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1.
Cell ; 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-39013470

RESUMO

Allogeneic chimeric antigen receptor (CAR)-T cells hold great promise for expanding the accessibility of CAR-T therapy, whereas the risks of allograft rejection have hampered its application. Here, we genetically engineered healthy-donor-derived, CD19-targeting CAR-T cells using CRISPR-Cas9 to address the issue of immune rejection and treated one patient with refractory immune-mediated necrotizing myopathy and two patients with diffuse cutaneous systemic sclerosis with these cells. This study was registered at ClinicalTrials.gov (NCT05859997). The infused cells persisted for over 3 months, achieving complete B cell depletion within 2 weeks of treatment. During the 6-month follow-up, we observed deep remission without cytokine release syndrome or other serious adverse events in all three patients, primarily shown by the significant improvement in the clinical response index scores for the two diseases, respectively, and supported by the observations of reversal of inflammation and fibrosis. Our results demonstrate the high safety and promising immune modulatory effect of the off-the-shelf CAR-T cells in treating severe refractory autoimmune diseases.

2.
Artigo em Inglês | MEDLINE | ID: mdl-39095057

RESUMO

BACKGROUND: The present study aims to evaluate the postprocessing image quality of a deep-learning (DL)-based automatic bone removal algorithm in the real clinical practice for cervical computed tomography angiography (CTA). MATERIALS AND METHODS: A total of 100 patients (31 females, 61.4 ± 12.4 years old) who had performed cervical CTA from January 2022 to July 2022 were included retrospectively. Three different types of scanners were used. Ipsilateral cervical artery was divided into 10 segments. The performance of the DL algorithm and conventional algorithm in terms of bone removal and vascular integrity was independently evaluated by two radiologists for each segment. The difference in the performance between the two algorithms was compared. Inter- and intrarater consistency were assessed, and the correlation between the degree of carotid artery stenosis and the rank of bone removal and vascular integrity was analyzed. RESULTS: Significant differences were observed in the rankings of bone removal and vascular integrity between the two algorithms on most segments on both sides. Compared to DL algorithm, the conventional algorithm showed a higher correlation between the degree of carotid artery stenosis and vascular integrity (r = -0.264 vs r = -0.180). The inter- and intrarater consistency of DL algorithm were found to be higher than or equal to those of conventional algorithm. CONCLUSIONS: The DL algorithm for bone removal in cervical CTA demonstrated significantly better performance than conventional postprocessing method, particularly in the segments with complex anatomical structures and adjacent to bone.

3.
Arthroscopy ; 40(4): 1197-1205, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37597705

RESUMO

PURPOSE: To develop a deep learning model to accurately detect anterior cruciate ligament (ACL) ruptures on magnetic resonance imaging (MRI) and to evaluate its effect on the diagnostic accuracy and efficiency of clinicians. METHODS: A training dataset was built from MRIs acquired from January 2017 to June 2021, including patients with knee symptoms, irrespective of ACL ruptures. An external validation dataset was built from MRIs acquired from January 2021 to June 2022, including patients who underwent knee arthroscopy or arthroplasty. Patients with fractures or prior knee surgeries were excluded in both datasets. Subsequently, a deep learning model was developed and validated using these datasets. Clinicians of varying expertise levels in sports medicine and radiology were recruited, and their capacities in diagnosing ACL injuries in terms of accuracy and diagnosing time were evaluated both with and without artificial intelligence (AI) assistance. RESULTS: A deep learning model was developed based on the training dataset of 22,767 MRIs from 5 centers and verified with external validation dataset of 4,086 MRIs from 6 centers. The model achieved an area under the receiver operating characteristic curve of 0.987 and a sensitivity and specificity of 95.1%. Thirty-eight clinicians from 25 centers were recruited to diagnose 3,800 MRIs. The AI assistance significantly improved the accuracy of all clinicians, exceeding 96%. Additionally, a notable reduction in diagnostic time was observed. The most significant improvements in accuracy and time efficiency were observed in the trainee groups, suggesting that AI support is particularly beneficial for clinicians with moderately limited diagnostic expertise. CONCLUSIONS: This deep learning model demonstrated expert-level diagnostic performance for ACL ruptures, serving as a valuable tool to assist clinicians of various specialties and experience levels in making accurate and efficient diagnoses. LEVEL OF EVIDENCE: Level III, retrospective comparative case series.


Assuntos
Lesões do Ligamento Cruzado Anterior , Aprendizado Profundo , Humanos , Lesões do Ligamento Cruzado Anterior/diagnóstico por imagem , Lesões do Ligamento Cruzado Anterior/cirurgia , Ligamento Cruzado Anterior , Estudos Retrospectivos , Inteligência Artificial , Imageamento por Ressonância Magnética/métodos
4.
Drug Chem Toxicol ; 46(3): 423-429, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35266432

RESUMO

Tea is consumed widely around the world owing to its refreshing taste and potential health benefits. However, drinking tea is considered a major route for dietary aluminum exposure in areas where tea consumption is relatively large. To assess the health risk associated with drinking tea, the contamination level of aluminum was determined in 81 tea samples. The transfer rate of aluminum during tea brewing was investigated. Then based on the site-specific exposure parameters such as consumption data and body weight for six different subpopulations in Fujian, the exposure risks were estimated using a probabilistic approach. Results demonstrate that the contents of aluminum in green tea, white tea, oolong tea, and black tea were significantly different according to the one-way ANOVA analysis (p < 0.05). The transfer rate of aluminum were 32.6%, 31.6%, 26.3%, and 14% for white tea, black tea, oolong tea, and green tea, respectively. With respect to the oral reference dose, the exposure of inhabitants in Fujian to aluminum through drinking tea is under control (even at the 99th percentile).


Assuntos
Alumínio , Camellia sinensis , Chá , Peso Corporal , Povidona/análise
5.
Environ Microbiol ; 24(11): 5574-5582, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36070190

RESUMO

Despite the importance of soil bacterial and fungal communities for ecosystem services and human welfare, how their ecological networks respond to climatic aridity have yet been evaluated. Here, we collected soil samples from 47 sites across 2500 km in coastal and inland areas of eastern Australia with contrasting status of aridity. We found that the diversity of both bacteria and fungi significantly differed between inland and coastal soils. Despite the significant differences in soil nutrient availability and stoichiometry between the inland and coastal regions, aridity was the most important predictor of bacterial and fungal community compositions. Aridity has altered the potential microbial migration rates and further impacted the microbial assembly processes by increasing the importance of stochasticity in bacterial and fungal communities. More importantly, ecological network analysis indicated that aridity enhanced the complexity and stability of the bacterial network but reduced that of the fungal network, possibly due to the contrasting impacts of aridity on the community-level habitat niche breadth and overlaps. Our work paves the way towards a more comprehensive understanding of how climate changes will alter soil microbial communities, which is integral to predicting their long-term consequences for ecosystem sustainability and resilience to future disturbances.


Assuntos
Microbiota , Solo , Humanos , Microbiologia do Solo , Ecossistema , Fungos/genética , Bactérias/genética
6.
BMC Infect Dis ; 22(1): 684, 2022 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-35945495

RESUMO

BACKGROUND: Papiliotrema flavescens is a rare environmental yeast, which has been isolated from air, trees, kernels of wheat and corn, fermenting soya sauce, and cerebrospinal fluid of patient with AIDS. Additionally, it is also reported to cause subcutaneous infection in a dog. In this case, we describe primary lung adenocarcinoma coexisting with Papiliotrema flavescens infection in a female patient diagnosed by next-generation sequencing (NGS) technique, which is the first such reported case. CASE PRESENTATION: The patient was a 52-year-old female with recurrent cough for 3 months. Chest CT examination revealed a ground glass nodule of 17 * 23 * 18 mm in the right upper lung, and 3 new pulmonary nodules appeared around it 2 months later. The patient underwent right upper lobe lobectomy and pathology confirmed that the primary 2-cm-lesion in the right upper lobe was invasive lung adenocarcinoma, and two of the three surrounding lung nodules were pathologically suggestive of pulmonary fungal infection (not known in specific fungal types). Hence, the patient received empirical anti-fungal treatments with fluconazole 400 mg/day for a week and follow-up CT scanning showed no tumor progression and no relapse of fungal infection. The specific pathogen was eventually identified as Papiliotrema flavescens by the next-generation sequencing of pathogen. DISCUSSION AND CONCLUSION: We first reported that lung cancer coexisting with Papiliotrema flavescens infection in a female patient. The diagnosis of lung cancer with typical CT imaging features is relatively simple, while the diagnosis of lung cancer coexisting with rare fungal infection is challenging. NGS technique is an effective supplementary technique for clinical diagnosis of bacterial or fungal infectious diseases, enabling precise clinical decision-making and appropriate treatment. In this case, the lung cancer may result in a degree of immune suppression, at least locally, resulting in the formation of pulmonary fungal nodular lesions around the tumor.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Micoses , Adenocarcinoma de Pulmão/complicações , Adenocarcinoma de Pulmão/diagnóstico , Animais , Basidiomycota , Cães , Sequenciamento de Nucleotídeos em Larga Escala , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/diagnóstico , Micoses/complicações , Recidiva Local de Neoplasia/complicações
7.
Phys Chem Chem Phys ; 24(20): 12621-12630, 2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35579403

RESUMO

It is generally believed that few-layer films of wurtzite materials remove the destabilizing dipole by converting to a flat hexagonal structure. However, using first-principles calculations, we demonstrate that contrary to the existing consensus these few-layer hexagonal films exhibit a small symmetric rumpling and are not perfectly flat. We then perform a systematic study of the rumpling behavior of a range of few-layer III-V and II-VI films. The symmetric rumpled configuration enables such films to cancel out the dipole and thereby to avoid the polar instability. This stabilization mechanism is quite distinct from those known for bulk and few-layer polar materials. Compared to the perfectly flat films, the rumpled films exhibit lower electrostatic potential energy, lower total energy, higher bonding strength, and thus greater stability and larger band gaps. We also discuss the relationship between rumpling behavior, interlayer interactions, and ionicity through electrostatic analysis.

8.
Drug Chem Toxicol ; 45(2): 932-939, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32752890

RESUMO

The objective of this study was to evaluate the residues of 42 pesticides subject to public concern in Tieguanyin tea produced in Fujian, China. The presence of 42 pesticide residues in 90 Tieguanyin tea samples were determined. A total of 17 pesticides were detected. At least one pesticide residue was detected in 65 samples (72.2%). The detected pesticides imidacloprid, tolfenpyrad, bifenthrin, acetamiprid were found in 55.6%, 33.3%, 18.9% and 16.7% of samples, respectively. Pesticide residues in Tieguanyin tea varied significantly over the seasons and across the production regions. Based on data obtained, the health risks associated with long-term exposure to those pesticides were assessed and risks of detected pesticides were ranked. The hazard quotients (HQs) among the detected pesticides range from 5 × 10-8 for fenpropathrin to 3 × 10-4 for imidacloprid. The results demonstrated that despite a high occurrence of pesticide residues in Tieguanyin tea, residue levels observed could not be considered as a serious public health problem. The risk ranking scheme showed dicofol and thiacloprid were considered to pose a medium-risk. The suggestions for 17 detected pesticides used in Tieguanyin tea plantation were made, including those already banned from use in China (dicofol and methomyl), recommended for diminished use (thiacloprid and chlorpyrifos), and permitted use with considering the pre-harvest interval (13 other pesticides).


Assuntos
Resíduos de Praguicidas , Praguicidas , China , Contaminação de Alimentos/análise , Resíduos de Praguicidas/toxicidade , Praguicidas/análise , Medição de Risco/métodos , Chá/química
9.
Acta Pharmacol Sin ; 42(12): 2144-2154, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34017067

RESUMO

Mitochondria are essential organelles that provide energy for mammalian cells and participate in multiple functions, such as signal transduction, cellular differentiation, and regulation of apoptosis. Compared with the mitochondria in somatic cells, oocyte mitochondria have an additional level of importance since they are required for germ cell maturation, dysfunction in which can lead to severe inherited disorders. Thus, a systematic proteomic profile of oocyte mitochondria is urgently needed to support the basic and clinical research, but the acquisition of such a profile has been hindered by the rarity of oocyte samples and technical challenges associated with capturing mitochondrial proteins from live oocytes. Here, in this work, using proximity labeling proteomics, we established a mitochondria-specific ascorbate peroxidase (APEX2) reaction in live GV-stage mouse oocytes and identified a total of 158 proteins in oocyte mitochondria. This proteome includes intrinsic mitochondrial structural and functional components involved in processes associated with "cellular respiration", "ATP metabolism", "mitochondrial transport", etc. In addition, mitochondrial proteome capture after oocyte exposure to the antitumor chemotherapeutic cisplatin revealed differential changes in the abundance of several oocyte-specific mitochondrial proteins. Our study provides the first description of a mammalian oocyte mitochondrial proteome of which we are aware, and further illustrates the dynamic shifts in protein abundance associated with chemotherapeutic agents.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Mitocôndrias/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Oócitos/efeitos dos fármacos , Proteoma/metabolismo , Animais , Ascorbato Peroxidases/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos ICR , Células NIH 3T3 , Proteômica/métodos
10.
Sensors (Basel) ; 21(19)2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34640692

RESUMO

Superpixel segmentation is one of the key image preprocessing steps in object recognition and detection methods. However, the over-segmentation in the smoothly connected homogenous region in an image is the key problem. That would produce redundant complex jagged textures. In this paper, the density peak clustering will be used to reduce the redundant superpixels and highlight the primary textures and contours of the salient objects. Firstly, the grid pixels are extracted as feature points, and the density of each feature point will be defined. Secondly, the cluster centers are extracted with the density peaks. Finally, all the feature points will be clustered by the density peaks. The pixel blocks, which are obtained by the above steps, are superpixels. The method is carried out in the BSDS500 dataset, and the experimental results show that the Boundary Recall (BR) and Achievement Segmentation Accuracy (ASA) are 95.0% and 96.3%, respectively. In addition, the proposed method has better performance in efficiency (30 fps). The comparison experiments show that not only do the superpixel boundaries have good adhesion to the primary textures and contours of the salient objects, but they can also effectively reduce the redundant superpixels in the homogeneous region.

11.
Sensors (Basel) ; 21(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34502673

RESUMO

In this research work, the gas sensing properties of halogenated chloroaluminum phthalocyanine (ClAlPc) thin films were studied at room temperature. We fabricated an air-stable ClAlPc gas sensor based on a vertical organic diode (VOD) with a porous top electrode by the solution process method. The surface morphology of the solution-processed ClAlPc thin film was examined by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The proposed ClAlPc-based VOD sensor can detect ammonia (NH3) gas at the ppb level (100~1000 ppb) at room temperature. Additionally, the ClAlPc sensor was highly selective towards NH3 gas compared to other interfering gases (NO2, ACE, NO, H2S, and CO). In addition, the device lifetime was tested by storing the device at ambient conditions. The effect of relative humidity (RH) on the ClAlPc NH3 gas sensor was also explored. The aim of this study is to extend these findings on halogenated phthalocyanine-based materials to practical electronic nose applications in the future.

12.
Sensors (Basel) ; 21(19)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34640867

RESUMO

With the emerging of wearable robots, the safety and effectiveness of human-robot physical interaction have attracted extensive attention. Recent studies suggest that online measurement of the interaction force between the robot and the human body is essential to the aspects above in wearable exoskeletons. However, a large proportion of existing wearable exoskeletons monitor and sense the delivered force and torque through an indirect-measure method, in which the torque is estimated by the motor current. Direct force/torque measuring through low-cost and compact wearable sensors remains an open problem. This paper presents a compact soft sensor system for wearable gait assistance exoskeletons. The contact force is converted into a voltage signal by measuring the air pressure within a soft pneumatic chamber. The developed soft force sensor system was implemented on a robotic hip exoskeleton, and the real-time interaction force between the human thigh and the exoskeleton was measured through two differential soft chambers. The delivered torque of the hip exoskeleton was calculated based on a characterization model. Experimental results suggested that the sensor system achieved direct force measurement with an error of 10.3 ± 6.58%, and torque monitoring for a hip exoskeleton which provided an understanding for the importance of direct force/torque measurement for assistive performance. Compared with traditional rigid force sensors, the proposed system has several merits, as it is compact, low-cost, and has good adaptability to the human body due to the soft structure.


Assuntos
Exoesqueleto Energizado , Procedimentos Cirúrgicos Robóticos , Marcha , Humanos , Monitorização Fisiológica , Torque
13.
Opt Express ; 28(14): 20609-20623, 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32680117

RESUMO

Nowadays, the requirement for achieving dynamic radiative cooling is more and more intense, so a cooling system is proposed and developed to meet the demand in this paper. This cooling system is composed of a filter and a periodic trapezoidal VO2-Ge multilayer absorber (VGMA). The filter on the top enables the VGMA to reflect most of the solar irradiation at daytime and the absorptance or emittance of the VGMA is very different in the spectrum band of 8-13 µm for insulating and metallic VO2 due to the phase transition characteristic of VO2. With this cooling system, close-to-zero absorptance in the range of 0.3-2.5 µm and high (low) absorptance from 8 to 13 µm are achieved for metallic (insulating) VO2. Based on changing the temperature and absorptivity or emissivity simultaneously, radiative heat can be transferred dynamically to the outer space. When VO2 is in the insulating phase, the absorption mechanism of the absorber is magnetic resonance and surface plasmon polariton resonance, and broadband high absorptivity is achieved by exciting slowlight waveguide mode at broadband wavelengths when VO2 is in metallic phase. The spectral absorptance characteristics of the absorber in the two phase states are investigated as a function of the layer number and the incident angle of the electromagnetic waves. The results show that the absorber designed is insensitive to the incident angle. Moreover, the net cooling power of the VGMA of metallic VO2 is instantly 4 times more than that of insulating VO2 once the phase change temperature is reached. This work will be beneficial to the advancement of dynamic radiative cooling.

14.
Environ Sci Technol ; 53(8): 4215-4223, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30882209

RESUMO

Diets of soil-feeding earthworms contain abundant nitrate and iron(III) oxides, which are potential electron acceptors for mineralization of organic compounds. The earthworm gut provides an ideal habitat for ingested iron(III)-reducing microorganisms. However, little is known about iron(III) reduction and its interaction with other processes in the guts of earthworms. Here, we determined the dynamics of iron(III) and revealed its interaction with the turnover of organic acids and nitrate in the gut of the earthworm Pheretima guillelmi. Samples from gut contents combined with anoxic incubation were used for chemical analysis and 16S rRNA based Illumina sequencing. Chemical analysis showed that higher ratios of iron(II)/iron(III), nitrite/nitrate, and more abundant organic acids were contained in the in vivo gut of the earthworm P. guillelmi than those in the in situ soil. A higher rate of iron(III) reduction was detected in treatments of microcosmic incubation with gut contents (IG gut) than that with soil (IG soil), and nitrate reduction occurred earlier than iron(III) reduction in both treatments. Potential iron(III) reducers were dominated by fermentative genera Clostridium, Bacillus, and Desulfotomaculum in the treatment of IG gut, while they were dominated by dissimilatory iron(III)-reducing genera Geobacter in the treatment of IG soil. The iron(III)-reducing microbial community shared several genera with denitrifers in the treatment of IG gut, revealing a close link between iron(III) reduction and denitrification in the gut of earthworms. Collectively, our findings demonstrated that iron(III) reduction occurred along the gut and provided novel insights into the great contribution of earthworm gut microbiota on Fe and the associated C and N cycling in soil environments.


Assuntos
Oligoquetos , Animais , Desnitrificação , Incubadoras , Ferro , RNA Ribossômico 16S , Solo , Microbiologia do Solo
16.
Sensors (Basel) ; 16(1)2016 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-26771614

RESUMO

A compact fiber-optic inclinometer is proposed and experimentally demonstrated based on a Fabry-Perot interference (FFPI). The sensing head consists of a short segment of thin-core fiber (TCF) following with a piece of hollow-core fiber (HCF). High-order cladding modes have been excited because of core diameter mismatch. A clear interference spectrum has been obtained as the consequence of interference among the reflected core modes and cladding modes. Fringe contrast of the interference spectrum is highly sensitive to fiber bending with direction independence, and good linearity has been observed during the bending range from 1° to 3° with a sensitivity of 2.71 dB/deg.

17.
Int J Mol Sci ; 17(7)2016 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-27409615

RESUMO

The bacterial-induced hollow cylinder NiO (HCNiO) nanomaterial was utilized for the enzymeless (without GOx) detection of glucose in basic conditions. The determination of glucose in 0.05 M NaOH solution with high sensitivity was performed using cyclic voltammetry (CV) and amperometry (i-t). The fundamental electrochemical parameters were analyzed and the obtained values of diffusion coefficient (D), heterogeneous rate constant (ks), electroactive surface coverage (Г), and transfer coefficient (alpha-α) are 1.75 × 10(-6) cm²/s, 57.65 M(-1)·s(-1), 1.45 × 10(-10) mol/cm², and 0.52 respectively. The peak current of the i-t method shows two dynamic linear ranges of calibration curves 0.2 to 3.5 µM and 0.5 to 250 µM for the glucose electro-oxidation. The Ni(2+)/Ni(3+) couple with the HCNiO electrode and the electrocatalytic properties were found to be sensitive to the glucose oxidation. The green chemistry of NiO preparation from bacteria and the high catalytic ability of the oxyhydroxide (NiOOH) is the good choice for the development of a glucose sensor. The best obtained sensitivity and limit of detection (LOD) for this sensor were 3978.9 µA mM(-1)·cm(-2) and 0.9 µM, respectively.


Assuntos
Bactérias/metabolismo , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas , Glucose/análise , Nanopartículas Metálicas/química , Níquel/química , Técnicas Biossensoriais/normas , Calibragem , Catálise , Técnicas Eletroquímicas/normas , Eletrodos , Glucose/normas , Cinética , Limite de Detecção , Oxirredução
18.
J Ethn Subst Abuse ; 15(2): 144-59, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26421948

RESUMO

This qualitative study explores the traumas of Chinese heroin users. The results showed that the Chinese experience traumas during (childhood, later in life but prior to heroin-use onset, and throughout their heroin-use career. Themes related to the traumas include the historical economic transition, the value of family orientation, an emphasis on scholarly pursuits, the shame orientation, and a scarcity of resources conducive to recovery. This article provides a framework to understand the traumas experienced by Chinese people and offers insights on how macrofactors may impact the trauma and its treatment in different societies.


Assuntos
Dependência de Heroína/psicologia , Trauma Psicológico/psicologia , Adulto , China/etnologia , Dependência de Heroína/etnologia , Humanos , Trauma Psicológico/etnologia , Pesquisa Qualitativa
19.
J Mater Sci Mater Med ; 26(2): 68, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25631261

RESUMO

Device-related infections have been a big problem for a long time. This paper describes a new method to inhibit bacterial growth on implanted device with tissue-penetrating X-ray radiation, where a thin metallic film deposited on the device is used as a radio-sensitizing film for bacterial inhibition. At a given dose of X-ray, the bacterial viability decreases as the thickness of metal film (bismuth) increases. The bacterial viability decreases with X-ray dose increases. At X-ray dose of 2.5 Gy, 98% of bacteria on 10 nm thick bismuth film are killed; while it is only 25% of bacteria are killed on the bare petri dish. The same dose of X-ray kills 8% fibroblast cells that are within a short distance from bismuth film (4 mm). These results suggest that penetrating X-rays can kill bacteria on bismuth thin film deposited on surface of implant device efficiently.


Assuntos
Bismuto/farmacologia , Materiais Revestidos Biocompatíveis/química , Próteses e Implantes/microbiologia , Pseudomonas aeruginosa/crescimento & desenvolvimento , Esterilização/métodos , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/efeitos da radiação , Bismuto/química , Bismuto/efeitos da radiação , Proliferação de Células/fisiologia , Proliferação de Células/efeitos da radiação , Materiais Revestidos Biocompatíveis/efeitos da radiação , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos da radiação , Raios X
20.
J Biol Chem ; 288(19): 13850-62, 2013 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-23546875

RESUMO

BACKGROUND: Small ubiquitin-like modifiers (SUMO) are covalently conjugated to other proteins including nuclear receptors leading to modification of various cellular processes. RESULTS: Ligand-dependent SUMOylation of farnesoid X receptor (FXR) negatively regulates the expression of its target genes. CONCLUSION: SUMO modification attenuates the capacity of FXR to function as a transcriptional activator. SIGNIFICANCE: Defining post-translation modification of FXR bySUMOis important to understanding how this nuclear receptor functions in health and disease. The farnesoid X receptor (FXR) belongs to a family of ligand-activated transcription factors that regulate many aspects of metabolism including bile acid homeostasis. Here we show that FXR is covalently modified by the small ubiquitin-like modifier (Sumo1), an important regulator of cell signaling and transcription. Well conserved consensus sites at lysine 122 and 275 in the AF-1 and ligand binding domains, respectively, of FXR were subject to SUMOylation in vitro and in vivo. Chromatin immunoprecipitation (ChIP) analysis showed that Sumo1 was recruited to the bile salt export pump (BSEP), the small heterodimer partner (SHP), and the OSTα-OSTß organic solute transporter loci in a ligand-dependent fashion. Sequential chromatin immunoprecipitation (ChIP-ReChIP) verified the concurrent binding of FXR and Sumo1 to the BSEP and SHP promoters. Overexpression of Sumo1 markedly decreased binding and/or recruitment of FXR to the BSEP and SHP promoters on ChIP-ReChIP. SUMOylation did not have an apparent effect on nuclear localization of FXR. Expression of Sumo1 markedly inhibited the ligand-dependent, transactivation of BSEP and SHP promoters by FXR/retinoid X receptor α (RXRα) in HepG2 cells. In contrast, mutations that abolished SUMOylation of FXR or siRNA knockdown of Sumo1 expression augmented the transactivation of BSEP and SHP promoters by FXR. Pathways for SUMOylation were significantly altered during obstructive cholestasis with differential Sumo1 recruitment to the promoters of FXR target genes. In conclusion, FXR is subject to SUMOylation that regulates its capacity to transactivate its target genes in normal liver and during obstructive cholestasis.


Assuntos
Regulação da Expressão Gênica , Receptores Citoplasmáticos e Nucleares/metabolismo , Sumoilação , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Motivos de Aminoácidos , Substituição de Aminoácidos , Animais , Colestase/metabolismo , Cromatina/metabolismo , Sequência Consenso , Técnicas de Silenciamento de Genes , Células Hep G2 , Humanos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mutagênese Sítio-Dirigida , Regiões Promotoras Genéticas , Ligação Proteica , Processamento de Proteína Pós-Traducional , Transporte Proteico , RNA Interferente Pequeno/genética , Receptores Citoplasmáticos e Nucleares/química , Receptores Citoplasmáticos e Nucleares/genética , Proteína SUMO-1/genética , Proteína SUMO-1/metabolismo , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/genética , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Transcrição Gênica
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