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 effect of genetic polymorphism of MTHFR C677T (rs1801133) on methotrexate (MTX) related toxicity in pediatric mature B-cell lymphoma patients. Methods:Fifty-eight intermediate and high risk patients under 18 years of age with mature B-cell lymphoma who received 5 g/m2 MTX (24 h intravenous infusion) in Sun Yat-sen University Cancer Center from August 2014 to December 2021 were included,and their toxicity of high-dose MTX (HD-MTX) were monitored and analyzed. Results:Among the 58 pediatric patients,the number of CC,CT,and TT genotypes for MTHFR C677T was 33,19 and 6,respectively. A total of 101 courses of HD-MTX therapy were counted,of which plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion were observed in 35 courses,≤0.2 μmol/L in 66 courses. Inter-group comparison showed that plasma MTX level>0.2 μmol/L at 48 h post-MTX infusion increased the risk of developing oral mucositis (P<0.05). Compared with wild-type (CC genotype),patients in the mutant group (CT+TT genotype) were more likely to develop myelosuppression,manifested as anemia,leucopenia,neutropenia and thrombocytopenia. However,plasma MTX level at 48 h was not associated with MTHFR C677T gene polymorphism. Conclusion:The risk of developing oral mucositis in children with mature B-cell lymphoma is associated with plasma MTX concentration. Polymorphism of MTHFR C677T gene is not related to plasma MTX concentration in children with mature B-cell lymphoma,but is related to grade Ⅲ to Ⅳ hematological toxicity.

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 differences in clinical characteristics among children on prolonged mechanical ventilation(PMV)due to different primary diseases.Methods A retrospective analysis was performed on the clinical data of 59 pediatric patients requiring PMV from July 2017 to September 2022.According to the primary disease,they were divided into respiratory disease(RD)group,central nervous system(CNS)group,neuromuscular disease(NMD)group,and other disease group.The four groups were compared in terms of general information,treatment,and outcome.Results There were significant differences among the four groups in age,body weight,Pediatric Logistic Organ Dysfunction-2(PELOD-2)score,Pediatric Risk of Mortality Ⅲ(PRISM Ⅲ)score,analgesic and sedative treatment,nutrition supply,rehabilitation treatment,tracheotomy,successful ventilator weaning,and outcomes(P＜0.05).Compared with the RD group,the CNS group and the other disease group had a significantly higher age and a significantly higher proportion of children receiving rehabilitation treatment,and the CNS group had a significantly higher proportion of children receiving tracheotomy(P＜0.008).Compared with the other disease group,the CNS group and the NMD group had significantly lower PELOD-2 and PRISM Ⅲ scores,and the CNS group had a significantly higher proportion of children with successful ventilator weaning and a significantly higher proportion of children who were improved and discharged(P＜0.008).Conclusions There are differences in clinical characteristics among children receiving PMV due to different etiologies.Most children in the RD group have a younger age,and children in the CNS group have a relatively good prognosis.

Objective:To investigate the application effect of comprehensive intervention combined with cognitive psychological care based on the quality chain in patients with BPH.Methods:We prospectively selected 110 cases of BPH treated in our hospital from January 2022 to March 2023 and equally randomized them into groups A and B,the former given routine intervention,while the latter comprehensive intervention combined with cognitive psychological care based on the quality chain in addition.We analyzed the results of intervention,the patients'scores on Self-Rating Anxiety Scale(SAS)and Self-Rating Depression Scale(SDS),improvement of clinical indicators,self-efficacy,disease awareness and treatment compliance,and compared the data obtained between the two groups of patients.Results:The effectiveness of intervention was significantly better in group B than in A(96.36%vs 65.45%,χ2=17.009,P<0.05).Compared with the baseline,the SAS and SDS scores were remarkably improved in the two groups after inter-vention(P<0.05),even more significantly in group B than in A(P<0.05).Group B also showed a markedly shorter duration of bladder spasm,lower frequency of bladder spasm per day,shorter urethral catheterization time and postoperative hospital stay,better e-motion control and health management,more regular schedule,higher disease knowledge awareness,and better treatment compliance than group A(all P<0.05).Conclusion:Comprehensive intervention combined with cognitive psychological care based on the quality chain is significantly effective in improving BPH patients'clinical indicators,disease awareness and treatment compliance,re-ducing their depression and anxiety,and enhancing their self-efficacy management.

Objective: To explore the influencing covariates of severe neutrophils and/or thrombocytopenia and their effect on treatment response and outcome in patients with chronic-phase chronic myeloid leukemia (CP-CML) receiving initial second-generation tyrosine kinase inhibitors (2G-TKI) . Methods: Data from consecutive patients aged ≥18 years with newly diagnosed CP-CML who received initial 2G-TKI at Peking University People's Hospital from September 2008 to November 2021 were interrogated. Binary logistic regression models and Fine-Gray and Cox regression models were applied. Results: Data from 267 patients who received initial 2G-TKI, including nilotinib (n=239, 89.5% ) and dasatinib (n=28, 10.5% ) , were interrogated. The median age was 36 (range, 18-73) years, and 156 (58.4% ) patients were male. At a median treatment period of 1.0 (0.1-3.0) month, 43 (16.1% ) patients developed grade ≥3 neutrophils and/or thrombocytopenia and recovered within 1.0 (0.1-24.6) month. Male (OR=2.9, 95% CI 1.2-6.8; P=0.018) , age of ≥36 years (OR=3.2, 95% CI 1.4-7.2, P=0.005) , a spleen below a costal margin of ≥7 cm (OR=2.8, 95% CI 1.2-6.6, P=0.020) , and a hemoglobin (HGB) level of <100 g/L (OR=2.9, 95% CI 1.3-6.8, P=0.012) at diagnosis were significantly associated with grade ≥ 3 neutrophils and/or thrombocytopenia. Based on their regression coefficients, male, age of ≥36 years, a spleen below a costal margin of ≥7 cm, and an HGB level of <100 g/L were given 1 point to form a predictive system. All patients were divided into three risk subgroups, and the incidence of severe cytopenia significantly differed among the three groups (P < 0.001) . Grade ≥3 neutrophils and/or thrombocytopenia for >2 weeks was significantly associated with lower cumulative incidences of complete cytogenetic response (CCyR, HR=0.5, 95% CI 0.3-0.7, P<0.001) and major molecular response (MMR, HR=0.4, 95% CI 0.3-0.8, P=0.004) and was not significantly associated with failure, progression, and survival. Conclusion: Male, advanced age, a large spleen, and a low HGB level were significantly associated with severe cytopenia. The four covariates were used to establish a prediction model, in which the incidence of severe cytopenia among different risk groups was significantly different. Severe cytopenia for >2 weeks was a negative factor for responses but not for outcomes.
Humans ; Male ; Adolescent ; Adult ; Female ; Protein Kinase Inhibitors/therapeutic use* ; Tyrosine Protein Kinase Inhibitors ; Treatment Outcome ; Retrospective Studies ; Dasatinib/therapeutic use* ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Leukemia, Myeloid, Chronic-Phase/drug therapy* ; Thrombocytopenia

Humans ; Infant ; Female ; Dandy-Walker Syndrome/diagnosis* ; Tomography, X-Ray Computed ; Craniocerebral Trauma/complications*

Objective: To analyze the prevalence and the risk factors of fungal sepsis in 25 neonatal intensive care units (NICU) among preterm infants in China, and to provide a basis for preventive strategies of fungal sepsis. Methods: This was a second-analysis of the data from the "reduction of infection in neonatal intensive care units using the evidence-based practice for improving quality" study. The current status of fungal sepsis of the 24 731 preterm infants with the gestational age of <34⁺⁰ weeks, who were admitted to 25 participating NICU within 7 days of birth between May 2015 and April 2018 were retrospectively analyzed. These preterm infants were divided into the fungal sepsis group and the without fungal sepsis group according to whether they developed fungal sepsis to analyze the incidences and the microbiology of fungal sepsis. Chi-square test was used to compare the incidences of fungal sepsis in preterm infants with different gestational ages and birth weights and in different NICU. Multivariate Logistic regression analysis was used to study the outcomes of preterm infants with fungal sepsis, which were further compared with those of preterm infants without fungal sepsis. The 144 preterm infants in the fungal sepsis group were matched with 288 preterm infants in the non-fungal sepsis group by propensity score-matched method. Univariate and multivariate Logistic regression analysis were used to analyze the risk factors of fungal sepsis. Results: In all, 166 (0.7%) of the 24 731 preterm infants developed fungal sepsis, with the gestational age of (29.7±2.0) weeks and the birth weight of (1 300±293) g. The incidence of fungal sepsis increased with decreasing gestational age and birth weight (both P<0.001). The preterm infants with gestational age of <32 weeks accounted for 87.3% (145/166). The incidence of fungal sepsis was 1.0% (117/11 438) in very preterm infants and 2.0% (28/1 401) in extremely preterm infants, and was 1.3% (103/8 060) in very low birth weight infants and 1.7% (21/1 211) in extremely low birth weight infants, respectively. There was no fungal sepsis in 3 NICU, and the incidences in the other 22 NICU ranged from 0.7% (10/1 397) to 2.9% (21/724), with significant statistical difference (P<0.001). The pathogens were mainly Candida (150/166, 90.4%), including 59 cases of Candida albicans and 91 cases of non-Candida albicans, of which Candida parapsilosis was the most common (41 cases). Fungal sepsis was independently associated with increased risk of moderate to severe bronchopulmonary dysplasia (BPD) (adjusted OR 1.52, 95%CI 1.04-2.22, P=0.030) and severe retinopathy of prematurity (ROP) (adjusted OR 2.55, 95%CI 1.12-5.80, P=0.025). Previous broad spectrum antibiotics exposure (adjusted OR=2.50, 95%CI 1.50-4.17, P<0.001), prolonged use of central line (adjusted OR=1.05, 95%CI 1.03-1.08, P<0.001) and previous total parenteral nutrition (TPN) duration (adjusted OR=1.04, 95%CI 1.02-1.06, P<0.001) were all independently associated with increasing risk of fungal sepsis. Conclusions: Candida albicans and Candida parapsilosis are the main pathogens of fungal sepsis among preterm infants in Chinese NICU. Preterm infants with fungal sepsis are at increased risk of moderate to severe BPD and severe ROP. Previous broad spectrum antibiotics exposure, prolonged use of central line and prolonged duration of TPN will increase the risk of fungal sepsis. Ongoing initiatives are needed to reduce fungal sepsis based on these risk factors.
Infant ; Infant, Newborn ; Humans ; Birth Weight ; Intensive Care Units, Neonatal ; Retrospective Studies ; Tertiary Care Centers ; Infant, Extremely Low Birth Weight ; Gestational Age ; Infant, Extremely Premature ; Sepsis/epidemiology* ; Retinopathy of Prematurity/epidemiology* ; Bronchopulmonary Dysplasia/epidemiology*

OBJECTIVE: To explore the expression pattern and clinical significance of Integral membrane protein 2A（ITM2A） in drug resistant patients with chronic myeloid leukemia (CML). METHODS: The expression of ITM2A in CML was evaluated by qRT-PCR, Western blot and immunocytochemistry. In order to understand the possible biological effects of ITM2A, apoptosis, cell cycle and myeloid differentiation antigen expression of CML cells were detected by flow cytometry after over-expression of ITM2A. The nuderlying molecular mechanism of its biological effect was explored. RESULTS: The expression of ITM2A in bone marrow of CML resistant patients was significantly lower than that of sensitive patients and healthy donors（P<0.05）. The CML resistant strain cell K562R was successfully constructed in vitro. The expression of ITM2A in the resistant strain was significantly lower than that in the sensitive strain(P<0.05). Overexpression of ITM2A in K562R cells increased the sensitivity of K562R cells to imatinib and blocked the cell cycle in G₂ phase(P<0.05), but did not affect myeloid differentiation. Mechanistically, up-regulation of ITM2A reduced phosphorylation in ERK signaling (P<0.05). CONCLUSION The expression of ITM2A was low in patients with drug resistance of CML, and the low expression of ITM2A may be the key factor of imatinib resistance in CML.
Humans ; Antineoplastic Agents/pharmacology* ; Apoptosis ; Drug Resistance, Neoplasm ; Imatinib Mesylate/therapeutic use* ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy* ; Signal Transduction

Purpose: Gastric cancer (GC) is the second most lethal cancer globally and is associated with poor prognosis. Fatty acid-binding proteins (FABPs) can regulate biological properties of carcinoma cells. FABP5 is overexpressed in many types of cancers; however, the role and mechanisms of action of FABP5 in GC remain unclear. In this study, we aimed to evaluate the clinical and biological functions of FABP5 in GC. Materials and Methods: We assessed FABP5 expression using immunohistochemical analysis in 79 patients with GC and evaluated its biological functions following in vitro and in vivo ectopic expression. FABP5 targets relevant to GC progression were determined using RNA sequencing (RNA-seq). Results: Elevated FABP5 expression was closely associated with poor outcomes, and ectopic expression of FABP5 promoted proliferation, invasion, migration, and carcinogenicity of GC cells, thus suggesting its potential tumor-promoting role in GC. Additionally, RNA-seq analysis indicated that FABP5 activates immune-related pathways, including cytokinecytokine receptor interaction pathways, interleukin-17 signaling, and tumor necrosis factor signaling, suggesting an important rationale for the possible development of therapies that combine FABP5-targeted drugs with immunotherapeutics. Conclusions These findings highlight the biological mechanisms and clinical implications of FABP5 in GC and suggest its potential as an adverse prognostic factor and/or therapeutic target.