Musculoskeletal Response to Whole-Body Vibration During Fracture Healing in Intact and Ovariectomized Rats

This study investigated the effect of vibration on bone healing and muscle in intact and ovariectomized rats. Thirty ovariectomized (at 3 months of age) and 30 intact 5-month old female Sprague-Dawley rats underwent bilateral metaphyseal osteotomy of tibia. Five days later, half of the ovariectomized and of the intact rats were exposed to whole-body vertical vibration (90 Hz, 0.5 mm, 4 × g acceleration) for 15 min twice a day during 30 days. The other animals did not undergo vibration. After decapitation of rats, one tibia was used for computed tomographic, biomechanical, and histological analyses; the other was used for gene expression analyses of alkaline phosphatase (Alp), osteocalcin (Oc), tartrate-resistant acid phosphatase 1, and insulinlike growth factor 1. Serum Alp and Oc were measured. Mitochondrial activity, fiber area and distribution, and capillary densities were analyzed in M. gastrocnemius and M. longissimus. We found that vibration had no effect on body weight and food intake, but it improved cortical and callus densities (97 vs. 99%, 72 vs. 81%), trabecular structure (9 vs. 14 trabecular nodes), blood supply (1.7 vs. 2.1 capillaries/fiber), and oxidative metabolism (17 vs. 23 pmol O2/s/mg) in ovariectomized rats. Vibration generally increased muscle fiber size. Tibia biomechanical properties were diminished after vibration. Oc gene expression was higher in vibrated rats. Serum Alp was increased in ovariectomized rats. In ovariectomized rats, vibration resulted in an earlier bridging; in intact rats, callus bridging occurred later after vibration. The chosen vibration regimen (90 Hz, 0.5 mm, 4 × g acceleration, 15 min twice a day) was effective in improving musculoskeletal tissues in ovariectomized rats but was not optimal for fracture healing

Diversity in clinical management and protocols for the treatment of major bleeding trauma patients across European level I Trauma Centres

Background: Uncontrolled haemorrhage is still the leading cause of preventable death after trauma and the primary focus of any treatment strategy should be related to early detection and control of blood loss including haemostasis. Methods: For assessing management practices across six European level I trauma centres with academic interest and research in the field of coagulopathy an online survey was conducted addressing local management practice for bleeding trauma patients including algorithms for detection, management and monitoring coagulation disorders and immediate interventions. Each centre provided their locally applied massive transfusion protocol. Results: All participating trauma centres have developed and implemented a local algorithm and protocol for the bleeding trauma patient. These are uniformly activated by clinical triggers and deactivated once the bleeding has stopped according to clinical assessment in combination with laboratory signs of achieved haemostasis. The severity of coagulopathy and shock is mostly assessed via standard coagulation tests and partially used extended viscoelastic tests. All centres have implemented the immediate use of tranexamic acid. Initial resuscitation is started either pre-hospital or after hospital admission by using transfusion packages with pre-fixed universal blood product combinations and ratios following the concept of "damage control resuscitation" at which applied ratios substantially vary. Two centres initially start with transfusion packages but with viscoelastic tests running in parallel to quickly allow a shift towards a viscoelastic test-guided therapy. Conclusion: Diversity in the management of bleeding trauma patients such as pre-hospital blood administration and routinely performed viscoelastic tests exists even among level I trauma centres. The paucity of consensus among these centres highlights the need for further primary research followed by clinical trials to improve the evidence for sophisticated guidelines and strategie

Monitoring wound healing in a 3D wound model by hyperspectral imaging and efficient clustering.

Wound healing is a complex and dynamic process with different distinct and overlapping phases from homeostasis, inflammation and proliferation to remodelling. Monitoring the healing response of injured tissue is of high importance for basic research and clinical practice. In traditional application, biological markers characterize normal and abnormal wound healing. Understanding functional relationships of these biological processes is essential for developing new treatment strategies. However, most of the present techniques (in vitro or in vivo) include invasive microscopic or analytical tissue sampling. In the present study, a non-invasive alternative for monitoring processes during wound healing is introduced. Within this context, hyperspectral imaging (HSI) is an emerging and innovative non-invasive imaging technique with different opportunities in medical applications. HSI acquires the spectral reflectance of an object, depending on its biochemical and structural characteristics. An in-vitro 3-dimensional (3-D) wound model was established and incubated without and with acute and chronic wound fluid (AWF, CWF), respectively. Hyperspectral images of each individual specimen of this 3-D wound model were assessed at day 0/5/10 in vitro, and reflectance spectra were evaluated. For analysing the complex hyperspectral data, an efficient unsupervised approach for clustering massive hyperspectral data was designed, based on efficient hierarchical decomposition of spectral information according to archetypal data points. It represents, to the best of our knowledge, the first application of an advanced Data Mining approach in context of non-invasive analysis of wounds using hyperspectral imagery. By this, temporal and spatial pattern of hyperspectral clusters were determined within the tissue discs and among the different treatments. Results from non-invasive imaging were compared to the number of cells in the various clusters, assessed by Hematoxylin/Eosin (H/E) staining. It was possible to correlate cell quantity and spectral reflectance during wound closure in a 3-D wound model in vitro

Low-Dose Blue Light (420 nm) Reduces Metabolic Activity and Inhibits Proliferation of Human Dermal Fibroblasts

Hypertrophic scarring in burn wounds is caused by overactive fibroblasts and myofibroblasts. Blue light reveals wavelength- and dose-dependent antibacterial and antiproliferative effects and may serve as a therapeutic option against wound infection and fibrotic conditions. Therefore, we evaluated in this study the effects of single and multiple irradiations with blue light at 420 nm (BL420) on the intracellular ATP concentration, and on the viability and proliferation of the human skin fibroblast (HDFs). In addition, possible BL420-induced effects on the catalase expression and differentiation were assessed by immunocytochemical staining and western blot analyses. Furthermore, we used RNA-seq analyses to identify BL420-affected genes. We found that BL420 induced toxicity in HDFs (up to 83%; 180 J/cm2). A low dose of 20 J/cm2 reduced the ATP concentration by ~50%. Multiple irradiations (4 × 20 J/cm2) inhibited proliferation without visible toxicity and reduced catalase protein expression by ~37% without affecting differentiation. The expression of about 300 genes was significantly altered. Many downregulated genes have functions in cell division/mitosis. BL420 can strongly influence the fibroblast physiology and has potential in wound therapy. However, it is important to consider the possible toxic and antiproliferative effects, which could potentially lead to impaired wound healing and reduced scar breaking strength

Prehospital volume resuscitation - Did evidence defeat the crystalloid dogma? An analysis of the TraumaRegister DGU (R) 2002-2012

Background: Various studies have shown the deleterious effect of high volume resuscitation following severe trauma promoting coagulopathy by haemodilution, acidosis and hypothermia. As the optimal resuscitation strategy during prehospital trauma care is still discussed, we raised the question if the amount and kind of fluids administered changed over the recent years. Further, if less volume was administered, fewer patients should have arrived in coagulopathic depletion in the Emergency Department resulting in less blood product transfusions. Methods: A data analysis of the 100 489 patients entered into the TraumaRegister DGU (R) (TR-DGU) between 2002 and 2012 was performed of which a total of 23512 patients (23.3 %) matched the inclusion criteria. Volume and type of fluids administered as well as outcome parameter were analysed. Results: Between 2002 and 2012, the amount of volume administered during prehospital trauma care decreased from 1790 ml in 2002 to 1039 ml in 2012. At the same time higher haemoglobin mean values, higher Quick's mean values and reduced mean aPTT can be observed. Simultaneously, more patients received catecholamines (2002: 9.2 to 2012: 13.0 %). Interestingly, the amount of volume administered decreased steadily regardless of the presence of shock. Fewer patients were in the need of blood products and the number of massive transfusions (>= 10 pRBC) more than halved. Discussion: The changes in volume therapy might have reduced haemodilution potentially resulting in an increase of the Hb value. During the period observed transfusion strategies have become more restrictiveand ratio based; the percentage of patients receiving MT halved as blood products may imply negative secondary effects. Furthermore, preventing administration of high blood product ratios result in less impairment of coagulation factors and inhibitors and an therfore improved coagulation. Conclusion: The volume administered in severely injured patients decreased considerably during the last decade possibly supporting beneficial effects such as minimizing the risk of coagulopathy and avoiding potential harmful effects caused by blood product transfusions. Despite outstanding questions in trauma resuscitation, principle evidence merges quickly into clinical practice and algorithms

Representative spectra of 3-dimensional wound models.

<p>(a) Cluster representatives after computing of XHC for the hyperspectral image data for. The number of cluster was set to <i>k</i> = 7 that could reflect biological processes in this cell culture system. The corresponding signatures represented different regions of the tissues. The dotted line was produced by a part of the tissue covered with fluid resulting in overexposure during the measurement. (b-c) The quantification of pixel densities per cluster. The y-axis is shown in log scale. AWF and CWF induced no significant differences in pixel densities compared to the control situation, however, the dark blue cluster was absent after 10 days <i>in vitro</i> without any supplements.</p

Comparison for Kmeans and XHC for different number of clusters.

<p>With increasing number of clusters, Kmeans resulted in more clusters around the wound as this area represented the major part of the tissue. XHC further highlighted the middle part of the images, which was the result of a hierarchical decomposition of the signatures. This allowed a better investigation and comparison of the wound tissue and healing progress.</p