanning and ultrasound showed large abdominal masses which were suspected to be metastases. Before initiating four cycles of chemotherapy, we checked their nature by Doppler sonography and found them to be recently developed abdominal varices due to an alcoholic liver cirrhosis. We were able to demonstrate that Doppler sonography can provide further information and is easy to use.

Abdomen↗
PubMed1995

Establishment and characterization of a multidrug-resistant human bladder carcinoma cell line RT112/D21.

A doxorubicin-resistant human bladder carcinoma cell line RT112/D21 was established by continuous exposure of the parental line RT112 to increasing concentrations of doxorubicin over a period of 9 months. RT112/D21 cells expressed significantly more P-170 glycoprotein than the parental line, and rhodamine 123 efflux, as a functional parameter of P-170 glycoprotein activity, was increased. RT112/D21 cells were 96 times more resistant to doxorubicin than RT112 cells, and cross-resistance to epirubicin and vinblastine was present. Sensitivity to methotrexate and mitomycin C remained unchanged. R-verapamil reversed resistance to doxorubicin, epirubicin and vinblastine in RT112/D21 cells but did not affect sensitivity to methotrexate and mitomycin C. In RT112 cells, R-verapamil had no effect on drug sensitivity. Thus, it may be assumed that primary or induced MDR1 gene-encoded P-170 glycoprotein expression is a relevant mechanism of chemoresistance in transitional cell carcinoma, and that chemotherapeutic strategies in combination with chemosensitizers improve response rates.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Successful interferon-alpha 2 a therapy for a patient with acute mumps orchitis.

Involvement of one or both gonads in postpuberty mumps is common and can often lead to infertility. Our report discusses the course of disease of a patient with acute mumps orchitis. Only 2 days after administration of interferon, clinical symptoms had drastically improved, and the infection subsided without any after-effects. We therefore recommend immediate interferon therapy, as soon as postpuberty mumps manifests, to prevent testicular atrophy and resulting infertility.

Acute Disease↗
PubMed1995

Ureteral laparoscopic surgery.

During the past years, laparoscopy has grown in popularity and become an alternative technique for the treatment of certain pathologies in urological practice. Retroperitoneal laparoscopic procedures for ureteral surgery were first attempted by Wickham in 1979: in this case a patient with a ureteral calculus underwent a successful ureterolithotomy; More recently, the introduction of the Gaur balloon has permitted quick dilatation and easier access to the retroperitoneum. However, in comparison, the transperitoneal method offers more space and better vision for identification of anatomical landmarks. In our clinic, we have performed laparoscopic ureteral surgery using the transperitoneal as well as the retroperitoneal approach. For situations requiring reconstructive surgery, we preferred the transperitoneal approach in 3 cases of ureterolysis; 2 diagnostical and 1 therapeutical. On the other hand, the retroperitoneal approach was employed for carrying out 2 pyeloplasty, 1 ureterocutaneostomy and 1 ureterolithotomy. Furthermore, we performed in similar fashion 3 nephroureterectomy and 1 heminephrectomy combined with partial ureterectomy. In 3 cases, transperitoneal nephroureterectomy with transurethral orifice circumcision was carried out. In all patients, laparoscopy revealed low morbidity with low grade postoperative pain and shorter hospital stay. Our experience shows that the progressive use of retroperitoneoscopic surgery can maintain minimal invasiveness and permit good access to various procedures without complications connected to use of the Veress needle or the presence of abdominal adhesions. In addition to our own laparoscopic experience, we have reviewed the literature and report on the most frequent ureteral surgery performed laparoscopically.

Humans↗