BACKGROUND: The normal clinical index and the standard error of ultrasonic bone density in the population of normalchildren aged 6-12 years have not yet been established. OBJECTIVE: To investigate the status of ultrasonic bone density in the population of normal children aged 6 to 12 years old in Shenzhen City and establish a normal reference index of ultrasonic bone density of this population. DESIGN: Cross-sectional survey. SETTING: Ultrasound Department of People's Hospital in Longgang District of Shenzhen City. PARTICIPANTS: The volunteers for ultrasonic bone density detection were chosen froma kindergarten, an elementary school and a middle school between March 2002 and April2003. Excluded were those who had bone fracture and received medication of hormone and other drugs within 6months that affected bone metabolism, and menstrual history. Altogether we chose 697 normal children, 367 boys and 330 girls whose age ranged from 6 to 12 years old. METHODS: SAHARA ultrasonic bone density apparatus (the US) was used, and corrected according to the standard body model after the operation began.The error of precision was below 1％ and the error of accuracy was 3％. Bone density of the left heel of the children was detected and body mass (kg) and height (cm) were also measured using the same height and weight scale. MAIN OUTCOME MEASURES: The correlation between bone densityof the heel and sex, age and body mass in the population of normal children aged 6 to 12 years. RESULTS: The normal reference values of bone density in the population from 6 to 12 years old were (0.445±0.166) g/cm2 in 6-year-old group,(0.509±0.151) g/cm2 in 7-year-old group, (0.510±0.133) g/cm2 in 8-year-old group, (0.519±0.132) g/cm2 in 9-year-old group, (0.520±0.153) g/cm2 in 10-year-old group, (0.53±0.175) g/cm2 in 11-year-old, and (0.545±0.206) g/cm2 in 12-year-old group. There were differences in bone density between boys and girls (P ＜ 0.001), and after correction by body mass, the difference disappeared. Bone density of the boys and girls had increasing linear correlation with age (male r=0.722, P ＜ 0.001; female r=0.785, P ＜ 0.001), and had significant relationship with body mass (r=0.984, P ＜ 0.001). CONCLUSION: In normal children aged 6 to 12 years old, bone density of the heel has no association with sex, but has increasing linear correlation with age and significant relationship with body mass.

OBJECTIVE: To establish a screening model for females of reproductive age carrying Duchenne muscular dystrophy (DMD) variants based on a current community health examination platform. METHODS: A total of 61 870 participants were recruited between October 2017 and October 2019. Serum creatine kinase (CK) was measured with a Roche Cobasc 701/702 using an enzymatic rate method. Genetic testing was offered to those with a CK level of ≥ 200 U/L. For carriers of DMD variants, genetic counseling and follow up were provided. RESULTS: For the 61 870 females participating in the program, 1078 were found with raised serum CK (≥ 200 U/L), of which 618 (57.33%) accepted CK re-measurement after at least a two-week interval. One hundred and twenty cases were found with sustained serum CK elevation, of which 6 were confirmed to be definite DMD carriers regardless of family history. Genetic testing was provided to 33 females with a family history for DMD, and 13 were determined as definite carriers. An affected fetus was detected by prenatal diagnosis. After genetic counseling, the parents had opted induced abortion. CONCLUSION Large-scale DMD carrier screening through a three-step approach based on the current community health examination platform is both feasible and cost effective.
Female ; Genetic Carrier Screening ; Genetic Counseling ; Genetic Testing ; Humans ; Muscular Dystrophy, Duchenne/genetics* ; Pregnancy ; Prenatal Diagnosis

Abstract Autism spectrum disorder (ASD) is a lifelong neurodevelopmental disorder. Early life social experience assessment before symptoms of ASD might be helpful for determining the causal link between social experiences and early childhood ASD. Younger children are exposed to excessive screen time in recent years. This paper summarizes the association between screen exposure with ASD in preschool children, and proposes future research directions and provides evidencebased guidance to optimize and support children s early media experiences.

Background and objective Invasive mucinous adenocarcinoma(IMA)was a rare and specific type of lung adenocarcinoma,which was often characterized by fewer lymphatic metastases.Therefore,it was difficult to evaluate the prognosis of these tumors based on the existing tumor-node-metastasis(TNM)staging.So,this study aimed to develop Nomo-grams to predict outcomes of patients with pathologic N0 in resected IMA.Methods According to the inclusion criteria and exclusion criteria,IMA patients with pathologic N0 in The Affiliated Lihuili Hospital of Ningbo University(training cohort,n=78)and Ningbo No.2 Hospital(validation cohort,n=66)were reviewed between July 2012 and May 2017.The prognostic value of the clinicopathological features in the training cohort was analyzed and prognostic prediction models were established,and the performances of models were evaluated.Finally,the validation cohort data was put in for external validation.Results Univariate analysis showed that pneumonic type,larger tumor size,mixed mucinous/non-mucinous component,and higher overall stage were significant influence factors of 5-year progression-free survival(PFS)and overall survival(OS).Multivariate analysis further indicated that type of imaging,tumor size,mucinous component were the independent prognostic factors for poor 5-year PFS and OS.Moreover,the 5-year PFS and OS rates were 62.82％and 75.64％,respectively.In subgroups,the sur-vival analysis also showed that the pneumonic type and mixed mucinous/non-mucinous patients had significantly poorer 5-year PFS and OS compared with solitary type and pure mucinous patients,respectively.The C-index of Nomograms with 5-year PFS and OS were 0.815(95％CI:0.741-0.889)and 0.767(95％CI:0.669-0.865).The calibration curve and decision curve analysis(DCA)of both models showed good predictive performances in both cohorts.Conclusion The Nomograms based on clinicopathological characteristics in a certain extent,can be used as an effective prognostic tool for patients with pathologic N0 after IMA resection.

Sarcopenia is observed to have age-related loss of skeletal muscle mass, muscle strength and physical performance, which can be an effective prognostic indicator for postoperative complications and poor survival outcomes in tumor patients. Sarcopenia could reflect tumor-host interactions and has the advantages in accuracy and generality compared with traditional predictors. This paper reviews the research progress of sarcopenia in predicting the prognosis of genitourinary tumors.