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Lipid and protein oxidation in catfish (Clarias lazera) surimi during processing and storage were assessed. Catfish surimi were washed in deionized water: M0 (no washing step), M1 (one washing step), and M2 (two washing steps). Lipid, protein, water, and iron contents were determined. M0, M1, and M2 were stored for 0, 1, 4, 7, or 10 days at 4 ± 1°C; at each time point, samples were removed for analyses. Lipid oxidation was assessed by measuring malondialdehyde content. Protein oxidation was assessed by measuring protein solubility and protein sulfhydryl and carbonyl group contents. Based on the results, lipid content, L* and a* (color parameters), and fatty acid content in M1 and M2 were significantly reduced. Lipid oxidation development was faster in M1, and the ranking was as follows: M1 > M2 > M0, with M0 being significantly less oxidized than M1. Increasing the number of washes increased protein oxidation, and the ranking was follows: M2 > M1 > M0. Altogether, lipid and protein oxidation and p...

The bones of channel catfish (Ictalurus punctatus), a kind of fish processing waste, were hydrolyzed with one of five proteases (alcalase, neutrase, papain, pepsin, and trypsin) in order to generate antibacterial agents. The antibacterial activity of hydrolysates recovered through enzyme hydrolysis was tested by radial diffusion assay (RDA). Pepsin hydrolysate was found to have the greatest antibacterial activity. Thus, the conditions of hydrolysis with pepsin were optimized by response surface methodology (RSM). After screening and optimization, a quadratic model was proposed. The model predicted that the maximum diameter of clear zone, which suggests the optimum antibacterial activity, was around 20.2 mm with a hydrolysis condition of pH 3.5, reaction temperature of 40°C, enzyme-substrate ratio of 1.97/100 (g/g), substrate concentration of 0.15 g/mL, and reaction time of 4 h. Verification experiments under this condition showed a clear zone of 19.8 mm, which agreed well with the model's predicted value....

Objectives To investigate the impacts of long-term right ventricular apical pacing on the ventricular remodelling and cardiac functions of patients with high-grade and third-degree atrioventricular blockage with normal heart structures and cardiac functions. In addition, we provide evidences for choosing an optimal electrode implantation site. Methods Study participants included patients who were admitted for pacemaker replacements and who revisited for examinations of implated pacemakers at outpatient. Pacemakers were implanted to treat high-grade and third-degree atrioventricular blockage. At the time of pacemaker implantation, patients had normal cardiac functions and showed no serious heart diseases or cardiac dilatation. The durations from the implantation to follow-up were more than 5 years. The pacing rate was higher than 80%. Patients with a left ventricular ejection fraction (LVEF) 55 mm were excluded. Ventricular remodelling was defined as: increase of LVEDD by 10% and a reduction of LVEF by 25% 5 years after implantation. Cardiac functions were evaluated according to the New York Heart Association (NYHA) classification. Results A total of 82 patients with a mean age of 66.97±13.19 years (range, 12–91 years old), including 39 male and 43 female were enrolled in this study. The average duration between two assessments was 8.7 years (104.4 months). Before pacemaker implantation, the average left atrial diameter (LA), LVEDD and LVEF were 37.0 mm, 50.23 mm and 64.87%, respectively. After the implantation, these values were 39.39 mm (p=0.000163), 50.82 mm (p=0.177842) and 60.50% (p=0.000104), respectively. 4 patients (4.87%) had ventricular remodelling with deteriorations of cardiac function. Among them, three patients had anterior wall myocardial infarction after implantation and one had type II diabetes. Clinical heart failure symptoms were not found in the patients who did not exhibit ventricular remodelling. Conclusion Through a long period follow-up study, we found that long-term right ventricular apical pacing in patients with normal heart structure and cardiac function generally would not cause ventricular remodelling and clinical deteriorations of cardiac function. Right ventricular apical is a safe and effective site for pacing electrode wire implantation.