The energy cost of shuttle running

The aim of this study was to: (1) determine directly the energy cost of shuttle running (C _Sh) and (2) compare it to the values indirectly estimated from kinematic data. C _Sh over distances of ≈10 or ≈20 m was determined on 65 subjects (group 1) from gas exchange measurements over 155 trials, or indirectly estimated on 10 subjects (group 2) from the time course of the speed as follows. (1) The cost to accelerate from zero to peak speed was estimated assuming a 25 % efficiency and added to that of constant-speed running, as obtained on subjects of group 1. (2) Since (i) accelerated running on flat terrain is equivalent to running uphill at constant speed, on a slope dictated by the forward acceleration (di Prampero et al. in J Exp Biol 208:2809–2816, 2005), and (ii) the energy cost of running uphill is known, C _Sh was obtained from the time course of the acceleration. C _Sh increased with the average speed, at any given speed being significantly greater for the shorter distances; e.g., at ≈4 m/s over 10 m, it amounted to ≈14 J/(kg m), i.e., 3.5-fold larger than that at constant speed. The two indirect methods yielded results not significantly different from C _Sh over the longer (≈20 m), but underestimated it over the shorter (≈10 m) distances. From our results, over ≈20 m C _Sh can be obtained with sufficient accuracy from actual measurements of peak speed alone, thus, greatly simplifying the experimental procedure. The so-obtained data can then be utilized to assess the athletic status of any subject, as well as to plan appropriate training strategies.     

质子泵抑制剂预防颅脑创伤后应激性溃疡652例合理性分析

目的：调查本院预防颅脑创伤后应激性溃疡的质子泵抑制剂（PPI）的使用情况,以促进PPI的合理应用。方法：抽查2019年1月～12月神经外科使用PPI预防应激性溃疡652例临床资料,回顾性分析其PPI使用情况。结果：在652例患者中,237例有1个或多个危险因素,有明确适应症,415例为无危险因素、无适应症用药;237例均选用注射用PPI,13例予雷贝拉唑40 mg qd静脉滴注,2例分别予埃索美拉唑80 mg qd、200 mg qd静脉滴注,129例分别予泮托拉唑40 mg bid、60 mg qd、60 mg bid静脉滴注;PPI预防用药疗程185例≤2 d、402例为3～7 d、65例为≥8 d;1例雷贝拉唑联合大剂量甲强龙;1例泮托拉唑联合双氯芬酸钠;8例PPI联合抗血栓药物;4例发生消化道出血,19例发生医院获得性肺炎。结论：本院使用PPI预防颅脑创伤后应激性溃疡存在诸多不合理应用情况,应加强药学监护与干预,降低用药风险和医疗负担,促进合理用药。     

Hyperbaric oxygen therapy improves angiogenesis and bone formation in critical sized diaphyseal defects

Besides the use of autologous bone grafting several osteoconductive and osteoinductive methods have been reported to improve bone healing. However, persistent non‐union occurs in a considerable number of cases and compromised angiogenesis is suspected to impede bone regeneration. Hyperbaric oxygen therapy (HBO) improves angiogenesis. This study evaluates the effects of HBO on bone defects treated with autologous bone grafting in a bone defect model in rabbits. Twenty‐four New‐Zealand White Rabbits were subjected to a unilateral critical sized diaphyseal radius bone defect and treated with autologous cancellous bone transplantation. The study groups were exposed to an additional HBO treatment regimen. Bone regeneration was evaluated radiologically and histologically at 3 and 6 weeks, angiogenesis was assessed by immunohistochemistry at three and six weeks. The additional administration of HBO resulted in a significantly increased new bone formation and angiogenesis compared to the sole treatment with autologous bone grafting. These results were apparent after three and six weeks of treatment. The addition of HBO therapy to autologous bone grafts leads to significantly improved bone regeneration. The increase in angiogenesis observed could play a crucial role for the results observed. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:513–520, 2015.     

Heating Lyophilised Factor VIII Does Not Alter Its Recognition by Specific Antibodies

Background and objectives: Alterations of factor VIII (FVIII) during preparation procedures can potentially affect its immunogenicity. One method evaluating such alterations could be by determining the reactivity of FVIII with specific antibodies. Materials and methods: Since heat treatment is currently used to reduce the risk of viral transmission, we evaluated the immunoreactivity of plasma-derived FVIII before and after heating at different temperatures and for different periods. Freeze-dried FVIII was used for these experiments as part of the validation procedure of a novel FVIII preparation. Results: Heating FVIII for up to 72 h at 80 °C does not alter its reactivity with specific rabbit antibodies or mouse monoclonal antibodies, although some loss of FVIII activity occurred after 72 h. After heating for 2 h at 100 °C, a procedure that reduced FVIII activity by about 50%, there were still no significant effects on FVIII reactivity with monoclonal antibodies. Conclusions: Freeze-dried preparations of plasma-derived FVIII seem to be resistant to heat-induced structural denaturation.     

Fetal liver cells produce both fetal and adult erythrocytes in semiallogeneic radiation chimeras: possible influence of adult environment

Two kinds of erythrocytes are released in the blood of irradiated adult hybrid mice grafted with parental fetal liver cells: fetal antigen- bearing erythrocytes (Ft+ cells) and adult-type Ft- erythrocytes. Both are of parental origin, as determined by immune lysis using histocompatibility alloantigens. The latter cells make up all the recipient's red blood cells 2 mo after receipt of the graft, Ft+ cells then being no longer detected. The transient duality of erythropoiesis in irradiated adults grafted with fetal liver cells has been confirmed by studying the kinetics of CFU-E populations, as characterized by their ability to give rise to Ft+ or Ft- erythrocytes. The results are discussed in terms of environmental factors that influenc erythroid differentiation.     

Calmodulin accelerates the rate of polymerization of human platelet actin and alters the structural characteristics of actin filaments.

Calmodulin stimulated the rate of Mg2+-induced polymerization of human platelet actin. The stimulatory effect was due to an increase in the nucleation phase of the reaction; there was no effect on the steady-state viscosity. The calmodulin antagonist trifluoperazine blocked the stimulatory effect of calmodulin. Addition of EGTA to the reaction mixture also stimulated the rate of actin polymerization; however, the effect of calmodulin on actin polymerization is not due to Ca2+ chelation, as is presumed to be the case for EGTA. Electron microscopy revealed structural differences in the filaments prepared in the presence of calmodulin as compared to those prepared with trifluoperazine. In the presence of calmodulin, the filaments were thicker, suggesting that they consisted of multiple actin polymers. In addition, numerous projections were present perpendicular to the filaments, as well as localized areas of filament bundling. It was not possible to demonstrate a direct interaction between calmodulin and actin, which raises the possibility that the calmodulin effect may be indirect through a calmodulin-binding protein or calmodulin-dependent enzyme. Regardless of whether calmodulin is acting directly or indirectly, these results provide evidence that calmodulin may play a regulatory role in either the polymerization of actin or in determining the structural characteristics of actin filaments.     

Preoperative assessment and classification of benign laryngotracheal stenosis: a consensus paper of the European Laryngological Society

Adult and pediatric laryngotracheal stenoses (LTS) comprise a wide array of various conditions that require precise preoperative assessment and classification to improve comparison of different therapeutic modalities in a matched series of patients. This consensus paper of the European Laryngological Society proposes a five-step endoscopic airway assessment and a standardized reporting system to better differentiate fresh, incipient from mature, cicatricial LTSs, simple one-level from complex multilevel LTSs and finally “healthy” from “severely morbid” patients. The proposed scoring system, which integrates all of these parameters, may be used to help define different groups of LTS patients, choose the best treatment modality for each individual patient and assess distinct post-treatment outcomes accordingly.     

Impairment of Left Atrial Mechanics Is an Early Sign of Myocardial Involvement in Systemic Sclerosis

Background

Left ventricular (LV) diastolic dysfunction is common in systemic sclerosis (SSc). Less is known, however, about left atrial (LA) mechanics in this context. The aim of this study was to investigate the correlation between LV diastolic function and LA mechanics in SSc patients with the use of volumetric and 2-dimensional speckle tracking–derived strain techniques and to compare the results with those obtained in healthy subjects.