Objective:To investigate the protective effects of a sunscreen lotion containing Calendula extracts on children′s skin against sun exposure, as well as to evaluate its safety and tolerability when applied to children.Methods:A single-center, randomized, split-body/face study was conducted on 200 healthy children aged 3 - < 18 years, who were enrolled from Beijing Children′s Hospital, Capital Medical University from July to August 2022. The participants were randomly and equally divided into Group A (the left side of the body/face topically treated with the test sunscreen, and the right side with the control sunscreen) and Group B (the right side of the body/face topically treated with the test sunscreen, and the left side with the control sunscreen) at a ratio of 1∶1. After applying the sunscreen, they were engaged in outdoor activities under sunlight. Skin tests were conducted on the temporal area, the extensor aspect of the upper arm and forearm before and after sun exposure. The test product was a mild sunscreen lotion containing Calendula extracts with the sun protection factor (SPF) being 50+ and the long-wave ultraviolet protection factor (PA) being +++, and the control product was a baby sunscreen containing licorice extracts (SPF35, PA++). Bilateral differential scales were used to assess clinical symptoms after sun exposure, erythema values to clinically evaluate erythema after sun exposure, and the multifunctional skin testing platform MPA10 to measure melanin and erythema values, stratum corneum hydration, and transepidermal water loss (TEWL) at the tested sites. Related adverse events were observed and recorded during the study. The paired t-test or Wilcoxon signed-rank test was used for the comparison of quantitative data, and chi-square test (Fisher′s exact test) for the comparison of count data. Results:Totally, 198 children completed the study and visits, including 100 males (50.5%) and 98 females (49.5%), aged from 3 to 17 years (8.11 ± 0.23 years), and there were 99 cases each in the Group A and Group B. The numbers of participants with more obvious sunburn symptoms after sun exposure in the 3 tested areas were all higher on the control side than on the test side (the temporal area: 11 cases vs. 4 cases; the extensor aspect of the upper arm: 16 cases vs. 2 cases; the extensor aspect of the forearm: 33 cases vs. 3 cases), with significant differences between the bilateral sides (all P<0.001). No significant differences were observed in the erythema values between the test side and control side in the 3 tested areas (all P > 0.05). In the extensor aspect of the upper arm and forearm, the difference in the melanin value before and after sun exposure was significantly smaller on the test side (3.57 ± 2.41, 1.74 ± 1.68, respectively) than on the control side (9.50 ± 2.21, 8.13 ± 1.87, respectively, both P < 0.001) ; in the temporal region and the extensor aspect of the upper arm and forearm, the difference in the stratum corneum hydration level before and after sun exposure was significantly greater on the test side (7.72[-2.19, 19.44], 9.56 ± 1.37, 9.05 ± 1.37, respectively) than on the control side (-3.25[-13.54, 9.94], 3.63 ± 1.32, 3.73 ± 1.31, respectively, all P < 0.001) in the temporal region and the extensor aspect of the upper arm and forearm. However, there were no significant differences in the changes in the erythema or TEWL values before and after sun exposure between the test side and control side in either of the 3 tested areas (all P > 0.05). During this study, 1 case (0.51%) experienced transient urticaria on the control side, and no serious adverse events occurred. Conclusion:The mild sunscreen lotion containing Calendula extracts demonstrated superior efficacy to the control product in improving skin symptoms after sun exposure such as hyperpigmentation among healthy children aged 3 - < 18 years, with good tolerability and a relatively low incidence of adverse reactions.

Objective:To evaluate the efficacy of daily use of a test emollient combined with topical glucocorticoids applied at the weekend for delaying the recurrence of atopic dermatitis (AD) in children during the maintenance period.Methods:A randomized, blank-controlled, multicenter clinical study was conducted in children with moderate AD from Beijing Children′s Hospital, Capital Medical University, Children′s Hospital of Chongqing Medical University and Shenzhen Children′s Hospital from March 2021 to February 2022. A total of 127 children aged 0 - 12 years with moderate AD were treated with topical glucocorticoids combined with emollients during the run-in period, 112 out of them achieved the investigator′s global assessment (IGA) score ≤ 1 point, and then the 112 patients were randomly divided into a test group (56 cases) and a control group (56 cases) at a ratio of 1∶1. Patients in the test group received treatment with a test emollient twice a day in combination with topical glucocorticoids applied at the weekend, and those in the control group were only treated with topical glucocorticoids at the weekend. Patients in the two groups were followed up at baseline, week 2 (± 3 d), week 4 (± 5 d), and week 12 (±7 d), as well as at the time of AD relapse, and the effect of the test emollient on the remission rate of AD in children during the maintenance period was evaluated, so were its effects on the dosage of topical glucocorticoids, pruritus, sleep, and skin pH. The occurrence of treatment-related adverse events was evaluated and recorded at the same time. Study endpoints were defined as AD relapse during the maintenance period, end of 12-week follow-up, or occurrence of serious adverse events. Comparisons of efficacy indicators between groups were conducted by using chi-square test, Kaplan-Meier survival analysis, Satterthwaite t′ test and Mann-Whitney U test. Results:In the full-analysis set, 45 (80.36%) patients with AD maintained remission in the test group (56 cases) and 30 (53.57%) in the control group (56 cases), and the remission rate difference between the two groups was 26.79% (95% confidence interval [ CI]: 10.09%, 43.49%; χ2 = 9.11, P = 0.003) ; the 12-week follow-up during the maintenance period showed that the time to first relapse was 75.05 ± 25.07 days in the test group, which was significantly longer than that in the control group (49.55 ± 33.92 days, t′ = 4.52, P < 0.001). At the study endpoint, the test group showed significantly decreased AD disease severity score (eczema area and severity index [EASI] score: 0.00 [0.00, 1.20] points vs. 0.60 [0.00, 4.00] points), pruritus visual analog scale (VAS) score (0.00 [0.00, 2.00] points vs. 2. 00 [0.00, 10.00] points), and sleep VAS score (0.00 [0.00, 0.00] points vs. 1.00 [0.00, 4.00] points) compared with the control group ( Z = -2.77, 2.43, 3.48, P = 0.006, = 0.015, < 0.001, respectively), while there was no significant difference in the pH value at the lesional sites between the test group and control group ( t = 0.97, P = 0.335). For the group aged 0 - 2 years, the average daily glucocorticoid dosage at the weekend in AD children during the maintenance period was significantly lower in the test group than in the control group ( Z = -1.97, P = 0.049) ; for the group aged >2 - 12 years, there was no significant difference in the average daily glucocorticoid dosage at the weekend between the two groups ( Z = -0.25, P = 0.802). During the study period, no significant difference was observed in the incidence of treatment-related adverse events between the test group (2/56, 3.57%) and control group (3/56, 5.36%; P = 1.000), and no serious adverse events occurred. Conclusion:Compared with the weekend treatment with topical glucocorticoids alone, the daily use of the test emollient combined with topical glucocorticoids at the weekend could markedly improve the remission rate of AD, prolong the time to relapse, and reduce the disease severity at relapse in children with AD during the maintenance period, which provides a new option for maintenance treatment of children with AD.

Objective:To evaluate the efficacy and tolerability of crisaborole 2% ointment in the treatment of childhood atopic dermatitis (AD) at the early stage, and to compare the efficacy of every-other-day (Qod) regimen versus twice-a-week (Biw) regimen against recurrence in the remission stage of AD.Methods:A multicenter, randomized, open-label clinical trial was conducted. Totally, 150 children with mild to moderate AD aged 2 - < 18 years were enrolled from 6 hospitals (including Beijing Children′s Hospital, Capital Medical University, etc), and randomly divided into the Qod group (76 cases) and the Biw group (74 cases). In the acute stage of AD, both groups were treated with topical crisaborole 2% ointment on skin lesions twice a day for 2 - 4 weeks, as well as with emollients throughout the whole body. The improvement of early clinical symptoms was evaluated, and the occurrence of adverse reactions was recorded in the follow up. Once the investigator′s static global assessment (ISGA) scores decreased to 1 point or less, the patient would be enrolled into the remission stage. In the remission stage of AD, patients in the Qod group and Biw group were treated with crisaborole ointment every other day and twice a week respectively; the recurrence rate of AD in the remission stage was evaluated, as well as the severity of skin lesions, itching, life quality, and the occurrence of adverse reactions at weeks 4, 8, and 12. Statistical analysis was carried out with SPSS 23.0 software by using t test for comparisons of normally distributed continuous data between two groups, Mann-Whitney U test for non-normally distributed data, chi-square test for enumeration data, and Kaplan-Meier method for analysis of survival rates. Results:A total of 142 patients were enrolled in the modified intention-to-treat population, including 71 in the Qod group and 71 in the Biw group. In the acute stage of AD, the improvement of itching and skin lesions self-reported by the children or their family members occurred on days 1.9 (1.0, 3.0) and 2.0 (1.0, 4.1) after the application of crisaborole ointment, respectively. At the end of treatment in the acute stage, 89 children (62.7%) achieved ISGA 0/1 and successfully transferred into the remission stage. The follow-up in the remission stage was completed in 83 patients (44 in the Qod group and 39 in the Biw group). In addition, recurrence occurred in 19 (43.2%) and 12 (30.8%) patients in the Qod group and Biw group respectively, and there was no significant difference in the recurrence rate between the two groups ( χ2 = 1.36, P = 0.243) ; the average time to recurrence was 64.25 (95% CI: 53.33 - 75.17) days and 75.78 (95% CI: 65.46 - 86.10) days in the Qod group and Biw group respectively. Among the patients who were in the remission stage and had not yet experienced relapse at weeks 4, 8, and 12, there were no significant differences in the eczema area and severity index (EASI) scores, ISGA scores, pruritus numerical rating scale (NRS) scores, or quality-of-life scores between the two groups (all P > 0.05) at any time points, except for the ISGA scores at week 12 (Biw group: 0 [0, 1] point vs. Qod group: 1 [0, 1] point; Z = -2.31, P = 0.021). A total of 146 patients were enrolled in the safety set. During the study period, 70 adverse events occurred in 65 patients, with an incidence rate of 44.5%, and all were mild or moderate adverse events; 55 (37.7%) patients experienced discomfort at the medication site, which mainly referred to pain (45 cases, 30.8%) and mostly occurred in the tender and skinfold areas. Conclusions:Crisaborole 2% ointment could effectively relieve clinical symptoms in children with mild to moderate AD in the early stage, and intermittent treatment could continuously relieve clinical symptoms in the remission stage. The common adverse reaction was discomfort at the application site in the early stage of AD. There was no significant difference in the impact on AD recurrence in the remission stage between the Qod regimen and Biw regimen.

Background: Co-infections of the porcine reproductive and respiratory syndrome virus (PRRSV) and the Haemophilus parasuis (HPS) are severe in Chinese pigs, but the immune response genes against co-infected with 2 pathogens in the lungs have not been reported. Objectives: To understand the effect of PRRSV and/or HPS infection on the genes expression associated with lung immune function. Methods: The expression of the immune-related genes was analyzed using RNA-sequencing and bioinformatics. Differentially expressed genes (DEGs) were detected and identified by quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC) and western blotting assays. Results: All experimental pigs showed clinical symptoms and lung lesions. RNA-seq analysis showed that 922 DEGs in co-challenged pigs were more than in the HPS group (709 DEGs) and the PRRSV group (676 DEGs). Eleven DEGs validated by qRT-PCR were consistent with the RNA sequencing results. Eleven common Kyoto Encyclopedia of Genes and Genomes pathways related to infection and immune were found in single-infected and co-challenged pigs, including autophagy, cytokine-cytokine receptor interaction, and antigen processing and presentation, involving different DEGs. A model of immune response to infection with PRRSV and HPS was predicted among the DEGs in the co-challenged pigs. Dual oxidase 1 (DUOX1) and interleukin-21 (IL21) were detected by IHC and western blot and showed significant differences between the co-challenged pigs and the controls. Conclusions These findings elucidated the transcriptome changes in the lungs after PRRSV and/or HPS infections, providing ideas for further study to inhibit ROS production and promote pulmonary fibrosis caused by co-challenging with PRRSV and HPS.

Objective:To investigate short-term efficacy and safety of subcutaneous injection of dupilumab in the treatment of moderate-to-severe childhood atopic dermatitis (AD) .Methods:A retrospective study was conducted on clinical data from children who were diagnosed with moderate-to-severe AD and subcutaneously injected with dupilumab in Department of Dermatology, Beijing Children′s Hospital, Capital Medical University from March 2021 to August 2021. Changes in the Eczema Area and Severity Index (EASI), itch Numeric Rating Scale (NRS) score, SCORing Atopic Dermatitis (SCORAD) index, and Dermatology Family quality of life Index (DFI) were analyzed before and 4 weeks after the first subcutaneous injection of dupilumab. Adverse events were collected during the first injection to the first follow-up visit at week 4 after the start of treatment. Normally distributed measurement indices were compared by using paired t test, non-normally distributed measurement indices were compared by using signed rank test, and logistic regression analysis was used to evaluate the effects of disease duration, eosinophil counts, IgE levels, personal and family history of allergic diseases on EASI50 (≥ 50% decrease in the EASI score) after dupilumab treatment. Results:A total of 39 children were enrolled in this study, including 21 males and 18 females. Twenty-one patients were aged 2 to < 6 years, 18 were aged 6 to < 18 years, and their median age ( Q1, Q3) was 65.0 (53.0, 111.0) months. Four weeks after the single-dose subcutaneous injection of dupilumab, 18 patients (84.85%) achieved ≥ 50% decrease in EASI score, 13 (60.61%) ≥ 75% decrease in EASI score; 18 (75.76%) experienced a decrease of ≥ 4 points in peak NRS, and 20 (81.82%) ≥ 3 points in peak NRS; the SCORAD score decreased by ≥ 50% in 15 (68.75%) patients, and by ≥ 75% in 7 (18.75%). Neither common adverse events such as conjunctivitis, skin infections, injection site reactions, nor serious adverse events were observed in any of the children from the first injection to the first follow-up visit at week 4. Logistic regression analysis showed no significant effect of the disease duration, eosinophil counts, IgE levels, personal or family history of allergic diseases on EASI50 (all P > 0.05) . Conclusion:A single-dose subcutaneous injection of dupilumab can markedly improve pruritus and severity of skin lesions in children with moderate-to-severe AD, and enhance the family quality of life, with favorable short-term safety.

Objective:To explore whether the regular feedback system in opportunistic screening of colorectal cancer can improve the adenoma detection rate (ADR) of endoscopists.Methods:This study was an observational study, divided into three stages: the baseline stage before intervention (the pre-intervention period), the regular feedback stage (the intervention period) and the post-intervention stage (the post-intervention period). In the pre-intervention period, all patients who underwent opportunistic screening of colorectal cancer in Department of Gastroenterology in Beijing Shijitan Hospital Affiliated to Capital Medical University from June 2017 to May 2018 were reviewed, and the ADR of each endoscopist was calculated. In the intervention period from June 2018 to November 2018, colonoscopies were performed on patients for opportunistic screening of colorectal cancer by endoscopists who participated in the feedback. The ADR of each endoscopist during the previous month was calculated at the beginning of each month and feedback was provided in the form of a report. In the post-intervention period from December 2018 to January 2019, colonoscopies were performed on patients for opportunistic screening of colorectal cancer by endoscopists who participated in the feedback. The ADR of each endoscopist was calculated after the feedback stopped. ADR and polyp detection rate (PDR) of three stages were compared.Results:A total of 1 768, 1 308 and 344 patients were enrolled for opportunistic screening of colorectal cancer during the pre-intervention, the intervention and the post-intervention period respectively. Eight endoscopists participated in the whole process of this study. The total ADR increased from 23.70% (419/1 768) in the pre-intervention period to 33.72% (441/1 308) in the intervention period ( χ2=37.449, P<0.05). Two months after intervention, ADR decreased slightly to 33.14% (114/344), but was still higher compared with before ( χ2=13.602, P<0.05). The total PDR increased from 47.17% (834/1 768) in the pre-intervention period to 52.68% (689/1 308) in the intervention period ( χ2=9.111, P<0.05). Two months after the intervention, PDR increased slightly to 53.78% (185/344), and still higher compared with before ( χ2=5.035, P<0.05). Conclusion:Regular feedback to endoscopists can improve ADR in opportunistic screening of colorectal cancer.

Objective: To analyze the role of school based symptom monitoring system in public health emergencies in Hangzhou, to provide the basis for prevention and control strategies for public health emergencies in schools. Methods: Data regarding school public health emergencies in Hangzhou in 2019 were collected from the Public Health Emergencies Report Management Information System, and data regarding public health early warning in schools were collected from the Hangzhou School Symptom Monitoring System. The usage of school symptom monitoring system was analyzed by SAS 9.0 software, and the positive warning events and public health emergencies were compared and analyzed, the rate and composition ratio were compared with the χ 2 test, the number of cases was compared with the non parameter rank and the Mann Whitney test, and the trend test was conducted using Cochran Armitage test. Results: In 2019, the average use rate of the city s school symptom monitoring system was 54.65%, the average response rate of automatic early warning was 70.68%, and the use rate (χ 2=860.79, p<0.01) and automatic early warning response rate (χ 2=1 615.91，P<0.01) of school systems varied greatly by region. In 2019, 161 positive early warning incidents were detected through the school symptom monitoring system, 197 public health emergencies were reported through the emergency network, and fewer public health emergencies were reported in areas where more positive warning events were detected(Z=10.65，P<0.01). The proportion of disease category in positive warning events was different from that in public health emergencies in(χ 2=28.33, P<0.01). The number of cases of positive early warning events of the same disease was much lower than the number of cases of public health emergencies without warning, and the time of positive warning signals was on average 4 days ahead of the time of receiving the report of public health emergencies. Conclusion Smartphone based school symptom monitoring system in Hangzhou plays a sentinel role in public health emergencies prevention and control in schools.

Objective:To observe the effect of remote exercise support on weight loss and maintenance in obese adolescents.Methods:From January 2018 to December 2018, a total of 118 adolescents with simple obesity who were treated in the Outpatient Department of Endocrinology and Metabolism in PKU Care Lu'an hospital were selected by the convenient sampling method. They were divided into the control group and the experimental group by the random number table method, with 59 cases in each group. The control group received a routine outpatient follow-up intervention for 6 months and the experimental group also received a 6-month outpatient intervention. The outpatient intervention included 3 months of intervention and 3 months of maintenance. During 3 months of intervention, the mobile wearable device was used to design the exercise scheme based on the internet, and the combination of the scheme and the supporting mobile APP monitoring system was used for remote exercise support. During the maintenance period of 3 months, the same intervention method as the control group was adopted. The study lasted for 6 months. The weight change and maintenance status were compared between the two groups at different intervention times.Results:In the intervention period (the first 3 months) , the weight showed a trend of weight loss in two groups, and the weight in the experimental group were lower than those in the control group. The differences were statistically significant ( P<0.05) . From the maintenance period (the last 3 months) , the weight of both groups rebounded, but the weight of patients in the experimental group were always lower than those of the control group, and the differences were statistically significant ( P<0.01) . By the end of the intervention period (the first 3 months) , there was no statistically significant difference in the standard-reaching rate of weight loss > 5% between the two groups ( P>0.05) . But the standard-reaching rates of weight loss >10% and weight loss >15% in the experimental group were higher than those in the control group, and the differences were statistically significant ( P<0.01) . During the maintenance period (the last 3 months) , the standard-reaching rates of weight loss >5%, weight loss >10% and weight loss>15% in the experimental group were all higher than those in the control group, and the differences were statistically significant ( P<0.01) . Conclusions:Remote exercise support can help obese adolescents further lose weight and delay body weight rebound.

Objective To evaluate the effect of an emollient containing Prinsepia utilis Royle oil extracts and other extracts on clinical symptoms and disease recurrence in children aged 2-12 years with atopic dermatitis (AD) in the remission period.Methods A multicenter,randomized,parallel-group,controlled clinical trial was conducted from December 2017 to September 2018.A total of 297 children aged 2-12 years with moderate AD were enrolled from 5 hospitals in China,and randomly divided into the test group (148 cases) and control group (149 cases).In the acute stage,the two groups were both topically treated with mometasone furoate cream once a day on the skin lesions,and with an emollient containing Prinsepia utilis Royle oil extracts and other extracts twice a day throughout the whole body for 2-4 weeks.The children would be enrolled into the remission stage if their Investigator's Global Assessment (IGA) score was ≤ 1 at following visits.In the remission stage,the test group was only topically treated with the emollient twice a day throughout the whole body,while mometasone furoate cream and the emollient were both withdrawn in the control group.At weeks 4,8 and 12 in the remission stage,the recurrence of AD,eczema area and severity index (EASI),children's dermatology life quality index (CDQOL) and adverse events were evaluated.Statistical analysis was carried out with SAS 9.4 software by using t test for comparison of normally distributed continuous data between two groups,chi-square test for comparison of unordered categorical data,Kaplan-Meier method for analysis of survival rates,Cox regression analysis for evaluating the effect of different therapies on AD recurrence in children in the remission stage,and Logistic regression analysis for analysis of odds ratio (OR) of EASI or CDQOL at week 4 in the remission stage between the test group and control group.Results Of the 297 children with AD,31 breached the clinical trial protocol,and 266 were included in the per protocol set (PPS),including 132 in the test group and 134 in the control group.In the PPS,114 and 106 patients completed the follow-up in the test group and control group respectively,and the recurrence rate was significantly lower in the test group (47,41.23％) than in the control group (84,79.25％;x2 =32.96,P ＜ 0.001).The time to recurrence was significantly longer in the test group(61.99 d ± 2.80 d)than in the control group(39.17 d ± 2.54 d,t =6.03,P ＜ 0.001),and the recurrence risk was significantly lower in the test group than in the control group (Log rank test,x2 =32.02,P ＜ 0.001).After adjustment for age and gender,Cox regression analysis showed that the recurrence risk in the test group was 0.35 times that in the control group (HR =0.35,95％ CI:0.24-0.51,P ＜ 0.01).At week 4 in the remission stage,the EASI score at P50-P75 and P75-P100 in the test group were 0.42,0.25 times that in the control group respectively (95％ CI:0.20-0.86,0.12-0.54 respectively;P =0.02,＜ 0.01respectively).Moreover,the CDQOL score at P75-P100 in the test group was 0.33 times that in the control group (95％ CI:0.17-0.65,P ＜ 0.01).No significant difference in the incidence of adverse events was observed between the two groups (P ＞ 0.05).Conclusion Maintenance treatment with the emollient containing Prinsepia utilis Royle oil extracts and other extracts can markedly reduce the recurrence risk in AD children,improve clinical symptoms,and enhance the quality of life.

Objective: To explore the mechanisms of vascular endothelial growth factor receptor 2 (VEGFR2) expression regulated by recombinant human erythropoietin (rh-EPO) in a premature rat model of periventricular white matter damage. Methods: Sprague-Dawley rats aged three days were randomly divided into five groups: sham group without hypoxia-ischemia (HI), HI group (HI with saline administration), HI+erythropoietin (EPO) group, HI+erythropoietin receptor (EPOR) antagonist group and HI+EPO+EPOR antagonist group. Rat pups were either subjected to permanent ligation of the right common carotid artery and 6% O₂+94% N₂ for two hours (HI) or sham operated and exposed to normal air (sham). After the operation, rats in the HI+EPOR antagonist and HI+EPO+EPOR antagonist groups received a single intraventricular injection of EPOR antagonist (5 μl). Four hours after the operation, rats in the HI+EPO and HI+EPO+EPOR antagonist groups received a single intraperitoneal injection of rh-EPO (5 U/g). Western-blot was performed to detect EPOR, phosphorylated EPOR (p-EPOR), extracellular regulated protein kinases (ERK) and phosphorylated ERK (p-ERK) at 60 and 90 minutes after the models were established successfully, and also used to analyze the expression of VECFR2 on day 2 and 4. Analysis of variance and SNK test were used as statistical methods. Results: At 60 and 90 minutes after model establishment, the expression of EPOR protein in rat brain tissues was increased in HI (1.717±0.206 and 1.416±0.242), HI+EPO (2.557±0.222 and 2.111±0.159) and HI+EPO+EPOR antagonist (1.547±0.170 and 1.452±0.250) groups as compared with that in sham group (1.095±0.182 and 0.751±0.136), that in HI+EPO group was higher than that in HI and HI+EPO+EPOR antagonist groups, and that in HI+EPOR antagonist group (1.088±0.160 and 1.020±0.174) was lower than that in HI group. All differences were statistically significant (F=30.154 and 20.265, both P<0.05). The expressions of p-EPOR, p-ERK and VEGFR2 in the five groups were consistent with the expression of EPOR, and the differences were also statistically significant (all P<0.05). In addition, the expression of VEGFR2 in HI+EPO+EPOR antagonist group was lower than that in HI group on day 4 (1.053±0.118 vs 1.439±0.074, F=54.248, P<0.05). No statistically significant difference in ERK expression was found among all groups at 60 or 90 minutes after modeling (F=1.117 and 0.734, both P>0.05). Conclusions ERK signaling pathways will be affected by EPO binding to EPOR. As a result, VEGFR2 expression was increased leading to enhanced angiogenesis in a premature rat model of periventricular white matter damage.