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1.
Small ; 20(8): e2303473, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37840383

RESUMO

Hierarchical porous materials have attracted the attention of researchers due to their enormous specific surface area, maximized active site utilization efficiency, and unique structure and properties. In this context, metal-organic frameworks (MOFs) offer a unique mix of properties that make them particularly appealing as tunable porous substrates containing highly active sites. This review focuses on recent advances in the types and synthetic strategies of hierarchical porous MOFs and their derived materials. Furthermore, it highlights the relationship between the mass diffusion and transport of hierarchical porous structures and the pore size with examples and simulations, while identifying their potential and limitations. On this basis, how the synthesis conditions affect the structure and electrochemical properties of MOFs based hierarchical porous materials with different structures is discussed, highlighting the prospects and challenges for the synthetization, as well as further scientific research and practical applications. Finally, some insights into current research and future design ideas for advanced MOFs based hierarchical porous materials are presented.

2.
Chem Res Toxicol ; 37(3): 451-454, 2024 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-38417054

RESUMO

Alkyl phosphotriester (alkyl-PTE) lesions in DNA are shown to be poorly repaired; however, little is known about how these lesions impact DNA replication in human cells. Here, we investigated how the SP and RP diastereomers of four alkyl-PTE lesions (alkyl = Me, Et, nPr, or nBu) at the TT site perturb DNA replication in HEK293T cells. We found that these lesions moderately impede DNA replication and that their replicative bypass is accurate. Moreover, CRISPR-Cas9-mediated depletion of Pol η or Pol ζ resulted in significantly attenuated bypass efficiencies for both diastereomers of nPr- and nBu-PTE adducts, and the SP diastereomer of Et-PTE. Diminished bypass efficiencies were also detected for the Rp diastereomer of nPr- and nBu-PTE lesions upon ablation of Pol κ. Together, our study uncovered the impact of the alkyl-PTE lesions on DNA replication in human cells and revealed the roles of individual translesion synthesis DNA polymerases in bypassing these lesions.


Assuntos
Replicação do DNA , Humanos , Células HEK293
3.
J Nat Prod ; 87(1): 160-165, 2024 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-38194474

RESUMO

One novel rearranged pimarane diterpenoid, pestanoid A (1), and two reported molecules, nodulisporenones A (2) and B (3), were discovered from Pestalotiopsis sp. NBUF145 fungus associated with a 62 m deep mesophotic ("twilight") zone Chalinidae sponge. The structures of 1-3 were identified by spectrometry, spectroscopy, quantum-chemical calculations, and X-ray crystallography. Compounds 1 and 2 inhibited bone marrow monocyte osteoclastogenesis in vitro with the IC50 values 4.2 ± 0.2 µM and 3.0 ± 0.4 µM, respectively, without observed cytotoxicity. Both 1 and 2 suppressed the receptor activator of NF-kB ligand-induced MAPK and NF-κB signaling by inhibiting the phosphorylation of ERK1/2-JNK1/2-p38 MAPKs and NF-κB nuclear translocation.


Assuntos
Osteoclastos , Osteogênese , NF-kappa B , Pestalotiopsis , Macrófagos , Abietanos , Ligante RANK
4.
Inflammopharmacology ; 32(2): 975-989, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38429613

RESUMO

Fibrosis is a prevailing pathology in chronic diseases and accounts for 45% of deaths in developed countries. This condition is primarily identified by the transformation of fibroblasts into myofibroblasts and the overproduction of extracellular matrix (ECM) by myofibroblasts. Pterostilbene (PTS) is a natural analogue of resveratrol and is most commonly found in blueberries. Research has shown that PTS exerts a wide range of pharmacological effects, such as antioxidant, anti-inflammatory, and anticancer effects. As a result, PTS has the potential to prevent and cure numerous diseases. Emerging evidence has indicated that PTS can alleviate myocardial fibrosis, renal fibrosis, pulmonary fibrosis, hepatic fibrosis, and colon fibrosis via the inhibition of inflammation, oxidative stress, and fibrogenesis effects in vivo and in vitro, and the potential mechanisms are linked to various pathways, including transforming growth factor-ß1 (TGF-ß1)/small mother against decapentaplegic proteins (Smads) signalling, the reactive oxygen species (ROS)-driven Pitx2c/mir-15b pathway, nuclear factor kappa B (NF-κB) signalling, Kelch-like epichlorohydrin-associated protein-1 (Keap-1)/NF-E2-related factor-2 (Nrf2) cascade, the NLR family pyridine structure domain 3 (NLRP3) pathway, the Janus kinase-2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway, and the Src/STAT3 pathway. In this review, we comprehensively summarize the antifibrotic effects of PTS both in vivo and in vitro and the pharmacological mechanisms, pharmacokinetics, and toxicology of PTS and provide insights into and strategies for exploring promising agents for the treatment of fibrosis.


Assuntos
Estresse Oxidativo , Fibrose Pulmonar , Humanos , Fibrose , Fibrose Pulmonar/tratamento farmacológico , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Antioxidantes/metabolismo , Cirrose Hepática/metabolismo
5.
Angew Chem Int Ed Engl ; 62(22): e202217449, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-36959732

RESUMO

Nickel-based catalysts have been regarded as one of the most promising electrocatalysts for urea oxidation reaction (UOR), however, their activity is largely limited by the inevitable self-oxidation reaction of Ni species (NSOR) during the UOR. Here, we proposed an interface chemistry modulation strategy to trigger the occurrence of UOR before the NSOR via constructing a 2D/2D heterostructure that consists of ultrathin NiO anchored Ru-Co dual-atom support (Ru-Co DAS/NiO). Operando spectroscopic characterizations confirm this unique triggering mechanism on the surface of Ru-Co DAS/NiO. Consequently, the fabricated catalyst exhibits outstanding UOR activity with a low potential of 1.288 V at 10 mA cm-2 and remarkable long-term durability for more than 330 h operation. DFT calculations and spectroscopic characterizations demonstrate that the favorable electronic structure induced by this unique heterointerface endows the catalyst energetically more favorable for the UOR than the NSOR.

6.
Am Nat ; 200(4): 457-466, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36150204

RESUMO

AbstractThis article proposes an evolutionary game theoretical model in which individuals negotiate to reach a compromise settlement on who takes the dominant role in a dominant-subordinate relationship. The negotiation process is formalized by bargaining theory in economics, which makes our model different from alternative models on the formation of dominant-subordinate relationships based on detailed biological mechanisms. We find that evolution leads to a "cooperative" ("selfish") behavior when an individual takes the dominant (subordinate) role. For example, consider two Polistes wasps in a nest-building pair who try to determine the role assignment of the queen and the subordinate cofoundress. After the roles are assigned, the queen chooses between either sharing or monopolizing reproduction, and the subordinate chooses between exerting either a high or a low effort in rearing or foraging activities. According to our model's prediction, the queen's behavior (sharing reproduction) increases the collective fitness of the colony but potentially hurts her reproductive interest, while the subordinate's behavior (exerting a low effort) decreases the productivity of the colony but helps her to save energy. Such a behavior pair is evolutionarily stable because it guarantees an individual to have the comparative advantage in taking the dominant role against any other individuals via negotiation. This result may shed new light on understanding the formation of dominant-subordinate relationships. In addition, agnostic of detailed biological mechanisms, our mathematical formulation of dominant-subordinate relationships might also have wide applications in animal behavior and beyond, as its empirical support is found in article wasps and humans.


Assuntos
Negociação , Vespas , Animais , Comportamento Animal , Feminino , Humanos , Reprodução
7.
Bioorg Chem ; 129: 106159, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36155091

RESUMO

BACKGROUND: The damage of podocytes is a primary hallmark of lupus nephritis (LN). Therefore, finding an effective way to inhibit the podocyte injury is important for improving the survival and development of patients with LN. Eucalyptus robusta exhibits anti-inflammatory properties. However, whether Formyl phloroglucinol meroterpenoids (FPMs), which are specialized metabolites of the genus Eucalyptus, is an anti-inflammatory active ingredient of E. robusta remains to be determined. PURPOSE: This study asimed to identify novel FPMs from E. robusta and investigated their anti-inflammatory effects. METHODS: Various separation methods were used to isolate and identify the compounds in the PE extract of E. robusta. The structures of the isolates were determined using 1D/2D NMR data and electron circular dichroism (ECD) calculations. The level of mitochondrial reactive oxygen species (ROS) level and mitochondrial membrane potential (MMP) of the podocyte cell line, MPC-5, were assessed using a multifunctional microplate reader combined with flow cytometry and fluorescence microscopy. RESULTS: Eight novel FPMs (1-8, Eucarbwenstols A-H, Fig. 1) and 15 known FPMs (9-23) were purified from the PE extract of E. robusta. It is noteworthy that compound 1 possesses an unprecedented FPM carbon skeleton. Among these compounds, compounds 1, 2, 4 and 5 showed the most promising potential for protecting MPC-5 cells because pretreatment with pro-inflammatory cytokines TGF-ß, IFN-α and IL-6 decreased ROS production and ameliorated the mitochondrial state. CONCLUSIONS: Our research contributes to the characterization of E. robusta constituents and highlights the anti-inflammatory effects of FPMs.


Assuntos
Eucalyptus , Humanos , Eucalyptus/química , Potencial da Membrana Mitocondrial , Espécies Reativas de Oxigênio/metabolismo , Floroglucinol/química , Extratos Vegetais/farmacologia
8.
Acta Radiol ; : 2841851221142783, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36503262

RESUMO

BACKGROUND: Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare autoimmune disease characterized by skin or osteoarticular damage. SAPHO syndrome is often misdiagnosed or missed diagnosis due to lack of overall understanding of the disease by clinicians. PURPOSE: To analyze the clinical symptoms and imaging features of six Han patients with SAPHO syndrome in order to provide reference for doctors to diagnose SAPHO syndrome. MATERIAL AND METHODS: This study retrospectively analyzed the clinical data of six Han patients with SAPHO syndrome. RESULTS: All six Han patients with SAPHO syndrome had severe acne or pustulosis of the hands and feet, and all of them had osteoarticular damage, including five cases involving the sternoclavicular joint. Some patients showed a specific and typical "bull's head" sign on 99mTc-labeled methylene diphosphonate bone imaging. Among the six patients recruited, there was one thoracic vertebra, one cervical vertebra, one sacroiliac joint, and one peripheral joint involvement. Two patients had limited activity due to severe osteoarticular damage. CONCLUSION: Due to the atypical clinical symptoms of SAPHO syndrome, most patients will experience a tortuous and long diagnostic process, while a correct understanding and timely intervention of SAPHO syndrome are essential to improve the prognosis of patients.

9.
Acta Biotheor ; 70(3): 17, 2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35713787

RESUMO

We propose a novel model to explain the mechanisms underlying dominance hierarchical structures. Guided by a predetermined social convention, agents with limited cognitive abilities optimize their strategies in a Hawk-Dove game. We find that several commonly observed hierarchical structures in nature such as linear hierarchy and despotism, emerge as the total fitness-maximizing social structures given different levels of cognitive abilities.


Assuntos
Cognição , Predomínio Social , Animais
10.
Sensors (Basel) ; 22(8)2022 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-35459076

RESUMO

In atmospheric laser communication, a beam is transmitted through an atmospheric channel, and the photocurrent output from a quadrant detector (QD) used as the tracking sensor fluctuates significantly. To ensure uninterrupted communication and to adapt to such fluctuations, in this paper we apply logarithmic amplifiers to process the output signals of a QD. To further improve the measurement accuracy of the spot position, we firstly propose an integral infinite log-ratio algorithm (IILRA) and an integral infinity log-ratio algorithm based on the signal-to-noise ratio (BSNR-IILRA) through analysis of the factors influencing the measurement error considering the signal-to-noise ratio (SNR) parameter. Secondly, the measurement error of the two algorithms under different SNRs and their variations are analyzed. Finally, a spot position detection experiment platform is built to correctly and efficiently verify the two algorithms. The experimental results show that when the SNR is 54.10 dB, the maximum error and root mean square error of the spot position of the IILRA are 0.0054 mm and 0.0039 mm, respectively, which are less than half those of the center approximation algorithm (CAA). When the SNR is 23.88 dB, the maximum error and root mean square error of the spot position of the BSNR-IILRA are 0.0046 mm and 0.0034 mm, respectively, which are one-thirtieth and one-twentieth of the CAA, respectively. The spot position measurement accuracy of the two proposed algorithms is significantly improved compared with the CAA.

11.
Angew Chem Int Ed Engl ; 61(32): e202205946, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35638304

RESUMO

Manipulating the coordination environment of the active center via anion modulation to reveal tailored activity and selectivity has been widely achieved, especially for carbon-based single-atom site catalysts (SACs). However, tuning ligand fields of the active center by single-site metal cation regulation and identifying the effects on the resulting electronic configuration is seldom explored. Herein, we propose a single-site Ru cation coordination strategy to engineer the electronic properties by constructing a Ru/LiCoO2 SAC with atomically dispersed Ru-Co pair sites. Benefitting from the strong electronic coupling between Ru and Co sites, the catalyst possesses an enhanced electrical conductivity and achieves near-optimal oxygen adsorption energies. Therefore, the optimized catalyst delivers superior oxygen evolution reaction (OER) activity with low overpotential, the high mass activity of 1000 A goxide -1 at a small overpotential of 335 mV, and excellent long-term stability. It also exhibits rapid kinetics with superior rate capability and outstanding durability in a zinc-air battery.

12.
J Biol Chem ; 295(26): 8775-8783, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32381504

RESUMO

Alkyl phosphotriester (alkyl-PTE) lesions are frequently induced in DNA and are resistant to repair. Here, we synthesized and characterized methyl (Me)- and n-butyl (nBu)-PTEs in two diastereomeric configurations (Sp and Rp) at six different flanking dinucleotide sites, i.e. XT and TX (X = A, C, or G), and assessed how these lesions impact DNA replication in Escherichia coli cells. When single-stranded vectors contained an Sp-Me-PTE in the sequence contexts of 5'-AT-3', 5'-CT-3', or 5'-GT-3', DNA replication was highly efficient and the replication products for all three sequence contexts contained 85-90% AT and 5-10% TG. Thus, the replication outcome was largely independent of the identity of the 5' nucleotide adjacent to an Sp-Me-PTE. Furthermore, replication across these lesions was not dependent on the activities of DNA polymerases II, IV, or V; Ada, a protein involved in adaptive response and repair of Sp-Me-PTE in E. coli, however, was essential for the generation of the mutagenic products. Additionally, the Rp diastereomer of Me-PTEs at XT sites and both diastereomers of Me-PTEs at TX sites exhibited error-free replication bypass. Moreover, Sp-nBu-PTEs at XT sites did not strongly impede DNA replication, and other nBu-PTEs displayed moderate blockage effects, with none of them being mutagenic. Taken together, these findings provide in-depth understanding of how alkyl-PTE lesions are recognized by the DNA replication machinery in prokaryotic cells and reveal that Ada contributes to mutagenesis of Sp-Me-PTEs in E. coli.


Assuntos
Dano ao DNA , Replicação do DNA , DNA Bacteriano/genética , Proteínas de Escherichia coli/metabolismo , Escherichia coli/genética , O(6)-Metilguanina-DNA Metiltransferase/metabolismo , Fatores de Transcrição/metabolismo , Alquilação , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Deleção de Genes , Mutagênese , O(6)-Metilguanina-DNA Metiltransferase/genética , Fatores de Transcrição/genética
13.
Chem Res Toxicol ; 34(3): 695-698, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33417436

RESUMO

Alkylation represents a main form of DNA damage. The N2 position of guanine is frequently alkylated in DNA. The SOS-induced polymerases have been shown to be capable of bypassing various DNA damage products in Escherichia coli. Herein, we explored the influences of four N2-alkyl-dG lesions (alkyl = ethyl, n-butyl, isobutyl, or sec-butyl) on DNA replication in AB1157 E. coli cells and the corresponding strains with polymerases (Pol) II, IV, and V being individually or simultaneously knocked out. We found that N2-Et-dG is slightly less blocking to DNA replication than the N2-Bu-dG lesions, which display very similar replication bypass efficiencies. Additionally, Pol II and, to a lesser degree, Pol IV and Pol V are required for the efficient bypass of the N2-alkyl-dG adducts, and none of these lesions was mutagenic. Together, our results support that the efficient replication across small N2-alkyl-dG DNA adducts in E. coli depends mainly on Pol II.


Assuntos
Adutos de DNA/metabolismo , DNA Polimerase II/metabolismo , DNA Bacteriano/metabolismo , Desoxiguanosina/metabolismo , Escherichia coli/metabolismo , Adutos de DNA/química , Replicação do DNA , Desoxiguanosina/análogos & derivados , Desoxiguanosina/química , Escherichia coli/citologia , Estrutura Molecular
14.
Anal Chem ; 92(4): 3373-3379, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-31941278

RESUMO

Single-atom nanozymes (SAzymes), as novel nanozymes with atomically dispersed active sites, are of great importance in the development of nanozymes for their high catalytic activities, the maximum utilization efficiency of metal atoms, and the simple model of active sites. Herein, the peroxidase-like SAzymes with high-concentration Cu sites on carbon nanosheets (Cu-N-C) were synthesized through a salt-template strategy. With the densely distributed active Cu atoms (∼5.1 wt %), the Cu-N-C SAzymes exhibit remarkable activity to mimic natural peroxidase. Integrating Cu-N-C SAzymes with natural acetylcholinesterase and choline oxidase, three-enzyme-based cascade reaction system was constructed for the colorimetric detection of acetylcholine and organophosphorus pesticides. This work not only provides a strategy to synthesize SAzymes with abundant active sites but also gives some new insights for robust nanozyme biosensing systems.


Assuntos
Acetilcolina/análise , Acetilcolinesterase/metabolismo , Oxirredutases do Álcool/metabolismo , Técnicas Biossensoriais , Cobre/metabolismo , Compostos Organofosforados/análise , Praguicidas/análise , Acetilcolina/metabolismo , Acetilcolinesterase/química , Oxirredutases do Álcool/química , Carbono/química , Carbono/metabolismo , Cobre/química , Nanopartículas/química , Nanopartículas/metabolismo , Compostos Organofosforados/metabolismo , Praguicidas/metabolismo
15.
Microb Pathog ; 140: 103940, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31863839

RESUMO

H9N2 viruses can cause great economic losses to the domestic poultry industry when co-infected with other influenza viruses or pathogens. . To better understand the molecular characteristics of H9N2 avian influenza viruses (AIVs) and analyze the genetic evolutionary relationship, we isolated three H9N2 subtypes AIVs from nasopharyngeal swab specimens from the three cases reported in Anhui province since 2015, and systematically reviewed the genome-wide data of 21 poultry--isolated H9N2 viruses during 1998-2017. The six internal genes of three human-isolated viruses and recent poultry-isolated viruses (since 2014) in Anhui province presented high gene homologies with HPAI H7N9, even including H10N8 and H5N6. The three human-isolated H9N2 AIVs and poultry-isolated viruses (since 2008) in Anhui province were highly similar, and classified into genotype S. Seven N-linked potential glycosylation sites in the HA protein were detected in the three human-isolated viruses, which also appeared in poultry-isolated H9N2 AIVs. None of the human-isolated H9N2 AIVs had the I368V mutation in PB1 protein, but all the poultry-isolated H9N2 viruses in 2017 carried this mutation. Multidisciplinary, cross-regional and cross-sectoral approaches are warranted to address complex public health challenges and achieve the goal of 'one health'.


Assuntos
Subtipo H7N9 do Vírus da Influenza A/genética , Vírus da Influenza A Subtipo H9N2/genética , Influenza Aviária/virologia , Aves Domésticas/virologia , Animais , Galinhas , China/epidemiologia , Genoma Viral , Humanos , Incidência , Subtipo H7N9 do Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A Subtipo H9N2/isolamento & purificação , Influenza Aviária/transmissão , Influenza Humana/transmissão , Influenza Humana/virologia , Filogenia , Doenças das Aves Domésticas/transmissão , Doenças das Aves Domésticas/virologia , Prevalência
16.
Chem Res Toxicol ; 33(2): 308-311, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-31916443

RESUMO

Genome integrity is constantly challenged by endogenous or exogenous genotoxic agents, which can give rise to various DNA adducts. After metabolic activation, tobacco-specific nitrosamines N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) can lead to pyridyloxobutylphosphotriesters (POB-PTEs) in DNA. Here, we synthesized oligodeoxyribonucleotides containing a site-specifically inserted SP- or RP-POB-PTE flanked by two thymidines, and we examined the impact that these lesions have on DNA replication in Escherichia coli cells. We found that these two lesions are not strong impediments to DNA replication, and their replicative bypass is not modulated by genetic depletion of the three SOS-induced DNA polymerases or Ada protein. In addition, neither SP- nor RP-POB-PTEs was mutagenic in E. coli cells. Together, our study unveiled, for the first time, the influence of tobacco-specific nitrosamine-induced POB-PTE lesions on DNA replication in vivo.


Assuntos
Adutos de DNA/metabolismo , Replicação do DNA , Escherichia coli/química , Escherichia coli/metabolismo , Organofosfonatos/metabolismo , Piridinas/metabolismo , Adutos de DNA/química , Escherichia coli/citologia , Escherichia coli/genética , Estrutura Molecular , Organofosfonatos/química , Piridinas/química
17.
Nucleic Acids Res ; 46(8): 4013-4021, 2018 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-29514270

RESUMO

Exposure to many endogenous and exogenous agents can give rise to DNA alkylation, which constitutes a major type of DNA damage. Among the DNA alkylation products, alkyl phosphotriesters have relatively high frequencies of occurrence and are resistant to repair in mammalian tissues. However, little is known about how these lesions affect the efficiency and fidelity of DNA replication in cells or how the replicative bypass of these lesions is modulated by translesion synthesis DNA polymerases. In this study, we synthesized oligodeoxyribonucleotides containing four pairs (Sp and Rp) of alkyl phosphotriester lesions at a defined site, and examined how these lesions are recognized by DNA replication machinery in Escherichia coli cells. We found that the Sp diastereomer of the alkyl phosphotriester lesions could be efficiently bypassed, whereas the Rp counterparts moderately blocked DNA replication. Moreover, the Sp-methyl phosphotriester induced TT→GT and TT→GC mutations at the flanking TT dinucleotide site, and the induction of these mutations required Ada protein, which is known to remove efficiently the methyl group from the Sp-methyl phosphotriester. Together, our study provided a comprehensive understanding about the recognition of alkyl phosphotriester lesions by DNA replication machinery in cells, and revealed for the first time the Ada-dependent induction of mutations at the Sp-methyl phosphotriester site.


Assuntos
Dano ao DNA , Replicação do DNA , Escherichia coli/genética , Mutação , Alquilação , Reparo do DNA , DNA Bacteriano/química , DNA Bacteriano/metabolismo , DNA Polimerase Dirigida por DNA/metabolismo , Escherichia coli/enzimologia , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Mutagênese , O(6)-Metilguanina-DNA Metiltransferase/metabolismo , Estereoisomerismo , Fatores de Transcrição/metabolismo
18.
Proc Natl Acad Sci U S A ; 114(34): E7082-E7091, 2017 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-28784758

RESUMO

Alkylated DNA lesions, induced by both exogenous chemical agents and endogenous metabolites, interfere with the efficiency and accuracy of DNA replication and transcription. However, the molecular mechanisms of DNA alkylation-induced transcriptional stalling and mutagenesis remain unknown. In this study, we systematically investigated how RNA polymerase II (pol II) recognizes and bypasses regioisomeric O2-, N3-, and O4-ethylthymidine (O2-, N3-, and O4-EtdT) lesions. We observed distinct pol II stalling profiles for the three regioisomeric EtdT lesions. Intriguingly, pol II stalling at O2-EtdT and N3-EtdT sites is exacerbated by TFIIS-stimulated proofreading activity. Assessment for the impact of the EtdT lesions on individual fidelity checkpoints provided further mechanistic insights, where the transcriptional lesion bypass routes for the three EtdT lesions are controlled by distinct fidelity checkpoints. The error-free transcriptional lesion bypass route is strongly favored for the minor-groove O2-EtdT lesion. In contrast, a dominant error-prone route stemming from GMP misincorporation was observed for the major-groove O4-EtdT lesion. For the N3-EtdT lesion that disrupts base pairing, multiple transcriptional lesion bypass routes were found. Importantly, the results from the present in vitro transcriptional studies are well correlated with in vivo transcriptional mutagenesis analysis. Finally, we identified a minor-groove-sensing motif from pol II (termed Pro-Gate loop). The Pro-Gate loop faces toward the minor groove of RNA:DNA hybrid and is involved in modulating the translocation of minor-groove alkylated DNA template after nucleotide incorporation opposite the lesion. Taken together, this work provides important mechanistic insights into transcriptional stalling, lesion bypass, and mutagenesis of alkylated DNA lesions.


Assuntos
DNA/genética , Transcrição Gênica , Alquilação , DNA/metabolismo , Reparo do DNA , Replicação do DNA , Humanos , Mutagênese , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/metabolismo
19.
BMC Surg ; 20(1): 264, 2020 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-33129303

RESUMO

BACKGROUND: It is rare that drains cannot be removed after surgery, however, this situation cannot be completely avoided, and is also hard to deal with. The main reason for a tethered drain is inadvertent suture fixation. At present, no effective way was published or widely accepted to locate the tethered drain. METHODS: Three cases of orthopedic trauma patients experienced unsuccessful removal of the drain after surgery. The ultrasound was used to locate the sutured site of the drain. Based on the sliding sign and vanishing point which can be detected by the ultrasound, the sutured site of the drain can be clearly identified. Finally, the suture was loosened through a small incision, and the drain was completely removed. RESULTS: The surgical procedure was very successful in all patients. The tethered drain was quickly and completely removed through a small incision with locating by ultrasound. Intravenous antibiotics were administered within 24 h after surgery, and no wound or deep infections occurred. CONCLUSIONS: Ultrasound can be used to locate a tethered drain based on the sliding sign. This method can simplify the release procedure and achieve fast removal of the drain. Furthermore, it will help lower the risk of a retained drain and soft tissue complications.


Assuntos
Remoção de Dispositivo , Drenagem , Corpos Estranhos/diagnóstico por imagem , Procedimentos Ortopédicos/efeitos adversos , Técnicas de Sutura/efeitos adversos , Ultrassonografia , Adulto , Animais , Remoção de Dispositivo/métodos , Drenagem/instrumentação , Feminino , Corpos Estranhos/etiologia , Corpos Estranhos/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Anatômicos , Procedimentos Ortopédicos/métodos , Suturas/efeitos adversos , Suínos
20.
J Stroke Cerebrovasc Dis ; 28(6): e60-e63, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30962082

RESUMO

For malignant cerebral venous sinus thrombosis (CVST) complicated with cerebral hernia, decompressive craniectomy may be life-saving, and thrombectomy combined with thrombolysis may obtain better outcomes. This report describes an approach performed on 2 patients diagnosed with CVST combined both thrombectomy and thrombolysis with decompressive craniectomy through incising the superior sagittal sinus. The general procedure of the operation is as follows. The anterior part of the superior sagittal sinus was exposed firstly. After cutting the dura matter for decompression, a superior sagittal sinus incision was taken to detect sinus thrombus. In order to facilitate hemostasis during detecting the sagittal sinus, 2 silk sutures were sutured along the incision. The incision was 5 millimeters long approximately along the middle line of the front third of the superior sagittal sinus. A silicone intubation was inserted in the sinus through the incision. Thrombus was seen in the suction tube. At a depth of about 10 cm, while it is difficult to penetrate the tube, we used the gelatin sponge to cover the sinus incision and fixed the suture lines after cross-knotting. The silicone intubation was drawn out through the forehead and connected to external micro pump for injecting anticoagulant drugs, then cut the dura mater into star-shaped and discard bone flap for decompression. Absorbable artificial dura mater was used to repair bilateral dura mater, respectively. At last, connect the catheter to the micro pump for pumping anticoagulant. After operation, the 2 patients received thrombolysis through the catheter placed in the sinus. Both of them recovered well. There was no incision-related bleeding occurred after surgery. Both the patients achieved incredibly good outcomes. For patients with malignant cerebral venous sinus thrombosis, acute cerebral hernia or cerebral hernia tendency, it may be an effective approach combined both thrombectomy and thrombolysis with decompressive craniectomy through incising the superior sagittal sinus.


Assuntos
Craniectomia Descompressiva , Encefalocele/terapia , Trombose dos Seios Intracranianos/terapia , Trombectomia/métodos , Terapia Trombolítica , Adulto , Angiografia Cerebral/métodos , Terapia Combinada , Encefalocele/diagnóstico por imagem , Encefalocele/etiologia , Feminino , Humanos , Angiografia por Ressonância Magnética , Flebografia/métodos , Trombose dos Seios Intracranianos/complicações , Trombose dos Seios Intracranianos/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Resultado do Tratamento
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