1.Studies on the inheritance of repellent tolerances in Aedes aegypti.
Rutledge LC1, Gupta RK, Piper GN, Lowe CA. J Am Mosq Control Assoc. 1994 Mar;10(1):93-100.
Two laboratory strains and 6 inbred strains of Aedes aegypti were tested against deet, ethyl hexanediol, dimethyl phthalate, and Indalone. Reciprocal crosses and backcrosses of 2 inbred strains were tested against deet only. Results obtained were compatible with a quantitative genetic model in which the effects of the factors involved were multiplicative. Certain inbred strains differed significantly from cognate laboratory and/or inbred strains in tolerance to one or more test materials. Heritability in the broad sense (H2) was estimated at 0.05 for deet, 0.22 for ethyl hexanediol, 0.48 for dimethyl phthalate, and 0.51 for Indalone. Partial dominance was observed in the inheritance of tolerance to deet.
2.Pharmacokinetics of 2-ethyl-1,3-hexanediol. II. Nonsystemic disposition following single percutaneous or peroral doses in Fischer 344 rats.
Frantz SW1, Beskitt JL, Grosse CM, Tallant MJ, Ballantyne B. Drug Metab Dispos. 1992 Jan-Feb;20(1):6-18.
The pharmacokinetics of [1,3-14C]-2-ethyl-1,3-hexanediol (EHD) were investigated following single percutaneous doses of 150 mg/kg, applied to male and female Fischer 344 rats, or single peroral doses of 1.5 or 150 mg EHD/kg given by gavage to male Fischer 344 rats. EHD-derived radioactivity was slowly absorbed through skin and relatively rapidly excreted through the urine in a first-order manner over 48 hr postdosing. Skin penetration of 14C was sufficiently slow that the terminal rate constant for the plasma concentration data had to be derived from the absorption phase of this curve, based on the terminal rate constant for a comparable intravenous dose plasma curve [Frantz et al.: Drug Metab. Dispos. 19, 881 (1991)]. Plasma data from perorally doses rats exhibited dose-linearity over a 1.5-150 mg/kg range, with plasma 14C concentration vs. time plots for oral doses of EHD resembling the iv time-course data. This resulted from a very rapid absorption phase (5.
3.Pharmacokinetics of 2-ethyl-1,3-hexanediol. III. In vitro skin penetration comparisons using the excised skin of humans, rats, and rabbits.
Frantz SW1, Ballantyne B, Beskitt JL, Tallant MJ, Greco RJ. Fundam Appl Toxicol. 1995 Nov;28(1):1-8.
Excised skin from Fischer 344 rats, New Zealand White rabbits, and human females (obtained from mammoplasty patients) were compared for their in vitro skin penetration potential with 2-[14C]-ethyl-1,3-hexanediol (EHD). EHD was applied as both an undiluted dose and a 3% v/v aqueous dose using a flowthrough skin penetration chamber design and was analyzed over 0-6 hr. The undiluted dose was equivalent to a 150 mg/kg dose used in vivo with rats (Frantz et al., Drug Metab. Dispos. 20(1), 6-18, 1992), but normalized on a per cm2 surface area basis, and applied under occluded conditions (covered as for in vivo studies). Undiluted applications of EHD did not substantially penetrate skin, with effluent recoveries of approximately 0.9% of the applied dose for human skin, 2-4% for rat skin, and 3-6% for rabbit skin. By comparison, nonoccluded human skin showed lower effluent radioactivity (0.6%), which was attributed to EHD evaporation from skin. With undiluted EHD, approximately 97% of the recovered 14C was an unabsorbed dose for human skin, with 94% for rat skin and 85% for rabbit skin (expressed as a percentage of the recovered dose).
4.Regioselective enzymatic diol esterification in batch and fixed-Bed adsorptive reactors: experiments and modeling.
Migliorini C1, Meissner JP, Mazzotti M, Carta G. Biotechnol Prog. 2000 Jul-Aug;16(4):600-9.
The dynamic behavior of batch and fixed-bed adsorptive reactors is studied for the enzyme-catalyzed regioselective esterification of propionic acid and 2-ethyl-1,3-hexanediol in hexane. The reaction is equilibrium-limited with an apparent equilibrium constant of 0.6 +/- 0.1 at 22 degrees C. Moreover, accumulation of water produced in the reaction onto the biocatalyst causes a decrease in the catalytic activity. As a result, improvements in both reaction rate and final conversion can be achieved by operating in an adsorptive-reactor mode. Control of water in the reactor is achieved with a catalytically inert ion-exchange resin in Na-form. The resin prevents an excessive accumulation of water on the biocatalyst and reduces equilibrium limitations. The thermodynamic activity of water is identified as a key parameter for the design of such reactors. A mathematical model capable of predicting the water activity as a function of the varying concentrations of reactants and products is thus developed and found to successfully predict the experimental behavior observed in laboratory reactors.