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Wolfram Lamadé

Publications and source records attributed to Wolfram Lamadé.

6 recordsLinked to original sources
PubMed2002

Experimental herpes simplex virus encephalitis: inhibition of the expression of inducible nitric oxide synthase in mouse brain tissue.

In the brain tissue of 36 mice infected with herpes simplex virus type 1, strain F, we determined the expression of inducible nitric oxide synthase (iNOS) with semiquantitative reverse transcription polymerase chain reaction. The viral burden was quantitated by polymerase chain reaction. Nitric oxide, induced by iNOS, may contribute to neuronal cell damage following virus infection. As the experimental therapeutic strategy in herpes simplex virus encephalitis (HSVE), we used: N-nitro-L-arginin (L-NA), a selective inhibitor of iNOS; and combination therapies of either methylprednisolone/acyclovir or L-NA/acyclovir. The viral burden peaked in acute disease, and then returned to a low baseline value, except in untreated controls. The expression of iNOS mRNA was suppressed by L-NA and by acyclovir/corticosteroids. INOS inhibition may provide an additional therapeutic strategy targeted specifically to suppress iNOS expression as a potential secondary mechanism of tissue damage in acute and chronic HSVE.

Acyclovir↗
PubMed2002

Navigation and image-guided HBP surgery: a review and preview.

Image-guided surgery and navigation have resulted from convergent developments in radiology, teletransmission, and computer science. Patient selection and preoperative planning in hepatobiliary-pancreatic (HBP) surgery rely on preoperative imaging. The operative procedure is finally led by the fusion of additional information gained by the palpating hand and intraoperative ultrasound. Despite advances in reducing morbidity and mortality, decisions are often hardly quantifiable and are restricted to super-specialists in HBP surgery. New developments in computed tomography (CT) and magnetic resonance imaging (MRI) technology have led to the possibility of the volumetric prediction of liver resections. These data can be shared via telemedicine and used for simulation and training. Three-dimensional (3D) reconstructions have led to a better topologic understanding of tumor-vascular tree relations in the individual patient. With the increasing use of ablative procedures and laparoscopy, intraoperative imaging and navigation will hold increasing significance for the HBP surgeon. Flat screen monitors adjacent to the surgical field present computer-generated 3D virtual liver resection proposals which can be transferred into the real liver. The main obstacles in HBP navigation are the flexibility and mobility of the target organ. Intrahepatic and surface markers seem to be mandatory for computer-navigated surgery. The first feasibility studies are promising.

Bile Ducts↗
PubMed2002

Evaluation of visualization techniques for image-guided navigation in liver surgery.

A substantial component of an image-guided surgery system (IGSS) is the kind of three-dimensional (3D) presentation to the surgeon because the visual depth perception of the complex anatomy is of significant relevance for orientation. Therefore, we examined in this contribution four different visualization techniques, which were evaluated by eight surgeons. The IGSS developed by our group supports the intraoperative orientation of the surgeon by depicting a visualization of the spatially tracked surgical instruments with respect to intrahepatic vessels that have to be conserved vitally, the tumor, and preoperatively calculated resection planes. In the prelimenary trial presented here we examined the human ability to percept an intraoperative virtual scene and to solve given navigation tasks. The focus of the experiments was to measure the ability of eight surgeons to orientate intrahepaticaly and to transfer the percepted spatial relation to movements in real space. An autostereoscopic visualization with a prism-based display yielded that the navigation can be performed faster and more accurately than with the other visualization techniques.

Anatomy, Regional↗
PubMedDate not supplied

Limits of Couinaud's liver segment classification: a quantitative computer-based three-dimensional analysis.

PURPOSE: Traditionally, liver surgery relies on Couinaud's liver segment classification. As the position and shape of these segments are variable and their borders are hidden within the homogeneous liver mass, the accuracy of segment identification methods needs computer-aided reevaluation. METHOD: The segmental liver anatomy of 23 patients receiving diagnostic helical CT scans because of suspected intrahepatic lesion was analyzed with the aid of a computer-based operation-planning system. We compared the standard Couinaud classification, which depends particularly on the main stems of portal and hepatic veins, with a method that calculates the segment borders by analyzing the complete portal venous tree. Volume, shape, and position of the liver segments found by each method were compared. RESULTS: With reference to the portal vein-based method, segmental volumes were overestimated by the classic Couinaud method by up to 24% and underestimated to 13%. Volumes of Couinaud segments 4a, 7, and 8 were generally larger compared with those obtained by the portal vein-based method, whereas segments 3 and 6 were smaller. Gross variations were found in segments 5, 7, and 8. When shape and position were considered, poor correlation was found for five segments (median kappa = 0.35-0.45). Only segments 2, 7, and 8 had kappa values clearly above 0.45 in the majority of cases. The plane that divides the two hemilivers along the middle hepatic vein and the border between the left sector (segments 2 and 3) and the medial sector (4a and 4b) were found in both methods with very good conformity (kappa > 0.75). CONCLUSION: Couinaud's method of dividing the liver into eight autonomous liver segments has to be accepted as a good approximation. Nevertheless, the volume, position, and shape of these segments and their segmental borders show significant variability.

Adult↗