Objective To assess the damage of limbic system pathways in relapsing-remitting multiple sclerosis (RRMS) by diffusion tensor imaging (DTI) tractography.Methods DTI tractography was used to acquire fiber numbers,fractional anisotropy (FA),mean diffusivity (MD) of cingulum,fornix,and uncinate fasciculus (UF) in 20 RRMS patients (MS group) and 20 healthy volunteers (control group),and statistical analysis was performed.Results Compared with control group,lower FA value (P＜0.01) and higher MD value (P＜0.05) were found in cingulum,fornix and UF of MS group,and the fiber numbers of fornix decreased in MS group (P＜0.001).There were significant differences between the left and the right UF in fiber numbers and FA value of control group and the fiber numbers of MS group.Negative correlations were found between FA value of cingulum and UF and EDSS scores in MS group (r=-0.572,-0.665,both P＜0.05),and positive correlations were found between MD value and EDSS scores (r=0.627,0.603,both P＜0.05).Conclusion DTI tractography is valuable in assessing MS associated limbic system damage and in monitoring the clinical progression of the disease.

Objective:To explore the method of establishing a modified demyelination and myelination regeneration model induced by dicyclohexanone oxalyl dihydrazone (CPZ) in mice with multiple sclerosis (MS), and to analyze the image markers of demyelination and myelination regeneration in mouse MS model.Methods:After the intragastrically administered with sodium carboxymethyl cellulose (CMCNa) for one week, a total of 30 C57BL/6 male mice were randomly divided into the control group ( n=10), the demyelination group ( n=10), and the remyelination group ( n=10). The mice of the control group were immediately performed MR scanning and pathological specimen obtaining; the mice in the demyelination group were administered with intragastrical CPZ-CMCNa once a day for 6 weeks for inducing demyelination, then received MR scanning and specimen obtaining with the same protocols used in control group; the mice in the remyelination group were administered with intragastrical CPZ-CMCNa once a day for six weeks for demyelination, then CPZ was withdrawn and normal diet was given for another four weeks. Then MR scanning and specimen obtaining were performed with the same protocols used in the other two groups. Regions of interest (ROIs) were set at the rostrum of corpus callosum (rCC), the bilateral normal appearing white matters (NAWM) of the rostrum of corpus callosum, and the bilateral cerebral cortex (Cx). The normalized T 2WI (T 2-normalized), fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) values were compared among the three groups by one-way ANOVA. Results:The demyelination and remyelination mice model of MS were successfully established. The T 2-normalized values of rCC in control group, demyelination group and remyelination group were 0.47±0.03, 0.72±0.04, 0.54±0.04, respectively, with statistically significant difference found ( F=90.511, P<0.05). Post-hoc multiple comparisons showed significant differences among those groups ( P<0.05). There was no significant difference of T 2-normalized value in NAWM and Cx among the three groups ( P>0.05). Moreover, there were significant differences in the FA values (0.36±0.04, 0.29±0.03, and 0.32±0.05), the MD values [(0.572±0.015), (0.598±0.034), and (0.626±0.043)×10 -3 mm 2/s], the AD values [(0.79±0.04), (0.77±0.06), and (0.83±0.04)×10 -3 mm 2/s], and the RD values [(0.46±0.02), (0.51±0.03), and (0.53±0.05)×10 -3 mm 2/s] of rCC of the control group, the demyelination group, and the remyelination group (all P<0.05). Significant difference was found in FA values between the demyelination group and the control group ( P<0.05), and in MD values between the remyelination group and the control group ( P<0.05), as well as in AD values between the remyelination group and the demyelination group ( P<0.05). There were also significant differences in RD values between the remyelination group and the control group, and the demyelination group and the control group (all P<0.05). However, no significant difference was found in all diffusion tensor imaging (DTI) metrics of NAWM and Cx among the three groups (all P>0.05). The LFB-eosin staining showed that the myelin sheath of rCC was lost in the demyelination group, and the rCC was partially regenerated and repaired in the remyelination group. Conclusion:The modified CPZ-CMCNa model can selectively induce demyelination and remyelination of rCC, and the changes of demyelination and remyelination of rCC in the modified CPZ-CMCNa model can be quantitatively detected by T 2WI combined with DTI, which might provide related theoretical basis for the study on dynamic changes of MS lesions.

OBJECTIVETo assess the feasibility and safety of using the modified active fixation pacing leads model to pace the right ventricular outflow tract septum.

METHODSA total of 136 patients undergoing artificial heart pacemaker implantation with active fixation pacing leads were randomized into two groups to receive conventional right ventricular outflow tract pacing (CRVOTP) or modified right ventricular outflow tract pacing (MRVOTP). The electrode lead wire core was modeled in a double-curved three-dimensional shape in CRVOTP group and in a J-shaped bend in MRVOTP group before fixation at the right ventricular outflow tract septum.

RESULTSRight ventricular outflow tract septum pacing was achieved successfully in all the patients. None of patients experienced serious complications. No significant differences were found between the two groups in the number of times of electrode fixation, pacing thresholds, impedance, R wave height or QRS wave width during the operation, but MRVOTP was associated with a reduced time of X -ray exposure and operation (P<0.05) due to the convenience in electrode modeling and in passing the leads through the tricuspid annulus and the direct access to the right ventricular outflow tract septum. Postoperative follow-up of the patients showed no incidence of active fixation pacing lead dislocation and comparable pacing thresholds of the ventricular electrodes, impedance, R wave height and QRS wave width between the two groups.

CONCLUTIONSUsing the modified active fixation pacing leads model to pace the right ventricular outflow tract septum can reduce the time of X -ray exposure and operation with a low probability of lead damage.

Objective To assess the changes of white matter microstructure in neuromyelitis optica spectrum disorders (NMOSD) with DTI based on tract-based spatial statistics (TBSS) method.Methods Conventional MR and DTI were performed in 20 NMOSD patients (NMOSD group) and 20 healthy volunteers (control group).DTI data were analyzed with TBSS procedure,which was a part of FSL software packages,and non-parametric statistical analysis was performed on the whole brain.Correlation between FA value of tracts with significant difference in NMOSD group and expanded disability status scale (EDSS) scores was analyzed.Results TBSS analysis revealed significantly (P＜ 0.05,FWE corrected) extensive decrease of FA value in cerebrum and cerebellum white matter fiber bundles,i.e.corpus callosum,fornix,corticospinal tract,unciform fasciculus,cerebellar peduncles etc.in NMOSD group,and decrease of AD value,increase of RD value in cingulum bundle,corpus callosum and fornix,while MD value only increased in fornix and retrolenticular part of the left internal capsule (P＜0.05,FWE corrected).Negative correlations were found between FA value of left uncinate fasciculus,right external capsule,left inferior cerebellar peduncle,bilateral anterior limb of internal capsule,medial lemniscus and EDSS scores (all P＜0.05).Conclusion Widespread white matter damage is observed in cerebrum and cerebellum in NMOSD patients by using TBSS analysis,which may partly correspond to the disabilities of NMOSD patients.However,the other microstructural changes of white matter tracts may suggest complicated pathological mechanism of NMOSD.

Objective:To review the clinical outcomes following perinatal multidisciplinary diagnosis and treatment of fetal D-transposition of great arteries (D-TGA).Methods:This retrospective analysis involved 37 fetuses (two fetuses were one of the twins) with D-TGA that were diagnosed by prenatal ultrasound at the Women and Children's Hospital, Qingdao University from January 2016 to December 2020. All the subjects received perinatal multidisciplinary diagnosis and treatment, from the Departments of Fetal Medicine, Genetics, Obstetrics, Ultrasonography, Pediatric Cardiology, Neonatology, etc., and the outcomes were described and summarized.Results:The detection rate of D-TGA was 0.059% (37/62 413), among which intact ventricular septum with D-TGA accounted for 56.8% (21/37) and ventricular septal defect with D-TGA for 43.2% (16/37). All the 37 cases were observed with normal nuchal translucency and four of them were at high risk in fetal Down syndrome screening. All the 31 cases who received non-invasive cell-free fetal DNA screening had normal results and two of 26 cases who received amniocentesis for karyotype analysis and chromosome microarray analysis were abnormal. In terms of pregnancy outcome, 19 pregnancies (51.4%) were terminated, of which 10 cases were terminated for medical reasons and others for non-medical reasons, and 18 cases gave birth to alive body (48.6%, 18/37). Postnatal ultrasound re-examination of one neonate revealed D-TGA with ventricular septal defect, patent ductus arteriosus, and bicuspid pulmonary valve malformation and severe hypoxia and acidosis occured. The patient was discharged after withdrawing treatment and was lost to follow-up. The other 17 neonates all underwent successful surgical treatment with a mean age of (10.2±6.0) d and length of hospital stay of (26.3±9.3) d. Postoperative follow-up (3.3±1.2) years showed all with good cardiac function.Conclusion:Perinatal multidisciplinary diagnosis and treatment of D-TGA can improve the success rate of postnatal treatment and prognosis.

Objective To assess the feasibility and safety of using the modified active fixation pacing leads model to pace the right ventricular outflow tract septum. Methods A total of 136 patients undergoing artificial heart pacemaker implantation with active fixation pacing leads were randomized into two groups to receive conventional right ventricular outflow tract pacing (CRVOTP) or modified right ventricular outflow tract pacing (MRVOTP). The electrode lead wire core was modeled in a double-curved three-dimensional shape in CRVOTP group and in a J-shaped bend in MRVOTP group before fixation at the right ventricular outflow tract septum. Results Right ventricular outflow tract septum pacing was achieved successfully in all the patients. None of patients experienced serious complications. No significant differences were found between the two groups in the number of times of electrode fixation, pacing thresholds, impedance, R wave height or QRS wave width during the operation, but MRVOTP was associated with a reduced time of X-ray exposure and operation (P<0.05) due to the convenience in electrode modeling and in passing the leads through the tricuspid annulus and the direct access to the right ventricular outflow tract septum. Postoperative follow-up of the patients showed no incidence of active fixation pacing lead dislocation and comparable pacing thresholds of the ventricular electrodes, impedance, R wave height and QRS wave width between the two groups. Conclusion Using the modified active fixation pacing leads model to pace the right ventricular outflow tract septum can reduce the time of X-ray exposure and operation with a low probability of lead damage.

Objective To assess the feasibility and safety of using the modified active fixation pacing leads model to pace the right ventricular outflow tract septum. Methods A total of 136 patients undergoing artificial heart pacemaker implantation with active fixation pacing leads were randomized into two groups to receive conventional right ventricular outflow tract pacing (CRVOTP) or modified right ventricular outflow tract pacing (MRVOTP). The electrode lead wire core was modeled in a double-curved three-dimensional shape in CRVOTP group and in a J-shaped bend in MRVOTP group before fixation at the right ventricular outflow tract septum. Results Right ventricular outflow tract septum pacing was achieved successfully in all the patients. None of patients experienced serious complications. No significant differences were found between the two groups in the number of times of electrode fixation, pacing thresholds, impedance, R wave height or QRS wave width during the operation, but MRVOTP was associated with a reduced time of X-ray exposure and operation (P<0.05) due to the convenience in electrode modeling and in passing the leads through the tricuspid annulus and the direct access to the right ventricular outflow tract septum. Postoperative follow-up of the patients showed no incidence of active fixation pacing lead dislocation and comparable pacing thresholds of the ventricular electrodes, impedance, R wave height and QRS wave width between the two groups. Conclusion Using the modified active fixation pacing leads model to pace the right ventricular outflow tract septum can reduce the time of X-ray exposure and operation with a low probability of lead damage.

Objective:To analyze the clinical value of serum 2019 novel coronavirus (2019-nCoV) immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies in the diagnosis of COVID-19.Methods:A total of 116 patients diagnosed with NCP in the First Affiliated Hospital of Hunan University of Chinese Medicine and the First Affiliated Hospital of Xiamen University were enrolled from January to February 2020 as the disease group. A total of 134 cases, including 84 non-NCP inpatients and 50 healthy individuals served as the control group. Serum samples from all subjects were collected. A fully-automated chemiluminescence immunoassay analyzer was used to detect the concentration of 2019-nCoV IgM and IgG antibodies in serum. The sensitivity and specificity of the 2019-nCoV IgM and IgG antibody single test and combined detection were compared using the χ 2 test. χ 2 test and Wilcoxon′s rank sum test were used to compare the positive rates and concentrations of IgM and IgG antibodies in NCP patients before and after their 2019-nCoV nucleic acid tests turning negative, respectively. The change trend of 2019-nCoV antibody concentration in the process of NCP patients was analyzed by Wilcoxon′s rank sum test. Results:The sensitivity of 2019-nCoV IgG (90.5%, 105/116) was higher than that of 2019-nCoV IgM (75.9%, 88/116), the difference was statistically significant (χ 2=8.91, P<0.05); The specificity of 2019-nCoV IgG (99.3%,133/134) was higher than that of 2019-nCoV IgM (94.0%, 126/134), the difference was statistically significant (χ 2=5.63, P<0.05). The sensitivity (89.7%,87/97) of 2019-nCoV IgM combined with IgG was higher than that of 2019-nCoV IgM, the difference was statistically significant (χ 2=6.89, P<0.05). The specificity (100%, 125/125) of 2019-nCoV IgM combined with IgG was higher than that of 2019-nCoV IgM, the difference was statistically significant (χ 2=7.70, P<0.05). After 2019-nCoV nucleic acid test converted to negative, the positive rate (9/17) and concentration [13.0 (4.9, 24.7) AU/ml] of serum 2019-nCoV IgM antibody were significantly lower than those when the nucleic acid test was positive, positive rate (15/17) and concentration [29.5 (14.0, 61.3) AU/ml], respectively (χ 2=5.10, Z=-3.195, both P<0.05). In the course of NCP, patients′ serum samples were collected from the first day of diagnosis to every three days, three times in total. The first 2019-nCoV IgM and IgG antibody concentrations [19.4 (12.4, 63.7) AU/ml, 105.8 (74.8, 126.1) AU/ml, respectively] were significantly higher than the second concentrations [15.8 (7.1, 40.3)AU/ml, 80.5 (66.7, 105.9) AU/ml], Z were-2.897,-3.179, both P<0.05. Conclusions:2019-nCoV IgG antibody has a good application value in the diagnosis of NCP. The concentration of 2019-nCoV IgM antibody has a certain correlation with the detection of 2019-nCoV nucleic acid. The combination of 2019-nCoV IgM and IgG antibodies with 2019-nCoV nucleic acid test may be the best laboratory index for the diagnosis of NCP at present.

Objective:To explore the motion and influencing factors of implanted gold markers in guiding liver stereotactic body radiation therapy (SBRT) using abdominal compression.Methods:Twenty patients with oligometastatic colorectal cancer or primary hepatocellular carcinoma from January 2016 to December 2019 were included. All patients were treated with SBRT under abdominal compression, with 1-3 gold markers were implanted within 2 cm from the lesion before positioning. Four-dimensional computed tomography (4DCT) scan was used for treatment planning. The respiratory cycle was divided into 0-90% respiratory phase images based on the respiratory signal, which were reconstructed by the system (Pinnacle 3 version 9.1; Philips Medical System, Madison, WI, USA), and cone beam CT validation images before radiation exposure were obtained. The liver volume was divided into 3 parts: within 2 cm from the main hepatic portal vein, 2-5 cm from the main hepatic portal vein, and>5 cm from the main hepatic portal vein. The motion of different tumor locations was evaluated. Results:The average intrafractional motion amplitude was (2.63±2.81) mm in the cranial-caudal (CC) direction, (1.35±1.23) mm in the anterior-posterior (AP) direction, and (0.76±0.88) mm in the left-right (LR) direction, respectively. The average interfractional motion amplitude was (3.45±3.06) mm, (2.64±2.60) mm, and (2.23±2.07) mm, respectively. Both the intra-or inter-fractional motion amplitudes in the CC direction were the highest, followed by those in the AP and LR direction (all P<0.001). The motion varied at different tumor locations. The longer distance from the main hepatic portal vein, the larger the intrafractional motion (all P<0.05). To cover the 95% population-based confidence interval, the internal target volume (ITV) was suggested to include the expansion of 3.9 mm, 5.2 mm and 7.9 mm in the LR, AP and CC direction. The expansion of 4.3 mm, 4.4 mm and 6.1 mm was delivered within 2 cm from the main hepatic portal vein, and 3.5 mm, 7.3 mm and 9.7 mm>5 cm from the main hepatic portal vein, respectively. The expansion varied significantly depending on the tumor location, whereas the motion in the CC direction was the largest regardless of the tumor location. The longer distance of the tumor from the main portal vein, the larger expansion in the CC direction. The expansion of tumor > 5 cm from the main portal vein in the AP direction was larger than that of inner parts. Conclusion:Liver tumors at different locations require individual external expansion of ITV.

Objective:To compare the outcomes of watch&wait (W&W) strategy in patients with locally advanced rectal cancer who achieved complete clinical response (cCR) after neoadjuvant therapy, with those who obtained pathological complete response (pCR) after total mesorectal excision (TME).Methods:This is a retrospective cohort analysis study. Patients histologically proven with locally advanced rectal adenocarcinoma (stage Ⅱ-Ⅲ) who had received neoadjuvant chemotherapy were eligible between January 2014 and December 2019. In whom we included patients who had cCR offered management with W&W strategy after completing neoadjuvant therapy and follow-up ≥1 year (W&W group), and patients who did not have cCR but pCR after TME (pCR group). The primary endpoints were 3-year and 5-year overall survival (OS), colostomy-free survival (CFS), disease-free survival (DFS), non-local regrowth disease-free survival (NR-DFS), and organ preservation rate. Kaplan-Meier analysis was used for survival analysis and log-rank test was performed. For comparative analysis, we also derived one-to-one paired cohorts of W&W versus pCR using propensity-score matching (PSM).Results:A total of 118 patients were enrolled, 49 of whom had cCR and managed by W&W, 69 had pCR, with a median follow-up period of 49.5 months (12.1-79.9 months). No difference was observed in the 3-year OS (97.1% vs. 96.7%) and 5-year OS (93.8% vs. 90.9%, P=0.696) between the W&W and pCR groups. Patients managed by W&W had significantly better 3-year and 5-year CFS (89.1% vs. 43.5%, P<0.001), better 3-year DFS (83.6% vs. 97.0%) and 5-year DFS (83.6% vs. 91.2%, P=0.047) compared with those achieving pCR. The 3-year NR-DFS (95.9% vs. 97.0%) and 5-year NR-DFS (92.8% vs. 97.0%, P=0.407) did not significantly differ between the W&W and pCR groups. Local regeneration occurred in six cases, and 87.7% of patients had successful rectum preservation in the W&W group. In the PSM analysis (34 patients in each group), absolutely better CFS (90.1% vs. 26.5%, P<0.001) was noted in the W&W group. A median interval of 17.5 weeks was observed for achieving cCR, while only 23.9% of patients achieved cCR within 5 to 12 weeks from radiation completion. Patients with short-course sequential chemoradiotherapy achieved cCR significantly later when compared with those with long-course concurrent chemoradiotherapy (19.0 vs. 9.8 weeks, P<0.001). Conclusions:The oncological outcomes of W&W strategy in patients with locally advanced rectal cancer are safe and effective, significantly improving the quality of life. Longer interval for cCR evaluation may improve rectal organ preservation rate.