A New Method for Determination of Pectin Content Using Spectrophotometry.

The study aimed at developing a new spectrophotometric method for determining the pectin content. Take commercial pectin as an example, and the method is based on the reaction of copper ions with pectin to produce copper pectate. The spectrophotometer was used to measure the remaining content of copper ions so as to calculate the pectin content. This method eliminated the weight step and avoided the error associated with it. Effects of reaction time, temperature, and pH on absorbance were also studied. Additionally, the accuracy of this method was verified. It indicated excellent repeatability and accuracy with the relative standard deviation of 2.09%. In addition, three different plant types were used to demonstrate the reliability of the method. To summarize, this method can be widely used for the determination of pectin content in many materials.

Biatrial enlargement as a predictor for reablation of atrial fibrillation.

Purpose: We aimed to determine whether biatrial enlargement could predict reablation of atrial fibrillation after first ablation. Methods: 519 consecutive patients with drug resistant atrial fibrillation [paroxysmal AF (PAF) 361, non-PAF 158] who underwent catheter ablation in Capital Medical University Xuanwu hospital between 2009 and 2014 were enrolled. Biatrial enlargement (BAE) was diagnosed according to trans-thoracic echocardiography (TTE). Ablation strategies included complete pulmonary vein isolation (PVI) in all patients and additional linear ablation across mitral isthmus, left atrium roof, left atrium bottom and tricuspid isthmus, or electrical cardioversion on the cases that AF could not be terminated by PVI. Anti-arrhythmic drugs or cardioversion were used to control the recurred atrial arrhythmia in patients with recurrence of atrial fibrillation after ablation. Reablation was advised when the drugs were resistant or that patient could not tolerate. Risk factors for reablation were analyzed. Results: After 33.11±21.45months, 170 patients recurred atrial arrhythmia, and reablation were applied in 117 patients. Multivariate Cox regression analysis demonstrated that that biatrial enlargement (BAE, HR 1.755, 95%CI 1.153-2.670, P=0.009) was an independent predictor for reablation and was associated with reablation (Log rank P=0.007). Conclusion: Biatrial enlargement is an independent risk predictor for the reablation in atrial fibrillation patients after first ablation.

Real-world investigation on discontinuation of oral anticoagulation after paroxysmal atrial fibrillation catheter ablation in China.

BACKGROUND: To find out the real-world investigation on discontinuation of oral anticoagulation after paroxysmal atrial fibrillation (AF) catheter ablation China. METHODS: We enrolled in our study 1,508 consecutive paroxysmal AF patients who underwent catheter ablation from five centers. Patients' clinical data and follow-up data were collected. Clinical data included on-admission characteristics such as gender, age, type and duration of AF, type of ablation, ablation sessions, history of diseases, CHA2DS2-VASc score, echocardiographic variables, medication, and blood test variables. Follow-up data included duration of follow-up, the status of oral anticoagulant (OAC) therapy, adverse events, and recurrence of AF. RESULTS: A total of 1,491 patients were included in the final analysis, while the other 17 patients lost contact. The follow-up duration was 12 to 74 months (27.8±14.6 months). Of 1,491 patients, 989 (66.3%) patients stopped OAC therapy 3 to 14 months after successful ablation during follow-up. Stroke or transient ischemic attack (TIA) occurred in 37 (2.5%) patients. Major bleeding occurred in 24 (1.6%) patients. Six (0.4%) patients died at follow-up. Patients who stopped OAC had lower CHA2DS2-VASc score (1.5±1.4 vs. 2.4±1.7, P<0.05) and lower incidence of major bleeding (11/989 vs. 13/502, P<0.05). Of 989 patients who stopped OAC, 318 stopped according to doctor's prescription, and 671 stopped on their own decision. In patients who underwent brain MRI, patients who stopped OAC had a lower incidence of silent cerebral infarction (SCI) (37/904 vs. 38/419, P<0.05). Among patients who did not stop warfarin therapy, there were 117 (117/397, 29.5%) patients had not to achieve target INR. CONCLUSIONS: The incidence of adverse events was relatively low in paroxysmal AF patients who stopped OAC. The patient partly determined when OAC was discontinued. Target INR was not achieved in many patients who had not to stop OAC.

Difference in adsorbable organic halogen formation between phenolic and non-phenolic lignin model compounds in chlorine dioxide bleaching.

Adsorbable organic halogen (AOX) is generally formed by the reaction of residual lignin in pulps with chlorine dioxide during bleaching. Lignin has a complex structure. Different functional groups and bonds are present in lignin structures. Phenolic hydroxyl is one of the important functional groups in lignin, and it significantly influences the chemical properties and reactivity. To study the effect of phenolic hydroxyl on AOX formation, vanillyl alcohol (VA) was selected as the phenolic lignin model compound, and veratryl alcohol (VE) was selected as the non-phenolic lignin model compound in this study. The kinetics of AOX formation by the reaction of VA or VE with chlorine dioxide was studied. The effects of pH, chlorine dioxide, lignin model compound concentration and reaction temperature on AOX formation are discussed. The activation energies of the reaction of VA and VE with chlorine dioxide are 16 242.47 J mol-1 and 281.34 J mol-1, respectively. Thus, we found that the non-phenolic lignin can react with chlorine dioxide to form AOX more easily than phenolic lignin.

Effect of lignin structure on adsorbable organic halogens formation in chlorine dioxide bleaching.

Adsorbable organic halogens (AOX) are formed in pulp bleaching as a result of the reaction of residual lignin with chlorine dioxide. The natural structure of lignin is very complex and it tends to be damaged by various extraction methods. All the factors can affect the study about the mechanism of AOX formation in the reaction of lignin with chlorine dioxide. Lignin model compounds, with certain structures, can be used to study the role of different lignin structures on AOX formation. The effect of lignin structure on AOX formation was determined by reacting phenolic and non-phenolic lignin model compound with a chlorine dioxide solution. Vanillyl alcohol (VA) and veratryl alcohol (VE) were selected for the phenolic and non-phenolic lignin model compound, respectively. The pattern consumption of lignin model compounds suggests that both VA and VE began reacting with chlorine dioxide within 10 min and then gradually steadied. The volume of AOX produced by VE was significantly higher than that produced by VA for a given initial lignin model compound concentration. In a solution containing a combination of VA and VE in chlorine dioxide, VE was the dominant producer of AOX. This result indicates that the non-phenolic lignin structure was more easily chlorinated, while the phenolic lignin structure was mainly oxidized. In addition, AOX content produced in the combined experiments exceeded the total content of the two separate experiments. It suggested that the combination of phenolic and non-phenolic lignin structure can promote AOX formation.

Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers have no beneficial effect on ablation outcome in chronic persistent atrial fibrillation.

OBJECTIVE: Previous studies have shown that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) could reverse structural and electrical atria remodelling and decrease atrial fibrillation (AF) onset or recurrence. The aim of this retrospective study was to investigate whether ACEIs/ARBs had beneficial effects on ablation outcome of chronic persistent AF. METHODS AND RESULTS: This study included 139 patients with chronic persistent AF who underwent radiofrequency ablation in our centre. Patients were divided into an ACEIs/ARBs group or a non-ACEIs/ARBs group. During follow-up (14.6 +/- 8.9 months) after AF ablation, AF-free survival in the ACEIs/ARBs group was not significantly different from the non-ACEIs/ARBs group (P = 0.339). Univariate analysis showed that predictors for AF-free survival were AF history (HR, 1.064; 95% CI, 1.021-1.108; P = 0.003) and duration of chronic persistent AF (HR, 1.012; 95% CI, 1.005-1.019; P = 0.001). Multivariate analysis showed that predictors for AF-free survival were AF history (HR, 1.051; 95% CI, 1.004-1.101; P = 0.035) and duration of chronic persistent AF (HR, 1.012; 95% CI, 1.004-1.020; P = 0.004). ACEIs/ARBs therapy was not a predictor for AF-free survival neither in univariate nor multivariate analysis. CONCLUSION: In this observational study, no effect of ACEIs or ARBs was seen on the AF recurrence after ablation of chronic persistent AF.ACEIs/ARBs did not help to predict a better ablation outcome. Predictors for ablation outcome are AF history and duration of chronic persistent AF.

Long-term efficacy of delayed cure after circumferential pulmonary vein ablation of atrial fibrillation.

INTRODUCTION: The reliability of delayed cure of early recurrence of atrial fibrillation (ERAF) is still undetermined. Furthermore, the predictors of recurrence after delayed cure of ERAF are less investigated in depth. AIMS OF THE STUDY: The purpose of this study was to investigate the long-term efficacy of delayed cure of ERAF after catheter ablation of AF and explore the he predictors of recurrence after delayed cure of ERAF. METHODS AND RESULTS: We prospectively studied 300 consecutive patients with atrial fibrillation (AF) who were referred for circumferential pulmonary vein ablation (CPVA). After a follow-up of 19.2 +/- 4.1months, of the 87 patients with early recurrence of AF 41 achieved delayed cure, 11 of them reoccurred AF subsequently. Univariate analysis showed that persistent AF, absence of pulmonary vein (PV) isolation and external cardioversion were related to reoccurrence after delayed cure. Logistic regression analysis identified only absence of PV isolation as a predictor of recurrent AF after delayed cure. CONCLUSIONS: Delayed cure after CPVA is relatively common and its efficacy at long-term follow-up is reasonably consistent. However, in patients without PV isolation, delayed cure is unstable and the risk of late recurrence is increased.

Can atrial vagal denervation influence ventricular function in a failing heart?

Atrial fibrillation (AF) and congestive heart failure (CHF) often coexist (AF-CHF), and each adversely affects the other with respect to management and prognosis. Therapy with antiarrhythmic drugs to maintain sinus rhythm was disappointing. Ablation is more successful than antiarrhythmic drug therapy for the prevention of AF with few complications, although in patients with AF-CHF it is noted. Ablating autonomic nerves and ganglia on the large vessels and the heart can result in AF suppression with little damage to healthy myocardium. Our study in patients with AF-CHF found that cardiac function aggravation was more frequent in patients with AF recurrence than that of those who successfully maintain sinus rhythm. The autonomic nervous system is a fine network spreading throughout the myocytes; hence the elimination of atrial vagal with radiofrequency catheter ablation can influence the innervation in sinus and AV nodes even in the ventricular region. Thus we propose that atrial vagal denervation may result in paratherapeutic sympathovagal imbalance in the ventricular region, which has a negative effect in a failing heart, although it is neutralized by the benefit accrued from sinus rhythm after successful ablation.