Martina Mogl

Effect of Enteral Nutrition and Synbiotics on Bacterial Infection Rates After Pylorus-preserving Pancreatoduodenectomy A Randomized, Double-blind Trial

Objective:Patients undergoing pancreas resection carry several risk factors for nosocomial bacterial infections. Pre- and probiotics (synbiotics) are potentially useful for prevention of these infections. Summary Background Data:First trials in patients following major abdominal surgery including liver transplantation using one Lactobacillus (LAB) and one fiber showed significant reduction of infection rates and reduced length of antibiotic therapy compared with a control group. The present study was designed to analyze whether a combination of different LAB and fibers would further improve outcome. Methods:A prospective randomized monocentric double-blind trial was undertaken in 80 patients following pylorus-preserving pancreatoduodenectomy (PPPD). All patients received enteral nutrition immediately postoperatively. One group (A) received a composition of 4 LAB and 4 fibers, and another group (B) received placebo (fibers only) starting the day before surgery and continuing for 8 days. Thirty-day infection rate, length of hospital stay, duration of antibiotic therapy, noninfectious complications, and side effects were recorded. Results:The incidence of postoperative bacterial infections was significantly lower with LAB and fibers (12.5%) than with fibers only (40%). In addition, the duration of antibiotic therapy was significantly shorter in the latter group. Fibers and LAB were well tolerated. Conclusion:Early enteral nutrition supplemented with a mixture of LAB and fibers reduces bacterial infection rates and antibiotic therapy following PPPD.

Older liver graft transplantation, cholestasis and synthetic graft function.

Older liver grafts are often discarded because of conservative selection criteria. We report on our clinical experience with graft‐age related outcome. Patients transplanted with livers older than 70 years (70.2–80.2 years, n = 38) were compared with controls transplanted with livers younger than 70 years. Pairs were matched for age, gender, indication and cold ischemic time. Mean donor age was 73.4 ± 2 vs. 39 ± 16 years. Patient and graft survival did not differ between both groups after 1‐year follow‐up (P = 0.19 and P = 0.24 respectively). Retransplantation rate was 10.5% vs. 5.3% (P = 0.40). Initial poor function occurred in two patients in the study group versus four patients in the control group (P = 0.69). The incidence of rejection episodes was comparable. Parameters of cholestasis and protein synthesis showed no difference 1‐year post‐transplant. Mean age of donor organs in matched pairs group B was near by half of that in the older donor group A (39.0 vs. 73.4 years). Post‐transplant outcome as indicated by patient and graft survival was comparable between both groups. Donor organ age had no impact on postoperative organ function. We recommend to accept liver grafts from organ donors older than 70 years to expand the donor pool.

CARS microscopy for the visualization of micrometer-sized iron oxide MRI contrast agents in living cells

Micrometer-sized iron oxide particles (MPIOs) attract increasing interest as contrast agents for cellular tracking by clinical Magnetic Resonance Imaging (MRI). Despite the great potential of MPIOs for in vivo imaging of labeled cells, little is known on the intracellular localization of these particles following uptake due to the lack of techniques with the ability to monitor the particle uptake in vivo at single-cell level. Here, we show that coherent anti-Stokes Raman scattering (CARS) microscopy enables non-invasive, label-free imaging of MPIOs in living cells with sub-micron resolution in three dimensions. CARS allows simultaneous visualization of the cell framework and the MPIOs, where the particles can be readily distinguished from other cellular components of comparable dimensions, and localized inside the cell.

Functionalizable Silica-Based Micron-Sized Iron Oxide Particles for Cellular Magnetic Resonance Imaging:

Cellular therapies require methods for noninvasive visualization of transplanted cells. Micron-sized iron oxide particles (MPIOs) generate a strong contrast in magnetic resonance imaging (MRI) and are therefore ideally suited as an intracellular contrast agent to image cells under clinical conditions. However, MPIOs were previously not applicable for clinical use. Here, we present the development and evaluation of silica-based micron-sized iron oxide particles (sMPIOs) with a functionalizable particle surface. Particles with magnetite content of >40% were composed using the sol-gel process. The particle surfaces were covered with COOH groups. Fluorescein, poly-l-lysine (PLL), and streptavidin (SA) were covalently attached. Monodisperse sMPIOs had an average size of 1.18 μm and an iron content of about 1.0 pg Fe/particle. Particle uptake, toxicity, and imaging studies were performed using HuH7 cells and human and rat hepatocytes. sMPIOs enabled rapid cellular labeling within 4 h of incubation; PLL-modified particles had the highest uptake. In T2*-weighted 3.0 T MRI, the detection threshold in agarose was 1,000 labeled cells, whereas in T1-weighted LAVA sequences, at least 10,000 cells were necessary to induce sufficient contrast. Labeling was stable and had no adverse effects on labeled cells. Silica is a biocompatible material that has been approved for clinical use. sMPIOs could therefore be suitable for future clinical applications in cellular MRI, especially in settings that require strong cellular contrast. Moreover, the particle surface provides the opportunity to create multifunctional particles for targeted delivery and diagnostics.

Labeling of Primary Human Hepatocytes With Micron-Sized Iron Oxide Particles in Suspension Culture Suitable for Large-Scale Preparation

Labeling of hepatocytes with micron-sized iron oxide particles (MPIOs) enables cell detection using clinical magnetic resonance equipment. For clinical applications, large numbers of cells must be labeled in a simple and rapid manner and have to be applied in suspension. However, all existing protocols are based on adhesion culture labeling with subsequent resuspension, only suitable for small experimental settings. The aim of this study was to investigate the feasibility of preparing MPIO-labeled primary human hepatocytes in a temporary suspension culture. Human hepatocytes were isolated from 16 donors and labeled with MPIOs in suspension, using the Rotary Cell Culture System. Particle incorporation was investigated by light and electron microscopy. Cells were compared with adhesion culture-labeled and subsequently enzymatically resuspended cells. During a period of 5 days, hepatocyte-specific parameters of cell damage (aspartate aminotransferase and alanine aminotransferase) and metabolic activity (urea and albumin) were analyzed (n=7). Suspension cultures showed a higher outcome in cell recovery compared with the conventional labeling method. When incubated with 180 particles/viable cell for 4 h, the mean particle uptake was 28.8 particles/cell at a labeling efficiency of 95.1%. Labeling in suspension had no adverse effects on cell integrity or metabolic activity. We conclude that labeling of human hepatocytes in suspension is feasible and simple and may serve future large-scale processing of cells.

An operational concept for long-term cinemicrography of cells in mono- and co-culture under highly controlled conditions – The SlideObserver

Cell morphology, proliferation and motility, as well as mono- and heterotypic cell-to-cell interactions, are of increasing interest for in vitro experiments. However, tightly controlling culture conditions whilst simultaneously monitoring the same set of cells is complicated. Moreover, video-microscopy of distinct cells or areas of cells over a prolonged period of time represents a technical challenge. The SlideObserver was designed for cinemicrography of cells in co-and monoculture. The core elements of the system are the SlideReactors, miniaturised hollow fibre-based bioreactors operated in closed perfusion loops. Within the SlideReactors, cells can be cultured under adaptable conditions as well as in direct- and indirect co-culture. The independent perfusion loops enable controlled variation of parameters such as medium, pH, and oxygenation. A combined automated microscope stage and camera set-up allows for micrograph acquisition of multiple user-defined regions of interest within the bioreactor units. For proof of concept, primary cells (HUVEC, human hepatocytes) and cell lines (HuH7, THP-1) were cultured under stable and varying culture conditions, as well as in mono- and co-culture. The operational system enabled non-stop imaging and automated control of process parameters as well as elective manipulation of either reactor. As opposed to non-perfused culture systems or comparable devices for cinemicrographic analysis, the SlideObserver allows simultaneous morphological monitoring of an entire culture of cells in multiple bioreactors.

Allogeneic Liver Transplantation and Subsequent Syngeneic Hepatocyte Transplantation in a Rat Model: Proof of Concept for in vivo Tissue Engineering

Objectives: Stable long-term functioning of liver cells after transplantation in humans is still not achieved successfully. A new approach for successful engraftment of liver cells may be the transplantation of syngeneic cells into an allogeneic liver graft. We therefore developed a new rat model for combined liver and liver cell transplantation (cLCTx) under stable immunosuppression. Materials and Methods: After inducing a mitotic block, liver grafts from female donor rats (Dark Agouti) were transplanted into female recipients (Lewis). In male Lewis rats, liver cell proliferation was induced with subsequent cell isolation and transplantation into female recipients after organ transplantation. Y-chromosome detection of the transplanted male cells was performed by quantitative polymerase chain reaction (qPCR) and fluorescence in situ hybridization (FisH) with localization of transplanted cells by immunohistochemistry. Results: Immunohistochemistry demonstrated the engraftment of transplanted cells, as confirmed by FisH, showing repopulation of the liver graft with 15.6% male cells (± 1.8 SEM) at day 90. qPCR revealed 14.15% (± 5.09 SEM) male DNA at day 90. Conclusion: Engraftment of transplanted syngeneic cells after cLCTx was achieved for up to 90 days under immunosuppression. Immunohistochemistry indicated cell proliferation, and the FisH results were partly confirmed by qPCR. This new protocol in rats appears feasible for addressing long-term functioning and eventually the induction of operational tolerance in the future.

How I Do It: New Dissector Device Allows for Effective Operative Field in Transoral Endoscopic Thyroid Surgery Using Vestibular Approach

Background. Minimally invasive thyroid and parathyroid resections are rarely performed. Promising new endoscopic transoral approaches to the anterior neck (transoral endoscopic thyroidectomy vestibular approach [TOETVA]) have been described with good results and few complications. This study evaluates a new device to allow the safe entrance of trocars in the subplatysmal space for TOETVA in a cadaver model. Methods. The technique was performed in 4 unilateral thyroidectomies in female cadavers. The technical steps consisted of a 10-mm incision made at the center of the oral vestibule followed by subplatysmal hydrodissection. The blunt dissector is a metallic stick with an olive at the end and promotes progressive gain in subplatysmal space enlarging the operative field. The instrument was inserted creating a space below the platysma to the anterior neck and the strap muscles. Three trocars were inserted in the vestibular area. The dissection begins by cutting the linea alba cervicalis. The isthmus was dissected and transected. Anatomical structures as the superior thyroid artery, parathyroid glands, and the recurrent laryngeal nerve could be safely identified with magnified vision. Results. Optimal operative field due to subplatysmal dissection by the device allowed for exposition of thyroid and parathyroid glands in all cases. Unilateral thyroidectomy was performed in a mean of 54 minutes with excellent aesthetic results. Conclusions. The new device is a promising feature to allow safe transoral thyroid surgery in a cadaver model. Further studies in clinical series are needed to evaluate the broad application of the device.

Adrenal Metastasis of Hepatocellular Carcinoma in Patients following Liver Resection or Liver Transplantation: Experience from a Tertiary Referral Center

Introduction Adrenal metastasis of hepatocellular carcinoma (HCC) is a rare entity and can be treated by resection, local ablative therapy, or systemic therapy. Unfortunately, data about treatment outcome, especially in liver transplant recipients, are rare. Patients and Methods From 2005 to 2015, 990 liver resections and 303 liver transplantations because of HCC were performed at our clinic. We retrospectively analyzed treatment outcome of the patients with metachronous adrenal metastasis of HCC, who received either resection, local ablation, or surveillance only. Results 10 patients were identified (0.8%). 7 patients received liver transplantation for primary HCC therapy, 3 liver resection, and 1 a local ablative therapy. 8 patients underwent adrenalectomy (one via retroperitoneoscopy), one was treated with local ablation, and one had surveillance only. Seven out of eight patients had no surgical complications and one experienced a pancreatic fistula, treated conservatively. 37.5% of the resected patients had recurrence 1 year after adrenalectomy and 75% after 2 years. The mean survival time after primary diagnosis of HCC was 96.6±22.4 months. After adrenalectomy, the mean survival time was 112.4±25.2 months. The mean time until tumor recurrence was 13.2±3.8 in the total cohort and 15.8±3.8 months in patients after adrenalectomy. The estimated overall survival after adrenalectomy was 77.2±17.4 months. Conclusion Metachronous adrenal metastasis occured in less than 1% of HCC patients. Adrenalectomy is a safe procedure and leads to acceptable survival rates even after liver transplantion. Therefore, it should be performed whenever the primary tumor is well controlled and the patient is in adequate physical condition.

Immunosuppression following liver transplantation and the course of inflammatory bowel disease – a case control study

AIM The aim of this study was to investigate the influence of immunosuppression following orthotopic liver transplantation (OLT) on course of inflammatory bowel disease (IBD) including disease activity and complications. METHODS Out of 1168 patients undergoing liver transplantation between 1988 and 2000 at our center, we identified those with IBD (n = 67). In a comparative cohort study, IBD patients after OLT were compared to controls without OLT. All drugs including immunosuppressive and anti-inflammatory medication and complications during follow-up were recorded in 6-month intervals. Also, surgical interventions before and after OLT as well as endoscopic interventions with macroscopic and microscopic findings were collected and analyzed. Additionally, development of malignant neoplasias was recorded. RESULTS Of the 67 individuals with IBD and OLT, 41 were available for analyses and compared with 42 controls. The mean follow-up was 7.4 (range: 3 - 15) years. Short-term therapy with calcineurin inhibitors or mycophenolate mofetil led to short-term remission, yet sustained remission could only be achieved in patients receiving mycophenolate mofetil. At 14.5 years, clinical remission was reached by significantly more patients in the transplant group (54 %) than in the control group (33 %, p = 0.0295). Patients in the control group required nearly 2 times as many surgical interventions related to IBD than patients in the transplant group. Neoplasias were more common in the OLT (n = 8) compared with 4 solid organ cancers in the control group, respectively. CONCLUSIONS Our data demonstrate an overall positive impact of immunosuppression following OLT on the course of IBD, especially with mycophenolate mofetil, but an increased rate of malignancies.