OBJECTIVE: To investigate the mechanism and to explore the measures of prevention and treatment of hypothermal vasoconstriction. METHODS: By the techniques of endothelial cell culture and scanning electron microscopy, and vasomotor functional test of isolated vascular vessels, the relation of hypothermal vasoconstriction and the release of endothelium-derived contractile and vasodilative factors were observed. RESULTS: Hypothermia obviously induced vasoconstriction of isolated vascular vessels, whether endothelium was intact or removed, the lower the temperature, the higher the vascular tension. Removal of endothelium could decrease the effect of vasoconstriction by hypothermia. The conditioned medium of bovine aortic endothelial cell could induce significantly vasoconstriction of isolated rat common neck arterial ring in hypothermia. It indicated that the bovine aortic endothelial cells secreted contractile factors into the medium. Reheating to 37 degrees C or vasodilator or reheating plus vasodilator did not obviously influence the hypothermia-induced vasoconstriction within 2 hours. When reheating to 50 degrees C, vascular tension was decreased, but only changed in range of 28% to 42%. CONCLUSION: Hypothermia vasoconstriction is relative to vasoconstrictor factors secreted by endothelium. Reheating to 37 degrees C or vasodilator does not antagonize the constriction of vascular vessels. Reheating to 50 degrees C only partially eliminates the constrict effect of blood vessels, so the prevention of hypothermia vasoconstriction should be emphasized.
Objective To investigate the protective effects and the mechanism of recombinant human growth hormone on the intestinal barrier function. Methods The literatures of recent years were reviewed and summarized． Results The recombinant human growth hormone not only prevent mucosal cells and immunological cells from apoptosis, but also antagonize the damage of NO, cytokines, as well as endotoxin on intestinal barrier. What’s more, it increases the intestinal uptake and utilization of glutamine. All of the above could maintain the integrity and functions of the intestinal barrier. Conclusion The recombinant human growth hormone protects the intestinal barrier function through different ways.
Cenobamate is one of the latest antiseizure medications (ASMs) developed for the treatment of focal onset seizures in adult patients. Cenobamate is characterized by a peculiar pharmacology. The mechanisms responsible for its anti-seizure activity include enhancement of the inactivated state of voltage-gated sodium channels with blockade of the persistent sodium current and positive allosteric modulation of GABAa receptors at a non-benzodiazepine binding site. Studies showed that cenobamate appears to be an effective treatment for focal epilepsy, showing reductions in seizure frequency, increased responder rates, and high rates of seizure freedom, and is well tolerated and safe. This article reviews the mechanism, pharmacokinetic characteristics, clinical efficacy, and safety of cenobamate as a novel anti-seizure drug
ObjectiveTo explore the effect of hydroxyapatite nanoparticle (nHAP) on hepatocellular carcinoma (HCC) and its mechanisms. MethodsThe literatures about the effect of nHAP on HCC were reviewed and summarized. ResultsAs a new nanoparticle, nHAP could suppress the DNA synthesis and subsequent division and proliferation of HCC cells through the inhibition of proliferating cell nuclear antigen (PCNA) and telomerase gene expression and increase of intracellular Ca2+. Moreover, nHAP was able to suppress the differentiation and metastases of HCC cells through the effect on the expressions of Paxillin and P130cas and the decrease of expressions of multiple drug resistance gene protein, microvessel density, and vascular endothelial growth factor. Finally, nHAP induced the apoptosis of HCC tumor cells by the regulation of bcl-2 and bax protein expressions. The combined use of nHAP and chemoembolization drugs could enhance the efficacy, prolong drug duration and reduce toxicity. ConclusionnHAP can inhibit the division, proliferation, differentiation, and metastases, and promote the apoptosis of HCC cells and combined use with chemoembolization drugs can enhance the efficacy and reduce toxicity.
Aiming at the status of muscle and joint damage caused on surgeons keeping surgical posture for a long time, this paper designs a medical multi-position auxiliary support exoskeleton with multi-joint mechanism by analyzing the surgical postures and conducting conformational studies on different joints respectively. Then by establishing a human-machine static model, this study obtains the joint torque and joint force before and after the human body wears the exoskeleton, and calibrates the strength of the exoskeleton with finite element analysis software. The results show that the maximum stress of the exoskeleton is less than the material strength requirements, the overall deformation is small, and the structural strength of the exoskeleton meets the use requirements. Finally, in this study, subjects were selected to participate in the plantar pressure test and biomechanical simulation with the man-machine static model, and the results were analyzed in terms of plantar pressure, joint torque and joint force, muscle force and overall muscle metabolism to assess the exoskeleton support performance. The results show that the exoskeleton has better support for the whole body and can reduce the musculoskeletal burden. The exoskeleton mechanism in this study better matches the actual working needs of surgeons and provides a new paradigm for the design of medical support exoskeleton mechanism.
Diabetic foot ulcer is one of the severe chronic complications that lead to disability and death of diabetic patients. In order to solve this problem, adjuvant therapy studies of diabetic foot ulcers have increased in recent years. Extracorporeal shock wave therapy is a novel adjuvant therapy that has been approved by the US Food and Drug Administration for diabetic foot ulcers wounds. In this paper, the mechanisms of extracorporeal shock wave therapy for diabetic foot ulcers are described, including wound angiogenesis, wound tissue blood perfusion, nerve regeneration, granulation tissue proliferation, inflammatory response, anti-infection, migration and differentiation of mesenchymal stem cells and endothelial progenitor cells. This study aims to provide a theoretical basis for the clinical application of extracorporeal shock wave therapy in clinical treatment of diabetic foot ulcers.
The therapeutic efficacy of Danshen and Jiangxiang in the treatment of ischemic stroke (IS) is relatively significant. Studying the mechanism of action of Danshen and Jiangxiang in the treatment of IS can effectively identify candidate traditional Chinese medicines (TCM) with efficacy. However, it is challenging to analyze the effector substances and explain the mechanism of action of Danshen-Jiangxiang from a systematic perspective using traditional pharmacological approaches. In this study, a systematic study was conducted based on the drug-target-symptom-disease association network using complex network theory. On the basis of the association information about Danshen, Jiangxiang and IS, the protein-protein interaction (PPI) network and the “drug pair-pharmacodynamic ingredient-target-IS” network were constructed. The different topological features of the networks were analyzed to identify the core pharmacodynamic ingredients including formononetin in Jiangxiang, cryptotanshinone and tanshinone IIA in Danshen as well as core target proteins such as prostaglandin G/H synthase 2, retinoic acid receptor RXR-alpha, sodium channel protein type 5 subunit alpha, prostaglandin G/H synthase 1 and beta-2 adrenergic receptor. Further, a method for screening IS candidates based on TCM symptoms was proposed to identify key TCM symptoms and syndromes using the “drug pair-TCM symptom-syndrome-IS” network. The results showed that three TCMs, namely Puhuang, Sanleng and Zelan, might be potential therapeutic candidates for IS, which provided a theoretical reference for the development of drugs for the treatment of IS.
Objective To assess the tolerance of preoperative carbohydrate-rich beverage, to determine its effect on postoperative insulin resistance and analyze its potential mechanism. Methods Thirty-two patients undergoing elective colorectal cancer resection were recruited to this randomized controlled study and assigned to two groups at random. Patient in control group was fasted before operation, while patient in study group was given oral water. Homeostasis model assessment (HOMA) indexes, activity of PTK, and mRNA and (or) protein expressions of PKB, PI3K and GluT4 were measured before and (or) immediately after surgery. Furthermore preoperative well-beings of patients were studied. Results Among well-beings, feeling of thirst, hunger and anxiety tended to be better in patients receiving carbohydrate-rich beverages compared with fasted ones (P＜0.05). Whole body insulin sensitivity decreased by 33% in the study group while 38% in the control group (P=0.007 2), and the activity of PTK, expressions of PI3K and PKB in study group were higher than those in control group (P＜0.05， P＜0.01), but no significantly difference was observed about GluT4 in both groups (Pgt;0.05）. Conclusion Preoperative consumption of carbohydrate-containing fluids is safe and effective. Provision of carbohydrate energy source prior to surgery may attenuate immediate postoperative insulin resistance. A carbohydrate-rich drink enhances insulin action at the time of onset of anaesthesia or surgery by activating three kinases named PTK, PI3K, PKB which are key enzymes in pathway of insulin signal transduction. It is likely to explain the effects on postoperative insulin resistance.
Erythropoietin （EPO） is known as a classical hematopoietic growth factor, which has been used to treat anemia caused by different reasons. In recent years, EPO＇s non-hematopoietic biological effects have gradually become a focus. Among these effects, EPO＇s tissue protection is most attractive and EPO has been proved to protect many different tissues and organs. Myocardial protection has always been the important and key topic in the field of cardiovascular diseases. Reports about EPO＇s myocardial protective effects have been published in the recent two years, which direct the research about myocardial protection with new ideas. In this article, the discoveries and unsolved problems associated with EPO＇s myocardial protection were reviewed.
Abstract： As the most common blunt thoracic injury, lung contusion may develop into acute lung injury, adult respiratory distress syndrome or ventilation associated pneumonia, which can cause a high mortality. However, the pathogenesis and pathophysiology of lung contusion is not well understood yet. Stress is laid by many researchers on inflammatory response in the pathogenesis of lung contusion. We review the potential role of inflammatory response in the pathogenesis and pathophysiological changes of lung contusion. Emphasis is put on studies of inflammatory cells, mediators, receptors, surfactant dysfunction, and the potential role of epithelial cell or neutrophil apoptosis. The animal models are essential to the study of lung contusion and the studies examining secondary injuries exacerbating lung contusion are also noted.