96 research outputs found
The Impact of Extrinsic Amino Acids and Solvent Fractionation on the in vitro Antioxidant Activity of Plastein Reaction-Stressed Casein Hydrolysates
Za pripremu hidrolizata kazeina stupnja hidrolize od 9,4 % upotrijebljen je enzim papain. Dobiveni je hidrolizat imao in vitro antioksidativnu aktivnost tj. sposobnost uklanjanja DPPH radikala od 38,7 % i EC50 vrijednost od 1,63 mg/mL. Dodatkom fenilalanina ili tirozina potaknuta je plastein reakcija katalizirana pomoću papaina. Metodom odzivnih površina optimirani su sljedeći parametri pri vremenu reakcije od 5 h: temperatura od 30 °C, koncentracija supstrata od 50 % (m/V), udjel enzima od 3 kU/g peptida i udjel aminokiselina od 0,74 mol/mol slobodnih aminokiselinskih grupa hidrolizata. Pripremljeno je nekoliko modificiranih hidrolizata, te je ispitana njihova antioksidativna aktivnost, i to sposobnost uklanjanja DPPH radikala i reducirajuća snaga. Dobiveni su rezultati pokazali da su svi modificirani hidrolizati imali znatno veću sposobnost uklanjanja radikala (p<0,05) i reducirajuću snagu od izvornih hidrolizata, a među njima je bio i jedan s najnižom EC50 vrijednosti od 1,09 mg/mL. Frakcioniranjem modificiranog hidrolizata najveće antioksidativne aktivnosti pomoću etanola i vode u omjerima od 3:7, 4:6, 5:5 i 6:4 dobiveni su supernatanti ili precipitati veće ili manje antioksidativne aktivnosti i reducirajuće snage, naročito pomoću otapala male polarnosti (npr. omjera etanola i vode od 6:4). Supernatanti s najvećom aktivnošću imali su EC50 vrijednost od 0,69 mg/mL. Rezultati pokazuju da se dodatkom fenilalanina ili tirozina u plastein reakciji hidrolizata kazeina te daljnjim frakcioniranjem otapalom mogu dobiti modificirani hidrolizati veće antioksidativne aktivnosti.Papain was used to prepare a casein hydrolysate with a degree of hydrolysis of 9.4 %. The hydrolysate had the in vitro antioxidant activity with a DPPH radical scavenging activity of 38.7 % and an EC50 of 1.63 mg/mL. Extrinsic phenylalanine or tyrosine was added to the hydrolysate for a papain-catalyzed plastein reaction. The temperature, substrate mass per volume fraction, and the levels of enzyme and amino acid addition during the reaction were optimized using response surface methodology with a fixed reaction time of 5 h, and were found to be 30 °C, 50 %, 3 kU per g of peptides and 0.74 mol per mol of the free amino groups of the hydrolysate, respectively. Some modified hydrolysates were prepared and their antioxidant activity was evaluated in terms of DPPH radical scavenging activity and reducing power. The results revealed that all prepared modified hydrolysates had significantly higher (p<0.05) scavenging activity and reducing power than the original hydrolysate, and among them one showed the lowest EC50 of 1.09 mg/mL against DPPH radical. When the modified hydrolysate with the highest activity was fractionated using ethanol/water solvents in volume ratios of 3:7, 4:6, 5:5 and 6:4, the supernatant or precipitate fraction exhibited an enhanced or decreased activity or reducing power, especially with the solvent of lower polarity (e.g. 6:4 by volume). The obtained supernatant with the highest activity thus exhibited an EC50 of 0.69 mg/mL. The results show that extrinsic phenylalanine or tyrosine addition in the plastein reaction of casein hydrolysate and further solvent fractionation of the modified hydrolysate is applicable to improve the antioxidant properties of products
Prognosis Risk of Urosepsis in Critical Care Medicine: A Prospective Observational Study
This study aimed to investigate the clinical features of urosepsis and to raise awareness of this problem. Of the 112 sepsis patients enrolled, 36 were identified as having urosepsis. The bacteria involved in the infection leading to urosepsis included Escherichia coli, Proteus species, Enterococcus species, Klebsiella species, other Gram-positive cocci, and Pseudomonas aeruginosa. Although the organ/system dysfunction appeared earlier in the urosepsis patients than in the other sepsis patients (4.7 ± 2.4 versus 7.2 ± 4.5 hours, < 0.001), the urosepsis patients presented with a better prognosis and lower 28-day mortality rate than the others (6% versus 37%). In the multivariate analysis, the type of sepsis (urosepsis, OR = 0.019, 95% CI = 0.001, 0.335, = 0.007) and SOFA score (OR = 1.896, 95% CI = 1.012, 3.554, = 0.046) remained significantly associated with the survival. The time of admission to the intensive care unit of 17 patients transferred from the Department of Urinary Surgery was significantly prolonged compared with those transferred from other departments (11.6 ± 7.3 versus 7.2 ± 4.9 hours, < 0.05). In conclusion, urosepsis suggested a better prognosis, but attention needs to be paid in clinical practice, especially in urinary surgery
Surgical treatment of tricuspid regurgitation after mitral valve surgery: a retrospective study in China
<p>Abstract</p> <p>Background</p> <p>Functional tricuspid regurgitation (TR) occurs in patients with rheumatic mitral valve disease even after mitral valve surgery. The aim of this study was to analyze surgical results of TR after previous successful mitral valve surgery.</p> <p>Methods</p> <p>From September 1996 to September 2008, 45 patients with TR after previous mitral valve replacement underwent second operation for TR. In those, 43 patients (95.6%) had right heart failure symptoms (edema of lower extremities, ascites, hepatic congestion, etc.) and 40 patients (88.9%) had atrial fibrillation. Twenty-six patients (57.8%) were in New York Heart Association (NYHA) functional class III, and 19 (42.2%) in class IV. Previous operations included: 41 for mechanical mitral valve replacement (91.1%), 4 for bioprosthetic mitral valve replacement (8.9%), and 7 for tricuspid annuloplasty (15.6%).</p> <p>Results</p> <p>The tricuspid valves were repaired with Kay's (7 cases, 15.6%) or De Vega technique (4 cases, 8.9%). Tricuspid valve replacement was performed in 34 cases (75.6%). One patient (2.2%) died. Postoperative low cardiac output (LCO) occurred in 5 patients and treated successfully. Postoperative echocardiography showed obvious reduction of right atrium and ventricle. The anterioposterior diameter of the right ventricle decreased to 25.5 ± 7.1 mm from 33.7 ± 6.2 mm preoperatively (P < 0. 05).</p> <p>Conclusion</p> <p>TR after mitral valve replacement in rheumatic heart disease is a serious clinical problem. If it occurs or progresses late after mitral valve surgery, tricuspid valve annuloplasty or replacement may be performed with satisfactory results. Due to the serious consequence of untreated TR, aggressive treatment of existing TR during mitral valve surgery is recommended.</p
Study on ventilation and noise reduction in the main transformer room in indoor substation
The noise emission should be considered in the ventilation and cooling design for the main transformer room of indoor substation. In this study, based on Soundplan software, effects of four common ventilation and cooling schemes on the cooling and sound insulation were compared. The research showed that the region with low noise requirement, the ventilation could be set on the outer wall or on the door of the main transformer room, while the region with high noise requirement, air inlet muffler or ventilation through the cable interlayer under the main transformer room must be used. All of the four kinds of ventilation schemes, ventilation through the cable interlayer is the best in cooling and noise reduction
Effect of the Plastein Reaction in Presence of Extrinsic Amino Acids on the Protective Activity of Casein Hydrolysate against Ethanol-Induced Damage in HHL-5 Cells
Casein hydrolysates (CH) were prepared using papain and modified by the plastein reaction (CH-P) in the presence of extrinsic phenylalanine (CH-P-Phe) or tryptophan (CH-P-Trp). The in vitro protective activity of CH and its modified products against ethanol-induced damage in HHL-5 cells was investigated. The results showed that the modification by the plastein reaction reduced the amino group content of CH. However, the modification by the plastein reaction in the presence of extrinsic amino acids could enhance the antioxidant, proliferative, cell cycle arresting, and anti-apoptosis activity of CH. Biological activities of CH and its modified products in the HHL-5 cells varied depending on the hydrolysate concentration (1, 2, and 3 mg/mL) and treatment time (24, 48, and 72 h). Generally, higher biological activities were found after cell treatment with CH or its modified products at concentration of 2 mg/mL for 48 h compared to other treatments. In addition, CH modified in the presence of tryptophan (CH-P-Trp) showed higher biological activity than that modified in the presence of phenylalanine (CH-P-Phe). Based on the obtained results, it can be concluded that casein hydrolysates with enhanced biological activity and potential health benefits can be produced by papain and the plastein reaction with the incorporation of extrinsic amino acids
Prognosis Risk of Urosepsis in Critical Care Medicine: A Prospective Observational Study
This study aimed to investigate the clinical features of urosepsis and to raise awareness of this problem. Of the 112 sepsis patients enrolled, 36 were identified as having urosepsis. The bacteria involved in the infection leading to urosepsis included Escherichia coli, Proteus species, Enterococcus species, Klebsiella species, other Gram-positive cocci, and Pseudomonas aeruginosa. Although the organ/system dysfunction appeared earlier in the urosepsis patients than in the other sepsis patients (4.7±2.4 versus 7.2±4.5 hours, P<0.001), the urosepsis patients presented with a better prognosis and lower 28-day mortality rate than the others (6% versus 37%). In the multivariate analysis, the type of sepsis (urosepsis, OR = 0.019, 95% CI = 0.001, 0.335, P=0.007) and SOFA score (OR = 1.896, 95% CI = 1.012, 3.554, P=0.046) remained significantly associated with the survival. The time of admission to the intensive care unit of 17 patients transferred from the Department of Urinary Surgery was significantly prolonged compared with those transferred from other departments (11.6±7.3 versus 7.2±4.9 hours, P<0.05). In conclusion, urosepsis suggested a better prognosis, but attention needs to be paid in clinical practice, especially in urinary surgery
Research on the application of active sound barriers for the transformer noise abatement
Sound barriers are a type of measure most commonly used in the noise abatement of transformers. In the noise abatement project of substations, the design of sound barriers is restrained by the portal frames which are used to hold up outgoing lines from the main transformers, which impacts the noise reduction effect. If active sound barriers are utilized in these places, the noise diffraction of sound barriers can be effectively reduced. At a 110kV Substation, an experiment using a 15-channel active sound barrier has been carried out. The result of the experiment shows that the mean noise reduction value (MNRV) of the noise measuring points at the substation boundary are 1.5 dB (A). The effect of the active noise control system is impacted by the layout of the active noise control system, the acoustic environment on site and the spectral characteristic of the target area
Research on the application of active sound barriers for the transformer noise abatement
Sound barriers are a type of measure most commonly used in the noise abatement of transformers. In the noise abatement project of substations, the design of sound barriers is restrained by the portal frames which are used to hold up outgoing lines from the main transformers, which impacts the noise reduction effect. If active sound barriers are utilized in these places, the noise diffraction of sound barriers can be effectively reduced. At a 110kV Substation, an experiment using a 15-channel active sound barrier has been carried out. The result of the experiment shows that the mean noise reduction value (MNRV) of the noise measuring points at the substation boundary are 1.5 dB (A). The effect of the active noise control system is impacted by the layout of the active noise control system, the acoustic environment on site and the spectral characteristic of the target area
Research on the application of active sound barriers for the transformer noise abatement
Sound barriers are a type of measure most commonly used in the noise abatement of transformers. In the noise abatement project of substations, the design of sound barriers is restrained by the portal frames which are used to hold up outgoing lines from the main transformers, which impacts the noise reduction effect. If active sound barriers are utilized in these places, the noise diffraction of sound barriers can be effectively reduced. At a 110kV Substation, an experiment using a 15-channel active sound barrier has been carried out. The result of the experiment shows that the mean noise reduction value (MNRV) of the noise measuring points at the substation boundary are 1.5 dB (A). The effect of the active noise control system is impacted by the layout of the active noise control system, the acoustic environment on site and the spectral characteristic of the target area
Antioxidant and Immunity Activities of Fufang Kushen Injection Liquid
We investigated the effects of Fufang Kushen Injection Liquid (FFKSIL) on gastric immunity and oxidant-antioxidant status during <em>N</em>-methyl-<em>N′-</em>nitro-<em>N</em>-nitroso-guanidine (MNNG)-induced gastric carcinogenesis. The extent of lipid peroxidation and the levels of reduced glutathione (GSH) and activities of the GSH-dependent enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were used to monitor the peroxidative balance. Enhanced lipid peroxidation in the gastric cancer animals was accompanied by significant decreases in the activities of GSH, GPx, GST and GR. Administration of FFKSIL significantly enhanced serum IgA, IgG, IgM, IL-2, IL-4 and IL-10 levels, decreased serum IL-6 and TNF-α levels, lowered the levels of lipid peroxides and enhanced GSH levels and activities of GSH-dependent enzymes. Our results suggest that FFKSIL blocks experimental gastric carcinogenesis by protecting against carcinogen-induced oxidative damage and improving immunity activity
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