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.
目的：建立高效液相色谱分离检测脑蛋白水解物注射液各种氨基酸的测定方法。方法：氨基酸含量测定采用异硫氰酸苯酯柱前衍生化；色谱柱为C18柱（VP-DOS；150 mm×46 mm）；流动相：A为0.1 mol/L醋酸钠溶液（冰醋酸调节pH 6.5）-乙腈（93∶7），B为水-乙腈（1∶4）；检测波长：254 nm；流速：1 mL/min；柱温：40℃。结果：16种氨基酸在32 min内完全分离，各种氨基酸之间没有出现干扰现象，且多次重复测定结果误差很小。结论：建立的高效液相色谱法准确性高、重现性好，可以有效地控制脑蛋白水解物注射液的质量。
【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 evaluate the effect of poly-amino acid/nano-hydroxyapatite/calcium sulfate (PHC) Cage in lumbar interbody fusion of the goat. MethodsEighteen mature female goats (weighing 29-33 kg) were divided into 3 groups randomly: PHC Cage group (group A), titanium Cage group (group B), and ilium group (group C). A left extraperitoneal approach was used to establish the animal model of discectomy and interbody fusion with Cage or ilium. The general situation was observed for 24 weeks after operation. X-ray films were taken to measure disc space height (DSH) before operation and at 4, 12, and 24 weeks after operation. CT three dimensional reconstuction was performed at 24 weeks after operation to evaluate the interbody fusion according to modified Brantigan grading. The specimens of L3, 4 were harvested for mechanical test, histological, and scanning electron microscope (SEM) observation at 24 weeks after operation. ResultsAll goats survived to the end of experiment. DSH at 4 weeks after operation increased when compared with preoperative one in each group, and then decreased;DSH was significantly lower at 12 and 24 weeks after operation than preoperative one in group C (P<0.05). There was no significant difference in DSH among 3 groups at preoperation and 4 weeks after operation (P>0.05);at 12 and 24 weeks after operation, DSH of groups A and B was significantly higher than that of group C (P<0.05), but no significant difference was found between groups A and B (P>0.05). CT three dimensional reconstuction showed that bony fusion was obtained in all goats of groups A and C, and in 3 goats of group B;according to modified Brantigan grading, the scores of groups A and C were significantlly higher than that of group B (P<0.05), but no significant difference between groups A and C (P>0.05). The biomechanical test showed that there was no significant difference in range of motion between group A and group B (P>0.05), which were significantly lower than that of group C (P<0.05). Microscopy and SEM observations showed that the interface between the Cage and vertebral body in group A was compact without obvious gap, and most conjunctive region was filled with osseous tissue;the interface was filled with soft tissue, and the connection was slack with obvious gap in some region in group B;the interface connection was compact, most region was filled with osseous tissue in group C. ConclusionThe interbody fusion with PHC Cage is effective in goat lumbar interbody fusion model. The interface connection is compact between the Cage and the host bone followed by micro-degradation of PHC Cage, but the long-term degradation need further observation.
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)
ObjectiveTo discuss the early effectiveness of polyaminoacid/nano-hydroxyapatite/calcium sulfate (PAA/HA/CS) Cage (PHC Cage) in lumbar fusion surgery. MethodsThirty cases undergoing lumbar fusion of single segment between March and September 2014 were enrolled in this study. The patients were randomly divided into the trial group (n=20) and the control group (n=10). The PHC Cage was implanted in the trial group, while the polyetheretherketone (PEEK) Cage was implanted in the control group. The patients of 2 groups mainly presented lumbocrural pain and lower limb radiation pain or numbness. There was no significant difference in gender, age, type, affected segment, disease duration, preoperative intervertebral height, the lordosis angle of fusion segments, and the Oswestry Disability Index (ODI) between 2 groups (P > 0.05). Lateral lumbar X-ray films and three dimensional CT were taken preoperatively and at 1 week and 3, 6, and 12 months postoperatively. The intervertebral height and the lordosis angle of fusion segments at 1 week and 3, 6, and 12 months after operation and ODI at 3, 6, and 12 months after operation were measured; and the bone graft fusion rate was evaluated according to Brantigan criteria. ResultsThere was no significant difference in operation time, intraoperative blood loss, and the amount of autologous blood transfusion between 2 groups (P > 0.05). Healing by first intention was obtained in 30 cases. All patients were followed up 12 months. The intervertebral height of fusion segments, the lordosis angle of fusion segments, and ODI at each time point after operation were significantly improved when compared with preoperative ones (P < 0.05). The ODI showed significant difference between 3 months and 6, 12 months (P < 0.05), but there was no significant difference between the other time points after operation (P > 0.05). There was no significant difference in the intervertebral height and the lordosis angle of fusion segments between groups at different time points (P > 0.05). There was no significant difference in the above indexes between the trial group and the control group at each time point (P > 0.05). At last follow-up, 5 cases were rated as Brantigan grade E, 13 cases as grade D, and 2 cases as grade C in the trial group; 4 cases were rated grade E, 5 cases as grade D, and 1 case as grade C in the control group. The bone fusion rate was 90% in 2 groups. ConclusionThe PHC Cage can effectively restore and maintain the disc height of fusion segment, normal sequence and biomechanical stability of the lumbar spine. The PHC Cage is similar to the PEEK Cage and has good clinical outcome in short-term follow-up.
Objective To monitor the release of amino acids of the whole retina during and after experimental glaucoma by increasing the intraocular pressure （IOP）． Methods Experimental glaucoma was induced in one of the two eyes of rabbits by increasing IOP at 120 mm Hg for 45 min under infusion of saline in anterior chamber；then the pressure was released and the needle inserted into the anterior chamber was removed，this state was maintained for another 45 min．Every 15 min during the experiment 5 rabbits were killed and experimental eyes were enucleated．Aliquots（20 μl）of the retinal extracts（see below）were mixed with ophthaldialdehyde reagent and analysed for amino acid content by the HPLC method of Wangwei，using a 150 mm×4.6 mm,5 μm C18 column． Results A large increase in the release of glutamate，but not of the other three amino acids monitored，occurred during initial experimental ocular hypertension．It reached peak value of（111.73±17.46）10-5 mmol/g at 15 min of hypertension．15 min after release of intraocular pressure，again，immediately large and specific increase in the concentration of glutamate was reached to（102.96±51.91）10-5 mmol/g．In eyes subjected to paracentesis of anterior chamber，no difference was found between experimental eyes and controls. Conclusion These results suggest that glutamate is triggered by increasing the IOP，and it releases not only during the period of experimental ocular hypertension，but also afterwards. (Chin J Ocul Fundus Dis, 2002, 18: 146-148)
ObjectiveTo investigate the postnatal changes in urinary metabolic amino acid levels in infants with retinopathy of prematurity (ROP) and their effect on ROP, and to analyze the amino acid metabolic pathways that may be involved in the development of ROP. MethodsA retrospective cohort study. From January 2020 to December 2023, 65 premature infants with severe ROP (ROP group) who were hospitalized, born with gestational age ＜32 weeks in Children's Hospital Affiliated to Zhengzhou University were included in the study. Fifty premature infants with matched sex and gestational age and no ROP were selected as the control group. Urine amino acids and their derivatives were detected by gas chromatography-mass spectrometry. The two groups were compared by independent sample t test. The metabonomics of urinary amino acids was analyzed by orthogonal partial least squares discriminant analysis (OPLS-DA) model. The variable projection importance (VIP) score ＞1 suggested that the substance was two groups of differentially expressed amino acids. The predictive value of urinary amino acids for severe ROP was compared by using the receiver's operating characteristic (ROC) curve and the area under the curve. After t test and metabolomics analysis, the two groups of amino acids with large differences were normalized and compared by Pearson correlation analysis. The Kyoto Encyclopedia of Genes and Genomes database was used to analyze the metabolic pathways of differentially expressed amino acids involved in ROP. ResultsCompared with the control group, the concentrations of oxalic acid -2 and thiodiacetic acid-2 in urine metabolites of children in ROP group were significantly decreased, while the concentrations of 4-hydroxybutyric acid-2, 3-methylpentadienoic acid-2(1), 2-ketoglutarate-ox-2(2) and 3, 6-epoxy-dodecanedioic acid-2 were significantly increased, with statistical differences (t=0.036, 0.005, 0.038, 0.032, 0.022, 0.011; P＜0.05). The results of OPLS-DA analysis showed that amino acids of urinary metabolites in ROP group and control group were distributed in the left and right regions of the scatter plot, and there was a satisfactory separation trend between the two groups (R2Ycum=0.057 4, Q2cum=0.025 7, P＜0.05). As shown in the S-Plot, the amino acids biased towards two stages are glycolic acid-2, phosphoric acid-3, oxalic acid-2, thiodiacetic acid-2, 4-hydroxybutyric acid-2, 3-methylcrotonylglycine-1, 3-methylpentadienoic acid-2(1), 2-ketoglutarate-ox-2(2) and 3, 6-epoxy- dodecanedioic acid-2, respectively. Eleven differentially expressed amino acids with VIP score ＞1 were screened, among which the highest VIP score was oxalate-2, glycerate-3, phosphoric acid-3, 3-methylcrotonylglycine-1, uranoic acid -3 and thiodiacetic acid-2. The difference of amino acid concentration between the two groups was the highest in 4-hydroxybutyric acid-2 and thiodiacetic acid-2. The correlation between oxalic acid-2 and glycerate-3 was the highest (r=0.830, P＜0.001), and most amino acids were positive correlated. ROC curve fitting analysis showed that the combined prediction of 11 differenly-expressed amino groups had the largest area under the curve (0.816), the cutoff value was 0.531, and the sensitivity and specificity were 83.1% and 70.0%, respectively. The enrichment analysis of these 11 amino acids with significant differences suggested that the main pathways involved included butyrate metabolism, glyoxylic acid and dicarboxylic acid metabolism and lipoic acid metabolism. ConclusionAbnormal amino acid metabolism of 4-hydroxybutyrate-2, 3-methylpentadienoic acid-2(1), thiodiacetic acid-2, 2-ketoglutarate-ox-2(2), 3, 6-epoxy-dodecanedioic acid-2 may have a certain effect on the occurrence of ROP.
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.