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K A Montgomery

Publications and source records attributed to K A Montgomery.

6 recordsLinked to original sources
PubMed1991

Effects of environmentally encountered epoxides on mouse liver epoxide-metabolizing enzymes.

Male mice were treated (i.p.) for 3 days with 15 different environmentally encountered epoxides, and the effects of these compounds on liver microsomal and cytosolic epoxide hydrolase (mEH and cEH), glutathione S-transferase (mGST and cGST) and carboxylesterase (mCE) activities were determined. The epoxides included the pesticides: heptachlor epoxide, dieldrin, tridiphane, and juvenoid R-20458; the natural products: disparlure, limonin, nomilin, and epoxymethyloleate; the endogenous steroids: lanosterol epoxide, cholesterol-alpha-epoxide, and progesterone epoxide; and the industrial or synthetic epoxides: epichlorohydrin, araldite, trans-stilbene oxide, and 4'-phenylchalcone oxide. The pesticide epoxides were the most effective inducers of liver weight, microsomal protein, and the enzyme activities measured, with mEH and cEH activities towards cis-stilbene oxide (mEHcso and cEHcso), cGST activities towards four of five substrates, and mCE towards clofibrate (mCEclof) and p-nitrophenylacetate (mCEpna) increased following treatment with most of the pesticides. The synthetic epoxides increased some of the same activities, while the natural products, except for increases in cGST activities, and endogenous steroid epoxides were generally not inductive. cEH activity towards trans-stilbene oxide (cEHtso) was increased only following treatment with the peroxisome proliferator, tridiphane, but decreased following treatment with several of the epoxides, while microsomal cholesterol epoxide hydrolase (mEHchol) was increased only moderately by disparlure. Microsomes could effectively conjugate glutathione to chlorodinitrobenzene (mGSTcdnb) and cis-stilbene oxide (mGSTcso). These two activities were differentially induced by a few of the epoxides, suggesting that they may be selective substrates for different isozymes of mGST. Correlation coefficients were determined for the relative response of liver weight, subfraction protein, and enzyme activities. A relatively high correlation was found between the response of liver weight and cytosolic hydrolysis of trans-stilbene oxide (r = 0.73) and cis-stilbene oxide (r = 0.62), and cytosolic glutathione conjugation of dichloronitrobenzene (r = 0.66) and trans-stilbene oxide (r = 0.75). In addition, relatively high correlations were found between the different cGST activities, in particular for dichloronitrobenzene with trans-stilbene oxide (r = 0.89). These studies show that there exists a wide variation in the response of xenobiotic-metabolizing enzymes to environmentally encountered epoxides and that a fairly strong correlation exists between the increases in liver size and increases in certain cytosolic enzyme activities; they also suggest further studies concerning the possibility of an additional isozyme of mGST.

Animals↗
PubMed1990

HMO databases: fertile ground for epidemiological research.

The computerized databases maintained by health maintenance organizations (HMOs) are a rich new source for health research. The authors describe the process by which health-related research became sanctioned at Lovelace Medical Center in Albuquerque, N.M., and its affiliated HMO. They review research conducted with several other HMO databases and suggest numerous possibilities for studying the incidence, distribution and control of disease using the vast data collected in managed care database systems.

Confidentiality↗
PubMed1976

Hyperamylasemia in heroin addicts. Characterization by isoamylase analysis.

Hyperamylasemia was noted in 17 (19%) of a group of 91 hospitalized heroin addicts. Thirteen of the 17 were in acute respiratory distress (12 with so-called "heroin lung" syndrome and one with status asthmaticus). Isoamylase analysis in the hyperamylasemic patients demonstrated S-type isoamylase dominance in 15, P-type isoamylase dominance in one and essentially equivalent P- and S-type isoamylase elevations in one. It would appear from these data that the hyperamylasemia after heroin in most persons addicted to the use of this drug arises from the sources other than the pancreas. Changes in the lungs occurring in association with heroin addiction seem to have an important role among the possible contributory factors.

Adolescent↗