Objective:To understand the current status of anemia, iron deficiency, and iron-deficiency anemia among preschool children in China.Methods:A cross-sectional study was conducted with a multi-stage stratified sampling method to select 150 streets or townships from 10 Chinese provinces, autonomous regions, or municipalities (East: Jiangsu, Zhejiang, Shandong, and Hainan; Central: Henan; West: Chongqing, Shaanxi, Guizhou, and Xinjiang; Northeast: Liaoning). From May 2022 to April 2023, a total of 21 470 children, including community-based children aged 0.5 to<3.0 years receiving child health care and kindergarten-based children aged 3.0 to<7.0 years, were surveyed. They were divided into 3 age groups: infants (0.5 to<1.0 year), toddlers (1.0 to<3.0 years), and preschoolers (3.0 to<7.0 years). Basic information such as sex and date of birth of the children was collected, and peripheral blood samples were obtained for routine blood tests and serum ferritin measurement. The prevalence rates of anemia, iron deficiency, and iron-deficiency anemia were analyzed, and the prevalence rate differences were compared among different ages, sex, urban and rural areas, and regions using the chi-square test.Results:A total of 21 460 valid responses were collected, including 10 780 boys (50.2%). The number of infants, toddlers, and preschoolers were 2 645 (12.3%), 6 244 (29.1%), and 12 571 (58.6%), respectively. The hemoglobin level was (126.7±14.8) g/L, and the serum ferritin level was 32.3 (18.5, 50.1) μg/L. The overall rates of anemia, iron deficiency, and iron-deficiency anemia were 10.4% (2 230/21 460), 28.3% (6 070/21 460), and 3.9% (845/21 460), respectively. The prevalence rate of anemia was higher for boys than for girls (10.9% (1 173/10 780) vs. 9.9% (1 057/10 680), χ2=5.58, P=0.018), with statistically significant differences in the rates for infants, toddlers and preschoolers (18.0% (475/2 645), 10.6% (662/6 244), and 8.7% (1 093/12 571), respectively, χ2=201.81, P<0.01), and the rate was significantly higher for children in rural than that in urban area (11.8% (1 516/12 883) vs. 8.3% (714/8 577), χ2=65.54, P<0.01), with statistically significant differences in the rates by region ( χ2=126.60, P<0.01), with the highest rate of 15.8% (343/2 173) for children in Central region, and the lowest rate of 5.3% (108/2 053) in Northeastern region. The prevalence rates of iron deficiency were 33.8% (895/2 645), 32.2% (2 011/6 244), and 25.2% (3 164/12 571) in infants, toddlers, and preschoolers, respectively, and 30.0% (3 229/10 780) in boys vs. 26.6% (2 841/10 680) in girls, 21.7% (1 913/8 821), 40.0% (870/2 173), 27.1% (2 283/8 413), 48.9% (1 004/2 053) in Eastern, Central, Western, and Northeastern regions, respectively, and each between-group showed a significant statistical difference ( χ2=147.71, 29.73, 773.02, all P<0.01). The prevalence rate of iron-deficiency anemia showed a significant statistical difference between urban and rural areas, 2.9% (251/8 577) vs. 4.6% (594/12 883) ( χ2=38.62, P<0.01), while the difference in iron deficiency prevalence was not significant ( χ2=0.51, P=0.476). Conclusions:There has been a notable improvement in iron deficiency and iron-deficiency anemia among preschool children in China, but the situation remains concerning. Particular attention should be paid to the prevention and control of iron deficiency and iron-deficiency anemia, especially among infants and children in the Central, Western, and Northeastern regions of China.

China has classified the Corona Virus Disease 2019(COVID-19) as a statutory category B infectious disease and managed it according to Category B since January 8, 2023.In view that Omicron variant is currently the main epidemic strain in China, in order to guide the treatment of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) infection in children with the times, refer to the Diagnosis and Treatment Protocol for Novel Coronavirus Infection (Trial 10 th Edition), Expert Consensus on Diagnosis, Treatment and Prevention of Novel Coronavirus Infection in Children (Fourth Edition) and the Diagnosis and Treatment Strategy for Pediatric Related Viral Infections.The Expert Consensus on the Diagnosis, Treatment and Prevention of Novel Coronavirus Infection in Children (Fifth Edition) has been formulated and updated accordingly on related etiology, epidemiology, pathogenic mechanism, clinical manifestations, auxiliary examination, diagnosis and treatment, and added key points for the treatment of COVID-19 related encephalopathy, fulminating myocarditis and other serious complications for clinical reference.

Monkeypox is a zoonotic disease.Previous studies have shown that children are vulnerable to monkeypox and are also at high risk for severe disease or complications.In order to improve pediatricians′ understanding of monkeypox and achieve early detection, early diagnosis, early treatment and early disposal, the committee composed of more than 40 experts in the related fields of infectious diseases, pediatrics, infection control and public health formulate this expert consensus, on the basis of the latest clinical management and infection prevention and control for monkeypox released by the World Health Organization (WHO), the guidelines for diagnosis and treatment of monkeypox (version 2022) issued by National Health Commission of the People′s Republic of China and other relevant documents.During the development of this consensus, multidisciplinary experts have repeatedly demonstrated the etiology, epidemiology, transmission, clinical manifestations, laboratory examinations, diagnosis and differential diagnosis, treatment, discharge criteria, prevention, case management process and key points of prevention and control about monkeypox.

Since December 2019, severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) infections have raged globally for more than 2 years.China has always adopted scientific and effective prevention and control measures to achieved some success.However, with the continuous variation of SARS-CoV-2 cases and imported cases from abroad, the prevention and control work has become more difficult and complex.With the variation of the mutant strain, the number of cases in children changed, and some new special symptoms and complications were found, which proposed a new topic for the prevention and treatment of SARS-CoV-2 infection in children in China.Based on the third edition, the present consensus according to the characteristics of the new strain, expounded the etiology, pathology, pathogenesis, and according to the clinical characteristics and experience of children′s cases, and puts forward recommendations on the diagnostic criteria, laboratory examination, treatment, prevention and control of children′s cases for providing reference for further guidance of effective prevention and treatment of SARS-CoV-2 infection in children in China.

At present, severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)infection is still rampant worldwide.As of September 10, 2021, there were about 222 million confirmed cases of corona virus disease 2019(COVID-19)and more than 4.6 million deaths worldwide.With the development of COVID-19 vaccines and the gradual vaccination worldwide, the increasing number of cases in children and unvaccinated young people has drawn attention.According to World Health Organization surveillance data, the proportion of COVID-19 infection cases in children gradually increased, and the proportion of cases in the age groups of under 5 years and 5-14 years increased from 1.0% and 2.5% in January 2020 to 2.0% and 8.7% in July 2021, respectively.At present, billions of adults have been vaccinated with various COVID-19 vaccines worldwide, and their protective effects including reducing infection and transmission, reducing severe disease and hospitalization, and reducing death, as well as high safety have been confirmed.Canada, the United States, Europe and other countries have approved the emergency COVID-19 vaccination in children and adolescents aged 12 to 17 years, and China has also approved the phased vaccination of COVID-19 vaccination in children and adolescents aged 3 to 17 years. For smooth advancement and implementation of COVID-19 vaccination in children, academic institutions, including National Clinical Research Center for Respiratory Diseases, National Center for Children′s Health, and The Society of Pediatrics, Chinese Medical Association organized relevant experts to reach this consensus on COVID-19 vaccination in children.

Severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)infection is still worldwide.As a vulnerable group, severe and dead pediatric cases are also reported.Under this severe epidemic situation, children should be well protected.With the widespread vaccination of SARS-CoV-2 vaccine in adults, the infection rate have decreased.Therefore, SARS-CoV-2 vaccine inoculation for children groups step by step is of great significance to the protection of children and the prevention and control of corona virus disease 2019(COVID-19) as a whole.But the safety of children vaccinated with SARS-CoV-2 vaccine is a main concern of parents.Therefore, in order to ensure the safety of vaccination and the implementation of vaccination work, National Clinical Research Center for Respiratory Diseases, National Center for Children′s Health and the Society of Pediatrics, Chinese Medical Association organized experts to interpret the main issue of parents about SARS-CoV-2 vaccine for children, in order to answer the doubts of parents.

Objective: To investigate low intensity pulsed ultrasound (LIPUS) on the expression of L-type calcium ion channels(cav1. 2) and Na +-Ca2 + exchangers(NCX1) during dentin-pulp complex injury and repair in rats. Methods: Cavity preparation was made on the upper right first molar of 40 male adult SD rats,20 of them and the upper left first molar of the other 20 were randomly chosen for LIPUS irradiation(frequency: 1. 5 MHz,200 μs pulses,pulse repetition frequency: 1 KHz,ISATA 30 mW/cm2,20 min /d),so the animals were randomly allocated into 4 groups(n = 10): Control group,LIPUS group,cavity preparation group and cavity preparation + LIPUS group. At 1,3,7,14 d post-irradiation the rats were sacrificed respectively for HE stain and immunohistochemical analysis. Results: Reparative dentin formation was observed at 14 days after cavity preparation and LIPUS irradiation,the expression of Cav1. 2(L-type) and NCX1 in this group were increased significantly at day 1 and day 3. Compared with the control group, the expression of Cav1. 2 in LIPUS group increased at day 1 post-irradiation. Conclusion: LIPUS may enhance tertiary dentin formation and up-regulate the expression of Cav1. 2 and NCX1 at the early period of dentin injury.

Objective: To investigate the role of granulocyte-colony stimulating factor (G-CSF) on the regulation of inflammatory cytokines in neonatal hypoxic-ischemic brain damage(HIBD) rat model, and to explore the possible mechanism involved in G-CSF neuroprotective effect via the mammalian target of Rapamycin/p70 ribosomal S6 protein kinase (mTOR/p70S6K) signaling pathway. Methods: A group of postnatal day 7 (P7) Sprague-Dawley rat pups (90 cases) were randomly divided into sham-operated group, hypoxia-ischemia(HI) group, G-CSF group, Rapamycin (RAP) group and control group, and the improved Rice method was used to establish a neonatal rat model of HIBD.One hour before HI induction, Rapamycin was administered intraperitoneally with a dose of 250 μg/kg, and the control group was given equal volume of ethanol injected intraperitoneally.One hour after HI, a dose of 50 μg/kg of G-CSF was injected intraperitoneally into the G-CSF group, Rapamycin group and control group.The same volume of normal saline was injected intraperitoneally into HI group and sham-operated group.Forty-eight hours after HI, Western blot was used to detect the protein levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-10, and the mTOR/p70S6K signaling pathway in brain tissue.Neuron injury of the hippocampal CA1 region and the cortex was assessed by Nissl staining, and infarct volume detected by 2, 3, 5-triphenyltetrazolium chloride staining. Results: The G-CSF group and control group were associated with significantly reduced infarction volume compared to the HI group [(12.87±1.54)%, (11.90±1.31)% vs.(24.21±3.28)%], and the differences were statistically significant(P<0.05). There was an increased positive neuron cell number in the ipsilateral hemispheres of the hippocampal CA1 region in the G-CSF group and the control group [(61.00±4.90) cell/field and (61.67±6.40) cell/field] and cortex [(92.67±6.68) cell/field and (90.17±4.45) cell/field] compared with those in HI group [(42.62±4.46) cell/field and (70.83±6.97) cell/field], and the differences were all statistically significant (all P<0.05). The expression levels of TNF-α and IL-1β were significantly decreased in the G-CSF group and the control group, compared with those in HI group(TNF-α: 0.67±0.07, 0.55±0.05 vs.0.86±0.05; IL-1β: 0.65±0.06, 0.52±0.10 vs.0.86±0.06), and the differences were all statistically significant (all P<0.05). There was increased expression levels of IL-10, p-mTOR/mTOR and p-p70S6K/p70S6K in the G-CSF group and the control group, compared with those in HI group (IL-10: 0.68±0.04, 0.62±0.05 vs.0.34±0.02; p-mTOR/mTOR: 0.53±0.02, 0.51±0.01 vs.0.26±0.01; p-p70S6K/p70S6K: 0.89±0.03, 0.90±0.03 vs.0.55±0.02), and the differences were all statistically significant(all P<0.05). There was an increased infarct volume in Rapamycin group [(25.70±1.50)%], compared with the G-CSF group and the control group, and there were decreased number of positive neuron cell count in the hippocampal CA1 region [(40.67±3.50) cell/field] and cortex [(68.33±8.17) cell/field], increased expression levels of TNF-α and IL-1β (0.97±0.06 and 0.98±0.10, respectively), decreased expression levels of IL-10, p-mTOR/mTOR and p-p70S6K/p70S6K (0.21±0.02, 0.30±0.01 and 0.55±0.01, respectively) in the Rapamycin group, and the differences were all statistically significant (all P<0.05). Conclusions G-CSF may inhibit inflammatory responses after HIBD by up-regulating the mTOR/p70S6K signaling pathway in neonatal HI encephalopathy.

Objective To investigate the effects of granulocyte-colony stimulating factor (G-CSF) on neuronal apoptosis after hypoxia-ischemia brain damage (HIBD) and the possible role of the mTOR/p70S6K signaling pathway in neonatal rats.Methods Ninety seven-day-old Sprague-Dawley rats were assigned into 5 equal groups (n=18):sham group,HIBD group,G-CSF group,rapamycin group and ethanol group by random number table method.Pups were subjected to unilateral carotid artery ligation followed by 2hrs hypoxia or sham surgery.HIBD animals received normal saline,G-CSF (50 μg/kg),G-CSF combined with rapamycin (250 μg/kg) or ethanol (vehicle for rapamycin).Pups were euthanized 48hrs post-HIBD to quantify the percentage of brain infraction area.The pathomorphologic changes in the hippocampal CA 1 area and cortex were observed by Nissl staining.Neuronal cell death was determined using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL).mTOR,activated mTOR (p-mTOR),p70S6K,activated p70S6K (p-p70S6K),Cleaved Caspase-3 (CC3),Bax,and Bcl-2 were quantified using Western blot analysis.Results G-CSF treatment resulted in significantly reduced percentage of brain infraction area (P＜0.05) and neuronal apoptosis in the hippocampal CA1 area and cortex (P＜0.05) after HIBD in neonatal rats.However,rapamycin administration reversed the neuroprotective effect of G-CSF.G-CSF administration ameliorated the pathomorphologic damage in the ipsilateral hemisphere.Compared with the HIBD group,the Nissl stained neurons significantly increased in the G-CSF group (P＜0.05).Furthermore,G-CSF increased the expression ofp-mTOR,p-p70S6K and Bcl-2 but decreased the expression levels of CC3 and Bax in the ipsilateral hemisphere,which were all significantly reversed by rapamycin (P＜0.05).Conclusion G-CSF may attenuate caspase activation and reduce neuronal apoptosis by up-regulating the activity of mTOR/p70S6K signaling pathway after experimental HIBD in rat pups.

Objective:To explore the effect of low intensity pulsed ultrasound (LIPUS) on TGF-β1/Smad 2,3 signal pathway during the dentin injury and repair.Methods:Among 25 Sprague-Dawley rats,5 rats served as a blank control group without treatment.The remaining 20 rats received modified caries preparation inbilateral maxillary first molars to establish a model of dentin-pulp injury and repair.The right maxillary first molars served as a LIPUS group,which received LIPUS irradiation (frequency:1.5 MHz,pulse width:200 μs,pulse repetition frequency:1 kHz,spatial averaged temporal averaged intensity:30 mW/cm2,20 min/d),and the left maxillary first molars served as a cavity-prepared group,which received fake LIPUS irradiation.The rats were sacrificed at 1,3,5,7 and 14 days after LIPUS irradiation.Immunohistochemical staining and Image-pro plus 6.0 were applied to detect the expression and distribution of transforming growth factor-beta1 (TGF-β1) and small mothers against decapentaplegic 2/3(Smad 2 and Smad 3).Results:Immunohistochemical staining showed that the expression of TGF-β1 and Smad 2,3were low innormal pulp,but they were increased in different degree after dentin injury.The result of image analysis showed that the expression of TGF-β1 in the cavity-prepared group gradually increased at the first day and peaked at day 5,and then it returned to normal level at day 14.However,the expression of TGF-β 1 in the LIPUS group were significantly higher than that in the cavity-prepared group at day 3 and 5 (bothP＜0.05).The expressions of Smad 2,3 in both the LIPUS group and the cavity-prepared group were consistently increased all the way, but the expressions in the LIPUS group were higher compared with that in the cavity-prepared group (P＜0.05).Conclusion:The TGF-β1/Smad 2,3 signal pathway can be activated during the dentin injury and repair.LIPUS can up-regulate the expression of TGF-β1 and Smad 2,3 in the early period,which may take part in the dentin-pulp complex injury and repair process.