Warm HTK donor pretreatment reduces liver injury during static cold storage in experimental rat liver transplantation

BACKGROUND： Organ shortage has led to an increased number of transplantations from extended criteria donors. These organs are more vulnerable to ischemia-reperfusion injury. Thus, improvement of organ preservation is needed. HTK is a widely used preservation solution for static cold storage in liver transplantation. The present study was to investigate the beneficial effect of warm HTK donor pretreatment on liver preservation.

Expert consensus on the prevention, diagnosis and treatment of cold injury in China, 2020

Cold injury refers to local or systemic injury caused by a rapid, massive loss of body heat in a cold environment. The incidence of cold injury is high. However, the current situation regarding the diagnosis and treatment of cold injury in our country is not ideal. To standardize and improve the level of clinical diagnosis and treatment of cold injury in China, it is necessary to make a consensus that is practical and adapted to the conditions in China. We used the latest population-level epidemiological and clinical research data, combined with relevant literature from China and foreign countries. The consensus was developed by a joint committee of multidisciplinary experts. This expert consensus addresses the epidemiology, diagnosis, on-site emergency procedures, in-hospital treatment, and prevention of cold injury.

Antioxidants in experimental ischemia-reperfusion injury of the testis: Where are we heading towards?

Testicular torsion(TT) is a medical emergency that primary affects newborns and young adolescents.It causes testicular injury due to the torsion of the spermatic cord and its components, initially in the venous blood flow and finally in the arterial blood flow.Prompt diagnosis and early surgical management are necessary in managing this urgent situation.The process of the pathophysiological events in ischemia-reperfusion is multifactorial and deals with the perception of the oxidative stress responsible for the consequences of ischemia/reperfusion(I/R) stress following TT.Duration and severity of torsion also play a significant role in the oxidative stress.A detrimental result of the defense system of the testes takes place resulting finally in testicular atrophy and impaired function.Antioxidant factors have been experimentally studied in an effort to front this state.They have been classified as endogenous or exogenous antioxidants.Endogenous antioxidants comprise a structure of enzymic enzymatic and nonenzymic enzymatic particles presented within cytoplasm and numerous other subunits in the cells.Exogenous antioxidants include a variety of natural and pharmaceutical agents that may prevent or ameliorate the harmful effects of I/R injury.In this study we review those factors and their ability to enhance the oxidative status of the testis.A feature insight into where we are heading is attempted.

Dexamethasone prevents vascular damage in earlystage non-freezing cold injury of the sciatic nerve

Non-freezing cold injury is a prevalent cause of peripheral nerve damage, but its pathogenic mechanism is poorly understood, and treatment remains inadequate. Glucocorticoids have anti-inflammatory and lipid peroxidation-inhibiting properties. We therefore examined whether dexamethasone, a synthetic glucocorticoid compound, would alleviate early-stage non-freezing cold injury of the sciatic nerve. We established Wistar rat models of non-freezing cold injury by exposing the left sciatic nerve to cold（3–5°C） for 2 hours, then administered dexamethasone（3 mg/kg intraperitoneally） to half of the models. One day after injury, the concentration of Evans blue tracer in the injured sciatic nerve of rats that received dexamethasone was notably lower than that in the injured sciatic nerve of rats that did not receive dexamethasone; neither Evans blue dye nor capillary stenosis was observed in the endoneurium, but myelinated nerve fibers were markedly degenerated in the injured sciatic nerve of animals that received dexamethasone. After dexamethasone administration, however, endoneurial vasculopathy was markedly improved, although damage to the myelinated nerve fiber was not alleviated. These findings suggest that dexamethasone protects the blood-nerve barrier, but its benefit in non-freezing cold injury is limited to the vascular system.

Experimental repetitive mild traumatic brain injury induces deficits in trabecular bone microarchitecture and strength in mice

To evaluate the long-term consequence of repetitive mild traumatic brain injury （mTBI） on bone, mTBI was induced in 10-week-old female C57BL/6J mice using a weight drop model, once per day for 4 consecutive days at different drop heights （0.5, 1 and 1.5 m） and the skeletal phenotype was evaluated at different time points after the impact. In vivo micro-CT （μ-CT） analysis of the tibial metaphysis at 2, 8 and 12 weeks after the impact revealed a 5%-32% reduction in trabecular bone mass. Histomorphometric analyses showed a reduced bone formation rate in the secondary spongiosa ofl.5 m impacted mice at 12 weeks post impact. Apparent modulus （bone strength）, was reduced by 30% （P 〈 0.05） at the proximal tibial metaphysis in the 1.5 m drop height group at 2 and 8 weeks post impact. Ex vivo μ-CT analysis of the fifth lumbar vertebra revealed a significant reduction in trabecular bone mass at 12 weeks of age in all three drop height groups. Serum levels of osteocalcin were decreased by 22%, 15%, and 19% in the 0.5, 1.0 and 1.5 m drop height groups, respectively, at 2 weeks post impact. Serum IGF-I levels were reduced by 18%-32% in mTBI mice compared to control mice at 2 weeks post impact. Serum osteocalcin and IGF-I levels correlated with trabecular BV/TV （r2 = 0.14 and 0.16, P 〈 0.05）. In conclusion, repetitive mTBI exerts significant negative effects on the trabecular bone microarchitecture and bone mechanical properties by influencing osteoblast function via reduced endocrine IGF-I actions.

An Experimental Study of Craniocerebral Injury Caused by 7. 62 mm Bullets in Dogs

The experimental models of craniocercbral wounds caused by 7. 62 mm bullets, i. e. thepenetrating craniocerebral injury, the tangential brain injury and the tangential skull injury, were es-tablished in dogs. The craniocerebral ballistics, craniocerebral pathology, serum and cerebrospinal flu-id total lactate dehydrogenase, blood-brain barrier permcabalities, and the pathophysiology ofcardiovascular and respiratory systems were studied. These results suggest that: 1. These injuries ofhigh-velocity missile can all cause general brain damage and intracranio-hematomas ; 2. The severityof the wound depends on the site of the injury, the kinetic energy of the missile force and the effectof the temporary cavity ; 3. The brain injury can seriously damage the blood brain barrier, leadingto brain edema ; 4. The dysfunction of respiratory and cardiovascular system is the fatal complicationendangering the life of the subjects ; 5. Estimating serum and cerebrospinal fluid total lactatedehydrogenase is a simple and valuable way to judge the severity and prognosis of this injury.

An Experimental Study on the Treatment with High Dose Dexamethasone of Craniocerebral Injury Caused by 7.62mm Bullets in Dogs

The effect of high dose dexamethasone(5 mg/kg wt,intravenous injection)to preventand treat secondary pathological damage due to craniocerebral injury was studied in an animal modelof craniocerebral injury caused by high-velocity missiles in dogs.We observed the physiologicalchanges,analyzed the level of serum and cerebrospinal fluid lactate dehydrogenase,cstimated thepermeability of blood brain barrier(BBB)and studied brain pathology by light and electronmicroscopy.The rusults suggest that high dose dexarnethasone can help to restore the structure andfunction of BBB,protect the brain cells,lessen the secondary pathological damage in the respiratoryand circulatory systams,and reduce the production of lipoperoxides(LPO).

Effect of Intra-arachnoid Space Perfusion on Thromboxane A and Prostacycline in Experimental Spinal Cord Injury

In order to understand the relation between TXA2- PGI2 and secondary trauma and the effect of intra-arachnoid perfusion of dexamethasone and verapamil on alteration of TXA,-PGI, following spinal cord injury, TXB2 and 6-keto-PGFconcentration and pathological changes in injured site 1, 2, 4 and 6 h after injury were studied using a rabbit spinal cord injury model by Allen's weight drop method.

Comparison of the effects of intravitreal bevacizumab and dexamethasone in experimental posterior penetrating eye injury

AIM： To compare the effects of intravitreal anti-vascular endothelial growth factor（VEGF） and dexamethasone in an experimental rabbit model of posterior penetrating ocular injury.METHODS： Thirty white New Zealand rabbits were included in the study. A posterior penetrating ocular injury was performed at the superotemporal quadrant. They were randomly divided into three groups. The rabbits in group 1 received intravitreal dexamethasone, in group 2 they received intravitreal bevacizumab and those in group 3 received intravitreal physiological saline solution in both eyes. All eyes were examined ophthalmologically on the 1^st, 3^rd, 7^th, 14^th and 28^th days following the injury and the clinical findings were scored. On the day 28, the eyes were enucleated, evaluated and scored macroscopically, histopathologically and scanning electron microscopically.RESULTS： The median clinical score on the 14 th and 28 th days and the median macroscopic score of the dexamethasone group was significantly better than that of control（P=0.004, 0.018）. Dexamethasone group was also better than that of bevacizumab group but the differences did not reach statistical significance. Retinal detachment rate was 8.3%, 16.6% and 12.5% in the dexamethasone group, bevacizumab group and control group, respectively（P=0.476）. More extensive fibrocelluler proliferations were observed in controls compared with dexamethasone and bevacizumab groups. But these differences did not reach the statistical significance（P=0.538）. In scanning electron microscopy all groups showed fibreous stalk and dense collagen fibrils in vitreous. CONCLUSION： This study shows that intravitreal injection of both dexamethasone and bevacizumab may reduce the intraocular fibrous proliferation after an experimental posterior penetrating ocular injury in rabbits.

Analysis on Meteorological Conditions of Winter Cold Injury of Sugar Orange Industry in Guilin

Yield and quality of sugar orange are closely related to meteorological conditions,especially the low temperature and cold injury in mature period of fruit. To study the influence of winter cold injury on sugar orange industry of Guilin,the chilling injury weather in each county of Guilin planting sugar orange is analyzed,and the disastrous cold weather and its defense measures are studied. Frost,freezing and cold wave happen in Guilin winter sometimes,and the disastrous weather could seriously harm maturing sugar orange or that in the tree,causing peel coke,dehiscent fruit,fruit drop and quality decline. It can effectively reduce the loss by chilling injury and guarantee excellent quantity and high yield of sugar orange by timely understanding weather change information,scientifically managing water and fertilizer,and doing film cover well.

Alteration of Nitric Oxide Synthase in Experimental Spinal Cord Injury in Rats

In order to detect the role of NO to the secondary damage following spinal cord injury (SCI). NOS in the injury site (T\-8) were studied using a rat SCI model induced by Allens weight drop method (10 g2.5 cm). The results suggested that activities of NOS significantly increased in 10 min\, 1\,2\,4\,8 h. The results indicated that NO was related to SCI. The rise of NO following SCI might lead to secondary spinal cord damage.\;

Experimental study of the dependences of retrieval efficiencies on time delay between magneto-optical-trap being turned off and optical storage

We report an experimental study of electromagnetically induced transparency（EIT）-based light storage in a cloud of cold atoms loaded into a magneto-optical-trap（MOT）. After the MOT is turned off, the retrieval efficiencies of rightand left-circularly polarized signal light fields each as a function of storage time are measured for different time delays between MOT off and the storage event, respectively. The results show that in the delay ranging from 0.015 ms to 3.5 ms,the retrieval efficiency for a zero-storage time（0.2 μs） and the storage lifetime can exceed 15% and 1.4 ms, respectively.The measured results will provide important help for optimizing the storage of the polarized entanglement photons in cold atomic ensembles.

Encapsulated Water Hammer: Theoretical/Experimental Study

Water hammer phenomenon involves the transformation of kinetic energy in pressure energy, this transformation occurs as the fluid conditions change inside the pipe in quite a short time. Industry requires to affront frequent flow interruptions in pipe systems due to the closing of valves or stopping of pumping equipment. This phenomenon can initiate serious damages like destruction of the pipe system involving leakage of the working fluid to the environment. If the system operates in a fragile environment, as in cold regions, concern about the consequences of leakage increases due to the variation of physical properties of fluid as well as the pipe material as a function of the temperature. Water hammer effects can be controlled focusing efforts on reducing the pressure increment that takes place once the phenomenon is presented. Some methods try to reduce the time of closure or the rate of change before the closure using special valves, others install additional elements to absorb the pressure surge and dissipate energy, others install relief valves to release the pressure, and others try to split the problem is smaller sections by installing check valves with dashpot or non-return valves. Splitting the pipeline into shorter sections is often used to help preventing the pipeline length of water falling back after a pump stops. In this paper the numerical results of maximum and minimum pressure values at both ends of a closed section are compared to experimental data. The numerical results follow the experimental trends.

Experimental nerve transfer model in the neonatal rat

Clinically,peripheral nerve reconstructions in neonates are most frequently applied in brachial plexus birth injuries.Most surgical concepts,however,have investigated nerve reconstructions in adult animal models.The immature neuromuscular system reacts differently to the effects of nerve lesion and surgery and is poorly investigated due to the lack of reliable experimental models.Here,we describe an experimental forelimb model in the neonatal rat,to study these effects on both the peripheral and central nervous systems.Within 24 hours after birth,three groups were prepared:In the nerve transfer group,a lesion of the musculocutaneous nerve was reconstructed by selectively transferring the ulnar nerve.In the negative control group,the musculocutaneous nerve was divided and not reconstructed and in the positive control group,a sham surgery was performed.The animal's ability to adapt to nerve lesions and progressive improvement over time were depict by the Bertelli test,which observes the development of grooming.Twelve weeks postoperatively,animals were fully matured and the nerve transfer successfully reinnervated their target muscles,which was indicated by muscle force,muscle weight,and cross sectional area evaluation.On the contrary,no spontaneous regeneration was found in the negative control group.In the positive control group,reference values were established.Retrograde labeling indicated that the motoneuron pool of the ulnar nerve was reduced following nerve transfer.Due to this post-axotomy motoneuron death,a diminished amount of motoneurons reinnervated the biceps muscle in the nerve transfer group,when compared to the native motoneuron pool of the musculocutaneous nerve.These findings indicate that the immature neuromuscular system behaves profoundly different than similar lesions in adult rats and explains reduced muscle force.Ultimately,pathophysiologic adaptations are inevitable.The maturing neuromuscular system,however,utilizes neonatal capacity of regeneration and seizes a variety of compensation mechanism to restore a functional extremity.The above described neonatal rat model demonstrates a constant anatomy,suitable for nerve transfers and allows all standard neuromuscular analyses.Hence,detailed investigations on the pathophysiological changes and subsequent effects of trauma on the various levels within the neuromuscular system as well as neural reorganization of the neonatal rat may be elucidated.This study was approved by the Ethics Committee of the Medical University of Vienna and the Austrian Ministry for Research and Science(BMWF-66.009/0187-WF/V/3 b/2015)on March 20,2015.

Experimental observation of rat's early-stage fracture healing with different kinds of nerve injuries

To investigate the impact of different kinds of nerve injuries of early-stage fracture healing.Methods Three groups of rats were included in the experiment among which group 1 was inflicted with femoral fracture and T10 spinal cord transsection (SCI),group 2 was inflicted with femoral and peripheral nerve resection (PNR),and group 3 with simple femoral fracture as control group.Two weeks after operation the femoral bones were collected for X-ray checking and 2 more weeks later X-ray checking was performed again followed by pathomorphologic exams.Results X-ray result showed no massive calluses in the bones in the 2nd week postoperatively,while in the 4th week,callus appeared with larger size in group 3 than that of group 1 and with smaller size than that of group 2.It was the same with the result of pathomorphologic examining.Cortical bone bridges between fracture point and osteiod were also found in group 2 and there were less normal blood vessels and worse bone remodeling than that of group 3.There were relatively immature calluses with more fibroblast-like cells and disordered bone structure in group 2.Group 3 showed normal healing process and callus structure.Conclusion Early-stage bone fracture healing can be influenced significantly by different kinds of nerve injuries.6 refs,6 figs.

Cold water swimming pretreatment reduces cognitive deficits in a rat model of traumatic brain injury

A moderate stress such as cold water swimming can raise the tolerance of the body to potentially injurious events. However, little is known about the mechanism of beneficial effects induced by moderate stress. In this study, we used a classic rat model of traumatic brain injury to test the hypothesis that cold water swimming preconditioning improved the recovery of cognitive functions and explored the mechanisms. Results showed that after traumatic brain injury, pre-conditioned rats（cold water swimming for 3 minutes at 4℃） spent a significantly higher percent of times in the goal quadrant of cold water swim, and escape latencies were shorter than for non-pretreated rats. The number of circulating endothelial progenitor cells was significantly higher in pre-conditioned rats than those without pretreatment at 0, 3, 6 and 24 hours after traumatic brain injury. Immunohistochemical staining and Von Willebrand factor staining demonstrated that the number of CD34~＋ stem cells and new blood vessels in the injured hippocampus tissue increased significantly in pre-conditioned rats. These data suggest that pretreatment with cold water swimming could promote the proliferation of endothelial progenitor cells and angiogenesis in the peripheral blood and hippocampus. It also ameliorated cognitive deficits caused by experimental traumatic brain injury.

Dose-dependent neuroprotective effect of enoxaparin on cold-induced traumatic brain injury

Recent evidence exists that enoxaparin can reduce brain injury because of its anticoagulant activity. To investigate the potential therapeutic effect of enoxaparin on cold-induced traumatic brain injury, at 20 minutes after modeling, male BALB/c mouse models of cold-induced traumatic brain injury were intraperitoneally administered 3 and 10 mg/kg enoxaparin or isotonic saline solution. Twenty-four hours later, enoxaparin at 10 mg/kg greatly reduced infarct volume, decreased cell apoptosis in the cortex and obviously increased serum level of total antioxidant status. By contrast, administration of enoxaparin at 3 mg/kg did not lead to these changes. These findings suggest that enoxaparin exhibits neuroprotective effect on cold-induced traumatic brain injury in a dose-dependent manner.

Neuroprotective effects of cold-inducible RNA-binding protein during mild hypothermia on traumatic brain injury

Cold-inducible RNA-binding protein（CIRP）, a key regulatory protein, could be facilitated by mild hypothermia in the brain, heart and liver. This study observed the effects of mild hypothermia at 31 ± 0.5℃ on traumatic brain injury in rats. Results demonstrated that mild hypothermia suppressed apoptosis in the cortex, hippocampus and hypothalamus, facilitated CIRP m RNA and protein expression in these regions, especially in the hypothalamus. The anti-apoptotic effect of mild hypothermia disappeared after CIRP silencing. There was no correlation between mitogen-activated extracellular signal-regulated kinase activation and CIRP silencing. CIRP silencing inhibited extracellular signal-regulated kinase-1/2 activation. These indicate that CIRP inhibits apoptosis by affecting extracellular signal-regulated kinase-1/2 activation, and exerts a neuroprotective effect during mild hypothermia for traumatic brain injury.

BH3-only protein Bim is involved in myocardial injury induced by co-stress of ischemia and cold stress in rats

Objectives To investigate the effect of co-exposure of myocardial ischemia and cold stress on myocardial injury in rats and the relative mechanism.Methods Myocardial ischemia model was established by ligation of left coronary artery.SD rats were randomly allocated to 4 groups; sham+normal temperature(S group),sham+cold stress(SC group),myocardial ischemia+ normal temperature(Ⅰgroup), myocardial ischemia+cold stress(IC group).On the condition of 26℃,SC and IC groups were keeped in a 4℃artificial chamber for 8h(8;00-16:00) for 4 consecu- tive days.Car diac function was assessed by echocardiography;pathological change was analyzed by HE staining;myocardial infarct size was determined by TTC staining;Bim,Caspase-3 expression in myocardium was determined by western blotting.Results It was demonstrated that co-exposure of myocardial ischemia and cold stress could significantly make the cardiac muscle in abnormal shape,increase the infarct size and the expression of Bim and Caspase-3.Conclusions Co-exposure of myocardial ischemia and cold stress may aggravate the cardiac injury,pro- apoptosis protein Bim is involved.

白藜芦醇对实验性自身免疫性心肌炎大鼠心肌巨噬细胞极化及心肌炎性损伤的影响

目的:探讨白藜芦醇(Res)对实验性自身免疫性心肌炎(EAM)大鼠心肌巨噬细胞极化及炎性损伤的影响。方法:建立EAM大鼠模型,分为对照组、EAM组、Resveratrol组,通过免疫荧光、HE染色观察心肌组织巨噬细胞浸润程度并对心肌病理损伤进行评分;采用Realtime PCR检测巨噬细胞极化标记分子诱生型一氧化氮合酶(iNOS)、精氨酸酶1(Arg1)及炎症因子白细胞介素6(IL-6)、白细胞介素1β(IL-1β)、肿瘤坏死因子-α(TNF-α)的表达变化,Western blot检测NLRP3炎性小体蛋白组分的表达变化。结果:EAM组大鼠心肌组织可见大量巨噬细胞浸润,伴有明显的心肌纤维断裂、溶解;IL-6、IL-1β、TNF-α、iNOS mRNA表达均较Control组显著增加(分别为P<0.05,P<0.05,P<0.01,P<0.01),而Arg1表达较Control组显著减少(P<0.05);Resveratrol可减少EAM大鼠心肌组织巨噬细胞浸润数量及心肌病理损伤积分(均P<0.05),减少IL-6、IL-1β、TNF-α、iNOS mRNA的表达(均P<0.05),增加Arg1的表达(P<0.01)。同时,与Control组比较,EAM大鼠心肌组织NLRP3和Caspase-p10、pro-Caspase-1及IL-1β蛋白表达明显升高(均P<0.05),Resveratrol可显著减少人NOD样受体家组蛋白3(NLRP3)、Caspase-p10、pro-Caspase-1及IL-1β蛋白表达,差异具有统计学意义(均P<0.05)。结论:巨噬细胞浸润并向M1型极化参与EAM大鼠心肌炎性损伤;Res可能通过抑制M1型巨噬细胞向M2型极化、NLRP3炎症小体激活及相关炎性因子释放减轻EAM心肌损伤。