Rates and patterns of mitochondrial DNA sequence evolution in fringilline finches (fringilla spp.) and the greenfinch (Carduelis chloris)

Rates and patterns of evolution in partial sequences of five mitochondrial genes (cytochrome b, ATPase 6, NADH dehydrogenase subunit 5, tRNA(Glu), and the control region) were compared among taxa in the passerine bird genera Fringilla and Carduelis. Rates of divergence do not vary significantly among genes, even in comparisons with the control region. Rate variation among lineages is significant only for the control region and NADH dehydrogenase subunit 5, and patterns of variation are consistent with the expectations of neutral theory. Base composition is biased in all genes but is stationary among lineages, and there is evidence for directional mutation pressure only in the control region. Despite these similarities, patterns of substitution differ among genes, consistent with alternative regimes of selective constraint. Rates of nonsynonymous substitution are higher in NADH dehydrogenase subunit 5 than in other protein-coding genes, and transitions exist in elevated proportions relative to transversions. Transitions appear to accumulate linearly with time in tRNA(Glu), and despite exhibiting the highest overall rate of divergence among species, there are no transversional changes in this gene. Finally, for resolving phylogenetic relationships among Fringilla taxa, the combined protein-coding data are broadly similar to those of the control region in terms of phylogenetic informativeness and statistical support.      

Effects of an energy-dense diet and nicotinic acid supplementation on production and metabolic variables of primiparous or multiparous cows in periparturient period

It is well observed that feeding energy-dense diets in dairy cows during the dry period can cause metabolic imbalances after parturition. Especially dairy cows with high body condition score (BCS) and fed an energy-dense diet were prone to develop production diseases due to metabolic disturbances postpartum. An experiment was conducted to determine the effects of an energy-dense diet and nicotinic acid (NA) on production and metabolic variables of primiparous and multiparous cows in late pregnancy and early lactation which were not pre-selected for high BCS. Thirty-six multiparous and 20 primiparous German Holstein cows with equal body conditions were fed with energy-dense (60% concentrate/40% roughage mixture; HC group) or adequate (30% concentrate/70% roughage mixture; LC group) diets prepartum. After parturition, concentrate proportion was dropped to 30% for all HC and LC groups and was increased to 50% within 16 days for LC and within 24 days for HC cows. In addition, half of the cows per group received 24 g NA supplement per day and cow aimed to attenuate the lipid mobilisation postpartum. Feeding energy-dense diets to late-pregnant dairy cows elevated the dry matter (p < 0.001) and energy intake (p < 0.001) as well as the energy balance (p < 0.001) without affecting the BCS (p = 0.265) during this period. However, this did not result in any metabolic deviation postpartum as the effects of prepartum concentrate feeding were not carried over into postpartum period. Multiparous cows responded more profoundly to energy-dense feeding prepartum compared with primiparous cows, and parity-related differences in the transition from late pregnancy to lactation were obvious pre- and postpartum. The supplementation with 24 g NA did not reveal any effect on energy metabolism. This study clearly showed that energy-dense feeding prepartum did not result in metabolic imbalances postpartum in multiparous and primiparous cows not selected for high BCS. A genetic predisposition for an anabolic metabolic status as indicated by high BCS may be crucial for developing production diseases at the onset of lactation.     

Effects of Inhibiting Dipeptidyl Peptidase-4 (DPP4) in Cows with Subclinical Ketosis

The inhibition of dipeptidyl peptidase-4 (DPP4) via specific inhibitors is known to result in improved glucose tolerance and insulin sensitivity and decreased accumulation of hepatic fat in type II diabetic human patients. The metabolic situation of dairy cows can easily be compared to the status of human diabetes and non-alcoholic fatty liver. For both, insulin sensitivity is reduced, while hepatic fat accumulation increases, characterized by high levels of non-esterified fatty acids (NEFA) and ketone bodies.Therefore, in the present study, a DPP4 inhibitor was employed (BI 14332) for the first time in cows. In a first investigation BI 14332 treatment (intravenous injection at dosages of up to 3 mg/kg body weight) was well tolerated in healthy lactating pluriparous cows (n = 6) with a significant inhibition of DPP4 in plasma and liver. Further testing included primi- and pluriparous lactating cows suffering from subclinical ketosis (β-hydroxybutyrate concentrations in serum > 1.2 mM; n = 12). The intension was to offer effects of DPP4 inhibition during comprehensive lipomobilisation and hepatosteatosis. The cows of subclinical ketosis were evenly allocated to either the treatment group (daily injections, 0.3 mg BI 14332/kg body weight, 7 days) or the control group. Under condition of subclinical ketosis, the impact of DPP4 inhibition via BI 14332 was less, as in particular β-hydroxybutyrate and the hepatic lipid content remained unaffected, but NEFA and triglyceride concentrations were decreased after treatment. Owing to lower NEFA, the revised quantitative insulin sensitivity check index (surrogate marker for insulin sensitivity) increased. Therefore, a positive influence on energy metabolism might be quite possible. Minor impacts on immune-modulating variables were limited to the lymphocyte CD4⁺/CD8⁺ ratio for which a trend to decreased values in treated versus control animals was noted. In sum, the DPP4 inhibition in cows did not affect glycaemic control like it is shown in humans, but was able to impact hyperlipemia, as NEFA and TG decreased.     

Spatial temperature distribution in human hairy and glabrous skin after infrared CO<Subscript>2</Subscript> laser radiation

Background  

CO₂ lasers have been used for several decades as an experimental non-touching pain stimulator. The laser energy is absorbed by the water content in the most superficial layers of the skin. The deeper located nociceptors are activated by passive conduction of heat from superficial to deeper skin layers.     

Increased sequence diversity coverage improves detection of HIV-specific T cell responses

The accurate identification of HIV-specific T cell responses is important for determining the relationship between immune response, viral control, and disease progression. HIV-specific immune responses are usually measured using peptide sets based on consensus sequences, which frequently miss responses to regions where test set and infecting virus differ. In this study, we report the design of a peptide test set with significantly increased coverage of HIV sequence diversity by including alternative amino acids at variable positions during the peptide synthesis step. In an IFN-gamma ELISpot assay, these "toggled" peptides detected HIV-specific CD4(+) and CD8(+) T cell responses of significantly higher breadth and magnitude than matched consensus peptides. The observed increases were explained by a closer match of the toggled peptides to the autologous viral sequence. Toggled peptides therefore afford a cost-effective and significantly more complete view of the host immune response to HIV and are directly applicable to other variable pathogens.     

The molecular and cellular identity of peripheral osmoreceptors

In mammals, the osmolality of the extracellular fluid (ECF) is highly stable despite radical changes in salt/water intake and excretion. Afferent systems are required to detect hypo- or hyperosmotic shifts in the ECF to trigger homeostatic control of osmolality. In humans, a pressor reflex is triggered by simply drinking water which may be mediated by peripheral osmoreceptors. Here, we identified afferent neurons in the thoracic dorsal root ganglia (DRG) of mice that innervate hepatic blood vessels and detect physiological hypo-osmotic shifts in blood osmolality. Hepatic sensory neurons are equipped with an inward current that faithfully transduces graded changes in osmolality within the physiological range (~15 mOsm). In mice lacking the osmotically activated ion channel, TRPV4, hepatic sensory neurons no longer exhibit osmosensitive inward currents and activation of peripheral osmoreceptors in vivo is abolished. We have thus identified a new population of sensory neurons that transduce ongoing changes in hepatic osmolality.     

Attenuated inflammatory response in aged mice brains following stroke

Background

Increased age is a major risk factor for stroke incidence, post-ischemic mortality, and severe and long-term disability. Stroke outcome is considerably influenced by post-ischemic mechanisms. We hypothesized that the inflammatory response following an ischemic injury is altered in aged organisms.

Methods and Results

To that end, we analyzed the expression pattern of pro-inflammatory cytokines (TNF, IL-1α, IL-1β, IL-6), anti-inflammatory cytokines (IL-10, TGFβ1), and chemokines (Mip-1α, MCP-1, RANTES) of adult (2 months) and aged (24 months) mice brains at different reperfusion times (6 h, 12 h, 24 h, 2 d, 7 d) following transient occlusion of the middle cerebral artery. The infarct size was assessed to monitor possible consequences of an altered inflammatory response in aged mice. Our data revealed an increased neuro-inflammation with age. Above all, we found profound age-related alterations in the reaction to stroke. The response of pro-inflammatory cytokines (TNF, and IL-1β) and the level of chemokines (Mip-1α, and MCP-1) were strongly diminished in the aged post-ischemic brain tissue. IL-6 showed the strongest age-dependent decrease in its post-ischemic expression profile. Anti-inflammatory cytokines (TGFβ1, and IL-10) revealed no significant age dependency after ischemia. Aged mice brains tend to develop smaller infarcts.

Conclusion

The attenuated inflammatory response to stroke in aged animals may contribute to their smaller infarcts. The results presented here highlight the importance of using aged animals to investigate age-associated diseases like stroke, and should be considered as a major prerequisite in the development of age-adjusted therapeutic interventions.     

Alteration in cellular functions in mouse macrophages after exposure to 50 Hz magnetic fields

The aim of the present study is to investigate whether extremely low frequency electromagnetic fields (ELF-EMF) affect certain cellular functions and immunologic parameters of mouse macrophages. In this study, the influence of 50 Hz magnetic fields (MF) at 1.0 mT was investigated on the phagocytic activity and on the interleukin-1beta (IL-1beta) production in differentiated macrophages. MF-exposure led to an increased phagocytic activity after 45 min, shown as a 1.6-fold increased uptake of latex beads in MF-exposed cells compared to controls. We also demonstrate an increased IL-1beta release in macrophages after 24 h exposure (1.0 mT MF). Time-dependent IL-1beta formation was significantly increased already after 4 h and reached a maximum of 12.3-fold increase after 24 h compared to controls. Another aspect of this study was to examine the genotoxic capacity of 1.0 mT MF by analyzing the micronucleus (MN) formation in long-term (12, 24, and 48 h) exposed macrophages. Our data show no significant differences in MN formation or irregular mitotic activities in exposed cells. Furthermore, the effects of different flux densities (ranging from 0.05 up to 1.0 mT for 45 min) of 50 Hz MF was tested on free radical formation as an endpoint of cell activation in mouse macrophage precursor cells. All tested flux densities significantly stimulated the formation of free radicals. Here, we demonstrate the capacity of ELF-EMF to stimulate physiological cell functions in mouse macrophages shown by the significantly elevated phagocytic activity, free radical release, and IL-1beta production suggesting the cell activation capacity of ELF-EMF in the absence of any genotoxic effects.