Biomedical subjects

L G Bennett

Publications and source records attributed to L G Bennett.

21 records · Page 2Linked to original sources

PubMed1975

Effects of lead on the lipid composition of Micrococcus luteus cells.

Micrococcus luteus cells cultivated in medium containing lead salts exhibited a sequence of changes in the quantity of total cellular lipids with essentially no changes from normal cellular yields. The lipid composition of cells cultivated one to four times was moderately decreased (phase I) whereas that of cells cultivated five to six times was reduced by as much as 50% (phase II). Cells cultivated more than six times in lead-containing media had progressively greater quantities of lipid (phase III) approaching that found in control cells. These cells with reestablished lipid contents showed no further effects from more prolonged exposure to lead salts. Chromatographic studies of total lipids of cells of each lipid phase revealed relatively complete lipid compositions. These results indicated that lead is apparently affecting a common biochemical parameter in the biosynthesis of lipids of lipid phase II cells. Changes in the relative quantities of individual components were observed in both the nonpolar and polar lipids in each lipid phase. The most notable changes were the decrease in aliphatic hydrocarbons with concomitant increases in the diglycerides and components identified as a complex family of ketones. Microscopy examinations of control and lead-treated cells revealed electron dense inclusion bodies in membrane fragments in only lead-treated cells.

Autoradiography↗

PubMed1974

Characterization of the antigenic subunits of the envelope protein of Yersinia pestis.

Chemical, physical, and immunological properties of the envelope antigen of Yersinia pestis strains have been investigated. The antigen consists of two components with isoelectric points (pI) of 4.6 and 4.8. One component (pI 4.6) is a protein bound to a small carbohydrate moiety identified as an oligomeric galactan; the other component (pI 4.8) is a simple protein. These two components are antigenically identical. In buffered solution, the antigen exists as aggregates of molecular weights larger than 300,000. The aggregates dissociate into a variety of smaller molecular weight forms depending on the nature of the treatment for dissociation. Each aggregate can be further dissociated into a single antigenic subunit fraction containing protein and glycoprotein species with molecular weights in the range from 15,000 to 17,000. The subunits can be obtained by a dissociation treatment with 0.1% mercaptoethanol in 0.25% sodium dodecyl sulfate at 95 C for 5 min. The subunits will readily reaggregate into a variety of larger molecular weight forms on the removal of dodecyl sulfate.

Amino Acids↗

PubMedDate not supplied

A new microcomputer-controlled neutron activation and analysis system. Description and applications for the analysis of bioenvironmental specimens.

A microcomputer-controlled irradiation and measurement system and a microprocessor-controlled sample changer have been installed at the SLOWPOKE-2 Facility at the Royal Military College of Canada (RMC). These systems can provide the gamut of instrumental neutron activation analysis (INAA) techniques for the analyst. Custom software has been created for system control, data acquisition, and off-line spectral analysis using programs that incorporate Gaussian peak-fitting methods of analysis. The design and use of the equipment is discussed, and the performance is illustrated with results obtained from the analysis of marine sediment and biological reference materials.

Microcomputers↗