Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 234
Filtrar
1.
Stroke ; 51(10): 3064-3073, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32883193

RESUMO

BACKGROUND AND PURPOSE: Understanding the mechanisms underlying progression/regression of symptomatic intracranial atherosclerotic stenosis (sICAS) will inform secondary prevention of the patients. Focal wall shear stress (WSS) may play an important role, which, however, had seldom been investigated. METHODS: Patients with acute ischemic stroke or transient ischemic attack (TIA) attributed to 50% to 99% intracranial atherosclerotic stenosis were recruited. All patients underwent cerebral computed tomography angiography at baseline, and a computational fluid dynamics model was built based on computed tomography angiography to simulate blood flow and quantify WSS in the vicinity of the sICAS lesion. All patients received optimal medical treatment and a second computed tomography angiography at 1 year. The change in the luminal stenosis from baseline to 1 year in sICAS was defined as progression (increased >10%), quiescence (±10%), or regression (decreased >10%). Associations between baseline WSS metrics and sICAS regression were analyzed. RESULTS: Among 39 patients (median age 62 years; 27 males), sICAS luminal stenosis progressed, remained quiescent and regressed in 6 (15.4%), 15 (38.5%), and 18 (46.2%) cases, respectively. A higher maximum WSS and larger high-WSS area, throughout the sICAS lesion or obtained separately in the proximal and distal parts of the lesion, were independently associated with regression of luminal stenosis in sICAS over 1 year. CONCLUSIONS: A majority of sICAS lesions regress or stay quiescent in the luminal stenosis over 1 year after stroke under optimal medical treatment, when higher focal WSS may facilitate stenosis regression. Further studies of the effects of hemodynamics including WSS in altering plaque vulnerability and stroke risks are needed.

2.
Ann Plast Surg ; 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32881745

RESUMO

BACKGROUND: A plump single eyelid with ptosis is the morphological feature of Asians. Orbicularis oculi muscle (OOM) technique can correct ptosis and get a good appearance. METHODS: A retrospective study was conducted in 121 Chinese patients who underwent double eyelid surgery with medial epicanthoplasty using OOM resection technique from December 2016 to December 2019. Preoperatively, all the patients had good or excellent levator function while skin fold overlapping the upper eyelid margin was found. Palpebral fissure height, upper eyelid margin reflex distance, complications, and cosmetic results were evaluated. Comparisons were performed preoperatively and postoperatively. RESULTS: The study included 121 patients. Mean follow-up time was 12.8 months (range, 6-32 months). Mean margin reflex distance increased from 1.96 ± 0.60 mm preoperatively to 3.74 ± 0.50 mm postoperatively (P < 0.001), mean palpebral fissure height increased from 6.31 ± 0.51 mm preoperatively to 8.33 ± 0.52 mm postoperatively (P < 0.001). Most patients obtained satisfactory results. Only 1 patient was under correction, 2 patients were with mild asymmetry 6 months postoperatively. CONCLUSIONS: Ptosis of the upper eyelid can be corrected by the OOM resection technique without any procedure on levator muscle. This technique can be an alternative method for the correction of ptosis of the upper eyelid.

3.
J Virol ; 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32967962

RESUMO

As the most severely lethal viral pathogen for crustaceans both in brackish water and freshwater, the white spot syndrome virus (WSSV) has a mechanism of infection that remains largely unknown, which profoundly limits the control of WSSV disease. By using a hematopoietic tissue (Hpt) stem cell culture from red claw crayfish Cherax quadricarinatus suitable for WSSV propagation in vitro, the intracellular trafficking of live WSSV was determined for the first time via live-cell imaging, in which the acidic pH-dependent endosomal environment was a prerequisite for WSSV fusion. When the acidic pH within the endosome was alkalized by chemicals, the intracellular WSSV virions were detained in dysfunctional endosomes, resulting in appreciable blocking of the viral infection. Furthermore, disrupted valosin-containing protein (CqVCP) activity resulted in considerable aggregation of endocytic WSSV virions in the disordered endosomes, which subsequently recruited autophagosomes, likely by binding to CqGABARAP via CqVCP, to eliminate the aggregated virions within the dysfunctional endosomes. Importantly, both autophagic sorting and the degradation of intracellular WSSV virions were clearly enhanced in the Hpt cells with increased autophagic activity, demonstrating that autophagy played a defensive role against the WSSV infection. Intriguingly, most of the endocytic WSSV virions were directed to the endosomal delivery system facilitated by CqVCP activity such that they avoided autophagy degradation and successfully delivered the viral genome into Hpt cell nucleus, which was followed by the propagation of progeny virions. These findings will benefit anti-WSSV target design against the most severe viral disease currently affecting farmed crustaceans.IMPORTANCEWhite spot disease is currently the most devastating viral disease in farmed crustaceans, such as shrimp and crayfish, which has resulted in a severe ecological problem for both brackish water and fresh water aquaculture areas worldwide. The efficient antiviral control against WSSV disease is still lacking due to our limited knowledge of its pathogenesis. Importantly, research on the WSSV infection mechanism is also quite meaningful for the elucidation of viral pathogenesis and virus-host coevolution, as WSSV is one of the largest animal viruses in terms of genome size which infects only crustaceans. Here, we found that most of the endocytic WSSV virions were directed to the endosomal delivery system strongly facilitated by CqVCP, such that they avoided autophagic degradation and successfully delivered the viral genome into the Hpt cell nucleus for propagation. Our data point to a virus-sorting model that might also explain the escape of other enveloped DNA viruses.

4.
IEEE Rev Biomed Eng ; PP2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32915747

RESUMO

The relatively limited understanding of the physiology of uterine activation prevents us from achieving optimal clinical outcomes for managing serious pregnancy disorders such as preterm birth or uterine dystocia. There is increasing awareness that multi-scale computational modeling of the uterus is a promising approach for providing a qualitative and quantitative description of uterine physiology. The overarching objective of such approach is to coalesce previously fragmentary information into a predictive and testable model of uterine activity that, in turn, informs the development of new diagnostic and therapeutic approaches to these pressing clinical problems. This article assesses current progress towards this goal. We summarize the electrophysiological basis of uterine activation as presently understood and review recent research approaches to uterine modeling at different scales from single cell to tissue, whole organ and organism with particular focus on transformative data in the last decade. We describe the positives and limitations of these approaches, thereby identifying key gaps in our knowledge on which to focus, in parallel, future computational and biological research efforts.

5.
Artigo em Inglês | MEDLINE | ID: mdl-32936409

RESUMO

SO3 in the copper smelting flue gas not only causes serious corrosion in heat exchange and dust collection equipment but also increases the amount of sewage acid (waste acid or polluted acid from copper smelting). In this study, we attempted to reduce the damage by ejecting pyrite into the flue to suppress SO3 formation in the flue. First, the Gibbs free energy for the chemical reactions between the substances was obtained after ejecting pyrite. Subsequently, the thermodynamic study of SO2-O2-H2O-N2-CO2-CO system was performed. Then, a kinetic study on the decomposition and oxidation behaviour of pyrite in the flue system was performed through thermogravimetric experiments. Results show that pyrite decomposition and oxidation in the flue system have a very strong oxygen consumption capacity. The SO3 formation in the copper smelting flue gas is suppressed by the consumption of oxygen in the flue to control the reaction direction of 2SO2 + O2 ⇋ 2SO3 and the partial pressure of SO3.

6.
Molecules ; 25(15)2020 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-32751110

RESUMO

The numerous interconnected biochemical pathways that make up the metabolism of a living cell comprise a fuzzy logic system because of its high level of complexity and our inability to fully understand, predict, and model the many activities, how they interact, and their regulation. Each cell contains thousands of proteins with changing levels of expression, levels of activity, and patterns of interactions. Adding more layers of complexity is the number of proteins that have multiple functions. Moonlighting proteins include a wide variety of proteins where two or more functions are performed by one polypeptide chain. In this article, we discuss examples of proteins with variable functions that contribute to the fuzziness of cellular metabolism.

7.
Pediatr Res ; 2020 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-32791515

RESUMO

BACKGROUND: The definition of pediatric AKI continues to evolve. We aimed to find a better AKI definition to predict outcomes and identify risk factors for AKI in a Chinese PICU. METHODS: This study consisted of 3338 patients hospitalized in a Chinese PICU between 2016 and 2018. AKI was defined and staged using pROCK criteria, which were compared with KDIGO criteria. AKI outcomes, including mortality, daily cost and length of stay (LOS), were assessed. Risk factors for AKI were also estimated. RESULTS: The incidence of AKI in the PICU was 7.7% according to pROCK criteria. The characteristics of patients with KDIGO-defined AKI who did not meet the pROCK were similar to those without AKI. pROCK outperformed KDIGO in predicting mortality with a higher c index in the Cox models (0.81 versus 0.79, P = 0.013). AKI, as well as AKI stages, were associated with higher mortality (HR: 10.5, 95%CI: 6.66-19.5), daily cost (ß = 2064, P < 0.01) and LOS (ß = 2.30, P < 0.01). Age, comorbidities, mechanical ventilation (MV), pediatric critical illness score (PCIS) and exposure to drugs had significant influence on AKI occurrence. CONCLUSIONS: The mortality predictability of pROCK was slightly greater than that of KDIGO. Older age, underlying comorbidities, MV, decreased PCIS and exposure to drugs were potential risk factors for AKI. IMPACT: Two AKI criteria, pROCK and KDIGO, were significantly associated with an increased risk of mortality and pROCK was slightly greater than that of KDIGO.Older age, comorbidities, mechanical ventilation, decreased PCIS and exposure to drugs were potential risk factors for AKI.This study first used the pROCK criteria to provide an epidemiologic description of pediatric AKI in Chinese PICU.This study compared the AKI outcomes across the pROCK and KDIGO AKI criteria, indicating the prior utility for AKI classification in Chinese children.This study indicated that the potential risk factors for AKI were older age, comorbidities, mechanical ventilation, decreased PCIS and exposure to drugs.

8.
Fish Shellfish Immunol ; 105: 244-252, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32693160

RESUMO

Barrier-to-autointegration factor (BAF) is a highly conserved DNA binding protein that participates in a variety of biological processes such as transcription, epigenetic regulation and antiviral immunity in vertebrates. However, the function of BAF is poorly understood in crustaceans. In this study, we identified a barrier-to-autointegration factor (CqBAF) from red claw crayfish Cherax quadricarinatus, which was responsive to white spot syndrome virus (WSSV) infection. The full-length cDNA sequence of CqBAF was 544 bp, including an open reading frame of 273 bp encoding 90 amino acids, a 107 bp of 5'-Untranslated Regions (5'-UTR) and a 164 bp of 3'-UTR. Gene expression analysis showed that CqBAF was distributed in all tissues examined with the highest expression in the crayfish haematopietic tissue (Hpt), which protein expression was also significantly up-regulated by WSSV infection in Hpt cells. Furthermore, the transcripts of both an immediate early gene IE1 and a late envelope protein gene VP28 of WSSV were clearly reduced in Hpt cells after gene silencing of CqBAF. Importantly, the promoter activity of two immediate early genes of WSSV, including WSV051 and IE1, was strongly enhanced by the increased phosphorylation of CqBAF, which also facilitated the accumulation of CqBAF protein in the cytoplasm of Sf9 cells. Taken together, these data suggest that CqBAF is likely to increase the replication of WSSV by promoting the transcription of viral immediate early genes, probably regulated by phosphorylation of CqBAF, which sheds new light on the molecular mechanism of WSSV infection.

9.
Comput Methods Programs Biomed ; 196: 105632, 2020 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-32615491

RESUMO

BACKGROUND AND OBJECTIVE: The instantaneous wave-free ratio (iFR) has been proposed to estimate the hemodynamic severity of atherosclerotic stenosis in coronary arteries. The atherosclerotic stenosis in a proximal coronary artery could change its distal microcirculatory resistance (MR). However, there is a lack of investigation about the effect of MR variation on the blood flow and iFR of stenotic coronary arteries. We aim to investigate the changes of blood flow and iFR caused by distal MR variation. METHODS: Four three-dimensional models of coronary arteries were reconstructed from the computed tomography images of two normal cases and two cases with 74.9% and 96.4% (in area) stenoses in a large branch of left anterior descending artery (LAD). Computational fluid dynamics simulation was performed on each model under 6 MR situations: hyperemia as the reference situation, resting when MR was multiplied by 8/3 in all outlet branches, h-one-1.5 and h-one-2 when MR was multiplied by 1.5 and 2.0 in one branch (the stenotic, or the corresponding branch in normal case) of LAD, h-branches-1.5 and h-branches-2 when MR was multiplied by 1.5 and 2.0 in the stenotic/corresponding and its cognate branches. Flow rate and iFR of each outlet branch were then calculated and compared between different MR situations to investigate the effect of MR variation on flow rate and iFR. RESULTS: In the 74.9% stenosed and normal cases, referring to the hyperemia situation, the increase of MR in any branch significantly decreased its flow rate and increased its iFR, with limited effect on the flow rate (<3%) and iFR (<0.01) of other branches. However, in the 96.4% stenosed case, the doubled MR in the stenosed branch (h-one-2) significantly increased the flow rate (>10%) and iFR (>0.05) of its cognate branches. CONCLUSION: The increase of MR in a normal or mildly stenosed branch of coronary artery decreases its blood flow and increases its iFR, with limited effect on other branches. Whereas, the increase of MR in a severely stenotic large branch could significantly increase the flow velocity and iFR of its cognate branches.

10.
Physiol Meas ; 41(9): 094001, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-32731213

RESUMO

OBJECTIVE: Based on different physiological mechanisms, the respiratory modulations of photoplethysmography (PPG) signals differ in strength and resultant accuracy of respiratory frequency (RF) estimations. We aimed to investigate the strength of different respiratory modulations and the accuracy of resultant RF estimations in different body sites and two breathing patterns. APPROACH: PPG and reference respiratory signals were simultaneously measured over 60 s from 36 healthy subjects in six sites (arm, earlobe, finger, forehead, wrist-under (volar side), wrist-upper (dorsal side)). Respiratory signals were extracted from PPG recordings using four demodulation approaches: amplitude modulation (AM), baseline wandering (BW), frequency modulation (FM) and filtering. RFs were calculated from the PPG-derived and reference respiratory signals. To investigate the strength of respiratory modulations, the energy proportion in the range that covers 75% of the total energy in the reference respiratory signal, with RF in the middle, was calculated and compared between different modulations. Analysis of variance and the Scheirer-Ray-Hare test were performed with post hoc analysis. MAIN RESULTS: In normal breathing, FM was the only modulation whose RF was not significantly different from the reference RF (p > 0.05). Compared with other modulations, FM was significantly higher in energy proportion (p < 0.05) and lower in RF estimation error (p < 0.05). As to energy proportion, measurements from the finger and the forehead were not significantly different (p > 0.05), but both were significantly different from the other four sites (p < 0.05). In deep breathing, the RFs derived by BW, filtering and FM were not significantly different from the reference RF (p > 0.05). The RF estimation error of FM was significantly less than that of AM or BW (p < 0.05). The energy proportion of FM was significantly higher than that of other modulations (p < 0.05). SIGNIFICANCE: Of all the respiratory modulations, FM has the highest strength and is appropriate for accurate RF estimation from PPG signals recorded at different sites and for different breathing patterns.

11.
JAMA Netw Open ; 3(6): e205842, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32492161

RESUMO

Importance: There is a lack of studies exploring the performance of a deep learning survival neural network in non-small cell lung cancer (NSCLC). Objectives: To compare the performances of DeepSurv, a deep learning survival neural network with a tumor, node, and metastasis staging system in the prediction of survival and test the reliability of individual treatment recommendations provided by the deep learning survival neural network. Design, Setting, and Participants: In this population-based cohort study, a deep learning-based algorithm was developed and validated using consecutive cases of newly diagnosed stages I to IV NSCLC between January 2010 and December 2015 in a Surveillance, Epidemiology, and End Results database. A total of 127 features, including patient characteristics, tumor stage, and treatment strategies, were assessed for analysis. The algorithm was externally validated on an independent test cohort, comprising 1182 patients with stage I to III NSCLC diagnosed between January 2009 and December 2013 in Shanghai Pulmonary Hospital. Analysis began January 2018 and ended June 2019. Main Outcomes and Measures: The deep learning survival neural network model was compared with the tumor, node, and metastasis staging system for lung cancer-specific survival. The C statistic was used to assess the performance of models. A user-friendly interface was provided to facilitate the survival predictions and treatment recommendations of the deep learning survival neural network model. Results: Of 17 322 patients with NSCLC included in the study, 13 361 (77.1%) were white and the median (interquartile range) age was 68 (61-74) years. The majority of tumors were stage I disease (10 273 [59.3%]) and adenocarcinoma (11 985 [69.2%]). The median (interquartile range) follow-up time was 24 (10-43) months. There were 3119 patients who had lung cancer-related death during the follow-up period. The deep learning survival neural network model showed more promising results in the prediction of lung cancer-specific survival than the tumor, node, and metastasis stage on the test data set (C statistic = 0.739 vs 0.706). The population who received the recommended treatments had superior survival rates than those who received treatments not recommended (hazard ratio, 2.99; 95% CI, 2.49-3.59; P < .001), which was verified by propensity score-matched groups. The deep learning survival neural network model visualization was realized by a user-friendly graphic interface. Conclusions and Relevance: The deep learning survival neural network model shows potential benefits in prognostic evaluation and treatment recommendation with respect to lung cancer-specific survival. This novel analytical approach may provide reliable individual survival information and treatment recommendations.

12.
Dev Comp Immunol ; 111: 103749, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32505616

RESUMO

The Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway is pivotal in immune responses for a variety of pathogens in both vertebrates and invertebrates. Domeless (Dome), as a unique cytokine receptor, involves in the upstream JAK/STAT pathway in invertebrates. In this study, the full-length cDNA sequence of a cytokine receptor Dome was identified from red claw crayfish Cherax quadricarinatus (named as CqDome), which contained an open reading frame of 4251 bp, encoding 1416 amino acids. The CqDome contained extracellular conservative domains of a signal peptide, two cytokine binding modules (CBM), three fibronectin-type-III-like (FN3) domains and a transmembrane region. Tissue distribution analysis showed that CqDome generally expressed in all the tissues selected with a high expression in hemocyte. The gene expression of both the viral immediately early gene (IE1) and a late gene envelope protein VP28 of white spot syndrome virus (WSSV) were significantly decreased after gene silencing of CqDome in crayfish haematopoietic tissue (Hpt) cells, indicating a key role of CqDome in promoting WSSV infection. Furthermore, the phosphorylation level of CqSTAT was significantly inhibited by gene silencing of CqDome in Hpt cells, indicating that CqDome participated in signal transduction of JAK/STAT pathway in red claw crayfish. These data together suggest that CqDome is likely to promote WSSV infection via JAK/STAT pathway, which sheds new light on further elucidation of the pathogenesis of WSSV.

13.
Front Immunol ; 11: 824, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32536909

RESUMO

The momentous discovery of phagocytic activity in teleost B cells has caused a dramatic paradigm shift from the belief that phagocytosis is performed mainly by professional phagocytes derived from common myeloid progenitor cells, such as macrophages/monocytes, neutrophils, and dendritic cells. Recent advances on phagocytic B cells and their microbicidal ability in teleost fish position B cells at the crossroads, bridging innate with adaptive immunity. Most importantly, an increasing body of experimental evidence demonstrates that, in both teleosts and mammals, phagocytic B cells can recognize, take up, and destroy particulate antigens and then present those processed antigens to CD4+ T cells to elicit adaptive immune responses and that the phagocytosis is mediated by pattern recognition receptors and involves multiple cytokines. Thus, current findings collectively indicate that teleost phagocytic B cells, as well as their counterpart mammalian B1-B cells, can be considered one kind of professional phagocyte. The aim of this review is to summarize recent advances regarding teleost phagocytic B cells, with a particular focus on the recognizing receptors and modulating mechanisms of phagocytic B cells and the process of antigen presentation for T-cell activation. We also attempt to provide new insights into the adaptive evolution of the teleost fish phagocytic B cell on the basis of its innate and adaptive roles.

14.
Comput Biol Chem ; 86: 107261, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32361585

RESUMO

Mutant isocitrate dehydrogenase 2 (mIDH2) is an emerging target for the treatment of cancer. AG-221 is the first mIDH2 inhibitor approved by the FDA for acute myeloid leukemia treatment, but its acquired resistance has recently been observed, necessitating the development of new inhibitor. In this study, a multi-step virtual screening protocol was employed for the analysis of a large database of compounds to identify potential mIDH2 inhibitors. To this end, we firstly utilized molecular dynamics (MD) simulations and binding free energy calculations to elucidate the key factors affecting ligand binding and drug resistance. Based on these findings, the receptor-ligand interaction-based pharmacophore (IBP) model and hierarchical docking-based virtual screening were sequentially carried out to assess 212,736 compounds from the Specs database. The resulting hits were finally ranked by PAINS filter and ADME prediction and the top compounds were obtained. Among them, six molecules were identified as mIDH2 putative inhibitors with high selectivity by interacting with the capping residue Asp312. Furthermore, subsequent docking and MD experiments demonstrated that compound V2 might have potential inhibitory activity against the AG-221-resistant mutants, thereby making it a promising lead for the development of novel mIDH2 inhibitors.

15.
ChemSusChem ; 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32394542

RESUMO

The emerging generation of flexible energy storage devices has accelerated the research pace in terms of new materials, new processing techniques, and new designs that can meet the demands of mechanical stability upon bending or stretching at an acceptable cost, without compromising their electrochemical performance. Among the materials currently explored, biomass-derived materials have received extensive attention, because they are renewable, low in cost, earth-abundant and structurally diverse. This review is focused on fundamentals and applications of the bio-derived material bacterial cellulose (BC) in flexible electrochemical energy storage systems. Specifically, recent advances are summarized in the utilization of BC in stretchable substrates, carbonaceous species, and scaffolds for flexible core component construction. Finally, several perspectives related to BC-based materials for flexible electrochemical energy storages are proposed, aiming to provide possible future research directions in these fields.

16.
Front Immunol ; 11: 560, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32425924

RESUMO

Cell-based immunotherapies have tremendous potential to treat many diseases, such as activating immunity in cancer or suppressing it in autoimmune diseases. Most cell-based cancer immunotherapies in the clinic provide adjuvant signals through genetic engineering to enhance T cell functions. However, genetically encoded signals have minimal control over dosing and persist for the life of a cell lineage. These properties make it difficult to balance increasing therapeutic efficacy with reducing toxicities. Here, we demonstrated the potential of phospholipid-coupled ligands as a non-genetic system for immune cell engineering. This system provides simple, controlled, non-genetic adjuvant delivery to immune cells via lipid-mediated insertion into plasma membranes. Lipid-mediated insertion (termed depoting) successfully delivered Toll-like receptor (TLR) ligands intracellularly and onto cell surfaces of diverse immune cells. These ligands depoted into immune cells in a dose-controlled fashion and did not compete during multiplex pairwise loading. Immune cell activation could be enhanced by autocrine and paracrine mechanisms depending on the biology of the TLR ligand tested. Depoted ligands functionally persisted on plasma membranes for up to 4 days in naïve and activated T cells, enhancing their activation, proliferation, and skewing cytokine secretion. Our data showed that depoted ligands provided a persistent yet non-permanent adjuvant signal to immune cells that may minimize the intensity and duration of toxicities compared to permanent genetic delivery. Altogether, these findings demonstrate potential for lipid-mediated depoting as a universal cell engineering approach with unique, complementary advantages to other cell engineering methods.

17.
Biomed Eng Online ; 19(1): 21, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32295576

RESUMO

BACKGROUND: As one of the major complications of diabetes, diabetic retinopathy (DR) is a leading cause of visual impairment and blindness due to delayed diagnosis and intervention. Microaneurysms appear as the earliest symptom of DR. Accurate and reliable detection of microaneurysms in color fundus images has great importance for DR screening. METHODS: A microaneurysms' detection method using machine learning based on directional local contrast (DLC) is proposed for the early diagnosis of DR. First, blood vessels were enhanced and segmented using improved enhancement function based on analyzing eigenvalues of Hessian matrix. Next, with blood vessels excluded, microaneurysm candidate regions were obtained using shape characteristics and connected components analysis. After image segmented to patches, the features of each microaneurysm candidate patch were extracted, and each candidate patch was classified into microaneurysm or non-microaneurysm. The main contributions of our study are (1) making use of directional local contrast in microaneurysms' detection for the first time, which does make sense for better microaneurysms' classification. (2) Applying three different machine learning techniques for classification and comparing their performance for microaneurysms' detection. The proposed algorithm was trained and tested on e-ophtha MA database, and further tested on another independent DIARETDB1 database. Results of microaneurysms' detection on the two databases were evaluated on lesion level and compared with existing algorithms. RESULTS: The proposed method has achieved better performance compared with existing algorithms on accuracy and computation time. On e-ophtha MA and DIARETDB1 databases, the area under curve (AUC) of receiver operating characteristic (ROC) curve was 0.87 and 0.86, respectively. The free-response ROC (FROC) score on the two databases was 0.374 and 0.210, respectively. The computation time per image with resolution of 2544×1969, 1400×960 and 1500×1152 is 29 s, 3 s and 2.6 s, respectively. CONCLUSIONS: The proposed method using machine learning based on directional local contrast of image patches can effectively detect microaneurysms in color fundus images and provide an effective scientific basis for early clinical DR diagnosis.

18.
Am J Nephrol ; 51(6): 453-462, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32349004

RESUMO

BACKGROUND: The lack of consensus criteria of acute on chronic kidney injury (ACKI) affects the judgment for its clinical prognosis. METHODS: In this study, we analyzed the data from 711,615 hospitalized adults who had at least 2 serum creatinine (SCr) tests within 30 days. We estimated the reference change value (RCV) of SCr given initial SCr level in adults without known risks of acute kidney injury other than chronic kidney disease (CKD). We proposed a criterion for ACKI based on the RCV of SCr (cROCK), which defined ACKI as a ≥25% increase in SCr in 7 days. We validated cROCK by its association with the risks of in-hospital mortality, death after discharge, and CKD progression in a large cohort of patients with CKD stage 3. RESULTS: In 21,661 patients with CKD stage 3, a total of 3,145 (14.5%), 1,512 (7.0%), and 221 (1.0%) ACKI events were detected by both cROCK and Kidney Disease Improving Global Outcomes (KDIGO), cROCK only, and KDIGO only, respectively. cROCK detected 40% more ACKI events than KDIGO. Compared with patients without ACKI by both definitions, those with cROCK- but not KDIGO-defined ACKI had a significantly increased risk of in-hospital mortality (hazard ratio [HR] 5.53; 95% CI 3.75-8.16), death after discharge (HR 1.51; 95% CI 1.21-1.83), and CKD progression (OR 5.65; 95% CI 3.05-10.48). CONCLUSIONS: RCV-based criterion (cROCK) for ACKI is clinically valid in that it has a substantially improved sensitivity in identifying patients with high risk of adverse outcomes.

19.
Front Immunol ; 11: 268, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32194551

RESUMO

Phagocytosis is an ancient, highly conserved process in all multicellular organisms, through which the host can protect itself against invading microorganisms and environmental particles, as well as remove self-apoptotic cells/cell debris to maintain tissue homeostasis. In crustacean, phagocytosis by hemocyte has also been well-recognized as a crucial defense mechanism for the host against infectious agents such as bacteria and viruses. In this review, we summarized the current knowledge of hemocyte-mediated phagocytosis, in particular focusing on the related receptors for recognition and internalization of pathogens as well as the downstream signal pathways and intracellular regulators involved in the process of hemocyte phagocytosis. We attempted to gain a deeper understanding of the phagocytic mechanism of different hemocytes and their contribution to the host defense immunity in crustaceans.

20.
Dev Comp Immunol ; 107: 103665, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32147597

RESUMO

Invertebrates rely solely on the innate immune system to protect against virus infection, while the viral infection must rely on the transcriptional system of the host cell to achieve the expression of viral genes, which is naturally regulated by the host's transcriptional system. However, the mechanism of the host against viral transcription in host cells is still poorly understood in crustaceans. Previously, we found that the partial transcript sequence of a negative elongation factor E (named as CqNELF-E) was up-regulated in a differentially expressed transcriptome library of the haematopietic tissue (Hpt) cells from red claw crayfish Cherax quadricarinatus upon white spot syndrome virus (WSSV) infection, suggesting a possible role of CqNELF-E in WSSV-host interaction. In the present study, we revealed the function of CqNELF-E. The full-length cDNA sequence of CqNELF-E was identified with 1726 bp from red claw crayfish, which contained an open reading frame of 816 bp, encoding 271 amino acids. Amino acid sequencing analysis revealed that the CqNELF-E had a conserved RNA recognition motif (RRM) and a leucine zipper motif (LZM). Tissue distribution analysis showed that CqNELF-E was widely expressed in various tissues with the highest expression in muscle, relatively abundant in Hpt and the lowest presence in heart. Interestingly, the gene expression of CqNELF-E was significantly up-regulated at both 6 and 12 hpi after WSSV infection in Hpt cell cultures in red claw crayfish. In addition, the expression of both the viral immediately early gene (IE) 1 (IE1) and a late gene envelope protein VP28 were significantly increased after gene silencing of CqNELF-E in Hpt cells, indicating the potential suppression role of CqNELF-E against the viral infection. Further study revealed that the CqNELF-E had an inhibitory effect on the promoter activity of WSSV IE genes WSV051, WSV069 (IE1) and WSV083 by a dual luciferase reporter gene assay. Taken together, these results suggest that CqNELF-E plays an antiviral role, probably via inhibition on the viral transcription activity in WSSV infection in a crustacean.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA