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1.
Neurobiol Dis ; 196: 106514, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38663633

RESUMEN

The olfactory bulb is involved early in the pathophysiology of Parkinson's disease (PD), which is consistent with the early onset of olfactory dysfunction. Identifying the molecular mechanisms through which PD affects the olfactory bulb could lead to a better understanding of the pathophysiology and etiology of olfactory dysfunction in PD. We specifically aimed to assess gene expression changes, affected pathways and co-expression network by whole transcriptomic profiling of the olfactory bulb in subjects with clinicopathologically defined PD. Bulk RNA sequencing was performed on frozen human olfactory bulbs of 20 PD and 20 controls without dementia or any other neurodegenerative disorder, from the Arizona Study of Aging and Neurodegenerative disorders and the Brain and Body Donation Program. Differential expression analysis (19 PD vs 19 controls) revealed 2164 significantly differentially expressed genes (1090 upregulated and 1074 downregulated) in PD. Pathways enriched in downregulated genes included oxidative phosphorylation, olfactory transduction, metabolic pathways, and neurotransmitters synapses while immune and inflammatory responses as well as cellular death related pathways were enriched within upregulated genes. An overrepresentation of microglial and astrocyte-related genes was observed amongst upregulated genes, and excitatory neuron-related genes were overrepresented amongst downregulated genes. Co-expression network analysis revealed significant modules highly correlated with PD and olfactory dysfunction that were found to be involved in the MAPK signaling pathway, cytokine-cytokine receptor interaction, cholinergic synapse, and metabolic pathways. LAIR1 (leukocyte associated immunoglobulin like receptor 1) and PPARA (peroxisome proliferator activated receptor alpha) were identified as hub genes with a high discriminative power between PD and controls reinforcing an important role of neuroinflammation in the olfactory bulb of PD subjects. Olfactory identification test score positively correlated with expression of genes coding for G-coupled protein, glutamatergic, GABAergic, and cholinergic receptor proteins and negatively correlated with genes for proteins expressed in glial olfactory ensheathing cells. In conclusion, this study reveals gene alterations associated with neuroinflammation, neurotransmitter dysfunction, and disruptions of factors involved in the initiation of olfactory transduction signaling that may be involved in PD-related olfactory dysfunction.

2.
J Pancreatol ; 7(1): 35-44, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38524856

RESUMEN

Abdominal pain is the most common symptom of chronic pancreatitis (CP) and is often debilitating for patients and very difficult to treat. To date, there exists no cure for the disease. Treatment strategies focus on symptom management and on mitigation of disease progression by reducing toxin exposure and avoiding recurrent inflammatory events. Traditional treatment protocols start with medical management followed by consideration of procedural or surgical intervention on selected patients with severe and persistent pain. The incorporation of adjuvant therapies to treat comorbidities including psychiatric disorders, exocrine pancreatic insufficiency, mineral bone disease, frailty, and malnutrition, are in its early stages. Recent clinical studies and animal models have been designed to improve investigation into the pathophysiology of CP pain, as well as to improve pain management. Despite the array of tools available, many therapeutic options for the management of CP pain provide incomplete relief. There still remains much to discover about the neural regulation of pancreas-related pain. In this review, we will discuss research from the last 5 years that has provided new insights into novel methods of pain phenotyping and the pathophysiology of CP pain. These discoveries have led to improvements in patient selection for optimization of outcomes for both medical and procedural management, and identification of potential future therapies.

3.
Int J Mol Sci ; 25(6)2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38542104

RESUMEN

Synaptic transmission is essential for nervous system function and the loss of synapses is a known major contributor to dementia. Alzheimer's disease dementia (ADD) is characterized by synaptic loss in the mesial temporal lobe and cerebral neocortex, both of which are brain areas associated with memory and cognition. The association of synaptic loss and ADD was established in the late 1980s, and it has been estimated that 30-50% of neocortical synaptic protein is lost in ADD, but there has not yet been a quantitative profiling of different synaptic proteins in different brain regions in ADD from the same individuals. Very recently, positron emission tomography (PET) imaging of synapses is being developed, accelerating the focus on the role of synaptic loss in ADD and other conditions. In this study, we quantified the densities of two synaptic proteins, the presynaptic protein Synaptosome Associated Protein 25 (SNAP25) and the postsynaptic protein postsynaptic density protein 95 (PSD95) in the human brain, using enzyme-linked immunosorbent assays (ELISA). Protein was extracted from the cingulate gyrus, hippocampus, frontal, primary visual, and entorhinal cortex from cognitively unimpaired controls, subjects with mild cognitive impairment (MCI), and subjects with dementia that have different levels of Alzheimer's pathology. SNAP25 is significantly reduced in ADD when compared to controls in the frontal cortex, visual cortex, and cingulate, while the hippocampus showed a smaller, non-significant reduction, and entorhinal cortex concentrations were not different. In contrast, all brain areas showed lower PSD95 concentrations in ADD when compared to controls without dementia, although in the hippocampus, this failed to reach significance. Interestingly, cognitively unimpaired cases with high levels of AD pathology had higher levels of both synaptic proteins in all brain regions. SNAP25 and PSD95 concentrations significantly correlated with densities of neurofibrillary tangles, amyloid plaques, and Mini Mental State Examination (MMSE) scores. Our results suggest that synaptic transmission is affected by ADD in multiple brain regions. The differences were less marked in the entorhinal cortex and the hippocampus, most likely due to a ceiling effect imposed by the very early development of neurofibrillary tangles in older people in these brain regions.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Humanos , Anciano , Enfermedad de Alzheimer/metabolismo , Ovillos Neurofibrilares/metabolismo , Encéfalo/metabolismo , Disfunción Cognitiva/metabolismo , Proteínas tau/metabolismo , Tomografía de Emisión de Positrones
4.
Issues Ment Health Nurs ; 45(2): 196-201, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38354381

RESUMEN

Nursing burnout has reached a new level of prevalence among professionals and is rising among nursing students and can impact student success in the classroom and clinical areas. Among advanced practice nurses, psychiatric-mental health nurse practitioners have the least favorable combination of low compassion satisfaction and high secondary traumatic stress, placing them at even greater risk for burnout compared to other specialties. Trauma informed teaching and learning principles can serve to prevent burnout and have a positive impact on learning outcomes. Through these teaching methods, nurse educators have the opportunity to both support students during their nursing education and prepare students for the professional stressors that contribute to burnout. This quality improvement project involved implementation and evaluation of a HRSA funded program to train PMHNP students interested in working in rural and underserved areas. The training intervention included didactic curricular enhancements, a trauma resiliency training and a longitudinal clinical practicum. Qualitative program outcomes indicated that trainees were implementing trauma-informed principles and skills with patients and for self-care during their nursing training and at one year follow-up. The program may offer practical upstream solutions for nurse educators and future studies should explore concepts more formally to develop best practice models.


Asunto(s)
Bachillerato en Enfermería , Educación en Enfermería , Resiliencia Psicológica , Estudiantes de Enfermería , Humanos , Bachillerato en Enfermería/métodos , Aprendizaje , Estudiantes , Estudiantes de Enfermería/psicología
5.
Artículo en Inglés | MEDLINE | ID: mdl-38354057

RESUMEN

Coccolithophores are biogeochemically and ecologically important phytoplankton that produce a composite calcium carbonate-based exoskeleton - the coccosphere - comprised of individual platelets, known as coccoliths. Coccoliths are stunning examples of biomineralization; their formation featuring exceptional control over both biomineral chemistry and shape. Understanding how coccoliths are formed requires information about minor element distribution and chemical environment. Here, the first high-resolution 3D synchrotron X-ray fluorescence (XRF) mapping of a coccolith is presented, showing that the lopadoliths of Scyphosphaera apsteinii display stripes of different Sr concentration. The presence of Sr stripes is unaffected by elevated Sr in the culture medium, macro-nutrient concentration, and light intensity, indicating that the observed stripiness is an expression of the fundamental coccolith formation process in this species. Current Sr fractionation models, by contrast, predict an even Sr distribution and will have to be modified to account for this stripiness. Additionally, nano-XANES analyses show that Sr resides in a Ca site in the calcite lattice in both high and low Sr stripes, confirming a central assumption of current Sr fractionation models.

6.
Dementia (London) ; 22(8): 1900-1920, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37879079

RESUMEN

Introduction: Tanzania is a low-income country with an increasing prevalence of dementia, which provides challenges for the existing healthcare system. People with dementia often don't receive a formal diagnosis, and with a lack of formal healthcare, are often predominantly supported by family relatives. There are very few published data relating to lived experiences of people with dementia in Tanzania. This study aimed to understand people with dementia, and their caregivers' experiences of living with dementia in Tanzania and the perceived needs of people with dementia.Methods: Qualitative, semi-structured interviews were conducted with 14 people with dementia and 12 caregivers in Moshi, Tanzania. Interviews were audio-recorded, translated, transcribed and analysed using a Framework Analysis approach.Results: Three sub-themes were identified within data describing the experience of 'Living with Dementia in Tanzania': 'Deteriorations in Health', 'Challenges to living with Dementia in Tanzanian Culture', and 'Lack of Support': people with dementia faced challenges due to social isolation, stigmatisation, and lack of caregiver knowledge on how best to provide support. Collectively, these impacted on both the physical and mental health of people with dementia. Misconceptions about dementia aetiology related to age, stresses of daily life and other co-morbidities. People with dementia were motivated to access treatment, exhibiting pluralistic health-seeking behaviours. There was an overall preference for non-pharmacological interventions over medication, with high levels of trust in medical professional opinions.Conclusions: Living with dementia in Tanzania is influenced by both cultural and religious factors. More work is needed to target supplementary healthcare (with efforts to promote accessibility), support for caregivers and public health education about dementia to overcome existent misconceptions and stigma.


Asunto(s)
Cuidadores , Demencia , Humanos , Cuidadores/psicología , Demencia/psicología , Tanzanía , Salud Mental , Investigación Cualitativa
7.
Int J Mol Sci ; 24(18)2023 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-37762097

RESUMEN

The determination of RNA integrity is a critical quality assessment tool for gene expression studies where the experiment's success is highly dependent on the sample quality. Since its introduction in 1999, the gold standard in the scientific community has been the Agilent 2100 Bioanalyzer's RNA integrity number (RIN), which uses a 1-10 value system, from 1 being the most degraded, to 10 being the most intact. In 2015, Agilent launched 4200 TapeStation's RIN equivalent, and reported a strong correlation of r2 of 0.936 and a median error < ±0.4 RIN units. To evaluate this claim, we compared the Agilent 4200 TapeStation's RIN equivalent (RINe) and DV200 to the Agilent 2100 Bioanalyzer's RIN for 183 parallel RNA samples. In our study, using RNA from a total of 183 human postmortem brain samples, we found that the RIN and RINe values only weakly correlate, with an r2 of 0.393 and an average difference of 3.2 RIN units. DV200 also only weakly correlated with RIN (r2 of 0.182) and RINe (r2 of 0.347). Finally, when applying a cut-off value of 6.5 for both metrics, we found that 95.6% of samples passed with RIN, while only 23.5% passed with RINe. Our results suggest that even though RIN (Bioanalyzer) and RINe (TapeStation) use the same 1-10 value system, they should not be used interchangeably, and cut-off values should be calculated independently.


Asunto(s)
Benchmarking , Encéfalo , Humanos , ARN
8.
ACS Appl Mater Interfaces ; 15(31): 37259-37273, 2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37524079

RESUMEN

Caries, a major global disease associated with dental enamel demineralization, remains insufficiently understood to devise effective prevention or minimally invasive treatment. Understanding the ultrastructural changes in enamel is hampered by a lack of nanoscale characterization of the chemical spatial distributions within the dental tissue. This leads to the requirement to develop techniques based on various characterization methods. The purpose of the present study is to demonstrate the strength of analytic methods using a correlative technique on a single sample of human dental enamel as a specific case study to test the accuracy of techniques to compare regions in enamel. The science of the different techniques is integrated to genuinely study the enamel. The hierarchical structures within carious tissue were mapped using the combination of focused ion beam scanning electron microscopy with synchrotron X-ray tomography. The chemical changes were studied using scanning X-ray fluorescence (XRF) and X-ray wide-angle and small-angle scattering using a beam size below 80 nm for ångström and nanometer length scales. The analysis of XRF intensity gradients revealed subtle variations of Ca intensity in carious samples in comparison with those of normal mature enamel. In addition, the pathways for enamel rod demineralization were studied using X-ray ptychography. The results show the chemical and structural modification in carious enamel with differing locations. These results reinforce the need for multi-modal approaches to nanoscale analysis in complex hierarchically structured materials to interpret the changes of materials. The approach establishes a meticulous correlative characterization platform for the analysis of biomineralized tissues at the nanoscale, which adds confidence in the interpretation of the results and time-saving imaging techniques. The protocol demonstrated here using the dental tissue sample can be applied to other samples for statistical study and the investigation of nanoscale structural changes. The information gathered from the combination of methods could not be obtained with traditional individual techniques.


Asunto(s)
Caries Dental , Esmalte Dental , Humanos , Microscopía Electrónica de Rastreo , Dispersión del Ángulo Pequeño , Rayos X , Microscopía Confocal , Esmalte Dental/diagnóstico por imagen , Caries Dental/diagnóstico por imagen
9.
medRxiv ; 2023 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-37461632

RESUMEN

Determining RNA integrity is a critical quality assessment tool for gene expression studies where the experiment's success is highly dependent on sample quality. Since its introduction in 1999, the gold standard in the scientific community has been the Agilent 2100 Bioanalyzer's RNA Integrity Number (RIN) which uses a 1-10 value system with 1 being the most degraded to 10 being the most intact. In 2015, Agilent launched the 4200 Tapestation's RIN equivalent and reported a strong correlation of r 2 of 0.936 and median error < ± 0.4 RIN units. To evaluate this claim, we compared the Agilent 4200 Tapestation's RIN equivalent (RINe) and DV200 to the Agilent 2100 Bioanalyzer's RIN for 183 parallel RNA samples. In our study, using RNA from a total of 183 human postmortem brain samples, we found that the RIN and RINe values only weakly correlate with an r 2 of 0.393 and an average difference of 3.2 RIN units. DV200 also only weakly correlated with RIN (r 2 of 0.182) and RINe (r 2 of 0.347). Finally, when applying a cut-off value of 6.5 for both metrics, we found that 95.6% of samples passed with RIN, while only 23.5% passed with RINe. Our results suggest that even though RIN (Bioanalyzer) and RINe (Tapestation) use the same 1-10 value system, they should not be used interchangeably, and cut-off values should be calculated independently.

10.
J Neuropathol Exp Neurol ; 82(6): 457-466, 2023 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-37071794

RESUMEN

Cerebral white matter rarefaction (CWMR) was considered by Binswanger and Alzheimer to be due to cerebral arteriolosclerosis. Renewed attention came with CT and MR brain imaging, and neuropathological studies finding a high rate of CWMR in Alzheimer disease (AD). The relative contributions of cerebrovascular disease and AD to CWMR are still uncertain. In 1181 autopsies by the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND), large-format brain sections were used to grade CWMR and determine its vascular and neurodegenerative correlates. Almost all neurodegenerative diseases had more severe CWMR than the normal control group. Multivariable logistic regression models indicated that Braak neurofibrillary stage was the strongest predictor of CWMR, with additional independently significant predictors including age, cortical and diencephalic lacunar and microinfarcts, body mass index, and female sex. It appears that while AD and cerebrovascular pathology may be additive in causing CWMR, both may be solely capable of this. The typical periventricular pattern suggests that CWMR is primarily a distal axonopathy caused by dysfunction of the cell bodies of long-association corticocortical projection neurons. A consequence of these findings is that CWMR should not be viewed simply as "small vessel disease" or as a pathognomonic indicator of vascular cognitive impairment or vascular dementia.


Asunto(s)
Enfermedad de Alzheimer , Trastornos Cerebrovasculares , Demencia Vascular , Sustancia Blanca , Femenino , Humanos , Sustancia Blanca/patología , Encéfalo/patología , Trastornos Cerebrovasculares/complicaciones , Trastornos Cerebrovasculares/diagnóstico por imagen , Trastornos Cerebrovasculares/patología , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/patología , Demencia Vascular/patología
11.
Brain ; 146(5): 1821-1830, 2023 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-36907221

RESUMEN

Therapeutics to reduce intracranial pressure are an unmet need. Preclinical data have demonstrated a novel strategy to lower intracranial pressure using glucagon-like peptide-1 (GLP-1) receptor signalling. Here, we translate these findings into patients by conducting a randomized, placebo-controlled, double-blind trial to assess the effect of exenatide, a GLP-1 receptor agonist, on intracranial pressure in idiopathic intracranial hypertension. Telemetric intracranial pressure catheters enabled long-term intracranial pressure monitoring. The trial enrolled adult women with active idiopathic intracranial hypertension (intracranial pressure >25 cmCSF and papilloedema) who receive subcutaneous exenatide or placebo. The three primary outcome measures were intracranial pressure at 2.5 h, 24 h and 12 weeks and alpha set a priori at less than 0.1. Among the 16 women recruited, 15 completed the study (mean age 28 ± 9, body mass index 38.1 ± 6.2 kg/m2, intracranial pressure 30.6 ± 5.1 cmCSF). Exenatide significantly and meaningfully lowered intracranial pressure at 2.5 h -5.7 ± 2.9 cmCSF (P = 0.048); 24 h -6.4 ± 2.9 cmCSF (P = 0.030); and 12 weeks -5.6 ± 3.0 cmCSF (P = 0.058). No serious safety signals were noted. These data provide confidence to proceed to a phase 3 trial in idiopathic intracranial hypertension and highlight the potential to utilize GLP-1 receptor agonist in other conditions characterized by raised intracranial pressure.


Asunto(s)
Diabetes Mellitus Tipo 2 , Seudotumor Cerebral , Adulto , Humanos , Femenino , Adulto Joven , Exenatida , Seudotumor Cerebral/tratamiento farmacológico , Receptor del Péptido 1 Similar al Glucagón/agonistas , Receptor del Péptido 1 Similar al Glucagón/uso terapéutico , Péptidos , Ponzoñas/uso terapéutico , Hipoglucemiantes/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico
12.
J Synchrotron Radiat ; 30(Pt 1): 200-207, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36601938

RESUMEN

The interaction of a focused X-ray beam with a sample in a scanning probe experiment can provide a variety of information about the interaction volume. In many scanning probe experiments X-ray fluorescence (XRF) is supplemented with measurements of the transmitted or scattered intensity using a pixelated detector. The automated extraction of different signals from an area pixelated detector is described, in particular the methodology for extracting differential phase contrast (DPC) is demonstrated and different processing methods are compared across a range of samples. The phase shift of the transmitted X-ray beam by the sample, extracted from DPC, is also compared with ptychography measurements to provide a qualitative and quantitative comparison. While ptychography produces a superior image, DPC can offer a simple, flexible method for phase contrast imaging which can provide fast results and feedback during an experiment; furthermore, for many science problems, such as registration of XRF in a lighter matrix, DPC can provide sufficient information to meet the experimental aims. As the DPC technique is a quantitative measurement, it can be expanded to spectroscopic studies and a demonstration of DPC for spectro-microscopy measurements is presented. Where ptychography can separate the absorption and phase shifts by the sample, quantitative interpretation of a DPC image or spectro-microscopy signal can only be performed directly when absorption is negligible or where the absorption contribution is known and the contributions can be fitted.

13.
Fluids Barriers CNS ; 19(1): 85, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36320018

RESUMEN

OBJECTIVES: Intracranial pressure (ICP) has been thought to vary diurnally. This study evaluates diurnal ICP measurements and quantifies changes in ICP occurring with changes in body posture in active idiopathic intracranial hypertension (IIH). METHODS: This prospective observational study utilized telemetric ICP monitoring in people with active IIH. Participants had the Raumedic p-Tel ICP intraparenchymal device (Raumedic, Hembrechts, Germany) surgically inserted. Changes in ICP in the supine position were evaluated. Then, the ICP was measured in the standing, sitting, supine, left lateral decubitus positions and with coughing and bending. Ultimately, changes in ICP over the course of 24 h were recorded. ISRCTN registration number 12678718. RESULTS: 15 women were included, mean (standard deviation) age 29.5 (9.5) years, body mass index 38.1 (6.2) kg/m2, and baseline mean ICP of 21.2 (4.8) mmHg (equivalent to 28.8 (6.5) cmCSF). Mean ICP rose with the duration in the supine position 1.2 (3.3) mmHg over 5-minutes (p = 0.175), 3.5 (2.8) mmHg over 30-minutes (p = 0.0002) and by a further 2.1 (2.2) mmHg over 3 h (p = 0.042). Mean ICP decreased by 51% when moving from the supine position to standing (21.2 (4.8) mmHg to 10.3 (3.7) mmHg respectively, p = 0.0001). Mean ICP increased by 13% moving from supine to the left lateral decubitus position (21.2 (4.8) mmHg to 24.0 (3.8) mmHg, p = 0.028). There was no significant difference in ICP measurements at any point during the daytime, or between 5-minute standing or supine recordings and prolonged ambulatory daytime and end of night supine recordings respectively. ICP, following an initial drop, increased progressively in conjunction with lying supine position from 23:00 h to 07:00 h by 34% (5.2 (1.9) mmHg, p = 0.026). CONCLUSION: This analysis demonstrated that ICP does not appear to have a diurnal variation in IIH, but varies by position and duration in the supine position. ICP rose at night whilst the patient was continuously supine. Furthermore, brief standing and supine ICP measures in the day predicted daytime prolonged ambulatory measures and end of night peak ICP respectively. This knowledge gives reassurance that ICP can be accurately measured and compared at any time of day in an ambulant IIH patient. These are useful findings to inform clinical measurements and in the interpretation of ICP analyses in IIH. TRIAL REGISTRATION: ISTCRN (12678718).


Asunto(s)
Presión Intracraneal , Seudotumor Cerebral , Femenino , Humanos , Adulto , Telemetría , Postura , Monitoreo Fisiológico
14.
J Neuropathol Exp Neurol ; 81(9): 666-695, 2022 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-35818336

RESUMEN

Brains of 42 COVID-19 decedents and 107 non-COVID-19 controls were studied. RT-PCR screening of 16 regions from 20 COVID-19 autopsies found SARS-CoV-2 E gene viral sequences in 7 regions (2.5% of 320 samples), concentrated in 4/20 subjects (20%). Additional screening of olfactory bulb (OB), amygdala (AMY) and entorhinal area for E, N1, N2, RNA-dependent RNA polymerase, and S gene sequences detected one or more of these in OB in 8/21 subjects (38%). It is uncertain whether these RNA sequences represent viable virus. Significant histopathology was limited to 2/42 cases (4.8%), one with a large acute cerebral infarct and one with hemorrhagic encephalitis. Case-control RNAseq in OB and AMY found more than 5000 and 700 differentially expressed genes, respectively, unrelated to RT-PCR results; these involved immune response, neuronal constituents, and olfactory/taste receptor genes. Olfactory marker protein-1 reduction indicated COVID-19-related loss of OB olfactory mucosa afferents. Iba-1-immunoreactive microglia had reduced area fractions in cerebellar cortex and AMY, and cytokine arrays showed generalized downregulation in AMY and upregulation in blood serum in COVID-19 cases. Although OB is a major brain portal for SARS-CoV-2, COVID-19 brain changes are more likely due to blood-borne immune mediators and trans-synaptic gene expression changes arising from OB deafferentation.


Asunto(s)
COVID-19 , SARS-CoV-2 , Encéfalo , Expresión Génica , Humanos , Inmunidad
15.
Faraday Discuss ; 235(0): 536-550, 2022 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-35388821

RESUMEN

Incorporating additives within host single crystals is an effective strategy for producing composite materials with tunable mechanical, magnetic and optical properties. The type of guest materials that can be occluded can be limited, however, as incorporation is a complex process depending on many factors including binding of the additive to the crystal surface, the rate of crystal growth and the stability of the additives in the crystallisation solution. In particular, the size of occluded guests has been restricted to a few angstroms - as for single molecules - to a few hundred nanometers - as for polymer vesicles and particles. Here, we present a synthetic approach for occluding micrometer-scale objects, including high-complexity unicellular organisms and synthetic hollow calcite spheres within calcite single crystals. Both of these objects can transport functional additives, including organic molecules and nanoparticles that would not otherwise occlude within calcite. Therefore, this method constitutes a generic approach using calcite as a delivery system for active compounds, while providing them with effective protection against environmental factors that could cause degradation.


Asunto(s)
Minerales , Nanopartículas , Carbonato de Calcio/química , Cristalización , Polímeros/química
16.
Rev Sci Instrum ; 93(4): 043712, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35489936

RESUMEN

A new stage design concept, the Delta Robot, is presented, which is a parallel kinematic design for scanning x-ray microscopy applications. The stage employs three orthogonal voice coils, which actuate parallelogram flexures. The design has a 3 mm travel range and achieves rms position jitter, integrated from 1 Hz to 1 kHz, of 2.8 and 1.3 nm perpendicular to the beam and 5.6 nm along the beam direction with loads up to 350 g. The Delta Robot design process used a mechatronics approach of iterative modeling and simulation to develop the system and validate performance. The design considerations, design process, stability, and operational performance on the hard x-ray nanoprobe at Diamond Light Source are presented.


Asunto(s)
Microscopía , Robótica , Simulación por Computador , Radiografía , Rayos X
17.
Animals (Basel) ; 12(3)2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-35158559

RESUMEN

A lack of national legislation for cat management in New Zealand poses challenges for ensuring that practices are consistently humane and effective. In this paper, we review the current cat management policies in New Zealand and the implications they have on the welfare of free-roaming cats (from here on, referred to as 'cats'). Our review demonstrates that there are multiple policy mechanisms used to manage cats in New Zealand for a variety of reasons, including animal welfare, pest management, and nuisance, and that these different policies have both positive and negative implications for cat welfare. We provide context pertaining to New Zealanders' acceptance of current or future laws and regulations and compare the New Zealand policy landscape with other countries, with a particular emphasis on Australia, to identify potential directions and outcomes of increased regulation. We discuss the future of the regulatory environment in New Zealand, including the need to better understand the impact of policies on cats, people, and other animals in urban, rural, and wild spaces. We further discuss the need to better understand the cat-human relationship for future policy decisions and offer a solution based on national cat legislation.

18.
J Neuropathol Exp Neurol ; 81(3): 158-171, 2022 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-35191506

RESUMEN

The spread of neurofibrillary tau pathology in Alzheimer disease (AD) mostly follows a stereotypical pattern of topographical progression but atypical patterns associated with interhemispheric asymmetry have been described. Because histopathological studies that used bilateral sampling are limited, this study aimed to assess interhemispheric tau pathology differences and the presence of topographically atypical cortical spreading patterns. Immunohistochemical staining for detection of tau pathology was performed in 23 regions of interest in 57 autopsy cases comparing bilateral cortical regions and hemispheres. Frequent mild (82% of cases) and occasional moderate (32%) interhemispheric density discrepancies were observed, whereas marked discrepancies were uncommon (7%) and restricted to occipital regions. Left and right hemispheric tau pathology dominance was observed with similar frequencies, except in Braak Stage VI that favored a left dominance. Interhemispheric Braak stage differences were observed in 16% of cases and were more frequent in advanced (IV-VI) versus early (I-III) stages. One atypical lobar topographical pattern in which occipital tau pathology density exceeded frontal lobe scores was identified in 4 cases favoring a left dominant asymmetry. We speculate that asymmetry and atypical topographical progression patterns may be associated with atypical AD clinical presentations and progression characteristics, which should be tested by comprehensive clinicopathological correlations.


Asunto(s)
Enfermedad de Alzheimer , Tauopatías , Enfermedad de Alzheimer/patología , Humanos , Ovillos Neurofibrilares/patología , Tomografía de Emisión de Positrones , Tauopatías/patología , Proteínas tau
19.
AJP Rep ; 12(1): e1-e9, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35036046

RESUMEN

Objective The aim of this study was to measure the effect of obesity and systemic opioids on respiratory events within the first 24 hours following cesarean. Methods Opioid-naive women undergoing cesarean between January 2016 and December 2017 were included in this retrospective cohort study. The primary outcome was the proportion of women experiencing at least one composite respiratory outcome (oxygen saturation less than 95% lasting 30+ seconds or need for respiratory support) within 24 hours of cesarean. The impact of obesity and total systemic opioid dose in 24 hours (measured in morphine milligram equivalents [MMEs]) on the composite respiratory compromise outcome were evaluated. Results Of 2,230 cesarean births, 790 women had at least one composite respiratory event. Predictors of the composite respiratory outcome included body mass index (BMI) as a continuous variable (odds ratio = 1.063 for every one unit increase in BMI [95% confidence interval (CI): 1.021-1.108], p = 0.003), and MME (odds ratio = 1.005 [95% CI: 1.002-1.008], p = 0.003), adjusting for magnesium sulfate use. The interaction between obesity and opioid dose demonstrated an odds ratio of 1.000 (95% CI: 0.999-1.000, p = 0.030). Conclusion The proportion of women experiencing respiratory events following cesarean birth increases with the degree of obesity and opioid dose. Key Points Respiratory events increase with obesity.Respiratory events increase with systemic opioid use.Odds ratio of respiratory events is 1.063/unit BMI increase.

20.
Clin Gerontol ; 45(1): 145-158, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34405768

RESUMEN

OBJECTIVES: To summarize adaptations due to COVID-19 for VA Problem Solving Training (PST) for clinicians serving medically complex patients and to compare patient mental health outcomes in the year before (2019) and during COVID-19 (2020). METHODS: Clinicians attended a multi-day workshop and up to 6 months of small-group consultation for two training cases. In 2019 and 2020, 122 Veteran patients completed baseline and posttreatment measures of depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder-7 item), and negative problem-solving beliefs (Negative Problem Orientation Questionnaire). Qualitative data were collected on clinician's pandemic-related treatment implementation challenges. RESULTS: Program adaptations during COVID-19 addressed challenges due to delivering treatment by telephone, video, or in person; Veteran patient recruitment barriers; and privacy issues for telephone and video. Veterans in both pre-pandemic and COVID-19 cohorts had significant improvements in depression, anxiety, and negative problem-solving beliefs, with no significant differences in the amount of improvement between the two cohorts. CONCLUSIONS: Flexibilities afforded to clinicians delivering the PST training program during the pandemic addressed key obstacles and barriers to recruitment, and implementation did not diminish the effectiveness of the intervention. CLINICAL IMPLICATIONS: Findings support continued implementation of the PST training program with added flexibility to treatment delivery beyond the pandemic.


Asunto(s)
COVID-19 , Veteranos , Ansiedad , Humanos , Solución de Problemas , SARS-CoV-2
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