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1.
J Am Heart Assoc ; 12(7): e026975, 2023 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-36942750

RESUMO

BACKGROUND Electrocardiography (ECG) may be performed as part of preparticipation sports screening. Recommendations on screening of athletes to identify individuals with previously unrecognized cardiac disease are robust; however, data guiding the preparticipation screening of unselected populations are scarce. T wave inversion (TWI) on ECG may suggest an undiagnosed cardiomyopathy. This study aims to describe the prevalence of abnormal TWI in an unselected young male cohort and the outcomes of an echocardiography-guided approach to investigating these individuals for structural heart diseases, focusing on the yield for cardiomyopathies. METHODS AND RESULTS Consecutive young male individuals undergoing a national preparticipation cardiac screening program for 39 months were studied. All underwent resting supine 12-lead ECG. Those manifesting abnormal TWI, defined as negatively deflected T waves of at least 0.1 mV amplitude in any 2 contiguous leads, underwent echocardiography. A total of 69 714 male individuals with a mean age of 17.9±1.1 years were studied. Of the individuals, 562 (0.8%) displayed abnormal TWI. This was most frequently observed in the anterior territory and least so in the lateral territory. A total of 12 individuals (2.1%) were diagnosed with a cardiomyopathy. Cardiomyopathy diagnoses were significantly associated with deeper maximum TWI depth and the presence of abnormal TWI in the lateral territory, but not with abnormal TWI in the anterior and inferior territories. No individual presenting with TWI restricted to solely leads V1 to V2, 2 inferior leads or both was diagnosed with a cardiomyopathy. CONCLUSIONS Cardiomyopathy diagnoses were more strongly associated with certain patterns of abnormal TWI. Our findings may support decisions to prioritize echocardiography in these individuals.


Assuntos
Cardiomiopatias , Ecocardiografia , Cardiopatias , Adolescente , Adulto , Humanos , Masculino , Adulto Jovem , Arritmias Cardíacas/diagnóstico , Cardiomiopatias/diagnóstico , Eletrocardiografia/métodos , Coração
2.
Arq. bras. cardiol ; 119(6): 940-945, dez. 2022. tab, graf
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1420136

RESUMO

Resumo Fundamento A síndrome de Wolff-Parkinson-White (WPW) é uma condição pró-arrítmica que pode exigir restrição de atividades extenuantes e é caracterizada por sinais de ECG, incluindo ondas delta. Observamos casos de padrões intermitentes de WPW apresentando-se como QRS alternante ('WPW alternante') em uma grande coorte de triagem de ECG pré-participação de homens jovens que se candidataram ao recrutamento militar. Objetivos Nosso objetivo foi determinar o padrão de WPW alternante, as características do caso e a prevalência de outros diagnósticos diferenciais relevantes apresentando-se como alternância de QRS em um ambiente de pré-participação. Métodos Cento e vinte e cinco mil cento e cinquenta e oito recrutas militares do sexo masculino prospectivos foram revisados de janeiro de 2016 a dezembro de 2019. Uma revisão de prontuários médicos eletrônicos identificou casos de WPW alternante e padrões ou síndrome de WPW. A revisão de prontuários médicos eletrônicos identificou casos de diagnósticos diferenciais relevantes que podem causar alternância de QRS. Resultados Quatro indivíduos (2,2%) apresentaram WPW alternante em 184 indivíduos com diagnóstico final de padrão ou síndrome de WPW. Dois desses indivíduos manifestaram sintomas ou achados eletrocardiográficos compatíveis com taquicardia supraventricular. A prevalência geral de WPW alternante foi de 0,003%, e a prevalência de WPW foi de 0,147%. As WPW alternantes representaram 8,7% dos indivíduos com QRS alternantes, e QRS alternantes tiveram prevalência de 0,037% em toda a população. Conclusões A WPW alternante é uma variante da WPW intermitente, que compreendeu 2,2% dos casos de WPW em nossa coorte de triagem pré-participação. Não indica necessariamente um baixo risco de taquicardia supraventricular. Deve ser reconhecido na triagem de ECG e distinguido de outras patologias que também apresentam QRS alternantes.


Abstract Background Wolff-Parkinson-White (WPW) syndrome is a proarrhythmic condition that may require restriction from strenuous activities and is characterized by ECG signs, including delta waves. We observed cases of intermittent WPW patterns presenting as QRS alternans ('WPW alternans') in a large pre-participation ECG screening cohort of young men reporting for military conscription. Objectives We aimed to determine the WPW alternans pattern, case characteristics, and the prevalence of other relevant differential diagnoses presenting as QRS alternans in a pre-participation setting. Methods One hundred twenty-five thousand one hundred fifty-eight prospective male military recruits were reviewed from January 2016 to December 2019. A review of electronic medical records identified cases of WPW alternans and WPW patterns or syndrome. Reviewing electronic medical records identified cases of relevant differential diagnoses that might cause QRS alternans. Results Four individuals (2.2%) had WPW alternans out of 184 individuals with a final diagnosis of WPW pattern or syndrome. Two of these individuals manifested symptoms or ECG findings consistent with supraventricular tachycardia. The overall prevalence of WPW alternans was 0.003%, and the prevalence of WPW was 0.147%. WPW alternans represented 8.7% of individuals presenting with QRS alternans, and QRS alternans had a prevalence of 0.037% in the entire population. Conclusions WPW alternans is a variant of intermittent WPW, which comprised 2.2% of WPW cases in our pre-participation screening cohort. It does not necessarily indicate a low risk for supraventricular tachycardia. It must be recognized at ECG screening and distinguished from other pathologies that also present with QRS alternans.

3.
Arq Bras Cardiol ; 119(6): 940-945, 2022 12.
Artigo em Inglês, Português | MEDLINE | ID: mdl-36417617

RESUMO

BACKGROUND: Wolff-Parkinson-White (WPW) syndrome is a proarrhythmic condition that may require restriction from strenuous activities and is characterized by ECG signs, including delta waves. We observed cases of intermittent WPW patterns presenting as QRS alternans ('WPW alternans') in a large pre-participation ECG screening cohort of young men reporting for military conscription. OBJECTIVES: We aimed to determine the WPW alternans pattern, case characteristics, and the prevalence of other relevant differential diagnoses presenting as QRS alternans in a pre-participation setting. METHODS: One hundred twenty-five thousand one hundred fifty-eight prospective male military recruits were reviewed from January 2016 to December 2019. A review of electronic medical records identified cases of WPW alternans and WPW patterns or syndrome. Reviewing electronic medical records identified cases of relevant differential diagnoses that might cause QRS alternans. RESULTS: Four individuals (2.2%) had WPW alternans out of 184 individuals with a final diagnosis of WPW pattern or syndrome. Two of these individuals manifested symptoms or ECG findings consistent with supraventricular tachycardia. The overall prevalence of WPW alternans was 0.003%, and the prevalence of WPW was 0.147%. WPW alternans represented 8.7% of individuals presenting with QRS alternans, and QRS alternans had a prevalence of 0.037% in the entire population. CONCLUSIONS: WPW alternans is a variant of intermittent WPW, which comprised 2.2% of WPW cases in our pre-participation screening cohort. It does not necessarily indicate a low risk for supraventricular tachycardia. It must be recognized at ECG screening and distinguished from other pathologies that also present with QRS alternans.


FUNDAMENTO: A síndrome de Wolff-Parkinson-White (WPW) é uma condição pró-arrítmica que pode exigir restrição de atividades extenuantes e é caracterizada por sinais de ECG, incluindo ondas delta. Observamos casos de padrões intermitentes de WPW apresentando-se como QRS alternante ('WPW alternante') em uma grande coorte de triagem de ECG pré-participação de homens jovens que se candidataram ao recrutamento militar. OBJETIVOS: Nosso objetivo foi determinar o padrão de WPW alternante, as características do caso e a prevalência de outros diagnósticos diferenciais relevantes apresentando-se como alternância de QRS em um ambiente de pré-participação. MÉTODOS: Cento e vinte e cinco mil cento e cinquenta e oito recrutas militares do sexo masculino prospectivos foram revisados de janeiro de 2016 a dezembro de 2019. Uma revisão de prontuários médicos eletrônicos identificou casos de WPW alternante e padrões ou síndrome de WPW. A revisão de prontuários médicos eletrônicos identificou casos de diagnósticos diferenciais relevantes que podem causar alternância de QRS. RESULTADOS: Quatro indivíduos (2,2%) apresentaram WPW alternante em 184 indivíduos com diagnóstico final de padrão ou síndrome de WPW. Dois desses indivíduos manifestaram sintomas ou achados eletrocardiográficos compatíveis com taquicardia supraventricular. A prevalência geral de WPW alternante foi de 0,003%, e a prevalência de WPW foi de 0,147%. As WPW alternantes representaram 8,7% dos indivíduos com QRS alternantes, e QRS alternantes tiveram prevalência de 0,037% em toda a população. CONCLUSÕES: A WPW alternante é uma variante da WPW intermitente, que compreendeu 2,2% dos casos de WPW em nossa coorte de triagem pré-participação. Não indica necessariamente um baixo risco de taquicardia supraventricular. Deve ser reconhecido na triagem de ECG e distinguido de outras patologias que também apresentam QRS alternantes.


Assuntos
Taquicardia Supraventricular , Síndrome de Wolff-Parkinson-White , Humanos , Masculino , Diagnóstico Diferencial , Eletrocardiografia , Estudos Prospectivos , Síndrome de Wolff-Parkinson-White/diagnóstico
4.
Appl Environ Microbiol ; 88(17): e0089522, 2022 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-35969059

RESUMO

The high host specificity of phages is a real challenge in the therapy applications of the individual phages. This study aimed to edit the long tail fiber proteins (pb1) of a T5-like phage to obtain the engineered phages with expanded plaquing host range. Two T5-like Salmonella phages with high genome sequence homology but different plaquing host ranges, narrow-host range phage vB STyj5-1 (STyj5-1) and wide-host range phage vB BD13 (BD13), were isolated and characterized. The pb1 parts of STyj5-1 were replaced by the corresponding part of BD13 using homologous recombination method to obtain the engineered phages. The alterations of the whole pb1 part or the N-terminal amino acids 1-400 of pb1 of STyj5-1 could expand their plaquing host ranges (from 20 strains to 30 strains) and improve their absorption rates (from 0.28-28.84% to 28.10-99.49%). Besides, the one-step growth curves of these engineered phages with modified pb1 parts were more similar to that of STyj5-1. The burst sizes of phages BD13, STyj5-1 and the engineered phages were 250, 236, 166, and 223 PFU per cell, respectively. The expanded plaquing host range and improved absorption rates of these engineered phages revealed that the pb1 part might be the primary determinant of the host specificities of some T5-like phages. IMPORTANCE Genetic editing can be used to change or expand the host range of phages and have been successfully applied in T2, T4 and other phages to obtain engineered phages. However, there are hardly any similar reports on T5-like phages due to that the determinant regions related to their host ranges have not been completely clarified and the editing of T5-like phages is more difficult compared to other phages. This study attempted and successfully expanded the host range of a narrow-host range T5-like phage (STyj5-1) by exchanging its whole pb1 part or the N-terminal 1-400aa of that part by a broad-host range phage (BD13). These demonstrated the pb1 part might be the primary determinant of the host specificities for some T5-like phages and provided an effective method of extension plaquing host range of these phages.


Assuntos
Bacteriófagos , Fagos de Salmonella , Bacteriófagos/química , Genoma Viral , Especificidade de Hospedeiro , Myoviridae/genética , Fagos de Salmonella/genética
5.
Virus Res ; 318: 198856, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35780912

RESUMO

Multidrug-resistant bacteria have become a major threat to global public health. Bacteriophages are regarded as a promising substitute. Here, we present a novel lytic Stenotrophomonas maltophilia phage, vB_SM_ytsc_ply2008005c, which was isolated from sewage water samples in Qingdao, east China. Virion morphology of phage particles indicated that ply2008005c has an icosahedral head (56 ± 5 nm in diameter) and a noncontractile sheathed tail (129 ± 6 nm in length), which are the typical characteristics of phages belonging to the family Siphoviridae. Phage ply2008005c could be used for phage therapy for its stability in a wide pH (4 to 12) range and high temperature (up to 70°C) environment. Genome analysis revealed that ply2008005c has a circular double-strand DNA of 42,318 bp with a G+C content of 63.02%. It shared the closest relationship with phage vB_PaeS_PAO1_Ab18, but the homology coverage is just 20%. There were 54 open reading frames predicted in its genome, including three unique proteins and 34 functional genes in different modules. The phylogenetic analysis revealed that ply2008005c forms a distinct branch of the family Siphoviridae. These results demonstrated that ply2008005c was supposed to be a representative new member within the family Siphoviridae, which could be considered a potential bioagent against multidrug-resistant S. maltophilia.


Assuntos
Bacteriófagos , Siphoviridae , Stenotrophomonas maltophilia , DNA Viral/química , DNA Viral/genética , Genoma Viral , Filogenia , Stenotrophomonas maltophilia/genética
6.
Talanta ; 248: 123627, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35661002

RESUMO

There is an urgent need to develop fast and sensitive detection methods for foodborne pathogens. But the conventional culture method that typically requires 2-3 days is not ideal for the rapid analysis. Food samples demonstrate a great challenge for direct detection due to the complex matrix. Hence, we present a new method based on the phage long-tail-fiber proteins (LTF4-a) immobilized magnetic nanoparticles (MNPs) for specific separation and concentration of Salmonella. The LTF4-a-MNP was prepared via the coupling of recombinant LTF4-a with MNPs and used to isolate and enrich Salmonella cells from contaminated food samples. The captured material was further integrated with the direct PCR program for accurate detection of Salmonella. Our study successfully established a new method for detecting contaminated food samples of Salmonella, the overall approach took no more than 3 h, which allowed a detection limit of 7 CFU/mL, demonstrating a promising alternative to the immunomagnetic separation method by replacing antibodies or aptamers, that is compatible with downstream analysis.


Assuntos
Bacteriófagos , Nanopartículas de Magnetita , Microbiologia de Alimentos , Separação Imunomagnética/métodos , Reação em Cadeia da Polimerase , Salmonella typhimurium/genética
7.
Foods ; 11(11)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35681328

RESUMO

Endolysins are enzymes used by bacteriophages to cleave the host cell wall in the final stages of the lytic cycle. As such, they are considered promising antibacterial agents for controlling and combating multidrug-resistant (MDR) bacteria. However, the application of endolysins targeting Gram-negative bacteria is greatly hindered by the outer membrane on these bacteria. Lysqdvp001, an endolysin with modular structure, has been reported as one of the most efficient endolysins against the Gram-negative bacterium Vibrio parahaemolyticus. In this study, Plychap001, the truncated recombinant catalytic domain of Lysqdvp001, was demonstrated to exhibit a direct and efficient bactericidal activity against broad spectrum of V. parahaemolyticus strains. Plychap001 was shown to be highly stable and retain high bactericidal activity at high temperatures, over a wide pH range, and at high NaCl concentrations. Plychap001 also exhibited a synergistic lytic effect with EDTA. Additionally, Plychap001 was found to efficiently degrade and eliminate V. parahaemolyticus biofilms on polystyrene surfaces. Our study establishes Plychap001 as a promising method for controlling V. parahaemolyticus in the food industry.

8.
Int J Nanomedicine ; 17: 537-551, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35140463

RESUMO

OBJECTIVE: To prepare a nanobody specific to dectin 1 and verify its specificity and anti-inflammatory effects on Aspergillus fumigatus keratitis. METHODS: The nanobody was selected from a high-quality shark-antibody library constructed with phage-display technology. The nanobody was developed in the expression systems of Escherichia coli. Indirect ELISA was used to determine the specificity of the nanobody to recombinant dectin 1 protein. The potential of the nanobody to be recognized and expressed on the surfaces of cells and corneas was detected by immunofluorescence, and its anti-inflammatory effect on A. fumigatus keratitis was further verified. After infection with A. fumigatus, eyes of C57B L/6 mice were treated with nanobodies. Human corneal epithelial cells (HCECs) were pretreated with nanobodies and then incubated with A. fumigatus. Clinical scores and slit-lamp photography were used to assess disease response in mouse corneas. RT-PCR and ELISA were used to evaluate mRNA and protein expression of IL1ß and IL6 in both mouse corneas and HCECs. RESULTS: The nanobody was successfully expressed through microbial system and showed specific high-affinity binding to recombinant dectin 1. Furthermore, it exhibited specific binding to dectin 1 expressed on the surfaces of cells and recognized dectin 1 in mouse corneas. Importantly, it reduced clinical scores of A. fumigatus keratitis in mice compared with a PBS-treatment group. In addition, it decreased mRNA and protein expression of IL1ß and IL6 in infected corneas and HCECs stimulated with A. fumigatus. CONCLUSION: These results suggest that this nanobody can bring about anti-inflammatory effects. This highlights the potential of these nanobodies as innovative therapeutic agents in A. fumigatus.


Assuntos
Aspergilose , Ceratite , Lectinas Tipo C/imunologia , Anticorpos de Domínio Único/uso terapêutico , Animais , Anti-Inflamatórios/uso terapêutico , Aspergilose/tratamento farmacológico , Ceratite/tratamento farmacológico , Camundongos , Camundongos Endogâmicos C57BL
9.
Eur Cardiol ; 16: e44, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34815752

RESUMO

Sports-related sudden cardiac death is a rare but devastating consequence of sports participation. Certain pathologies underlying sports-related sudden cardiac death could have been picked up pre-participation and the affected athletes advised on appropriate preventive measures and/or suitability for training or competition. However, mass screening efforts - especially in healthy young populations - are fraught with challenges, most notably the need to balance scarce medical resources and sustainability of such screening programmes, in healthcare systems that are already stretched. Given the rising trend of young sports participants across the Asia-Pacific region, the working group of the Asian Pacific Society of Cardiology (APSC) developed a sports classification system that incorporates dynamic and static components of various sports, with deliberate integration of sports events unique to the Asia-Pacific region. The APSC expert panel reviewed and appraised using the Grading of Recommendations Assessment, Development, and Evaluation system. Consensus recommendations were developed, which were then put to an online vote. Consensus was reached when 80% of votes for a recommendation were agree or neutral. The resulting statements described here provide guidance on the need for cardiovascular pre-participation screening for young competitive athletes based on the intensity of sports they engage in.

10.
Arch Virol ; 166(1): 325-329, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33221988

RESUMO

A novel Salmonella bacteriophage (phage), named αα, was the first reported member of the family Microviridae to exhibit tolerance to both extreme acidic and alkaline conditions (pH 2-12 for 1 h). Phage αα has a circular single-stranded DNA genome of 5,387 nt with a G+C content of 44.66%. A total of 11 putative gene products and no tRNA genes are encoded in the phage αα genome. Whole-genome sequence comparisons revealed that phage αα shares 95% identity with coliphage phiX174 and had a close evolutionary relationship to the phages NC1 and NC7. Phylogenetic analysis of the structural proteins of phage αα and 18 other phiX174-like phages showed that a phylogenetic tree based on protein B sequences had a topology similar to that obtained using whole genome sequences. In addition, variable sites in proteins F and G distributed on the surface of the mature capsid and the conserved protein J were probably involved in maintaining the structural integrity of the phage under extreme pH conditions. Our findings could open up new perspectives for identifying more extreme-pH-resistant phages and their structural proteins and understanding the mechanism of phage adaptation and evolution under extreme environmental stress.


Assuntos
Bacteriófagos/genética , Genoma Viral/genética , Microviridae/genética , Fagos de Salmonella/genética , Composição de Bases/genética , DNA Viral/genética , Concentração de Íons de Hidrogênio , Filogenia , Sequenciamento Completo do Genoma/métodos
11.
J Electrocardiol ; 51(4): 667-673, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29997009

RESUMO

INTRODUCTION: Mutations within SCN5A are found in a significant proportion (15-30%) of Brugada syndrome (BrS) cases and impair sodium transport across excitable cardiac cells that mediate ventricular contractions. Genetic testing offers a means to clinically assess and manage affected individuals and their family members. METHODS AND RESULTS: The proband at age 44 years old exhibited a syncopal event during exercise, and presented later with a spontaneous type-I BrS pattern on 12­lead resting electrocardiogram (ECG). Mutational analysis performed across all SCN5A exons revealed a unique three base-pair deletion p.M741_T742delinsI (c.2223_2225delGAC), in a heterozygous state in the proband and 2 siblings. This mutation was not seen in a cohort of 105 ethnicity-matched controls or in public genome databases. Patch clamp electrophysiology study conducted in TSA201 cells showed an abolishment of sodium current (INa). The proband, and several relatives, also harboured a known SCN5A variant, p.R1193Q (c.3578G>A). CONCLUSION: Our study has demonstrated the deleterious effect of a novel SCN5A mutation p.M741_T742delinsI (c.2223_2225delGAC). The findings highlight the complex effects of gender and age in phenotype manifestation. It also offers insights into improving the long-term management of BrS, and the utility of cascade genetic screening for risk stratification.


Assuntos
Síndrome de Brugada/genética , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Deleção de Sequência , Adulto , Síndrome de Brugada/complicações , Feminino , Humanos , Masculino , Linhagem , Fenótipo , Síncope/etiologia
12.
J Nanosci Nanotechnol ; 18(3): 1517-1527, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29448625

RESUMO

A novel aptamers-based fluorescence resonance energy transfer (FRET) assay was developed employing the oppositely charged thioglycolic acid-capped CdTe quantum dots (TGA-CdTe QDs) and cysteamine-stabilized gold nanoparticles (cysteamine-AuNPs). The fluorescence of TGA-CdTe QDs was significantly quenched with addition of cysteamine-AuNPs via the FRET. The FRET process can be modulated by 17ß-estradiol in that the specific recognition between 17ß-estradiol and aptamers could show different effects on the aptamers-mediated aggregation of cysteamine-AuNPs, and correspondingly adjust the FRET process. The feasibility of the method has been demonstrated by carrying out the detection of 17ß-estradiol with the wide linear range from 0.5·ng mL-1 to 150 ng·mL-1 and the low detection limit of 0.057 ng·mL-1. The established assay exhibited favorable selectivity towards 17ß-estradiol over other endocrine disrupting compounds and probably coexisting chemicals in real samples. Furthermore, the assay has been successfully applied to detect 17ß-estradiol in real tap water samples and feeds samples with good performance. The results were in full consistence with those from HPLC method, indicating the reliability of the detection system. The aptamers-based FRET assay is expected to offer a new opportunity for the rapid analysis of 17ß-estradiol in real samples.

13.
Skinmed ; 14(6): 469-471, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28031140

RESUMO

A 62-year-old woman presented with a 2-year history of extensive, pruritic dermatosis over her face, trunk, and limbs. She was initially treated for psoriasis with methotrexate 5 mg twice weekly and topical clobetasol cream; however, her condition worsened, and she was admitted for generalized exfoliative dermatitis. Examination showed generalized erythema and scaling affecting her face (Figure 1A), chest (Figure 1B), back, and limbs. There were also cervical, axillary, and inguinal lymphadenopathy. Laboratory studies revealed a high white blood cell count of 125×109/L (reference range: 4-10×109/L), hemoglobin level of 11.9 g/dL (reference range: 12-16 g/dL), and normal platelet level of 396×109/L (reference range: 140-440×109/L). Results from direct Coombs test were negative and lactate dehydrogenase levels were normal.


Assuntos
Linfoma Cutâneo de Células T/patologia , Neoplasias Cutâneas/patologia , Dermatite Esfoliativa/patologia , Fármacos Dermatológicos/uso terapêutico , Feminino , Humanos , Linfadenopatia Imunoblástica , Linfoma Cutâneo de Células T/diagnóstico , Metotrexato/uso terapêutico , Pessoa de Meia-Idade , Prognóstico , Psoríase/tratamento farmacológico , Neoplasias Cutâneas/diagnóstico
14.
Anal Bioanal Chem ; 408(2): 557-66, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26521176

RESUMO

This paper reports a novel aptamer-based fluorescent detection method for small molecules represented by acetamiprid based on the specific binding of aptamers with acetamiprid, and the inner filter effect (IFE) of gold nanoparticles (AuNPs) on the fluorescence of CdTe quantum dots (CdTe QDs). When CdTe QDs were mixed with AuNPs, the fluorescence of CdTe QDs was significantly quenched via IFE. The IFE efficiency could be readily modulated by the absorption and the aggregation state of AuNPs. The presence of salt could easily induce the aggregation of AuNPs, resulting in the fluorescence recovery of the quenched QDs. Acetamiprid-binding aptamer (ABA) could adsorb on the negatively charged AuNPs through the coordination interaction to protect AuNPs from salt-induced aggregation, so the fluorescence of CdTe QDs would be quenched by the IFE of AuNPs. However, the specific binding of ABA with acetamiprid could release the ABA from the surfaces of AuNPs and decrease the salt tolerance of AuNPs, so the IFE-decreased fluorescence of CdTe QDs was regained with the presence of acetamiprid, and the fluorescence enhancement efficiency was driven by the concentration of acetamiprid. Based on this principle, the aptamer-based fluorescent method for acetamiprid has been established and optimized. The assay exhibited excellent selectivity towards acetamiprid over its analogues and other pesticides which may coexist with acetamiprid. Under the optimum experiment conditions, the established method could be applied for the determination of acetamiprid with a wide linear range from 0.05 to 1.0 µM, and a low detection limit of 7.29 nM (3σ). Furthermore, this IFE-based method has been successfully utilized to detect acetamiprid in six types of vegetables, and the results were in full agreement with those from HPLC and LC-MS. The proposed method displays remarkable advantages of high sensitivity, rapid analysis, excellent selectivity, and would be suitable for the practical application of target screening in real samples.


Assuntos
Cádmio/química , Inseticidas/análise , Nanopartículas Metálicas/química , Piridinas/análise , Pontos Quânticos/química , Técnica de Seleção de Aptâmeros/métodos , Telúrio/química , Aptâmeros de Nucleotídeos/química , Fluorescência , Ouro/química , Neonicotinoides
15.
J Dig Dis ; 14(2): 100-4, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23253473

RESUMO

OBJECTIVE: This study was aimed to assess whether the efficacy of one-week triple therapy comprising of proton pump inhibitor, amoxicillin and clarithromycin (PPI/A/C) on Helicobacter pylori (H. pylori) infection in Singapore has decreased over the duration from 2005 to 2010. METHODS: The clinical data of H. pylori-positive patients treated with one-week PPI/A/C in 2005 and 2010 were reviewed retrospectively using a registry database. The primary endpoint was the difference in treatment success rate. RESULTS: A total of 465 patients (n = 174 in 2005 and n = 291 in 2010) were analyzed. In 2010, compared with 2005, the mean age of patients was younger (47 vs 56 years, P < 0.001) and the proportion of foreigners was higher (19.9% vs 5.7%, P < 0.001). The success rate of H. pylori eradication remained similar over the two time periods (90.2% in 2005 vs 88.7% in 2010, P = 0.597). Multinomial logistic regression revealed that mean age, gender, diagnosis and nationality had no impact on the success of H. pylori eradication. CONCLUSIONS: From 2005 to 2010, there was no significant decrease in the efficacy of one-week PPI/A/C for the treatment of H. pylori infection. This treatment regime remained an effective first-line therapy for H. pylori infection in Singapore.


Assuntos
Amoxicilina/uso terapêutico , Antibacterianos/uso terapêutico , Claritromicina/uso terapêutico , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori , Inibidores da Bomba de Prótons/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Quimioterapia Combinada , Feminino , Gastrite/tratamento farmacológico , Gastrite/microbiologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/microbiologia , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/tratamento farmacológico , Úlcera Péptica/microbiologia , Estudos Retrospectivos , Singapura , Resultado do Tratamento , Adulto Jovem
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