Gallium-rich Pd-Ga phases as supported liquid metal catalysts.

A strategy to develop improved catalysts is to create systems that merge the advantages of heterogeneous and molecular catalysis. One such system involves supported liquid-phase catalysts, which feature a molecularly defined, catalytically active liquid film/droplet layer adsorbed on a porous solid support. In the past decade, this concept has also been extended to supported ionic liquid-phase catalysts. Here we develop this idea further and describe supported catalytically active liquid metal solutions (SCALMS). We report a liquid mixture of gallium and palladium deposited on porous glass that forms an active catalyst for alkane dehydrogenation that is resistant to coke formation and is thus highly stable. X-ray diffraction and X-ray photoelectron spectroscopy, supported by theoretical calculations, confirm the liquid state of the catalytic phase under the reaction conditions. Unlike traditional heterogeneous catalysts, the supported liquid metal reported here is highly dynamic and catalysis does not proceed at the surface of the metal nanoparticles, but presumably at homogeneously distributed metal atoms at the surface of a liquid metallic phase.

Liver transplantation for hilar cholangiocarcinoma: a German survey.

BACKGROUND: The present study reports a German survey addressing outcomes in nonselected historical series of liver transplantation (OLT) for hilar cholangiocarcinoma (HL). PATIENTS AND METHODS: We sent to all 25 German transplant centers performing OLT a survey that addressed (1) the number of OLTs for HL and the period during which they were performed; (2) the incidence of HL diagnosed prior to OLT/rate of incidental HL (for example, in primary sclerosing cholangitis); (3) tumor stages according to Union Internationale Centre le Cancer; (4) patient survival; and (5) tumor recurrence rate. RESULTS: Eighty percent of centers responded, reporting 47 patients who were transplanted for HL. Tumors were classified as pT2 (25%), pT3 (73%), or pT4 (2%). HL was diagnosed incidentally in 10% of cases. A primary diagnosis of PSC was observed in 16% of patients. Overall median survival was 35.5 months. When in-hospital mortality (n = 12) was excluded, the median survival was 45.4 months, corresponding to 3- and 5-year survival rates of 42% and 31%, versus 31% and 22% when in-hospital mortality was included. HL recurred in 34% of cases. Three- and 5-year survivals for the 15 patients transplanted since 1998 was 57% and 48%, respectively. Median survival ranged from 20 to 42 months based on the time period (P = .014). CONCLUSIONS: The acceptable overall survival, the improved results after careful patient selection since 1998, and the encouraging outcomes from recent studies all suggest that OLT may be a potential treatment for selected cases of HL. Prospective multicenter randomized studies with strict selection criteria and multimodal treatments seem necessary.

Stent-protected carotid angioplasty using a membrane stent: a comparative cadaver study.

PURPOSE: To evaluate the performance of a prototype membrane stent, MembraX, in the prevention of acute and late embolization and to quantify particle embolization during carotid stent placement in human carotid explants in a proof of concept study. METHODS: Thirty human carotid cadaveric explants (mild stenoses 0-29%, n = 23; moderate stenoses 30-69%, n = 3; severe stenoses 70-99%, n = 2) that included the common, internal and external carotid arteries were integrated into a pulsatile-flow model. Three groups were formed according to the age of the donors (mean 58.8 years; sample SD 15.99 years) and randomized to three test groups: (I) MembraX, n = 9; (II) Xpert bare stent, n = 10; (III) Xpert bare stent with Emboshield protection device, n = 9. Emboli liberated during stent deployment (step A), post-dilatation (step B), and late embolization (step C) were measured in 100 microm effluent filters. When the Emboshield was used, embolus penetration was measured during placement (step D) and retrieval (step E). Late embolization was simulated by compressing the area of the stented vessel five times. RESULTS: Absolute numbers of particles (median; >100 microm) caught in the effluent filter were: (I) MembraX: A = 7, B = 9, C = 3; (II) bare stent: A = 6.5, B = 6, C = 4.5; (III) bare stent and Emboshield: A = 7, B = 7, C.=.5, D = 8, E = 10. The data showed no statistical differences according to whether embolic load was analyzed by weight or mean particle size. When summing all procedural steps, the Emboshield caused the greatest load by weight (p = 0.011) and the largest number (p = 0.054) of particles. CONCLUSIONS: On the basis of these limited data neither a membrane stent nor a protection device showed significant advantages during ex vivo carotid angioplasty. However, the membrane stent seems to have the potential for reducing the emboli responsible for supposed late embolization, whereas more emboli were observed when using a protection device. Further studies are necessary and warranted.

An in vitro analysis of a carotid artery stent with a protective porous membrane.

PURPOSE: To prove the effectiveness of a new stent concept with integrated protection (MembraX [MX]) by comparing it with five cerebral protection devices designed for carotid angioplasty in an in vitro model. MATERIALS AND METHODS: Two simulation series of embolization from carotid angioplasty have been performed. In the first series, polyvinyl-alcohol particles (150-250 microm [small], 355-500 microm [medium], 710-1000 microm [large]; 5 mg each) were injected into a silicone flow model simulating the aortic arch with a carotid bifurcation. The particles were injected proximally to the partially deployed MX stent or one of the following protection devices: Angioguard (AG), FilterWire EX (EX), Trap, Neuroshield (NS), or GuardWire Plus (GW). Particles evading the protection device were caught in a filter at the end of the flow model and weighed. In the second series, human plaque material (8-12 particles; total weight 6.09 +/- 0.01 mg; 500-1500 microm) was injected into the model with the respective devices. MX was compared with the AG, EX, Trap, and NS devices. RESULTS: MX had the most effective overall filtration performance for polyvinyl alcohol particles in the effluent of the internal carotid artery (ICA; 0.43 mg, 2.9%), compared with NS (0.53 mg, 3.5%), GW (1.10 mg, 7.0%), EX and AG (1.18 and 1.21 mg, respectively; 7.8% and 8.0%), and Trap (1.24 mg, 8.2%). MX performed best for the small particles (2.0% passed particles into ICA; P < .05 compared with all). Human plaque material was retained best in the in vitro model by MX (0.0%), followed by NS (0.8%), EX (1.3%), Trap (2.6%), and AG (4.4%). CONCLUSIONS: In vitro, none of the tested devices had the ability to prevent embolization completely. Comparing current designs, the MX device captured the highest percentage of the three different particle groups. Tested with human plaque emboli, MX performed effectively in filtering the particles in the ICA.

[Echinococcosis - a rare differential diagnosis of a tumorous hepatic lesion]. / Echinokokkose - seltene Differenzialdiagnose einer malignitätsverdächtigen hepatischen Raumforderung.

We report the case of a 44-year-old woman who was admitted to our hospital because of a newly developed painless jaundice. Though she felt quite well sonographic and radiographic evaluation showed a tumor of the liver. An extensive diagnostic workup was performed but it was not until laparotomy that a malignant tumor could definitely be ruled out and the presumptive diagnosis of an echinococcosis was proven. A partial resection of the liver was performed.

[Blood management in surgery--an analysis]. / Blutmanagement in der Chirurgie--eine Analyse.

The surgeon has a tremendous influence on the usage of blood and blood products. He determines the indication and operative strategy. So the co-operation of anesthetist, intensivist, transfusion specialist, and surgeon is essential to achieve improvement in blood saving. Guidelines of blood saving methods can support the aim of an effective blood management. We analyzed the today's situation of blood saving in surgery and discuss the matter by a questionnaire sent to all surgical institutions of Nordrhein-Westfalen. The data observed cover the results of the Sanguis study from 1994 and the resume that the indication of blood transfusion mostly is not driven by clinical and scientific facts alone. Till today no evidence based data exist on indications for transfusion of blood and blood products. This is required for the next years in order to create changes in the current system of blood saving. The key points to stay within the low range of the number of transfusions are to develop a specific peri-, intra-, and postoperative strategy according to patient, disease, and expected procedure. The surgical aspects are discussed.

Causative factors, surgical treatment and outcome of incisional hernia after liver transplantation.

BACKGROUND: Little is known about the incidence and causes of herniation, and the results of hernia repair in patients undergoing liver transplantation. Likewise, nothing is known about the best surgical approach for hernia repair. METHODS: A retrospective analysis was conducted of the occurrence of incisional hernia in 290 patients who had liver transplantation between 1990 and 2000, and survived more than 6 months. Follow-up data were obtained from medical records and the outpatient service. Patients were evaluated for various clinical and surgical factors. Hernias were analysed with respect to localization, type of surgical repair and recurrence rate. RESULTS: Some 17 per cent of the transplanted patients experienced an incisional hernia. Risk factors were acute rejection with affiliated steroid bolus therapy (P = 0.025), a low platelet count after transplantation (P = 0.048), and a transverse abdominal incision with upper midline approach (P = 0.04). Hernias were mainly located at the junction of the transverse and midline incision (P < 0.001) and the recurrence rate was highest here (P = 0.007). Prosthetic hernia repair achieved the lowest rate of recurrence and did not increase the incidence of infectious complications. CONCLUSION: Improved immunosuppression should avoid early steroid bolus therapy after transplantation. A low platelet count promotes herniation. Transverse abdominal incision seems to be the best approach for liver transplantation. Prosthetic hernia repair does not increase the complication rate.

Serum bile acids in liver transplantation--early indicator for acute rejection and monitor for antirejection therapy.

We studied the course of serum bile acids to investigate its reliability in the diagnosis of acute rejection after liver transplantation in relation to pathohistological findings. Serum bile acid concentration, bilirubin and transaminases were measured in 41 patients who underwent liver transplantation. Their course was correlated to liver biopsy. Group I (n = 19) patients were without acute rejection, whereas group II (n = 22) patients showed acute rejection. Bile acid concentrations in group II showed a statistically highly significant (P < or = 0.001) threefold increase 3 days prior to biopsy. Successful antirejection treatment was correlated with a statistically significant (P = 0.008) decrease of serum bile acid 1 day after initiation of therapy. Patients without acute rejection showed a baseline bile acid concentration at the time of biopsy. Bilirubin and transaminases did not show any statistically significant correlation to acute rejection. Infection did not lead to a significant bile acid increase. Our study shows that serum bile acids monitored after liver transplantation can easily be used to detect acute rejection and at the same time they reflect the success of antirejection therapy.

Auxiliary rat liver transplantation with portal vein arterialization in acute hepatic failure.

BACKGROUND: The aim of our work was to study the effect of the portal vein arterialization of an auxiliary liver graft on survival, liver function, and regeneration of the native liver suffering from surgically induced acute liver failure (ALF). METHODS: In Lewis rats (control group: n=10), ALF was induced by resection of about 85% of liver tissue. The auxiliary liver graft (reduced size of 30%) was transplanted into the right upper quadrant of the abdomen (trial group: n=12). The portal vein was arterialized via the renal artery. The infrahepatic vena cava was anastomosed end-to-side, and the bile duct was implanted into the duodenum. RESULTS: Survival rate over a 3-month period was 10/12 in the trial group vs. 2/10 in the controls. In the trial group, the prothrombin time rose up to 38+/-2 sec on day 1 after surgery (control group: 66+/-6 sec); on day 5 after surgery, it returned to values of 30+/-1 sec. On day 1 after surgery, serum albumin fell to 25+/-1 g/L (preoperative value: 32+/-1 g/L). Within 3 weeks, it returned to normal. The hepatobiliary scan on day 7 after surgery showed normal uptake in the liver graft, whereas the uptake of the native liver was distinctly reduced. After 3 months, the transplanted liver had atrophied (0.6% of body weight), the native liver hypertrophied (2.5% of body weight), with a normal total weight for both livers of 3.1% of body weight. CONCLUSIONS: Thus, auxiliary liver transplantation with arterialized portal vein allows maintenance of liver function at the time of ALF and regeneration of the native liver.

[Long-term follow up of bile duct injury by laparoscopic cholecystectomy and reconstruction with jejunum interposition]. / Langzeitverlauf nach Gallengangverletzung durch laparoskopische Cholecystektomie und Rekonstruktion durch ein Jejunuminterponat.

The follow-up of patients with severe bile duct lesions after laparoscopic cholecystectomy often shows secondary complications. We report on a female patient suffering from long-lasting complications after bile duct injury and early reconstruction by end-to-end anastomosis via a T-tube drainage. More than 5 years later and after multiple dilatation and stenting of the bile duct stenosis the patient was treated with an expanding metal stent. The severe cholangitis persisted. So the patient was operated on: bile duct and connected stent were resected. The reconstruction was performed with an isoperistaltic jejunal conduit. More than 24 months later the patient is healthy and at work again.

[Assessing the quality of life after pancreas-kidney transplantation]. / Einschätzung der Lebensqualität nach Pankreas-Nierentransplantation.

The pancreas-kidney transplantation strives for a reestablishment both of the physiological regulation of blood glucose levels without external insulin and of kidney function without the need of dialysis. Nevertheless, the postoperative morbidity of the combined transplantation is high. In long lasting diabetes type I, a strict selection of transplant candidates is necessary to minimize the risks of cardio-vascular complications. Between 1990 and 1997 only 17 of 44 patients really were accepted for transplantation in our unit. 13/17 patients are actually independent from external insulin and dialysis. Two other patients are free of dialysis, but the pancreas transplants had to be removed due to thrombosis or infection. In one case therapy-resistant acute rejection occurred and both organs had to be removed after two months. One women died four years after transplantation with a functioning kidney graft from myocardial infarction. 10 patients with stable transplant function are at work again. After normal pregnancy two women gave birth to healthy children, in one case twins. Drug regimen and outpatients visits are not seen as significant restrictions of the quality of life.

Monitoring of soluble HLA class I size variants after liver transplantation.

To monitor soluble HLA class I (sHLA-I) and their size variants after liver transplantation (LTX) plasma samples from 22 LTX patients were studied by sHLA-I ELISA, SDS-PAGE, and densitometry. Samples collected were classified into three groups: Group 1 comprised samples taken during episodes without complications, group 2 during episodes of cholangitis/cholestasis (CC), and group 3 during episodes of acute rejection (AR). Compared to group 1 (0.27 +/- 0.03 SEM microg/ml) mean sHLA-I increments in groups 2 and 3 were with 0.53 +/- 0.05 SEM microg/ml and 0.47 +/- 0.04 SEM microg/ml increased (p < 0.001). The same samples were studied by SDS-PAGE and the 43, 39, and 35 kD sHLA-I variants were quantified densitometrically. In samples of group 1 ratios of 43 vs. 39 kD bands revealed a mean of 2.1 +/- 0.3, whereas in group 2 and 3 these were only 0.8 +/- 0.1 SEM and 0.9 +/- 0.1 SEM, respectively, (p < 0.001). For the relation between 43 and 35 kD variants a reduced ratio of 1.1 +/- 0.2 SEM was confined to group 3 samples (p < 0.001), as groups 1 and 2 had ratios of 13.4 +/- 2.3 SEM and 8.4 +/- 2.9 SEM, respectively. This indicates that elevated sHLA-I levels during CC or AR are mainly caused by increases of 39 and/or 35 kD sized molecules. Therefore, our study demonstrates, that after LTX the contribution of sHLA-I size variants to total sHLA-I amounts changes drastically during immune activation pointing to different mechanisms of sHLA-I release.

Auxiliary liver transplantation in acute liver failure in the rat -- an illustrated description of a new surgical approach.

INTRODUCTION: To investigate auxiliary liver transplantation successfully in rats suffering from acute liver failure, we developed a new surgical approach. METHODS: A 70% hepatectomized liver graft was implanted into the right upper quadrant of the abdomen. The donor portal vein was anastomosed with the recipient's right renal artery using the splint technique. The donor infrahepatic vena cava was attached onto the recipient vena cava end to side. The bile duct was implanted into the duodenum.