Biomedical subjects

Nikolaus Schmeller

Publications and source records attributed to Nikolaus Schmeller.

8 recordsLinked to original sources

PubMed2004

Decrease of mitochondrial DNA content and energy metabolism in renal cell carcinoma.

To elucidate the relationship between tumor genesis and the mitochondrial energy metabolism in renal neoplasms, we studied three individual enzyme activities of the oxidative phosphorylation, two components of the Krebs cycle and the mitochondrial DNA content of renal carcinomas including 29 conventional, five papillary, two unclassified carcinomas with sarcomatoid features and one collecting duct carcinoma. A significant reduction of all mitochondrial enzyme activities including complex V, as well as of the mitochondrial DNA content was detected in 34 of 37 renal carcinoma tissues as compared with control kidney. Mitochondrial enzyme activities and mitochondrial DNA levels were not statistically different between the conventional, papillary and unclassified sarcomatoid type of renal carcinoma and did not correlate with tumour grade, metastasis, ploidy and proliferative activity as determined by Ki-67 staining. Taken together, our data indicate that a co-ordinated down-regulation of all components necessary for mitochondrial energy metabolism occurs in most renal carcinomas as an early event in carcinoma formation, which does not change with progression of the disease.

Adult↗

PubMed2004

Improved detection of urothelial carcinoma in situ with hexaminolevulinate fluorescence cystoscopy.

PURPOSE: In this European multicenter study we compared hexaminolevulinate (HAL) fluorescence cystoscopy and standard white light cystoscopy for the detection of carcinoma in situ (CIS) in patients suspected of having high risk bladder cancer. MATERIALS AND METHODS: This study was a prospective controlled, within-patient comparison of standard and HAL fluorescence cystoscopy. Eligible patients received an intravesical instillation of 50 ml HAL 8 mM solution. Cystoscopy was performed using a D light system, which provided white and blue light at 375 to 440 nm. The bladder wall was inspected and mapped, first under white light, followed by blue light. All tumors and suspicious areas identified under white light and by red fluorescence were resected or biopsied. Histological findings were assessed by an independent central pathologist blinded to the identity of the biopsies. RESULTS: Of 211 evaluable patients 83 (39%) had CIS, of whom 18 (22%) were detected by HAL cystoscopy only, 62 (75%) were detected by standard and HAL cystoscopy, 2 (2%) were detected by standard cystoscopy only and 1 (1%) was detected by nonguided biopsy. Therefore, HAL cystoscopy identified 28% more patients with CIS than standard cystoscopy. The side effects of HAL instillation were negligible and no unexpected events were reported. CONCLUSIONS: HAL fluorescence cystoscopy improves the detection of bladder CIS significantly, which has consequences for clinical management and may improve the patient prognosis. The procedure is easily implemented as an adjunct to standard cystoscopy and it adds no significant risk of complications.

Adult↗

PubMed2003

Local recurrence in patients after radical cystectomy and orthotopic ileal neobladder: impact on function.

Whether an orthotopic bladder substitute should be constructed in patients with locally advanced or lymph node positive bladder cancer remains a subject of debate. These patients are at risk that local recurrence may impair reservoir function in orthotopic neobladders. We retrospectively assessed reservoir function in 68 consecutive patients with locally advanced bladder cancer. Tumor stage was multifocal carcinoma in situ, multifocal pT1 disease, pT2, pT3a, pT3b, and pT4a in 3, 4, 19, 11, 25, and 6 patients respectively. Lymph nodes were positive for carcinoma in 17 patients. Out of the 68 patients, 65 could be followed for at least three months. Within a median follow-up of 26 months (range three to 87 months), recurrence developed in 16 of the 65 patients (25%). 7 patients (11%) had distant failure. 9 patients (14%) showed local and distant recurrence. In the six out of the nine patients with local recurrence located lateral, dorsal, or cranial of the neobladder, adequate neobladder function was retained until the last follow-up visit or until death. Only those three patients with local recurrence involving the pelvic floor or urethra needed a suprapubic catheter due to urinary retention caused by tumor obstruction. Excluding pelvic floor and anterior urethral disease, we recommend orthotopic bladder substitution even in locally advanced but resectable disease as far as the patient is in a good performance status.

Adult↗

PubMed2003

Risks and complications in 160 living kidney donors who underwent nephroureterectomy.

BACKGROUND: The rate of living donor renal transplantations has increased. However, in view of the possible complications, the question as to whether the condition of the recipient justifies operation of the donor still remains unanswered. The present retrospective study evaluates the perioperative and post-operative risks and complications for the donor at a single major transplantation centre. METHODS: From 1994 to 2001, 160 live donor nephroureterectomies were performed. The median age of living donors was 51 years (range 21-77 years); 19 patients were older than 61 years. After confirming blood group compatibility and negative cross-match, donors underwent an extensive medical and psychological examination. Comorbidities and anatomical features of the donor were evaluated and the impact they may have on the outcome was determined. The nephroureterectomies were performed transperitoneally, with the right kidney being preferred. Pre-operative, intraoperative and post-operative complications were documented. Serum creatinine levels as well as new-onset proteinuria or hypertension were used as criteria for assessing long-term renal function. RESULTS: Complications were observed in 41 donors: 35 were minor and six were major (splenectomy; revisions due to liver bleeding, incarcerated umbilical hernia or infected pancreatic pseudocyst; pneumothorax; and acute renal failure). No patient died. Multiple arteries (14 patients), significant renal artery stenosis (two patients) and additional risk factors (e.g. increased age and previous operations) did not affect the complication rate. In the post-operative follow-up period of 0.5-62 months (mean: 38 months), renal function remained stable in all donors. CONCLUSIONS: Living donor nephrectomy appears to be a safe intervention in specialized centres, where it entails a low morbidity for the donor. Even in high-risk donors, long-term complications were not observed.

Adult↗

PubMed2003

Measurements of complement factor H-related protein (BTA-TRAK assay) and nuclear matrix protein (NMP22 assay)--useful diagnostic tools in the diagnosis of urinary bladder cancer?

Between 1997 and 2000 we investigated in a prospective study the voided urine samples of all consecutive patients undergoing cystoscopy independent from their clinical background (n = 705) with the BTA-TRAK assay (Bard Diagnostics, Redmont, USA) detecting a complement factor H-related protein (CFHrP) and the NMP22 assay (Matritech, Newton, USA) measuring a nuclear matrix protein, which is supposed to be specific for bladder cancer. The individuals were divided into three groups concerning the clinical background: 233 patients had urological diseases, 268 patients had urinary bladder cancer and 150 patients had other urological malignancies. Based on the clinical findings we compared our results with well established diagnostic methods for urinary bladder cancer such as cytology and the detection of hematuria. In addition, we investigated urine samples from 30 healthy individuals and 24 patients with urinary tract infection without performing cystoscopy. Following the recommendations of the European Group on Tumor Markers we used 95% specificity for benign urological diseases and urinary tract infections, which resulted in a sensitivity of 17% for active bladder cancer for the BTA-TRAK assay and 31% for NMP22. We compared these results with the detection of hematuria (specificity: 72%) and cytology, which had a sensitivity of 64% and 89%, respectively. Subsequently, we calculated sensitivity and specificity for the detection of relapse of the disease. Again using 95% specificity, in this case for patients with no evidence of disease (NED), in patients with recurrent disease the BTA-TRAK assay showed 8% sensitivity as compared to 12% for the NMP22 assay. Due to an insufficient specificity and sensitivity, both tests can neither be clinically useful in screening of high risk patients, nor in primary diagnosis of bladder cancer. They cannot replace neither cystoscopy nor cytology. In the follow-up care more investigations may be necessary to prove the benefit of existing diagnostic strategies for the discrimination between active and inactive bladder cancer.

Biomarkers, Tumor↗

PubMed2002

Role of 5-aminolevulinic acid in the detection of urothelial premalignant lesions.

BACKGROUND: The authors evaluated the role of 5-aminolevulinic acid (5-ALA)-induced fluorescence endoscopy (AFE) in the detection of flat urothelial lesions in light of the suggestions made for flat neoplastic lesions within the 1999 World Health Organization (WHO) classification of urinary bladder tumors. METHODS: From 1995 to 2000, 713 patients underwent 1414 AFE procedures for the detection of transitional cell carcinoma of the bladder (TCCB). Fluorescence imaging was performed with an incoherent light source (D-light; 380-440 nm) that was filtered for efficient protoporphyrin IX excitation and with cystoscopes partially blocking reflected excitation light to enable fluorescence evaluation by a red/blue color contrast 2-3 hours after 50 mL of a 3% solution of 5-ALA was instilled into the bladder. In total, 3834 biopsy specimens (mean, 2.7 specimens per AFE procedure) were taken. RESULTS: Malignant disease was found in 1250 (32.6%) of all biopsies, with 304 biopsies (24.3%) showing carcinoma in situ (cis) and dysplasia II degrees (dys II) according to the previous diagnostic criteria of the WHO. Under prior conventional white-light endoscopy, 30.3% of specimens with dys II and 52.8% of specimens with cis had been missed. CONCLUSIONS: The current results suggest that 5-ALA may be more effective in the detection of flat urothelial lesions than the current diagnostic devices.

Aminolevulinic Acid↗

PubMed2002

New aspect of photodynamic diagnosis of bladder tumors: fluorescence cytology.

OBJECTIVES: To establish a new diagnostic method for the detection and follow-up of bladder cancer that combines the principles of photodynamic diagnosis and urinary cytology. METHODS: We investigated 46 patients scheduled for transurethral resection of a bladder tumor immediately before the resection was carried out. After intravesical instillation of either 5-aminolevulinic acid (ALA) or hypericin, urinary cytology specimens were obtained. Induced fluorescence of urothelial cells was detected by fluorescence microscopy. The results were compared with the conventional cytologic and histologic findings. RESULTS: In the 46 patients, 42 cases of urothelial carcinoma and 4 cases of nonspecific inflammation were diagnosed. Of the 42 patients with cancer, 19 had Stage Ta, 9 had T1, 3 had carcinoma in situ, and 11 had invasive bladder cancer. The grading was G1 in 17 patients, G2 in 6 patients, and G3 in 19 patients. In 38 cases we instilled ALA and in 8 hypericin. All 4 patients diagnosed with nonspecific inflammation had received ALA. We detected ALA-induced fluorescence in 34 of 38 cases. One of the four histologically negative cases had a false-positive finding and 1 case of urothelial carcinoma did not show fluorescence. After instillation of hypericin we could detect induced fluorescence in all cases. CONCLUSIONS: Our first results suggest that fluorescence cytology is more sensitive than other noninvasive tests. After additional investigation, it may become a valuable diagnostic method and may reduce the number of cystoscopies in the follow-up of bladder tumors.

Aged↗

PubMed2002

Use of veno-venous bypass for resection of malignant pheochromocytoma with vena caval thrombus.

Surgical management of malignant pheochromocytoma with tumor-induced venous obstruction involving the entrance to the right atrium is challenging. The risk of marked hypotension and hemodynamic instability following clamping of the vena cava is increased as a consequence of the sudden decrease in circulating catecholamines. The use of cardiac bypass, however is burdened with additional operating time and coagulopathy. The present report illustrates that veno-venous bypass is a valuable tool during resection of phenochromocytoma with a large vena caval tumor thrombus.

Adrenal Gland Neoplasms↗