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1.
Rejuvenation Res ; 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38814828

RESUMEN

This study aims to investigate the expression differences of peripheral blood mononuclear cells (PBMCs) in patients with elderly rheumatoid arthritis (ERA). Differentially expressed genes (DEGs) of PBMCs between young patients with RA (RA_Y) and elderly patients with RA (RA_A) were identified by RNA sequencing using the DESeq2 package, followed by bioinformatics analysis. The overlapped targets of the current DEGs and proteomic differentially expressed proteins (another set of unpublished data) were identified and further validated. The bioinformatics analysis revealed significant transcriptomic heterogeneity between RA_A and RA_Y. A total of 348 upregulated and 363 downregulated DEGs were identified. Gene functional enrichment analysis indicated that the DEGs, which represented senescence phenotype for patients with ERA, were enriched in pathways such as Phosphatidylinositol3 kinase/AKT serine-threonine protein kinase (PI3K/Akt) signaling, Mitogen-activated protein kinases (MAPK) signaling, toll-like receptor family, neutrophil degranulation, and immune-related pathways. Gene set enrichment analysis further confirmed the activation of humoral immune response pathways in RA_A. Quantitative polymerase chain reaction validated the expression of five representative DEGs such as SPTA1, SPTB, VNN1, TNXB, and KRT1 in PBMCs of patients with ERA. Patients with ERA have significant senescence phenotype differences versus the young patients. The DEGs identified may facilitate exploring the biomarkers of senescence in RA.

2.
Clin Rheumatol ; 43(5): 1521-1530, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38509241

RESUMEN

OBJECTIVES: Systemic lupus erythematosus (SLE) and the Epstein-Barr virus (EBV) are very closely related. This study estimated the impact of EBV infection status on clinical manifestations and disease remission in patients with SLE. METHOD: A retrospective study was performed using electronic health records of patients with SLE. The SLE disease activity index (SLEDAI-2 K) was used to assess disease activity. VCAIgM or EAIgM positive or EBVDNA copies ≥ 50 IU/mL were defined as lytic infection group, EBNA-IgG or VCAIgG-positive and who were negative for both VCAIgM and EAIgM with EBVDNA copies < 50 IU/mL were defined as the latent infection group. The endpoint (disease remission) was defined as a decrease in SLEDAI-2 K score of ≥ 1 grade or ≥ 4 points from baseline. The association between EBV infection status and disease remission was assessed using propensity score weighting and multivariable Cox regression models. RESULTS: There were 75 patients with SLE in the EBV lytic infection group and 142 patients in the latent infection group. The SLEDAI-2 K score was higher in the lytic infection group (10.00 (6.25, 16.00) vs. 8.00 (5.00, 10.00), Z = 3.96, P < 0.001). There was a significant difference in the effect of EBV lytic infection on disease remission compared to latent infection (HR 0.30, 95% CI 0.19-0.49, P < 0.001). CONCLUSIONS: Patients with SLE with lytic EBV infection have higher disease activity and take longer to achieve remission. Our study furthers our understanding of the relationship between SLE and EBV infection and may inform better treatment practices in the future.


Asunto(s)
Infecciones por Virus de Epstein-Barr , Infección Latente , Lupus Eritematoso Sistémico , Humanos , Herpesvirus Humano 4/genética , Infecciones por Virus de Epstein-Barr/complicaciones , Estudios Retrospectivos , Lupus Eritematoso Sistémico/complicaciones , Infección Latente/complicaciones , Anticuerpos Antivirales
3.
Biochem Pharmacol ; 222: 116071, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38387527

RESUMEN

Inhibition of the human ubiquitin-specific protease 7 (USP7), the key deubiquitylating enzyme in regulating p53 protein levels, has been considered an attractive anticancer strategy. In order to enhance the cellular activity of FT671, scaffold hopping strategy was employed. This endeavor resulted in the discovery of YCH2823, a novel and potent USP7 inhibitor.YCH2823 demonstrated remarkable efficacy in inhibiting the growth of a specific subset of TP53 wild-type, -mutant, and MYCN-amplified cell lines, surpassing the potency of FT671 by approximately 5-fold. The mechanism of action of YCH2823 involves direct interaction with the catalytic domain of USP7, thereby impeding the cleavage of ubiquitinated substrates. An increase in the expression of p53 and p21, accompanied by G1 phase arrest and apoptosis, was observed upon treatment with YCH2823. Subsequently, the knockdown of p53 or p21 in CHP-212 cells exhibited a substantial reduction in sensitivity to YCH2823, as evidenced by a considerable increase in IC50 values up to 690-fold. Furthermore, YCH2823 treatment specifically enhanced the transcriptional and protein levels of BCL6 in sensitive cells. Moreover, a synergistic effect between USP7 inhibitors and mTOR inhibitors was observed, suggesting the possibility of novel therapeutic strategies for cancer treatment. In conclusion, YCH2823 exhibits potential as an anticancer agent for the treatment of both TP53 wild-type and -mutant tumors.


Asunto(s)
Neoplasias , Proteína p53 Supresora de Tumor , Humanos , Línea Celular Tumoral , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Peptidasa Específica de Ubiquitina 7/metabolismo , Apoptosis , Neoplasias/tratamiento farmacológico , Neoplasias/genética
4.
Acta Biochim Biophys Sin (Shanghai) ; 56(2): 151-161, 2024 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-38167929

RESUMEN

MicroRNAs (miRNAs) are small noncoding RNAs (ncRNAs) that play their roles in the regulation of physiological and pathological processes. Originally, it was assumed that miRNAs only modulate gene expression posttranscriptionally in the cytoplasm by inducing target mRNA degradation. However, with further research, evidence shows that mature miRNAs also exist in the cell nucleus, where they can impact gene transcription and ncRNA maturation in several ways. This review provides an overview of novel models of nuclear miRNA functions. Some of the models remain to be verified by experimental evidence, and more details of the miRNA regulation network remain to be discovered in the future.


Asunto(s)
MicroARNs , MicroARNs/genética , MicroARNs/metabolismo , Regulación de la Expresión Génica , Citoplasma/genética , Citoplasma/metabolismo
5.
Sci Rep ; 13(1): 19194, 2023 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-37932299

RESUMEN

The role of host genetic factors in COVID-19 outcomes remains unclear despite various genome-wide association studies (GWAS). We annotate all significant variants and those variants in high LD (R2 > 0.8) from the COVID-19 host genetics initiative (HGI) and identify risk genes by recognizing genes intolerant nonsynonymous mutations in coding regions and genes associated with cis-expression quantitative trait loci (cis-eQTL) in non-coding regions. These genes are enriched in the immune response pathway and viral life cycle. It has been found that host RNA binding proteins (RBPs) participate in different phases of the SARS-CoV-2 life cycle. We collect 503 RBPs that interact with SARS-CoV-2 RNA concluded from in vitro studies. Combining risk genes from the HGI with RBPs, we identify two COVID-19 risk loci that regulate the expression levels of FUBP1 and RAB2A in the lung. Due to the risk allele, COVID-19 patients show downregulation of FUBP1 and upregulation of RAB2A. Using single-cell RNA sequencing data, we show that FUBP1 and RAB2A are expressed in SARS-CoV-2-infected upper respiratory tract epithelial cells. We further identify NC_000001.11:g.77984833C>A and NC_000008.11:g.60559280T>C as functional variants by surveying allele-specific transcription factor sites and cis-regulatory elements and performing motif analysis. To sum up, our research, which associates human genetics with expression levels of RBPs, identifies FUBP1 and RAB2A as two risk genes for COVID-19 and reveals the anti-viral role of FUBP1 and the pro-viral role of RAB2A in the infection of SARS-CoV-2.


Asunto(s)
COVID-19 , Proteínas de Unión al ADN , Proteínas de Unión al ARN , Proteínas de Unión al GTP rab , Humanos , COVID-19/genética , Proteínas de Unión al ADN/genética , Estudio de Asociación del Genoma Completo , ARN Viral , Proteínas de Unión al ARN/genética , SARS-CoV-2 , Proteínas de Unión al GTP rab/genética
6.
Phys Rev Lett ; 131(4): 043201, 2023 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-37566830

RESUMEN

Intense x-ray and extreme ultraviolet (XUV) light sources have been available for decades, however, due to weak nonlinear interaction in the XUV photon energy range, observation of Rabi oscillation induced by XUV pulse remains a very challenging experimental task. Here we suggest a scheme where photoionization of a He medium by an intense XUV pump pulse is followed by a strong population inversion and Rabi oscillation at the He^{+}(1s-3p) transition and is accompanied by superfluorescence (SF) of the 7.56 eV pulse at the He^{+}(3p-2s) transition. Our numerical simulations show that the Rabi oscillation at the He^{+}(1s-3p) transition induced by an XUV pulse with photon energy 48.36 eV results in significant signatures in the SF spectra, allowing us to identify and characterize the XUV induced Rabi-oscillatory regime. The proposed scheme provides a sensitive tool to monitor and control ultrafast nonlinear dynamics in atoms and molecules triggered by intense XUV.

7.
J Phys Chem Lett ; 14(24): 5475-5480, 2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37289034

RESUMEN

Resonant Auger scattering (RAS) provides information on the core-valence electronic transition and impresses a rich fingerprint of the electronic structure and nuclear configuration at the time-initiating RAS process. Here, we suggest using a femtosecond X-ray pulse to trigger RAS in a distorted molecule, which is generated from the nuclear evolution on a valence excited state pumped by a femtosecond ultraviolet pulse. With the time delay varied, the amount of molecular distortion can be controlled and the RAS measurements imprint both their electronic structures and changing geometries. This strategy is showcased in H2O prepared in an O-H dissociative valence state, where molecular and fragment lines appear in RAS spectra as signatures of ultrafast dissociation. Given the generality of this approach for a broad class of molecules, this work opens a new alternative pump-probe technique for mapping the core and valence dynamics with ultrashort X-ray probe pulses.

8.
Front Immunol ; 13: 940713, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35983055

RESUMEN

Objective: To evaluate a novel fully automated immunoturbidimetric assay developed by Qiangsheng Biotechnology Company for the detection of anticyclic citrullinated peptide antibodies (anti-CCP) in serum of patients with rheumatoid arthritis (RA) and compare it to the conventional EUROIMMUN- anti-CCP ELISA. Two other commonly used automated assays, the Elecsys anti-CCP assay, an ECLIA that is run on the Modular Analystics E170 (Cobas Diagnostics, Germany), and an anti-CCP CLIA developed by YHLO that is run on the iFlash 3000 Chemiluminescence Immunoassay Analyzer, were included as reference standards. Methods: A total of 264 serum samples were collected from patients attending the First People's Hospital of Wenling affiliated to Wenzhou Medical University between July 2020 and November 2020. These included 131 serum samples collected from patients with RA, 70 serum samples collected from patients with other autoimmune diseases, and 63 serum samples collected from healthy controls at a physical examination. The clinical performance and sensitivity and specificity of the four anti-CCP assays for the diagnosis of RA were compared using receiver operating characteristic (ROC) curve analysis. Results: The Kappa statistic indicated almost perfect agreement between the EUROIMMUN-anti-CCP ELISA and the Elecsys anti-CCP ECLIA (Cobas) (0.863), the EUROIMMUN-anti-CCP ELISA and the anti-CCP CLIA (YHLO) (0.862), and the Elecsys anti-CCP ECLIA (Cobas) and the anti-CCP CLIA (YHLO) (0.816). On ROC curve analysis, AUC values were 0.955 for the EUROIMMUN-anti-CCP ELISA, 0.948 for the anti-CCP CLIA (YHLO), 0.947 for the Elecsys anti-CCP ECLIA (Cobas) and 0.903 for Qiangsheng, indicating all the assays had a good diagnostic performance for RA. Conclusion: The anti-CCP assays provided similar diagnostic information. The novel fully automated immunoturbidimetric assay for anti-CCP developed by Qiangsheng Biotechnology Company may be especially useful for large scale clinical screening in RA as it has a shorter testing time than the commercially available alternatives.


Asunto(s)
Anticuerpos Antiproteína Citrulinada , Artritis Reumatoide , Autoanticuerpos , Ensayo de Inmunoadsorción Enzimática , Humanos , Péptidos Cíclicos
9.
Eur J Med Chem ; 240: 114574, 2022 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-35785724

RESUMEN

Based on the reported synthetic lethality of the combination of PARP inhibitor olaparib with the natural product alantolactone, we designed several series of new PARP1 inhibitors by structurally merging both compounds into a single hybrid compound. Among them, compounds 20e and 25a displayed not only high biochemical activity (IC50 = 2.99 nM and 5.91 nM vs 11.36 nM), but also higher inhibitory effects against proliferation of BRCA1-deficient UWB1.289 cells than olaparib (IC50 = 0.27 µM and 0.41 µM vs 0.66 µM). Much weak activity was observed in BRCA1 wild-type human fetal lung IMR-90 and WI-38 cells (IC50s > 10 µM). Treatment with compounds 20e and 25a was found to induce increased levels of γH2AX in a concentration-dependent manner in both MDA-MB-436 and Capan-1 cells to a degree comparable with that of olaparib. Further mechanism study indicated that these compounds activated the cell cycle checkpoints, and subsequently induced G2/M arrest and apoptosis. The results validated that merging PARP inhibitors with other DNA-damage related compounds would produce more potent PARP inhibitors for anticancer studies. However, the poor aqueous solubility and low cell penetration of the current hybrid compounds call for further structural optimization.


Asunto(s)
Productos Biológicos , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Apoptosis , Productos Biológicos/farmacología , Línea Celular Tumoral , Puntos de Control de la Fase G2 del Ciclo Celular , Humanos , Lactonas , Ftalazinas/química , Piperazinas , Poli(ADP-Ribosa) Polimerasa-1 , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Sesquiterpenos de Eudesmano
10.
Neoplasia ; 32: 100823, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35907292

RESUMEN

Inhibition of the NEDD8-activating enzyme (NAE), the key E1 enzyme in the neddylation cascade, has been considered an attractive anticancer strategy with the discovery of the first-in-class NAE inhibitor, MLN4924. In this study, we identified SOMCL-19-133 as a highly potent, selective, and orally available NAE inhibitor, which is an analog to AMP. It effectively inhibited NAE with an IC50 value of 0.36 nM and exhibited more than 2855-fold selectivity over the closely related Ubiquitin-activating enzyme (UAE). It is worth noting that treatment with SOMCL-19-133 prominently inhibited Cullin neddylation and delayed the turnover of a panel of Cullin-RING ligases (CRLs) substrates (e.g., Cdt1, p21, p27, and Wee1) at lower effective concentrations than that of MLN4924, subsequently caused DNA damage and Chk1/Chk2 activation, and thus triggered cell cycle arrest and apoptosis. Moreover, SOMCL-19-133 exhibited potent antiproliferative activity against a broad range of human tumor cell lines (mean IC50 201.11 nM), which was about 5.31-fold more potent than that of MLN4924. In vivo, oral delivery treatments with SOMCL-19-133, as well as the subcutaneous injection, led to significant tumor regression in mouse xenograft models. All of the treatments were well tolerated on a continuous daily dosing schedule. Compared with MLN4924, SOMCL-19-133 had a 5-fold higher peak plasma concentration, lower plasma clearance, and a 4-fold larger area under the curve (AUClast). In conclusion, SOMCL-19-133 is a promising preclinical candidate for treating cancers owing to its profound in vitro and in vivo efficacy and favorable pharmacokinetic properties.


Asunto(s)
Proteínas Cullin , Neoplasias , Animales , Apoptosis , Línea Celular Tumoral , Humanos , Ratones , Proteína NEDD8 , Enzimas Activadoras de Ubiquitina , Ubiquitinas
11.
RSC Adv ; 11(16): 9600-9607, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-35423438

RESUMEN

It is very interesting and challenging to investigate the electronic structures of diatomic dications, due to the nature of coulombic repulsive and bound attractive dissociation limits and their avoided diabatic interactions. Using the multi-reference configuration interaction approach, comprehensive ab initio calculations of the first 36 electronic states, corresponding to 15 dissociation limits, of dication HF2+ are reported. Good agreements for the vertical excitation energies and dissociation limits are achieved with the available references. Besides the common interesting quantities as adiabatic potential energy curves, dipole moments and spectral constants for the bound states, the nonadiabatic radial coupling matrix elements for the 1,3Π states are also presented. A showcase for the diabatic potentials of 3Π states are presented and discussed. Furthermore, predissociation states from the nonadiabatic couplings or avoided crossing of potential energy curves, known as shape resonances in collisions, are also investigated by using the WKB and scattering methods.

12.
Nanomaterials (Basel) ; 10(2)2020 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-32085559

RESUMEN

Low energy ion measurements in the vicinity of a comet have provided us with important information about the planet's evolution. The calibration of instruments for thermal ions in the laboratory plays a crucial role when analysing data from in-situ measurements in space. A new low energy ion source based on carbon nanotube electron emitters was developed for calibrating the ion-mode of mass spectrometers or other ion detectors. The electron field emission (FE) properties of carbon nanotubes (CNTs) for H2, He, Ar, O2, and CO2 gases were tested in the experiments. H2, He, Ar, and CO2 adsorbates could change the FE temporarily at pressures from10-6 Pa to10-4 Pa. The FE of CNT remains stable in Ar and increases in H2, but degrades in He, O2, and CO2. All gas adsorbates lead to temporary degradation after working for prolonged periods. The ion current of the ion source is measured by using a Faraday cup and the sensitivity is derived from this measurement. The ion currents for the different gases were around 10 pA (corresponding to 200 ions/cm3 s) and an energy of ~28 eV could be observed.

13.
J Am Soc Mass Spectrom ; 31(2): 434-440, 2020 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-32031385

RESUMEN

A miniature reflectron time-of-flight mass spectrometer (TOF MS) with orthogonal extraction coupled with electron impact (EI) ionization source can be used to perform in situ gas composition analysis in a planetary environment. However, performances such as the mass resolution, sensitivity, limit of detection, mass range, and mass accuracy are often decreased because of miniaturization. Herein, a compact instrument for space applications has been developed, and its performance has been evaluated. The mass of the TOF MS is 13.4 kg, with dimensions of 300 mm × 200 mm × 200 mm, and the power consumption is 25 W. In this paper, the design of the ion source, mass analyzer, and detector is discussed in detail. The upper limit of the mass range is greater than 500 amu, and the best resolving power obtained so far on the miniature TOF MS is around 405 at full width half maximum (FWHM); other performance indexes of the instrument are also determined, where the worst case for mass stability is 0.49%, together with a mass accuracy of 0.12% and a sensitivity of 0.6 mV/ppm.

14.
Biosci Rep ; 40(1)2020 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-31854447

RESUMEN

Rheumatoid arthritis (RA), a chronic systemic disease, is featured with inflammatory synovitis, which can lead to destruction on bone and cartilage and even cause disability. Emerging studies demonstrated that Fibroblast-like synoviocytes (FLS) is a vital cellular participant in RA progression. Long non-coding RNAs (lncRNAs) are also reported to participate in the pathogenesis of RA. In our present study, lncRNA microarray analysis was applied to screen out lncRNAs differentially expressed in RA FLS. Among which, cytoskeleton regulator RNA (LINC00152) presented biggest fold change. Gain- or loss-of function assays were further carried out in RA FLS, and the results revealed that LINC00152 promoted proliferation but induced apoptosis in RA FLS. Furthermore, up-regulation of LINC00152 may induce promotion of Wnt/ß-catenin signaling pathway in RA FLS. Mechanistically, we found that forkhead box M1 (FOXM1) transcriptionally activated LINC00152 in RA FLS. Additionally, LINC00152 positively regulated FOXM1 via sponging miR-1270. In conclusion, the present study focused on elucidating the function of FOXM1/LINC00152 positive feedback loop in RA FLS and its association with Wnt/ß-catenin signaling.


Asunto(s)
Apoptosis/genética , Artritis Reumatoide/genética , Proliferación Celular/genética , Proteína Forkhead Box M1/genética , ARN Largo no Codificante/genética , Sinoviocitos/metabolismo , Vía de Señalización Wnt/genética , Células Cultivadas , Fibroblastos/metabolismo , Humanos , MicroARNs/genética , Regulación hacia Arriba/genética , beta Catenina/genética
15.
Materials (Basel) ; 12(18)2019 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-31514335

RESUMEN

Titanium (Ti)-coated multiwall carbon nanotubes (CNTs) emitters based on the magnetron sputtering process are demonstrated, and the influences of modification to CNTs on the residual gas adsorption, gas desorption, and their field emission characteristic are discussed. Experimental results show that Ti nanoparticles are easily adsorbed on the surface of CNTs due to the "defects" produced by Ar+ irradiation pretreatment. X-ray photoelectron spectroscopy (XPS) characterization showed that Ti nanoparticles contribute to the adsorption of ambient molecules by changing the chemical bonding between C, Ti, and O. Field emission of CNTs coated with Ti nanoparticles agree well with the Fowler-Nordheim theory. The deviation of emission current under constant voltage is 6.3% and 8.6% for Ti-CNTs and pristine CNTs, respectively. The mass spectrometry analysis illustrated that Ti-coated CNTs have a better adsorption capacity at room temperature, as well as a lower outgassing effect than pristine CNTs after degassing in the process of field emission.

16.
Nat Prod Res ; 33(20): 2988-2994, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30270680

RESUMEN

A new indole diterpene, named penicindopene A (1), together with seven known compounds (2 - 8), was isolated from the deep-sea fungus Penicillium sp. YPCMAC1. The structure of penicindopene A was elucidated by extensive spectroscopic analyses (1 D and 2 D NMR, and HRESIMS data), in addition to the ECD calculations for the assignments of its absolute configuration. Penicindopene A represented the first example of indole diterpenes possessing a 3-hydroxyl-2-indolone moiety, and it exhibited moderate cytotoxicities against A549 and HeLa cell lines with IC50 values of 15.2 and 20.5 µM, respectively.


Asunto(s)
Diterpenos/aislamiento & purificación , Indoles/aislamiento & purificación , Conformación Molecular , Penicillium/química , Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Línea Celular Tumoral , Diterpenos/química , Ensayos de Selección de Medicamentos Antitumorales , Hongos , Células HeLa , Humanos , Indoles/química , Concentración 50 Inhibidora , Espectroscopía de Resonancia Magnética/métodos , Estructura Molecular
17.
Mar Drugs ; 16(10)2018 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-30275364

RESUMEN

Chemical examination of the EtOAc extract of the deep sea-derived fungus Penicillium sp. YPGA11 resulted in the isolation of four new farnesylcyclohexenones, peniginsengins B⁻E (1⁻4), and a known analog peniginsengin A (5). The structures of compounds 1⁻4 were determined on the basis of comprehensive analyses of the nuclear magnetic resonance (NMR) and mass spectroscopy (MS) data, and the absolute configurations of 1, 2, and 4 were determined by comparisons of experimental electronic circular dichroism (ECD) with calculated ECD spectra. Compounds 1⁻5, characterized by a highly oxygenated 1-methylcyclohexene unit and a (4E,8E)-4,8-dimethyldeca-4,8-dienoic acid side chain, are rarely found in nature. Compounds 2⁻4 exhibited antibacterial activity against Staphylococcus aureus.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Ciclohexanonas/química , Diterpenos/química , Hongos/química , Alcaloides Indólicos/química , Penicillium/química , Dicroismo Circular/métodos , Ciclohexanonas/farmacología , Diterpenos/farmacología , Alcaloides Indólicos/farmacología , Espectroscopía de Resonancia Magnética/métodos , Espectrometría de Masas/métodos , Pruebas de Sensibilidad Microbiana , Staphylococcus aureus/efectos de los fármacos
18.
Eur J Mass Spectrom (Chichester) ; 24(4): 322-329, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29759016

RESUMEN

A miniaturized linear ion trap mass spectrometer with continuous atmospheric pressure interface has been built in our lab. Significant extension in mass range and reduction in power consumption have been realized by the supplemental alternating current frequency scan mode. However, relatively poor sensitivity has been witnessed, which is directly dominated by the detection efficiency of the ion detector. Theoretical analysis has been implemented to find ways to improve the detection efficiency. The results show that enhanced sensitivity can be obtained by applying a direct current voltage on the pair of electrodes in eject direction. Experiments show that the sensitivity has been improved by more than one time due to the application of direct current voltage. With this design, this homemade miniature linear ion trap mass spectrometer can be used to analyze more rarefied samples, especially to on-site chemical analysis and space application.

19.
Nan Fang Yi Ke Da Xue Xue Bao ; 38(7): 830-835, 2018 Jul 30.
Artículo en Chino | MEDLINE | ID: mdl-33168502

RESUMEN

OBJECTIVE: To study the protective effect of MRL-45696, an inhibitor of poly(ADP-ribose) polymerase-1 (PARP-1), against DNA damage after myocardial ischemia/reperfusion (I/R) in diabetic rats. METHODS: Rat models of type 2 diabetes mellitus were established by high-fat feeding and a single peritoneal dose of streptozotocin. Forty diabetic rats were randomized equally into diabetic group, sham-operated group, sham-operated group with MRL-45696 treatment, I/R injury model group and I/R injury group with MRL-45696 treatment. The rats in MRL-45696-treated groups were subjected to daily intragastric administration of MRL-45696 (50 mg/kg) for 7 consecutive days, after which sham operation was performed or myocardial I/R injury was induced by ligation of the left anterior descending coronary artery for 30 min followed by reperfusion for 120 min. The range of myocardial infarction, plasma cardiac troponin I (cTnI), serum creatine kinase (CK), lactate dehydrogenase (LDH) activity, malondialdehyde (MDA), superoxide dismutase (SOD) activity, and cardiac myocyte apoptosis were detected. The levels of γ-H2AX, cleaved caspase-3, PARP-1, and PAR were detected with Western blotting, and the level of NAD was detected using colorimetry. RESULTS: The infarct size was significantly smaller in MRL-45696 treatment group than in I/R injury group (P < 0.05). In I/R model group, the levels of cTnI, CK, and LDH in the plasma or serum and MDA, γ-H2AX, cleaved caspase-3 and apoptotic rate in the cardiac myocytes were significantly higher than those in the other groups (P < 0.05), and SOD activity was significantly decreased (P < 0.05). Compared with I/R model group, the rats with MRL- 45696 treatment showed significantly decreased levels of cTnI, CK, LDH, MDA, γ-H2AX, cleaved caspase-3, PARP- 1, PAR expression and cell apoptosis with significantly increased levels of SOD and NAD (P < 0.05). CONCLUSIONS: MRL-45696 can inhibit excessive activation of PARP-1, increase intracellular level of NAD and inhibit cardiac myocyte apoptosis to alleviate myocardial I/R-induced DNA damage and reduce myocardial infarct size in diabetic rats.

20.
Eur J Mass Spectrom (Chichester) ; 24(2): 196-205, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29232983

RESUMEN

In this paper, the effects of constant uniform magnetic fields on a miniature linear ion trap mass spectrometer with hyperbolic electrodes are simulated using SIMION 8.0 3D software. Magnetic fields in different directions have different effects on the trajectories of the trapped ions and the shape of the ion cloud. When the magnetic field is applied in the z-direction, namely the ion injection direction, the magnetic field will cause the ions focusing to the z-axis, and exert a compression effect on the ion cloud. When the magnetic field is applied in the x-y plane, the original ion cloud will be expanded due to the action of the applied magnetic field, and the ion cloud plane after expansion is always perpendicular to the direction of the magnetic field. The discovery of influence field of magnetic will bring some useful inspiration for the improvement of ion trapping efficiency, mass resolution, sensitivity and trapping capacity, which is conductive to the performance enhancement utilization of magnetic field, even in the industrial application development and other aspects.

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