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1.
World J Surg Oncol ; 22(1): 113, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38664776

RESUMO

BACKGROUND: The standard curative treatments for extremity soft tissue sarcoma (ESTS) include surgical resection with negative margins and perioperative radiotherapy. However, the optimal resection margin remains controversial. This study aimed to evaluate the outcomes in ESTS between microscopically positive margin (R1) and microscopically negative margin (R0) according to the Union for International Cancer Control (UICC) (R + 1 mm) classification. METHODS: Medical records of patients with localized ESTS who underwent primary limb-sparing surgery and postoperative radiotherapy between 2004 and 2015 were retrospectively reviewed. Patients were followed for at least 5 years or till local or distant recurrence was diagnosed during follow-up. Outcomes were local and distal recurrences and survival. RESULTS: A total of 52 patients were included in this study, in which 17 underwent R0 resection and 35 underwent R1 resection. No significant differences were observed in rates of local recurrence (11.4% vs. 35.3%, p = 0.062) or distant recurrence (40.0% vs. 41.18%, p = 0.935) between R0 and R1 groups. Multivariate analysis showed that distant recurrences was associated with a Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) grade (Grade III vs. I, adjusted hazard ratio (aHR): 12.53, 95% confidence interval (CI): 2.67-58.88, p = 0.001) and tumor location (lower vs. upper extremity, aHR: 0.23, 95% CI: 0.07-0.7, p = 0.01). Kaplan-Meier plots showed no significant differences in local (p = 0.444) or distant recurrent-free survival (p = 0.161) between R0 and R1 groups. CONCLUSIONS: R1 margins, when complemented by radiotherapy, did not significantly alter outcomes of ESTS as R0 margins. Further studies with more histopathological types and larger cohorts are necessary to highlight the path forward.


Assuntos
Extremidades , Margens de Excisão , Recidiva Local de Neoplasia , Sarcoma , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Sarcoma/cirurgia , Sarcoma/patologia , Sarcoma/radioterapia , Sarcoma/mortalidade , Estudos Retrospectivos , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/cirurgia , Extremidades/patologia , Extremidades/cirurgia , Adulto , Seguimentos , Taxa de Sobrevida , Idoso , Prognóstico , Radioterapia Adjuvante/métodos , Radioterapia Adjuvante/estatística & dados numéricos , Tratamentos com Preservação do Órgão/métodos , Tratamentos com Preservação do Órgão/estatística & dados numéricos , Adulto Jovem , Neoplasias de Tecidos Moles/cirurgia , Neoplasias de Tecidos Moles/patologia , Neoplasias de Tecidos Moles/radioterapia , Neoplasias de Tecidos Moles/mortalidade , Adolescente
2.
J Med Internet Res ; 24(3): e26634, 2022 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-35294369

RESUMO

BACKGROUND: Gestational diabetes mellitus (GDM) is a common endocrine metabolic disease, involving a carbohydrate intolerance of variable severity during pregnancy. The incidence of GDM-related complications and adverse pregnancy outcomes has declined, in part, due to early screening. Machine learning (ML) models are increasingly used to identify risk factors and enable the early prediction of GDM. OBJECTIVE: The aim of this study was to perform a meta-analysis and comparison of published prognostic models for predicting the risk of GDM and identify predictors applicable to the models. METHODS: Four reliable electronic databases were searched for studies that developed ML prediction models for GDM in the general population instead of among high-risk groups only. The novel Prediction Model Risk of Bias Assessment Tool (PROBAST) was used to assess the risk of bias of the ML models. The Meta-DiSc software program (version 1.4) was used to perform the meta-analysis and determination of heterogeneity. To limit the influence of heterogeneity, we also performed sensitivity analyses, a meta-regression, and subgroup analysis. RESULTS: A total of 25 studies that included women older than 18 years without a history of vital disease were analyzed. The pooled area under the receiver operating characteristic curve (AUROC) for ML models predicting GDM was 0.8492; the pooled sensitivity was 0.69 (95% CI 0.68-0.69; P<.001; I2=99.6%) and the pooled specificity was 0.75 (95% CI 0.75-0.75; P<.001; I2=100%). As one of the most commonly employed ML methods, logistic regression achieved an overall pooled AUROC of 0.8151, while non-logistic regression models performed better, with an overall pooled AUROC of 0.8891. Additionally, maternal age, family history of diabetes, BMI, and fasting blood glucose were the four most commonly used features of models established by the various feature selection methods. CONCLUSIONS: Compared to current screening strategies, ML methods are attractive for predicting GDM. To expand their use, the importance of quality assessments and unified diagnostic criteria should be further emphasized.


Assuntos
Diabetes Gestacional , Feminino , Humanos , Modelos Logísticos , Aprendizado de Máquina , Gravidez , Prognóstico , Fatores de Risco
3.
J Pediatr Hematol Oncol ; 43(7): e907-e912, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33235154

RESUMO

OBJECTIVE: To investigate the clinical utility of short-course induction chemotherapy followed by low-dose radiotherapy without a tumor bed boost in patients with primary central nervous system (CNS) germinomas. METHODS: We retrospectively reviewed the clinical records of patients with primary CNS germinomas who received short-course induction chemotherapy (2 cycles of cisplatin 20 mg/m2 plus etoposide 40 or 100 mg/m2 for 5 days) followed by low-dose radiotherapy (dose: 2340 cGy) without a tumor bed boost. Disease-free survival and overall survival served as the main outcome measures. RESULTS: Between February 2002 and June 2018, 24 patients (20 males and 4 females; median age: 14.1 y; age range: 7.9 to 21.2 y) with pathology-proven CNS germinomas were included. The median follow-up time was 106 months (range: 17 to 169 mo). Isolated and multifocal lesions were identified in 13 and 11 patients, respectively. Tumor location was as follows: pineal gland (n=17), suprasellar region (n=13), periventricular region (n=7), and basal ganglia (n=2). Five patients had increased levels (>5 mIU/mL) of beta-human chorionic gonadotropin (ß-hCG), whereas alpha-fetoprotein concentrations were within the reference range in all participants. A total of 16 patients achieved remission after induction chemotherapy. The complete response rates of patients with increased and normal ß-hCG levels were 40.0% and 72.2%, respectively (P=0.208). Low-dose radiotherapy without a tumor bed boost was subsequently delivered to either the whole ventricle (n=16) or the whole brain (n=8), resulting in complete remission in all participants. Compared with patients without increased ß-hCG levels, those with ß-hCG-secreting germinomas had less favorable 5-year disease-free survival rates (100% vs. 60%, respectively, P=0.000115). CONCLUSIONS: Some children with primary CNS germinoma may benefit from short-course induction chemotherapy followed by low-dose radiotherapy to the whole ventricle without a tumor bed boost. The validity of our findings needs to be confirmed in a randomized phase II study for children with ß-hCG levels <5 mIU/mL.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Sistema Nervoso Central/terapia , Quimiorradioterapia/mortalidade , Gonadotropina Coriônica/sangue , Germinoma/terapia , Quimioterapia de Indução/mortalidade , Adolescente , Adulto , Neoplasias do Sistema Nervoso Central/sangue , Neoplasias do Sistema Nervoso Central/patologia , Criança , Cisplatino/administração & dosagem , Etoposídeo/administração & dosagem , Feminino , Seguimentos , Germinoma/sangue , Germinoma/patologia , Humanos , Masculino , Prognóstico , Dosagem Radioterapêutica , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
4.
Adv Radiat Oncol ; 9(1): 101302, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38260237

RESUMO

Purpose: The aim of this study was to determine whether escalating the local radiation dose can improve the outcome of residual bladder cancer after transurethral resection of bladder tumor without increasing treatment-related toxicity. Methods and Materials: The treatment plans and medical records of patients with bladder cancer treated with curative-intent radiation therapy between 2008 and 2020 were reviewed. Those who had residual tumors in the computed tomography simulation images were included. A cumulative radiation dose higher than 6600 cGy was defined as dose escalation. The effect of dose escalation on 3-year locoregional control, progression-free survival, and overall survival was evaluated. Results: A total of 149 patients with residual tumors were identified. The median follow-up period was 27.5 months. Among them, 51 patients received an escalated radiation dose, and 98 received a standard dose in the residual tumor area. Patients in the dose-escalation group had higher 3-year locoregional control (65.6% vs 27.8%; P < .001) and progression-free survival (42.6% vs 18.2%; P < .001) than the standard-dose group. Overall survival also showed a trend favoring the dose-escalation group (54.9% vs 36.2%; P = .059). In the multivariate analyses, the differences between the dose-escalation and standard-dose groups were significant in terms of locoregional control (hazard ratio, 0.32; CI, 0.18-0.59; P = <.001) and progression-free survival (hazard ratio, 0.51; CI, 0.32-0.82; P = .005). There was no statistical difference in acute and chronic treatment-related toxicities between the 2 groups. Conclusions: The outcome of residual bladder cancer after transurethral resection of bladder tumor could be improved by dose-escalated radiation therapy.

5.
Br J Radiol ; 95(1131): 20210670, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34558308

RESUMO

OBJECTIVE: Localized prostate cancer can be treated with several radiotherapeutic approaches. Proton therapy (PT) can precisely target tumors, thus sparing normal tissues and reducing side-effects without sacrificing cancer control. However, PT is a costly treatment compared with conventional photon radiotherapy, which may undermine its overall efficacy. In this review, we summarize current data on the dosimetric rationale, clinical benefits, and cost of PT for prostate cancer. METHODS: An extensive literature review of PT for prostate cancer was performed with emphasis on studies investigating dosimetric advantage, clinical outcomes, cost-effective strategies, and novel technology trends. RESULTS: PT is safe, and its efficacy is comparable to that of standard photon-based therapy or brachytherapy. Data on gastrointestinal, genitourinary, and sexual function toxicity profiles are conflicting; however, PT is associated with a low risk of second cancer and has no effects on testosterone levels. Regarding cost-effectiveness, PT is suboptimal, although evolving trends in radiation delivery and construction of PT centers may help reduce the cost. CONCLUSION: PT has several advantages over conventional photon radiotherapy, and novel approaches may increase its efficacy and safety. Large prospective randomized trials comparing photon therapy with proton-based treatments are ongoing and may provide data on the differences in efficacy, toxicity profile, and quality of life between proton- and photon-based treatments for prostate cancer in the modern era. ADVANCES IN KNOWLEDGE: PT provides excellent physical advantages and has a superior dose profile compared with X-ray radiotherapy. Further evidence from clinical trials and research studies will clarify the role of PT in the treatment of prostate cancer, and facilitate the implementation of PT in a more accessible, affordable, efficient, and safe way.


Assuntos
Neoplasias da Próstata/radioterapia , Terapia com Prótons/métodos , Análise Custo-Benefício , Previsões , Humanos , Masculino , Terapia com Prótons/economia , Dosagem Radioterapêutica
6.
Cancers (Basel) ; 14(5)2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35267637

RESUMO

Purpose: The purpose of this pilot prospective study is to examine the gallium-68-prostate-specific membrane antigen-11 ([68Ga]Ga-PSMA-11) positron emission tomography/computed tomography (PET/CT) imaging response in patients with advanced or metastatic hormone-naïve prostate cancer (PC) after 3 months of androgen deprivation therapy (ADT). Methods: We prospectively included men with untreated, clinical stage III or IV PC scheduled to receive ADT for at least 6 months. [68Ga]Ga-PSMA-11 PET/CT images were obtained before the start of ADT and 10−14 weeks thereafter. The following indices were examined: maximum standardized uptake value (SUVmax), mean SUV, PSMA total volume, and PSMA total lesion values of the prostate, nodes, bones, and whole-body. The therapeutic response was assessed using the modified PET response criteria in solid tumors 1.0. A subgroup analysis of patients with the International Society of Urological Pathology (ISUP) grade group 5 versus <5 was also performed. Results: A total of 30 patients were eligible. All PSMA PET/CT indices were significantly reduced (p < 0.001) after 3 months of ADT. Twenty-four (80%) patients showed partial response. Complete response, stable disease, and disease progression were observed in two patients each. Sixteen patients with ISUP grade group 5 showed a less prominent SUVmax reduction (p = 0.006), and none of them reached complete response. Conclusions: Three months of ADT in patients with untreated, advanced PC significantly reduced PSMA PET/CT indices. While most participants partially responded to ADT, patients with ISUP grade group 5 showed a less prominent SUVmax reduction. Collectively, our pilot results indicate that [68Ga]Ga-PSMA-11 PET/CT imaging holds promise to monitor treatment response after the first three months of ADT.

7.
Cancer Med ; 10(6): 1975-1988, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33624454

RESUMO

BACKGROUND: We sought to compare the prognostic significance of different preoperative complete blood count cell ratios in patients with oral cavity squamous cell carcinoma (OSCC) treated with surgery and postoperative radiotherapy (PORT). METHODS: We retrospectively reviewed the clinical records of 890 patients with OSCC who were treated with surgery and PORT. The following preoperative complete blood count cell ratios were collected: neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR). Overall survival (OS), local control, regional control, and distant control (DC) served as the main outcomes of interest. RESULTS: The results of multivariate analysis in the entire study cohort revealed that a low NLR was the only independently favorable marker of both OS (adjusted hazard ratio [HR]: 0.794, 95% confidence interval (CI): 0.656-0.961, bootstrap p = 0.028) and DC (adjusted HR: 0.659, 95% CI: 0.478-0.909, bootstrap p = 0.015). Both LMR and PLR were not retained in the model as independent predictors. Subgroup analyses in high-risk patients (i.e., those bearing T4 disease, N3 disease, or poor differentiation) revealed that a high NLR was a significant adverse risk factor for both OS and DC (all p < 0.03)-with a borderline significance being evident for DC in patients with T4 disease (p = 0.058). CONCLUSIONS: A high pretreatment NLR was an independent unfavorable risk factor for both OS and DC in patients with OSCC who underwent surgery and PORT. No other preoperative complete blood count parameters and cell ratios were found to have prognostic significance.


Assuntos
Contagem de Células Sanguíneas , Carcinoma de Células Escamosas/sangue , Neoplasias Bucais/sangue , Adulto , Plaquetas/citologia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/cirurgia , Intervalos de Confiança , Feminino , Humanos , Estimativa de Kaplan-Meier , Linfócitos/citologia , Masculino , Pessoa de Meia-Idade , Monócitos/citologia , Neoplasias Bucais/mortalidade , Neoplasias Bucais/radioterapia , Neoplasias Bucais/cirurgia , Análise Multivariada , Neutrófilos/citologia , Cuidados Pré-Operatórios , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos
8.
Cancer Med ; 10(2): 649-658, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33325655

RESUMO

OBJECTIVES: To investigate the prognostic value of the preoperative systemic immune-inflammation index (SII) in patients with oral cavity squamous cell carcinoma (OC-SCC) treated with curative surgery followed by adjuvant radiotherapy (RT) or chemoradiotherapy (CCRT). MATERIALS AND METHODS: We retrospectively reviewed the clinical records of patients with OC-SCC who received surgery and postoperative adjuvant RT/CCRT between January 2005 and December 2012. Blood samples were drawn in the 2 weeks preceding surgery. SII was calculated by multiplying the absolute neutrophil and platelet counts, and then, divided by the absolute lymphocyte count, and its optimal cutoff value was identified using the Youden's index. The study endpoints included overall survival (OS), local control (LC), regional control (RC), and distant control (DC). RESULTS: The study sample consisted of 993 patients (58.8% of them treated with CCRT). The optimal cutoff value for SII was 810.6. A total of 347 (34.9%) study participants had high preoperative SII values. After allowance for potential confounders in multivariable analysis, high SII values were independently associated with less favorable DC (adjusted hazard ratio [HR] = 1.683, p = 0.001) and OS (adjusted HR = 1.466, p < 0.001). No independent association between SII and LC/RC was observed. CONCLUSION: Increased SII values predict poor DC and OS in patients with OC-SCC treated with curative resection and adjuvant RT/CCRT. Owing to the higher risk of systemic failure in this patient group, a thorough follow-up surveillance schedule may be advisable pending independent confirmation of our data.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/patologia , Linfócitos do Interstício Tumoral/imunologia , Neoplasias Bucais/patologia , Neutrófilos/imunologia , Procedimentos Cirúrgicos Bucais/mortalidade , Cuidados Pré-Operatórios , Idoso , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/terapia , Terapia Combinada , Feminino , Seguimentos , Humanos , Linfócitos do Interstício Tumoral/patologia , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/imunologia , Neoplasias Bucais/terapia , Neutrófilos/patologia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
9.
Radiother Oncol ; 154: 76-86, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32941957

RESUMO

BACKGROUND AND PURPOSE: We sought to investigate whether dynamic changes in lymphocyte-to-monocyte ratio (LMR) occurring during the course of radiotherapy (RT) may have prognostic value in patients with head and neck cancer (HNC). MATERIALS AND METHODS: We retrospectively reviewed the clinical records of patients with HNC who underwent RT at our center between 2005 and 2013. Generalized estimating equations were used to longitudinally assess changes in LMR through the course of RT. Delta-LMR was calculated as the difference between LMR measured during treatment and baseline LMR values. Freedom from metastasis (FFM) and overall survival (OS) served as the main outcome measures. RESULTS: A total of 1431 patients with HNC were enrolled. After a median follow-up of 9 years, 636 (44.4%) patients died and 240 (16.8%) had distant metastases. Compared with patients with low delta-LMR at two weeks, those with high delta-LMR experienced less favorable outcomes (five-year OS: 73% versus 59%, respectively, p < 0.001; five-year FFM: 87% versus 80%, respectively, p = 0.015). Similar findings were observed for delta-LMR measured at four weeks (five-year OS: 72% versus 60%, p < 0.001; five-year FFM: 86% versus 79%, respectively, p = 0.002) and six weeks (five-year OS: 72% versus 57%, p < 0.001; five-year FFM: 87% versus 79%, respectively, p = 0.002). Multivariate analysis identified delta-LMR as an independent prognostic factor for both FFM and OS. CONCLUSION: Delta-LMR is a simple and inexpensive biomarker that may be clinically useful for predicting FFM and OS in patients with HNC treated with RT.


Assuntos
Neoplasias de Cabeça e Pescoço , Monócitos , Estudos de Coortes , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Contagem de Linfócitos , Linfócitos , Prognóstico , Estudos Retrospectivos
10.
Radiat Oncol ; 15(1): 194, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32795324

RESUMO

BACKGROUND: We sought to investigate the prognostic impact of missed RT sessions in patients who had undergone surgery for oral cavity squamous cell carcinoma (OCSCC). METHODS: The study sample consisted of 905 patients with surgically treated OCSCC who fulfilled criteria of RT course ≤8 weeks. The study participants were divided into three groups based on the characteristics of missed RT, as follows: 1) early missed RT, 2) late missed RT, and 3) RT as scheduled. RESULTS: The 5-year overall survival (OS) rates in the early missed RT, late missed RT, and RT as scheduled groups were 53.0, 58.1, and 64.5%, respectively (p = 0.046). In multivariate analysis, early missed RT was independently associated with both OS (hazard ratio (HR) = 1.486; 95% confidence interval (CI): 1.122-1.966; p = 0.006) and the occurrence of distant metastasis (HR = 1.644; 95% CI: 1.047-2.583; p = 0.031). CONCLUSION: Early missed RT was independently associated with a higher occurrence of distant metastasis and less favorable OS in patients who had undergone surgery for OCSCC.


Assuntos
Carcinoma de Células Escamosas/secundário , Neoplasias Bucais/patologia , Recidiva Local de Neoplasia/patologia , Cooperação do Paciente/estatística & dados numéricos , Radioterapia Adjuvante/mortalidade , Carcinoma de Células Escamosas/radioterapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/radioterapia , Recidiva Local de Neoplasia/radioterapia , Cooperação do Paciente/psicologia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
11.
Talanta ; 188: 58-65, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30029416

RESUMO

In this study,we proposed a triangular silver nanosheets (Tri-SNSs)-layered, Chitosan (CS)-supported three-dimensional of reduced graphene oxide (3D-ERGO) electrochemiluminescence (ECL) biosensing platform using self-designed dual-Ru(bpy)32+ scDNA (Ru2-DNA) as capture probe for ECL biosensing of single-chain DNA (scDNA). Based on the different affinity with scDNA and double chain DNA (dcDNA), the biosensor is designed to recognize the target DNA (t-DNA), which leads to the desorption of a hybrid molecule from the surface of the biosensor, further removing the Ru2-DNA and inhibiting the ECL. Analytical results clearly showed that the electrochemical and ECL behaviors of proposed biosensing platform on the glassy carbon electrode (GCE) exhibited outstanding performance, which was due to large specific surface area, high carrier mobility and strong π-π non-covalent attraction toward single-chain DNA (scDNA) of the stable 3D platform, and ECL amplification of Tri-SNSs. Besides, based on such a system, this strategy can effectively identify full match and mismatched target DNA (M-DNA) with a wide concentration range beyond 7 orders of magnitude and detection limit down to 16.2 aM. Therefore, the 3D biosensing strategy shows potential for the application of bioassays.


Assuntos
Técnicas Biossensoriais/métodos , DNA de Cadeia Simples/análise , Técnicas Eletroquímicas/métodos , Grafite/química , Nanoestruturas/química , Prata/química , 2,2'-Dipiridil/análogos & derivados , 2,2'-Dipiridil/química , Quitosana/química , Complexos de Coordenação/química , DNA de Cadeia Simples/química , Eletrodos , Limite de Detecção , Luminescência , Medições Luminescentes/métodos , Hibridização de Ácido Nucleico , Óxidos/química , Reprodutibilidade dos Testes
12.
Cancer Med ; 7(7): 2808-2815, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29790672

RESUMO

We aimed to investigate the prognostic significance of combined pretreatment lymphocyte counts (LCs) and body mass index (BMI) in patients with head and neck cancer (HNC) treated with radiation therapy (RT). Nine hundred and twelve patients with HNC who were treated with RT were retrospectively reviewed. Survival was analyzed by stratifying the patients according to pretreatment LCs and BMI. Patients with low pretreatment LCs and BMI were characterized by a more advanced T stage, fewer nasopharyngeal subsites, less smoking and drinking, and fewer comorbidities. Patients with low pretreatment LCs and BMI had a significantly poorer overall and distant metastasis-free survival than those with high pretreatment LCs and BMI. No significant differences were observed in terms of local or regional recurrence-free survival. Combined pretreatment LCs and BMI may be more effective at predicting overall and distant metastasis-free survival in patients with HNC treated with RT.

13.
Biosens Bioelectron ; 89(Pt 1): 585-591, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26856634

RESUMO

Endonucleases cleavage of DNA plays an important role in biological and medicinal chemistry. This work was going to develop a reliable and sensitive electrochemiluminescent (ECL) biosensor for detecting endonucleases by using gold nanoparticles graphene composite (GNPs-graphene) as a signal amplifier. Firstly, the GNPs and graphene were simultaneously deposited on the glassy carbon electrode (GCE) by cyclic voltammetry. Then a stem DNA was anchored on the surface of GCE. And with a modifying DNA introduced into the electrode by DNA assembly, a strong ECL signal was obtained. After a DNA modified with ferrocene assembly to the stem DNA, the ECL signal had a sharp decrease due to the quench effect of ferrocene to and the biosensor comes into being a "off" state. With the effect of endonuclease, the ECL signal had a recovery because of the ferrocene being released and the biosensor formed a "on" state. Moreover, the recovery of ECL signal was related to the concentration of endonucleases. Combining specific defined DNA and endonuclease, this method has a potential to detect different endonucleases. In this work, we took the EcoRI as an example to identify the feasibility of ECL biosensor in applying in sensitive detection of endonucleases using a GNPs-graphene signal amplifier. Under optimal condition, the proposed biosensor obtained a low limit of detection (LOD) 5.6×10-5UmL-1. And the stability, selectivity and reproducibility of the biosensor also were researched.


Assuntos
Desoxirribonuclease EcoRI/análise , Técnicas Eletroquímicas/métodos , Ouro/química , Grafite/química , Medições Luminescentes/métodos , Nanoestruturas/química , Técnicas Biossensoriais/métodos , DNA/química , Compostos Ferrosos/química , Limite de Detecção , Metalocenos , Nanopartículas/química , Nanopartículas/ultraestrutura , Nanoestruturas/ultraestrutura , Reprodutibilidade dos Testes
14.
Talanta ; 166: 1-7, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28213208

RESUMO

A novel fluorescence sensor based on controlling the surface passivation degree of carbon quantum dots (CQDs) was developed for glutathione (GSH) detection. First, we found that the fluorescence intensity of the CQDs which was obtained by directly pyrolyzing citric acid would increased largely after the surface passivation treatment by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC). In the light of this phenomenon, we designed a simple, rapid and selective fluorescence sensor based on the surface passivated CQDs. A certain and excess amount of EDC were mixed with GSH, part of EDC would form a stable complex with GSH owing to the exposed sulfhydryl group of GSH. As the synthesized CQDs were added into the above mixture solution, the fluorescence intensity of the (EDC/GSH)/CQDs mixture solution could be directly related to the amount of GSH. Compared to other fluorescence analytical methods, the fluorescence sensor we design is neither the traditional fluorescent "turn on" probes nor "turn off" probes. It is a new fluorescence analytical method that target object indirectly control the surface passivation degree of CQDs so that it can realize the detection of the target object. Moreover, the proposed method manifested great advantages including short analysis time, low cost and ease of operation.


Assuntos
Carbono/química , Glutationa/análise , Limite de Detecção , Pontos Quânticos/química , Espectrometria de Fluorescência/instrumentação , Glutationa/sangue , Glutationa/química , Humanos , Propriedades de Superfície
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