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1.
Nature ; 630(8018): 836-840, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38768634

RESUMO

Interactions between exoplanetary atmospheres and internal properties have long been proposed to be drivers of the inflation mechanisms of gaseous planets and apparent atmospheric chemical disequilibrium conditions1. However, transmission spectra of exoplanets have been limited in their ability to observationally confirm these theories owing to the limited wavelength coverage of the Hubble Space Telescope (HST) and inferences of single molecules, mostly H2O (ref. 2). In this work, we present the panchromatic transmission spectrum of the approximately 750 K, low-density, Neptune-sized exoplanet WASP-107b using a combination of HST Wide Field Camera 3 (WFC3) and JWST Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI). From this spectrum, we detect spectroscopic features resulting from H2O (21σ), CH4 (5σ), CO (7σ), CO2 (29σ), SO2 (9σ) and NH3 (6σ). The presence of these molecules enables constraints on the atmospheric metal enrichment (M/H is 10-18× solar3), vertical mixing strength (log10Kzz = 8.4-9.0 cm2 s-1) and internal temperature (>345 K). The high internal temperature is suggestive of tidally driven inflation4 acting on a Neptune-like internal structure, which can naturally explain the large radius and low density of the planet. These findings suggest that eccentricity-driven tidal heating is a critical process governing atmospheric chemistry and interior-structure inferences for most of the cool (<1,000 K) super-Earth-to-Saturn-mass exoplanet population.

2.
Nature ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009005

RESUMO

Transmission spectroscopy has been a workhorse technique over the past two decades to constrain the physical and chemical properties of exoplanet atmospheres 1-5. One of its classical key assumptions is that the portion of the atmosphere it probes - the terminator region - is homogeneous. Several works in the past decade, however, have put this into question for highly irradiated, hot (Teq ≳ 1000 K) gas giant exoplanets both empirically 6-10 and via 3-dimensional modelling 11-17. While models predict clear differences between the evening (day-to-night) and morning (night-to-day) terminators, direct morning/evening transmission spectra in a wide wavelength range has not been reported for an exoplanet to date. Under the assumption of precise and accurate orbital parameters on WASP-39 b, here we report the detection of inhomogeneous terminators on the exoplanet WASP-39 b, which allows us to retrieve its morning and evening transmission spectra in the near-infrared (2 - 5 µm) using JWST. We observe larger transit depths in the evening which are, on average, 405±88 ppm larger than the morning ones, also having qualitatively larger features than the morning spectrum. The spectra are best explained by models in which the evening terminator is hotter than the morning terminator by 177 - 57 + 65 K with both terminators having C/O ratios consistent with solar. General circulation models (GCMs) predict temperature differences broadly consistent with the above value and point towards a cloudy morning terminator and a clearer evening terminator.

3.
Sex Transm Dis ; 51(3): 162-170, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38412463

RESUMO

BACKGROUND: People experiencing incarceration are disproportionately impacted by HIV and are potential candidates for HIV preexposure prophylaxis (PrEP). We explored factors associated with PrEP interest and PrEP uptake and described barriers to PrEP uptake among incarcerated men in a state correctional system. METHODS: From September 2019 to July 2022, incarcerated men at the Rhode Island Department of Corrections were screened for PrEP eligibility and referred to a PrEP initiation study. We used bivariate analyses and multivariable logistic regression models to explore factors associated with PrEP interest and uptake in the screening sample. RESULTS: Of the men screened and determined to be eligible for PrEP, approximately half (50%) were interested in taking PrEP. Individuals identifying as men who have sex with men (adjusted odds ratio, 4.46; 95% confidence interval, 1.86-11.4) and having multiple female sex partners (adjusted odds ratio, 2.98; 95% confidence interval, 1.47-6.27) were more likely to express interest in PrEP (interested/not interested) than those not reporting these behavioral factors. Preexposure prophylaxis uptake (yes/no) was 38%. Lack of PrEP interest, low self-perceived risk of HIV acquisition, and unpredictable lengths of incarceration were the most frequently encountered barriers to PrEP uptake. CONCLUSIONS: Men reporting sexual transmission behaviors were more interested in PrEP and had higher uptake than other men. Preexposure prophylaxis interest and HIV risk factors were both moderately high, which suggests that men experiencing incarceration should be screened for and offered PrEP as part of standard clinical care. Study findings have important implications for research and practice to adapt PrEP care to correctional systems.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Profilaxia Pré-Exposição , Minorias Sexuais e de Gênero , Masculino , Humanos , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Infecções por HIV/tratamento farmacológico , Homossexualidade Masculina , Fármacos Anti-HIV/uso terapêutico , Comportamento Sexual
4.
J Magn Reson Imaging ; 59(1): 82-96, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37084171

RESUMO

Neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD) present a major health burden to society. Changes in brain structure and cognition are generally only observed at the late stage of the disease. Although advanced magnetic resonance imaging (MRI) techniques such as diffusion imaging may allow identification of biomarkers at earlier stages of neurodegeneration, early diagnosis is still challenging. Magnetic resonance elastography (MRE) is a noninvasive MRI technique for studying the mechanical properties of tissues by measuring the wave propagation induced in the tissues using a purpose-built actuator. Here, we present a systematic review of preclinical and clinical studies in which MRE has been applied to study neurodegenerative diseases. Actuator systems for data acquisition, inversion algorithms for data analysis, and sample demographics are described and tissue stiffness measures obtained for the whole brain and internal structures are summarized. A total of six animal studies and eight human studies have been published. The animal studies refer to 123 experimental animals (68 AD and 55 PD) and 121 wild-type animals, while the human studies refer to 142 patients with neurodegenerative disease (including 56 AD and 17 PD) and 166 controls. The animal studies are consistent in the reporting of decreased stiffness of the hippocampal region in AD mice. However, in terms of disease progression, although consistent decreases in either storage modulus or shear modulus magnitude are reported for whole brain, there is variation in the results reported for the hippocampal region. The clinical studies are consistent in reports of a significant decrease in either whole brain storage modulus or shear modulus magnitude, in both AD and PD and with different brain structures affected in different neurodegenerative diseases. MRE studies of neurodegenerative diseases are still in their infancy, and in future it will be interesting to investigate potential relationships between brain mechanical properties and clinical measures, which may help elucidate the mechanisms underlying onset and progression of neurodegenerative diseases. EVIDENCE LEVEL: 1. TECHNICAL EFFICACY: Stage 2.


Assuntos
Doença de Alzheimer , Técnicas de Imagem por Elasticidade , Doenças Neurodegenerativas , Doença de Parkinson , Humanos , Camundongos , Animais , Doenças Neurodegenerativas/diagnóstico por imagem , Técnicas de Imagem por Elasticidade/métodos , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Doença de Alzheimer/diagnóstico por imagem
5.
Surgeon ; 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38395646

RESUMO

INTRODUCTION: "Subureteric Teflon INGection" (STING) of polytetrafluoroethylene (PTFE/polytef) paste to treat vesicoureteral reflux (VUR) in children was popularised in 1984. It was later abandoned as an implantation material because of the possibility of migration from the injection site. Giant-cell foreign-body granuloma to Polytef in the bladder is a rare cause of ureteric obstruction. Only a handful of cases have been reported in the literature. METHODS: We performed a prospective analysis of a series of 6 adult patients who had childhood STING and presented with foreign-body granuloma to Polytef in the bladder. We report their clinical presentation, findings and treatment. RESULTS: 1 male and 5 females with a history of STING procedure in childhood for VUR presented in later life with foreign-body granuloma to Polytef. The median age at first STING procedure and at presentation to the Urology Department was 3 and 34 years respectively. The most common clinical presentations were flank pain and urinary tract infection (UTI) and all patients had radiological findings of calcified lesions at the vesicoureteric junction(s). 4 patients had histological findings of giant-cell foreign-body granuloma. 4 patients required definitive ureteric reimplantation. CONCLUSION: Polytef granuloma causing distal ureteric obstruction may give rise to significant morbidity and renal damage. Due to the likelihood of progression of the granuloma, excision and ureteric reimplantation is considered the standard approach in the management of patients with viable kidneys. LEVEL OF EVIDENCE: Level 5.

6.
Neuropsychopharmacol Rep ; 44(1): 129-142, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38155535

RESUMO

BACKGROUND: Research on cannabis-based medicinal products (CBMPs) in anxiety remains inconclusive due to a paucity of high-quality evidence. Studies indicate a bidirectional relationship between generalized anxiety disorder (GAD) and sleep disruption, but it is unclear how this affects CBMP treatment outcomes. This study aims to compare the patient-reported outcome measures (PROMs) of patients prescribed CBMPs for GAD, with and without impaired sleep. METHODS: Changes in PROMs were recorded from baseline to 1, 3, 6, and 12 months between those with impaired or unimpaired sleep. Multivariate logistic regression was applied to compare factors associated with a clinically significant improvement in GAD-7 at 12 months. Secondary outcomes included adverse event incidence and frequency. RESULTS: Of the 302 patients that fit the inclusion criteria, mean GAD-7, single-item sleep quality, and EQ-5D-5L index values improved at all time points (p < 0.001). A relationship between sleep impairment and clinically significant changes in GAD-7 at 1 and 3 months was identified (p ≤ 0.01). On multivariate regression, only baseline GAD severity was associated with an increased likelihood of observing a clinically significant improvement in anxiety (p < 0.001). Seven hundred and seven (234%) adverse events were reported by 55 (18.21%) participants. CONCLUSIONS: This study observed an association between CBMP treatment and improvements in anxiety in patients with GAD. While patients with comorbid sleep disruption had greater improvements in anxiety, the differences were not maintained in a multivariate analysis. Baseline anxiety severity may be a predictor for CBMP treatment outcomes.


Assuntos
Maconha Medicinal , Humanos , Estudos de Coortes , Transtornos de Ansiedade/epidemiologia , Ansiedade , Sono
7.
Cells ; 13(6)2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38534327

RESUMO

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, yet the cellular and molecular mechanisms underlying the AF substrate remain unclear. Isolevuglandins (IsoLGs) are highly reactive lipid dicarbonyl products that mediate oxidative stress-related injury. In murine hypertension, the lipid dicarbonyl scavenger 2-hydroxybenzylamine (2-HOBA) reduced IsoLGs and AF susceptibility. We hypothesized that IsoLGs mediate detrimental pathophysiologic effects in atrial cardiomyocytes that promote the AF substrate. Using Seahorse XFp extracellular flux analysis and a luminescence assay, IsoLG exposure suppressed intracellular ATP production in atrial HL-1 cardiomyocytes. IsoLGs caused mitochondrial dysfunction, with reduced mitochondrial membrane potential, increased mitochondrial reactive oxygen species (ROS) with protein carbonylation, and mitochondrial DNA damage. Moreover, they generated cytosolic preamyloid oligomers previously shown to cause similar detrimental effects in atrial cells. In mouse atrial and HL-1 cells, patch clamp experiments demonstrated that IsoLGs rapidly altered action potentials (AP), implying a direct effect independent of oligomer formation by reducing the maximum Phase 0 upstroke slope and shortening AP duration due to ionic current modifications. IsoLG-mediated mitochondrial and electrophysiologic abnormalities were blunted or totally prevented by 2-HOBA. These findings identify IsoLGs as novel mediators of oxidative stress-dependent atrial pathophysiology and support the investigation of dicarbonyl scavengers as a novel therapeutic approach to prevent AF.


Assuntos
Fibrilação Atrial , Benzilaminas , Doenças Mitocondriais , Animais , Camundongos , Miócitos Cardíacos/metabolismo , Lipídeos/química , Espécies Reativas de Oxigênio/metabolismo
8.
Sci Rep ; 14(1): 5621, 2024 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-38454046

RESUMO

Chronic non-healing wounds significantly strain modern healthcare systems, affecting 1-2% of the population in developed countries with costs ranging between $28.1 and $96.8 billion annually. Additionally, it has been established that chronic wounds resulting from comorbidities, such as peripheral vascular disease and diabetes mellitus, tend to be polymicrobial in nature. Treatment of polymicrobial chronic wounds with oral and IV antibiotics can result in antimicrobial resistance, leading to more difficult-to-treat wounds. Ideally, chronic ulcers would be topically treated with antibiotic combinations tailored to the microbiome of a patient's wound. We have previously shown that a topical collagen-rich hydrogel (cHG) can elute single antibiotics to inhibit bacterial growth in a manner that is nontoxic to mammalian cells. Here, we analyzed the microbiology of cultures taken from human patients diagnosed with diabetes mellitus suffering from chronic wounds present for more than 6 weeks. Additionally, we examined the safety of the elution of multiple antibiotics from collagen-rich hydrogel in mammalian cells in vivo. Finally, we aimed to create tailored combinations of antibiotics impregnated into cHG to successfully target and treat infections and eradicate biofilms cultured from human chronic diabetic wound tissue. We found that the majority of human chronic wounds in our study were polymicrobial in nature. The elution of multiple antibiotics from cHG was well-tolerated in mammalian cells, making it a potential topical treatment of the polymicrobial chronic wound. Finally, combinations of antibiotics tailored to each patient's microbiome eluted from a collagen-rich hydrogel successfully treated bacterial cultures isolated from patient samples via an in vitro assay.


Assuntos
Antibacterianos , Pé Diabético , Animais , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Hidrogéis , Cicatrização , Colágeno , Pé Diabético/tratamento farmacológico , Biofilmes , Mamíferos
9.
Mar Pollut Bull ; 202: 116285, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38555802

RESUMO

Oil spilled into an aquatic environment produces oil droplet and dissolved component concentrations and compositions that are highly variable in space and time. Toxic effects on aquatic biota vary with sensitivity of the organism, concentration, composition, environmental conditions, and frequency and duration of exposure to the mixture of oil-derived dissolved compounds. For a range of spill (surface, subsea, blowout) and oil types under different environmental conditions, modeling of oil transport, fate, and organism behavior was used to quantify expected exposures over time for planktonic, motile, and stationary organisms. Different toxicity models were applied to these exposure time histories to characterize the influential roles of composition, concentration, and duration of exposure on aquatic toxicity. Misrepresenting these roles and exposures can affect results by orders of magnitude. Well-characterized laboratory studies for <24-hour exposures are needed to improve toxicity predictions of the typically short-term exposures that characterize spills.


Assuntos
Poluição por Petróleo , Petróleo , Poluentes Químicos da Água , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise , Petróleo/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Animais , Monitoramento Ambiental
10.
Brain Commun ; 6(2): fcae073, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38505229

RESUMO

Vascular brain injury results in loss of structural and functional connectivity and leads to cognitive impairment. Its various manifestations, including microinfarcts, microhaemorrhages and white matter hyperintensities, result in microstructural tissue integrity loss and secondary neurodegeneration. Among these, tissue microstructural alteration is a relatively early event compared with atrophy along the aging and neurodegeneration continuum. Understanding its association with cognition may provide the opportunity to further elucidate the relationship between vascular health and clinical outcomes. Magnetic resonance elastography offers a non-invasive approach to evaluate tissue mechanical properties, providing a window into the microstructural integrity of the brain. This retrospective study evaluated brain stiffness as a potential biomarker for vascular brain injury and its role in mediating the impact of vascular dysfunction on cognitive impairment. Seventy-five participants from the Mayo Clinic Study of Aging underwent brain imaging using a 3T MR imager with a spin-echo echo-planar imaging sequence for magnetic resonance elastography and T1- and T2-weighted pulse sequences. This study evaluated the effects of vascular biomarkers (white matter hyperintensities and cardiometabolic condition score) on brain stiffness using voxelwise analysis. Partial correlation analysis explored associations between brain stiffness, white matter hyperintensities, cardiometabolic condition and global cognition. Mediation analysis determined the role of stiffness in mediating the relationship between vascular biomarkers and cognitive performance. Statistical significance was set at P-values < 0.05. Diagnostic accuracy of magnetic resonance elastography stiffness for white matter hyperintensities and cardiometabolic condition was evaluated using receiver operator characteristic curves. Voxelwise linear regression analysis indicated white matter hyperintensities negatively correlate with brain stiffness, specifically in periventricular regions with high white matter hyperintensity levels. A negative association between cardiovascular risk factors and stiffness was also observed across the brain. No significant patterns of stiffness changes were associated with amyloid load. Global stiffness (µ) negatively correlated with both white matter hyperintensities and cardiometabolic condition when all other covariables including amyloid load were controlled. The positive correlation between white matter hyperintensities and cardiometabolic condition weakened and became statistically insignificant when controlling for other covariables. Brain stiffness and global cognition were positively correlated, maintaining statistical significance after adjusting for all covariables. These findings suggest mechanical alterations are associated with cognitive dysfunction and vascular brain injury. Brain stiffness significantly mediated the indirect effects of white matter hyperintensities and cardiometabolic condition on global cognition. Local cerebrovascular diseases (assessed by white matter hyperintensities) and systemic vascular risk factors (assessed by cardiometabolic condition) impact brain stiffness with spatially and statistically distinct effects. Global brain stiffness is a significant mediator between vascular disease measures and cognitive function, highlighting the value of magnetic resonance elastography-based mechanical assessments in understanding this relationship.

11.
Mult Scler Relat Disord ; 87: 105665, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38728958

RESUMO

INTRODUCTION: Whilst disease-modifying therapies are the cornerstone for treatment of multiple sclerosis (MS), there is a need to develop novel therapeutics for the symptomatic sequalae of the disease. Cannabis-based medicinal products (CBMPs) have been suggested as a potential therapy for the associated pain, spasticity, and mental health disorders. However, there is a paucity of clinical evidence on CBMPs in MS. The aim of this study is to assess changes in MS-specific and general health-related quality of life (HRQoL) outcomes alongside adverse event incidence in patients prescribed CBMPs for MS from the UK Medical Cannabis Registry (UKMCR). METHOD: Patients prescribed CBMPs for MS symptoms for longer than one month were identified from the UKMCR. The primary outcomes were changes from baseline in MS Quality of Life-54 (MSQoL-54), Generalised Anxiety Disorder-7 (GAD-7), Single-Item Sleep Quality Scale (SQS), and EQ-5D-5L scales at one month, three months and six months. p < 0.050 was defined as statistically significant. RESULTS: 141 patients met the inclusion criteria for the study. There was an improvement in the following subscales of the MSQoL-54 at 6 months: change in health scale, cognitive function, mental health composition, physical health, role limitations due to physical limitation and due to emotional problems, as well as social and sexual function (p < 0.050). There were also improvements in the EQ-5D-5L index value, GAD-7 and SQS (p < 0.050). 146 (103.55 %) adverse events were reported in total. Most were considered mild (n = 47; 33.33 %) and moderate (n = 72; 51.06 %). CONCLUSIONS: This preliminary analysis demonstrates a possible association with improved general health-related quality of life in those prescribed CBMPs for MS. Moreover, the results suggest that CBMPs are well-tolerated in the first 6 months of treatment. However, this must be interpreted with caution considering the limitations of the observational study design.


Assuntos
Maconha Medicinal , Esclerose Múltipla , Qualidade de Vida , Sistema de Registros , Humanos , Masculino , Feminino , Maconha Medicinal/uso terapêutico , Maconha Medicinal/efeitos adversos , Adulto , Esclerose Múltipla/tratamento farmacológico , Pessoa de Meia-Idade , Reino Unido
12.
PLoS One ; 19(6): e0305247, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38917107

RESUMO

Meningiomas, the most prevalent primary benign intracranial tumors, often exhibit complicated levels of adhesion to adjacent normal tissues, significantly influencing resection and causing postoperative complications. Surgery remains the primary therapeutic approach, and when combined with adjuvant radiotherapy, it effectively controls residual tumors and reduces tumor recurrence when complete removal may cause a neurologic deficit. Previous studies have indicated that slip interface imaging (SII) techniques based on MR elastography (MRE) have promise as a method for sensitively determining the presence of tumor-brain adhesion. In this study, we developed and tested an improved algorithm for assessing tumor-brain adhesion, based on recognition of patterns in MRE-derived normalized octahedral shear strain (NOSS) images. The primary goal was to quantify the tumor interfaces at higher risk for adhesion, offering a precise and objective method to assess meningioma adhesions in 52 meningioma patients. We also investigated the predictive value of MRE-assessed tumor adhesion in meningioma recurrence. Our findings highlight the effectiveness of the improved SII technique in distinguishing the adhesion degrees, particularly complete adhesion. Statistical analysis revealed significant differences in adhesion percentages between complete and partial adherent tumors (p = 0.005), and complete and non-adherent tumors (p<0.001). The improved technique demonstrated superior discriminatory ability in identifying tumor adhesion patterns compared to the previously described algorithm, with an AUC of 0.86 vs. 0.72 for distinguishing complete adhesion from others (p = 0.037), and an AUC of 0.72 vs. 0.67 for non-adherent and others. Aggressive tumors exhibiting atypical features showed significantly higher adhesion percentages in recurrence group compared to non-recurrence group (p = 0.042). This study validates the efficacy of the improved SII technique in quantifying meningioma adhesions and demonstrates its potential to affect clinical decision-making. The reliability of the technique, coupled with potential to help predict meningioma recurrence, particularly in aggressive tumor subsets, highlights its promise in guiding treatment strategies.


Assuntos
Técnicas de Imagem por Elasticidade , Imageamento por Ressonância Magnética , Neoplasias Meníngeas , Meningioma , Humanos , Meningioma/diagnóstico por imagem , Meningioma/patologia , Meningioma/cirurgia , Técnicas de Imagem por Elasticidade/métodos , Feminino , Pessoa de Meia-Idade , Masculino , Neoplasias Meníngeas/diagnóstico por imagem , Neoplasias Meníngeas/patologia , Neoplasias Meníngeas/cirurgia , Idoso , Adulto , Imageamento por Ressonância Magnética/métodos , Recidiva Local de Neoplasia/diagnóstico por imagem , Aderências Teciduais/diagnóstico por imagem , Algoritmos
13.
Radiol Cardiothorac Imaging ; 6(3): e230140, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38780427

RESUMO

Purpose To investigate the feasibility of using quantitative MR elastography (MRE) to characterize the influence of aging and sex on left ventricular (LV) shear stiffness. Materials and Methods In this prospective study, LV myocardial shear stiffness was measured in 109 healthy volunteers (age range: 18-84 years; mean age, 40 years ± 18 [SD]; 57 women, 52 men) enrolled between November 2018 and September 2019, using a 5-minute MRE acquisition added to a clinical MRI protocol. Linear regression models were used to estimate the association of cardiac MRI and MRE characteristics with age and sex; models were also fit to assess potential age-sex interaction. Results Myocardial shear stiffness significantly increased with age in female (age slope = 0.03 kPa/year ± 0.01, P = .009) but not male (age slope = 0.008 kPa/year ± 0.009, P = .38) volunteers. LV ejection fraction (LVEF) increased significantly with age in female volunteers (0.23% ± 0.08 per year, P = .005). LV end-systolic volume (LVESV) decreased with age in female volunteers (-0.20 mL/m2 ± 0.07, P = .003). MRI parameters, including T1, strain, and LV mass, did not demonstrate this interaction (P > .05). Myocardial shear stiffness was not significantly correlated with LVEF, LV stroke volume, body mass index, or any MRI strain metrics (P > .05) but showed significant correlations with LV end-diastolic volume/body surface area (BSA) (slope = -3 kPa/mL/m2 ± 1, P = .004, r2 = 0.08) and LVESV/BSA (-1.6 kPa/mL/m2 ± 0.5, P = .003, r2 = 0.08). Conclusion This study demonstrates that female, but not male, individuals experience disproportionate LV stiffening with natural aging, and these changes can be noninvasively measured with MRE. Keywords: Cardiac, Elastography, Biological Effects, Experimental Investigations, Sexual Dimorphisms, MR Elastography, Myocardial Shear Stiffness, Quantitative Stiffness Imaging, Aging Heart, Myocardial Biomechanics, Cardiac MRE Supplemental material is available for this article. Published under a CC BY 4.0 license.


Assuntos
Envelhecimento , Técnicas de Imagem por Elasticidade , Ventrículos do Coração , Humanos , Feminino , Adulto , Masculino , Pessoa de Meia-Idade , Idoso , Técnicas de Imagem por Elasticidade/métodos , Idoso de 80 Anos ou mais , Adolescente , Estudos Prospectivos , Envelhecimento/fisiologia , Ventrículos do Coração/diagnóstico por imagem , Adulto Jovem , Fatores Sexuais , Função Ventricular Esquerda/fisiologia , Imageamento por Ressonância Magnética , Estudos de Viabilidade
14.
AJNR Am J Neuroradiol ; 45(5): 662-667, 2024 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-38485194

RESUMO

BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension is a condition resulting from a leak of CSF from the spinal canal arising independent of a medical procedure. Spontaneous intracranial hypotension can present with normal brain MR imaging findings and nonspecific symptoms, leading to the underdiagnosis in some patients and unnecessary invasive myelography in others who are found not to have the condition. Given the likelihood that spontaneous intracranial hypotension alters intracranial biomechanics, the goal of this study was to evaluate MR elastography as a potential noninvasive test to diagnose the condition. MATERIALS AND METHODS: We performed MR elastography in 15 patients with confirmed spontaneous intracranial hypotension from September 2022 to April 2023. Age, sex, symptom duration, and brain MR imaging Bern score were collected. MR elastography data were used to compute stiffness and damping ratio maps, and voxelwise modeling was performed to detect clusters of significant differences in mechanical properties between patients with spontaneous intracranial hypotension and healthy control participants. To evaluate diagnostic accuracy, we summarized each examination by 2 spatial pattern scores (one each for stiffness and damping ratio) and evaluated group-wise discrimination by receiver operating characteristic curve analysis. RESULTS: Patients with spontaneous intracranial hypotension exhibited significant differences in both stiffness and damping ratio (false discovery rate-corrected, Q < 0.05). Pattern analysis discriminated patients with spontaneous intracranial hypotension from healthy controls with an area under the curve of 0.97 overall, and the area under the curve was 0.97 in those without MR imaging findings of spontaneous intracranial hypotension. CONCLUSIONS: Results from this pilot study demonstrate MR elastography as a potential imaging biomarker and a noninvasive method for diagnosing spontaneous intracranial hypotension, including patients with normal brain MR imaging findings.


Assuntos
Técnicas de Imagem por Elasticidade , Hipotensão Intracraniana , Imageamento por Ressonância Magnética , Humanos , Hipotensão Intracraniana/diagnóstico por imagem , Técnicas de Imagem por Elasticidade/métodos , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética/métodos , Idoso , Adulto Jovem
15.
AJNR Am J Neuroradiol ; 45(3): 328-334, 2024 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-38272572

RESUMO

BACKGROUND AND PURPOSE: Normal pressure hydrocephalus is a treatable cause of dementia associated with distinct mechanical property signatures in the brain as measured by MR elastography. In this study, we tested the hypothesis that specific anatomic features of normal pressure hydrocephalus are associated with unique mechanical property alterations. Then, we tested the hypothesis that summary measures of these mechanical signatures can be used to predict clinical outcomes. MATERIALS AND METHODS: MR elastography and structural imaging were performed in 128 patients with suspected normal pressure hydrocephalus and 44 control participants. Patients were categorized into 4 subgroups based on their anatomic features. Surgery outcome was acquired for 68 patients. Voxelwise modeling was performed to detect regions with significantly different mechanical properties between each group. Mechanical signatures were summarized using pattern analysis and were used as features to train classification models and predict shunt outcomes for 2 sets of feature spaces: a limited 2D feature space that included the most common features found in normal pressure hydrocephalus and an expanded 20-dimensional (20D) feature space that included features from all 4 morphologic subgroups. RESULTS: Both the 2D and 20D classifiers performed significantly better than chance for predicting clinical outcomes with estimated areas under the receiver operating characteristic curve of 0.66 and 0.77, respectively (P < .05, permutation test). The 20D classifier significantly improved the diagnostic OR and positive predictive value compared with the 2D classifier (P < .05, permutation test). CONCLUSIONS: MR elastography provides further insight into mechanical alterations in the normal pressure hydrocephalus brain and is a promising, noninvasive method for predicting surgical outcomes in patients with normal pressure hydrocephalus.


Assuntos
Técnicas de Imagem por Elasticidade , Hidrocefalia de Pressão Normal , Hidrocefalia , Humanos , Hidrocefalia de Pressão Normal/diagnóstico por imagem , Hidrocefalia de Pressão Normal/cirurgia , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Resultado do Tratamento
16.
Cardiovasc Res ; 120(8): 899-913, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38377486

RESUMO

AIMS: The lymphocyte adaptor protein (LNK) is a negative regulator of cytokine and growth factor signalling. The rs3184504 variant in SH2B3 reduces LNK function and is linked to cardiovascular, inflammatory, and haematologic disorders, including stroke. In mice, deletion of Lnk causes inflammation and oxidative stress. We hypothesized that Lnk-/- mice are susceptible to atrial fibrillation (AF) and that rs3184504 is associated with AF and AF-related stroke in humans. During inflammation, reactive lipid dicarbonyls are the major components of oxidative injury, and we further hypothesized that these mediators are critical drivers of the AF substrate in Lnk-/- mice. METHODS AND RESULTS: Lnk-/- or wild-type (WT) mice were treated with vehicle or 2-hydroxybenzylamine (2-HOBA), a dicarbonyl scavenger, for 3 months. Compared with WT, Lnk-/- mice displayed increased AF duration that was prevented by 2-HOBA. In the Lnk-/- atria, action potentials were prolonged with reduced transient outward K+ current, increased late Na+ current, and reduced peak Na+ current, pro-arrhythmic effects that were inhibited by 2-HOBA. Mitochondrial dysfunction, especially for Complex I, was evident in Lnk-/- atria, while scavenging lipid dicarbonyls prevented this abnormality. Tumour necrosis factor-α (TNF-α) and interleukin-1 beta (IL-1ß) were elevated in Lnk-/- plasma and atrial tissue, respectively, both of which caused electrical and bioenergetic remodelling in vitro. Inhibition of soluble TNF-α prevented electrical remodelling and AF susceptibility, while IL-1ß inhibition improved mitochondrial respiration but had no effect on AF susceptibility. In a large database of genotyped patients, rs3184504 was associated with AF, as well as AF-related stroke. CONCLUSION: These findings identify a novel role for LNK in the pathophysiology of AF in both experimental mice and humans. Moreover, reactive lipid dicarbonyls are critical to the inflammatory AF substrate in Lnk-/- mice and mediate the pro-arrhythmic effects of pro-inflammatory cytokines, primarily through electrical remodelling.


Assuntos
Potenciais de Ação , Proteínas Adaptadoras de Transdução de Sinal , Fibrilação Atrial , Modelos Animais de Doenças , Interleucina-1beta , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miócitos Cardíacos , Animais , Feminino , Humanos , Masculino , Potenciais de Ação/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Fibrilação Atrial/metabolismo , Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/genética , Benzilaminas/farmacologia , Predisposição Genética para Doença , Frequência Cardíaca/efeitos dos fármacos , Mediadores da Inflamação/metabolismo , Interleucina-1beta/metabolismo , Interleucina-1beta/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mitocôndrias Cardíacas/metabolismo , Mitocôndrias Cardíacas/patologia , Mitocôndrias Cardíacas/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Estresse Oxidativo/efeitos dos fármacos , Fenótipo , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/genética
17.
Front Cell Neurosci ; 17: 1329823, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38269112

RESUMO

B lymphocytes are immune cells studied predominantly in the context of peripheral humoral immune responses against pathogens. Evidence has been accumulating in recent years on the diversity of immunomodulatory functions that B cells undertake, with particular relevance for pathologies of the central nervous system (CNS). This review summarizes current knowledge on B cell populations, localization, infiltration mechanisms, and function in the CNS and associated tissues. Acute and chronic neurodegenerative pathologies are examined in order to explore the complex, and sometimes conflicting, effects that B cells can have in each context, with implications for disease progression and treatment outcomes. Additional factors such as aging modulate the proportions and function of B cell subpopulations over time and are also discussed in the context of neuroinflammatory response and disease susceptibility. A better understanding of the multifactorial role of B cell populations in the CNS may ultimately lead to innovative therapeutic strategies for a variety of neurological conditions.

18.
World J Radiol ; 15(12): 359-369, 2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38179201

RESUMO

BACKGROUND: Missing occult cancer lesions accounts for the most diagnostic errors in retrospective radiology reviews as early cancer can be small or subtle, making the lesions difficult to detect. Second-observer is the most effective technique for reducing these events and can be economically implemented with the advent of artificial intelligence (AI). AIM: To achieve appropriate AI model training, a large annotated dataset is necessary to train the AI models. Our goal in this research is to compare two methods for decreasing the annotation time to establish ground truth: Skip-slice annotation and AI-initiated annotation. METHODS: We developed a 2D U-Net as an AI second observer for detecting colorectal cancer (CRC) and an ensemble of 5 differently initiated 2D U-Net for ensemble technique. Each model was trained with 51 cases of annotated CRC computed tomography of the abdomen and pelvis, tested with 7 cases, and validated with 20 cases from The Cancer Imaging Archive cases. The sensitivity, false positives per case, and estimated Dice coefficient were obtained for each method of training. We compared the two methods of annotations and the time reduction associated with the technique. The time differences were tested using Friedman's two-way analysis of variance. RESULTS: Sparse annotation significantly reduces the time for annotation particularly skipping 2 slices at a time (P < 0.001). Reduction of up to 2/3 of the annotation does not reduce AI model sensitivity or false positives per case. Although initializing human annotation with AI reduces the annotation time, the reduction is minimal, even when using an ensemble AI to decrease false positives. CONCLUSION: Our data support the sparse annotation technique as an efficient technique for reducing the time needed to establish the ground truth.

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