NAPL migration and ecotoxicity of conventional and renewable fuels in accidental spill scenarios.

Fuels derived from non-petroleum renewable resources have raised interest due to their potential in replacing petroleum-based fuels, but information on their fate and effects in the terrestrial and aquatic environments in accidental spill scenario is limited. In this study, migration of four fuels (conventional diesel, conventional gasoline, renewable diesel NExBTL, and ethanol-blended gasoline RE85 containing maximum 85% ethanol) as non-aqueous phase liquids (NAPL) in soil was demonstrated in a laboratory-scale experiment. Ecotoxicity data was produced for the same fuels. There was no significant difference in migration of conventional and renewable diesel, but gasoline migrated 1.5 times deeper and 7-9 times faster in sand than diesel. RE85 spread horizontally wider but not as deep (p < 0.05) as conventional gasoline. Conventional gasoline was the most toxic (lethal concentration [LC50] 20 mg/kg total hydrocarbon content [THC]) among the studied fuels in soil toxicity test with earthworm Eisenia fetida followed by ethanol-blended gasoline (LC50 1,643 mg/kg THC) and conventional diesel (LC50 2,432 mg/kg THC), although gasoline evaporated fast from soil. For comparison, the toxicity of the water-accommodated fractions (WAF) of the fuels was tested with water flea Daphnia magna and Vibrio fischeri, also demonstrating groundwater toxicity. The WAF of conventional gasoline and RE85 showed almost similar toxicity to both the aquatic test species. EC50 values of 1:10 (by volume) WAF were 9.9 %WAF (gasoline) and 9.3 %WAF (RE85) to D. magna and 9.3 %WAF (gasoline) and 12.3 %WAF (RE85) to V. fischeri. Low solubility decreased toxicity potential of conventional diesel in aquatic environment, but direct physical effects of oil phase pose a threat to organisms in nature. Renewable diesel NExBTL did not show clear toxicity to any test species.

The association of myeloperoxidase promoter polymorphism with carotid atherosclerosis is abolished in patients with type 2 diabetes.

OBJECTIVES: Type 2 diabetes mellitus (DM) enhances the development of atherosclerosis and reduces the activity of the oxidative myeloperoxidase (MPO) enzyme. MPO gene has a functional promoter polymorphism -463G/A which leads to high- (GG) and low-expression (AG, AA) genotypes. DESIGN AND METHODS: We studied the association of MPO polymorphism with carotid artery intima-media thickness (IMT) in 198 randomly selected Finnish men of Caucasian origin, 161 non-diabetics and 37 with type 2 DM. Their carotid IMT was measured by high-resolution ultrasonography, and the overall mean IMT value was calculated. MPO genotypes were determined by the PCR-RFLP method. RESULTS: We found significant MPO genotype-by-study-group (control/DM) interactions with the overall mean IMT and internal carotid IMT (p=0.05 and p=0.04, respectively). Among non-diabetic subjects, the overall carotid IMT was 7.3% higher in subjects with the low-activity genotype when compared to the high-activity (G/G) group. The results remained significant after adjustment for total cholesterol and smoking (p=0.015). No similar genotypic association was found for the subjects with type 2 DM. CONCLUSIONS: This data suggests that in subjects with normal glucose metabolism, MPO gene variation may modify the carotid artery IMT.

Bilateral hemodynamic responses to auditory stimulation in newborn infants.

We studied hemodynamic auditory evoked responses of 20 healthy full-term neonates with near-infrared spectroscopy. The instrument used allows the measurements to be performed simultaneously above both auditory cortices. The stimulation consisted of 5-s trains of sound (700-ms interstimulus interval) with a 25-s silent interval. In response to the stimulation, a significant increase in concentration of oxygenated hemoglobin was detected in 14 out of 21 measurements. The mean latency of the largest response was 9.63+/-2.20 s (mean+/-SD) and the mean amplitude was 1.02+/-0.53 microM. The response amplitude was significantly larger in active (1.28+/-0.59 microM) than in quiet sleep (0.76+/-0.32 microM). The latency of the oxygenated hemoglobin concentration response was significantly shorter (r=-0.70 and p=0.0023) for infants with higher gestational age.

Myeloperoxidase gene variation and coronary flow reserve in young healthy men.

Chronic inflammation may lead to endothelial dysfunction, which manifests as an impaired coronary reactivity. Impairment in coronary flow reserve (CFR), preceding the clinical symptoms of coronary artery disease, can be measured noninvasively by positron emission tomography. Myeloperoxidase (MPO) is an oxidative enzyme present in phagocytes and atherosclerotic lesions. The MPO gene has a promoter polymorphism (-463G/A) which affects gene transcription. Whether these variants associate with coronary artery function is not known. Myocardial blood flow at rest and during adenosine-induced hyperemia was assessed in 49 healthy young men with normal or slightly elevated serum total cholesterol. These subjects were divided into high (G/G) and low (A/G, A/A) MPO expression groups and effect of MPO genotype on myocardial blood flow was evaluated. We found a significant difference between MPO genotypes in CFR after adjusting for age, body mass index, smoking and family history of cardiovascular disease (p = 0.019). Men with G/G genotype had 18.1% lower CFR than subjects with low-expression genotypes (A/G and A/A). This was due to an 11.5% lower adenosine-stimulated flow of the G/G genotype carriers (p = 0.049). These findings provide evidence that MPO polymorphism is associated with coronary artery reactivity. However, the number of individuals investigated was low and our observation should be confirmed by a larger number of subjects.

Effect of long-term hormone replacement therapy on atherosclerosis progression in postmenopausal women relates to myeloperoxidase promoter polymorphism.

Myeloperoxidase (MPO) is an oxidative enzyme present in phagocytes and atherosclerotic lesions. The MPO gene has a promoter polymorphism -463G/A, which leads to high (GG) and low expression (AG, AA) genotypes. We investigated the effect of long-term hormone replacement therapy (HRT) on the progression of atherosclerosis in a 5-yr follow-up study of postmenopausal women with different MPO genotypes. Eighty-seven nonsmoking postmenopausal women, aged 45-71 yr, were divided into three groups based on the use of HRT. The HRT-EVP group (n = 25) used sequential estradiol valerate plus progestin, the HRT-EV group used estradiol valerate alone (n = 32), and the control group (n = 30) used no HRT. The atherosclerosis severity score (ASC) for abdominal aorta and carotid arteries was determined by ultrasonography, and the MPO genotype was analyzed. In subjects with the GG genotype, the progression of ASC was significantly faster in the control group than in the HRT group (genotype by time interaction, P = 0.042), whereas in A allele carriers there were no significant differences in ASC progression between control and HRT. The effects of HRT on atherosclerosis progression in subjects with the GG genotype seem to be especially beneficial compared with controls with the same genotype but without HRT. These results may help us understand in greater detail the benefit and possible risk of HRT in atherosclerotic diseases.

Myeloperoxidase gene variation as a determinant of atherosclerosis progression in the abdominal and thoracic aorta: an autopsy study.

Myeloperoxidase (MPO) is an enzyme that transforms low-density lipoprotein into atherogenic particles. The MPO gene has a promoter polymorphism at position -463, which affects gene transcription and leads to high- (G/G) and low-expression (A/A, A/G) genotypes. To determine if these genotypes are associated with the severity of atherosclerosis, we performed an autopsy study of 300 men aged 33 to 69 years (Helsinki Sudden Death Study). We examined the percentage area of fatty streaks and fibrotic, calcified, and complicated lesions using computer-assisted planimetry. The MPO genotypes were determined by PCR. There were significant interactions of MPO genotype with the mean area of fibrotic (p < 0.01) and calcified (p < 0.05) lesions in the abdominal aorta and in fibrotic lesions in the thoracic aorta (p = 0.003). In the abdominal aorta, men < 53 years with low-expression genotypes had on average a 38.6% larger area of fibrotic lesions and a 43.8% larger area of calcified lesions than did the subjects with the G/G genotype. This association weakened with advancing age. Among men < 53 years, the MPO genotype was an independent predictor of fibrotic (p = 0.037) and calcified (p = 0.001) lesion area in the abdominal aorta after adjustment for age, body mass index, diabetes, hypertension, and smoking. MPO gene variation may modify the extent of advanced atherosclerotic lesions in the human aorta in early middle age.

Ethanol: Novel Actions on Nerve Cell Physiology Explain Impaired Functions.

Molecular biological tools have revealed receptor proteins for excitatory and inhibitory neurotransmitters on cell membranes as targets of ethanol action. Behavioral and pharmacogenetic assays using rodent lines have supported this neurotransmitter theory of ethanol action and given a firm basis for future identification of the relevant genes and the central physiological processes vulnerable to ethanol.