Robustness of MEK-ERK Dynamics and Origins of Cell-to-Cell Variability in MAPK Signaling.

Cellular signaling processes can exhibit pronounced cell-to-cell variability in genetically identical cells. This affects how individual cells respond differentially to the same environmental stimulus. However, the origins of cell-to-cell variability in cellular signaling systems remain poorly understood. Here, we measure the dynamics of phosphorylated MEK and ERK across cell populations and quantify the levels of population heterogeneity over time using high-throughput image cytometry. We use a statistical modeling framework to show that extrinsic noise, particularly that from upstream MEK, is the dominant factor causing cell-to-cell variability in ERK phosphorylation, rather than stochasticity in the phosphorylation/dephosphorylation of ERK. We furthermore show that without extrinsic noise in the core module, variable (including noisy) signals would be faithfully reproduced downstream, but the within-module extrinsic variability distorts these signals and leads to a drastic reduction in the mutual information between incoming signal and ERK activity

A Design Exploration of Health-Related Community Displays

The global population is ageing, leading to shifts in healthcare needs. It is well established that increased physical activity can improve the health and wellbeing of many older adults. However, motivation remains a prime concern. We report findings from a series of focus groups where we explored the concept of using community displays to promote physical activity to a local neighborhood. In doing so, we contribute both an understanding of the design space for community displays, as well as a discussion of the implications of our work for the broader CSCW community. We conclude that our work demonstrates the potential for developing community displays for increasing physical activity amongst older adults

Typical investigational medicinal products follow relatively uniform regulations in 10 European Clinical Research Infrastructures Network (ECRIN) countries

<p>Abstract</p> <p>Background</p> <p>In order to facilitate multinational clinical research, regulatory requirements need to become international and harmonised. The EU introduced the Directive 2001/20/EC in 2004, regulating investigational medicinal products in Europe.</p> <p>Methods</p> <p>We conducted a survey in order to identify the national regulatory requirements for major categories of clinical research in ten European Clinical Research Infrastructures Network (ECRIN) countries-Austria, Denmark, France, Germany, Hungary, Ireland, Italy, Spain, Sweden, and United Kingdom-covering approximately 70% of the EU population. Here we describe the results for regulatory requirements for typical investigational medicinal products, in the ten countries.</p> <p>Results</p> <p>Our results show that the ten countries have fairly harmonised definitions of typical investigational medicinal products. Clinical trials assessing typical investigational medicinal products require authorisation from a national competent authority in each of the countries surveyed. The opinion of the competent authorities is communicated to the trial sponsor within the same timelines, i.e., no more than 60 days, in all ten countries. The authority to which the application has to be sent to in the different countries is not fully harmonised.</p> <p>Conclusion</p> <p>The Directive 2001/20/EC defined the term 'investigational medicinal product' and all regulatory requirements described therein are applicable to investigational medicinal products. Our survey showed, however, that those requirements had been adopted in ten European countries, not for investigational medicinal products overall, but rather a narrower category which we term 'typical' investigational medicinal products. The result is partial EU harmonisation of requirements and a relatively navigable landscape for the sponsor regarding typical investigational medicinal products.</p

Emerging infectious disease implications of invasive mammalian species : the greater white-toothed shrew (Crocidura russula) is associated with a novel serovar of pathogenic Leptospira in Ireland

The greater white-toothed shrew (Crocidura russula) is an invasive mammalian species that was first recorded in Ireland in 2007. It currently occupies an area of approximately 7,600 km2 on the island. C. russula is normally distributed in Northern Africa and Western Europe, and was previously absent from the British Isles. Whilst invasive species can have dramatic and rapid impacts on faunal and floral communities, they may also be carriers of pathogens facilitating disease transmission in potentially naive populations. Pathogenic leptospires are endemic in Ireland and a significant cause of human and animal disease. From 18 trapped C. russula, 3 isolates of Leptospira were cultured. However, typing of these isolates by standard serological reference methods was negative, and suggested an, as yet, unidentified serovar. Sequence analysis of 16S ribosomal RNA and secY indicated that these novel isolates belong to Leptospira alstonii, a unique pathogenic species of which only 7 isolates have been described to date. Earlier isolations were limited geographically to China, Japan and Malaysia, and this leptospiral species had not previously been cultured from mammals. Restriction enzyme analysis (REA) further confirms the novelty of these strains since no similar patterns were observed with a reference database of leptospires. As with other pathogenic Leptospira species, these isolates contain lipL32 and do not grow in the presence of 8-azagunaine; however no evidence of disease was apparent after experimental infection of hamsters. These isolates are genetically related to L. alstonii but have a novel REA pattern; they represent a new serovar which we designate as serovar Room22. This study demonstrates that invasive mammalian species act as bridge vectors of novel zoonotic pathogens such as Leptospira

Comparative review of human and canine osteosarcoma: morphology, epidemiology, prognosis, treatment and genetics

Osteosarcoma (OSA) is a rare cancer in people. However OSA incidence rates in dogs are 27 times higher than in people. Prognosis in both species is poor, with five year osteosarcoma survival rates in people not having improved in decades. For dogs, one year survival rates are only around ~45%. Improved and novel treatment regimens are urgently required to improve survival in both humans and dogs with OSA. Utilising information from genetic studies could assist in this in both species, with the higher incidence rates in dogs contributing to the dog population being a good model of human disease. This review compares the clinical characteristics, gross morphology and histopathology, aetiology, epidemiology, and genetics of canine and human osteosarcoma. Finally, the current position of canine osteosarcoma genetic research is discussed and areas for additional work within the canine population are identified

Cell viability in three ex vivo rat models of spinal cord injury

Spinal cord injury (SCI) is a devastating disorder that has a poor prognosis of recovery. Animal models of SCI are useful to understand the pathophysiology of SCI and the potential use of therapeutic strategies for human SCI. Ex vivo models of central nervous system (CNS) trauma, particularly mechanical trauma, have become important tools to complement in vivo models of injury in order to reproduce the sequelae of human CNS injury. Ex vivo organotypic slice cultures (OSCs) provide a reliable model platform for the study of cell dynamics and therapeutic intervention following SCI. In addition, these ex vivo models support the 3R concept of animal use in SCI research - replacement, reduction and refinement. Ex vivo models cannot be used to monitor functional recovery, nor do they have the intact blood supply of the in vivo model systems. However, the ex vivo models appear to reproduce many of the post traumatic events including acute and secondary injury mechanisms. Several well-established OSC models have been developed over the past few years for experimental spinal injuries ex vivo in order to understand the biological response to injury. In this study, we investigated cell viability in three ex vivo OSC models of SCI: stab injury, transection injury and contusion injury. Injury was inflicted in postnatal day 4 rat spinal cord slices. Stab injury was performed using a needle on transverse slices of spinal cord. Transection injury was performed on longitudinal slices of spinal cord using a double blade technique. Contusion injury was performed on longitudinal slices of spinal cord using an Infinite Horizon impactor device. At days 3 and 10 post-injury, viability was measured using dual staining for propidium iodide and fluorescein diacetate. In all ex vivo SCI models, the slices showed more live cells than dead cells over 10 days in culture, with higher cell viability in control slices compared with injured slices. Although no change in cell viability was observed between time-points in stab- and contusion-injured OSCs, a reduction in cell viability was observed over time in transection-injured OSCs. Taken together, ex vivo SCI models are a useful and reliable research tool that reduces the cost and time involved in carrying out animal studies. The use of OSC models provides a simple way to study the cellular consequences following SCI, and they can also be used to investigate potential therapeutics regimes for the treatment of SCI.The authors acknowledge the facilities, scientific and technical assistance (Mr Mark Canney and Dr Kerry Thompson) of the Centre for Microscopy and Imaging at the National University of Ireland, Galway (www.imaging.nuigalway.ie), a facility which is co‐funded by the Irish Government Programme for Research in Third Level Institutions, Cycles 4 and 5, National Development Plan 2007‐2013. Funding for this project was provided by the Malaysia Ministry of Education and the College of Medicine, Nursing and Health Science at NUI Galway.peer-reviewed2019-11-1

Cell viability in three ex vivo rat models of spinal cord injury

Spinal cord injury (SCI) is a devastating disorder that has a poor prognosis of recovery. Animal models of SCI are useful to understand the pathophysiology of SCI and the potential use of therapeutic strategies for human SCI. Ex vivo models of central nervous system (CNS) trauma, particularly mechanical trauma, have become important tools to complement in vivo models of injury in order to reproduce the sequelae of human CNS injury. Ex vivo organotypic slice cultures (OSCs) provide a reliable model platform for the study of cell dynamics and therapeutic intervention following SCI. In addition, these ex vivo models support the 3R concept of animal use in SCI research - replacement, reduction and refinement. Ex vivo models cannot be used to monitor functional recovery, nor do they have the intact blood supply of the in vivo model systems. However, the ex vivo models appear to reproduce many of the post traumatic events including acute and secondary injury mechanisms. Several well-established OSC models have been developed over the past few years for experimental spinal injuries ex vivo in order to understand the biological response to injury. In this study, we investigated cell viability in three ex vivo OSC models of SCI: stab injury, transection injury and contusion injury. Injury was inflicted in postnatal day 4 rat spinal cord slices. Stab injury was performed using a needle on transverse slices of spinal cord. Transection injury was performed on longitudinal slices of spinal cord using a double blade technique. Contusion injury was performed on longitudinal slices of spinal cord using an Infinite Horizon impactor device. At days 3 and 10 post-injury, viability was measured using dual staining for propidium iodide and fluorescein diacetate. In all ex vivo SCI models, the slices showed more live cells than dead cells over 10 days in culture, with higher cell viability in control slices compared with injured slices. Although no change in cell viability was observed between time-points in stab- and contusion-injured OSCs, a reduction in cell viability was observed over time in transection-injured OSCs. Taken together, ex vivo SCI models are a useful and reliable research tool that reduces the cost and time involved in carrying out animal studies. The use of OSC models provides a simple way to study the cellular consequences following SCI, and they can also be used to investigate potential therapeutics regimes for the treatment of SCI.The authors acknowledge the facilities, scientific and technical assistance (Mr Mark Canney and Dr Kerry Thompson) of the Centre for Microscopy and Imaging at the National University of Ireland, Galway (www.imaging.nuigalway.ie), a facility which is co‐funded by the Irish Government Programme for Research in Third Level Institutions, Cycles 4 and 5, National Development Plan 2007‐2013. Funding for this project was provided by the Malaysia Ministry of Education and the College of Medicine, Nursing and Health Science at NUI Galway.2019-11-1

GDNF Schwann cells in hydrogel scaffolds promote regional axon regeneration, remyelination and functional improvement after spinal cord transection in rats

Positively-charged oligo[poly(ethylene glycol)fumarate] (OPF+) is a biodegradable hydrogel used for spinal cord injury repair. We compared scaffolds containing primary Schwann cells (SCs) to scaffolds delivering SCs genetically modified to secrete high concentrations of glial cell-derived neurotrophic factor (GDNF). Multichannel OPF+ scaffolds loaded with SCs or GDNF-SCs were implanted into transected rat spinal cords for 4 weeks. GDNF-SCs promoted regeneration of more axons into OPF+ scaffolds (2773.0 +/- 396.0) than primary SC OPF+ scaffolds (1666.0 +/- 352.2) (p = 0.0491). This increase was most significant in central and ventral-midline channels of the scaffold. Axonal remyelination was quantitated by stereologic analysis. Increased myelination of regenerating axons was observed in the GDNF-SC group. Myelinating cell and axon complexes were formed by host SCs and not by implanted cells or host oligodendrocytes. Fast Blue retrograde tracing studies determined the rostral-caudal directionality of axonal growth. The number of neurons that projected axons rostrally through the GDNF-SC scaffolds was higher (7929 +/- 1670) than in animals with SC OPF+ scaffolds (1069 +/- 241.5) (pThis work was supported by the National Institutes of Health (EB002390) (A. J. W.), the Wilson, Morton and Mayo Foundations (A. J. W.) and the Health Research Board of Ireland (RP/2007/143) (N. M. and S. S. M.). We thank Thomas Ritter, National University of Ireland, Galway, for supplying source plasmids, James Tarara at Mayo Clinic for expertise in confocal microscopy, and Andrew Knight and Trent Chiang for the GDNF ELISA studies. We thank Ann Schmeichel and Shuya Zhang for expertise in immunohistochemistry, Jarred Nesbitt for expert animal care and Jane Meyer for her role in manuscript preparation.peer-reviewe

Therapeutic effect of neurotrophin-3 treatment in an injectable collagen scaffold following rat spinal cord hemisection injury

Spinal cord injury (SCI) patients display varying quantities of spinal cord tissue damage with injuries that present as complete, incomplete or compressive. One theory proposed to repair the injured spinal cord and regain motor control is to regenerate axons through the lesion site. This study was designed to quantify the impact of a local injectable in situ forming hydrogel reservoir therapy following rat hemisection SCI. We investigated the effect of hydrogel only treatment following SCI in addition to hydrogels loaded with a neurotrophic factor, Neurotrophin-3 (NT-3), immediately following SCI. Functional recovery, assessed by Basso Beattie Bresnahan (BBB) locomotor test, and local healing mechanisms, including neuronal growth, glial scar formation, inflammation and collagen deposition were investigated one and 6 weeks postsurgery. Delivery of an injectable hydrogel significantly increased functional recovery at four and 6 weeks post injury. In addition, a significant reduction in the inhibitory glial scar and in inflammation was observed at the injury site. Similarly hydrogel + NT-3 delivered directly into the injury site significantly reduced glial scarring and collagen deposition. The hydrogel + NT-3 also resulted in a significant increase in neurons at 6 weeks post injury. This study represents a novel and effective therapy combining growth factor and a biomaterial based therapy following SCI.B.B. and H.K. were supported by Covidien LLC and the Industrial Development Agency (IDA) of Ireland grant. R.R. and A.K. supported by EU 7th Framework Programme Grant 304936 and CÚRAM Science Foundation Ireland (SFI) Grant 13/RC/2073. A.P. was supported by Malaysia Ministry of Education. T.S. was supported by by Covidien LLC. A.P. and S.M. were supported by CÚRAM Science Foundation Ireland (SFI) Grant 13/RC/2073.peer-reviewe