Examining spatial patterns in polycyclic aromatic compounds measured in stream macroinvertebrates near a small subarctic oil and gas operation.

The Cameron River runs through a small, remote petrochemical development in the Cameron Hills (Northwest Territories, Canada). In order to evaluate the exposure of aquatic biota to contaminants from oil and gas activities, we measured polycyclic aromatic compounds (PACs) in macroinvertebrates collected from sites and tributaries along the Cameron River, including upstream and downstream of the development, and sites located near drilled wells (developed). Macroinvertebrate tissue PAC burdens ranged from 0.2-2.8 µg g(-1) lipid for unsubstituted compounds, and from 4.2-63.2 µg g(-1) lipid for alkylated compounds, relatively low compared to similar studies from more industrialized regions in North America. There was no significant difference in tissue PAC burdens between upstream, downstream, or developed sites (p = 0.12), although alkyl PACs in five out of seven developed sites were higher than the regional average. Petrogenic PACs were dominant in most samples, including alkyl fluorines, alkyl phenanthrene/anthracenes, and alkyl dibenzothiophenes. Minimal changes in PAC composition in macroinvertebrate tissues were detected along the Cameron River, with the exception of the two sites furthest downstream that had high concentrations of C3-C4 naphthalene. Overall, our results suggest that oil and gas development in the Cameron Hills has not resulted in substantial increases in PAC bioaccumulation in stream macroinvertebrates, although the potential that alkyl naphthalenes are being transported downstream from the development warrants further attention.

Localized enrichment of polycyclic aromatic hydrocarbons in soil, spruce needles, and lake sediments linked to in-situ bitumen extraction near Cold Lake, Alberta.

The extraction of bitumen from the Alberta oil sands using in-situ technologies is expanding at a rapid rate; however, investigations into the environmental impacts of oil sands development have focused on surface mining in the Athabasca region. We measured polycyclic aromatic hydrocarbons (PAH) in soils, spruce needles, and lake sediment cores in the Cold Lake oil sands region to provide a historical and spatial perspective on PAH contamination related to in-situ extraction activities. A pronounced increase in PAH concentrations was recorded in one of two study lakes (Hilda Lake) corresponding to the onset of commercial bitumen production in ~1985. Distance from extraction rigs was not an important predictor of PAH concentrations in soils, although two samples located near installations were elevated in alkyl PAHs. Evidence of localized PAH contamination in Hilda Lake and two soil samples suggests that continued environmental monitoring is justified to assess PAH contamination as development intensifies.

Omeprazole and talampanel as two examples of retrometabolic drug design.

The goal of retrometabolic drug design is: "to design safe, locally active compounds with an improved therapeutic index". Here we describe two cases from our own practice, talampanel and omeprazole.

Effect of aging and diabetes on the enteroinsular axis.

BACKGROUND: The current studies were designed to examine the effect of aging and diabetes on the enteroinsular axis. METHODS: Healthy young control subjects (n = 10 young; age 23 +/- 1 years; body mass index [BMI] 24 +/- 1 kg/m(2)), healthy elderly subjects (n = 10; age 80 +/- 2 years; BMI 26 +/- 1 kg/m(2)), and elderly patients with type 2 diabetes (n = 10; age 76 +/- 2 years; BMI 26 +/- 2 kg/m(2)) underwent a 3-hour oral glucose tolerance test (glucose dose 40 gm/m(2)). RESULTS: Insulin responses were not different between young controls and elderly patients with diabetes but were significantly lower in elderly patients with diabetes and young controls than in elderly controls (young control: 178 +/- 27 pM; elderly control: 355 +/- 57 pM; elderly diabetes: 177 +/- 30 pM; p <.05 elderly control vs young control and elderly diabetes). Total glucagon-like peptide 1 (GLP-1) responses were not significantly different between young and elderly controls and patients with diabetes (young control: 15 +/- 2 pM; old control: 8 +/- 2 pM; elderly diabetes: 12 +/- 3 pM; p = ns). Active GLP-1 responses were also not different between young and elderly controls and patients with diabetes (young control: 5 +/- 1 pM; old control: 6 +/- 1 pM; elderly diabetes: 7 +/- 1 pM; p = ns). However, the difference between total and active GLP levels was significantly greater in the young controls (young control: 10 +/- 2 pM; old control: 2 +/- 2 pM; elderly diabetes: 4 +/- 2 pM; p <.05, young vs elderly). Glucose-dependent insulinotropic polypeptide responses were not different between young and elderly controls and between elderly controls and patients with diabetes but were significantly higher in elderly patients with diabetes than in young controls (young control: 97 +/- 12 pM; elderly control: 121 +/- 16 pM; elderly diabetes: 173 +/- 27 pM; p <.05, young vs elderly diabetes). Glucagon responses were reduced in elderly controls but were similar in young controls and elderly patients with diabetes (young control: 15 +/- 1 pM; elderly control: 9 +/- 1 pM; elderly diabetes: 16 +/- 1 pM; p <.01 elderly control vs young control and elderly diabetes). Dipeptidyl peptidase IV levels were lower in both elderly controls and patients with diabetes when compared with young controls (young control: 0.17 +/- 0.01; elderly control: 0.15 +/- 0.01; elderly diabetes: 0.15 +/- 0.01 DeltaOD/20 minutes; p <.05, elderly vs young). CONCLUSIONS: We conclude that normal aging and diabetes are associated with multiple changes in the enteroinsular axis.

A new psychoactive 5H-2,3-benzodiazepine with a unique spectrum of activity.

The neuropharmacological effects of 1-(4-amino-phenyl)-4-methyl-7,8-dimethoxy-5H-2,3-benzodiazepine (GYKI 52 322) were investigated and compared with those of chlordiazepoxide and chlorpromazine. This novel 2,3-benzodiazepine displays neuroleptic activity in the apomorphine-climbing (ED50 = 1.15 mg/kg i.p.) and swim-induced grooming (ED50 = 6.9 mg/kg i.p.) tests in mice and it inhibits the conditioned avoidance response in rats (ED50 = 8.2 mg/kg i.p. and 9.8 mg/kg p.o.). However, it does not antagonize apomorphine-evoked vomiting in dogs; or stereotypy, hypermotility and turning in rats even at as high a dose as 50 mg/kg i.p. On the other hand it is active in the hole board test in mice (MED (minimal effective dose) = 0.5 mg/kg i.p.) and in the lick conflict assay in rats (MED = 5 mg/kg i.p.), indicating anxiolytic property. It shows antiaggressive effect in the fighting mice test (ED50 = 8.1 mg/kg p.o.) and the carbachol-rage procedure in cats (active at 10 mg/kg i.p.) According to the biochemical findings, this compound does not bind to the central dopamine receptors (IC50 greater than 10(-4) mol/l), but it shows affinity to the 5-HT1 receptors (IC50 = 7.1 x 10(-6) mol/l) and inhibits brain cAMP-phosphodiesterase (IC50 = 2.4 x 10(-5) mol/l). The substance causes no elevation of dopamine turnover and serum prolactin level suggesting fewer side effects. So the term "atypical neuroleptic agent" is proposed to characterize this molecule.

Neuropharmacology of a new psychotropic 2,3-benzodiazepine.

1-(3-Chlorophenyl)-4-methyl-7,8-dimethoxy-5H-2,3-benzodiazepine (GYKI 51189) is a new analogue of tofisopam. Due to the novel chemical structure this molecule displays a peculiar spectrum of pharmacological activity. In many respects tofisopam and its new analogue differ from the traditional 1,4-benzodiazepines, e.g. in that they possess selective anxiolytic action without muscle relaxant and anticonvulsive activity, as well as they do not show any affinity for the 1,4-benzodiazepine receptors. This new compound exerts more pronounced anxiolytic potency than tofisopam. In addition to its main action it possesses significant antidepressant activity. It attenuates psychomotor agitation and exerts significant antiaggressive effect by reducing both spontaneous and induced aggressiveness. Vegetative responses (rise in blood pressure and heart rate) induced by electric stimulation of the hypothalamus are also inhibited by this compound, while motor functions remain unaffected and no somnolence is induced. The new tofisopam analogue fails to exert any potentiating effect either on ethanol or on barbiturates. GYKI-51189 has a highly favourable therapeutic index and only few side effects. Neither tolerance nor dependence was observed during the chronic toxicological investigations.

Investigation of the metabolites of tofizopam in man and animals by gas-liquid chromatography-mass spectrometry.

The metabolites of tofizopam [Grandaxin; 1-(3,4-dimethoxyphenyl)-4-methyl-5-ethyl-7,8-dimethoxy-5H-2,3-benzodiazepine] have been studied in patients and animals. The major pathway of the metabolic transformation of tofizopam was found to be demethylation. The position in which demethylation takes place and the rate of this process in various species were determined. Gas-liquid chromatography-mass spectrometry-mass chromatography was used for the identification of the metabolites.