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1.
Artigo em Inglês | MEDLINE | ID: mdl-34753654

RESUMO

OBJECTIVES: Congenital heart disease (CHD) after cardiopulmonary bypass can cause systemic inflammation, and its degree is closely related to the incidence of acute respiratory distress syndrome (ARDS). The purpose of this study was to determine the effectiveness of high-frequency oscillatory ventilation (HFOV) combined with volume guarantee (VG) in reducing systemic inflammation in infants with ARDS after cardiopulmonary bypass for congenital heart surgery. DESIGN: A randomized controlled trial. SETTING: Single-center study in a tertiary teaching hospital. PARTICIPANTS: A total of 58 infants with ARDS after congenital heart surgery were eligible and were randomized to the HFOV (n = 29) or the HFOV-VG (n = 29) between January 2020 and January 2021. INTERVENTIONS: Tracheal aspirate samples for the measurement of interleukin (IL)-6, IL-8, and tumor necrosis factor-α (TNF-α) were obtained on days one, two, and three of HFOV or HFOV-VG ventilation. MEASUREMENTS AND MAIN RESULTS: The authors found a significantly increasing trend in the HFOV group mean values of IL-6, IL-8, and TNF-α (p < 0.05 on days two and three v day one), and IL-6, IL-8, and TNF-α levels were significantly higher on day three in the HFOV group versus the HFOV+VG group (p < 0.05). In addition, the incidences of hypocapnia and hypercapnia in infants supported with HFOV-VG were significantly lower (p < 0.05). Furthermore, the postoperative mechanical ventilation duration in the HFOV-VG group also was shorter than that in the HFOV group (p < 0.05). CONCLUSION: Compared with HFOV alone, HFOV-VG reduced proinflammatory systemic reactions after congenital cardiac surgery, decreased the incidences of hypercapnia and hypocapnia, and shortened the postoperative mechanical ventilation duration.

2.
Artigo em Inglês | MEDLINE | ID: mdl-34593311

RESUMO

OBJECTIVE: This study aimed to compare the effects of nasal high-frequency oscillatory ventilation (NHFOV) and noninvasive positive-pressure ventilation (NIPPV) as the initial postextubation therapies on preventing extubation failure (EF) in high-risk infants younger than three months after congenital heart surgery (CHS). DESIGN: This was a single-center, randomized, unblinded clinical trial. SETTING: The study was performed in a teaching hospital. PARTICIPANTS: Between January 2020 and January 2021, a total of 150 infants underwent CHS in the authors' hospital. INTERVENTIONS: Infants younger than three months with a high risk for extubation failure who were ready for extubation were randomized to either an NHFOV therapy group or an NIPPV therapy group, and received the corresponding noninvasive mechanical ventilation to prevent EF. MEASUREMENTS: Primary outcomes were reintubation, long-term noninvasive ventilation (NIV) support (more than 72 hours), and the time in NIV therapy. The secondary outcomes were adverse events, including mild-moderate hypercapnia, severe hypercapnia, severe hypoxemia, treatment intolerance, signs of discomfort, unbearable dyspnea, inability to clear secretions, emesis, and aspiration. MAIN RESULTS: Of 92 infants, 45 received NHFOV therapy, and 47 received NIPPV therapy after extubation. There were no significant differences between the NHFOV and the NIPPV therapy groups in the incidences of reintubation, long-term NIV support, and total time under NIV therapy. No significant difference was found of the severe hypercapnia between the two groups, but NHFOV treatment significantly decreased the rate of mild-moderate hypercapnia (p < 0.05). Other outcomes were similar in the two groups. CONCLUSIONS: Among infants younger than three months after CHS who had undergone extubation, NIPPV therapy and NHFOV therapy were the equivalent NIV strategies for preventing extubation failure, and NHFOV therapy was more effective in avoiding mild-moderate hypercapnia.

3.
Front Pediatr ; 9: 700632, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34485193

RESUMO

Objective: This study aimed to evaluate the effects of nasal high-frequency oscillatory ventilation (NHFOV) vs. nasal continuous positive airway pressure (NCPAP) on postextubation respiratory failure (PRF) in infants after congenital heart surgery (CHS). Method: Eighty infants underwent postoperative invasive mechanical ventilation for more than 12 h and planned extubation. The infants were randomized to undergo either NHFOV or NCPAP after extubation. Primary outcomes were the incidence of PRF and reintubation, the average PaCO2 level, the average oxygenation index (OI), and pulmonary recruitment in the early extubation phase. Secondary outcomes included the NCPAP/NHFOV time, length of hospital stay, treatment intolerance, signs of discomfort, pneumothorax, adverse hemodynamic effects, nasal trauma, and mortality. Results: Except for PaCO2 within 12 after extubation (39.3 ± 5.8 vs. 43.6 ± 7.3 mmHg, p = 0.05), there was no statistically significant difference for any of the primary outcome measure (PRF, reintubation within 12 h after extubation, oxygenation index within 12 h after extubation, or lung volumes on X-ray after extubation) or secondary outcome measures (duration of non-invasive ventilation, duration of hospital stay, ventilation intolerance, signs of discomfort, pneumothorax, nasal trauma, adverse hemodynamic effects, or death prior to discharge), p > 0.1 for each comparison. Conclusion: NHFOV therapy after extubation in infants after CHS was more efficient in improving CO2 cleaning than NCPAP therapy, but there was no difference in other outcomes (PRF, reintubation, oxygenation index, and pulmonary recruitment).

4.
Front Cardiovasc Med ; 8: 675213, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34368243

RESUMO

Background: This study aimed to evaluate the effects of pulmonary surfactant (PS) combined with high-frequency oscillatory ventilation (HFOV) or conventional mechanical ventilation (CMV) in infants with acute respiratory distress syndrome (ARDS) after congenital cardiac surgery. Methods: A total of 61 infants with ARDS were eligible and were randomised to the CMV + PS group (n = 30) or the HFOV + PS group (n = 31) between January 2020 and December 2020. The primary outcomes were the changes in arterial blood gas parameters. The duration of mechanical ventilation, length of hospitalisation and the incidence of complications were considered secondary outcomes. Results: A total of 61 infants completed the study. In the HFOV + PS group, the blood gas analysis results were significantly improved (P < 0.05), while the duration of mechanical ventilation and length of hospitalisation were shorter than the CMV + PS group (P < 0.05). However, the incidence of complications was not different between the two groups (P > 0.05). Conclusions: Compared with the CMV + PS group, the HFOV + PS group showed significantly improved ABG variables and had a shortened length of hospitalisation and mechanical ventilation in infants with ARDS after cardiac surgery. Clinical Trial Registration: Chinese Clinical Trial Registry; Number: ChiCTR2000039457.

5.
Pediatr Pulmonol ; 56(8): 2621-2626, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33964188

RESUMO

OBJECTIVE: This study aimed to evaluate the efficacy and safety of high-frequency oscillation ventilation combined with volume guarantee (HFOV-VG) compared with the safety and efficacy of HFOV alone in infants with acute hypoxemic respiratory failure (AHRF) after congenital heart surgery. METHODS: We retrospectively analyzed the clinical data of 44 infants who were ventilated for AHRF after congenital heart surgery between January 2020 and January 2021. HFOV alone was used in 23 of the 44 infants, whereas HFOV-VG was used in the other 21 infants. RESULTS: The average frequency tidal volume (VThf) of the HFOV-VG group was lower than that of the HFOV group, and the proportion of VThf exceeding the target range of infants in the HFOV-VG group was also lower (p < .01). In addition, the incidence of hypocapnia and hypercapnia in infants supported with HFOV-VG was significantly lower (p < .01). Furthermore, the duration of invasive ventilation and the median ventilator adjustment per hour in the HFOV-VG group was also lower than that in the HFOV group (p < .01). CONCLUSIONS: Compared with HFOV alone, HFOV-VG decreases the fluctuation of VThf and the incidence of hypercapnia and hypocapnia. Moreover, it reduces the workload of bedside medical staff. Further studies are needed to confirm the efficacy and safety of HFOV-VG as a routine respiratory support strategy for congenital heart disease during the perioperative period.

6.
Heart Surg Forum ; 24(2): E249-E255, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33798054

RESUMO

OBJECTIVE: This study aimed to evaluate the application of synchronized nasal intermittent positive pressure ventilation (SNIPPV) in the respiratory weaning of infants after congenital heart surgery. METHODS: We retrospectively analyzed the clinical data of 63 infants who were extubated from mechanical ventilation after congenital heart surgery between January 2020 and September 2020. The data, including demographics, anatomic diagnosis, radiology and laboratory test results, and perioperative variables were recorded. RESULTS: The extubation failure rate within 48 h after extubation was significantly lower in the SNIPPV group than in the nasal continuous positive airway pressure (NCPAP) group. The PaO2 level and PaO2/FiO2 ratio within 48 h after extubation were higher in the SNIPPV group than in the NCPAP group (P < .05). Meanwhile, the PaCO2 level within 48 h was significantly lower in the SNIPPV group (P < .05). Compared with the NCPAP group, the median duration of postoperative noninvasive support and the duration from extubation to hospital discharge were shorter in the SNIPPV group; the total hospital cost was lower in the SNIPPV group. No significant differences were observed between the two groups concerning VAP, pneumothorax, feeding intolerance, sepsis, mortality, and other complications (P > .05). CONCLUSION: SNIPPV was shown to be superior to NCPAP in avoiding reintubation after congenital heart surgery in infants and significantly improved oxygenation and reduced PaCO2 retention after extubation. Further studies are needed to confirm the efficacy and safety of SNIPPV as a routine weaning strategy.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Pressão Positiva Contínua nas Vias Aéreas/métodos , Cardiopatias Congênitas/cirurgia , Ventilação com Pressão Positiva Intermitente/métodos , Desmame do Respirador/métodos , Extubação/métodos , Feminino , Seguimentos , Humanos , Lactente , Masculino , Estudos Retrospectivos
7.
Pharmacol Rep ; 72(6): 1706-1716, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32451735

RESUMO

BACKGROUND: In this study, we investigated the effect of forskolin (FSK, a selective adenylate cyclase agonist) on the automatic diastolic depolarization of sinus node cells (SNC) with hypoxia/reoxygenation (H/R) injury. METHODS: The SNC of the newborn rat was randomly assigned into the control group, the H/R (H/R injury) group, or the H/R + FSK (H/R injury + FSK treatment) group. Patch-clamp was performed to record the action potential and electrophysiological changes. The cellular distribution of intracellular calcium concentration was analyzed by fluorescence staining. RESULTS: Compared with the control cells, spontaneous pulsation frequency (SPF) and diastolic depolarization rate (DDR) of H/R cells were reduced from 244.3 ± 10.6 times/min and 108.7 ± 7.8 mV/s to 130.5 ± 7.6 times/min and 53.4 ± 6.5 mV/s, respectively. FSK significantly increased SPF and DDR of H/R cells to 208.3 ± 8.3 times/min and 93.2 ± 8.9 mV/s (n = 15, both p < 0.01), respectively. H/R reduced the current densities of If, ICa,T and inward INCX, which were significantly increased by 10 µM FSK treatment (n = 15, p < 0.01). Furthermore, reduced expression of HCN4 and NCX1.1 channel protein were significantly increased by FSK. Inhibitor studies showed that both SQ22536 (a selective adenylate cyclase inhibitor) and H89 (a selective protein kinases A [PKA] inhibitor) blocked the effects of FSK on SPF and DDR. CONCLUSIONS: H/R causes pacemaker dysfunction in newborn rat sinoatrial node cells leading to divergence of the DD and the slow of spontaneous APs, which change can be dramatically reversed by FSK through increasing INCX and If current in H/R injury.


Assuntos
Potenciais de Ação/efeitos dos fármacos , Cálcio/metabolismo , Colforsina/farmacologia , Nó Sinoatrial/efeitos dos fármacos , Adenilil Ciclases/efeitos dos fármacos , Adenilil Ciclases/metabolismo , Animais , Animais Recém-Nascidos , Hipóxia Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Masculino , Ratos , Ratos Wistar , Nó Sinoatrial/metabolismo
8.
World J Clin Cases ; 8(5): 887-899, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32190625

RESUMO

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) may be technically difficult in patients with cavernous transformation of the portal vein (CTPV). Computed tomography (CT) is widely used for assessing the situation of the portal vein and its tributaries before TIPS, and an ultrasound-based Yerdel grading system has been developed, which is deemed useful for liver transplantation. Therefore, we hypothesized that a CT-based CTPV scoring system could be useful for predicting technical and midterm outcomes in TIPS treatment for symptomatic portal cavernoma. AIM: To investigate the clinical significance of a CT-based score model/nomogram for predicting technical success and midterm outcome in TIPS treatment for symptomatic CTPV. METHODS: Patients with symptomatic CTPV who had undergone TIPS from January 2010 to June 2017 were retrospectively analysed. The CTPV was graded with a score of 1-4 based on contrast-CT imaging findings of the diseased vessel. Outcome measures were technical success rate, stent patency rate, and midterm survival. Cohen's kappa statistic, the Kaplan-Meier and log-rank tests, and uni- and multivariable analyses were performed. A nomogram was constructed and verified by calibration and decision curve analysis. RESULTS: A total of 76 patients (45 men and 31 women; mean age, 52.3 ± 14.7 years) were enrolled in the study. The inter-reader agreement (κ) of the CTPV score was 0.81. TIPS was successfully placed in 78% of patients (59/76). The independent predictor of technical success was CTPV score (odds ratio [OR] = 5.56, 95% confidence interval [CI]: 3.55-9.67, P = 0.002). The independent predictors of primary TIPS patency were CTPV score and splenectomy (OR = 9.22, 95%CI: 4.78-13.45, P = 0.009; OR = 4.67, 95%CI: 2.59-7.44, P = 0.017). The survival rates differed significantly between the TIPS success and failure groups. The clinical nomogram was made up of patient age, model for end-stage liver disease score, and CTPV score. The calibration curves and decision curve analysis verified the usefulness of the CTPV score-based nomogram for clinical practice. CONCLUSION: TIPS should be considered a safe and feasible therapy for patients with symptomatic CTPV. Furthermore, the CT-based score model/nomogram might aid interventional radiologists in therapeutic decision-making.

9.
Neuroscience ; 433: 230-240, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31982470

RESUMO

OBJECTIVE: The spontaneous action potential of isolated sinoatrial node (SAN) cells is regulated by a coupled-clock system of two clocks: the calcium clock and membrane clock. However, it remains unclear whether calcium clock inhibitors have a direct effect on the membrane clock. The purpose of this study was to investigate the direct effect of cyclopiazonic acid (CPA), a selective calcium clock inhibitor, on the function of the membrane clock of SAN cells. METHODS: at SAN cells were isolated by trypsinization and identified based on morphology and electrophysiology. If and HCN currents were recorded via patch clamp technique. The expression of the HCN channel protein was determined by Western blotting analysis. RESULTS: The diastolic depolarization rate of spontaneous action potentials and the current densities of If were reduced by exposure to 10 µM CPA. The inhibitory effect of CPA was concentration-dependent with an IC50 value of 16.3 µM and a Hill coefficient of 0.98. The effect of CPA on If current was also time-dependent, and the If current amplitude was partially restored after washout. Furthermore, the steady-state activation curve of the If current was shifted to a negative potential, indicating that channel activation slowed down. Finally, the protein expression of HCN4 in HEK293 cells was markedly downregulated by CPA. CONCLUSIONS: These results indicate that the direct inhibition effect of CPA on the If current in SAN cells is both concentration- and time-dependent. The underlying mechanisms may involve slowing down steady-state activation and the downregulation of pacemaker channel protein expression.


Assuntos
Marca-Passo Artificial , Nó Sinoatrial , Potenciais de Ação , Cálcio , Células HEK293 , Humanos , Indóis/farmacologia
10.
Cardiovasc J Afr ; 30(2): 79-86, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30882133

RESUMO

AIM: We aimed to study the effect of allocryptopine (All) on the late sodium current (INa,Late) of atrial myocytes in spontaneously hypertensive rats (SHR). METHODS: The enzyme digestion method was used to separate single atrial myocytes from SHR and Wistar-Kyoto (WKY) rats. INa,Late was recorded using the patch-clamp technique, and the effect of All was evaluated on the current. RESULTS: Compared with WKY rat cells, an increase in the INa,Late current in SHR myocytes was found. After treatment with 30 µM All, the current densities were markedly decreased; the ratio of INa,Late/INa,peak of SHR was reduced by 30 µM All. All reduced INa,Late by alleviating inactivation of the channel and increasing the window current of the sodium channel. Furthermore, INa,Late densities of three SCN5A mutations declined substantially with 30 µM All in a concentration-dependent manner. CONCLUSIONS: The results clearly show that an increase in INa,Late in SHR atrial myocytes was inhibited by All derived from Chinese herbal medicine.


Assuntos
Antiarrítmicos/farmacologia , Fibrilação Atrial/prevenção & controle , Alcaloides de Berberina/farmacologia , Átrios do Coração/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Miócitos Cardíacos/efeitos dos fármacos , Canal de Sódio Disparado por Voltagem NAV1.5/efeitos dos fármacos , Sódio/metabolismo , Potenciais de Ação , Animais , Fibrilação Atrial/etiologia , Fibrilação Atrial/metabolismo , Fibrilação Atrial/fisiopatologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Células HEK293 , Átrios do Coração/metabolismo , Frequência Cardíaca , Humanos , Hipertensão/complicações , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Masculino , Mutação , Miócitos Cardíacos/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Fatores de Tempo
11.
J Cell Mol Med ; 23(4): 3032-3039, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30697920

RESUMO

OBJECTIVE: This study aimed to investigate the effects of transforming growth factor ß1 (TGF ß1) and hepatocyte growth factor (HGF) on the expression of connective tissue growth factor (CTGF) in human atrial fibroblasts, and to explore the relationship of these factors in atrial fibrosis and atrial anatomical remodelling (AAR) of patients with atrial fibrillation (AF). METHODS: Fresh right auricular appendix tissue of 20 patients with rheumatic heart disease undergoing valve replacement surgery was collected during surgeries, 10 patients had sinus rhythm(SR), and 10 patients had chronic atrial fibrillation (CAF). Atrial fibroblasts were then cultured from the tissues with differential attachment technique and treated with either TGFß1 (10 ng/mL) or HGF (100 ng/mL). CTGF mRNA levels were measured by RT-PCR, and CTGF protein content was determined using immunofluorescence and Western blotting assays. RESULTS: CAF group had higher left atrial diameters (LADs) and higher CTGF mRNA expression in atrial fibroblasts compared with SR group. The CTGF protein content in CAF group was higher than that of SR group and positively correlated with LAD and AF duration. After CAF group was treated with TGFß1, CTGF mRNA and protein expression were significantly down-regulated, whereas when treated with HGF, expression was up-regulated compared with SR group. CONCLUSIONS: Increased CTGF expression was associated with enlarged LAD, atrial fibrosis and AAR in patients with AF. TGFß1 and HGF regulate CTGF expression in human atrial fibroblasts with up-regulation of mRNA and down-regulation of protein, therefore, either promote or inhibit atrial fibrosis, which could be related to the incidence and persistence of AF.


Assuntos
Remodelamento Atrial , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Fibroblastos/patologia , Fibrose/etiologia , Fator de Crescimento de Hepatócito/metabolismo , Cardiopatia Reumática/complicações , Fator de Crescimento Transformador beta1/metabolismo , Adulto , Fibrilação Atrial/etiologia , Fibrilação Atrial/metabolismo , Fibrilação Atrial/patologia , Células Cultivadas , Fator de Crescimento do Tecido Conjuntivo/genética , Feminino , Fibroblastos/metabolismo , Fibrose/metabolismo , Fibrose/patologia , Fator de Crescimento de Hepatócito/genética , Humanos , Masculino , Cardiopatia Reumática/metabolismo , Cardiopatia Reumática/patologia , Fator de Crescimento Transformador beta1/genética
12.
Front Physiol ; 9: 1447, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30450052

RESUMO

Aim: We investigated the underlying mechanisms in atrial fibrillation (AF) associated with R33Q mutation and Ca2+-triggered activity. Methods and Results: We examined AF susceptibility with intraesophageal burst pacing in the sarcoplasmic reticulum (SR) Ca2+ leak model calsequestrin 2 R33Q (Casq2R33Q/R33Q) mice. Atrial trigger appeared in R33Q mice but not WT mice (17.24%, 5/29 vs. 0.00%, 0/32, P < 0.05). AF was induced by 25 Hz pacing in R33Q mice (48.27%, 14/29 vs. 6.25%, 2/32, P < 0.01). The mice were given 1.5 mg/kg isoproterenol (Iso), and the incidences of AF increased (65.51%, 19/29 vs. 9.21%, 3/32, P < 0.01). Electrophysiology experiments and the recording of intracellular Ca2+ indicated significant increases in the Ca2+ sparks (5.24 ± 0.75 100 µM-1.s-1 vs. 0.29 ± 0.04 100 µM-1.s-1, n = 20, P < 0.05), intracellular free Ca2+ (0.238 ± 0.009 µM vs. 0.172 ± 0.006 µM, n = 20, P < 0.05), Ca2+ wave (11.74% vs. 2.24%, n = 20, P < 0.05), transient inward current (ITi) (-0.56 ± 0.02 pA/pF vs. -0.42 ± 0.01 pA/pF, n = 10, P < 0.05), and oscillation in membrane potentials (10.71%, 3/28 vs. 4.16%, 1/24, P < 0.05) in the R33Q group, but there was no significant difference in the L-type calcium current. These effects were enhanced by Iso, and the inhibition of calmodulin-dependent protein kinase II (CaMKII) by 1 µM KN93 reversed the effects of Iso on Ca2+ sparks (5.01 ± 0.66 100 µm-1.s-1 vs. 11.33 ± 1.63 100 µm-1.s-1, P < 0.05), intracellular Ca2+ (0.245 ± 0.005 µM vs. 0.324 ± 0.008 µM, P < 0.05), Ca2+ wave (12.35% vs. 17.83%, P < 0.05), ITi (-0.61 ± 0.02 pA/pF vs. -0.78 ± 0.03 pA/pF, n = 10, P < 0.05), and oscillation in membrane potential (17.85% 5/28 vs. 32.17% 9/28, P < 0.05). The reduction of ryanodine receptor 2 (RyR2) stable subunits (Casq2, triadin, and junctin) rather than RYR2 and the increase in CaMKII, phosphor-CaMKII, phosphor-RyR2 (Ser 2814), SERCA, and NCX1.1 was reflected in the R33Q group. Conclusion: This study demonstrates that the increase in spontaneous calcium elevations corresponding to ITi that may trigger the oscillation in membrane potentials in the R33Q group, thereby increasing the risk of AF. The occurrence of spontaneous calcium elevations in R33Q atrial myocytes is due to the dysfunction of RyR2 stable subunits, CaMKII hyperactivity, and CaMKII-mediated RyR phosphorylation. An effective therapeutic strategy to intervene in Ca2+-induced AF associated with the R33Q mutation may be through CaMKII inhibition.

13.
Biosens Bioelectron ; 118: 80-87, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30056303

RESUMO

Understanding the role of gold nanoparticles (AuNPs) in electrochemiluminescence (ECL) processes of the Ru(bpy)32+ (bpy= 2, 2'-bipyridine)/tripropylamine (TPA) system would be beneficial to develop novel ECL sensors for a variety of applications. In this work, we found that the AuNPs on the surface of indium tin oxide (ITO) electrode could catalyze the electrochemical oxidation of TPA, greatly enhancing the ECL signal of Ru(bpy)32+/TPA, present in the solution. If physical separation of AuNPs away from electrode surface after hybridization with target ssDNA, ECL signal decreased dramatically due to the loss of electrochemical activity of AuNPs, based on which a sensitive and specific DNA sensor in a "switch-off" mode was constructed with a detection limit of 0.2 pM. In addition, a suppressing effect of the AuNPs on the ECL of Ru(bpy)32+ was experimentally confirmed by decreasing the electrocatalytic effect to overall ECL emission, including selection of oxalate as a coreactant instead of TPA, or introduction of gold electrode as substrate. Furthermore, when Ru(bpy)32+ and AuNPs were both immobilized on the ITO electrode at close proximity, the ECL quenching induced by energy/electron transfer was predominant. ECL emission of the Ru(bpy)32+/TPA system resulted from a competition between electrocatalytic enhancement and quenching effect. However, the quenched ECL signal would return in case of the AuNPs moving far away from ECL emitters after a hybridization reaction as before, and a separation distance dependent surface enhancement was observed as well. Based on the role change for AuNPs from quenching to enhancing ECL intensity of Ru(bpy)32+/TPA system, a novel ECL DNA sensing strategy in a "turn-on" mode was developed, enabling quantitative analysis of target ssDNA over the range of 0.05 pM to 0.5 nM with a detection limit of 12 fM. Overall, we demonstrated the existence of three effects of AuNPs on the ECL of Ru(bpy)32+/TPA system, and which played the leading role was dependent on the placement of AuNPs, Ru(bpy)32+, and their separation distance. The ECL sensors based on the role change for AuNPs showed both high sensitivity and excellent selectivity.


Assuntos
Técnicas Biossensoriais/métodos , Ouro , Medições Luminescentes , Nanopartículas Metálicas/química , Propilaminas , Rutênio
14.
J Mol Model ; 23(5): 151, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28374216

RESUMO

Coarse-grained molecular dynamics (CGMD) simulation was employed to investigate how stable chondroitin sulfate-graft-polycaprolactone (CS-PCL, CP) copolymers self-assemble into micelles in an aqueous environment. Three types of CP containing low (2.4%), medium (6.3%), and high (18.7%) PCL contents (denoted L-CP, M-CP, and H-CP, respectively) in which PCL molecules consisting of 63 monomers were grafted onto each CS molecule consisting of 120 monomers were considered. L-CP and M-CP were found to display spheroidal micellar structures, while H-CP presented a rod-like structure, in agreement with previous experimental observations. In addition, the entanglement of the PCL segment increased as its molecular weight was increased. The number density distribution profiles of PCL, CS, and water molecules indicated that there were a few water molecules between the PCL core of the micelle and the water solution surrounding the micelle (in the micelle layer immediately above the core), and the number density of water in the CP micelle increased as the PCL content decreased. Using the radius of gyration, the three-dimensional conformations of the micelles were explored. When the number of CP chains was 3, H-CP adopted a long nanorod form, whereas L-CP and M-CP were roughly nanospherical. When the number of CP chains was increased beyond 3, however, the structure of L-CP changed from a nanosphere to a nanodisk. Finally, the slope of the mean square displacement profile was greatest when the molecular weight of the PCL segment was lowest, indicating that the mobilities of the CS and PCL segments are highest in L-CP. The self-diffusion coefficients of the CS and PCL segments decreased as the number of PCL segments grafted increased. Graphical abstract Morphologies of H-CP micelle.

15.
Medicine (Baltimore) ; 96(7): e5922, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28207509

RESUMO

BACKGROUND: To detect drug resistance in Shigella obtained from the dung of the giant panda, explore the factors leading to drug resistance in Shigella, understand the characteristics of clustered, regularly interspaced, short, palindromic repeats (CRISPR), and assess the relationship between CRISPR and drug resistance. METHODS: We collected fresh feces from 27 healthy giant pandas in the Giant Panda Conservation base (Wolong, China). We identified the strains of Shigella in the samples by using nucleotide sequence analysis. Further, the Kirby-Bauer paper method was used to determine drug sensitivity of the Shigella strains. CRISPR-associated protein genes cas1 and cas2 in Shigella were detected by polymerase chain reaction (PCR), and the PCR products were sequenced and compared. RESULTS: We isolated and identified 17 strains of Shigella from 27 samples, including 14 strains of Shigella flexneri, 2 strains of Shigella sonnei, and 1 strain of Shigella dysenteriae. Further, drug resistance to cefazolin, imipenem, and amoxicillin-clavulanic acid was identified as a serious problem, as multidrug-resistant strains were detected. Further, cas1 and cas2 showed different degrees of point mutations. CONCLUSION: The CRISPR system widely exists in Shigella and shares homology with that in Escherichia coli. The cas1 and cas 2 mutations contribute to the different levels of resistance. Point mutations at sites 3176455, 3176590, and 3176465 in cas1 (a); sites 3176989, 3176992, and 3176995 in cas1 (b); sites 3176156 and 3176236 in cas2 may affect the resistance of bacteria, cause emergence of multidrug resistance, and increase the types of drug resistance.


Assuntos
Proteínas Associadas a CRISPR/genética , Farmacorresistência Bacteriana Múltipla/genética , RNA Ribossômico 16S/genética , Shigella/genética , Ursidae/microbiologia , Animais , Proteínas de Bactérias/genética , Fezes/microbiologia , Testes de Sensibilidade Microbiana , Shigella/citologia , Shigella/isolamento & purificação
16.
Molecules ; 21(1): E8, 2015 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-26729072

RESUMO

Seven metabolites of 2',3',5'-tri-O-acetyl-N6-(3-hydroxyphenyl) adenosine (WS070117) were synthesized by deacetylation, hydrolysis, cyclization, sulfonylation and glycosylation reactions, respectively. All these compounds, which could be useful as material standards for metabolic research, were characterized by NMR and HPLC-MS (ESI) analyses.


Assuntos
Adenosina/análogos & derivados , Adenosina/química , Ciclização , Glicosilação , Hidrólise , Estrutura Molecular
17.
Mol Genet Genomics ; 289(6): 1237-40, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24994558

RESUMO

Treacher Collins syndrome (TCS) is the most common and well-known craniofacial disorder caused by mutations in the genes involved in pre-rRNA transcription, which include the TCOF1 gene. This study explored the role of TCOF1 mutations in Chinese patients with TCS. Mutational analysis of the TCOF1 gene was performed in three patients using polymerase chain reaction and direct sequencing. Among these three patients, two additional TCOF1 variations, a novel 18 bp deletion and a novel 1 bp insertion mutation, were found in patient 1, together with a novel nonsense mutation (p.Ser476X) and a previously reported 4 bp deletion (c.1872_1875delTGAG) in other patients. Pedigree analysis allowed for prediction of the character of the mutation, which was either pathological or not. The 18 bp deletion of six amino acids, Ser-Asp-Ser-Glu-Glu-Glu (798*803), which was located in the CKII phosphorylation site of treacle, seemed relatively benign for TCS. By contrast, another novel mutation of c.1072_1073insC (p.Gln358ProfsX23) was a frameshift mutation and expected to result in a premature stop codon. This study provides insights into the functional domain of treacle and illustrates the importance of clinical and family TCS screening for the interpretation of novel sequence alterations.


Assuntos
Disostose Mandibulofacial/genética , Mutação , Proteínas Nucleares/genética , Fosfoproteínas/genética , Adolescente , China , Códon sem Sentido , Humanos , Recém-Nascido , Disostose Mandibulofacial/diagnóstico , Mutagênese Insercional
18.
J Asian Nat Prod Res ; 16(5): 522-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24611744

RESUMO

Myricetin-3-O-ß-d-glucuronide, a bioactive flavonol glycoside, was synthesized effectively starting from myricetrin in a total yield of 49.2%. The structures of all synthetic compounds were confirmed by (1)H, (13)C NMR, and HR-MS techniques.


Assuntos
Flavonoides/síntese química , Glucuronídeos/síntese química , Flavonoides/química , Flavonóis/química , Glucuronídeos/química , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Estereoisomerismo
19.
Zhongguo Dang Dai Er Ke Za Zhi ; 14(11): 856-8, 2012 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-23146735

RESUMO

OBJECTIVE: To investigate the mutation of glucose-6-phosphatase gene (G6PC gene) in a patient with glycogen storage disease Ⅰa. METHODS: PCR was used to amplify all five exons of G6PC gene. The PCR products were directly sequenced to detect the mutations. RESULTS: A heterozygous 743G>A mutation was found in the patient and his mother, resulting in the substitution of glycine (G) by arginine (R) in codon 222(G222R) in the putative membrane-spanning domain in human G6Pase, but not in his father and his sister. CONCLUSIONS: G222R mutation in G6PC gene was first identified in a patient with glycogen storage disease Ⅰa in mainland China.


Assuntos
Doença de Depósito de Glicogênio Tipo I/genética , Pré-Escolar , Glucose-6-Fosfatase/genética , Humanos , Masculino , Mutação , Análise de Sequência de DNA
20.
Zhongguo Dang Dai Er Ke Za Zhi ; 14(6): 445-8, 2012 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-22738453

RESUMO

OBJECTIVE: Prader-Willi syndrome (PWS) with different pathogenesis has different clinical manifestations, prognosis and genetic risks. Pathogenesis of the disease cannot be explained by conventional diagnostic method MS-PCR. This study employed methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) for the diagnosis of PWS in order to explore the role of this method in the diagnosis and assessment of pathogenesis of PWS. METHODS: A system antithetical method was employed. Peripheral blood samples were collected from 30 children for MS-PCR. Of the 30 children, 16 were diagnosed with PWS by MS-PCR and the other 14 showed negative MS-PCR. MS-MLPA kit Me028 was used to detect DNA extracted from the 30 samples. RESULTS: The results showed by MS-MLPA and MS-PCR were identical. MS-MLPA demonstrated that 4 cases were maternal uniparental disomy and 12 cases were paternal dfeletion in 15q11-q13 region. CONCLUSIONS: MS-MLPA is a reliable method of genetic testing for PWS which can distinguish pathogenesis of PWS.


Assuntos
Metilação de DNA , Técnicas de Amplificação de Ácido Nucleico/métodos , Síndrome de Prader-Willi/diagnóstico , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Reação em Cadeia da Polimerase , Síndrome de Prader-Willi/genética
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