Sequence Analysis of the Genome of Piscine Orthoreovirus (PRV) Associated with Heart and Skeletal Muscle Inflammation (HSMI) in Atlantic Salmon (Salmo salar)

Piscine orthoreovirus (PRV) is associated with heart- and skeletal muscle inflammation (HSMI) of farmed Atlantic salmon (Salmo salar). We have performed detailed sequence analysis of the PRV genome with focus on putative encoded proteins, compared with prototype strains from mammalian (MRV T3D)- and avian orthoreoviruses (ARV-138), and aquareovirus (GCRV-873). Amino acid identities were low for most gene segments but detailed sequence analysis showed that many protein motifs or key amino acid residues known to be central to protein function are conserved for most PRV proteins. For M-class proteins this included a proline residue in μ2 which, for MRV, has been shown to play a key role in both the formation and structural organization of virus inclusion bodies, and affect interferon-β signaling and induction of myocarditis. Predicted structural similarities in the inner core-forming proteins λ1 and σ2 suggest a conserved core structure. In contrast, low amino acid identities in the predicted PRV surface proteins μ1, σ1 and σ3 suggested differences regarding cellular interactions between the reovirus genera. However, for σ1, amino acid residues central for MRV binding to sialic acids, and cleavage- and myristoylation sites in μ1 required for endosomal membrane penetration during infection are partially or wholly conserved in the homologous PRV proteins. In PRV σ3 the only conserved element found was a zinc finger motif. We provide evidence that the S1 segment encoding σ3 also encodes a 124 aa (p13) protein, which appears to be localized to intracellular Golgi-like structures. The S2 and L2 gene segments are also potentially polycistronic, predicted to encode a 71 aa- (p8) and a 98 aa (p11) protein, respectively. It is concluded that PRV has more properties in common with orthoreoviruses than with aquareoviruses.     

Trends in bowhead whales in West Greenland: Aerial surveys vs. genetic capture‐recapture analyses

We contrast two methods for estimating the trends of bowhead whales (Balaena mysticetus) in West Greenland: (1) double platform visual aerial survey, corrected for missed sightings and the time the whales are available at the surface; and (2) a genetic capture‐recapture approach based on a 14‐yr‐long biopsy sampling program in Disko Bay. The aerial survey covered 39,000 km² and resulted in 58 sightings, yielding an abundance estimate of 744 whales (CV = 0.34, 95% CI: 357–1,461). The genetic method relied on determining sex, mitochondrial haplotypes and genotypes of nine microsatellite markers. Based on samples from a total of 427 individuals, with 11 recaptures from previous years in 2013, this resulted in an estimate of 1,538 whales (CV = 0.24, 95% CI: 827–2,249). While the aerial survey is considered a snapshot of the local spring aggregation in Disko Bay, the genetic approach estimates the abundance of the source of this aggregation. As the whales in Disko Bay primarily are adult females that do not visit the bay annually, the genetic method would presumably yield higher estimates. The studies indicate that an increase in abundance observed between 1998 and 2006 has leveled off.     

Consequences of abnormal CDK activity in S phase

Cyclin Dependent Kinases (CDKs) are important regulators of DNA replication. In this work we have investigated the consequences of increasing or decreasing the CDK activity in S phase. To this end we identified S-phase regulators of the fission yeast CDK, Cdc2, and used appropriate mutants to modulate Cdc2 activity. In fission yeast Mik1 has been thought to be the main regulator of Cdc2 activity in S phase. However, we find that Wee1 has a major function in S phase and thus we used wee1 mutants to investigate the consequences of increased Cdc2 activity. These wee1 mutants display increased replication stress and, particularly in the absence of the S-phase checkpoint, accumulate DNA damage. Notably, more cells incorporate EdU in a wee1^? strain as compared to wildtype, suggesting altered regulation of DNA replication. In addition, a higher number of cells contain chromatin-bound Cdc45, an indicator of active replication forks. In addition, we found that Cdc25 is required to activate Cdc2 in S phase and used a cdc25 mutant to explore a situation where Cdc2 activity is reduced. Interestingly, a cdc25 mutant has a higher tolerance for replication stress than wild-type cells, suggesting that reduced CDK activity in S phase confers resistance to at least some forms of replication stress.     

Ubiquitinated annexin A2 is enriched in the cytoskeleton fraction

Annexin A2 is a multifunctional protein and its cellular functions are regulated by post-translational modifications and ligand binding. When purified from porcine intestinal mucosa and transformed mouse Krebs II cells, SDS-PAGE revealed high-molecular-mass forms in addition to the 36 kDa protomer. These forms were identified as poly-/multi-ubiquitin conjugates of annexin A2, and ubiquitination represents a novel post-translational modification of this protein. Subcellular fractionation of mouse Krebs II cells revealed an enrichment of annexin A2-ubiquitin conjugates in the Triton X-100 resistant cytoskeleton fraction, suggesting that ubiquitinated annexin A2 may have a role associated with its function as an actin-binding protein.     

Amphipathic sulfonamidobenzamides mimicking small antimicrobial marine natural products; investigation of antibacterial and anti-biofilm activity against antibiotic resistant clinical isolates

There is an urgent need for novel antimicrobial agents to address the threat of bacterial resistance to modern society. We have used a structural motif found in antimicrobial marine hit compounds as a basis for synthesizing a library of antimicrobial sulfonamidobenzamide lead compounds. Potent in vitro antimicrobial activity against clinically relevant bacterial strains was demonstrated for two compounds, G6 and J18, with minimal inhibitory concentrations (MIC) of 4–16?μg/ml against clinical methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE). The two compounds G6 and J18, together with several other compounds of this library, also caused ≥90% eradication of pre-established biofilm of methicillin-resistant S. epidermidis (MRSE) at 40?μg/ml. Using a luciferase assay, the mechanism of action of G6 was shown to resemble the biocide chlorhexidine by targeting the bacterial cell membrane.     

Palms tracking climate change

Aim  Many species are currently expanding their ranges in response to climate change, but the mechanisms underlying these range expansions are in many cases poorly understood. In this paper we explore potential climatic factors governing the recent establishment of new palm populations far to the north of any other viable palm population in the world.
Location  Southern Switzerland, Europe, Asia and the world.
Methods  We identified ecological threshold values for the target species, Trachycarpus fortunei , based on gridded climate data, altitude and distributional records from the native range and applied them to the introduced range using local field monitoring and measured meteorological data as well as a bioclimatic model.
Results  We identified a strong relationship between minimum winter temperatures, influenced by growing season length and the distribution of the palm in its native range. Recent climate change strongly coincides with the palm's recent spread into southern Switzerland, which is in concert with the expansion of the global range of palms across various continents.
Main conclusions  Our results strongly suggest that the expansion of palms into (semi-)natural forests is driven by changes in winter temperature and growing season length and not by delayed population expansion. This implies that this rapid expansion is likely to continue in the future under a warming climate. Palms in general, and T. fortunei in particular, are significant bioindicators across continents for present-day climate change and reflect a global signal towards warmer conditions.     

Surgical Site Infections after Deep Brain Stimulation Surgery: Frequency,Characteristics and Management in a 10-Year Period

Background/Aims

Deep brain stimulation (DBS) implant infection is a feared complication, as it is difficult to manage and leads to increased patient morbidity. We wanted to assess the frequency and possible risk factors of DBS related infections at our centre. In the purpose of evaluating treatment options, we also analyzed treatment, and the clinical and microbiological characteristics of the infections.

Methods

Electronic medical records of all patients undergoing DBS surgery at our centre, from 2001 through 2010, were retrospectively reviewed.

Results

Of the 588 procedures performed 33 (5.6%) led to an infection. Some patients underwent several procedures, thus 32 out of totally 368 patients (8.7%), and 19 out of 285 patients (6.7%) who received primary lead implantation, developed an infection. Most infections (52%) developed within the first month and 79% within three months. In the majority of the infections (79%) hardware removal was performed. Staphylococcus aureus infections were the most frequent (36%), and more likely to have earlier onset, pus formation, a more aggressive development and lead to hardware removal. No risk factors were identified.

Conclusions

Our results indicate that infections with more severe symptoms and growth of staphylococcus aureus should be treated with local hardware removal and antibiotic therapy. In other infections, an initial trial of antibiotic treatment could be considered. New knowledge about the microbiology of DBS related infections may lead to more effective antimicrobial treatment.     

Silencing of renal DNaseI in murine lupus nephritis imposes exposure of large chromatin fragments and activation of Toll like receptors and the Clec4e

Recent studies demonstrate that transformation of mild lupus nephritis into end-stage disease is imposed by silencing of renal DNaseI gene expression in (NZBxNZW)F1 mice. Down-regulation of DNaseI results in reduced chromatin fragmentation, and in deposition of extracellular chromatin-IgG complexes in glomerular basement membranes in individuals that produce IgG anti-chromatin antibodies. The main focus of the present study is to describe the biological consequences of renal DNaseI shut-down and reduced chromatin fragmentation with a particular focus on whether exposed large chromatin fragments activate Toll like receptors and the necrosis-related Clec4e receptor in murine and human lupus nephritis. Furthermore, analyses where performed to determine if matrix metalloproteases are up-regulated as a consequence of chromatin-mediated Toll like receptors/Clec4e stimulation. Mouse and human mRNA expression levels of DNaseI, Toll like receptors 7-9, Clec4e, pro-inflammatory cytokines and MMP2/MMP9 were determined and compared with in situ protein expression profiles and clinical data. We demonstrate that exposure of chromatin significantly up-regulate Toll like receptors and Clec4e in mice, and also but less pronounced in patients with lupus nephritis treated with immunosuppresants. In conclusion, silencing of renal DNaseI gene expression initiates a cascade of inflammatory signals leading to progression of both murine and human lupus nephritis. Principal component analyses biplot of data from murine and human lupus nephrits demonstrate the importance of DNaseI gene shut down for progression of the organ disease.