Publications by authors named "Gary Morris"

Capillary pericytes are important regulators of cerebral blood flow, blood-brain barrier integrity and neuroinflammation, but can become lost or dysfunctional in disease. The consequences of pericyte loss or dysfunction is extremely difficult to discern when it forms one component of a complex disease process. To evaluate this directly, we examined the effect of adult pericyte loss on mouse voluntary movement and motor function, and physiological responses such as hypoxia, blood-brain barrier (BBB) integrity and glial reactivity.

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  • The study investigates the role of brain pericytes in the microvascular no-reflow phenomenon after reopening an artery during ischemic stroke.
  • It finds that mTOR inhibition via rapamycin reduces pericyte contraction during simulated ischemia, though it doesn't significantly affect cell survival.
  • In a mouse model, rapamycin improves capillary diameter and increases the number of open capillaries following arterial recanalization, suggesting it could be a helpful treatment to enhance blood flow in the brain after a stroke.
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  • Approximately 20% of microglia were found to form "plugs," or direct contact points with blood vessels, predominantly located near the cell body and favored near venules.
  • This research highlights the significance of microglial contact with endothelial cells over pericytes, providing a basis for understanding how these interactions influence brain function and disease.
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Background: Pericytes are multifunctional contractile cells that reside on capillaries. Pericytes are critical regulators of cerebral blood flow and blood-brain barrier function, and pericyte dysfunction may contribute to the pathophysiology of human neurological diseases including Alzheimers disease, multiple sclerosis, and stroke. Induced pluripotent stem cell (iPSC)-derived pericytes (iPericytes) are a promising tool for vascular research.

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Introduction: Accurate modelling of molecular changes in Alzheimer's disease (AD) dementia is crucial for understanding the mechanisms driving neuronal pathology and for developing treatments. Synaptic dysfunction has long been implicated as a mechanism underpinning memory dysfunction in AD and may result in part from changes in adenosine deaminase acting on RNA (ADAR) mediated RNA editing of the GluA2 subunit of AMPA receptors and changes in AMPA receptor function at the post synaptic cleft. However, few studies have investigated changes in proteins which influence RNA editing and notably, AD studies that focus on studying changes in protein expression, rather than changes in mRNA, often use traditional western blotting.

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Objective: To establish a scope of practice, competency (through education) and governance framework for ultrasound image guided injection of botulinum toxin in the management of spasticity.

Design: Delphi study.

Setting: International, web-based survey.

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Background: RNA editing at the Q/R site of GluA2 occurs with ~99% efficiency in the healthy brain, so that the majority of AMPARs contain GluA2(R) instead of the exonically encoded GluA2(Q). Reduced Q/R site editing infcreases AMPA receptor calcium permeability and leads to dendritic spine loss, neurodegeneration, seizures and learning impairments. Furthermore, GluA2 Q/R site editing is impaired in Alzheimer's disease (AD), raising the possibility that unedited GluA2(Q)-containing AMPARs contribute to synapse loss and neurodegeneration in AD.

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The wild Tasmanian devil (Sarcophilus harrisii) population has suffered a devastating decline due to two clonal transmissible cancers. The first devil facial tumor 1 (DFT1) was observed in 1996, followed by a second genetically distinct transmissible tumor, the devil facial tumor 2 (DFT2), in 2014. DFT1/2 frequently metastasize, with lymph nodes being common metastatic sites.

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  • Cerebral blood flow (CBF) is crucial for brain function, and its dysregulation is linked to Alzheimer's disease; microglia may play a role in regulating CBF and the blood-brain barrier (BBB).
  • Researchers discovered a specific type of microglia, called pericyte-associated microglia (PEM), that closely interacts with pericytes, cells that help control CBF and maintain the BBB, present in the brain and spinal cord.
  • The study found that the number of PEM decreases in the superior frontal gyrus of individuals with Alzheimer's, suggesting a potential new mechanism behind vascular dysfunction in neurodegenerative diseases.
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Cognitive-behavioral testing in preclinical models of Alzheimer's disease has failed to capture deficits in goal-directed action control. Here, we provide the first comprehensive investigation of goal-directed action in a transgenic mouse model of Alzheimer's disease. Specifically, we tested outcome devaluation performance in male and female human amyloid precursor protein (hAPP)-J20 mice.

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Stroke therapy has largely focused on preventing damage and encouraging repair outside the ischemic core, as the core is considered irreparable. Recently, several studies have suggested endogenous responses within the core are important for limiting the spread of damage and enhancing recovery, but the role of blood flow and capillary pericytes in this process is unknown. Using the Rose Bengal photothrombotic model of stroke, we illustrate blood vessels are present in the ischemic core and peri-lesional regions 2 weeks post stroke in male mice.

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Purpose: Osseointegration of dental endosseous implants has proven to be effective, predictable, and clinically successful. Unloaded healing protocols were originally used in treating edentulous patients. Full arch immediate occlusal loading protocols have been shown to be as effective as unloaded healing protocols.

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The quantification of labeled cells in tissue sections is crucial to the advancement of biological knowledge. Traditionally, this was a tedious process, requiring hours of careful manual counting in small portions of a larger tissue section. To overcome this, many automated methods for cell analysis have been developed.

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Whole slide scanning technology has enabled the generation of high-resolution images from complete tissue sections. However, commonly used analysis software is often unable to handle the large data files produced. Here, we present a method using the open-source software QuPath to detect, classify and quantify fluorescently-labeled cells (microglia and pericytes) in whole coronal brain tissue sections.

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Background: Multiple professional bodies have temporarily revised recommendations for gestational diabetes mellitus (GDM) testing during the COVID-19 pandemic to reduce person-to-person contact. The current Australian temporary criteria advise that if the fasting glucose is ≤4.6 mmol/L, then no glucose tolerance test (GTT) is required.

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Calcium (Ca)-permeable AMPA receptors may, in certain circumstances, contribute to normal synaptic plasticity or to neurodegeneration. AMPA receptors are Ca-permeable if they lack the GluA2 subunit or if GluA2 is unedited at a single nucleic acid, known as the Q/R site. In this study, we examined mice engineered with a point mutation in the intronic editing complementary sequence (ECS) of the GluA2 gene, Gria2.

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Background: Accurately assessing promising therapeutic interventions for human diseases depends, in part, on the reproducibility of preclinical disease models. With the development of transgenic mice, the rapid adaptation of a 6-OHDA mouse model of Parkinson's disease that was originally described for the use in rats has come with a lack of a comprehensive characterization of lesion progression. In this study we therefore first characterised the time course of neurodegeneration in the substantia nigra pars compacta and striatum over a 4 week period following 6-OHDA injection into the medial forebrain bundle of mice.

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The ozonesonde is a small balloon-borne instrument that is attached to a standard radiosonde to measure profiles of ozone from the surface to 35 km with ~100-m vertical resolution. Ozonesonde data constitute a mainstay of satellite calibration and are used for climatologies and analysis of trends, especially in the lower stratosphere where satellites are most uncertain. The electrochemical-concentration cell (ECC) ozonesonde has been deployed at ~100 stations worldwide since the 1960s, with changes over time in manufacture and procedures, including details of the cell chemical solution and data processing.

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The dominant hypothesis of Alzheimer's disease (AD) aetiology, the neuropathological guidelines for diagnosing AD and the majority of high-profile therapeutic efforts, in both research and in clinical practice, have been built around one possible causal factor, amyloid-β (Aβ). However, the causal link between Aβ and AD remains unproven. Here, in the context of a detailed assessment of historical and contemporary studies, we raise critical questions regarding the role of Aβ in the definition, diagnosis and aetiology of AD.

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Objective: To provide national consensus and establish priorities with regards to the factors that promote the implementation and continued development of non-medical prescribing within health services.

Design: Classic e-Delphi survey.

Setting: National study in Wales.

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Multi-drug resistant infections have been identified as one of the greatest threats to human health. Healthcare professionals are involved in an array of patient care activities for which an understanding of antimicrobial stewardship is important. Although antimicrobial prescribing and stewardship competencies have been developed for healthcare professionals who adopt the role of a prescriber, competencies do not exist for other medicine-related stewardship activities.

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Objectives: To identify (1) the non-medical healthcare professionals in Wales qualified to prescribe medicines (including job title, employer, where the prescribing qualification is used, care setting and service provided); (2) the mode of prescribing used by these healthcare professionals, the frequency with which medicines are prescribed and the different ways in which the prescribing qualification is used; and (3) the safety and clinical governance systems within which these healthcare professionals practise.

Design: National questionnaire survey.

Setting: All three National Health Service (NHS) Trusts and seven Health Boards (HB) in Wales.

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Objective: To determine the effect of different seasons on the prevalence of gestational diabetes mellitus (GDM) by using World Health Organization criteria.

Research Design And Methods: The results of all pregnancy glucose tolerance tests (GTTs) were prospectively collected over a 3-year period in a temperate climate, and the results were grouped by season.

Results: The results of 7,369 pregnancy GTTs were available for consideration.

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Knowledge of the fasting plasma glucose of healthy women may assist in the setting of treatment targets for women with hyperglycaemia in pregnancy (HIP). This study examines the pregnancy glucose tolerance test results of 3344 women without HIP collected over a three-year period. The median fasting plasma glucose was 4.

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