Roboterunterstützte Laparoskopie in der Urologie Radikale Prostatektomie und rekonstruktive retroperitoneale Eingriffe

Complex reconstructive laparoscopic procedures in the field of urology such as radical prostatectomy and pyeloplasty have attracted increased attention in the past 2 years. However, extensive laparoscopic experience is required to master these procedures. Therefore, it remains questionable whether these techniques, which have been shown to be of profit to the patient in the hands of a specialist, will achieve widespread distribution. We have employed computer technology to bridge the gap between open surgery and laparoscopic access and used the daVinci Surgical System to establish laparoscopic radical prostatectomy as well as pyeloplasty and other retroperitoneal procedures at our institution. With experience of more than 70 procedures, we find that with the assistance of the daVinci Surgical System both radical prostatectomy and retroperiteoneal procedures can be easily translated from open to minimally invasive procedures with a considerably shorter learning curve and without compromising patient safety. We expect that large incisions will be soon a thing of the past in urologic surgery. Computer technology, together with mechanical engineering, will play a major role in enabling us to achieve better results despite minimal invasiveness.     

Syntactic and semantic modulation of neural activity during auditory sentence comprehension

In previous functional neuroimaging studies, left anterior temporal and temporal-parietal areas responded more strongly to sentences than to randomly ordered lists of words. The smaller response for word lists could be explained by either (1) less activation of syntactic processes due to the absence of syntactic structure in the random word lists or (2) less activation of semantic processes resulting from failure to combine the content words into a global meaning. To test these two explanations, we conducted a functional magnetic resonance imaging study in which word order and combinatorial word meaning were independently manipulated during auditory comprehension. Subjects heard six different stimuli: normal sentences, semantically incongruent sentences in which content words were randomly replaced with other content words, pseudoword sentences, and versions of these three sentence types in which word order was randomized to remove syntactic structure. Effects of syntactic structure (greater activation to sentences than to word lists) were observed in the left anterior superior temporal sulcus and left angular gyrus. Semantic effects (greater activation to semantically congruent stimuli than either incongruent or pseudoword stimuli) were seen in widespread, bilateral temporal lobe areas and the angular gyrus. Of the two regions that responded to syntactic structure, the angular gyrus showed a greater response to semantic structure, suggesting that reduced activation for word lists in this area is related to a disruption in semantic processing. The anterior temporal lobe, on the other hand, was relatively insensitive to manipulations of semantic structure, suggesting that syntactic information plays a greater role in driving activation in this area.     

Successful antidepressant therapy restores the disturbed interplay between TNF-alpha system and HPA axis.

BACKGROUND: In depressed patients, alterations in the hypothalamo-pituitary-adrenocortical (HPA) system are the most consistent neurobiological finding. HPA axis activity and cytokines are intrinsically intertwined: inflammatory cytokines stimulate adrenocorticotropic hormone (ACTH) and cortisol secretion, while, in turn, glucocorticoids suppress the synthesis of proinflammatory cytokines. METHODS: We examined alterations in plasma levels of tumor necrosis factor-alpha (TNF-alpha), levels of its soluble receptors p55 (sTNF-R p55) and p75 (sTNF-R p75) as well as changes in the HPA system function using the combined dexamethasone/corticotropin-releasing hormone (dex/CRH) test on admission and at discharge in 70 depressed inpatients without inflammation. RESULTS: On admission, TNF-alpha levels were inversely associated with the ACTH response to the combined dex/CRH test. Changes in TNF-alpha, sTNF-R p55, and sTNF-R p75 plasma levels from admission to discharge were positively correlated with the dex/CRH test outcome at discharge. Subgroup analysis revealed that this association was restricted to those patients achieving remission. In this subgroup, TNF-alpha levels at discharge were also positively correlated with dex/CRH test response at discharge. CONCLUSIONS: Our results suggest that elevated HPA axis activity in acute depression suppresses TNF-alpha system activity, while after remission, when HPA axis activity has normalized, the TNF-alpha system seems to gain influence on the HPA system.     

Reduction of severe ischemia/reperfusion injury in rat kidney grafts by a soluble P-selectin glycoprotein ligand

BACKGROUND: Inflammatory leukocyte-endothelium interactions, mediated by selectins, contribute to renal ischemia/reperfusion (I/R) injury. We examined the influence of the soluble P-selectin glycoprotein ligand 1 (sPSGL) on early I/R-induced changes in a rat kidney transplantation model with long cold ischemia. METHODS: After 24 hr of cold storage, syngeneic kidneys were grafted into bilaterally nephrectomized rats. Before transplantation, recipients received either 1 mg/kg of sPSGL or vehicle (n=8 per group). Six hours after reperfusion, grafts were removed for light microscopy and immunohistochemistry. Capillary blood flow was measured under a fluorescence microscope by using the concentric-circles method. RESULTS: A greater proportion, 74.7+/-7.2% (sPSGL) vs. 28+/-7.4% (controls), of all dye-labeled outer medullary capillaries appeared in the 12-microm radius (P<0.01), indicating dense blood flow, whereas 7.6+/-2.9% vs. 43.3+/-9.7%, respectively, appeared in the 60-microm radius (P<0.05), indicating rarefied blood flow. In the sPSGL-treated group, the extent of severe tubular damage within the inner stripe of the outer medulla was lower compared with controls (37.5+/-8.3% vs. 78.4+/-3.5%, P<0.01). Outer medullary heat shock protein 72 expression was 14.5+/-1.6% in the sPSGL-treated group compared with 9.6+/-1.4% in controls (P<0.05). The number of infiltrating polymorphonuclear leukocytes was similar in both groups. Treatment with sPSGL had no influence on the serum creatinine level. CONCLUSIONS: Our data suggest that impairment of outer medullary blood flow is crucial in I/R injury of kidney grafts with prolonged cold storage. Reduction of capillary blood flow perturbations by sPSGL protects tubular cells from severe structural damage. Blocking early selectin-mediated leukocyte adhesion may have therapeutic implications in improving the prognosis of renal transplants with severe I/R injury.     

Inhibition of neointimal formation after stent placement with adenovirus-mediated gene transfer of I kappa B alpha in the hypercholesterolemic rabbit model: initial results

PURPOSE: To evaluate the feasibility and efficacy of the local application of a replication-defective adenovirus construct for the expression of the antiinflammatory protein I kappa B alpha, inhibitor of nuclear factor kappa B (NF-kappa B), to reduce neointimal formation after stent placement. MATERIALS AND METHODS: Nitinol stents were implanted in the iliac arteries of hypercholesterolemic rabbits, followed by balloon dilation (30 seconds at 6 atm). Local adenovirus-mediated transfer of I kappa B alpha (3 mL of 10(9) plaque-forming units per milliliter at 6 atm) was performed and compared with three control groups: stent alone, stent plus local delivery of phosphate-buffered saline (PBS) (3 mL at 6 atm), and stent plus local delivery of control adenovirus coding for green fluorescent protein (GFP) (3 mL of 10(9) plaque-forming units per milliliter at 6 atm). A multichannel balloon was used for local drug delivery and balloon dilation. Animals were sacrificed 1 or 4 weeks after treatment. Effective transfection was demonstrated with immunofluorescence staining. Angiographic patency and luminal diameter were evaluated at quantitative angiography. Luminal and neointimal areas were measured on surface-stained ground sections with methylmethacrylate embedding and the cutting-grinding technique. RESULTS: All vessels with stents were patent at angiography. Neointimal area was negligible in all groups 1 week after stent placement (range, 0.42-0.52 mm(2); P =.44; analysis of variance). Neointimal formation was demonstrated in all groups 4 weeks after implantation but was significantly reduced with I kappa B alpha treatment compared with treatment with stent alone (by 22%, from 2.80 mm(2) +/- 0.20 to 2.28 mm(2) +/- 0.14, P =.05), stent plus PBS (by 43%, from 3.26 mm(2) +/- 0.25 to 2.28 mm(2) +/- 0.14, P =.005), and stent plus GFP (by 53%, from 2.32 mm(2) +/- 0.19 to 1.51 mm(2) +/- 0.08, P <.005). CONCLUSION: Local adenovirus-mediated I kappa B alpha gene transfer has the potential to reduce intimal hyperplasia after stent placement.     

Fibronectin binding to thrombin-stimulated platelets: evidence for fibrin(ogen) independent and dependent pathways

Plasma fibronectin binds in a specific and saturable manner to thrombin- stimulated platelets. gamma-Thrombin stimulated 80% as much fibronectin binding to platelets as alpha-thrombin with conversion of less than or equal to 1% of platelet fibrinogen to fibrin. Afibrinogenemic and normal platelets bound similar quantities of fibronectin in the presence of calcium or magnesium-ethylene glycol tetra-acetic acid (EGTA). These observations indicate that fibronectin can interact with platelets without involvement of fibrin or fibrinogen. Nevertheless, two different effects of fibrin(ogen) on fibronectin binding were observed. First, exogenous fibrinogen inhibited fibronectin binding to thrombin-stimulated platelets. This inhibition was unidirectional, as fibronectin did not inhibit fibrinogen binding to ADP or thrombin- stimulated cells. Second, formaldehyde-fixed cells with surface- associated fibrin bound significant quantities of fibronectin. This interaction required calcium and did not occur on fixed cells with or without surface-bound fibrinogen. A portion of the ligand bound to fixed cells with surface-associated fibrin was modified to form a derivative with a molecular weight identical to that of the fibronectin subunit cross-linked to the alpha-chain of fibrin. This high mol wt derivative was also observed to a variable extent with living cells in the presence of magnesium or calcium but not in the presence of magnesium-EGTA. Thus, fibronectin binds to platelets by at least two mechanisms: (1) a fibrin(ogen)-independent pathway that requires divalent ions and is inhibited by exogenous fibrinogen; and (2) a fibrin-dependent pathway with an absolute calcium requirement. With nonaggregated, thrombin-stimulated platelets, the former pathway appears to predominate.     

Serum antielastase and neutrophil elastase levels in PiM phenotype cigarette smokers with airflow obstruction

In order to assess blood factors which might explain why some cigarette smokers develop airflow obstruction while others do not, we compared two groups of PiM phenotype volunteers matched for age, sex and total pack-years of cigarette smoking; one group had airflow obstruction and the other did not. Functional levels of alpha-2-macroglobulin (alpha-2-M) and alpha-1-protease inhibitor (alpha-1-PI) were separately assessed by a protease binding procedure. Neutrophils were isolated from blood by counterflow centrifugation, and their elastase content was assayed with 3H-elastin-SDS (sodium dodecyl sulfate). The obstructed and nonobstructed groups were not different with respect to functional or immunoreactive levels of alpha-1-PI and alpha-2-M or elastase levels in their neutrophils. We do not find imbalances of circulating elastase or antielastase levels in PiM phenotype smokers with airflow obstruction.     

Familial occurrence of complement dysfunction in Crohn's disease: correlation with intestinal symptoms and hypercatabolism of complement.

Complement was studied in Crohn's disease probands with early onset and in their first degree relatives. Controls included 24 healthy volunteers and 24 patients with ulcerative colitis or peptic ulcers. Subnormal generation of chemotactic activity by the alternative pathway was shown in eight of 21 probands and in six of 33 relatives, a frequency in both groups significantly different from controls (p less than 0.005), with a strong connection between findings in patients and relatives. As previously shown in patients with Crohn's disease, the subnormal generation was related to decreased utilisation of complement C3 in relatives. Raised levels of circulating complement C3c split products suggested complement involvement in Crohn's disease probands. In contrast, plasma C3c was normal in all relatives, and none of the six cases with complement dysfunction had gastrointestinal symptoms or a history of inflammatory bowel disease. Our data suggest, that complement abnormality seen in Crohn's disease patients does not simply reflect mucosal inflammation or hypercatabolism of complement.     

Intrathecal saline infusion in the treatment of obtundation associated with spontaneous intracranial hypotension: technical case report

OBJECTIVE AND IMPORTANCE: Spontaneous intracranial hypotension is an increasingly recognized cause of postural headache. However, appropriate management of obtundation caused by intracranial hypotension is not well defined. CLINICAL PRESENTATION: A 43-year-old man presented with postural headache followed by rapid decline in mental status. Imaging findings were consistent with the diagnosis of spontaneous intracranial hypotension, with bilateral subdural hematomas, pachymeningeal enhancement, and caudal displacement of posterior fossa structures and optic chiasm. INTERVENTION: Despite treatment with lumbar epidural blood patch, worsening stupor necessitated intubation and mechanical ventilation. Contrast-enhanced magnetic resonance imaging and computed tomographic myelography of the spine failed to demonstrate the site of cerebrospinal fluid fistula. The enlarging subdural fluid collections were drained, and a ventriculostomy was performed. Postoperatively, the patient remained semicomatose. To restore intraspinal and intracranial pressures, intrathecal infusion of saline was initiated. After several hours of lumbar saline infusion, lumbar and intracranial pressures normalized, and the patient's stupor resolved rapidly. Repeat computed tomographic myelography accomplished via C1-C2 puncture demonstrated a large ventrolateral T1-T3 leak, which was treated successfully with a thoracic epidural blood patch. Follow-up magnetic resonance imaging demonstrated resolution of intracranial hypotension, and the patient was discharged in excellent condition. CONCLUSION: Spontaneous intracranial hypotension may cause a decline of mental status and require lumbar intrathecal saline infusion to arrest or reverse impending central (transtentorial) herniation. This case demonstrates the use of simultaneous monitoring of lumbar and intracranial pressures to appropriately titrate the infusion and document resolution of intracranial hypotension. Maneuvers aimed at sealing the cerebrospinal fluid fistula then can be performed in a less emergent fashion after the patient's mental status has stabilized.     

Extensor tenodesis to the retinaculum extensorum: anatomic and biomechanical study

INTRODUCTION: The extensor tenodesis is a direct dynamic tenodesis which is activated by wrist flexion due either to hand weight or flexor carpi radialis. This tenodesis is usually performed to the distal radius, but it is possible to fix EDC (extensor digitorum communis) to the retinaculum extensorum. MATERIAL AND METHODS: Biomechanical study concerned 12 anatomical subjects (24 wrists). The biometric and radiological analysis of retinaculum displacement distalwards was made under low (1 kg) and moderate (6 kg) pulling. Surgical clips were placed on the proximal and distal limits of the retinaculum in order to study their positions on roentgenograms. RESULTS: Average width of the retinaculum was 19 mm. Average movement under 1 kg drive was 6 mm and 8.6 mm under 6 kg drive. X-rays showed that the proximal border of the retinaculum was always located proximally to the wrist rotate centre, whatever the traction. DISCUSSION: We found the same anatomical features described by different authors, except for the width of the retinaculum. Our study suggests that the retinaculum is strong enough to support a surgical tenodesis.