Objective To investigate the effect of early postoperative enteral nutrition support on the balance of free amino acid spectrum in plasma for patients with cardiac valve replacement during perioperative period. Methods (Forty-seven) patients undergoing cardiac valve replacement were divided into two groups randomly, the routine diet group and the Nutrison Fibre group. The levels of free amino acids in plasma were measured with pre-column derivatization of high-performance liquid chromatography. Results During perioperative period most free amino acids in plasma decreased significantly in the routine diet group (Plt;0.05). Despite some free amino acids in plasma decreased significantly in the Nutrison Fibre group(Plt;0.05), all free amino acids in plasma returned to (Pgt;05) or were higher than the preoperative levels in the postoperative sixth day (Plt;0.05). At the same postoperative points, most free amino acids in plasma in the Nutrison Fibre group were higher than that of the routine diet group (Plt;0.05). Conclusions The levels of free amino acids in plasma decrease significantly in patients with cardiac valve replacement after operation. Early postoperative Nutrison Fibre enteral nutrition support is helpful for keeping the balance of free amino acids in plasma for patients with cardiac valve replacement.
Heat sensitive protein medicines are increasingly exhibiting their critical importance on treatment of various diseases at present. But their popularization and application meet a great challenge because of their heat instability. In the present study, insulin was taken as a heat sensitive protein medicine and amino acid as bio-protective agent in order to investigate if these amino acids can protect the insulin from losing its bioactivity due to desiccation. The experiment was performed by using replica exchange molecular simulation (REMD) method and Gromacs software with Gromos96 (53a6) force field. The REMD results indicated that these amino acids could protect the bioactive structure of insulin during desiccation. The configurations of the protected insulin were preserved very well. Those results proved that amino acid is a kind of good bioactive protective agent for the heat sensitive protein medicines.
【Abstract】 Objective To study the effects of glutamine (Gln) combined with growth hormone （GH） on the levels of cytokine (TNF-α, IL-1, IL-6), coritsol and amino acid metabolism in septic rats. Methods Ten out of 79 SD rats were randomly collected as the control group. Thirty of 69 septic SD rats, which were made by cecal ligation and perforation (CLP) method and were given parenteral nutrition (PN) lived to day 6. They were also randomly divided into three groups as follows: septic group (n=10), parenteral supplemented glutamine group (Gln group, n=10), and Gln combined with GH (Gln+GH group, n=10). On the 6th day, blood drew from portal veins of the dead rats was used to detect the levels of TNF-α， IL-1， IL-6 and cortisol by ELISA. The plasma concentrations of free amino acids were determined by amino acid auto-analyzer. The muscle tissue of extensor digitorum longus was used to determine 3-methyl-histidine (3-MH) by high performance liquid chromatographic (HPLC). Results Except for the control group, most rats developed celiac abscess, hepatic abscess and pulmonary infection. The serum levels of TNF-α, IL-1, IL-6 and cortisol were significantly higher in the septic group than those of the other three groups, and they were significantly lower in the Gln+GH group than those of the Gln group, P＜0.05. Compared with the other three groups, the concentration of total amino acid in the septic group increased more, among which the glutamine and the branched chain amino acids were prominent. Most of concentrations of the amino acids decreased in the Gln group and the Gln+GH group, and the decreased amplitude of the Gln+GH group was larger, P＜0.05, albeit its level of Gln markedly increased. The concentration of 3-MH in muscle tissue was the highest in septic group, and it was significantly higher in the Gln group than that of the Gln+GH group, P＜0.01. ConclusionIt may be necessary to supplement GH combined with Gln as the content of PN to decrease cytokine levels and im-prove amino acid metabolism for septic case.
ObjectiveTo observe the ability of osteogenesis in vivo using the injected absorbable polyamine acid/calcium sulfate (PAA/CS) composites and assess their ability to repair bone defects. MethodWe selected 48 New Zealand white rabbits, and half of them were male with a weight between 2.0 and 2.5 kg. Bone defect models were made at the rabbit femoral condyle using electric drill, and the rabbits were divided into two groups. One group accepted implantation of the material at the defect, while nothing was done for the control group. After four, eight, twelve and sixteen weeks, the animals were killed. The line X-ray and hard tissue slices histological examination (HE, MASSON staining) were observed to assess the situation of degradation, absorption and bone formation of the material. ResultsFour weeks after operation, bone defect of the experimental group had no obvious callus growth on X-ray imaging. Histology showed that the material began to degrade and new immature trabecular bone grew. The bone defect of the experimental group had a small amount of callus growth on X-ray imaging after eight weeks. And histology showed that the material continued to degrade and new immature trabecular bone grew continually. There was an obvious callus growth after twelve weeks, and the bone defect area had smaller residual low-density shadow on X-ray imaging. Histology showed that most of the materials degraded and parts of woven bone grew into lamellar bone. After sixteen weeks, the composites were absorbed completely, replaced by new bone tissues, and the new bone was gradually changed from woven bone into mature plate of bone. There was no significant change in bone defect in the control group within twelve weeks, and part of bone defect hole became smaller, and partial edge repair could be detected. ConclusionsThe PAA/CS composites can be completely degraded and absorbed, with a certain activity of bone formation, expected to be used as bone repair materials.
Objective To quantify the mRNA expression of NMDAR1 gene in the retina of eyes with acute elevation of IOP in rabbit． Methods Tweenty-six eyes of 16 rabbits were divided into three groups: Group 1: The IOP of one eye in 10 rabbits was elevated to 60 mm Hg by ante ri or chamber infusion． Group 2: The another eye of the same rabbit in group 1 was maintained the IOP to 20 mm Hg by anterior chamber infusion． Group 3: Unilat eral eyes of six rabbits were enucleated to evaluate the mRNA levels as normal control group． PCR product was identified by Southern blotting and the mRNA expression level was quantified by RT-PCR． Results The results revealed no significant difference between group 1 and group 2． Conclusion This implies that acute elevated IOP may not affect the mRNA expression level of NMDAR1 gene． (Chin J Ocul Fundus Dis, 2001,17:50-51)
Skeletal muscle and metabolic function are important factors affecting the health status of the elderly. Branched-chain amino acids (BCAA) can improve muscle recovery, reduce muscle soreness after exercise, and BCAA can also enhance metabolic health, helping to regulate blood sugar levels and improve insulin sensitivity in the elderly. In addition, BCAA can improve cognitive function, reducing the risk of age-related cognitive decline. This article reviews the relationship between BCAA and aging, skeletal muscle, and metabolic diseases, explaining how BCAA can support and promote muscle mass and function in the elderly, as well as have a positive impact on metabolic health and cognitive function.
Objective To investigate the change of N-terminal pro-B-type natriuretic peptide ( NT-proBNP) levels in plasma of patients with stable chronic obstructive pulmonary disease ( COPD) at exertion. Methods Pulmonary function testing, increamental and constant cycle ergometer exercise testing were performed in 19 patients with stable COPD and 10 healthy subjects. Arterial blood gas analysis were measured at rest and maximal exertion in incremental testing. Venous blood samples were drawn both at rest and maximal exercise in constant-load exercise testing and NT-proBNP levels were measured. Results NT-proBNP levels did not change significantly during exercise in the patients with stable COPD[ ( 4803. 86 ±1027. 07 ) ng/L vs ( 4572. 39 ±1243. 33 ) ng /L, P = 0. 542 ] and the control group [ ( 4303. 18 ±771. 74) ng/L vs ( 4475. 71 ±1025. 50) ng /L, P = 0. 676] . NT-proBNP levels were not correlated with parameters of cardiopulmonary exercise testing. Conclusion The factors other than cardiac function may contribute to the exercise intolerance in stable COPD patients without heart failure.
To investigate the protective effect of propofol on ischemia/reperfusion induced spinal cord injury in rabbits and its influence on excitatory amino acid (EAA). Methods Sixty New Zealand white rabbits weighing 2.0-2.5 kg, half males and half females, were selected. The infrarenal circumaortic clamping model was used. And 6 mL/kg different fluids were continuously infused through a catheter into the aorta distal to the clamping site at a speed of 12 mL/(kg?h) during the 30 minutes ischemia period. According to the different infusing l iquids, the rabbits were randomized into 6 groups(n=10 per group): group A, normal sal ine; group B, 10% intral ipid; group C, propofol 30 mg/kg; group D, propofol 40 mg/kg; group E, propofol 50 mg/kg; group F, propofol 60 mg/kg. At 0, 6, 24, and 48 hours after reperfusion, neurologic outcomes were scored on a Tarlov scale system. At 48 hours after reperfusion, the number of normal neurons in the anterior spinal cord was counted, and concentration of EAA in the lumbar spinal cord was measured by high performance l iquid chromatography. Results The neuroethological score was better in groups C, D, E and F than that of groups A and B (P lt; 0.05), the score of group E was the highest (P lt; 0.05), and there was no significant difference between group A and group B (P gt; 0.05). The number of normal neurons in the anterior spinal cord of groups C, D, E and F was greater than that of groups A and B (P lt; 0.05), and group E was greater than groups C, D and F (P lt; 0.05). The concentration of EAA in groups A, B, C, D, E and F was greater than that of normal tissue, the group E was the lowest (P lt; 0.05), the groups A and B were the highest (P lt; 0.05), and there was no significant difference between group A and group B (P gt; 0.05). Concentrations of glutamate and aspartic acid were negatively correlated to normal neuron numbers in the anterior spinal cord and neuroethological scores 48 hours after reperfusion, and the corresponding correlation coefficient was — 0.613, — 0.536, — 0.874 and — 0.813, respectively (P lt; 0.01). Conclusion Propofol can significantly inhibit the accumulation of EAA in spinal cord and provide a protective effect against the ischemia/reperfusion injury induced spinal cord in rabbits.
ObjectiveTandem mass spectrometry is used to observe the changes in amino acids level in peripheral blood of patients with chronic obstructive pulmonary disease (COPD) of different severity, and explore the related factors that affect the level of amino acids in COPD patients.MethodsA collection of 99 COPD patients from the First Affiliated Hospital of Jinzhou Medical University between May 2020 and August 2020 were divided into GOLD Ⅰ/Ⅱ group, GOLD Ⅲ group and GOLD Ⅳ group according to the results of their lung function. Thirty healthy physical examination subjects during the same period were enrolled as a healthy control group. Peripheral amino acids were detected by liquid chromatography-tandem mass spectrometry (LC-MS).ResultsThe metabolism of 11 amino acids was correlated with the onset of COPD and the disorder of amino acid metabolism became more significant with the aggravation of the disease, and branched-chain amino acids (leucine, valine) had statistically significant differences in the COPD patients with different GOLD grades (P<0.05 and VIP>1). The difference between glutamate and glutamine was statistically significant only in GOLD Ⅳ stage (P<0.05 and VIP>1). The content of tyrosine and phenylalanine gradually increased with the increase of disease severity, and had significant difference in GOLD stage Ⅳ (P<0.05).ConclusionsCOPD patients with different GOLD grades have obvious amino acid metabolism disorders, including insufficient intake of essential amino acids and increased amino acids related to muscle protein catabolism. Understanding the mechanism between amino acid metabolism and COPD may provide a new direction for the diagnosis and treatment of the disease.