Celastrol and wilforlide A are the main active triterpenoids of the traditional Chinese medicine Lei Gong Teng, which have anti-tumour, anti-inflammatory and immunosuppressive activities, and are the material basis for the clinical efficacy of Lei Gong Teng-related Chinese medicinal preparations. By analysing the biosynthetic pathway of active ingredients, optimizing genetic elements and utilizing "cell factory" to produce triterpenoids heterologously will be an effective way to obtain from Tripterygium wilfordii in the future in a "low-cost and high-efficient" manner. CYP712Ks are the first cytochrome P450s involved in the skeleton modification of friedelane-type and oleanane-type triterpenoids in T. wilfordii, and they can catalyse the generation of polpunonic acid from friedelin and 3-epi-katonic acid from β-amyrin by carboxylation at C-29 position. In this study, four multifunctional TwCYP712K1/2/3/5 were used to clarify the catalytic function and substrate selection preference using in vivo functional characterization in Saccharomyces cerevisiae. The spatial structure of the protein-substrate binding was clarified through homology modeling and molecular docking, and then the differential amino acids in the active pocket of the protein were mutated to clarify the crucial amino acids determining the catalytic function and the selection of substrate structure. A total of 63 mutant elements were constructed, and the amino acid sites affecting the carboxylation function of TwCYP712Ks were analyzed. In particular, the key amino acids affecting the substrate selectivity of TwCYP712K2 towards oleanane-type and friedelane-type triterpenoids were revealed and the TwCYP712K2^F127I and TwCYP712K2^A227T mutants would result in a reversal of the product ratio. In conclusion, four proteins of TwCYP712Ks were semi-rationally designed by homologous protein alignment and mutual mutation to elucidate multiple amino acid sites determining the catalytic function of the proteins, and a series of activity-enhancing or altering mutants were obtained, which provide abundant catalytic elements for the biosynthesis of active triterpenoids from T. wilfordii, and the mechanism of carboxylation in the C-29 position was initially elucidated.

Three-dimensional graphene hydrogel(3DGH)was successfully prepared through a hydrothermal method,followed by its composition with gold nanoparticles(AuNPs)to construct a highly sensitive Au/3DGH graphene electrochemical transistor(GECT)dopamine(DA)sensor.AuNPs are efficient electrocatalytic materials.However,their tendency to aggregate during electrodeposition hinds the practical application.The porous and interconnected network structure of 3DGH provided abundant attachment sites,effectively preventing AuNPs aggregation.By modifying the sensor's gate with Au/3DGH,the excellent electrocatalytic performance of Au/3DGH towards DA and the high sensitivity of GECT were utilized to achieve highly sensitive detection of DA.The sensor exhibited a low detection limit of 20 nmol/L and a linear range of 20 nmol/L to 2.5 mmol/L.Remarkably,the sensor showed high sensitivity,excellent selectivity and strong stability,and hold great potnetial in highly sensitive portable detection of DA in disease prevention and clinical monitoring.

Objective To evaluate and compare the success rate and short-term clinical prognosis of transfemoral transcatheter aortic valve replacement(TF-TAVR)for patients with pure aortic regurgitation(PAR)of different annulus sizes.Methods This study is a single center retrospective study,selecting symptomatic PAR patients who received TF-TAVR treatment at Zhongshan Hospital Fudan University from September 2019 to September 2023.Based on preoperative CT results,all patients were divided into three groups:Group A(aortic annulus circumference＜80 mm),Group B(80 mm≤aortic annulus circumference＜85 mm),and Group C(aortic annulus circumference≥ 85 mm).The primary endpoint was success rate and 30d all-cause mortality,while the secondary endpoint was TAVR related complications.Results A total of 61 PAR patients were included in this study,including 27 in Group A,21 in Group B,and 13 in Group C.The overall success rate is 82.0％,and the 30 d all-cause mortality rate is 3.3％.The success rate of Group C patients was significantly lower(P=0.012),with higher rates of conversion to surgery and valve-in-valve implantation(P=0.022 and P=0.040).In terms of secondary endpoint events,there were no significant differences among the three groups in major bleeding events,major vascular complications,stroke,myocardial infarction,newly developed atrial fibrillation,implantation of new pacemakers,coronary artery occlusion,and postoperative moderate to severe perivalvular leakage(all P＞0.05).Conclusions The circumference of the aortic valve annulus is a key factor affecting the success rate of TF-TAVR in PAR,and PAR patients with an aortic valve annulus circumference less than 85mm may be more suitable for TF-TAVR.

The R-loop is a three-stranded nucleic acid structure, which consists of a RNA: DNA hybrid and a DNA single strand. R-loop can be divided into two types: physiological and pathological. The physiological R-loop is involved in many physiological processes such as DNA replication, transcription, and gene expression regulation, while the pathological R-loop induces DNA damage and genome rearrangement. There are many factors that affect the formation of R-loops. Unregulated R-loops destroy genomic stability by interfering with DNA replication and double-strand DNA break repair, and can cause cancer. Therefore, the regulation of R-loops is very important. RNA/ DNA helicase Senataxin (SETX), DEAD-box helicase 5 (DDX5), ribonuclease H (RNase H) and DNA topoisomerase I (topo) play an important role in regulating the balance of R-loops in vivo. Among them, SETX is one of the most characteristic R-loop decomposing enzymes, which can dissolve the R-loops produced during transcriptional termination sites, replication-transcriptional conflicts and DNA damage repair. Senataxin mutations will lead to ataxia with eye movement apraxia type 2 (AOA2) and amyotrophic lateral sclerosis type 4 (ALS4). Currently there are still many unsolved issues, although many in-depth studies of R-loops have been carried out. Therefore, the structure and function of physiological and pathological R-loops still need to be further explored. This review mainly focuses on the definition and classification of R-loops, the factors that affect the formation of R-loops, the influence of R-loops on genomic stability and R-loop-related diseases, and explores the possibility of using R-loops as a therapeutic target in the future.

Chronic pancreatitis (CP) is a progressive and irreversible fibroinflammatory disorder, accompanied by pancreatic exocrine insufficiency and dysregulated gut microbiota. Recently, accumulating evidence has supported a correlation between gut dysbiosis and CP development. However, whether gut microbiota dysbiosis contributes to CP pathogenesis remains unclear. Herein, an experimental CP was induced by repeated high-dose caerulein injections. The broad-spectrum antibiotics (ABX) and ABX targeting Gram-positive (G⁺) or Gram-negative bacteria (G^-) were applied to explore the specific roles of these bacteria. Gut dysbiosis was observed in both mice and in CP patients, which was accompanied by a sharply reduced abundance for short-chain fatty acids (SCFAs)-producers, especially G⁺ bacteria. Broad-spectrum ABX exacerbated the severity of CP, as evidenced by aggravated pancreatic fibrosis and gut dysbiosis, especially the depletion of SCFAs-producing G⁺ bacteria. Additionally, depletion of SCFAs-producing G⁺ bacteria rather than G^- bacteria intensified CP progression independent of TLR4, which was attenuated by supplementation with exogenous SCFAs. Finally, SCFAs modulated pancreatic fibrosis through inhibition of macrophage infiltration and M2 phenotype switching. The study supports a critical role for SCFAs-producing G⁺ bacteria in CP. Therefore, modulation of dietary-derived SCFAs or G⁺ SCFAs-producing bacteria may be considered a novel interventive approach for the management of CP.

Aortic Valve/surgery* ; Aortic Valve Stenosis/surgery* ; Atrial Septum/surgery* ; Heart Valve Prosthesis ; Humans ; Risk Factors ; Transcatheter Aortic Valve Replacement ; Treatment Outcome

To explore the composition and diversity of the intestinal microflora of Leopoldamys edwardsi in Hainan Island. In November 2019, DNA was extracted from fecal samples of 25 adult Leopoldamys edwardsi (14 males and 11 females) in Hainan Island at the Joint Laboratory of tropical infectious diseases of Hainan Medical College and Hong Kong University. Based on the IonS5TMXL sequencing platform, single-end sequencing (Single-End) was used to construct a small fragment library for single-end sequencing. Based on Reads shear filtration and OTUs clustering. The species annotation and abundance analysis of OTUs were carried out by using mothur method and SSUrRNA database, and further conducted α diversity and β diversity analysis. A total of 1481842 high quality sequences, belonging to 14 Phyla, 85 families and 186 Genera, were obtained from 25 intestinal excrement samples of Leopoldamys edwardsi. At the level of phyla classification, the main core biota of the Leopoldamys edwardsi contained Firmicutes (46.04%),Bacteroidetes (25.34%), Proteobacteria (17.09%), Tenericutes (7.38%) and Actinobacteria (1.67%), these five phyla account for 97.52% of all phyla. The ratio of Helicobacter which occupied the largest proportion at the genus level was 12.44%, followed by Lactobacillus (11.39%), Clostridium (6.19%),Mycoplasma (4.23%) and Flavonifractor (3.52%). High throughput sequencing analysis showed that the intestinal flora of Leopoldamys edwardsi in Hainan Island was complex and diverse, which had the significance of further research.
Adult ; Animals ; Bacteria/genetics* ; Feces/microbiology* ; Female ; Gastrointestinal Microbiome/genetics* ; High-Throughput Nucleotide Sequencing ; Humans ; Intestines ; Male ; Murinae/genetics*

OBJECTIVES: To explore the optimal maintenance dose of caffeine citrate for preterm infants requiring assisted ventilation and caffeine citrate treatment. METHODS: A retrospective analysis was performed on the medical data of 566 preterm infants (gestational age ≤34 weeks) who were treated and required assisted ventilation and caffeine citrate treatment in the neonatal intensive care unit of 30 tertiary hospitals in Jiangsu Province of China between January 1 and December 31, 2019. The 405 preterm infants receiving high-dose (10 mg/kg per day) caffeine citrate after a loading dose of 20 mg/kg within 24 hours after birth were enrolled as the high-dose group. The 161 preterm infants receiving low-dose (5 mg/kg per day) caffeine citrate were enrolled as the low-dose group. RESULTS: Compared with the low-dose group, the high-dose group had significant reductions in the need for high-concentration oxygen during assisted ventilation (P=0.044), the duration of oxygen inhalation after weaning from noninvasive ventilation (P<0.01), total oxygen inhalation time during hospitalization (P<0.01), the proportion of preterm infants requiring noninvasive ventilation again (P<0.01), the rate of use of pulmonary surfactant and budesonide (P<0.05), and the incidence rates of apnea and bronchopulmonary dysplasia (P<0.01), but the high-dose group had a significantly increased incidence rate of feeding intolerance (P=0.032). There were no significant differences between the two groups in the body weight change, the incidence rates of retinopathy of prematurity, intraventricular hemorrhage or necrotizing enterocolitis, the mortality rate, and the duration of caffeine use (P>0.05). CONCLUSIONS This pilot multicenter study shows that the high maintenance dose (10 mg/kg per day) is generally beneficial to preterm infants in China and does not increase the incidence rate of common adverse reactions. For the risk of feeding intolerance, further research is needed to eliminate the interference of confounding factors as far as possible.
Caffeine/therapeutic use* ; Citrates ; Humans ; Infant ; Infant, Newborn ; Infant, Premature ; Respiration, Artificial ; Retrospective Studies

To analyze the risk factors for urinary tract infection (UTI) among inpatients. The case data of 1 875 inpatients receiving urinary bacterial culture in Beijing Haidian Hospital from October 2019 to May 2021 were analyzed retrospectively. According to the etiological diagnostic criteria of UTI, they were divided into infection group and non-infection group. The species and distribution of pathogens in the infection group were analyzed, and the case data and laboratory indexes were subjected to univariate analysis. The variables with statistical significance were selected for binary logistic regression to analyze the risk factors of urinary tract infection and establish a prediction model. The receiver operating characteristic (ROC) curve was drawn for each parameter included in the model, and the area under the curve (AUC) was calculated. The diagnostic and predictive efficacy of each parameter alone and their combination for UTI were evaluated. So, a total of 1 162 patients with non-infection group and 713 patients with UTI were detected. Among the cultured pathogens, the constituent ratio of Gram-negative bacteria, Gram-positive bacteria and fungi was 57.2%(408/713), 35.9%(256/713) and 6.9%(49/713) respectively. Multivariate analysis showed that, Age, duration of urinary catheterization>7 d, stroke and orthopedic surgery were the risk factors of UTI among inpatients. The use of antibiotics is a protective factor for urinary tract infections. The prediction model of UTI was established by the risk factors, age, duration of urinary catheterization>7 d, stroke, orthopedic surgery, urinary leukocyte esterase, urinary nitrite and Coefficient of variability of red blood cell volume distribution width (RDW-CV). The AUC of the combination of the eight parameters in diagnosing and predicting UTI was 0.835 (95%CI: 0.816-0.855), with the sensitivity of 70.7% and the specificity of 82.8%. In conclusion,the combination of the eight parameters can better assist in the diagnosis and prediction of UTI, and provide an experimental basis for clinicians to judge UTI.
Humans ; Retrospective Studies ; Inpatients ; Urinary Tract Infections/microbiology* ; Urinalysis ; Stroke