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Dive into the research topics where Christoph Durek is active.

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Featured researches published by Christoph Durek.


The Journal of Urology | 1997

Laparoscopic Bilateral Nephrectomy: Results in 11 Renal Transplant Patients

Paolo Fornara; Christian Doehn; Lutz Fricke; Christoph Durek; Gregor Thyssen; Dieter Jocham

PURPOSE We report our experience with bilateral laparoscopic nephrectomy after renal transplantation. MATERIALS AND METHODS Between August 1994 and October 1995, 11 patients who had previously undergone renal transplantation underwent bilateral laparoscopic nephrectomy at our hospital due to poorly controlled hypertension. The records of 10 patients undergoing bilateral open nephrectomy were reviewed for comparison. RESULTS Mean operative time in the laparoscopy group was 195 minutes (range 125 to 270). Mean blood loss was 345 ml. and 1 patient required conversion to an open operation. Oral intake and mobilization were begun 1 day postoperatively. Mean postoperative morphine equivalent consumption was 14 mg., mean hospital stay was 4.2 days (range 3 to 6) and mean return to normal activities was 14 days. At a mean followup of 10.4 months blood pressure had improved significantly in 8 patients (73%). Mean operative time in the open surgery group was 145 minutes (range 115 to 170) and mean postoperative morphine equivalent required was 44 mg. Compared to the laparoscopy group the interval to resumption of oral intake (3.5 days), duration of hospital stay (10.7 days) and return to normal activities (36 days) were prolonged in the open surgery group. CONCLUSIONS According to our results, bilateral laparoscopic nephrectomy could be an effective alternative for the treatment of severe hypertension after renal transplantation. Compared to open nephrectomy most patients benefit from the laparoscopic approach.


European Urology | 2000

Sensitivity of BCG to Modern Antibiotics

Christoph Durek; S. Rüsch-Gerdes; Dieter Jocham; Andreas Böhle

The viability of bacillus Calmette-Guérin (BCG) in intravesical instillation therapy has been demonstrated to be crucial for the prevention of bladder tumour recurrence. The aim of the present study was to determine the effects of modern antibacterial chemotherapeutics on BCG viability, particularly cycloserine, which has been recommended in the treatment of BCG-induced sepsis. The minimal inhibitory concentrations (MICs) of 32 antibacterial drugs potentially effective against the Connaught BCG strain were measured in vitro by the radiometric BACTEC 460TB method. The MICs were compared with the drug concentrations achievable in blood and urine. Susceptibility testing of cycloserine was performed with three different strains (Connaught, Tice and RIVM), using the modified proportion method, as defined in the German guidelines for anti-tuberculosis drug testing. The Connaught BCG strain was highly susceptible to fluoroquinolones, but was resistant to β-lactams, macrolides (except clarithromycin), and some aminoglycosides. It was also sensitive to doxycycline and gentamicin at dosages that typically occur in the urine of patients after a normal dose. Connaught BCG was susceptible to all the tuberculostatic drugs tested, except for pyrazinamide. All the BCG strains analysed were resistant to cycloserine. During intravesical BCG instillation therapy, simultaneous administration of fluoroquinolones, doxycycline or gentamicin should be avoided. In cases of severe systemic complications, or if one of the antituberculosis drugs is not tolerated, fluoroquinolones may be used. Cycloserine is no longer recommended for the early treatment of BCG sepsis.


The Journal of Urology | 2001

THE FATE OF BACILLUS CALMETTE-GUERIN AFTER INTRAVESICAL INSTILLATION

Christoph Durek; Elvira Richter; Alexander Basteck; Sabine Rüsch-Gerdes; Johannes Gerdes; Dieter Jocham; Andreas Böhle

PURPOSE Long-term activation of immunocompetent cells of the bladder wall as well as case reports of systemic infections some months or years after intravesical bacillus Calmette-Guerin (BCG) therapy imply that mycobacteria may persist in the body. Therefore. we investigated the fate of BCG in patients after uncomplicated intravesical instillation therapy. MATERIAL AND METHODS A total of 49 patients were included in the study, from whom various numbers of specimens were used for mycobacterial culture and molecular biological detection techniques. In 23 patients who received a total of 128 instillations urine, sputum, venous blood and bladder biopsies were screened for BCG by acid-fast staining and culture at different times before and after instillation. From 16 of the 23 patients and from an additional 26 a total of 180 bladder biopsies obtained at intervals 3 to 30 months after instillation were screened for mycobacterial 16S ribosomal DNA by a nested polymerase chain reaction protocol. RESULTS No viable BCG was found in venous blood or in 127 of 128 sputum specimens before and 2 hours after instillation. Two of 56 bladder biopsies were culture positive. In urine BCG was detected in 96.4% of the specimens after 2 hours and in 67.9% after 24 hours after instillation. The number of positive specimens decreased and it was 27.1% on day 7 immediately before the next instillation. In 14 of 44 bladder biopsies (31.8%) mycobacterial ribosomal DNA was found within 1 week after the sixth instillation. A positive polymerase chain reaction was evident up to 24 months in between 4.2% and 37.5% of the investigated biopsies. After 30 months no ribosomal DNA was evident in the 6 samples available for testing. CONCLUSIONS Nontraumatic intravesical instillation of BCG is not accompanied by systemic mycobacterial spread. Local persistence during the instillation course is evident since viable BCG is commonly found in the urine. Long lasting and persistent BCG DNA in the bladder wall may account for long-term immuno-activation. However, the remaining BCG may be a possible source of late systemic infections.


Journal of Immunotherapy | 2000

Feasibility of the Adoptive Transfusion of Allogenic Human Leukocyte Antigen-matched Natural Killer Cells in Patients With Renal Cell Carcinoma

Christoph Frohn; Christian Doehn; Christoph Durek; Andreas Böhle; Peter Schlenke; Dieter Jocham; Holger Kirchner

Patients with metastasized renal cell carcinoma have a poor prognosis with conventional therapies. The feasibility and safety of donating purified natural killer (NK) cells without additional cytokines were evaluated. In contrast to all previous studies, the NK cells were derived from allogenic donors. The NK cell donors were HLA-C matched to enable NK cell inhibition via killer cell inhibitory receptors and HLA-C. This should obviate a graft-versus-host reaction against nonmalignant HLA-expressing tissues in the allogenic constellation. The average number of cells applied per transfusion was 1.02 ± 0.265 × 109. The purity of the NK cells was 85% to 95%, and most of the contaminating cells were monocytes. Twenty-six transfusions given to 11 patients did not cause any minor or major adverse effects, with the exception of one episode of transient fever. One patient had an objective regression of his lung metastases that had been progressing continuously before. No cytotoxic HLA antibodies could be detected 3 weeks after the transfusions. The observed tolerance to this therapeutic regimen suggests the need for further studies with increased doses of cytokine-activated NK cells.


The Journal of Urology | 1999

Interference of modern antibacterials with bacillus Calmette-Guerin viability.

Christoph Durek; Sabine Rüsch-Gerdes; Dieter Jocham; Andreas Böhle

PURPOSE We determine the effects of modern antibacterial chemotherapeutics on bacillus Calmette-Guerin (BCG) viability, particularly those of cycloserine, which has been recommended for treating BCG induced sepsis. MATERIALS AND METHODS The minimal inhibitory concentrations of 31 antibacterial drugs against Connaught BCG strain were determined in vitro by the radiometric BACTEC 460TB method. Minimal inhibitory concentrations were compared with the drug concentrations achievable in blood and urine to estimate systemic or intravesical susceptibility. Susceptibility testing of cycloserine was performed with Connaught, Tice and RIVM BCG strains, using the modified proportion method on Lowenstein-Jensen agar. RESULTS Connaught BCG was susceptible to quinolones in systemic infections but resistant to beta-lactams, macrolides and some aminoglycosides. It was resistant to pyrazinamide but showed good susceptibility toward the other antituberculosis drugs tested. All 3 BCG strains analyzed were resistant to cycloserine. Most antibacterials may interfere with BCG in the bladder because of high urinary recovery. CONCLUSIONS Antibacterial drug interference with BCG viability should be avoided during intravesical instillation therapy. In cases of severe complications quinolones rather than cycloserine may be given in addition to standard triple antituberculosis drug therapy or if one of these drugs is not tolerated. Our data may contribute toward enhancing the therapeutic safety and efficacy of intravesical BCG immunotherapy by the appropriate use of antibacterial drugs.


The Journal of Urology | 2002

Optimal treatment of systemic bacillus calmette-guerin infection: Investigations in an animal model

Christoph Durek; A. Jurczok; H. Werner; Dieter Jocham; Andreas Böhle

PURPOSE Hematogenous spread of bacillus Calmette-Guerin (BCG) after intravesical instillation for bladder cancer is rare but it may result in systemic infection and hypersensitivity reaction. We investigated fluoroquinolones and steroids in an animal model to improve the therapeutic options in local and systemic BCG infection. Furthermore, the antitumor effectiveness of intravesical BCG with simultaneous application of fluoroquinolones and/or steroids was tested. MATERIALS AND METHODS Oral antimicrobial therapy with and without steroids was started immediately after intraperitoneal injection using fluoroquinolones or trimethoprim-sulfamethoxazole. To evaluate the therapeutic options against a hyperergic reaction after repeat systemic BCG infection re-challenge was performed with intraperitoneal BCG 7 days after primary infection and oral therapy was given with fluoroquinolones or trimethoprim-sulfamethoxazole with and without steroids. The influence of continuous oral fluoroquinolone therapy on the antitumor effect of BCG was also tested in the MB 49 orthotopic murine bladder tumor model. RESULTS After primary systemic infection fluoroquinolone therapy alone led to significantly prolonged survival in mice (log rank test p = 0.041), whereas trimethoprim-sulfamethoxazole was ineffective. There was no additional effect of steroid administration. Steroids alone led to premature death (log rank test p = 0.022). After secondary BCG infection only steroid treated animals had prolonged survival (log rank test p = 0.032), whereas antimicrobials alone had no effect. The therapeutic efficacy of BCG in the orthotopic bladder tumor model was not affected by continuous oral fluoroquinolones in terms of survival (log rank test p = 0.001) or bladder weight (Wilcoxon test p = 0.001) compared with untreated controls. CONCLUSIONS In a mouse model fluoroquinolones had a beneficial effect for primary systemic BCG infections, whereas the hyperergic reaction after repeat BCG infection was susceptible only to steroids. Administering fluoroquinolones during an intravesical treatment course does not affect the antitumor efficacy of BCG.


Cancer Immunology, Immunotherapy | 1997

Effects of colony-stimulating factors on cellular cytotoxicity

Christoph Durek; Ingmar Schäfer; Henning Braasch; Artur J. Ulmer; Martin Ernst; Hans-Dieter Flad; Dieter Jocham; Andreas Böhle

Abstract Colony-stimulating factors (CSF) are used clinically in the treatment of chemotherapy-induced myelosuppression and in support of bone marrow transplantation. As CSF are known to have pleiotropic functions, their effects on cellular cytotoxicity were analysed in vitro against bladder carcinoma cell lines. By means of an L-[3H]methionine-release assay, the cytotoxicity of peripheral blood mononuclear cells against the natural-killer(NK)-cell-resistant bladder carcinoma cell lines BT-A and SBC-7 was measured using different effector/target-cell ratios. Costimulatory effects of granulocyte-colony-stimulating factor (G-CSF), granulocyte/macrophage-colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) and stem cell factor (SCF) on the generation of lymphokine-activated killer (LAK), bacillus Calmette-Guérin-activated killer (BAK) and natural killer (NK) cell cytotoxicity were investigated in this assay. Furthermore, the effect of CSF on proliferation of urothelial tumor cells in vitro was determined by a [3H]thymidine DNA-labelling technique. GM-CSF, but not G-CSF, IL-3 or SCF, was able to increase NK, BAK and LAK cytotoxicity in a dose-dependent manner. No acceleration of carcinoma cell proliferation was evident under the conditions of our assay. These data indicate the costimulatory effect of GM-CSF on cellular cytotoxicity, which might be used for immunotherapeutic purposes.


Surgery Today | 2007

Giant Bladder Diverticulum as a Rare Cause of Intestinal Obstruction: Report of a Case

Lutz Mirow; Andreas Brügge; Frank Fischer; Uwe J. Roblick; Christoph Durek; Conny Bürk; Dieter Jocham; Hans-Peter Bruch

We report a case of intestinal obstruction as an unusual manifestation of bladder diverticulum. To our knowledge, this is the first report of a giant bladder diverticulum causing acute abdomen as a result of mechanical bowel obstruction.


Current Opinion in Urology | 1999

Recent perspectives in topical therapy in superficial bladder cancer.

Andreas Böhle; Christoph Durek

With regard to side-effects in intravesical bacillus Calmette-Guérin instillation therapy and the limited efficacy of intravesical chemotherapy, there is still a need for improvement of these standard therapies. Recently, technical adjuvant means or the modification of cytostatic drugs have been undertaken to improve the efficacy of intravesical chemotherapy. Prognostic indicators of the response to bacillus Calmette-Guérin immunotherapy have been identified, but indicators of side-effects are needed in order to improve the benefit-to-risk ratio of bacillus Calmette-Guérin instillation therapy. Many innovative treatment options, however, still require a definition of their clinical value.


Medical Laser Application | 2003

New Strategies in Photodynamic Diagnosis of Bladder Cancer

Christoph Durek; Dieter Jocham

Summary Hexyl 5-aminolevulinate hydrochloride (Hexvix®) has been investigated prior to routine clinical use for fluorescence diagnosis of bladder cancer. Preclinical evaluation revealed the drugs safety and tolerability in animals. The feasibility and efficacy of hexyl-5-ALA after intravesical instillation was assessed in 25 patients. There was a preferential PPIX accumulation in neoplastic tissue and after a two hour dwell time the resulting fluorescence intensity was increased at lower concentration as compared to 5-ALA. In a further Phase II multicenter study conducted by Jichlinski et al. 43 out of 45 patients with tumors were diagnosed with the help of hexyl-5-ALA cystoscopy compared to 33 patients with standard cystoscopy which resulted in a sensitivity of 96% compared to 73% under white light. The specificity was found at 80%. Especially 12 out of 13 patients with CIS lesions were diagnosed by hexyl-5-ALA whereas only 4 of these would have been detected under white light cystoscopy. The drug was well tolerated by all patients and did not add any adverse reactions to white light cystoscopy. In June 2002 a Phase III multicenter study with hexyl-5-ALA was initiated by our institution to compare patients management decisions following Hexvix® cystoscopy and standard white light cystoscopy. The study was designed to investigate whether the potentially improved detection of tumors with Hexvix® cystoscopy leads to a different and better treatment of patients with bladder cancer. The study was able to recruit patients rapidly and data management as well as statistics are underway. Study results are expected within the next 6 months.

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Sven Brandau

University of Duisburg-Essen

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Marc-Oliver Grimm

Dresden University of Technology

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K.H. Kurth

University of Amsterdam

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