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Objective To investigate the effect of long-term high-fat diet on cognitive function and hippocampus neurons ultrastructure in obese rats.Methods Forty SD rats were randomly assigned to a high fat diet (HFD) group and a common diet (CD) group.Meanwhile,HFD-induced obese rat model were established.The spatial learning and memory were measured by the Morris water maze,and the neurons ultrastructural changes in rat hippocampus CA1 region at the corresponding period were observed by transmission electron microscopy.Results The average weight of rats was 25％,28％,and 22％ higher in the HFD group than in the CD group at the 12,16,and 20 weeks,respectively;the Lee's indexes were 6％,4％,and 8％ higher;the average swimming latency were 52％,44％,and 40％ longer;the average swimming distance were 85％,45％,and 51％ longer;the average swimming speed were 57％,34％,and 18％ higher;the duration of staying in the target quadrant were 32％,54％,and 63％ shorter;and the average times of crossing the plate form were 30％,34％,and 34％ shorter,respectively (all P ＜0.001).In comparison of ultrastructure in hippocampus CA1 region of rats at corresponding time points,the amounts of degenerated and necrosis neurons,of the deformed and vacuolar mitochondria,and of the less rough endoplasmic reticulum were significantly more at 12,16,and 20 weeks in the HFD group than in the CD group.Conclusions Long-term HFD-induced obesity damages the structure of neurons in the hippocampus,impairs spatial learning and memory function,and accelerates cognitive aging in rats.
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AIM:To observe and analyze the effect of cardiopulmonary bypass ( CPB) for 30 min on surface ultra-structure and mechanical properties of the erythrocyte membrane by atomic force microscopy (AFM).METHODS:Ten cases of elective patients in cardiac surgery were selected in the study and divided into control ( CON) group and CPB group.The central venous blood (2 mL) before surgery and 30 min after CPB was collected with heparin anticoagulation . The non-circular red blood cells were counted under a stand fluorescence microscope .AFM was used to examine the ultra-structure of the membrane surface and measure the force curve of the erythrocytes .RESULTS:The percentage of non-cir-cular red blood cells in CPB group showed no statistically significant differences as compared with CON group .AFM images showed that the significant differences of membrane surface concave and convex , evenness , particle distribution , the sur-face average roughness (Ra), the surface root mean square roughness (Rq) and cell membrane adhesion between CPB group and CON group were observed .However, the membrane deformation resilience and curve slope had no significant difference between the 2 groups.CONCLUSION:Cardiopulmonary bypass for 30 min changes the morphology and ultra-structure of the erythrocyte membrane surface , and increases the adhesion between cells .
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<p><b>OBJECTIVE</b>To investigate the correlation between arterial partial pressure of CO2 (PaCO2) and end expiratory tidal partial pressure of CO2 (Pet-CO2) in morbidly obese patients during anesthesia for laparoscopic gastric bypass surgery.</p><p><b>METHODS</b>Forty morbidly obese patients with a body mass index (BMI) between 35 and 50 kg/m(2) underwent laparoscopic gastric bypass surgery under general anesthesia. PaCO2 and Pet-CO2 were measured after intubation and before induction of pneumoperitoneum (T0), at 30 min (T1), 60 min (T2), and 120 min (T3) during pneumoperitoneum, and at 30 min (T4) and 60 min (T5) after deflation.</p><p><b>RESULTS</b>At each time point of measurement, Pet-CO2 was lower than PaCO2 in all the patients. PaCO2 and Pet-CO2 were positively correlated before, during, and after pneumoperitoneum (P<0.05). At a moderate pressure of CO2 pneumoperitoneum (16 mmHg), the level of correlation between PaCO2 and Pet-CO2 at T1, T2, and T3 differed from that before and after post-pneumoperitoneum.</p><p><b>CONCLUSIONS</b>PaCO2 and Pet-CO2 are closely correlated during a moderate CO2 pneumoperitoneum in morbidly obese patients undergoing laparoscopic gastric bypass surgery.</p>