Bioartifizielle Materialien in der Urologie

The scope of our research is the development of polymer-based bioabsorbable stents for urologic applications and in vitro testing of tissue reactions of cultured ureteral and urethral segments induced by implanted polymer stent prototypes. For these purposes a tissue cultivation model was developed using selected techniques of tissue engineering. Essential advantages of degradable over nondegradable urethral stents are elimination of the adverse extraction of epithelialized stents and the potential for recovery of organ-specific functionality. Moreover, the biocompatibility of a degradable urethral stent could potentially reduce the risk of restenosis due to hyperplasia and could be used, even repeatedly, for the treatment of a number of subvesical obstructions. For the treatment of tumor-induced strictures, application of degradable polymer stents coated with cytostatic drugs may be possible. The mechanical effect of the drug-loaded stent as a “place holder” could be complemented by adjuvant or palliative approaches such as local chemotherapy. We have developed and tested in vitro a degradable urethral stent incorporated with the model drug methotrexate for local drug delivery (LDD) by diffusion and during stent degradation.     

Impact of neuronavigation and image-guided extensive resection for adult patients with supratentorial malignant astrocytomas: a single-institution retrospective study.

Neuronavigation has become an effective therapeutic modality and is used routinely for intra-axial tumor removal. This retrospective study was conducted to evaluate the clinical impact of neuronavigation and image-guided extensive resection for adult patients with supratentorial malignant astrocytomas. Between 1990 and 2002, 76 adult patients with pathologically confirmed malignant astrocytomas underwent craniotomy and removal of the tumors at the Toyama Medical and Pharmaceutical University Hospital. Of these 76 patients, 42 were treated using neuronavigation with conventional microneurosurgery and the other 34 were treated with conventional microneurosurgery alone. Postoperative early MRI with contrast enhancement was done, and gross total resection was defined as the complete absence of residual tumor. Survival time was analyzed with the Kaplan-Meier method. Prognostic factors were obtained from the Cox proportional hazards model. In univariate analysis, age (< 65), grade 3, preoperative KPS (>/= 80), use of neuronavigation, and gross total resection were significantly associated with longer survival. However, when the data were submitted to multivariate analysis, grade 3, preoperative KPS (>/= 80), and gross total resection were independent prognostic factors. The median survival periods of patients receiving gross total resection (vs. partial resection) and neuronavigation (vs. no neuronavigation) were 16 (vs. 9) months and 16 (vs. 10) months, respectively. The percentage of a gross total resection was significantly higher in the neuronavigation group compared to that in the no-navigation group (64.3 % vs. 38.2 %, p < 0.05). Neurological deterioration occurred in 4 of 42 (9.5 %) and in 6 of 34 (17.6 %) patients after surgery with neuronavigation and surgery without neuronavigation, respectively, although this difference was not statistically significant. Our results showed that neuronavigation increases the radicality in the resection of malignant astrocytomas and is objectively useful for improving survival time.     

ISOLATION OF VIRULENT TREPONEMA PALLIDUM FRQM HUMAN AORTA THIRTY-TWO HOURS AFTER DEATH FROM CARDIOVASCULAR SYPHILIS

After a comprehensive rernew of the literature on syphilitic aortitis, Longcope, (1) stated in 1913; ": . . . the presence of spiro: chetes in these lesions, as might be expected, cannot by any means be constantly demonstrated with Levaaiti stain. . . . . . . That these organisms are ''Treponema pallidum seems almost certain thouS:h actual proof of such by culture from the arterial lesions, a most difficult task, or direct inoculation into animals, has not as yet been accomplished."     

Use of the Cytobrush for concurrent cytology and chlamydia sampling: a comparison of immunofluorescence and culture for detection of chlamydia

Five hundred and thirty-three women attending a genitourinary medicine clinic underwent concurrent cytology and Chlamydia trachomatis screening using a Cytobrush (Medscand AB). In each case, the same Cytobrush was used to give a sample for direct immunofluorescence and culture. 11.1% of samples were positive by immunofluorescence, while 10.6% were positive by culture. This was a close agreement (Kappa = 0.875). The ability of the same instrument to be used for both cytology and chlamydial screening, where direct immunofluorescence is used for detection of chlamydiae, may allow more widespread screening for chlamydia to be practical.