Tumor metabolic reprogramming and immune escape synergistically promote tumor progression, in which methionine (Met) metabolism plays a key role through epigenetic regulation and immune microenvironment remodelling. This paper systematically summarzes the mechanisms by which aberrant Met metabolism leads to “methionine addiction” and maintains the malignant phenotype of tumor cells, and describes its multiple modulations of the immune system: inducing T-cell depletion, promoting the polarization of M2-type macrophages, inhibiting the activity of NK cells, and enhancing the function of tumor-associated fibroblasts. Furthermore, therapeutic strategies targeting Met metabolism, including methionine-restricted diets, metabolic enzyme (MAT2A, NNMT) inhibitors, and epigenetic targets (PRMT5 inhibitors), are explored to provide theoretical reference for the development of Met-targeted therapies.

T7 RNA polymerase (T7 RNAP) is one of the simplest known RNA polymerases. Its unique structural features make it a critical model for studying the mechanisms of RNA synthesis. This review systematically examines the static crystal structure of T7 RNAP, beginning with an in-depth examination of its characteristic “thumb”, “palm”, and “finger” domains, which form the classic “right-hand-like” architecture. By detailing these structural elements, this review establishes a foundation for understanding the overall organization of T7 RNAP. This review systematically maps the functional roles of secondary structural elements and their subdomains in transcriptional catalysis, progressively elucidating the fundamental relationships between structure and function. Further, the intrinsic flexibility of T7 RNAP and its applications in research are also discussed. Additionally, the review presents the structural diagrams of the enzyme at different stages of the transcription process, and through these diagrams, it provides a detailed description of the complete transcription process of T7 RNAP. By integrating structural dynamics and kinetics analyses, the review constructs a comprehensive framework that bridges static structure to dynamic processes. Despite its advantages, T7 RNAP has a notable limitation: it generates double-stranded RNA (dsRNA) as a byproduct. The presence of dsRNA not only compromises the purity of mRNA products but also elicits nonspecific immune responses, which pose significant challenges for biotechnological and therapeutic applications. The review provides a detailed exploration of the mechanisms underlying dsRNA formation during T7 RNAP catalysis, reviews current strategies to mitigate this issue, and highlights recent progress in the field. A key focus is the semi-rational design of T7 RNAP mutants engineered to minimize dsRNA generation and enhance catalytic performance. Beyond its role in transcription, T7 RNAP exhibits rapid development and extensive application in fields, including gene editing, biosensing, and mRNA vaccines. This review systematically examines the structure-function relationships of T7 RNAP, elucidates the mechanisms of dsRNA formation, and discusses engineering strategies to optimize its performance. It further explores the engineering optimization and functional expansion of T7 RNAP. Furthermore, this review also addresses the pressing issues that currently need resolution, discusses the major challenges in the practical application of T7 RNAP, and provides an outlook on potential future research directions. In summary, this review provides a comprehensive analysis of T7 RNAP, ranging from its structural architecture to cutting-edge applications. We systematically examine: (1) the characteristic right-hand domains (thumb, palm, fingers) that define its minimalistic structure; (2) the structure-function relationships underlying transcriptional catalysis; and (3) the dynamic transitions during the complete transcription cycle. While highlighting T7 RNAP’s versatility in gene editing, biosensing, and mRNA vaccine production, we critically address its major limitation—dsRNA byproduct formation—and evaluate engineering solutions including semi-rationally designed mutants. By synthesizing current knowledge and identifying key challenges, this work aims to provide novel insights for the development and application of T7 RNAP and to foster further thought and progress in related fields.

Objective To establish a scientific, comprehensive, and operable community resilience evaluation index system for emergent major infectious diseases. Methods Based on the social ecosystem theory, a preliminary evaluation index system was formed by using content analysis and boundary analysis. The index system was then supplemented and revised through panel discussions. The final index system and index weights were clarified by two rounds of Delphi method. Results The expert positive coefficient, expert authority coefficient, and expert coordination coefficient of the two rounds of expert consultations were examined. According to the screening principle of the ^“threshold method^”, the indicators were screened, and the weights of each indicator were determined in the second round of Delphi expert consultation. The analysis of the reliability of the indicator system showed Cronbach's α= 0.399 , indicating that the indicator system had a relatively high reliability. Factor analysis was carried out on 7 primary indicators, and the measure of sampling adequacy (MSA) values were all greater than 0.5, which passed the validity test. Conclusion A set of evaluation index system that can accurately reflect the resilience level of communities with emergent major infectious diseases has been constructed, including 7 primary indicators, 21 secondary indicators, 54 tertiary indicators, and 108 tertiary indicators, which has realized the quantitative evaluation of the hidden resilience level of communities.

OBJECTIVE: This study reports the first imported case of Lassa fever (LF) in China. Laboratory detection and molecular epidemiological analysis of the Lassa virus (LASV) from this case offer valuable insights for the prevention and control of LF. METHODS: Samples of cerebrospinal fluid (CSF), blood, urine, saliva, and environmental materials were collected from the patient and their close contacts for LASV nucleotide detection. Whole-genome sequencing was performed on positive samples to analyze the genetic characteristics of the virus. RESULTS: LASV was detected in the patient's CSF, blood, and urine, while all samples from close contacts and the environment tested negative. The virus belongs to the lineage IV strain and shares the highest homology with strains from Sierra Leone. The variability in the glycoprotein complex (GPC) among different strains ranged from 3.9% to 15.1%, higher than previously reported for the seven known lineages. Amino acid mutation analysis revealed multiple mutations within the GPC immunogenic epitopes, increasing strain diversity and potentially impacting immune response. CONCLUSION The case was confirmed through nucleotide detection, with no evidence of secondary transmission or viral spread. The LASV strain identified belongs to lineage IV, with broader GPC variability than previously reported. Mutations in the immune-related sites of GPC may affect immune responses, necessitating heightened vigilance regarding the virus.
Humans ; China/epidemiology* ; Genome, Viral ; Lassa Fever/virology* ; Lassa virus/classification* ; Molecular Epidemiology ; Phylogeny

OBJECTIVES: This study aimed to use machine learning algorithms to build a prediction model of the first permanent molar caries of 9-year-old children in Suzhou and screen out risk factors. METHODS: Random stratified whole group sampling was applied to randomly select 9-year-old students from 38 primary schools in 14 townships and streets in Wuzhong District for oral examination and questionnaire survey. Multifactor Logistics regression was used to analyze the risk factors of tooth decay. The data set was randomly divided into training sets and verification sets according to 8∶2, and R 4.3.1 was used to build five machine learning algorithms: random forest, decision tree, extreme gradient boosting (XGBoost), Logistics regression, and lightweight gradient enhancement (LightGBM). The predictive effect of these five models was evaluated using the area under the characteristic curve (AUC). The marginal contribution of quantitative characteristics to the caries prediction model was determined through Shapley additive explanations (SHAP). RESULTS: This study included 7 225 samples that met the standard. The caries rate of the first permanent molar was 54.96%. Multifactor Logistic regression analysis showed that sweet drinks, dessert and candy, snack frequency, and snacks before going to bed after brushing teeth were correlated with the occurrence of first permanent molar caries (P<0.05). The AUC values of decision tree, Logistic regression, LightGBM, random forest, and XGBoost were 75.5%, 83.9%, 88.6%, 88.9%, and 90.1%, respectively. Compared with the variables after single heat coding, the SHAP value of high-frequency sweets (such as dessert candy ≥2 times a day, mother's sugary diet ≥2 times a day) and bad oral hygiene habits (such as frequent snacks before going to bed after brushing teeth and irregular brushing teeth) exhibited the highest positive. CONCLUSIONS XGBoost algorithm has a good prediction effect for first permanent molar caries in 9-year-old children. High-frequency sweet factors and bad oral hygiene habits have a strong positive impact on the risk of first permanent molar caries and are key drivers that can be used in the formulation of targeted interventions.
Humans ; Dental Caries/epidemiology* ; Child ; Machine Learning ; China/epidemiology* ; Molar ; Risk Factors ; Female ; Logistic Models ; Male ; Decision Trees ; Algorithms

Objective:To investigate the liver-protective effect of Peipi Shugan Decoction (PSD) in rats with liver fibrosis through network pharmacology and experimental animal models.Methods:TCMSP was used to retrieve the active components of Peipi Shugan Decoction, GeneCards database was used to obtain the liver fibrosis related targets, and Venny 2.1 was used to obtain the intersection targets. A protein-protein interaction (PPI) network was constructed using the STRING 12.0 database, and Go function and KEGG pathway enrichment analysis were performed through David database. A total of 60 male Sprague-Dawley (SD) rats were divided into two groups: a blank control group ( n=10) and a model establishment group ( n=50) with random number table method. Liver fibrosis models were induced in the model group by intraperitoneal injection of a 40% CCl?- olive oil solution. After successful modeling, the rats were randomly assigned to the following groups ( n=10 per group): model group, colchicine group, and Peipi Shugan Decoction low-, medium-, and high-dosage groups. The colchicine group received colchicine suspension at 0.2 ml/kg via intragastric administration. Peipi Shugan Decoction low-, medium-, and high-dosage groups were administered the decoction at dosages of 2.81, 5.63, and 11.25 g/kg, respectively. The blank control and model groups received an equal volume of normal saline. All treatments were administered once daily for 8 consecutive weeks. HE staining and Masson staining were used to observe the morphological changes of liver tissue and the deposition of collagen fibers. he levels of GPT, GOT and ALP were detected by automatic biochemical analyzer. The expressions of JAK2/STAT1 signaling pathway related proteins, α - smooth muscle actin (α-SMA) and Collagen Ⅰ in rat liver were detected by Western blot. The expression of α-SMA protein in liver tissue was detected by immunohistochemistry. The number and ratio of CD4 + T cells and CD8 + T cells in liver tissue were analyzed by flow cytometry. The levels of IL-6, IL-1β and TNF-α in serum were detected by ELISA. Results:A total of 94 active components were screened out from Peipi Shugan Decoction; the prediction analysis results revealed that this compound formula shared 122 common targets with liver fibrosis diseases; The top five core targets with degree values in the PPI network are AKT1, TNF, IL-6, TP53, and IL-1β. GO enrichment analysis further indicated that Peipi Shugan Decoction mainly achieved anti-liver fibrosis effects by regulating JAK2/STAT1 signaling pathway and other mechanisms. Compared with the model group, the colchicine group and Peipi Shugan Decoction low-, medium-, and high-dosage groups exhibited decreased serum levels of GPT, GOT, ALP, IL-6, TNF-α, and IL-1β ( P<0.05), as well as reduced expression of α-SMA in liver tissue ( P<0.05). Peipi Shugan Decoction medium- and high-dosage groups showed increased protein expression of p-STAT1/STAT1 in liver tissue ( P<0.05), while Peipi Shugan Decoction high-dosage group demonstrated decreased α-SMA protein expression ( P<0.05). Additionally, Peipi Shugan Decoction medium- and high-dosage groups exhibited reduced expressions of CD4 + and CD8 + ( P<0.05). Conclusions:Peipi Shugan Decoction has the characteristics of multi-component, multi-target and multi-pathway in the treatment of liver fibrosis. Its mechanism is mainly related to activating the JAK2/STAT1 signaling pathway, inhibiting cellular inflammatory responses and hindering the activation of hepatic stellate cells (HSC).

Objective To analyze the correlation between hemoglobin(Hb),anemia,and sarcopenia in the elderly population in Chongqing communities.Methods A cross-sectional study was conducted on elderly individuals who underwent healthy examinations at 5 community health service centers in Chongqing from March to August 2023.Demographic characteristics,social factors,body composition measurement,grip strength,6-meter gait speed and blood tests were assessed.Receiver operating characteristic(ROC)curve was utilized to evaluate the accuracy of Hb in predicting sarcopenia,and the Youden index was employed to determine the optimal Hb cut-off value for diagnosing sarcopenia and its components.Both unadjusted and adjusted logistic regression analyses were performed to examine the relationship between Hb and anemia with sarcopenia and its components.Results A total of 531 elderly populations were included,with an average age of(71.1±6.5)years.The overall prevalence of sarcopenia was 13.6%(72/531),including 29 males(40.3%)and 43 females(59.7%).Unadjusted analyses showed that Hb was correlated with sarcopenia,decreased muscle mass,slower gait speed,and reduced grip strength(P<0.05).After adjusting for all potential risk factors,Hb was still significantly associated with sarcopenia and reduced grip strength(P<0.05).For every 10 g/L increase in Hb,the risk of sarcopenia decreased by 2.3%,and the risk of reduced grip strength decreased by 1.7%(P<0.05).Anemia was correlated with sarcopenia,reduced muscle mass,and decreased grip strength in unadjusted analyses(P<0.05),while the correlation between anemia and reduced grip strength remained significant after adjustment for all potential risk factors(P<0.05).The optimal Hb cut-off value for diagnosing sarcopenia in males and females were 148 g/L and 128 g/L,respectively.Conclusions Hb is an independent risk factor for sarcopenia and reduced grip strength.Anemia is associated with sarcopenia,but is not an independent risk factor for sarcopenia.

Objective To investigate the predictive value of temperature gradients on the mortality of sepsis patients and their correlation with fluid input.Methods By means of a prospective observational method,154 patients with sepsis or septic shock admitted to the Department of Critical Care Medicine at Nanfang Hospital,Southern Medical University from November 2019 to November 2021 were included as research subjects.They were divided into a survivor group(n=118)and a non-survivor group(n=36)according to whether they survived within 28 days.The core-to-toe temperature gradient(CTTG)and toe-to-room temperature gradient(TRTG)were monitored and calculated immediately upon admission to the intensive care unit(ICU)and 6 hours after admission.Receiver operating characteristic(ROC)curve was used to explore the predictive value of temperature gradients on mortality,and multivariate Cox regression analysis was performed to explore the risk factors of 28-day mortality in sepsis patients.The results were verified through survival analysis.Correlation analysis and multivariate analysis of variance were used to explore the correlation between temperature gradients and fluid input,as well as noradrenaline doses.Results Among the 154 patients,118 survived within 28 days(survivor group),and 36 died(non-survivor group).ROC curve and multivariate Cox regression analysis showed that a toe-to-room temperature gradient of≤5.35℃within 6 hours after admission was a risk factor for 28-day mortality.Compared with patients with a high toe-to-room temperature gradient(>5.35℃),patients with a low toe-to-room temperature gradient(≤5.35℃)had a 2.74-fold increase in the risk of 28-day mortality(P=0.004,95%CI 1.54,9.12).The CTTG and TRTG upon admission to the ICU and 6 hours after admission were not significantly associated with fluid input or noradrenaline doses(P>0.05).Conclusions A toe-to-room temperature gradient of less than or equal to 5.35℃within 6 hours after ICU admission is a risk factor for 28-day mortality in sepsis patients.The improvement of temperature gradients at different time points is not associated with fluid input.