ABSTRACT
Objective:To evaluate the effect of long-term intake of ω-3 polyunsaturated fatty acids (ω-3 PUFAs) on the activation of hippocampal microglia in a mouse model of postoperative cognitive dysfunction (POCD).Methods:Ninety-six clean-grade healthy male C57BL/6 mice, aged 8 weeks, weighing 18-24 g, were stratified according to body weight and divided into 4 groups ( n=24 each) by a random number table method: control diet group (group C), ω-3 PUFAs group (group ω), control diet plus POCD group (group C+ P) and ω-3 PUFAs plus POCD group (group ω+ P). Mice were fed a special ω-3 PUFAs diet (DHA 0.14 g/100 g, EPA 0.03 g/100 g) for 12 weeks in group ω and group ω+ P, while mice were fed with a control diet for 12 weeks in group C and group C+ P.Tibial fracture procedures were performed under isoflurane anesthesia to develop the POCD model after 12 weeks of feeding.The fear conditioning test and Y maze test were performed on 1st and 3rd days after developing the model.The mice were sacrificed after behavioral tests, and the hippocampal tissues were removed for determination of the contents of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) (by gas chromatography-mass spectroscopy), density of Iba-1 positive microglia (by immunofluorescence staining), and expression of mature brain-derived neurotrophic factor (mBDNF) and precursor brain-derived neurotrophic factor (pro-BDNF) (by Western blot), and contents of interleukin-1beta (IL-1β) and interleukin-6 (IL-6) (by enzyme-linked immunosorbent assay). Results:Compared with group C, the contents of DHA and EPA were significantly increased, the percentage of freezing time in the contextual test was increased, mBDNF/pro-BDNF ratio was increased ( P<0.05), no significant change was found in the rotation accuracy in Y maze test, density of Iba-1 positive microglia and contents of IL-1β and IL-6 in hippocampus ( P>0.05) in group ω ( P<0.05), and no significant change was found in the contents of DHA and EPA ( P>0.05), the percentage of freezing time in the contextual test and accuracy of rotation in Y maze test were decreased on 1st and 3rd days after operation, the density of Iba-1 positive microglia and contents of IL-1β and IL-6 were increased, and mBDNF/pro-BDNF ratio was decreased in group C+ P ( P<0.05). Compared with group C+ P, the contents of DHA and EPA were significantly increased, the percentage of freezing time in the contextual test and accuracy of rotation in Y maze test were increased on 1st and 3rd days after operation, the density of Iba-1 positive microglia and contents of IL-1β and IL-6 were decreased, and mBDNF/pro-BDNF ratio was increased in group ω+ P ( P<0.05). Conclusions:Long-term intake of ω-3 PUFAs can improve cognitive function in a mouse model of POCD, and the mechanism may be related to inhibition of activation of hippocampal microglia, reduction of inflammatory responses, and thus increasing the mBDNF/Pro-BDNF ratio.
ABSTRACT
Objective:To explore the imaging rate and diagnostic rate of positioning the fetal conus medullaris by three-dimensional ultrasound method to detect atlantoaxial intervertebral space, comparing it with the traditional two-dimensional and three-dimensional ultrasound methods.Methods:Consecutively 318 singleton fetuses received routine ultrasound screening during the second trimester were enrolled from November 2017 to December 2018 in Shenzhen Luohu People′s Hospital and Shenzhen People′s Hospital. These fetuses included 276 normal cases and 42 abnormal cases. The abnormal group contained 11 cases tethered cords fetuses(tethered cords group) and 31 cases non-tethered fetuses(non-tethered group). A new ultrasound method named detecting atlanto-axial intervertebral space with three-dimensional ultrasound and traditional two-dimensional and three-dimensional ultrasound methods were used to acquire and store the images. The positions of the fetal conus medullaris were analyzed blindly and recorded by three experienced physicians using three different methods with off-line software.Results:①The χ 2 test comparing multiple sample rates was used to compare the imaging acquisition success rate of fetal conus medullaris by three ultrasound methods. The test level was adjusted to be α′=0.05/4=0.0125, the results showed that there were no statistically significant differences between the three methods in the normal group (χ 2=7.39, P=0.025) and the abnormal group (χ 2=5.32, P=0.070). ②The χ 2 test comparing multiple sample rates was used to compare the diagnostic accuracy of fetal conus medullaris position in normal group by three methods, it showed there was no significant difference in the correct rate of conus medullaris position in the normal group (χ 2=2.52, P=0.284). ③The χ 2 test comparing multiple sample rates was used to compare the diagnostic accuracy of the fetal conus medullaris in tethered cord group and non-tethered group using 3 methods, the difference was not statistically significant in tethered cord group (χ 2=1.22, P=0.543), while the difference was statistically significant in non-tethered group(χ 2=9.69, P=0.008). Conclusions:The method of detecting atlanto-axial intervertebral space with three-dimensional ultrasound has a high imaging rate and diagnostic accuracy in positioning the fetal conus medullaris. Positioning of fetal conus medullaris by detecting atlanto-axial intervertebral space with three-dimensional ultrasound is better than traditional two-dimensional and three-dimensional ultrasound in the abnormal non-tethered fetuses, which can provide more valuable information for prenatal diagnosis consultation and prenatal and postnatal care.
ABSTRACT
Objective To study the feasibility of visualization of atlanto-axial intervertebral space for the localization of fetal centrums with three-dimensional ultrasound and to explore the relationship of intervertebral space with gestational weeks. Methods A total of 223 cases of normal single pregnancy in the second trimester were enrolled in the study to acquire the 3D volume of fetal spines. The distances between the transverse processes of cervical vertebra were measured in vertical horizontal line.The distance between the first and second cervical vertebra was labeled C1,and then labelled C2,C3,C4,C5 and C6 as follows.Results The successful rate of 3D acquisition of 206 cases was 92.4%.The distance between ICC values of C1 -C6 were 0.985,0.984,0.971,0.956,0.978,0.923,respectively and the consistency data measuring was well.The atlanto-axial intervertebral space was significantly larger than other intervertebral space ( P =0.012) and the mean ratios of C1 to C2 -C6 were 1.41,1.39,1.37,1.40,1.39,respectively, which had no correlation with gestational ages ( P = 0.877,0.915,0.838,0.859,0.908,respectively). Conclusions Visualization of the atlanto-axial intervertebral space with three-dimensional ultrasound is a direct and simple method without any consumption,which can help to quickly locate the axial vertebra and other vertebras and conus medullaris.