The Prx Q protein of Arabidopsis thaliana is a member of the luminal chloroplast proteome

Peroxiredoxins have been discovered in many organisms ranging from eubacteria to mammals, and their known biological functions include both oxidant defense and signal transduction. The genome of Arabidopsis thaliana encodes for ten individual peroxiredoxins, of which four are located in the chloroplast. The best-characterized member of the chloroplast peroxiredoxins is 2-Cys Prx that is associated with the stroma side of the thylakoid membrane and is considered to participate in antioxidant defense and protection of photosynthesis. This study addressed the chloroplast peroxiredoxin Prx Q and showed that its subcellular location is the lumen of the thylakoid membrane. To get insight in the biological function of the Prx Q protein of Arabidopsis, the protein levels of the Prx Q protein in thylakoid membranes were studied under different light conditions and oxidative stress. A T-DNA knockout mutant of Prx Q did not show any visible phenotype and had normal photosynthetic performance with a slightly increased oxygen evolving activity.     

Gastroprotective and blood pressure lowering effects of dietary nitrate are abolished by an antiseptic mouthwash

Recently, it has been suggested that the supposedly inert nitrite anion is reduced in vivo to form bioactive nitric oxide with physiological and therapeutic implications in the gastrointestinal and cardiovascular systems. Intake of nitrate-rich food such as vegetables results in increased levels of circulating nitrite in a process suggested to involve nitrate-reducing bacteria in the oral cavity. Here we investigated the importance of the oral microflora and dietary nitrate in regulation of gastric mucosal defense and blood pressure. Rats were treated twice daily with a commercial antiseptic mouthwash while they were given nitrate-supplemented drinking water. The mouthwash greatly reduced the number of nitrate-reducing oral bacteria and as a consequence, nitrate-induced increases in gastric NO and circulating nitrite levels were markedly reduced. With the mouthwash the observed nitrate-induced increase in gastric mucus thickness was attenuated and the gastroprotective effect against an ulcerogenic compound was lost. Furthermore, the decrease in systemic blood pressure seen during nitrate supplementation was now absent. These results suggest that oral symbiotic bacteria modulate gastrointestinal and cardiovascular function via bioactivation of salivary nitrate. Excessive use of antiseptic mouthwashes may attenuate the bioactivity of dietary nitrate.     

Effects of the swimbladder parasite Anguillicola crassus on the migration of European silver eels Anguilla anguilla in the Baltic Sea

In a mark–recapture study in 2006, migrating European Anguilla anguilla silver eels were caught, tagged and released in the Baltic Sea and recaptures in commercial pound nets examined for possible effects on migration of infection with the swimbladder parasite Anguillicola crassus . The overall recapture rate was 36%. The prevalence of infection was lowest at the northernmost sampling site. There were no significant differences between infected and uninfected A. anguilla in condition indices, body fat content and estimated migration speeds. Parasite infection intensity levels were significantly negatively correlated with times and distances covered between release and recapture, but did not correlate with migration speed. It appears that more heavily infected A. anguilla were relatively more vulnerable to recapture in pound nets. It is hypothesized that parasite-induced damage to the swimbladder inhibited vertical migrations and infected A. anguilla tended to migrate in shallower coastal waters, relatively close to the shore.     

Secreted Protein Acidic and Rich in Cysteine (SPARC) in Human Skeletal Muscle

Secreted protein acidic and rich in cysteine (SPARC)/osteonectin is expressed in different tissues during remodeling and repair, suggesting a function in regeneration. Several gene expression studies indicated that SPARC was expressed in response to muscle damage. Studies on myoblasts further indicated a function of SPARC in skeletal muscle. We therefore found it of interest to study SPARC expression in human skeletal muscle during development and in biopsies from Duchenne and Becker muscular dystrophy and congenital muscular dystrophy, congenital myopathy, inclusion body myositis, and polymyositis patients to analyze SPARC expression in a selected range of inherited and idiopathic muscle wasting diseases. SPARC-positive cells were observed both in fetal and neonatal muscle, and in addition, fetal myofibers were observed to express SPARC at the age of 15–16 weeks. SPARC protein was detected in the majority of analyzed muscle biopsies (23 of 24), mainly in mononuclear cells of which few were pax7 positive. Myotubes and regenerating myofibers also expressed SPARC. The expression-degree seemed to reflect the severity of the lesion. In accordance with these in vivo findings, primary human-derived satellite cells were found to express SPARC both during proliferation and differentiation in vitro. In conclusion, this study shows SPARC expression both during muscle development and in regenerating muscle. The expression is detected both in satellite cells/myoblasts and in myotubes and muscle fibers, indicating a role for SPARC in the skeletal muscle compartment. (J Histochem Cytochem 57:29–39, 2009)     

Lead poisoning in woodpeckers in Sweden

Lead poisoning was demonstrated in two gray-headed woodpeckers (Picus canus) and one white-backed woodpecker (Dendrocopus leucotos) in Sweden; they had liver lead levels between 9.4 and 26.2 mg(-1) wet weight. At necropsy one gray-headed woodpecker showed signs of emaciation and the other one had severe traumatic injuries, caused by a cat. The white-backed woodpecker died in the transportation box during a translocation program. The source of the lead could not be determined, but it was suspected that it may have originated from lead pellets shot into trees and picked out by the woodpeckers during food search.     

Plasma galanin, vasopressin, and oxytocin in patients with Addison's disease.

Galanin is colocalized with adrenocorticotrophin (ACTH) in the human pituitary and with corticotrophin releasing hormone, arginine, vasopressin, and oxytocin in the hypothalamus. Galanin, vasopressin, and oxytocin influence the secretion of pituitary ACTH. The aim of this study was to investigate if the endogenous stimulation of ACTH release in Addison's disease was reflected in plasma galanin, vasopressin, and oxytocin. ACTH, galanin, vasopressin, and oxytocin were measured in plasma from 14 patients with Addison's disease, one patient with Nelson's syndrome, and 14 healthy controls. Eight patients had elevated plasma ACTH whereas six patients and all controls had ACTH levels within the reference-range. There was no difference in galanin or vasopressin between patients and controls or between samples with low or high ACTH concentrations. In contrast, oxytocin was higher in patients with elevated plasma ACTH compared to patients and controls with normal or low ACTH. No relation was found between galanin or oxytocin and age or sex. A tendency towards lower vasopressin with increasing age was found among the men (p=0.057). The highest ACTH and galanin levels were found in the patient with Nelson's syndrome. In conclusion, increased plasma ACTH was not reflected in elevated plasma galanin or vasopressin. In contrast, elevated ACTH levels were accompanied by higher oxytocin levels.     

Parallel DNA template preparation using a vacuum filtration sample transfer device

Solid-phase techniques have facilitated the handling of biochemical analytes. This has stimulated the development of systems by which large sample panels can be analyzed with high levels of security and quality. We describe a sample transfer device based on the principle of vacuum filtration, which enables parallel handling of 96 samples of analytes bound to Sepharose beads. The tool was employed for strand separation of DNA samples, by attracting the beads to filter probes while passing them between the reagent solutions. The samples were analyzed using Pyrosequencing technology and proved to yield genotyping results of high quality. The presented sample preparation procedure provides an important link in the development of integrated systems for rapid genetic analysis at a low cost. In addition, the same filter could be reused extensively with very low risk for detectable cross-contamination between assays and without any reduction in processing capacity, thus further reducing the cost per analyzed sample.     

Lack of molecular genetic divergence between sea-ranched and wild sea trout (Salmo trutta)

The supportive breeding programme for sea trout (Salmo trutta) in the River Dalälven, Sweden, is based on a sea‐ranched hatchery stock of local origin that has been kept ‘closed’ to the immigration of wild genes since the late 1960s (about seven generations). In spite of an apparent potential for substantial uni directional gene flow from sea‐ranched to wild (naturally produced) trout, phenotypic differences with a presumed genetic basis have previously been observed between the two ‘stocks’. Likewise, two previous studies of allozyme and mitochondrial DNA variation based on a single year of sampling have indicated genetic differentiation. In the present study we used microsatellite and allozyme data collected over four consecutive years, and tested for the existence of overall genetic stock divergence while accounting for temporal heterogeneity. Statistical analyses of allele frequency variation (F‐statistics) and multilocus genotypes (assignment tests) revealed that wild and sea‐ranched trout were significantly different in three of four years, whereas no overall genetic divergence could be found when temporal heterogeneity among years within stocks was accounted for. On the basis of estimates of effective population size in the two stocks, and of F_ST between them, we also assessed the level of gene flow from sea‐ranched to wild trout to be ≈ 80% per generation (with a lower confidence limit of ≈ 20%). The results suggest that the reproductive success of hatchery and naturally produced trout may be quite similar in the wild, and that the genetic characteristics of the wild stock are largely determined by introgressed genes from sea‐ranched fish.