High altitude heart disease(HAHD)is a chronic mountain sickness in which the body is exposed to high altitude(＞2 500 m)hypobaric hypoxia environment for a long time.HAHD has high morbidity and poor prognosis,and pulmonary hypertension is the main causative mechanism for its develop-ment.The phosphodiesterase-5 inhibitor sildenafil has become a hot drug for the treatment of pulmonary hypertension.This paper reviews the progress of HAHD and discusses the mechanism of action and effectiveness of sildenafil in the treatment of HAHD,with a view to providing a basis for the treatment of HAHD with sildenafil.

Objective Prepubertal mice are administered subcutaneously with letrozole sustained-release pellets behind the neck and treated with a high-fat diet to establish a mouse model of polycystic ovary syndrome(PCOS).The liver transcriptomes of the model mice are compared with those of the placebo control mice to investigate the underlying mechanisms of liver involvement in the pathogenesis of PCOS.Methods A customized 2 mg dose of letrozole sustained-release pellets with a 40-day release period was used.The control placebo and letrozole pellets were implanted subcutaneously in the dorsal cervical region of 3-4-week-old C57BL/6J mice(8 mice per group)to establish the control group and letrozole-induced PCOS model group.Both groups were treated with a high-fat diet starting the day after administration.The modeling period lasted for 5 weeks,during which body weight and 24-hour food intake were monitored in each group every week.When samples were collected,liver weight was recorded.Pathological changes in ovarian and hepatic tissues were examined by hematoxylin-eosin(HE)staining,while hepatic lipid deposition was observed by Oil Red O staining.The extent of macrophage infiltration in the liver was evaluated via F4/80 immunohistochemical staining,and hepatic fibrosis levels were observed by Masson's trichrome staining.Transcriptomic sequencing was performed to analyze differentially expressed genes(DEGs)in liver tissues between the control and model groups,followed by enrichment analysis of significant DEGs.Quantitative real-time fluorescent quantitative PCR(qPCR)was subsequently used to validate the expression of significant DEGs in liver tissues of both groups.Results Compared with the control group,the model group which received subcutaneous letrozole sustained-release pellets combined with a high-fat diet exhibited significantly increased body weight(P＜0.001),prominent polycystic ovarian morphology,and significantly decreased liver-to-body weight ratio(P＜0.05).However,no significant changes were observed in absolute liver weight(P＞0.05),hepatic histomorphology,or lipid deposition.Transcriptome sequencing identified 119 upregulated and 217 downregulated DEGs in the liver tissues of letrozole-treated mice,which were predominantly enriched in pathways related to cholesterol and steroid biosynthesis,steroid hormone metabolism,and inflammatory responses.qPCR validation demonstrated that mRNA expression of HSD3B2 and HMGCR was significantly upregulated in liver(P＜0.01),while mRNA expression of IL4,CCL2 and COL1A1 was downregulated(P＜0.05)in the model group compared with the control group.However,Masson's trichrome staining and F4/80 immunohistochemical analysis showed no significant changes in hepatic fibrosis or macrophage infiltration.Conclusion Subcutaneous administration of letrozole sustained-release pellets combined with a high-fat diet successfully establishes a mouse model of PCOS.The model mice exhibited significant changes in hepatic gene expression.Liver may contribute to PCOS pathogenesis through regulating cholesterol and steroid metabolism.

Objective:To present a set of clinically representative quality assurance (QA) test cases for stereotactic radiosurgery (SRT) plans of multiple intracranial metastases, in order to assess the plan quality and machine execution capabilities.Methods:Based on the clinical characteristics of multiple brain metastases, four groups of test cases with three target volumes (TVs), six TVs, nine TVs, and TVs near organs at risk (OARs) were designed. For these cases, SRT plans were developed, and plan quality was assessed using metrics including the Radiation Therapy Oncology Group conformality index (RTOG CI), gradient index (GI), homogeneity index (HI), and the volume of normal brain tissue receiving a dose of 24 Gy ( V24 Gy), which was defined as the volume enclosed by the 24 Gy isodose line around the Brain-PTV ( V24 Gy of Brain-PTV). Verification plans were generated for each test case, including the verification of point doses, planar doses (PD), and SRS MapCHECK (SMC) semiconductor matrix planar doses. Compared with the calculated result of the treatment planning system (TPS), the criteria for the γ analysis of planar doses were set at 1 mm/2% and 2 mm/2%. Results:For the four groups of test cases, the mean CI, GI, HI, and V24 Gy of Brain-PTV were 1.04±0.03, 3.79±0.40, 0.73±0.01 and (7.46±3.80) cm 3, respectively. The mean deviations of the point doses were 0.88%±0.98%, 1.47%±0.79%, 1.52%± 0.76%, and 1.17% ± 0.38%, respectively. The mean γ passing rates of the single fields for PDs were greater than 98% at 2 mm/2% and exceeding 96% at 1 mm/2%, and the mean γ pass rates of the SMC semiconductor matrix for PDs were 97.75% ± 2.31% and 99.33% ± 0.62%, at 1 mm/2% and 2 mm/2% respectively. Conclusions:The proposed QA test cases for SRT of multiple intracranial metastases allow for the effective assessments of the plan quality and machine execution capabilities and, thus, can assist various centers in clinical applications.

High altitude heart disease(HAHD)is a chronic mountain sickness in which the body is exposed to high altitude(＞2 500 m)hypobaric hypoxia environment for a long time.HAHD has high morbidity and poor prognosis,and pulmonary hypertension is the main causative mechanism for its develop-ment.The phosphodiesterase-5 inhibitor sildenafil has become a hot drug for the treatment of pulmonary hypertension.This paper reviews the progress of HAHD and discusses the mechanism of action and effectiveness of sildenafil in the treatment of HAHD,with a view to providing a basis for the treatment of HAHD with sildenafil.

Objective Prepubertal mice are administered subcutaneously with letrozole sustained-release pellets behind the neck and treated with a high-fat diet to establish a mouse model of polycystic ovary syndrome(PCOS).The liver transcriptomes of the model mice are compared with those of the placebo control mice to investigate the underlying mechanisms of liver involvement in the pathogenesis of PCOS.Methods A customized 2 mg dose of letrozole sustained-release pellets with a 40-day release period was used.The control placebo and letrozole pellets were implanted subcutaneously in the dorsal cervical region of 3-4-week-old C57BL/6J mice(8 mice per group)to establish the control group and letrozole-induced PCOS model group.Both groups were treated with a high-fat diet starting the day after administration.The modeling period lasted for 5 weeks,during which body weight and 24-hour food intake were monitored in each group every week.When samples were collected,liver weight was recorded.Pathological changes in ovarian and hepatic tissues were examined by hematoxylin-eosin(HE)staining,while hepatic lipid deposition was observed by Oil Red O staining.The extent of macrophage infiltration in the liver was evaluated via F4/80 immunohistochemical staining,and hepatic fibrosis levels were observed by Masson's trichrome staining.Transcriptomic sequencing was performed to analyze differentially expressed genes(DEGs)in liver tissues between the control and model groups,followed by enrichment analysis of significant DEGs.Quantitative real-time fluorescent quantitative PCR(qPCR)was subsequently used to validate the expression of significant DEGs in liver tissues of both groups.Results Compared with the control group,the model group which received subcutaneous letrozole sustained-release pellets combined with a high-fat diet exhibited significantly increased body weight(P＜0.001),prominent polycystic ovarian morphology,and significantly decreased liver-to-body weight ratio(P＜0.05).However,no significant changes were observed in absolute liver weight(P＞0.05),hepatic histomorphology,or lipid deposition.Transcriptome sequencing identified 119 upregulated and 217 downregulated DEGs in the liver tissues of letrozole-treated mice,which were predominantly enriched in pathways related to cholesterol and steroid biosynthesis,steroid hormone metabolism,and inflammatory responses.qPCR validation demonstrated that mRNA expression of HSD3B2 and HMGCR was significantly upregulated in liver(P＜0.01),while mRNA expression of IL4,CCL2 and COL1A1 was downregulated(P＜0.05)in the model group compared with the control group.However,Masson's trichrome staining and F4/80 immunohistochemical analysis showed no significant changes in hepatic fibrosis or macrophage infiltration.Conclusion Subcutaneous administration of letrozole sustained-release pellets combined with a high-fat diet successfully establishes a mouse model of PCOS.The model mice exhibited significant changes in hepatic gene expression.Liver may contribute to PCOS pathogenesis through regulating cholesterol and steroid metabolism.

OBJECTIVE To analyze the blood components of Suanzaoren Decoction after oral administration using UHPLC-Q Exactive Orbitrap-MS technology.METHODS Female Sprague-Dawley(SD)rats were used as experimental subjects,and Suanza-oren Decoction was administered orally.Serum samples were collected,and the aqueous extract of Suanzaoren Decoction and the serum were analyzed using UHPLC-Q Exactive Orbitrap-MS technology to identify the prototype components and metabolites absorbed into the blood by comparing and analyzing with the LuMet-TCM database.RESULTS It showed that a total of 458 components were iden-tified in the aqueous extract of Suanzaoren Decoction,and 26 chemical components were identified in the blood,including 23 prototype components and 3 metabolites.CONCLUSION The prototype components absorbed into the blood discovered in this study may be the active ingredients of Suanzaoren Decoction,providing a reference for the research on the pharmacodynamic material basis of Suanza-oren Decoction.

Objective:To analyze the epidemiological characteristics and trends of preterm births in China using medical institution survey data, thereby providing epidemiological data support for perinatal care.Methods:Based on a nationwide sampling survey on healthcare quality data from 2017 to 2022, this study included 3 547, 4 436, 4 513, 4 535, 5 068, and 5 790 medical institutions, with 7 039 107, 8 926 441, 9 006 420, 7 051 984, 7 311 862, and 7 354 062 parturient women, respectively. The overall rates of preterm birth (live births at 28 to 36 +6 weeks of gestation/overall live births) and early preterm birth (live births at 28 to <34 weeks of gestation/overall live births) were calculated at the national level, across diverse provinces, autonomous regions, municipalities and Xinjiang Production and Construction Corps, and for various levels of medical institutions. Generalized estimating equations were used to analyze the influence of maternal characteristics and medical institution characteristics on the rates of preterm birth and early preterm birth. Results:From 2017 to 2022, both the preterm birth rate and the early preterm birth rate in China showed a continuous increase. The preterm birth rate rose from 5.13% (363 036/7 079 454) in 2017 to 6.56% (487 150/7 424 734) in 2022, and the early preterm birth rate increased from 1.32% (118 021/8 971 870) in 2018 to 1.43% (106 157/7 424 734) in 2022. These rates showed an overall increasing trend in private, secondary public specialty, and general hospitals. In tertiary public specialty hospitals, these rates fluctuated around 8.0% and 2.0% from the year 2018, respectively, while in tertiary public general hospitals, these rates peaked in 2020 at 8.63% (205 570/2 381 523) and 2.19% (52 197/2 381 523), respectively. Compared with 2017, by 2022, the preterm birth rate had increased to varying degrees in all provinces, autonomous regions, municipalities and Xinjiang Production and Construction Corps, except for Henan Province [preterm birth rate in 2017 was 6.22% (27 173/437 187); preterm birth rate in 2022 was 5.83% (37 604/645 104)]. As for the early preterm birth rate, it showed a decline in Fujian, Guangdong, Guangxi, Hainan, Henan, Jiangsu, Shanghai, Xinjiang, Yunnan, and Zhejiang, but had increased to varying degrees in all other provinces , autonomous regions, municipalities and Xinjiang Production and Construction Corps across the country. The grade and location of medical institutions both had a significant impact on the preterm birth rate and early preterm birth rate (both P<0.05). For every 1% increase in the proportions of multiparous women, women of advanced maternal age, or twin pregnancies, the preterm birth rate increased by 0.014%, 0.042%, and 0.763%, and the early preterm birth rate increased by 0.004%, 0.013%, and 0.239%, respectively (all P<0.05). Conclusion:From 2017 to 2022, the preterm birth rate and early preterm birth rate in China have continued to rise, reflecting the dual challenges of changing characteristics in the childbearing population and the uneven distribution of medical and health resources faced by maternal and child healthcare in China.

Objective:To investigate the hepatoprotective effect of N-acetylcysteine(NAC)on rats with liver injury induced by cisplatin and its effect on intestinal flora and the expression of interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),and nuclear factor-kappa B(NF-κB).Methods:Male Sprague-Dawley rats were randomly divided into control group(CG),cisplatin group(CP),and NAC group.The rats in the NAC group were given NAC 15 mg/kg by gavage for 8 consecutive days.At half an hour after intragastric administration on the fifth day,all rats except those in the NC group were given intraperitoneal injection of 8 mg/kg cisplatin to induce acute liver injury.An automatic biochemical analyzer was used to measure the content of aspartate aminotransferase(AST),alanine aminotransferase(ALT),alkaline phosphatase(ALP),and total bilirubin(TBIL);liver index was calculated for the rats;Western blot was used to measure the relative expression levels of NF-κB,IL-6,and TNF-α in liver tissue;the 16S rDNA technique was used to measure and analyze the amplification information of the V3-V4 regions of each sample.Results:Compared with the NC group,the CP group had significant increases in the content of AST,ALT,ALP,and TBIL,while NAC reversed the abnormal liver function caused by cisplatin.Compared with the NC group,the CP group had a sig-nificant increase in liver index(P=0.000),while the NAC group had a significant reduction in liver index compared with the CP group(P=0.007).Compared with the NC group,the CP group had signifi-cant increases in the expression levels of IL-6,TNF-α,and NF-κB,while the NAC group showed reductions in the expression of these genes,with significant differences in the expression of IL-6 and TNF-α(P=0.006 and 0.000).Compared with the NC group,the CP group had a significant increase in the α-diversity index of intesti-nal flora,while compared with the CP group,the NAC group tended to have a reduction in the α-diversity index of intestinal flora.Com-pared with the CP group at the phylum level,the NAC group had an increase in the abundance of Actinobacteria and a reduction in the abundance of Firmicutes.Compared with the CP group at the genus level,the NAC group had a reduction in the abundance of Rumino-coccaceae and increases in the abundance of Bifidobacterium and Allobaculum.Conclusion:NAC can alleviate acute liver injury caused by cisplatin,possibly by downregulating the expression of IL-6,TNF-α,and NF-κB and regulating the abundance and diver-sity of intestinal flora.

Objective:To investigate the nutritional risk status of children in PICU and analyze its influencing factors.Methods:From July 2021 to February 2023,all children aged 1 to 18 years admitted to PICU of Beijing Children's Hospital were investigated by using the pediatric Yorkhill Malnutrition Scoring tool(PYMS)and the clinical data questionnaire.Results:A total of 492 children in PICU were enrolled.The first nutritional risk screening results showed that there were 32 cases of no/low nutritional risk(6.5%),76 cases of medium risk(15.4%),and 384 cases of high risk(78.1%).The incidence of medium/high nutritional risk was as high as 93.5%.The PYMS score of nutritional risk in PICU was(2.61±1.42).The results of multiple linear regression analysis showed that weight,fever time before admission,white blood cells,body mass index,primary diagnosis,father's education,and diet before illness were the main influencing factors of nutritional risk of children in PICU(P<0.05).Conclusion:Children in PICU are in a state of high nutritional risk.It is suggested that children in PICU should carry out nutritional screening in a standardized manner,identify children with high nutritional risk and its influencing factors early.To actively conduct nutritional assessment and nutritional intervention could improve the clinical outcome of children in PICU.

Objective:To analyze the epidemiological characteristics and trends of preterm births in China using medical institution survey data, thereby providing epidemiological data support for perinatal care.Methods:Based on a nationwide sampling survey on healthcare quality data from 2017 to 2022, this study included 3 547, 4 436, 4 513, 4 535, 5 068, and 5 790 medical institutions, with 7 039 107, 8 926 441, 9 006 420, 7 051 984, 7 311 862, and 7 354 062 parturient women, respectively. The overall rates of preterm birth (live births at 28 to 36 +6 weeks of gestation/overall live births) and early preterm birth (live births at 28 to <34 weeks of gestation/overall live births) were calculated at the national level, across diverse provinces, autonomous regions, municipalities and Xinjiang Production and Construction Corps, and for various levels of medical institutions. Generalized estimating equations were used to analyze the influence of maternal characteristics and medical institution characteristics on the rates of preterm birth and early preterm birth. Results:From 2017 to 2022, both the preterm birth rate and the early preterm birth rate in China showed a continuous increase. The preterm birth rate rose from 5.13% (363 036/7 079 454) in 2017 to 6.56% (487 150/7 424 734) in 2022, and the early preterm birth rate increased from 1.32% (118 021/8 971 870) in 2018 to 1.43% (106 157/7 424 734) in 2022. These rates showed an overall increasing trend in private, secondary public specialty, and general hospitals. In tertiary public specialty hospitals, these rates fluctuated around 8.0% and 2.0% from the year 2018, respectively, while in tertiary public general hospitals, these rates peaked in 2020 at 8.63% (205 570/2 381 523) and 2.19% (52 197/2 381 523), respectively. Compared with 2017, by 2022, the preterm birth rate had increased to varying degrees in all provinces, autonomous regions, municipalities and Xinjiang Production and Construction Corps, except for Henan Province [preterm birth rate in 2017 was 6.22% (27 173/437 187); preterm birth rate in 2022 was 5.83% (37 604/645 104)]. As for the early preterm birth rate, it showed a decline in Fujian, Guangdong, Guangxi, Hainan, Henan, Jiangsu, Shanghai, Xinjiang, Yunnan, and Zhejiang, but had increased to varying degrees in all other provinces , autonomous regions, municipalities and Xinjiang Production and Construction Corps across the country. The grade and location of medical institutions both had a significant impact on the preterm birth rate and early preterm birth rate (both P<0.05). For every 1% increase in the proportions of multiparous women, women of advanced maternal age, or twin pregnancies, the preterm birth rate increased by 0.014%, 0.042%, and 0.763%, and the early preterm birth rate increased by 0.004%, 0.013%, and 0.239%, respectively (all P<0.05). Conclusion:From 2017 to 2022, the preterm birth rate and early preterm birth rate in China have continued to rise, reflecting the dual challenges of changing characteristics in the childbearing population and the uneven distribution of medical and health resources faced by maternal and child healthcare in China.