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1.
ACS Sens ; 9(7): 3520-3530, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-38967449

RESUMO

Biosensing by particle motion is a biosensing technology that relies on single-molecule interactions and enables the continuous monitoring of analytes from picomolar to micromolar concentration levels. However, during sensor operation, the signals are observed to change gradually. Here, we present a comprehensive methodology to elucidate the molecular origins of long-term changes in a particle motion sensor, focusing on a competitive sensor design under conditions without flow. Experiments were performed wherein only the particles or only the surfaces were aged in order to clarify how each individual component changes over time. Furthermore, distributions of particle motion patterns and switching activity were studied to reveal how particle populations change over timespans of several days. For a cortisol sensor with anticortisol antibodies on the particles and cortisol analogues on the sensing surface, the leading hypotheses for the long-term changes are (i) that the particles lose antibodies and develop nonspecific interactions and (ii) that analogue molecules dissociate from the sensing surface. The developed methodologies and the acquired insights pave a way for realizing sensors that can operate over long timespans.


Assuntos
Técnicas Biossensoriais , Hidrocortisona , Técnicas Biossensoriais/métodos , Hidrocortisona/análise
2.
J Clin Ultrasound ; 52(3): 305-314, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38149658

RESUMO

OBJECTIVES: Radiomics-based eXtreme gradient boosting (XGBoost) model was developed to differentiate benign thyroid nodules from malignant thyroid nodules and to prevent unnecessary thyroid biopsies, including positive and negative effects. METHODS: The study evaluated a data set of ultrasound images of thyroid nodules in patients retrospectively, who initially received ultrasound-guided fine-needle aspiration biopsy (FNAB) for diagnostic purposes. According to ACR TI-RADS, a total of five ultrasound feature categories and the maximum size of the nodule were determined by four radiologists. A radiomics score was developed by the LASSO algorithm from the ultrasound-based radiomics features. An interpretative method based on Shapley additive explanation (SHAP) was developed. XGBoost was compared with ACR TI-RADS for its diagnostic performance and FNAB rate and was compared with six other machine learning models to evaluate the model performance. RESULTS: Finally, 191 thyroid nodules were examined from 177 patients. The radiomics score were calculated using 8 features, which were selected among 789 candidate features generated from the ultrasound images. The model yielded an AUC of 93% in the training cohort and 92% in the test cohort. It outperformed traditional machine learning models in assessing the nature of thyroid nodules. Compared with ACR TI-RADS, the FNAB rate decreased from 34% to 30% in training and from 35% to 41% in test. CONCLUSIONS: The radiomics-based XGBoost model proposed could distinguish benign and malignant thyroid nodules, thereby reduced significantly the number of unnecessary FNAB. It was effective in making preoperative decisions and managing selected patients using the SHAP visual interpretation tools.


Assuntos
Nódulo da Glândula Tireoide , Humanos , Nódulo da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/patologia , Estudos Retrospectivos , Radiômica , Diagnóstico Diferencial , Ultrassonografia/métodos , Biópsia por Agulha Fina
3.
Anal Chem ; 95(20): 7950-7959, 2023 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-37178186

RESUMO

Industrial food processes are monitored to ensure that food is being produced with good quality, yield, and productivity. For developing innovative real-time monitoring and control strategies, real-time sensors are needed that can continuously report chemical and biochemical data of the manufacturing process. Here, we describe a generalizable methodology to develop affinity-based biosensors for the continuous monitoring of small molecules in industrial food processes. Phage-display antibody fragments were developed for the measurement of small molecules, as exemplified with the measurement of glycoalkaloids (GAs) in potato fruit juice. The recombinant antibodies were selected for use in a competition-based biosensor with single-molecule resolution, called biosensing by particle motion, using assay architectures with free particles as well as tethered particles. The resulting sensor measures GAs in the micromolar range, is reversible, has a measurement response time below 5 min, and enables continuous monitoring of GAs in protein-rich solutions for more than 20 h with concentration measurement errors below 15%. The demonstrated biosensor gives the perspective to enable a variety of monitoring and control strategies based on continuous measurement of small molecules in industrial food processes.


Assuntos
Técnicas Biossensoriais , Solanum tuberosum , Técnicas Biossensoriais/métodos , Imunoensaio , Movimento (Física) , Alimentos
4.
Nat Commun ; 13(1): 6052, 2022 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-36229441

RESUMO

There is a need for sensing technologies that can continuously monitor concentration levels of critical biomolecules in applications such as patient care, fundamental biological research, biotechnology and food industry, as well as the environment. However, it is fundamentally difficult to develop measurement technologies that are not only sensitive and specific, but also allow monitoring over a broad concentration range and over long timespans. Here we describe a continuous biomolecular sensing methodology based on the free diffusion of biofunctionalized particles hovering over a sensor surface. The method records digital events due to single-molecule interactions and enables biomarker monitoring at picomolar to micromolar concentrations without consuming any reagents. We demonstrate the affinity-based sensing methodology for DNA-based sandwich and competition assays, and for an antibody-based cortisol assay. Additionally, the sensor can be dried, facilitating storage over weeks while maintaining its sensitivity. We foresee that this will enable the development of continuous monitoring sensors for applications in fundamental research, for studies on organs on a chip, for the monitoring of patients in critical care, and for the monitoring of industrial processes and bioreactors as well as ecological systems.


Assuntos
Técnicas Biossensoriais , Biomarcadores , Técnicas Biossensoriais/métodos , DNA , Humanos , Hidrocortisona , Nanotecnologia
5.
ACS Sens ; 7(10): 3041-3048, 2022 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-36255855

RESUMO

Cortisol is a steroid hormone involved in a wide range of medical conditions. The level of the hormone fluctuates over time, but with traditional laboratory-based assays, such dynamics cannot be monitored in real time. Here, a reversible cortisol sensor is reported that allows continuous monitoring of cortisol in blood plasma using sampling by microdialysis. The sensor is based on measuring single-molecule binding and unbinding events of tethered particles. The particles are functionalized with antibodies and the substrate with cortisol-analogues, causing binding and unbinding events to occur between particles and substrate. The frequency of binding events is reduced when cortisol is present in the solution as it blocks the binding sites of the antibodies. The sensor responds to cortisol in the high nanomolar to low micromolar range and can monitor cortisol concentrations over multiple hours. Results are shown for cortisol monitoring in filtered and in microdialysis-sampled human blood plasma.


Assuntos
Técnicas Biossensoriais , Hidrocortisona , Humanos , Hidrocortisona/química , Microdiálise/métodos , Técnicas Biossensoriais/métodos , Imunoensaio/métodos , Anticorpos , Plasma
6.
Front Plant Sci ; 12: 748242, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34707631

RESUMO

Sulfur is an essential nutrient for plant growth and development. Sulfate transporters (Sultrs) are critical for sulfate ( SO 4 2 - ) uptake from the soil by the roots in higher plants. However, knowledge about Sultrs in apples (Malus domestica) is scarce. Here, nine putative MdSultrs were identified and classified into two groups according to the their phylogenetic relationships, gene structures, and conserved motifs. Various cis-regulatory elements related to abiotic stress and plant hormone responsiveness were found in the promoter regions of MdSultrs. These MdSultrs exhibited tissue-specific expression patterns and responded to low sulfur (S), abscisic acid (ABA), indole-3-acetic acid (IAA), and methyl jasmonate (MeJA), wherein MdSultr3;1a was especially expressed in the roots and induced by low S. The uptake of SO 4 2 - in cultivated apples depends on the roots of its rootstock, and MhSultr3;1a was isolated from Malus hupehensis roots used as a rootstock. MhSultr3;1a shared 99.85% homology with MdSultr3;1a and localized on the plasma membrane and nucleus membrane. Further function characterization revealed that MhSultr3;1a complemented an SO 4 2 - transport-deficient yeast mutant and improved the growth of yeast and apple calli under low S conditions. The MhSultr3;1a-overexpressing apple calli had a higher fresh weight compared with the wild type (WT) under a low-S treatment because of the increased SO 4 2 - and cysteine (Cys) content. These results demonstrate that MhSultr3;1a may increase the content of SO 4 2 - and Cys to meet the demands of S-containing compounds and improve their growth under S-limiting conditions.

7.
ACS Sens ; 6(5): 1980-1986, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-33985333

RESUMO

Sensing technologies for the real-time monitoring of biomolecules will allow studies of dynamic changes in biological systems and the development of control strategies based on measured responses. Here, we describe a molecular architecture and coupling process that allow continuous measurements of low-concentration biomolecules over long durations in a sensing technology with single-molecule resolution. The sensor is based on measuring temporal changes of the motion of particles upon binding and unbinding of analyte molecules. The biofunctionalization involves covalent coupling by click chemistry to PLL-g-PEG bottlebrush polymers. The polymer is grafted to a surface by multivalent electrostatic interactions, while the poly(ethylene glycol) suppresses nonspecific binding of biomolecules. With this biofunctionalization strategy, we demonstrate the continuous monitoring of single-stranded DNA and a medically relevant small-molecule analyte (creatinine), in sandwich and competitive assays, in buffer and in filtered blood plasma, with picomolar, nanomolar, and micromolar analyte concentrations, and with continuous sensor operation over 10 h.


Assuntos
Química Click , Polímeros , DNA de Cadeia Simples
8.
Medicine (Baltimore) ; 100(12): e25217, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33761708

RESUMO

ABSTRACT: Lung ultrasound (LUS) has recently been used to identify interstitial lung disease (ILD). However, data on the role of LUS in the detection of ILD remain limited. The aim of this study was to investigate the diagnostic value of LUS compared with high-resolution computed tomography (HRCT) in patients with ILD.The retrospective study was carried out by reviewing the medical records of patients with respiratory signs and symptoms discharged from the respiratory ward. Only patients with suspected ILD who underwent HRCT and LUS within a week were selected. ILD was identified with a semi-quantitative score of B-lines >5 and a Warrick score >0 points. The endpoints of LUS in diagnosing ILD (i.e., sensitivity, specificity, positive likelihood ratio [PLR], negative likelihood ratio [NLR], positive predictive value [PPV], and negative predictive value [NPV], and receiver operating characteristic [ROC] curve) was compared with that of HRCT. The reference standard used for the diagnosis of ILD was based on history, clinical findings and examination, and laboratory and instrumental tests, including pulmonary function tests, lung histopathology, and HRCT (without LUS findings).The final clinical diagnosis of ILD was 55 in 66 patients with suspected ILD. HRCT was positive in 55 patients, whereas LUS detected ILD in 51 patients. Four patients with negative LUS findings were positive on HRCT. The results showed 93% sensitivity, 73% specificity, 3.40 PLR, 0.10 NLR, 94% PPV, and 67% NPV for LUS, whereas 100% sensitivity, 82% specificity, 5.49 PLR, 0.01 NLR, 97% PPV, and 100% NPV for HRCT. Comparison of the 2 ROC curves revealed significant difference in the diagnostic value of the 2 methods for the diagnosis of ILD (P = .048).Our results indicated that LUS is a useful technique to identify ILD. Considering its non-radiation, portable and non-invasive advantages, LUS should be recommended as a valuable screening tool in patients with suspected ILD.


Assuntos
Doenças Pulmonares Intersticiais , Pulmão/diagnóstico por imagem , Ultrassonografia , China/epidemiologia , Feminino , Humanos , Doenças Pulmonares Intersticiais/diagnóstico , Doenças Pulmonares Intersticiais/epidemiologia , Masculino , Programas de Rastreamento/métodos , Registros Médicos Orientados a Problemas , Pessoa de Meia-Idade , Aceitação pelo Paciente de Cuidados de Saúde , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Testes de Função Respiratória , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Ultrassonografia/métodos , Ultrassonografia/estatística & dados numéricos
9.
Eur J Clin Microbiol Infect Dis ; 40(6): 1245-1252, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33447913

RESUMO

At present, it has been noticed that some patients recovered from COVID-19 present a recurrent positive RNA test of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) after being discharged from hospitals. The purpose of the current study was to characterize the clinical features of re-hospitalized patients with recurrent SARS-CoV-2 positive results. From January 12 to April 1 of 2020, our retrospective study was conducted in China. The exposure history, baseline data, laboratory findings, therapeutic schedule, and clinical endpoints of the patients were collected. All the patients were followed until April 10, 2020. Among all COVID-19 patients included in the current study, there were 14 re-hospitalized patients due to recurrent positive tests of SARS-CoV-2 RNA. Fever (11 [78.6%]), cough (10 [71.4%]), and fatigue (7 [50.0%]) were the most common symptoms on the patient's first admission, and less symptoms were found on their second admission. The average duration from the onset of symptoms to admission to hospital was found to be 8.4 days for the first admission and 2.6 days for the second admission (P = 0.002). The average time from the detection of RNA (+) to hospitalization was 1.9 days for the first admission and 2.6 days for the second admission (P = 0.479), and the average time from RNA (+) to RNA (-) was 11.1 days for the first admission and 6.3 days for the second admission (P = 0.030). Moreover, the total time in hospital was 18.6 days for the first admission and 8.0 days for the second admission (P = 0.000). It may be necessary to increase the isolation observation time and RT-PCR tests should be timely performed on multiple samples as soon as possible.


Assuntos
COVID-19/diagnóstico , Readmissão do Paciente , RNA Viral/isolamento & purificação , Adulto , Idoso , COVID-19/patologia , Teste de Ácido Nucleico para COVID-19 , China , Tosse/virologia , Fadiga/virologia , Feminino , Febre/virologia , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2 , Adulto Jovem
11.
Medicine (Baltimore) ; 99(50): e23671, 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33327356

RESUMO

BACKGROUND: The aim of this meta-analysis was to evaluate the diagnostic value of lung ultrasound (LUS) in comparison to chest radiography (CXR) in children with pneumonia. METHODS: Computer-based retrieval was performed on PubMed and EMBASE. Quality was evaluated according to the quality assessment of diagnostic accuracy studies-2, and Meta-Disc was adopted to perform meta-analysis. Heterogeneity was assessed using Q and I statistics. The pooled sensitivity, specificity, and diagnostic odds ratio (DOR) with 95% confidence intervals (CIs) as the primary outcomes were calculated for each index test. RESULTS: Twenty two studies with a total of 2470 patients met the inclusion criteria. Our results showed that the pooled sensitivity, specificity, and DOR for children with pneumonia diagnosed by LUS were 0.95 (95% CI: 0.94 to 0.96), 0.90 (95% CI: 0.87 to 0.92), and 137.49 (95% CI: 60.21 to 313.98), respectively. The pooled sensitivity, specificity, and DOR for pediatric pneumonia diagnosed by CXR was 0.91 (95% CI: 0.90 to 0.93), 1.00 (95% CI: 0.99 to 1.00), and 369.66 (95% CI: 137.14 to 996.47), respectively. Four clinical signs, including pulmonary consolidation, positive air bronchogram, abnormal pleural line, and pleural effusion were most frequently observed using LUS in the screening of children with pneumonia. CONCLUSIONS: The available evidence suggests that LUS is a reliable, valuable, and alternative method to CXR for the diagnosis of pediatric pneumonia.


Assuntos
Pneumonia/diagnóstico , Radiografia Torácica/métodos , Ultrassonografia/métodos , Adolescente , Fatores Etários , Broncografia/métodos , Broncografia/normas , Criança , Pré-Escolar , Humanos , Lactente , Pulmão/diagnóstico por imagem , Derrame Pleural/patologia , Pneumonia/diagnóstico por imagem , Pneumonia/patologia , Radiografia Torácica/normas , Sensibilidade e Especificidade , Fatores Sexuais , Ultrassonografia/normas
12.
Am J Gastroenterol ; 115(5): 766-773, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32287140

RESUMO

OBJECTIVE: Since the outbreak of Coronavirus Disease 2019 (COVID-19) in December 2019, various digestive symptoms have been frequently reported in patients infected with the virus. In this study, we aimed to further investigate the prevalence and outcomes of COVID-19 patients with digestive symptoms. METHODS: In this descriptive, cross-sectional, multicenter study, we enrolled confirmed patients with COVID-19 who presented to 3 hospitals from January 18, 2020, to February 28, 2020. All patients were confirmed by real-time polymerase chain reaction and were analyzed for clinical characteristics, laboratory data, and treatment. Data were followed up until March 18, 2020. RESULTS: In the present study, 204 patients with COVID-19 and full laboratory, imaging, and historical data were analyzed. The average age was 52.9 years (SD ± 16), including 107 men and 97 women. Although most patients presented to the hospital with fever or respiratory symptoms, we found that 103 patients (50.5%) reported a digestive symptom, including lack of appetite (81 [78.6%] cases), diarrhea (35 [34%] cases), vomiting (4 [3.9%] cases), and abdominal pain (2 [1.9%] cases). If lack of appetite is excluded from the analysis (because it is less specific for the gastrointestinal tract), there were 38 total cases (18.6%) where patients presented with a gastrointestinal-specific symptom, including diarrhea, vomiting, or abdominal pain. Patients with digestive symptoms had a significantly longer time from onset to admission than patients without digestive symptoms (9.0 days vs 7.3 days). In 6 cases, there were digestive symptoms, but no respiratory symptoms. As the severity of the disease increased, digestive symptoms became more pronounced. Patients with digestive symptoms had higher mean liver enzyme levels, lower monocyte count, longer prothrombin time, and received more antimicrobial treatment than those without digestive symptoms. DISCUSSION: We found that digestive symptoms are common in patients with COVID-19. Moreover, these patients have a longer time from onset to admission, evidence of longer coagulation, and higher liver enzyme levels. Clinicians should recognize that digestive symptoms, such as diarrhea, are commonly among the presenting features of COVID-19 and that the index of suspicion may need to be raised earlier in at-risk patients presenting with digestive symptoms. However, further large sample studies are needed to confirm these findings.


Assuntos
Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Gastroenteropatias/epidemiologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Adulto , Idoso , COVID-19 , China/epidemiologia , Infecções por Coronavirus/terapia , Estudos Transversais , Feminino , Gastroenteropatias/terapia , Gastroenteropatias/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/terapia , Prevalência , Resultado do Tratamento
13.
ACS Sens ; 5(4): 1168-1176, 2020 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-32189498

RESUMO

The ability to continuously measure concentrations of small molecules is important for biomedical, environmental, and industrial monitoring. However, because of their low molecular mass, it is difficult to quantify concentrations of such molecules, particularly at low concentrations. Here, we describe a small-molecule sensor that is generalizable, sensitive, specific, reversible, and suited for continuous monitoring over long durations. The sensor consists of particles attached to a sensing surface via a double-stranded DNA tether. The particles transiently bind to the sensing surface via single-molecular affinity interactions, and the transient binding is optically detected as digital binding events via the Brownian motion of the particles. The rate of binding events decreases with increasing analyte concentration because analyte molecules inhibit binding of the tethered particle to the surface. The sensor enables continuous measurements of analyte concentrations because of the reversibility of the intermolecular bonds and digital read-out of particle motion. We show results for the monitoring of short single-stranded DNA sequences and creatinine, a small-molecule biomarker (113 Da) for kidney function, demonstrating a temporal resolution of a few minutes. The precision of the sensor is determined by the statistics of the digital switching events, which means that the precision is tunable by the number of particles and the measurement time.


Assuntos
Técnicas Biossensoriais/métodos , Imagem Individual de Molécula
14.
Nat Commun ; 10(1): 3854, 2019 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-31451692

RESUMO

Exosomes have been implicated in numerous biological processes, and they may serve as important disease markers. Surface proteins on exosomes carry information about their tissues of origin. Because of the heterogeneity of exosomes it is desirable to investigate them individually, but this has so far remained impractical. Here, we demonstrate a proximity-dependent barcoding assay to profile surface proteins of individual exosomes using antibody-DNA conjugates and next-generation sequencing. We first validate the method using artificial streptavidin-oligonucleotide complexes, followed by analysis of the variable composition of surface proteins on individual exosomes, derived from human body fluids or cell culture media. Exosomes from different sources are characterized by the presence of specific combinations of surface proteins and their abundance, allowing exosomes to be separately quantified in mixed samples to serve as markers for tissue-specific engagement in disease.


Assuntos
Exossomos/metabolismo , Perfilação da Expressão Gênica/métodos , Proteínas de Membrana/metabolismo , Líquidos Corporais/citologia , Linhagem Celular Tumoral , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Imunoconjugados/genética , Imunoconjugados/metabolismo , Proteínas de Membrana/genética , Sondas Moleculares/genética , Sondas Moleculares/metabolismo , Oligonucleotídeos/genética , Oligonucleotídeos/metabolismo , Análise de Sequência de DNA/métodos
15.
BMC Pulm Med ; 19(1): 122, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286925

RESUMO

BACKGROUND: Granulomatosis with polyangiitis (GPA) is characterised by the main violation of the upper and lower respiratory tract and kidney. GPA is considered a systemic vasculitis of medium-sized and small blood vessels where aortic involvement is extremely rare. CASE PRESENTATION: A 28-year-old male was admitted to the hospital due to 4 h of chest pain. Computed tomography scan of the aorta showed a thickened aortic wall, pulmonary lesions, bilateral pleural effusion and pericardial effusion. The aortic dissection should be considered. An emergency operation was performed on the patient. Surgical biopsies obtained from the aortic wall showed destructive changes, visible necrosis, granulation tissue hyperplasia and a large number of acute and chronic inflammatory cells. Nearly a year later, the patient was re-examined for significant pulmonary lesions. His laboratory studies were significantly positive for anti-neutrophilic antibody directed against proteinase 3. Finally, the diagnosis of GPA was obviously established. CONCLUSIONS: Although GPA rarely involves the aorta, we did not ignore the fact that GPA may involve large blood vessels. In addition, GPA should be included in the systemic vasculitis that can give rise to aortitis and even aortic dissection.


Assuntos
Dissecção Aórtica/diagnóstico por imagem , Aortite/diagnóstico por imagem , Granulomatose com Poliangiite/diagnóstico , Pulmão/patologia , Adulto , Anticorpos Anticitoplasma de Neutrófilos/sangue , Dor no Peito/etiologia , Ecocardiografia , Granulomatose com Poliangiite/complicações , Granulomatose com Poliangiite/fisiopatologia , Humanos , Masculino , Mieloblastina/imunologia , Tomografia Computadorizada por Raios X
16.
Nat Commun ; 9(1): 2541, 2018 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-29959314

RESUMO

Healthcare is in demand of technologies for real-time sensing in order to continuously guard the state of patients. Here we present biomarker-monitoring based on the sensing of particle mobility, a concept wherein particles are coupled to a substrate via a flexible molecular tether, with both the particles and substrate provided with affinity molecules for effectuating specific and reversible interactions. Single-molecular binding and unbinding events modulate the Brownian particle motion and the state changes are recorded using optical scattering microscopy. The technology is demonstrated with DNA and protein as model biomarkers, in buffer and in blood plasma, showing sensitivity to picomolar and nanomolar concentrations. The sensing principle is direct and self-contained, without consuming or producing any reactants. With its basis in reversible interactions and single-molecule resolution, we envisage that the presented technology will enable biosensors for continuous biomarker monitoring with high sensitivity, specificity, and accuracy.


Assuntos
Técnicas Biossensoriais , Sondas de DNA/química , DNA/sangue , Microscopia de Vídeo/métodos , Imagem Individual de Molécula/métodos , Trombina/análise , Animais , Biomarcadores/sangue , Biotina/química , Bovinos , Sondas de DNA/síntese química , DNA de Cadeia Simples/sangue , Humanos , Cinética , Nanopartículas de Magnetita/química , MicroRNAs/sangue , Monitorização Fisiológica/métodos , Sensibilidade e Especificidade , Imagem Individual de Molécula/instrumentação , Estreptavidina/química
17.
TH Open ; 2(3): e250-e260, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31276087

RESUMO

Extracellular vesicles (EVs) derived from blood cells are promising biomarkers for various diseases. However, they are difficult to measure accurately in plasma due to their small size. Here, we demonstrate that platelet-derived EVs in plasma can be measured using solid-phase proximity ligation assay with high sensitivity and specificity using very small sample volume of biological materials. The results correlate well with high-sensitivity flow cytometry with the difference that the smallest EVs are detected. Briefly, the EVs are first captured on a solid phase, using lactadherin binding, and detection requires recognition with two antibodies followed by qPCR. The assay, using cholera toxin subunit-B or lactadherin as capture agents, also allowed detection of the more rare population of tissue factor (TF)-positive EVs at a concentration similar to sensitive TF activity assays. Thus, this assay can detect different types of EVs with high specificity and sensitivity, and has the potential to be an attractive alternative to flow cytometric analysis of preclinical and clinical samples. Improved techniques for measuring EVs in plasma will hopefully contribute to the understanding of their role in several diseases.

18.
Sci Rep ; 7(1): 1490, 2017 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-28473697

RESUMO

Detection and quantification of proteins and their post-translational modifications are crucial to decipher functions of complex protein networks in cell biology and medicine. Capillary isoelectric focusing together with antibody-based detection can resolve and identify proteins and their isoforms with modest sample input. However, insufficient sensitivity prevents detection of proteins present at low concentrations and antibody cross-reactivity results in unspecific detection that cannot be distinguished from bona fide protein isoforms. By using DNA-conjugated antibodies enhanced signals can be obtained via rolling circle amplification (RCA). Both sensitivity and specificity can be greatly improved in assays dependent on target recognition by pairs of antibodies using in situ proximity ligation assays (PLA). Here we applied these DNA-assisted RCA techniques in capillary isoelectric focusing to resolve endogenous signaling transducers and isoforms along vascular endothelial growth factor (VEGF) signaling pathways at concentrations too low to be detected in standard assays. We also demonstrate background rejection and enhanced specificity when protein detection depended on binding by pairs of antibodies using in situ PLA, compared to assays where each antibody preparation was used on its own.


Assuntos
Eletroforese Capilar/métodos , Focalização Isoelétrica/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Proteínas/análise , Neoplasias Colorretais/diagnóstico , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Nanopartículas/química , Fosforilação , Sensibilidade e Especificidade , Transdução de Sinais/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/farmacologia
19.
Ultrasound Med Biol ; 43(3): 601-606, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27988221

RESUMO

Ultrasound (US) has become one of the important imaging methods for differentiating benign from malignant breast lesions. In 2013, the American College of Radiology published the fifth edition of the Breast Imaging-Reporting and Data System (BI-RADS). BI-RADS is a guide with recommendations for the standardization of breast imaging (US, mammography and magnetic resonance imaging) reports and for the auditing of centers employing such methods. Its objective is to standardize the nomenclature used in the reports. However, current US examinations are neither adequately sensitive nor sufficiently specific enough. The average Young's modulus was measured through shear wave elastography (SWE) to evaluate the diagnostic value of the BI-RADS classification in conjunction with SWE in differentiating BI-RADS 3 and 4 nodules. A total of 100 consecutive women with 126 breast lesions, including 65 benign and 61 malignant lesions, were included. The average Young's modulus of breast nodules and peri-nodule tissue (Emean1 and Emean2) was also determined through SWE. A receiver operating characteristic curve was drawn on the basis of pathologic results. The highest cut-off values were C1 and C2. At Emean1 > C1 or Emean2 > C2, BI-RADS 3 was increased to 4a and BI-RADS 4a was increased to 4b. At Emean1 ≤ C1 and Emean2 ≤ C2, BI-RADS 4b was decreased to 4a. Other BI-RADS classifications remained unchanged. BI-RADS 3 and 4a were considered benign. BI-RADS 4b and 4c were malignant. The area under the curve, sensitivity and specificity of the BI-RADS classification in conjunction with SWE were 0.952, 93.4% and 95.4%, respectively. The area under the curve, sensitivity and specificity of the original BI-RADS classification were 0.883, 82.0% and 87.7%, respectively. Differences were statistically significant (p = 0.028, Z-test). The diagnostic sensitivity and specificity were increased effectively. As a new method, BI-RADS classification in conjunction with SWE that combines the average Young's modulus yields a high value in terms of the differential diagnosis of breast nodules.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Técnicas de Imagem por Elasticidade/métodos , Sistemas de Informação em Radiologia , Ultrassonografia Mamária/métodos , Adulto , Idoso , Mama/diagnóstico por imagem , Neoplasias da Mama/classificação , Diagnóstico Diferencial , Módulo de Elasticidade , Feminino , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
20.
J Diabetes Investig ; 8(2): 201-209, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27370357

RESUMO

AIMS/INTRODUCTION: A meta-analysis was carried out to evaluate the efficacy of yoga in adults with type 2 diabetes mellitus. MATERIALS AND METHODS: The PubMed, EMBASE and Cochrane databases were searched to obtain eligible randomized controlled trials. The primary outcome was fasting blood glucose, and the secondary outcomes included glycosylated hemoglobin A1c, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride and postprandial blood glucose. Weighted mean differences and 95% confidence intervals (CIs) were calculated. The I2 statistic represented heterogeneity. RESULTS: A total of 12 randomized controlled trials with a total of 864 patients met the inclusion criteria. The pooled weighted mean differences were -23.72 mg/dL (95% CI -37.78 to -9.65; P = 0.001; I2 = 82%) for fasting blood glucose and -0.47% (95% CI -0.87 to -0.07; P = 0.02; I2 = 82%) for hemoglobin A1c. The weighted mean differences were -17.38 mg/dL (95% CI -27.88 to -6.89; P = 0.001; I2 = 0%) for postprandial blood glucose, -18.50 mg/dL (95% CI -29.88 to -7.11; P = 0.001; I2 = 75%) for total cholesterol, 4.30 mg/dL (95% CI 3.25 to 5.36; P < 0.00001; I2 = 10%) for high-density lipoprotein cholesterol, -12.95 mg/dL (95% CI -18.84 to -7.06; P < 0.0001; I2 = 37%) for low-density lipoprotein cholesterol and -12.57 mg/dL (95% CI -29.91 to 4.76; P = 0.16; I2 = 48%) for triglycerides. CONCLUSIONS: The available evidence suggests that yoga benefits adult patients with type 2 diabetes mellitus. However, considering the limited methodology and the potential heterogeneity, further studies are necessary to support our findings and investigate the long-term effects of yoga in type 2 diabetes mellitus patients.


Assuntos
Diabetes Mellitus Tipo 2/terapia , Yoga , Adulto , Glicemia , Colesterol/sangue , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Triglicerídeos/sangue
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