Integrative phylogenetic, phylogeographic and morphological characterisation of the Unio crassus species complex reveals cryptic diversity with important conservation implications.

The global decline of freshwater mussels and their crucial ecological services highlight the need to understand their phylogeny, phylogeography and patterns of genetic diversity to guide conservation efforts. Such knowledge is urgently needed for Unio crassus, a highly imperilled species originally widespread throughout Europe and southwest Asia. Recent studies have resurrected several species from synonymy based on mitochondrial data, revealing U. crassus to be a complex of cryptic species. To address long-standing taxonomic uncertainties hindering effective conservation, we integrate morphometric, phylogenetic, and phylogeographic analyses to examine species diversity within the U. crassus complex across its entire range. Phylogenetic analyses were performed using cytochrome c oxidase subunit I (815 specimens from 182 populations) and, for selected specimens, whole mitogenome sequences and Anchored Hybrid Enrichment (AHE) data on âˆ¼ 600 nuclear loci. Mito-nuclear discordance was detected, consistent with mitochondrial DNA gene flow between some species during the Pliocene and Pleistocene. Fossil-calibrated phylogenies based on AHE data support a Mediterranean origin for the U. crassus complex in the Early Miocene. The results of our integrative approach support 12 species in the group: the previously recognised Unio bruguierianus, Unio carneus, Unio crassus, Unio damascensis, Unio ionicus, Unio sesirmensis, and Unio tumidiformis, and the reinstatement of five nominal taxa: Unio desectusstat. rev., Unio gontieriistat. rev., Unio mardinensisstat. rev., Unio nanusstat. rev., and Unio vicariusstat. rev. Morphometric analyses of shell contours reveal important morphospace overlaps among these species, highlighting cryptic, but geographically structured, diversity. The distribution, taxonomy, phylogeography, and conservation of each species are succinctly described.

Investigation of the safety and feasibility of AAV1/SERCA2a gene transfer in patients with chronic heart failure supported with a left ventricular assist device - the SERCA-LVAD TRIAL.

The SERCA-LVAD trial was a phase 2a trial assessing the safety and feasibility of delivering an adeno-associated vector 1 carrying the cardiac isoform of the sarcoplasmic reticulum calcium ATPase (AAV1/SERCA2a) to adult chronic heart failure patients implanted with a left ventricular assist device. The SERCA-LVAD trial was one of a program of AAV1/SERCA2a cardiac gene therapy trials including CUPID1, CUPID 2 and AGENT trials. Enroled subjects were randomised to receive a single intracoronary infusion of 1 × 1013 DNase-resistant AAV1/SERCA2a particles or a placebo solution in a double-blinded design, stratified by presence of neutralising antibodies to AAV. Elective endomyocardial biopsy was performed at 6 months unless the subject had undergone cardiac transplantation, with myocardial samples assessed for the presence of exogenous viral DNA from the treatment vector. Safety assessments including ELISPOT were serially performed. Although designed as a 24 subject trial, recruitment was stopped after five subjects had been randomised and received infusion due to the neutral result from the CUPID 2 trial. Here we describe the results from the 5 patients at 3 years follow up, which confirmed that viral DNA was delivered to the failing human heart in 2 patients receiving gene therapy with vector detectable at follow up endomyocardial biopsy or cardiac transplantation. Absolute levels of detectable transgene DNA were low, and no functional benefit was observed. There were no safety concerns in this small cohort. This trial identified some of the challenges of performing gene therapy trials in this LVAD patient cohort which may help guide future trial design.

Fibula physeal fracture causing syndesmotic diastasis.

We report an unusual physeal fibula fracture seen in a 12 year old child. The fragment was rotated and incarcerated in the distal tibiofibular joint causing syndesmotic diastasis. The fragment required open reduction and the fibula was stabilised with k-wires. The patient made an excellent recovery.

Environmentally friendly splints for limb immobilisation: a systematic review.

INTRODUCTION: Climate change is estimated to be the biggest global health threat of the 21st century, and has prompted calls to move away from processes in healthcare associated with high energy consumption and greenhouse gas emission. In musculoskeletal medicine, splints are widely used for limb immobilisation. These have typically been made from single-use materials such as gypsum, although in recent years purportedly environmentally friendly splints have been designed. In this systematic review, we set out to assess the clinical effectiveness of all commercially available environmentally friendly splinting materials, including Woodcast®. METHODS: The AMED (Allied and Complementary Medicine Database), CINAHL® (Cumulative Index to Nursing and Allied Health Literature), Cochrane Central Register of Controlled Trials, Embase®, Emcare® and MEDLINE® databases were searched to identify studies assessing the clinical effectiveness of biodegradable and environmentally friendly splints prior to paper review and data extraction. Formal quantitative synthesis was not possible owing to the substantial heterogeneity in the study designs and outcome measures. RESULTS: Six papers met the inclusion criteria, all investigating one particular splint material (Woodcast®). One was a case series, two were cohort studies and three were randomised controlled trials. Primary outcome measures were heterogeneous but the environmentally friendly splints were generally equivalent to traditional splint materials. Studies were mostly at a high risk of bias. CONCLUSIONS: There is limited research assessing 'green' splints in practice although the data suggest similarity with existing materials and no substantial safety concerns. Further scrutiny of the clinical effectiveness and environmental credentials of such splints is also required.

Effect of prolonged exercise and pre-exercise dietary manipulation on hepatic triglycerides in trained men.

The purpose of this study was to examine the effect of exercise and pre-exercise dietary manipulation on hepatic triglyceride concentration (HTGC). HTGC was measured by proton magnetic resonance spectroscopy ((1)H-MRS) before and after 90 min of moderate intensity cycling in six endurance trained males following 67 h of mixed diet (M) and an isocaloric minimal carbohydrate (2%) high fat (83%) diet (HF). Diets were administered by balanced crossover design. Whole-body fat oxidation, plasma-free fatty acid (FFA), glycerol and triglyceride concentrations were significantly elevated during exercise in HF versus M (P < 0.05 for all). There was no significant treatment × time interaction for HTGC (P = 0.368). However, there was a significant net increase in HTGC (time effect) during the combined 6 h exercise and post-exercise period (P = 0.037). In conclusion, we observed no measurable net change in the hepatic triglyceride pool across a period involving a prolonged exercise bout. Furthermore, manipulation of pre-exercise dietary intake did not influence the interaction between the hepatic triglyceride concentration and exercise in lean trained men. This supports the contention that hepatic triglycerides do not meaningfully contribute to the high rate of fat oxidation observed during acute exercise, or the enhancement of this with regular exercise training and/or pre-exercise dietary manipulation.

The relationship between temperature and hip and wrist fracture incidence.

INTRODUCTION: Predicting when fracture incidence will rise assists in healthcare planning and delivery of preventative strategies. The aim of this study was to investigate the relationship between temperature and the incidence of hip and wrist fractures. METHODS: Data for adults presenting to our unit with a hip or wrist fracture over a seven and eight-year period respectively were analysed. Incidence rates were calculated and compared with meteorological records. A Poisson regression model was used to quantify the relationship between temperature and fracture rate. RESULTS: During the respective study periods, 8,380 patients presented with wrist fractures and 5,279 patients were admitted with hip fractures. All women (≥50 years: p<0.001; <50 years: p<0.001) and men aged ≥50 years (p=0.046) demonstrated an increased wrist fracture rate with reduced temperature. Men aged <50 years also had an increased wrist fracture rate with increased temperature (p<0.001).The hip fracture rate was highest in women aged ≥50 years but was not associated with temperature (p=0.22). In men aged ≥50 years, there was a significant relationship between reduced temperature and increased fracture rate (p<0.001). CONCLUSIONS: Fragility fracture of the wrist is associated with temperature. Compared with an average summer, an additional 840 procedures are performed for wrist fractures during an average winter in our trust with an additional 798 bed days taken up at a cost of £3.2 million. The winter increase seen in male hip fracture incidence requires approximately 888 surgical procedures, with 18,026 bed days, and costs £7.1 million. Hip fracture incidence in older women is not related to temperature.

Proximal humerus fracture-dislocation managed by mini-open reduction and percutaneous screw fixation.

BACKGROUND: We describe a minimally open reduction and percutaneous fixation technique for three- and four-part proximal humeral fracture-dislocations which preserves soft tissues. METHODS: Eleven consecutive patients with three-and four-part proximal humeral fracture-dislocations (eight anterior, three posterior dislocations) were treated this way. The dislocation is reduced using a mini-open deltopectoral approach with a horizontal split in subscapularis. Fracture fragments are fixed with percutaneous screws. Constant and Oxford Shoulder Score were collected prospectively. RESULTS: Mean age was 51 years (range 32-65). Mean follow-up was 36 months (range 24-72 months). At last follow-up mean Constant score was 75 (range 64-86) compared to 88 (range 85-92) for the uninjured shoulder. Mean Oxford shoulder score was 41 (range 34-46). One patient developed avascular necrosis. Screw back out was seen in three patients. These were removed under local anaesthesia. There were no screw penetrations of articular surface. One patient suffered a radial nerve neuropraxia which resolved. CONCLUSION: These results are promising and comparable to published literature with other means of fixation for this complex problem. Due to minimal soft tissue dissection the complications rate is low.

Trends in paediatric distal radius fractures: an eight-year review from a large UK trauma unit.

INTRODUCTION: This observational study investigated the incidence of distal radius fractures in children, to determine whether the rate is rising, the effect of seasonal variation on incidence and whether fracture type and rate of surgical intervention has changed, to help in determining costs for secondary care and to aid resource allocation. MATERIALS AND METHODS: All paediatric patients(n = 6529) who sustained a distal radius fracture over an eight-year period (2007-2014) were identified. Poisson regression modelling was used to identify change in trends. RESULTS: There was no change in distal radius fracture incidence, rate of surgical intervention (P = 0.36) or fracture type (P = 0.70). Overall incidence was 337 fractures per 100,000 patient/years. The highest fracture incidence was seen in older school boys (708 per 100,000 patient/years, P < 0.005). Overall fracture rate was lower in winter (P < 0.005). Incidence is highest in summer and the main variation is related to season. DISCUSSION: These data can help to predict accurately the number of children presenting to the emergency department with wrist fractures depending on the time of year.

A systematic review and meta-analysis of interval training versus moderate-intensity continuous training on body adiposity.

Interval training (including high-intensity interval training [HIIT] and sprint interval training [SIT]) is promoted in both scientific and lay media as being a superior and time-efficient method for fat loss compared with traditional moderate-intensity continuous training (MICT). We evaluated the efficacy of HIIT/SIT when directly compared with MICT for the modulation of body adiposity. Databases were searched to 31 August 2016 for studies with exercise training interventions with minimum 4-week duration. Meta-analyses were conducted for within-group and between-group comparisons for total body fat percentage (%) and fat mass (kg). To investigate heterogeneity, we conducted sensitivity and meta-regression analyses. Of the 6,074 studies netted, 31 were included. Within-group analyses demonstrated reductions in total body fat (%) (HIIT/SIT: -1.26 [95% CI: -1.80; -0.72] and MICT: -1.48 [95% CI: -1.89; -1.06]) and fat mass (kg) (HIIT/SIT: -1.38 [95% CI: -1.99; -0.77] and MICT: -0.91 [95% CI: -1.45; -0.37]). There were no differences between HIIT/SIT and MICT for any body fat outcome. Analyses comparing MICT with HIIT/SIT protocols of lower time commitment and/or energy expenditure tended to favour MICT for total body fat reduction (p = 0.09). HIIT/SIT appears to provide similar benefits to MICT for body fat reduction, although not necessarily in a more time-efficient manner. However, neither short-term HIIT/SIT nor MICT produced clinically meaningful reductions in body fat.

Comparison of distal radius fracture intra-articular step reduction with volar locking plates and K wires: a retrospective review of quality and maintenance of fracture reduction.

This study investigated the accuracy and maintenance of reduction of intra-articular steps achieved with closed reduction and percutaneous K wires and open reduction and a volar locking plate for the treatment of intra-articular distal radius fractures. We performed a retrospective review of 359 patients with an intra-articular fracture of their distal radius. Multivariate linear regression was undertaken to investigate the influence of multiple variables such as age, gender, initial displacement and treatment method on reduction despite differences between groups. A total of 36% of patients treated with K wires and 29% with volar locking plate had a step greater than or equal to 1 mm present on the first post-operative radiograph. A total of 23% treated with K wires and 28% with volar locking plate had a residual step of 1 mm or more on the last available radiograph. There was no difference identified between the two techniques for quality of initial reduction or persisting step on the last available radiographs. Step behaviour and further reduction of step post-operatively was similar for both treatment methods. Initial displacement and increased age influenced initial reduction. Initial fracture displacement shown radiologically was the only variable identified that influenced the persistence of a step on post-operative radiographs. LEVEL OF EVIDENCE: IV.

Risk factors for intramedullary nail breakage in proximal femoral fractures: a 10-year retrospective review.

INTRODUCTION Intramedullary nailing is a common treatment for proximal femoral fractures. Fracture of the nail is a rare but devastating complication that exposes often frail patients to complex revision surgery. We investigated which risk factors predict nail failure. METHODS We reviewed all cases of nail breakage seen over a 10-year period in a single busy trauma unit; 22 nail fractures were seen in 19 patients. Comparison was made with a group of 209 consecutive patients who underwent intramedullary fixation of a proximal femur fracture with no nail breakage over a 2-year period. RESULTS In the fractured nail group, mean age was 70.4 years (range 55-88 years).The mean time to fracture was 10 months (range 2.5-23 months). Logistical regression was used to show that low American Society of Anesthesiologists (ASA) score, subtrochanteric fracture and pathological fracture were independent risk factors for nail fracture. CONCLUSIONS Young patients with a low ASA score are at highest risk of nail breakage. We advise close follow-up of patients with these risk factors until bony union has been achieved. In addition, there may be merit in considering other treatment options, such as proximal femoral replacement, especially for those with pathological fracture with a good prognosis.

Exercise and ectopic fat in type 2 diabetes: A systematic review and meta-analysis.

Ectopic adipose tissue surrounding the intra-abdominal organs (visceral fat) and located in the liver, heart, pancreas and muscle, is linked to cardio-metabolic complications commonly experienced in type 2 diabetes. A systematic review and meta-analysis was performed to determine the effect of exercise on ectopic fat in adults with type 2 diabetes. Relevant databases were searched to February 2016. Included were randomised controlled studies, which implemented≥4 weeks of aerobic and/or resistance exercise and quantified ectopic fat via magnetic resonance imaging, computed tomography, proton magnetic resonance spectroscopy or muscle biopsy before and after intervention. Risk of bias and study quality was assessed using Egger's funnel plot test and modified Downs and Black checklist, respectively. Of the 10,750 studies retrieved, 24 were included involving 1383 participants. No studies were found assessing the interaction between exercise and cardiac or pancreas fat. One study assessed the effect of exercise on intramyocellular triglyceride concentration. There was a significant pooled effect size for the meta-analysis comparing exercise vs. control on visceral adiposity (ES=-0.21, 95% CI: -0.37 to -0.05; P=0.010) and a near-significant pooled effect size for liver steatosis reduction with exercise (ES=-0.28, 95% CI: -0.57 to 0.01; P=0.054). Aerobic exercise (ES=-0.23, 95% CI: -0.44 to -0.03; P=0.025) but not resistance training exercise (ES=-0.13, 95% CI: -0.37 to 0.12; P=0.307) was effective for reducing visceral fat in overweight/obese adults with type 2 diabetes. These data suggest that exercise effectively reduces visceral and perhaps liver adipose tissue and that aerobic exercise should be a key feature of exercise programs aimed at reducing visceral fat in obesity-related type 2 diabetes. Further studies are required to assess the relative efficacy of exercise modality on liver fat reduction and the effect of exercise on pancreas, heart, and intramyocellular fat in type 2 diabetes and to clarify the effect of exercise on ectopic fat independent of weight loss.

An empirical test of the meiotic drive models of hybrid sterility: sex-ratio data from hybrids between Drosophila simulans and Drosophila sechellia.

Recently, there has been much discussion regarding the hypothesis that divergence of meiotic drive systems in isolated populations can generate the patterns of reproductive isolation observed in animal hybridizations. One prediction from this hypothesis is that the sex ratio of hybrids with heterospecific sex chromosomes should greatly deviate from the Mendelian expectation of 50% female. From sex-ratio data in our Drosophila hybridization studies, we find no such deviation: the sex ratio of offspring of males with introgressed heterospecific Y chromosomes with various autosomal backgrounds does not differ from that of the pure species. We also discuss other aspects of the current meiotic drive models.

The population genetics of synthetic lethals.

Synthetic lethals are variants at different loci that have little or no effect on viability singly but cause lethality in combination. The importance of synthetic lethals and, more generally, of synthetic deleterious loci (SDL) has been controversial. Here, we derive the expected frequencies for SDL under a mutation-selection balance for the complete haploid model and selected cases of the diploid model. We have also obtained simple approximations that demonstrate good fit to exact solutions based on numerical iterations. In the haploid case, equilibrium frequencies of carrier haplotypes (individuals with only a single mutation) are comparable to analogous single-locus results, after allowing for the effects of linkage. Frequencies in the diploid case, however, are much higher and more comparable to the square root of the single-locus results. In particular, when selection operates only on the double-mutant homozygote and linkage is not too tight, the expected frequency of the carriers is approximately the quartic root of the ratio between the mutation rate and the selection coefficient of the synthetics. For a reasonably wide set of models, the frequencies of carriers can be on the order of a few percent. The equilibrium frequencies of these deleterious alleles can be relatively high because, with SDL, both dominance and epistasis act to shield carriers from exposure to selection. We also discuss the possible role of SDL in maintaining genetic variation and in hybrid breakdown.

Analysis of autosomal polygenic variation for the expression of Haldane's rule in flour beetles.

Haldane's rule states that, in interspecific crosses, when hybrid viability or fertility is diminished more in one sex of the hybrids than in the other, the heterogametic sex is more adversely affected. We used quantitative genetic methods to investigate the genetic basis of variation for the expression of the viability aspect of Haldane's rule when Tribolium castaneum males are crossed to Tribolium freemani females. Using a half-sib design, we found significant genetic variance for the expression of Haldane's rule, i.e., variation among T. castaneum sires in the hybrid sex ratios produced by their sons. We also derived 23 independent lineages from the same base population by 8 generations of brother-sister mating. From the same experiments, we also found heritable variation among surviving hybrid males in the incidence of antennal deformities. Upon inbreeding, the variance of both traits (hybrid sex ratio and proportion deformities) increased substantially but the means changed little. Because fitness within T. castaneum lineages declined substantially with inbreeding, we infer that hybrid male viability may have a different genetic basis than viability fitness within species. Deleterious recessive alleles held within species by mutation/selection balance appear not to be a major contributor to hybrid incompatibility.

The effects of interspecific Y chromosome replacements on hybrid sterility within the Drosophila simulans clade.

We attempted to introgress Y chromosomes between three sibling species of Drosophila: D. simulans, D. sechellia and D. mauritiana. Four D. sechellia Y chromosomes were introgressed into D. simulans without loss of fertility whereas the four reciprocal introgressions (D. simulans Y introgressed into D sechellia) all result in sterility. Both reciprocal Y introgressions of D. simulans and D. mauritiana (four of each) also result in sterility. Compared with D. simulans males, the males with the D. sechellia Y chromosome in D. simulans background had lower productivity but only after multiple matings with virgin females. These males also were inferior compared with pure species males in sperm displacement and/or remating ability. The two different Y genotype males, however, were comparable in viability, longevity and mating success in female choice tests. We also use our results to estimate the effective number of autosomal loci interacting with X-linked genes to produce hybrid male sterility.

Genetics of reproductive isolation in the Drosophila simulans clade: DNA marker-assisted mapping and characterization of a hybrid-male sterility gene, Odysseus (Ods).

In this study, we address the question of whether there exist major genes that cause complete male sterility in the interspecific hybrids of Drosophila and, if they do, how these genes may be characterized at the molecular level. Our approach is to introgress small segments of the X chromosome from Drosophila mauritiana (or Drosophila sechellia) into Drosophila simulans by repeated backcrosses for more than 20 generations. The introgressions are monitored by both visible mutations and a series of DNA markers. We compare the extent of introgressions that cause male sterility with those that do not. If a major sterility factor exists, there should be a sharp boundary between these two classes of introgressions and their breakpoints should demarcate such a gene. Furthermore, if male sterility is the only major fitness effect associated with the introgression, recombination analysis should yield a pattern predicted by the classical three-point cross. Both the genetic and molecular analyses suggest the presence of a major sterility factor from D. mauritiana, which we named Odysseus (Ods), in the cytological interval of 16D. We thus formalize three criteria for inferring the existence of a major gene within an introgression: (1) complete penetrance of sterility, (2) complementarity in recombination analysis, and (3) physical demarcation. Introgressions of Ods from D. sechellia do not cause sterility. Twenty-two introgressions in our collection have breakpoints in this interval of about 500 kb, making it possible to delineate Ods more precisely for molecular identification. The recombination analysis also reveals the complexity of the introgressed segments--even relatively short ones may contain a second male sterility factor and partial viability genes and may also interfere with crossovers. The spermatogenic defects associated with Ods and/or a second factor were characterized by phase-contrast microscopy.

Genetics of reproductive isolation in the Drosophila simulans clade: complex epistasis underlying hybrid male sterility.

We have analyzed the sterility associated with introgressions of the distal one-fourth of the X chromosome from either Drosophila mauritiana or Drosophila sechellia into the genome of Drosophila simulans using a series of visible and DNA markers. Because in Drosophila hybrids, male sterility is usually complete and is often tightly linked with each of several markers used in crosses, a simple genetic basis has generally been assumed. In our low resolution mapping experiment, we were not able to reject the null hypothesis that a single gene, introgressed from either D. mauritiana or D. sechellia, is the cause of male sterility. High resolution mapping, however, reveals a much more complex picture. At least three distinct factors from D. mauritiana, or two from D. sechellia, were identified that need to be jointly present to confer full sterility. Each individual factor by itself is relatively ineffective in causing sterility, or even a partial spermatogenic defect. Moreover, there appear to be more sterility factors on comparable introgressions from D. mauritiana than from D. sechellia. On the basis of these observations, we propose a model which suggests that multilocus weak allele interactions are a very common cause of reproductive incompatibility between closely related species. We also present theoretical argument and empirical evidence against extrapolating the results of within-species analysis to interpret the genetic basis of species differences. The implications of this model on the theories of evolution of species differences and the attempt to understand the mechanisms of hybrid sterility/inviability at the molecular level are discussed.

High mutability in male hybrids of Drosophila melanogaster.

The frequencies of sex-linked lethal mutations arising in hybrid male offspring from crosses and in nonhybrid controls were determined. The hybrids were produced by crossing representative strains of the P-M system of hybrid dysgenesis in all possible combinations. Males from the cross of P males x M females had a mutation rate about 15 times higher than that of nonhybrid males from the P strain. Genetically identical males from the reciprocal cross had a mutation rate 3 to 4 times that of the nonhybrids. For crosses involving a Q strain, a significant increase in the mutation rate was detected in males produced by matings of Q males with M females. No increase was observed in genetically identical males from the reciprocal mating. Crosses between P and Q strains gave male hybrids with mutation rates not different from those of nonhybrids. Many of the lethals that occurred in hybrids from the cross of P males x M females appeared to be unstable; fewer lethals that arose in hybrids from the cross of Q males x M females were unstable. The relationship between P and Q strains is discussed with respect to a model of mutation induction in dysgenic hybrids.

Genetic variation segregating in natural populations of Tribolium castaneum affecting traits observed in hybrids with T. freemani.

We investigated patterns of within-species genetic variation for traits observed in hybrids (hybrid numbers, hybrid sex ratios, and hybrid male deformities) between two species of flour beetles, Tribolium castaneum and T. freemani. We found genetic variation segregating among four natural populations of T. castaneum as well as within these populations. For some hybrid traits, we observed as much variation among populations 750 km apart as between populations on different continents, suggesting genetic differentiation at a local scale. Within natural populations, the variation segregating among sires is greater than that found in an earlier study for an outbred laboratory population and comparable to that observed between inbred lines derived from the outbred stock by eight generations of brother-sister mating. When sires from T. castaneum are mated to conspecific and heterospecific females, we do not observe a significant correlation at the level of the family mean between the intraspecific and interspecific phenotypes, suggesting the independence of the hybrid traits from comparable traits within species. We discuss our findings in relation to the evolutionary genetics of speciation and the expression of epistatic genetic variance in interspecific crosses.