Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.455
Filtrar
1.
Adv Sci (Weinh) ; : e2400140, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38973255

RESUMO

Most clinical PARP inhibitors (PARPis) trap PARP1 in a chromatin-bound state, leading to PARPi-mediated cytotoxicity. PARPi resistance impedes the treatment of ovarian cancer in clinical practice. However, the mechanism by which cancer cells overcome PARP1 trapping to develop PARPi resistance remains unclear. Here, it is shown that high levels of KAT6A promote PARPi resistance in ovarian cancer, regardless of its catalytic activity. Mechanistically, the liquid-liquid phase separation (LLPS) of KAT6A, facilitated by APEX1, inhibits the cytotoxic effects of PARP1 trapping during PARPi treatment. The stable KAT6A-PARP1-APEX1 complex reduces the amount of PARP1 trapped at the DNA break sites. In addition, inhibition of KAT6A LLPS, rather than its catalytic activity, impairs DNA damage repair and restores PARPi sensitivity in ovarian cancer both in vivo and in vitro. In conclusion, the findings demonstrate the role of KAT6A LLPS in fostering PARPi resistance and suggest that repressing KAT6A LLPS can be a potential therapeutic strategy for PARPi-resistant ovarian cancer.

2.
Adv Sci (Weinh) ; : e2402086, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38946582

RESUMO

Diabetic neuropathic pain (DNP), one of the most common complications of diabetes, is characterized by bilateral symmetrical distal limb pain and substantial morbidity. To compare the differences  is aimed at serum metabolite levels between 81 DNP and 73 T2DM patients without neuropathy and found that the levels of branched-chain amino acids (BCAA) are significantly lower in DNP patients than in T2DM patients. In high-fat diet/low-dose streptozotocin (HFD/STZ)-induced T2DM and leptin receptor-deficient diabetic (db/db) mouse models, it is verified that BCAA deficiency aggravated, whereas BCAA supplementation alleviated DNP symptoms. Mechanistically, using a combination of RNA sequencing of mouse dorsal root ganglion (DRG) tissues and label-free quantitative proteomic analysis of cultured cells, it is found that BCAA deficiency activated the expression of L-type amino acid transporter 1 (LAT1) through ATF4, which is reversed by BCAA supplementation. Abnormally upregulated LAT1 reduced Kv1.2 localization to the cell membrane, and inhibited Kv1.2 channels, thereby increasing neuronal excitability and causing neuropathy. Furthermore, intraperitoneal injection of the LAT1 inhibitor, BCH, alleviated DNP symptoms in mice, confirming that BCAA-deficiency-induced LAT1 activation contributes to the onset of DNP. These findings provide fresh insights into the metabolic differences between DNP and T2DM, and the development of approaches for the management of DNP.

3.
Oncologist ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38990195

RESUMO

BACKGROUND: Encouraging antitumor activity of nab-paclitaxel plus S-1 (AS) has been shown in several small-scale studies. This study compared the efficacy and safety of AS versus standard-of-care nab-paclitaxel plus gemcitabine (AG) as a first-line treatment for advanced pancreatic cancer (PC). METHODS: In this multicenter, randomized, phase II trial, eligible patients with unresectable, locally advanced, or metastatic PC were recruited and randomly assigned (1:1) to receive AS (nab-paclitaxel 125 mg/m2 on days 1 and 8; S-1 twice daily on days 1 through 14) or AG (nab-paclitaxel 125 mg/m2 on days 1 and 8; gemcitabine 1000 mg/m2 on days 1 and 8) for 6 cycles. The primary endpoint was progression-free survival (PFS). RESULTS: Between July 16, 2019, and September 9, 2022, 62 patients (AS, n = 32; AG, n = 30) were treated and evaluated. With a median follow-up of 8.36 months at preplanned interim analysis (data cutoff, March 24, 2023), the median PFS (8.48 vs 4.47 months; hazard ratio [HR], 0.402; P = .002) and overall survival (OS; 13.73 vs 9.59 months; HR, 0.226; P < .001) in the AS group were significantly longer compared to the AG group. More patients had objective response in the AS group than AG group (37.50% vs 6.67%; P = .005). The most common grade 3-4 adverse events were neutropenia and leucopenia in both groups, and gamma glutamyl transferase increase was observed only in the AG group. CONCLUSION: The first-line AS regimen significantly extended both PFS and OS of Chinese patients with advanced PC when compared with the AG regimen, with a comparable safety profile. (ClinicalTrials.gov Identifier: NCT03636308).

4.
Cell ; 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38971151

RESUMO

Homologous recombination deficiency (HRD) is prevalent in cancer, sensitizing tumor cells to poly (ADP-ribose) polymerase (PARP) inhibition. However, the impact of HRD and related therapies on the tumor microenvironment (TME) remains elusive. Our study generates single-cell gene expression and T cell receptor profiles, along with validatory multimodal datasets from >100 high-grade serous ovarian cancer (HGSOC) samples, primarily from a phase II clinical trial (NCT04507841). Neoadjuvant monotherapy with the PARP inhibitor (PARPi) niraparib achieves impressive 62.5% and 73.6% response rates per RECIST v.1.1 and GCIG CA125, respectively. We identify effector regulatory T cells (eTregs) as key responders to HRD and neoadjuvant therapies, co-occurring with other tumor-reactive T cells, particularly terminally exhausted CD8+ T cells (Tex). TME-wide interferon signaling correlates with cancer cells upregulating MHC class II and co-inhibitory ligands, potentially driving Treg and Tex fates. Depleting eTregs in HRD mouse models, with or without PARP inhibition, significantly suppresses tumor growth without observable toxicities, underscoring the potential of eTreg-focused therapeutics for HGSOC and other HRD-related tumors.

5.
Shanghai Kou Qiang Yi Xue ; 33(2): 130-134, 2024 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-39005087

RESUMO

PURPOSE: To investigate the therapeutic effect of atorvastatin on alveolar bone defect model in rats, and to observe the effect of atorvastatin on Wnt/ß-catenin. METHODS: Thirty rats were randomly divided into normal group (group N), model group (group M) and atorvastatin administration group (group ATV). Except group N, bone defects were made in other rats' alveolar bone to construct alveolar bone defect model. After successful modeling, 20 mg/kg atorvastatin suspension was administered by gavage in group ATV, and the same amount of sodium carboxymethyl cellulose solution was administered by gavage in group N and group M for twenty-one days. After the last administration, tail vein blood was collected to detect the concentrations of serum osteoprotegerin (OPG), alkaline phosphatase (ALP) and osteocalcin (BPG). H-E staining was used to observe the pathological changes of maxillary defect area, and lane Sandhu score was performed. Tartrate resistant acid phosphatase(TRAP) staining was used to detect the number of osteoclasts in the defect area. Real time fluorescence quantitative PCR(RT-qPCR) and Western blot(WB) were used to detect Wnt, ß-catenin and Runx2 mRNA protein expression. Statistical analysis was performed with SPSS 23.0 software package. RESULTS: Compared with group N, the concentrations of OPG, ALP, BGP and Lane Sandhu score in group M decreased, and the number of osteoclasts increased. Compared with group M, the concentrations of OPG, ALP and BGP and lane Sandhu score in group ATV increased, and the number of osteoclasts decreased. After H-E staining, the amount of bone formation in maxillary defect area in group N was more,there was fewer bone tissues in the defect area in group M, the amount of bone tissues in the defect area increased in group ATV. Compared with group N, Wnt, ß-catenin and Runx2 mRNA protein decreased. Compared with group M, Wnt, ß-catenin and Runx2 mRNA protein expression increased. CONCLUSIONS: Atorvastatin can promote the healing of alveolar bone defect and accelerate bone reconstruction in rat models. This effect may be related to the activation of Wnt/ß-catenin signaling pathway.


Assuntos
Fosfatase Alcalina , Atorvastatina , Osteocalcina , Osteoprotegerina , Via de Sinalização Wnt , beta Catenina , Animais , Atorvastatina/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , Ratos , Osteoprotegerina/metabolismo , Osteoprotegerina/genética , beta Catenina/metabolismo , beta Catenina/genética , Osteocalcina/metabolismo , Osteocalcina/genética , Osteocalcina/sangue , Fosfatase Alcalina/metabolismo , Fosfatase Alcalina/sangue , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Processo Alveolar/efeitos dos fármacos , Processo Alveolar/metabolismo
6.
Artigo em Inglês | MEDLINE | ID: mdl-38980778

RESUMO

This article is committed to studying projective synchronization and complete synchronization (CS) issues for one kind of discrete-time variable-order fractional neural networks (DVFNNs) with time-varying delays. First, two new variable-order fractional (VF) inequalities are built by relying on nabla Laplace transform and some properties of Mittag-Leffler function, which are extensions of constant-order fractional (CF) inequalities. Moreover, the VF Halanay inequality in discrete-time sense is strictly proved. Subsequently, some sufficient projective synchronization and CS criteria are derived by virtue of VF inequalities and hybrid controllers. Finally, we exploit numerical simulation examples to verify the validity of the derived results, and a practical application of the obtained results in image encryption is also discussed.

7.
Biotechnol J ; 19(7): e2400287, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39014925

RESUMO

The d-amino acid oxidase (DAAO) is pivotal in obtaining optically pure l-glufosinate (l-PPT) by converting d-glufosinate (d-PPT) to its deamination product. We screened and designed a Rasamsonia emersonii DAAO (ReDAAO), making it more suitable for oxidizing d-PPT. Using Caver 3.0, we delineated three substrate binding pockets and, via alanine scanning, identified nearby key residues. Pinpointing key residues influencing activity, we applied virtual saturation mutagenesis (VSM), and experimentally validated mutants which reduced substrate binding energy. Analysis of positive mutants revealed elongated side-chain prevalence in substrate binding pocket periphery. Although computer-aided approaches can rapidly identify advantageous mutants and guide further design, the mutations obtained in the first round may not be suitable for combination with other advantageous mutations. Therefore, each round of combination requires reasonable iteration. Employing VSM-assisted screening multiple times and after four rounds of combining mutations, we ultimately obtained a mutant, N53V/F57Q/V94R/V242R, resulting in a mutant with a 5097% increase in enzyme activity compared to the wild type. It provides valuable insights into the structural determinants of enzyme activity and introduces a novel rational design procedure.


Assuntos
D-Aminoácido Oxidase , Engenharia de Proteínas , D-Aminoácido Oxidase/genética , D-Aminoácido Oxidase/metabolismo , D-Aminoácido Oxidase/química , Engenharia de Proteínas/métodos , Especificidade por Substrato , Mutagênese , Mutagênese Sítio-Dirigida/métodos , Aminobutiratos/metabolismo , Modelos Moleculares , Mutação , Sítios de Ligação
8.
J Agric Food Chem ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39016055

RESUMO

Butachlor is widely used in agriculture around the world and therefore poses environmental and public health hazards due to persistent and poor biodegradability. Ferroptosis is a type of iron-mediated cell death controlled by glutathione (GSH) and GPX4 inhibition. P62 is an essential autophagy adaptor that regulates Keap1 to activate nuclear factor erythroid 2-related factor 2 (Nrf2), which effectively suppresses lipid peroxidation, thereby relieving ferroptosis. Here, we found that butachlor caused changes in splenic macrophage structure, especially impaired mitochondrial morphology with disordered structure, which is suggestive of the occurrence of ferroptosis. This was further confirmed by the detection of iron metabolism, the GSH system, and lipid peroxidation. Mechanistically, butachlor suppressed the protein level of p62 and promoted Keap1-mediated degradation of Nrf2, which results in decreased GPX4 expression and accelerated splenic macrophage ferroptosis. These findings suggest that targeting the p62-Nrf2-GPX4 signaling axis may be a promising strategy for treating inflammatory diseases.

9.
Curr Med Sci ; 44(3): 623-632, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38853192

RESUMO

OBJECTIVE: Endometrial carcinoma (EC) is a prevalent gynecological malignancy characterized by increasing incidence and mortality rates. This underscores the critical need for novel therapeutic targets. One such potential target is cell division cycle 20 (CDC20), which has been implicated in oncogenesis. This study investigated the effect of the CDC20 inhibitor Apcin on EC and elucidated the underlying mechanism involved. METHODS: The effects of Apcin on EC cell proliferation, apoptosis, and the cell cycle were evaluated using CCK8 assays and flow cytometry. RNA sequencing (RNA-seq) was subsequently conducted to explore the underlying molecular mechanism, and Western blotting and coimmunoprecipitation were subsequently performed to validate the results. Animal studies were performed to evaluate the antitumor effects in vivo. Bioinformatics analysis was also conducted to identify CDC20 as a potential therapeutic target in EC. RESULTS: Treatment with Apcin inhibited proliferation and induced apoptosis in EC cells, resulting in cell cycle arrest. Pathways associated with apoptosis and the cell cycle were activated following treatment with Apcin. Notably, Apcin treatment led to the upregulation of the cell cycle regulator p21, which was verified to interact with CDC20 and consequently decrease the expression of downstream cyclins in EC cells. In vivo experiments confirmed that Apcin treatment significantly impeded tumor growth. Higher CDC20 expression was observed in EC tissue than in nonmalignant tissue, and increased CDC20 expression in EC patients was associated with shorter overall survival and progress free interval. CONCLUSION: CDC20 is a novel molecular target in EC, and Apcin could be developed as a candidate antitumor drug for EC treatment.


Assuntos
Apoptose , Proteínas Cdc20 , Pontos de Checagem do Ciclo Celular , Proliferação de Células , Inibidor de Quinase Dependente de Ciclina p21 , Neoplasias do Endométrio , Feminino , Neoplasias do Endométrio/tratamento farmacológico , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/metabolismo , Humanos , Apoptose/efeitos dos fármacos , Proteínas Cdc20/genética , Proteínas Cdc20/metabolismo , Animais , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Camundongos , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Proliferação de Células/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Antineoplásicos/farmacologia , Camundongos Nus
10.
Acta Pharmacol Sin ; 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902502

RESUMO

The vasopressin V2 receptor (V2R) is a validated therapeutic target for autosomal dominant polycystic kidney disease (ADPKD), with tolvaptan being the first FDA-approved antagonist. Herein, we used Gaussian accelerated molecular dynamics simulations to investigate the spontaneous binding of tolvaptan to both active and inactive V2R conformations at the atomic-level. Overall, the binding process consists of two stages. Tolvaptan binds initially to extracellular loops 2 and 3 (ECL2/3) before overcoming an energy barrier to enter the pocket. Our simulations result highlighted key residues (e.g., R181, Y205, F287, F178) involved in this process, which were experimentally confirmed by site-directed mutagenesis. This work provides structural insights into tolvaptan-V2R interactions, potentially aiding the design of novel antagonists for V2R and other G protein-coupled receptors.

11.
Value Health ; 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38843980

RESUMO

OBJECTIVES: Controls and governance over the methodology and reporting of indirect treatment comparisons (ITCs) have been introduced to minimize bias and ensure scientific credibility and transparency in healthcare decision making. The objective of this study was to highlight ITC techniques that are key to conducting objective and analytically sound analyses and to ascertain circumstantial suitability of ITCs as a source of comparative evidence for healthcare interventions. METHODS: Ovid MEDLINE was searched from January 2010 through August 2023 to identify publicly available ITC-related documents (ie, guidelines and best practices) in the English language. This was supplemented with hand searches of websites of various international organizations, regulatory agencies, and reimbursement agencies of Europe, North America, and Asia-Pacific. The jurisdiction-specific ITC methodology and reporting recommendations were reviewed. RESULTS: Sixty-eight guidelines from 10 authorities worldwide were included for synthesis. Many of the included guidelines were updated within the last 5 years and commonly cited the absence of direct comparative studies as primary justification for using ITCs. Most jurisdictions favored population-adjusted or anchored ITC techniques opposed to naive comparisons. Recommendations on the reporting and presentation of these ITCs varied across authorities; however, there was some overlap among the key elements. CONCLUSIONS: Given the challenges of conducting head-to-head randomized controlled trials, comparative data from ITCs offer valuable insights into clinical-effectiveness. As such, multiple ITC guidelines have emerged worldwide. According to the most recent versions of the guidelines, the suitability and subsequent acceptability of the ITC technique used depends on the data sources, available evidence, and magnitude of benefit/uncertainty.

12.
Biochem Pharmacol ; 226: 116338, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38848780

RESUMO

ITFG2, as an immune-modulatory intracellular protein that modulate the fate of B cells and negatively regulates mTORC1 signaling. ITFG2 is highly expressed in the heart, but its pathophysiological function in heart disease is unclear. In this study, we found that in MI mice, overexpression of ITFG2 via an AAV9 vector significantly reduced the infarct size and ameliorated cardiac function. Knockdown of endogenous ITFG2 by shRNA partially aggravated ischemia-induced cardiac dysfunction. In cardiac-specific ITFG2 transgenic (TG) mice, myocardial infarction size was smaller, eject fraction (EF) and fractional shortening (FS) was higher compared to those in wild-type (WT) mice, suggesting ITFG2 reversed cardiac dysfunction induced by MI. In hypoxic neonatal cardiomyocytes (NMCMs), overexpression of ITFG2 maintained mitochondrial function by increasing intracellular ATP production, reducing ROS levels, and preserving the mitochondrial membrane potential (MMP). Overexpression of ITFG2 reversed the mitochondrial respiratory dysfunction in NMCMs induced by hypoxia. Knockdown of endogenous ITFG2 by siRNA did the opposite. Mechanism, ITFG2 formed a complex with NEDD4-2 and ATP 5b and inhibited the binding of NEDD4-2 with ATP 5b leading to the reduction ubiquitination of ATP 5b. Our findings reveal a previously unknown ability of ITFG2 to protect the heart against ischemic injury by interacting with ATP 5b and thereby regulating mitochondrial function. ITFG2 has promise as a novel strategy for the clinical management of MI.

13.
Funct Integr Genomics ; 24(3): 114, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38862667

RESUMO

With advances in radioactive particle implantation in clinical practice, Iodine-125 (125I) seed brachytherapy has emerged as a promising treatment for cholangiocarcinoma (CCA), showing good prognosis; however, the underlying molecular mechanism of the therapeutic effect of 125I seed is unclear. To study the effects of 125I seed on the proliferation and apoptosis of CCA cells. CCA cell lines, RBE and HCCC-9810, were treated with reactive oxygen species (ROS) scavenger acetylcysteine (NAC) or the p53 functional inhibitor, pifithrin-α hydrobromide (PFTα). Cell counting kit-8 (CCK-8) assay, 5-bromo-2-deoxy-uridine (BrdU) staining, and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay and flow cytometry assay were performed to test the radiation-sensitivity of 125I seed toward CCA cells at different radiation doses (0.4 mCi and 0.8 mCi). 2,7-dichlorofluorescein diacetate (DCF-DA) assay, real-time quantitative polymerase chain reaction (RT-qPCR), and western blot analysis were performed to assess the effect of 125I seed on the ROS/p53 axis. A dose-dependent inhibitory effect of 125I seeds on the proliferation of CCA cells was observed. The 125I seed promoted apoptosis of CCA cells and induced the activation of the ROS/p53 pathway in a dose-dependent manner. NAC or PFTα treatment effectively reversed the stimulatory effect of 125I seed on the proliferation of CCA cells. NAC or PFTα suppressed apoptosis and p53 protein expression induced by the 125I seed. 125I seed can inhibit cell growth mainly through the apoptotic pathway. The mechanism may involve the activation of p53 and its downstream apoptotic pathway by up-regulating the level of ROS in cells.


Assuntos
Apoptose , Proliferação de Células , Colangiocarcinoma , Radioisótopos do Iodo , Espécies Reativas de Oxigênio , Proteína Supressora de Tumor p53 , Colangiocarcinoma/metabolismo , Colangiocarcinoma/radioterapia , Colangiocarcinoma/patologia , Colangiocarcinoma/genética , Colangiocarcinoma/tratamento farmacológico , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Espécies Reativas de Oxigênio/metabolismo , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Linhagem Celular Tumoral , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/patologia , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/radioterapia , Acetilcisteína/farmacologia , Benzotiazóis/farmacologia , Transdução de Sinais/efeitos dos fármacos
14.
Bioorg Chem ; 150: 107594, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38941701

RESUMO

Inhibition of human dihydroorotate dehydrogenase (hDHODH) represents a promising strategy for suppressing the proliferation of cancer cells. To identify novel and potent hDHODH inhibitors, a total of 28 piperine derivatives were designed and synthesized. Their cytotoxicities against three human cancer cell lines (NCI-H226, HCT-116, and MDA-MB-231) and hDHODH inhibitory activities were also evaluated. Among them, compound H19, exhibited the strongest inhibitory activities (NCI-H226 IC50 = 0.95 µM, hDHODH IC50 = 0.21 µM). Further pharmacological investigations revealed that H19 exerted anticancer effects by inducing ferroptosis in NCI-H226 cells, with its cytotoxicity being reversed by ferroptosis inhibitors. This was supported by the intracellular growth or decline of ferroptosis markers, including lipid peroxidation, Fe2+, GSH, and 4-HNE. Overall, H19 emerges as a promising hDHODH inhibitor with potential anticancer properties warranting development.


Assuntos
Alcaloides , Antineoplásicos , Benzodioxóis , Proliferação de Células , Di-Hidro-Orotato Desidrogenase , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos , Ferroptose , Piperidinas , Alcamidas Poli-Insaturadas , Humanos , Alcaloides/farmacologia , Alcaloides/química , Alcaloides/síntese química , Di-Hidro-Orotato Desidrogenase/antagonistas & inibidores , Piperidinas/farmacologia , Piperidinas/química , Piperidinas/síntese química , Benzodioxóis/farmacologia , Benzodioxóis/síntese química , Benzodioxóis/química , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/síntese química , Relação Estrutura-Atividade , Ferroptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Alcamidas Poli-Insaturadas/farmacologia , Alcamidas Poli-Insaturadas/química , Alcamidas Poli-Insaturadas/síntese química , Estrutura Molecular , Relação Dose-Resposta a Droga , Descoberta de Drogas , Linhagem Celular Tumoral
15.
Rev Sci Instrum ; 95(6)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38888403

RESUMO

The acquisition of low-frequency vibration signals in earthquake exploration is a crucial aspect of seismic exploration technology. Addressing the difficulty current fiber optic sensors face in monitoring low-frequency vibrations, this paper proposes an acceleration sensor based on S-type Fiber Bragg Grating (FBG). First, an FBG acceleration sensor model is established and theoretically analyzed. Then, the impact of structural parameters on the sensor's sensitivity and natural frequency is examined, employing the ANSYS finite element analysis software for static stress and modal simulation analysis. Finally, a prototype is developed, and a low-frequency vibration testing system is assembled to test the sensor's performance. The results show that the sensor has a natural frequency of 34 Hz, operates in a frequency band of 0.2-14 Hz, has a dynamic range of 63.5 dB, a lateral interference of less than 3%, a sensitivity of ∼274.45 pm/g, good linearity, and is insensitive to temperature. The findings provide a reference for the development of similar sensors and further exploration of the lower frequency limit.

16.
Artigo em Inglês | MEDLINE | ID: mdl-38923247

RESUMO

Significant pharmacokinetic (PK) differences exist between different forms of valproic acid (VPA), such as syrup and sustained-release (SR) tablets. This study aimed to develop a population pharmacokinetic (PopPK) model for VPA in children with epilepsy and offer dose adjustment recommendation for switching dosage forms as needed. The study collected 1411 VPA steady-state trough concentrations (Ctrough) from 617 children with epilepsy. Using NONMEM software, a PopPK model was developed, employing a stepwise approach to identify possible variables such as demographic information and concomitant medications. The final model underwent internal and external evaluation via graphical and statistical methods. Moreover, Monte Carlo simulations were used to generate a dose tailoring strategy for typical patients weighting 20-50 kg. As a result, the PK characteristics of VPA were described using a one-compartment model with first-order absorption. The absorption rate constant (ka) was set at 2.64 and 0.46 h-1 for syrup and SR tablets. Body weight and sex were identified as significant factors affecting VPA's pharmacokinetics. The final PopPK model demonstrated acceptable prediction performance and stability during internal and external evaluation. For children taking syrup, a daily dose of 25 mg/kg resulted in the highest probability of achieving the desired target Ctrough, while a dose of 20 mg/kg/day was appropriate for those taking SR tablets. In conclusion, we established a PopPK model for VPA in children with epilepsy to tailor VPA dosage when switching between syrup and SR tablets, aiming to improve plasma VPA concentrations fluctuations.

17.
Imeta ; 3(1): e165, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38868519

RESUMO

Consumption of dietary fiber and anthocyanin has been linked to a lower incidence of colorectal cancer (CRC). This study scrutinizes the potential antitumorigenic attributes of a black rice diet (BRD), abundantly rich in dietary fiber and anthocyanin. Our results demonstrate notable antitumorigenic effects in mice on BRD, indicated by a reduction in both the size and number of intestinal tumors and a consequent extension in life span, compared to control diet-fed counterparts. Furthermore, fecal transplants from BRD-fed mice to germ-free mice led to a decrease in colonic cell proliferation, coupled with maintained integrity of the intestinal barrier. The BRD was associated with significant shifts in gut microbiota composition, specifically an augmentation in probiotic strains Bacteroides uniformis and Lactobacillus. Noteworthy changes in gut metabolites were also documented, including the upregulation of indole-3-lactic acid and indole. These metabolites have been identified to stimulate the intestinal aryl hydrocarbon receptor pathway, inhibiting CRC cell proliferation and colorectal tumorigenesis. In summary, these findings propose that a BRD may modulate the progression of intestinal tumors by fostering protective gut microbiota and metabolite profiles. The study accentuates the potential health advantages of whole-grain foods, emphasizing the potential utility of black rice in promoting health.

18.
Neuro Oncol ; 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38864832

RESUMO

BACKGROUND: Super-enhancers (SEs) typically govern the expression of critical oncogenes and play a fundamental role in the initiation and progression of cancer. Focusing on genes that are abnormally regulated by SE in cancer may be a new strategy for understanding pathogenesis. In the context of this investigation, we have identified a previously unreported SE-driven gene IRF2BP2 in neuroblastoma (NB). METHODS: The expression and prognostic value of IRF2BP2 were detected in public databases and clinical samples. The effect of IRF2BP2 on NB cell growth and apoptosis was evaluated through in vivo and in vitro functional loss experiments. The molecular mechanism of IRF2BP2 was investigated by the study of chromatin regulatory regions and transcriptome sequencing. RESULTS: The sustained high expression of IRF2BP2 results from the activation of a novel SE established by NB master transcription factors MYCN, MEIS2 and HAND2, and they form a new complex that regulates the gene network associated with the proliferation of NB cell populations. We also observed a significant enrichment of the AP-1 family at the binding sites of IRF2BP2. Remarkably, within NB cells, AP-1 plays a pivotal role in shaping the chromatin accessibility landscape, thereby exposing the binding site for IRF2BP2. This orchestrated action enables AP-1 and IRF2BP2 to collaboratively stimulate the expression of the NB susceptibility gene ALK, thereby upholding the highly proliferative phenotype characteristic of NB. CONCLUSION: Our findings indicate that SE-driven IRF2BP2 can bind to AP-1 to maintain the survival of tumor cells via regulating chromatin accessibility of NB susceptibility gene ALK.

19.
Angew Chem Int Ed Engl ; 63(29): e202404314, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38712987

RESUMO

Atomically precise low-nuclearity (n<10) silver nanoclusters (AgNCs) have garnered significant interest due to their size-dependent optical properties and diverse applications. However, their synthesis has remained challenging, primarily due to their inherent instability. The present study introduces a new feasible approach for clustering silver ions utilizing highly negative and redox-inert polyoxoniobates (PONbs) as all-inorganic ligands. This strategy not only enables the creation of novel Ag-PONb composite nanoclusters but also facilitates the synthesis of stable low-nuclearity AgNCs. Using this method, we have successfully synthesized a small octanuclear rhombic [Ag8]6+ AgNC stabilized by six highly negative [LiNb27O75]14- polyoxoanions. This marks the first PONb-protected superatomic AgNC, designated as {Ag8@(LiNb27O75)6} (Ag8@Nb162), with an aesthetically spherical core-shell structure. The crystalline Ag8@Nb162 is stable under ambient conditions, What's more, it is water-soluble and able to maintain its molecular cluster structure intact in water. Further, the stable small [Ag8]6+ AgNC has interesting temperature- and pH-dependent reversible fluorescence response, based on which a multiple optical encryption mode for anti-counterfeit technology was demonstrated. This work offers a promising avenue for the synthesis of fascinating and stable PONb-protected AgNCs and sheds light on the development of new-type optical functional materials.

20.
Int Immunopharmacol ; 134: 112236, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38744174

RESUMO

Chronic rhinosinusitis (CRS) represents a heterogeneous disorder primarily characterized by the persistent inflammation of the nasal cavity and paranasal sinuses. The subtype known as chronic rhinosinusitis with nasal polyposis (CRSwNP) is distinguished by a significantly elevated recurrence rate and augmented challenges in the management of nasal polyps. The pathogenesis underlying this subtype remains incompletely understood. Macrophages play a crucial role in mediating the immune system's response to inflammatory stimuli. These cells exhibit remarkable plasticity and heterogeneity, differentiating into either the pro-inflammatory M1 phenotype or the anti-inflammatory and reparative M2 phenotype depending on the surrounding microenvironment. In CRSwNP, macrophages demonstrate reduced production of Interleukin 10 (IL-10), compromised phagocytic activity, and decreased autophagy. Dysregulation of pro-resolving mediators may occur during the inflammatory resolution process, which could potentially hinder the adequate functioning of anti-inflammatory macrophages in facilitating resolution. Collectively, these factors may contribute to the prolonged inflammation observed in CRSwNP. Additionally, macrophages may enhance fibrin cross-linking through the release of factor XIII-A (FAXIII), promoting fibrin deposition and plasma protein retention. Macrophages also modulate vascular permeability by releasing Vascular endothelial growth factor (VEGF). Moreover, they may disrupt the balance between Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinases (TIMPs), which favors extracellular matrix (ECM) degradation, edema formation, and pseudocyst development. Accumulating evidence suggests a close association between macrophage infiltration and CRSwNP; however, the precise mechanisms underlying this relationship warrant further investigation. In different subtypes of CRSwNP, different macrophage phenotypic aggregations trigger different types of inflammatory features. Increasing evidence suggests that macrophage infiltration is closely associated with CRSwNP, but the mechanism and the relationship between macrophage typing and CRSwNP endophenotyping remain to be further explored. This review discusses the role of different types of macrophages in the pathogenesis of different types of CRSwNP and their contribution to polyp formation, in the hope that a better understanding of the role of macrophages in specific CRSwNP will contribute to a precise and individualized understanding of the disease.


Assuntos
Macrófagos , Pólipos Nasais , Rinite , Sinusite , Humanos , Macrófagos/imunologia , Pólipos Nasais/imunologia , Sinusite/imunologia , Animais , Rinite/imunologia , Doença Crônica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...