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1.
Ren Fail ; 46(1): 2303395, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38264967

RESUMO

BACKGROUND: Acute kidney injury (AKI) is a common and serious complication in severe acute pancreatitis (AP), associated with high mortality rate. Early detection of AKI is crucial for prompt intervention and better outcomes. This study aims to develop and validate predictive models using machine learning (ML) to identify the onset of AKI in patients with AP. METHODS: Patients with AP were extracted from the MIMIC-IV database. We performed feature selection using the random forest method. Model construction involved an ensemble of ML, including random forest (RF), support vector machine (SVM), k-nearest neighbors (KNN), naive Bayes (NB), neural network (NNET), generalized linear model (GLM), and gradient boosting machine (GBM). The best-performing model was fine-tuned and evaluated through split-set validation. RESULTS: We analyzed 1,235 critically ill patients with AP, of which 667 cases (54%) experienced AKI during hospitalization. We used 49 variables to construct models, including GBM, GLM, KNN, NB, NNET, RF, and SVM. The AUC for these models was 0.814 (95% CI, 0.763 to 0.865), 0.812 (95% CI, 0.769 to 0.854), 0.671 (95% CI, 0.622 to 0.719), 0.812 (95% CI, 0.780 to 0.864), 0.688 (95% CI, 0.624 to 0.752), 0.809 (95% CI, 0.766 to 0.851), and 0.810 (95% CI, 0.763 to 0.856) respectively. In the test set, the GBM's performance was consistent, with an area of 0.867 (95% CI, 0.831 to 0.903). CONCLUSIONS: The GBM model's precision is crucial, aiding clinicians in identifying high-risk patients and enabling timely interventions to reduce mortality rates in critical care.


Assuntos
Injúria Renal Aguda , Pancreatite , Humanos , Doença Aguda , Teorema de Bayes , Estado Terminal , Aprendizado de Máquina
2.
Brief Bioinform ; 22(6)2021 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-34226915

RESUMO

Pseudouridine is a ubiquitous RNA modification type present in eukaryotes and prokaryotes, which plays a vital role in various biological processes. Almost all kinds of RNAs are subject to this modification. However, it remains a great challenge to identify pseudouridine sites via experimental approaches, requiring expensive and time-consuming experimental research. Therefore, computational approaches that can be used to perform accurate in silico identification of pseudouridine sites from the large amount of RNA sequence data are highly desirable and can aid in the functional elucidation of this critical modification. Here, we propose a new computational approach, termed Porpoise, to accurately identify pseudouridine sites from RNA sequence data. Porpoise builds upon a comprehensive evaluation of 18 frequently used feature encoding schemes based on the selection of four types of features, including binary features, pseudo k-tuple composition, nucleotide chemical property and position-specific trinucleotide propensity based on single-strand (PSTNPss). The selected features are fed into the stacked ensemble learning framework to enable the construction of an effective stacked model. Both cross-validation tests on the benchmark dataset and independent tests show that Porpoise achieves superior predictive performance than several state-of-the-art approaches. The application of model interpretation tools demonstrates the importance of PSTNPs for the performance of the trained models. This new method is anticipated to facilitate community-wide efforts to identify putative pseudouridine sites and formulate novel testable biological hypothesis.


Assuntos
Biologia Computacional/métodos , Pseudouridina/química , RNA/química , RNA/genética , Algoritmos , Aprendizado de Máquina , Pseudouridina/genética , Reprodutibilidade dos Testes , Análise de Sequência de RNA/métodos
3.
Hum Genomics ; 16(1): 29, 2022 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-35906672

RESUMO

BACKGROUND: Spinocerebellar ataxia type 1 (SCA1) is a neurodegenerative disease caused by a polyglutamine expansion in the ataxin-1 protein. The pathogenic mechanism resulting in SCA1 is still unclear. Protein-protein interactions affect the function and stability of ataxin-1. METHODS: Wild-type and mutant ataxin-1 were expressed in HEK-293T cells. The levels of expression were assessed using real-time polymerase chain reaction (PCR) and Western blots. Co-immunoprecipitation was done in HEK-293T cells expressing exogenous wild-type and mutant ataxin-1 using anti-Flag antibody following by tandem affinity purification in order to study protein-protein interactions. The candidate interacting proteins were validated by immunoprecipitation. Chromatin immunoprecipitation and high-throughput sequencing and RNA immunoprecipitation and high-throughput sequencing were performed using HEK-293T cells expressing wild-type or mutant ataxin-1. RESULTS: In this study using HEK-293T cells, we found that wild-type ataxin-1 interacted with MCM2, GNAS, and TMEM206, while mutant ataxin-1 lost its interaction with MCM2, GNAS, and TMEM206. Two ataxin-1 binding targets containing the core GGAG or AAAT were identified in HEK-293T cells using ChIP-seq. Gene Ontology analysis of the top ataxin-1 binding genes identified SLC6A15, NTF3, KCNC3, and DNAJC6 as functional genes in neurons in vitro. Ataxin-1 also was identified as an RNA-binding protein in HEK-293T cells using RIP-seq, but the polyglutamine expansion in the ataxin-1 had no direct effects on the RNA-binding activity of ataxin-1. CONCLUSIONS: An expanded polyglutamine tract in ataxin-1 might interfere with protein-protein or protein-DNA interactions but had little effect on protein-RNA interactions. This study suggested that the dysfunction of protein-protein or protein-DNA interactions is involved in the pathogenesis of SCA1.


Assuntos
Sistemas de Transporte de Aminoácidos Neutros , Ataxias Espinocerebelares , Ataxina-1/genética , Ataxina-1/metabolismo , Ataxinas/genética , Ataxinas/metabolismo , Humanos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/genética , RNA , Ataxias Espinocerebelares/genética , Ataxias Espinocerebelares/patologia
4.
Med Mycol ; 61(10)2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37777835

RESUMO

Candida tropicalis, a human conditionally pathogenic yeast, is distributed globally, especially in Asia-Pacific. The increasing morbidity and azole resistance of C. tropicalis have made clinical treatment difficult. The correlation between clonality and antifungal susceptibility of clinical C. tropicalis isolates has been reported. To study the putative correlation in C. tropicalis isolated from normally sterile body fluid specimens and explore the distinct clonal complex (CC) in Hefei, 256 clinical C. tropicalis isolates were collected from four teaching hospitals during 2016-2019, of which 30 were fluconazole-resistant (FR). Genetic profiles of 63 isolates, including 30 FR isolates and 33 fluconazole-susceptible (FS) isolates, were characterized using multilocus sequence typing (MLST). Phylogenetic analysis of the data was conducted using UPGMA (unweighted pair group method with arithmetic averages) and the minimum spanning tree algorithm. MLST clonal complexes (CCs) were analyzed using the goeBURST package. Among 35 differentiated diploid sequence types (DSTs), 16 DSTs and 1 genotype were identified as novel. A total of 35 DSTs were assigned to five major CCs based on goeBURST analysis. CC1 (containing DST376, 505, 507, 1221, 1222, 1223, 1226, and 1229) accounted for 86.7% (26/30) of the FR isolates. However, the genetic relationships among the FS isolates were relatively decentralized. The local FR CC1 belongs to a large fluconazole non-susceptible CC8 in global isolates, of which the putative founder genotype was DST225. The putative correlation between MLST types and antifungal susceptibility of clinical C. tropicalis isolates in Hefei showed that DSTs are closely related to FR clones.


A local prevalent FR CC1, accounted for 86.7% of the FR isolates in Hefei, China, which showed that fluconazole resistance is closely related to the genetic background, a finding of great value to local medical treatment and possible reasons for the increase in azole resistance of Candida tropicalis.


Assuntos
Líquidos Corporais , Fluconazol , Humanos , Fluconazol/farmacologia , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candida tropicalis/genética , Tipagem de Sequências Multilocus/veterinária , Filogenia , Farmacorresistência Fúngica , China , Células Clonais , Testes de Sensibilidade Microbiana/veterinária
5.
Phys Chem Chem Phys ; 25(22): 15153-15161, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37221896

RESUMO

N 6-Hydroxymethyladenosine (hm6A) and N6-formyladenosine (f6A) are two important intermediates during the demethylation process of N6-methyladenosine (m6A), which has been proven to show epigenetic function in mRNA. However, there is no knowledge about how the chemical integrity and stability could be altered when these two nucleosides are exposed to ultraviolet (UV) radiation. Herein, we report the first study on excited state dynamics of hm6A and f6A in solutions by using femtosecond time-resolved spectroscopy and quantum chemistry calculations. Surprisingly, triplet excited species are clearly identified in both hm6A and f6A after UV excitation, which is in sharp contrast to the 10-3 level triplet yield of adenosine scaffolds. Moreover, the doorway states leading to triplet states are found to be an intramolecular charge transfer state and a lower-lying dark nπ* state in hm6A and f6A, respectively. These discoveries pave the way to further study their effects on RNA strands and provide insight for understanding RNA photochemistry.


Assuntos
Nucleosídeos , RNA , RNA/química , RNA Mensageiro , Análise Espectral , Epigênese Genética
6.
Chaos ; 33(2): 023120, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36859197

RESUMO

Neuromorphic computing provides unique computing and memory capabilities that could break the limitation of conventional von Neumann computing. Toward realizing neuromorphic computing, fabrication and synthetization of hardware elements and circuits to emulate biological neurons are crucial. Despite the striking progress in exploring neuron circuits, the existing circuits can only reproduce monophasic action potentials, and no studies report on circuits that could emulate biphasic action potentials, limiting the development of neuromorphic devices. Here, we present a simple third-order memristive circuit built with a classical symmetrical Chua Corsage Memristor (SCCM) to accurately emulate biological neurons and show that the circuit can reproduce monophasic action potentials, biphasic action potentials, and chaos. Applying the edge of chaos criterion, we calculate that the SCCM and the proposed circuit have the symmetrical edge of chaos domains with respect to the origin, which plays an important role in generating biphasic action potentials. Also, we draw a parameter classification map of the proposed circuit, showing the edge of chaos domain (EOCD), the locally active domain, and the locally passive domain. Near the calculated EOCD, the third-order circuit generates monophasic action potentials, biphasic action potentials, chaos, and ten types of symmetrical bi-directional neuromorphic phenomena by only tuning the input voltage, showing a resemblance to biological neurons. Finally, a physical SCCM circuit and some experimentally measured neuromorphic waveforms are exhibited. The experimental results agree with the numerical simulations, verifying that the proposed circuit is suitable as artificial neurons.

7.
Immunol Invest ; 51(5): 1198-1210, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33929277

RESUMO

Human leukocyte antigen (HLA) class II alleles are considered to play a key role in the progress of rheumatoid arthritis (RA). This study was carried out to investigate the presence of HLA class II alleles and their influence on disease risk and autoantibody status in Chinese Han patients with RA. Here, HLA-DRB1, DQB1 and DPB1 genotyping was performed in 125 RA patients and 120 healthy controls by using the next-generation sequencing (NGS). Strong positive associations were shown between high-resolution typed HLA-DRB1*04:05:01, DRB1*10:01:01, DQB1*04:01:01, DPB1*02:01:02 and RA patients. Moreover, the haplotypes HLA-DRB1*04:05:01~ DQB1*04:01:01 and HLA-DRB1*10:01:01~ DQB1*05:01:01 were found to be more frequent in RA populations than in healthy controls. These possible susceptible HLA alleles (HLA-DRB1*04:05:01, DRB1*10:01:01, DQB1*04:01:01 and DPB1*02:01:02) also showed higher frequencies in seropositive RA patients as compared to normal controls. The present study provided evidence that alleles HLA-DRB1*04:05:01, DRB1*10:01:01, DQB1*04:01:01 and DPB1*02:01:02 constituted RA risk alleles, and haplotypes HLA-DRB1*04:05:01~ DQB1*04:01:01, HLA-DRB1*10:01:01~ DQB1*05:01:01 also showed prevalence in Chinese Han patients with RA. Serological results preliminary demonstrated patients carrying RA-risk HLA alleles might elevate the serum level of anti-citrullinated protein antibodies and rheumatoid factor and affect RA progression.


Assuntos
Artrite Reumatoide , Cadeias beta de HLA-DP , Cadeias beta de HLA-DQ , Cadeias HLA-DRB1 , Alelos , Anticorpos Antiproteína Citrulinada/sangue , Anticorpos Antiproteína Citrulinada/genética , Anticorpos Antiproteína Citrulinada/imunologia , Artrite Reumatoide/sangue , Artrite Reumatoide/epidemiologia , Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Autoanticorpos/sangue , Autoanticorpos/genética , Autoanticorpos/imunologia , China/epidemiologia , Frequência do Gene , Predisposição Genética para Doença/genética , Cadeias beta de HLA-DP/genética , Cadeias beta de HLA-DP/imunologia , Cadeias beta de HLA-DQ/genética , Cadeias beta de HLA-DQ/imunologia , Cadeias HLA-DRB1/genética , Cadeias HLA-DRB1/imunologia , Haplótipos , Humanos , Risco
8.
Phys Chem Chem Phys ; 24(2): 875-882, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34908064

RESUMO

Selenium nucleic acids possess unique properties and have been demonstrated to have a wide range of applications such as in DNA X-ray crystallography and novel medical therapies. However, as a heavy atom, selenium substitution may easily alter the photophysical properties of a nucleic acid by red-shifting the absorption spectra and introducing effective intersystem crossing to triplet excited states. In present work, the excited state dynamics of a naturally occurring selenium substituted uracil (2-selenuracil, 2SeU) is studied by using femtosecond transient absorption spectroscopy as well as quantum chemistry calculations. Ultrafast intersystem crossing to the lowest triplet state (T1) and effective non-radiative decay of this state to the ground state (S0) are demonstrated in the neutral form 2SeU. However, the triplet lifetime of the deprotonated form 2SeU is found to be almost one order of magnitude longer than that in the neutral one. Quantum chemistry calculations indicate that the short triplet lifetime in 2SeU is due to excited state population decay through a crossing point between T1 and S0. In the deprotonated form, shortening the N1-C2 bond length makes the structural distortion more difficult and brings a larger energy barrier on the pathway to the T1/S0 crossing point, resulting in one order of magnitude increase of the triplet state lifetime. Our study reveals one key factor to regulate the triplet lifetime of 2SeU and sets the stage to further investigate the photophysical and photochemical properties of 2SeU-containing DNA/RNA duplexes.


Assuntos
Selênio/química , Uracila/química , Teoria da Densidade Funcional , Simulação de Dinâmica Molecular , Prótons
9.
Chaos ; 32(9): 093101, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36182357

RESUMO

Memristor-based neuromorphic systems have a neuro-bionic function, which is critical for possibly overcoming Moore's law limitation and the von Neumann bottleneck problem. To explore neural behaviors and complexity mechanisms in memristive circuits, this paper proposes an N-type locally active memristor, based on which a third-order memristive circuit is constructed. Theoretical analysis shows that the memristive circuit can exhibit not only various action potentials but also self-sustained oscillation and chaos. Based on Chua's theory of local activity, this paper finds that the neural behaviors and chaos emerge near the edge of chaos through subcritical Hopf bifurcation, in which the small unstable limit cycle is depicted by the dividing line between the attraction basin of the large stable limit cycle and the attraction basin of the stable equilibrium point. Furthermore, an analog circuit is designed to imitate the action potentials and chaos, and the simulation results are in agreement with the theoretical analysis.


Assuntos
Potenciais de Ação , Simulação por Computador
10.
Chaos ; 31(6): 063114, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34241294

RESUMO

To explore the complexity of the locally active memristor and its application circuits, a tristable locally active memristor is proposed and applied in periodic, chaotic, and hyperchaotic circuits. The quantitative numerical analysis illustrated the steady-state switching mechanism of the memristor using the power-off plot and dynamic route map. For any pulse amplitude that can achieve a successful switching, there must be a minimum pulse width that enables the state variable to move beyond the attractive region of the equilibrium point. As local activity is the origin of complexity, the locally active memristor can oscillate periodically around a locally active operating point when connected in series with a linear inductor. A chaotic oscillation evolves from periodic oscillation by adding a capacitor in the periodic oscillation circuit, and a hyperchaotic oscillation occurs by further putting an extra inductor into the chaotic circuit. Finally, the dynamic behaviors and complexity mechanism are analyzed by utilizing coexisting attractors, dynamic route map, bifurcation diagram, Lyapunov exponent spectrum, and the basin of attraction.

11.
Biochem Biophys Res Commun ; 526(3): 685-691, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32248976

RESUMO

Epithelial ovarian cancer (EOC) is one of the most common and lethal gynecological cancers. Novel therapeutic agents have been developed for EOC, but patient survival remains poor. Trastuzumab has been approved for breast and gastric cancers with high expression of human epidermal growth factor receptor 2 (HER2), but it has not achieved any clinical success in EOC. Dysregulated Wnt/ß-catenin signaling is involved in cancer development, but whether it plays a role in EOC resistance to trastuzumab remains largely unknown. Here, we observed that high expression of Wnt3a, ß-catenin and TCF7L2, which can form a signaling axis in the Wnt/ß-catenin pathway, commonly existed in HER2-positive EOC tissue samples and was correlated with a poor patient prognosis. Cell proliferation and migration assays and nude mouse xenograft model experiments demonstrated that the Wnt3a/ß-catenin/TCF7L2 signaling axis promoted tumor cell growth and metastasis and reduced tumor sensitivity to trastuzumab. Analysis of downstream Akt signaling suggested that the function of the Wnt3a/ß-catenin/TCF7L2 signaling axis was mediated, at least in part, through increasing Akt phosphorylation. Overall, this study reveals a crucial role for the Wnt3a/ß-catenin/TCF7L2 signaling axis in EOC resistance to trastuzumab and the potential application of HER2-targeted drugs combined with inhibitors of this signaling axis for EOC treatment.


Assuntos
Antineoplásicos Imunológicos/farmacologia , Carcinoma Epitelial do Ovário/tratamento farmacológico , Receptor ErbB-2/metabolismo , Proteína 2 Semelhante ao Fator 7 de Transcrição/metabolismo , Trastuzumab/farmacologia , Proteína Wnt3A/metabolismo , beta Catenina/metabolismo , Animais , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Lentivirus , Camundongos Nus , Neoplasias Experimentais , Fosforilação , Prognóstico , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética , Transfecção , Via de Sinalização Wnt
12.
Nano Lett ; 19(3): 1467-1478, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30730145

RESUMO

Sustaining blood retention for theranostic nanoparticles is a big challenge. Various approaches have been attempted and have demonstrated some success but limitations remain. We hypothesized that peptides capable of increasing blood residence time for M13 bacteriophage, a rod-shaped nanoparticle self-assembled from proteins and nucleic acids, should also prolong blood circulation for engineered nanoparticles. Here we demonstrate the feasibility of this approach by identifying a series of blood circulation-prolonging (BCP) peptides through in vivo screening of an M13 peptide phage display library. Intriguingly, the majority of the identified BCP peptides contained an arginine-glycine-aspartic acid (RGD) motif, which was necessary but insufficient for the circulation-prolonging activity. We further demonstrated that the RGD-mediated specific binding to platelets was primarily responsible for the enhanced blood retention of BCP1. The utility of the BCP1 peptide was demonstrated by fusion of the peptide to human heavy-chain ferritin (HFn), leading to significantly improved pharmacokinetic profile, enhanced tumor cell uptake and optimum anticancer efficacy for doxorubicin encapsulated in the HFn nanocage. Our results provided a proof-of-concept for an innovative yet simple strategy, which utilizes phage display to discover novel peptides with the capability of substantially prolonging blood circulation for engineered theranostic nanoparticles.


Assuntos
Doxorrubicina/farmacologia , Ferritinas/química , Nanopartículas/química , Peptídeos/química , Sequência de Aminoácidos/genética , Arginina/química , Ácido Aspártico/química , Bacteriófago M13/química , Transporte Biológico/genética , Técnicas de Visualização da Superfície Celular , Doxorrubicina/química , Glicina/química , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Biblioteca de Peptídeos , Peptídeos/sangue
13.
Small ; 14(13): e1703711, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29457340

RESUMO

Transcription factor EB (TFEB) is a master regulator of autophagy and lysosomal biogenesis. Here, silver nanoparticles (Ag NPs)-induced cytoprotective autophagy required TFEB is shown. Ag NPs-induced nucleus translocation of TFEB through a well-established mechanism involving dephosphorylation of TFEB at serine-142 and serine-211 but independent of both the mTORC1 and ERK1/2 pathways. TFEB nucleus translocation precedes autophagy induced by Ag NPs and leads to enhanced expression of autophagy-essential genes. Knocking down the expression of TFEB attenuates the autophagy induction is demonstrated, and in the meantime, enhanced cell killing in HeLa cells treats with Ag NPs, indicating that TFEB is the key mediator for Ag NPs-induced cytoprotective autophagy. The results pinpoint TFEB as a potential target for developing more effective Ag NPs-based cancer therapeutics.


Assuntos
Autofagia/efeitos dos fármacos , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Núcleo Celular/metabolismo , Nanopartículas Metálicas/química , Prata/química , Prata/farmacologia , Células HeLa , Humanos , Transporte Proteico/efeitos dos fármacos , Reação em Cadeia da Polimerase em Tempo Real
14.
Phys Chem Chem Phys ; 20(17): 11876-11881, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29662995

RESUMO

Solvent assisted excited state intramolecular proton or hydrogen transfer has received much attention in bi-functional molecules with hydrogen donating and hydrogen accepting groups. As a typical photoacid, 1-naphthol exhibits photo-stable behavior in methanol; whether this would be disrupted by a bonded hydrogen accepting group contained in the molecule is still not assured. We present nanosecond transient absorption measurements relating to kinetics and the characteristic absorption of key intermediates upon the excitation of 4-nitro-1-naphthol in alcoholic solutions, and also transient resonance Raman spectroscopy studies combined with theoretical calculations to identify the structures of these intermediates, and we reveal the reaction mechanism to be stepwise deprotonation, hydrogen abstraction and protonation. These results demonstrate that alcohol assisted intramolecular proton or hydrogen transfer cannot occur in this system, but that the solvent cluster plays an important role during such stepwise reactions.

15.
J Phys Chem A ; 122(7): 1831-1837, 2018 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-29432008

RESUMO

Nanosecond transient absorption and theoretical calculations have been used to investigate the intermolecular hydrogen abstractions from alcohols and 1-naphthol by the lowest excited triplet (T1) of 1-chloro-4-nitronaphthalene upon excitation of the compound in organic solvents. The hydrogen abstraction of T1 from hydroxy group of 1-naphthol takes place through an electron transfer followed by a proton transfer through hydrogen bonding interaction with rate constants of ∼109 M-1 s-1. Hydrogen-bonding is crucial in this process, indicated by the observation of a half reduction for T1 yield when increasing the concentration of 1-naphthol. The hydrogen abstraction in this way can be decelerated by increasing solvent polarity and hydrogen-bonding donor ability. The T1 of 1-chloro-4-nitronaphthalene can undergo one-step H atom abstraction from alkyl hydrogen in alcoholic solvents, with rate constants of ∼104 M-1 s-1, and produce radical intermediates with the absorption maximum at 368 nm. DFT calculation results indicate both oxygens of the nitro group are active sites for hydrogen abstraction, and the difference of activation barriers for formation of two radical isomers is only 1.0 kcal/mol.

16.
Gynecol Endocrinol ; 34(4): 272-277, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29084464

RESUMO

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women, and it is the main cause of infertility in women of reproductive age due to anovulation. PCOS also increases the risk of diseases such as cardiovascular disease and type 2 diabetes in women with this disorder. The mechanism of pathogenesis is not clear, as it may be related to heredity, the environment and internal embryonic factors; thus, the treatment strategies remain unclear. This review summarizes current treatments for PCOS worldwide. Lifestyle modification (LSM) is considered the first-line treatment, regardless of fertility status, without the addition of metformin. Oral contraceptive (OC) pills should be used as a first-line treatment for long-term management for patients with no reproductive requirements. For patients with fertility requirements, ovulation therapy is an effective treatment. For refractory ovulation disorders, patients can choose from among the latest treatments, including ovarian hippocampal signal path block theory, the theory of leptin, inositol treatment, bilateral ovarian drilling to stimulate ovulation and assisted reproductive technology. Because current treatments cannot cure PCOS, lifelong administration is still the mainstream method of management; however, the optimal treatment plan needs further research and exploration.


Assuntos
Anticoncepcionais Orais Hormonais/uso terapêutico , Estilo de Vida , Síndrome do Ovário Policístico/terapia , Feminino , Humanos , Síndrome do Ovário Policístico/tratamento farmacológico , Resultado do Tratamento
17.
Small ; 13(7)2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27925395

RESUMO

The diverse biological effects of nanomaterials form the basis for their applications in biomedicine but also cause safety issues. Induction of autophagy is a cellular response after nanoparticles exposure. It may be beneficial in some circumstances, yet autophagy-mediated toxicity raises an alarming concern. Previously, it has been reported that upconversion nanoparticles (UCNs) elicit liver damage, with autophagy contributing most of this toxicity. However, the detailed mechanism is unclear. This study reveals persistent presence of enlarged autolysosomes in hepatocytes after exposure to UCNs and SiO2 nanoparticles both in vitro and in vivo. This phenomenon is due to anomaly in the autophagy termination process named autophagic lysosome reformation (ALR). Phosphatidylinositol 4-phosphate (PI(4)P) relocates onto autolysosome membrane, which is a key event of ALR. PI(4)P is then converted into phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2 ) by phosphatidylinositol-4-phosphate 5-kinase. Clathrin is subsequently recruited by PI(4,5)P2 and leads to tubule budding of ALR. Yet it is observed that PI(4)P cannot be converted in nanoparticle-treated hepatocytes cells. Exogenous supplement of PI(4,5)P2 suppresses the enlarged autolysosomes in vitro. Abolishment of these enlarged autolysosomes by autophagy inhibitor relieves the hepatotoxicity of UCNs in vivo. The results provide evidence for disrupted ALR in nanoparticle-treated hepatocytes, suggesting that the termination of nanoparticle-induced autophagy is of equal importance as the initiation.


Assuntos
Autofagia , Hepatócitos/citologia , Hepatócitos/metabolismo , Lisossomos/metabolismo , Nanopartículas/química , Animais , Autofagia/efeitos dos fármacos , Células Cultivadas , Hepatócitos/efeitos dos fármacos , Fígado/metabolismo , Lisossomos/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Modelos Biológicos , Nanopartículas/toxicidade , Fosfatos de Fosfatidilinositol/metabolismo
18.
Small ; 12(41): 5759-5768, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27593892

RESUMO

Many nanomaterials are reported to disrupt lysosomal function and homeostasis, but how cells sense and then respond to nanomaterial-elicited lysosome stress is poorly understood. Nucleus translocation of transcription factor EB (TFEB) plays critical roles in lysosome biogenesis following lysosome stress induced by starvation. The authors previously reported massive cellular vacuolization, along with autophagy induction, in cells treated with rare earth oxide (REO) nanoparticles. Here, the authors identify these giant cellular vacuoles as abnormally enlarged and alkalinized endo/lysosomes whose formation is dependent on macropinocytosis. This vacuolization causes deactivation of mammalian target of rapamycin (mTOR), a TFEB-interacting kinase that resides on the lysosome membrane. Subsequently, TFEB is dephosphorylated at serine 142 and translocated into cell nucleus. This nucleus translocation of TFEB is observed only in vacuolated cells and it is critical for maintaining lysosome homeostasis after REO nanoparticle treatment, as knock-down of TFEB gene significantly compromises lysosome function and enhances cell death in nanoparticle-treated cells. Our results reveal that cellular vacuolization, which is commonly observed in cells treated with REOs and other nanomaterials, represents a condition of profound lysosome stress, and cells sense and respond to this stress by facilitating mTOR-dependent TFEB nucleus translocation in an effort to restore lysosome homeostasis.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Núcleo Celular/metabolismo , Lisossomos/metabolismo , Metais Terras Raras/química , Nanopartículas/química , Óxidos/química , Serina-Treonina Quinases TOR/metabolismo , Vacúolos/metabolismo , Álcalis/química , Sobrevivência Celular , Endossomos/metabolismo , Células HeLa , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Modelos Biológicos , Pinocitose , Transporte Proteico
19.
Methods ; 90: 65-7, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25982137

RESUMO

The evanescent wave fiber immunosensors (EWFI) technique was developed for the real-time rapidly sensitive and specific detection of the monoclonal antibody 3E2 of BTV. The outer-core protein VP7 of BTV was labled on the surface of the exposed fiber-optic core. The monoclonal antibody 3E2 of BTV VP7 were added and then the goat ant-rat IgG conjugated with Cy3 was captured. After the 532nm pulse (excitation source) reached the fiber probe, evanescent wave was generated, which excited the Cy3 bound to the immuno-complex and produced the fluorescent signal, which was changed into electrical signals read through computer. The preliminary results suggested that a detection limit of 10ng/ml was measured for the monoclonal antibody 3E2, which is equal to the sensitivity of ELISA. The 3E2 sample was specifically detected through the EWFI assay in 15min, and the fiber can be recycled at least ten times through TEA solution condition. This developed EWFI was a real-time rapidly sensitive and specific way for the detection of BTV antibodies.


Assuntos
Técnicas Biossensoriais , Vírus Bluetongue/isolamento & purificação , Animais , Anticorpos Monoclonais/análise , Bluetongue/diagnóstico , Tecnologia de Fibra Óptica/métodos , Gado/virologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Mol Pharm ; 11(11): 4015-22, 2014 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-25269793

RESUMO

The biologically inspired transdermal enhanced peptide TD1 has been discovered to specifically facilitate transdermal delivery of biological macromolecules. However, the biological behavior of TD1 has not been fully defined. In this study, we find that energy is required for the TD1-mediated transdermal protein delivery through rat and human skins. Our results show that the permeation activity of TD1-hEGF, a fusion protein composed of human epidermal growth factor (hEGF) and the TD1 sequence connected with a glycine-serine linker (GGGGS), can be inhibited by the energy inhibitor, rotenone or oligomycin. In addition, adenosine triphosphate (ATP), the essential energetic molecule in organic systems, can effectively facilitate the TD1 directed permeation of the protein-based drug into the skin in a dose-dependent fashion. Our results here demonstrate a novel energy-dependent permeation process during the TD1-mediated transdermal protein delivery that could be valuable for the future development of promising new transdermal drugs.


Assuntos
Sistemas de Liberação de Medicamentos , Metabolismo Energético/efeitos dos fármacos , Fator de Crescimento Epidérmico/administração & dosagem , Chaperonas Moleculares , Fragmentos de Peptídeos/farmacologia , Pele/metabolismo , Administração Cutânea , Adolescente , Animais , Humanos , Oligomicinas/farmacologia , Ratos , Ratos Sprague-Dawley , Rotenona/farmacologia , Pele/efeitos dos fármacos , Pele/patologia , Absorção Cutânea/efeitos dos fármacos , Desacopladores/farmacologia
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