[Current status of pubertal sexual characteristics development of 2 704 girls aged 6-18 years in Tongzhou District of Beijing]

Objective: To understand the current status of pubertal sexual characteristics development of girls aged 6-18 years in Tongzhou District of Beijing and to compare the differences in sexual characteristics development among girls characterized as thin, normal, overweight, and obese. Methods: A cross-sectional survey was conducted among 2 844 girls aged 6-18 years in Tongzhou District of Beijing from September 2022 to July 2023. The developmental stages of breast and pubic hair were assessed on site, and menarche status was inquired. Weight and height were measured. The girls were subsequently characterized into thin, normal, overweight and obese groups. Basic information (including family and personal history) was obtained through questionnaires. Probit probability unit regression was applied to calculate the age of each Tanner stage of sexual characteristics development and the age of menarche. The χ2 test was applied to compare the counting data between two or multiple groups. Results: A total of 2 844 girls were surveyed and 2 704 girls met the inclusion criteria, resulting in a valid response rate of 95.1%. Among these girls, 1 105 (40.9%) were aged 6-9 years, 1 053 (38.9%) were aged 10-13 years, and 546 (20.2%) were aged 14-18 years. The of height-for-age Z-score (HAZ), weight-for-age Z-score (WAZ), and body mass index-for-age Z-score (BAZ) were 0.46(-0.23,1.16), 0.69(-0.16,1.67), and 0.67(-0.27,1.73) respectively. The prevalences of thin, overweight, and obesity were respectively 1.7% (45/2 704), 17.3% (467/2 704), and 19.9% (538/2 704), respectively. There were 45 girls in the thin group, 1 654 girls in the normal weight group, 1 005 girls in the overweight and obesity group. The age of Tanner stage breast 2 (B2), Tanner stage pubic hair 2 (P2), and menarche was 9.0 (95%CI 8.9-9.1), 10.5 (95%CI 10.4-10.6), and 11.4 (95%CI 11.3-1.5) years, respectively. The current status of breast and pubic hair maturity in girls with pubertal development shows that 64.6% (1 211/1 874) of these girls had breast development preceding pubic hair development, 32.4% (607/1 874) had concurrent breast and pubic hair development, and 3.0% (56/1 874) had pubic hairs development preceding breast development. The interval age between B2 and B5 was 4.7 (95%CI 4.6-4.8) years, between P2 and P5 was 4.5 (95%CI 4.4-4.6) years, and between B2 and menarche was 2.4 (95%CI 2.3-2.5) years. The ages of sexual characteristics development in overweight and obese groups were earlier than that in normal and thin groups. The ages of B2 in thin, normal, overweight, and obese groups were 10.0 (95%CI 9.5-10.6), 9.3 (95%CI 9.2-9.4), and 8.6 (95%CI 8.4-8.7) years, respectively. The age of menarche in thin, normal, overweight, and obese groups were 13.1 (95%CI 12.4-13.7), 11.6 (95%CI 11.4-11.7), and 11.1 (95%CI 11.0-11.2) years, respectively. The interval ages between B2 and B5 and between P2 and P5 was 4.5 and 4.1 years, respectively in the overweight and obese groups, and those in normal group and thin group was 4.7 and 4.5 years, 4.6 and 4.7 years, respectively. Conclusions: The ages of sexual characteristics development and menarche tend in Tongzhou District of Beijing to be earlier than that being reported of Beijing's survey 20 years ago. Girls characterized as overweight and obese not only start puberty at an earlier age than girls of normal weight, but also have a shorter developmental process.

[Effects of screen exposure on language skills in children]

Objective: To investigate the association between screen exposure and language skills in children aged 2-5 years. Methods: There were 299 children aged 2-5 years, recruited by convenience sampling from those who visited the Center of Children's Healthcare, Children's Hospital, Capital Institute of Pediatrics for routine physical examination from November 2020 to November 2021. Their development status were evaluated by the children neuropsychological and behavioral scale (revision 2016). A self-designed questionnaire for parents was conducted to collect demographic and socioeconomic information and screen exposure characteristics (time and quality). One-way ANOVA and independent sample t test were applied to compare the differences in language development quotient of children with different screen exposure time and quality. Multiple linear regression was used to analyze the correlation between screen exposure time and quality with language developmental quotient. Multivariate Logistic regression was used to analyze the risk of language underdevelopment in children with different screen exposure time and quality. Results: Among 299 children, 184 (61.5%) were boys and 115 (38.5%) were girls, with the age of (3.9±1.1) years. The number of children with daily screen time <60, 60-120 and>120 min was 163 children (54.5%), 86 children (28.8%) and 50 children (16.7%), respectively, with the language development quotients of 94±13, 90±13, 84±14, respectively, demonstrating a statistically significant difference (F=8.92, P<0.001). Logistic regression analysis revealed that screen exposure time of 60-120 and >120 min per day were both risk factors for children's language developmental quotients (OR=2.28, 95%CI 1.00-5.17, P=0.043; OR=3.96, 95%CI 1.86-9.17, P<0.001), and co-viewing and exposure to educational programs were both protective factors for children's language developmental quotients (OR=0.48, 95%CI 0.25-0.91, P=0.024, OR=0.36, 95%CI 0.19-0.70, P=0.003). Conclusions: Excessive exposure screen time and inappropriate screen exposure habits are associated with children's poorer language development. Screen exposure time should be limited and screen use should be rational to promote children's language skills.

Bacteriophage Effectively Rescues Pneumonia Caused by Prevalent Multidrug-Resistant Klebsiella pneumoniae in the Early Stage

Pneumonia caused by multidrug-resistant (MDR) Klebsiella pneumoniae of sequence types ST11 and ST383 have highlighted the necessity for new therapies against these prevalent pathogens. Bacteriophages (phages) may be used as alternatives or complements to antibiotics for treating MDR bacteria because they show potential efficacy in mouse models and even individual clinical cases, and they also cause fewer side effects, such as microbiota-imbalance-induced diseases. In the present study, we screened two phages, pKp11 and pKp383, that targeted ST11 and ST383 MDR K. pneumoniae isolates collected from patients with pneumonia, and they exhibited a broad host range, high lytic activity, and high environmental adaptability. Both phages pKp11 and pKp383 provided an effective treatment for the early stage of pneumonia in a murine infection model without promoting obvious side effects, and cocktails consisting of the two phages were more effective for reducing bacterial loads, inflammation, and pathogenic injuries. Our findings support the application of phages as new medications for refractory ST11 and ST383 K. pneumoniae infections and emphasize the potential of enhancing phage therapy modalities through phage screening. These data provided important resources for assessing and optimizing phage therapies for MDR ST11 and ST383 infection treatment. However, substantial amounts of further work are needed before phage therapy can be translated to human therapeutics. IMPORTANCE K. pneumoniae is recognized as the most common pathogen of hospital- and community-acquired pneumonia across the world. The strains of ST11 and ST383 are frequently reported in patients with pneumonia. However, the efficacy of antibiotics toward K. pneumoniae is decreasing dramatically. As a new approach to combat MDR bacteria, phages have exhibited positive clinical effects and efficacy as synergetic or alternative strategies to antibiotics. Thus, we screened two phages that targeted ST11 and ST383 MDR K. pneumoniae, and they exhibited a broad host range, high lytic activity, and high environmental adaptability. Both phages provided an effective treatment for the early stage of pneumonia in mice, and cocktails consisting of the two phages were more effective in reducing bacterial loads, inflammation, and pathogenic injuries. Although these data suggest that phages are effective alternatives or complements to antibiotics, more research is needed before they can be translated into therapeutics for humans.