There is a pathological process before the attack of stroke. The current primary and secondary preventions of stroke focus on the cerebral vascular conditions, risk factors, and triggering factors. However, the stroke-prone status followed by the occurrence of stroke has not been paid appropriate attention to, which is named in this article as the process of stroke attack. The biomarkers implying the stroke-prone status would inspire innovative ideas to study the process of stroke attack, and help find the precise prevention through the whole process of stroke.

Objective:To investigate the correlation between asymmetrically prominent cortical veins (APCV) on susceptibility-weighted imaging (SWI) and early neurological deterioration (END) in patients with acute ischemic stroke.Methods:From October 2016 to September 2018, patients with acute ischemic stroke admitted to the Department of Neurology, Donghua Hospital Affiliated to Sun Yat-sen University were enrolled retrospectively. They completed MRI within 3 d of onset. APCV was evaluated using SWI. END was defined as the National Institutes of Health Stroke Scale (NHISS) score at any time point within 7 d after the onset increased by ≥2 or the motor function item score increased by ≥1 from baseline. Multivariate logistic regression analysis was used to determine the independent correlation between APCV and END. Results:A total of 133 patients with acute ischemic stroke were enrolled, including 40 females and 93 males, with a median age of 57.3 years (interquartile range: 47.5-67.5 years). Baseline NIHSS score was 5.9±5.0. Fifty-one (38.3%) patients had APCV, and 38 (28.6%) had END. The proportions of APCV, ipsilateral large vessel stenosis, and patients receiving anticoagulation after admission were significantly different between the END group and the non-END group ( P<0.05). Multivariate logistic regression analysis showed that after adjusting for age and gender, APCV was an independent risk factor for END in patients with acute ischemic stroke (odds ratio 6.907, 95% confidence interval 2.798-17.052; P<0.001). Conclusions:APCV on SWI was an independent risk factor for END in patients with acute ischemic stroke.

Objective To investigate the preventive effect and mechanisms of Naoshuantong capsule in stroke induced by artificial cold wave in hypertensive rats.Methods A total of 130 SD rats were randomly divided into a sham operation group (n =30),a model control group (n =50) and a Naoshuantong treatment group (n=50;intragastric administration of Naoshuantong,0.5 g/kg,2/d for 7 days).Renovascular hypertensive rats model were established by two-kidney,two clip method.At 13th week after operation,rats were exposed to artificial cold wave for 3 days (12 h light of 22 ℃ and 12 h dark of 4 ℃,3 cycles).The brain tissue samples were extracted at the end of the experiment.Differential protein proteomic techniques were used for the identification,functional classification and preliminary analysis of the differentially expressed protein spots,and Western blot was used for the validation of some key proteins.Results There was no occurrence of stroke in the sham operation group,and the incidence of stroke in the model control group (36.00％,18/50) was significantly higher than that in the Naoshuantong treatment group (18.00％,9 / 50;x2 =4.110,P =0.043).With the two-dimensional gel electrophoresis analysis,6 different proteins were identified from 14 protein spots.Among them,the up-regulated superoxide dismutase 2 (SOD2) and the down-regulated B-cell lymphoma 10 (Bcl-10) were found to be at the central location of protein interactions,which has been verified by Western blot.Conclusion Naoshuantong can reduce the occurrence of stroke induced by artificial cold wave in renovascular hypertensive rats.SOD2 up-regulating and Bcl-10 downregulating may be involved in the mechanisms of of Naoshuantong in the prevention of cold wave-induced stroke in hypertensive rats.

The cold wave is one of the common meteorological factors which related to occurrence of disease,and growth of animals and plants.Due to seasonal restrictions and differences of the main indicators of each cold wave,it is difficult to be consistent when studying the relationship between cold wave and disease,cold wave and growth of animals and plants.In order to make the experimental results more objective and credible,it is necessary to simulate a cold spell artificially.The key technique for simulating a cold wave is to control the temperature manually,so that can achieve the standard of cold wave.Nowadays,the equipments for cold wave simulating include "artificial climate chamber" or "climate simulator",which can be used in the study of the relationship between cold wave and disease,cold wave and growth of animals and plants.The intelligent artificial climate chambers can successfully create an experimental environment that similar to the natural cold wave,thus the study of the relationship between temperature and growth or incidence of animals and plants is no longer restricted by seasonal restrictions,and maintains the consistency between different artificial cold waves,which is beneficial for analysis and judgment.However,the intelligent artificial climate chambers still needs to be further improved in terms of expanding space and manual control of air pressure and humidity.

Cold wave will increase the incidence of stroke,especially in individuals with vascular disease such as hypertension.The blood pressure fluctuations induced by cold wave may be the main cause of stroke onset.The main responsible mechanisms for blood pressure changes are related to hormone changes,vasomotor factor disorders,calcium channel changes,hemodynamic changes,etc.All of these,the activation of the renin-angiotensin-aldosterone system plays a leading role.Therefore,actively taking warm measures during cold wave can effectively prevent the occurrence of stroke.

Epidemiological studies and clinical observations have indicated that cold temperature can trigger the occurrence of stroke in individuals at high risk.However,the underlying mechanisms are still unknown.Matrix metalloproteinase-9 (MMP-9) has been found to be associated with the formation,progression and rapture of atherosclerotic plaques and cerebral aneurysms,which is the pathological basis of stroke.Cold temperature activates renin-angiotensin system (RAS) in circulation and tissue.Angiotensin Ⅱ has been implicated in the inducing MMP-9 expression and activation.An increase of MMP-9 may facilitate destabilization and rupture of atherosclerotic plaques or cerebral aneurysms,resulting in the occurrence of stroke.

ObjectiveTo verify the reliability of the mouse model of cerebral cortical microinfarct induced by two-photon microscopy and to explore its pathological changes.MethodsSeventeen male C57BL/6J mice were randomly divided into a microinfarct group (n=11) or a sham operation group (n=6).A thinned cranial window of 3 mm diameter was performed over the cerebral cortex with a high-speed micro-drill until the small blood vessels were clearly observed under a dissecting microscope.Then, a permanent single cortical penetrating arteriole occlusion was induced with a gradually enhanced ultrashort laser irradiation through the thinned cranial window with two-photon microscopy.At 7 days after modeling, the cerebral microinfarct volume was measured with HE staining, and the neuron loss, activation of glial cells and deposition of 3-nitrotyrosine were assessed using immunohistochemistry.ResultsThe target vessels of cerebral cortex in 8 (72.7%) mice were occluded and the microinfarcts formed in the microinfarct group, and the average microinfarct volume was 317.23±20.29 μm3.There were remarkable neuron loss and microglia infiltration in the infarcted core, a large number of reactive astrocytes surrounding the infarcted lesion, and massive deposition of 3-nitrotyrosine in the peri-infarct area.No infarcts were observed in the sham operation group.The deposition of 3-nitrotyrosine in the sham operation group was significantly less than that in the microinfarct group (8.00±1.48 vs.98.38±9.10;t=23.962, P<0.001).Conclusions The mouse model of cerebral cortical microinfarct induced by two-photon microscopy is reliable, and its histopathologic changes are consistent with the pathologic features of cerebral microinfarct.

Epidemiological data,clinical observation and animal experiments have shown that cold wave is closely associated with the onset of stroke.When a population with stroke etiology or risk factors is under pre-stroke state,they will have stroke under the influence of various inducing factors.Cold wave is the external factor that causes the body to enter the pre-stroke state and there are many possible mechanisms.The drug intervention of stroke-prone hypertensive rats at 1 week before the cold wave can reduce the occurrence of stroke during cold wave,suggesting that it is of great significance to conduct preventive intervention to the pre-stroke population before the cold wave coming.