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Introduction: Sclerotherapy is a commonly utilized treatment approach for venous malformations. Absolute ethanol is renowned for its remarkable efficacy as a potent sclerosants, but it is potentially associated with severe complications. Foam sclerotherapy is considered superior to liquid sclerotherapy owing to its heightened efficacy and diminished incidence of complications. Thus, our objective was to devise an ethanol foam sclerosant that delivers exceptional efficacy while mitigating complications. Methods: In the first set of experiments, we identified the suitable range of ethanol concentrations for sclerotherapy through human umbilical vein endothelial cell proliferation assays and blood clotting experiments. Next, the surfactants polysorbate 80, egg yolk lecithin, and hyaluronic acid were added to create stable ethanol foam, with their ratios meticulously optimized. Results: The optimal concentration range of ethanol was determined to be 30-60%. Eventually, a 48% ethanol foam was successfully produced with excellent stability. Other than ethanol, the formulation included 5 × 10-3 g/mL polysorbate 80, 10-2 g/mL egg yolk lecithin, and 0.04 mL/mL hyaluronic acid. Discussion: The novel ethanol foam produced here could be a promising candidate for the treatment of venous malformations.
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BACKGROUND: Elevated soluble stimulating factor 2 (sST2) level is observed in cardiovascular diseases, such as heart failure and acute coronary syndrome, which reflects myocardial fibrosis and hypertrophy, indicating adverse clinical outcomes. However, the association between sST2 and hypertensive heart disease are less understood. This study aimed to determine the relationship of sST2 with left ventricular hypertrophy (LVH) and geometric remodeling in essential hypertension (EH). METHODS: We enrolled 483 patients (aged 18-80 years; 51.35% female). sST2 measurements and echocardiographic analyses were performed. RESULTS: Stepwise multiple linear regression analysis showed significant associations between sST2, left ventricular (LV) mass, and LV mass index. The prevalence of LVH and concentric hypertrophy (CH) increased with higher sST2 grade levels (p for trend<0.05). Logistic regression analysis suggested that the highest tertile of sST2 was significantly associated with increased LVH risk, compared with the lowest tertile (multivariate-adjusted odds ratio [OR] of highest group: 6.61; p<0.001). Similar results were observed in the left ventricular geometric remodeling; the highest tertile of sST2 was significantly associated with increased CH risk (multivariate-adjusted OR of highest group: 5.80; p<0.001). The receiver operating characteristic analysis results revealed that sST2 had potential predictive value for LVH (area under the curve [AUC]: 0.752, 95% confidence interval [CI]: 0.704-0.800) and CH (AUC: 0.750, 95% CI: 0.699-0.802) in patients with EH. CONCLUSIONS: High sST2 level is strongly related to LVH and CH in patients with EH and can be used as a biomarker for the diagnosis and risk assessment of hypertensive heart disease.
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Most known chemiluminescence (CL) systems are flash-type that generate weak luminescence and decline quickly after dozens of seconds, while the glow-type CL systems have stable emission for an extended period to achieve accurate quantitation. In this work, a long-term CL system based on hydrazine-hydrate (N2H4·H2O) modified carbon quantum dots (N-CQDs) as a luminescent probe, with K2S2O8 and H2O2 as co-reactants, was proposed. The CL emission enhanced by H2O2 increased 18-fold more than that of N-CQDs and K2S2O8 direct reaction, and decayed by 5% of the maximum intensity over 700 s. In the reaction system, K2S2O8 and H2O2 co-reactants can promote each other to continuously generate corresponding radicals (â¢OH, O2â¢-, 1O2), which in turn trigger the CL emission of N-CQDs. This phenomenon was identified as the primary cause for the production of persistent CL. In addition, a stable and selective CL sensor based on the N-CQDs-K2S2O8-H2O2 CL enhancing system was developed for ascorbic acid quantitation in the linear range from 0.1 to 10.0 mM with a detection limit of 0.036 mM. The method has been applied to the analysis of tablet samples and holds potential in pharmaceutical analysis field.
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PURPOSE: Immunohistochemical staining of programmed death-ligand 1 (PD-L1) in tumor biopsies acquired through invasive procedures is routinely employed in clinical practice to identify patients who are most likely to benefit from anti-programmed cell death protein 1 (PD-1) therapy. Nevertheless, PD-L1 expression is observed in various cellular subsets within tumors and their microenvironments, including tumor cells, dendritic cells, and macrophages. The impact of PD-L1 expression across these different cell types on the responsiveness to anti-PD-1 treatment is yet to be fully understood. METHODS: We synthesized polymer-based lysosome-targeting chimeras (LYTACs) that incorporate both PD-L1-targeting motifs and liver cell-specific asialoglycoprotein receptor (ASGPR) recognition elements. Small-animal positron emission tomography (PET) imaging of PD-L1 expression was also conducted using a PD-L1-specific radiotracer 89Zr-αPD-L1/Fab. RESULTS: The PD-L1 LYTAC platform was capable of specifically degrading PD-L1 expressed on liver cancer cells through the lysosomal degradation pathway via ASGPR without impacting the PD-L1 expression on host cells. When coupled with whole-body PD-L1 PET imaging, our studies revealed that host cell PD-L1, rather than tumor cell PD-L1, is pivotal in the antitumor response to anti-PD-1 therapy in a mouse model of liver cancer. CONCLUSION: The LYTAC strategy, enhanced by PET imaging, has the potential to surmount the limitations of knockout mouse models and to provide a versatile approach for the selective degradation of target proteins in vivo. This could significantly aid in the investigation of the roles and mechanisms of protein functions associated with specific cell subsets in living subjects.
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Verticillium wilt, caused by Verticillium dahliae, is a soil-borne disease affecting eggplant. Wild eggplant, recognized as an excellent disease-resistant resource against verticillium wilt, plays a pivotal role in grafting and breeding for disease resistance. However, the underlying resistance mechanisms of wild eggplant remain poorly understood. This study compared two wild eggplant varieties, LC-2 (high resistance) and LC-7 (sensitive) at the phenotypic, transcriptomic, and metabolomic levels to determine the molecular basis of their resistance to verticillium wilt. These two varieties exhibit substantial phenotypic differences in petal color, leaf spines, and fruit traits. Following inoculation with V. dahliae, LC-2 demonstrated significantly higher activities of polyphenol oxidase, superoxide dismutase, peroxidase, phenylalanine ammonia lyase, ß-1,3 glucanase, and chitinase than did LC-7. RNA sequencing revealed 4,017 differentially expressed genes (DEGs), with a significant portion implicated in processes associated with disease resistance and growth. These processes encompassed defense responses, cell wall biogenesis, developmental processes, and biosynthesis of spermidine, cinnamic acid, and cutin. A gene co-expression analysis identified 13 transcription factors as hub genes in modules related to plant defense response. Some genes exhibited distinct expression patterns between LC-2 and LC-7, suggesting their crucial roles in responding to infection. Further, metabolome analysis identified 549 differentially accumulated metabolites (DAMs) between LC-2 and LC-7, primarily consisting of compounds such as flavonoids, phenolic acids, lipids, and other metabolites. Integrated transcriptome and metabolome analyses revealed the association of 35 gene-metabolite pairs in modules related to the plant defense response, highlighting the interconnected processes underlying the plant defense response. These findings characterize the molecular basis of LC-2 resistance to verticillium wilt and thus have potential value for future breeding of wilt-resistant eggplant varieties.
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The gut microbiota significantly influences host physiology and provides essential ecosystem services. While diet can affect the composition of the gut microbiota, the gut microbiota can also help the host adapt to specific dietary habits. The carrion crow ( Corvus corone), an urban facultative scavenger bird, hosts an abundance of pathogens due to its scavenging behavior. Despite this, carrion crows infrequently exhibit illness, a phenomenon related to their unique physiological adaptability. At present, however, the role of the gut microbiota remains incompletely understood. In this study, we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing, China. Our findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria (75.51%) and Firmicutes (22.37%). Significant differences were observed in the relative abundance of Enterococcus faecalis among groups, highlighting its potential as a biomarker of facultative scavenging behavior in carrion crows. Subsequently, E. faecalis isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against Salmonella enterica infection. Results showed that E. faecalis down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), and interleukin 6 (IL-6), prevented S. enterica colonization, and regulated the composition of gut microbiota in mice, thereby modulating the host's immune regulatory capacity. Therefore, E. faecalis exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior, offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.
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Corvos , Animais , Camundongos , Enterococcus faecalis , Ecossistema , RNA Ribossômico 16S , Comportamento Alimentar , AvesRESUMO
We present a study on the electrocatalysis of 214-type perovskite oxides LnSrCoO4 (Ln = La, Pr, Sm, Eu, and Ga) with semiconducting-like behavior synthesized using the sol-gel method. Among these five catalysts, PrSrCoO4 exhibits the optimal electrochemical performance in both the oxygen evolution reaction and the hydrogen evolution reaction, mainly due to its larger electrical conductivity, mass activity, and turnover frequency. Importantly, the weak dependency of LSV curves in a KOH solution with different pH values, revealing the adsorbate evolving mechanism in PrSrCoO4, and the density functional theory (DFT) calculations indicate that PrSrCoO4 has a smaller Gibbs free energy and a higher density of states near the Fermi level, which accelerates the electrochemical water splitting. The mutual substitution of different rare-earth elements will change the unit-cell parameters, regulate the electronic states of catalytic active site Co ions, and further affect their catalytic performance. Furthermore, the magnetic results indicate strong spin-orbit coupling in the electroactive sites of Co ions in SmSrCoO4 and EuSrCoO4, whereas the magnetic moments of Co ions in the other three catalysts mainly arise from the spin itself. Our experimental results expand the electrochemical applications of 214-type perovskite oxides and provide a good platform for a deeper understanding of their catalytic mechanisms.
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Electrocatalytic reduction of nitrate to ammonia (NRA) has emerged as an alternative strategy for sewage treatment and ammonia generation. Despite excellent performances having been achieved over cobalt-based electrocatalysts, the reaction mechanism as well as veritable active species across a wide potential range are still full of controversy. Here, we adopt CoP, Co, and Co3O4 as model materials to solve these issues. CoP evolves into a core@shell structured CoP@Co before NRA. For CoP@Co and Co catalysts, a three-step relay mechanism is carried out over superficial dynamical Coδ+ active species under low overpotential, while a continuous hydrogenation mechanism from nitrate to ammonia is unveiled over superficial Co species under high overpotential. In comparison, Co3O4 species are stable and steadily catalyze nitrate hydrogenation to ammonia across a wide potential range. As a result, CoP@Co and Co exhibit much higher NRA activity than Co3O4 especially under a low overpotential. Moreover, the NRA performance of CoP@Co is higher than Co although they experience the same reaction mechanism. A series of characterizations clarify the reason for performance enhancement highlighting that CoP core donates abundant electrons to superficial active species, leading to the generation of more active hydrogen for the reduction of nitrogen-containing intermediates.
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Left ventricular hypertrophy (LVH) is a hypertensive heart disease that significantly escalates the risk of clinical cardiovascular events. Its etiology potentially incorporates various clinical attributes such as gender, age, and renal function. From mechanistic perspective, the remodeling process of LVH can trigger increment in certain biomarkers, notably sST2 and NT-proBNP. This multicenter, retrospective study aimed to construct an LVH risk assessment model and identify the risk factors. A total of 417 patients with essential hypertension (EH), including 214 males and 203 females aged 31-80 years, were enrolled in this study; of these, 161 (38.6%) were diagnosed with LVH. Based on variables demonstrating significant disparities between the LVH and Non-LVH groups, three multivariate stepwise logistic regression models were constructed for risk assessment: the "Clinical characteristics" model, the "Biomarkers" model (each based on their respective variables), and the "Clinical characteristics + Biomarkers" model, which amalgamated both sets of variables. The results revealed that the "Clinical characteristics + Biomarkers" model surpassed the baseline models in performance (AUC values of the "Clinical characteristics + Biomarkers" model, the "Biomarkers" model, and the "Clinical characteristics" model were .83, .75, and .74, respectively; P < .0001 for both comparisons). The optimized model suggested that being female (OR: 4.26, P <.001), being overweight (OR: 1.88, p = .02) or obese (OR: 2.36, p = .02), duration of hypertension (OR: 1.04, P = .04), grade III hypertension (OR: 2.12, P < .001), and sST2 (log-transformed, OR: 1.14, P < .001) were risk factors, while eGFR acted as a protective factor (OR: .98, P = .01). These findings suggest that the integration of clinical characteristics and biomarkers can enhance the performance of LVH risk assessment.
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Hipertensão , Hipertrofia Ventricular Esquerda , Feminino , Humanos , Masculino , Biomarcadores , Hipertensão Essencial/complicações , Hipertensão Essencial/epidemiologia , Hipertensão/complicações , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Hipertrofia Ventricular Esquerda/diagnóstico , Hipertrofia Ventricular Esquerda/epidemiologia , Hipertrofia Ventricular Esquerda/etiologia , Nomogramas , Estudos Retrospectivos , Medição de Risco , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou maisRESUMO
OBJECTIVE: The aim of this study is to develop a nomogram model for predicting the occurrence of intramyocardial hemorrhage (IMH) in patients with Acute Myocardial Infarction (AMI) following Percutaneous Coronary Intervention (PCI). The model is constructed utilizing clinical data and the SYNTAX Score (SS), and its predictive value is thoroughly evaluated. METHODS: A retrospective study was conducted, including 216 patients with AMI who underwent Cardiac Magnetic Resonance (CMR) within a week post-PCI. Clinical data were collected for all patients, and their SS were calculated based on coronary angiography results. Based on the presence or absence of IMH as indicated by CMR, patients were categorized into two groups: the IMH group (109 patients) and the non-IMH group (107 patients). The patients were randomly divided in a 7:3 ratio into a training set (151 patients) and a validation set (65 patients). A nomogram model was constructed using univariate and multivariate logistic regression analyses. The predictive capability of the model was assessed using Receiver Operating Characteristic (ROC) curve analysis, comparing the predictive value based on the area under the ROC curve (AUC). RESULTS: In the training set, IMH post-PCI was observed in 78 AMI patients on CMR, while 73 did not show IMH. Variables with a significance level of P < 0.05 were screened using univariate logistic regression analysis. Twelve indicators were selected for multivariate logistic regression analysis: heart rate, diastolic blood pressure, ST segment elevation on electrocardiogram, culprit vessel, symptom onset to reperfusion time, C-reactive protein, aspartate aminotransferase, lactate dehydrogenase, creatine kinase, creatine kinase-MB, high-sensitivity troponin T (HS-TnT), and SYNTAX Score. Based on multivariate logistic regression results, two independent predictive factors were identified: HS-TnT (Odds Ratio [OR] = 1.61, 95% Confidence Interval [CI]: 1.21-2.25, P = 0.003) and SS (OR = 2.54, 95% CI: 1.42-4.90, P = 0.003). Consequently, a nomogram model was constructed based on these findings. The AUC of the nomogram model in the training set was 0.893 (95% CI: 0.840-0.946), and in the validation set, it was 0.910 (95% CI: 0.823-0.970). Good consistency and accuracy of the model were demonstrated by calibration and decision curve analysis. CONCLUSION: The nomogram model, constructed utilizing HS-TnT and SS, demonstrates accurate predictive capability for the risk of IMH post-PCI in patients with AMI. This model offers significant guidance and theoretical support for the clinical diagnosis and treatment of these patients.
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Infarto do Miocárdio , Intervenção Coronária Percutânea , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Nomogramas , Estudos Retrospectivos , Infarto do Miocárdio/diagnóstico , Hemorragia/diagnóstico por imagem , Hemorragia/etiologia , Hemorragia/epidemiologiaRESUMO
Background: The hand skeletal features of children and adolescents at different growth statuses and development periods, and the correlation between these skeletal features and hand asymmetric force are currently unclear. Thus, this study sought to investigate the hand skeletal features of children and adolescents at different growth statuses and at different periods of development, and the correlation between these skeletal features and asymmetric force in hands. Methods: A retrospective study was performed on subjects aged 4-20 years with good growth status (group A) or short stature (group B). Additional subjects aged 4-20, 21-40, and >40 years were enrolled in groups C, D, and E, respectively. All the subjects underwent left-hand posteroanterior X-ray radiography. Brachymesophalangia-V (BMP-V), conical epiphysis, epiphysis/metaphysis symmetry of the proximal phalanx (ESP), and the angle of the metacarpal-phalangeal axis were analyzed. Results: Of the 654 children and teenagers aged 4-20 years (median: 11 years) enrolled in the study, 432 were allocated to group A, of whom 237 (54.9%) were male and 195 (45.1%) were female, and 222 matched cases were allocated to group B, of whom 112 (50.5%) were male and 110 (49.5%) were female. The first to third ESPs were significantly (P<0.05) greater in group A than in group B, while the first to third angles of the metacarpal-phalangeal axis were significantly (P<0.05) smaller in group A than in group B. The correlation analysis revealed a highly significant (P<0.01) negative correlation between the ESP and angle of the metacarpal-phalangeal axis (r=-0.948, -0.926, -0.940, -0.885, and -0.848, respectively). The incidence of BMP-V was 15.4% in all patients, while that of conical epiphysis was 19.5%. The incidence of BMP-V and conical epiphysis was significantly (P<0.05) smaller in group A than in group B (11.1% vs. 23.8% for BMP-V and 16.6% vs. 25.2% for conical epiphysis, respectively). Additionally, 216 subjects were enrolled in group C (108 male and 108 female), 185 subjects were enrolled in in group D (93 male and 92 female), and 176 subjects were enrolled in in group E (104 male and 72 female). The second to fifth ESPs in group C were significantly (P<0.05) smaller than those in both groups D and E, while the second to fifth angles of the metacarpal-phalangeal axis were significantly (P<0.05) larger in group C than in both groups D and E. A BMP-V was present in 35 (16.2%) patients in group C, 8 (4.3%) in group D, and 2 (1.1%) in group E, and the difference among the three groups was statistically significant (P<0.05). Conclusions: The epiphyseal symmetry of the proximal phalanges is poor in short stature children and adolescents, and the angle between the metacarpal and phalangeal axes is larger in children and adolescents with short stature than those with normal height and good growth status. A negative correlation was found between the epiphyseal symmetry of the proximal phalanges and asymmetrical stress.
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Metabolic changes have been linked to the development of inflammatory bowel disease (IBD), which includes colitis. Allulose, an endogenous bioactive monosaccharide, is vital to the synthesis of numerous compounds and metabolic processes within living organisms. Nevertheless, the precise biochemical mechanism by which allulose inhibits colitis remains unknown. Allulose is an essential and intrinsic protector of the intestinal mucosal barrier, as it maintains the integrity of tight junctions in the intestines, according to the current research. It is also important to know that there is a link between the severity of inflammatory bowel disease (IBD) and colorectal cancer (CRC), chemically-induced colitis in rodents, and lower levels of allulose in the blood. Mice with colitis, either caused by dextran sodium sulphate (DSS) or naturally occurring colitis in IL-10-/- mice, had less damage to their intestinal mucosa after being given allulose. Giving allulose to a colitis model starts a chain of reactions because it stops cathepsin B from ejecting and helps lysosomes stick together. This system effectively stops the activity of myosin light chain kinase (MLCK) when intestinal epithelial damage happens. This stops the breakdown of tight junction integrity and the start of mitochondrial dysfunction. To summarise, the study's findings have presented data that supports the advantageous impact of allulose in reducing the advancement of colitis. Its ability to stop the disruption of the intestinal barrier enables this. Therefore, allulose has potential as a medicinal supplement for treating colitis.
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Colite , Enterite , Frutose , Doenças Inflamatórias Intestinais , Doenças Mitocondriais , Humanos , Camundongos , Animais , Catepsina B/metabolismo , Células CACO-2 , Doenças Inflamatórias Intestinais/metabolismo , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/metabolismo , Mucosa Intestinal , Junções Íntimas , Doenças Mitocondriais/metabolismo , Sulfato de Dextrana/farmacologia , Camundongos Endogâmicos C57BL , Modelos Animais de DoençasAssuntos
Neoplasias , Linfócitos T , Humanos , Engenharia Tecidual , Neoplasias/terapia , ImunoterapiaRESUMO
Purpose: The interaction between inflammatory cells and integrin in the endothelium plays a key role during infiltration. Previous evidence has shown that synthetic C16 peptide selectively binds to integrins αvß3 and α5ß1 and exhibits a neuroprotective effect. It has also been reported to inhibit the differentiation of microglia into the M1 (pro-inflammatory) phenotype while promoting its differentiation to the M2 (anti-inflammatory) phenotype. This study aimed to investigate the mechanisms of action of the C16 peptide in multiple sclerosis using a rodent model. Methods: Molecular, morphological, and neurophysiological assays were used to investigate the neuroprotective effects of C16 peptide and related signaling pathways in a model of EAE. Results: The results showed that C16 significantly improved the clinical score and cortical somatosensory/motor evoked potential. It also alleviated inflammatory responses, including microglial activation and leukocyte infiltration, relieved the impairment of the brain blood barrier and edema, and reduced neuronal apoptosis, axonal loss, and demyelination induced by EAE. The C16 peptide increased the expressions of pTie-2 and Tie-2, integrin αvß3, and α5ß1 and activated the PI3K/Akt signal pathway but decreased the expression of Rho. Co-treatment of C16 with Tie-2 inhibitor and PI3K inhibitor LY294002 attenuated these effects of C16. Conclusion: The C16 peptide demonstrated neuroprotection in the EAE model through the integrin, Tie-2, and PI3K/Akt signaling pathways, and it could be a potential strategy for treating inflammation-related diseases in the central nervous system.
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Refractory high-entropy alloys (RHEAs) are of interest for ultrahigh-temperature applications. To overcome their drawbacks - low-temperature brittleness and poor creep strength at high temperatures - improved fundamental understanding is needed. Using experiments, theory, and modeling, we investigated prototypical body-centered cubic (BCC) RHEAs, TiZrHfNbTa and VNbMoTaW. The former is compressible to 77 K, whereas the latter is not below 298 K. Hexagonal close-packed (HCP) elements in TiZrHfNbTa lower its dislocation core energy, increase lattice distortion, and lower its shear modulus relative to VNbMoTaW whose elements are all BCC. Screw dislocations dominate TiZrHfNbTa plasticity, but equal numbers of edges and screws exist in VNbTaMoW. Dislocation cores are compact in VNbTaMoW and extended in TiZrHfNbTa, and different macroscopic slip planes are activated in the two RHEAs, which we attribute to the concentration of HCP elements. Our findings demonstrate how ductility and strength can be controlled through the ratio of HCP to BCC elements in RHEAs.
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The concept of multi-target-directed ligands offers fresh perspectives for the creation of brand-new Alzheimer's disease medications. To explore their potential as multi-targeted anti-Alzheimer's drugs, eighteen new bakuchiol derivatives were designed, synthesized, and evaluated. The structures of the new compounds were elucidated by IR, NMR, and HRMS. Eighteen compounds were assayed for acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in vitro using Ellman's method. It was shown that most of the compounds inhibited AChE and BuChE to varying degrees, but the inhibitory effect on AChE was relatively strong, with fourteen compounds showing inhibition of >50% at the concentration of 200 µM. Among them, compound 3g (IC50 = 32.07 ± 2.00 µM) and compound 3n (IC50 = 34.78 ± 0.34 µM) showed potent AChE inhibitory activities. Molecular docking studies and molecular dynamics simulation showed that compound 3g interacts with key amino acids at the catalytically active site (CAS) and peripheral anionic site (PAS) of acetylcholinesterase and binds stably to acetylcholinesterase. On the other hand, compounds 3n and 3q significantly reduced the pro-inflammatory cytokines TNF-α and IL-6 released from LPS-induced RAW 264.7 macrophages. Compound 3n possessed both anti-acetylcholinesterase activity and anti-inflammatory properties. Therefore, an in-depth study of compound 3n is expected to be a multi-targeted anti-AD drug.
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Doença de Alzheimer , Butirilcolinesterase , Fenóis , Humanos , Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/química , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade , Desenho de FármacosRESUMO
Transcription factors respond to multilevel stimuli and co-occupy promoter regions of target genes to activate RNA polymerase (RNAP) in a cooperative manner. To decipher the molecular mechanism, here we report two cryo-electron microscopy structures of Anabaena transcription activation complexes (TACs): NtcA-TAC composed of RNAP holoenzyme, promoter and a global activator NtcA, and NtcA-NtcB-TAC comprising an extra context-specific regulator, NtcB. Structural analysis showed that NtcA binding makes the promoter DNA bend by â¼50°, which facilitates RNAP to contact NtcB at the distal upstream NtcB box. The sequential binding of NtcA and NtcB induces looping back of promoter DNA towards RNAP, enabling the assembly of a fully activated TAC bound with two activators. Together with biochemical assays, we propose a 'DNA looping' mechanism of cooperative transcription activation in bacteria.
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Proteínas de Bactérias , Compostos Nitrosos , Tiazolidinas , Tiocianatos , Transativadores , Transativadores/genética , Ativação Transcricional , Microscopia Crioeletrônica , Sequência de Bases , Proteínas de Bactérias/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Transcrição Gênica , Regulação Bacteriana da Expressão GênicaRESUMO
Cancer poses a substantial risk to human life and wellbeing as a result of its elevated incidence and fatality rates. Endoplasmic reticulum stress (ERS) is an important pathway that regulates cellular homeostasis. When ERS is under- or overexpressed, it activates the protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK)-, inositol-requiring enzyme 1 (IRE1)- and activating transcription Factor 6 (ATF6)-related apoptotic pathways to induce apoptosis. Tumor cells and microenvironment are susceptible to ERS, making the modulation of ERS a potential therapeutic approach for treating tumors. The use of natural products to treat tumors has substantially progressed, with various extracts demonstrating antitumor effects. Nevertheless, there are few reports on the effectiveness of natural products in inducing apoptosis by specifically targeting and regulating the ERS pathway. Further investigation and elaboration of its mechanism of action are still needed. This paper examines the antitumor mechanism of action by which natural products exert antitumor effects from the perspective of ERS regulation to provide a theoretical basis and new research directions for tumor therapy.
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OBJECTIVES: To explore the neural mechanism of visceral pain and related somatic (acupoints) sensitization by using in vivo calcium imaging of dorsal root ganglia (DRG) neurons. METHODS: Eight BALB/c mice were randomly divided into control and model groups, with 4 mice in each group. The colitis model was induced by colorectal perfusion of 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) once daily for 7 days. Mice of the control group received colorectal perfusion of normal saline once daily for 7 days. The location and area of the somatic neurogenic inflammation (cutaneous exudation of Evans blue ï¼»EBï¼½) of the 2 groups of mice were observed after intravenous injection of EB. For pain behavioral tests, sixteen C57BL/6J mice were randomly divided into control and model groups, with 8 mice in each group, and a Von Frey filament was used to stimulate the referred somatic reactive regions in colitis mice, and the number of avoidance and paw withdraw reaction within 10 tests was recorded. For in vivo DRG calcium imaging tests, 24 Pirt-GCaMP6s transgenic mice were randomly and equally divided into control group and colitis model group. The responses of the neurons in L6 or L4 DRG to colorectal distension (CRD), lower back brushing, or mechanical stimulation at the hindpaw were observed using confocal fluorescence microscope. RESULTS: Compared with the control group, the area of EB exudation spot in the hindpaw and lower back regions was increased in the colitis model group (P<0.05), and the avoidance or paw withdraw numbers induced by Von Frey stimulation at the lower back and hindpaw were increased (P<0.01, P<0.05), indicating that colitis induced regional skin (acupoints) sensitization in the lower back and hindpaw regions. Compared with the control group, the percentage of L6 DRG neurons activated by 60 mm Hg CRD in the colitis model mice were apparently increased (P<0.01), the activated neurons mainly involved the medium-sized DRG neurons (P<0.01). In Pirt-GCaMP6s transgenic mice, following brushing the skin of the receptive field (lower back) of L6 DRG neurons, the fluorescence intensity of the brushing-activated DRG neurons and small, medium and large-sized neurons were significantly higher in the colitis model group than those in the control group (P<0.001, P<0.01, P<0.05). After brushing and clamping the skin of the right hindpaw (receptive field of L4 DRG neurons), the percentages of the activated L4 DRG neurons were obviously higher in the colitis model group than those in the control group (P<0.01, P<0.05), while there were no significant changes in the proportion of small, medium and large-sized neurons between the control and colitis model groups. CONCLUSIONS: Colitis may lead to body surface sensitization at the same and adjacent neuro-segments as well as to an increase of the number and activity of the responsive lumbar DRG neurons, among which the L6 DRG neurons at the same neuro-segment as the rectum colon showed an increase in the number of responders and intensity of calcium fluorescence signal while L4 DRG neurons at the level adjacent to the rectum colon showed an increase in the number of responders, suggesting that there may be different mechanisms of peripheral neural sensitization.
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Colite , Neoplasias Colorretais , Dor Visceral , Camundongos , Animais , Dor Visceral/genética , Cálcio , Pontos de Acupuntura , Camundongos Endogâmicos C57BL , Colite/induzido quimicamente , Colite/genética , Trinitrobenzenos , Camundongos TransgênicosRESUMO
To investigate the pollution characteristics and formation mechanism of ambient air ozone(O3) in a typical tropical seaside city, we conducted an observational experiment on O3 and its precursors at an urban site in Haikou, Hainan Province, from June to October 2019. The O3 pollution characteristics were analyzed comprehensively; the O3-NOx-VOCs sensitivities and key precursors were determined, and the control strategies for O3 pollution were carried out. The results were as follows:1 O3 pollution in Haikou mainly occurred in September and October, with daily maximum 8-h O3 concentrations in the range of 39-190 µg·m-3, and the daily variation in O3 was unimodal, peaking at approximately 14:00. 2 The concentrations of NO2 and VOCs were higher during O3 pollution episodes than their respective mean values in Haikou City. The increased O3 precursor concentrations were an important factor leading to O3 pollution, whereas O3 pollution was also influenced by regional transport, with pollutants mainly transported from the northeastern part of Haikou City. 3 O3-NOx-VOCs sensitivity in Haikou City was in the VOCs and NOx transitional regime, and the most sensitive precursors in various months were different. O3 formation in September was sensitive to anthropogenic VOCs the most; however, in October it was sensitive to NOx. 4 In the future, the reduction ratio of VOCs to NOx should be 1:1-4:1 to control O3 pollution effectively in Haikou.