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1.
Artigo em Inglês | MEDLINE | ID: mdl-34595806

RESUMO

A gold-catalyzed room temperature allenation of terminal alkynes (ATA) with aldehydes affording 1,3-disubstituted allenes with diverse functional groups has been developed by identifying a gold(I) catalyst and an amine. The practicality of this reaction has been demonstrated by a ten gram-scale synthesis and the synthetic potentials have been demonstrated via various transformations and formal total synthesis of (-)-centrolobine. Mechanistic studies revealed that the gold catalyst, the aldehyde effect, and the structure of amine are vital in this room temperature ATA reaction.

2.
Artigo em Inglês | MEDLINE | ID: mdl-34637384

RESUMO

Till March 31st, 2021, the coronavirus disease 2019 (COVID-19) has reportedly infected more than 127 million people and caused over 2.5 million deaths worldwide. Timely diagnosis of COVID-19 is crucial for management of individual patients as well as containment of the highly contagious disease. Having realized the clinical value of non-contrast chest computed tomography (CT) for diagnosis of COVID-19, deep learning (DL) based automated methods have been proposed to aid the radiologists in reading the huge quantities of CT exams as a result of the pandemic. In this work, we address an overlooked problem for training deep convolutional neural networks for COVID-19 classification using real-world multi-source data, namely, the data source bias problem. The data source bias problem refers to the situation in which certain sources of data comprise only a single class of data, and training with such source-biased data may make the DL models learn to distinguish data sources instead of COVID-19. To overcome this problem, we propose MIx-aNd-Interpolate (MINI), a conceptually simple, easy-to-implement, efficient yet effective training strategy. The proposed MINI approach generates volumes of the absent class by combining the samples collected from different hospitals, which enlarges the sample space of the original source-biased dataset. Experimental results on a large collection of real patient data (1,221 COVID-19 and 1,520 negative CT images, and the latter consisting of 786 community acquired pneumonia and 734 non-pneumonia) from eight hospitals and health institutions show that: 1) MINI can improve COVID-19 classification performance upon the baseline (which does not deal with the source bias), and 2) MINI is superior to competing methods in terms of the extent of improvement.

3.
Hum Brain Mapp ; 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34498785

RESUMO

Even clinically "asymptomatic" carotid stenosis is associated with multidomain cognitive impairment, gray matter (GM) atrophy, and silent lesion. However, the links between them remain unclear. Using structural MRI data, we examined GM asymmetry index (AI) and white matter hyperintensity (WMH) in 24 patients with severe asymptomatic carotid stenosis (SACS), 24 comorbidity-matched controls, and independent samples of 84 elderly controls and 22 young adults. As compared to controls, SACS patients showed worse verbal memories, higher WMH burden, and right-lateralized GM in posterior middle temporal and mouth-somatomotor regions. These clusters extended to pars triangularis, lateral temporal, and cerebellar regions, when compared with young adults. Further, a full-path of WMH burden (X), GM volume (atrophy, M1), AI (asymmetry, M2), and neuropsychological variables (Y) through a serial mediation model was analyzed. This analysis identified that left-dominated GM atrophy and right-lateralized asymmetry in the posterior middle temporal cortex mediated the relationship between WMH burden and recall memory in SACS patients. These results suggest that the unbalanced hemispheric atrophy in the posterior middle temporal cortex is crucial to mediating relationship between WMH burden and verbal recall memories, which may underlie accelerated aging and cognitive deterioration in patients with SACS and other vascular cognitive impairment.

4.
Cell Metab ; 33(10): 2059-2075.e10, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34536344

RESUMO

Myocardial ischemia-reperfusion (MIR) injury is a major cause of adverse outcomes of revascularization after myocardial infarction. To identify the fundamental regulator of reperfusion injury, we performed metabolomics profiling in plasma of individuals before and after revascularization and identified a marked accumulation of arachidonate 12-lipoxygenase (ALOX12)-dependent 12-HETE following revascularization. The potent induction of 12-HETE proceeded by reperfusion was conserved in post-MIR in mice, pigs, and monkeys. While genetic inhibition of Alox12 protected mouse hearts from reperfusion injury and remodeling, Alox12 overexpression exacerbated MIR injury. Remarkably, pharmacological inhibition of ALOX12 significantly reduced cardiac injury in mice, pigs, and monkeys. Unexpectedly, ALOX12 promotes cardiomyocyte injury beyond its enzymatic activity and production of 12-HETE but also by its suppression of AMPK activity via a direct interaction with its upstream kinase TAK1. Taken together, our study demonstrates that ALOX12 is a novel AMPK upstream regulator in the post-MIR heart and that it represents a conserved therapeutic target for the treatment of myocardial reperfusion injury.

5.
Neuroimage ; 242: 118473, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34390876

RESUMO

OBJECTIVE: The age-related changes in the resting-state networks (RSNs) exhibited temporally specific patterns in humans, and humans and rhesus monkeys have similar RSNs. We hypothesized that the RSNs in rhesus monkeys experienced similar developmental patterns as humans. METHODS: We acquired resting-state fMRI data from 62 rhesus monkeys, which were divided into childhood, adolescence, and early adulthood groups. Group independent component analysis (ICA) was used to identify monkey RSNs. We detected the between-group differences in the RSNs and static, dynamic, and effective functional network connections (FNCs) using one-way variance analysis (ANOVA) and post-hoc analysis. RESULTS: Eight rhesus RSNs were identified, including cerebellum (CN), left and right lateral visual (LVN and RVN), posterior default mode (pDMN), visuospatial (VSN), frontal (FN), salience (SN), and sensorimotor networks (SMN). In internal connections, the CN, SN, FN, and SMN mainly matured in early adulthood. The static FNCs associated with FN, SN, pDMN primarily experienced fast descending slow ascending type (U-shaped) developmental patterns for maturation, and the dynamic FNCs related to pDMN (RVN, CN, and SMN) and SMN (CN) were mature in early adulthood. The effective FNC results showed that the pDMN and VSN (stimulated), SN (inhibited), and FN (first inhibited then stimulated) chiefly matured in early adulthood. CONCLUSION: We identified eight monkey RSNs, which exhibited similar development patterns as humans. All the RSNs and FNCs in monkeys were not widely changed but fine-tuned. Our study clarified that the progressive synchronization, exploration, and regulation of cognitive RSNs within the pDMN, FN, SN, and VSN denoted potential maturation of the RSNs throughout development. We confirmed the development patterns of RSNs and FNCs would support the use of monkeys as a best animal model for human brain function.

6.
Eur J Radiol ; 143: 109892, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34388419

RESUMO

PURPOSE: To prospectively compare the differences in intravoxel incoherent motion (IVIM)-derived quantitative parameters in different anatomic locations of the normal pancreas with different breathing techniques in a healthy population. METHOD: Twenty-six volunteers successfully underwent pancreas axial IVIM imaging with a 3.0-T MR system using 11 b-values (from 0 to 1000 sec/mm2) with three different breathing techniques: free breath (FB), liver dome scout (LDS), and phase scout (PS). The IVIM-derived quantitative parameters in three anatomic locations (head, body, and tail of the pancreas) were calculated. The intra-, inter-, and short-term consistency of IVIM-derived quantitative parameters were assessed by comparing 95% confidence interval (CI) of limits of agreement (LOA) of difference between measurements and clinical maximum allowed difference using the Bland-Altman method. The Kruskal-Wallis test was used to compare pancreatic IVIM-derived parameters. RESULTS: In Bland-Altman graph, the maximum values of the 95% CIs of LOAs of Dslow, Dfast, and f were (0.123 ± 0.022) × 10-3 mm2/sec, (22.093 ± 4.997) × 10-3 mm2/sec, and (3.942 ± 0.621)%, and the consistency of Dslow and f was good and that of Dfast was poor overall. The Dslow, Dfast, and f values of normal pancreas were (1.056 ± 0.121) × 10-3 mm2/sec, (55.755 ± 13.011) × 10-3 mm2/sec, and (26.036 ± 2.361)%, respectively, and there aren't any breathing technique (P > 0.05) or location (P > 0.05) dependent differences. CONCLUSIONS: Our study shows that IVIM-derived quantitative parameters of the pancreas may not be affected by breathing techniques and anatomic locations. The f and Dslow values have good repeated measurement consistency under different breathing techniques.


Assuntos
Imagem de Difusão por Ressonância Magnética , Fígado , Humanos , Movimento (Física) , Pâncreas/diagnóstico por imagem , Reprodutibilidade dos Testes
7.
Curr Opin Pharmacol ; 60: 200-207, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34461565

RESUMO

Lonicerae japonicae flos (LJF), known as Jin Yin Hua in Chinese, is one of the most commonly used traditional Chinese herbs and nutraceuticals. Nowadays, LJF is broadly applied in an array of afflictions, such as fever, sore throat, flu infection, cough, and arthritis, with the action mechanism to be elucidated. Here, we strove to summarize the main phytochemical components of LJF and review its updated pharmacological effects, including inhibition of inflammation, pyrexia, viruses, and bacteria, immunoregulation, and protection of the liver, nervous system, and heart, with a focus on the potential efficacy of LJF on coronavirus disease-2019 based on network pharmacology so as to fully underpin the utilization of LJF as a medicinal herb and a favorable nutraceutical in daily life.

8.
J Integr Neurosci ; 20(2): 331-340, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34258931

RESUMO

Previous studies have confirmed the sex difference of gray matter asymmetry in typically developing controls and the abnormal gray matter asymmetry in autism spectrum disorders. However, whether and how sex differences of gray matter asymmetry exist in autism spectrum disorders remains studied. This paper analyzes the above issues and explores correlations between gray matter asymmetry and autistic symptoms. Data from 72 children (36 males and 36 females) with autism spectrum disorders and 72 typically developing-controls (36 males and 36 females) between 8 and 14 years were included and obtained from the autism brain imaging data exchange repository (autism brain imaging data exchange I and autism brain imaging data exchange II). The voxel-based morphometry approach was used to assess gray matter asymmetry in T1-weighted brain data, and gray matter asymmetry was quantified as asymmetry index. A 2 × 2 analysis of covariance was used to identify asymmetry index differences among the four groups. Pearson correlation analysis was performed for asymmetry index values extracted from the clusters with significant differences between the four groups and autistic symptoms (social impairments, communication difficulties, and restricted, repetitive behaviors) measured by the revised autism diagnostic interview scale. Results showed that specific brain regions showed significant main effects for diagnosis in which autism spectrum disorders patients had more leftward asymmetry than typically developing-controls for the parahippocampal gyrus and the postcentral gyrus; specific brain regions showed significant main effects for sex in which females showed more rightward asymmetry for the middle temporal gyrus, inferior frontal gyrus, angular gyrus, and postcentral gyrus and minor rightward asymmetry for the superior frontal gyrus than males; significant diagnosis × sex interaction effects were identified in the angular gyrus and middle occipital gyrus. Pearson correlation analysis showed that males with autism spectrum disorders had a positive association between the asymmetry index value in the middle occipital gyrus and more significant verbal impairment measured by the revised autism diagnostic interview (r = 0.387, p = 0.026). The asymmetry index value in the parahippocampal gyrus was positively associated with more severe social impairment in females with autism spectrum disorders (r = 0.422, p = 0.020). We identified that the sex difference of gray matter asymmetry in children with autism spectrum disorders is qualitative rather than quantitative, which is relatively novel. Our findings provide the theoretical basis for conducting separate studies and using sex-specific diagnostic methods and treatments for males and females children with autism spectrum disorders.

9.
FEMS Microbiol Lett ; 368(13)2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34156066

RESUMO

Until recently, classical breeding has been used to generate improved commercial mushroom strains; however, classical breeding remains to be laborious and time-consuming. In this study, we performed gene mutagenesis using Cas9 ribonucleoprotein (Cas9 RNP) as a plasmid-free genome editing in Pleurotus ostreatus, which is one of the most economically important cultivated mushrooms. The pre-assembled Cas9/sgRNA targeting pyrG was introduced into protoplasts of a wild-type monokaryotic P. ostreatus strain PC9, which resulted in a generation of strains exhibiting resistance to 5-fluoroorotic acid. Small insertions/deletions at the target site were identified using genomic PCR followed by sequencing. The results showed Cas9 RNP-assisted gene mutagenesis could be applied for the molecular breeding in P. ostreatus and in other edible mushroom strains. Furthermore, gene disruption via split-marker recombination using the Cas9 RNP system was also successfully demonstrated in wild-type P. ostreatus PC9. This method could overcome the disadvantages of NHEJ-deficiency in conventional studies with gene targeting, and also difficulty in gene targeting in various non-model agaricomycetes.

10.
J Immunol Res ; 2021: 6657894, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34150910

RESUMO

Background: The 2019 novel coronavirus SARS-CoV-2 caused large outbreaks of COVID-19 worldwide. COVID-19 resembles community-acquired pneumonia (CAP). Our aim was to identify lymphocyte subpopulations to distinguish between COVID-19 and CAP. Methods: We compared the peripheral blood lymphocytes and their subsets in 296 patients with COVID-19 and 130 patients with CAP. Parameters for independent prediction of COVID-19 were calculated by logistic regression. Results: The main lymphocyte subpopulations (CD3+CD4+, CD16+CD56+, and CD4+/CD8+ ratio) and cytokines (TNF-α and IFN-γ) of COVID-19 patients were significantly different from that of CAP patients. CD16+CD56+%, CD4+/CD8+ratio, CD19+, and CD3+CD4+ were identified as predictors of COVID-19 diagnosis by logistic regression. In addition, the CD3+CD4+counts, CD3+CD8+ counts, andTNF-α are independent predictors of disease severity in patients. Conclusions: Lymphopenia is an important part of SARS-CoV-2 infection, and lymphocyte subsets and cytokines may be useful to predict the severity and clinical outcomes of the disease.


Assuntos
Relação CD4-CD8 , COVID-19/sangue , Interferon gama/sangue , Subpopulações de Linfócitos/citologia , Pneumonia/sangue , Fator de Necrose Tumoral alfa/sangue , Adulto , Idoso , COVID-19/imunologia , COVID-19/patologia , Teste para COVID-19 , Infecções Comunitárias Adquiridas/microbiologia , Feminino , Humanos , Subpopulações de Linfócitos/imunologia , Linfopenia/sangue , Linfopenia/patologia , Masculino , Pessoa de Meia-Idade , Pneumonia/imunologia , Pneumonia/patologia , Prognóstico , SARS-CoV-2/imunologia , Índice de Gravidade de Doença
11.
Eur J Pharmacol ; 906: 174253, 2021 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-34118224

RESUMO

Dysregulated Wnt/ß-catenin signaling pathway plays a critical role in the pathogenesis of colorectal cancer (CRC). Scutellarin, a flavonoid compound in Scutellaria barbata, has been reported to suppress CRC, with the action mechanism elusive. In this study, Scutellarin was found to inhibit the carcinogenesis of colitis-associated cancer (CAC) in mice caused by azoxymethane/dextran sulfate sodium, with alleviation of pathologic symptoms. Besides, Scutellarin attenuated mouse serum concentrations of TNF-α and IL-6, heightened Bax expression and diminished B-cell lymphoma-2 (Bcl-2) level in CAC tissues of mice, through down-regulating Wnt/ß-catenin signaling cascade. In CRC HT-29 cells, Scutellarin retarded the proliferation and migration, induced apoptosis, with boosted Bax expression and decreased Bcl-2 level, which may be attributed to its repression of Wnt/ß-catenin signals in HT-29 cells. Our findings demonstrate that Scutellarin may ameliorate colitis-associated colorectal cancer by weakening Wnt/ß-catenin signaling cascade.

12.
NMR Biomed ; 34(7): e4529, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33982808

RESUMO

MRI signals are intrinsically multi-dimensional, and signal behavior may be orthogonal among different dimensions. Such dimensional orthogonality can be utilized to eliminate unwanted effects and facilitate mathematical simplicity during image processing for improved outcomes. In this work, we will demonstrate and analyze the principles and performance of a newly developed multi-dimensional integration (MDI) strategy in MR T2 * mapping. By constructing a complex signal function to extract the inter-echo signal changes, MDI solves an optimization problem by processing all signal dimensions (eg echoes, flip angles and coil channels) in one integrative step. MDI was compared with routine curve fitting methods on noise behavior, quantification accuracy and computational efficiency. All methods were tested and compared on simulation, phantom and knee data. Monte Carlo simulations were performed on simulation and all MRI data to investigate noise propagation from k space to T2 * maps. For phantom tests, T2 * values in regions of interest were extracted on a voxel-wise basis and analyzed using a paired t-test between scanning parameters and mapping methods, with p < 0.05 being significantly different. MDI facilitated a straightforward processing procedure, yielding homogeneous, high-signal-to-noise-ratio (SNR) and artifact-free T2 * maps without explicit coil combination or additional measures. Compared with routine fitting methods, MDI offered significantly (p < 0.05) improved SNR and quantitative accuracy/robustness, with two to three orders higher computational efficiency. MDI also represented low-SNR signals with low T2 * values, avoiding misinterpretation with long-T2 * species.

13.
Neuroscience ; 467: 16-27, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34022325

RESUMO

Carotid stenosis is a major contributor to vascular dementia. Recent studies suggest that even clinically "asymptomatic" carotid stenosis is linked with cognitive decline and neuroimaging changes. Here we examined surface-based cortical morphometry, white matter hyperintensity (WMH), and multidomain cognitive performance in unilateral severe (>70% narrowing) asymptomatic carotid stenosis (SACS). We included 24 SACS patients (19 males/5 females; 64.25 ± 7.18 years) and 24 comorbidities-matched controls (19 males/5 females; 67.16 ± 6.10 years), and measured cortical thickness, sulcal depth, gyrification, cortical complexity, and WMH loads with structural MRI images. The SACS patients exhibited: (1) thinner cortex in bilateral somatosensory/motor, bilateral inferior frontal, bilateral fusiform, and left lateral temporal areas; (2) shallower sulci in left lateral temporal, parietal, insular and somatosensory/motor areas; (3) both hyper- and hypo-gyrification in lateral temporal and frontal cortices; (4) lower complexity (fractal dimension) in left insular and right superior temporal areas. Further association analyses showed that the cortical alterations were significantly correlated with verbal memory and WMH burden in SACS. These results suggest that SACS patients present a left-dominated damage tendency, especially in the Perisylvian cortices that span across several large-scale systems of somatosensory/motor and language. Our findings also provide cortical anatomy evidence for cognitive impairment in SACS, suggesting a neuroanatomical predisposition to dementia and cerebrovascular events.


Assuntos
Estenose das Carótidas , Substância Branca , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Cognição , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Substância Branca/diagnóstico por imagem
14.
Pattern Recognit ; : 108006, 2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-34002101

RESUMO

The fast pandemics of coronavirus disease (COVID-19) has led to a devastating influence on global public health. In order to treat the disease, medical imaging emerges as a useful tool for diagnosis. However, the computed tomography (CT) diagnosis of COVID-19 requires experts' extensive clinical experience. Therefore, it is essential to achieve rapid and accurate segmentation and detection of COVID-19. This paper proposes a simple yet efficient and general-purpose network, called Sequential Region Generation Network (SRGNet), to jointly detect and segment the lesion areas of COVID-19. SRGNet can make full use of the supervised segmentation information and then outputs multi-scale segmentation predictions. Through this, high-quality lesion-areas suggestions can be generated on the predicted segmentation maps, reducing the diagnosis cost. Simultaneously, the detection results conversely refine the segmentation map by a post-processing procedure, which significantly improves the segmentation accuracy. The superiorities of our SRGNet over the state-of-the-art methods are validated through extensive experiments on the built COVID-19 database.

15.
Curr Res Transl Med ; 69(2): 103274, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33836320

RESUMO

Signal Transducer and Activator of Transcription (STAT) belongs to the acyltransferase family and participates in cell viability response to different cell stimuli and pathogens. By mediating the expression of a variety of genes, the STAT family plays a prominent part in mammal immunity, proliferation and differentiation. Dysregulations and mutations of STAT factors have been revealed in many kinds of cancers including diffuse gliomas; however, expression characteristic and prognostic value of STAT in diffuse gliomas remain to be elucidated. In this study, we analyzed the transcriptional and survival data of gliomas using ONCOMINE, cBioPortal, GEPIA, COXPRESDB and WEBGESTALTR databases. The results demonstrated that the transcriptional level of STAT1, STAT3 and STAT5A in gliomas was significantly higher than that in normal tissue. Furthermore, dysregulations of STAT1, STAT3, STAT4, STAT5B and STAT6 were referred to as the potential biomarkers to sub-group analysis of gliomas. Survival analysis by the Kaplan-Meier Plotter suggested that glioma patients with high expression of STAT1, STAT3 and STAT5B tended to have poor survival. These data revealed that the STAT family may be an essential aspect of glioma progression and prognosis.

16.
Pharmacol Ther ; 226: 107868, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33901505

RESUMO

Colorectal cancer (CRC) is one of malignant afflictions burdening people worldwide, mainly caused by shortages of effective medical intervention and poorly mechanistic understanding of the pathogenesis of CRC. Non-coding RNAs (ncRNAs) are a type of heterogeneous transcripts without the capability of coding protein, but have the potency of regulating protein-coding gene expression. Autophagy is an evolutionarily conserved catabolic process in which cytoplasmic contents are delivered to cellular lysosomes for degradation, resulting in the turnover of cellular components and producing energy for cell functions. A growing body of evidence reveals that ncRNAs, autophagy, and the crosstalks of ncRNAs and autophagy play intricate roles in the initiation, progression, metastasis, recurrence and therapeutic resistance of CRC, which confer ncRNAs and autophagy to serve as clinical biomarkers and therapeutic targets for CRC. In this review, we sought to delineate the complicated roles of ncRNAs, mainly including miRNAs, lncRNAs and circRNAs, in the pathogenesis of CRC, particularly focus on the regulatory role of ncRNAs in CRC-related autophagy, attempting to shed light on the complex pathological mechanisms, involving ncRNAs and autophagy, responsible for CRC tumorigenesis and development, so as to underpin the ncRNAs- and autophagy-based therapeutic strategies for CRC in clinical setting.

17.
Am J Chin Med ; 49(4): 805-828, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33827382

RESUMO

Based on the study and research on the pathogenesis of colorectal cancer, the types and functions of gut microbiota, and its role in guiding and regulating the occurrence and development of diseases, we have explored the mechanism of traditional Chinese medicine in the treatment of colorectal cancer by regulating the gut microbiota. Genetic variation, abnormal responses of innate and adaptive immunity, mucosal barrier dysfunction, imbalance of intestinal microbial colonization, personal and environmental risk factors are the main pathogenesis of colorectal cancer. The gut microbiota mainly includes Sclerotium (including Clostridium, Enterococcus, Lactobacillus and Ruminococcus) and Bacteroides (including Bacteroides and Prevotella), which have biological antagonism, nutrition for the organism, metabolic abilities, immune stimulation, and ability to shape cancer genes functions to body. The gut microbiota can be related to the health of the host. Current studies have shown that Chinese herbal compound, single medicinal materials, and monomer components can treat colorectal cancer by regulating the gut microbiota, such as Xiaoyaosan can increase the abundance of Bacteroides, Lactobacillus, and Proteus and decrease the abundance of Desulfovibrio and Rickerella. Therefore, studying the regulation and mechanism of gut microbiota on colorectal cancer is of great benefit to disease treatment.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Medicina Tradicional Chinesa/métodos , Humanos , Fatores de Risco
18.
Eur Radiol ; 31(11): 8197-8207, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33914116

RESUMO

OBJECTIVE: To evaluate the potential of diffusional variance decomposition (DIVIDE) for grading, molecular feature classification, and microstructural characterization of gliomas. MATERIALS AND METHODS: Participants with suspected gliomas underwent DIVIDE imaging, yielding parameter maps of fractional anisotropy (FA), mean diffusivity (MD), anisotropic mean kurtosis (MKA), isotropic mean kurtosis (MKI), total mean kurtosis (MKT), MKA/MKT, and microscopic fractional anisotropy (µFA). Tumor type and grade, isocitrate dehydrogenase (IDH) 1/2 mutant status, and the Ki-67 labeling index (Ki-67 LI) were determined after surgery. Statistical analysis included 33 high-grade gliomas (HGG) and 17 low-grade gliomas (LGG). Tumor diffusion metrics were compared between HGG and LGG, among grades, and between wild and mutated IDH types using appropriate tests according to normality assessment results. Receiver operating characteristic and Spearman correlation analysis were also used for statistical evaluations. RESULTS: FA, MD, MKA, MKI, MKT, µFA, and MKA/MKT differed between HGG and LGG (FA: p = 0.047; MD: p = 0.037, others p < 0.001), and among glioma grade II, III, and IV (FA: p = 0.048; MD: p = 0.038, others p < 0.001). All diffusion metrics differed between wild-type and mutated IDH tumors (MKI: p = 0.003; others: p < 0.001). The metrics that best discriminated between HGG and LGGs and between wild-type and mutated IDH tumors were MKT and FA respectively (area under the curve 0.866 and 0.881). All diffusion metrics except FA showed significant correlation with Ki-67 LI, and MKI had the highest correlation coefficient (rs = 0.618). CONCLUSION: DIVIDE is a promising technique for glioma characterization and diagnosis. KEY POINTS: • DIVIDE metrics MKI is related to cell density heterogeneity while MKA and µFA are related to cell eccentricity. • DIVIDE metrics can effectively differentiate LGG from HGG and IDH mutation from wild-type tumor, and showed significant correlation with the Ki-67 labeling index. • MKI was larger than MKA which indicates predominant cell density heterogeneity in gliomas. • MKA and MKI increased with grade or degree of malignancy, however with a relatively larger increase in the cell eccentricity metric MKA in relation to the cell density heterogeneity metric MKI.

19.
Phys Med Biol ; 66(10)2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33845467

RESUMO

Personalized assessment and treatment of severe patients with COVID-19 pneumonia have greatly affected the prognosis and survival of these patients. This study aimed to develop the radiomics models as the potential biomarkers to estimate the overall survival (OS) for the COVID-19 severe patients. A total of 74 COVID-19 severe patients were enrolled in this study, and 30 of them died during the follow-up period. First, the clinical risk factors of the patients were analyzed. Then, two radiomics signatures were constructed based on two segmented volumes of interest of whole lung area and lesion area. Two combination models were built depend on whether the clinic risk factors were used and/or whether two radiomics signatures were combined. Kaplan-Meier analysis were performed for validating two radiomics signatures and C-index was used to evaluated the predictive performance of all radiomics signatures and combination models. Finally, a radiomics nomogram combining radiomics signatures with clinical risk factors was developed for predicting personalized OS, and then assessed with respect to the calibration curve. Three clinical risk factors were found, included age, malignancy and highest temperature that influence OS. Both two radiomics signatures could effectively stratify the risk of OS in COVID-19 severe patients. The predictive performance of the combination model with two radiomics signatures was better than that only one radiomics signature was used, and became better when three clinical risk factors were interpolated. Calibration curves showed good agreement in both 15 d survival and 30 d survival between the estimation with the constructed nomogram and actual observation. Both two constructed radiomics signatures can act as the potential biomarkers for risk stratification of OS in COVID-19 severe patients. The radiomics+clinical nomogram generated might serve as a potential tool to guide personalized treatment and care for these patients.


Assuntos
COVID-19/mortalidade , Processamento de Imagem Assistida por Computador/métodos , Pulmão/patologia , Nomogramas , Radiografia Torácica/métodos , Tomografia Computadorizada por Raios X/métodos , Idoso , COVID-19/diagnóstico por imagem , COVID-19/patologia , COVID-19/virologia , Feminino , Humanos , Pulmão/diagnóstico por imagem , Pulmão/virologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , SARS-CoV-2/isolamento & purificação , Taxa de Sobrevida
20.
Eur Radiol ; 31(8): 6049-6058, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33740092

RESUMO

OBJECTIVE: To analyze and compare the imaging workflow, radiation dose, and image quality for COVID-19 patients examined using either the conventional manual positioning (MP) method or an AI-based automatic positioning (AP) method. MATERIALS AND METHODS: One hundred twenty-seven adult COVID-19 patients underwent chest CT scans on a CT scanner using the same scan protocol except with the manual positioning (MP group) for the initial scan and an AI-based automatic positioning method (AP group) for the follow-up scan. Radiation dose, patient positioning time, and off-center distance of the two groups were recorded and compared. Image noise and signal-to-noise ratio (SNR) were assessed by three experienced radiologists and were compared between the two groups. RESULTS: The AP operation was successful for all patients in the AP group and reduced the total positioning time by 28% compared with the MP group. Compared with the MP group, the AP group had significantly less patient off-center distance (AP 1.56 cm ± 0.83 vs. MP 4.05 cm ± 2.40, p < 0.001) and higher proportion of positioning accuracy (AP 99% vs. MP 92%), resulting in 16% radiation dose reduction (AP 6.1 mSv ± 1.3 vs. MP 7.3 mSv ± 1.2, p < 0.001) and 9% image noise reduction in erector spinae and lower noise and higher SNR for lesions in the pulmonary peripheral areas. CONCLUSION: The AI-based automatic positioning and centering in CT imaging is a promising new technique for reducing radiation dose and optimizing imaging workflow and image quality in imaging the chest. KEY POINTS: • The AI-based automatic positioning (AP) operation was successful for all patients in our study. • AP method reduced the total positioning time by 28% compared with the manual positioning (MP). • AP method had less patient off-center distance and higher proportion of positioning accuracy than MP method, resulting in 16% radiation dose reduction and 9% image noise reduction in erector spinae.


Assuntos
Inteligência Artificial , COVID-19 , Adulto , Humanos , Doses de Radiação , SARS-CoV-2 , Tomografia Computadorizada por Raios X
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