Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 expression in early focal cerebral infarction following urokinase thrombolysis in rats

Activity of matrix metalloproteinase-9 increases following cerebral ischemia/reperfusion,and is associated with cerebral microvascular permeability,blood-brain barrier destruction,inflammatory cell infiltration and brain edema.Matrix metalloproteinase-9 also likely participates in thrombolysis.A rat model of middle cerebral artery infarction was established by injecting autologous blood clots into the internal carotid artery.At 3 hours following model induction,urokinase was injected into the caudal vein.Decreased neurological severity score,reduced infarct volume,and increased expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 were observed in the cerebral cortex 24 hours after urokinase thrombolysis.These results suggest that urokinase can suppress damage in the acute-early stage of cerebral infarction.

Numerical Simulation of the Impact of Urban Non-uniformity on Precipitation

To evaluate the influence of urban non-uniformity on precipitation, the area of a city was divided into three categories(commercial, high-density residential, and low-density residential) according to the building density data from Landsat satellites. Numerical simulations of three corresponding scenarios(urban non-uniformity, urban uniformity, and non-urban) were performed in Nanjing using the WRF model. The results demonstrate that the existence of the city results in more precipitation, and that urban heterogeneity enhances this phenomenon. For the urban non-uniformity, uniformity, and non-urban experiments, the mean cumulative summer precipitation was 423.09 mm, 407.40 mm, and 389.67 mm, respectively. Urban non-uniformity has a significant effect on the amount of heavy rainfall in summer. The cumulative precipitation from heavy rain in the summer for the three numerical experiments was 278.2 mm, 250.6 mm, and 236.5 mm, respectively. In the nonuniformity experiments, the amount of precipitation between 1500 and 2200(LST) increased significantly. Furthermore, the adoption of urban non-uniformity into the WRF model could improve the numerical simulation of summer rain and its daily variation.

Plasma fibrinogen beta-148C/T gene polymorphism in cerebral infarction patients

BACKGROUND: Plasma fibrinogen (Fg) β-148C/T gene polymorphism is a risk factor for ischemic angiopathy. OBJECTIVE: To explore the frequency distribution of Fg β-148C/T gene polymorphism and its relationship with plasma Fg levels in patients with cerebral infarction. DESIGN, TIME AND SETTING: Case control experiment of gene polymorphism was performed at the Central Laboratory of Qingdao University Medical College from January 2003 to June 2004. PARTICIPANTS: A total of 88 patients with cerebral infarction were recruited from the Affiliated Hospital of Qingdao University Medical College, including 52 males and 36 females, averaging (61 ± 14) years of age. In addition, 80 healthy cases served as the control group, comprising 48 males and 32 females, with an average age of (58 ± 12) years. METHODS: Blood DNA was extracted, and electrophoresis results were observed using an ultraviolet single photon image system. The frequency distribution of Fg β-148C/T was analyzed by polymerase chain reaction-restriction fragment length polymorphism method. Plasma Fg levels were measured by cerebral infarction time. MAIN OUTCOME MEASURES: Plasma Fg β-148C/T gene polymorphism and plasma Fg levels in patients with cerebral infarction. RESULTS: The frequency of the T allele, and plasma Fg levels in CC, CT, and CC+CT genotype subgroup, were significantly greater in the cerebral infraction group, compared with the control group (P < 0.05). However, there was no significant difference between the TT genotype subgroup and the control group (P > 0.05). The plasma Fg levels in the CT, TT, and CT+TT genotype groups were significantly greater than the CC genotype group (P < 0.05). However, in the control group, plasma Fg levels in the TT genotype subgroup were significantly greater than the remaining genotype subgroups (P < 0.05). CONCLUSION: Plasma Fg β-148C/T gene polymorphism is an important hereditary factor for differences in plasma Fg levels. The T allele plays a crucial role in influencing plasma Fg levels in cerebral infarction. Fg β-148C/T may be a susceptibility factor for cerebral infarction.

Synchronization clusters located on epileptic onset zones in neocortical epilepsy

Background Brain function is thought to rely on complex interactions of dynamic neural systems,which depend on the integrity of structural and functional networks.Focal epilepsy is considered to result from excessive focal synchronization in the network.Synchronization analysis of multichannel electrocorticography(ECoG)contributes to the understanding of and orientation of epilepsy.The aim of this study was to explore the synchronization in multichannel ECoG recordings from patients with neocortical epilepsy and characterize neural activity inside and outside the onset zone.Methods Four patients with neocortical epilepsy,who became seizure-free for more than 1 year after surgery guided by ECoG monitoring,were included in this study.ECoG data recorded during pre-surgical evaluation were analyzed.Synchronizations in phase and amplitude of different frequency bands between ECoG channels was analyzed using MATLAB.We generated 100 surrogate data from the original ECoG data using Amplitude Adjusted Fourier Transform to calculate the enhanced synchronization.The relationship between synchronization characteristics and seizure onset zone was analyzed.Results We found synchronization clusters in the 14–30 Hz and 30–80 Hz bands around the onset areas during both interictal and the beginning of ictal periods in all four patients.Conclusions The enhanced-synchronization clusters play a central role in epilepsy,and may activate the onset areas and contribute to the spreading of epileptiform activity.