144 research outputs found

    An artificial neural network‐based model to predict chronic kidney disease in aged cats

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    Background Chronic kidney disease (CKD) frequently causes death in older cats; its early detection is challenging. Objectives To build a sensitive and specific model for early prediction of CKD in cats using artificial neural network (ANN) techniques applied to routine health screening data. Animals Data from 218 healthy cats ≄7 years of age screened at the Royal Veterinary College (RVC) were used for model building. Performance was tested using data from 3546 cats in the Banfield Pet Hospital records and an additional 60 RCV cats—all initially without a CKD diagnosis. Methods Artificial neural network (ANN) modeling used a multilayer feed‐forward neural network incorporating a back‐propagation algorithm. Clinical variables from single cat visits were selected using factorial discriminant analysis. Independent submodels were built for different prediction time frames. Two decision threshold strategies were investigated. Results Input variables retained were plasma creatinine and blood urea concentrations, and urine specific gravity. For prediction of CKD within 12 months, the model had accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 88%, 87%, 70%, 53%, and 92%, respectively. An alternative decision threshold increased specificity and PPV to 98% and 87%, but decreased sensitivity and NPV to 42% and 79%, respectively. Conclusions and Clinical Importance A model was generated that identified cats in the general population ≄7 years of age that are at risk of developing CKD within 12 months. These individuals can be recommended for further investigation and monitoring more frequently than annually. Predictions were based on single visits using common clinical variables

    Differential recognition of the Multiple Banded Antigen isoforms across Ureaplasma parvum and Ureaplasma urealyticum species by monoclonal antibodies

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    Two separate species of Ureaplasma have been identified that infect humans: Ureaplasma parvum and Ureaplasma urealyticum. Most notably, these bacteria lack a cell wall and are the leading infectious organism associated with infection-related induction of preterm birth. Fourteen separate representative prototype bacterial strains, called serovars, are largely differentiated by the sequence of repeating units in the C-terminus of the major surface protein: multiple-banded antigen (MBA). Monoclonal antibodies that recognise single or small groups of serovars have been previously reported, but these reagents remain sequestered in individual research laboratories. Here we characterise a panel of commercially available monoclonal antibodies raised against the MBA and describe the first monoclonal antibody that cross-reacts by immunoblot with all serovars of U. parvum and U. urealyticum species. We also describe a recombinant MBA expressed by Escherichia coli which facilitated further characterisation by immunoblot and demonstrate immunohistochemistry of paraffin-embedded antigens. Immunoblot reactivity was validated against well characterised previously published monoclonal antibodies and individual commercial antibodies were found to recognise all U. parvum strains, only serovars 3 and 14 or only serovars 1 and 6, or all strains belonging to U. parvum and U. urealyticum. MBA mass was highly variable between strains, consistent with variation in the number of C-terminal repeats between strains. Antibody characterisation will enable future investigations to correlate severity of pathogenicity to MBA isoform number or mass, in addition to development of antibody-based diagnostics that will detect infection by all Ureaplasma species or alternately be able to differentiate between U. parvum, U. urealyticum or mixed infections

    Effect of rhPDGF-BB on bone turnover during periodontal repair

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    Purpose : Growth factors such as platelet-derived growth factor (PDGF) exert potent effects on wound healing including the regeneration of periodontia. Pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) is a well-known biomarker of bone turnover, and as such is a potential indicator of osseous metabolic activity. The objective of this study was to evaluate the release of the ICTP into the periodontal wound fluid (WF) following periodontal reconstructive surgery using local delivery of highly purified recombinant human PDGF (rhPDGF)-BB. Methods : Forty-seven human subjects at five treatment centres possessing chronic severe periodontal disease were monitored longitudinally for 24 weeks following PDGF regenerative surgical treatment. Severe periodontal osseous defects were divided into one of three groups and treated at the time of surgery with either: Β -tricalcium phosphate (TCP) osteoconductive scaffold alone (active control), Β -TCP+0.3 mg/ml of rhPDGF-BB, or Β -TCP+1.0 mg/ml of rhPDGF-BB. WF was harvested and analysed for local ICTP levels by radioimmunoassay. Statistical analysis was performed using analysis of variance and an area under the curve analysis (AUC). Results : The 0.3 and 1.0 mg/ml PDGF-BB treatment groups demonstrated increases in the amount of ICTP released locally for up to 6 weeks. There were statistically significant differences at the week 6 time point between Β -TCP carrier alone group versus 0.3 mg/ml PDGF-BB group ( p <0.05) and between Β -TCP alone versus the 1.0 mg/ml PDGF-BB-treated lesions ( p <0.03). The AUC analysis revealed no statistical differences amongst groups. Conclusion : This study corroborates the release of ICTP as a measure of active bone turnover following local delivery of PDGF-BB to periodontal osseous defects. The amount of ICTP released from the WF revealed an early increase for all treatment groups. Data from this study suggests that when PDGF-BB is delivered to promote periodontal tissue engineering of tooth-supporting osseous defects, there is a direct effect on ICTP released from the wound.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72239/1/j.1600-051X.2005.00870.x.pd

    Assessing competency in Evidence Based Practice: strengths and limitations of current tools in practice

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    <p>Abstract</p> <p>Background</p> <p>Evidence Based Practice (EBP) involves making clinical decisions informed by the most relevant and valid evidence available. Competence can broadly be defined as a concept that incorporates a variety of domains including knowledge, skills and attitudes. Adopting an evidence-based approach to practice requires differing competencies across various domains including literature searching, critical appraisal and communication. This paper examines the current tools available to assess EBP competence and compares their applicability to existing assessment techniques used in medicine, nursing and health sciences.</p> <p>Discussion</p> <p>Only two validated assessment tools have been developed to specifically assess all aspects of EBP competence. Of the two tools (<it>Berlin </it>and <it>Fresno </it>tools), only the <it>Fresno </it>tool comprehensively assesses EBP competency across all relevant domains. However, both tools focus on assessing EBP competency in medical students; therefore neither can be used for assessing EBP competency across different health disciplines. The Objective Structured Clinical Exam (OSCE) has been demonstrated as a reliable and versatile tool to assess clinical competencies, practical and communication skills. The OSCE has scope as an alternate method for assessing EBP competency, since it combines assessment of cognitive skills including knowledge, reasoning and communication. However, further research is needed to develop the OSCE as a viable method for assessing EBP competency.</p> <p>Summary</p> <p>Demonstrating EBP competence is a complex task – therefore no single assessment method can adequately provide all of the necessary data to assess complete EBP competence. There is a need for further research to explore how EBP competence is best assessed; be it in written formats, such as the <it>Fresno </it>tool, or another format, such as the OSCE. Future tools must also incorporate measures of assessing how EBP competence affects clinician behaviour and attitudes as well as clinical outcomes in real-time situations. This research should also be conducted across a variety of health disciplines to best inform practice.</p

    Levels of resilience and delivery of HIV care in response to urban violence and crime

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    Aims To understand the impact of urban violence and crime on HIV care delivery. Background Urban violence and crime can put pressure on the health care system and on nursing staff. Whilst the impact this has at the individual level has been researched, there is less research that places this within the context of the overall social eco system. Design A qualitative design using inductive thematic analysis. Methods Between July 2016 February 2017, in‐depth interviews were conducted with 10 nurses working in two neighbourhoods with high levels of violence in Cape Town, South Africa. Results The effects of crime and violence were evident at multiple levels resulting in participants feeling ‘safe and unsafe’ in a context where crime is viewed as endemic. Resilience emerged as a key concept in the findings. Resilience was apparent at individual, community and organizational levels and enabled continued delivery of HIV care. Conclusion The findings demonstrate the potential role of resilience within the social eco‐health system required to sustain delivery of HIV care in the midst of urban violence and gangsterism. Impact This study examined the impact of and response to urban violence on HIV care delivery. The findings indicate that resilience manifests at all levels of the social eco‐system. Understanding the mechanisms employed to cope with endemic violence helps to address these challenges in the study setting, but also has a much wider application to other areas with endemic urban violence and crime

    The Berkeley sample of Type II supernovae: BVRI light curves and spectroscopy of 55 SNe II

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    In this work, BVRI light curves of 55 Type II supernovae (SNe II) from the Lick Observatory Supernova Search programme obtained with the Katzman Automatic Imaging Telescope and the 1 m Nickel telescope from 2006 to 2018 are presented. Additionally, more than 150 spectra gathered with the 3 m Shane telescope are published. We conduct an analyse of the peak absolute magnitudes, decline rates, and time durations of different phases of the light and colour curves. Typically, our light curves are sampled with a median cadence of 5.5 d for a total of 5093 photometric points. In average, V-band plateau declines with a rate of 1.29 mag (100 d)−1, which is consistent with previously published samples. For each band, the plateau slope correlates with the plateau length and the absolute peak magnitude: SNe II with steeper decline have shorter plateau duration and are brighter. A time-evolution analysis of spectral lines in term of velocities and pseudo-equivalent widths is also presented in this paper. Our spectroscopic sample ranges between 1 and 200 d post-explosion and has a median ejecta expansion velocity at 50 d post-explosion of 6500 km s−1 (H α line) and a standard dispersion of 2000 km s−1. Nebular spectra are in good agreement with theoretical models using a progenitor star having a mass <16M⊙. All the data are available to the community and will help to understand SN II diversity better, and therefore to improve their utility as cosmological distance indicators
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