BACKGROUND:The recovery of function after spinal cord injury depends on the functional remodeling of the motor cortex.However,the anatomical evidence underlying the functional remodeling of the motor cortex is still illusive.Analyzing the anatomical changes in the motor cortex after spinal cord injury can provide new ideas and research directions for regulating functional recovery and rehabilitation after spinal cord injury. OBJECTIVE:To analyze the neural circuit structural basis of functional remodeling of the primary motor cortex after spinal cord injury. METHODS:C57BL/6J mice were randomly divided into a sham operation group and a spinal cord injury group.The adeno-associated virus vectors expressing the fusion protein of Cre recombinase were injected into C4 of mice of both groups.The adeno-associated virus vectors with Cre recombinase-inducible expression of avian sarcoma/leukosis envelope glycoprotein receptor TVA and rabies glycoprotein were injected into the primary motor cortex.Fourteen days later,a C6 dorsal hemisection mice model was established in the spinal cord injury group.The pseudotyped rabies virus was injected into the primary motor cortex of mice of both groups.After 7 days,brain samples were collected and frozen sections were made.The distribution of input neurons innervating corticospinal motor neurons in the brain was observed and analyzed quantitatively. RESULTS AND CONCLUSION:Fluorescence microscopy observation and quantitative analysis found that input neurons innervating corticospinal motor neurons of the primary motor cortex in mice of both groups were distributed in the cerebral cortex,thalamus and midbrain.Among them,in the sham operation group,the number of input neurons in the mouse cerebral cortex accounted for(84.0±3.6)%of total brain input neurons;that in the thalamus accounted for(10.6±2.3)%,and that in the midbrain accounted for(0.7±0.4)%.Direct synaptic input neurons in the spinal cord injury group accounted for(81.7±1.0)%,(13.1±0.5)%,and(1.6±0.8)%in the cerebral cortex,thalamus and midbrain,respectively.The proportion and number of primary motor cortex input neurons in the three regions of the spinal cord injury group did not differ significantly from that of the sham operation group.After spinal cord injury,the number of input neurons innervating corticospinal pyramidal motor neurons in various brain regions did not change significantly,suggesting that functional remodeling of the motor cortex after spinal cord injury may not only depend on changes in synaptic input related to injured corticospinal motor neurons,but also on transcriptional regulation changes within the injured neurons themselves.

Objective:To learn about the iodine nutrition level of school-age children aged 8 - 10 in Shaanxi Province.Methods:From 2017 to 2020, in counties (cities, districts) under the jurisdiction of Shaanxi Province, one township (street) was selected from five directions: East, West, South, North and Middle, one primary school was selected from each township (street), and 42 non-boarding school-age children aged 8 - 10 (age balanced, half male and half female) were selected from each primary school. Random urine samples of children were collected once, and urinary iodine was detected by arsenic-cerium catalytic spectrophotometry.Results:A total of 91 766 children's urine samples were tested from 2017 to 2020, and the median urinary iodine was 221.7 μg/L. Urinary iodine < 100 μg/L accounted for 10.4% (9 554/91 766), 100 - < 200 μg/L accounted for 32.3% (29 602/91 766), 200 - < 300 μg/L accounted for 30.6% (28 065/91 766), and ≥300 μg/L accounted for 26.7% (24 545/91 766). The median of children's urinary iodine in each year was 228.5, 218.0, 211.7, and 230.1 μg/L, respectively, the difference between years was statistically significant ( H = 278.66, P < 0.001). Conclusion:From 2017 to 2020, the iodine nutrition of school-age children aged 8 - 10 in Shaanxi Province is generally in an ultra-suitable state.

Objective:To master the iodine nutrition status of children and pregnant women after adjustment of salt iodization content in Shaanxi Province, and provide scientific basis for preventing and treating iodine deficiency disorders.Methods:In 2018, 107 counties (cities, districts) in Shaanxi Province were divided into three districts in Guanzhong, northern Shaanxi and southern Shaanxi for studying iodine nutrition based on terrain distribution. Among them, each monitoring county (city, district) was further divided into 5 sampling areas according to east, west, south, north, and middle locations. One township (street) was selected in each location, and forty-two 8 - 10 years old non-boarding children (age and sex balanced) and 21 pregnant women were selected in each township (street), edible salt samples and random urine samples were collected for salt iodine, urinary iodine testing, and goiter of children was examined.Results:A total of 34 264 edible salt samples from 8 - 10 years old children and pregnant women were collected, the median salt iodine was 23.80 mg/kg, and the qualified iodized salt consumption rate was 96.98% (33 229/34 264). The median salt iodine and the qualified iodized salt consumption rate were statistically significantly different among the three regions in Guanzhong, northern Shaanxi, and southern Shaanxi ( H = 26.471, χ 2 = 32.371, P < 0.05). A total of 22 895 urine samples were collected from children, with a median urinary iodine of 218.00 μg/L, which was at an ultra-suitable level of iodine nutrition; and 11 369 urine samples from pregnant women were collected, with a median urinary iodine of 181.03 μg/L, which was at an appropriate level of iodine nutrition. The median urinary iodine of pregnant women in Guanzhong, northern Shaanxi, and southern Shaanxi was 186.39, 177.52, and 176.00 μg/L, respectively. A total of 22 895 children aged 8 to 10 years old were examined, the goiter rate was 1.35% (309/22 895), and there was no significant difference between different regions (χ 2 = 3.395, P > 0.05). Conclusions:Shaanxi Province has reached the standard for elimination of persistent iodine deficiency, children's iodine nutrition is at a ultra-suitable level, and pregnant women is at an appropriate level.

Objective:This study aims to provide scientific evidence for prevention and treatment of iodine deficiency disorders through monitoring the iodine nutrition status of children and pregnant women in Shaanxi Province.Methods:Totally 110 counties (cities, districts) in Shaanxi Province in 2019 were surveyed. Each of the counties (cities, districts) was further divided into five sampled regions along five different geographic directions: east, west, south, north and middle. From each region, one town was selected and then one primary school was selected from each town. Finally, there were a total of 42 non-boarding students aged 8 - 10 years old (age and gender balanced) selected from each school, who would be tested household salt iodine's level and urinary iodine's level. Also, we did the same test for 21 pregnant women who were selected from each town randomly. Additionally, we examined the children's thyroid by B-scan ultrasonograph in 39 counties (cities, districts).Results:A total of 23 101 salt and urine samples were collected from children aged 8 - 10 years old, the average of salt iodine content of the children' family was (24.07 ± 3.71) mg/kg; the consumption rate of qualified iodized salt was 97.55% (22 536/23 101); the median urinary iodine was 211.68 μg/L; and the thyroid goiter rate (TGR) was 1.50% (123/8 191). A total of 11 555 salt and urine samples from pregnant women were collected, the salt iodine content was (24.05 ± 3.66) mg/kg; and the consumption rate of qualified iodized salt was 97.57% (11 274/11 555); the median urinary iodine was 182.74 μg/L.Conclusions:In 2019, the iodine nutrition of children in Shaanxi Province is in the super appropriate level, and the iodine nutrition of pregnant women is appropriate. The iodine content of edible salt can be adjusted. It is suggested that pregnant women should be supplied special iodized salt.

Objective To evaluate the urinary iodine detection ability of Iodine Deficiency Disorder Laboratory in Shaanxi Province,and to test the quality of laboratory construction.Methods In Shaanxi Province,ten city-level and 107 county-level urinary iodine labs of Center for Disease Control and Prevention or Institute for Endemic Disease Prevention and Control were selected in 2018,and two urinary iodine quality-control samples were measured by As3+-Ce4+ catalytic spectrophotometry.The results of urinary iodine quality control were evaluated through standard Z score generated from all the participatory labs.Results All 117 labs had feedback their testing results.There was one lab with an inter-laboratory |Z| score≥3,and 3 labs with inter-laboratory |Z| score≥3,and the qualified rate was 96.58％ (113/117).In 107 county-level urinary iodine labs,there was one lab with an interlaboratory | Z| score ≥ 3,and 3 labs with inter-laboratory | Z[score ≥ 3,and the qualified rate was 96.26％ (103/107).Conclusions The construction of urinary iodine lab has achieved great results in Shaanxi Province,the testing ability of iodine determination laboratory is maintained at a high level,which has laid a solid foundation for prevention and treatment of iodine deficiency disorders in Shaanxi Province.

Objective To compare selenium content in hair samples of people in Kaschin-Beck disease (KBD) areas and control areas in Shaanxi Province two years after stopping the selenium salt prevention,and to provide a scientific basis for development of targeted prevention measures and for decision-making.Methods In July 2014,the four KBD counties of Yongshou,Yuyang,Linyou and Nanzheng were selected as survey counties,meanwhile,four non KBD counties of Wugong,Mizhi,Qishan and Chenggu were selected as rural control groups and Lianhu District in Xi'an City was selected as a urban settlement control county.Four villages (communities) were selected as monitoring sites according to four directions as east,west,south and north in each county.In each monitoring site,hair samples of 8 children aged 7-12 years old (gender balanced) and 8 adults over the age of 16 (gender balanced) were selected to determine hair selenium.Samples were prepared by wet digestion method,the content of selenium was determined by 2,3-diaminonaphthalene fluorescence method.Results A total of 576 hair samples were collected.The average hair selenium in each monitoring site was more than 0.20 mg/kg.Hair selenium was compared in KBD areas,rural non KBD areas,and urban non KBD areas,the differences were not statistically significant [(0.35 ± 0.18),(0.41 ± 0.28),(0.46 ± 0.19) mg/kg,F =1.544,P ＞ 0.05].In KBD areas and non KBD areas,there were 45 and 45 people with selenium content ＜ 0.20 mg/kg,accounting for 17.58％ and 14.06％;47 and 25 people with selenium content 0.20-＜ 0.25 mg/kg,accounting for 18.36％ and 7.81％;113 and 159 people with 0.25-＜ 0.50 mg/kg,accounting for 44.14％ and 49.69％;51 and 91 people with ≥0.50 mg/kg,accounting for 19.92％ and 28.44％.Hair selenium content of children aged 7-12 and adults was compared in KBD areas,rural non KBD areas,and urban non KBD areas [children:(0.43 ± 0.35),(0.38 ± 0.19),(0.50 ± 0.16) mg/kg;adults:(0.32 ± 0.17),(0.38 ± 0.19),(0.42 ± 0.21) mg/kg],the differences were not statistically significant (F =2.131,1.789,P ＞ 0.05).Hair selenium content was compared in different gender in KBD areas,rural non KBD areas,and urban non KBD areas [male:(0.35 ± 0.18),(0.44 ± 0.33),(0.52 ± 0.15) mg/kg;female:(0.35 ± 0.19),(0.38 ± 0.22),(0.41 ± 0.21) mg/kg],the differences were not statistically significant (F=1.598,1.790,P ＞ 0.05).Conclusion Two years after stopping the selenium salt prevention in Shaanxi Province,the selenium of population in Kashin-Beck disease areas in Shaanxi Province exceeds the human health threshold (0.20 mg/kg),and most people are in the medium or high levels of selenium,and are close to the levels of selenium in non-endemic areas.

Objective To investigate health-related quality of life (HRQOL) and influencing factors in adult patients with Kashin-Beck disease (KBD) in Shaanxi Province for improving health-related quality of life of KBD patients.Methods By the two-stage cluster random sampling method,data of 901 cases of KBD patients with the disease severity of grade 1 and higher were collected from higher KBD incidence areas of Baoji,Xianyang and Tongchuan in Shaanxi Province in February 2016.The Chinese version of SF-36 (including 8 dimensions:physical functioning,role-physical,bodily pain,general health,vitality,social functioning,role-emotional,mental health) was used to measure the HRQOL.Multiple linear regression was used to analyze the influencing factors of HRQOL.Results In 901 cases of KBD patients,male accounted for 55.49％ (500/901),female accounted for 44.51 (401/901).The median age of patients was 58 (22-83) years old.According to the severity of disease criteria,patients with grade Ⅰ were 37.18％ (335/901),patients with grade Ⅱ were 53.50％ (482/901) and patients with grade Ⅲ] were 9.32％ (84/901).The scores of each dimension of SF-36 scale in patients of male patients had higher scores in GH and MH than women [GH:35 (25,50) vs 30 (20,45),MH:56 (48,72) vs 56 (44,68),.9 ＜ 0.05].There were significant differences in PF,RP,BP,GH,VT and SF scores among different age groups (P ＜ 0.05).Similarly,there were significant differences in PF,RP,GH,VT,SF,RE and MH scores among patients with different educational levels (P ＜ 0.05).Married group was only higher in the PF and SF scores than other marital status groups [PF:55 (40,75) vs 50 (35,65),SF:62 (50,75) vs 50 (38,75),P ＜ 0.05].As expected,there were significant differences in the scores of PF,BP,GH and SF between the severity of diseases.There were also significant differences in the scores of PF,BP,GH,VT,SF and MH in KBD patients from different regions (P ＜ 0.05).According to multiple linear regression analysis results,male was the conservation factor of GH and MH scores compared with female;age was a risk factor for PF,RP,BP,GH,VT and SF scores;compared with the illiterate,primary school education was a protective factor for PF and RE scores,junior high school and above were PF,RP,VT,SF,RE and MH scores protective factors;compared with degree Ⅰ KBD,degree Ⅱ and degree Ⅲ were risk factors for PF,BP,GH and SF scores;compared with Baoji area,Xianyang area was a protective factor of SF score,however,Tongchuan area was a protective factor for PF,GH,VT,SF and MH scores.Conclusions KBD has severely damaged the HRQOL of patients.Priority should be given to age,educational attainment and severity of the disease for developing measures to improve KBD patients' HRQOL in different regions.

Objective To investigate the level of perceived social support and its influencing factors in Kashin-Beck disease (KBD) patients in Shaanxi Province,and to provide a theoretical basis for improving the service to KBD patients.Methods By the two-stage cluster random sampling method,KBD patients with the severity of disease of grade Ⅰ and above were investigated in Baoji,Xianyang and Tongchuan areas in Shaanxi Province,which were higher incidence areas of KBD.The Chinese version of perceived social support scale (PSSS) was used to measure family support,friend support,and other supportive comprehension social support levels by household survey method,the total score of PSSS is low support state from 12 to 36,intermediate support state from 37 to 60,and high support state from 61 to 84,and the effects of gender,age,education level,marital status,occupation,disease severity and region on the level of perceived social support were analyzed.Results In 901 cases of KBD patients,males accounted for 55.49％ (500/901),females accounted for 44.51％ (401/901).The median age of patients was 58 years old.According to the severity of KBD criteria,grade Ⅰ patients were 37.18％ (335/901),grade Ⅱ patients were 53.50％ (482/901) and grade Ⅲ patients were 9.32％ (84/901).The median (quartile) PSSS score was 62 (54,70),the low support status accounted for 8.55％ (77/901),the intermediate support status accounted for 36.96％ (333/901),and the high support status was 54.50％ (491/901).Age was a risk factor for friend support,other support dimensions and total score;compared with illiteracy,primary school education was the protective factor of total score,and junior high school and above education was the protective factor of family support dimension and total score.Compared with Baoji area,Xianyang area and Tongchuan area were the protective factors of family support dimension,other support dimension,and total score.In addition,Xianyang area was also a protective factor of friend support dimension.Conclusion The level of perceived social support of KBD patients in Shaanxi is generally above moderate.Age,education,and regional factors are main factors affecting perceived social support.

Objective To understand selenium content in hair samples of children in Kashin-Beck diseased and non-disease areas in Shaanxi Province,and to provide decision-making basis for prevention and treatment of Kashin-Beck disease.Methods In July 2016,two history serious diseased areas Linyou County and Yongshou County were selected as monitoring counties in Shaanxi Province;Fengxiang County and Liquan County were selected as non-disease monitoring counties.According to stratified random sampling,in the 7-12 year old resident children at each monitoring county,5 males and 5 females were taken from each age group,and their hair samples were collected.Samples were digested by wet digestion method,the contents of selenium were determined by 2,3-diaminonaphthalene fluorescence method.Judging criteria:selenium content ＜ 0.20 mg/kg was a selenium deficiency,0.20-＜ 0.25 mg/kg was a selenium edge deficiency,0.25-＜ 0.50 mg/kg was a selenium nutrient medium level,≥0.50 mg/kg is a selenium nutrient high level.Results A total of 240 hair samples were collected,120 cases in the diseased and non-diseased areas,respectively.The selenium contents of children in the diseased and non-disease areas was (0.28 ± 0.13),(0.33 ± 0.13) mg/kg,and the means were between 0.25-＜ 0.50 mg/kg.There was no significant difference in the selenium content in the children between diseased and non-disease areas (t =2.753,P ＞ 0.05).In diseased and non-disease areas,there were 36 and 20 children with selenium content ＜ 0.20 mg/kg,accounting for 30.00％ and 16.67％;15 and 11 children with selenium content 0.20-＜ 0.25 mg/kg,accounting for 12.50％o and 9.17％;61 and 75 children with selenium content 0.25-＜ 0.50 mg/kg,accounting for 50.83％ and 62.50％;8 and 14 children with selenium content ≥0.50 mg/kg,accounting for 6.67％ and 11.67％.There were no significant differences in the selenium contents of hair in boys [(0.27 ± 0.13),(0.33 ± 0.12) mg/kg] and girls [(0.30 ± 0.13),(0.33 ± 0.13) mg/kg] between diseased and non-disease areas (t =2.793,1.219,P ＞ 0.05).Conclusions The selenium contents of children of Kashin-Beck diseased areas in Shaanxi Province are close to the levels of selenium in non-disease areas,and most children are in the medium or high levels of selenium.

Objective To evaluate the detection capability of water iodine of 74 iodine deficiency disorders (IDD) laboratories in Shaanxi Province,and to ensure the determining quality of water iodine in the national survey in 2017.Methods Totally 11 city-level IDD laboratories and 63 county-level IDD laboratories of centers for disease control (CDC) or endemic prevention and control institutions were selected in 2017.The IDD laboratory measured the mass concentration of high,low water iodine quality-control samples.The capabilities of all laboratories tested were evaluated through standard Z score generated from all the participatory laboratories.Results All 74 laboratories had feedback their testing results.Totally 71 laboratories were considered as qualified,and the qualified rate was 95.95％.Three laboratories were considered as unqualified,and the unqualified rate was 4.05％.Conclusions The results of the quality control have showed that the testing ability of all levels of iodine determination laboratories in Shaanxi Province in 2017 is maintained at a high level.Qualified laboratories in quality control could protect the project of drinking water iodine content survey in Shaanxi Province in 2017.