Objectives Partial hepatectomy induces a rapid transformation within the remnant liver, prompting a wave of hepatocyte mitosis which abates when the lost cell mass has been recovered. The mechanism of co-ordinated con...Objectives Partial hepatectomy induces a rapid transformation within the remnant liver, prompting a wave of hepatocyte mitosis which abates when the lost cell mass has been recovered. The mechanism of co-ordinated control of metabolism and maintenance of function during this period of dynamic change is incompletely understood. Furthermore, the biochemical basis of growth regulation in the regenerating liver has not been well defined. We have studied human liver regeneration using in vivo 31-phosphorus magnetic resonance spectroscopy (31 P MRS). This non-invasive technique allows assay of high-energy phosphate compounds and also of phospholipid metabolites thought to be involved in cellular renewal processes.Methods Five patients undergoing liver resection were studied. Hepatic metabolism was evaluated using 31P MRS before surgery and on postoperative days 2,4,6 and 14. Estimation of liver volume by magnetic resonance imaging and blood sampling for biochemistry were performed at the same time points.Results We found that the regenerative response following loss of liver parenchyma produced a reversible decline in energy state which necessitated compensatory adjustments in liver synthetic and excretory (unctions. Volume regain was associated with alterations in phospholipid metabolism, which normalized when the hepatic growth spurt was completed.Conclusion These observations indicate that modulation of hepatocyte energy economy is necessary for the integrated recovery of liver cell mass and function. We propose that deficient hepatic energy production may explain the mechanism of liver failure after hepatectomy, and suggest that in vivo measurement of liver metabolism may provide a rational basis for the development and evaluation of hepatic support strategies.展开更多
Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids we...Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).展开更多
The utility of GIS （geographic information system） methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X...The utility of GIS （geographic information system） methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X-ray techniques and SEM （scanning electron microscopy）. The elemental neighborhood associations of a single element, P （phosphorus）, were quantified at a magnification of 3,000 ×. For each of the 170,000 pixels on the images which displayed a strong P concentration, neighborhoods from 0.1μm^2 to 12 μm^2 were examined for associated elemental concentrations. PCA （principal component analysis） revealed two significant neighborhood types associated with P in samples of pH 4, and three neighborhood types at pH 8. These neighborhoods corresponded to Mg-P associations commonly found to be chemically prevalent in river sediments impacted by agricultural operations. Discriminant analysis showed that the greatest accuracy in predicting sample pH could be achieved by using a neighborhood size of 12 ~m2. Potassium at relatively large neighborhood sizes was the element most significant in predicting pH. While many of the chemical associations in close proximity to P could be predicted and explained through mineral solubility, spatial analysis provided some interesting insights into the structure of the samples. Results also indicted differences in the spatial scale associated with different processes.展开更多
文摘Objectives Partial hepatectomy induces a rapid transformation within the remnant liver, prompting a wave of hepatocyte mitosis which abates when the lost cell mass has been recovered. The mechanism of co-ordinated control of metabolism and maintenance of function during this period of dynamic change is incompletely understood. Furthermore, the biochemical basis of growth regulation in the regenerating liver has not been well defined. We have studied human liver regeneration using in vivo 31-phosphorus magnetic resonance spectroscopy (31 P MRS). This non-invasive technique allows assay of high-energy phosphate compounds and also of phospholipid metabolites thought to be involved in cellular renewal processes.Methods Five patients undergoing liver resection were studied. Hepatic metabolism was evaluated using 31P MRS before surgery and on postoperative days 2,4,6 and 14. Estimation of liver volume by magnetic resonance imaging and blood sampling for biochemistry were performed at the same time points.Results We found that the regenerative response following loss of liver parenchyma produced a reversible decline in energy state which necessitated compensatory adjustments in liver synthetic and excretory (unctions. Volume regain was associated with alterations in phospholipid metabolism, which normalized when the hepatic growth spurt was completed.Conclusion These observations indicate that modulation of hepatocyte energy economy is necessary for the integrated recovery of liver cell mass and function. We propose that deficient hepatic energy production may explain the mechanism of liver failure after hepatectomy, and suggest that in vivo measurement of liver metabolism may provide a rational basis for the development and evaluation of hepatic support strategies.
文摘Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).
文摘The utility of GIS （geographic information system） methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X-ray techniques and SEM （scanning electron microscopy）. The elemental neighborhood associations of a single element, P （phosphorus）, were quantified at a magnification of 3,000 ×. For each of the 170,000 pixels on the images which displayed a strong P concentration, neighborhoods from 0.1μm^2 to 12 μm^2 were examined for associated elemental concentrations. PCA （principal component analysis） revealed two significant neighborhood types associated with P in samples of pH 4, and three neighborhood types at pH 8. These neighborhoods corresponded to Mg-P associations commonly found to be chemically prevalent in river sediments impacted by agricultural operations. Discriminant analysis showed that the greatest accuracy in predicting sample pH could be achieved by using a neighborhood size of 12 ~m2. Potassium at relatively large neighborhood sizes was the element most significant in predicting pH. While many of the chemical associations in close proximity to P could be predicted and explained through mineral solubility, spatial analysis provided some interesting insights into the structure of the samples. Results also indicted differences in the spatial scale associated with different processes.
