PubMed Health⌕ Search

Biomedical subjects

Stephan Roth

Publications and source records attributed to Stephan Roth.

17 recordsLinked to original sources

Evaluation of primary human liver cells in bioreactor cultures for extracorporeal liver support on the basis of urea production.

Primary human liver cells from donor organs unsuitable for transplantation were cultivated in bioreactors developed for extracorporeal liver support. Because each system contains cells originating from an individual organ, each bioreactor culture must be individually characterized. The objective of this study was to identify suitable decisive parameters for the evaluation of cell culture performance. We analyzed the data from 47 bioreactor cultures containing 437 +/- 110 g of cells. Choosing urea production as the decisive parameter, the bioreactor cultures were divided into high-performance (daily urea production > or = 110 mg per bioreactor between culture days 3 and 14) and low-performance cultures. Comparing the mean courses of the groups revealed a significant distinction in most other investigated biochemical parameters. In conclusion, urea production seems to be an appropriate parameter for evaluating the performance of liver cell cultures in bioreactors because it corresponds to all other evaluated parameters of cell function.

Adult↗

Adjuvant cisplatin plus methotrexate versus methotrexate, vinblastine, epirubicin, and cisplatin in locally advanced bladder cancer: results of a randomized, multicenter, phase III trial (AUO-AB 05/95).

PURPOSE: Radical cystectomy as standard treatment of muscle-invasive urothelial carcinoma of the urinary bladder cures less than 50% of patients with locally advanced bladder cancer. We compared two adjuvant combination chemotherapies in patients with stage pT3a-4a and/or pathologic node-positive transitional-cell carcinoma of the bladder after radical cystectomy. PATIENTS AND METHODS: A total of 327 patients were randomly assigned to either adjuvant systemic chemotherapy with three cycles of cisplatin 70 mg/qm(2) on day 1 and methotrexate 40 mg/qm(2) on days 8 and 15 of a 21-day cycle (CM) or three cycles of methotrexate 30 mg/qm(2) on days 1, 15, and 22, vinblastine 3 mg/qm(2) on days 2, 15, and 22, epirubicin 45 mg/qm(2) on day 2, and cisplatin 70 mg/qm(2) on day 2 of a 28-day cycle (M-VEC). RESULTS: The hazard ratio for progression-free survival as the primary end point was 1.13 (90% CI, 0.86 to 1.48) for 163 CM patients compared with 164 M-VEC patients whose right-hand limit remained below the upper bound compatible with the noninferiority hypothesis (alpha = .0403). The 5-year progression-free, tumor-specific, and overall survival rates (point estimates +/- SE) for CM versus M-VEC were 46.3% +/- 4.6% v 48.8% +/- 4.5%, 52.0% +/- 4.6% v 52.3% +/- 4.8%, and 46.1% +/- 4.3% v 45.1% +/- 4.6%, respectively. WHO grade 3 and 4 leukopenia occurred in 7.0% of patients treated with CM and 22.2% of patients treated with M-VEC (P < .0001). CONCLUSION: CM cannot be considered inferior to M-VEC with regard to progression-free survival of patients with locally advanced bladder cancer after radical cystectomy. Moreover, patients receiving adjuvant CM combination therapy experienced significantly less grade 3 and 4 leukopenia than patients treated with M-VEC.

Adult↗

Laparoscopic ureteral reconstruction: intracorporal reconfiguration of ileum and colon in a porcine model.

BACKGROUND AND PURPOSE: Long ureteral defects can be reconstructed in humans with reconfigured short colonic or ileal segments. We undertook the present study to evaluate whether laparoscopy with completely intracorporal reconfiguration could replicate open surgery results. MATERIALS AND METHODS: In eight renoureteral units of six pigs, a ureteral defect of 4.5 to 8.0 cm (mean 6.6 cm) was created. Ileum was used for reconstruction in six renal units and colon in two. A 3-cm-long segment was isolated from the intestinal tract and transversely reconfigured into a long pedicled tubular graft, which was then interposed into the ureteral defect. Reconfiguration and all anastomoses were performed by freehand intracorporal suturing and knot-tying. RESULTS: Reconstruction was successful in all cases. No significant blood loss or open conversions occurred. The mean total surgical time was 296 minutes (range 234-353 minutes). CONCLUSIONS: Ureteral repair with intracorporally reconfigured intestinal segments is technically feasible. Clinical application will await survival studies.

Anastomosis, Surgical↗

Transurethral approach to the distal ureter in nephroureterectomy: transurethral extraction vs. "pluck" technique with long-term follow-up.

OBJECTIVES: We retrospectively compared two techniques of transurethral management of the lower ureter in nephroureterectomy. PATIENTS AND METHODS: From August 1992 to December 2003, 34 patients underwent either transurethral detachment of the intramural ureter and cephalad extraction ("pluck"; Group 1, N = 18) or transection of the ureter with subsequent transurethral extraction (Group 2, N = 16). Choice of technique was left to the operating surgeon. All patients with upper tract urothelial carcinoma (TCC) were regularly followed by cystoscopy and abdominal ultrasound. RESULTS: Of the 34 patients, 29 had upper tract TCC. Mean follow-up in these was 44 months (range: 1-129), with 24 (83.8%) over 24 months. On follow-up, 14 bladder tumors (all superficial) occurred in 7 patients (24.1%), but in no case on the scar of the excised ureteral orifice. No extravesical recurrences in the former ureteral bed were found. Of the 29 with upper tract TCC, 19 (65.5%) are alive without disease (median 45 months, range: 6-129), 5 (17.2%) have died with no evidence of disease (median 34 months, range: 20-58), and 4 (13.8%) have died from progressive disease (median 18 months, range: 1-33); 1 patient was lost to follow-up at 34 months with no evidence of disease. Differences between techniques with regard to blood loss, operative time, complications, and oncologic outcome were not significant. CONCLUSION: Both techniques proved technically and oncologically safe. Bladder tumor recurrence rate was in the range reported for classic nephroureterectomy. No extravesical tumor recurrence in the former ureteral bed or on the scar of the resected ureteral orifice occurred.

Adult↗

Reconfigured colon segments as a ureteral substitute.

Reconfigured colon was used as a ureteral substitute in seven selected patients. In four patients, a single reconfigured colon segment was interposed into an extensive defect of the upper ureter. In an additional three patients with solitary kidney, reconfigured colon segments were used for the construction of a conduit. At a mean follow-up of 23 months (range: 2-38 months), no complications related to the reconfigured colon segments were noted. Two patients died of progressive disease, but with no evidence of malfunction of the ureteral substitute. Surgical access is mainly retroperitoneal, and intraperitoneal surgery is minimal. The colonic segments are taken immediately proximal to the ureteral defect, necessitating little mobilization of the mesenteric pedicle. In patients with renal insufficiency or a history of irradiation, this technique may be superior to the use of ileum. Before wider use, long term follow-up data on the uretero-intestinal anastomosis will be necessary.

Adult↗

[Not Available].

Explore the source record for details and available documents.

Journal Article↗