MALDI-TOF MS of phosphatidylethanolamines: different adducts cause different post source decay (PSD) fragment ion spectra

Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) is increasingly applied to lipids. However, positional acyl chain analysis of lipids by MALDI was so far scarcely described. In this paper, the fragmentation behavior of phosphatidylethanolamine (PE) is investigated by using post-source decay (PSD) MS. In dependence on the investigated adduct, significant differences could be obtained. It will be shown that in particular the negative ion spectra enable the determination of the individual acyl chains as well as their positions (sn-1 or sn-2). Therefore, MALDI-TOF PSD spectra are a real alternative to more sophisticated MS/MS methods.     

Genetic differentiation and the evolution of cooperation in chimpanzees and humans

It has been proposed that human cooperation is unique among animals for its scale and complexity, its altruistic nature and its occurrence among large groups of individuals that are not closely related or are even strangers. One potential solution to this puzzle is that the unique aspects of human cooperation evolved as a result of high levels of lethal competition (i.e. warfare) between genetically differentiated groups. Although between-group migration would seem to make this scenario unlikely, the plausibility of the between-group competition model has recently been supported by analyses using estimates of genetic differentiation derived from contemporary human groups hypothesized to be representative of those that existed during the time period when human cooperation evolved. Here, we examine levels of between-group genetic differentiation in a large sample of contemporary human groups selected to overcome some of the problems with earlier estimates, and compare them with those of chimpanzees. We find that our estimates of between-group genetic differentiation in contemporary humans are lower than those used in previous tests, and not higher than those of chimpanzees. Because levels of between-group competition in contemporary humans and chimpanzees are also similar, these findings suggest that the identification of other factors that differ between chimpanzees and humans may be needed to provide a compelling explanation of why humans, but not chimpanzees, display the unique features of human cooperation.     

Skin conductance response to the pain of others predicts later costly helping

People show autonomic responses when they empathize with the suffering of another person. However, little is known about how these autonomic changes are related to prosocial behavior. We measured skin conductance responses (SCRs) and affect ratings in participants while either receiving painful stimulation themselves, or observing pain being inflicted on another person. In a later session, they could prevent the infliction of pain in the other by choosing to endure pain themselves. Our results show that the strength of empathy-related vicarious skin conductance responses predicts later costly helping. Moreover, the higher the match between SCR magnitudes during the observation of pain in others and SCR magnitude during self pain, the more likely a person is to engage in costly helping. We conclude that prosocial motivation is fostered by the strength of the vicarious autonomic response as well as its match with first-hand autonomic experience.     

Evaluation of the antimicrobial activities of plant oxylipins supports their involvement in defense against pathogens

Plant oxylipins are a large family of metabolites derived from polyunsaturated fatty acids. The characterization of mutants or transgenic plants affected in the biosynthesis or perception of oxylipins has recently emphasized the role of the so-called oxylipin pathway in plant defense against pests and pathogens. In this context, presumed functions of oxylipins include direct antimicrobial effect, stimulation of plant defense gene expression, and regulation of plant cell death. However, the precise contribution of individual oxylipins to plant defense remains essentially unknown. To get a better insight into the biological activities of oxylipins, in vitro growth inhibition assays were used to investigate the direct antimicrobial activities of 43 natural oxylipins against a set of 13 plant pathogenic microorganisms including bacteria, oomycetes, and fungi. This study showed unequivocally that most oxylipins are able to impair growth of some plant microbial pathogens, with only two out of 43 oxylipins being completely inactive against all the tested organisms, and 26 oxylipins showing inhibitory activity toward at least three different microbes. Six oxylipins strongly inhibited mycelial growth and spore germination of eukaryotic microbes, including compounds that had not previously been ascribed an antimicrobial activity, such as 13-keto-9(Z),11(E),15(Z)-octadecatrienoic acid and 12-oxo-10,15(Z)-phytodienoic acid. Interestingly, this first large-scale comparative assessment of the antimicrobial effects of oxylipins reveals that regulators of plant defense responses are also the most active oxylipins against eukaryotic microorganisms, suggesting that such oxylipins might contribute to plant defense through their effects both on the plant and on pathogens, possibly through related mechanisms.     

A field study into the appropriateness of transcutaneous ultrasonography in the diagnoses of uterine disorders in reproductively failed pigs

This study was conducted to define the characteristics of the uterus of reproductively failed pigs by transcutaneous ultrasonography (SONO) in order to investigate the appropriateness of SONO to diagnose presumptive uterine disorders. Zearalenone (ZEA) is known to affect uterine function and causes endometrial liquid accumulation and was also determined. In 33 sows and 14 gilts, of unknown reproductive stages and culled for failing to conceive, the uterus was scanned transcutaneously and the females slaughtered on the same day or the day after scanning. Parameters determined by SONO were uterine echotexture (UET; graded 1 for homogeneous to 4 for highly heterogeneous), uterine size (US; expressed as the mean sectional area of two to three cross-sections of the uterine horns given in cm2) and intrauterine content. Post mortem, the ovarian structures were assessed and females grouped accordingly into those in estrus (n=2), early diestrus (n=14), diestrus (n=15), late diestrus (n=1), anestrus (n=10) and having polycystic ovarian degeneration (n=5). The uterine weight (UW) was recorded and uterine specimens microscopically evaluated for an endometrial oedema (EO; grades 1 for none, to 4, if an oedema was clearly evident) and for immune cells to assess endometritis. Total ZEA was analysed in bile and females with >or=50 ng/ml judged as positive. The uterus could be examined in all animals. UET, US, UW and EO was found to be different between groups, and a positive correlation (P<0.001) established for US and UET (r=0.71), US and EO (r=0.51), UET and EO (r=0.57), US and UW (UW=357.6 x US(0.801); r=0.88). One female had intrauterine fluid and an acute-chronic endometritis diagnosed. Almost all females had a chronic endometritis and a majority found ZEA positive. No differences were observed between groups and a relationship between ZEA or chronic endometritis and UET, US, UW and EO were not established. In conclusion, transcutaneous SONO is appropriate to examine the uterus in reproductively failed pigs on farms, and the estimation of UET and US gives information on EO and UW. Intrauterine fluid is indicative for a severe uterine inflammation. Since groups differed in UET and US, but were equally ZEA positive and the uteri chronically inflamed, an UET and US specifically associated with ZEA or chronic endometritis is questioned.     

Oxidation-induced ferritin turnover in microglial cells: role of proteasome

Highly oxidized protein aggregates accumulating in the brain during neurodegenerative diseases are often surrounded by microglia. Most of the microglial cells surrounding these plaques are activated and release a high amount of oxidizing species. In order to develop their toxic effects numerous oxidizing species need iron. To prevent this iron-dependent oxidation an iron-sequestering apparatus exists, including the major iron storage protein ferritin. Microglial cells damage their own protein pool during activation and it is still unknown whether microglial cells are able to maintain their iron-sequestering function during oxidative stress. Therefore, we explored the microglial cell line RAW to test the maintenance of ferritin under oxidizing conditions. Our investigations revealed a half-life of both ferritin chains of 3-3.5 h and a reduced half-life due to oxidation. This was due to the removal of oxidized ferritin by the proteasomal system. Ferritin de novo synthesis was also severely affected by oxidation. This results in a decreased ferritin pool due to acute oxidative stress. These data let us conclude that microglial cells do not increase their ferritin amount after oxidative stress and an increase in the iron storage capacity in these cells after treatment might be achieved only by a high iron saturation of the existing ferritin molecules.     

Sulfonylureas correct trafficking defects of ATP-sensitive potassium channels caused by mutations in the sulfonylurea receptor

The pancreatic ATP-sensitive potassium (K(ATP)) channel, a complex of four sulfonylurea receptor 1 (SUR1) and four potassium channel Kir6.2 subunits, regulates insulin secretion by linking metabolic changes to beta-cell membrane potential. Sulfonylureas inhibit K(ATP) channel activities by binding to SUR1 and are widely used to treat type II diabetes. We report here that sulfonylureas also function as chemical chaperones to rescue K(ATP) channel trafficking defects caused by two SUR1 mutations, A116P and V187D, identified in patients with congenital hyperinsulinism. Sulfonylureas markedly increased cell surface expression of the A116P and V187D mutants by stabilizing the mutant SUR1 proteins and promoting their maturation. By contrast, diazoxide, a potassium channel opener that also binds SUR1, had no effect on surface expression of either mutant. Importantly, both mutant channels rescued to the cell surface have normal ATP, MgADP, and diazoxide sensitivities, demonstrating that SUR1 harboring either the A116P or the V187D mutation is capable of associating with Kir6.2 to form functional K(ATP) channels. Thus, sulfonylureas may be used to treat congenital hyperinsulinism caused by certain K(ATP) channel trafficking mutations.     

Antioxidants effectively prevent oxidation-induced protein damage in OLN 93 cells

Oxidative stress is supposed to play an important role in demyelinating diseases. Oligodendrocytes are the myelin-forming cells in the brain and are highly susceptible to oxidative stress due to their low antioxidative defense systems and high metabolic rate. In the present work, we tested the response of the oligodendrocyte cell line OLN 93 to oxidative stress. OLN 93 cell cultures are characterized by a loss of cell viability after oxidation. This loss of cell viability is accompanied by an increase in protein oxidation and consequently an elevated overall proteolysis. To minimize the oxidative damage, we tested the effects of the antioxidants alpha-lipoic acid and coenzyme Q(10). Both compounds were able to elevate cell viability and to decrease intracellular protein turnover and oxidant induced protein oxidation. Therefore, we concluded that the excessive oxidative damage of oligodendrocytes and their protein pool can be prevented by the usage of antioxidants.     

Polyphyly of the grass tribe Hainardieae (Poaceae: Pooideae): identification of its different lineages based on molecular phylogenetics, including morphological and cytogenetic characteristics

The small pooid grass tribe Hainardieae comprises six genera with approximately ten species; however, this tribe was not accepted by all previous taxonomic treatments. To study the relationships among these genera and to infer the phylogeny and evolutionary patterns, we used sequence variation of the internal transcribed spacers (ITS) of nuclear ribosomal and chloroplast (cp) matK DNA and morphology. Many genera of the Aveneae/Poeae tribe complex additionally were included. Both molecular datasets showed Hainardieae to be highly polyphyletic, and its genera to branch with different groups of the Aveneae/Poeae. Parapholis and Hainardia are corroborated as being closely related, and belonging to a firmly supported Eurasian clade together with Catapodium incl. Scleropoa, Cutandia, Desmazeria, Sphenopus, Vulpiella (subtribe Parapholiinae) and with Cynosurus as sister to this assemblage. The other genera of traditionally recognised Hainardieae are positioned phylogenetically distant: Mediterranean Narduroides is verified as more or less related to Festuca and relatives (subtribe Loliinae), whereas the west Eurasian Pholiurus is close to the lineage of Poa and relatives (subtribe Poinae). North American Scribneria is sister to Deschampsia and both genera should be unified under a common subtribe (Aristaveninae or Holcinae). The phylogenetic position of the Algerian genus Agropyropsis (close to Narduroides and within the Loliinae) is suggested on morphology only, because no molecular data was obtained for it. Considering classification, we support the abandonment of tribe Hainardieae and argue to abandon Poeae subtribe Scribneriinae. Poeae subtribe Parapholiinae is redefined with a novel genus content, due to the exclusion of Agropyropsis and Pholiurus and the inclusion of Vulpiella.