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1.
Glia ; 71(10): 2456-2472, 2023 10.
Article in English | MEDLINE | ID: mdl-37395323

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder in which patients lose motor functions due to progressive loss of motor neurons in the cortex, brainstem, and spinal cord. Whilst the loss of neurons is central to the disease, it is becoming clear that glia, specifically astrocytes, contribute to the onset and progression of neurodegeneration. Astrocytes play an important role in maintaining ion homeostasis in the extracellular milieu and regulate multiple brain functions by altering their extracellular concentrations. In this study, we have investigated the ability of astrocytes to maintain K+ homeostasis in the brain via direct measurement of the astrocytic K+ clearance rate in the motor and somatosensory cortices of an ALS mouse model (SOD1G93A ). Using electrophysiological recordings from acute brain slices, we show region-specific alterations in the K+ clearance rate, which was significantly reduced in the primary motor cortex but not the somatosensory cortex. This decrease was accompanied by significant changes in astrocytic morphology, impaired conductivity via Kir4.1 channels and low coupling ratio in astrocytic networks in the motor cortex, which affected their ability to form the K+ gradient needed to disperse K+ through the astrocytic syncytium. These findings indicate that the supportive function astrocytes typically provide to motoneurons is diminished during disease progression and provides a potential explanation for the increased vulnerability of motoneurons in ALS.


Subject(s)
Amyotrophic Lateral Sclerosis , Mice , Animals , Astrocytes , Superoxide Dismutase-1 , Motor Neurons/physiology , Spinal Cord , Disease Models, Animal , Disease Progression , Mice, Transgenic , Superoxide Dismutase
2.
Clin Nutr ; 42(8): 1276-1291, 2023 08.
Article in English | MEDLINE | ID: mdl-37352818

ABSTRACT

INTRODUCTION: There is growing evidence of increased muscle atrophy in IBD patients, likely resulting in a higher sarcopenia prevalence in IBD. The aims of this systematic review are A1; to estimate sarcopenia prevalence in IBD patients, A2; to investigate its impact on IBD patients, and A3; the effectiveness of nutritional interventions on muscle mass and/or strength in IBD patients. METHODS: On 28 July 2021, three electronic databases were used to identify eligible studies, including peer-reviewed studies (randomised controlled trials [RCTs], non-RCTs, observation studies) in adult (⩾ 18 years) IBD patients. For A1 and A2 only, studies defined low muscle mass and/or strength cut-off points. For A2, studies assessed association between sarcopenia and IBD complication. For A3, studies assessed the nutrition effect among IBD patients. RESULTS: 35 studies were included, 34 for A1, 20 for A2, and three for A3. 42% of adult IBD patients have myopenia, 34% have pre-sarcopenia, and 17% sarcopenia. Myopenic IBD was significantly associated with therapy failure including IBD-related surgery risk in six studies, risk of medical therapy failure in four studies, risk of hospitalisation in one study. A significant association existed with postoperative complications risk in IBD patients in four studies, reduction in BMD in two studies, and increased incidence of non-alcoholic fatty liver disease (NAFLD) in one study. Sarcopenia in IBD was significantly associated with a reduction in BMD in one study. Two studies found a personalised nutrition plan (high protein) in IBD patients significantly improved muscle mass. One study found a significant positive association between muscle mass and dietary intake including high protein intake. CONCLUSION: Over one third of adult IBD patients have myopenia and pre-sarcopenia, and nearly a fifth have sarcopenia. Myopeninc IBD is significantly associated with increased risk of IBD therapy failure, postoperative complications, and low BMD, with possible association with increased NAFLD risk. Nutritional therapy may play a role in reversing low muscle mass though yet unclear if this is through disease activity reversal. Further studies on adult IBD patients focusing on sarcopenia/myopenia are needed with recommended study designs of 1) standardised population-based definitions with recommended standard methods used to measure skeletal muscle mass, 2) prospective studies with IBD patients stratified by Montreal classification, disease activity, disease duration and concomitant medication to observe muscle changes, 3) mechanistic studies on sarcopenia aetiology, specifically focusing on protein handling atrophy and absorption, 4) properly designed RCT to assess nutrition intervention in sarcopenic IBD patients.


Subject(s)
Inflammatory Bowel Diseases , Non-alcoholic Fatty Liver Disease , Sarcopenia , Adult , Humans , Sarcopenia/complications , Sarcopenia/epidemiology , Non-alcoholic Fatty Liver Disease/complications , Inflammatory Bowel Diseases/complications , Inflammatory Bowel Diseases/epidemiology , Inflammatory Bowel Diseases/therapy , Nutritional Status , Muscular Atrophy/complications
3.
BMC Med Res Methodol ; 23(1): 16, 2023 01 16.
Article in English | MEDLINE | ID: mdl-36647003

ABSTRACT

BACKGROUND: High quality longitudinal studies investigating changes in health behaviours over the transition into early adulthood are critical. However, recruiting and retaining adolescents is challenging. This study explored adolescents' perspectives of signing up to and continuing involvement in a hypothetical longitudinal health research study. METHODS: Forty-eight individuals (15-20y) participated in nine in-person focus groups about recruitment and retention in research. Participants were (a) school students in the last year of compulsory school (Year 11, 15-16y), (b) school/college students in Sixth Form (Year 13, 17-18y), (c) Further Education students studying after secondary education, but not higher education (16-18y) and (d) young adults not in education, employment, or training (18-20y) across England. Thematic analysis resulted in seven themes. RESULTS: Driving factors for sign-up included social connection e.g., joining with peer groups, personalised feedback, and incentives, primarily financial. Key barriers were lack of interest, the perception of commitment, and timing of recruitment. Young people preferred recruitment processes via social media with messages tailored to their motivations, monthly data collection of maximally 20-30 min, and hybrid data collection with some in-person contact with a consistent, non-judgemental researcher. The provision of autonomy, choice, and financial incentives were perceived to promote retention. CONCLUSIONS: Adolescent recruitment and retention strategies need to align with contemporary interests and motivations. Studies should involve adolescents early to develop a planned, systematic approach to participant sign-up and follow-up. Effective and ineffective recruitment and retention strategies should be reported as part of study findings. Future research should trial how perceived barriers to study engagement can be overcome.


Subject(s)
Students , Young Adult , Humans , Adolescent , Adult , Qualitative Research , Focus Groups , Longitudinal Studies , England
4.
Diagnostics (Basel) ; 11(10)2021 Oct 18.
Article in English | MEDLINE | ID: mdl-34679624

ABSTRACT

Endoscopy is the gold standard for objective assessment of colonic disease activity in inflammatory bowel disease (IBD). Non-invasive colonic imaging using bowel ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) may have a role in quantifying colonic disease activity. We reviewed the diagnostic accuracy of these modalities for assessment of endoscopically or histopathologically defined colonic disease activity in IBD. We searched Embase, MEDLINE, and the Web of Science from inception to 20 September 2021. QUADAS-2 was used to evaluate the studies' quality. A meta-analysis was performed using a bivariate model approach separately for MRI and US studies only, and summary receiver operating characteristic (ROC) curves were obtained. CT studies were excluded due to the absence of diagnostic test data. Thirty-seven studies were included. The mean sensitivity and specificity for MRI studies was 0.75 and 0.91, respectively, while for US studies it was 0.82 and 0.90, respectively. The area under the ROC curves (AUC) was 0.88 (95% CI, 0.82 to 0.93) for MRI, and 0.90 (95% CI, 0.75 to 1.00) for US. Both MRI and US show high diagnostic accuracy in the assessment of colonic disease activity in IBD patients.

5.
Nutrients ; 13(7)2021 Jul 14.
Article in English | MEDLINE | ID: mdl-34371917

ABSTRACT

Diabetes mellitus is a chronic condition characterized by increased blood glucose levels from dysfunctional carbohydrate metabolism. Dietary intervention can help to prevent and manage the disease. Food hydrocolloids have been shown to have favorable properties in relation to glycaemic regulation. However, the use of food hydrocolloids of bacterial origin to modulate glucose responses is much less explored than other types of hydrocolloids. We, therefore, carried out the first review examining the impact of intake of food hydrocolloids of bacterial origin (as a direct supplement or incorporated into foods) on glycemic response in humans. Fourteen studies met the inclusion criteria. They used either xanthan gum, pullulan, or dextran as interventions. There was a wide variation in the amount of hydrocolloid supplementation provided and methods of preparation. Postprandial blood glucose responses were reduced in half of the studies, particularly at higher intake levels and longer chain hydrocolloids. When xanthan gum was added to the cooking process of muffins and rice, a significant reduction in postprandial blood glucose was observed. The use of these hydrocolloids is potentially effective though more research is needed in this area.


Subject(s)
Bacteria/chemistry , Blood Glucose/drug effects , Dextrans/therapeutic use , Diabetes Mellitus, Type 2/drug therapy , Glucans/therapeutic use , Glycemic Control , Hypoglycemic Agents/therapeutic use , Polysaccharides, Bacterial/therapeutic use , Adolescent , Adult , Aged , Biomarkers/blood , Blood Glucose/metabolism , Colloids , Dextrans/adverse effects , Dextrans/isolation & purification , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/diagnosis , Female , Glucans/adverse effects , Glucans/isolation & purification , Glycemic Control/adverse effects , Humans , Hypoglycemic Agents/adverse effects , Hypoglycemic Agents/isolation & purification , Male , Middle Aged , Polysaccharides, Bacterial/adverse effects , Polysaccharides, Bacterial/isolation & purification , Treatment Outcome , Young Adult
6.
Int J Mol Sci ; 22(5)2021 Mar 03.
Article in English | MEDLINE | ID: mdl-33802343

ABSTRACT

Potassium homeostasis is fundamental for brain function. Therefore, effective removal of excessive K+ from the synaptic cleft during neuronal activity is paramount. Astrocytes play a key role in K+ clearance from the extracellular milieu using various mechanisms, including uptake via Kir channels and the Na+-K+ ATPase, and spatial buffering through the astrocytic gap-junction coupled network. Recently we showed that alterations in the concentrations of extracellular potassium ([K+]o) or impairments of the astrocytic clearance mechanism affect the resonance and oscillatory behavior of both the individual and networks of neurons. These results indicate that astrocytes have the potential to modulate neuronal network activity, however, the cellular effectors that may affect the astrocytic K+ clearance process are still unknown. In this study, we have investigated the impact of neuromodulators, which are known to mediate changes in network oscillatory behavior, on the astrocytic clearance process. Our results suggest that while some neuromodulators (5-HT; NA) might affect astrocytic spatial buffering via gap-junctions, others (DA; Histamine) primarily affect the uptake mechanism via Kir channels. These results suggest that neuromodulators can affect network oscillatory activity through parallel activation of both neurons and astrocytes, establishing a synergistic mechanism to maximize the synchronous network activity.


Subject(s)
Astrocytes/metabolism , Neurotransmitter Agents/metabolism , Potassium/metabolism , Animals , Gap Junctions/metabolism , Homeostasis/physiology , Mice , Mice, Inbred C57BL , Neurons/metabolism , Sodium-Potassium-Exchanging ATPase/metabolism
7.
Brain Sci ; 11(2)2021 Jan 22.
Article in English | MEDLINE | ID: mdl-33499073

ABSTRACT

Type 1 and type 2 diabetes mellitus have an impact on the microstructural environment and cognitive functions of the brain due to its microvascular/macrovascular complications. Conventional Magnetic Resonance Imaging (MRI) techniques can allow detection of brain volume reduction in people with diabetes. However, conventional MRI is insufficiently sensitive to quantify microstructural changes. Diffusion Tensor Imaging (DTI) has been used as a sensitive MRI-based technique for quantifying and assessing brain microstructural abnormalities in patients with diabetes. This systematic review aims to summarise the original research literature using DTI to quantify microstructural alterations in diabetes and the relation of such changes to cognitive status and metabolic profile. A total of thirty-eight published studies that demonstrate the impact of diabetes mellitus on brain microstructure using DTI are included, and these demonstrate that both type 1 diabetes mellitus and type 2 diabetes mellitus may affect cognitive abilities due to the alterations in brain microstructures.

8.
Front Cell Neurosci ; 14: 278, 2020.
Article in English | MEDLINE | ID: mdl-32973460

ABSTRACT

Glia, a non-excitable cell type once considered merely as the connective tissue between neurons, is nowadays acknowledged for its essential contribution to multiple physiological processes including learning, memory formation, excitability, synaptic plasticity, ion homeostasis, and energy metabolism. Moreover, as glia are key players in the brain immune system and provide structural and nutritional support for neurons, they are intimately involved in multiple neurological disorders. Recent advances have demonstrated that glial cells, specifically microglia and astroglia, are involved in several neurodegenerative diseases including Amyotrophic lateral sclerosis (ALS), Epilepsy, Parkinson's disease (PD), Alzheimer's disease (AD), and frontotemporal dementia (FTD). While there is compelling evidence for glial modulation of synaptic formation and regulation that affect neuronal signal processing and activity, in this manuscript we will review recent findings on neuronal activity that affect glial function, specifically during neurodegenerative disorders. We will discuss the nature of each glial malfunction, its specificity to each disorder, overall contribution to the disease progression and assess its potential as a future therapeutic target.

9.
PLoS One ; 15(8): e0236820, 2020.
Article in English | MEDLINE | ID: mdl-32756578

ABSTRACT

Dance may help individuals living with Parkinson's disease (PD) improve motor and non-motor symptoms that impact quality of life (QOL). The primary aim of this systematic review of randomized controlled trials (RCTs) was to evaluate the efficacy of dance in improving motor and non-motor symptoms of PD and QOL. The secondary aims of this review were to evaluate the methodological quality of included studies by assessing risk of bias across nine categories and to inform the direction of future research. Peer-reviewed RCTs that included people living with PD at all disease stages and ages and measured the effects of a dance intervention longer than one day were included. Sixteen RCTs involving 636 participants with mild to moderate PD were eligible for inclusion in the qualitative synthesis and nine in the meta-analysis. Overall, the reviewed evidence demonstrated that dance can improve motor impairments, specifically balance and motor symptom severity in individuals with mild to moderate PD, and that more research is needed to determine its effects on non-motor symptoms and QOL. RCTs that use a mixed-methods approach and include larger sample sizes will be beneficial in fully characterizing effects and in determining which program elements are most important in bringing about positive, clinically meaningful changes in people with PD.


Subject(s)
Dancing , Motor Disorders/complications , Parkinson Disease/pathology , Quality of Life , Activities of Daily Living , Cognition/physiology , Gait , Humans , Mental Health , Parkinson Disease/complications , Postural Balance
10.
J Neurosci ; 40(4): 843-851, 2020 01 22.
Article in English | MEDLINE | ID: mdl-31748377

ABSTRACT

Detailed representations of past events rely on the ability to form associations between items and their contextual features (i.e., source memory), as well as the ability to distinctly represent a new event from a similar one stored in memory (i.e., pattern separation). These processes are both known to engage the hippocampus, although whether they share similar mechanisms remains unclear. It is also unknown if, and in which region(s), activity related to these processes overlaps and/or interacts. Here, we used high-resolution fMRI to examine the contributions of hippocampal subfields and neocortical areas to pattern separation and source memory with an experimental paradigm that concurrently tested both. During encoding, male and female human subjects incidentally studied items in one of four quadrants on the screen. During test, they viewed repeated items (targets), similar items (lures), and new items (foils) and were asked to indicate whether each item was old, similar, or new. Following each item judgment, subjects were asked to indicate the quadrant in which the original stimulus was presented. Thus, each lure trial had a lure discrimination component (taxing pattern separation) and a location judgment (source memory). We found two main response profiles: (1) pattern separation-related signals in DG/CA3 and perirhinal cortex and (2) source memory signals in posterior CA1, parahippocampal cortex, and angular gyrus. Whole-brain voxelwise analysis revealed that activity related to lure discrimination and source memory was largely nonoverlapping. These findings suggest that distinct processes underlie the retrieval of pattern separated item representations and recollection of source information.SIGNIFICANCE STATEMENT Recalling past events with detail and accuracy depends on the ability to remember the contextual features of an event (i.e., source memory) as well as the ability to distinguish among similar events in memory (i.e., pattern separation). Previous work has shown that these processes are behaviorally dissociable (e.g., people can have clear memory for context but misidentify people or items). However, both processes engage the hippocampus, and it is unclear whether they rely on shared or distinct neural mechanisms. Here, we used high-resolution fMRI to concurrently assess hippocampal and neocortical activity related to source memory and pattern separation. We found that activity related to these processes was largely nonoverlapping, shedding light on two complementary but distinct mechanisms supporting episodic memory.


Subject(s)
Hippocampus/physiology , Memory, Episodic , Mental Recall/physiology , Neocortex/physiology , Adolescent , Adult , Female , Functional Neuroimaging , Hippocampus/diagnostic imaging , Humans , Magnetic Resonance Imaging , Male , Neocortex/diagnostic imaging , Young Adult
11.
Diagnostics (Basel) ; 9(4)2019 Dec 13.
Article in English | MEDLINE | ID: mdl-31847098

ABSTRACT

BACKGROUND: functional gastrointestinal disorders (FGID) are common conditions in children and adults, often associated with abnormalities of whole gut transit. Currently, transit tests can be performed using several imaging methods, including tracking of radiopaque markers, gamma scintigraphy with the use of radioisotopes, magnetic tracking methods, tracking of movement of wireless motility capsules, and emerging magnetic resonance imaging (MRI) approaches. OBJECTIVES: to review recent literature on diagnostic imaging techniques used to investigate whole gut transit in FGIDs. METHODS: a systematic review was carried out. The different techniques are described briefly, with particular emphasis on contemporary literature and new developments, particularly in the field of MRI. CONCLUSIONS: emerging MRI capsule marker methods are promising new tools to study whole gut transit in FGIDs.

12.
Neuron ; 102(4): 887-898.e5, 2019 05 22.
Article in English | MEDLINE | ID: mdl-30979537

ABSTRACT

How do we remember emotional events? While emotion often leads to vivid recollection, the precision of emotional memories can be degraded, especially when discriminating among overlapping experiences in memory (i.e., pattern separation). Communication between the amygdala and the hippocampus has been proposed to support emotional memory, but the exact neural mechanisms remain unclear. Here, we used intracranial recordings in pre-surgical epilepsy patients to show that successful pattern separation of emotional stimuli is associated with theta band (3-7 Hz)-coordinated bidirectional interactions between the amygdala and the hippocampus. In contrast, discrimination errors (i.e., failure to discriminate similar stimuli) were associated with alpha band (7-13 Hz)-coordinated unidirectional influence from the amygdala to the hippocampus. These findings imply that alpha band synchrony may impair discrimination of similar emotional events via the amygdala-hippocampal directional coupling, which suggests a target for treatments of psychiatric conditions such as post-traumatic stress disorder, in which aversive experiences are often overgeneralized.


Subject(s)
Alpha Rhythm/physiology , Amygdala/physiology , Emotions , Hippocampus/physiology , Memory, Episodic , Theta Rhythm/physiology , Adult , Discrimination, Psychological , Electrocorticography , Electroencephalography Phase Synchronization , Female , Humans , Male , Memory , Middle Aged , Neural Pathways/physiology , Young Adult
13.
Proc Natl Acad Sci U S A ; 115(40): 10148-10153, 2018 10 02.
Article in English | MEDLINE | ID: mdl-30224452

ABSTRACT

The hippocampus plays a critical role in spatial memory. However, the exact neural mechanisms underlying high-fidelity spatial memory representations are unknown. We report findings from presurgical epilepsy patients with bilateral hippocampal depth electrodes performing an object-location memory task that provided a broad range of spatial memory precision. During encoding, patients were shown a series of objects along the circumference of an invisible circle. At test, the same objects were shown at the top of the circle (0°), and patients used a dial to move the object to its location shown during encoding. Angular error between the correct location and the indicated location was recorded as a continuous measure of performance. By registering pre- and postimplantation MRI scans, we were able to localize the electrodes to specific hippocampal subfields. We found a correlation between increased gamma power, thought to reflect local excitatory activity, and the precision of spatial memory retrieval in hippocampal CA1 electrodes. Additionally, we found a similar relationship between gamma power and memory precision in the dorsolateral prefrontal cortex and a directional relationship between activity in this region and in the CA1, suggesting that the dorsolateral prefrontal cortex is involved in postretrieval processing. These results indicate that local processing in hippocampal CA1 and dorsolateral prefrontal cortex supports high-fidelity spatial memory representations.


Subject(s)
CA1 Region, Hippocampal , Magnetic Resonance Imaging , Prefrontal Cortex , Spatial Memory/physiology , Adult , CA1 Region, Hippocampal/diagnostic imaging , CA1 Region, Hippocampal/physiology , Female , Humans , Male , Middle Aged , Prefrontal Cortex/diagnostic imaging , Prefrontal Cortex/physiology
14.
BMJ Open ; 7(1): e013623, 2017 01 20.
Article in English | MEDLINE | ID: mdl-28110286

ABSTRACT

OBJECTIVE: To explore pressure area related pain as a predictor of category ≥2 pressure ulcer (PU) development. DESIGN: Multicentre prospective cohort study. SETTING: UK hospital and community settings. PARTICIPANTS INCLUSION: Consenting acutely ill patients aged ≥18 years, defined as high risk (Braden bedfast/chairfast AND completely immobile/very limited mobility; pressure area related pain or; category 1 PU). EXCLUSION: Patients too unwell, unable to report pain, 2 or more category ≥2 PUs. FOLLOW-UP: Twice weekly for 30 days. PRIMARY AND SECONDARY OUTCOME MEASURES: Development and time to development of one or more category ≥2 PUs. RESULTS: Of 3819 screened, 1266 were eligible, 634 patients were recruited, 32 lost to follow-up, providing a 602 analysis population. 152 (25.2%) developed one or more category ≥2 PUs. 464 (77.1%) patients reported pressure area related pain on a healthy, altered or category 1 skin site of whom 130 (28.0%) developed a category ≥2 PU compared with 22 (15.9%) of those without pain. Full stepwise variable selection was used throughout the analyses. (1) Multivariable logistic regression model to assess 9 a priori factors: presence of category 1 PU (OR=3.25, 95% CI (2.17 to 4.86), p<0.0001), alterations to intact skin (OR=1.98, 95% CI (1.30 to 3.00), p=0.0014), pressure area related pain (OR=1.56, 95% CI (0.93 to 2.63), p=0.0931). (2) Multivariable logistic regression model to account for overdispersion: presence of category 1 PU (OR=3.20, 95% CI (2.11 to 4.85), p<0.0001), alterations to intact skin (OR=1.90, 95% CI (1.24 to 2.91), p=0.0032), pressure area related pain (OR=1.85, 95% CI (1.07 to 3.20), p=0.0271), pre-existing category 2 PU (OR=2.09, 95% CI (1.35 to 3.23), p=0.0009), presence of chronic wound (OR=1.66, 95% CI (1.06 to 2.62), p=0.0277), Braden activity (p=0.0476). (3) Accelerated failure time model: presence of category 1 PU (AF=2.32, 95% CI (1.73 to 3.12), p<0.0001), pressure area related pain (AF=2.28, 95% CI (1.59 to 3.27), p<0.0001). (4) 2-level random-intercept logistic regression model: skin status which comprised 2 levels (versus healthy skin); alterations to intact skin (OR=4.65, 95% CI (3.01 to 7.18), p<0.0001), presence of category 1 PU (OR=17.30, 95% CI (11.09 to 27.00), p<0.0001) and pressure area related pain (OR=2.25, 95% CI (1.53 to 3.29), p<0.0001). CONCLUSIONS: This is the first study to assess pain as a predictor of category ≥2 PU development. In all 4 models, pain emerged as a risk factor associated with an increased probability of category ≥2 PU development.


Subject(s)
Pain/diagnosis , Pressure Ulcer/diagnosis , Skin/pathology , Aged , Aged, 80 and over , Female , Humans , Logistic Models , Male , Middle Aged , Odds Ratio , Pain/etiology , Pressure , Pressure Ulcer/classification , Pressure Ulcer/complications , Prospective Studies , Risk Factors , Severity of Illness Index
15.
Sci Rep ; 6: 19938, 2016 Feb 02.
Article in English | MEDLINE | ID: mdl-26832850

ABSTRACT

In contrast to annual plants, in perennial plants, the shoot apical meristem (SAM) can undergo seasonal transitions between dormancy and activity; understanding this transition is crucial for understanding growth in perennial plants. However, little is known about the molecular mechanisms of SAM development in trees. Here, light and transmission electron microscopy revealed that evident changes in starch granules, lipid bodies, and cell walls thickness of the SAM in C. lanceolata during the transition from dormancy to activation. HPLC-ESI-MS/MS analysis showed that levels of indole-3-acetic acid (IAA) increased and levels of abscisic acid (ABA) decreased from dormant to active stage. Examination of 20 genes and 132 differentially expressed proteins revealed that the expression of genes and proteins potentially involved in cell division and expansion significantly increased in the active stage, whereas those related to the abscisic acid insensitive 3(ABI3), the cytoskeleton and energy metabolism decreased in the dormant stage. These findings provide new insights into the complex mechanism of gene and protein expression and their relation to cytological and physiological changes of SAM in this coniferous species.


Subject(s)
Cunninghamia/metabolism , Gene Expression Regulation, Plant/physiology , Meristem/metabolism , Plant Dormancy/physiology , Plant Proteins/biosynthesis , Cunninghamia/genetics , Plant Proteins/genetics , Proteomics
16.
Behav Neurosci ; 129(3): 257-68, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26030427

ABSTRACT

Several studies in our lab and others have demonstrated age-related declines in mnemonic discrimination during a recognition memory paradigm using repeated items, similar lures, and novel foils. In particular, older adults exhibit a shift in lure discriminability, identifying similar lures as old items at a greater rate than young adults. This shift likely reflects deficits in pattern separation processing as a result of underlying changes in the dentate gyrus of the hippocampus. Here, we explored whether alterations in the task design could rescue the age-related impairment or whether it was ubiquitous as one might expect if the neurobiological mechanisms were truly disturbed by typical aging. Despite overt instructions to study item details during encoding, we replicated the age-related deficit in mnemonic discrimination. We established reliable effects with short lists of stimuli and with repeated testing. Altering the task design from a study/test to a continuous recognition paradigm replicated the age-related shift in lure discrimination as well. Modifying the task to an old/new response (rather than old/similar/new) showed the same effect and a d' analysis showed that lure items were more akin to target items in older adults. Finally, we varied the test instructions in order to promote gist or veridical responses in the old/new task. Even these overt veridical test instructions did not ameliorate older adults' lure discrimination problems. Together, these findings demonstrate the robust nature of this age-related deficit and support the hypothesis that typical aging results in neurobiological changes that underlie this impairment.


Subject(s)
Aging/psychology , Discrimination, Psychological , Memory Disorders/diagnosis , Neuropsychological Tests , Pattern Recognition, Visual , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Young Adult
17.
BMC Nurs ; 13: 16, 2014.
Article in English | MEDLINE | ID: mdl-25024642

ABSTRACT

BACKGROUND: Pressure ulcers are costly to the healthcare provider and can have a major impact on patient's quality of life. One of the most distressing symptoms reported is pain. There is very little published data on the prevalence and details of pain experienced by patients with pressure ulcers, particularly in community populations. The study was conducted in two community NHS sites in the North of England. METHODS: The aim was to estimate the prevalence of pressure area related pain within a community population. We also explored the type and severity of the pain and its association with pressure ulcer classification. A cross-sectional survey was performed of community nurses caseloads to identify adult patients with pressure ulcers and associated pain. Consenting patients then had a full pain assessment and verification of pressure ulcer grade. RESULTS: A total of 287 patients were identified with pressure ulcers (0.51 per 1000 adult population). Of the 176 patients who were asked, 133 (75.6%) reported pain. 37 patients consented to a detailed pain assessment. Painful pressure ulcers of all grades and on nearly all body sites were identified. Pain intensity was not related to number or severity of pressure ulcer. Both inflammatory and neuropathic pain were reported at all body sites however the proportion of neuropathic pain was greater in pressure ulcers on lower limbs. CONCLUSIONS: This study has identified the extent and type of pain suffered by community patients with pressure ulcers and indicates the need for systematic and regular pain assessment and treatment.

18.
BMC Nurs ; 12(1): 19, 2013 Jul 31.
Article in English | MEDLINE | ID: mdl-23902583

ABSTRACT

BACKGROUND: Patients with pressure ulcers (PUs) report that pain is their most distressing symptom, but there are few PU pain prevalence studies. We sought to estimate the prevalence of unattributed pressure area related pain (UPAR pain) which was defined as pain, soreness or discomfort reported by patients, on an "at risk" or PU skin site, reported at a patient level. METHODS: We undertook pain prevalence surveys in 2 large UK teaching hospital NHS Trusts (6 hospitals) and a district general hospital NHS Trust (3 hospitals) during their routine annual PU prevalence audits. The hospitals provide secondary and tertiary care beds in acute and elective surgery, trauma and orthopaedics, burns, medicine, elderly medicine, oncology and rehabilitation. Anonymised individual patient data were recorded by the ward nurse and PU prevalence team. The analysis of this prevalence survey included data summaries; no inferential statistical testing was planned or undertaken. Percentages were calculated using the total number of patients from the relevant population as the denominator (i.e. including all patients with missing data for that variable). RESULTS: A total of 3,397 patients in 9 acute hospitals were included in routine PU prevalence audits and, of these, 2010 (59.2%) patients participated in the pain prevalence study. UPAR pain prevalence was 16.3% (327/2010). 1769 patients had no PUs and of these 223 patients reported UPAR pain, a prevalence of 12.6%. Of the 241 people with pressure ulcers, 104 patients reported pain, a UPAR pain prevalence of 43.2% (104/241). CONCLUSION: One in six people in acute hospitals experience UPAR pain on 'at risk' or PU skin sites; one in every 8 people without PUs and, more than 2 out of every five people with PUs. The results provide a clear indication that all patients should be asked if they have pain at pressure areas even when they do not have a PU.

19.
Int J Nurs Stud ; 50(11): 1550-7, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23764144

ABSTRACT

BACKGROUND: Changes in healthcare and ageing populations have led to an increasing emphasis on the provision of healthcare in the community. Quality initiatives in healthcare have led to a focus upon pressure ulcer rates. However, published data on pressure ulcer prevalence in a community setting is currently very limited. OBJECTIVE: The objective of this cross-sectional observational study was to determine the prevalence of patients with pressure ulcers in a community setting in the United Kingdom. DESIGN: A cross-sectional observational study. SETTING: Two community settings in the North of England. PARTICIPANTS: Patients in the community who were aged 18 years or older at the time of the pressure ulcer prevalence audit were included. There were no exclusion criteria and consent was not a requirement. METHODS: Each site used a different method to collect the data as per their usual method of prevalence data collection. Site 1 assessed all patients on the community nursing caseload: patients in residential homes, rehabilitation units, specialist palliative care units and all nursing homes in the locality, whether they were known to have a pressure ulcer or not. Site 2 assessed only those on the community nursing caseload who were known to have a pressure ulcer. Site 1 collected data between 8th February and 2nd April 2010 and site 2 between 12th April and 7th May 2010. RESULTS: In site 1, 185 patients were assessed as having a pressure ulcer Grade ≥ 1, a prevalence rate of 0.77 per 1000 adults. In Site 2 102 patients were assessed as having a Grade ≥ 1 pressure ulcer, a prevalence rate of 0.40 per 1000 adults. Removing patients in nursing homes from the calculation gives a prevalence of 0.38 per 1000 adults for site 1 and 0.39 per 1000 adults for site 2. CONCLUSIONS: This study provides prevalence data in a community setting which can be used to assess resource allocation and staff training. This study has highlighted that differences in methodology can affect prevalence results, and this should be taken into account in future research.


Subject(s)
Pressure Ulcer/epidemiology , Adult , Aged , Aged, 80 and over , Beds , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Prevalence , Risk Assessment , United Kingdom/epidemiology
20.
Physiol Plant ; 148(3): 322-33, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23517122

ABSTRACT

Over 13% of all genes in the Arabidopsis thaliana genome encode for proteins classified as having a completely unknown function, with the function of >30% of the Arabidopsis proteome poorly characterized. Although empirical data in the form of mRNA and proteome profiling experiments suggest that many of these proteins play an important role in different biological processes, their functional characterization remains one of the major challenges in modern biology. To expand the annotation of genes with unknown function involved in the response of Arabidopsis to different environmental stress conditions, we selected 1007 such genes and tested the response of their corresponding homozygous T-DNA insertional mutants to salinity, oxidative, osmotic, heat, cold and hypoxia stresses. Depending on the specific abiotic stresses tested, 12-31% of mutants had an altered stress-response phenotype. Interestingly, 832 out of 1007 mutants showed tolerance or sensitivity to more than one abiotic stress treatment, suggesting that genes of unknown function could play an important role in abiotic stress-response signaling, or general acclimation mechanisms. Further analysis of multiple stress-response phenotypes within different populations of mutants revealed interesting links between acclimation to heat, cold and oxidative stresses, as well as between sensitivity to ABA, osmotic, salinity, oxidative and hypoxia stresses. Our findings provide a significant contribution to the biological characterization of genes with unknown function in Arabidopsis and demonstrate that many of these genes play a key role in the response of plants to abiotic stresses.


Subject(s)
Arabidopsis/genetics , Arabidopsis/physiology , Genes, Plant/genetics , High-Throughput Screening Assays , Stress, Physiological/genetics , Abscisic Acid/pharmacology , Adaptation, Physiological/drug effects , Adaptation, Physiological/genetics , DNA, Bacterial/genetics , Gene Expression Regulation, Plant/drug effects , Mutagenesis, Insertional/drug effects , Mutagenesis, Insertional/genetics , Mutation/genetics , Phenotype , Plant Roots/drug effects , Plant Roots/genetics , Plant Roots/growth & development , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reactive Oxygen Species/metabolism , Seedlings/drug effects , Seedlings/genetics , Stress, Physiological/drug effects
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