Objective To study the effects from varying stenosis degrees of the mesencephalic aqueduct on intracranial cerebrospinal fluid(CSF)flow field.Methods Based on the clinical magnetic resonance image sequences of a male volunteer,a complete normal CSF circulation model was reconstructed by using semi-automated image segmentation technique.Subsequently,eight ideal models representing different stenosis degrees of the mesencephalic aqueduct were manually created.Computational fluid dynamics(CFD)was then performed to simulate the CSF flow field in the nine models.Results The stenosis degree of the mesencephalic aqueduct was positively correlated with the maximum pressure difference between the aqueduct upstream and downstream and the maximum velocity of CSF within the stenosed aqueduct.In the normal model,the maximum pressure difference was 0.84 Pa and the maximum velocity was 11.4 mm/s.While in the maximum stenosed model,the maximum pressure difference and velocity were 21.36 Pa and 60.3 mm/s,respectively.Compared to the normal model,the maximum pressure difference and velocity were approximately increased by 25 times and 5 times,respectively.Moreover,the maximum pressure difference was inversely proportional to the stenosis area square of the aqueduct,and there was a linear relationship between the pressure difference and the quadratic of the maximun CSF velocity.Conclusions The pressure difference and velocity of the stenosed mesencephalic aqueduct was not apparently increased with mild stenosis with respect to the normal aqueduct,while the great aqueductal stenosis increased the risk of hydrocephalus.This study provides a theoretical framework which contributes to understanding the development of obstructive hydrocephalus and intracranial hypertension.

Objective To study the effects from varying stenosis degrees of the mesencephalic aqueduct on intracranial cerebrospinal fluid(CSF)flow field.Methods Based on the clinical magnetic resonance image sequences of a male volunteer,a complete normal CSF circulation model was reconstructed by using semi-automated image segmentation technique.Subsequently,eight ideal models representing different stenosis degrees of the mesencephalic aqueduct were manually created.Computational fluid dynamics(CFD)was then performed to simulate the CSF flow field in the nine models.Results The stenosis degree of the mesencephalic aqueduct was positively correlated with the maximum pressure difference between the aqueduct upstream and downstream and the maximum velocity of CSF within the stenosed aqueduct.In the normal model,the maximum pressure difference was 0.84 Pa and the maximum velocity was 11.4 mm/s.While in the maximum stenosed model,the maximum pressure difference and velocity were 21.36 Pa and 60.3 mm/s,respectively.Compared to the normal model,the maximum pressure difference and velocity were approximately increased by 25 times and 5 times,respectively.Moreover,the maximum pressure difference was inversely proportional to the stenosis area square of the aqueduct,and there was a linear relationship between the pressure difference and the quadratic of the maximun CSF velocity.Conclusions The pressure difference and velocity of the stenosed mesencephalic aqueduct was not apparently increased with mild stenosis with respect to the normal aqueduct,while the great aqueductal stenosis increased the risk of hydrocephalus.This study provides a theoretical framework which contributes to understanding the development of obstructive hydrocephalus and intracranial hypertension.

Objective To evaluate the association between LDL-C and ischemic stroke in patients with nonvalvular atrial fibrillation (AF).Method A total of 2 470 patients with nonvalvular AF were included in the present study.The clinical data and laboratory examination results of the patients in the hospital were collected.The subjects were either divided into the ischemic stroke history (n =560),and non-ischemic stroke history groups (n =1 910),or divided into the low-middle risk (n =566) and high risk groups (n =1 904) based on CHA2 DS2-VASc score.Results There were significant differences in the proportion of Han,the ratio of gender,age,hemoglobin,hematocrit,ALT,serum uric acid,HDL-C and LDL-C between the patients with ischemic stroke history and without (all P ＜ 0.05).Similarly,there were significant differences in the proportion of Han,the ratio of gender,age,white blood cell count,hemoglobin,hematocrit,platelet count,ALT,albumin,TG and LDL-C between subjects in the low-middle risk group and those in the high risk group (all P ＜ 0.05).A logistical regression analysis showed that LDL-C was an independent risk factor for both the ischemic stroke history (OR 2.089,95％ CI 1.860-2.347,P ＜0.05),and future ischemic stroke risk (OR 1.270,95％ CI 1.079-1.494,P ＜ 0.05) in patients with nonvalvular AF.Conclusion LDL-C is associated with ischemic stroke in patients with nonvalvular AF,and it is also an independent risk factor for future ischemic stroke in these patients.

OBJECTIVETo assess the association of VKORC1 gene -1639G/A polymorphism with atrial fibrillation (AF) in ethnic Uygurs and Hans from Xinjiang.

METHODSThe above polymorphism was detected among 100 Uygur and 102 Han AF patients and 103 Uygur and 111 Han subjects that have no AF with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTSA statistically significant difference was detected between the patient and control groups of Uygur origin in terms of genotypic and allelic frequencies (P<0.05). Logistic regression analysis also indicated the -1639G/A polymorphism as an independent risk factor for AF in Uygur population (OR=2.085, 95% CI: 1.067-4.072, P=0.031). No similar statistical difference was found between the patient and control groups of Han origin (P>0.05).

CONCLUSIONThe -1639G/A polymorphism of VKORC1 gene is associated with AF in the Uygur population but not in Hans.

Adult ; Aged ; Asian Continental Ancestry Group ; ethnology ; genetics ; Atrial Fibrillation ; ethnology ; genetics ; Base Sequence ; China ; ethnology ; Female ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Polymorphism, Single Nucleotide ; Vitamin K Epoxide Reductases ; genetics