Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Environ Monit Assess ; 196(5): 426, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38573396

RESUMO

This article, based on OMI data products, utilizes spatial distribution, ozone-sensitive control areas, Pearson correlation methods, and the Ben-MAP model to study the changes in ozone column concentration from 2018 to 2022, along with the influencing factors and the health of populations exposed to ozone. The findings suggest a spatial variation in the ozone column concentration within the study area, with an increasing trend observed from west to east and from south to north. Over time, the ozone column concentration exhibits an initial increase followed by a subsequent decrease, with the peak concentration observed in 2019 at 37.45 DU and the nadir recorded in 2022 at 33.10 DU. The monthly mean distribution exhibits an inverted V-shaped pattern during the warm season from April to September, with a peak in July (46.71 DU) and a trough in April (35.29 DU). The Hetao Plain Oasis area is primarily a NOx control area in sensitive control areas. The concentrations of O3 and precursor HCHO exhibited significant positive correlations with vegetation index and air temperature, while showing significant negative correlations with wind speed and air pressure. The precursor NO2, in contrast, exhibited a significant negative correlation with both the vegetation index and relative humidity. Based on the ground-based monitoring sites and analysis of human health benefits, the study area witnessed 1944.45 deaths attributed to warm season O3 exposure in 2018, with a subsequent reduction in premature deaths by 149.7, 588.2, and 231.75 for the years 2019 to 2021 respectively when compared to the baseline year. In 2021, the observed decrease in warm-season O3 concentration within that region compared to 2018 resulted in a significant reduction, leading to the prevention of 126 premature deaths.


Assuntos
Monitoramento Ambiental , Ozônio , Humanos , Mortalidade Prematura , Ozônio/toxicidade , Estações do Ano , Temperatura
2.
J Coll Physicians Surg Pak ; 34(2): 141-145, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38342861

RESUMO

OBJECTIVE: To explore the anti-BP230/180 and anti-BP180 antibodies in patients with bullous pemphigoid (BP) combined with neurological diseases, and to analyse the relevant factors. STUDY DESIGN: Analytical study. Place and Duration of the Study: Neurology Department, Cangzhou People's Hospital, Cangzhou, from April 2019 to June 2022. METHODOLOGY: Eighty BP patients were chosen based on associated neurological diseases, they were split into single (n=42) and combined groups (n=38). Expression of anti-BP180/230 antibodies was compared between the two groups. Associations with neurological diseases were analysed and the factors affecting the expression of anti-BP180/230 antibodies were explored. RESULTS: Out of 80 patients, 61 were positive for anti-BP180 antibodies and 58 were positive for anti-BP230 antibodies. The proportion of patients with positive anti-BP230/180 antibodies in the single group was considerably lower than in the combined group (p<0.05). Presence of both nervous system diseases and BP was found to be associated with the presence of anti-BP230/180 antibodies (p<0.001). Univariate analysis showed statistically significant association with age (<70 years, total IgE (>100 IU/ml), and EOS count >0.5 x 109/L (p<0.05). Logistic analysis demonstrated that age, total IgE and EOS count were independent risk factors affecting the expression of anti-BP180 and anti-BP23 antibodies (p<0.05). CONCLUSION: Serum anti-BP230/180 antibodies expression is abnormally high in BP patients having nervous system diseases. Combined nervous system diseases, age, total IgE and EOS count are independent risk factors affecting expression of anti-BP180/230 antibodies. KEY WORDS: Anti-BP180 antibody, Anti-BP230 antibody, Bullous pemphigoid, Nervous system diseases.


Assuntos
Doenças do Sistema Nervoso , Penfigoide Bolhoso , Humanos , Idoso , Colágeno Tipo XVII , Colágenos não Fibrilares , Autoantígenos , Autoanticorpos , Ensaio de Imunoadsorção Enzimática , Imunoglobulina E
3.
Environ Monit Assess ; 195(11): 1336, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37853142

RESUMO

Climate change and air pollution are one of the global environmental problems. It is significant to grasp the air pollution situation of Western Europe in recent 10 years for its or the global pollution control. Based on the OMI tropospheric nitrogen dioxide (NO2) column density data, the spatial and temporal distribution characteristics, variation trend, transmission path, and influencing factors of NO2 in 15 countries in Western Europe from 2011 to 2022 are discussed in this paper. Meanwhile, the annual average spatial and temporal distribution in 2023 is predicted by the random forest (RF) model. The results showed that (1) the 12-year spatial distribution map showed an increasing trend from southwest to northeast, with the border area of the Netherlands and Germany and Milan as two high-value areas, and the overall trend over time was that the high-concentration area gradually shrank, the low-concentration area gradually expanded, and the annual average concentration gradually decreased. (2) The inter-month trend presents a "U" shape, with the mean NO2 pollution ranking in winter > autumn > spring > summer. (3) Natural factors are one of the reasons affecting NO2; for instance, NO2 pollution has a strong positive correlation with the lifted index, relative humidity, and wind speed and a moderately strong negative correlation with precipitable water and air temperature. (4) Exogenous atmospheric transport is another important factor affecting the change of NO2 pollution in Western Europe. The HYSPLIT model is used to analyze the backward trajectory of Milan, Italy, and Nijmegen, Netherlands, in the four seasons of 2022. Both are mainly influenced by westerly airflows, and therefore, the transport effect in the atmosphere brings air pollutants from westerly regions in the atmosphere.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Dióxido de Nitrogênio/análise , Monitoramento Ambiental/métodos , Poluição do Ar/análise , Poluentes Atmosféricos/análise , Europa (Continente) , Material Particulado/análise , China , Estações do Ano
4.
J Biol Chem ; 299(8): 105049, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37451485

RESUMO

Rufomycins constitute a class of cyclic heptapeptides isolated from actinomycetes. They are secondary metabolites that show promising treatment against Mycobacterium tuberculosis infections by inhibiting a novel drug target. Several nonproteinogenic amino acids are integrated into rufomycins, including a conserved 3-nitro-tyrosine. RufO, a cytochrome P450 (CYP)-like enzyme, was proposed to catalyze the formation of 3-nitro-tyrosine in the presence of O2 and NO. To define its biological function, the interaction between RufO and the proposed substrate tyrosine is investigated using various spectroscopic methods that are sensitive to the structural change of a heme center. However, a low- to high-spin state transition and a dramatic increase in the redox potential that are commonly found in CYPs upon ligand binding have not been observed. Furthermore, a 1.89-Å crystal structure of RufO shows that the enzyme has flexible surface regions, a wide-open substrate access tunnel, and the heme center is largely exposed to solvent. Comparison with a closely related nitrating CYP reveals a spacious and hydrophobic distal pocket in RufO, which is incapable of stabilizing a free amino acid. Molecular docking validates the experimental data and proposes a possible substrate. Collectively, our results disfavor tyrosine as the substrate of RufO and point to the possibility that the nitration occurs during or after the assembly of the peptides. This study indicates a new function of the unique nitrating enzyme and provides insights into the biosynthesis of nonribosomal peptides.


Assuntos
Aminoácidos , Sistema Enzimático do Citocromo P-450 , Oligopeptídeos , Sistema Enzimático do Citocromo P-450/metabolismo , Heme/metabolismo , Simulação de Acoplamento Molecular , Nitratos , Tirosina/metabolismo , Actinobacteria , Oligopeptídeos/biossíntese
5.
Nat Commun ; 14(1): 910, 2023 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-36801853

RESUMO

Transcriptional memory, by which cells respond faster to repeated stimuli, is key for cellular adaptation and organism survival. Chromatin organization has been shown to play a role in the faster response of primed cells. However, the contribution of post-transcriptional regulation is not yet explored. Here we perform a genome-wide screen to identify novel factors modulating transcriptional memory in S. cerevisiae in response to galactose. We find that depletion of the nuclear RNA exosome increases GAL1 expression in primed cells. Our work shows that gene-specific differences in intrinsic nuclear surveillance factor association can enhance both gene induction and repression in primed cells. Finally, we show that primed cells present altered levels of RNA degradation machinery and that both nuclear and cytoplasmic mRNA decay modulate transcriptional memory. Our results demonstrate that mRNA post-transcriptional regulation, and not only transcription regulation, should be considered when investigating gene expression memory.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Regulação Fúngica da Expressão Gênica , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Expressão Gênica , Estabilidade de RNA/genética , Transcrição Gênica
6.
Langmuir ; 38(49): 15353-15360, 2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36454949

RESUMO

The wetting property of a solid surface has been a hotspot for centuries, and many studies suggest that the hydrophobicity is highly related to the polar components. However, the underlying mechanism of polar moieties on the hydrophobicity remains unclear. Here, we tailor the surface polar moieties of epoxy resin (EP) by ozone modification and assess their wetting properties. Our results show that, for the modified EP with more (60.54%) polar moieties, the polar effect on hydrophobicity cannot be empirically observed. To reveal the underlying mechanism, the absorption parameters, including equilibrium distance, adsorption radius, and effective adsorption sites for water on EP before and after ozone treatment, are calculated on the basis of molecular simulations. After ozone modification, the equilibrium distance (from 1.95 to 1.70 Å), adsorption radius (from 3.80 to 4.50 Å), and effective adsorption sites (from 1 to 2) change slightly and the EP surface remains hydrophobic, although the polar groups significantly increase. Therefore, it is concluded that the wetting properties of solid surfaces are dominated by the equilibrium distance, adsorption radius, and effective adsorption sites for water on solids, and the nonlinear relationship between polar groups and hydrophilicity is clarified.

7.
Methods Enzymol ; 655: 85-118, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34183135

RESUMO

The development of high-throughput technologies has revealed pervasive transcription in all genomes that have been investigated so far. This has uncovered a highly interleaved transcriptome organization involving thousands of overlapping coding and non-coding RNA isoforms that challenge our traditional definitions of genes and functional regions of the genome. In this chapter, we discuss the application of an improved Transcript Isoform Sequencing approach (TIF-Seq2) able to concurrently determine the start and end sites of individual RNA molecules. We exemplify its use for the investigation of the human transcriptome and show how it is especially well suited to discriminate between overlapping molecules and accurately define their boundaries.


Assuntos
Genoma , Transcriptoma , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Isoformas de Proteínas/genética , RNA Mensageiro/genética , Análise de Sequência de RNA
8.
Med Phys ; 48(2): 745-759, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33119126

RESUMO

PURPOSE: In order to improve the reconstruction accuracy of magnetic induction tomography (MIT) and achieve fast imaging especially in the detection of cerebral hemorrhage, artificial intelligence algorithms are proposed to improve the accuracy of MIT inverse problem. METHODS: According to the standard geometric data of human head, a three-dimensional (3D) head model containing four layer tissues is established for brain image reconstruction of MIT. Four deep learning (DL) networks, including restricted Boltzmann machine (RBM), deep belief network (DBN), stacked autoencoder (SAE), and denoising autoencoder (DAE), are used to solve the nonlinear reconstruction problem of MIT, and the reconstruction results of DL networks and back-projection algorithm are compared. Finally, in order to verify the practical value of DL algorithms, the phantom experiment is carried out with MIT detection system. RESULTS: Using the nonlinear data learning ability of DL algorithms, the rapid and high-precision imaging of cerebral hemorrhage can be realized. Compared with the back-projection algorithm, the DL improves the artifact and the accuracy of the reconstruction image. The location and volume of bleeding can be reconstructed and the prediction time reaches 20 ms. Moreover, the anti-noise performance of the networks can reach 20 dB. CONCLUSIONS: The DL can effectively improve the reconstruction accuracy and prediction speed of the image when it is applied to the reconstruction of cerebral hemorrhage in MIT. This feasibility study MIT to be a potential technology for brain diseases to fully meet the needs of accurate, rapid, and low-cost clinical diagnosis and continuous monitoring.


Assuntos
Encefalopatias , Aprendizado Profundo , Algoritmos , Inteligência Artificial , Encéfalo/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Fenômenos Magnéticos , Imagens de Fantasmas , Tomografia
9.
Rev Sci Instrum ; 91(9): 091501, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33003827

RESUMO

Magnetic induction tomography (MIT) is a non-invasive and non-contact imaging technology, which can be used in medical diagnosis by reconstructing the electrical distribution of biological tissues. Unlike other large medical imaging equipment, the device of MIT is with small size and low cost. The theoretical basis of MIT is by measuring the phase difference of magnetic flux density generated around the imaging objects, analyzing the eddy current distribution, and then using the reconstruction algorithms to obtain the electrical characteristic distribution of the object. This review introduces the development of imaging systems and the reconstruction algorithms of MIT as a medical assisted diagnostic technology, including the optimal design of the sensors, the excitation methods of the system, the calculation methods of the eddy current, and the improved methods of different reconstruction algorithms.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Fenômenos Magnéticos , Tomografia/instrumentação , Humanos
10.
Rev Sci Instrum ; 91(8): 083705, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32872929

RESUMO

The commonly used respiratory monitoring methods in clinical medicine are chest belt or ventilators, which are not easy to carry and cumbersome to operate. In order to solve this problem, a low-cost and portable magnetic induction phase detection system for respiratory monitoring is proposed. In this study, a magnetic induction tomography system for respiration detection is established, and the phase sensitivity of the system to conductive object is evaluated through a series of experiments. At the same time, phantom experiments are carried out to simulate the respiratory process, and the phase monitoring indicators are collected to describe different respiratory states. The experimental results show that the phase detection results are consistent with the changes in the respiratory cycle. The signal-to-noise ratio of the system is 79 dB. It proves the feasibility of using magnetic induction phase measurement in respiratory monitoring and provides a new detection method of respiratory monitoring.


Assuntos
Desenho de Equipamento , Imãs , Monitorização Fisiológica/instrumentação , Respiração , Humanos , Imagens de Fantasmas
11.
Nucleic Acids Res ; 48(18): e104, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-32816037

RESUMO

Eukaryotic transcriptomes are complex, involving thousands of overlapping transcripts. The interleaved nature of the transcriptomes limits our ability to identify regulatory regions, and in some cases can lead to misinterpretation of gene expression. To improve the understanding of the overlapping transcriptomes, we have developed an optimized method, TIF-Seq2, able to sequence simultaneously the 5' and 3' ends of individual RNA molecules at single-nucleotide resolution. We investigated the transcriptome of a well characterized human cell line (K562) and identified thousands of unannotated transcript isoforms. By focusing on transcripts which are challenging to be investigated with RNA-Seq, we accurately defined boundaries of lowly expressed unannotated and read-through transcripts putatively encoding fusion genes. We validated our results by targeted long-read sequencing and standard RNA-Seq for chronic myeloid leukaemia patient samples. Taking the advantage of TIF-Seq2, we explored transcription regulation among overlapping units and investigated their crosstalk. We show that most overlapping upstream transcripts use poly(A) sites within the first 2 kb of the downstream transcription units. Our work shows that, by paring the 5' and 3' end of each RNA, TIF-Seq2 can improve the annotation of complex genomes, facilitate accurate assignment of promoters to genes and easily identify transcriptionally fused genes.


Assuntos
Perfilação da Expressão Gênica/métodos , RNA , Análise de Sequência de RNA/métodos , Transcriptoma/genética , Genoma Humano , Humanos , Células K562 , Isoformas de Proteínas/genética
12.
Nucleic Acids Res ; 48(15): 8509-8528, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32710631

RESUMO

The ribonucleolytic exosome complex is central for nuclear RNA degradation, primarily targeting non-coding RNAs. Still, the nuclear exosome could have protein-coding (pc) gene-specific regulatory activities. By depleting an exosome core component, or components of exosome adaptor complexes, we identify ∼2900 transcription start sites (TSSs) from within pc genes that produce exosome-sensitive transcripts. At least 1000 of these overlap with annotated mRNA TSSs and a considerable portion of their transcripts share the annotated mRNA 3' end. We identify two types of pc-genes, both employing a single, annotated TSS across cells, but the first type primarily produces full-length, exosome-sensitive transcripts, whereas the second primarily produces prematurely terminated transcripts. Genes within the former type often belong to immediate early response transcription factors, while genes within the latter are likely transcribed as a consequence of their proximity to upstream TSSs on the opposite strand. Conversely, when genes have multiple active TSSs, alternative TSSs that produce exosome-sensitive transcripts typically do not contribute substantially to overall gene expression, and most such transcripts are prematurely terminated. Our results display a complex landscape of sense transcription within pc-genes and imply a direct role for nuclear RNA turnover in the regulation of a subset of pc-genes.


Assuntos
Exossomos/genética , Genoma Humano/genética , Fases de Leitura Aberta/genética , RNA/genética , Sítio de Iniciação de Transcrição , Regulação da Expressão Gênica/genética , Células HeLa , Humanos , Anotação de Sequência Molecular , Estabilidade de RNA/genética , RNA Mensageiro/genética , RNA não Traduzido/genética
13.
Nat Commun ; 11(1): 2589, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444691

RESUMO

RNA polymerase II (RNAPII) transcription converts the DNA sequence of a single gene into multiple transcript isoforms that may carry alternative functions. Gene isoforms result from variable transcription start sites (TSSs) at the beginning and polyadenylation sites (PASs) at the end of transcripts. How alternative TSSs relate to variable PASs is poorly understood. Here, we identify both ends of RNA molecules in Arabidopsis thaliana by transcription isoform sequencing (TIF-seq) and report four transcript isoforms per expressed gene. While intragenic initiation represents a large source of regulated isoform diversity, we observe that ~14% of expressed genes generate relatively unstable short promoter-proximal RNAs (sppRNAs) from nascent transcript cleavage and polyadenylation shortly after initiation. The location of sppRNAs correlates with the position of promoter-proximal RNAPII stalling, indicating that large pools of promoter-stalled RNAPII may engage in transcriptional termination. We propose that promoter-proximal RNAPII stalling-linked to premature transcriptional termination may represent a checkpoint that governs plant gene expression.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Regiões Promotoras Genéticas , Terminação da Transcrição Genética , Proteínas de Arabidopsis/metabolismo , Cromatina/genética , Fator Estimulador de Clivagem/genética , Regulação da Expressão Gênica de Plantas , Mutação , Plantas Geneticamente Modificadas , Poliadenilação , Isoformas de Proteínas/genética , RNA de Plantas , Nicotiana/genética , Sítio de Iniciação de Transcrição
14.
Mol Cell ; 74(1): 196-211.e11, 2019 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-30799147

RESUMO

The compendium of RNA-binding proteins (RBPs) has been greatly expanded by the development of RNA-interactome capture (RIC). However, it remained unknown if the complement of RBPs changes in response to environmental perturbations and whether these rearrangements are important. To answer these questions, we developed "comparative RIC" and applied it to cells challenged with an RNA virus called sindbis (SINV). Over 200 RBPs display differential interaction with RNA upon SINV infection. These alterations are mainly driven by the loss of cellular mRNAs and the emergence of viral RNA. RBPs stimulated by the infection redistribute to viral replication factories and regulate the capacity of the virus to infect. For example, ablation of XRN1 causes cells to be refractory to SINV, while GEMIN5 moonlights as a regulator of SINV gene expression. In summary, RNA availability controls RBP localization and function in SINV-infected cells.


Assuntos
Células Epiteliais/virologia , Perfilação da Expressão Gênica/métodos , RNA Viral/genética , Proteínas de Ligação a RNA/genética , Sindbis virus/genética , Transcriptoma , Neoplasias do Colo do Útero/virologia , Regiões 5' não Traduzidas , Sítios de Ligação , Células Epiteliais/metabolismo , Exorribonucleases/genética , Exorribonucleases/metabolismo , Feminino , Regulação Viral da Expressão Gênica , Células HEK293 , Células HeLa , Interações Hospedeiro-Patógeno , Humanos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Ligação Proteica , RNA Viral/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas Nucleares Pequenas/genética , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Proteínas do Complexo SMN , Sindbis virus/crescimento & desenvolvimento , Sindbis virus/metabolismo , Sindbis virus/patogenicidade , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo , Replicação Viral
15.
Nanotechnology ; 30(3): 035705, 2019 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-30444728

RESUMO

Near-infrared absorbing dyes are catching people's attention as they are committed to find materials with greater photoacoustic (PA) and photothermal (PT) effect. In this study, a new series of organic π-conjugated discotic derivatives synthesized via [2 + 2] click chemistry were introduced. The PA intensity and PT conversion effect of the derivatives were monitored. It was found that the π-conjugated discotic derivatives had a proper absorption peak and PA intensity by introducing the click regents. Furthermore, the PA intensity remained relatively high, while B12 molecules were embedded in hydrophobic phospholipid bilayer of liposomes (B12⊂L). The application in biological therapy for tumors become possible as the toxicity of B12⊂L was low. What's more, when B12 molecules embedded in poly (N-isopropylacrylamide)-block-poly (2-nitrobenzyl methacrylate) (PNIPAM-b-PNBM) thermosensitive micelles were irradiated by laser, the molecules could take the place of direct temperature stimulus. This work affords us a way to solve the problem in which direct temperature stimulus is inapplicable.

16.
Cell Death Dis ; 9(9): 923, 2018 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-30206203

RESUMO

The induced pluripotent stem cell (iPSC) technology has provided a unique opportunity to develop disease-specific models and personalized treatment for genetic disorders, and is well suitable for the study of Werner syndrome (WS), an autosomal recessive disease with adult onset of premature aging caused by mutations in the RecQ like helicase (WRN) gene. WS-derived fibroblasts were previously shown to be able to generate iPSCs; however, it remains elusive how WS-derived iPSCs behave and whether they are able to mimic the disease-specific phenotype. The present study was designed to address these issues. Unexpectedly, we found that a specific WS fibroblast line of homozygous truncation mutation was difficult to be reprogrammed by using the Yamanaka factors even under hypoxic conditions due to their defect in induction of hTERT, the catalytic unit of telomerase. Ectopic expression of hTERT restores the ability of this WS fibroblast line to form iPSCs, although with a low efficiency. To examine the phenotype of WRN-deficient pluripotent stem cells, we also generated WRN knockout human embryonic stem (ES) cells by using the CRISPR/Cas9 method. The iPSCs derived from WS-hTERT cells and WRN-/- ESCs are fully pluripotent, express pluripotent markers and can differentiate into three germ layer cells; however, WS-iPSCs and WRN-/- ESCs show S phase defect in cell cycle progression. Moreover, WS-iPSCs and WRN-/- ESCs, like WS patient-derived fibroblasts, remain hypersensitive to topoisomerase inhibitors. Collectively, WS-derived iPSCs and WRN-/- ESCs mimic the intrinsic disease phenotype, which may serve as a suitable disease model, whereas not be good for a therapeutic purpose without gene correction.


Assuntos
Técnicas de Reprogramação Celular/métodos , Reprogramação Celular/fisiologia , Fibroblastos/citologia , Células-Tronco Pluripotentes Induzidas/citologia , Helicase da Síndrome de Werner/genética , Síndrome de Werner/patologia , Sistemas CRISPR-Cas , Células Cultivadas , Técnicas de Inativação de Genes , Humanos , Telomerase/metabolismo , Inibidores da Topoisomerase/farmacologia
17.
Chem Commun (Camb) ; 54(73): 10240-10243, 2018 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-30069554

RESUMO

Herein, we report an efficient and practical strategy for the synthesis of five types of imidazo[2,1-a]isoquinolines via Cp*RhIII-catalyzed [4+2] annulation of 2-arylimidazoles and α-diazoketoesters, whose structural and substituted diversity at 5- or 6-position can be precisely controlled by the α-diazoketoester coupling partners. Compared with previous reports, in this study, we merged two attractive C-C cleavage strategies (retro-Claisen and decarboxylation) into the classical C-H functionalization/condensation process by choosing appropriate ester groups (-COOEt, -COOtBu or -COOiPr) or inexpensive additives (HOAc or KOAc). Moreover, the synthetic efficacies of these methods were demonstrated by the concise synthesis of several bioactive compounds and the late-stage modification of representative drugs.

18.
Biomaterials ; 176: 50-59, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29857274

RESUMO

Anti-tuberculosis chemotherapy with a long duration and adequate dosing is the mainstay for treatment of osteoarticular tuberculosis (TB). However, it is difficult for systemic administration to reach adequate local drug concentrations and achieve effective treatment. Herein, a hydroxyapatite (HA) scaffold implant combined with a drug-releasing system was designed to achieve in situ and long-term anti-TB drug release and highly efficient therapeutic activity in vitro and in vivo. The clinical anti-TB drugs hydrophilic isoniazid (INH) and hydrophobic rifampicin (RFP) were molecularly dispersed into polyvinyl alcohol (PVA) through immersion-curing techniques and were steadily adhered onto the surfaces of HA scaffolds (HA-drug@PVA). The HA-drug@PVA scaffolds showed a long-term, sustained drug release profile and killed proliferating Mycobacterium in vitro. In vivo experimental results revealed that the HA-drug@PVA scaffolds provided over 10- and 100-fold higher concentrations in muscles and bones, respectively, as well as a much lower concentration (<0.025) in blood. Furthermore, the HA-drug@PVA scaffold implanted in an osteoarticular TB rabbit model showed obvious bone regeneration and fusion due to the inhibition of TB-associated inflammatory changes. The excellent therapeutic effects indicate that in situ implant materials combined with a long-term drug release system are promising for the treatment of osteoarticular TB and other osteoarticular infections.


Assuntos
Antituberculosos/administração & dosagem , Durapatita/química , Isoniazida/administração & dosagem , Próteses e Implantes , Rifampina/administração & dosagem , Alicerces Teciduais/química , Tuberculose Osteoarticular/tratamento farmacológico , Animais , Antituberculosos/farmacologia , Materiais Biocompatíveis/química , Regeneração Óssea/efeitos dos fármacos , Adesão Celular , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Quimioterapia Combinada , Humanos , Isoniazida/farmacologia , Camundongos , Mycobacterium tuberculosis/efeitos dos fármacos , Álcool de Polivinil/química , Coelhos , Rifampina/farmacologia
19.
Ann Hematol ; 97(7): 1299, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29744585

RESUMO

The original version of this article contained a mistake. The name of Magnus Björkhom should have been Magnus Björkholm.

20.
Nat Commun ; 9(1): 1802, 2018 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-29728565

RESUMO

Cerebral amyloid ß-peptide (Aß) accumulation resulting from an imbalance between Aß production and clearance is one of the most important causes in the formation of Alzheimer's disease (AD). In order to preserve the maintenance of Aß homeostasis and have a notable AD therapy, achieving a method to clear up Aß plaques becomes an emerging task. Herein, we describe a self-destructive nanosweeper based on multifunctional peptide-polymers that is capable of capturing and clearing Aß for the effective treatment of AD. The nanosweeper recognize and bind Aß via co-assembly through hydrogen bonding interactions. The Aß-loaded nanosweeper enters cells and upregulates autophagy thus promoting the degradation of Aß. As a result, the nanosweeper decreases the cytotoxicity of Aß and rescues memory deficits of AD transgenic mice. We believe that this resourceful and synergistic approach has valuable potential as an AD treatment strategy.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Nanopartículas/química , Peptídeos/metabolismo , Placa Amiloide/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Sequência de Aminoácidos , Peptídeos beta-Amiloides/química , Animais , Autofagia/efeitos dos fármacos , Proteína Beclina-1/química , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/ultraestrutura , Linhagem Celular Tumoral , Quitosana/química , Modelos Animais de Doenças , Humanos , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Nanopartículas/administração & dosagem , Nanopartículas/ultraestrutura , Peptídeos/administração & dosagem , Peptídeos/química , Placa Amiloide/química , Polietilenoglicóis/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...