OBJECTIVE To provide references for optimizing the review and approval system of clinically urgent overseas-marketed drugs in China. METHODS The characteristics of the review and approval system for clinically urgent overseas-marketed drugs were analyzed. A comparative research method was employed to examine differences between China and Australia， Switzerland， and Canada in three dimensions： qualification determination for clinical urgency （i.e.， access qualification）， review methods， and approval modalities. RESULTS & CONCLUSIONS In China’s current system， the legal nature of communication and consultation meetings is ambiguous， as the qualification determination function is embedded within technical consultation procedures without remedy channels. The pre-marketing clinical trial exemption for drugs is disconnected from the post-marketing confirmation obligation， and insufficient access to complete overseas review information weakens risk control effectiveness. A differentiated triage mechanism based on the timing of global approval has not been established， providing insufficient incentives for global simultaneous research and development. International typical regulatory models set access qualification， review methods， and approval modalities as independent modules， forming a quid pro quo relationship by relaxing pre-marketing access conditions and establishing post-marketing conditional approval mechanisms. It is recommended to formulate technical guidelines for the determination of clinically urgent drugs to clarify objective discretionary benchmarks， clarify the legal nature of communication and consultation meetings and allocate remedy channels， mandatorily include clinical trial-exempted varieties in the conditional approval procedure and establish a negative signal linkage mechanism， and implement differentiated triage based on approval timing， so as to improve China’s review and approval system.

Objective:To investigate the differences in acute intestinal injury and regulatory mechanisms in mice following carbon ion FLASH radiotherapy (FLASH-RT) and conventional dose rate radiotherapy (CONV-RT).Methods:Healthy C57BL/6J mice were randomly divided into three groups: control group, FLASH-RT group (100 Gy/s), and CONV-RT group (0.1 Gy/s), with 9 mice in each group. All mice received carbon ion whole abdominal radiotherapy. DNA double-strand breaks (DSB) and cell proliferation were evaluated by measuring the expression of phosphorylated histone H2AX (γ-H2AX) and nuclear-associated antigen 67 (Ki67) using immunohistochemistry; apoptosis was analyzed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL); transcriptome sequencing was used to analyze the differences in molecular pathways between FLASH-RT and CONV-RT.Results:Compared with the CONV-RT group, the FLASH-RT group showed significantly reduced intestinal γ-H2AX signal at 3 h after radiotherapy ( t=3.80, P<0.01), significantly increased expression of Ki67 at the base of intestinal crypts at 6 h after radiotherapy ( t=4.30, P<0.001), and a significantly decreased number of TUNEL-positive cells at 12 h after radiotherapy ( t=3.08, P<0.01). Transcriptome sequencing analysis showed that FLASH-RT specifically activated the insulin-like growth factor (IGF) pathway, avoiding the excessive activation of CONV-RT-induced nuclear factor-κB and B cell receptor inflammatory pathways as well as the inhibition of energy metabolism. Conclusions:Compared with CONV-RT, carbon ion FLASH-RT can reduce DSB damage, preserve the proliferative activity of intestinal stem cells, activate the IGF pathway, and regulate inflammatory, immune, and metabolic pathways, thereby significantly alleviating acute intestinal epithelial injury. Specifically, the regulation of repair pathways mediated by reduced DSB and the inhibition of inflammatory pathways are potential protective mechanisms for normal tissues.

FLASH irradiation (FLASH-IR) is one of the cutting-edge research directions in the field of tumor radiotherapy. Previous studies have demonstrated that FLASH-IR can effectively eradicate tumors while significantly reducing damage to normal tissues, exhibiting unique biological effects characterized by high efficiency and low toxicity. Monte Carlo simulation at the microscopic scale is a critical method for studying radiobiological effects and has been widely applied in conventional radiotherapy research. In recent years, its application in microscopic reaction analysis and mechanistic exploration of FLASH-IR has grown rapidly. This article systematically reviews the latest advances and key challenges in microscopic Monte Carlo simulation studies of FLASH-IR, aiming to provide theoretical insights and method ological guidance for future research.

OBJECTIVE: To explore the clinical manifestations and genetic etiology of a child with Progressive familial intrahepatic cholestasis (PFIC2). METHODS: From April 2024 to June 2024, a child with jaundice, hepatomegaly and abnormal liver function who was repeatedly admitted to the First Department of Pediatrics of Qinzhou Maternal and Child Health Care Hospital was selected as the study subject. Clinical data of the child were collected. Peripheral blood samples were collected from the child and her parents. Genomic DNA was extracted for trio-whole exome sequencing, the candidate variant was verified by Sanger sequencing and bioinformatic analysis using REVEL, BLAST/BLAT, Swiss-Model and Swiss-Pdb Viewer software. This study was approved by the Medical Ethics Committee of the Qinzhou Maternal and Child Health Care Hospital (Ethics No.: L20240116). RESULTS: The child was a 1.5-month-old female. Her main clinical manifestations included jaundice, hepatomegaly, brownish urine and earth-like stool. Laboratory examination showed increased levels of bilirubin, mainly direct bilirubin, increased aminotransferase, especially glutamic oxalacetic aminotransferase, accompanied by increased bile acid. Genetic testing revealed that the she has harbored a homozygous c.3410T>G (p.V1137G) variant of the ABCB11 gene, for which both of her parents were heterozygous carriers. The variant was unreported previously, and was predicted to be pathogenic based on REVEL. Prediction with BLAST/BLAT software showed that the amino acids were highly conserved among different species. Swiss-Pdb Viewer software predicted that the variant has resulted in changes in hydrogen bonds between amino acids. According to the guidelines from the American Collage for Medical Genetics and Genomics (ACMG), the variant was determined to be likely pathogenic (PM1+PM2_Supporting+PM3_Supporting+PP3_Moderate). CONCLUSION The homozygous variant of the ABCB11 gene may be the genetic cause of this child. Genetic testing is helpful for confirming the diagnosis and enrich the mutational spectrum of the ABCB11 gene.
Humans ; Cholestasis, Intrahepatic/genetics* ; Female ; Infant ; ATP Binding Cassette Transporter, Subfamily B, Member 11/genetics* ; Homozygote ; Mutation

Objective:To explore the clinical manifestations and genetic etiology of a child with Progressive familial intrahepatic cholestasis (PFIC2).Methods:From April 2024 to June 2024, a child with jaundice, hepatomegaly and abnormal liver function who was repeatedly admitted to the First Department of Pediatrics of Qinzhou Maternal and Child Health Care Hospital was selected as the study subject. Clinical data of the child were collected. Peripheral blood samples were collected from the child and her parents. Genomic DNA was extracted for trio-whole exome sequencing, the candidate variant was verified by Sanger sequencing and bioinformatic analysis using REVEL, BLAST/BLAT, Swiss-Model and Swiss-Pdb Viewer software. This study was approved by the Medical Ethics Committee of the Qinzhou Maternal and Child Health Care Hospital (Ethics No.: L20240116).Results:The child was a 1.5-month-old female. Her main clinical manifestations included jaundice, hepatomegaly, brownish urine and earth-like stool. Laboratory examination showed increased levels of bilirubin, mainly direct bilirubin, increased aminotransferase, especially glutamic oxalacetic aminotransferase, accompanied by increased bile acid. Genetic testing revealed that the she has harbored a homozygous c. 3410T>G (p.V1137G) variant of the ABCB11 gene, for which both of her parents were heterozygous carriers. The variant was unreported previously, and was predicted to be pathogenic based on REVEL. Prediction with BLAST/BLAT software showed that the amino acids were highly conserved among different species. Swiss-Pdb Viewer software predicted that the variant has resulted in changes in hydrogen bonds between amino acids. According to the guidelines from the American Collage for Medical Genetics and Genomics (ACMG), the variant was determined to be likely pathogenic (PM1+ PM2_Supporting+ PM3_Supporting+ PP3_Moderate). Conclusion:The homozygous variant of the ABCB11 gene may be the genetic cause of this child. Genetic testing is helpful for confirming the diagnosis and enrich the mutational spectrum of the ABCB11 gene.

Objective:To investigate the influencing factors of adult dental fluorosis in drinking water-borne endemic fluorosis areas of Inner Mongolia Autonomous Region.Methods:A case-control study was conducted in January 2024 to select adult fluorosis patients (case group) and healthy individuals (control group) from the drinking water-borne endemic fluorosis areas in Helinger County, Hohhot City, Inner Mongolia Autonomous Region as the survey subjects. Urine samples were collected to determine urinary fluoride concentration. A questionnaire survey was conducted. SPSS 25.0 software was used for χ 2 test and multivariate logistic regression analysis. Restricted cubic spline (RCS) was used to analyze the association between urinary fluoride concentration and the risk of dental fluorosis in adults. Results:A total of 161 individuals were included in the survey, including 100 in the case group and 61 in the control group. The results of univariate analysis showed that there were statistically significant differences in the distribution of gender, smoking, and urinary fluoride concentration between the case group and the control group (χ 2 = 7.54, 5.02, 9.69, P < 0.05). The results of multivariate logistic regression analysis indicated that gender ( OR = 0.36, 95% CI: 0.18 - 0.73, P = 0.005) and urinary fluoride concentration ( OR = 3.08, 95% CI: 1.46 - 6.67, P = 0.003) were the influencing factors of adult fluorosis. RCS analysis showed a significant linear dose-response relationship between the risk of dental fluorosis and urinary fluoride concentration ( Poverall trend = 0.001, Pnonlinear = 0.071). When the urinary fluoride concentration was greater than 1.57 mg/L, the risk of dental fluorosis increased with the increase of urinary fluoride concentration. Conclusion:Gender and urinary fluoride concentration are the risk factors of dental fluorosis in adults in drinking water-borne endemic fluorosis areas of Inner Mongolia Autonomous Region.

Objective:To investigate the differences in acute intestinal injury and regulatory mechanisms in mice following carbon ion FLASH radiotherapy (FLASH-RT) and conventional dose rate radiotherapy (CONV-RT).Methods:Healthy C57BL/6J mice were randomly divided into three groups: control group, FLASH-RT group (100 Gy/s), and CONV-RT group (0.1 Gy/s), with 9 mice in each group. All mice received carbon ion whole abdominal radiotherapy. DNA double-strand breaks (DSB) and cell proliferation were evaluated by measuring the expression of phosphorylated histone H2AX (γ-H2AX) and nuclear-associated antigen 67 (Ki67) using immunohistochemistry; apoptosis was analyzed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL); transcriptome sequencing was used to analyze the differences in molecular pathways between FLASH-RT and CONV-RT.Results:Compared with the CONV-RT group, the FLASH-RT group showed significantly reduced intestinal γ-H2AX signal at 3 h after radiotherapy ( t=3.80, P<0.01), significantly increased expression of Ki67 at the base of intestinal crypts at 6 h after radiotherapy ( t=4.30, P<0.001), and a significantly decreased number of TUNEL-positive cells at 12 h after radiotherapy ( t=3.08, P<0.01). Transcriptome sequencing analysis showed that FLASH-RT specifically activated the insulin-like growth factor (IGF) pathway, avoiding the excessive activation of CONV-RT-induced nuclear factor-κB and B cell receptor inflammatory pathways as well as the inhibition of energy metabolism. Conclusions:Compared with CONV-RT, carbon ion FLASH-RT can reduce DSB damage, preserve the proliferative activity of intestinal stem cells, activate the IGF pathway, and regulate inflammatory, immune, and metabolic pathways, thereby significantly alleviating acute intestinal epithelial injury. Specifically, the regulation of repair pathways mediated by reduced DSB and the inhibition of inflammatory pathways are potential protective mechanisms for normal tissues.

FLASH irradiation (FLASH-IR) is one of the cutting-edge research directions in the field of tumor radiotherapy. Previous studies have demonstrated that FLASH-IR can effectively eradicate tumors while significantly reducing damage to normal tissues, exhibiting unique biological effects characterized by high efficiency and low toxicity. Monte Carlo simulation at the microscopic scale is a critical method for studying radiobiological effects and has been widely applied in conventional radiotherapy research. In recent years, its application in microscopic reaction analysis and mechanistic exploration of FLASH-IR has grown rapidly. This article systematically reviews the latest advances and key challenges in microscopic Monte Carlo simulation studies of FLASH-IR, aiming to provide theoretical insights and method ological guidance for future research.

Objective:To investigate the influencing factors of adult dental fluorosis in drinking water-borne endemic fluorosis areas of Inner Mongolia Autonomous Region.Methods:A case-control study was conducted in January 2024 to select adult fluorosis patients (case group) and healthy individuals (control group) from the drinking water-borne endemic fluorosis areas in Helinger County, Hohhot City, Inner Mongolia Autonomous Region as the survey subjects. Urine samples were collected to determine urinary fluoride concentration. A questionnaire survey was conducted. SPSS 25.0 software was used for χ 2 test and multivariate logistic regression analysis. Restricted cubic spline (RCS) was used to analyze the association between urinary fluoride concentration and the risk of dental fluorosis in adults. Results:A total of 161 individuals were included in the survey, including 100 in the case group and 61 in the control group. The results of univariate analysis showed that there were statistically significant differences in the distribution of gender, smoking, and urinary fluoride concentration between the case group and the control group (χ 2 = 7.54, 5.02, 9.69, P < 0.05). The results of multivariate logistic regression analysis indicated that gender ( OR = 0.36, 95% CI: 0.18 - 0.73, P = 0.005) and urinary fluoride concentration ( OR = 3.08, 95% CI: 1.46 - 6.67, P = 0.003) were the influencing factors of adult fluorosis. RCS analysis showed a significant linear dose-response relationship between the risk of dental fluorosis and urinary fluoride concentration ( Poverall trend = 0.001, Pnonlinear = 0.071). When the urinary fluoride concentration was greater than 1.57 mg/L, the risk of dental fluorosis increased with the increase of urinary fluoride concentration. Conclusion:Gender and urinary fluoride concentration are the risk factors of dental fluorosis in adults in drinking water-borne endemic fluorosis areas of Inner Mongolia Autonomous Region.

Objective To investigate the role of poly(rC)-binding protein 1(PCBP1)in cadmium(Cd)-induced ferroptosis in mouse neuroblastoma Neuro-2a(N2A)cells.Methods N2A cells were exposed to a concentration gradient of CdCl?(0,1,2,4 μmol/L)for 72 h.Cell viability was assessed by trypan blue staining.Western blotting was employed to detect the expression of ferroptosis-related proteins(GPX4,HMOX1,ACSL4)and PCBP1.Intracellular Fe2? level and lipid peroxidation were detected using FerroOrange and BODIPY581/591 C11 probes,respectively.Ferrostatin-1(Fer-1),a ferroptosis inhibitor,was applied to confirm the critical role of ferroptosis in Cd-induced cytotoxicity.Molecular docking was performed to elucidate the interaction between PCBP1 and ferritin,as well as the binding sites of Cd2?.PCBP1 overexpression plasmid was further constructed for functional validation.Results Cd exposure suppressed cell viability in N2A cells in a dose-dependent manner(P<0.01),significantly down-regulated GPX4 expression(P<0.05),up-regulated HMOX1 expression(P<0.01),and induced Fe2? overload and lipid peroxidation(P<0.01).Molecular docking revealed that Cd2? directly bound to the KH2 domain of PCBP1 and then co-localized on the outer surface of ferritin heavy chain.Overexpression of PCBP1 markedly reversed Cd-induced Fe2? accumulation,GPX4 down-regulation,lipid peroxidation,and cell death.Conclusion Cd exposure disrupts PCBP1-mediated iron homeostasis via transcriptional suppression and competitive displacement of metal ions,and then synergistically drives Fe2? overload-triggered ferroptosis cascades,ultimately leading to neurotoxicity.Targeting PCBP1-mediated iron homeostasis can effectively mitigate Cd-induced neurotoxicity,and may serve as a novel therapeutic strategy.