• Attitudes of general hospital staff towards patients who self-harm in South India: A cross-sectional study

      Kumar, Narendra; Rajendra, Rajagopal; Majgi, Sumanth M.; Krishna, Murali; Keenan, Paul; Jones, Steven; University of Chester (Medknow, 30/11/2016)
      Background: There is growing global interest into the attitudes and clinical management of persons who deliberately self-harm. People who self-harm experience many problems and typically have many needs related to management of their psychological wellbeing. A positive attitude amongst general hospital staff should prevail with people who self-harm. The principal purpose was to determine student staff attitudes towards patients who self-harmed from a professional and cultural perspective, which might influence patient treatment following hospital admission. The focus concentrated upon staff knowledge, attitudes and beliefs regarding self-harm. Methods: A cross sectional survey of the hospital staff using a validated questionnaire was carried out. This paper reports on interdisciplinary staff from two large general hospitals in Mysuru, South India (n=773). Results: Findings suggest that within a general hospital setting there is wide variation in staff attitudes and knowledge levels related to self-harm. Whilst there is attitudinal evidence for staff attitudes, this study investigates interprofessional differences in an attempt to progress treatment approaches to a vulnerable societal group. Very few staff had any training in assessment of self harm survivors. Conclusion: There is an urgent need for training general hospital staff in self harm assessment and prevention in south India. The results allow a series of recommendations for educational and skills initiatives before progressing to patient assessment and treatment projects and opens potential for cross cultural comparison studies. In addition, interventions must focus on current resources and contexts to move the evidence base and approaches to patient care forward.
    • Autologous chondrocyte implantation-derived synovial fluids display distinct responder and non-responder proteomic profiles

      Hulme, Charlotte H.; Wilson, Emma L.; Peffers, Mandy J.; Roberts, Sally; Simpson, Deborah M.; Richardson, James B.; Gallacher, Pete; Wright, Karina T.; Keele University; Robert Jones and Agnes Hunt Orthopaedic Hospital; University of Chester; University of Liverpool (BioMed Central, 30/06/2017)
      Background Autologous chondrocyte implantation (ACI) can be used in the treatment of focal cartilage injuries to prevent the onset of osteoarthritis (OA). However, we are yet to understand fully why some individuals do not respond well to this intervention. Identification of a reliable and accurate biomarker panel that can predict which patients are likely to respond well to ACI is needed in order to assign the patient to the most appropriate therapy. This study aimed to compare the baseline and mid-treatment proteomic profiles of synovial fluids (SFs) obtained from responders and non-responders to ACI. Methods SFs were derived from 14 ACI responders (mean Lysholm improvement of 33 (17–54)) and 13 non-responders (mean Lysholm decrease of 14 (4–46)) at the two stages of surgery (cartilage harvest and chondrocyte implantation). Label-free proteome profiling of dynamically compressed SFs was used to identify predictive markers of ACI success or failure and to investigate the biological pathways involved in the clinical response to ACI. Results Only 1 protein displayed a ≥2.0-fold differential abundance in the preclinical SF of ACI responders versus non-responders. However, there is a marked difference between these two groups with regard to their proteome shift in response to cartilage harvest, with 24 and 92 proteins showing ≥2.0-fold differential abundance between Stages I and II in responders and non-responders, respectively. Proteomic data has been uploaded to ProteomeXchange (identifier: PXD005220). We have validated two biologically relevant protein changes associated with this response, demonstrating that matrix metalloproteinase 1 was prominently elevated and S100 calcium binding protein A13 was reduced in response to cartilage harvest in non-responders. Conclusions The differential proteomic response to cartilage harvest noted in responders versus non-responders is completely novel. Our analyses suggest several pathways which appear to be altered in non-responders that are worthy of further investigation to elucidate the mechanisms of ACI failure. These protein changes highlight many putative biomarkers that may have potential for prediction of ACI treatment success.
    • Standards and core components for cardiovascular disease prevention and rehabilitation; BACPR

      Cowie, A; Buckley, John P.; Doherty, Patrick; Furze, Gill; Hayward, Jo; Jones, Jennifer; Speck, Linda; Dalal, Hayes; Mills, Joseph; University Centre Shrewsbury (BMJ, 30/01/2019)
      In 2017, the British Association for Cardiovascular Prevention and Rehabilitation published its official document detailing standards and core components for cardiovascular prevention and rehabilitation. Building on the success of previous editions of this document (published in 2007 and 2012), the 2017 update aims to further emphasise to commissioners, clinicians, politicians and the public the importance of robust, quality indicators of cardiac rehabilitation (CR) service delivery. Otherwise, its overall aim remains consistent with the previous publications—to provide a precedent on which all effective cardiovascular prevention and rehabilitation programmes are based and a framework for use in assessment of variation in service delivery quality. In this 2017 edition, the previously described seven standards and core components have both been revised to six, with a greater focus on measurable clinical outcomes, audit and certification. The principles within the updated document underpin the six-stage pathway of care for CR, and reflect the extensive evidence base now available within the field. To help improve current services, close collaboration between commissioners and CR providers is advocated, with use of the CR costing tool in financial planning of programmes. The document specifies how quality assurance can be facilitated through local audit, and advocates routine upload of individual-level data to the annual British Heart Foundation National Audit of Cardiac Rehabilitation, and application for national certification ensuring attainment of a minimum quality standard. Although developed for the UK, these standards and core components may be applicable to other countries.
    • An Interpretive Phenomenological Analysis (IPA) of coercion towards community dwelling older adults with dementia: Findings from MYsore studies of Natal effects on Ageing and Health (MYNAH)

      Danivas, Vijay; Bharmal, Mufaddal; Keenan, Paul; Jones, Steven; Karat, Samuel C.; Kalyanaraman, Kumaran; Prince, Martin; Fall, Caroline H. D.; Krishna, Murali; University of Chester (Springer, 29/09/2016)
      Purpose Limited availability of specialist services places a considerable burden on caregivers of Persons with Dementia (PwD) in Low- and Middle-Income Countries (LMICs). There are limited qualitative data on coercive behavior towards PwD in an LMIC setting. Aim The aim of this study was to find relevant themes of the lived experience of relatives as caregivers for PwD in view of their use of coercive measures in community setting in South India. Method Primary caregivers (n = 13) of PwDs from the Mysore study of Natal effects on Ageing and Health (MYNAH) in South India were interviewed to explore the nature and impact of coercion towards community dwelling older adults with dementia. The narrative data were coded using an Interpretative Phenomenological Analysis (IPA) approach for thematic analysis and theory formation. Results Caregivers reported feeling physical and emotional burn-out, a lack of respite care, an absence of shared caregiving arrangements, limited knowledge of dementia, and a complete lack of community support services. They reported restrictions on their lives through not being able take employment, a poor social life, reduced income and job opportunities, and restricted movement that impacted on their physical and emotional well-being. Inappropriate use of sedatives, seclusion and environmental restraint, and restricted dietary intake, access to finances and participation in social events, was commonly reported methods of coercion used by caregivers towards PwD. Reasons given by caregivers for employing these coercive measures included safeguarding of the PwD and for the management of behavioral problems and physical health. Conclusion There is an urgent need for training health and social care professionals to better understand the use of coercive measures and their impact on persons with dementia in India. It is feasible to conduct qualitative research using IPA in South India.
    • Mitochondrial ROS regulate oxidative damage and mitophagy but not age-related muscle fiber atrophy

      Nye, Gareth; Sakellariou, Giorgos; Pearson, Timothy; Lightfoot, Adam; Wells, Nicola; Giakoumaki, Ifigeneia; Vasilaki, Aphrodite; Griffiths, Richard; Jackson, Malcolm; McArdle, Anne; et al. (Nature Research, 29/09/2016)
      Age-related loss of skeletal muscle mass and function is a major contributor to morbidity and has a profound effect on the quality of life of older people. The potential role of age-dependent mitochondrial dysfunction and cumulative oxidative stress as the underlying cause of muscle aging remains a controversial topic. Here we show that the pharmacological attenuation of age-related mitochondrial redox changes in muscle with SS31 is associated with some improvements in oxidative damage and mitophagy in muscles of old mice. However, this treatment failed to rescue the age-related muscle fiber atrophy associated with muscle atrophy and weakness. Collectively, these data imply that the muscle mitochondrial redox environment is not a key regulator of muscle fiber atrophy during sarcopenia but may play a key role in the decline of mitochondrial organelle integrity that occurs with muscle aging.
    • High CIP2A levels correlate with an antiapoptotic phenotype that can be overcome by targeting BCL-XL in chronic myeloid leukemia. Leukemia

      Lucas, Claire; Milani, Mateus; Butterworth, Michael; Carmell, Natasha; Scott, Laura; Clark, Richard; Cohen, Gerald; Varadarajan, Shankar; University of Liverpool (Nature, 29/02/2016)
      Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a predictive biomarker of disease progression in many malignancies, including imatinib-treated chronic myeloid leukemia (CML). Although high CIP2A levels correlate with disease progression in CML, the underlying molecular mechanisms remain elusive. In a screen of diagnostic chronic phase samples from patients with high and low CIP2A protein levels, high CIP2A levels correlate with an antiapoptotic phenotype, characterized by downregulation of proapoptotic BCL-2 family members, including BIM, PUMA and HRK, and upregulation of the antiapoptotic protein BCL-XL. These results suggest that the poor prognosis of patients with high CIP2A levels is due to an antiapoptotic phenotype. Disrupting this antiapoptotic phenotype by inhibition of BCL-XL via RNA interference or A-1331852, a novel, potent and BCL-XL-selective inhibitor, resulted in extensive apoptosis either alone or in combination with imatinib, dasatinib or nilotinib, both in cell lines and in primary CD34(+) cells from patients with high levels of CIP2A. These results demonstrate that BCL-XL is the major antiapoptotic survival protein and may be a novel therapeutic target in CML.
    • An in vitro spinal cord injury model to screen neuroregenerative materials

      Weightman, Alan P.; Pickard, Mark R.; Yang, Ying; Chari, Divya M.; Keele University (Elsevier, 29/01/2014)
      Implantable 'structural bridges' based on nanofabricated polymer scaffolds have great promise to aid spinal cord regeneration. Their development (optimal formulations, surface functionalizations, safety, topographical influences and degradation profiles) is heavily reliant on live animal injury models. These have several disadvantages including invasive surgical procedures, ethical issues, high animal usage, technical complexity and expense. In vitro 3-D organotypic slice arrays could offer a solution to overcome these challenges, but their utility for nanomaterials testing is undetermined. We have developed an in vitro model of spinal cord injury that replicates stereotypical cellular responses to neurological injury in vivo, viz. reactive gliosis, microglial infiltration and limited nerve fibre outgrowth. We describe a facile method to safely incorporate aligned, poly-lactic acid nanofibre meshes (±poly-lysine + laminin coating) within injury sites using a lightweight construct. Patterns of nanotopography induced outgrowth/alignment of astrocytes and neurons in the in vitro model were strikingly similar to that induced by comparable materials in related studies in vivo. This highlights the value of our model in providing biologically-relevant readouts of the regeneration-promoting capacity of synthetic bridges within the complex environment of spinal cord lesions. Our approach can serve as a prototype to develop versatile bio-screening systems to identify materials/combinatorial strategies for regenerative medicine, whilst reducing live animal experimentation.
    • Stent Frame Movement Following Endovascular Aneurysm Sealing in the Abdominal Aorta

      Yafawi, Asma; McWilliams, Richard G.; Fisher, Robert K.; England, Andrew; Karouki, Maria; Torella, Francesco (SAGE Publications, 28/11/2018)
    • The ReSiT study (reducing sitting time): rationale and protocol for an exploratory pilot study of an intervention to reduce sitting time among office workers

      Gardner, Benjamin; Dewitt, Stephen; Smith, Lee; Biddle, Stuart J. H.; Mansfield, Louise; Buckley, John P.; University Centre Shrewsbury (BMC, 28/11/2017)
      Background: Desk-based workers engage in long periods of uninterrupted sitting time, which has been associated with morbidity and premature mortality. Previous workplace intervention trials have demonstrated the potential of providing sit-stand workstations, and of administering motivational behaviour change techniques, for reducing sitting time. Yet, few studies have combined these approaches or explored the acceptability of discrete sitting-reduction behaviour change strategies. This paper describes the rationale for a sitting-reduction intervention that combines sit-stand workstations with motivational techniques, and procedures for a pilot study to explore the acceptability of core intervention components among university office workers. Methods: The intervention is based on a theory and evidence-based analysis of why office workers sit, and how best to reduce sitting time. It seeks to enhance motivation and capability, as well as identify opportunities, required to reduce sitting time. Thirty office workers will participate in the pilot study. They will complete an initial awareness-raising monitoring and feedback task and subsequently receive a sit-stand workstation for a 12-week period. They will also select from a ‘menu’ of behaviour change techniques tailored to self-declared barriers to sitting reduction, effectively co-producing and personally tailoring their intervention. Interviews at 1, 6, and 12 weeks post-intervention will explore intervention acceptability. Discussion: To our knowledge, this will be the first study to explore direct feedback from office workers on the acceptability of discrete tailored sitting-reduction intervention components that they have received. Participants’ choice of and reflections on intervention techniques will aid identification of strategies suitable for inclusion in the next iteration of the intervention, which will be delivered in a self-administered format to minimise resource burden.
    • CIP2A- and SETBP1-mediated PP2A inhibition reveals AKT S473 phosphorylation to be a new biomarker in AML

      Hills, Robert; Burnett, Alan; Lucas, Claire; Scott, Laura; Carmell, Natasha; Holcroft, Alison; Clark, Richard; University of Liverpool, Royal Liverpool University hospital, University of Cardiff (American Society for Hematology, 27/04/2018)
      Key Points PP2A inhibition occurs in AML by 2 different pathways: CIP2A in normal karyotype patients and SETBP1 in adverse karyotype patients. AKTS473 phosphorylation is a predictor of survival, and diagnostic levels of AKTS473 could be a novel biomarker in AML.
    • Human placental oxygenation in late gestation: experimental and theoretical approaches

      Nye, Gareth; Ingram, Emma; Jenson, Oliver; Johnstone, Edward; Schneider, Henning; Lewis, Rohan; Chernyavsky, Igor; Brownbill, Paul; University of Manchester, University of Southampton, University of Bern (Wiley, 26/01/2018)
      The placenta is crucial for life. It is an ephemeral but complex organ acting as the barrier interface between maternal and fetal circulations, providing exchange of gases, nutrients, hormones, waste products and immunoglobulins. Many gaps exist in our understanding of the detailed placental structure and function, particularly in relation to oxygen handling and transfer in healthy and pathological states in utero. Measurements to understand oxygen transfer in vivo in the human are limited, with no general agreement on the most appropriate methods. An invasive method for measuring partial pressure of oxygen in the intervillous space through needle electrode insertion at the time of Caesarean sections has been reported. This allows for direct measurements in vivo whilst maintaining near normal placental conditions; however, there are practical and ethical implications in using this method for determination of placental oxygenation. Furthermore, oxygen levels are likely to be highly heterogeneous within the placenta. Emerging non-invasive techniques, such as MRI, and ex vivo research are capable of enhancing and improving current imaging methodology for placental villous structure and increase the precision of oxygen measurement within placental compartments. These techniques, in combination with mathematical modelling, have stimulated novel cross-disciplinary approaches that could advance our understanding of placental oxygenation and its metabolism in normal and pathological pregnancies, improving clinical treatment options and ultimately outcomes for the patient.
    • Will Plan S put learned societies in jeopardy?

      Purton, Mary; Michelangeli, Francesco; Fésüs, László (Wiley, 25/02/2019)
    • Mental Health Decisions; what every officer should consider

      Williams, B; Jones, Steven; University of Chester (Police Professional, 24/05/2012)
      It can often appear to Police officers that they are damned if they do make decisions, and damned if they don’t in mental health cases. A culture has evolved that triggers decision apathy and defensive decisions that arguably do not benefit the Police, public, or the mental health arrestee. Decisions of this presenting complexity in whatever profession must be made and firmly rooted within the current evidence base, lawful, and also be reasonable in the given situation. It is therefore not unreasonable to expect officers to explain and account for how and why they acted as they did, and the frameworks (statutes/ codes) which should underpin such practice decisions. It is of paramount importance that Police officers are kept appraised of developments in mental health cases and how this crucially will inform, and sometimes correct custom and practice. This article in three parts aims firstly to refresh officer’s knowledge. Second, inform current practice and address practice from recent cases involving the police and mental health patients. Thirdly, and perhaps the most crucial through case examples offer a decision making framework to support operational staff in the right direction for mental health practice and defend practice challenges that may arise at all levels.
    • Using magnetic nanoparticles for gene transfer to neural stem cells: stem cell propagation method influences outcomes

      Pickard, Mark R.; Adams, Christopher F.; Barraud, Perrine; Chari, Divya M.; Keele University, United Kingdom; University of Cambridge, United Kingdom (Multidisciplinary Digital Publishing Institute, 24/04/2015)
      Genetically engineered neural stem cell (NSC) transplants offer a key strategy to augment neural repair by releasing therapeutic biomolecules into injury sites. Genetic modification of NSCs is heavily reliant on viral vectors but cytotoxic effects have prompted development of non-viral alternatives, such as magnetic nanoparticle (MNPs). NSCs are propagated in laboratories as either 3-D suspension "neurospheres" or 2-D adherent "monolayers". MNPs deployed with oscillating magnetic fields ("magnetofection technology") mediate effective gene transfer to neurospheres but the efficacy of this approach for monolayers is unknown. It is important to address this issue as oscillating magnetic fields dramatically enhance MNP-based transfection in transplant cells (e.g., astrocytes and oligodendrocyte precursors) propagated as monolayers. We report for the first time that oscillating magnetic fields enhanced MNP-based transfection with reporter and functional (basic fibroblast growth factor; FGF2) genes in monolayer cultures yielding high transfection versus neurospheres. Transfected NSCs showed high viability and could re-form neurospheres, which is important as neurospheres yield higher post-transplantation viability versus monolayer cells. Our results demonstrate that the combination of oscillating magnetic fields and a monolayer format yields the highest efficacy for MNP-mediated gene transfer to NSCs, offering a viable non-viral alternative for genetic modification of this important neural cell transplant population.
    • Neuropsychiatric symptoms following metal-on-metal implant failure with cobalt and chromium toxicity

      Green, Ben; Griffiths, Emily; Almond, Solomon; University of Chester; Public Health England (BioMed Central, 24/01/2016)
      Background: There were at least 31,171 metal-on-metal (MoM) hip implants in the UK between 2003 and 2011. Some of these were subject to failure and widescale recalls and revisions followed. Method This is a presentation of ten cases (mean age 60 years) where we evaluated neuropsychiatric morbidity following metal-on-metal hip implant failure and revision. Implants were ASR total hip replacement (acetabular implant, taper sleeve adaptor and unipolar femoral implants) performed between 2005 and 2009. This case series describes, for the first time, neuropsychiatric complications after revision where there has been cobalt and chromium toxicity. Results Pre-revision surgery, nine patients had toxic levels of chromium and cobalt (mean level chromium 338 nmol/l, mean cobalt 669.4 nmol/l). Depression assessment showed 9 of 9 respondents fulfilled the BDI criteria for depression and 3 of these were being treated. 7 of 9 patients showing short term memory deficit with mean mini mental state examination score of 24.2. The normal population mean MMSE for this group would be expected to be 28 with <25 indicating possible dementia. Conclusions We found neurocognitive and depressive deficits after cobalt and chromium metallosis following MoM implant failure. Larger studies of neurocognitive effects are indicated in this group. There may be implications for public health.
    • Training nurses in Mental Health Assessment using GMHAT/PC in India

      Jones, Steven; Keenan, Paul; Danivas, Vijay; Krishna, Murali; Rajendra, Rajgopal; University of Chester (Indian Psychiatric Society, 23/07/2017)
      Book chapter; Training of Indian general nurses in a hospital setting required the structure offered by the Global Mental Health Assessment Tool (GMHAT) that would provide a framework to underpin mental health assessment training. Attitudes of those undertaking the training and current levels of knowledge and awareness to mental health issues was explored prior to any training occurring in the use of GMHAT, that we considered fundamental to good mental health practice
    • Ca

      Wong, Vincent K-W.; Qiu, Congling; Xu, Su-Wei; Law, Betty Yuen Kwan; Zeng, Wu; Wang, Hui; Michelangeli, Francesco; Dias, Ivo Ricardo De Seabra Rodrigues; Qu, Yuan Qing; Chan, Tsz Wai; et al. (23/05/2019)
      Celastrol exhibits anti-arthritic effect in rheumatoid arthritis (RA), but the role of celastrol-mediated Ca mobilization in treatment of RA remains unelucidated. Here, we illustrate the regulatory role of celastrol-induced Ca signalling in synovial fibroblasts of RA patients and adjuvant-induced arthritis (AIA) in rats. Molecular target of celastrol was determined by computational docking, Ca dynamic and functional assays on SERCA. Ca -mediated autophagy in RASFs/RAFLS and the underlying mechanism were verified by quantification of endogenous LC3-II puncta, immunoblotting, and flow cytometry with the Ca chelator (BAPTA/AM) or suitable inhibitors. The anti-arthritic effect of celastrol, autophagy induction and growth rate of synovial fibroblasts in AIA rats were monitored by microCT and immunofluorescence staining. mRNA from joint tissues of AIA rats was isolated for transcriptional analysis of inflammatory genes. The role of Ca in regulating the identified genes was investigated by knockdown of calmodulin, calpains, and calcineurin. Celastrol inhibited SERCA to induce autophagy-dependent cytotoxicity in RASFs/RAFLS via CaMKKβ-AMPK-mTOR pathway and repressed arthritis symptoms in AIA rats. BAPTA/AM hampered the in vitro and in vivo effectiveness of celastrol. Inflammatory- and autoimmunity-associated genes downregulated by celastrol in joint tissues of AIA rat were restored by BAPTA/AM. Knockdown of calmodulin, calpains, and calcineurin in RAFLS confirmed the role of Ca in celastrol-regulated gene expression. Celastrol triggered Ca signalling to induce autophagic cell death in RASFs/RAFLS and ameliorated arthritis in AIA rats mediated by calcium-dependent/-binding proteins facilitating the exploitation of anti-arthritic drugs based on manipulation of Ca signalling. [Abstract copyright: This article is protected by copyright. All rights reserved.]
    • Long-term administration of the mitochondria-targeted antioxidant mitoquinone mesylate fails to attenuate age-related oxidative damage or rescue the loss of muscle mass and function associated with aging of skeletal muscle

      Nye, Gareth; Sakellariou, Giorgos; Lightfoot, Adam; Pearson, Timothy; Wells, Nicola; McArdle, Anne; Jackson, Malcolm; Giakoumaki, Ifigeneia; Griffiths, Richard; University of Liverpool (Faseb Journal, 22/08/2016)
      Age-related skeletal muscle dysfunction is the underlying cause of morbidity that affects up to half the population aged 80 and over. Considerable evidence indicates that oxidative damage and mitochondrial dysfunction contribute to the sarcopenic phenotype that occurs with aging. To examine this, we administered the mitochondria-targeted antioxidant mitoquinone mesylate {[10-(4,5-dimethoxy-2-methyl-3,6-dioxo-1,4-cyclohexadien-1-yl)decyl] triphenylphosphonium; 100 μM} to wild-type C57BL/6 mice for 15 wk (from 24 to 28 mo of age) and investigated the effects on age-related loss of muscle mass and function, changes in redox homeostasis, and mitochondrial organelle integrity and function. We found that mitoquinone mesylate treatment failed to prevent age-dependent loss of skeletal muscle mass associated with myofiber atrophy or alter a variety of in situ and ex vivo muscle function analyses, including maximum isometric tetanic force, decline in force after a tetanic fatiguing protocol, and single-fiber-specific force. We also found evidence that long-term mitoquinone mesylate administration did not reduce mitochondrial reactive oxygen species or induce significant changes in muscle redox homeostasis, as assessed by changes in 4-hydroxynonenal protein adducts, protein carbonyl content, protein nitration, and DNA damage determined by the content of 8-hydroxydeoxyguanosine. Mitochondrial membrane potential, abundance, and respiration assessed in permeabilized myofibers were not significantly altered in response to mitoquinone mesylate treatment. Collectively, these findings demonstrate that long-term mitochondria-targeted mitoquinone mesylate administration failed to attenuate age-related oxidative damage in skeletal muscle of old mice or provide any protective effect in the context of muscle aging
    • Quantifying the impact of tissue metabolism on solute transport in feto-placental microvascular networks

      Nye, Gareth; erlich, alexander; Brownbill, Paul; Chernyavsky, Igor; Jenson, Oliver; University of Manchester (Royal Society, 2019-08-16)
      The primary exchange units in the human placenta are terminal villi, in which fetal capillary networks are surrounded by a thin layer of villous tissue, separating fetal from maternal blood. To understand how the complex spatial structure of villi influences their function, we use an image-based theoretical model to study the effect of tissue metabolism on the transport of solutes from maternal blood into the fetal circulation. For solute that is taken up under first-order kinetics, we show that the transition between flow-limited and diffusion-limited transport depends on two new dimensionless parameters defined in terms of key geometric quantities, with strong solute uptake promoting flow-limited transport conditions. We present a simple algebraic approximation for solute uptake rate as a function of flow conditions, metabolic rate and villous geometry. For oxygen, accounting for nonlinear kinetics using physiological parameter values, our model predicts that villous metabolism does not significantly impact oxygen transfer to fetal blood, although the partitioning of fluxes between the villous tissue and the capillary network depends strongly on the flow regime
    • Lamin A/C dysregulation contributes to cardiac pathology in a mouse model of severe spinal muscular atrophy

      Šoltić, Darija; Shorrock, Hannah K.; Allardyce, Hazel; Wilson, Emma L.; Holt, Ian; Synowsky, Silvia A.; Shirran, Sally L.; Parson, Simon H.; Gillingwater, Thomas H.; Fuller, Heidi R. (Oxford University Press (OUP), 2019-08-09)
      Abstract Cardiac pathology is emerging as a prominent systemic feature of spinal muscular atrophy (SMA), but little is known about the underlying molecular pathways. Using quantitative proteomics analysis, we demonstrate widespread molecular defects in heart tissue from the Taiwanese mouse model of severe SMA. We identify increased levels of lamin A/C as a robust molecular phenotype in the heart of SMA mice, and show that lamin A/C dysregulation is also apparent in SMA patient fibroblast cells and other tissues from SMA mice. Lamin A/C expression was regulated in-vitro by knockdown of the E1 ubiquitination factor UBA1, a key downstream mediator of SMN-dependent disease pathways, converging on β-catenin signalling. Increased levels of lamin A are known to increase the rigidity of nuclei, inevitably disrupting contractile activity in cardiomyocytes. The increased lamin A/C levels in the hearts of SMA mice therefore provide a likely mechanism explaining morphological and functional cardiac defects, leading to blood pooling. Therapeutic strategies directed at lamin A/C may therefore offer a new approach to target cardiac pathology in SMA.