0.05). On day 4, GI, SBI and OS were lower than those on day 1 (P0.05). On day 8, the parameters were lower than those on day 4(P0.05). Conclusion: 1 g/L cetylpyridinium chloride is effective in the treatment of simple gingivitis.

Objective:To summarize the clinical manifestation and imaging of superficial siderosis of the central nervous system and explore the potential etiology.Methods:The clinical and imaging data of 7 patients diagnosed as superficial siderosis of the central nervous system in Peking Union Medical College Hospital from May 2013 to November 2019 were retrospectively reviewed. The etiology and follow-up prognosis through phone call were analyzed.Results:There were 7 patients included (3 male and 4 female) with an average age of 53 years (41-58 years). The cardinal manifestations were sensorineural deafness (all 7 cases), cerebellar ataxia (all 7 cases) and pyramidal signs (all 7 cases). Dizziness (6 cases), bladder disturbance (5 cases), headache (3 cases), double vision (2 cases) and congnitive impairment (1 case) could also happen. Magnetic resonance imaging showed symmetrical well-defined curvilinear homogeneous low signal on T 2 or blood-sensitive sequences (T 2* gradient echo or susceptibility-weighted imaging) over the superficial surface of cerebellar, brain stem, and spinal cord or cranio-cervical junction. All the 7 patients showed cerebellar atrophy especially the upper vermis. The potential causes included trauma history in 3 cases, intraspinal fluid-filled collection which indicated dural defect or duropathologies in 3 cases, intraspinal mass in 1 case and vertebral and disc degeneration in all 7 patients. The 5 patients who successsfully got follow-up showed exacerbation of variable degree. Conclusions:Classical superficial siderosis of the central nervous system is a rare disease with cardinal manifestation of progressive ataxia, sensorineural deafness and pyramidal signs. T 2WI of magnetic resonance imaging showing low signal over the superficial surface of cerebellar, brain stem, and spinal cord could indicate the diagnosis, and blood-sensitive sequences such as T 2* gradient echo or susceptibility-weighted imaging were more sensitive. Duropathologies or dural defect may be the most probable causes of the disease and should be examined and treated carefully.

Objective: To investigate the refractive status of children and adolescents aged 4-18 years in Chengdu, and to analyze the epidemiological characteristics of refractive parameters. Methods: A cross sectional survey was conducted among 82 024 children and adolescents aged 4-18 years in Gaoxin District of Chengdu from August to September 2021. The prevalence of screening myopia, low vision rate, high myopia rate, refractive status and axial development were analyzed. Results: The prevalence of screening myopia in students aged 4-18 years was 40.42%(33 158/82 024). Low myopia was 24.51%(20 108/82 024), moderate myopia was 13.05%(10 703/82 024) and high myopia was 2.86%(2 347/82 024). The prevalence of screening myopia was 1.81% (233/12 848) in kindergarten, 34.44%(17 095/49 644) in primary school, 79.73%(9 738/12 214) in junior high school and 83.25% (6 092/7 318) in senior high school. The rate of visual impairment increased by year from the age of 4, and the rate of myopia increased most rapidly from 6 to 15 years old, the prevalenct of high myopia was compared between adjacent age groups: there were statistical differences between 9-15 years old were more likely to be nearsighted than boys( P <0.035 7). Significant differences in screening myopia between 5- and 7-17 year old groups,and in boys and girls.The median total diopter was 0.40 D at the age of 4 and developed to -2.90 D at the age of 18 . The diopter of girls aged 8-15 years was higher than that of boys, and there was statistical significance( Z=-2.53, -4.09, -5.67, -8.64, -5.56, -4.97, -2.52, -2.14, P <0.05). The axial length gradually increased with age, with the mean value of (22.31±0.59) mm at 4 years old and (24.91±1.00) mm at 18 years old. The mean corneal curvature did not change with age (43.19±1.47)D. Conclusion 6-15 years old is a especially critical period for myopia development. More efforts need to be taken to decrease the prevalence of myopia before 6 years old. Prevention of the development of high myopia should start before the age of 10. The prevalence of myopia in girls is higher than that in boys, more prevention and control of myopia should focus on girls.

Objective:To elucidate the clinical and genetic characteristics of PLA2G6-related parkinsonism. Methods:The clinical, imaging and genetic data of 6 patients with PLA2G6-related parkinsonism admitted to Peking Union Medical College Hospital from January 2015 to December 2022 were retrospectively collected and analyzed. The prognosis was followed up through phone call. Results:There were 3 male and 3 female patients, and the age of disease onset was (24.3±5.4) years. Phenotypically, 5 of them had dystonia-parkinsonism (DP) with obvious atrophy of cerebellum and 1 presented as early-onset Parkinson′s disease (EOPD) with no brain structural abnormality. Only 1 patient presented with abnormal brain iron deposition. All of the patients were partially responsive to levodopa. Three cases underwent levodopa challenge test with the objective levodopa responsiveness varied from 10.3% and 10.6% in 2 DP patients, to 77.0% in 1 EOPD patient. Levodopa-induced dyskinesias were present in 4 of them, and all appeared within the first year since the initiation of dopaminergic treatment. Two patients underwent bilateral deep brain stimulation (DBS) of subthalamic nucleus and globus pallidus internus respectively, albeit revealed poor outcome. Genetically, 8 PLA2G6 variants were identified. Two of them were found to be novel (c.1973A>G and exon2 heterozygous deletion), and the most frequent variant was the c.991G>T mutation which was detected in 4 patients. Conclusions:The phenotype of PLA2G6-related parkinsonism is complex. Cerebellar atrophy is a frequent magnetic resonance imaging feature. Levodopa responsiveness tends to depend on the clinical phenotype, and EOPD is better than DP. DBS might not be promising in DP patients with obvious cerebral atrophy. The c.991G>T mutation is the most frequent mutation, suggesting a common founder effect.

Early screening based on computed tomography (CT) pulmonary nodule detection is an important means to reduce lung cancer mortality, and in recent years three dimensional convolutional neural network (3D CNN) has achieved success and continuous development in the field of lung nodule detection. We proposed a pulmonary nodule detection algorithm by using 3D CNN based on a multi-scale attention mechanism. Aiming at the characteristics of different sizes and shapes of lung nodules, we designed a multi-scale feature extraction module to extract the corresponding features of different scales. Through the attention module, the correlation information between the features was mined from both spatial and channel perspectives to strengthen the features. The extracted features entered into a pyramid-similar fusion mechanism, so that the features would contain both deep semantic information and shallow location information, which is more conducive to target positioning and bounding box regression. On representative LUNA16 datasets, compared with other advanced methods, this method significantly improved the detection sensitivity, which can provide theoretical reference for clinical medicine.
Algorithms ; Humans ; Lung Neoplasms/diagnostic imaging* ; Neural Networks, Computer ; Radiographic Image Interpretation, Computer-Assisted/methods* ; Tomography, X-Ray Computed/methods*