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1.
Stem Cell Res Ther ; 15(1): 59, 2024 Mar 03.
Article in English | MEDLINE | ID: mdl-38433209

ABSTRACT

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. However, it is unclear how iPericytes functionally compare to primary human brain vascular pericytes (HBVPs). METHODS: We differentiated iPSCs into iPericytes of either the mesoderm or neural crest lineage using established protocols. We compared iPericyte and HBVP morphologies, quantified gene expression by qPCR and bulk RNA sequencing, and visualised pericyte protein markers by immunocytochemistry. To determine whether the gene expression of neural crest iPericytes, mesoderm iPericytes or HBVPs correlated with their functional characteristics in vitro, we quantified EdU incorporation following exposure to the key pericyte mitogen, platelet derived growth factor (PDGF)-BB and, contraction and relaxation in response to the vasoconstrictor endothelin-1 or vasodilator adenosine, respectively. RESULTS: iPericytes were morphologically similar to HBVPs and expressed canonical pericyte markers. However, iPericytes had 1864 differentially expressed genes compared to HBVPs, while there were 797 genes differentially expressed between neural crest and mesoderm iPericytes. Consistent with the ability of HBVPs to respond to PDGF-BB signalling, PDGF-BB enhanced and a PDGF receptor-beta inhibitor impaired iPericyte proliferation. Administration of endothelin-1 led to iPericyte contraction and adenosine led to iPericyte relaxation, of a magnitude similar to the response evoked in HBVPs. We determined that neural crest iPericytes were less susceptible to PDGFR beta inhibition, but responded most robustly to vasoconstrictive mediators. CONCLUSIONS: iPericytes express pericyte-associated genes and proteins and, exhibit an appropriate physiological response upon exposure to a key endogenous mitogen or vasoactive mediators. Therefore, the generation of functional iPericytes would be suitable for use in future investigations exploring pericyte function or dysfunction in neurological diseases.


Subject(s)
Induced Pluripotent Stem Cells , Pericytes , Humans , Becaplermin/pharmacology , Endothelin-1/pharmacology , Adenosine , Cell Proliferation
2.
Mol Neurodegener ; 18(1): 65, 2023 09 28.
Article in English | MEDLINE | ID: mdl-37759260

ABSTRACT

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. If true, then inhibiting expression of unedited GluA2(Q), while maintaining expression of GluA2(R), may be a novel strategy of preventing synapse loss and neurodegeneration in AD. METHODS: We engineered mice with the 'edited' arginine codon (CGG) in place of the unedited glutamine codon (CAG) at position 607 of the Gria2 gene. We crossbred this line with the J20 mouse model of AD and conducted anatomical, electrophysiological and behavioural assays to determine the impact of eliminating unedited GluA2(Q) expression on AD-related phenotypes. RESULTS: Eliminating unedited GluA2(Q) expression in AD mice prevented dendritic spine loss and hippocampal CA1 neurodegeneration as well as improved working and reference memory in the radial arm maze. These phenotypes were improved independently of Aß pathology and ongoing seizure susceptibility. Surprisingly, our data also revealed increased spine density in non-AD mice with exonically encoded GluA2(R) as compared to their wild-type littermates, suggesting an unexpected and previously unknown role for unedited GluA2(Q) in regulating dendritic spines. CONCLUSION: The Q/R editing site of the AMPA receptor subunit GluA2 may act as an epigenetic switch that regulates dendritic spines, neurodegeneration and memory deficits in AD.


Subject(s)
Alzheimer Disease , Dendritic Spines , Animals , Mice , Receptors, AMPA , Alzheimer Disease/genetics , Epigenesis, Genetic , Cognition
4.
Immunol Invest ; 52(6): 661-680, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37267050

ABSTRACT

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. MHC-I downregulation by DFT1 cells is a primary means of evading allograft immunity aimed at polymorphic MHC-I proteins. DFT2 cells constitutively express MHC-I, and MHC-I is upregulated on DFT1/2 cells by interferon gamma, suggesting other immune evasion mechanisms may contribute to overcoming allograft and anti-tumor immunity. Human clinical trials have demonstrated PD1/PDL1 blockade effectively treats patients showing increased expression of PD1 in tumor draining lymph nodes, and PDL1 on peritumoral immune cells and tumor cells. The effects of DFT1/2 on systemic immunity remain largely uncharacterized. This study applied the open-access software QuPath to develop a semiautomated pipeline for whole slide analysis of stained tissue sections to quantify PD1/PDL1 expression in devil lymph nodes. The QuPath protocol provided strong correlations to manual counting. PD-1 expression was approximately 10-fold higher than PD-L1 expression in lymph nodes and was primarily expressed in germinal centers, whereas PD-L1 expression was more widely distributed throughout the lymph nodes. The density of PD1 positive cells was increased in lymph nodes containing DFT2 metastases, compared to DFT1. This suggests PD1/PDL1 exploitation may contribute to the poorly immunogenic nature of transmissible tumors in some devils and could be targeted in therapeutic or prophylactic treatments.Abbreviations: PD1: programmed cell death protein 1; PDL1: programmed death ligand 1; DFT1: devil facial tumor 1; DFT2: devil facial tumor 2; DFTD: devil facial tumor disease; MCC: Matthew's correlation coefficient; DAB: diaminobenzidine; ROI: region of interest.


Subject(s)
B7-H1 Antigen , Facial Neoplasms , Humans , B7-H1 Antigen/genetics , Programmed Cell Death 1 Receptor/genetics , Lymph Nodes/pathology , Tumor Microenvironment
5.
Glia ; 71(8): 1847-1869, 2023 08.
Article in English | MEDLINE | ID: mdl-36994950

ABSTRACT

Cerebral blood flow (CBF) is important for the maintenance of brain function and its dysregulation has been implicated in Alzheimer's disease (AD). Microglia associations with capillaries suggest they may play a role in the regulation of CBF or the blood-brain-barrier (BBB). We explored the relationship between microglia and pericytes, a vessel-resident cell type that has a major role in the control of CBF and maintenance of the BBB, discovering a spatially distinct subset of microglia that closely associate with pericytes. We termed these pericyte-associated microglia (PEM). PEM are present throughout the brain and spinal cord in NG2DsRed × CX3 CR1+/GFP mice, and in the human frontal cortex. Using in vivo two-photon microscopy, we found microglia residing adjacent to pericytes at all levels of the capillary tree and found they can maintain their position for at least 28 days. PEM can associate with pericytes lacking astroglial endfeet coverage and capillary vessel width is increased beneath pericytes with or without an associated PEM, but capillary width decreases if a pericyte loses a PEM. Deletion of the microglia fractalkine receptor (CX3 CR1) did not disrupt the association between pericytes and PEM. Finally, we found the proportion of microglia that are PEM declines in the superior frontal gyrus in AD. In summary, we identify microglia that specifically associate with pericytes and find these are reduced in number in AD, which may be a novel mechanism contributing to vascular dysfunction in neurodegenerative diseases.


Subject(s)
Alzheimer Disease , Pericytes , Mice , Humans , Animals , Pericytes/metabolism , Mice, Transgenic , Microglia , Brain/metabolism , Blood-Brain Barrier/metabolism , Alzheimer Disease/metabolism
6.
eNeuro ; 10(2)2023 02.
Article in English | MEDLINE | ID: mdl-36650070

ABSTRACT

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. Mice were first trained to press left and right levers for pellet and sucrose outcomes, respectively (counterbalanced), over 4 d. On test, mice were prefed one of the outcomes to satiety and given a choice between levers. Devaluation performance was intact for 36-week-old wild-types of both sexes, who responded more on the valued relative to the devalued lever (Valued > Devalued). By contrast, devaluation was impaired (Valued = Devalued) for J20 mice of both sexes, and for 52-week-old male mice regardless of genotype. After additional lever press training (i.e., 8-d lever pressing in total), devaluation was intact for all mice, demonstrating that the initial deficits were not a result of a nonspecific impairment in reward processing, depression, or locomotor activity in J20 or aging mice. Follow-up analyses revealed that microglial expression in the dorsal CA1 region of the hippocampus was associated with poorer outcome devaluation performance on initial, but not later tests. Together, these data demonstrate that goal-directed action is initially impaired in J20 mice of both sexes and in aging male mice regardless of genotype, and that this impairment is related to neuroinflammation in the dorsal CA1 hippocampal region.


Subject(s)
Alzheimer Disease , Mice , Male , Humans , Female , Animals , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Amyloid beta-Protein Precursor/genetics , Amyloid beta-Protein Precursor/metabolism , Goals , Mice, Transgenic , Hippocampus/metabolism , Disease Models, Animal
7.
J Neurosci Res ; 101(2): 278-292, 2023 02.
Article in English | MEDLINE | ID: mdl-36412274

ABSTRACT

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. A FITC-albumin gel cast of the vasculature revealed perfusion of these vessels, suggesting cerebral blood flow (CBF) may be partially present, without vascular leakage. The length of these vessels is significantly reduced compared to uninjured regions, but the average width is greater, suggesting they are either larger vessels that survived the initial injury, smaller vessels that have expanded in size (i.e., arteriogenesis), or that neovascularization begins with larger vessels. Concurrently, we observed an increase in platelet-derived growth factor receptor beta (PDGFRß, a marker of pericytes) expression within the ischemic core in two distinct patterns, one which resembles pericyte-derived fibrotic scarring at the edge of the core, and one which is vessel associated and may represent blood vessel recovery. We find little evidence for dividing cells on these intralesional blood vessels 2 weeks post stroke. Our study provides evidence flow is present in PDGFRß-positive vessels in the ischemic core 2 weeks post stroke. We hypothesize intralesional CBF is important for limiting injury and for encouraging endogenous repair following cerebral ischemia.


Subject(s)
Rose Bengal , Serum Albumin , Male , Mice , Animals
8.
J Prosthodont ; 32(3): 204-213, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36375088

ABSTRACT

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. This paper reports on the results, benefits, and limitations of one specific immediate loading protocol using site specific implants for fresh extraction and healed extraction sites. MATERIALS AND METHODS: Ten consecutive patients [{13 arches} (age range: 64-81 years; average: 70.1) (4 males/6 females) were treated by the first 2 authors in private practice settings. Hopeless teeth were scheduled for extraction with immediate implant placement and immediate loading with insertion of full arch, screw-retained, acrylic resin interim prostheses within 24 hours. Implants were also placed into healed edentulous ridges. Insertion torque values for each implant were recorded. Interim prostheses were removed after at least 3 months of healing. Implants were reverse torque tested (35 Ncm) and evaluated for macroscopic mobility. Definitive full arch prostheses were made. Patients were followed for 21 to 48 months postimplant surgery. Panoramic radiographs were taken immediately postimplant placement and 1 year postoperative. RESULTS: Thirteen arches were treated; 11 ultrawide diameter implants were placed into molar sockets, 26 inverted body-shift implants were placed into anterior sockets; 25 standard diameter, tapered implants were placed into edentulous sites; 2 zygomatic implants were placed in one patient. The total number of implants placed was 64 (4 preexisting implants were also used and not included in this study). The minimum implant insertion torque value was 20 Ncm. After 12 to 18 months of function (average 14 months), the implant and prosthetic survival rates were 100%. Eight patients were restored with definitive zirconia or acrylic resin hybrid fixed prostheses. Two patients were restored with bar titanium frameworks and removable overdenture prostheses. No prosthetic complications were reported for the definitive prostheses. CONCLUSIONS: The results of this clinical series with site specific implants and immediate full arch occlusal loading in treating edentulous patients resulted in 100% clinical implant and prosthetic survival rates. According to this study, this protocol can be used with high levels of anticipated success.


Subject(s)
Dental Implants , Immediate Dental Implant Loading , Jaw, Edentulous , Mouth, Edentulous , Male , Female , Humans , Middle Aged , Aged , Aged, 80 and over , Follow-Up Studies , Jaw, Edentulous/surgery , Osseointegration , Mouth, Edentulous/surgery , Acrylic Resins , Immediate Dental Implant Loading/methods , Dental Prosthesis, Implant-Supported , Dental Implantation, Endosseous/methods , Treatment Outcome
9.
Arch Rehabil Res Clin Transl ; 5(4): 100299, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38163024

ABSTRACT

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. Participants: A purposively selected multidisciplinary (physicians, physiotherapists, occupational therapists) panel of experts (n=15) in the use of ultrasound image guided injection of botulinum toxin for management of spasticity. Panel members were predominantly based in the UK (11/15). Interventions: In round 1, open-ended questions were posed relating to potential scope of practice for 'ultrasound imaging in spasticity management'; (specifically relating to ultrasound image guided injection of Botulinum Toxin) education/competency and governance considerations. In round 2, respondents were asked to rate their level of agreement with the statements generated. Outcome measures: 5-point Likert scale used for rating the statements. Threshold for consensus agreement was set at 70% or above. Results: Three different scopes of practice relating to ultrasound imaging in spasticity management were accepted. The primary scope of practice was the use of ultrasound imaging to guide safe and accurate delivery of botulinum toxin. Relating to this primary scope, 7 competency requirements were agreed relating to areas including image optimization and interpretation, needle visualization and safety. A singular, broad governance statement was generated. Conclusion: Relating specifically to guided injection of botulinum toxin for management of spasticity, we present a scope of practice, competency, and governance framework. These are integrated within a framework approach to provide a mechanism for increased patient access to accurate, safe, and effective focal spasticity treatment. The framework supports focused training routes, greater inter-profession communication and wider clinical community engagement in spasticity management using this modality.

10.
Front Mol Neurosci ; 16: 1338065, 2023.
Article in English | MEDLINE | ID: mdl-38299128

ABSTRACT

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. Methods: Here, we demonstrate the value of automated capillary western blotting to investigate the protein expression of AMPA receptor subunits (GluA1-4), the ADAR RNA editing proteins (ADAR1-3), and proteins known to regulate RNA editing (PIN1, WWP2, FXR1P, and CREB1), in the J20 AD mouse model. We describe extensive optimisation and validation of the automated capillary western blotting method, demonstrating the use of total protein to normalise protein load, in addition to characterising the optimal protein/antibody concentrations to ensure accurate protein quantification. Following this, we assessed changes in proteins of interest in the hippocampus of 44-week-old J20 AD mice. Results: We observed an increase in the expression of ADAR1 p110 and GluA3 and a decrease in ADAR2 in the hippocampus of 44-week-old J20 mice. These changes signify a shift in the balance of proteins that play a critical role at the synapse. Regression analysis revealed unique J20-specific correlations between changes in AMPA receptor subunits, ADAR enzymes, and proteins that regulate ADAR stability in J20 mice, highlighting potential mechanisms mediating RNA-editing changes found in AD. Discussion: Our findings in J20 mice generally reflect changes seen in the human AD brain. This study underlines the importance of novel techniques, like automated capillary western blotting, to assess protein expression in AD. It also provides further evidence to support the hypothesis that a dysregulation in RNA editing-related proteins may play a role in the initiation and/or progression of AD.

11.
Bio Protoc ; 12(13)2022 Jul 05.
Article in English | MEDLINE | ID: mdl-35937935

ABSTRACT

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. Recent advances in whole slide scanning technologies have provided the means to image cells in entire tissue sections. However, common automated analysis tools do not have the capacity to deal with the large image files produced. Herein, we present a protocol for the quantification of two fluorescently labeled cell populations, namely pericytes and microglia, in whole brain tissue sections. This protocol uses custom-made scripts within the open source software QuPath to provide a framework for the careful optimization and validation of automated cell detection parameters. Images obtained from a whole-slide scanner are first loaded into a QuPath project. Manual counts are performed on small sample regions to optimize cell detection parameters prior to automated quantification of cells across entire brain regions. Even though we have quantified pericytes and microglia, any fluorescently labeled cell with clear labeling in and around the nucleus can be analyzed using these methods. This protocol provides a user-friendly and cost-effective framework for the automated analysis of whole tissue sections.

12.
eNeuro ; 8(6)2021.
Article in English | MEDLINE | ID: mdl-34642225

ABSTRACT

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. Whole-brain sections from both male and female NG2DsRed x CX3CR1+/GFP mice were analyzed. Small regions of interest were selected and manual counts were compared with counts generated from an automated approach, across a range of detection parameters. The optimal parameters for detecting cells and classifying them as microglia or pericytes in each brain region were determined and applied to annotations corresponding to the entire somatosensory and motor cortices, hippocampus, thalamus, and hypothalamus in each section. 3.74% of all detected cells were classified as pericytes; however, this proportion was significantly higher in the thalamus (6.20%) than in other regions. In contrast, microglia (4.51% of total cells) were more abundant in the cortex (5.54%). No differences were detected between male and female mice. In conclusion, QuPath offers a user-friendly solution to whole-slide image analysis which could lead to important new discoveries in both health and disease.


Subject(s)
Microglia , Pericytes , Animals , Brain , Female , Histological Techniques , Image Processing, Computer-Assisted , Male , Mice
13.
Aust N Z J Obstet Gynaecol ; 60(5): 671-674, 2020 10.
Article in English | MEDLINE | ID: mdl-32662072

ABSTRACT

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. AIMS: The aim of this study is to examine the extent of underdiagnosis of GDM using a fasting glucose ≤4.6 mmol/L as a cut-off to determine that a GTT is not necessary. MATERIALS AND METHODS: De-identified data from pregnant women having a GTT test in the Illawarra area during a six-year period was used to determine the number of women with GDM and the proportion of positive cases that would be missed for different fasting glucose values. RESULTS: There were 16 522 results identified and GDM was diagnosed in 12.2%. The majority of women were more than 30 years of age (85.2%) and diagnosed at ≥20 weeks gestation (81.1%). Of those diagnosed with GDM, 29% had a fasting glucose of ≤4.6 mmol/L and would have been missed. CONCLUSIONS: Our results show that using a fasting glucose of 4.6 mmol/L or less would miss nearly a third of women who would otherwise be diagnosed with GDM.


Subject(s)
Coronavirus Infections/prevention & control , Diabetes, Gestational/diagnosis , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Pregnancy Complications, Infectious/prevention & control , Pregnancy Outcome , Severe Acute Respiratory Syndrome/prevention & control , Adult , Australia , Blood Glucose/analysis , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques/methods , Cohort Studies , Coronavirus Infections/diagnosis , Coronavirus Infections/epidemiology , Databases, Factual , Female , Glucose Tolerance Test , Humans , Infection Control/methods , Patient Isolation/methods , Pneumonia, Viral/epidemiology , Pregnancy , Prenatal Care/methods , Retrospective Studies , Risk Assessment , Severe Acute Respiratory Syndrome/epidemiology
14.
Mol Brain ; 13(1): 27, 2020 02 27.
Article in English | MEDLINE | ID: mdl-32102661

ABSTRACT

Calcium (Ca2+)-permeable AMPA receptors may, in certain circumstances, contribute to normal synaptic plasticity or to neurodegeneration. AMPA receptors are Ca2+-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. Mice heterozygous for the ECS mutation (named GluA2+/ECS(G)) had a ~ 20% reduction in GluA2 RNA editing at the Q/R site. We conducted an initial phenotypic analysis of these mice, finding altered current-voltage relations (confirming expression of Ca2+-permeable AMPA receptors at the synapse). Anatomically, we observed a loss of hippocampal CA1 neurons, altered dendritic morphology and reductions in CA1 pyramidal cell spine density. Behaviourally, GluA2+/ECS(G) mice exhibited reduced motor coordination, and learning and memory impairments. Notably, the mice also exhibited both NMDA receptor-independent long-term potentiation (LTP) and vulnerability to NMDA receptor-independent seizures. These NMDA receptor-independent seizures were rescued by the Ca2+-permeable AMPA receptor antagonist IEM-1460. In summary, unedited GluA2(Q) may have the potential to drive NMDA receptor-independent processes in brain function and disease. Our study provides an initial characterisation of a new mouse model for studying the role of unedited GluA2(Q) in synaptic and dendritic spine plasticity in disorders where unedited GluA2(Q), synapse loss, neurodegeneration, behavioural impairments and/or seizures are observed, such as ischemia, seizures and epilepsy, Huntington's disease, amyotrophic lateral sclerosis, astrocytoma, cocaine seeking behaviour and Alzheimer's disease.


Subject(s)
CA1 Region, Hippocampal/pathology , Dendritic Spines/metabolism , Learning , Memory Disorders/complications , Neurons/pathology , RNA Editing , Receptors, AMPA/metabolism , Seizures/complications , Animals , Base Sequence , Body Weight , CA1 Region, Hippocampal/physiopathology , Fear , Long-Term Potentiation , Memory Disorders/physiopathology , Mice , Motor Activity , Neuronal Plasticity , Neurons/metabolism , Receptors, N-Methyl-D-Aspartate/metabolism , Seizures/physiopathology , Survival Analysis , Synaptic Transmission
15.
BMC Neurosci ; 20(1): 5, 2019 Feb 13.
Article in English | MEDLINE | ID: mdl-30760214

ABSTRACT

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. We then utilised the model to assess the anti-dyskinetic efficacy of recombinant activin A, a putative neuroprotectant and anti-inflammatory that is endogenously upregulated during the course of Parkinson's disease. RESULTS: We found that degeneration of fibers in the striatum was fully established within 1 week following 6-OHDA administration, but that the loss of neurons continued to progress over time, becoming fully established 3 weeks after the 6-OHDA injection. In assessing the anti-dyskinetic efficacy of activin A using this model we found that treatment with activin A did not significantly reduce the severity, or delay the time-of-onset, of dyskinesia. CONCLUSION: First, the current study concludes that a 3 week duration is required to establish a complete lesion of the nigrostriatal tract following 6-OHDA injection into the medial forebrain bundle of mice. Second, we found that activin A was not anti-dyskinetic in this model.


Subject(s)
Activins/pharmacology , Dyskinesia, Drug-Induced/drug therapy , Medial Forebrain Bundle/physiopathology , Neurodegenerative Diseases/physiopathology , Neuroprotective Agents/pharmacology , Parkinsonian Disorders/drug therapy , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Antiparkinson Agents/adverse effects , Antiparkinson Agents/pharmacology , Disease Progression , Dyskinesia, Drug-Induced/pathology , Dyskinesia, Drug-Induced/physiopathology , Levodopa/adverse effects , Levodopa/pharmacology , Male , Medial Forebrain Bundle/drug effects , Medial Forebrain Bundle/pathology , Mice, Inbred C57BL , Neurodegenerative Diseases/drug therapy , Neurodegenerative Diseases/pathology , Neurons/drug effects , Neurons/pathology , Neurons/physiology , Oxidopamine , Parkinsonian Disorders/pathology , Parkinsonian Disorders/physiopathology , Random Allocation , Treatment Failure
16.
Bull Am Meteorol Soc ; 100(1): 155-171, 2019 Jan.
Article in English | MEDLINE | ID: mdl-33005057

ABSTRACT

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. As a consequence, there are biases among different stations and discontinuities in profile time-series from individual site records. For 22 years the Jülich [Germany] Ozone Sonde Intercomparison Experiment (JOSIE) has periodically tested ozonesondes in a simulation chamber designated the World Calibration Centre for Ozonesondes (WCCOS) by WMO. In October-November 2017 a JOSIE campaign evaluated the sondes and procedures used in SHADOZ (Southern Hemisphere Additional Ozonesondes), a 14-station sonde network operating in the tropics and subtropics. A distinctive feature of the 2017 JOSIE was that the tests were conducted by operators from eight SHADOZ stations. Experimental protocols for the SHADOZ sonde configurations, which represent most of those in use today, are described, along with preliminary results. SHADOZ stations that follow WMO-recommended protocols record total ozone within 3% of the JOSIE reference instrument. These results and prior JOSIEs demonstrate that regular testing is essential to maintain best practices in ozonesonde operations and to ensure high-quality data for the satellite and ozone assessment communities.

17.
Acta Neuropathol ; 136(5): 663-689, 2018 11.
Article in English | MEDLINE | ID: mdl-30349969

ABSTRACT

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-ß (Aß). However, the causal link between Aß 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 Aß in the definition, diagnosis and aetiology of AD. We illustrate that a holistic view of the available data does not support an unequivocal conclusion that Aß has a central or unique role in AD. Instead, the data suggest alternative views of AD aetiology are potentially valid, at this time. We propose that an unbiased way forward for the field, beyond the current Aß-centric approach, without excluding a role for Aß, is required to come to an accurate understanding of AD dementia and, ultimately, an effective treatment.


Subject(s)
Alzheimer Disease , Amyloid beta-Peptides/metabolism , Alzheimer Disease/diagnosis , Alzheimer Disease/etiology , Alzheimer Disease/metabolism , Amyloid beta-Peptides/adverse effects , Animals , Humans
18.
BMJ Open ; 8(9): e024161, 2018 09 19.
Article in English | MEDLINE | ID: mdl-30232116

ABSTRACT

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. PARTICIPANTS: Pharmacists, nurses and allied health professionals with the independent/supplementary prescribing qualification. RESULTS: A total of 55 non-medical prescribers agreed to become members of the expert panel of whom 42 (76%) completed the round 1 questionnaire, 40/42 (95%) completed round 2 and 34/40 (85%) responded to round 3. Twenty-one statements were developed, and consensus was achieved on nine factors representing those necessary for the successful implementation of non-medical prescribing and five representing actions required for its continued development. Strategic fit between non-medical prescribing and existing service provision, organisation preparedness, visible benefits, good managerial and team support, and a clear differentiation of roles were each important influences. CONCLUSION: Given the high degree of consensus, this list of factors and actions should provide guidance to managers and commissioners of services wishing to initiate or extend non-medical prescribing. This information should be considered internationally by other countries outside of the UK wishing to implement prescribing by non-medical healthcare professionals.


Subject(s)
Allied Health Personnel , Drug Prescriptions , Health Services Administration/standards , Nurses , Pharmacists , Safety Management , Allied Health Personnel/standards , Allied Health Personnel/statistics & numerical data , Attitude of Health Personnel , Consensus , Delphi Technique , Drug Prescriptions/standards , Drug Prescriptions/statistics & numerical data , Health Care Surveys , Humans , Nurses/standards , Nurses/statistics & numerical data , Organizational Culture , Pharmacists/standards , Pharmacists/statistics & numerical data , Professional Autonomy , Safety Management/methods , Safety Management/organization & administration , Wales
19.
J Interprof Care ; 32(5): 638-640, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29658808

ABSTRACT

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. Undergraduate education provides an ideal opportunity to prepare healthcare professionals for these roles and activities. This report presents a protocol for a study designed to provide national consensus on antimicrobial stewardship competencies appropriate for undergraduate healthcare professional education. A modified Delphi process will be used in which a panel of Experts, comprising members from across the United Kingdom, with expertise in prescribing and medicines management with regard to the education and practice of healthcare professionals, and antimicrobial prescribing and stewardship, will be invited to take part in two survey rounds. The competencies developed will be applicable to all undergraduate healthcare professional education programmes. They will help to standardise curricula content and enhance the impact of antimicrobial stewardship education.


Subject(s)
Antimicrobial Stewardship/organization & administration , Education, Nursing/methods , Education, Pharmacy/methods , Evidence-Based Medicine/education , Anti-Bacterial Agents/adverse effects , Anti-Infective Agents/adverse effects , Consensus , Drug Prescriptions , Education, Medical, Undergraduate/methods , Humans , Outcome Assessment, Health Care , United Kingdom
20.
BMJ Open ; 7(9): e015313, 2017 Sep 24.
Article in English | MEDLINE | ID: mdl-28947441

ABSTRACT

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. PARTICIPANTS: Non-medical prescribers. RESULTS: 379 (63%) participants responded to the survey. Most of these prescribers (41.1%) were specialist nurses who work in a variety of healthcare settings (primarily in secondary care) within each HB/NHS Trust, and regularly use independent prescribing to prescribe for a broad range of conditions. Nearly a quarter of the sample (22%) reported that prior to undertaking the prescribing programme, they had completed master's level specialist training and 65.5% had 5 years qualified experience. Over half (55.8%) reported that there were plans to increase non-medical prescriber numbers within the team in which they worked. Only 7.1% reported they did not prescribe and the median number of items prescribed per week was between 21 and 30. Nearly all (87.8%) of the sample reported that they perceived prescribing to have ensured better use of their skills and 91.5% indicated that they believed it had improved the quality of care they were able to provide. CONCLUSION: Non-medical prescribing has been implemented across the whole of Wales; however, its uptake within HBs and NHS Trusts has been inconsistent, and it has not been considered across all services, particularly those in primary care. Opportunities therefore exist to share learning across organisations.


Subject(s)
Drug Prescriptions/statistics & numerical data , Nurse Clinicians/statistics & numerical data , Allied Health Personnel/statistics & numerical data , Attitude of Health Personnel , Delegation, Professional/organization & administration , Female , Health Services Needs and Demand , Humans , Male , Middle Aged , National Health Programs , Nurse Clinicians/education , Nurse Clinicians/legislation & jurisprudence , Nurse's Role , Pharmacists/statistics & numerical data , Primary Health Care/statistics & numerical data , Professional Autonomy , Surveys and Questionnaires , Wales
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