Anatomy, morphology and evolution of the patella in squamate lizards and tuatara (Sphenodon punctatus)

The patella (kneecap) is the largest and best-known of the sesamoid bones, postulated to confer biomechanical advantages including increasing joint leverage and reinforcing the tendon against compression. It has evolved several times independently in amniotes, but despite apparently widespread occurrence in lizards, the patella remains poorly characterised in this group and is, as yet, completely undescribed in their nearest extant relative Sphenodon (Rhynchocephalia). Through radiography, osteological and fossil studies we examined patellar presence in diverse lizard and lepidosauromorph taxa, and using computed tomography, dissection and histology we investigated in greater depth the anatomy and morphology of the patella in 16 lizard species and 19 Sphenodon specimens. We have found the first unambiguous evidence of a mineralised patella in Sphenodon, which appears similar to the patella of lizards and shares several gross and microscopic anatomical features. Although there may be a common mature morphology, the squamate patella exhibits a great deal of variability in development (whether from a cartilage anlage or not, and in the number of mineralised centres) and composition (bone, mineralised cartilage or fibrotendinous tissue). Unlike in mammals and birds, the patella in certain lizards and Sphenodon appears to be a polymorphic trait. We have also explored the evolution of the patella through ancestral state reconstruction, finding that the patella is ancestral for lizards and possibly Lepidosauria as a whole. Clear evidence of the patella in rhynchocephalian or stem lepidosaurian fossil taxa would clarify the evolutionary origin(s) of the patella, but due to the small size of this bone and the opportunity for degradation or loss we could not definitively conclude presence or absence in the fossils examined. The pattern of evolution in lepidosaurs is unclear but our data suggest that the emergence of this sesamoid may be related to the evolution of secondary ossification centres and/or changes in knee joint conformation, where enhancement of extensor muscle leverage would be more beneficial.Sophie Regnault, Marc E. H. Jones, Andrew A. Pitsillides, John R. Hutchinso

Acute kidney injury and adverse outcomes of critical illness: correlation or causation?

Critically ill patients who develop acute kidney injury (AKI) are more than twice as likely to die in hospital. However, it is not clear to what extent AKI is the cause of excess mortality, or merely a correlate of illness severity. The Bradford Hill criteria for causality (plausibility, temporality, magnitude, specificity, analogy, experiment & coherence, biological gradient and consistency) were applied to assess the extent to which AKI may be causative in adverse short-term outcomes of critical illness. Plausible mechanisms exist to explain increased risk of death after AKI, both from direct pathophysiological effects of renal dysfunction and mechanisms of organ cross-talk in multiple-organ failure. The temporal relationship between increased mortality following AKI is consistent with its pathophysiology. AKI is associated with substantially increased mortality, an association that persists after accounting for known confounders. A biological gradient exists between increasing severity of AKI and increasing short-term mortality. This graded association shares similar features to the increased mortality observed in ARDS; an analogous condition with a multifactorial aetiology. Evidence for the outcomes of AKI from retrospective cohort studies and experimental animal models is coherent however both of these forms of evidence have intrinsic biases and shortcomings. The relationship between AKI and risk of death is maintained across a range of patient ages, comorbidities and underlying diagnoses. In conclusion many features of the relationship between AKI and short-term mortality suggest causality. Prevention and mitigation of AKI and its complications are valid targets for studies seeking to improve short-term survival in critical care

Deserved attention for acute kidney injury after major trauma

This is a post-peer-review, pre-copyedit version of an article published in Intensive Care Medicine. The final authenticated version is available online at: https://doi.org/10.1007/s00134-019-05609-xDear Editor, The systematic review of acute kidney injury (AKI) after trauma by Søvik et al. [1] adds much-needed data on the incidence and outcomes of trauma-associated AKI. The authors reported a pooled incidence of AKI of 24%across 24 studies including over 25,000 patients. These results duplicate those of a recently published meta-analysis of AKI in trauma by Haines et al. [2]. Furthermore, data on AKI in 3111 patients from a French multicentre trauma registry has now been published by Harrois et al. [3] where an independent association between AKI and mortality persisted. When included amongst studies reporting adjusted odds ratios of death in trauma-ICU patients with AKI, the association with mortality is convincin

Representation in Wales: an empirical analysis of the policy divisions between voters and candidates

Politics in Wales is often portrayed as being relatively consensual when compared with the rest of the United Kingdom and enjoying healthy levels of trust between voters and elites. Recent events like the decision of Welsh voters to reject the European Union membership against the advice of most of its political establishment, however, are calling to question this perception. Using 2016 Welsh Candidate Study and 2016 Welsh Election Study data, this paper evaluates the extent of policy divisions between voters and candidates in Wales. I find that candidates hold more liberal policy positions and are less likely to think of immigration as the most important policy priority. In addition, they tend to favour a different approach to parliamentary representation, deeming it more acceptable for Assembly Members to discard the views of their voters in favour of their own views or those of their party

Prognostic association of routinely measured biomarkers in patients admitted to critical care: a systematic review.

“This is an Accepted Manuscript of an article published by Taylor & Francis in Biomarkers on 05 Nov 2020, available online: http://www.tandfonline.com/10.1080/1354750X.2020.1842498.”PURPOSE: To examine reported prognostic associations of routine blood measurements in the intensive care unit. MATERIALS AND METHODS: We searched PubMed, EMBASE through 28th May 2020 to identify all studies in adult critical care investigating associations between parameters measured routinely in whole blood, plasma or serum, and length of stay or mortality. Registration: PROSPERO; CRD42019122058. RESULTS: A total of 128 studies, reporting 28 different putative prognostic biomarkers, met eligibility criteria. Those most frequently examined were red cell distribution width, neutrophil-to-lymphocyte ratio, C-reactive protein, and platelet count. A higher red cell distribution width, a lower platelet count, and a higher neutrophil-to-lymphocyte ratio were consistently associated with both increased mortality and length of stay. A lower level of albumin was consistently associated with greater mortality. C-reactive protein was inconsistent. Most studies (n = 110) used regression modelling with wide variation in variable selection and covariate-adjustment; none externally validated the proposed predictive models. CONCLUSIONS: Simple regression models have so far proved inadequate for the complexity of data available from routine blood sampling in critical care. Adoption of a direct causal framework may help better assess mechanistic processes, aid design of future studies, and guide clinical decision making using routine data

A statistical analysis proposal: Emergency hospital admissions associated with Non-Communicable Diseases 1998-2019: An Ecological Study

A statistical analysis proposal to use aggregated hospital admission data from 1998-2019 to investigate the relationship between non-communicable disease groups and associated emergency admissions to hospital

An additional muscle belly of the first lumbrical muscle

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens