Driving pressure in mechanical ventilation:A review

Driving pressure(ΔP)is a core therapeutic component of mechanical ventilation(MV).Varying levels ofΔP have been employed during MV depending on the type of underlying pathology and severity of injury.However,ΔP levels have also been shown to closely impact hard endpoints such as mortality.Considering this,conducting an in-depth review ofΔP as a unique,outcome-impacting therapeutic modality is extremely important.There is a need to understand the subtleties involved in making sureΔP levels are optimized to enhance outcomes and minimize harm.We performed this narrative review to further explore the various uses ofΔP,the different parameters that can affect its use,and how outcomes vary in different patient populations at different pressure levels.To better utilizeΔP in MV-requiring patients,additional large-scale clinical studies are needed.

Patient Safety in the Use of Mechanical Restraints: Regulatory Compliance among Hospitals in the City of Buenos Aires and Proposal for Its Improvement

Introduction: Mechanical or physical restraint is an exceptional therapeutic resource to immobilize a subject and thus guarantee the safety of the patient and/or third parties in the face of high-risk behaviors, but it entails multiple crossings (bioethical, philosophical, medical, psychological, legal). Framed in the so-called “safety culture” developed by the WHO, based on the Protocol for its implementation of the CABA and attentive to its frequent use in CABA by different hospital services (medical clinic, geriatrics, intensive care and medical guards) we consider it necessary its study in terms of compliance with the risks it entails and its management. Objectives: Identify regulatory compliance with the GCABA Mechanical restraint (MR) Protocol from a patient safety perspective, as well as describe the clinical and medicolegal aspects, and propose the usefulness of a tool for its management and control. Methodology: Observational, descriptive, transversal and prospective work through the analysis of Clinical Records with indication of MR using a rubric-type form. 177 cases were analyzed between September-November 2023 from three hospitals of the Government of the City of Buenos Aires, statistical parameters were applied and graphs were made. Results: Only 12.99% complied with the Protocol. In the mental health specialized hospital compliance was almost 5 times greater than in the general one, and in the emergency services compliance was 12 times greater than in Inpatient services. We found that the start or end time of MR was not recorded and only 43% described the causes/justifications for the indication (mostly in Emergency and Specialized hospitals), with the MR average time being shorter in Emergency. Conclusions: Only 1.3 out of 10 patients reliably completed the Protocol and it was mostly in the mental health specialized hospital and the emergency services. The results show non-compliance behavior in the application and management of the risk that the use of mechanical restraints entails, being causes for criminal litigation. We consider that the checklists are useful to complete the Protocol and thus provide security to patients and professionals.

Mechanism of spinal cord injury regeneration and the effect of human neural stem cells-secretome treatment in rat model

BACKGROUND Globally,complete neurological recovery of spinal cord injury(SCI)is still less than 1%,and 90%experience permanent disability.The key issue is that a pharmacological neuroprotective-neuroregenerative agent and SCI regeneration mechanism have not been found.The secretomes of stem cell are an emerging neurotrophic agent,but the effect of human neural stem cells(HNSCs)secretome on SCI is still unclear.AIM To investigate the regeneration mechanism of SCI and neuroprotective-neuroregenerative effects of HNSCs-secretome on subacute SCI post-laminectomy in rats.METHODS An experimental study was conducted with 45 Rattus norvegicus,divided into 15 normal,15 control(10 mL physiologic saline),and 15 treatment(30μL HNSCssecretome,intrathecal T10,three days post-traumatic).Locomotor function was evaluated weekly by blinded evaluators.Fifty-six days post-injury,specimens were collected,and spinal cord lesion,free radical oxidative stress(F2-Isoprostanes),nuclear factor-kappa B(NF-κB),matrix metallopeptidase 9(MMP9),tumor necrosis factor-alpha(TNF-α),interleukin-10(IL-10),transforming growth factor-beta(TGF-β),vascular endothelial growth factor(VEGF),B cell lymphoma-2(Bcl-2),nestin,brain-derived neurotrophic factor(BDNF),glial cell line-derived neurotrophic factor(GDNF)were analyzed.The SCI regeneration mechanism was analyzed using partial least squares structural equation modeling(PLS SEM).RESULTS HNSCs-secretome significantly improved locomotor recovery according to Basso,Beattie,Bresnahan(BBB)scores and increased neurogenesis(nestin,BDNF,and GDNF),neuroangiogenesis(VEGF),anti-apoptotic(Bcl-2),anti-inflammatory(IL-10 and TGF-β),but decreased proinflammatory(NF-κB,MMP9,TNF-α),F2-Isoprostanes,and spinal cord lesion size.The SCI regeneration mechanism is valid by analyzed outer model,inner model,and hypothesis testing in PLS SEM,started with pro-inflammation followed by anti-inflammation,anti-apoptotic,neuroangiogenesis,neurogenesis,and locomotor function.CONCLUSION HNSCs-secretome as a potential neuroprotective-neuroregenerative agent for the treatment of SCI and uncover the SCI regeneration mechanism.

Injury rate,mechanism,and risk factors of hamstring strain injuries in sports:A review of the literature

Hamstring strains are one of most common sports injuries.The purpose of this literature review is to summarize studies on hamstring strain injury rate,mechanism,and risk factors in the last several decades with a focus on the prevention and rehabilitation of this injury.Hamstring injury commonly occurs in sporting events in which high speed sprinting and kicking are frequently performed,such as Australian football. English rugby,American football,and soccer.Basic science studies have demonstrated that a muscle strain injury occurs due to excessive strain in eccentric contraction instead of force,and that elongation speed and duration of activation before eccentric contraction affect the severity of the injury.Hamstring strain injury is likely to occur during the late swing phase and late stance phase of sprint running.Shortened optimum muscle length,lack of muscle flexibility,strength imbalance,insufficient warm-up,fatigue,lower back injury,poor lumbar posture,and increased muscle neural tension have been identified as modifiable risk factors while muscle compositions,age,race,and previous injuries are non-modifiable risk factors.The theoretical basis of some of these risk factors,however,is lacking,and the results of clinical studies on these risk factors are inconsistent.Future studies are needed to establish the cause-and-effect relationships between those proposed risk factors and the injury.

Edaravone promotes functional recovery after mechanical peripheral nerve injury

Edaravone has been shown to reduce ischemia/reperfusion-induced peripheral nerve injury. However, the therapeutic effect of edaravone on peripheral nerve injury caused by mechanical factors is unknown. In the present study, we established a peripheral nerve injury model by crushing the sciatic nerve using hemostatic forceps, and then administered edaravone 3 mg/kg intraperitoneally. The sciatic functional index and superoxide dismutase activity of the sciatic nerve were increased, and the malondialdehyde level was decreased in animals in the edaravone group compared with those in the model group. Bcl-2 expression was increased, but Bax expres- sion was decreased in anterior horn cells of the L4-6 spinal cord segments. These results indicated that edaravone has a neuroprotective effect following peripheral nerve injury caused by mechan- ical factors through alleviating free radical damage to cells and inhibiting lipid peroxidation, as well as regulating apoptosis-related protein expression.

Transplantation of human amniotic epithelial cells repairs brachial plexus injury:pathological and biomechanical analyses

A brachial plexus injury model was established in rabbits by stretching the C6 nerve root. Imme- diately after the stretching, a suspension of human amniotic epithelial cells was injected into the injured brachial plexus. The results of tensile mechanical testing of the brachial plexus showed that the tensile elastic limit strain, elastic limit stress, maximum stress, and maximum strain of the injured brachial plexuses were significantly increased at 24 weeks after the injection. The treatment clearly improved the pathological morphology of the injured brachial plexus nerve, as seen by hematoxylin eosin staining, and the functions of the rabbit forepaw were restored. These data indicate that the injection of human amniotic epithelial cells contributed to the repair of brachial plexus injury, and that this technique may transform into current clinical treatment strategies.

Biomechanical analysis of optic nerve injury treated by compound light granules and ciliary neurotrophic factor

In this study, rabbit models of optic nerve injury were reproduced by the clamp method. After modeling, rabbit models were given one injection of 50 ng recombinant human ciliary neurotrophic factor into the vitreous body and/or intragastric injection of 4 g/kg compound light granules containing Radix Angelicae Sinensis and Raidix Paeoniae Alba at 4 days after modeling, once per day for 30 consecutive days. After administration, the animals were sacrificed and the intraorbital optic nerve was harvested. Hematoxylin-eosin staining revealed that the injured optic nerve was thinner and optic nerve fibers were irregular. After treatment with recombinant human ciliary neurotrophic factor, the arrangement of optic nerve fibers was disordered but they were not markedly thinner. After treatment with compound light granules, the arrangement of optic nerve fibers was slightly disordered and their structure was intact. After combined treatment with recombinant human ciliary neurotrophic factor and compound light granules, the arrangement of optic nerve fibers was slightly disordered and the degree of injury was less than after either treatment alone. Results of tensile mechanical testing of the optic nerve showed that the tensile elastic limit strain, elastic limit stress, maximum stress and maximum strain of the injured optic nerve were significantly lower than the normal optic nerve. After treatment with recombinant human ciliary neurotrophic factor and/or compound light granules, the tensile elastic limit strain, elastic limit stress, maximum stress and maximum strain of the injured optic nerve were significantly increased, especially after the combined treatment. These experimental findings indicate that compound light granules and ciliary neurotrophic factor can alleviate optic nerve injury at the histological and biochemical levels, and the combined treatment is more effective than either treatment alone.

Preemptive mechanical ventilation can block progressive acute lung injury

Mortality from acute respiratory distress syndrome(ARDS) remains unacceptable, approaching 45% in certain high-risk patient populations. Treating fulminant ARDS is currently relegated to supportive care measures only. Thus, the best treatment for ARDS may lie with preventing this syndrome from ever occurring. Clinical studies were examined to determine why ARDS has remained resistant to treatment over the past several decades. In addition, both basic science and clinical studies were examined to determine the impact that early, protective mechanical ventilation may have on preventing the development of ARDS in at-risk patients. Fulminant ARDS is highly resistant to both pharmacologic treatment and methods of mechanical ventilation. However, ARDS is a progressive disease with an early treatment window that can be exploited. In particular, protective mechanical ventilation initiated before the onset of lung injury can prevent the progression to ARDS. Airway pressure release ventilation(APRV) is a novel mechanical ventilation strategy for delivering a protective breath that has been shown to block progressive acute lung injury(ALI) and prevent ALI from progressing to ARDS. ARDS mortality currently remains as high as 45% in some studies. As ARDS is a progressive disease, the key to treatment lies with preventing the disease from ever occurring while it remains subclinical. Early protective mechanical ventilation with APRV appears to offer substantial benefit in this regard and may be the prophylactic treatment of choice for preventing ARDS.

Neurophysiological, histological, and behavioral characterization of animal models of distraction spinal cord injury: a systematic review

Distraction spinal cord injury is caused by some degree of distraction or longitudinal tension on the spinal cord and commonly occurs in patients who undergo corrective operation for severe spinal deformity.With the increased degree and duration of distraction,spinal cord injuries become more serious in terms of their neurophysiology,histology,and behavior.Very few studies have been published on the specific characteristics of distraction spinal cord injury.In this study,we systematically review 22 related studies involving animal models of distraction spinal cord injury,focusing particularly on the neurophysiological,histological,and behavioral characteristics of this disease.In addition,we summarize the mechanisms underlying primary and secondary injuries caused by distraction spinal cord injury and clarify the effects of different degrees and durations of distraction on the primary injuries associated with spinal cord injury.We provide new concepts for the establishment of a model of distraction spinal cord injury and related basic research,and provide reference guidelines for the clinical diagnosis and treatment of this disease.

Explosive eye injuries: characteristics, traumatic mechanisms, and prognostic factors for poor visual outcomes

Background: Explosions can produce blast waves, high-speed medium, thermal radiation, and chemical spatter,leading to complex and compound eye injuries. However, few studies have comprehensively investigated the clinical features of different eye injury types or possible risk factors for poor prognosis.Methods: We retrospectively reviewed all consecutive records of explosive eye injuries(1449 eyes in 1115 inpatients)in 14 tertiary referral hospitals in China over 12 years(between January 1, 2008 and December 31, 2019). Data on demographics, eye injury types, ocular findings, treatments, and factors affecting visual prognosis were extracted from a standardized database of eye injuries and statistically analyzed.Results: Mechanical ocular trauma accounted for 94.00% of explosion-related eye injuries, among which intraocular foreign bodies(IOFBs) resulted in 55.17% of open globe injuries(OGIs) and contusion caused 60.22% of close globe injuries(CGIs). Proliferative vitreous retinopathy(PVR) was more common in perforating(47.06%) and IOFB(26.84%)than in penetrating(8.79%) injuries, and more common with laceration(24.25%) than rupture(9.22%, P<0.01).However, no difference was observed between rupture and contusion. Ultimately, 9.59% of eyes were removed and the final vision was ≤4/200 in 45.82% of patients. Poor presenting vision [odds ratio(OR)=5.789], full-thickness laceration of the eyeball ≥5 mm(OR=3.665), vitreous hemorrhage(OR=3.474), IOFB(OR=3.510), non-mechanical eye injury(NMEI, OR=2.622), rupture(OR=2.362), traumatic optic neuropathy(OR=2.102), retinal detachment(RD,OR=2.033), endophthalmitis(OR=3.281), contusion(OR=1.679), ciliary body detachment(OR=6.592), zone Ⅲ OGI(OR=1.940), and PVR(OR=1.615) were significant negative predictors for poor visual outcomes(P<0.05).Conclusions: Explosion ocular trauma has complex mechanisms, with multiple eyes involved and poor prognosis. In lethal level Ⅰ explosion injuries, eyeball rupture is a serious condition, whereas contusion is more likely to improve. In level Ⅱ injuries, IOFBs are more harmful than penetrating injuries, and level Ⅳ represents burn-related eye injuries.PVR is more associated with penetrating mechanisms than with OGI. Identifying the risk predictors for visual prognosis can guide clinicians in the evaluation and treatment of ocular blast injuries.

Expiratory flow-limitation in mechanically ventilated patients: A risk for ventilator-induced lung injury?

Expiratory flow limitation(EFL), that is the inability of expiratory flow to increase in spite of an increase of the driving pressure, is a common and unrecognized occurrence during mechanical ventilation in a variety of intensive care unit conditions. Recent evidence suggests that the presence of EFL is associated with an increase in mortality, at least in acute respiratory distress syndrome(ARDS) patients, and in pulmonary complications in patients undergoing surgery. EFL is a major cause of intrinsic positive end-expiratory pressure(PEEPi), which in ARDS patients is heterogeneously distributed, with a consequent increase of ventilation/perfusion mismatch and reduction of arterial oxygenation. Airway collapse is frequently concomitant to the presence of EFL.When airways close and reopen during tidal ventilation, abnormally high stresses are generated that can damage the bronchiolar epithelium and uncouple small airways from the alveolar septa, possibly generating the small airways abnormalities detected at autopsy in ARDS. Finally, the high stresses and airway distortion generated downstream the choke points may contribute to parenchymal injury, but this possibility is still unproven. PEEP application can abolish EFL, decrease PEEPi heterogeneity, and limit recruitment/derecruitment.Whether increasing PEEP up to EFL disappearance is a useful criterion for PEEP titration can only be determined by future studies.

Effects of brachial plexus injury anastomosis simulation on biomechanical properties of adult brachial plexus

BACKGROUND： Previous studies of peripheral nerve mechanical properties in animals have utilized one-dimensional drawing methods. OBJECTIVE： To analyze the effects of brachial plexus injury anastomosis simulation on biomechanical properties of adult brachial plexus by observing tensile mechanical properties, stress relaxation, and creep deformation of the brachial plexus in normal human cadavers and brachial plexus from simulated brachial plexus injury anastomosis samples. DESIGN, TIME AND SETTING： The in vitro experiment was performed at the Mechanics Experimental Center, Jilin University, China from April to May 2007. MATERIALS： A total of six adult, male cadavers, who had died from acute trauma, and were aged 20-29 years, were supplied by the Research Room of Anatomy, Medical Department, Jilin University, China. AG-10TA Universal Material Testing Machine （Shimadzu, Japan） was used in this study. METHODS： A total of 36 samples of fresh brachial plexus were collected from the cadavers, comprising 12 C5 nerve roots, 12 C6 nerve roots at the left and right sides of the superior truck, and 12 C7 nerve roots at the middle truck. The C5 and C6 nerve roots were processed into 50 samples and the C7 nerve roots into 24 samples. A total of 36 C5 and C6 nerve root samples were randomly assigned to a non-surgery control group （n = 18） and brachial plexus injury anastomosis simulation group （n = 18）. Brachial plexus injury simulation anastomosis samples underwent an incision in the middle, and then received anastomosis. Samples in both groups underwent a tension test at 5 mm/min on the AG-10TA universal material testing machine. A total of 24 samples from the C6 superior trunk and C7 middle trunk of the brachial plexus were subjected to stress relaxation and creep tests. Test duration was 7 200 seconds. A total of 100 data points were collected and analyzed using a normalization method. MAIN OUTCOME MEASURES： The following parameters were measured： tension maximum displacement, maximum load, maximum stress, maximum strain and stress-strain curve, stress relaxation at 7 200 seconds, creep deformation at 7 200 seconds, stress relaxation, and creep curve in the non-surgery control group and brachial plexus injury simulation anastomosis group. RESULTS： The tension maximum load of brachial plexus was （140.36 ± 30.50） N, maximum stress was （10.67 ± 2.52） MPa, maximum displacement was （7.78 ± 1.48） mm, and maximum strain was （31.64 ± 5.32）% in the non-surgery control group. The tension maximum load of brachial plexus was （93.23 ± 20.65） N, maximum stress was （7.09 ± 1.57） MPa, maximum displacement was （6.13 ± 0.86） mm,and maximum strain was （24.55 ± 3.45）% in the brachial plexus injury simulation anastomosis group. The above-mentioned indices were greater in the non-surgery control group than in the brachial plexus injury simulation anastomosis group （P 〈 0.01）. Stress relaxation at 7 200 seconds was 2.07 MPa and 2.11 MPa, respectively, in the non-surgery control and brachial plexus injury simulation anastomosis groups. Creep deformation at 7 200 seconds was 4.68% and 3.52%, respectively, in the non-surgery control and brachial plexus injury simulation anastomosis groups. CONCLUSION： Decreased tension maximum load, maximum displacement, maximum stress, maximum strain, and creep deformation at 7 200 seconds affected the biomechanical properties of the brachial plexus following brachial plexus injury.

Biomechanical characteristics of an anterior cruciate ligament injury in javelin throwing

目的:理解标枪运动中前十字韧带的损伤机制以及与前十字韧带损伤相关的标枪技术。方法:受试者是一名高水平女子标枪运动员,她在健康状态下完成前3次实验。在最近一次的田径大会期间进行了第4次实验,这次试验中她的左膝存在非外力引起的前十字韧带损伤。我们采集到损伤和非损伤实验中的三维运动学数据并从标枪生物力学数据库中获得52名男子和54名女子高水平标枪运动员的相关数据。结果:损伤和非损伤相比,在前25%的投掷阶段后,受试者质心向前的速度更大,垂直方向的速度更小:投掷阶段前21%的过程中,受试者左膝屈曲角度和角速度都更小,但左膝外翻和内旋角度没有明显差异。在损伤实验投掷阶段30%时,摄影图像中显示出明显的胫骨前移;受试者左脚触地时,左膝屈曲角度和角速度以及在投掷阶段中左膝最大屈曲角度与数据库中52名男子和54名女子优秀标枪运动员的数据没有相关性。结论:研究中的前十字韧带损伤发生在投掷阶段的前30%,更可能是前25%。左腿膝关节屈曲角度小,导致硬着陆是损伤的主要原因。标枪运动员应弯曲膝关节进行软着陆,这样能帮助他们预防前十字韧带损伤而不影响运动表现。

Expression of metabotropic glutamate receptor 1a in a rat cortical neuronal model of in vitro mechanical injury and the effects of its competitive antagonist (RS)-1-aminoindan-1,5-dicarboxylic acid

The present study established a rat cortical neuronal model of in vitro mechanical injury. At 30 minutes after injury, the survival rate of the injured cortical neurons was decreased compared with normal neurons, and was gradually decreased with aggravated degree of injury. Reverse transcription-polymerase chain reaction results showed that at 1 hour after injury, there was increased expression of metabotropic glutamate receptor la in cortical neurons. Immunohistochemical staining results showed that at 30 minutes after injury, the number of metabotropic glutamate receptor 1a-positive cells increased compared with normal neurons. At 12 hours after injury, lactate dehydrogenase activity in the （RS）-l-aminoindan-1, 5-dicarboxylic acid （AIDA）-treated injury neurons was si[jnificantly decreased than that in the pure injury group. At 1 hour after injury, intracellular free Ca＂＋ concentration was markedly decreased in the AIDA-treated injury neurons than that in the pure injury neurons. These findings suggest that after mechanical injury to cortical neurons, metabotropic glutamate receptor la expression increased. The resulting increase in intracellular free Ca2＋ concentration was blocked by AIDA, indicating that AIDA exhibits neuroprotective effects after mechanical injury.

Effect of sequential mechanical ventilation on cardiac function, endothelial injury and oxidative stress response in patients with cor pulmonale

Objective: To study the effect of sequential mechanical ventilation on cardiac function, endothelial injury and oxidative stress response in patients with cor pulmonale (CCP). Methods: Patients with cor pulmonale complicated by respiratory failure who were treated in Dongfeng People's Hospital between May 2014 and February 2017 were selected and randomly divided into the sequential group who received sequential mechanical ventilation combined with conventional therapy and the control group who received invasive positive pressure ventilation combined with conventional therapy. The serum levels of cardiac function-related neurohumoral indicators, endothelial injury indicators and oxidative stress response indicators were detected before treatment as well as 3 d and 7 d after treatment. Results: 3 d and 7 d after treatment, serum NT-proBNP, Copeptin, Ang-II, ALD, ET-1, vWF, sST2 levels of both groups of patients were significantly lower than those before treatment while NO, SOD, GSH-Px and T-AOC levels were significantly higher than those before treatment;serum NT-proBNP, Copeptin, Ang-II, ALD, ET-1, vWF, sST2, NO, 8-iso-PGF2a, MDA, SOD, GSH-Px and T-AOC levels of sequential group 3 d after treatment were not significantly different from those of control group;serum NT-proBNP, Copeptin, Ang-II, ALDET-1, vWF, sST2, 8-iso-PGF2a and MDA levels of sequential group 7 d after treatment were significantly lower than those of control group while NO, SOD, GSH-Px and T-AOC levels were significantly higher than those of control group. Conclusion: Sequential mechanical ventilation for cor pulmonale can improve the cardiac function and reduce the degree of endothelial injury and oxidative stress response.

Repair mechanism of astrocytes and non-astrocytes in spinal cord injury

BACKGROUND Spinal cord injury(SCI)is a destructive disease that incurs huge personal and social costs,and there is no effective treatment.Although the pathogenesis and treatment mechanism of SCI has always been a strong scientific focus,the pathogenesis of SCI is still under investigation.AIM To determine the key genes based on the modularization of in-depth analysis,in order to identify the repair mechanism of astrocytes and non-astrocytes in SCI.METHODS Firstly,the differences between injured and non-injured spinal cord of astrocyte(HA),injured and non-injured spinal cord of non-astrocyte(FLOW),injured spinal cord of non-injured astrocyte(HA)and non-injured spinal cord of nonastrocyte(FLOW),and non-injured spinal cord of astrocyte(HA)and nonastrocyte(FLOW)were analyzed.The total number of differentially expressed genes was obtained by merging the four groups of differential results.Secondly,the genes were co-expressed and clustered.Then,the enrichment of GO function and KEGG pathway of module genes was analyzed.Finally,non-coding RNA,transcription factors and drugs that regulate module genes were predicted using hypergeometric tests.RESULTS In summary,we obtained 19 expression modules involving 5216 differentially expressed genes.Among them,miR-494,XIST and other genes were differentially expressed in SCI patients,and played an active regulatory role in dysfunction module,and these genes were recognized as the driving genes of SCI.Enrichment results showed that module genes were significantly involved in the biological processes of inflammation,oxidation and apoptosis.Signal pathways such as NF-kappa B/A20,AMPK and MAPK were significantly regulated.In addition,non-coding RNA pivot(including miR-136-5p and let-7d-5p,etc.)and transcription factor pivot(including NFKB1,MYC,etc.)were identified as significant regulatory dysfunction modules.CONCLUSION Overall,this study uncovered a co-expression network of key genes involved in astrocyte and non-astrocyte regulation in SCI.These findings helped to reveal the core dysfunction modules,potential regulatory factors and driving genes of the disease,and to improve our understanding of its pathogenesis.

Contribution of spinal glia activation to mechanical hyperalgesia induced by spared nerve injury in rats

Objective: To investigate the role of spinal glial cells activation in neuropathic pain in a recently developed spared nerve injury (SNI) animal model by Decosterd and Woolf. Methods: A lesion was made to two of the three terminal branches of the sciatic nerve of rats (tibial and common peroneal nerves) leaving the sural nerve intact. Continuous intrathecai administration of propentofyliine, a glial modulating agent, 1 d before and 5 d after operation, was performed to disrupt spinal cord glia function. The vehicle was intrathecally administrated as control. The paw withdrawal threshold to mechanical stimulation (paw withdrawal mechaical threshold PWMT), body mass and motor function were determined pre- and post-surgery. Results: It produced a prolonged mechanical allodynia in the medial and lateral part of the ipsilateral hind paw in SNL models. The treatment with propentofylline significantly prevented the development of mechanical allodynia located in either medial or lateral plantar surface. Rats in two groups showed normal motor function and body weight increase. Conclusion:SNI model can be applied as a useful method with little variance in searching the mechanism of neuropathic pain. These study suggest that spinal glia activation may contribute to mechanical allodynia induced by SNI.

Evaluation of vascular recanalization rate and nerve injury of mechanical thrombectomy combined with rt-PA thrombolysis in treatment of acute cerebral infarction

Objective:To investigate the vascular recanalization rate of mechanical thrombectomy combined with recombinant tissue-type plasminogen activator (rt-PA) thrombolysis in the treatment of acute cerebral infarction and the effect on the nerve injury in patients.Methods:A total of 90 patients with acute cerebral infarction who were treated in our hospital between January 2016 and January 2019 were retrospectively analyzed and divided into the control group (n=46) receiving rt-PA thrombolysis and the observation group (n=44) receiving mechanical thrombectomy combined with rt-PA thrombolysis. The differences in vascular recanalization rate 24 h after treatment as well as serum levels of inflammatory mediators [interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-7 (IL-7), interleukin-17 (IL-17) and hypersensitive C-reactive protein (hs-CRP)], nerve injury markers [brain-derived neurotrophic factor (BDNF), neuron-specific enolase (NSE) and S100B protein (S100B)] and neurotransmitters [glutamate (Glu) and 5-hydroxytryptamine (5-HT)] before and after treatment were compared between the two groups of patients.Results: 24 h after treatment, the vascular recanalization rate of the observation group was higher than that of the control group (P<0.05). 24 h after treatment and 1 week after treatment, serum IL-1, IL-6, IL-7, IL-17 and hs-CRP levels in the observation group were lower than those in the control group;BDNF level was higher than that in the control group, while NSE and S100B levels were lower than those in the control group;Glu and 5-HT levels were lower than those in the control group (P<0.05). Conclusions: Mechanical thrombectomy combined with rt-PA thrombolysis can increase the early postoperative vascular recanalization rate in patients with acute cerebral infarction, and it also plays an active role in alleviating nerve injury.

Hepatic ischemia-reperfusion injury in liver transplant setting:mechanisms and protective strategies

Hepatic ischemia-reperfusion injury is a major cause of liver transplant failure,and is of increasing significance due to increased use of expanded criteria livers for transplantation.This review summarizes the mechanisms and protective strategies for hepatic ischemia-reperfusion injury in the context of liver transplantation.Pharmacological therapies,the use of pre-and post-conditioning and machine perfusion are discussed as protective strategies.The use of machine perfusion offers significant potential in the reconditioning of liver grafts and the prevention of hepatic ischemia-reperfusion injury,and is an exciting and active area of research,which needs more study clinically.