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1.
Drug Deliv ; 28(1): 920-929, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33974471

RESUMO

Oxaliplatin resistance is one of the main causes of failed colorectal cancer treatment, followed by recurrence and metastasis. In this study, we found that colorectal cancer cells secrete a high level of hyaluronic acid (HA), which interacts with its receptor CD44v6 to mediate colorectal cancer resistance to chemotherapy. HA oligosaccharide (oHA) is a degradation product of HA. We found that it competitively binds to CD44v6, reversing the HA-CD44v6-mediated effect of HA on oxaliplatin resistance. In addition, oHA showed no toxicity or immunogenicity but exhibited good biocompatibility and tumor-targeting capability. Therefore, we synthesized oHA-loaded oxaliplatin liposome nanoparticles (oHA-Lipid-Oxa) using a thin-film hydration method. The cytotoxicity of oHA-Lipid-Oxa was assessed in vitro using flow cytometry, which revealed greater lethality than oxaliplatin alone. Finally, we established a tumor-bearing nude mouse model and separately injected oHA-Lipid-Oxa, Lipid-Oxa, Oxa, oHA, and phosphate-buffered saline (PBS) into the tail vein to observe the antitumor effects of nanoparticles in vivo. The oHA-Lipid-Oxa group exhibited the highest tumor suppression rate, but the weight loss was not obvious. Hematoxylin and eosin staining showed greatest lymphocyte and macrophage infiltration in the oHA-Lipid-Oxa group. Moreover, oHA-Lipid-Oxa induced tumor cell apoptosis and necrosis most robustly compared with the other groups. We showed that oHA-Lipid-Oxa has excellent histocompatibility and CD44v6-targeting capabilities, thus greatly increasing the sensitivity to oxaliplatin and reducing adverse reactions. Accordingly, oHA-Lipid-Oxa has a broad potential for therapeutic application.

2.
Dalton Trans ; 50(17): 5865-5870, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33949503

RESUMO

One NIR luminescent 14-metal Nd(iii) nanoring (1, molecular size: 1.0 × 2.2 × 2.6 nm) was obtained from a rigid tridentate ligand, which can absorb and transfer light energy to the Nd(iii) ions. 1 shows interesting luminescence sensing activity to antibiotics, in particular to NFAs with high sensitivity due to the inner filter effect. The quenching constants and the limits of detection of 1 to NFAs are 1.05 × 104 M-1-2.33 × 104 M-1 and 3.05 µM-6.75 µM, respectively. The high fluorescence sensitivities of 1 to NFAs are not changed by the existence of other antibiotics. It also exhibits high sensitivity in the luminescent detection of NFAs contained in real antibiotic drugs.

3.
Talanta ; 231: 122399, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33965049

RESUMO

Straightforward and accurate measurement of medical biomarkers is of essential importance in clinical diagnostics and treatments. However, the major challenge is the diversity in dynamic range of different biomarkers ranging from pg mL-1 to µg mL-1 in various body fluids and tissues among patients. Here, we develop a mesoporous silica (MS)-mediated controllable electrochemiluminescence (ECL) quenching of immunosensor that allows accurate immunoassays with simplicity, sensitivity and tunable sensing range. MS is employed to enhance the sensitivity and tune ECL quenching to broaden the detection range just by altering luminophore (Ru(bpy)32+) and coreactant (DBAE) concentration without additional modifications. The immunoassay is followed: homogeneous sandwich immunoreaction, magnetic separation, and ECL quenching detection. As a proof-of-concept, simple and sensitive detection of IgG is achieved ranging from pg mL-1 to µg mL-1, and applications of the strategy are extended by the combination of ECL immunosensor with commercial ELISA kit. This study will not only be expected to serve as a new avenue for the assay of physiological and clinical implications of immunological biomarkers, but also benefit a wide range of applications that require a tunable detection range and ultrahigh sensitivity.

4.
Colloids Surf B Biointerfaces ; 204: 111785, 2021 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-33932894

RESUMO

Bone is an electrically responsive tissue, so electroactive materials that can deliver electrical cues to bone are helpful for enhancing regeneration under electrical stimulation (ES), and conductive materials are crucial in ES transmission to determine osteogenesis. Compared with polyesters, biodegradable polyorganophosphazenes (POPPs) show superiority in the field of bone tissue engineering thanks to their rich phosphorus/nitrogen contents, suggesting that the combination of POPPs-based conductive substrates with ES may achieve synergistic enhancements on osteogenesis. Herein, conductive composite films were fabricated by blending poly[(alanine ethyl ester)-(glycine ethyl ester)]phosphazene (PAGP) with carbon nanotubes (CNTs). After surface modification with polydopamine (PDA), bone marrow mesenchymal stromal cells (BMSCs) were cultured on the films under ES, using the cells cultured on conductive films composed of poly(L-lactide) (PLLA) and CNTs as controls. The BMSCs on PAGP/CNT films demonstrated significantly faster proliferation rates and stronger osteogenic differentiation potentials than those on PLLA/CNT films, while cell attachments on the two PDA-coated substrates were similar. Under appropriate ES, further increases in the expressions of osteogenic markers as alkaline phosphatase, collagen I and calcium deposition were identified in comparison with the cases without ES. The contributions of the osteocompatible POPPs, the substrate conductivity and the ES treatment to enhanced osteogenesis suggested new strategies for the design of bone repair materials.

5.
Med Image Anal ; 71: 102035, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33813286

RESUMO

The loss function is an important component in deep learning-based segmentation methods. Over the past five years, many loss functions have been proposed for various segmentation tasks. However, a systematic study of the utility of these loss functions is missing. In this paper, we present a comprehensive review of segmentation loss functions in an organized manner. We also conduct the first large-scale analysis of 20 general loss functions on four typical 3D segmentation tasks involving six public datasets from 10+ medical centers. The results show that none of the losses can consistently achieve the best performance on the four segmentation tasks, but compound loss functions (e.g. Dice with TopK loss, focal loss, Hausdorff distance loss, and boundary loss) are the most robust losses. Our code and segmentation results are publicly available and can serve as a loss function benchmark. We hope this work will also provide insights on new loss function development for the community.

6.
Inorg Chem ; 60(8): 5764-5770, 2021 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-33829775

RESUMO

Two NIR luminescent Zn(II)/Cd(II)-Yb(III) complexes were obtained by the use of a Schiff base ligand with a binaphthyl backbone. Cd(II)-Yb(III) complex 2 has a triangular structure and exhibits interesting luminescent sensing activity to antibiotics, in particular to ciprofloxacin (CPFX) and norfloxacin (NFX) due to the inner filter effect. The limits of the detection of 2 to CPFX and NFX are 0.18 and 0.36 µM, respectively, and the fluorescence sensitivity is not changed with the existence of other antibiotics tested in this study.

7.
Reprod Sci ; 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33721297

RESUMO

This study aimed to evaluate the efficacy of SHBG in predicting insulin resistance (IR) in newly diagnosed, untreated patients with polycystic ovary syndrome (PCOS). Hundred newly diagnosed, untreated patients with PCOS and 61 subjects without PCOS (41 healthy volunteers with normal BMI and 20 subjects with overweight/obese) were included in the study. Receiver-operating characteristic (ROC) analysis was used to assess the effectiveness of SHBG in predicting IR in overweight/obese and non-overweight PCOS patients and the optimal cut-off values of SHBG. The results showed negative correlations between log-SHBG and log-I0 (r = - 0.372, P < 0.001) and log-SHBG and log-Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) (r = - 0.393, P < 0.001) after adjusting for blood pressure, serum lipid, age, and body mass index (BMI) in all of the PCOS patients. In patients with IR (defined as HOMA-IR ≥2.29), the area under the ROC curves (AUCs) of the SHBG for ROC analysis in the non-overweight group, overweight/obese group, and all PCOS patients were 0.774 (P = 0.0001), 0.922 (P = 0.0001), and 0.885 (P = 0.0001), respectively. The optimal cut-off value of SHBG was 37 nmol/L with a sensitivity of 97.62% and specificity of 80.85% in the overweight group. In patients with IR (HOMA-IR ≥2.5), the AUCs of SHBG for ROC analysis in the non-overweight group, overweight/obese group, and all PCOS patients were 0.741 (P = 0.0003), 0.928 (P = 0.0001), and 0.880 (P = 0.0001), respectively. The optimal cut-off value of SHBG was 30.2 nmol/L with a sensitivity of 97.44% and specificity of 82.69% in the overweight/obese group. In conclusion, this study observed a negative correlation between SHBG and HOMA-IR in PCOS patients after adjustment of confounding factors. SHBG was an independent influential factor of HOMA-IR and can be used as a positive predictive marker for IR in PCOS patients, especially in those who are overweight/obese.

8.
FEBS Open Bio ; 11(5): 1440-1451, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33742560

RESUMO

Inhibitors of ataxia-telangiectasia mutated (ATM), such as KU-55933 (Ku), represent a promising class of novel anticancer drugs. In addition, the biguanide derivative phenformin exhibits antitumor activity superior to that of the AMPK activator metformin. Herein, we assessed the potential combinatorial therapeutic efficacy of phenformin and Ku when used to inhibit the growth of liver cancer cells, and we assessed the mechanisms underlying such efficacy. The Hep-G2 and SMMC-7721 liver cancer cell lines were treated with phenformin and Ku either alone or in combination, after which the impact of these drugs on cellular proliferation was assessed via 3-(4,5-dimethylthiazol) 2, 5-diphenyltetrazolium and colony formation assays, whereas Transwell assays were used to gauge cell migratory activity. The potential synergy between these two drugs was assessed using the CompuSyn software, while flow cytometry was employed to evaluate cellular apoptosis. In addition, western blotting was utilized to measure p-ATM, p-AMPK, p-mTOR, and p-p70s6k expression, while mitochondrial functionality was monitored via morphological analyses, JC-1 staining, and measurements of ATP levels. Phenformin and Ku synergistically impacted the proliferation, migration, and apoptotic death of liver cancer cells. Together, these compounds were able to enhance AMPK phosphorylation while inhibiting the phosphorylation of mTOR and p70s6k. These data also revealed that phenformin and Ku induced mitochondrial dysfunction as evidenced by impaired ATP synthesis, mitochondrial membrane potential, and abnormal mitochondrial morphology. These findings suggest that combination treatment with phenformin and Ku may be an effective approach to treating liver cancer via damaging mitochondria within these tumor cells.

9.
Bioorg Med Chem Lett ; 39: 127912, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33691167

RESUMO

A series of novel artemisinin ester derivatives were designed and synthesized for targeting mitochondria. Cytotoxicity against SMMC-7721, HepG2, OVCAR3, A549 and J82 cancer cell lines was evaluated. Compound 2c (IC50 = 3.0 µM) was the most potent anti-proliferative molecule against the OVCAR3 cells with low cytotoxicity in normal HUVEC cells. The mechanism of action of compound 2c was further investigated by analyzing cell apoptosis, mitochondrial membrane potential (Δψm) and intracellular ROS generation. The results indicated that compound 2c targeted mitochondria and induced cell apoptosis. ROS and heme attributed to the cytotoxicity and cell apoptosis of compound 2c. These promising findings indicated the compound 2c could serve as a great candidate against ovarian cancer for further investigation.

11.
Food Res Int ; 141: 110153, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33642019

RESUMO

Tea polyphenols (TPs) are now widely used in foods for various biological activities. However, they are rarely used in foods to regulate gut microbiota dysbiosis induced by antibiotics. We assessed the regulation of TPs on gut microbiota with an antibiotic-induced intestinal flora disorder mouse model. The mice were orally administered with cefixime for 8 days, then received TPs for 28 days. We found that the antibiotic had a profound impact on the gut microbiota. Compared with the normal group, significant decreases in the species richness and diversity and the production of short-chain fatty acids (SCFAs) were still observed 28 days after the antibiotic treatment, although there was no significant difference in the colonic mucosa. TPs significantly alleviated the decrease of the richness and diversity of gut microbiota caused by the antibiotic treatment, and significantly increased the relative abundance of beneficial microbes such as Lactobacillus, Akkermansia, Blautia, Roseburia, and Eubacterium. The function prediction showed that TPs significantly decreased the relative abundance of genes related to human diseases, yet significantly increased the relative abundance of genes related to cell growth and death, cell motility, and energy metabolism. These showed that TPs could regulate the gut microbiota dysbiosis induced by antibiotics, thus decreasing the risk of diseases such as obesity, cancer, and diabetes. These suggest that TPs have a great potential to be used as a functional food ingredient to prevent or reduce adverse effects of antibiotics.

12.
J Ovarian Res ; 14(1): 32, 2021 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-33583431

RESUMO

BACKGROUND: The aims of this study were to compare the efficacy of different androgens measured by liquid chromatography-mass spectrometry (LC-MS/MS) in representing hyperandrogenemia and to evaluate adrenal-origin androgens with a dexamethasone suppression test in patients with polycystic ovary syndrome (PCOS). METHODS: One hundred and two patients with PCOS and 41 healthy volunteers were recruited and total serum testosterone (TT), androstenedione (AD), dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) were measured by LC-MS/MS. ROC analysis was performed to compare the efficacy of different androgens in representing hyperandrogenemia. Dexamethasone suppression test was performed in 51 patients with PCOS and above indicators were measured after dexamethasone administration. The prediction efficacy of DHEA and DHEA-S at baseline in the dexamethasone suppression test was evaluated with ROC analysis. RESULTS: The AUCs of TT, AD, free androgen index (FAI) and DHEA-S in ROC analysis for representing hyperandrogenemia were 0.816, 0.842, 0.937 and 0.678, respectively. The optimal cutoff value of TT was 0.337 ng/ml, with a sensitivity of 72.0% and specificity of 82.93%. The optimal cutoff value for AD was 1.309 ng/ml, with a sensitivity of 81.0% and specificity of 73.17%. The optimal cutoff value of the FAI was 2.50, with a sensitivity of 87.0% and specificity of 92.68%. Alternatively, AD or FAI more than the optimal cutoff values as evidence of hyperandrogenemia had the highest sensitivity of 91.18%. The levels of cortisol, DHEA and DHEA-S were all suppressed to narrow ranges after dexamethasone administration. Nine and 8 of 51 patients with PCOS had significant decreases in TT and AD, respectively. DHEA can be used as a indicator for predicting significant decrease of TT in dexamethasone suppression test with cutoff value of 13.28 ng/ml. A total of 27.5% (14/51) of patients had DHEA-S excess, but only 1 of 9 patients who had a significant decrease in TT had elevated level of DHEA-S at baseline. CONCLUSIONS: AD measured by LC-MS/MS can represent hyperandrogenemia in PCOS patients and, combined with TT or FAI, can improve the screening efficiency of hyperandrogenemia. Seventeen percent of PCOS patients had adrenal-origin androgen dominance, with TT significantly decreasing after 2 days of dexamethasone administration. Adrenal-origin androgen dominance was not parallel with DHEA-S excess in patients with PCOS.

13.
Biomed Mater ; 16(2): 022006, 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33440367

RESUMO

The repair and treatment of articular cartilage injury is a huge challenge of orthopedics. Currently, most of the clinical methods applied in treating cartilage injuries are mainly to relieve pains rather than to cure them, while the strategy of tissue engineering is highly expected to achieve the successful repair of osteochondral defects. Clear understandings of the physiological structures and mechanical properties of cartilage, bone and osteochondral tissues have been established, but the understanding of their physiological heterogeneity still needs further investigation. Apart from the gradients in the micromorphology and composition of cartilage-to-bone extracellular matrixes, an oxygen gradient also exists in natural osteochondral tissue. The response of hypoxia-inducible factor (HIF)-mediated cells to oxygen would affect the differentiation of stem cells and the maturation of osteochondral tissue. This article reviews the roles of oxygen level and HIF signaling pathway in the development of articular cartilage tissue, and their prospective applications in bone and cartilage tissue engineering. The strategies for regulating HIF signaling pathway and how these strategies finding their potential applications in the regeneration of integrated osteochondral tissue are also discussed.

14.
Biomater Sci ; 9(5): 1547-1573, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33439158

RESUMO

Despite breakthroughs in tissue engineering, a tremendous problem still lies in repairing the interfacial tissue which connects soft tissue to hard tissue, particularly cartilage-bone, tendon/ligament-bone, and cementum-ligament-bone interfaces. The challenge comes from the complicated biophysical and biochemical characteristics of interfacial tissues, involving a graded variation of chemical components, structures, and mechanical properties as well as a heterogeneous cell distribution from the soft end to the hard end. Accordingly, significant progress has been made in the design of hierarchical and heterogeneous hydrogel systems in order to solve this problem. Advanced programmable technologies, such as 3D printing and microfluidic platforms, have shown potential in constructing templates or scaffolds with tissue-specific characteristics. The structural specialty of the three aforementioned interfacial tissues is summarized in this review. Then the text concentrates on how to utilize different scale hydrogels (from chemical variation, nanoscale, microscale to cellular regulation) to fabricate gradient constructions for regenerating interfacial tissues, together with in vitro and in vivo outcomes. In particular, the fabrication of continuous gradients is highlighted in this review. Promisingly, the versatile designs involved in fabricating hierarchical and heterogeneous hydrogel systems are predicted to tackle the unsolved problems, and this interfacial tissue engineering methodology is expected to expand its use in therapeutic applications.

15.
IEEE Trans Med Imaging ; 40(5): 1363-1376, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33507867

RESUMO

To better understand early brain development in health and disorder, it is critical to accurately segment infant brain magnetic resonance (MR) images into white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF). Deep learning-based methods have achieved state-of-the-art performance; h owever, one of the major limitations is that the learning-based methods may suffer from the multi-site issue, that is, the models trained on a dataset from one site may not be applicable to the datasets acquired from other sites with different imaging protocols/scanners. To promote methodological development in the community, the iSeg-2019 challenge (http://iseg2019.web.unc.edu) provides a set of 6-month infant subjects from multiple sites with different protocols/scanners for the participating methods. T raining/validation subjects are from UNC (MAP) and testing subjects are from UNC/UMN (BCP), Stanford University, and Emory University. By the time of writing, there are 30 automatic segmentation methods participated in the iSeg-2019. In this article, 8 top-ranked methods were reviewed by detailing their pipelines/implementations, presenting experimental results, and evaluating performance across different sites in terms of whole brain, regions of interest, and gyral landmark curves. We further pointed out their limitations and possible directions for addressing the multi-site issue. We find that multi-site consistency is still an open issue. We hope that the multi-site dataset in the iSeg-2019 and this review article will attract more researchers to address the challenging and critical multi-site issue in practice.

16.
Nat Biotechnol ; 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33510483

RESUMO

Although genomic analyses predict many noncanonical open reading frames (ORFs) in the human genome, it is unclear whether they encode biologically active proteins. Here we experimentally interrogated 553 candidates selected from noncanonical ORF datasets. Of these, 57 induced viability defects when knocked out in human cancer cell lines. Following ectopic expression, 257 showed evidence of protein expression and 401 induced gene expression changes. Clustered regularly interspaced short palindromic repeat (CRISPR) tiling and start codon mutagenesis indicated that their biological effects required translation as opposed to RNA-mediated effects. We found that one of these ORFs, G029442-renamed glycine-rich extracellular protein-1 (GREP1)-encodes a secreted protein highly expressed in breast cancer, and its knockout in 263 cancer cell lines showed preferential essentiality in breast cancer-derived lines. The secretome of GREP1-expressing cells has an increased abundance of the oncogenic cytokine GDF15, and GDF15 supplementation mitigated the growth-inhibitory effect of GREP1 knockout. Our experiments suggest that noncanonical ORFs can express biologically active proteins that are potential therapeutic targets.

17.
J Phys Chem A ; 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33390013

RESUMO

Two d-4f complexes [Zn2NdL2(OAc)2]·OH (1) and [Cd3Sm3L3(OAc)6(OH)3] (2) with a designed Schiff base ligand N,N'-bis(3-methoxysalicylidene)(binaphthyl)-1,4-diamine (H2L) were synthesized. The Schiff base ligands coordinate with metal ions by µ2(η1:η2:η1:η1:η2:η1) and µ2(η1:η2:η1:η1:η2:η1) modes in the complexes, which show typical lanthanide emissions. The triangular Cd-Sm complex 2 shows both visible and NIR luminescent responses to nitrobenzene explosive 2,4,6-trinitrophenol (PA).

18.
Artigo em Inglês | MEDLINE | ID: mdl-33470114

RESUMO

Flexible thermoelectric materials and devices have gained wide attention due to their capability to stably and directly convert body heat or industrial waste heat into electric energy. Many research and synthetic methods of flexible high-performance p-type thermoelectric materials have made great progress. However, their counterpart flexible n-type organic thermoelectric materials are seldom studied due to the complex synthesis of conductive polymer and poor stability of n-type materials. In this work, bismuth tellurium (Bi2Te3) nanosheets are in situ grown on single-walled carbon nanotubes (SWCNTs) assisted by poly(vinylpyrrolidone) (PVP). A series of flexible SWCNTs@Bi2Te3 composite films on poly(vinylidene fluoride) (PVDF) membranes are obtained by vacuum-assisted filtration. The high electrical conductivity of 253.9 S/cm, and a corresponding power factor (PF) of 57.8 µW/m·K2 is obtained at 386 K for SWCNTs@Bi2Te3-0.8 film. Moreover, high electrical conductivity retention of 90% can be maintained after a 300-cycle bending test and no obvious attenuation can be detected after being stored in an Ar atmosphere for 9 months, which exhibits good flexibility and excellent stability of the SWCNTs@Bi2Te3 composite films. This work shows a convenient method to fabricate n-type and flexible thermoelectric composite film and further promotes the practical application of n-type flexible thermoelectric materials.

19.
Magn Reson Imaging ; 77: 148-158, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33309922

RESUMO

PURPOSE: To compare multiple quantitative parameters from breast magnetic resonance imaging (MRI) with the synthetic MRI sequence included for discrimination of molecular subtypes of invasive breast cancer. MATERIALS AND METHODS: Between March 2019 and September 2020, two hundred breast cancer patients underwent preoperative breast multiparametric MRI examinations including synthetic MRI, diffusion weighted imaging (DWI) and dynamic contrast enhancement (DCE)-MRI sequences. MRI morphological features, T1 and T2 relaxation times (T1, T2) and proton density (PD) values from synthetic MRI, Ktrans, Kep, and Ve from DCE-MRI, mean apparent diffusion coefficient (ADC) from DWI and tumor volume were measured. Quantitative parameters were compared according to molecular markers and subtypes. Logistic regression were performed to find the related MRI parameters and establish combined parameters. The comparison between single and combined quantitative parameters by using DeLong tests. RESULTS: T1, T2 values were significantly higher in hormone receptor (HR)- negative and Ki67 > 14% tumors (p < 0.05). Human epidermal growth factor receptor 2 (HER2)-positive tumors demonstrated significantly higher Ktrans and Kep (p < 0.01). Mean ADC values were significantly decreased in HR-positive and Ki67 > 14% tumors (p < 0.01). Tumor volumes were significantly higher in HER2-positive and Ki67 > 14% tumors (p < 0.05). Independent influencing factors were lower T2 values (p < 0.001), smaller tumor volume (p = 0.031) and higher mean ADC (p = 0.002) associated with luminal A subtype, while T1 values (p = 0.007) was the only quantitative parameter associated with triple-negative subtype. The diagnostic efficiency of combined parameters (T2 + mean ADC + volume) (AUC = 0.765) was significantly higher than that of mean ADC (AUC = 0.666, p = 0.031 by DeLong test) and volume (AUC = 0.650, p = 0.008 by DeLong test) for separating luminal A subtype. CONCLUSIONS: MRI quantitative parameters could help distinguish molecular markers and subtypes. The emerging synthetic MRI parameters - T1 values were associated with the TN subtype, and combined parameters with added T2 values might improve the discrimination of the luminal A subtype. Application of synthetic MRI can enrich quantitative descriptors from breast MRI.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Mama/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Adulto , Idoso , Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Carga Tumoral
20.
Med Phys ; 48(3): 1197-1210, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33354790

RESUMO

PURPOSE: Accurate segmentation of lung and infection in COVID-19 computed tomography (CT) scans plays an important role in the quantitative management of patients. Most of the existing studies are based on large and private annotated datasets that are impractical to obtain from a single institution, especially when radiologists are busy fighting the coronavirus disease. Furthermore, it is hard to compare current COVID-19 CT segmentation methods as they are developed on different datasets, trained in different settings, and evaluated with different metrics. METHODS: To promote the development of data-efficient deep learning methods, in this paper, we built three benchmarks for lung and infection segmentation based on 70 annotated COVID-19 cases, which contain current active research areas, for example, few-shot learning, domain generalization, and knowledge transfer. For a fair comparison among different segmentation methods, we also provide standard training, validation and testing splits, evaluation metrics and, the corresponding code. RESULTS: Based on the state-of-the-art network, we provide more than 40 pretrained baseline models, which not only serve as out-of-the-box segmentation tools but also save computational time for researchers who are interested in COVID-19 lung and infection segmentation. We achieve average dice similarity coefficient (DSC) scores of 97.3%, 97.7%, and 67.3% and average normalized surface dice (NSD) scores of 90.6%, 91.4%, and 70.0% for left lung, right lung, and infection, respectively. CONCLUSIONS: To the best of our knowledge, this work presents the first data-efficient learning benchmark for medical image segmentation, and the largest number of pretrained models up to now. All these resources are publicly available, and our work lays the foundation for promoting the development of deep learning methods for efficient COVID-19 CT segmentation with limited data.


Assuntos
/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Pulmão/diagnóstico por imagem , Aprendizado de Máquina , Tomografia Computadorizada por Raios X , Benchmarking , Humanos
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