The effects of ischemia-reperfusion injury and hepatic artery ischemia on CD14 expression in canine auto-transplantation livers

Objective： To study the effect of ischemia-reperfusion injury（IRI） and hepatic artery ischemia（HAI） on CD14 expression in canine auto-transplantation livers. Methods：Liver orthotopic auto-transplantation models were applied with 30 healthy male Xi＇ an canines which were randomly divided into a control group, simultaneous reperfusion（SR） group and HAI group, CD14 protein expression, Malonaldehyde （MDA） Contents in hepatic tissues and ALT values in serum were detected, and the pathological changes of hepatic tissues was investigated under the light microscopy. Results：The level of CD14 protein expression in SR and HAI group tended to be time-dependent and both higher than controls with statistical significance（P 〈 0.01）; The peak values of these two groups both occurred at 4 h, but the level in HAI group （11.94 ± 0.43） was evidently higher than that in SR group（3.04 ± 0.34）. MDA contents in liver tissue, ALT values in serum and pathological changes showed the same changing tendency as CD 14 expression. Conclusion：（1） Up-regulation of CD14 expression may be the receptor-mechanism of Kupffer cells（KCs） activation in liver transplantation. （2） HAI can upregulate CD14 expression after portal vein reperfusion, improve the activity of KCs further more, increase OFRs production and cooperate with portal reperfusion, and finally aggravate the grafts injury.

Nonhuman primate models of focal cerebral ischemia

Rodents have been widely used in the production of cerebral ischemia models. However, successful therapies have been proven on experimental rodent stroke model, and they have often failed to be effective when tested clinically. Therefore, nonhuman primates were recommended as the ideal alternatives, owing to their similarities with the human cerebrovascular system, brain metabolism, grey to white matter ratio and even their rich behavioral repertoire. The present review is a thorough summary of ten methods that establish nonhuman primate models of focal cerebral ischemia; electrocoagulation, endothelin-1-induced occlusion, microvascular clip occlusion, autologous blood clot embolization, balloon inflation, microcatheter embolization, coil embolization, surgical suture embolization, suture, and photochemical induction methods. This review addresses the advantages and disadvantages of each method, as well as precautions for each model, compared nonhuman primates with rodents, different species of nonhuman primates and different modeling methods. Finally it discusses various factors that need to be considered when modelling and the method of evaluation after modelling. These are critical for understanding their respective strengths and weaknesses and underlie the selection of the optimum model.

Monitoring cerebral ischemia during carotid endarterectomy and stenting

Current therapy for carotid stenosis mainly includes carotid endarterectomy and endovascular stenting,which may incur procedure-related cerebral ischemia.Several methods have been employed for monitoring cerebral ischemia during surgery,such as awake neurocognitive assessment,electroencephalography,evoked potentials,transcranial Doppler,carotid stump pressure,and near infrared spectroscopy.However,there is no consensus on the gold standard or the method that is superior to others at present.Keeping patient awake for real time neurocognitive assessment is effective and essential;however,not every surgeon adopts it.In patients under general anesthesia,cerebral ischemia monitoring has to rely on non-awake technologies.The advantageous and disadvantageous properties of each monitoring method are reviewed.

Expression of insulin-like growth factor-1 mRNA and protein level of corpora striata in ischemic side at the early stage of middle cerebral artery ischemia/reperfusion in rhesus monkeys

BACKGROUND： Insulin-like growth factor-I（IGF-1）, as one of the important members of growth factor family, participants in the regulation of many physiological functions and behaviors, having very strong neuroprotective effect. However, the expression of IGF-1 following cerebral ischemia/reperfusion is still disputed. OBJECTIVE： To observe the expression of IGF-1 and protein of corpora striata in ischemic side at the early stage of middle cerebral artery ischemia/reperfusion in rhesus monkey. DESIGN ： A completely randomized grouping design, controlled animal experiment SETTING ： Institute of Cerebrovascular Disease, Affiliated Hospital of Medical College of Qingdao University MATERIALS： ① Totally 17 rhesus monkeys , of either gender, aged 4 to 5 years, were enrolled . Seven rhesus monkeys observed with gene chip were randomly divided into 2 groups： sham operation group （n=3） and ischemia/reperfusion group 〈n=4〉. Ten rhesus monkeys observed with in situ hybridization and immunohistochemistry method were randomly divided into 2 groups： sham operation group 〈n=3 〉and ischemia/reperfusion group （n=7）. Rhesus monkeys observed under microscope were divided into 2 groups： sham operation group （n=6） and ischamia/reperfusion group （n=-11）.②Materials used in the experiment： cresyl violet （Sigma Company, America）; immunohistochemical reagent kit （ Huamei Bio-engineering Company）; In situ hybridization reagent kit （Boshide Bio-engineering Co.Ltd, Wuhan）; 12 800 dots chip （Boxing Company, Shanghai）. METHODS ： This experiment was carried out at the Institute of Cerebrovascular Disease, Affiliated Hospital of Medical College of Qingdao University from January 2001 to December 2003.① The onset area of middle cerebral artery was blocked for 2 hours, middle cerebral artery ischemia/reperfusion models were created.② After ischemia/reperfusion for 24 hours, cerebral tissue sections of rhesus monkeys were prepared and stained with cresyl violet. Image analysis was performed with 5001W image analysis software. Morphological change of corpora striata of operative side was observed in the rhesus monkeys between two groups. Total RNA was extracted from cerebral tissue. ③ Detection of gene chip： Cy3-duTP and Cy5-duTP were used to respectively perform reverse transcription labeling. The sample was reversely transcribed into cDNA, then hybridized with cDNA of cerebral tissue. Genes with the separate absolute value of cy3 and cy5〉800, cY3/cy5 〉 2（high expression） or 〈 0.5 （low expression） were found out. Those were genes with differential expression. ④ The expressions of IGF-1 mRNA and protein level of corpora striata in ischemic side of rhe- sus monkeys were detected between sham operation group and ischemia/reperfusion group at 9 and 24 hours after ischemia/reperfusion with in situ hybridization method and immunohistochemical method. Brown granules were IGF-1 protein positive cells. ⑤ Analysis of variance was used in the difference comparison of measurement data among groups. MAIN OUTCOME MEASURES ： ① Change of morphological structure of corpora striata at ischemic side in rhesus monkeys. ② Change of cerebral gene expression profiles at ischemia/reperfusion in rhesus monkeys between two groups.③ Expression of IGF-1 mRNA and protein level of corpora striata at ischemia/reperfu- sion in rhesus monkeys between two groups. RESULTS ： ① Pathological change ： Obvious pathological change of cerebral infarction appeared in the ischemia and reperfusion group, while there was no such pathological change in the sham operation group.② Change of gene expression profile ： There were 4480 genes with difference expression in the ischemia/reperfusion group and sham-operation group, in which, 260 genes had high expression and their absolute value was over 800, and 63 genes had low expression, cy3/cy5 of IGF-1 was 0.379, being relative low ex- pression. ③ IGF-1 mRNA and protein positive cell counts in corpora striata at cerebral ischemic side[IGF-1 mRNA： 〈9.72±1.18）,（9.11 ±0.76）,（14.77±0.60） counts/field：lGF-1 protein： （15.11 ±1.83）,（15.39±0.78）, （34.62±0.97）counts/field, P 〈 0.05-0.01]. CONCLUSION： IGF-1 mRNA and protein are lowly expressed in middle cerebral artery of rhesus monkeys at ischemia/reperfusion.

A Clinical Study on the Effect of Yinxing Damo (银杏达莫) Combined with Betahistine Hydrochloride Injection on Vertebral Basilar Artery Ischemic Vertigo

To evaluate the therapeutic efficacy of Yinxing Damo （银杏达莫, YXDM） combined with Betahistine Hydrochloride Injection （BHI） on vertebra basilar artery ischemic vertigo （VBIV）. Methods： Ninety patients with VBIV were randomly divided into two groups; 45 patients （the treated group） were treated with YXDM and BHI intravenous dripping, once a day for 14 days. Another 45 patients （control group） were treated with Xueshuantong （血栓通） and BHI intravenous dripping, once daily for 14 days. The clinical syndromes and the index of the transcranial Doppler （TCD） and hemorheology were observed. Results： The total effective rate was 100% in the treated group, which was better than that in the control group 90.5%, （P〈0. 05）. The indexes of TCD and hemorheology in the treated group were obviously improved after treatment, （P〈0.01）. Conclusion： YXDM combined with BHT injection had better effect in treating patients with VBIV is an ideal drug for VBIV.

Aquaporin-4 gene silencing protects injured neurons after early cerebral infarction

Aquaporin-4 regulates water molecule channels and is important in tissue regulation and water transportation in the brain. Upregulation of aquaporin-4 expression is closely related to cellular edema after early cerebral infarction. Cellular edema and aquaporin-4 expression can be determined by measuring cerebral infarct area and apparent diffusion coefficient using diffusion-weighted imaging（DWI）. We examined the effects of silencing aquaporin-4 on cerebral infarction. Rat models of cerebral infarction were established by occlusion of the right middle cerebral artery and si RNA-aquaporin-4 was immediately injected via the right basal ganglia. In control animals, the area of high signal intensity and relative apparent diffusion coefficient value on T2-weighted imaging（T2WI） and DWI gradually increased within 0.5–6 hours after cerebral infarction. After aquaporin-4 gene silencing, the area of high signal intensity on T2 WI and DWI reduced, relative apparent diffusion coefficient value was increased, and cellular edema was obviously alleviated. At 6 hours after cerebral infarction, the apparent diffusion coefficient value was similar between treatment and model groups, but angioedema was still obvious in the treatment group. These results indicate that aquaporin-4 gene silencing can effectively relieve cellular edema after early cerebral infarction; and when conducted accurately and on time, the diffusion coefficient value and the area of high signal intensity on T2 WI and DWI can reflect therapeutic effects of aquaporin-4 gene silencing on cellular edema.

Experimental study on inhibitory effect of bridgy duct of hepatic artery on apoptosis of liver and bile duct cells

Objective： To investigate whether the method of bridgy duct established between the recipient＇s spleen artery and the donor＇s gastroduodenal artery could inhibit the apoptosis of liver and bile duct cells caused by hepatic artery ischemia. Methods： Twenty-four mongrel dogs from Xi＇an area were used to establish simplified models of dog orthotopic liver transplantation and divided into three groups randomly： HAI group （hepatic artery ischemia group）,BBB group（bypassing the blood by a bridgy duct） and control group. After cold perfusion, The samples were collected from liver and bile duct in each group at different time and fixed in glutaraldehyde and 4% polyformaldehyde respectively. At last, the apoptosis of liver and bile duct cells were observed and the apoptotic indexes were calculated. Results： Two hours after cold perfusion, apoptotic phenomenon was common in HAI group, rare in BBB group, while no apoptotic phenomenon was observed in control group. TUNEL staining showed that there was no significant difference in apoptotic index among the three groups immediately after cold perfusion. However, with time going, the apoptotic cells were increased in three groups, and the difference in apoptotic index was significant among three groups （P 〈 0.01 ）. Conclusions： Bridgy duct of hepatic artery can inhibit the apoptosis of liver and bile duct cells caused by HAI significantly.

Sudden Sensorineural Hearing Loss after Pituitary Adenoma Resection-A Case Series with Literature Review

Objective Complications after transsphenoidal surgery for pituitary adenoma have been well documented in the literatures,but the occurrence of delved sudden sensorineural hearing loss(SNHL)after pituitary adenoma resection is extremely rare.In this study three cases who developed sudden SNHL 3 to 7 days after pituitary adenoma surgery without experiencing cerebrospinal fluid leak or meningitis were presented,and the possible causes of SNHL were discussed.Methods Three cases with sudden hearing loss after transsphenoidal surgery for pituitary adenoma were reviewed.The past medical history,onset of sudden hearing loss,accompanying symptoms such as headache,tinnitus,dizziness and aural fullness,and the post-operative MRI images,therapy and hearing results were reported.Results Three cases developed profound sudden SNHL on the 3rd to 7th post-operative day,all accompanied by prior headache,tinnitus and dizziness.One patient developed episodic vertigo,ear fullness accompanying with fluctuating hearing loss in the first post-operative month.Two patients had past medical history of arteriosclerosis and coronary heart disease or cerebral infarction.Two of three demonstrated obstructive hydrocephalus on MRI on the first post-operative day.Under treatment with prednisone orally,dexamethasone intratympanic mjection,neurotrophic and vasodilatation drugs for 3 to 8 months,hearing of all three improved partially.Obstructive hydrocephalus and ischemia might be responsible for the hearing loss.Conclusion Post-operative obstructive hydrocephalus and ischemia of labyrinthine arteries might lead to the delayed SNHL after transsphenoidal surgery for pituitary adenoma.

Evaluation of murine models of permanent focal cerebral ischemia

Background To date murine models of permanent focal cerebral ischemia have not been well characterized. The purposes of this paper were to compare three different permanent middle cerebral artery occlusion (MCAo) models with or without cra niectomy, and to identify an ideal mouse model of permanent focal cerebral ischemia. Methods Experiments were performed on 45 healthy adult male Kunming mice, weighing 28 to 42 g. The animals were randomly assigned to three groups (n=15 in every group) based on surgical procedure: MCAo via the external carotid artery (ECA), MCAo via the common carotid artery (CCA), and direct ligation of the middle cerebral artery (MCA). Each day post-ischemia, the animals were scored using an eight-grade n eurological function scale, and mortality was also recorded. Seven days post-ischemia, the brains were removed for lesion size determination using triphenyltetrazoli um chloride staining. Correlation analysis of lesion volume and neurological score was carried out. Results Mortality in the group receiving direct MCA ligation was lowest among the three groups, and there was a significant difference between the direct MCA ligation group and the two intraluminal occlusion groups (P<0.05). In all groups, neurological scores gradually increased with prolongation of ischemic duration, peaking after two days, then gradually decreasing. In the direct MCA ligation group, however, neurological scores were relatively stable. There was a significant correlation between infarct volume and neurological score 7 days after MCAo in every group (all r>0.7, P<0.05), suggesting good reproducibility of lesion volume in the three groups, but the infarct volume was more constant in the direct MCA ligation group. Conclusion The direct ligation model of MCAo provides an optimal means of studying permanent focal cerebral ischemia, and is preferable to the models using intraluminal sutures.