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1.
Acta Derm Venereol ; 104: adv11917, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38270257

RESUMO

Epidermolysis bullosa acquisita (EBA) rarely develops in childhood. This study retrospectively recruited paediatric patients with EBA (age ≤ 16 years), diagnosed by clinical and histopathological features and results of immunofluorescence, immunoblotting and enzyme-linked immunosorbent assay (ELISA), and reviews their clinical manifestations, histopathology, immunological features, and responses to various treatments. All 7 included patients presented with inflammatory EBA. Among them, 3 had a bullous pemphigoid-like phenotype. Pathologically, in addition to dermal-epidermal blistering, in all patients, the distribution of neutrophils was superficial perivascular or interstitial, or in the dermal papilla. Mixed neutrophils and eosinophils were detected in 2 of the 3 patients with bullous pemphigoid-like phenotypes. In addition to treatment with glucocorticoids, dapsone was administered in 4 patients, while thalidomide and sulfasalazine were administered in 1 patient. All patients responded to the these therapies. Relapse was mainly due to reduction and cessation of glucocorticoids. In conclusion, EBA in childhood may be unique, and thus distinct from its adult counterpart. Specific treatment and follow-up protocols are required for therapy of this rare autoimmune skin disease in children.


Assuntos
Doenças Autoimunes , Epidermólise Bolhosa Adquirida , Penfigoide Bolhoso , Adulto , Humanos , Criança , Adolescente , Epidermólise Bolhosa Adquirida/diagnóstico , Epidermólise Bolhosa Adquirida/tratamento farmacológico , Estudos Retrospectivos , Dapsona/uso terapêutico , Glucocorticoides/uso terapêutico
2.
J Invest Dermatol ; 144(3): 585-592.e1, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37839777

RESUMO

Unicentric Castleman disease (UCD) is a rare lymphoproliferative disorder. Paraneoplastic pemphigus (PNP) is a major complication associated with poor UCD prognosis. However, the genomic profiles and prognostic biomarkers of PNP-associated UCD remain unclear. In this study, we performed whole-exome sequencing analysis for 28 matched tumor-normal pairs and 9 tumor-only samples to define the genomic landscape of Chinese patients with PNP-associated UCD. An integrative analysis was performed to identify somatic variants, the mutational signatures, and key pathways in tumors. Besides, we analyzed the relationship among mutated genes, clinical characteristics, and prognosis. Sixty-one somatic mutant genes were identified in >1 patient with PNP-associated UCD. Specifically, IL6ST and PDGFRB were the most frequently mutated genes (32%), followed by DPP6 (18%) and MUC4 (18%). Signaling molecules and interactions, cellular processes, and signal transduction pathways were enriched. Furthermore, we found that poor overall survival was related to IL6ST variants (P = .02). Finally, we classified PNP-associated UCD into 4 genomic subgroups: IL6ST, PDGFRB, IL6ST-PDGFRB, and an unknown subgroup. In summary, we defined the molecular profile of PNP-associated UCD and identified a potential molecular biomarker for predicting prognosis, which may provide therapeutic targets for treating this severe disorder.


Assuntos
Hiperplasia do Linfonodo Gigante , Síndromes Paraneoplásicas , Pênfigo , Humanos , Hiperplasia do Linfonodo Gigante/diagnóstico , Hiperplasia do Linfonodo Gigante/genética , Hiperplasia do Linfonodo Gigante/complicações , Pênfigo/genética , Prognóstico , Sequenciamento do Exoma , Receptor beta de Fator de Crescimento Derivado de Plaquetas , Síndromes Paraneoplásicas/diagnóstico , Síndromes Paraneoplásicas/genética , Biomarcadores , Receptor gp130 de Citocina
3.
JAMA Dermatol ; 159(9): 953-960, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37531116

RESUMO

Importance: Dupilumab is a theoretically novel therapy for bullous pemphigoid (BP). However, its effectiveness and safety have yet to be confirmed in a large-scale study. Objective: To assess the efficacy and safety of dupilumab in patients with BP and evaluate factors that potentially affect short-term and long-term outcomes. Design, Setting, and Participants: A retrospective cohort study was conducted from January 1, 2021, to July 31, 2022. The median (IQR) follow-up period was 24.6 (11.5-38.4) weeks. This multicenter study was performed in 6 dermatology departments of the National Autoimmune Bullous Diseases Cooperative Group of China. Adult patients with BP that received 300 mg of dupilumab every 2 weeks following an initial dose of 600 mg were included. Patients were eligible if they had a clinical presentation of BP combined with immunological or pathological evidence. Patients with drug-induced BP, with less than 4 weeks of follow-up, and who received dupilumab or any other biologics within 6 months were excluded. Main Outcomes and Measures: The primary outcome was the proportion of patients who achieved disease control within 4 weeks. Disease control was defined as the absence of new lesions and pruritus, combined with the healing of existing lesions. Complete remission rates, relapse rates, changes in Bullous Pemphigoid Disease Area Index (BPDAI) scores, itching numerical rating scale (NRS) scores, laboratory results within 64 weeks, and adverse events (AEs) were also assessed. Results: Among 146 patients (median [IQR] age, 73 [64-85] years; 86 [58.9%] male patients) included in the study, 127 (87.0%) patients achieved disease control within 4 weeks, with a median (IQR) time of 14 (7-14) days. A total of 52 (35.6%) patients achieved complete remission, and 13 (8.9%) patients relapsed during the observation period. The complete remission rate and cumulative relapse rate at week 64 were 62.5% (5 of 8) and 30.9%, respectively. There was rapid and sustained improvement in clinical indicators and laboratory examination results after dupilumab treatment, including BPDAI scores, itching NRS scores, serum anti-BP180 and anti-BP230 antibodies, total IgE levels, and eosinophil count. Of these 146 patients, 107 (73.3%) did not report any AEs. The most common AEs were infections and eosinophilia. Serum anti-BP180 antibody levels of greater than 50 relative units (RU)/mL (OR, 3.63; 95% CI, 0.97-12.61; P = .045) were associated with 4-week disease control, and male patients were more likely to relapse (HR, 10.97; 95% CI, 1.42-84.92; P = .02). Conclusions and Relevance: In this retrospective cohort study, dupilumab treatment was associated with improved clinical symptoms in patients with BP. The safety profile was favorable, although concurrent infection and eosinophilia might pose potential concerns. This study suggests that patients with anti-BP180 antibody levels of at least 50 RU/mL and female sex may respond better.


Assuntos
Doenças Autoimunes , Penfigoide Bolhoso , Adulto , Humanos , Masculino , Feminino , Idoso , Penfigoide Bolhoso/diagnóstico , Estudos Retrospectivos , Prurido/tratamento farmacológico , Autoanticorpos , Autoantígenos , Recidiva
4.
J Dermatol ; 50(10): 1347-1352, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37248863

RESUMO

Therapy discontinuation of systemic glucocorticoid treatment for pemphigus remains uncertain at the clinical end point of complete remission. The objective of this study was to identify the factors associated with achieving complete remission off therapy (CROT) and analyze the occurrence of relapse after therapy discontinuation. A retrospective cohort study was conducted at the Department of Dermatology of Peking University First Hospital. A total of 447 patients with pemphigus treated from 2005 to 2020 were identified. Univariate and multivariate analyses were conducted to analyze the associated factors of CROT and to evaluate the outcomes. The mean age was 48 years (±13.4 years), and 54.6% of the patients were women. During a median follow-up of 59 months (43-87.5 months), 160 of 447 (35.8%) patients achieved CROT after a median treatment duration of 51 months (38-66.2 months). Patients with a shorter therapy duration to complete remission on minimal therapy and negative desmoglein antibodies tested in remission were more likely to achieve early CROT. Thirty-five of 160 (21.9%) patients experienced relapse after CROT. Patients who discontinued therapy without guidance experienced significantly faster and higher occurrences of relapse than those withdrawing under guidance (log-rank p = 0.01). Minimal therapy maintenance ≤8 months from complete remission on minimal therapy and positive desmoglein antibodies tested at withdrawal increased the risk of early relapse after CROT.


Assuntos
Pênfigo , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Pênfigo/tratamento farmacológico , Glucocorticoides/uso terapêutico , Estudos Retrospectivos , Resultado do Tratamento , Indução de Remissão , Recidiva , Desmogleínas
6.
Front Immunol ; 13: 886226, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35911677

RESUMO

Paraneoplastic pemphigus (PNP) is an autoimmune bullous disease associated with underlying neoplasms and characterized by antibodies against desmoglein 3 (Dsg 3) and plakins. Autoantibodies against desmoglein 3 in sera of patients with PNP have been proven to cause acantholysis in vivo in neonatal mice. As a member of the plakin family, autoantibodies against desmoplakin were detected frequently by immunoprecipitation in the sera of PNP. The recombinant C-terminus of desmoplakin was expressed and purified to adsorb the specific autoantibodies against the C-terminus of desmoplakin. In vitro dispase-dependent keratinocyte dissociation assay and in vivo IgG passive transfer into neonatal mice assay were performed, followed by the electronic microscopy examination and TUNEL assay. We found that anti-C terminus of desmoplakin autoantibodies caused blisters and acantholysis in mice skin at a dose-dependent manner. Moreover, dissociated fragments were observed after incubation with the purified IgG against desmoplakin, compared with normal human IgG (P-value =0.0207). The electronic microscopy examination showed the disconnection of keratin intermediate filaments from desmosomes. Lastly, apoptosis of keratinocytes in the TUNEL assay was all detected in the skins of neonatal mice after injection of the anti-C terminus of desmoplakin autoantibodies. Taken together, the study suggests that autoantibodies against the C-terminus of desmoplakin might be pathogenic in PNP.


Assuntos
Acantólise , Autoanticorpos , Desmoplaquinas , Acantólise/etiologia , Acantólise/imunologia , Animais , Doenças Autoimunes/complicações , Desmogleína 3 , Desmoplaquinas/imunologia , Humanos , Imunoglobulina G , Camundongos , Síndromes Paraneoplásicas/imunologia , Pênfigo/imunologia
7.
J Dermatol Sci ; 108(3): 121-126, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36608995

RESUMO

BACKGROUND: Bullous pemphigoid (BP) mostly involves elderly patients. The diagnosis of BP requires special immunological tests, which makes some patients unable to be diagnosed and treated timely. OBJECTIVE: The accuracy and application value of immune colloidal gold technique (ICGT) in BP were evaluated. The colloidal gold was conjugated with recombinant BP180 NC16A protein and mouse IgG antibody. As the test and control lines, the mouse-anti-human IgG and goat-anti-mouse IgG, respectively, were blotted on the nitrocellulose membrane. METHODS: 414 serum samples of consecutive patients with suspected BP and 15 samples from healthy donors were recruited. The consistency between ICGT and ELISA, and between serum and plasma/whole blood were evaluated. Subgroup analyses were performed in terms of clinical characteristics. We also followed up 65 BP patients' strip results to explore the predictive value of ICGT. RESULTS: Strong agreements between ICGT and ELISA(κ = 0.902) and between plasma/whole blood and serum samples (κ = 0.980) with good stability were observed. The ICGT achieved sensitivity of 93.9%, and specificity of 97.6%. In subgroup analysis, the sensitivity was significantly higher in older patients (96.3%), and with more typical lesions such as blisters (96.2%) and erosions (92.4%). In follow-up, we also found BP patients who kept ICGT-negative in remission state all got consecutive positive strips 1-3 weeks prior to mild new activity or flare. CONCLUSION: ICGT shows high potential as a rapid and stable option for the diagnosis and monitoring of BP. Further investigations are needed to re-evaluate this technique in a prospective study with a multicenter design.


Assuntos
Autoantígenos , Colágenos não Fibrilares , Penfigoide Bolhoso , Humanos , Autoanticorpos , Autoantígenos/química , Autoantígenos/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina G , Colágenos não Fibrilares/química , Colágenos não Fibrilares/imunologia , Penfigoide Bolhoso/diagnóstico por imagem , Estudos Prospectivos , Coloide de Ouro/química
8.
Adv Skin Wound Care ; 34(7): 365-370, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34125726

RESUMO

OBJECTIVE: To explore the features and risk factors of bacterial skin infections (BSIs) in hospitalized patients with bullous pemphigoid (BP). METHODS: Records were retrospectively reviewed for 110 hospitalized patients with BP admitted to Peking University First Hospital between 2013 and 2019. Bacterial species and drug resistance were assessed, and then the underlying risk factors for BSIs were evaluated. RESULTS: Infections were present in 40% (44/110) of the patients. Staphylococcus aureus (72.7%, 32/44) was the most common bacterium, and it was highly resistant to penicillin (81.3%, 26/32), erythromycin (62.5%, 20/32), and clindamycin (56.3%, 18/32), but 100.0% sensitive to vancomycin and tigecycline. Coronary heart disease (P = .02; odds ratio [OR], 12.68), multisystem comorbidities (P = .02; OR, 3.67), hypoalbuminemia (P = .04; OR, 3.70), high levels of anti-BP180 antibodies (>112.4 U/mL; P = .003; OR, 6.43), and season (spring: reference; summer: P = .002; OR, 23.58; autumn: P = .02; OR, 12.19; winter: P = .02; OR, 13.19) were significantly associated with BSIs. CONCLUSIONS: Hospitalized patients with BP had a high incidence of BSIs, and those patients with underlying risk factors require careful management to prevent and control BSIs.


Assuntos
Penfigoide Bolhoso/complicações , Infecções dos Tecidos Moles/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Penfigoide Bolhoso/epidemiologia , Estudos Retrospectivos , Dermatopatias Bacterianas/epidemiologia , Dermatopatias Bacterianas/etiologia , Infecções dos Tecidos Moles/epidemiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/etiologia , Infecções Estafilocócicas/fisiopatologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/patogenicidade
11.
Acta Derm Venereol ; 100(18): adv00312, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33074341

RESUMO

Paraneoplastic autoimmune multiorgan syndrome is a complex and deadly disease. We retrospectively reviewed the clinical features and risk factors for paraneoplastic autoimmune multiorgan syndrome in 145 Chinese patients. The most common neoplasm was Castleman disease (56%), and patients with Castleman disease tended to be younger (≤ 42 years old: 83% vs. 29%) and to have a greater proportions of lichen planus-like lesions (47% vs. 27%) and bronchiolitis obliterans (49% vs. 29%), compared to other neoplasm-associated patients. Among all 145 patients in the study, the survival rates were 84% at 1 year, 65% at 3 years, and 54% at 5 years. Kaplan-Meier curve analysis revealed that mortality was associated with older age (> 42 years), neoplasm type, labial lesions, and larger skin lesion area (> 17.5% of the body surface area). However, only older age and larger skin lesion area were independent factors associated with mortality in multivariate analysis. We suggest that patients with Castleman disease and paraneoplastic autoimmune multiorgan syndrome have many unique characteristics and the underlying risk factors for death require further exploration.


Assuntos
Síndromes Paraneoplásicas , Pênfigo , Adulto , Idoso , China/epidemiologia , Humanos , Síndromes Paraneoplásicas/diagnóstico , Síndromes Paraneoplásicas/epidemiologia , Estudos Retrospectivos , Fatores de Risco
12.
Ann Clin Microbiol Antimicrob ; 19(1): 46, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33032608

RESUMO

BACKGROUND: Infections were the primary cause of death (34.3-55.5%) in patients with pemphigus. Skin was usually the origin of infections. The study aimed to explore features and associated factors of bacterial skin infections (BSIs) in inpatients with pemphigus. METHODS: One hundred and seventy-seven inpatients with pemphigus hospitalizing from November 2014 to April 2019 were continuously recruited through Peking University First Hospital's inpatient records inpatients with pemphigus hospitalizing from November 2014 to April 2019 were continuously recruited through Peking University First Hospital's inpatient records. Then, we retrieved the clinical and laboratory data to explore the characteristics and associated factors of BSIs. RESULTS: Of patients enrolled, pemphigus vulgaris (PV, n = 142) and pemphigus foliaceus (PF, n = 9) were most common, followed by pemphigus erythematosus (PE, n = 25) and pemphigus vegetans (Pveg, n = 1). Eighty-seven of 177 (49.2%) inpatients developed BSIs, and they had a longer length of stay compared with inpatients without BSIs (median: 18.9 vs. 14.1 days, p = 0.008). Staphylococcus aureus was the most common bacteria (71.3%, 62/87) and highly resistant to penicillin (91.9%, 57/62). Higher levels of anti-Dsg1 autoantibodies (> 124.2 U/mL) (p < 0.001, odds ratio [OR] = 3.564, 95% confidence interval [CI]: 1.784-7.123) and anti-Dsg3 autoantibodies (> 169.5 U/mL) (p = 0.03, OR = 2.074, 95% CI: 1.084-3.969) were underlying risk factors of BSIs when analyzed by binary regression analysis. As for Gram's stain of bacteria, females had a lower rate of Gram-positive infections (p = 0.03). Patients using oral antibiotics (p = 0.05) had a higher rate of Gram-negative infections. Inpatients who were hospitalized in other hospitals within 2 weeks before the current admission had a higher rate of Gram-negative and co-infections (p = 0.03). CONCLUSIONS: Inpatients with pemphigus had a high incidence of BSIs. Some factors were associated with the susceptibility of BSIs and bacterial species.


Assuntos
Pênfigo/imunologia , Pênfigo/microbiologia , Dermatopatias Bacterianas/imunologia , Dermatopatias Bacterianas/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Autoanticorpos/sangue , China , Comorbidade , Farmacorresistência Bacteriana Múltipla , Feminino , Humanos , Pacientes Internados , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
13.
Eur J Dermatol ; 30(4): 338-344, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32969793

RESUMO

BACKGROUND: Autoimmune blistering diseases (AIBDs) are a group of fatal diseases with specific autoantibodies. BIOCHIP mosaic is a novel and all-in-one measure used for the rapid diagnosis of AIBDs. OBJECTIVES: To evaluate the diagnostic accuracy based on BIOCHIP mosaic (FA1501-1005-60) in Chinese patients with AIBDs. MATERIALS AND METHODS: Seventy-seven patients with AIBDs and 20 controls were enrolled. The BIOCHIP mosaic was performed using both serum and plasma samples. RESULTS: Based on BIOCHIP mosaic, the data from paired plasma and serum samples demonstrated a high degree of concordance (Cohen's kappa = 0.896-1.000) for autoantibodies against Dsg1, Dsg3, BP180-NC16A-4X, BP230gC, prickle-cell desmosomes, and pemphigoid antigens. Moreover, BIOCHIP mosaic also demonstrated a high degree of consistency for the detection rate of anti-Dsg1, Dsg3, plakins, BP180-NC16A-4X and non-collagenous domain of type VII collagen autoantibodies for the diagnosis of pemphigus foliaceus (77.3%), pemphigus vulgaris (88.6%), paraneoplastic pemphigus (100.0%), bullous pemphigoid (92.8%) and epidermolysis bullosa acquisita (99.0%), respectively. CONCLUSION: Using BIOCHIP mosaic, serum and plasma samples may be used interchangeably at 1/10 dilution. Overall, the BIOCHIP mosaic was shown to be a useful and accurate tool for the diagnosis of AIBDs.


Assuntos
Doenças Autoimunes/diagnóstico , Técnica Indireta de Fluorescência para Anticorpo/métodos , Dermatopatias Vesiculobolhosas/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Povo Asiático , Autoanticorpos/sangue , Autoantígenos/imunologia , Doenças Autoimunes/imunologia , Estudos de Casos e Controles , Desmogleína 1/imunologia , Desmogleína 3/imunologia , Distonina/imunologia , Humanos , Proteínas com Domínio LIM/imunologia , Pessoa de Meia-Idade , Colágenos não Fibrilares/imunologia , Plaquinas/imunologia , Valor Preditivo dos Testes , Dermatopatias Vesiculobolhosas/imunologia , Proteínas Supressoras de Tumor/imunologia , Adulto Jovem
15.
Am J Clin Pathol ; 154(3): 403-413, 2020 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-32459333

RESUMO

OBJECTIVES: We aimed to describe the clinical and histopathologic features of Castleman disease (CD), particularly emphasizing its associations with paraneoplastic pemphigus (PNP) and prognosis. METHODS: We retrospectively enrolled 123 CD patients at our center. Clinical, pathologic, and laboratory data were reviewed. RESULTS: Fifty percent of the patients had PNP. Compared with those without PNP, patients with PNP-associated CD had more hyaline vascular (HV) variants (83.9% vs 57.4%), fewer mixed cellular variants (16.1% vs 24.6%), and no plasmacytic variants (0% vs 18.0%). Thirty-eight of 87 patients with the HV variant of CD (HV-CD) had stroma-rich (SR) features, and the incidence rate was higher in those with PNP-associated CD than in those without PNP (48.4% vs 13.1%, P < .001). The SR variant was associated with higher PNP-associated IgG titers than SR absence before surgery (median 1:160 vs 1:80, P = .019) or after surgery (median 1:160 vs 1:40, P = .013). The SR variant was also an unfavorable prognostic factor for CD survival in univariate analysis. The 3-year survival rates were 47.5% among those with PNP and 87.7% among those without PNP (P < .001). CONCLUSIONS: PNP is associated with specific subtypes of CD and affects survival. The SR variant of HV-CD positively correlates with the incidence of PNP.


Assuntos
Hiperplasia do Linfonodo Gigante/patologia , Diarreia/patologia , Oftalmopatias Hereditárias/patologia , Enteropatias/patologia , Síndromes Paraneoplásicas/patologia , Pênfigo/patologia , Anormalidades da Pele/patologia , Doenças Vasculares/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
16.
ACS Sens ; 4(8): 2131-2139, 2019 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-31366194

RESUMO

The development of multiplex assays to simultaneously monitor multiclass chemical contaminants that commonly coexist in foods, such as heavy metal ions, antibiotics, and estrogen residues, is gaining attention. Here, a microfluidic chip (MC)-based multianalysis method coupled with magnetic encoded aptamer probes was used for simultaneous detection of kanamycin, 17ß-estradiol, and lead ion (Pb2+). Using this innovative strategy, the magnetic bead (MB)-based encoded probes labeled with aptamer hybrid chains were first used to selectively capture multiple targets, followed by generating single-stranded primers. The primers triggered a multibranched hybridization chain reaction (mHCR). Finally, three kinds of complementary strands (C-DNAs) with different lengths were hybridized with the arms of the mHCR products to form three types of multibranched DNA nanostructures. The decrement signals of C-DNAs were employed for qualification of targets. As the signal tags corresponded to different targets, the DNA nanostructures realized "one target for the decrease of massive C-DNAs" to improve sensitivity. The use of MB-based encoded probes could achieve magnetic separation to eliminate interference in the complex. The detection limits of this method were 1.76 × 10-4 nM (kanamycin), 1.18 × 10-4 nM (17ß-estradiol), and 1.29 × 10-4 nM (lead ion). Furthermore, the MC platform is reusable and can be used for more than 4000 samples. The assay combining the MC with MB-based encoded probes with multibranched DNA signal tags offers a universal, reusable, and high-throughput detection platform for screening multiclass chemical contaminants in food samples with complex matrices.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais , DNA/química , Contaminação de Alimentos/análise , Técnicas Analíticas Microfluídicas , Nanoestruturas/química , Técnicas Eletroquímicas , Estradiol/análise , Humanos , Íons/análise , Canamicina/análise , Chumbo/análise , Fenômenos Magnéticos
18.
J Chromatogr A ; 1589: 173-181, 2019 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-30635170

RESUMO

It is crucially important to rapidly, simultaneously, and sensitively determine trace amounts of heavy metal ions in complex samples. Herein, a stirring bar modified with two kinds of encoded hairpin DNA probes (H0 and H0') was used in a multiplexed strategy allowing for specific extraction of Hg2+ and Ag+ coupled to microchip electrophoresis (MCE) separation and LED induced fluorescence (LIF) detection. The extraction step utilizes stir bars, which are functionalized with designed hairpin DNA probes (H0 with TT and H0' with CC mismatches in stems). This allows the specific capture of Hg2+ and Ag+ through CAg+C and THg2+T interactions. These complexes are then enzymatically degraded by the action of exonuclease III (Exo III). The ions released during this enzymatic reaction can initiate a new cycle of interactions with hairpin structures and enzymatic reactions and so on. This cyclic step is specific to the presence of Hg2+ and Ag+ and represents the first round of amplification of the presence of the selected ions. The resulting single strand DNAs on the stirring bars after enzymatic degradation were used in the second step as primers to trigger the catalytic hairpin assembly (CHA) in the presence of a couple of hairpin structures in solution. Such a reaction allows producing duplexes that can be monitored by MCE-LIF. The fluorescence intensity of CHA products (IP) increased and that of hairpin DNAs (IR) decreased with the increase of target concentrations. The signal ratios (IP/IR and IP'/IR') consisted of targets. The assay was employed for Hg2+ and Ag+ detection in several mediums including water, milk, and fish samples with complex matrices. The results showed that the assay could avoid matrix interference to increase the sensitivity. Therefore, the multiplexed assay was ideal to simultaneously and quickly detect metal ions in complex samples.


Assuntos
Eletroforese em Microchip/métodos , Mercúrio/química , Sondas Moleculares/química , Prata/química , Animais , DNA , DNA de Cadeia Simples , Exodesoxirribonucleases , Peixes , Íons , Leite
19.
Talanta ; 189: 494-501, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30086951

RESUMO

Excessive intake of kanamycin (KANA) can cause some serious drug-resistant diseases, so it is urgent to develop some accurate and rapid analytical methods for monitor KANA residues in foodstuffs with complex matrix. Recently, many ratiometric assays were reported to be capable of overcoming matrix interference. Herein, a ratiometric and homogeneous assay for KANA detection based on microchip electrophoresis (MCE) was developed. First, by one single strand DNA (S-DNA) and one hairpin DNA (H-DNA), a novel R shape DNA probe (R-DNA) was prepared. After the probe was incubated with KANA, the S-DNA-KANA complex was formed, and H-DNA was released. Moreover, in the presence of exonuclease I (Exo-I), S-DNA-KANA complex would be digested to release the captured KANA for triggering target recycling and signal amplification. With the reaction going on, the fluorescence intensity of H-DNA (IH) increased and that of R-DNA (IR) decreased. They can be separated at different voltage intensities and converted to fluorescent signals for signal readout by MCE. The signal ratio of IH/IR was found to be linear toward target from 0.5 pg mL-1 to 10 ng mL-1, and the limit of detection was 150 fg mL-1. Moreover, it was successfully employed for KANA detection in milk and fish samples with consistent results of enzyme linked immune sorbent assay (ELISA). The R-DNA probe can quantitatively convert the amount of target to the intensity of DNA without label by MCE, and achieved exonuclease assisted signal amplification in homogenous solution. It was valuable to detect antibiotics residues in foodstuff with complex matrix. This approach broadened the application field of MCE to detect antibiotics without derivatization, which provided a promising platform for rapid screening of antibiotic residues in food.


Assuntos
Sondas de DNA/química , Eletroforese em Microchip/métodos , Exodesoxirribonucleases/metabolismo , Contaminação de Alimentos/análise , Canamicina/análise , Animais , Sondas de DNA/metabolismo , DNA de Cadeia Simples/química , DNA de Cadeia Simples/metabolismo , Estudos de Viabilidade , Peixes , Sequências Repetidas Invertidas , Canamicina/química , Limite de Detecção , Leite/química
20.
Biosens Bioelectron ; 112: 202-208, 2018 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-29709830

RESUMO

It is critically important to detect antibiotic residues for monitoring food safety. In this study, an enzyme- and label-free electrochemical aptasensor for antibiotics, with kanamycin (Kana) as a typical analyte, was developed based on a double stir bar-assisted toehold-mediated strand displacement reaction (dSB-TMSDR) for dual-signal amplification. First, we modified two gold electrodes (E-1 and E-2) with different DNA probes (S1/S2 hybrid probe in E-1 and DNA fuel strand S3 in E-2). In the presence of Kana, an S1/S2 probe can be disassembled from E-1 to form an S2/Kana complex in supernatant. The S2/Kana could react with S3 on E-2 to form S2/S3 hybrid and release Kana through TMSDR. After then, the target recycling was triggered. Subsequently, the formed S2/S3 hybrid can also trigger a hybridization chain reaction (HCR). Consequently, the dual-signal amplification strategy was established, which resulted in many long dsDNA chains on E-2. The chains can associate with methylene blue (MB) as redox probes to produce a current response for the quantification of Kana. The assay exhibited high sensitivity and specificity with a detection limit at 16 fM Kana due to the dual-signal amplification. The double stir bars system can both increase phase separation and prevent leakage of DNA fuel to reduce background interference. Moreover, it allows flexible sequence design of the TMSDR probes. The assay was successfully employed to detect Kana residues in food and showed potential application value in food safety detection.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais , Técnicas Eletroquímicas , Canamicina/isolamento & purificação , Condutometria , Sondas de DNA/química , Sondas de DNA/genética , Ouro/química , Canamicina/química , Limite de Detecção , Hibridização de Ácido Nucleico
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