Minimally Invasive Aortic Valve Replacement Via Right Anterior Mini-Thoracotomy: Propensity Matched Initial Experience.

BACKGROUND: Aortic valve replacement by way of a right anterior mini-thoracotomy (RAMT) has shown excellent results in terms of mortality and morbidity. The aim of the present study was to compare RAMT aortic valve replacement (AVR) with conventional full sternotomy in regards to early perioperative outcomes and mortality. METHODS: This was a retrospective, observational, cohort study of prospectively collected data from patients who underwent isolated, first time AVR between January 2013 and October 2016. Fifty-three RAMT patients were matched to a control group (conventional full sternotomy) using propensity score analysis. RESULTS: The characteristics of the two cohorts were similar. The in-hospital mortality was 1.9% utilising the RAMT approach versus 5.7% using the sternotomy approach (p=0.34). Ventilation times were similar in both groups (7 [5-2] vs 8 [5-13] hrs; p=0.61). However, ICU length of stay was significantly longer in the RAMT group (median, 46.5 [23-59.5] vs 20 [14-23] hrs; p<0.001), which translated into a significantly longer postoperative hospital length of stay for the RAMT group (median, 8 [6-12] vs 6 [5.5-9.5] days; p=0.04) compared to the sternotomy group. RAMT was associated with a trend towards a higher incidence of postoperative AF in comparison to the sternotomy group, although this was not statistically significant (41.5% vs 28.3%; p=0.17). Patients in the RAMT group had lower 4-hour chest drain output (102.5 vs 1141ml; p=0.0.07). There was no statistically significant difference in rates of non-red cell transfusions between the two groups, (17%vs28.3%; p=0.10). The occurrence of stroke, re-exploration for bleeding, red-cell transfusion and wound infection was similar in both groups. CONCLUSIONS: Right anterior mini-thoracotomy in patients undergoing isolated aortic valve surgery is a safe approach in select patients, although associated with longer cardiopulmonary bypass times and ICU length of stay.

Global distribution of Chelonid fibropapilloma-associated herpesvirus among clinically healthy sea turtles.

BACKGROUND: Fibropapillomatosis (FP) is a neoplastic disease characterized by cutaneous tumours that has been documented to infect all sea turtle species. Chelonid fibropapilloma-associated herpesvirus (CFPHV) is believed to be the aetiological agent of FP, based principally on consistent PCR-based detection of herpesvirus DNA sequences from FP tumours. We used a recently described PCR-based assay that targets 3 conserved CFPHV genes, to survey 208 green turtles (Chelonia mydas). This included both FP tumour exhibiting and clinically healthy individuals. An additional 129 globally distributed clinically healthy individual sea turtles; representing four other species were also screened. RESULTS: CFPHV DNA sequences were obtained from 37/37 (100%) FP exhibiting green turtles, and 45/300 (15%) clinically healthy animals spanning all five species. Although the frequency of infected individuals per turtle population varied considerably, most global populations contained at least one CFPHV positive individual, with the exception of various turtle species from the Arabian Gulf, Northern Indian Ocean and Puerto Rico. Haplotype analysis of the different gene markers clustered the CFPHV DNA sequences for two of the markers (UL18 and UL22) in turtles from Turks and Caicos separate to all others, regardless of host species or geographic origin. CONCLUSION: Presence of CFPHV DNA within globally distributed samples for all five species of sea turtle was confirmed. While 100% of the FP exhibiting green turtles yielded CFPHV sequences, surprisingly, so did 15% of the clinically healthy turtles. We hypothesize that turtle populations with zero (0%) CFPHV frequency may be attributed to possible environmental differences, diet and/or genetic resistance in these individuals. Our results provide first data on the prevalence of CFPHV among seemingly healthy turtles; a factor that may not be directly correlated to the disease incidence, but may suggest of a long-term co-evolutionary latent infection interaction between CFPHV and its turtle-host across species. Finally, computational analysis of amino acid variants within the Turks and Caicos samples suggest potential functional importance in a substitution for marker UL18 that encodes the major capsid protein gene, which potentially could explain differences in pathogenicity. Nevertheless, such a theory remains to be validated by further research.

Darwin's Fancy Revised: An Updated Understanding of the Genomic Constitution of Pigeon Breeds.

Through its long history of artificial selection, the rock pigeon (Columba livia Gmelin 1789) was forged into a large number of domestic breeds. The incredible amount of phenotypic diversity exhibited in these breeds has long held the fascination of scholars, particularly those interested in biological inheritance and evolution. However, exploiting them as a model system is challenging, as unlike with many other domestic species, few reliable records exist about the origins of, and relationships between, each of the breeds. Therefore, in order to broaden our understanding of the complex evolutionary relationships among pigeon breeds, we generated genome-wide data by performing the genotyping-by-sequencing (GBS) method on close to 200 domestic individuals representing over 60 breeds. We analyzed these GBS data alongside previously published whole-genome sequencing data, and this combined analysis allowed us to conduct the most extensive phylogenetic analysis of the group, including two feral pigeons and one outgroup. We improve previous phylogenies, find considerable population structure across the different breeds, and identify unreported interbreed admixture events. Despite the reduced number of loci relative to whole-genome sequencing, we demonstrate that GBS data provide sufficient analytical power to investigate intertwined evolutionary relationships, such as those that are characteristic of animal domestic breeds. Thus, we argue that future studies should consider sequencing methods akin to the GBS approach as an optimal cost-effective approach for addressing complex phylogenies.

Promises and pitfalls of using high-throughput sequencing for diet analysis.

The application of high-throughput sequencing-based approaches to DNA extracted from environmental samples such as gut contents and faeces has become a popular tool for studying dietary habits of animals. Due to the high resolution and prey detection capacity they provide, both metabarcoding and shotgun sequencing are increasingly used to address ecological questions grounded in dietary relationships. Despite their great promise in this context, recent research has unveiled how a wealth of biological (related to the study system) and technical (related to the methodology) factors can distort the signal of taxonomic composition and diversity. Here, we review these studies in the light of high-throughput sequencing-based assessment of trophic interactions. We address how the study design can account for distortion factors, and how acknowledging limitations and biases inherent to sequencing-based diet analyses are essential for obtaining reliable results, thus drawing appropriate conclusions. Furthermore, we suggest strategies to minimize the effect of distortion factors, measures to increase reproducibility, replicability and comparability of studies, and options to scale up DNA sequencing-based diet analyses. In doing so, we aim to aid end-users in designing reliable diet studies by informing them about the complexity and limitations of DNA sequencing-based diet analyses, and encourage researchers to create and improve tools that will eventually drive this field to its maturity.