The antioxidative function of eicosapentaenoic acid in a marine bacterium, Shewanella marinintestina IK-1

When the eicosapentaenoic acid (EPA)-deficient mutant strain IK-1Delta8 of the marine EPA-producing Shewanella marinintestina IK-1 was treated with various concentrations of hydrogen peroxide (H(2)O(2)), its colony-forming ability decreased more than that of the wild type. Protein carbonylation, induced by treating cells with 0.01 mM H(2)O(2) under bacteriostatic conditions, was enhanced only in cells lacking EPA. The amount of cells recovered from the cultures was decreased more significantly by the presence of H(2)O(2) for cells lacking EPA than for those producing EPA. Treatment of the cells with 0.1 mM H(2)O(2) resulted in much lower intracellular concentrations of H(2)O(2) being consistently detected in cells with EPA than in those without EPA. These results suggest that cellular EPA can directly protect cells against oxidative damage by shielding the entry of exogenously added H(2)O(2) in S. marinintestina IK-1.     

Effects of worn-out soles on lower limb stability, shock absorption and energy cost during prolonged walking

This study investigated the effects of worn-out shoes on lower leg stability, shock absorption and energy cost during prolonged walking. Seven male subjects (23.4 +/- 0.5 yr) walked at 4.8 km/h for 60 minutes wearing three different pairs of shoes: two of these pairs had severely and moderately worn soles (EASC: Excessive Attrite Shoe Condition and MASC: Moderate Attrite Shoe Condition, respectively) and the other pair had no wear (NASC: No Attrite Shoe Condition). Impact acceleration at the subtalar at heel strike, rearfoot angles (the subtalar joint and the lower leg) during stance phase, and oxygen uptake (VO2) were measured throughout the 60-minute walk. At the 10th minute of walking, worn-out shoes increased the supination of the subtalar joint and extortion of the lower leg. In addition, VO2 was significant larger in EASC (808.3 ml x min(-1)) than in NASC (749.5 ml x min(-1)). During the 60-minute walk, however, there were no time effects of shoe condition on the rearfoot angles and on VO2. In contrast, impact acceleration at the subtalar joint in EASC remained almost constant until the 30th minute of walking, and then began to elevate. In conclusion, worn-out shoes increased the energy cost and reduced lower leg stability during walking, although these changes were not influenced by walking duration within 60 minutes. However, prolonged walking showed the potential negative effect of worn-out shoe on shock absorption.     

Exercise effect on weight and body fat in men and women

Objectives: The effect of national exercise recommendations on adiposity is unknown and may differ by sex. We examined long‐term effects of aerobic exercise on adiposity in women and men. Research Methods and Procedures: This was a 12‐month randomized, controlled clinical trial testing exercise effect on weight and body composition in men (N = 102) and women (N = 100). Sedentary/unfit persons, 40 to 75 years old, were recruited through physician practices and media. The intervention was facility‐ and home‐based moderate‐to‐vigorous intensity aerobic activity, 60 min/d, 6 days/wk vs. controls (no intervention). Results: Exercisers exercised a mean 370 min/wk (men) and 295 min/wk (women), and seven dropped the intervention. Exercisers lost weight (women, ?1.4 vs. +0.7 kg in controls, p = 0.008; men, ?1.8 vs. ?0.1 kg in controls, p = 0.03), BMI (women, ?0.6 vs. +0.3 kg/m² in controls, p = 0.006; men, ?0.5 kg/m² vs. no change in controls, p = 0.03), waist circumference (women, ?1.4 vs. +2.2 cm in controls, p < 0.001; men, ?3.3 vs. ?0.4 cm in controls, p = 0.003), and total fat mass (women, ?1.9 vs. +0.2 kg in controls, p = 0.001; men, ?3.0 vs. +0.2 kg in controls, p < 0.001). Exercisers with greater increases in pedometer‐measured steps per day had greater decreases in weight, BMI, body fat, and intra‐abdominal fat (all p trend < 0.05 in both men and women). Similar trends were observed for increased minutes per day of exercise and for increases in maximal oxygen consumption. Discussion: These data support the U.S. Department of Agriculture and Institute of Medicine guidelines of 60 min/d of moderate‐to‐vigorous physical activity.     

HIV/AIDS in Asia: The shape of epidemics and their molecular epidemiology

The Asia-Pacific region is a home to 60% of the population in the world and to approximately one quarter of people with HIV/AIDS. Close to a million of people has been infected and a half million people died of AIDS annually in Asia, becoming the second largest epicenter of global AIDS epidemic. Molecular epidemiology has been useful tool to track a course of HIV spread. In-depth knowledge from the studies on molecular epidemiology elucidates the dynamics of HIV spread and the interrelationship of epidemics in the different regions in Asia. Foundation items: Grant support from Ministry of Health, Labour and Welfare and Ministry of Education, Science and Technology in Japan; Japanese Foundation for AIDS Prevention.     

Backbone 1H, 13C and 15N assignments of a 59 kDa Salmonella typhimurium periplasmic oligopeptide binding protein, OppA

Salmonella typhimurium OppA is the periplasmic oligopeptide-binding protein. Backbone resonances of OppA(D419N) on its own were assigned for ∼90% of residues. Missing residues are localised around the ligand-binding site, suggesting conformational flexibility in the unliganded state.     

Population dynamics of the harmful diatom Eucampia zodiacus Ehrenberg causing bleachings of Porphyra thalli in aquaculture in Harima-Nada, the Seto Inland Sea, Japan

The diatom Eucampia zodiacus Ehrenberg is one of the harmful diatom species which indirectly cause bleachings of Nori (Porphyra thalli) in aquaculture through competitive utilizing of nutrients (especially nitrogen) and resultant nutrient depletion in water columns during the bloom events. The seasonal changes in environmental factors, cell density and cell size of E. zodiacus were investigated for 4 years (April 2002–December 2005) to understand the population ecology of this diatom in Harima-Nada, the eastern part of the Seto Inland Sea, Japan. Vegetative cells of E. zodiacus were usually detected year-round. Total cell densities of E. zodiacus annually peaked from mid-February to early April, and high cell densities were observed in the whole water columns during the bloom-period. Nutrient concentrations decreased with the increase of cell density of E. zodiacus, and low nutrients concentrations continued throughout the E. zodiacus bloom-period. The average cell size (length of apical axis) of E. zodiacus populations ranged from 10.8 μm to 81.2 μm, and the restoration of cell size occurred once in autumn every year just after reaching the minimum cell size. In addition, its great seasonal regularity was confirmed by the decrease and restoration of its cell size through 4-year study period. Temperature and nutrients were suitable in autumn for the growth of E. zodiacus, its blooms never occur in that season. These results strongly suggest that E. zodiacus did not have a resting stage, and it spends autumn for size restoration and starts to bloom thereafter in Harima-Nada in winter and spring, causing fishery damage to Nori aquaculture by resulting nutrient deprivation.     

Purification,Characterization and Cloning of a Chymotrypsin Inhibitor (CI-9) from the Hemolymph of the Silkworm, <Emphasis Type="Italic">Bombyx mori</Emphasis>

Hemolymph chymotrypsin inhibitor 9 (CI-9) from the hemolymph of the silkworm, Bombyx mori, was purified by ammonium sulfate precipitation, Butyl Toyopearl hydrophobic chromatography, gel filtration through Sephadex C-50 and chymotrypsin-sepharose 4B affinity chromatography. Checked by Native PAGE and SDS-PAGE in combination with silver staining, the final preparation appeared homogeneous. In tricine SDS-PAGE, CI-9 displayed a molecular weight of 7.5 kD, which was determined to be 7167 Da with the Voyager TOFMass analyser. The pI value for CI-9, revealed by 2D-PAGE (two-dimensional polyacrylamide gel electrophoresis), was 4.3. CI-9 exhibited inhibitory activity at a temperature as high as 100°C and a stability against a wide range of pH (1–12). In N-terminal amino-acid analysis of CI-9, 40 amino acid residues were obtained. The C-terminal 22 amino acid residues were deduced by subsequently cloned cDNA and genomic fragments. MW and pI of CI-9 were predicted to be 7170.98 Da and 4.61, respectively, on the website. Its low molecular weight, high stability, conserved active site and Kunitz domain showed that CI-9 is a Kunitz-type CI. The difference of sequence and pI between CI-9 and other Kunitz type CIs indicated that it is a novel chymotrypsin inhibitor.     

The genetic structure of endangered indigenous populations of the amago salmon, <Emphasis Type="Italic">Oncorhynchus</Emphasis><Emphasis Type="Italic">masou</Emphasis><Emphasis Type="Italic">ishikawae</Emphasis>, in Japan

The amago salmon, Oncorhynchus masou ishikawae, is an endemic subspecies of O. masou in Japan. Owing to the extensive stocking of hatchery fish throughout Japan, indigenous populations of O. m. ishikawae are now on the verge of extinction. We examined the genetic effects of stocking hatchery fish on wild populations in the River Koza, Japan, using microsatellite and mitochondrial DNA (mtDNA) markers. For mtDNA, haplotype mt1, which is common in wild populations, was present exclusively in isolated wild populations assumed to be unaffected by previous stocking, while it was never observed in hatchery fish. Genetic diversity was much higher in wild populations in the stocked area, which shared many mtDNA haplotypes with hatchery fish, than in isolated wild populations with haplotype mt1. Pairwise F _ST estimates based on microsatellites showed significant differentiation among the isolated populations with many microsatellite loci monomorphic. Significant deviation from Hardy–Weinberg equilibrium was observed in wild populations in the area subject to stocking, where a Bayesian-based assignment test showed a high level of introgression with hatchery fish. These results suggest that wild populations with haplotype mt1, which became isolated through anthropogenic environmental change in the 1950–1960s, represent indigenous populations of O. m. ishikawae in the River Koza. They have low genetic diversity, most likely caused by genetic bottlenecks following damming and environmental deterioration, while stocking of hatchery fish over the past 30 years apparently had a large impact on the genetic structure of wild populations in the main channel of the River Koza.     

AMPK mediates autophagy during myocardial ischemia in vivo

We have recently shown that autophagy is induced by ischemia and reperfusion in the mouse heart in vivo. Ischemia stimulates autophagy through an AMP activated protein kinase (AMPK)-dependent mechanism, whereas reperfusion after ischemia stimulates autophagy through a Beclin 1-dependent, but AMPK-independent, mechanism. Autophagy plays distinct roles during ischemia and reperfusion: autophagy may be protective during ischemia, whereas it may be detrimental during reperfusion. We will discuss the role of AMPK in mediating autophagy during myocardial ischemia in vivo.