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 investigate the impact of ionizing radiation(IR)on the structure and function of the testis and pro-vide some strategies for the prevention and treatment of IR-induced damage(IRD).Methods:Using radiation dose simulation,se-men analysis,hormone testing,electron microscopy and single-cell transcriptome sequencing,we assessed and analyzed a case of IRD.We established a mouse model of IRD to validate the results of single-cell sequencing,and investigated the specific biological mecha-nisms of IRD and potential strategies for its intervention.Results:IR at 1-2 Gy significantly reduced sperm concentration and mo-tility,which gradually recovered after 12 months but the percentage of morphologically normal sperm remained low.It also caused im-balanced levels of various steroid hormones,decreased testosterone and dehydroepiandrosterone sulfate,increased progesterone,prolac-tin,luteinizing hormone,and follicle-stimulating hormone.Electron microscopy revealed damages to the testis structure,including loss of germ cells,atrophy of the seminiferous tubules,nuclear membrane depression of the spermatocytes,mitochondrial atrophy and de-formation,and reduction of mitochondrial cristae.Single-cell sequencing indicated significant changes in the function of the Leydig cells and macrophages and disrupted lipid-related metabolic pathways after IRD.Administration of L-carnitine to the mouse model im-proved lipid metabolism disorders and partially alleviated IRD to the germ cells.Conclusion:Ionizing radiation can cause disorders of testicular spermatogenesis and sexual hormones and inhibit lipid metabolism pathways in Leydig cells and macrophages.Improving lipid metabolism can alleviate IRD to germ cells.

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 incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Human viral respiratory disease is a kind of widely prevalent infectious disease. The incidence rate of respiratory virus infection occupies a major position in the overall structure of global incidence rate of residents, and is one of the main causes of acute and fatal human diseases. Natural products have diverse structures and novel mechanisms of action, which can regulate body immunity and resist respiratory viruses, and have unique advantages in the treatment of respiratory viral diseases. This article summarizes the current research progress of natural drugs in the prevention and treatment of respiratory viruses, classifies the action mechanism of the active components of natural drugs against respiratory viruses, to provide reference basis for clinical treatment and drug discovery of respiratory diseases in the future.

Temporomandibular joint (TMJ) diseases are common clinical conditions. The number of patients with TMJ diseases is large, and the etiology, epidemiology, disease spectrum, and treatment of the disease remain controversial and unknown. To understand and master the current situation of the occurrence, development and prevention of TMJ diseases, as well as to identify the patterns in etiology, incidence, drug sensitivity, and prognosis is crucial for alleviating patients′suffering.This will facilitate in-depth medical research, effective disease prevention measures, and the formulation of corresponding health policies. Cohort construction and research has an irreplaceable role in precise disease prevention and significant improvement in diagnosis and treatment levels. Large-scale cohort studies are needed to explore the relationship between potential risk factors and outcomes of TMJ diseases, and to observe disease prognoses through long-term follw-ups. The consensus aims to establish a standard conceptual frame work for a cohort study on patients with TMJ disease while providing ideas for cohort data standards to this condition. TMJ disease cohort data consists of both common data standards applicable to all specific disease cohorts as well as disease-specific data standards. Common data were available for each specific disease cohort. By integrating different cohort research resources, standard problems or study variables can be unified. Long-term follow-up can be performed using consistent definitions and criteria across different projects for better core data collection. It is hoped that this consensus will be facilitate the development cohort studies of TMJ diseases.

Objective With the help of the cloud platform software of ancient and modern medical records,to analyze the prescription medication rule of Chinese medical master Chen Keji's application of Corydalis yanhusuo in the treatment of heart diseases,and to summarize and inherit the medication experience.Methods Medical record prescriptions with Corydalis yanhusuo used by Academician Chen Keji to treat heart diseases from 2002 to 2010 were collected and sorted out.Improved mutual information method,association rules,complex system clustering,unsupervised entropy hierarchical clustering and other methods were used to conduct statistical,correlation and cluster analysis on the normalization,frequency of application and combination of drug pairs in the prescriptions.Results A total of 146 clinical cases of by Academician Chen Keji were collected,and the main diseases were chest arthralgia,palpitation,and vertigo.In addition to Corydalis yanhusuo,Radix Salviae liguliobae,Radix chuanxiong and Radix Paeoniae Rubra had the highest frequency of single drug use.In the treatment of chest Bi disease,the use of xin,bitter,warm drugs,liver,heart,spleen meridian,high frequency drug for Radix chuanxiong-Corydalis yanhusuo,Radix Paeoniae Rubra-Corydalis yanhusuo;Commonly used angle herbs are Radix Paeoniae Rubra-Radix chuanxiong-Corydalis yanhusuo,Trichosanthes Kirilowii Maxim-Bulbus Allii Macrostemi-Corydalis yanhusuo.Cluster analysis suggested that the commonly used prescriptions for the treatment of chest Bi were Guanxin No.2,Gualsankyu Baibanxia Decoction and Bupleurum Shugan Powder.In the treatment of palpitation,sweet,bitter and warm drugs are mainly used,which are classified into liver,lung and spleen channels.The high-frequency counterpart herbs are Radix Sophorae flavescentis-Corydalis yanhusuo;Commonly used horn medicine is Ophiopogon japonicus-Corydalis yanhusuo-Schisandra chinensis.Cluster analysis suggested that Shengmai Decoction and Tianwang Buxin Dan were commonly used by Academician Chen,and Corydalis yanhusuo,Radix Sophorae flavescentis and Rhizoma Coptidis were his characteristic herbs for palpitation.In the treatment of vertigo,sweet,bitter,warm and plain Chinese medicines were mainly used.The correlation analysis of drug combinations suggested that Ramulus Uncariae cum Uncis-Corydalis yanhusuo and Gastrodia elata-Corydalis yanhusuo were commonly used as paired herbs,Gastrodia elata-Ramulus Uncariae cum Uncis-Corydalis yanhusuo were commonly used as angle herbs.Conclusion Academician Chen Keji,based on the combination of traditional Chinese and western medicine,used Corydalis yanhusuo to promote blood circulation and relieve pain in the treatment of chest Bi,to promote blood circulation and eliminate palpitation in the treatment of palpitation,and to calm down and eliminate daze in the treatment of vertigo.

Background/Aims: Chronic hepatitis C (CHC) patients who failed antiviral therapy are at increased risk for hepatocellular carcinoma (HCC). This study assessed the potential role of metformin and statins, medications for diabetes mellitus (DM) and hyperlipidemia (HLP), in reducing HCC risk among these patients. Methods: We included CHC patients from the T-COACH study who failed antiviral therapy. We tracked the onset of HCC 1.5 years post-therapy by linking to Taiwan’s cancer registry data from 2003 to 2019. We accounted for death and liver transplantation as competing risks and employed Gray’s cumulative incidence and Cox subdistribution hazards models to analyze HCC development. Results: Out of 2,779 patients, 480 (17.3%) developed HCC post-therapy. DM patients not using metformin had a 51% increased risk of HCC compared to non-DM patients, while HLP patients on statins had a 50% reduced risk compared to those without HLP. The 5-year HCC incidence was significantly higher for metformin non-users (16.5%) versus non-DM patients (11.3%; adjusted sub-distribution hazard ratio [aSHR]=1.51; P=0.007) and metformin users (3.1%; aSHR=1.59; P=0.022). Statin use in HLP patients correlated with a lower HCC risk (3.8%) compared to non-HLP patients (12.5%; aSHR=0.50; P<0.001). Notably, the increased HCC risk associated with non-use of metformin was primarily seen in non-cirrhotic patients, whereas statins decreased HCC risk in both cirrhotic and non-cirrhotic patients. Conclusions Metformin and statins may have a chemopreventive effect against HCC in CHC patients who failed antiviral therapy. These results support the need for personalized preventive strategies in managing HCC risk.

With the approach of untargeted metabolomics and correlation analysis, this study aimed to explore the mechanism of Aurantii Fructus from Lingnan region in alleviating dryness by analyzing the different effects of raw Aurantii Fructus(RAF) and processed Aurantii Fructus(PAF) on fecal endogenous metabolism in normal rats. Eighteen Sprague-Dawley(SD) rats were randomly divided into a control group(C), an RAF group(10 g·kg~(-1)), and a PAF group(10 g·kg~(-1)). After seven days of administration, the effects of RAF and PAF on dryness-related indexes were compared, including water intake, fecal water content, salivary secretion, the expression of AQP5, VIP, and 5-HT in the submandibular gland, as well as the expression of AQP3, VIP, and 5-HT in the colon. The fecal samples in each group were determined by LC-MS. Multivariate statistical analysis and Pearson correlation coefficient were used for screening the differential metabolites and metabolic pathways in alleviating dryness of RAF. The results indicated that both RAF and PAF showed certain dryness, and the dryness of RAF was more significant. Moreover, PAF could alleviate dryness of RAF to a certain extent by reducing the water intake, fecal water content, and the expression of AQP3, VIP, and 5-HT in the colon and increasing the salivary secretion and the levels of AQP5, VIP, and 5-HT in the submandibular gland. According to the analysis of fecal metabolomics, 99 and 58 metabolites related to dryness were found in RAF and PAF respectively, where 16 of them played an important role in alleviating dryness of RAF. Pathway analysis revealed that the mechanism of PAF in alleviating dryness of RAF was presumably related to the regulation of riboflavin metabolism, purine metabolism, arginine biosynthesis, pyrimidine metabolism, alanine metabolism, aspartate metabolism, glutamate metabolism, and retinol metabolism pathways. This study suggested that PAF might alleviate dryness of RAF by affecting the metabolic levels of the body, which provides a new basis for further clarifying the processing mechanism of PAF.
Rats ; Animals ; Drugs, Chinese Herbal/pharmacology* ; Rats, Sprague-Dawley ; Serotonin ; Metabolomics ; Water

Objective: To explore the clinical effects of island posterior femoral composite tissue flaps in the repair of sinus cavity pressure ulcers in the areas of ischial tuberosity and greater trochanter. Methods: The retrospective observational study was conducted. From December 2018 to December 2021, 23 patients with sinus cavity pressure ulcers in the areas of ischial tuberosity and greater trochanter who met the inclusion criteria were admitted to Ganzhou People's Hospital, including 16 males and 7 females, aged 45 to 86 years. The size of pressure ulcers in ischial tuberosity ranged from 1.5 cm×1.0 cm to 8.0 cm×5.0 cm, and the size of pressure ulcers in greater trochanter ranged from 4.0 cm×3.0 cm to 20.0 cm×10.0 cm before debridement. After treatment of underlying diseases, debridement and vacuum sealing drainage for 5 to 14 days were performed. All the wounds were repaired by island posterior femoral composite tissue flaps, with area of 4.5 cm×3.0 cm-24.0 cm×12.0 cm, pedicle width of 3-5 cm, pedicle length of 5-8 cm, and rotation radius of 30-40 cm. Most of the donor site wounds were sutured directly, and only 4 donor site wounds were repaired by intermediate thickness skin graft from the contralateral thigh. The survival of composite tissue flaps, wound healing of the donor and recipient sites and the complications were observed. The recurrence of pressure ulcers, and the appearance and texture of flaps were observed during follow-up. Results: A total of 32 wounds in 23 patients were repaired by island posterior femoral composite tissue flaps (including 3 fascio subcutaneous flaps, 24 fascial flaps+fascio subcutaneous flaps, 2 fascial flaps+fascial dermal flaps, 2 fascial flaps+fascio subcutaneous flaps+femoral biceps flaps, and one fascial flap+fascio subcutaneous flap+gracilis muscle flap). Among them, 31 composite tissue flaps survived well, and a small portion of necrosis occurred in one fascial flap+fascio subcutaneous flap post surgery. The survival rate of composite tissue flap post surgery was 96.9% (31/32). Twenty-nine wounds in the recipient sites were healed, and 2 wounds were torn at the flap pedicle due to improper postural changes, and healed one week after bedside debridement. One wound was partially necrotic due to the flap bruising, and healed 10 days after re-debridement. Thirty-one wounds in the donor sites (including 4 skin graft areas) were healed, and one wound in the donor site was torn due to improper handling at discharge, and healed 15 days after re-debridement and suture. The complication rate was 12.5% (4/32), mainly the incision dehiscence of the flap pedicle and the donor sites (3 wounds), followed by venous congestion at the distal end of flap (one wound). During the follow-up of 3 to 24 months, the pressure ulcers did not recur and the flaps had good appearance and soft texture. Conclusions: The island posterior femoral composite tissue flaps has good blood circulation, large rotation radius, and sufficient tissue volume. It has a high survival rate, good wound healing, low skin grafting rate in the donor site, few postoperative complications, and good long-term effect in the repair of sinus cavity pressure ulcers in the areas of ischial tuberosity and greater trochanter.
Male ; Female ; Humans ; Plastic Surgery Procedures ; Pressure Ulcer/etiology* ; Soft Tissue Injuries/surgery* ; Treatment Outcome ; Skin Transplantation ; Femur/surgery* ; Necrosis/surgery* ; Perforator Flap