Escherichia coli sepsis increases hepatic apolipoprotein B secretion by inhibiting degradation

Sepsis leads to hypertriglyceridemia in both humans and animals. Previously, we reported that plasma very low density lipoprotein apolipoprotein (apo) B and hepatic production of apoB increased during Escherichia coli sepsis. The present experiments were undertaken to determine whether the altered hepatic secretion of apoB was associated with an increase in synthesis or a decrease in degradation rate. Sepsis was induced in male, Lewis rats (225–275 g) by intravenous injection of 3.8×10⁸ live E. coli colonies/100 g body. Twenty-four hours later rats were sacrificed, and primary hepatocytes were prepared and incubated overnight with ³⁵S-methionine. Hepatocytes from E. coli-treated rats secreted twice as much apoB-48 and total apoB than the hepatocytes from control rats. Escherichia coli sepsis increased celular triglyceride mass by 86%, which was due to a stimulation in triglyceride synthesis from newly synthesized fatty acids, measured by ³H₂O incorporation into triglycerides. The apoB synthesis rate, apoB mRNA levels, and apoB mRNA editing were not altered during E. coli sepsis. The pulse-chase experiments showed that the rate of apoB degradation decreased in E. coli-treated rats. These findings demonstrate that the secretion of apoB is regulated posttranslationally during E. coli sepsis by decreasing the degradation of newly synthesized apoB, which contributes to the development of hypertriglyceridemia.     

Density measurement of small porous particles by mercury porosimetry

The concept of density of solid particles is discussed, and the relation between these concepts and the different measurement methods is considered with the emphasis on the porousness (i.e. the property of ‘porous’ or ‘non-porous’) of the solid particles.Mercury porosimetry was used to determine the density of porous small particles. The limitations of this method and the influence of surface roughness and other particle characteristics on the density values obtained are also discussed.     

Dilatant plastic deformation of granular materials

A geometrical interpretation is given to the modified associated flow rule derived in the previous paper[l]. According to it, the dilatancy must be regarded as an internal constraint of deformation. The modified associated flow rule then gives equations of plastic deformation which exhibits the specified dilatancy. Hardening and elastic strains can also be incorporated. It is shown that the deformation is non-coaxial in general.     

Macroscale and microscale analyses of nitrification and denitrification in biofilms attached on membrane aerated biofilm reactors

A membrane aerated biofilm reactor (MABR), in which O(2) was supplied from the bottom of the biofilm and NH(4)(+) and organic carbon were supplied from the biofilm surface, was operated at different organic carbon loading rates and intra-membrane air pressures to investigate the occurrence of simultaneous chemical oxygen demand (COD) removal, nitrification and denitrification. The spatial distribution of nitrification and denitrification zones in the biofilms was measured with microelectrodes for O(2), NH(4)(+), NO(2)(-), NO(3)(-) and pH. When the MABR was operated at approximately 1.0 g-COD/m(2)/day of COD loading rate, simultaneous COD removal, nitrification and denitrification could be achieved. The COD loading rates and the intra-membrane air pressures applied in this study had no effect on the start-up and the maximum rates of NH(4)(+) oxidation in the MABRs. Microelectrode measurements showed that O(2) was supplied from the bottom of the MABR biofilm and penetrated the whole biofilm. Because the biofilm thickness increased during the operations, an anoxic layer developed in the upper parts of the mature biofilms while an oxic layer was restricted to the deeper parts of the biofilms. The development of the anoxic zones in the biofilms coincided with increase in the denitrification rates. Nitrification occurred in the zones from membrane surface to a point of ca. 60microm. Denitrification mainly occurred just above the nitrification zones. The COD loading rates and the intra-membrane air pressures applied in this study had no effect on location of the nitrification and denitrification zones.     

Quantitative hydrogen analysis of zircaloy-4 in laser-induced breakdown spectroscopy with ambient helium gas

This experiment was carried out to address the need for overcoming the difficulties encountered in hydrogen analysis by means of plasma emission spectroscopy in atmospheric ambient gas. The result of this study on zircaloy-4 samples from a nuclear power plant demonstrates the possibility of attaining a very sharp emission line from impure hydrogen with a very low background and practical elimination of spectral contamination of hydrogen emission arising from surface water and water vapor in atmospheric ambient gas. This was achieved by employing ultrapure ambient helium gas as well as the proper defocusing of the laser irradiation and a large number of repeated precleaning laser shots at the same spot of the sample surface. Further adjustment of the gating time has led to significant reduction of spectral width and improvement of detection sensitivity to ~50 ppm. Finally, a linear calibration curve was also obtained for the zircaloy-4 samples with zero intercept. These results demonstrate the feasibility of this technique for practical in situ and quantitative analysis of hydrogen impurity in zircaloy-4 tubes used in a light water nuclear power plant.     

Accuracy assessment of a noninvasive device for monitoring beat-by-beat blood pressure in the radial artery using the volume-compensation method

For the noninvasive and accurate measurement of instantaneous blood pressure (BP) in the radial artery, the performance of a device based on the principle of volume-compensation was assessed by comparison with simultaneous measurement of direct (invasive) radial artery pressure in nine healthy subjects. Bias and precision of systolic BP (SBP) and diastolic BP (DBP) derived from Bland-Altman plots of data from the present system and the direct method averaged -0.5 +/- 2.1 mmHg and 0.6 +/- 1.8 mmHg respectively, over a wide range of SBP and DBP. These results clearly indicate that, using this system, instantaneous radial artery pressure can be measured noninvasively with high accuracy.