Plastische Chirurgie nach forcierter Gewichtsreduktion "Kosmetik" oder Rekonstruktion?

Zusammenfassung: Die epidemieartige Zunahme der Übergewichtigkeit in den westlichen Ländern ist auch mit einer steigenden Inzidenz der morbiden Adipositas verbunden. Effiziente und lang anhaltende Gewichtsverluste sind ist hier meist nur mit operativen Interventionen zu erzielen, die heute zuverlässig und sicher durchgeführt werden. Hierdurch können die mit der Adipositas assoziierten Komorbiditäten verbessert oder beseitigt werden. Die Behandlung der Folgezustände nach bariatrischen Operationen mit oft dramatischem Gewichtsverlust und generalisiertem Hautüberschuss ist eine Herausforderung für den Plastischen Chirurgen. Ziel ist die Wiederherstellung einer normalen Körperform als Voraussetzung für eine vollständige psychosoziale Integration der Patienten, die durch ihre äußere Erscheinung oft nicht nur vor, sondern auch nach dem Gewichtsverlust stigmatisiert sind. Die vorliegende Arbeit gibt eine Übersicht über aktuelle Verfahren und Trends der postbariatrischen plastischen Chirurgi

Somatosensory Evoked Potentials suppression due to remifentanil during spinal operations; a prospective clinical study

<p>Abstract</p> <p>Background</p> <p>Somatosensory evoked potentials (SSEP) are being used for the investigation and monitoring of the integrity of neural pathways during surgical procedures. Intraoperative neurophysiologic monitoring is affected by the type of anesthetic agents. Remifentanil is supposed to produce minimal or no changes in SSEP amplitude and latency. This study aims to investigate whether high doses of remifentanil influence the SSEP during spinal surgery under total intravenous anesthesia.</p> <p>Methods</p> <p>Ten patients underwent spinal surgery. Anesthesia was induced with propofol (2 mg/Kg), fentanyl (2 mcg/Kg) and a single dose of cis-atracurium (0.15 mg/Kg), followed by infusion of 0.8 mcg/kg/min of remifentanil and propofol (30-50 mcg/kg/min). The depth of anesthesia was monitored by Bispectral Index (BIS) and an adequate level (40-50) of anesthesia was maintained. Somatosensory evoked potentials (SSEPs) were recorded intraoperatively from the tibial nerve (P37) 15 min before initiation of remifentanil infusion. Data were analysed over that period.</p> <p>Results</p> <p>Remifentanil induced prolongation of the tibial SSEP latency which however was not significant (p > 0.05). The suppression of the amplitude was significant (p < 0.001), varying from 20-80% with this decrease being time related.</p> <p>Conclusion</p> <p>Remifentanil in high doses induces significant changes in SSEP components that should be taken under consideration during intraoperative neuromonitoring.</p

Structure of the TPR Domain of AIP: Lack of Client Protein Interaction with the C-Terminal alpha-7 Helix of the TPR Domain of AIP Is Sufficient for Pituitary Adenoma Predisposition

PMCID: PMC3534021This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Prediction of post-operative necrosis after mastectomy: A pilot study utilizing optical diffusion imaging spectroscopy

<p>Abstract</p> <p>Introduction</p> <p>Flap necrosis and epidermolysis occurs in 18-30% of all mastectomies. Complications may be prevented by intra-operative detection of ischemia. Currently, no technique enables quantitative valuation of mastectomy skin perfusion. Optical Diffusion Imaging Spectroscopy (ViOptix T.Ox Tissue Oximeter) measures the ratio of oxyhemoglobin to deoxyhemoglobin over a 1 × 1 cm area to obtain a non-invasive measurement of perfusion (StO₂).</p> <p>Methods</p> <p>This study evaluates the ability of ViOptix T.Ox Tissue Oximeter to predict mastectomy flap necrosis. StO₂measurements were taken at five points before and at completion of dissection in 10 patients. Data collected included: demographics, tumor size, flap length/thickness, co-morbidities, procedure length, and wound complications.</p> <p>Results</p> <p>One patient experienced mastectomy skin flap necrosis. Five patients underwent immediate reconstruction, including the patient with necrosis. Statistically significant factors contributing to necrosis included reduction in medial flap StO₂(p = 0.0189), reduction in inferior flap StO₂(p = 0.003), and flap length (p = 0.009).</p> <p>Conclusion</p> <p>StO₂reductions may be utilized to identify impaired perfusion in mastectomy skin flaps.</p

Acute effects of remote ischemic preconditioning on cutaneous microcirculation - a controlled prospective cohort study

<p>Abstract</p> <p>Background</p> <p>Therapeutic strategies aiming to reduce ischemia/reperfusion injury by conditioning tissue tolerance against ischemia appear attractive not only from a scientific perspective, but also in clinics. Although previous studies indicate that remote ischemic intermittent preconditioning (RIPC) is a systemic phenomenon, only a few studies have focused on the elucidation of its mechanisms of action especially in the clinical setting. Therefore, the aim of this study is to evaluate the acute microcirculatory effects of remote ischemic preconditioning on a distinct cutaneous location at the lower extremity which is typically used as a harvesting site for free flap reconstructive surgery in a human in-vivo setting.</p> <p>Methods</p> <p>Microcirculatory data of 27 healthy subjects (25 males, age 24 ± 4 years, BMI 23.3) were evaluated continuously at the anterolateral aspect of the left thigh during RIPC using combined Laser-Doppler and photospectrometry (Oxygen-to-see, Lea Medizintechnik, Germany). After baseline microcirculatory measurement, remote ischemia was induced using a tourniquet on the contralateral upper arm for three cycles of 5 min.</p> <p>Results</p> <p>After RIPC, tissue oxygen saturation and capillary blood flow increased up to 29% and 35% during the third reperfusion phase versus baseline measurement, respectively (both p = 0.001). Postcapillary venous filling pressure decreased statistically significant by 16% during second reperfusion phase (p = 0.028).</p> <p>Conclusion</p> <p>Remote intermittent ischemic preconditioning affects cutaneous tissue oxygen saturation, arterial capillary blood flow and postcapillary venous filling pressure at a remote cutaneous location of the lower extremity. To what extent remote preconditioning might ameliorate reperfusion injury in soft tissue trauma or free flap transplantation further clinical trials have to evaluate.</p> <p>Trial registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01235286">NCT01235286</a></p

The crystal structure of the Sgt1-Skp1 complex: the link between Hsp90 and both SCF E3 ubiquitin ligases and kinetochores

The essential cochaperone Sgt1 recruits Hsp90 chaperone activity to a range of cellular factors including SCF E3 ubiquitin ligases and the kinetochore in eukaryotes. In these pathways Sgt1 interacts with Skp1, a small protein that heterodimerizes with proteins containing the F-box motif. We have determined the crystal structure of the interacting domains of Saccharomyces cerevisiae Sgt1 and Skp1 at 2.8 Å resolution and validated the interface in the context of the full-length proteins in solution. The BTB/POZ domain of Skp1 associates with Sgt1 via the concave surface of its TPR domain using residues that are conserved in humans. Dimerization of yeast Sgt1 occurs via an insertion that is absent from monomeric human Sgt1. We identify point mutations that disrupt dimerization and Skp1 binding in vitro and find that the interaction with Skp1 is an essential function of Sgt1 in yeast. Our data provide a structural rationale for understanding the phenotypes of temperature-sensitive Sgt1 mutants and for linking Skp1-associated proteins to Hsp90-dependent pathways

Secondary structure of rhBMP-2 in a protective biopolymeric carrier material

Efficient delivery of growth factors is one of the great challenges of tissue engineering. Polyelectrolyte multilayer films (PEM) made of biopolymers have recently emerged as an interesting carrier for delivering recombinant human bone morphogenetic protein 2 (rhBMP-2 noted here BMP-2) to cells in a matrix-bound manner. We recently showed that PEM made of poly(l-lysine) and hyaluronan (PLL/HA) can retain high and tunable quantities of BMP-2 and can deliver it to cells to induce their differentiation in osteoblasts. Here, we investigate quantitatively by Fourier transform infrared spectroscopy (FTIR) the secondary structure of BMP-2 in solution as well as trapped in a biopolymeric thin film. We reveal that the major structural elements of BMP-2 in solution are intramolecular β-sheets and unordered structures as well as α-helices. Furthermore, we studied the secondary structure of rhBMP-2 trapped in hydrated films and in dry films since drying is an important step for future applications of these bioactive films onto orthopedic biomaterials. We demonstrate that the structural elements were preserved when BMP-2 was trapped in the biopolymeric film in hydrated conditions and, to a lesser extent, in dry state. Importantly, its bioactivity was maintained after drying of the film. Our results appear highly promising for future applications of these films as coatings of biomedical materials, to deliver bioactive proteins while preserving their bioactivity upon storage in dry state.This work was supported by the French Ministry of Research through an ANR-EmergenceBIO grant (ANR-09-EBIO-012-01), by the European Commission (FP7 program) via a European Research Council starting grant (BIOMIM, GA 259370), and by GRAVIT (081012_FIBIOS). C.P. is grafetul to IUF for financial support

Downregulation of the Hsp90 System Causes Defects in Muscle Cells of Caenorhabditis Elegans

The ATP-dependent molecular chaperone Hsp90 is required for the activation of a variety of client proteins involved in various cellular processes. Despite the abundance of known client proteins, functions of Hsp90 in the organismal context are not fully explored. In Caenorhabditis elegans, Hsp90 (DAF-21) has been implicated in the regulation of the stress-resistant dauer state, in chemosensing and in gonad formation. In a C. elegans strain carrying a DAF-21 mutation with a lower ATP turnover, we observed motility defects. Similarly, a reduction of DAF-21 levels in wild type nematodes leads to reduced motility and induction of the muscular stress response. Furthermore, aggregates of the myosin MYO-3 are visible in muscle cells, if DAF-21 is depleted, implying a role of Hsp90 in the maintenance of muscle cell functionality. Similar defects can also be observed upon knockdown of the Hsp90-cochaperone UNC-45. In life nematodes YFP-DAF-21 localizes to the I-band and the M-line of the muscular ultrastructure, but the protein is not stably attached there. The Hsp90-cofactor UNC-45-CFP contrarily can be found in all bands of the nematode muscle ultrastructure and stably associates with the UNC-54 containing A-band. Thus, despite the physical interaction between DAF-21 and UNC-45, apparently the two proteins are not always localized to the same muscular structures. While UNC-45 can stably bind to myofilaments in the muscular ultrastructure, Hsp90 (DAF-21) appears to participate in the maintenance of muscle structures as a transiently associated diffusible factor

Hsp70 chaperones: Cellular functions and molecular mechanism

Hsp70 proteins are central components of the cellular network of molecular chaperones and folding catalysts. They assist a large variety of protein folding processes in the cell by transient association of their substrate binding domain with short hydrophobic peptide segments within their substrate proteins. The substrate binding and release cycle is driven by the switching of Hsp70 between the low-affinity ATP bound state and the high-affinity ADP bound state. Thus, ATP binding and hydrolysis are essential in vitro and in vivo for the chaperone activity of Hsp70 proteins. This ATPase cycle is controlled by co-chaperones of the family of J-domain proteins, which target Hsp70s to their substrates, and by nucleotide exchange factors, which determine the lifetime of the Hsp70-substrate complex. Additional co-chaperones fine-tune this chaperone cycle. For specific tasks the Hsp70 cycle is coupled to the action of other chaperones, such as Hsp90 and Hsp100