Cerebral Metabolic Profiling of Hypothermic Circulatory Arrest with and Without Antegrade Selective Cerebral Perfusion: Evidence from Nontargeted Tissue Metabolomics in a Rabbit Model.

BACKGROUND: Antegrade selective cerebral perfusion (ASCP) is regarded to perform cerebral protection during the thoracic aorta surgery as an adjunctive technique to deep hypothermic circulatory arrest (DHCA). However, brain metabolism profile after ASCP has not been systematically investigated by metabolomics technology. METHODS: To clarify the metabolomics profiling of ASCP, 12 New Zealand white rabbits were randomly assigned into 60 min DHCA with (DHCA+ASCP [DA] group, n = 6) and without ( DHCA [D] group, n = 6) ASCP according to the random number table. ASCP was conducted by cannulation on the right subclavian artery and cross-clamping of the innominate artery. Rabbits were sacrificed 60 min after weaning off cardiopulmonary bypass. The metabolic features of the cerebral cortex were analyzed by a nontargeted metabolic profiling strategy based on gas chromatography-mass spectrometry. Variable importance projection values exceeding 1.0 were selected as potentially changed metabolites, and then Student's t-test was applied to test for statistical significance between the two groups. RESULTS: Metabolic profiling of brain was distinctive significantly between the two groups (Q 2 Y = 0.88 for partial least squares-DA model). In comparing to group D, 62 definable metabolites were varied significantly after ASCP, which were mainly related to amino acid metabolism, carbohydrate metabolism, and lipid metabolism. Kyoto Encyclopedia of Genes and Genomes analysis revealed that metabolic pathways after DHCA with ASCP were mainly involved in the activated glycolytic pathway, subdued anaerobic metabolism, and oxidative stress. In addition, L-kynurenine (P = 0.0019), 5-methoxyindole-3-acetic acid (P = 0.0499), and 5-hydroxyindole-3-acetic acid (P = 0.0495) in tryptophan metabolism pathways were decreased, and citrulline (P = 0.0158) in urea cycle was increased in group DA comparing to group D. CONCLUSIONS: The present study applied metabolomics analysis to identify the cerebral metabolic profiling in rabbits with ASCP, and the results may shed new lights that cerebral metabolism is better preserved by ASCP compared with DHCA alone.

A novel and feasible way to cultivate and purify endothelial progenitor cells from bone marrow of children with congenital heart diseases.

BACKGROUND: Endothelial progenitor cells (EPCs) are used in vascular tissue engineering and clinic therapy. Some investigators get EPCs from the peripheral blood for clinic treatment, but the number of EPCs is seldom enough. We have developed the cultivation and purification of EPCs from the bone marrow of children with congenital heart disease, to provide enough seed cells for a small calibre vascular tissue engineering study. METHODS: The 0.5-ml of bone marrow was separated from the sternum bone, and 5-ml of peripheral blood was collected from children with congenital heart diseases who had undergone open thoracic surgery. CD34+ and CD34+/VEGFR+ cells in the bone marrow and peripheral blood were quantified by flow cytometry. CD34+/VEGFR+ cells were defined as EPCs. Mononuclear cells in the bone marrow were isolated by Ficoll(®) density gradient centrifugation and cultured by the EndoCult Liquid Medium Kit(™). Colony forming endothelial cells was detected. Immunohistochemistry staining for Dil-ac-LDL and FITC-UEA-1 confirmed the endothelial lineage of these cells. RESULTS: CD34+ and CD34+/VEGFR+ cells in peripheral blood were (0.07 ± 0.05)% and (0.05 ± 0.02)%, respectively. The number of CD34+ and CD34+/VEGFR+ cells in bone marrow were significantly higher than in blood, (4.41 ± 1.47)% and (0.98 ± 0.65)%, respectively (P < 0.0001). Many colony forming units formed in the culture. These cells also expressed high levels of Dil-ac-LDL and FITC-UEA-1. CONCLUSION: This is a novel and feasible approach that can cultivate and purify EPCs from the bone marrow of children with congenital heart disease, and provide seed cells for small calibre vascular tissue engineering.

Passive graft perfusion in off-pump coronary artery bypass grafting.

BACKGROUND: Myocardial protection during off-pump coronary artery bypass grafting (OPCABG) is a multifactorial problem in which maintaining stable systemic hemodynamics is very important. In this study passive graft perfusion (PGP) was applied to investigate the effect during and after OPCABG as evaluated by cardiac troponin I (CTnI) and hemodynamic indexes. METHODS: Thirty first-time patients underwent OPCABG under one surgeon. They were randomly divided into two groups: The passive graft perfusion group (PGP, n = 15) received distal coronary perfusion during the anastomosis and immediate graft perfusion after the distal anastomosis. The control group, no graft perfusion group, (NGP, n = 15) received no graft perfusion after the distal anastomosis. The results of the two protocols were evaluated by concentration of CTnI and hemodynamic indexes before induction and after operation. RESULTS: There were no statistically significant differences between these two groups in their perioperation parameters. The level of CTnI increased postoperatively, reached its peak at 6 hours (P < 0.05) and recovered by the 6 days postoperative. Compared with the control group the concentration of CTnI in the PGP group was significantly lower at 6 and 24 hours (P < 0.01). Compared with the NGP group, cardiac index (CI) in the PGP group was higher at 12 and 24 hours after operation (P < 0.05). The period of mechanical ventilation was significantly shorter in the PGP group than in the NGP group (P < 0.05). CONCLUSION: PGP can increase the flow to the myocardium and shorten the heart ischemia time, thus maintain stable systemic hemodynamics, supply a satisfactory CI after surgery and improve surgery outcome.

[Comparative study of pulmonary function after conventional ultrafiltration or modified ultrafiltration during cardiac surgery of infants].

OBJECTIVE: To compare the effects of conventional ultrafiltration and modified ultrafiltration in protecting patients' pulmonary function during cardiopulmonary bypass. METHODS: Thirty infants patients (less than 7 kg) were divided into two groups: conventional ultrafiltration group (CUF, n = 15) and modified ultrafiltration group (MUF, n = 15). The volume of ultrafiltration, transfusion, hematocrit (HCT) before and after ultrafiltration, patients' respiration function (respiration index, A-aDO2, airway pressure), the time of mechanical ventilation and ICU in the two groups were respectively monitored. RESULTS: The transfusion in MUF group was significantly less than in CUF group (P < 0.01), and the volume of ultrafiltration in MUF group was significantly more than in CUF group (P < 0.01). The time of mechanical ventilation and ICU staying in MUF group were significantly shorter in MUF group than that in CUF group (P < 0.05). At 12 and 24 hours after operations, the A-aDO2 in MUF group was lower than that in CUF group (P < 0.05), and the respiratory index in MUF group was higher than that in CUF group (P < 0.05). CONCLUSION: The modified ultrafiltration can effectively improve pulmonary function after operations for low weight infants.