433 research outputs found
Potential changes to French recommendations about peri-prosthetic infections based on the international consensus meeting (ICMPJI)
AbstractBackgroundDespite the large volume of studies on the prevention, diagnosis, and treatment of peri-prosthetic infections, surgical practice often rests on limited scientific evidence in this field. The vast International Consensus Meeting on Peri-prosthetic Joint Infection (ICMPJI) held in 2013 produced robust recommendations.HypothesisFrench consensus conference recommendations show no major differences with ICMPJI recommendations.Materials and methodsThe 207 recommendations developed by 300 experts at the ICMPJI were translated, and the translation was then examined by four reviewers, including 2 having participated in the consensus conference. The reviewers looked for any differences with French practices and recommendations.ResultsTwenty-three major differences or innovations were identified compared to French recommendations and standard practice. Among them, pre-operative screening for nasal or urinary micro-organisms is performed routinely in France but should be reserved according to the ICMPJI for symptomatic patients and/or patients at high risk for infection. The ICMPJI emphasizes the role for the operating room environment as a vector for infection; more specifically, the operating lamp handle and suction cannula deserve close attention. A wound discharge persisting longer than 5–7 days requires irrigation and debridement. This procedure is effective only within the first 3 post-operative months and/or the first 3 weeks after symptom onset and must include exchange of all modular implants. The ICMPJI warns against both irrigation-debridement in fungal infections (suggesting two-stage prosthesis replacement) and one-stage replacement in patients with sinus tracts. The use of spacers (articulating at the knee) is recommended in the event of two-stage prosthesis replacement.DiscussionThe ICMPJI recommendations differed in many ways with French recommendations and standard practice. They can be expected to impact practices in France, although a point worth noting is that only 1 of the 207 recommendations received unanimous agreement by the conference experts (keeping operating room traffic to a minimum)
Comparative ploidy response to experimental hydrogen peroxide exposure in Atlantic salmon (Salmo salar)
While research into the growth, survival, nutrition and, more recently, disease susceptibility of triploid Atlantic salmon has expanded, there remains an overall lack of studies assessing the response of triploids to chemical treatments. It is essential that the response of triploids to disease treatments be characterised to validate their suitability for commercial production. This study aimed to investigate and compare the stress and immune responses of triploid and diploid Atlantic salmon following an experimental treatment with hydrogen peroxide (H2O2). A dose response test was first undertaken to determine a suitable test dose for both diploid and triploid Atlantic salmon. Following this, diploids and triploids were exposed to H2O2 (1800 ppm) for 20 min, as per commercial practices, after which blood glucose and lactate, and plasma cortisol and lysozyme were measured, along with the expression of oxidative stress and immune-related genes. In the first 6 h post-exposure to H2O2, comparable mortalities occurred in both diploid and triploid Atlantic salmon. Cortisol, glucose and lactate were not significantly influenced by ploidy suggesting that, physiologically, triploid Atlantic salmon are able to cope with the stress associated with H2O2 exposure as well as their diploid counterparts. Exposure to H2O2 significantly elevated the expression of cat and sod2 in diploid livers and gr, il1β and crp/sap1b in diploid gills, while it significantly decreased the expression of saa5 and crp/sap1a in diploid gills. In triploids, the expression levels of cat, hsp70, sod1, saa5, crp/sap1a and crp/sap1b in liver was significantly higher in fish exposed to H2O2 compared to control fish. The expression of gr, sod1 and il1β in triploid gills was also elevated in response to H2O2 exposure. This study represents the first experimental evidence of the effects of H2O2 exposure on triploid Atlantic salmon and continues to support their application into commercial production
Short term cold storage and sperm concentration assessment of lumpfish (Cyclopterus lumpus. L) Milt
There is increased commercial interest in the production of lumpfish (Cyclopterus lumpus) as a biological control against sea lice infections in Atlantic salmon farming. To ensure a sustainable supply of lumpfish, reliable captive reproduction is required however, optimal husbandry and conditions for captive broodstock performance remain unknown. Artificial fertilisation of gametes remains the preferred management strategy for lumpfish, but this requires an effective milt management protocol. The present study tested several milt extender solutions for short term cold storage and validated sperm concentration assessment of lumpfish milt. Results demonstrated lumpfish sperm has a long motility survival time (motile for up to 3 h) when compared to other marine teleosts. Importantly, all extenders used in the study were non-activating on dilution of the milt. Lumpfish milt was successfully stored at 4 °C in Modified Turbot Extender (MTE), Herring Ringers Solution and Aquaboost SpermCoat (Cryogenetics, Norway) for up to 14 days post stripping. MTE performed more effectively with regards to maintenance of sperm activation time in comparison to the other tested extenders. There was a significant positive correlation between sperm concentration identified through cell counts using a haemocytometer and both packed cell volume (spermatocrit) and measured optical density at 640 nm (r2 = 97.42 ± 2.14). This suggests both packed cell volume and spectrophotometric measurements can be effective methods for rapidly assessing sperm concentration in lumpfish. This study validated several options for quantifying sperm concentration and short-term cold storage of lumpfish milt that can be used for hatchery management in lumpfish aquaculture
A Temporally Dynamic Gut Microbiome in Atlantic Salmon During Freshwater Recirculating Aquaculture System (RAS) Production and Post-seawater Transfer
This study was funded by the UKRI project ROBUSTSMOLT (BBSRC BB/S004270/1 and BB/S004432/1). There was also cofunding from the Scottish Aquaculture Innovation Centre. ACKNOWLEDGMENTS The authors would like to thank John Richmond and staff at MOWI and the Centre for Genome Enabled Biology and Medicine (CGEBM) at the University of Aberdeen, particularly Dr. Ewan Campbell, for help with amplification protocols, conducting 16S library preparation and sequencing. The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: https://www.ncbi.nlm.nih.gov/bioproject/PRJNA729215.Peer reviewedPublisher PD
Seasonal variation in collective mood via Twitter content and medical purchases
The analysis of sentiment contained in vast amounts of Twitter messages has reliably shown seasonal patterns of variation in multiple studies, a finding that can have great importance in the understanding of seasonal affective disorders, particularly if related with known seasonal variations in certain hormones. An important question, however, is that of directly linking the signals coming from Twitter with other sources of evidence about average mood changes. Specifically we compare Twitter signals relative to anxiety, sadness, anger, and fatigue with purchase of items related to anxiety, stress and fatigue at a major UK Health and Beauty retailer. Results show that all of these signals are highly correlated and strongly seasonal, being under-expressed in the summer and over-expressed in the other seasons, with interesting differences and similarities across them. Anxiety signals, extracted from both Twitter and from Health product purchases, peak in spring and autumn, and correlate also with the purchase of stress remedies, while Twitter sadness has a peak in the Winter, along with Twitter anger and remedies for fatigue. Surprisingly, purchase of remedies for fatigue do not match the Twitter fatigue, suggesting that perhaps the names we give to these indicators are only approximate indications of what they actually measure. This study contributes both to the clarification of the mood signals contained in social media, and more generally to our understanding of seasonal cycles in collective mood
Response of triploid Atlantic salmon (Salmo salar) to commercial vaccines
While triploid Atlantic salmon represent a practical and affordable solution to the issues associated with sexual maturation in the salmonid aquaculture industry, empirical evidence suggests triploids are more susceptible to disease and vaccine side-effects than diploids. With vaccination now part of routine husbandry, it is essential their response be studied to confirm their suitability for commercial production. This study tested the response of triploid and diploid Atlantic salmon to vaccination with commercially available vaccines. Triploid and diploid Atlantic salmon siblings were injected with one of three commercial vaccines (or sham-vaccinated) and monitored for performance throughout a commercial production cycle. Sampling at smolt and harvest was undertaken along with individual weight and length assessments through the cycle. Antibody response to Aeromonas salmonicida vaccination was similar in both ploidy, with a positive response in vaccine-injected fish. For both adhesions and melanin, analysis found that higher scores were more likely to occur as the anticipated severity of the vaccine increased. In addition, for adhesion scores at smolt and melanin scores at smolt and harvest, triploids were statistically more likely to exhibit high scores than diploids. Triploids maintained a significantly higher body weight during freshwater and until 11 months post-seawater transfer, with diploids weighing significantly more at harvest. Growth, represented by thermal growth coefficient (TGC), decreased in both ploidy as the severity of adhesions increased, and regression patterns did not differ significantly between ploidy. Vertebral deformity prevalence was consistently higher in triploids (smolt 12.3 ± 4.5%; harvest 34.9 ± 5.9%) than diploids (smolt 0.8 ± 0.5%; harvest 15.9 ± 1.9%), with no significant difference between vaccine groups in each ploidy. This study demonstrates that triploids respond as well to vaccination as diploids and provides further supporting evidence of triploid robustness for commercial aquaculture
The Impact of Escaped Farmed Atlantic Salmon (Salmo salar L.) on Catch Statistics in Scotland
In Scotland and elsewhere, there are concerns that escaped farmed Atlantic salmon (Salmo salar L.) may impact on wild salmon stocks. Potential detrimental effects could arise through disease spread, competition, or inter-breeding. We investigated whether there is evidence of a direct effect of recorded salmon escape events on wild stocks in Scotland using anglers' counts of caught salmon (classified as wild or farmed) and sea trout (Salmo trutta L.). This tests specifically whether documented escape events can be associated with reduced or elevated escapes detected in the catch over a five-year time window, after accounting for overall variation between areas and years. Alternate model frameworks were somewhat inconsistent, however no robust association was found between documented escape events and higher proportion of farm-origin salmon in anglers' catch, nor with overall catch size. A weak positive correlation was found between local escapes and subsequent sea trout catch. This is in the opposite direction to what would be expected if salmon escapes negatively affected wild fish numbers. Our approach specifically investigated documented escape events, contrasting with earlier studies examining potentially wider effects of salmon farming on wild catch size. This approach is more conservative, but alleviates some potential sources of confounding, which are always of concern in observational studies. Successful analysis of anglers' reports of escaped farmed salmon requires high data quality, particularly since reports of farmed salmon are a relatively rare event in the Scottish data. Therefore, as part of our analysis, we reviewed studies of potential sensitivity and specificity of determination of farmed origin. Specificity estimates are generally high in the literature, making an analysis of the form we have performed feasible
High temperature is detrimental to captive lumpfish (Cyclopterus lumpus, L) reproductive performance
There is increased commercial interest in the production of Lumpfish (Cyclopterus lumpus, Linnaeus, 1758) as a biological control for sea lice infections in Atlantic salmon farming. To ensure sustainability, reliable captive breeding is required however, optimal husbandry conditions for broodstock performance remain unknown. The present study investigated the effects of holding temperature on spawning productivity and gamete quality in captivity reared lumpfish. Sexually mature lumpfish (15 month old) were held on three temperature regimes (6 °C, 9 °C and 14 °C) from the onset of first spawning. Holding mature lumpfish at high temperatures (14 °C) resulted in a notable reduction in spawning activity with a significant reduction in sperm density (50% reduction compared to pre-treatment levels) and furthermore resulted in the production of non-viable oocytes (0% to eyeing rate). Holding lumpfish at 9 °C and 6 °C did not have a similar negative impact on gamete quality, however the spawning season for the 6 °C treatment was twice as long as the 9 °C treatment. These results indicate that holding temperature for lumpfish broodstock should not reach the 14 °C degree threshold, with a possible thermal optimum below 10 °C. The current findings are the first step in identifying optimal rearing conditions for captive Lumpfish broodstock
Environmental Cycles, Melatonin, and Circadian Control of Stress Response in Fish
Fish have evolved a biological clock to cope with environmental cycles, so they display circadian rhythms in most physiological functions including stress response. Photoperiodic information is transduced by the pineal organ into a rhythmic secretion of melatonin, which is released into the blood circulation with high concentrations at night and low during the day. The melatonin rhythmic profile is under the control of circadian clocks in most fish (except salmonids), and it is considered as an important output of the circadian system, thus modulating most daily behavioral and physiological rhythms. Lighting conditions (intensity and spectrum) change in the underwater environment and affect fish embryo and larvae development: constant light/darkness or red lights can lead to increased malformations and mortality, whereas blue light usually results in best hatching rates and growth performance in marine fish. Many factors display daily rhythms along the hypothalamus-pituitary-interrenal (HPI) axis that controls stress response in fish, including corticotropin-releasing hormone (Crh) and its binding protein (Crhbp), proopiomelanocortin A and B (Pomca and Pomcb), and plasma cortisol, glucose, and lactate. Many of these circadian rhythms are under the control of endogenous molecular clocks, which consist of self-sustained transcriptional-translational feedback loops involving the cyclic expression of circadian clock genes (clock, bmal, per, and cry) which persists under constant light or darkness. Exposing fish to a stressor can result in altered rhythms of most stress indicators, such as cortisol, glucose, and lactate among others, as well as daily rhythms of most behavioral and physiological functions. In addition, crh and pomca expression profiles can be affected by other factors such as light spectrum, which strongly influence the expression profile of growth-related (igf1a, igf2a) genes. Additionally, the daily cycle of water temperature (warmer at day and cooler at night) is another factor that has to be considered. The response to any acute stressor is not only species dependent, but also depends on the time of the day when the stress occurs: nocturnal species show higher responses when stressed during day time, whereas diurnal fish respond stronger at night. Melatonin administration in fish has sedative effects with a reduction in locomotor activity and cortisol levels, as well as reduced liver glycogen and dopaminergic and serotonergic activities within the hypothalamus. In this paper, we are reviewing the role of environmental cycles and biological clocks on the entrainment of daily rhythms in the HPI axis and stress responses in fish
Metabolomic profiling to dissect the role of visceral fat in cardiometabolic health
OBJECTIVE: Abdominal obesity is associated with increased risk of type 2 diabetes (T2D) and cardiovascular disease. The aim of this study was to assess whether metabolomic markers of T2D and blood pressure (BP) act on these traits via visceral fat (VF) mass. METHODS: Metabolomic profiling of 280 fasting plasma metabolites was conducted on 2,401 women from TwinsUK. The overlap was assessed between published metabolites associated with T2D, insulin resistance, or BP and those that were identified to be associated with VF (after adjustment for covariates) measured by dual‐energy X‐ray absorptiometry. RESULTS: In addition to glucose, six metabolites were strongly associated with both VF mass and T2D: lactate and branched‐chain amino acids, all of them related to metabolism and the tricarboxylic acid cycle; on average, 38.5% of their association with insulin resistance was mediated by their association with VF mass. Five metabolites were associated with BP and VF mass including the inflammation‐associated peptide HWESASXX, the steroid hormone androstenedione, lactate, and palmitate. On average, 29% of their effect on BP was mediated by their association with VF mass. CONCLUSIONS: Little overlap was found between the metabolites associated with BP and those associated with insulin resistance via VF mass
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