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.

BACKGROUND: Based on the China-VHD database, this study sought to develop and validate a Valvular Heart Disease- specific Age-adjusted Comorbidity Index (VHD-ACI) for predicting mortality risk in patients with VHD. METHODS & RESULTS: The China-VHD study was a nationwide, multi-centre multi-centre cohort study enrolling 13,917 patients with moderate or severe VHD across 46 medical centres in China between April-June 2018. After excluding cases with missing key variables, 11,459 patients were retained for final analysis. The primary endpoint was 2-year all-cause mortality, with 941 deaths (10.0%) observed during follow-up. The VHD-ACI was derived after identifying 13 independent mortality predictors: cardiomyopathy, myocardial infarction, chronic obstructive pulmonary disease, pulmonary artery hypertension, low body weight, anaemia, hypoalbuminaemia, renal insufficiency, moderate/severe hepatic dysfunction, heart failure, cancer, NYHA functional class and age. The index exhibited good discrimination (AUC, 0.79) and calibration (Brier score, 0.062) in the total cohort, outperforming both EuroSCORE II and ACCI (P < 0.001 for comparison). Internal validation through 100 bootstrap iterations yielded a C statistic of 0.694 (95% CI: 0.665-0.723) for 2-year mortality prediction. VHD-ACI scores, as a continuous variable (VHD-ACI score: adjusted HR (95% CI): 1.263 (1.245-1.282), P < 0.001) or categorized using thresholds determined by the Yoden index (VHD-ACI ≥ 9 vs. < 9, adjusted HR (95% CI): 6.216 (5.378-7.184), P < 0.001), were independently associated with mortality. The prognostic performance remained consistent across all VHD subtypes (aortic stenosis, aortic regurgitation, mitral stenosis, mitral regurgitation, tricuspid valve disease, mixed aortic/mitral valve disease and multiple VHD), and clinical subgroups stratified by therapeutic strategy, LVEF status (preserved vs. reduced), disease severity and etiology. CONCLUSION The VHD-ACI is a simple 13-comorbidity algorithm for the prediction of mortality in VHD patients and providing a simple and rapid tool for risk stratification.

OBJECTIVE: To investigate the effectiveness of Xuanshen Yishen Decoction (XYD) in the treatment of hypertension. METHODS: Hospital electronic medical records from 2019-2023 were utilized to emulate a randomized pragmatic clinical trial. Hypertensive participants were eligible if they were aged ⩾40 years with baseline systolic blood pressure (BP) ⩾140 mm Hg. Patients treated with XYD plus antihypertensive regimen were assigned to the treatment group, whereas those who followed only antihypertensive regimen were assigned to the control group. The primary outcome assessed was the attainment rate of intensive BP control at discharge, with the secondary outcome focusing on the 6-month all-cause readmission rate. RESULTS: The study included 3,302 patients, comprising 2,943 individuals in the control group and 359 in the treatment group. Compared with the control group, a higher proportion in the treatment group achieved the target BP for intensive BP control [8.09% vs. 17.5%; odds ratio (OR)=2.29, 95% confidence interval (CI)=1.68 to 3.13; P<0.001], particularly in individuals with high homocysteine levels (OR=3.13; 95% CI=1.72 to 5.71; P<0.001; P for interaction=0.041). Furthermore, the 6-month all-cause readmission rate in the treatment group was lower than in the control group (hazard ratio=0.58; 95% CI=0.36 to 0.91; P=0.019), and the robustness of the results was confirmed by sensitivity analyse. CONCLUSIONS XYD could be a complementary therapy for intensive BP control. Our study offers real-world evidence and guides the choice of complementary and alternative therapies. (Registration No. ChiCTR2400086589).
Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Antihypertensive Agents/pharmacology* ; Blood Pressure/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Hypertension/physiopathology* ; Patient Readmission ; Treatment Outcome

Patients suffering from nerve injury often experience exacerbated pain responses and complain of memory deficits. The dorsal hippocampus (dHPC), a well-defined region responsible for learning and memory, displays maladaptive plasticity upon injury, which is assumed to underlie pain hypersensitivity and cognitive deficits. However, much attention has thus far been paid to intracellular mechanisms of plasticity rather than extracellular alterations that might trigger and facilitate intracellular changes. Emerging evidence has shown that nerve injury alters the microarchitecture of the extracellular matrix (ECM) and decreases ECM rigidity in the dHPC. Despite this, it remains elusive which element of the ECM in the dHPC is affected and how it contributes to neuropathic pain and comorbid cognitive deficits. Laminin, a key element of the ECM, consists of α-, β-, and γ-chains and has been implicated in several pathophysiological processes. Here, we showed that peripheral nerve injury downregulates laminin β1 (LAMB1) in the dHPC. Silencing of hippocampal LAMB1 exacerbates pain sensitivity and induces cognitive dysfunction. Further mechanistic analysis revealed that loss of hippocampal LAMB1 causes dysregulated Src/NR2A signaling cascades via interaction with integrin β1, leading to decreased Ca²⁺ levels in pyramidal neurons, which in turn orchestrates structural and functional plasticity and eventually results in exaggerated pain responses and cognitive deficits. In this study, we shed new light on the functional capability of hippocampal ECM LAMB1 in the modulation of neuropathic pain and comorbid cognitive deficits, and reveal a mechanism that conveys extracellular alterations to intracellular plasticity. Moreover, we identified hippocampal LAMB1/integrin β1 signaling as a potential therapeutic target for the treatment of neuropathic pain and related memory loss.
Animals ; Laminin/genetics* ; Hippocampus/metabolism* ; Neuralgia/metabolism* ; Cognitive Dysfunction/etiology* ; Male ; Peripheral Nerve Injuries/metabolism* ; Extracellular Matrix/metabolism* ; Integrin beta1/metabolism* ; Pyramidal Cells/metabolism* ; Signal Transduction

Objective:To report the long-term outcomes of Chinese rectal cancer patients after adopting a Watch and Wait (W&W) strategy following neoadjuvant therapy (NAT).Methods:This multicenter, cross-sectional study was based on real-world data. The study cohort comprised rectal cancer patients who had achieved complete or near complete clinical responses (cCRs, near-cCRs) after NAT and were thereafter managed by a W&W approach, as well as a few patients who had achieved good responses after NAT and had then undergone local excision for confirmation of pathological complete response. All participants had been followed up for ≥2 years. Patients with distant metastases at baseline or who opted for observation while living with the tumor were excluded. Data of eligible patients were retrospectively collected from the Chinese Wait-and-Watch Data Collaboration Group database. These included baseline characteristics, type of NAT, pre-treatment imaging results, evaluation of post-NAT efficacy, salvage measures, and treatment outcomes. We herein report the long-term outcomes of Chinese rectal cancer patients after NAT and W&W and the differences between the cCR and near-cCR groups.Results:Clinical data of 318 rectal cancer patients who had undergone W&W for over 2 years and been followed up were collected from eight medical centers (Peking University Cancer Hospital, Fudan University Shanghai Cancer Center, Sun Yat-sen University Cancer Center, Shanghai Changhai Hospital, Peking Union Medical College Hospital, Liaoning Cancer Hospital, the First Hospital of Jilin University, and Yunnan Cancer Hospital.) The participants comprised 221 men (69.4%) and 107 women (30.6%) of median age 60 (26-86) years. The median distance between tumor and anal verge was 3.4 (0-10.4) cm. Of these patients, 291 and 27 had achieved cCR or near-cCR, respectively, after NAT. The median duration of follow-up was 48.4 (10.2-110.3) months. The 5-year cumulative overall survival rate was 92.4% (95%CI: 86.8%-95.7%), 5-year cumulative disease-specific survival (CSS) rate 96.6% (95%CI: 92.2%-98.5%), 5-year cumulative organ-preserving disease-free survival rate 86.6% (95%CI: 81.0%-90.7%), and 5-year organ preservation rate 85.3% (95%CI: 80.3%-89.1%). The overall 5-year local recurrence and distant metastasis rates were 18.5% (95%CI: 14.9%-20.8%) and 8.2% (95%CI: 5.4%-12.5%), respectively. Most local recurrences (82.1%, 46/56) occurred within 2 years, and 91.0% (51/56) occurred within 3 years, the median time to recurrence being 11.7 (2.5-66.6) months. Most (91.1%, 51/56) local recurrences occurred within the intestinal lumen. Distant metastases developed in 23 patients; 60.9% (14/23) occurred within 2 years and 73.9% (17/23) within 3 years, the median time to distant metastasis being 21.9 (2.6-90.3) months. Common sites included lung (15/23, 65.2%), liver (6/23, 26.1%), and bone (7/23, 30.4%) The metastases involved single organs in 17 patients and multiple organs in six. There were no significant differences in overall, cumulative disease-specific, or organ-preserving disease-free survival or rate of metastases between the two groups (all P>0.05). The 5-year local recurrence rate was higher in the near-cCR than in the cCR group (41.6% vs. 16.4%, P<0.01), with a lower organ preservation rate (69.2% vs. 88.0%, P<0.001). The success rates of salvage after local recurrence and distant metastasis were 82.1% (46/56) and 13.0% (3/23), respectively. Conclusion:Rectal cancer patients who achieve cCR or near-cCR after NAT and undergo W&W have favorable oncological outcomes and a high rate of organ preservation. Local recurrence and distant metastasis during W&W follow certain patterns, with a relatively high salvage rate for local recurrence. Our findings highlight the importance of close follow-up and timely intervention during the W&W process.

Objective To investigate whether Heshouwuyin can delay the aging of Leydig cells in rat testis through DNA methyltransferase 1(DNMT1).Methods Totally 40 male Wistar rats were randomly divided into 4 groups,with 10 rats in each group.Immunohistochemistry was used to detect the expression levels of DNMT1 in testis tissue of rats.Testosterone content in serum of rats in each group was detected by ELISA test.A rat Leydig cell aging model was established by free radical oxidative damage.DNMT1 was knocked down by lentivirus in Leydig cells,and the cell senescence status and the testosterone content and testosterone synthesis key enzyme 3β-hydroxysteroid dehydrogenase(3β-HSD),cytochrome P450 family member 11A1(CYP11A1)content secreted by cells were detected by β-galactosidase(β-GAL)staining,immunofluorescenct staining and ELISA.Results Compared with the young control group(YCG),the expression of P16 protein and the positive rate of β-GAL in the testis tissue of rats in the natural aging group(NAG)increased significantly,and the expression of DNMT1 and serum testosterone levels decreased(P＜0.05).However,after Heshouwuyin intervention,the expression of P16 protein and the positive rate of β-GAL in the testis of aging rats were reduced,and DNMT1 expression and the serum testosterone levels increased(P＜0.05).The same trend was observed in Leydig cells.Knockdown of DNMT1 in Leydig cells,β-GAL positivity and P16 protein expression increased significantly,and testosterone secretion and testosterone synthesis key enzymes 3β-HSD,CYP11A1 content from Leydig cells decreased significantly,compared with the normal control group(NCG)(P＜0.05).When Heshouwuyin was added,the above phenomenon was improved.Conclusion Heshouwuyin can delay the aging of rat Leydig cells through DNMT1.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To investigate the antibacterial effect and its preliminary mechanism of lavender essential oil on multi-drug resistant Acinetobacter baumannii.Methods Micro-dilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)of lavender essential oil against multi-drug resistant Acinetobacter baumannii,and bactericidal kinetic study was employed to determine the onset and maintenance time of lavender essential oil.Meanwhile,the promoting and therapeutic effects of lavender essential oil on wound healing were observed in a mouse model of infection.Subsequently,crystal violet staining was used to determine the inhibition and clearance of multi-drug resistant Acinetobacter baumannii biofilm by lavender essential oil,and laser confocal microscopy was utilized to observe the survival of bacteria in biofilms.NanoDrop instrument was utilized to quantify the leakage of bacterial DNA nucleic acid and protein after intervention with 3 and 6 mg/mL lavender essential oil,and the leakage of bacterial potassium ion was measured by potassium ion test kit.Proteomics technology combined with bio-informatics were applied to explore the action mechanism of lavender essential oil against multi-drug resistant Acinetobacter baumannii.Results The MIC and MBC of lavender essential oil were both 6 mg/mL,which could kill almost all multi-drug resistant Acinetobacter baumannii at the time point of 120 min,and showed an obvious dose-and time-dependent manner.The overall animal model evaluation showed that both 3 and 6 mg/mL lavender essential oil could promote wound healing,and the curative effect was obvious.Further studies confirmed that 3 mg/mL lavender essential oil had a certain biofilm inhibitory effect on multi-drug resistant Acinetobacter baumannii,and 6 mg/mL also had a certain biofilm clearance effect under the same conditions.Meanwhile,when incubated at 37℃ for 1 h,the dose of 3 mg/mL could increase the leakage of DNA nucleic acid and protein,and significantly promote the efflux of potassium ions.Proteomic analysis suggested that the antibacterial effect of lavender essential oil may be related to affecting the oxidorereductase activity and cell metabolic process of multi-drug resistant Acinetobacter baumannii,and interfering with the biosynthesis of cell wall/membrane/envelope and other structures.Conclusion Lavender essential oil at 3 mg/mL can play an antibacterial effect against multi-drug resistant Acinetobacter baumannii,and its mechanism may be related to the destruction of bacterial biofilm and interference with bacterial metabolism.

Objective To investigate the distribution of traditional Chinese medicine(TCM)syndromes in patients with type 2 diabetic retinopathy(T2DR)and to explore the correlation of TCM syndromes with serum inflammatory factors and adiponectin(APN)levels,so as to provide evidence for TCM syndrome differentiation of T2DR.Methods A cross-sectional case-control study was conducted in 42 patients(involving 84 eyes)diagnosed as T2DR in the Department of Ophthalmology,Ganzhou People's Hospital from September 2022 to March 2023.The correlation between fundus fluorescein angiography(FFA)staging and TCM syndrome differentiation in patients with T2DR was explored.The relationship between TCM syndrome types and serum levels of inflammatory factors and APN,as well as the differences in serum inflammatory factors and APN levels of the patients with various FFA stages were analyzed.The correlation between each variable and TCM syndrome types in patients with T2DR was investigated.Results(1)Among the 42 patients with T2DR,27 cases were male and 15 cases were female,and their age averaged(54.0±12.0)years old.Among them,14 cases(33.3％)were differentiated as liver-kidney deficiency with malnutrition of eye collateral syndrome,15 cases(35.7％)were differentiated as yin-essence deficiency with internal dry-heat syndrome,9 cases(21.4％)were differentiated as qi-yin deficiency with collateral stasis and obstruction syndrome,4 cases(9.5％)were differentiated as yin-yang deficiency with blood stasis and phlegm coagulation syndrome,and none case(0.0％)was differentiated as spleen dysfunction and water-damp obstruction syndrome.(2)FFA staging showed that FFA staging ≥ 4[i.e.,having proliferative diabetic retinopathy(PDR)]was found in 78.6％(11/14)of the patients with liver-kidney deficiency with malnutrition of eye collaterals syndrome,73.3％(11/15)of the patients with yin-essence deficiency with internal dry-heat syndrome,100％(9/9)of the patients with qi-yin deficiency with collateral stasis and obstruction syndrome,and 100％(4/4)of the patients with yin-yang deficiency with blood stasis and phlegm coagulation syndrome.But the intergroup comparison showed no significant differences among various syndrome types(P=0.272).(3)Among the 42 patients with T2DR,35 patients(83.3％)had higher level of tumor necrosis factor-α(TNF-α),28 patients(68.3％)had higher level of C-reactive protein(CRP)and 38 patients(90.5％)had higher level of glycosylated hemoglobin(HbA1c)than the normal.However,there was no significant difference in the levels of serum inflammatory factors of TNF-α,CRP,interleukin-6(IL-6)and vascular endothelial growth factor(VEGF),APN and HbA1c among the patients with different FFA stages(P＞0.05),neither did the difference in serum APN,TNF-α,CRP,IL-6 and VEGF levels among the patients with different TCM syndrome types(P＞0.05).(4)The correlation analysis showed that the patients with yin-yang deficiency with blood stasis and phlegm coagulation syndrome had a shorter course of eye diseases than the patients with liver-kidney deficiency with malnutrition of eye collaterals syndrome(r=-0.467,P=0.051),had higher CRP level than the patients with yin-essence deficiency with internal dry-heat syndrome(r=0.592,P=0.010),and had higher CRP level(r=0.668,P=0.013)and a longer course of diabetes(r=0.629,P=0.021)than the patients with qi-yin deficiency with collateral stasis and obstruction syndrome.Conclusion Increased serum TNF-α and CRP expressions are presented in the patients with T2DR.Liver-kidney deficiency with malnutrition of eye collaterals syndrome and yin-essence deficiency with internal dry-heat syndrome are the common syndromes in T2DR.Yin-yang deficiency with blood stasis and phlegm coagulation syndrome is closely correlated with CRP level,and the patients with yin-yang deficiency with blood stasis and phlegm coagulation syndrome have a longer course of diabetes.

Umbilical cord mesenchymal stem cells (UC-MSCs) have been widely used in regenerative medicine, but there is limited research on the stability of UC-MSCs formulation during production. This study aims to assess the stability of the cell stock solution and intermediate product throughout the production process, as well as the final product following reconstitution, in order to offer guidance for the manufacturing process and serve as a reference for formulation reconstitution methods. Three batches of cell formulation were produced and stored under low temperature (2-8 ℃) and room temperature (20-26 ℃) during cell stock solution and intermediate product stages. The storage time intervals for cell stock solution were 0, 2, 4, and 6 h, while for intermediate products, the intervals were 0, 1, 2, and 3 h. The evaluation items included visual inspection, viable cell concentration, cell viability, cell surface markers, lymphocyte proliferation inhibition rate, and sterility. Additionally, dilution and culture stability studies were performed after reconstitution of the cell product. The reconstitution diluents included 0.9% sodium chloride injection, 0.9% sodium chloride injection + 1% human serum albumin, and 0.9% sodium chloride injection + 2% human serum albumin, with dilution ratios of 10-fold and 40-fold. The storage time intervals after dilution were 0, 1, 2, 3, and 4 h. The reconstitution culture media included DMEM medium, DMEM + 2% platelet lysate, 0.9% sodium chloride injection, and 0.9% sodium chloride injection + 1% human serum albumin, and the culture duration was 24 h. The evaluation items were viable cell concentration and cell viability. The results showed that the cell stock solution remained stable for up to 6 h under both low temperature (2-8 ℃) and room temperature (20-26 ℃) conditions, while the intermediate product remained stable for up to 3 h under the same conditions. After formulation reconstitution, using sodium chloride injection diluted with 1% or 2% human serum albumin maintained a viability of over 80% within 4 h. It was observed that different dilution factors had an impact on cell viability. After formulation reconstitution, cultivation in medium with 2% platelet lysate resulted in a cell viability of over 80% after 24 h. In conclusion, the stability of cell stock solution within 6 h and intermediate product within 3 h meets the requirements. The addition of 1% or 2% human serum albumin in the reconstitution diluent can better protect the post-reconstitution cell viability.