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1.
Artigo em Inglês | MEDLINE | ID: mdl-38715792

RESUMO

Data scarcity and data imbalance are two major challenges in training deep learning models on medical images, such as brain tumor MRI data. The recent advancements in generative artificial intelligence have opened new possibilities for synthetically generating MRI data, including brain tumor MRI scans. This approach can be a potential solution to mitigate the data scarcity problem and enhance training data availability. This work focused on adapting the 2D latent diffusion models to generate 3D multi-contrast brain tumor MRI data with a tumor mask as the condition. The framework comprises two components: a 3D autoencoder model for perceptual compression and a conditional 3D Diffusion Probabilistic Model (DPM) for generating high-quality and diverse multi-contrast brain tumor MRI samples, guided by a conditional tumor mask. Unlike existing works that focused on generating either 2D multi-contrast or 3D single-contrast MRI samples, our models generate multi-contrast 3D MRI samples. We also integrated a conditional module within the UNet backbone of the DPM to capture the semantic class-dependent data distribution driven by the provided tumor mask to generate MRI brain tumor samples based on a specific brain tumor mask. We trained our models using two brain tumor datasets: The Cancer Genome Atlas (TCGA) public dataset and an internal dataset from the University of Texas Southwestern Medical Center (UTSW). The models were able to generate high-quality 3D multi-contrast brain tumor MRI samples with the tumor location aligned by the input condition mask. The quality of the generated images was evaluated using the Fréchet Inception Distance (FID) score. This work has the potential to mitigate the scarcity of brain tumor data and improve the performance of deep learning models involving brain tumor MRI data.

2.
Radiol Artif Intell ; : e230218, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38775670

RESUMO

"Just Accepted" papers have undergone full peer review and have been accepted for publication in Radiology: Artificial Intelligence. This article will undergo copyediting, layout, and proof review before it is published in its final version. Please note that during production of the final copyedited article, errors may be discovered which could affect the content. Purpose To develop a radiomics framework for preoperative MRI-based prediction of IDH mutation status, a crucial glioma prognostic indicator. Materials and Methods Radiomics features (shape, first-order statistics, and texture) were extracted from the whole tumor or the combination of nonenhancing, necrosis, and edema regions. Segmentation masks were obtained via the federated tumor segmentation tool or the original data source. Boruta, a wrapper-based feature selection algorithm, identified relevant features. Addressing the imbalance between mutated and wild-type cases, multiple prediction models were trained on balanced data subsets using Random Forest or XGBoost and assembled to build the final classifier. The framework was evaluated using retrospective MRI scans from three public datasets (The Cancer Imaging Archive (TCIA, 227 patients), the University of California San Francisco Preoperative Diffuse Glioma MRI dataset (UCSF, 495 patients), and the Erasmus Glioma Database (EGD, 456 patients)) and internal datasets collected from UT Southwestern Medical Center (UTSW, 356 patients), New York University (NYU, 136 patients), and University of Wisconsin-Madison (UWM, 174 patients). TCIA and UTSW served as separate training sets, while the remaining data constituted the test set (1617 or 1488 testing cases, respectively). Results The best-performing models trained on the TCIA dataset achieved area under the receiver operating characteristic curve (AUC) values of 0.89 for UTSW, 0.86 for NYU, 0.93 for UWM, 0.94 for UCSF, and 0.88 for EGD test sets. The best-performing models trained on the UTSW dataset achieved slightly higher AUCs: 0.92 for TCIA, 0.88 for NYU, 0.96 for UWM, 0.93 for UCSF, and 0.90 for EGD. Conclusion This MRI radiomics-based framework shows promise for accurate preoperative prediction of IDH mutation status in patients with glioma. Published under a CC BY 4.0 license.

3.
Clin Imaging ; 108: 110117, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38457905

RESUMO

INTRODUCTION: The complex practice environment and responsibilities incumbent on diagnostic radiologists creates a workflow susceptible to disruption. While interruptions have been shown to contribute to medical errors in the healthcare delivery environment, the exact impact on highly subspecialized services such as diagnostic radiology is less certain. One potential source of workflow disruption is the use of a departmental instant messaging system (Webex), to facilitate communications between radiology faculty, residents, fellows, and technologists. A retrospective review was conducted to quantify the frequency of interruption experienced by our neuroradiology fellows. MATERIALS AND METHODS: Data logs were gathered comprising all instant messages sent and received within the designated group chats from July 5-December 31, 2021, during weekday shifts staffed by neuroradiology fellows. Interruptions per shift were calculated based on month, week, and day of the week. RESULTS: 14,424 messages were sent across 289 total shifts. The 6 fellows assigned to the main neuroradiology reading room sent 3258 messages and received 10,260 messages from technologists and other staff. There was an average of 50 interruptions per shift when examined by month (range 48-53), and 52 interruptions per shift when examined by day of the week (range 40-60). CONCLUSION: Neuroradiology fellows experience frequent interruptions from the departmental instant messaging system. These disruptions, when considered in conjunction with other non-interpretative tasks, may have negative implications for workflow efficiency, requiring iterative process improvements when incorporating new technology into the practice environment of diagnostic radiology.


Assuntos
Radiologistas , Radiologia , Humanos , Fluxo de Trabalho , Estudos Retrospectivos
4.
Sci Rep ; 14(1): 4897, 2024 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418516

RESUMO

The inspired sinewave technique (IST) is a non-invasive method to measure lung heterogeneity indices (including both uneven ventilation and perfusion or heterogeneity), which reveal multiple conditions of the lung and lung injury. To evaluate the reproducibility and predicted clinical outcomes of IST heterogeneity values, a comparison with a quantitative lung computed tomography (CT) scan is performed. Six anaesthetised pigs were studied after surfactant depletion by saline-lavage. Paired measurements of lung heterogeneity were then taken with both the IST and CT. Lung heterogeneity measured by the IST was calculated by (a) the ratio of tracer gas outputs measured at oscillation periods of 180 s and 60 s, and (b) by the standard deviation of the modelled log-normal distribution of ventilations and perfusions in the simulation lung. In the CT images, lungs were manually segmented and divided into different regions according to voxel density. A quantitative CT method to calculate the heterogeneity (the Cressoni method) was applied. The IST and CT show good Pearson correlation coefficients in lung heterogeneity measurements (ventilation: 0.71, and perfusion, 0.60, p < 0.001). Within individual animals, the coefficients of determination average ventilation (R2 = 0.53) and perfusion (R2 = 0.68) heterogeneity. Strong concordance rates of 98% in ventilation and 89% when the heterogeneity changes were reported in pairs measured by CT scanning and IST methods. This quantitative method to identify heterogeneity has the potential to replicate CT lung heterogeneity, and to aid individualised care in ARDS.


Assuntos
Pulmão , Síndrome do Desconforto Respiratório , Suínos , Animais , Reprodutibilidade dos Testes , Pulmão/diagnóstico por imagem , Síndrome do Desconforto Respiratório/diagnóstico por imagem , Modelos Animais , Tomografia Computadorizada por Raios X/métodos
5.
J Sports Sci ; 41(14): 1410-1422, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37877884

RESUMO

Footballers with vision impairment (VI) are eligible to compete in the Para sport if they meet a minimum impairment criteria (MIC) based on measures of their visual acuity (VA) and/or visual field. Despite the requirements of the International Paralympic Committee Athlete Classification Code that each sport uses an evidence-based classification system, VI football continues to use a medical-based system that lacks evidence to demonstrate the relationship between impairment and performance in the sport. The aim of this study was to systematically simulate vision loss to establish the minimum level of impairment that would affect performance in futsal. Nineteen skilled sighted players completed tests of individual technical skill and anticipation performance under six levels of simulated blur that decreased both VA and contrast sensitivity (CS). VA needed to be reduced to a level of acuity that represents worse vision than that currently used for inclusion in VI football before meaningful decreases in performance were observed. CS did not have a clear effect on football performance. These findings produce the first evidence for the minimum impairment criteria in VI football and suggest a more severe degree of impairment may be required for the MIC.


Assuntos
Paratletas , Futebol , Transtornos da Visão , Humanos , Desempenho Atlético
6.
Bioengineering (Basel) ; 10(9)2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37760146

RESUMO

Isocitrate dehydrogenase (IDH) mutation status has emerged as an important prognostic marker in gliomas. This study sought to develop deep learning networks for non-invasive IDH classification using T2w MR images while comparing their performance to a multi-contrast network. Methods: Multi-contrast brain tumor MRI and genomic data were obtained from The Cancer Imaging Archive (TCIA) and The Erasmus Glioma Database (EGD). Two separate 2D networks were developed using nnU-Net, a T2w-image-only network (T2-net) and a multi-contrast network (MC-net). Each network was separately trained using TCIA (227 subjects) or TCIA + EGD data (683 subjects combined). The networks were trained to classify IDH mutation status and implement single-label tumor segmentation simultaneously. The trained networks were tested on over 1100 held-out datasets including 360 cases from UT Southwestern Medical Center, 136 cases from New York University, 175 cases from the University of Wisconsin-Madison, 456 cases from EGD (for the TCIA-trained network), and 495 cases from the University of California, San Francisco public database. A receiver operating characteristic curve (ROC) was drawn to calculate the AUC value to determine classifier performance. Results: T2-net trained on TCIA and TCIA + EGD datasets achieved an overall accuracy of 85.4% and 87.6% with AUCs of 0.86 and 0.89, respectively. MC-net trained on TCIA and TCIA + EGD datasets achieved an overall accuracy of 91.0% and 92.8% with AUCs of 0.94 and 0.96, respectively. We developed reliable, high-performing deep learning algorithms for IDH classification using both a T2-image-only and a multi-contrast approach. The networks were tested on more than 1100 subjects from diverse databases, making this the largest study on image-based IDH classification to date.

7.
J Adolesc Young Adult Oncol ; 12(1): 93-100, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-35319264

RESUMO

Purpose: Adolescent and young adult (AYA) cancer patients frequently demonstrate sexual dysfunction; however, there is a lack of data quantifying the severity and frequency. Methods: Males aged 18-39 years, diagnosed with cancer of any kind and who were scheduled to begin, were actively receiving, or had completed cancer treatment within 6 months, were offered validated surveys during their oncology appointment. These surveys included the International Index of Erectile Function (IIEF-6), Masturbation Erection Index (MEI), 36-Item Short Form Survey, and 5-point Likert scales to assess their desire and ability to engage in sex and masturbation. Results: Forty subjects completed the IIEF survey with a mean score of 17.7 ± 11, erectile dysfunction (ED) prevalence accordingly was 58%. Thirty-eight subjects completed the MEI with a mean score of 25.3 ± 5.3, ED prevalence was again 58%. Age and IIEF scores demonstrated a statistically significant (p < 0.05, n = 38) Pearson's correlation coefficient of 0.40, patients younger than 30 years had an ED prevalence of 72% (mean IIEF 13), whereas patients aged 30 years and older had an ED prevalence of 45% (mean IIEF 22). All treatment modalities had ED rates >30%: chemotherapy demonstrated the highest prevalence at 64% (mean IIEF 17), whereas radiation therapy had the lowest prevalence at 33% (mean IIEF 23). Conclusion: This study demonstrates that the prevalence of sexual dysfunction among male AYA patients undergoing treatment for cancer is high. AYA oncologists should discuss potential sexual health concerns when treating this population. The exact cause of ED (non-organic vs. organic) within this group should be explored further.


Assuntos
Disfunção Erétil , Neoplasias , Saúde Sexual , Masculino , Humanos , Adolescente , Adulto Jovem , Disfunção Erétil/epidemiologia , Disfunção Erétil/etiologia , Disfunção Erétil/tratamento farmacológico , Ereção Peniana , Inquéritos e Questionários , Neoplasias/complicações
8.
PLoS One ; 17(1): e0262125, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35025924

RESUMO

INTRODUCTION: Public health policy and practice is strengthened by the application of quality evidence to decision making. However, there is limited understanding of how initiatives that support the generation and use of evidence in public health are operationalised. This study examines factors that support the internal functioning of a partnership, the Western Australian Sexual Health and Blood-borne Virus Applied Research and Evaluation Network (SiREN). SiREN aims to build research and evaluation capacity and increase evidence-informed decision making in a public health context. METHODS: This study was informed by systems concepts. It developed a causal loop diagram, a type of qualitative system model that illustrated the factors that influence the internal operation of SiREN. The causal loop diagram was developed through an iterative and participatory process with SiREN staff and management (n = 9) via in-depth semi-structured interviews (n = 4), workshops (n = 2), and meetings (n = 6). RESULTS: Findings identified critical factors that affected the functioning of SiREN. Central to SiREN's ability to meet its aims was its capacity to adapt within a dynamic system. Adaptation was facilitated by the flow of knowledge between SiREN and system stakeholders and the expertise of the team. SiREN demonstrated credibility and capability, supporting development of new, and strengthening existing, partnerships. This improved SiREN's ability to be awarded new funding and enhanced its sustainability and growth. SiREN actively balanced divergent stakeholder interests to increase sustainability. CONCLUSION: The collaborative development of the diagram facilitated a shared understanding of SiREN. Adaptability was central to SiREN achieving its aims. Monitoring the ability of public health programs to adapt to the needs of the systems in which they work is important to evaluate effectiveness. The detailed analysis of the structure of SiREN and how this affects its operation provide practical insights for those interested in establishing a similar project.


Assuntos
Avaliação de Programas e Projetos de Saúde , Participação dos Interessados/psicologia , Política de Saúde , Humanos , Entrevistas como Assunto , Formulação de Políticas
9.
J Med Genet ; 59(10): 965-975, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34930816

RESUMO

BACKGROUND: High-impact pathogenic variants in more than a thousand genes are involved in Mendelian forms of neurodevelopmental disorders (NDD). METHODS: This study describes the molecular and clinical characterisation of 28 probands with NDD harbouring heterozygous AGO1 coding variants, occurring de novo for all those whose transmission could have been verified (26/28). RESULTS: A total of 15 unique variants leading to amino acid changes or deletions were identified: 12 missense variants, two in-frame deletions of one codon, and one canonical splice variant leading to a deletion of two amino acid residues. Recurrently identified variants were present in several unrelated individuals: p.(Phe180del), p.(Leu190Pro), p.(Leu190Arg), p.(Gly199Ser), p.(Val254Ile) and p.(Glu376del). AGO1 encodes the Argonaute 1 protein, which functions in gene-silencing pathways mediated by small non-coding RNAs. Three-dimensional protein structure predictions suggest that these variants might alter the flexibility of the AGO1 linker domains, which likely would impair its function in mRNA processing. Affected individuals present with intellectual disability of varying severity, as well as speech and motor delay, autistic behaviour and additional behavioural manifestations. CONCLUSION: Our study establishes that de novo coding variants in AGO1 are involved in a novel monogenic form of NDD, highly similar to the recently reported AGO2-related NDD.


Assuntos
Proteínas Argonautas , Deficiência Intelectual , Transtornos do Neurodesenvolvimento , Humanos , Aminoácidos/genética , Heterozigoto , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Transtornos do Neurodesenvolvimento/genética , Transtornos do Neurodesenvolvimento/patologia , RNA Mensageiro , Proteínas Argonautas/genética
11.
Artigo em Inglês | MEDLINE | ID: mdl-33654391

RESUMO

BACKGROUND: There is marked variability in the symptoms and outcomes of patients with chronic obstructive pulmonary disease (COPD) which are poorly predicted by spirometry/FEV1%pred. Furthermore, as spirometry requires the performance of potentially distressing respiratory manoeuvres which are to some extent user-effort dependent, there is need for non-invasive and simple-to-perform techniques to identify subtypes of COPD which are more closely related to clinically relevant outcomes. MATERIALS AND METHODS: The inspired sinewave test (IST) sinusoidally modulates the inspired concentration of a tracer gas (N2O) over successive tidal breaths. A single-compartment tidal-ventilation lung model processes the amplitude/phase of the expired N2O sinewave and estimates cardiopulmonary variables including: effective lung volume and indices of ventilatory heterogeneity (VH; ELV180/FRCpleth and ELV180/ELVpred). 83 COPD patients and 53 healthy controls performed the IST test, standard pulmonary function tests (Spirometry, body plethysmography and the single breath test of carbon monoxide uptake), and symptom severity questionnaires (COPD assessment test, CAT; mMRC dyspnoea-scale, mMRC-DS; Cough+Mucus score; C+M score). RESULTS: ELV180/FRCpleth and ELV180/ELVpred were significantly lower in patients with COPD vs healthy participants (0.34±0.11 vs 0.68±0.14 and 0.7±0.27 vs 0.98±0.15, respectively; P<0.05). Multivariable regression analysis demonstrated that ELV180/FRCpleth was a stronger and independent predictor of CAT, mMRC-DS and C+M score vs FEV1%pred. ELV180/ELVpred was a stronger and independent and better predictor of C+M score vs FEV1%pred. Phenotyping patients, based upon ELV180/ELVpred and FRC%pred, uncovered significant symptomatic differences between groups. CONCLUSION: The IST indices of VH were superior and independent predictors of symptom severity vs FEV1%pred and has potential as a non-invasive and simple-to-perform method to stratify patients into subgroups related to clinically relevant features of COPD.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Dispneia , Volume Expiratório Forçado , Humanos , Pulmão , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Testes de Função Respiratória , Espirometria
12.
J Pharmacol Exp Ther ; 376(1): 51-63, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33115824

RESUMO

Asthma is still an incurable disease, and there is a recognized need for novel small-molecule therapies for people with asthma, especially those poorly controlled by current treatments. We previously demonstrated that calcium-sensing receptor (CaSR) negative allosteric modulators (NAMs), calcilytics, uniquely suppress both airway hyperresponsiveness (AHR) and inflammation in human cells and murine asthma surrogates. Here we assess the feasibility of repurposing four CaSR NAMs, which were originally developed for oral therapy for osteoporosis and previously tested in the clinic as a novel, single, and comprehensive topical antiasthma therapy. We address the hypotheses, using murine asthma surrogates, that topically delivered CaSR NAMs 1) abolish AHR; 2) are unlikely to cause unwanted systemic effects; 3) are suitable for topical application; and 4) inhibit airway inflammation to the same degree as the current standard of care, inhaled corticosteroids, and, furthermore, inhibit airway remodeling. All four CaSR NAMs inhibited poly-L-arginine-induced AHR in naïve mice and suppressed both AHR and airway inflammation in a murine surrogate of acute asthma, confirming class specificity. Repeated exposure to inhaled CaSR NAMs did not alter blood pressure, heart rate, or serum calcium concentrations. Optimal candidates for repurposing were identified based on anti-AHR/inflammatory activities, pharmacokinetics/pharmacodynamics, formulation, and micronization studies. Whereas both inhaled CaSR NAMs and inhaled corticosteroids reduced airways inflammation, only the former prevented goblet cell hyperplasia in a chronic asthma model. We conclude that inhaled CaSR NAMs are likely a single, safe, and effective topical therapy for human asthma, abolishing AHR, suppressing airways inflammation, and abrogating some features of airway remodeling. SIGNIFICANCE STATEMENT: Calcium-sensing receptor (CaSR) negative allosteric modulators (NAMs) reduce airway smooth muscle hyperresponsiveness, reverse airway inflammation as efficiently as topical corticosteroids, and suppress airway remodeling in asthma surrogates. CaSR NAMs, which were initially developed for oral therapy of osteoporosis proved inefficacious for this indication despite being safe and well tolerated. Here we show that structurally unrelated CaSR NAMs are suitable for inhaled delivery and represent a one-stop, steroid-free approach to asthma control and prophylaxis.


Assuntos
Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Indanos/uso terapêutico , Naftalenos/uso terapêutico , Fenilpropionatos/uso terapêutico , Quinazolinonas/uso terapêutico , Receptores de Detecção de Cálcio/agonistas , Regulação Alostérica , Animais , Antiasmáticos/efeitos adversos , Antiasmáticos/farmacologia , Brônquios/efeitos dos fármacos , Brônquios/metabolismo , Reposicionamento de Medicamentos , Células HEK293 , Humanos , Indanos/efeitos adversos , Indanos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Naftalenos/efeitos adversos , Naftalenos/farmacologia , Fenilpropionatos/efeitos adversos , Fenilpropionatos/farmacologia , Quinazolinonas/efeitos adversos , Quinazolinonas/farmacologia , Receptores de Detecção de Cálcio/metabolismo
13.
Abdom Radiol (NY) ; 46(4): 1746-1751, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33040173

RESUMO

RATIONALE AND OBJECTIVE: Variation of visual selective attention through the day has been demonstrated in several arenas of human performance, including radiology. It is uncertain whether this variation translates to an identifiable diurnal pattern of error rates for radiology interpretation. The purpose of this study was to attempt to identify particular days of the week and times of the day when radiologists might be most prone to error. MATERIALS AND METHODS: Abdomen/pelvis CT studies containing at least one major error were collected from a 10-year period from the quality assurance (QA) database at our institution. A major error was defined as a missed finding that had altered management in a way potentially detrimental to the patient. The identified studies were categorized by the day of the week and hour of the day that the study was interpreted. Study volume data over this same period was also obtained by day of the week and time of day, so to normalize the data based on case volume. Standard errors of the volume-adjusted error rates were obtained based on the binomial distribution. The null hypothesis of constant error rates over time was tested using a weighted logistic regression model with linear time as predictor. RESULTS: A total of 252 major errors were identified. More errors were made on Monday than on any other day of the week (n = 58). Major error rates increased through the mid to late morning (9 am to 12 pm), and then decreased progressively through the afternoon until 4 pm, when a rise in the error rate was seen. This pattern persisted when error rates were normalized by study volume within each hour. Overall tests of time-constancy of error rates by day and hour were statistically significant (both p-values < 0.001). CONCLUSION: Our study shows that error rates in abdominal CT do seem to vary with time of day and day of the week. During the workweek, error rates were highest in the late morning and at the close of the workday, and greater on Mondays than other days.


Assuntos
Radiologia , Abdome , Ritmo Circadiano , Humanos , Pelve/diagnóstico por imagem , Tomografia Computadorizada por Raios X
14.
15.
Radiology ; 297(3): 556-562, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32990511

RESUMO

Background Gadoxetic acid (GA) has distinctive pharmacokinetic properties with important applications in hepatobiliary imaging. However, there are limited data evaluating the safety of GA administration in patients with impaired kidney function and the incidence of nephrogenic systemic fibrosis (NSF). Purpose To evaluate safety of GA regarding risk of NSF in patients with impaired kidney function. Materials and Methods This retrospective study identified all GA-enhanced MRI (hereafter, GA MRI) examinations performed between July 2008 and December 2019 through a search of the electronic medical record. Serum creatinine values within 180 days or less of each GA MRI examination were retrieved and estimated glomerular filtration rate (eGFR) was calculated. The eGFR value nearest to each MRI examination was used. A separate search in the electronic medical record was also performed to identify patients with NSF. Dermatologists, nephrologists, and nephrologists at our institution were surveyed for any cases of NSF. In patients with NSF, all MRI examinations performed and contrast agents administered to these patients were recorded. Results Overall, 7820 GA MRI examinations were identified, performed in 5351 patients (3022 women and 2329 men). These included 299 examinations (242 patients) with eGFR of 30-44 mL/min/1.73 m2 and 183 examinations (157 patients) with eGFR less than 30 mL/min/1.73 m2. There were 109 examinations (in 94 patients) with eGFR of 15-29 mL/min/1.73 m2, 40 examinations (in 39 patients) with eGFR less than 15 mL/min/1.73 m2, and 34 examinations in 27 patients undergoing hemodialysis. Seventeen patients with eGFR less than 30 mL/min/1.73 m2 or undergoing dialysis underwent GA MRI two or more times. Eighteen patients with biopsy-confirmed NSF were identified, none of whom were exposed to GA. The mean follow-up period for GA MRI examinations performed in patients with severe kidney impairment was 4.2 years (range, 0.2-11.3 years). Conclusion Gadoxetic acid may be safe with respect to nephrogenic systemic fibrosis in this patient population, although further studies are needed to confirm this. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Davenport and Shankar in this issue.


Assuntos
Meios de Contraste/administração & dosagem , Gadolínio DTPA/administração & dosagem , Imageamento por Ressonância Magnética , Dermopatia Fibrosante Nefrogênica/induzido quimicamente , Insuficiência Renal/fisiopatologia , Biópsia , Meios de Contraste/efeitos adversos , Feminino , Gadolínio DTPA/efeitos adversos , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
16.
Exp Physiol ; 105(12): 2250-2253, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32978846

RESUMO

Mechanically and metabolically sensitive thin fibre (group III and IV) muscle afferents are activated during exercise, causing reflex cardiovascular responses that are essential to normal cardiovascular control. Impaired exercise performance in some disease states can be linked to abnormal muscle mechanoreflex and muscle metaboreflex activity. A role for this same afferent feedback in contributing to the hyperpnoea of exercise and the dyspnoea experienced by some patient groups on exercise has recently received increased attention. Evidence is summarised here that supports a role for muscle mechanoreflex and muscle metaboreflex involvement in the human ventilatory response to exercise and also their synergistic interaction with the central chemoreflex during muscular activity. The effects of local muscle training induced attenuation of the human muscle metaboreflex on this synergistic interaction and associated decrease in ventilation is discussed.


Assuntos
Músculo Esquelético/fisiologia , Ventilação Pulmonar/fisiologia , Reflexo/fisiologia , Animais , Pressão Sanguínea/fisiologia , Sistema Cardiovascular/fisiopatologia , Exercício Físico/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Hiperventilação/fisiopatologia , Pulmão/fisiologia , Condicionamento Físico Animal/fisiologia , Respiração
18.
Prehosp Disaster Med ; 35(1): 115-118, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31928564

RESUMO

External aortic compression (EAC) has long been used to control exsanguinating post-partum hemorrhage, but it has only recently been described in the prehospital trauma setting. This paper reports four cases where manual EAC was used during transport to manage life-threatening bleeding, twice from stab wounds, once from ruptured ectopic pregnancy, and once from severe lower-limb trauma. It showed that EAC has life-saving potential in the prehospital setting, but that safety and efficacy during transport requires the use of a hands-free compression device, such as an aortic tourniquet.


Assuntos
Reanimação Cardiopulmonar , Exsanguinação/terapia , Gravidez Ectópica , Pressão , Ferimentos Perfurantes , Adulto , Serviços Médicos de Emergência , Feminino , Humanos , Masculino , Gravidez
19.
J Clin Gastroenterol ; 54(8): 733-740, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31567625

RESUMO

BACKGROUND AND GOAL: The incidence of nonalcoholic fatty liver disease (NAFLD)-associated hepatocellular carcinoma (HCC) is rising. We aimed to characterize risk factors for NAFLD-HCC development. METHODS: We performed a retrospective case-control study of HCC cases from a cohort of NAFLD patients who underwent at least 2 computed tomography scans. NAFLD-HCC cases confirmed on contrast imaging and/or biopsy were included. Controls were NAFLD patients without HCC matched by sex and age. Clinical variables were assessed. Visceral adipose tissue and subcutaneous adipose tissue were measured by computed tomography at 2 timepoints: before HCC diagnosis and at diagnosis. RESULTS: We identified 102 subjects [34 HCC cases, 68 controls, 65% (n=66) males, mean age: 69 y] from 2002 to 2016. Cirrhosis was present in 91%. In multivariate analysis, statin use was protective against HCC [odds ratio (OR)=0.20, 95% confidence interval (CI): 0.07-0.60, P=0.004], while hypertension was a risk factor for HCC (OR=5.80, 95% CI: 2.01-16.75, P=0.001). In multivariate analysis, visceral adipose tissue in males was higher before HCC diagnosis and declined by HCC diagnosis in 86%, which was a significant difference compared with controls (OR=2.78, 95% CI: 1.10-7.44, P=0.04). CONCLUSIONS: In a cohort of NAFLD-HCC patients, statin use was protective against HCC, while hypertension conferred an increased risk. Visceral adiposity at baseline was not a risk factor, but was higher in male patients before HCC development, declining in the majority by HCC diagnosis.


Assuntos
Carcinoma Hepatocelular , Inibidores de Hidroximetilglutaril-CoA Redutases , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Idoso , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/prevenção & controle , Estudos de Casos e Controles , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/prevenção & controle , Masculino , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Estudos Retrospectivos , Fatores de Risco
20.
BMJ Open ; 9(9): e026706, 2019 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-31542735

RESUMO

INTRODUCTION: Partnership models that bring researchers, policymakers and service providers closer together are gaining traction as a strategy to improve public health practice. Yet, there is little evidence of how these models work, or indeed if they do work. The Sexual Health and Blood-borne Virus Applied Research and Evaluation Network (SiREN) is one such model. SiREN is a partnership between researchers, policymakers and service providers that aims to develop the research and evaluation capacity and evidence-informed decision making capability of professionals working to address sexual health and bloodborne virus issues in Western Australia. This study will use a systems approach to identify the mechanisms of action, impacts and outcomes of SiREN and inform the development of evaluation tools. METHODS AND ANALYSIS: Data will be collected from organisational documents, surveys, in-depth interviews and a workshop. It will be analysed using a complex adaptive systems lens and findings will be used to inform the development of a type of qualitative systems model called a causal loop diagram. The causal loop diagram will illustrate the: contextual factors influencing engagement; mechanisms of action; and impacts and outcomes of SiREN. Evaluation tools will then be developed that can be used to assess the indicators identified in the causal loop diagram. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Curtin University Human Research Ethics Committee (approval number: HRE2017-0090). Participants will be free to withdraw from the study at any point and confidentiality will be maintained by de-identifying participant responses in any published or shared data. The findings from this study will be shared in conference presentations, reports, peer-reviewed journals and online through websites and social media.


Assuntos
Fortalecimento Institucional/organização & administração , Colaboração Intersetorial , Formulação de Políticas , Pesquisa em Sistemas de Saúde Pública/métodos , Saúde Sexual , Viroses , Austrália , Patógenos Transmitidos pelo Sangue , Estudos de Avaliação como Assunto , Administração de Serviços de Saúde , Humanos , Projetos de Pesquisa , Integração de Sistemas
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