Antiarrhythmic and electrophysiological effects of long-chain ω-3 polyunsaturated fatty acids

Abstract  Recent studies indicate that a diet enriched in -3 polyunsaturated fatty acids may prevent sudden cardiac death. The goal of the present study was to elucidate how -3 polyunsaturated fatty acids such as docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and -linolenic acid (ALA; 1–20 M) may affect the cardiac activation and repolarization pattern. For this reason, DHA, EPA or ALA was infused in spontaneously beating isolated rabbit heart (Langendorff technique) and subjected to 256 electrodes epicardial mapping. All compounds exhibited a negative inotropic and chronotropic effect. EPA and ALA, but not DHA, prolonged QTc. The dispersion was enhanced at higher concentrations (>5 M) by DHA and less (or not affected) by the others. The total activation time, reflecting ventricular conduction, was prolonged predominantly by DHA and to a lower extent by the other drugs. Atrioventricular conduction time was slowed only by DHA and EPA. To analyze of the pattern of activation, we determined the timepoint of activation as t(dU/dtmin) for all 256 electrodes. The beat-to-beat similarity of these patterns was moderately reduced by all drugs. Regarding antiarrhythmic activity we found that the threshold for elicitation of a ventricular extrasystole was concentration-dependently enhanced by DHA and EPA, but not by ALA. DHA dose-dependently reduced longitudinal propagation velocity VL and to a lower extent transverse velocity VT. Anisotropy was not significantly changed. EPA and ALA did not exhibit a systematic effect on VL or VT. These results clearly demonstrate that DHA, EPA, and ALA exhibit direct electrophysiological effects with different profiles.

Anthropometry, carbohydrate and lipid metabolism in the East Flanders Prospective Twin Survey: heritabilities

Abstract Aims/hypothesis  We determined the genetic contribution of 18 anthropometric and metabolic risk factors of type 2 diabetes using a young healthy twin population.

Anthropometric features and body composition of young athletes practicing karate at a high and medium competitive level

Abstract.   The aim of the study was to examine the anthropometricfeatures and body composition of athletes practising karate at ahigh and medium competitive level. Our study was carried out ona sample of 35 subjects practising karate and aged from 16.0 to32.5 years. This sample was divided into two groups: group 1(n=14 elite athletes) andgroup 2 (n=21 amateurathletes). Various anthropometric measurements were taken(weight, height both standing and sitting, diameters,circumferences and skinfold thickness) from which differentanthropometric indices were calculated (body mass index, Scelicand Grant indices, arm muscle circumference and area), and thesomatotype was then determined. The body composition of eachsubject was assessed using the skinfold technique and theJackson-Pollock (J-P) and Sloan-Weir (S-W) equations. The twogroups of athletes showed very similar measurements regardinganthropometric characteristics. Only the Scelix index presenteda significantly different value in the two groups (49.6±1.3 forgroup 1 vs. 51.1±1.3 for group 2; p<0.01). Group 1 showed amesomorphic-ectomorphic somatotype, while the amateur athletespresented a balanced mesomorphic type. Moreover, a lowerpercentage of fat mass was more frequent in the first group(J-P=8.1±2.4%; S-W=8.9±3.3%) than in the second one(J-P=9.8±1.6%; S-W=11.2±3.7%), although the differences betweenthe two groups were not significant. We conclude that group 1 ischaracterized by a slightly prominent vertical development ofthe skeletal frame. This could be an anthropometriccharacteristic that is best suited to meet the specificfunctional requirements of this sport. Moreover, both groups ofathletes are characterized by a low percentage of fat mass,particularly the elite group.

Antagonizing potencies of saturated and unsaturated long-chain free fatty acids to isoflurane in goldfish

Purpose  We have previously reported that myristate, a saturated free fatty acid (FFA) with 14 carbons (C14), antagonizes volatile anesthetics in goldfish. The hydrophobicity and molecular configuration of FFAs may play an important role in the antagonizing effect. To examine their contribution, we investigated the antagonizing potencies of saturated and unsaturated long-chain FFAs in goldfish.Methods  Saturated and monounsaturated FFAs of C14–18 were tested. We determined the anesthetic concentration producing a 50% effect (EC50) of isoflurane in the absence or presence of FFA by observing the escape reaction of goldfish against an electrical stimulus.

Antagonism of croton oil inflammation by topical emu oil in CD-1 mice

Abstract  Emu oil is derived from the emu (Dromaius novaehollandiae), which originated in Australia, and has been reported to have anti-inflammatory properties. Inflammation was induced in anesthetized CD-1 mice by applying 50 μL of 2% croton oil to the inner surface of the left ear. After 2 h, the area was treated with 5μL of emu, fish, flaxseed, olive, or liquified chicken fat, or left untreated. Animals were euthanized at 6 h postapplication of different oils, and earplugs (FP) and plasma samples were collected. Inflammation was evaluated by change in earlobe thickness, increase in weight of EP tissue (compared to the untreated ear), and induction in cytokines interleukin (IL)-1α and tumor necrosis factor-α (TNF-α) in EP homogenates. Al-though reductions relative to control (croton oil) were noted for all treatments, auricular thickness and EP weights were, significantly reduced (−72 and −71%, respectively) only in the emu oil-treated group. IL-1α levels in homogenates of auricular tissue were significantly reduced in the fish oil (−57%) and emu oil (−70%) groups relative to the control group. The cytokine TNF-α from auricular homogenates was significantly reduced in the olive oil (−52%) and emu oil (−60%) treatment groups relative to the control group. Plasma cytokine levels were not changed by croton oil treatment. Although auricular thickness and weight were significantly correlated with each other (r=0.750, P<0.003), auricular thickness but not weight was significantly correlated with cytokine IL-1α (r=0.750, P<0.006) and TNF-α (r=0.690, P<0.02). These studies indicate that topical emu oil has anti-inflammatory properties in the CD-1 mouse that are associated with decreased auricular thickness and weight, and with the cytokines IL-1α and TNF-α.

Ant benefits in a seed dispersal mutualism

Abstract  Myrmecochorous plant seeds have nutrient rich appendages, elaiosomes, which induce some ant species to carry the seeds back to their nest where the elaiosome is consumed and the seed is discarded unharmed. The benefits to plants of dispersal of their seeds in this way have been well documented, but the benefits to the ants from consuming the elaiosomes have rarely been measured and are less clear. Ant benefits from myrmecochory were investigated in a laboratory experiment using the ant Myrmica ruginodis and seeds of Ulex species. To separate the effects of elaiosome consumption on the development of newly produced larvae versus existing larvae, ten ‘Queenright’ colonies containing a queen were compared to ten ‘Queenless’ colonies. Six measures of colony fitness over a complete annual cycle were taken: sexual production, larval weight and number, pupal weight and number, and worker survival. Queenless colonies fed with elaiosomes produced 100.0±29.3 (mean ± SE) of larvae compared to non-elaiosome fed colonies which produced 49.6±19.0; an increase of 102%. Larval weight increased in both Queenright and Queenless colonies. In colonies fed with elaiosomes, larvae weighed 1.02±0.1 mg, but in non-elaiosome fed colonies larvae weighed 0.69±0.1 mg; an increase of 48%. The food supplement provided by Ulex elaiosomes was trivial in energetic terms, under the conditions of an ample diet, suggesting that these effects might be due to the presence of essential nutrients. Chemical analysis of Ulex elaiosomes showed the presence of four essential fatty acids and four essential sterols for ants.

Anoxybacillus rupiensis sp. Nov., a novel thermophilic bacterium isolated from Rupi basin (Bulgaria)

Abstract  Three strains of a novel thermophilic, strictly aerobic, Gram-positive, spore-forming hemo-organotrophic bacterium were isolated from three hot springs in the region of Rupi basin, Bulgaria as producers of amylolytic enzymes. Their 16S rRNA gene sequences (first 500 nucleotides) were very similar (99.8%). Strains were able to ferment a wide spectrum of carbohydrates such as sugars, polyols, and polysaccharides like xylan, glycogen and starch. Optimal growth was observed at 55–58°C, and pH at 6.0–6.5. Phylogenetic analysis of the whole 16S rRNA gene sequence clustered the strain R270T with the representatives of the genus Anoxybacillus and with Geobacillus tepidamans. The G + C content of the genomic DNA was 41.7%. DNA–DNA hybridization analysis revealed low homology with the closest relatives (32.0 mol% homology to Geobacillus tepidamans). Fatty acid profile (major fatty acids iso-C15:0 and iso-C17:0) confirmed the affiliation of the strain to the genus Anoxybacillus. On the basis of the data presented here, we propose that strain R270T, represents a new species of the genus Anoxybacillus for which, we recommend the name Anoxybacillus rupiensis sp. nov. (=DSM 17127T = NBIMCC 8387T). The 16S rRNA gene sequence data of a strain R270T have been deposited in the EMBL databases under the accession number AJ879076.