Structural and functional characterization of a mycobacterial methylenetetrahydrofolate reductase utilizing NADH as the exclusive cofactor.

5,10-Methylenetetraydrofolate reductase (MTHFR) is a key enzyme in folate metabolism. MSMEG_6649, a non-canonical MTHFR from Mycobacterium smegmatis, was previously reported as a monomeric protein lacking the flavin coenzyme. However, the structural basis for its unique flavin-independent catalytic mechanism remains poorly understood. Here, we determined the crystal structures of apo MTHFR MSMEG_6649 and its complex with NADH from M. smegmatis. Structural analysis revealed that the groove formed by the loops 4 and 5 of non-canonical MSMEG_6649 interacting with FAD was significantly larger than that of canonical MTHFR. Meanwhile, the NADH-binding site in MSMEG_6649 is highly similar to the FAD binding site in canonical MTHFR, suggesting that NADH plays the same role (immediate hydride donor for methylenetetraydrofolate) as FAD in the catalytic reaction. Using biochemical analysis, molecular modeling, and site-directed mutagenesis, the critical residues participating in the binding of NADH and the substrate 5,10-methylenetetrahydrofolate as well as the product 5-methyltetrahydrofolate were identified and validated. Taken together, this work not only provides a good starting point for understanding the potential catalytic mechanism for MSMEG_6649, but also identifies an exploitable target for the development of anti-mycobacterial drugs.

Efficiencies and mechanism of enhanced coagulation pre-treatment on domestic sewage with PAC-HCA compound.

Poly dimethyl diallyl propyl ammonium chloride (HCA) and poly aluminum chloride (PAC) were used to prepare complex coagulants for the enhanced coagulation (EC) pretreatment of domestic sewage. The influences of hydraulic conditions, the dosage ratio of PAC-HCA complex coagulants, initial pH value, and dosage on the removal efficiency of SS, COD, and TP in domestic sewage were investigated. The fractal dimension and Zeta potential were used to verify and characterize the experimental results. The results showed that the optimum coagulant conditions were as follows: G1 = 200.0-265.0 s-1, T1 = 1.5 min, G2 = 40.0 s-1, T2 = 5 min, PAC: HCA = 25:1, dosage = 15 mL/L, pH = 8. At the mentioned point, the removal rates of SS, COD, and TP are 98.74%, 44.63%, and 89.85%, respectively. In addition, through comparative tests, PAC-HCA compound coagulants show better treatment efficiency than PAC and HCA used alone. When the HCA dosage was 15 mg/L, Zeta potential and flocs fractal dimension was 2.29 mv and 0.9844, respectively. This indicates that PAC-HCA has a good treatment effect on domestic sewage, and the mechanism of enhanced coagulation to remove nutrients is mainly electrical neutralization.

Synthesis of 4-methylvaleric acid, a precursor of pogostone, involves a 2-isobutylmalate synthase related to 2-isopropylmalate synthase of leucine biosynthesis.

We show here that the side chain of pogostone, one of the major components of patchouli oil obtained from Pogostemon cablin and possessing a variety of pharmacological activities, is derived from 4-methylvaleric acid. We also show that 4-methylvaleric acid is produced through the one-carbon α-ketoacid elongation pathway with the involvement of the key enzyme 2-isobutylmalate synthase (IBMS), a newly identified enzyme related to isopropylmalate synthase (IPMS) of leucine (Leu) biosynthesis. Site-directed mutagenesis identified Met132 in the N-terminal catalytic region as affecting the substrate specificity of PcIBMS1. Even though PcIBMS1 possesses the C-terminal domain that in IPMS serves to mediate Leu inhibition, it is insensitive to Leu. The observation of the evolution of IBMS from IPMS, as well as previously reported examples of IPMS-related genes involved in making glucosinolates in Brassicaceae, acylsugars in Solanaceae, and flavour compounds in apple, indicate that IPMS genes represent an important pool for the independent evolution of genes for specialised metabolism.

Paeoniflorin attenuates monocrotaline-induced pulmonary arterial hypertension in rats by suppressing TAK1-MAPK/NF-κB pathways.

Pulmonary arterial hypertension (PAH) characterized by pulmonary vascular remodeling is a lethal disease. Paeoniflorin (PF) is a monoterpene glycoside with numerous beneficial functions, such as vasodilation, anti-inflammation and immunomodulation. This study aims to investigate the effects of PF on monocrotaline (MCT)-induced PAH rats. Our data showed that both prophylactic or therapeutic administration of PF alleviated MCT-induced increasing of right ventricular systolic pressure (RVSP), prevented right ventricle hypertrophy and pulmonary arterial remodeling, as well as inhibited inflammatory cell infiltration around pulmonary arteries. Meanwhile, PF blocked MCT-induced endothelial-mesenchymal transition (EndMT) as indicated by the restored expression of endothelial markers in lung. Moreover, PF inhibited MCT-induced down-regulation of bone morphogenetic protein receptor 2 (BMPR2) and suppressed MCT-induced phosphorylation of transforming growth factor-ß (TGFß) activated kinase 1 (TAK1) in vivo. In vitro studies indicated that PF prevented human pulmonary arterial smooth muscle cells (PASMCs) from platelet-derived growth factor-BB (PDGF-BB)-stimulated proliferation and migration. PF also partially reversed TGFß1, interleukin-1ß (IL-1ß) and tumor necrosis factor (TNF-α) co-stimulated endothelial-to-mesenchymal transition (EndMT) in cultured human pulmonary artery endothelial cells (HPAECs). Signaling pathway analysis demonstrated that the underlying mechanism might be associated with the inhibition of TAK1-MAPK/NF-κB pathways. Taken together, our results suggested that PF could be a potential drug for the treatment of PAH.

Functional Prediction of trans-Prenyltransferases Reveals the Distribution of GFPPSs in Species beyond the Brassicaceae Clade.

Terpenoids are the most diverse class of plant primary and specialized metabolites, and trans-prenyltransferases (trans-PTs) are the first branch point to synthesize precursors of various chain lengths for further metabolism. Whereas the catalytic mechanism of the enzyme is known, there is no reliable method for precisely predicting the functions of trans-PTs. With the exponentially increasing number of available trans-PTs genes in public databases, an in silico functional prediction method for this gene family is urgently needed. Here, we present PTS-Pre, a web tool developed on the basis of the "three floors" model, which shows an overall 86% prediction accuracy for 141 experimentally determined trans-PTs. The method was further validated by in vitro enzyme assays for randomly selected trans-PTs. In addition, using this method, we identified nine new GFPPSs from different plants which are beyond the previously reported Brassicaceae clade, suggesting these genes may have occurred via convergent evolution and are more likely lineage-specific. The high accuracy of our blind prediction validated by enzymatic assays suggests that PTS-Pre provides a convenient and reliable method for genome-wide functional prediction of trans-PTs enzymes and will surely benefit the elucidation and metabolic engineering of terpenoid biosynthetic pathways.

The Effects of Lipoaspirate-Derived Fibrous Tissue on Survival Quality and Mechanical Property of Fat Grafts.

BACKGROUND: Fibrous connective tissue (referred to as fiber) in lipoaspirates would be discarded before lipotransfer in case of cannula blockage. However, the fiber contains extracellular matrix which provide structure support and is rich in stromal vascular fractions (SVFs). Removal of the fiber might theoretically affect the survival quality and mechanical properties of fat grafts. But there is few evidence in vivo and vitro about how the fiber affects the fat grafts. OBJECTIVE: To assess the effect of fibers on the survival quality and mechanical property of fat grafts. METHODS: The SVFs in both fat and fiber were obtained by collagenase digestion for cells counting and comparison. Three groups were designed according to the different proportions of fat and fiber: the fat group (100% fat), the mixed group (50% fat, 50% fiber in volume ratio), and the fiber group (100% fiber). Three groups of grafts were transplanted in vivo to evaluate the differences in volume retention rate, histological characteristics and mechanical properties. RESULTS: The amount of SVF cells in fibers (3.47 ±â€Š1.49 × 104 cells/mL) was significantly lower than that in fat (12.3 ±â€Š4.95 × 104 cells/mL) (P < 0.05). Grafts in the mixed group and the fiber group showed an increase of volume retention at week 4, but the fiber content showed no significant effects on the volume retention of grafts in three groups at week 12. Elasticity modulus of grafts in the fat group was higher than that in the fiber group and the mixed group at week 4 and 8, the fiber content showed no significant effects on the elasticity modulus of grafts in three groups at week 12. The addition of the fiber reduced the inflammation, cysts, fibrosis, and capillaries density of the grafts. CONCLUSIONS: There were few SVF cells in the fiber. When it was mixed with fat in different proportions and transplanted in vivo, the content of fiber showed no significantly different effects on the long-term volume retention and mechanical property of fat grafts. Due to the risk of blockage, it is recommended to discard the fiber in lipoaspirates.

The Efficacy and Safety of Subcutaneous Radiofrequency After Liposuction: A New Application for Face and Neck Skin Tightening.

BACKGROUND: Minimally invasive or noninvasive skin-tightening procedures have become trends in facial and neck rejuvenation. Radiofrequency-assisted liposuction (RFAL) is a new choice for the treatment of skin relaxation that is more effective than noninvasive surgery without surgical incision. OBJECTIVES: The authors recommend a 2-step method in which radiofrequency is applied after appropriate liposuction is performed. This approach is safer and more effective than traditional RFAL, and the authors detail the safety guidelines, operative techniques, postoperative satisfaction results, and complications. METHODS: A total of 227 patients with lower face and neck skin laxity underwent RFAL between April 2012 and June 2019. The following data were collected: age, body mass index, operative duration, volume of fat aspirated, amount of energy delivered, and number and type of complications. Patient satisfaction was surveyed postoperatively and assessed by third-party surgeons at 3 and 6 months. RESULTS: At 6 months after operation, 78.8% of patients considered the results moderate to excellent, whereas 21.2% of the patients considered the results to be poor or thought there was no change. The photograph evaluation performed by independent plastic surgeons showed moderate to excellent results in 89.1% of patients. There were no major complications that required further medical or surgical intervention. CONCLUSIONS: This 2-step method is a safe and effective improvement in the application of radiofrequency for face and neck skin tightening. Patients can achieve significant contour correction via minimally invasive surgery with a lower risk of side effects.

Dynamin-related protein-1 promotes lung cancer A549 cells apoptosis through the F-actin/bax signaling pathway.

Dynamin-related protein-1 (Drp1) has been found to be associated with cell death. The role of Drp1 in A549 cells death has not been explored. In this study, adenovirus-mediated Drp1 overexpression was used to investigate the influence of Drp1 on A549 cell viability with a focus on F-actin and Bax. Cell viability, protein expression, oxygen consumption, energy metabolism, and growth rate were measured through ELISA, qPCR, western blots and pathway analysis. Our results indicated that Drp1 overexpression promoted A549 cell death through apoptosis. Mechanistically, cytoskeletal F-actin was impaired and Bax expression was elevated in response to Drp1 overexpression. Besides, energy metabolism was reduced and oxygen consumption was interrupted. Therefore, our results demonstrated that A549 cell viability, apoptosis and growth were regulated by the Drp1/F-actin/Bax signaling pathways. These data explain a new role played by Drp1 in regulating cell viability and also provide a potential target to affect the progression of lung cancer through induction of cell death.

Botulinum Toxin to Treat Horizontal Forehead Lines: A Refined Injection Pattern Accommodating the Lower Frontalis.

BACKGROUND: When treating horizontal forehead lines with botulinum toxin type A the traditional approach requires that injection points should stay 1.5 to 2 cm above the orbital rim to avoid brow ptosis. Failure to treat the lower frontalis may potentially cause worse rhytides in the lower forehead. OBJECTIVES: The aim of this study was to present a refined injection pattern accommodating the lower frontalis and evaluate its clinical efficacy and safety. METHODS: Patients were categorized into 4 types according to the patterns of their forehead wrinkles. Moderate and severe wrinkles in the upper forehead were treated by the "safe zone" technique. Mild wrinkles and rhytides in the lower forehead were treated by the Microbotox technique. Standard photographs and measurements were taken before and after treatment. The effect on wrinkle reduction and changes in brow heights were assessed. RESULTS: In total, 330 treatments were followed up in the clinic, and 246 treatments were followed up by telephone. Among the 330 treatments, 213 were evaluated in our clinic 2 to 4 weeks later, and the patients who received these treatments were recruited for effect evaluation and brow height measurements. The posttreatment severity of forehead wrinkles was significantly reduced (P < 0.05), and brow heights remained unchanged (P > 0.05). No severe adverse events were documented. Patient satisfaction was quite high. CONCLUSIONS: The refined injection pattern is an effective and safe technique to treat horizontal forehead lines. The Microbotox technique enables treatment of the lower frontalis without changes in brow position.

Characterization of a Type 1 Metallothionein Gene from the Stresses-Tolerant Plant Ziziphus jujuba.

Plant metallothioneins (MTs) are a family of low molecular weight, cysteine-rich, and metal-binding proteins, which play an important role in the detoxification of heavy metal ions, osmotic stresses, and hormone treatment. Sequence analysis revealed that the open-reading frame (ORF) of ZjMT was 225 bp, which encodes a protein composed of 75 amino acid residues with a calculated molecular mass of 7.376 kDa and a predicated isoelectric point (pI) of 4.83. ZjMT belongs to the type I MT, which consists of two highly conserved cysteine-rich terminal domains linked by a cysteine free region. Our studies showed that ZjMT was primarily localized in the cytoplasm and the nucleus of cells and ZjMT expression was up-regulated by NaCl, CdCl2 and polyethylene glycol (PEG) treatments. Constitutive expression of ZjMT in wild type Arabidopsis plants enhanced their tolerance to NaCl stress during the germination stage. Compared with the wild type, transgenic plants accumulate more Cd2+ in root, but less in leaf, suggesting that ZjMT may have a function in Cd2+ retension in roots and, therefore, decrease the toxicity of Cd2+.

Effect and mechanism of iron-carbon micro-electrolysis pretreatment of organic peroxide production wastewater.

The wastewater from organic peroxide production has high chemical oxygen demand (COD) concentration and poor biodegradability, so it is necessary to find a cost-effective treatment method. The iron-carbon microelectrolysis (IC-ME) technology was used to pretreat the organic peroxide production wastewater, and the influence of reaction conditions on the removal effect of pollutants and the degradation mechanism were studied. The effects of initial pH, iron filings, iron-carbon ratio, and reaction time on the wastewater treatment were investigated by single-factor and response surface optimization experiments, and the degradation mechanism was analyzed by three-dimensional fluorescence spectroscopy, UV-Vis, and gas chromatography mass spectrometry (GC-MS). The experimental results showed that the COD removal efficiency was 35.67% and the biodegradability of wastewater was increased from 0.113 to 0.173 under the conditions of initial pH of 3.1, the dosage of iron filings of 30.5 g/L, the ratio of iron-carbon of 1.01, and the reaction time of 122.8 min, and the process of IC-ME for degrading COD of wastewater from the production of organic peroxide was consistent with the secondary reaction. The IC-ME process could decompose macromolecular organic compounds such as tyrosine proteins and aromatic proteins, and improve the biodegradability of wastewater. It provides a theoretical reference for the practical application of IC-ME to treat this type of wastewater.

A bibliometric analysis of contrast-enhanced ultrasound over the past twenty years.

Background: Contrast-enhanced ultrasound (CEUS) technology has been developed for decades, and its application is becoming increasingly more extensive. In this study, bibliometrics was used to characterize the development status of CEUS over the past 20 years and to identify future research hotspots. Methods: We collected data from the Web of Science and analyzed the literature related to CEUS published from 2002 to 2022. We examined 6,382 publications and analyzed the publication year, country of origin, affiliated institutions, authors, journal, categories, keywords, and research frontiers within the relevant literature. Using bibliometric analysis, we aimed to determine the general research direction and current publication trends. This allowed us to identify the most prolific and outstanding authors, institutions, countries, and keywords in CEUS research. For data collection, analysis, and visualization, we employed VOSviewer (Leiden University, Leiden, the Netherlands), Excel (Microsoft Corp., Redmond, WA, USA), CiteSpace, and biblioshiny. These tools helped us gather, analyze, and visualize the data effectively. Results: The analyzed publications indicated a consistent upward trend in the number of works published between 2002 and 2022. Notably, China and Sun Yat-sen University emerged as the most prolific countries and institutions, respectively. China published 391 articles with 5,817 citations and was the leader in terms of international cooperation. Moreover, pediatrics-related keywords have surged in frequency in recent years. Conclusions: The amount of research on CEUS has increased rapidly and continues to grow, with China being at the forefront of this research field. The application of CEUS in some pediatric diseases is a recent research hotspot and perhaps warrants close attention.

Epidemiological investigation of feline chronic gingivostomatitis and its relationship with oral microbiota in Xi'an, China.

Feline chronic gingivostomatitis (FCGS) is an ulcerative and/or proliferative disease that typically affects the palatoglossal folds. Because of its unknown pathogenesis and long disease course, it is difficult to treat and has a high recurrence rate. Most of the bacteria in the oral microbiota exist in the mouth symbiotically and maintain a dynamic balance, and when the balance is disrupted, they may cause disease. Disturbance of the oral microbiota may play an important role in the development of FCGS. In this study, the medical records of 3109 cats in three general pet hospitals in Xi 'an were collected. Sixty-one cats with FCGS were investigated via questionnaires, routine oral examinations and laboratory examinations. Oral microbiota samples were collected from 16 FCGS-affected cats, and microbial species were identified by 16S rDNA sequencing. The results showed that the incidence of FCGS had no significant correlation with age, sex or breed. However, the incidence of FCGS was associated with immunization, a history of homelessness and multicat rearing environments. The number of neutrophils and the serum amyloid A concentration were increased, and the percentage of cells positive for calicivirus antigen was high in all cases. All the cats had different degrees of dental calculus, and there were problems such as loss of alveolar bone or tooth resorption. Compared with those in healthy cats, the bacterial diversity and the abundance of anaerobic bacteria were significantly increased in cats with FCGS. Porphyromonas, Treponemas and Fusobacterium were abundant in the mouths of the affected cats and may be potential pathogens of FCGS. After tooth extraction, a shift could be seen in the composition of the oral microbiota in cats with FCGS. An isolated bacteria obtained from the mouths of the affected cats was homologous to P. gulae. Both the identified oral microbiota and the isolated strain of the cats with FCGS had high sensitivity to enrofloxacin and low sensitivity to metronidazole. This study provides support to current clinical criteria in diagnosing FCGS and proposes a more suitable antibiotic therapy.

NLRP3 inflammasome mediates abnormal epithelial regeneration and distal lung remodeling in silica­induced lung fibrosis.

NOD-like receptor protein 3 (NLRP3) inflammasome is closely related to silica particle­induced chronic lung inflammation but its role in epithelial remodeling, repair and regeneration in the distal lung during development of silicosis remains to be elucidated. The present study aimed to determine the effects of the NLRP3 inflammasome on epithelial remodeling and cellular regeneration and potential mechanisms in the distal lung of silica­treated mice at three time points. Pulmonary function assessment, inflammatory cell counting, enzyme­linked immunosorbent assay, histological and immunological analyses, hydroxyproline assay and western blotting were used in the study. Single intratracheal instillation of a silica suspension caused sustained NLRP3 inflammasome activation in the distal lung. Moreover, a time­dependent increase in airway resistance and a decrease in lung compliance accompanied progression of pulmonary fibrosis. In the terminal bronchiole, lung remodeling including pyroptosis (membrane­distributed GSDMD+), excessive proliferation (Ki67+), mucus overproduction (mucin 5 subtype AC and B) and epithelial­mesenchymal transition (decreased E­Cadherin+ and increased Vimentin+), was observed by immunofluorescence analysis. Notably, aberrant spatiotemporal expression of the embryonic lung stem/progenitor cell markers SOX2 and SOX9 and ectopic distribution of bronchioalveolar stem cells were observed in the distal lung only on the 7th day after silica instillation (the early inflammatory phase of silicosis). Western blotting revealed that the Sonic hedgehog/Glioma­associated oncogene (Shh/Gli) and Wnt/ß­catenin pathways were involved in NLRP3 inflammasome activation­mediated epithelial remodeling and dysregulated regeneration during the inflammatory and fibrotic phases. Overall, sustained NLRP3 inflammasome activation led to epithelial remodeling in the distal lung of mice. Moreover, understanding the spatiotemporal profile of dysregulated epithelial repair and regeneration may provide a novel therapeutic strategy for inhalable particle­related chronic inflammatory and fibrotic lung disease.

Deubiquitylase USP31 Induces Autophagy and Promotes the Progression in Lung Squamous Cell Carcinoma Cells by Stabilizing E2F1 Expression.

BACKGROUND: Autophagy exerts a vital role in the progression of lung squamous cell carcinoma (LUSC). Ubiquitin-specific peptidase 31 (USP31) has recently been found to be involved in the development of a variety of cancers. However, whether USP31 modulates autophagy in LUSC remains unclear. METHODS: This study revealed that high levels of USP31 were discovered in LUSC tissue samples employing the Gene Expression Profiling Interactive Analysis (GEPIA) database, quantitative real- time PCR (qRT-PCR), and Western blot analysis. Cell proliferation was tested via cell counting kit 8 (CCK-8) as well as colony formation, demonstrating that USP31-stable knockdown reduced cell viability. RESULTS: Immunofluorescence analysis illustrated that USP31 knockdown blocked the occurrence of LUSC autophagy. Meanwhile, USP31 has been shown to stabilize the expression of E2F transcription factor 1 (E2F1) through the proteasome pathway. Furthermore, overexpressed E2F1 effectively eliminated the effect of USP31 knockdown on LUSC cell proliferation and autophagy. CONCLUSION: In summary, this investigation proved that USP31 promoted LUSC cell growth and autophagy, at least in part by stabilizing E2F1 expression, which provided a potential therapeutic gene for the treatment of LUSC.

A meta-analysis: elucidating diagnostic thresholds of peak systolic flow velocities in thyroid arteries for the discrimination of Graves' disease and destructive thyrotoxicosis.

Objective: This meta-analysis examines peak systolic velocities (PSVs) in thyroid arteries as potential biomarkers for thyroid disorders, which includes treated and untreated Graves' disease(GD) and destructive thyrotoxicosis(DT). Methods: A search across databases including PubMed, Google Scholar, Embase, and Web of Science identified studies assessing peak systolic flow velocity in the inferior thyroid artery (ITA-PSV) and superior thyroid artery (STA-PSV) diagnostic efficacy in GD and DT.And the search was restricted to publications in the English language.The analysis compared STA-PSV and ITA-PSV across patient groups, evaluating intra-group variances and synthesizing sensitivity and specificity data. Results: The analysis covered 18 studies with 1276 GD, 564 DT patients, and 544 controls. The difference of STA-PSV between GD group, DT group and normal group and the difference of ITA-PSV were analyzed in subgroups, and there was no statistical significance between subgroups when comparing any two groups. Normal subjects displayed intra-group ITA-PSV and STA-PSV differences with established cut-off values of 20.33 cm/s (95% CI, 17.48-23.18) for ITA-PSV and 25.61 cm/s (95% CI, 20.37-30.85) for STA-PSV. However, no significant intra-group differences were observed in the STA-PSV and ITA-PSV cut-off values among groups with GD or DT. The combined cut-off values for these patient groups and normal subjects were 68.63 cm/s (95% CI, 59.12-78.13), 32.08 cm/s (95% CI, 25.90-38.27), and 23.18 cm/s (95% CI, 20.09-26.28), respectively. The diagnostic odds ratio(DOR) for these values was 35.86 (95% CI, 18.21-70.60), and the area under the summary receiver operating characteristic (SROC) curve was 0.91, with a sensitivity estimate of 0.842 (95% CI, 0.772-0.866). Conclusion: PSVs in thyroid arteries are useful diagnostic tools in distinguishing DT from GD. A PSV above 68.63 cm/s significantly improves GD diagnosis with up to 91% efficacy. No notable differences were found between superior and inferior thyroid arteries in these conditions.

Risk of Acute Respiratory Distress Syndrome in Community-Acquired Pneumonia Patients: Use of an Artificial Neural Network Model.

This study aimed to explore the independent risk factors for community-acquired pneumonia (CAP) complicated with acute respiratory distress syndrome (ARDS) and to predict and evaluate the risk of ARDS in CAP patients based on artificial neural network models (ANNs). We retrospectively analyzed eligible 989 CAP patients (632 men and 357 women) who met the criteria from the comprehensive intensive care unit (ICU) and the respiratory and critical care medicine department of Changzhou Second People's Hospital, Jiangsu Provincial People's Hospital, Nanjing Military Region General Hospital, and Wuxi Fifth People's Hospital between February 2018 and February 2021. The best predictors to model the ANNs were selected from 51 variables measured within 24 h after admission. By using this model, patients were divided into a training group (n = 701) and a testing group (n = 288 patients). Results showed that in 989 CAP patients, 22 important variables were identified as risk factors. The sensitivity, specificity, and accuracy of the ANNs model training group were 88.9%, 90.1%, and 89.7%, respectively. When ANNs were used in the test group, their sensitivity, specificity, and accuracy were 85.0%, 87.3%, and 86.5%, respectively; when ANNs were used to predict ARDS, the area under the receiver operating characteristic (ROC) curve was 0.943 (95% confidence interval (0.918-0.968)). The nine most important independent variables affecting the ANNs models were lactate dehydrogenase (100%), activated partial thromboplastin time (84.6%), procalcitonin (83.8%), age (77.9%), maximum respiratory rate (76.0%), neutrophil (75.9%), source of admission (68.9%), concentration of total serum kalium (61.3%), and concentration of total serum bilirubin (50.4%) (all important >50%). The ANNs model and the logistic regression models were significantly different in predicting and evaluating ARDS in CAP patients. Thus, the ANNs model has a good predictive value in predicting and evaluating ARDS in CAP patients, and its performance is better than that of the logistic regression model in predicting the incidence of ARDS patients.

Identification of a Potential Antimycobacterial Drug Sensitizer Targeting a Flavin-Independent Methylenetetrahydrofolate Reductase.

The increasing antibiotic resistance of Mycobacterium tuberculosis and pathogenic nontuberculosis mycobacteria highlights the urgent need for new prevention and treatment strategies. Recently, the cocrystal structure of a Mycobacterium smegmatis flavin-independent 5,10-methylenetetrahydrofolate reductase (MsmMTHFR) that binds with a reduced nicotinamide adenine dinucleotide (NADH) has been well-determined, providing a structural basis for the screening of antimycobacterial leads targeting MsmMTHFR, a new enzyme involved in tetrahydrofolic acid (THF) biosynthesis. In this study, we identified compound AB131 as a promising candidate that fits well into the NADH binding pocket of MsmMTHFR through virtual screening. We discovered that AB131 and its derivatives (13 and 14) can sensitize the antimycobacterial activity of the antitubercular drug para-aminosalicyclic acid (PAS) by 2-5-fold against various species of mycobacteria. Although the compounds themselves do not exhibit any antimycobacterial activity, the high binding affinity of AB131 with MsmMTHFR or Rv2172c was evaluated by microscale thermophoresis analysis. Additionally, we predicted and validated the key residues (V115, V117, P118, and R163) of MsmMTHFR that are involved in the interaction with AB131 by using molecular docking and mutagenesis analysis. These findings offer a potential exploitable target for developing potent and specific antimycobacterial drug sensitizers.

[Establishing prediction model of community-acquired pneumonia complicated with acute respiratory distress syndrome based on artificial neural network].

OBJECTIVE: To investigate the independent risk factors of community-acquired pneumonia (CAP) complicated with acute respiratory distress syndrome (ARDS), and the accuracy and prevention value of ARDS prediction based on artificial neural network model in CAP patients. METHODS: A case-control study was conducted. Clinical data of 414 patients with CAP who met the inclusion criteria and were admitted to the comprehensive intensive care unit and respiratory department of Changzhou Second People's Hospital Affiliated to Nanjing Medical University from February 2020 to February 2021 were analyzed. They were divided into two groups according to whether they had complicated with ARDS. The clinical data of the two groups were collected within 24 hours after admission, the influencing factors of ARDS were screened out by univariate analysis, and the artificial neural network model was constructed. Through the artificial neural network model, the importance of input layer independent variables (that was, the influence factors obtained from univariate analysis) on the output layer dependent variables (whether ARDS occurred) was drawn. The artificial neural network modeling data pairs were randomly divided into training group (n = 290) and verification group (n = 124) in a ratio of 7:3. The overall prediction accuracy of the training group and the verification group was calculated respectively. At the same time, the receiver operator characteristic curve (ROC curve) was drawn, and the area under the ROC curve (AUC) was calculated. RESULTS: All 414 patients were enrolled in the analysis, including 82 patients with ARDS and 332 patients without ARDS. Univariate analysis showed that gender, age, heart rate (HR), maximum systolic blood pressure (MSBP), maximum respiratory rate (MRR), source of admission, C-reactive protein (CRP), procalcitonin (PCT), erythrocyte sedimentation rate (ESR), neutrophil count (NEUT), eosinophil count (EOS), fibrinogen equivalent unit (FEU), activated partial thromboplastin time (APTT), total bilirubin (TBil), albumin (ALB), lactate dehydrogenase (LDH), serum creatinine (SCr), hemoglobin (Hb) and blood glucose (GLU) were significantly different between the two groups, which might be the risk factors of CAP patients complicated with ARDS. Taking the above 19 risk factors as the input layer and whether ARDS occurred as the output layer, the artificial neural network model was constructed. Among the input layer independent variables, the top five indicators with the largest influence weight on the neural network model were LDH (100.0%), PCT (74.4%), FEU (61.5%), MRR (56.9%), and APTT (51.6%), indicating that that these five indicators had a greater impact on the occurrence of ARDS in patients with CAP. The overall prediction accuracy of the artificial neural network model in the training group was 94.1% (273/290), and that of the verification group was 89.5% (111/124). The AUC predicted by the aforementioned artificial neural network model for ARDS in CAP patients was 0.977 (95% confidence interval was 0.956-1.000). CONCLUSIONS: The prediction model of ARDS in CAP patients based on artificial neural network model has good prediction ability, which can be used to calculate the accuracy of ARDS in CAP patients, and specific preventive measures can be given.

Single session of combined microfat and subcision in the treatment of Grade 4 atrophic acne scars.

BACKGROUND: Severe atrophic acne scars (AAS) remain the "Achilles's heel" of AAS treatment. The combination of microfat and subcision treatment is a potential solution for severe AAS. AIMS: This study aimed to evaluate the efficacy and safety of combined microfat and subcision treatment for severe (Grade 4) AAS. METHODS: Data of patients with Grade 4 AAS who underwent combined microfat and subcision treatment between September 2016 and December 2020 were reviewed. Post-treatment evaluation was performed at least 3 months postoperatively. The severity of AAS was graded based on Goodman's qualitative classification. The volume of concavities was measured using an Antera 3D camera. Complications were documented. RESULTS: A total of 42 patients received a single treatment session. Excellent response was observed in 5 (11.9%) patients, very good in 13 (31.0%), good in 22 (52.4%), and poor response in 2 (4.7%). The average reduction of the total volume of concavities was 28.0%. The most common minor side effects were mild swelling and bruising. No major complications were observed. CONCLUSIONS: Combined microfat and subcision treatment is a safe and effective treatment for severe AAS. The approach will be a significant treatment for severe AAS.