345 research outputs found

    Arthroscopic removal of palmar intermediate carpal bone fracture fragments in four horses using a transthecal approach through the carpal flexor tendon sheath

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    OBJECTIVE: To describe the removal of palmar intermediate carpal bone (ICB) fracture fragments using a transthecal approach through the carpal flexor tendon sheath. STUDY DESIGN: Case series. ANIMALS: Four horses with fractures of the palmar aspect of the ICB. METHODS: Two horses were injured when falling and two during recovery from general anesthesia. Three horses underwent MRI to supplement conventional imaging. Three horses had concurrent fractures of the radial and/or accessory carpal bones. Conventional proximolateral carpal sheath arthroscope and instrument portals were used, supplemented with a medial instrument portal through the carpal flexor retinaculum to access the palmar carpal ligament. Optimized dissection through the latter was facilitated by needle guidance and radiography. The fragment was dissected from the soft tissue attachments and the palmar ICB fragments retrieved through the carpal sheath in all horses. Surgery time was 85 to 142 min. RESULTS: Limitations of this technique include a long surgery time and the potential for hemorrhage to impair visibility during surgery. All four horses were discharged 3 to 8 days postoperatively. Three horses returned to full athletic work within 9 months postoperatively and one horse was euthanized due to persistent lameness. CONCLUSION: A tenoscopic transthecal carpal flexor tendon sheath approach provides access for removal of palmar ICB fracture fragments but should be viewed as an advanced arthroscopic procedure. CLINICAL SIGNIFICANCE: A transthecal approach through the carpal flexor tendon sheath offers an alternative technique for removal of palmar ICB fracture fragments

    Approaches for combining primary care electronic health record data from multiple sources: a systematic review of observational studies

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    OBJECTIVE: To identify observational studies which used data from more than one primary care electronic health record (EHR) database, and summarise key characteristics including: objective and rationale for using multiple data sources; methods used to manage, analyse and (where applicable) combine data; and approaches used to assess and report heterogeneity between data sources. DESIGN: A systematic review of published studies. DATA SOURCES: Pubmed and Embase databases were searched using list of named primary care EHR databases; supplementary hand searches of reference list of studies were retained after initial screening. STUDY SELECTION: Observational studies published between January 2000 and May 2018 were selected, which included at least two different primary care EHR databases. RESULTS: 6054 studies were identified from database and hand searches, and 109 were included in the final review, the majority published between 2014 and 2018. Included studies used 38 different primary care EHR data sources. Forty-seven studies (44%) were descriptive or methodological. Of 62 analytical studies, 22 (36%) presented separate results from each database, with no attempt to combine them; 29 (48%) combined individual patient data in a one-stage meta-analysis and 21 (34%) combined estimates from each database using two-stage meta-analysis. Discussion and exploration of heterogeneity was inconsistent across studies. CONCLUSIONS: Comparing patterns and trends in different populations, or in different primary care EHR databases from the same populations, is important and a common objective for multi-database studies. When combining results from several databases using meta-analysis, provision of separate results from each database is helpful for interpretation. We found that these were often missing, particularly for studies using one-stage approaches, which also often lacked details of any statistical adjustment for heterogeneity and/or clustering. For two-stage meta-analysis, a clear rationale should be provided for choice of fixed effect and/or random effects or other models

    Targeted neutralization of calmodulin in the nucleus blocks DNA synthesis and cell cycle progression

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    AbstractCalmodulin (CaM) is a major intracellular calcium binding protein which has been implicated in the regulation of cell proliferation. Previous studies using chemically synthesized CaM antagonists and anti-sense RNA indicated that CaM is important for initiation of DNA synthesis and cell cycle progression. However, these methods reduce total intracellular CaM and globally interfering with all the CaM-dependent processes. In order to explore the function of nuclear CaM during the cell cycle, a CaM inhibitor peptide was targeted to the nucleus of intact mammalian cells. Cell progression through S-phase was assessed by incorporation of the thymidine analogue, BrdU. Cells were transfected for 48 h with either the CaM inhibitor peptide gene or the control plasmid prior to analysis. Approx. 70% of the control cells incorporated BrdU. In striking contrast, double immunofluorescent labeling demonstrated that none of the cells expressing the CaM inhibitor peptide entered S-phase. This result indicates that neutralization of nuclear CaM by targeted expression of a CaM inhibitor peptide blocks DNA synthesis and cell cycle progression

    Environmentally relevant concentrations of titanium dioxide nanoparticles pose negligible risk to marine microbes.

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    Nano-sized titanium dioxide (nTiO ) represents the highest produced nanomaterial by mass worldwide and, due to its prevalent industrial and commercial use, it inevitably reaches the natural environment. Previous work has revealed a negative impact of nTiO upon marine phytoplankton growth, however, studies are typically carried out at concentrations far exceeding those measured and predicted to occur in the environment currently. Here, a series of experiments were carried out to assess the effects of both research-grade nTiO and nTiO extracted from consumer products upon the marine dominant cyanobacterium, , and natural marine communities at environmentally relevant and supra-environmental concentrations ( , 1 μg L to 100 mg L ). Cell declines observed in cultures were associated with the extensive aggregation behaviour of nTiO in saline media and the subsequent entrapment of microbial cells. Hence, higher concentrations of nTiO particles exerted a stronger decline of cyanobacterial populations. However, within natural oligotrophic seawater, cultures were able to recover over time as the nanoparticles aggregated out of solution after 72 h. Subsequent shotgun proteomic analysis of cultures exposed to environmentally relevant concentrations confirmed minimal molecular features of toxicity, suggesting that direct physical effects are responsible for short-term microbial population decline. In an additional experiment, the diversity and structure of natural marine microbial communities showed negligible variations when exposed to environmentally relevant nTiO concentrations ( , 25 μg L ). As such, the environmental risk of nTiO towards marine microbial species appears low, however the potential for adverse effects in hotspots of contamination exists. In future, research must be extended to consider any effect of other components of nano-enabled product formulations upon nanomaterial fate and impact within the natural environment

    MyChEMBL: A Virtual Platform for Distributing Cheminformatics Tools and Open Data

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    MyChEMBL is an open virtual platform which provides a free, secure, standardised and easy to use chemoinformatics environment for bioactivity data mining, machine learning, application development, learning and teaching. The main technical features of myChEMBL along with its applications and future plans are discussed here.FWN – Publicaties zonder aanstelling Universiteit Leide

    Bisphosphonates to reduce bone fractures in stage 3B+ chronic kidney disease:a propensity-score matched cohort study

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    BackgroundBisphosphonates are contraindicated in patients with stage 4+ chronic kidney disease. However, they are widely used to prevent fragility fractures in stage 3 chronic kidney disease, despite a lack of good-quality data on their effects.ObjectivesThe aims of each work package were as follows. Work package 1: to study the relationship between bisphosphonate use and chronic kidney disease progression. Work package 2: to study the association between using bisphosphonates and fracture risk. Work package 3: to determine the risks of hypocalcaemia, hypophosphataemia, acute kidney injury and upper gastrointestinal events associated with using bisphosphonates. Work package 4: to investigate the association between using bisphosphonates and changes in bone mineral density over time.DesignThis was a new-user cohort study design with propensity score matching.Setting and data sourcesData were obtained from UK NHS primary care (Clinical Practice Research Datalink GOLD database) and linked hospital inpatient records (Hospital Episode Statistics) for work packages 1–3 and from the Danish Odense University Hospital Databases for work package 4.ParticipantsPatients registered in the data sources who had at least one measurement of estimated glomerular filtration rate of < 45 ml/minute/1.73 m2 were eligible. A second estimated glomerular filtration rate value of < 45 ml/minute/1.73 m2 within 1 year after the first was requested for work packages 1 and 3. Patients with no Hospital Episode Statistics linkage were excluded from work packages 1–3. Patients with < 1 year of run-in data before index estimated glomerular filtration rate and previous users of anti-osteoporosis medications were excluded from work packages 1–4.Interventions/exposureBisphosphonate use, identified from primary care prescriptions (for work packages 1–3) or pharmacy dispensations (for work package 4), was the main exposure.Main outcome measuresWork package 1: chronic kidney disease progression, defined as stage worsening or starting renal replacement. Work package 2: hip fracture. Work package 3: acute kidney injury, hypocalcaemia and hypophosphataemia identified from Hospital Episode Statistics, and gastrointestinal events identified from Clinical Practice Research Datalink or Hospital Episode Statistics. Work package 4: annualised femoral neck bone mineral density percentage change.ResultsBisphosphonate use was associated with an excess risk of chronic kidney disease progression (subdistribution hazard ratio 1.12, 95% confidence interval 1.02 to 1.24) in work package 1, but did not increase the probability of other safety outcomes in work package 3. The results from work package 2 suggested that bisphosphonate use increased fracture risk (hazard ratio 1.25, 95% confidence interval 1.13 to 1.39) for hip fractures, but sensitivity analyses suggested that this was related to unresolved confounding. Conversely, work package 4 suggested that bisphosphonates improved bone mineral density, with an average 2.65% (95% confidence interval 1.32% to 3.99%) greater gain in femoral neck bone mineral density per year in bisphosphonate users than in matched non-users.LimitationsConfounding by indication was a concern for the clinical effectiveness (i.e. work package 2) data. Bias analyses suggested that these findings were due to inappropriate adjustment for pre-treatment risk. work packages 3 and 4 were based on small numbers of events and participants, respectively.ConclusionsBisphosphonates were associated with a 12% excess risk of chronic kidney disease progression in participants with stage 3B+ chronic kidney disease. No other safety concerns were identified. Bisphosphonate therapy increased bone mineral density, but the research team failed to demonstrate antifracture effectiveness.Future workRandomised controlled trial data are needed to demonstrate antifracture efficacy in patients with stage 3B+ chronic kidney disease. More safety analyses are needed to characterise the renal toxicity of bisphosphonates in stage 3A chronic kidney disease, possibly using observational data

    Bright spots as climate-smart marine spatial planning tools for conservation and blue growth

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    Marine spatial planning that addresses ocean climate-driven change (‘climate-smart MSP’) is a global aspiration to support economic growth, food security and ecosystem sustainability. Ocean climate change (‘CC’) modelling may become a key decision-support tool for MSP, but traditional modelling analysis and communication challenges prevent their broad uptake. We employed MSP-specific ocean climate modelling analyses to inform a real-life MSP process; addressing how nature conservation and fisheries could be adapted to CC. We found that the currently planned distribution of these activities may become unsustainable during the policy's implementation due to CC, leading to a shortfall in its sustainability and blue growth targets. Significant, climate-driven ecosystem-level shifts in ocean components underpinning designated sites and fishing activity were estimated, reflecting different magnitudes of shifts in benthic versus pelagic, and inshore versus offshore habitats. Supporting adaptation, we then identified: CC refugia (areas where the ecosystem remains within the boundaries of its present state); CC hotspots (where climate drives the ecosystem towards a new state, inconsistent with each sectors’ present use distribution); and for the first time, identified bright spots (areas where oceanographic processes drive range expansion opportunities that may support sustainable growth in the medium term). We thus create the means to: identify where sector-relevant ecosystem change is attributable to CC; incorporate resilient delivery of conservation and sustainable ecosystem management aims into MSP; and to harness opportunities for blue growth where they exist. Capturing CC bright spots alongside refugia within protected areas may present important opportunities to meet sustainability targets while helping support the fishing sector in a changing climate. By capitalizing on the natural distribution of climate resilience within ocean ecosystems, such climate-adaptive spatial management strategies could be seen as nature-based solutions to limit the impact of CC on ocean ecosystems and dependent blue economy sectors, paving the way for climate-smart MSP

    La proteína quinasa dependiente de Ca2+ y calmodulina (CaMKII): ¿es proarritmogénica en reperfusión?

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    La reperfusión del miocardio isquémico lo hace más propenso a la aparición de arritmias. Experimentos previos de nuestro laboratorio mostraron que al inicio de la reperfusión (R), momento en el que se detecta el mayor número de arritmias, aumenta la fosforilación dependiente de CaMKII del residuo PT17 de fosfolamban (PLN) (Vittone, 2002). El objetivo de este trabajo, fue evaluar la posibilidad de que la activación de CaMKII al inicio de la reperfusión sea un mecanismo proarritmogénico.Facultad de Ciencias Médica
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