Microsurgical training course for clinicians and scientists: a 10-year experience at the Münster University Hospital.

BACKGROUND: Microsurgical techniques are an important part of clinical and experimental research. Here we present our step-by-step microsurgery training course developed at the Münster University Hospital. The goal of this course was to create a short, modular curriculum with clearly described and easy to follow working steps in accordance with the Guidelines for Training in Surgical Research in Animals by the Academy of Surgical Research. METHODS: Over the course of 10 years, we conducted an annual 2.5 day (20 h) microsurgical training course with a total of 120 participants. RESULTS: Prior to the course, 90% of the participants reported to have never performed a microanastomosis before. During the 10 years a total of 84.2% of the participants performed microanastomoses without assistance, 15% required assistance and only 0.8% failed. CONCLUSIONS: Our step-by-step microsurgery training course gives a brief overview of the didactic basics and the organization of a microsurgical training course and could serve as a guide for teaching microsurgical skills. During the 2.5-day curriculum, it was possible to teach, and for participants to subsequently perform a microsurgical anastomosis. The independent reproducibility of the learned material after the course is not yet known, therefore further investigations are necessary. With this step-by-step curriculum, we were able to conduct a successful training program, shown by the fact that each participant is able to perform microvascular anastomoses on a reproducible basis.

EPOR2/ßcR2-independendent effects of low-dose epoetin-α in porcine liver transplantation.

Ischemia-reperfusion injury (IRI) remains a key component of graft damage during transplantation. Erythropoietin (EPO) induces anti-inflammatory and anti-apoptotic effects via the EPOR2/ßcR2 complex, with a potential risk of thrombosis. Previous work indicates that EPO has EPOR2/ßcR2-independent protective effects via direct effects on the endothelium. As the EPOR2/ßcR2 receptor has a very low affinity for EPO, we aimed to test the hypothesis that EPO doses below the level that stimulate this receptor elicit cytoprotective effects via endothelial stimulation in a porcine liver transplantation model. Landrace pigs underwent allogenic liver transplantation (follow-up: 6 h) with a portojugular shunt. Animals were divided into two groups: donor and recipient treatment with low-dose EPO (65 IU/kg) or vehicle, administered 6 h before cold perfusion and 30 min after warm reperfusion. Fourteen of 17 animals (82.4%) fulfilled the inclusion criteria. No differences were noted in operative values between the groups including hemoglobin, cold or warm ischemic time. EPO-treated animals showed a significantly lower histopathology score, reduced apoptosis, oxidative stress, and most important a significant up-regulation of endothelial nitric oxide (NO) synthase (eNOS). Donor and recipient treatment with low-dose EPO reduces the hepatic IRI via EPOR2/ßcR2-independent cytoprotective mechanisms and represents a clinically applicable way to reduce IRI.

Endothelin-1 receptor A blocker darusentan decreases hepatic changes and improves liver repopulation after cell transplantation in rats.

UNLABELLED: Cell transplantation-induced hepatic ischemia and recruitment of vasoconstrictors (e.g., endothelin-1; Edn1) leads to clearance of transplanted cells and poses problems for liver repopulation. Therefore, we determined whether darusentan (DAR), which potently blocks Edn1 receptor type A, could benefit cell engraftment. We transplanted primary F344 rat hepatocytes with or without DAR in dipeptidyl peptidase IV-deficient rats. Analysis of microcirculatory events included hepatic ischemia, endothelial injury, including with gene expression arrays, and activations of Kupffer cells (KCs), neutrophils, or hepatic stellate cells (HSCs). The retrorsine-partial hepatectomy model was used for liver repopulation studies. Whether DAR was directly cytoprotective was examined in cultured rat hepatocytes or CFSC-8B rat HSCs. We found that DAR induced hepatic sinusoidal vasodilation, caused more transplanted cells to be deposited in liver parenchyma, and decreased hepatic ischemia and endothelial injury. This lessened perturbations in expression of endothelial biology genes, including regulators of vessel tone, inflammation, cell adhesion, or cell damage, versus drug-untreated controls. Moreover, in DAR-treated animals, cell transplantation-induced activation of KCs, albeit not of neutrophils, decreased, and fewer HSCs expressed desmin. In DAR-treated rats, improvements in cell engraftment led to greater extent of liver repopulation, compared to drug-untreated controls. In cell-culture assays, DAR did not stimulate release of cytoprotective factors, such as vascular endothelial growth factor, from HSCs. Moreover, DAR did not protect hepatocytes from tumor necrosis factor alpha- or oxidative stress-induced toxicity. Endothelin receptor A blockade in vitro did not improve engraftment of subsequently transplanted hepatocytes. CONCLUSION: Systemic administration of DAR decreases hepatic ischemia-related events and thus indirectly improves cell engraftment and liver repopulation. This vascular mechanism may permit the development of combinatorial drug-based regimens to help optimize cell therapy.

Growth factors and gastrointestinal anastomotic healing.

BACKGROUND: Failure of anastomotic healing in the gastrointestinal tract is a major source of surgery-related morbidity, repeated surgical procedures, and impaired quality of life. Growth factors have been shown to be involved in healing processes in various tissues including the gastrointestinal tract. This opens the perspective to use growth factors therapeutically to support impaired anastomotic healing. The aim of the present study was to review the particular role of several growth factors in different phases of anastomotic healing, experimental approaches of growth factor application, and to discuss possibilities and limitations of growth factor-directed interventions in gastrointestinal surgery. MATERIALS AND METHODS: A PubMed search was performed to examine the potential role of fibroblast growth factor, epidermal growth factor, heparin binding EGF-like growth factor, transforming growth factor ß, insulin-like growth factor I, vascular endothelial growth factor, and platelet-derived growth factor during anastomotic healing. RESULTS: Growth factors show beneficial effects on a broad range of cell types and regulate various processes during all phases of tissue healing. Despite extensive research in the field of growth factors, additional evidence is needed before translating into a clinical setting. CONCLUSIONS: Future research should focus on adequate sustained but limited drug delivery. Undesired side effects, such as formation of strictures, development of peritoneal adhesions, and potential induction of malignancies, have to be reflected. Although growth factor application is currently far from clinical routine in gastrointestinal surgery, it might find application in selected patients at risk for impaired anastomotic healing, such as patients with long-time steroid therapy, immunosuppressives, inflammatory disorders, sepsis, hemodynamic shock, malnutrition, or neoadjuvant radiochemotherapy.

Vessel size imaging (VSI) by robust magnetic resonance (MR) relaxometry: MR-VSI of solid tumors in correlation with immunohistology and intravital microscopy.

The aim of this study was to evaluate a robust magnetic resonance (MR) vessel size imaging (VSI) method for the noninvasive assessment of mean vessel size in solid tumors in a clinical dose range of ultrasmall superparamagnetic particles of iron oxide (USPIO). Therefore, USPIO-enhanced MR-VSI was performed on DU-4475, MDA-MB-435, and EOMA tumor-bearing mice xenografts with known differences in angiogenic activity and vessel morphology. MR results were compared to vessel sizes determined by immunohistochemistry (anti-CD31) and by intravital microscopy (IVM). MR-VSI revealed significantly different mean vessel sizes between the xenograft models at both USPIO doses (DU-4475: 20.6 ± 4.9 µm; MDA-MB-435: 37.4 ± 8.8 µm; and EOMA: 60.3 ±9.6 µm at 80 µmol/kg; p < .05). Immunohistochemistry revealed lower values for all tumor entities, whereas the size distribution was in line with MR-measurements. IVM corroborated the MR results for DU-4475 and MDA-MB435, but showed similar vessel sizes for MDA-MB-435 and EOMA. Our MR-VSI method allowed a noninvasive estimation of the mean vessel size in mice xenograft solid tumors with variable vascularity using a clinically relevant USPIO dose range.

Dietary copper triggers onset of fulminant hepatitis in the Long-Evans cinnamon rat model.

AIM: To investigate the impact of dietary copper given at different time points on the onset of fulminant hepatitis. METHODS: The Long-Evans cinnamon (LEC) rat model of Wilson's disease (WD) was used to study the impact of high dietary copper (hCu) on the induction of fulminant hepatitis at early or late time points of life. High Cu diet was started in rat pups or in adults (month 5) for three months. Animals that received reduced dietary copper (rCu) throughout their lifetime served as a control. Hepatitis-associated serum markers (alanine aminotransferase, aspartate transaminase, bilirubin) were analyzed in animal groups receiving hCu or rCu. Liver copper content and liver histology were revealed at sacrifice. A set of 5 marker genes previously found to be affected in injured liver and which are related to angiogenesis (Vegfa), fat metabolism (Srebf1), extracellular matrix (Timp1), oxidative stress (Hmox1), and the cell cycle (Cdkn1a) were analyzed by real-time polymerase chain reaction. RESULTS: Regardless of the time point when hCu was started, LEC rats (35/36) developed fulminant hepatitis and died. Animals receiving rCu (36/36) remained healthy, did not develop hepatitis, and survived long term without symptoms of overt disease, although liver copper accumulated in adult animals (477 ± 75 µg/g). With regard to start of hCu, onset of fulminant hepatitis was significantly (P < 0.001) earlier in adults (35 ± 9 d) that showed pre-accumulation of liver copper as compared to the pup group (77 ± 15 d). Hepatitis-associated serum markers, liver copper and liver histology, as well as gene expression, were affected in LEC rats receiving hCu. However, except for early and rapid onset of hepatitis, biochemical and molecular markers were similar at the early and late time points of disease. CONCLUSION: Rapid onset of fulminant hepatitis in asymptomatic LEC rats with elevated liver copper suggests that there is a critical threshold of liver copper which is important to trigger the course of WD.

Longitudinal analysis of serum miR-122 in a rat model of Wilson's disease.

PURPOSE: MicroRNA-122 (miR-122) has recently been shown to represent a novel biomarker of liver disease. However, the presence of serum miR-122 after liver injury was mostly studied at singular time points. The course of serum miR-122 was determined at consecutive time points during the onset of disease. METHODS: Fulminant hepatitis was induced by a high-copper diet in Long-Evans Cinnamon (LEC) rats that were used as models for Wilson's disease (WD). Levels of serum miR-122, alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and liver histology were determined. RESULTS: Toxic copper given to isolated hepatocytes induced release of miR-122 into the tissue culture medium. Levels of serum miR-122 were highly elevated (21.9 ± 5) in LEC rats after high-copper diet in fulminant hepatitis, whereas healthy rats showed low (<0.6) baseline levels of miR-122. Levels of miR-122 in the serum of LEC rats after high-copper diet continuously increased for about 4 weeks prior to the onset of fulminant hepatitis. In most of the animals (77.8%), significantly increased levels of miR-122 were detected about 2 weeks (13.7 ± 2 days) earlier as compared to hepatitis-associated serum markers ALT, AST, and bilirubin. Analysis of miR-122 in survivors after cell-based therapy of WD demonstrated a rapid decrease of miR-122 levels following hepatocyte transplantation. miR-122 expression in the serum was normalized to baseline levels in most of the (4/5) survivors. CONCLUSION: Our results suggest that longitudinal analysis of miR-122 allows detection of severe liver disease at an early stage and might be excellently suited to monitor therapy, at least when severe liver disease can be restored as observed after cell-based therapy of WD. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12072-012-9348-5) contains supplementary material, which is available to authorized users.

Repeated transplantation of hepatocytes prevents fulminant hepatitis in a rat model of Wilson's disease.

The outcome of consecutive hepatocyte transplants was explored in a rat model of Wilson's disease before the onset of fulminant hepatitis without preconditioning regimens. Rats received a high-copper diet in order to induce a rapid induction of liver failure. Sham-operated rats (15/15) developed jaundice and fulminant hepatitis, and they died within 4 weeks of first transplantation. Despite the continuation of a high dietary copper challenge, long-term survival was observed for a notable proportion of the transplanted animals (7/18). All survivors displayed normalized levels of hepatitis-associated serum markers and ceruloplasmin oxidase activity by posttransplant days 50 and 98, respectively. The liver copper concentrations, the liver histology, and the expression of marker genes were significantly restored within 4 months of transplantation in comparison with the control group. The high expression of a copper transporter gene (ATPase Cu++ transporting beta polypeptide) in the livers of the survivors indicated a high rate of repopulation by donor hepatocytes. Our data suggest that repeated cell transplantation can overcome the limitations of a single therapy session in rats with severe hepatic disease by functionally restoring the host liver without preconditioning.

Type of steatosis influences microcirculation and fibrogenesis in different rat strains.

This study investigates the impact of rat strain on the development of nonalcoholic fatty liver disease (NAFLD) focusing on morphological features and microcirculation. Male rats of Lewis, Wistar, and Sprague Dawley (n = 6 per strain and group) were randomized into a high-fat group which was fed with a special high-fat nutrition for a 3-week period and a control group which received standard nutrition. Intravital microscopy was used for the evaluation of microcirculation and correlated to morphological changes using a fatty liver scoring system. All three strains receiving a high-fat diet developed a grade 3 steatosis (>66% liver cell steatosis). Whereas Lewis showed a solely microvesicular steatosis, Wistar developed a mixed form and Sprague Dawley showed a pure macrovesicular steatosis and the highest degree of fibrosis and hepatocyte damage. Microcirculatory results revealed that sinusoidal density was already affected by a microvesicular steatosis and decreased with increasing macrovesicular proportion (Lewis: 18%, Wistar: 31%, Sprague Dawley: 23%). The degree of steatosis correlates with reduced blood flow velocity in central veins as well as in sinusoids (Lewis: 28%, Wistar: 39%, Sprague Dawley 44%). The densities of hepatocytes and hepatic stellate cells were only impaired once macrovesicular cell steatosis (Wistar and Sprague Dawley) was present. The development of NAFLD in the rat revealed strain-specific morphological features correlating with microcirculatory changes that should be considered in further studies using these models.

Role of angiotensin-1 receptor blockade in cirrhotic liver resection.

BACKGROUND: The regeneration capacity of cirrhotic livers might be affected by angiotensin-1 (AT1) receptors located on hepatic stellate cells (HSC). The effect of AT1 receptor blockade on microcirculation, fibrosis and liver regeneration was investigated. MATERIALS AND METHODS: In 112 Lewis rats, cirrhosis was induced by repetitive intraperitoneal injections of CCl(4) . Six hours, 3, 7 and 14 days after partial hepatectomy or sham operation, rats were sacrificed for analysis. Animals were treated with either vehicle or 5 mg/kg body weight losartan pre-operatively and once daily after surgery by gavage. Microcirculation and portal vein flow were investigated at 6 h. The degree of cirrhosis was assessed by Azan Heidenhein staining, activation of HSC by desmin staining, apoptosis by ssDNA detection and liver regeneration by Ki-67 staining. Changes in expression of various genes important for liver regeneration and fibrosis were analysed at 6 h and 3 days. Haemodynamic parameters and liver enzymes were monitored. RESULTS: Losartan treatment increased sinusoidal diameter, sinusoidal blood flow and portal vein flow after partial hepatectomy (P<0.05), but not after sham operation. AT1 receptor blockade resulted in increased apoptosis early after resection. HSC activation was reduced and after 7 days, a significantly lower degree of cirrhosis in resected animals was observed. Losartan increased the proliferation of hepatocytes at late time-points and of non-parenchymal cells early after partial hepatectomy (P<0.05). Tumour necrosis factor (TNF)-α was significantly upregulated at 6 h and stem cell growth factor (SCF) was downregulated at 3 days (P<0.05). CONCLUSION: Losartan increased hepatic blood flow, reduced HSC activation and liver fibrosis, but interfered with hepatocyte proliferation after partial hepatectomy in cirrhotic livers.

From longitudinal gastric resection to sleeve gastrectomy--revival of a previously established surgical procedure.

INTRODUCTION: Sleeve gastrectomy is becoming increasingly popular within bariatric surgery. Initially introduced as a component of complex interventions and later as part of a two-stage operation in high-risk patients, the procedure is now more common as one-stage operation and subject of avid scientific discussion. However, the concept of longitudinal gastric resection is not new. The procedure was already established in ulcer surgery but soon faded into insignificance. This article aims to trace the historical development of resection of the greater curvature with particular reference to its origin in ulcer and bariatric surgery. The contribution of ulcer surgery to modern sleeve gastrectomy is highlighted. Furthermore, the current value of sleeve gastrectomy within the spectrum of bariatric surgical procedures will be discussed. Relevant medical literature from PubMed to April 2010 was reviewed. DISCUSSION: Besides bariatric surgery modern sleeve gastrectomy has one more so far largely neglected origin: segmental and later longitudinal gastric resection used in ulcer surgery. Experience and achievements from ulcer surgery simplified and facilitated development of sleeve gastrectomy which is not the desired universal procedure for bariatric surgery but certainly an attractive treatment option. It should be performed in a more standardized manner and with due regard to future long-term results.

A new technique for ureteral defect lesion reconstruction using an autologous vein graft and a biodegradable endoluminal stent.

PURPOSE: Ureteral defect lesions are severe complications caused by iatrogenic lesions or trauma. For ureteral defect lesions elaborate surgical intervention is needed, such as autotransplantation or ureteral replacement with small bowel. Thus, we developed a new technique for ureteral defect reconstruction in a pig model using an autologous vein graft splinted by an endoluminal biodegradable poly-L-lactic acid stent (Institute of Textile Technology and Process Engineering, Denkendorf, Germany). MATERIALS AND METHODS: In 42 pigs we removed the external jugular vein and used it as an autologous vein graft. After median laparotomy a 3 cm segment was resected from the proximal ureter and replaced by the vein with or without an endoluminal biodegradable poly-L-lactic acid stent. As controls, we used 14 pigs. We observed survival, kidney function, and neoureteral and kidney morphological changes for 7 days and for 6 months. RESULTS: After 6 months the stent material was completely broken down and the vein graft was relined with urothelium. It resembled native ureter with cytokeratin-7 positive columnar epithelium and newly formed capillaries in the ureteral wall. All animals had normal kidney function without renal pelvis congestion. CONCLUSIONS: This new technique for ureteral defect reconstruction using an autologous vein graft and a biodegradable endoluminal stent is feasible. It is an interesting alternative in the clinic due to the preservation of physiological urine passage and the antireflux mechanism.

Morphological changes during creation of a neo-bile duct using a vein and a biodegradable endoluminal stent.

Major bile duct lesions are usually treated by a hepaticojejunostomy which is often complicated by cholangitis and liver fibrosis. The aim of this study was to investigate the morphologic features of a neo-bile duct created from a vein and a biodegradable endoluminal stent. The neo-bile duct was created using a segment of the external jugular vein which was endoluminally stented by a biodegradable poly-lactate-acid stent. In 18 pigs, the common bile duct was resected and replaced by the vein with (n = 12) or without endoluminal stent (n = 6). Six animals served as controls. Survival, liver function and morphological changes of the neo-bile duct and the liver were observed for six months. After six months, the neo-bile duct morphologically resembled the native bile duct showing Ck7-positive columnar epithelium and newly formed capillaries in the bile duct wall. The biodegradable stent disappeared after four months. All animals survived and showed normal liver function and no cholestasis. In contrast, after sole vein reconstruction of the bile duct, four animals died due to biliary peritonitis and cholangitis. Creation of a neo-bile duct which morphologically resembles the native bile duct is feasible by using a body's own vein and a biodegradable endoluminal stent.

ATIII attenuates endotoxemia induced healing impairment in the colon.

BACKGROUND: Intra-abdominal infections are considered a contributing factor to the impairment of anastomotic healing in patients undergoing surgical procedures of digestive system. Antithrombin (ATIII) is known to improve the microcirculation in sepsis. We hypothesized that it may also positively influence the healing of the colon anastomoses under endotoxemia. MATERIALS AND METHODS: Ninety Balb/c mice (n = 10 per group on day 2, 4, and 7) were randomly assigned to three groups: Control (N), Sepsis (S) (administration of lipopolysaccharides (LPS) dosed at 2 mg/kg bodyweight, 18 h before colon surgery), and Sepsis with ATIII therapy (SIII) (administration of LPS and ATIII). All the animals underwent colonic anastomoses. Immediately after their completion, microcirculatory parameters were measured, and both macroscopic and histological parameters were assessed on day 2, 4, and 7 postoperation. Additionally, immunohistology studies were performed for CD31, ssDNA, and iNOS, along with an examination for bacterial translocation to the mesenteric lymph nodes. RESULTS: Compared with group S, the functional capillary network was denser in the control group N (P < 0.001) and group SIII (P < 0.01). Mean bursting pressures were significantly lower in group S compared with group N, on day 2, 4, and 7, and with group SIII on day 2 and 7. At the anastomosis, the inflammatory infiltrate in group S was denser compared with groups N (P < 0.001) and SIII (P < 0.01). Furthermore, the apoptotic rate was higher, and the vascular density was lower on day 7 in group S compared with groups SIII and N (P < 0.05). Bacterial translocation decreased over time (P < 0.05) with no significant differences between the groups. CONCLUSION: ATIII improved the anastomotic microcirculatory parameters and anastomotic healing in mice with endotoxemia, though the improvement failed to achieve the levels of the control mice.

Microcirculatory dysfunction in endotoxemic bowel anastomosis: the pathogenetic contribution of microcirculatory dysfunction to endotoxemia-induced healing impairment.

BACKGROUND: An established intra-abdominal infection as in perforated diverticulitis is considered to contribute to anastomotic healing impairment. Since microvascular dysfunction in sepsis is known to be due to organ failure, the influence of inflammation on the anastomotic microcirculation needs further investigation. MATERIAL AND METHODS: Sixty BALB/c mice (n = 10 per group and day 2, 4, and 7) were randomized to two groups: Control and Sepsis (lipopolysaccharide administration 2 mg/kg bodyweight 18 h before colon surgery). All animals underwent colonic anastomosis. Immediately after its completion intravital fluorescence microscopy of the anastomosis was performed, and both macroscopic and histological parameters were assessed on days 2, 4, and 7 postoperatively. Additionally, immunohistology was performed for CD31 (platelet endothelial cell adhesion molecule-1), single-strand DNA, and inducible nitric oxide synthase. RESULTS: As compared to Control the functional capillary network of the perianastomotic region was decreased in Sepsis (P < 0.001) as well as the hemoglobin O(2) saturation in the antimesenteric region of the anastomosis (P < 0.05). Bursting pressure was significantly decreased in Sepsis compared to Control at days 2, 4, and 7. On day 7 there were significant differences between the two groups in the anastomotic region: neutrophil infiltration in Sepsis was higher (P < 0.001); vascular density and differentiation in Sepsis was lower (P < 0.01, P < 0.05, respectively); and apoptosis was higher in Sepsis (P < 0.05). CONCLUSION: The inflammatory state increases microvascular dysfunction at the anastomosis resulting in healing impairment.

Influence of heme oxygenase-1 on microcirculation after kidney transplantation.

BACKGROUND: Cytoprotective proteins, such as heme oxygenase-1 (HO-1), play a decisive role in ischemia-reperfusion injury during kidney transplantation. The aim of this study was to investigate the impact of heme oxygenase-1 on microcirculation and on ischemia-reperfusion injury in an isogenic kidney transplantation rat model. MATERIALS AND METHODS: Seventy male Lewis rats were distributed into three groups. In Group 1(control), the kidneys were only mobilized. In Groups 2 and 3, bilateral nephrectomy was performed, and a kidney from another Lewis rat was orthotopically transplanted on the left side. The donor animals in Group 3 received preconditioning with the HO-1 inductor hemin. 24 h after reperfusion graft function and morphology were examined. Microcirculation was investigated by in vivo microscopy of the renal surface 1 h after reperfusion. RESULTS: HO-1 preconditioning led to significantly lower serum creatinine and serum urea, as well as less histological damage and inducible nitric oxide synthase expression. Microcirculation was improved by a significant enlargement of the vascular diameter and an increase of the capillary flow. CONCLUSIONS: Treatment with hemin improves microcirculation by induction of HO-1 and reduces ischemia-reperfusion injury after kidney transplantation. HO-1 induction was shown to be a promising approach in the preconditioning of donor kidneys.

Impact of rapamycin on liver regeneration.

The remarkable capacity of the liver to regenerate after injury and the prospects of organ self-renewal have attracted much interest in the understanding and modulation of the underlying molecular events. We investigated the effect of mammalian target of rapamycin (mTOR) inhibitor rapamycin (RAPA) on liver by correlating intravital microscopy, immunohistochemistry, and reverse transcriptase polymerase chain reaction in a rat model of 2/3 hepatectomy. RAPA significantly retarded proliferation of hepatocytes, endothelial cells, and hepatic stellate cells (HSCs) mostly between days 2 and 4 after hepatectomy and downregulated major cytokines and growth factors (tumor necrosis factor alpha, hepatocyte growth factor, platelet-derived growth factor, platelet-derived growth factor receptor, insulin-like growth factor-1, transforming growth factor beta 1) important for liver regeneration. These effects were almost absent at later time points. RAPA also had a transient, but broad effect on angiogenesis, and impaired sinusoidal density as well as mRNA levels of vascular endothelial growth factor, vascular endothelial growth factor receptor 1, vascular endothelial growth factor receptor 2, and angiopoietin-1. Activation of HSC was also transiently suppressed as observed by smooth muscle protein 1 alpha protein expression and intercellular adhesion molecule-1 mRNA levels. The rate of apoptosis in liver was significantly increased by RAPA between day 3 and day 7. The effect of RAPA on liver repair, angiogenesis, and HSC activation is confined to the phase of active cell proliferation. This transient effect might allow further exploration of mTOR inhibitors in clinical situations that involve liver regeneration, and seems to have implications beyond immunosuppression.

Attenuated cold storage injury of rat livers using a modified HTK solution.

BACKGROUND: Preservation injury is a main factor leading to graft failure in liver transplantation. The aim of the study was to minimize preservation injury by modifications of the histidine-tryptophan-ketoglutarate (HTK) solution (incorporation of N-acetyl-histidine, aspartate, glycine, alanine, and arginine). MATERIALS AND METHODS: The study was carried out in rats and subdivided into four parts. (1) Systemic toxicity of the modified HTK solution in comparison to the standard HTK solution was tested. (2) Hemodynamic and microcirculatory parameters were analyzed after i.v. injection of the respective solution. (3) Preservation injury after cold storage for different periods of time was assessed microscopically. (4) Reperfusion injury was analyzed in the isolated perfused liver by enzyme release and bile production. RESULTS: Blood values, hemodynamic and microcirculatory parameters after i.v. and i.p. application did not significantly differ from control. The modified HTK solution led to an attenuated preservation injury after cold preservation for 24 h compared with standard HTK solution. There was a significantly decreased lactate dehydrogenase release after ischemia for 72 h and reperfusion using the modified solution. After 24 h cold storage and reperfusion the apoptosis index was reduced and bile production significantly increased. CONCLUSION: Optimizing the HTK solution may be a promising therapeutic strategy for attenuation of cold storage injury.

A new laparoscopic technique for weight reduction with implanted gastric banding basket.

BACKGROUND: Nowadays, obesity is frequently an indication for implantation of an adjustable stomach or gastric band. Among the side effects, in addition to band erosion and port chamber complications, pouch dilation in the sense of increasing enlargement of the forestomach and resulting insufficiency of initial surgical measures consistently occurs. Implantation of a soft basket band will prevent this. The objective of this study was to investigate the practical feasibility of the soft basket band. METHODS: Ten patients were investigated in an observation study over a period from November 2006 to June 2007. Seven patients were women and three patients were men, with an average age of 43.6 years (25-66 years). RESULTS: The average body mass index (BMI) at the time of the operation was 47.4 +/- 5.5 kg/m(2), with an average body weight of 134.5 +/- 24.6 kg. After a median follow-up period of 1 month, an average BMI of 44.9 +/- 5.8 kg/m(2) was achieved, and after 3 months, an average BMI of 41.4 +/- 4.8 kg/m(2). The excessive weight loss was 7.4 +/- 4.3 kg after 1 month and 17.9 +/- 6.4 kg after 3 months. A local wound infection occurred as a complication in one patient. CONCLUSION: Laparoscopy procedures enable mortality to be lowered compared to bypass operations with minimal complications and substantial reduction of weight.