Mechanisms of vascular injury in neurotrauma: A critical review of the literature

One in every two individuals will experience a traumatic brain injury in their lifetime with significant impacts on the global economy and healthcare system each year.Neurovascular injury is a key aspect of neurotrauma to both the brain and the spinal cord and an important avenue of current and future research seeking innovative therapies.In this paper,we discuss primary and secondary neurotrauma,mechanisms of injury,the glymphatic system,repair and recovery.Each of these topics are directly connected to the vasculature of the central ner-vous system,affecting severity of injury and recovery.Consequently,neurova-scular injury in trauma represents a promising target for future therapeutics and innovation.

Upper extremity vascular injuries:Etiology,management and outcome

BACKGROUND Vascular injuries of the upper extremities are considered relatively rare injuries affecting mostly the young population.They often are complex injuries accompanied by other musculoskeletal trauma or trauma in other anatomic locations.Their management is challenging since they can lead to disabilities with major socioeconomic effects.AIM To analyze data about the mechanism of injury,the management algorithm and functional outcomes of vascular injuries of the upper extremity.METHODS One hundred and fifteen patients(96 males and 19 females)with arterial injuries of the upper extremity treated in a tertiary trauma center from January 2003 to December 2022 was conducted.Mean patients’age was 33.7 years and the mean follow up time was 7.4 years.Patients with Mangled Extremity Severity Score≥7 and Injury Severity Score≥20,previous upper limb surgery or major trauma and any neuromuscular or psychiatric disease were excluded,from the study.RESULTS A penetrating trauma was the most common cause of injury.The radial artery was the artery injured in most of the cases(37.4%)followed by the ulnar(29.5%),the brachial(12.1%)and the axillary(6%).A simultaneous injury of both of the forearm’s arteries was in 15.6%of the cases.In 93%of the cases there were other concomitant musculoskeletal injuries of the extremity.Tendon lacerations were the most common,followed by nerve injuries.The postoperative functional scores(full Disabilities of the Arm,Shoulder,and Hand and VAS)had very satisfactory values.CONCLUSION Although vascular injuries of the upper extremity are rare,they may occur in the context of major combined musculoskeletal trauma.Although a multidisciplinary approach is essential to optimize outcome,the ability of trained hand surgeons to repair all injuries in combined vascular and musculoskeletal upper extremity trauma,excluding isolated vascular injuries,ensures shorter operative times and better functional outcomes.

Silence of STIM1 attenua=tes the proliferation and migration of EPCs after vascular injury and its mechanism

Objective:To investigate the effect of stromal interaction molecule 1（STIM1） knockdown on the proliferation and migration of endothelial progenitor cells（EPCs） after vascular injury and its mechanism.Methods:The rat bone marrow derived EPCs were divided into three groups:adenovirus negative control（group NSC）,rat STIM1 adenovirus vector transfection group（group si/rSTIM1） and rat &human recombinant STIM1 adenovirus transfection group（group si/rSTlM1+hSTIM1）.The STIM1 expressions in each group were detected by reverse transcription PCR after transfection;the cell proliferation was tested by[3H]thymidine incorporation assay（3HTdR）;Cell cycle was analyzed by flow cytometry;the cells’ migration activity was detected by Boyden assay;Calcium ion concentration was detected by using laser confocal method.Results:48 h later after transfection,the expression level of STIM1 in si/rSTIM1 cells was significantly lower than that in NSC group（0.21±0.12 vs 1.01±0.01,P【0.05）;EPCs that stayed in G1 phase in si/rSTIM1 group[（93.3l±0.24）%]were significantly more than that in NSC group[（78.03±0.34）%,P【0.05];EPCs’ migration activity in si/rSTIM1 group（10.03±0.33） was significantly lower than that in NSC group:（32.11±0.54,P【0.05）;EPCs calcium ion concentration changes in EPCs in si/rSTIM1group（38.03±0.13） was significantly lower than that in NSC group（98.11±0.34,P【0.05）.While there was no significant difference between si/rSTIM1+hSTIM1 group and NSC group on the four indexes above.Conclusions:Silence of STIM1 attenuates EPCs proliferation and migration after vascular injury,by mediating the calcium ion concentration in EPCs.

Vascular endothelial growth factor A promotes platelet adhesion to collagen Ⅳ and causes early brain injury after subarachnoid hemorrhage

The role of vascular endothelial growth factor A in platelet adhesion in cerebral microvessels in the early stage of subarachnoid hemorrhage remains unclear.In this study,the endovascular puncture method was used to produce a rat model of subarachnoid hemorrhage.Then,30 minutes later,vascular endothelial growth factor A antagonist anti-vascular endothelial growth factor receptor 2 antibody,10μg,was injected into the right ventricle.Immunohistochemistry and western blot assay were used to assess expression of vascular endothelial growth factor A,occludin and claudin-5.Immunohistochemical double labeling was conducted to examine co-expression of GP Ⅰa-Ⅱ integrin and type Ⅳ collagen.TUNEL was used to detect apoptosis in the hippocampus.Neurological score was used to assess behavioral performance.After subarachnoid hemorrhage,the expression of vascular endothelial growth factor A increased in the hippocampus,while occludin and claudin-5 expression levels decreased.Co-expression of GP Ⅰa-Ⅱ integrin and type Ⅳ collagen and the number of apoptotic cells increased,whereas behavioral performance was markedly impaired.After treatment with anti-vascular endothelial growth factor receptor 2 antibody,occludin and claudin-5 expression recovered,while co-expression of GP Ⅰa-Ⅱ integrin and type Ⅳ collagen and the number of apoptotic cells decreased.Furthermore,behavioral performance improved notably.Our findings suggest that increased vascular endothelial growth factor A levels promote platelet adhesion and contribute to early brain injury after subarachnoid hemorrhage.This study was approved by the Biomedical Ethics Committee,Medical College of Xi’an Jiaotong University,China in December 2015.

Elevated levels of interleukin-1β, interleukin-6, tumor necrosis factor-α and vascular endothelial growth factor in patients with knee articular cartilage injury

BACKGROUND Inflammatory cytokines play a vital role in the occurrence of osteoarticular injury and inflammation. Whether inflammation-associated factors interleukin-1β(IL- 1β), IL-6, tumor necrosis factor-α(TNF-α) and vascular endothelial growth factor (VEGF) are involved in the pathogenesis of keen articular cartilage injury remains poorly understood. AIM To measure the levels of inflammatory factors [IL-1β, IL-6, TNF-α and VEGF] in patients with knee articular cartilage injury. METHODS Fifty-five patients with knee articular cartilage injury were selected as patient groups, who were divided into three grades [mild (n = 20), moderate (n = 19) and severe (n = 16)] according to disease severity and X-ray examinations. Meanwhile, 30 healthy individuals who underwent physical examination were selected as the control group. The levels of IL-1β, IL-6, TNF-α and VEGF were measured by ELISA and immunohistochemical staining. RESULTS Compared with the control group, patient groups displayed significantly higher levels of IL-1β, IL-6, TNF-α and VEGF, and the extent of increase was directly proportional to the severity of injury (P < 0.05). In addition, the number of cells with positive staining of IL-1β, IL-6, TNF-α and VEGF in the synovial membrane were significantly increased, along with increased disease severity (P < 0.05). After treatment, the scores of visual analogue scale and the Western Ontario and McMaster University of Orthopaedic Index in patient groups were 2.26 ± 1.13 and 15.56 ± 7.12 points, respectively, which were significantly lower than those before treatment (6.98 ± 1.32 and 49.48 ± 8.96). Correlation analysis suggested that IL-1β and TNF-α were positively correlated with VEGF. CONCLUSION IL-1β, IL-6, TNF-α and VEGF levels are increased in patients with knee articular cartilage injury, and are associated with the disease severity, indicating they might play an important role in the occurrence and development of knee articular cartilage injury. Furthermore, therapeutically targeting them might be a novel approach for the treatment of keen articular cartilage injury.

Ferroptosis inhibition protects vascular endothelial cells and maintains integrity of the blood-spinal cord barrier after spinal cord injury

Maintaining the integrity of the blood-spinal cord barrier is critical for the recove ry of spinal cord injury.Ferro ptosis contributes to the pathogenesis of spinal cord injury.We hypothesized that ferroptosis is involved in disruption of the blood-s pinal cord barrier.In this study,we administe red the ferroptosis inhibitor liproxstatin-1 intraperitoneally after contusive spinal co rd injury in rats.Liproxstatin-1 improved locomotor recovery and somatosensory evoked potential electrophysiological performance after spinal cord inju ry.Liproxstatin-1 maintained blood-spinal cord barrier integrity by upregulation of the expression of tight junction protein.Liproxstatin-1 inhibited ferroptosis of endothelial cell after spinal cord injury,as shown by the immunofluorescence of an endothelial cell marker(rat endothelium cell antigen-1,RECA-1) and fe rroptosis markers Acyl-CoA synthetase long-chain family member 4 and 15-lipoxygenase.Liproxstatin-1reduced brain endothelial cell ferroptosis in vitro by upregulating glutathione peroxidase 4 and downregulating Acyl-CoA synthetase long-chain family member4 and 15-lipoxygenase.Furthermore,inflammatory cell recruitment and astrogliosis were mitigated after liproxstatin-1 treatment.In summary,liproxstatin-1im proved spinal cord injury recovery by inhibiting ferroptosis in endothelial cells and maintaining blood-s pinal co rd barrier integrity.

Sustained delivery of vascular endothelial growth factor mediated by bioactive methacrylic anhydride hydrogel accelerates peripheral nerve regeneration after crush injury

Neurotrophic factors,currently administered orally or by intravenous drip or intramuscular injection,are the main method for the treatment of peripheral nerve crush injury.However,the low effective drug concentration arriving at the injury site results in unsatisfactory outcomes.Therefore,there is an urgent need for a treatment method that can increase the effective drug concentration in the injured area.In this study,we first fabricated a gelatin modified by methacrylic anhydride hydrogel and loaded it with vascular endothelial growth factor that allowed the controlled release of the neurotrophic factor.This modified gelatin exhibited good physical and chemical properties,biocompatibility and supported the adhesion and proliferation of RSC96 cells and human umbilical vein endothelial cells.When injected into the epineurium of crushed nerves,the composite hydrogel in the rat sciatic nerve crush injury model promoted nerve regeneration,functional recovery and vascularization.The results showed that the modified gelatin gave sustained delivery of vascular endothelial growth factors and accelerated the repair of crushed peripheral nerves.

Effects of bone marrow-derived mesenchymal stemcells engraftment on vascular endothelial cell growthfactor in lung tissue and plasma at early stage of smoke inhalation injury

BACKGROUND： This study was undertaken to determine the effect of mesenchymal stem cells （MSCs） engraftment on vascular endothelial cell growth factor （VEGF） in lung tissue, plasma and extravascular lung water at early stage of smoke inhalation injury.METHODS： A rabbit smoke inhalation injury model was established using a home-made smoke inhalation injury generator, and rabbits were divided into two groups randomly： a control group （S group, n=32） and a MSCs treatment group （M group, n=32）. 10 ml PBS was injected via the ear marginal vein immediately at injury into the S group. Third generation MSCs with a concentration of 1×107/10 ml PBS were injected via the ear marginal vein immediately at injury into the M group. VEGF in peripheral blood and lung tissue were measured at 0 （baseline）, 2, 4 and 6 hours after injection respectively and analyzed. The right lungs of rabbits were taken to measure lung water mass fraction.RESULTS： In the lung tissue, VEGF decreased gradually in the S group （P〈0.05） and signi？ cantly decreased in the M group （P〈0.05）, but it increased more signi？ cantly than the values at the corresponding time points （P〈0.05）. In peripheral blood, VEGF increased gradually in the S group （P〈0.05） and markedly increased in the M group （P〈0.05）, but it decreased more signi？ cantly than the values at corresponding time points （P〈0.05）.CONCLUSION： MSCs engraftment to smoke inhalation injury could increase VEGF in lung tissue, decrease VEGF in plasma and reduce extravascular lung water, indicating its protective effect on smoke inhalation injury.

Pretreatment with Dingnaofang reduces vascular endothelial cell apoptosis induced by cerebral ischemia/perfusion injury

BACKGROUND： Vascular endothelial cell apoptosis participates in cerebral ischemia/reperfusion injury, and the method of Qi-supplementation and blood-activation has remarkable neuroprotective effects against cerebral ischemia/reperfusion injury. OBJECTIVE： To explore the molecular mechanism that Dingnaofang （Chinese herbs for supplementing Qi and activating blood circulation） inhibits vascular endothelial cell apoptosis induced by cerebral ischemia/reperfusion injury. DESIGN, TIME AND SETFING： A randomized controlled animal experiment was performed at the Department of Central Laboratory, Third Xiangya Hospital, Central South University, China, between October 2007 and December 2008. MATERIALS： Dingnaofang consisted of Huangqi （Milkvetch Root; Radix Astragah）, Chuanxiong （Szechwan Lovage Rhizome; Rhizoma Chuanxiong）, Yinxingye （ginkgo leaf; Fofium Ginkgo）, Dilong （earthworm; Pheretima）, Danggui （Chinese Angelica; Radix Angelicae Sinensis）, Tianqi （Radix Notoginseng）, and Gancao （Radix Glycyrrhizae; Radix Glycytthizae）, with a proportion of 5：2：2： 1： 1： 1： 1. METHODS： A total of 130 Sprague Dawley rats were randomly divided into sham-surgery （n = 10）, cerebral ischemia/reperfusion （n = 40）, cerebral ischemia pretreatment （n = 40） and Dingnaofang pretreatment groups （n = 40）. Middle cerebral artery occlusion was used to induce cerebral ischemic injury. The bilateral common carotid artery in the cerebral ischemia pretreatment group was blocked for 10 minutes on days 7, 3 and 1 prior to ischemia/reperfusion injury, while rats in Dingnaofang pretreatment group were intragastrically administrated with 4 g Dingnaofang 1 week prior to cerebral ischemia once per day, for 7 successive days. MAIN OUTCOME MEASURES： Apoptosis ratios in vascular endothelial cells were measured using Hoechst 33258 staining and flow cytometry; apoptosis was detected by monitoring DNA gradient bands and the activation of caspase-3, 8, 9 and Bid using Western blot. RESULTS： Following cerebral ischemiaJreperfusion injury, the number of apoptotic vascular endothelial cells in the middle cerebral artery significantly increased （P 〈 0.01）; however, cerebral ischemia pretreatment and Dingnaofang pretreatment groups significantly reduced apoptosis induced by cerebral ischemia/reperfusion injury （P 〈 0.01）. In particular, DNA gradient bands were not observed following Dingnaofang pretreatment. At 24 hours after cerebral ischemia/reperfusion injury, cleaved fragments of caspase-3, 8 and 9 were detected at 11 kD （P 11）, 20 kD （P 20） and 10 kD （P 10）, respectively, following Western blot. Bid was also cleaved into its truncated form （tBid; 15 kD）. Gray scale analysis indicated that P 11, P 20, P 10 and tBid band values in the Dingnaofang pretreatment group were significantly less than in the cerebral ischemia/reperfusion and cerebral ischemia pretreatment groups （P 〈 0.01 or P 〈 0.05）. CONCLUSION： Dingnaofang inhibits vascular endothelial cell apoptosis induced by cerebral ischemia/reperfusion injury via inhibition of apoptotic signal transduction pathways.

Update in combined musculoskeletal and vascular injuries of the extremities

Combined musculoskeletal and vascular injuries of the extremities are conditions in which a multidisciplinary approach is a sine qua non to ensure life initially and limb viability secondarily.Vascular injuries as part of musculoskeletal trauma are usually the result of the release of a high energy load in the wound site so that the prognosis is determined by the degree of soft-tissue damage,duration of limb ischemia,patient’s medical status and presence of associated injuries.The management of these injuries is challenging and requires a specific algorithm of action,because they are usually characterized by increased morbidity,amputation rate,infection,neurological and functional deficits,and they could be life threatening.Although vascular injuries are rare and occur either isolated or in the context of major combined musculoskeletal trauma,the high index of suspicion,imaging control,and timely referral of the patient to organized trauma centers ensure the best functional outcome of the extremity in such challenging cases.Even after a successful initial treatment of a combined trauma pattern,long-term follow-up is crucial to prevent and detect early possible complications.The purpose of this manuscript is to provide an update on diagnosis and treatment of combined musculoskeletal and vascular injuries of the extremities,from an orthopedic point of view.

Neuron-specific enolase expression in a rat model of radiation-induced brain injury following vascular endothelial growth factor-modified neural stem cell transplantation

BACKGROUND： Previous studies have shown that transplantation of vascular endothelial growth factor （VEGF）-modified neural stem cells （NSC） provides better outcomes, compared with neural stem cells, in the treatment of brain damage. OBJECTIVE： To compare the effects of VEGF-modified NSC transplantation and NSC transplantation on radiation-induced brain injury, and to determine neuron-specific enolase （NSE） expression in the brain. DESIGN, TIME, AND SETTING： The randomized, controlled study was performed at the Linbaixin Experimental Center, Second Affiliated Hospital, Sun Yat-sen University, China from November 2007 to October 2008. MATERIALS： VEGF-modified C17.2 NSCs were supplied by Harvard Medical School, USA. Streptavidin-biotin-peroxidase-complex kit （Boster, China） and 5, 6-carboxyfluorescein diacetate succinimidyl ester （Fluka, USA） were used in this study. METHODS： A total of 84 Sprague Dawley rats were randomly assigned to a blank control group （n = 20）, model group （n = 20）, NSC group （n = 20）, and a VEGF-modified NSC group （n = 24）. Rat models of radiation-induced brain injury were established in the model, NSC, and VEGF-modified NSC groups. At 1 week following model induction, 10 pL （5 ×10^4 cells/μL） VEGF-modified NSCs or NSCs were respectively infused into the striatum and cerebral cortex of rats from the VEGF-modified NSC and NSC groups. A total of 10μL saline was injected into rats from the blank control and model groups. MAIN OUTCOME MEASURES： NSE expression in the brain was detected by immunohistochemistry following VEGF-modified NSC transplantation. RESULTS： NSE expression was significantly decreased in the brains of radiation-induced brain injury rats （P 〈 0.05）. The number of NSE-positive neurons significantly increased in the NSC and VEGF-modified NSC groups, compared with the model group （P 〈 0.05）. NSE expression significantly increased in the VEGF-modified NSC group, compared with the NSC group, at 6 weeks following transplantation （P 〈 0.05）. CONCLUSION： VEGF-modified NSC transplantation increased NSE expression in rats with radiation-induced brain injury, and the outcomes were superior to NSC transplantation.

Vascular injury during laparoscopic cholecystectomy:An oftenoverlooked complication

Laparoscopic cholecystectomy is one of the most frequently performed procedures in gastrointestinal surgery worldwide.Bleeding complications due to vascular injuries represent an important cause of morbidity and mortality,especially when facing major bleeding during laparoscopy,where bleeding control can be technically challenging in inexperienced hands.Interestingly,the reported incidence rate of conversion to open surgery due to vascular lesions is approximately 0%-1.9%,with a mortality rate of approximately 0.02%.The primary aim of this article was to perform an up-to-date overview regarding the incidence and surgical management of vascular injuries during laparoscopic cholecystectomy according to the available scientific evidence.

Downregulation of miR-491-5p promotes neovascularization after traumatic brain injury

Micro RNA-491-5 p(miR-491-5 p) plays an important role in regulating cell proliferation and migration;however,the effect of miR-491-5 p on neovascularization after traumatic brain injury remains poorly understood.In this study,a controlled cortical injury model in C57 BL/6 mice and an oxygen-glucose deprivation model in microvascular endothelial cells derived from mouse brain were established to simulate traumatic brain injury in vivo and in vitro,respectively.In the in vivo model,quantitative real-time-polymerase chain reaction results showed that the expression of miR-491-5 p increased or decreased following the intracerebroventricular injection of an miR-491-5 p agomir or antagomir,respectively,and the expression of miR-491-5 p decreased slightly after traumatic brain injury.To detect the neuroprotective effects of miR-491-p,neurological severity scores,Morris water maze test,laser speckle techniques,and immunofluorescence staining were assessed,and the results revealed that miR-491-5 p downregulation alleviated neurological dysfunction,promoted the recovery of regional cerebral blood flow,increased the number of lectin-stained microvessels,and increased the survival of neurons after traumatic brain injury.During the in vitro experiments,the potential mechanism of miR-491-5 p on neovascularization was explored through quantitative real-time-polymerase chain reaction,which showed that miR-491-5 p expression increased or decreased in brain microvascular endothelial cells after transfection with an miR-491-5 p mimic or inhibitor,respectively.Dual-luciferase reporter and western blot assays verified that metallothionein-2 was a target gene for miR-491-5 p.Cell counting kit 8(CCK-8) assay,flow cytometry,and 2′,7′-dichlorofluorescein diacetate(DCFH-DA) assay results confirmed that the downregulation of miR-491-5 p increased brain microvascular endothelial cell viability,reduced cell apoptosis,and alleviated oxidative stress under oxygen-glucose deprivation conditions.Cell scratch assay,Transwell assay,tube formation assay,and western blot assay results demonstrated that miR-491-5 p downregulation promoted the migration,proliferation,and tube formation of brain microvascular endothelial cells through a metallothionein-2-dependent hypoxia-inducible factor-1α/vascular endothelial growth factor pathway.These findings confirmed that miR-491-5 p downregulation promotes neovascularization,restores cerebral blood flow,and improves the recovery of neurological function after traumatic brain injury.The mechanism may be mediated through a metallothionein-2-dependent hypoxia-inducible factor-1α/vascular endothelial growth factor signaling pathway and the alleviation of oxidative stress.All procedures were approved by Ethics Committee of the First Affiliated Hospital of Chongqing Medical University,China(approval No.2020-304) on June 22,2020.

Agmatine induces gastric protection against ischemic injury by reducing vascular permeability in rats

AIM:To investigate the effect of administration of agmatine(AGM) on gastric protection against ischemia reperfusion(I/R) injury.METHODS:Three groups of rats(6/group);sham,gastric I/R injury,and gastric I/R + AGM(100 mg/kg,i.p.given 15 min prior to gastric ischemia) were recruited.Gastric injury was conducted by ligating celiac artery for 30 min and reperfusion for another 30 min.Gastric tissues were histologically studied and immunostained with angiopoietin 1(Ang-1) and Ang-2.Vascular endothelial growth factor(VEGF) and monocyte chemoattractant protein-1(MCP-1) were measured in gastric tissue homogenate.To assess whether AKt/phosphatidyl inositol-3-kinase(PI3K) mediated the effect of AGM,an additional group was pretreated with Wortmannin(WM)(inhibitor of Akt/PI3K,15 μg/kg,i.p.),prior to ischemic injury and AGM treatment,and examined histologically and immunostained.Another set of experiments was run to study vascular permeability of the stomach using Evan's blue dye.RESULTS:AGM markedly reduced Evan's blue dye extravasation(3.58 ± 0.975 μg/stomach vs 1.175 ± 0.374 μg/stomach,P < 0.05),VEGF(36.87 ± 2.71 pg/100 mg protein vs 48.4 ± 6.53 pg/100 mg protein,P < 0.05) and MCP-1 tissue level(29.5 ± 7 pg/100 mg protein vs 41.17 ± 10.4 pg/100 mg protein,P < 0.01).It preserved gastric histology and reduced congestion.Ang-1 and Ang-2 immunostaining were reduced in stomach sections of AGM-treated animals.The administration of WM abolished the protective effects of AGM and extensive hemorrhage and ulcerations were seen.CONCLUSION:AGM protects the stomach against I/R injury by reducing vascular permeability and inflammation.This protection is possibly mediated by Akt/PI3K.

Vascular endothelial growth factor induced angiogenesis following focal cerebral ischemia/reperfusion injury in rabbits

BACKGROUND： Therapeutic angiogenesis has opened up new pathway for the treatment of ischemic cerebrovascular disease in recent years. The exploration of the effect of vascular endothelial growth factor （VEGF） on inducing angiogenesis following ischemia/reperfusion injury can provide better help for the long-term treatment of cerebrovascular disease in clinic. OBJECTIVE： To observe the effect of VEGF on inducing angiogenesis following focal cerebral ischemia /reperfusion injury in rabbits through the angiogenesis of microvessels reflected by the expression of the factors of vascular pseudohemophilia. DESIGN： A randomized controlled animal tria SETTNG： Department of Medical Imaging, Second Hospital of Hebei Medical University MATERIALS： Sixty-five healthy male New Zealand rabbits of clean degree, weighing （2.6±0.2） kg, aged 4.5-5 months, were used. The polyclonal antibody against vascular pseudohemophilia （Beijing Zhongshan Company）, recombinant VEGF165 （Peprotech Company, USA）, biotinylated second antibody and ABC compound （Wuhan Boster Company） were applied. METHODS： The experiments were carried out in the Laboratory of Neuromolecular Imaging and Neuropathy, Second Hospital of Hebei Medical University from May to August in 2005. （1） The rabbits were randomly divided into three groups： sham-operated group （n=15）, control group （n=25） and VEGF-treated group （n=-25）. In the control group and VEGF-treated group, models were established by middle cerebral artery occlusion （MCAO） induced focal cerebral ischemia/reperfusion. In the VEGF-treated group, VEGF165 （2.5 mg/L） was stereotactically injected into the surrounding regions of the infarcted sites immediately after the 2-hour ischemia/reperfusion; Saline of the same dosage was injected in the control group. But the rabbits in the sham-operated group were only drilled but not administrated. （2） The experimental indexes were observed on the 3^rd 7^th, 14^th, 28^th and 70^th days of the experiment respectively, 3 rabbits in the sham-operated group and 5 in the control group and VEGF-treated group were observed at each time point. The brain tissues in the surrounding regions of the infarcted sites were collected. The positive expressions of the factors of vascular pseudohemophilia in vascular endothelial cells were analyzed with immunohistochemical method. The microvessels in unit statistical field were counted with the imaging analytical software. MAIN OUTCOME MEASURES： The changes of microvascular density in the brain tissue and the positive expressions of the factors of vascular pseudohemophilia in the surrounding regions of the infarcted sites were observed on the 3^rd 7^th, 14^th, 28^th and 70^th days of the experiment. RESULTS： All the 65 New Zealand rabbits were involved in the analysis of results without deletion. Changes of the number of microvessels at different time points in each group： There were no obvious changes at different time points in the sham-operated group. The numbers of microvessels at 7 and 14 days were obviously more in the control group than in the sham-operated group [（6.0±1.1）, （9.0±0.9） microvessels; （3.0±1.1）, （3.0±1.1） microvessels; P〈 0.05-0.01], and those at 3, 7, 14 and 28 days were obviously more in the VEGF-treated group than in the control group [（8.3±2.0）, （13.4±1.4）, （15.5±2.3）, （6.8± 1.0） microvessels; （3.4±0.6）, （6.0±1.1）, （9.0±0.9）, （3.2±0.8） microvessels; P 〈 0.01]. （2） Positive expressions of the factors of vascular pseudohemophilia in the surrounding regions of infarcted sites： There were no obvious changes at different time points in the sham-operated group. In the control group, the changing law of the expressions was the same as that for the number of microvessels that the expression began to mildly increase at 7 days, reached the peak value at 14 days, and began to reduce at 28 days. In the VEGF-treated group, the expression was obviously increased at 3 days, also reached the peak value at 14 days, and reduced to the normal level at 70 days, but the expressions were obviously stronger than those in the control group at the same time points. CONCLUSION： Angiogenesis can be obviously induced in rabbits after the focal cerebral ischemia/reperfusion injury is treated with VEGF for 18 days.

Reperfusion injury components and manifestations determined by cardiovascular MR and MDCT imaging

Advances in magnetic resonance(MR) and computed tomography(CT) imaging have improved visualization of acute and scar infarct.Over the past decade,there have been and continues to be many significant technical advancements in cardiac MR and multi-detector computed tomography(MDCT) technologies.The strength of MR imaging relies on a variety of pulse sequences and the ability to noninvasively provide information on myocardial structure,function and perfusion in a single imaging session.The recent technical developments may also allow CT technologies to rise to the forefront for evaluating clinical ischemic heart disease.Components of reperfusion injury including myocardial edema,hemorrhage,calcium deposition and microvascular obstruction(MO) have been demonstrated using MR and CT technologies.MR imaging can be used serially and noninvasively in assessing acute and chronic consequences of reperfusion injury because there is no radiation exposure or administration of radioactive materials.MDCT is better suited for assessing coronary artery stenosis and as an alternative technique for as-sessing viability in patients where MR imaging is contraindicated.Changes in left ventricular(LV) volumes and function measured on cine MR are directly related to infarct size measured on delayed contrast enhanced images.Recent MR studies found that transmural infarct,MO and peri-infarct zone are excellent predictors of poor post-infarct recovery and mortality.Recent MR studies provided ample evidence that growth factor genes and stem cells delivered locally have beneficial effects on myocardial viability,perfusion and function.The significance of deposited calcium in acute infarct detected on MDCT requires further studies.Cardiac MR and MDCT imaging have the potential for assessing reperfusion injury components and manifestations.

Feasibility study of emergency intervention for vascular injury outside the hospital

Background: Minimally invasive surgery in the field of traumatic vascular injury diagnosis and treatment has achieved good results. This study was designed to determine whether pre-hospital emergency intervention is feasible for vascular injury in a field intervention cabin under the condition of war or a disaster site.Methods: Different types of animal experiments of vascular injury intervention were performed in a field intervention cabin. Treatment capacity was evaluated by data collection, including duration of surgery, clinical evaluation, image clarity, and equipment handling. Environmental adaptability and mobility were evaluated by maneuverability and long-distance mobility.Results: A total of 56 surgeries(7 types) were performed in the field intervention cabin. Digital subtraction angiography(DSA) had good imaging performance. A total of 4800 km of long-distance mobility was performed, and all the equipment operated normally without any equipment failure. We participated in the medical service maneuver twice. The cabin unfolded and worked properly. There was no equipment damage during the medical service maneuver.Conclusion: Use of a field intervention cabin under the conditions of war or disaster is feasible for pre-hospital emergency intervention of vascular injury.

Effects of recombinant adeno-associated viruses expressing human vascular endothelial growth factor 165 on spinal cord injury

Numerous studies have confirmed that vascular endothelial growth factor （VEGF） improves the function of neural cells following spinal cord injury （SCI）. However, some studies have also verified that VEGF cannot significantly induce the increase in vascular density at or surrounding the lesion, and that VEGF therapy exacerbated secondary damage following SCI. Based on the dual effects of VEGF on SCI, we constructed the recombinant adeno-associated viruses （rAAV）-hVEGF165-IRES-human recombinant green fluorescent protein （hrGFP） （AAV-VEGF） and rAAV-IRES-hrGFP （AAV-GFP）. Our results suggested that rAAV expressed hVEGFles, and a low dose of VEGF relieved increased vascular permeability, improved microcirculation in the local spinal cord, lessened spinal cord edema, and decreased neuronal apoptosis. These results verified that the releasing effects of the rAAV virus vector had protective effects on the spinal cord.

Effects of kallikrein gene transfer on penumbral microvascular proliferation and on regional cerebral blood flow following cerebral ischemia/reperfusion injury

BACKGROUND： Recent findings have demonstrated that the kallikrein-kinin system （KKS） participates in the pathological process of cerebral ischemia/reperfusion injury. Kallikrein gene transfer exhibits neural protective effects following cerebral infarction. OBJECTIVE： To observe the effects of kallikrein gene transfer on vascular proliferation in the peripheral infarct focus and on regional cerebral blood flow （rCBF） following cerebral ischemia/reperfusion injury. DESIGN, TIME AND SETTING： The completely randomized, controlled experiment was performed at the Lin Baixin Laboratory Center, the Second Affiliated Hospital of Sun Yat-sun University between September 2007 and April 2008. MATERIALS： pUCI9-HTK plasmid was constructed and maintained in the Laboratory for Neurology, the Second Affiliated Hospital of Sun Yat-sen University, China. Mouse anti-human kallikrein 1 monoclonal antibody was purchased from R＆D Systems, USA. METHODS Ninety healthy, male, Sprague Dawley rats were used. Middle cerebral artery occlusion （MCAO） was established in all rats to induce cerebral ischemia/reperfusion injury. Following MCAO establishment, all rats were randomly divided into three groups （n = 30）： blank control, saline, and pAdCMV-HTK. The saline and pAdCMV-HTK groups were stereotactically micro-injected with 5μL of physiological saline or with pAdCMV-HTK [multiplicity of infection （MOI） = 20], respectively, into the ischemic penumbra. In the blank control group, only sham injection was performed. MAIN OUTCOME MEASURES： At 12, 24, and 72 hours after treatment, cerebral infarction volume was measured by 2, 3, 5-triphenyltetrazolium chloride （TTC） staining. Exogenous HTK expression, as well as regional vascular endothelial growth factor （VEGF） expression, was detected by immunohistochemistry. rCBF was examined by 14C-iodoantipyrine micro tracing. In addition, neurological severity score （NSS） was performed. Higher scores indicated more severe neurological deficits. RESULTS： NSS results demonstrated that compared with the saline and the blank control groups, the pAdCMV-HTK group exhibited lower NSSs 24 hours after pAdCMV-HTK injection （P 〈 0.05）. The NSSs were further decreased after 72 hours （P 〈 0.01）. Cerebral infarction volume at 24 hours, and in particular at 72 hours after treatment, was significantly reduced in the pAdCMV-HTK group compared with the blank control and saline groups （P 〈 0.05）. The rCBF in the area surrounding the infarction lesion was slightly decreased in all groups compared with the contralateral area. At 24 and 72 hours following treatment, the rCBF in the peripheral infarction lesion was significantly elevated in the pAdCMV-HTK group compared with the blank control and saline groups （P 〈 0.05）. Immunohistochemistry results revealed that VEGF-positive cells were primarily found in the cortex and in some white matter surrounding the cerebral infarction lesion. In addition, the expression of VEGF in the pAdCMV-HTK group was significantly higher compared with that in the blank control and saline groups at 12, 24, and 72 hours following treatment （P 〈 0.05）. CONCLUSION： Following cerebral ischemia/reperfusion, kallikrein gene transfer can promote vascular proliferation in the brain tissue surrounding the infarction lesion, improve rCBF, and reduce infarction volume, thereby exhibiting protective effects to attenuate neurological deficits.

Vascular Surgery and the General Surgeon: Review Article

The vascular surgeon is trained in the management of diseases affecting all parts of the vascular system except that of the heart and brain whereas cardiothoracic surgeons manage surgical diseases of the heart and its vessels. Although vascular surgery is previously a field within general surgery, it is now considered a specialty on its own right in many countries such as the UK and the United States. Other countries such as Iraq have a mixed practice in which the cardiac or thoracic surgeon performs vascular surgery. Programs of training in vascular surgery are slightly different depending on the region of the world one is in. In the United States, a 5-year general surgery residency is followed by 2 years training in vascular surgery. In Iraq, the time table allocated for the general surgical trainee in vascular surgery is unfortunately short (1 - 3 months). This period is hardly enough for the candidate to grasp the decision-making and technical skills of vascular surgery. We believe that general surgeons need to have adequate training and expertise in vascular surgery particularly in areas and situations lacking this facility to deal with the life- and/or limb-threatening emergencies. This review article aims to orient the general surgical trainee about the scope of vascular surgery and enable them to correctly diagnose and treat common vascular emergencies such as extremity and abdominal vascular injuries (AVI).