Thermal acclimation,mitochondrial capacities and organ metabolic profiles in a reptile (<Emphasis Type="Italic">Alligator mississippiensis</Emphasis>)

Reptiles thermoregulate behaviourally, but change their preferred temperature and the optimal temperature for performance seasonally. We evaluated whether the digestive and locomotor systems of the alligator show parallel metabolic adjustments during thermal acclimation. To this end, we allowed juvenile alligators to grow under thermal conditions typical of winter and summer, providing them with seasonally appropriate basking opportunities. Although mean body temperatures of alligators in these groups differed by approximately 10°C, their growth and final anatomic status was equivalent. While hepatic mitochondria isolated from cold-acclimated alligators had higher oxidative capacities at 30°C than those from warm-acclimated alligators, the capacities did not differ at 20°C. Cold acclimation decreased maximal oxidative capacities of muscle mitochondria. For mitochondria from both organs and acclimation groups, palmitate increased oligomycin-inhibited respiration. GDP addition reduced palmitate-uncoupled rates more in liver mitochondria from warm- than cold-acclimated alligators. In muscle mitochondria, carboxyatractyloside significantly reduced palmitate-uncoupled rates. This effect was not changed by thermal acclimation. The aerobic capacity of liver, skeletal muscle and duodenum, as estimated by activities of cytochrome c oxidase (COX), increased with cold acclimation. At acclimation temperatures, the activities of COX and citrate synthase (CS) in these organs were equivalent. By measuring COX and CS in isolated mitochondria and tissue extracts, we estimated that cold acclimation did not change the mitochondrial content in liver, but increased that of muscle. The thermal compensation of growth rates and of the aerobic capacity of the locomotor and digestive systems suggests that alligators optimised metabolic processes for the seasonally altered, preferred body temperature. The precision of this compensatory response exceeds that typically shown by aquatic ectotherms whose body temperatures are at the mercy of their habitat.     

Oral exposure of pigs to the mycotoxin deoxynivalenol does not modulate the hepatic albumin synthesis during a LPS-induced acute-phase reaction

The sensitivity of pigs to deoxynivalenol (DON) might be influenced by systemic inflammation (SI) which impacts liver. Besides following acute-phase proteins, our aim was to investigate both the hepatic fractional albumin (ALB) synthesis rate (FSR) and the ALB concentration as indicators of ALB metabolism in presence and absence of SI induced by LPS via pre- or post-hepatic venous route. Each infusion group was pre-conditioned either with a control diet (CON, 0.12 mg DON/kg diet) or with a DON-contaminated diet (DON, 4.59 mg DON/kg diet) for 4 wk. A depression of ALB FSR was observed 195 min after LPS challenge, independent of feeding group or LPS application route, which was not paralleled by a down-regulated ALB mRNA expression but by a reduced availability of free cysteine. The drop in ALB FSR only partly explained the plasma ALB concentrations which were more depressed in the DON-pre-exposed groups, suggesting that ALB levels are influenced by further mechanisms. The abundances of haptoglobin, C-reactive protein, serum amyloid A, pig major acute-phase protein, fibrinogen and LPS-binding protein mRNA were up-regulated upon LPS stimulation but not accompanied by increases in the plasma concentrations of these proteins, pointing at an imbalance between synthesis and consumption.     

The FapF Amyloid Secretion Transporter Possesses an Atypical Asymmetric Coiled Coil

Gram-negative bacteria possess specialized biogenesis machineries that facilitate the export of amyloid subunits, the fibers of which are key components of their biofilm matrix. The secretion of bacterial functional amyloid requires a specialized outer-membrane protein channel through which unfolded amyloid substrates are translocated. We previously reported the crystal structure of the membrane-spanning domain of the amyloid subunit transporter FapF from Pseudomonas. However, the structure of the periplasmic domain, which is essential for amyloid transport, is yet to be determined. Here, we present the crystal structure of the N-terminal periplasmic domain at 1.8-Å resolution. This domain forms a novel asymmetric trimeric coiled coil that possesses a single buried tyrosine residue as well as an extensive hydrogen-bonding network within a glutamine layer. This new structural insight allows us to understand this newly described functional amyloid secretion system in greater detail.     

Gezonde levensverwachting op oudere leeftijd: een vergelijking van migranten en niet-migranten in drie Europese landen over tijd

We analysed differences in healthy life expectancy at age 50 (HLE₅₀) between migrants and non-migrants in Belgium, the Netherlands, and England and Wales, and their trends over time between 2001 and 2011 in the latter two countries. Population, mortality and health data were derived from registers, census or surveys. HLE₅₀ was calculated for non-migrants, western and non-western migrants by sex. We applied decomposition techniques to determine whether differences in HLE₅₀ between origin groups and changes in HLE₅₀ over time were attributable to either differences in mortality or health. The results show that in all three countries and among both sexes, older migrants, in particular those from non-western origin, could expect to live fewer years in good health than older non-migrants, mainly because of differences in self-rated health. Differences in HLE₅₀ between migrants and non-migrants diminished over time in the Netherlands, but they increased in England and Wales. Improvements in HLE₅₀ over time were mainly attributable to mortality decline. Interventions aimed at reducing the health and mortality inequalities between older migrants and non-migrants should focus on prevention, and target especially non-western migrants.     

Collodion baby treated at a tertiary hospital in Tanzania: a case report

Background

The term “collodion baby” is used to describe a newborn covered with a translucent, parchment-like skin sheet. It is an extremely rare condition with an estimated incidence of 1 in 300,000 live births. Clinically, the baby will present with a collodion membrane with fissures, ectropium, eclabium, and hypoplastic digits. Shedding of the membrane increases risk of dehydration and infection.

Case presentation

We present the case of an African baby girl, who died when she was 7-months old, who presented with features of collodion membrane at birth. She later developed hypernatremic dehydration and a constricted band on her lower limb that required urgent surgical release. She stayed in our hospital for 35 days; she was then discharged home after improvement for 6 months of follow-up clinics at Muhimbili National Hospital: neonatal; dermatology; ear, nose, and throat; and physiotherapy units. She died at 7 months of age.

Conclusion

Despite limited resources, the early survival of these babies can be improved by providing basic care.

     

The major birch pollen allergen, Bet v 1, shows ribonuclease activity

The major birch (Betula alba L.) pollen allergen, Bet v 1, has been shown to be homologous to pathogenesis-related proteins in a number of plants. Recently, it was demonstrated that a ginseng protein with high homology to an intracellular pathogenesis-related protein of parsley and to Bet v 1 is a ribonuclease (RNase). Birch pollen extract was separated in an RNase activity gel. Four major RNase bands were excised from the gel, reseparated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and identified by Western blotting with a specific Bet v 1 monoclonal antibody and patient's serum. Thus the monomer and the dimer of Bet v 1 showed RNase activity. Purified recombinant Bet v 1 was shown to degrade plant RNA. The RNase activity of recombinant Bet v 1 was 180 units · mg^?1.     

Über die Heilung von Hautwunden bei der MehlmotteEphestia Kühniella Zeller

Zusammenfassung An Raupen der MehlmotteEphestia kühniella Zeller wurde im letzten oder vorletzten Raupenstadium auf der Rückenseite des 4. Abdominalsegments durch Hitze ein Epidermisbezirk unter der Kutikula abgetötet.Um die Wunde breitet sich ein Bereich aus, in dem die Zellen eine Umstellung in einen neuen, auf die Heilung zugeschnittenen Reaktionszustand durchmachen. Die angeregten Zellen unterliegen einer Mitosenhemmung, sie haben kontrahierte Kerne und entwässertes Zytoplasma und wandern auf die Lücke zu, die so verschlossen wird. Die Anregung wird von einer Zelle zur anderen weitergegeben, sie verringert sich während der Ausbreitung. Sie klingt ab, wenn die Epidermislücke durch die zuwandernden Zellen aufgefüllt ist.In der Raupenepidermis treten während der Heilung Riesenzellen auf, in der Puppen- und Falterkutikula entsprechende kutikulare Bildungen.In der Diskussion wird die Heilung nach den Brennverletzungen dem Schließen eines Hautimplantatbläschens gegenübergestellt. Eine Brennwunde verheilt mittels Epithelwanderung unter Mitosenhemmung, das Implantatbläschen schließt sich durch Epithelwachstum unter Zellteilungen. Riesenzellen treten in beiden Fällen auf.Meinem hochverehrten Lehrer, Professor Dr.Alfred Kühn, danke ich für die Anregung und Förderung dieser Arbeit.     

Specific leaf area of European Larch (<Emphasis Type="Italic">Larix decidua</Emphasis> M<Emphasis Type="SmallCaps">ill</Emphasis>.)

Key message

The specific leaf area of European larch depends on branch height and canopy depth, indicating that both, the effect of hydraulic limitations and low water potentials in greater branch heights, and light availability affect specific leaf area.

Abstract

Specific leaf area (SLA) is defined as the ratio between projected leaf area and needle dry mass. It often serves as parameter in ecosystem modelling as well as indicator for potential growth rate. We explore the SLA of European larch (Larix decidua) and the most important factors which have an influence on it. Data were collected from eight stands in Styria, Austria. The stands varied in age, elevation and species mixture. Four stands were pure larch stands with only minor proportions of Norway spruce (Picea abies), whereas the other four were mixed stands of larch and spruce. In each stand 15 representative sample trees were felled. The crown of each sample tree was divided into three sections of equal length and in each section a random sample of needles was taken for determining projected leaf area and dry mass of 50 needles. The mean SLA of larch was established to be 117 cm² g^?1 with a standard deviation of ±27.9 cm² g^?1. SLA varies within the crown, but neither between different mixtures nor years of observation nor social position of the trees. A mixed-effects model, with the plots as random effect, revealed that SLA of larch decreased with increasing branch height (p = 0.0012) and increased with increasing canopy depth (p = 0.029). We conclude that both the hydraulic limitations due to low water potentials in greater branch heights and light availability affect specific leaf area.

     

Targeted gene exchange in plant cells mediated by a zinc finger nuclease double cut

Genome modification by homology‐directed repair (HDR) is an attractive tool for the controlled genetic manipulation of plants. Here, we report the HDR‐mediated gene exchange of expression cassettes in tobacco BY‐2 cells using a designed zinc finger nuclease (ZFN). The target contained a 7‐kb fragment flanked by two ZFN cutting sites. That fragment was replaced with a 4‐kb donor cassette, which integrates gene markers for selection (kanamycin resistance) and for scoring targeting (red fluorescent protein, RFP). Candidates resulting from cassette exchange were identified by molecular analysis of calli generated by transformation via direct DNA delivery. The precision of HDR‐mediated donor integration was evaluated by Southern blot analysis, sequencing of the integration locus and analysis of RFP fluorescence by flow cytometry. Screening of 1326 kanamycin‐resistant calli yielded 18 HDR events, 16 of which had a perfect cassette exchange at the insert junction and 13 of which produced functional RFP. Our results demonstrate that ZFN‐based HDR can be used for high frequency, precise, targeted exchange of fragments of sizes that are commercially relevant in plants.