Track A Basic Science

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138319/1/jia218438.pd

The Gas Chromatographic Separation of Some Chlorinated Hydrocarbon Insecticides from PCB and PCN Matrices

Typical chlorinated hydrocarbon insecticides (aldrin, dieldrin, mirex, etc.) were extracted from excessive matrices of polychlorinated biphenyls and naphthalenes (Aroclor 1242, Halowax 1013) by a gas chromatographic peak transfer technique. The sample was injected onto a nonpolar column and the appropriate fraction transferred by valve to a second, polar column, where in most cases, the insecticide separated cleanly from the PCB or PCN matrix. Typical chlorinated hydrocarbon insecticides (aldrin, dieldrin, mirex, etc. ) were extracted from excessive matrices of polychlorinated biphenyls and naphthalenes by a gas chromatographic peak transfer technique. The sample was injected onto a nonpolar column and the appropriate fraction transferred by valve to a second, polar column, where in most cases, the insecticide separated cleanly from the PCB or PCN matrix

A Gas Chromatograph with Plasma Reactor

A plasma reactor has been developed, which is inserted into a gas-chromatographic flow system so that any effluent emerging from the first column can be routed through the plasma and the resulting products separated in a second column. Plasma processing is based, typically, on a weak, β-stimulated argon discharge, and a variety of doping gases can be added to provide different chemical environments. The resulting product patterns are characteristic of the compounds processed and can serve analytical or physiochemical ends. © 1978 Springer Verlag

HIV is inactivated after transepithelial migration via adult oral epithelial cells but not fetal epithelial cells

AbstractOral transmission of human immunodeficiency virus (HIV) in adult populations is rare. However, HIV spread across fetal/neonatal oropharyngeal epithelia could be important in mother-to-child transmission. Analysis of HIV transmission across polarized adult and fetal oral epithelial cells revealed that HIV transmigrates through both adult and fetal cells. However, only virions that passed through the fetal cells – and not those that passed through the adult cells – remained infectious. Analysis of expression of anti-HIV innate proteins beta-defensins 2 and 3, and secretory leukocyte protease inhibitor in adult, fetal, and infant oral epithelia showed that their expression is predominantly in the adult oral epithelium. Retention of HIV infectivity after transmigration correlated inversely with the expression of these innate proteins. Inactivation of innate proteins in adult oral keratinocytes restored HIV infectivity. These data suggest that high-level innate protein expression may contribute to the resistance of the adult oral epithelium to HIV transmission