Isolation, Characterization, and Stability of Discretely-Sized Nanolipoprotein Particles Assembled with Apolipophorin-III

Background: Nanolipoprotein particles (NLPs) are discoidal, nanometer-sized particles comprised of self-assembled phospholipid membranes and apolipoproteins. NLPs assembled with human apolipoproteins have been used for myriad biotechnology applications, including membrane protein solubilization, drug delivery, and diagnostic imaging. To expand the repertoire of lipoproteins for these applications, insect apolipophorin-III (apoLp-III) was evaluated for the ability to form discretely-sized, homogeneous, and stable NLPs. Methodology: Four NLP populations distinct with regards to particle diameters (ranging in size from 10 nm to.25 nm) and lipid-to-apoLp-III ratios were readily isolated to high purity by size exclusion chromatography. Remodeling of the purified NLP species over time at 4uC was monitored by native gel electrophoresis, size exclusion chromatography, and atomic force microscopy. Purified 20 nm NLPs displayed no remodeling and remained stable for over 1 year. Purified NLPs with 10 nm and 15 nm diameters ultimately remodeled into 20 nm NLPs over a period of months. Intra-particle chemical cross-linking of apoLp-III stabilized NLPs of all sizes. Conclusions: ApoLp-III-based NLPs can be readily prepared, purified, characterized, and stabilized, suggesting their utilit

Choline glycerophospholipid biosynthesis in the guinea pig heart

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A sensitive method for the quantitation of lysophosphatidylcholine in canine heart

We have developed a procedure for the determination of small amounts of lysophosphatidylcholine in cardiac tissue. Lysophosphatidylcholine from canine heart was separated from the major phospholipid by column chromatography, and then acetylated with labeled acetic anhydride. The acetylated lysophosphatidylcholine was isolated by thin-layer chromatography and the lysophosphatidylcholine content was calculated from the radioactivity associated wth the acetylated product. Although the sensitivity of the assay depends on the specific radioactivity of the acetic anhydride used, as low as 0.5 nmol of lysophospholipid in tissue samples can be readily quantitated. The results obtained from the control and ischemic canine cardiac tissues by this assay compares favorably with those obtained by lipid-phosphorus assay. The sensitivity and specificity of the present procedure allows us and other investigators to assay for lysophosphatidylcholine content in very small (10 mg wet weight) tissue samples.link_to_subscribed_fulltex

Chamber studies on nonvented decorative fireplaces using liquid or gelled ethanol fuel

Decorative ethanol fireplaces are becoming more and more commonly used in many different countries. These fireplaces are constructed such that they have no fume extraction system, and so all of the gases from combustion, volatile organic compounds, and particulate emissions are released into the room. In order to determine the release behavior and the chemical composition of the emissions, a variety of combinations of ethanol fireplaces and fuels were examined in a 48 m3 emission test chamber under typical living room environmental conditions. Four ethanol fireplaces with 8 different fuels (3 liquid samples, 5 gel-type samples) were tested. The ventilation conditions were set up corresponding to the manufacturers' recommendations and DIN 4734-1. The air concentrations in the chamber were evaluated based on guideline values for indoor air. Of the combustion gases examined, the quantity of carbon dioxide and nitrogen dioxide in particular were close to or even above the guideline values in many cases. A release of components of the fuel (e.g., the denaturing substances) was also detected in the chamber air. In two experiments, a benzene concentration of over 12 ppb and an increased formaldehyde concentration (>0.1 ppm) were identified in the chamber air. The ethanol fireplaces were - irrespective of the type of fuel used - strong sources of fine and ultrafine particles. Overall, ethanol fireplaces have a considerable influence on the quality of the indoor air due to the lack of ventilation. This aspect should - in addition to fire protection - be properly considered when using such devices

The peritoneal cell carcinogenicity test Final report

SIGLETIB: D.Dt.F./AC 1000 (23,49) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman