Evaluation of Liver Function Tests to Predict Operative Risk in Liver Surgery

Despite numerous studies in the past it is not possible yet to predict postoperative liver failure and safe limits for hepatectomy. In this study the following liver function tests ICG-ER (indocyaninegreen elimination rate), GEC (galactose elimination capacity) and MEGX-F (monoethylglycinexylidid formation) are examined with regard to loss of liver tissue and prediction of operative risk. Liver function tests were assessed in 20 patients prior to liver resection and on the 10th. postoperative day. Liver and tumor volume were measured by ultrasound and pathologic specimen and the parenchymal resection rate was calculated. In patients without cirrhosis (n = 10) ICG-ER and MEGX-F remained unchanged after resection, GEC was reduced but did not correspond to the resection rate. Patients with cirrhosis (n = 10) had a significantly lower ICG-ER and GEC before resection than patients without cirrhosis. After resection these tests were unchanged. Patients with liver related complications and cirrhosis (n = 5) had lower ICG-ER and GEC than patients with cirrhosis and no complications. In the postoperative course all liver function tests in these patients were significantly lower compared to preoperative results. Comparing liver function tests ICG serves best to indicate postoperative liver failure. Liver function tests do not correspond with loss of liver tissue

Characterization of neutralizing epitopes within the major capsid protein of human papillomavirus type 33

BACKGROUND: Infections with papillomaviruses induce type-specific immune responses, mainly directed against the major capsid protein, L1. Based on the propensity of the L1 protein to self-assemble into virus-like particles (VLPs), type-specific vaccines have already been developed. In order to generate vaccines that target a broader spectrum of HPV types, extended knowledge of neutralizing epitopes is required. Despite the association of human papillomavirus type 33 (HPV33) with cervical carcinomas, fine mapping of neutralizing conformational epitopes on HPV33 has not been reported yet. By loop swapping between HPV33 and HPV16 capsid proteins, we have identified amino acid sequences critical for the binding of conformation-dependent type-specific neutralizing antibodies to surface-exposed hyper variable loops of HPV33 capsid protein L1. RESULTS: Reactivities of monoclonal antibodies (mAbs) H33.B6, H33.E12, H33.J3 and H16.56E with HPV16:33 and HPV33:16 hybrid L1 VLPs revealed the complex structures of their conformational epitopes as well as the major residues contributing to their binding sites. Whereas the epitope of mAb H33.J3 was determined by amino acids (aa) 51–58 in the BC loop of HPV33 L1, sequences of at least two hyper variable loops, DE (aa 132–140) and FGb (aa 282–291), were found to be essential for binding of H33.B6. The epitope of H33.E12 was even more complex, requiring sequences of the FGa loop (aa 260–270), in addition to loops DE and FGb. CONCLUSION: These data demonstrate that neutralizing epitopes in HPV33 L1 are mainly located on the tip of the capsomere and that several hyper variable loops contribute to form these conformational epitopes. Knowledge of the antigenic structure of HPV is crucial for designing hybrid particles as a basis for intertypic HPV vaccines

Management of aseptic nonunions and severe bone defects: let us get this thing healed!

Effective nonunion and bone defect management requires consideration of multiple potential contributing factors including biomechanics, biology, metabolic, and patient factors. This article reviews these factors as well as several potential nonunion or bone defect treatments including bone grafts, bone graft substitutes, the induced membrane technique, and distraction osteogenesis. A summary of these concepts and guidelines for an overall approach to management are also provided

Cost-effectiveness analysis of surgical proximal femur fracture prevention in elderly: a Markov cohort simulation model

BACKGROUND Hip fractures are a common and costly health problem, resulting in significant morbidity and mortality, as well as high costs for healthcare systems, especially for the elderly. Implementing surgical preventive strategies has the potential to improve the quality of life and reduce the burden on healthcare resources, particularly in the long term. However, there are currently limited guidelines for standardizing hip fracture prophylaxis practices. METHODS This study used a cost-effectiveness analysis with a finite-state Markov model and cohort simulation to evaluate the primary and secondary surgical prevention of hip fractures in the elderly. Patients aged 60 to 90 years were simulated in two different models (A and B) to assess prevention at different levels. Model A assumed prophylaxis was performed during the fracture operation on the contralateral side, while Model B included individuals with high fracture risk factors. Costs were obtained from the Centers for Medicare & Medicaid Services, and transition probabilities and health state utilities were derived from available literature. The baseline assumption was a 10% reduction in fracture risk after prophylaxis. A sensitivity analysis was also conducted to assess the reliability and variability of the results. RESULTS With a 10% fracture risk reduction, model A costs between $8,850 and$46,940 per quality-adjusted life-year ($/QALY). Additionally, it proved most cost-effective in the age range between 61 and 81 years. The sensitivity analysis established that a reduction of ≥ 2.8$11,000/QALY and $74,000/QALY, which is below the defined willingness to pay threshold. CONCLUSION Due to the high cost of hip fracture treatment and its increased morbidity, surgical prophylaxis strategies have demonstrated that they can significantly relieve the healthcare system. Various key assumptions facilitated the modeling, allowing for adequate room for uncertainty. Further research is needed to evaluate health-state-associated risks

STRUCTURING OF ELECTRODE SURFACES WITH LIGAND-FREE NANOPARTICLES VIA ELECTROPHORETIC DEPOSITION- FUNDAMENTALS AND IN VIVO APPLICATIONS

Electrodes for neural stimulation and recording are highly relevant in modern medicine, e.g. for the treatment of movement disorders. As these electrodes have to be implanted directly into the patient´s brain, impaired biocompatibility as well as reduced performance due to increased impedance upon tissue contact are serious problems. Strategies to improve the efficiency of electrodes entail the implementation of defined nanoscopic structures to the electrode surface, which increase the surface area and improve the current flow by possible edge effects1. In this context electrophoretic deposition (EPD) of nanoparticles (NP) constitutes an efficient and feasible way for surface structuring as in contrast to e.g. ablative laser machining, electric field lines are naturally ordered perpendicular to the implant´s surface, so that electrophoretic deposition is well compatible to shaped implants and curved surfaces. In this work an EPD process for the structuring of Pt electrode surfaces with NP is systematically investigated. Reference NP from a modern synthesis route named pulsed laser ablation in liquids (PLAL)2 are utilized as they possess a high surface charge density in order to ease their movement in an electric field. The electrophoretic velocity of these NP was examined and found to be linearly-correlated with the electric field strength, while the slope is dictated by the NP´s surface charge density (zeta-potential).3, 4 On the other hand the PLAL-generated NP are, by design, completely free of organic ligand, which significantly affected their deposition in an EPD setup. It was found that the deposited mass linearly increased with process time, yielding a well scalable process, while on the other hand control experiments with ligands showed a saturation of the deposited mass due to electrochemical shielding of the surface by charged ligands.4 It was furthermore demonstrated that the EPD process with ligand-free NP could also be done in a continuous flow-through setup suitable for the parallel structuring of multiple electrodes.5 Interestingly, the deposition velocity was not size dependent as particle size distributions prior to and after EPD were identical.5 In consecutive experiments, the surface properties like coverage, oxidation, wettability6 and impedance of the electrode materials were evaluated and correlated with the EPD process parameters electric field strength, colloid concentration and deposition time. As a result a detailed map was obtained, which allows a defined tuning of Pt surface properties by Pt NP EPD. Finally, the impedance of electrodes coated with ligand-free Pt NP were evaluated in long term stimulation experiments with rats. The NP coating could stabilize the impedance of the electrodes in vivo, while it continuously increased in non-coated controls.7 Furthermore, the coated electrodes exhibited excellent biocompatibility similar to the controls7 while no significant NP desorption from the surface was found upon mechanical tear. 1. X. F. F. Wei and W. M. Grill, J. Neural Eng., 2005, 2, 139-147. 2. V. Amendola and M. Meneghetti, Phys. Chem. Chem. Phys., 2013, 15, 3027-3046. 3. A. Menendez-Manjon, J. Jakobi, K. Schwabe, J. K. Krauss and S. Barcikowski, J. Laser Micro Nanoeng., 2009, 4, 95-99. 4. C. Streich, S. Koenen, M. Lelle, K. Peneva and S. Barcikowski, Appl. Surf. Sci., 2015, 348, 92-99. 5. S. Koenen, R. Streubel, J. Jakobi, K. Schwabe, J. K. Krauss and S. Barcikowski, J. Electrochem. Soc., 2015, 162, D174-D179. 6. A. Heinemann, S. Koenen, K. Schwabe, C. Rehbock and S. Barcikowski, Key engineering materials, 2015, 654, 218-223. 7. S. D. Angelov, S. Koenen, J. Jakobi, H. E. Heissler, M. Alam, K. Schwabe, S. Barcikowski and J. K. Krauss, J. Nanobiotechnol., 2016, 14

Electrochemical approaches to design materials for potential sensing and energy related applications

Extended conference abstrac

Electrochemical approaches in synthesis of high surface area materials

It is the aim of our work to carry out fundamental studies on designing and synthesizing high surface area functionalized foam and ordered structures for their potential sensing and energy related applications. We combine electrochemical synthesis with structural studies on different length scales including transmission electron microscopy. Templates are directly grown by electrodeposition, either by hydrogen bubble formation or by utilizing of ordered structures formed by anodic electrochemical oxidation. [1-3] We employed an elegant approach to obtain open, foam deposits of Ni and Ni alloys, by using electrodeposition at high current densities, to promote hydrogen evolution and bubble templating (cf. Fig.1). [1] In the next step, the high surface area of such materials was funtionalized by Pd utilizing galvanic displacement reaction. Electrochemical testing of the obtained open foam deposits shows promissing catalytical activity for hydrogen evolution in alkaline environments, as well as methanol and ethanol oxidation. In the case of fabrication of nanodendritic Ag simultaneously grown with porous anodic aluminium oxide we accomplished well anchored dendritic Ag nanostructures [2] of long-term stability [3]. 1. L. D. Rafailović, C. Gammer, C. Rentenberger, T. Trišović, C. Kleber, H. P. Karnthaler, Nano Energy, 2 (2012) 523 https://doi.org/10.1016/j.nanoen.2012.12.004 2. L.D. Rafailovic, C. Gammer, C. Rentenberger, T. Trisovic, C. Kleber, H.P. Karnthaler, Adv. Mater. 27 (2015) 6438 https://doi.org/10.1002/adma.201502451 3. L.D. Rafailovic, C. Gammer, J. Srajer, T. Trisovic, J. Rahel, H.P. Karnthaler; RSC Adv., 6 (2016) 33348, https://doi.org/10.1039/c5ra26632

Early Change Trajectories in Cognitive-Behavioral Therapy for Binge-Eating Disorder

Rapid response is considered the most well-established outcome predictor across treatments of binge-eating disorder (BED), including cognitive-behavioral therapy (CBT). This study sought to identify latent trajectories of early change in CBT and compare them to common rapid response classifications. In a multicenter randomized trial, 86 adults with BED (DSM-IV) or subsyndromal BED provided weekly self-reports of binge eating over the first 4 weeks of CBT, which were analyzed to predict binge eating, depression, and body mass index at posttreatment, 6-, and 18-month follow-up. Using latent growth mixture modeling, three patterns of early change—including moderate and low decreasing—as well as low stable binge eating were identified, which significantly predicted binge-eating remission at 6-month follow-up. Other classifications of rapid response based on Receiver Operating Characteristics curve analyses or on the literature (≥ 10% reduction in binge eating at week 1, ≥ 70% reduction in binge eating at week 4) only predicted posttreatment remission or overall depression, respectively. Latent change trajectories, but not other rapid response classifications, predicted binge-eating frequency over time. A fine-grained analysis of change over the first 4 weeks of CBT for BED revealed different trajectories of early change in binge eating that led to an improved prediction of binge-eating outcome, compared to that of common rapid response classifications. Thorough monitoring of early change trajectories during treatment may have clinical utility