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1.
Sci Adv ; 10(21): eadk3321, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38781340

RESUMO

Symmetry plays a key role in determining the physical properties of materials. By Neumann's principle, the properties of a material remain invariant under the symmetry operations of the space group to which the material belongs. Continuous phase transitions are associated with a spontaneous reduction in symmetry. Less common are examples where proximity to a continuous phase transition leads to an increase in symmetry. We find signatures of an emergent tetragonal symmetry close to a charge density wave (CDW) bicritical point in a fundamentally orthorhombic material, ErTe3, for which the two distinct CDW phase transitions are tuned via anisotropic strain. We first establish that tension along the a axis favors an abrupt rotation of the CDW wave vector from the c to a axis and infer the presence of a bicritical point where the two continuous phase transitions meet. We then observe a divergence of the nematic elastoresistivity approaching this putative bicritical point, indicating an emergent tetragonality in the critical behavior.

2.
Ear Hear ; 45(1): 23-34, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37599396

RESUMO

OBJECTIVES: The prevalence of hearing loss increases with age. Untreated hearing loss is associated with poorer communication abilities and negative health consequences, such as increased risk of dementia, increased odds of falling, and depression. Nonetheless, evidence is insufficient to support the benefits of universal hearing screening in asymptomatic older adults. The primary goal of the present study was to compare three hearing screening protocols that differed in their level of support by the primary care (PC) clinic and provider. The protocols varied in setting (in-clinic versus at-home screening) and in primary care provider (PCP) encouragement for hearing screening (yes versus no). DESIGN: We conducted a multisite, pragmatic clinical trial. A total of 660 adults aged 65 to 75 years; 64.1% female; 35.3% African American/Black completed the trial. Three hearing screening protocols were studied, with 220 patients enrolled in each protocol. All protocols included written educational materials about hearing loss and instructions on how to complete the self-administered telephone-based hearing screening but varied in the level of support provided in the clinic setting and by the provider. The protocols were as follows: (1) no provider encouragement to complete the hearing screening at home, (2) provider encouragement to complete the hearing screening at home, and (3) provider encouragement and clinical support to complete the hearing screening after the provider visit while in the clinic. Our primary outcome was the percentage of patients who completed the hearing screening within 60 days of a routine PC visit. Secondary outcomes following patient access of hearing healthcare were also considered and consisted of the percentage of patients who completed and failed the screening and who (1) scheduled, and (2) completed a diagnostic evaluation. For patients who completed the diagnostic evaluation, we also examined the percentage of those who received a hearing loss intervention plan by a hearing healthcare provider. RESULTS: All patients who had provider encouragement and support to complete the screening in the clinic completed the screening (100%) versus 26.8% with encouragement to complete the screening at home. For patients who were offered hearing screening at home, completion rates were similar regardless of provider encouragement (26.8% with encouragement versus 22.7% without encouragement); adjusted odds ratio of 1.25 (95% confidence interval 0.80-1.94). Regarding the secondary outcomes, roughly half (38.9-57.1% depending on group) of all patients who failed the hearing screening scheduled and completed a formal diagnostic evaluation. The percentage of patients who completed a diagnostic evaluation and received a hearing loss intervention plan was 35.0% to 50.0% depending on the group. Rates of a hearing loss intervention plan by audiologists ranged from 28.6% to 47.5% and were higher compared with those by otolaryngology providers, which ranged from 15.0% to 20.8% among the groups. CONCLUSIONS: The results of the pragmatic clinical trial showed that offering provider encouragement and screening facilities in the PC clinic led to a significantly higher rate of adherence with hearing screening associated with a single encounter. However, provider encouragement did not improve the significantly lower rate of adherence with home-based hearing screening.


Assuntos
Surdez , Perda Auditiva , Idoso , Feminino , Humanos , Masculino , Pessoal de Saúde , Audição , Perda Auditiva/diagnóstico , Testes Auditivos , Atenção Primária à Saúde
3.
J Xenobiot ; 13(3): 492-499, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37754843

RESUMO

A sharp rise in autism spectrum disorder (ASD) prevalence estimates, beginning in the 1990s, suggested factors additional to genetics were at play. This stimulated increased research investment in nongenetic factors, including the study of environmental chemical exposures, diet, nutrition, lifestyle, social factors, and maternal medical conditions. Consequently, both peer- and non-peer-reviewed bodies of evidence investigating environmental contributors to ASD etiology have grown significantly. The heterogeneity in the design and conduct of this research results in an inconclusive and unwieldy 'virtual stack' of publications. We propose to develop a Web-based tool for Autism Research and the Environment (aWARE) to comprehensively aggregate and assess these highly variable and often conflicting data. The interactive aWARE tool will use an approach for the development of systematic evidence maps (SEMs) to identify and display all available relevant published evidence, enabling users to explore multiple research questions within the scope of the SEM. Throughout tool development, listening sessions and workshops will be used to seek perspectives from the broader autism community. New evidence will be indexed in the tool annually, which will serve as a living resource to investigate the association between environmental factors and ASD.

5.
Healthcare (Basel) ; 10(6)2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35742165

RESUMO

Telemedicine is defined as the delivery of healthcare services at a distance using electronic means. The incorporation of 3D printing in the telemedicine cycle could result in pharmacists designing and manufacturing personalised medicines based on the electronic prescription received. Even with the advantages of telemedicine, numerous barriers to the uptake hinder the wider uptake. Of particular concern is the cyber risk associated with the remote digital transfer of the computer-aided design (CAD) file (acting as the electronic prescription) to the 3D printer and the reproducibility of the resultant printed medicinal products. This proof-of-concept study aimed to explore the application of secure remote 3D printing of model solid dosage forms using the patented technology, DEFEND3D, which is designed to enhance cybersecurity and intellectual property (IP) protection. The size, shape, and colour of the remote 3D-printed model medicinal products were also evaluated to ensure the end-product quality was user-focused. Thermoplastic polyurethane (TPU) and poly(lactic) acid (PLA) were chosen as model polymers due to their flexibility in preventing breakage printing and ease of printing with fused deposition modelling (FDM). Our work confirmed the potential of secure remote 3D (FDM) printing of prototype solid dosage forms resulting in products with good reproducibility, resolution, and quality towards advancements in telemedicine and digital pharmacies. The limitation of the work presented here was the use of model polymers and not pharmaceutically relevant polymers. Further work could be conducted using the same designs chosen in this study with pharmaceutically relevant polymers used in hot-melt extrusion (HME) with shown suitability for FDM 3D printing. However, it should be noted that any challenges that may occur with pharmaceutically relevant polymers are likely to be related to the polymer's printability and printer choice as opposed to the ability of the CAD file to be transferred to the printer remotely.

6.
Ear Hear ; 43(3): 712-721, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34611117

RESUMO

OBJECTIVES: The objective of this study was to understand the functional impact of vestibular dysfunction on balance control in children with hearing loss. The vestibular system is an important contributor to maintaining balance. In adults, vestibular dysfunction is known to lead to unsteadiness and falls. Considerably less is known about the effects of vestibular dysfunction in children with hearing loss. DESIGN: We conducted a systematic review in concordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. We included articles on children with hearing loss who underwent vestibular and balance testing. The Downs and Black checklist was used to assess the risk of bias. RESULTS: A total of 20 articles were included in this systematic review, of which, 17 reported an association between vestibular dysfunction and balance abnormalities in children with hearing loss. Bias (as measured by the Downs and Black Checklist) was a concern, as most studies were nonblinded cohort studies or case series selected through convenience sampling. CONCLUSIONS: Research to date has predominantly found that children with concomitant hearing loss and vestibular impairment tend to perform more poorly on balance measures than either children with hearing loss and normal vestibular function or children with both normal-hearing and normal vestibular function. A standardized approach to assessing both vestibular function and balance would better characterize the impact of vestibular dysfunction in children with hearing loss at the population level.


Assuntos
Surdez , Perda Auditiva Neurossensorial , Perda Auditiva , Doenças Vestibulares , Vestíbulo do Labirinto , Criança , Humanos , Equilíbrio Postural , Doenças Vestibulares/complicações
7.
J Clin Sleep Med ; 18(9): 2261-2271, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34170222

RESUMO

STUDY OBJECTIVES: Poor sleep impedes children's cognitive, emotional, and psychosocial development. Pediatric sleep dysregulation is common, and children who live in communities of low socioeconomic status experience additional risk factors for short sleep duration and poor sleep quality. School-based training in mindfulness and yoga-informed practices can improve children's behavior and well-being, but effects on objectively measured sleep are unknown. METHODS: Effects of a school-based health and mindfulness curriculum, which taught practices such as paced breathing, on sleep and stress were examined in 115 children (49 girls, ages 8 to 11 at baseline). Fifty-eight children in a community of low socioeconomic status received the curriculum twice weekly for 2 years. Fifty-seven children in a socioeconomic status-matched community engaged in their usual physical education class instead. In-home ambulatory polysomnography and perceived social stress were measured in all children at 3 time points: at baseline (ie, prior to curriculum exposure) and at 2 yearly follow-ups. RESULTS: Children receiving the curriculum gained an average of 74 minutes of total sleep time, and 24 minutes of rapid eye movement sleep, per night over the 2-year study period. Children not receiving the curriculum experienced a decrease in total sleep time averaging 64 minutes per night, with no changes in rapid eye movement sleep. Sleep improved within the first 3 months of curriculum exposure, in a dose-dependent fashion. Higher curriculum engagement (eg, using the breathing exercises outside of class) was associated with larger gains in total and rapid eye movement sleep duration. Aggregate within-group changes in social stress were not significant. However, among children receiving the curriculum, those who experienced larger gains in total and rapid eye movement sleep duration also experienced larger increases in perceived social stress. CONCLUSIONS: A school-based health and mindfulness curriculum improved children's objectively measured sleep over 2 years. Social stress did not mediate these effects; instead, mindfulness training may have increased awareness of environmental stressors, while developing tools to reduce stress vulnerability. CITATION: Chick CF, Singh A, Anker LA, et al. A school-based health and mindfulness curriculum improves children's objectively measured sleep: a prospective observational cohort study. J Clin Sleep Med. 2022;18(9):2261-2271.


Assuntos
Atenção Plena , Criança , Currículo , Feminino , Humanos , Polissonografia , Estudos Prospectivos , Sono
8.
IEEE Robot Autom Lett ; 6(2): 1059-1065, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33912664

RESUMO

Standardized acquisitions and diagnoses using robots and AI would potentially increase the general usability and reliability of medical ultrasound. Working towards this prospect, this paper presents the recent developments of a standardized acquisition workflow using a novel dual-probe ultrasound robot, for a project known as intelligent Fetal Imaging and Diagnosis (iFIND). The workflow includes an abdominal surface mapping step to obtain a non-parametric spline surface, a rule-based end-point calculation method to position each individual joint, and a motor synchronization method to achieve a smooth motion towards a target point. The design and implementation of the robot are first presented in this paper and the proposed workflow is then explained in detail with simulation and volunteer experiments performed and analyzed. The closed-form analytical solution to the specific motion planning problem has demonstrated a reliable performance controlling the robot to move towards the expected scanning areas and the calculated proximity of the robot to the surface shows that the robot maintains a safe distance while moving around the abdomen. The volunteer study has successfully demonstrated the reliable working and controllability of the robot in terms of acquiring desired ultrasound views. Our future work will focus on improving the motion planning, and on integrating the proposed standardized acquisition workflow with newly- developed ultrasound image processing methods to obtain diagnostic results in an accurate and consistent way.

9.
Otolaryngol Head Neck Surg ; 165(4): 493-506, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33430703

RESUMO

OBJECTIVE: To describe the impact of vestibular dysfunction on gross motor development in children with hearing loss. DATA SOURCES: MEDLINE (PubMed), Embase (Elsevier), Web of Science (Clarivate), and the Cumulative Index of Nursing and Allied Health Literature (EBSCO). REVIEW METHODS: A systematic review was reported in concordance with the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses). Articles on children with hearing loss who underwent at least 1 instrumented measure of vestibular function and had gross motor milestones assessed were included. The Downs and Black checklist was used to assess risk of bias and methodological quality. RESULTS: Eleven articles were included in the systematic review. Three articles stratified quantitative results of gross motor milestone acquisition by severity of vestibular impairment. Over half of studies were case series published within the last 5 years. This systematic review showed that children with hearing loss and severe, bilateral vestibular dysfunction demonstrate delayed gross motor milestones. However, it was difficult to draw conclusions on whether milder forms of vestibular dysfunction significantly affect gross motor milestone acquisition in children with hearing loss. The reason is that most studies were of low to moderate quality, used different assessment methods, and contained results that were descriptive in nature. CONCLUSIONS: This emerging area would benefit from future research, such as higher-quality studies to assess vestibular function and gross motor milestones. This would allow for better characterization of the impacts of vestibular impairment, especially milder forms, in children with hearing loss.


Assuntos
Desenvolvimento Infantil , Perda Auditiva/complicações , Destreza Motora , Doenças Vestibulares/complicações , Criança , Humanos , Testes de Função Vestibular
10.
J Pediatr ; 231: 68-73, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33359471

RESUMO

OBJECTIVE: To characterize the association between hyperbilirubinemia and a failed newborn hearing screen in infants born at 22-32 weeks of gestation. STUDY DESIGN: We included infants with gestational ages of 22-32 weeks who were discharged from neonatal intensive care units in the US from 2002 to 2017 with available newborn hearing screen results obtained after 34 weeks postmenstrual age. We excluded infants with severe birth asphyxia or craniofacial abnormalities. We identified 95 672 infants from 313 neonatal intensive care units. We used multivariable logistic regression to examine the association between maximum total bilirubin at <21 days postnatal age with failed hearing screen, adjusting for important demographic and clinical risk factors. RESULTS: The median gestational age and birth weight were 30 weeks (IQR, 28-32 weeks) and 1330 g (IQR, 1010-1630 g), respectively. The median maximum total bilirubin was 8.3 mg/dL (IQR, 6.7-10.0 mg/dL), and 5275 infants (6%) failed their newborn hearing screen. On adjusted analysis, each 1 mg/dL increase in maximum total bilirubin was associated with a small, but significant, increase in odds of a failed hearing screen (OR, 1.03; 95% CI, 1.02-1.04). CONCLUSIONS: An increased maximum total bilirubin level was independently associated with hearing screen failure. Further prospective studies are needed to understand whether this increased risk of hearing screen failure translates to increased risk of hearing loss.


Assuntos
Perda Auditiva/etiologia , Testes Auditivos , Hiperbilirrubinemia/complicações , Doenças do Prematuro/etiologia , Triagem Neonatal , Feminino , Perda Auditiva/diagnóstico , Humanos , Hiperbilirrubinemia/diagnóstico , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/diagnóstico , Unidades de Terapia Intensiva Neonatal , Modelos Logísticos , Masculino , Estudos Retrospectivos , Fatores de Risco
11.
Integr Environ Assess Manag ; 16(6): 831-840, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32592520

RESUMO

Neonicotinoids are the most widely used insecticide class worldwide, and unfortunately, the widely used neonicotinoid imidacloprid is problematic for pollinators and other nontarget organisms. These nontarget impacts and the development of resistance prompt the ongoing development and testing of new neonicotinoids. The novel neonicotinoid cycloxaprid was described in 2011 and registered in China in 2015. Studies investigating its use and effect on target and nontarget species are recent and ongoing, and empirical evidence has not yet been collectively considered. Therefore, a systematic review was performed to identify and summarize data associated with target and nontarget, lethal and sublethal impacts of cycloxaprid for its use as a new insecticide. We performed keyword literature searches in Web of Science, PubMed, Academic Search Complete, and Google Scholar and explored citations used in identified articles. The search strategy yielded 66 citations; 25 citations fulfilled eligibility criteria and were included in the review. Under experimental conditions, cycloxaprid reduced populations of plant-feeding insect pests, suppressed populations of sucking and biting insect pests, and affected reproduction, development time, longevity, growth, gene regulation and expression, and phloem-feeding behavior of various life stages of certain insects. Studies focus on pest control efficacy and comparison with imidacloprid. Five nontarget organisms have been evaluated: Apis mellifera, Chrysoperla sinica, Harmonia axyridis, Daphnia magna, and Eisenia fetida. Variation in study design, to date, precludes a metaanalysis. However, these results provide valuable insight into possible effects to target and nontarget arthropods. Because cycloxaprid is a new insecticide, additional research is needed to clarify the mechanism of action of cycloxaprid and its metabolites, and to determine if it harms natural enemies or other nontarget organisms, if resistance develops, and if it exhibits cross-resistance with other insecticides. Although research on target arthropods will inform some effects on nontarget organisms, studies focusing explicitly on impacts to nontarget organisms are needed. Integr Environ Assess Manag 2020;16:831-840. © 2020 SETAC.


Assuntos
Artrópodes , Inseticidas , Animais , Abelhas , China , Compostos Heterocíclicos com 3 Anéis , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Piridinas
12.
Nano Lett ; 20(1): 145-151, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31746607

RESUMO

Multiferroic BiFeO3 (BFO) films with spontaneously formed periodic stripe domains can generate above-gap open circuit voltages under visible light illumination; nevertheless the underlying mechanism behind this intriguing optoelectronic response has not been understood to date. Here, we make contact-free measurements of light-induced currents in epitaxial BFO films via detecting terahertz radiation emanated by these currents, enabling a direct probe of the intrinsic charge separation mechanisms along with quantitative measurements of the current amplitudes and their directions. In the periodic stripe samples, we find that the net photocurrent is dominated by the charge separation across the domain walls, whereas in the monodomain samples the photovoltaic response arises from a bulk shift current associated with the non-centrosymmetry of the crystal. The peak current amplitude driven by the charge separation at the domain walls is found to be 2 orders of magnitude higher than the bulk shift current response, indicating the prominent role of domain walls acting as nanoscale junctions to efficiently separate photogenerated charges in the stripe domain BFO films. These findings show that domain-wall-engineered BFO thin films offer exciting prospects for ferroelectric-based optoelectronics, as well as bias-free strong terahertz emitters.

13.
J Vis Exp ; (143)2019 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-30663700

RESUMO

With the potential for high precision, dexterity, and repeatability, a self-tracked robotic system can be employed to assist the acquisition of real-time ultrasound. However, limited numbers of robots designed for extra-corporeal ultrasound have been successfully translated into clinical use. In this study, we aim to build a bespoke robotic manipulator for extra-corporeal ultrasound examination, which is lightweight and has a small footprint. The robot is formed by five specially shaped links and custom-made joint mechanisms for probe manipulation, to cover the necessary range of motion with redundant degrees of freedom to ensure the patient's safety. The mechanical safety is emphasized with a clutch mechanism, to limit the force applied to patients. As a result of the design, the total weight of the manipulator is less than 2 kg and the length of the manipulator is about 25 cm. The design has been implemented, and simulation, phantom, and volunteer studies have been performed, to validate the range of motion, the ability to make fine adjustments, mechanical reliability, and the safe operation of the clutch. This paper details the design and implementation of the bespoke robotic ultrasound manipulator, with the design and assembly methods illustrated. Testing results to demonstrate the design features and clinical experience of using the system are presented. It is concluded that the current proposed robotic manipulator meets the requirements as a bespoke system for extra-corporeal ultrasound examination and has great potential to be translated into clinical use.


Assuntos
Robótica/instrumentação , Ultrassonografia , Fenômenos Biomecânicos , Desenho Assistido por Computador , Desenho de Equipamento , Humanos , Imagens de Fantasmas , Reprodutibilidade dos Testes
14.
Appl Sci (Basel) ; 9(9): 1900, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-32754346

RESUMO

Robotic systems have great potential to assist ultrasound (US) examination. Currently, the safety management method to limit the force that a US robot can apply mostly relies on force sensing and software-based algorithms. This causes the concern that the potential failure of sensors, electrical systems, or software could lead to patient injuries. In this paper, we investigated a customized spring-loaded ball clutch joint designed for a newly developed US robot to passively limit the force applied. The working mechanism of the clutch was modelled and the kinematic-based analysis was performed to understand the variation of the limited force at different postures of the robot. The triggering torque of the clutch was found to be 3928 N·mm, which results in the mean limited force 22.10 ± 1.76 N at the US probe end based on potential postures. The real measurement of the implemented design indicated that the limited force could be set between 17 and 24 N at the neutral posture depending on the preload. With the maximum preload, the mean limited force was found to be 21.98 ± 0.96 N based on 30 repeated measurements. The practically measured results meet the expectation from the theoretical calculation, and the resulting small variation has indicated a good repeatability of the clutch. Based on this evidence, it is concluded that the proposed clutch meets the design aim that it can limit the force applied within a safe range while at the same time ensuring that the required force is applied at different postures.

15.
Indian J Anaesth ; 62(11): 858-864, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30532321

RESUMO

BACKGROUND AND AIMS: Second-generation supraglottic airway devices are widely used in current anaesthesia practice. This randomised study was undertaken to evaluate and compare laryngeal mask airway: ProSeal laryngeal mask airway (PLMA), Supreme laryngeal mask airway (SLMA) and I-gel. METHODS: Eighty-four adult patients undergoing elective surgery were randomly allocated to three groups: group P (PLMA), group I (I-gel) and group S (SLMA) of 28 patients each. Insertion times, number of insertion attempts, haemodynamic response to insertion, ease of insertion of airway device and gastric tube, oropharyngeal leak pressure (OLP) and pharyngolaryngeal morbidity were assessed. The primary outcome measure was the OLP after successful device insertion. Statistical analysis was performed using Statistical Package for the Social Sciences version 18.0 software using Chi-squared/Fisher's exact test (categorical data) and analysis of variance (continuous data) tests. P < 0.05 was considered statistically significant. RESULTS: The demographic profile of patients was comparable. OLP measured after insertion, 30 minutes later and at the end of surgery differed significantly between the three groups (P < 0.001). The mean OLP was 32.64 ± 4.14 cm·H2O in group P and 29.79 ± 3.70 cm·H2O in group S. In group I, the mean OLP after insertion was 26.71 ± 3.45 cm H2O, which increased to 27.36 ± 3.22 cm H2O at 30 minutes and to 27.50 ± 3.24 cm H2O towards the end of surgery. However, these increases were not statistically significant (P = 0.641). Device insertion time was longest for group P (P = 0.001) and gastric tube insertion time was longest for group I (P = 0.001). Haemodynamic response to insertion and pharyngolaryngeal morbidity were similar with all three devices. CONCLUSION: PLMA provides better sealing pressure but takes longer to insert. I-gel and SLMA have similar sealing pressures. I-gel insertion time is quicker.

16.
J Biomed Mater Res A ; 105(2): 377-388, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27648820

RESUMO

Culture conditions that induce hepatic spheroidal aggregates sustain liver cells with metabolism that mimics in vivo hepatocytes. Here we present an array of elastin-like polypeptide conjugate coating materials (Aminated-ELPs) that are biocompatible, have spheroid-forming capacity, can be coated atop traditional culture surfaces, and maintain structural integrity while ensuring adherence of spheroids over long culture period. The Aminated-ELPs were synthesized either by direct conjugation of ELP and various polyelectrolytes or by conjugating both ELP and various small electrolytes to the reactive polymer poly(2-vinyl-4,4-dimethyl azlactone) (PVDMA). Spheroid morphology, cellular metabolic function, and liver-specific gene expression over the long-term, 20-day culture period were assessed through optical microscopy, measurement of total protein content and albumin and urea production, and quantitative real-time (qRT) PCR. We found that the amine content of the Aminated-ELP coatings dictated the initial hepatocyte attachment, but not the subsequent hepatocyte spheroid formation and their continued attachment. A lower amine content was generally found to sustain higher albumin production by the spheroids. Out of the 19 Aminated-ELP coatings tested, we found that the lysine-containing substrates comprising ELP-polylysine or ELP-PVDMA-butanediamine proved to consistently culture productive spheroidal hepatocytes. We suggest that the incorporation of lysine functional groups in Aminated-ELP rendered more biocompatible surfaces, increasing spheroid attachment and leading to increased liver-specific function. Taken together, the Aminated-ELP array presented here has the potential to create in vitro hepatocyte culture models that mimic in vivo liver functionality and thus, lead to better understanding of liver pathophysiology and superior screening methods for drug efficacy and toxicity. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 377-388, 2017.


Assuntos
Materiais Revestidos Biocompatíveis/química , Elastina/química , Hepatócitos/metabolismo , Esferoides Celulares/metabolismo , Animais , Técnicas de Cultura de Células/métodos , Células Cultivadas , Hepatócitos/citologia , Masculino , Ratos , Ratos Zucker , Esferoides Celulares/citologia , Fatores de Tempo
17.
Am J Pathol ; 187(1): 33-41, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27855279

RESUMO

Hereditary tyrosinemia type 1 (HT1) is an autosomal recessive disease caused by deficiency in fumarylacetoacetate hydrolase, the last enzyme in the tyrosine catabolic pathway. In this study, we investigated whether fumarylacetoacetate hydrolase deficient (FAH-/-) pigs, a novel large-animal model of HT1, develop fibrosis and cirrhosis characteristic of the human disease. FAH-/- pigs were treated with the protective drug 2-(2-nitro-4-trifluoromethylbenzoyl)-1, 3 cyclohexandione (NTBC) at a dose of 1 mg/kg per day initially after birth. After 30 days, they were assigned to one of three groups based on dosing of NTBC. Group 1 received ≥0.2 mg/kg per day, group 2 cycled on/off NTBC (0.05 mg/kg per day × 1 week/0 mg/kg per day × 3 weeks), and group 3 received no NTBC thereafter. Pigs were monitored for features of liver disease. Animals in group 1 continued to have weight gain and biochemical analyses comparable to wild-type pigs. Animals in group 2 had significant cessation of weight gain, abnormal biochemical test results, and various grades of fibrosis and cirrhosis. No evidence of hepatocellular carcinoma was detected. Group 3 animals declined rapidly, with acute liver failure. In conclusion, the FAH-/- pig is a large-animal model of HT1 with clinical characteristics that resemble the human phenotype. Under conditions of low-dose NTBC, FAH-/- pigs developed liver fibrosis and portal hypertension, and thus may serve as a large-animal model of chronic liver disease.


Assuntos
Tirosinemias/patologia , Animais , Doença Crônica , Modelos Animais de Doenças , Técnicas de Imagem por Elasticidade , Feminino , Heptanoatos/metabolismo , Humanos , Hidrolases/deficiência , Hidrolases/metabolismo , Rim/metabolismo , Rim/patologia , Fígado/patologia , Fígado/fisiopatologia , Cirrose Hepática/patologia , Espectroscopia de Ressonância Magnética , Masculino , Redes e Vias Metabólicas , Fenótipo , Pressão na Veia Porta , Sus scrofa , Tirosina/metabolismo , Aumento de Peso
18.
Vasc Health Risk Manag ; 4(4): 893-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19066007

RESUMO

AIM: The rheological properties of erythrocytes are impaired in diabetes mellitus, especially because of changes in their membrane lipid composition.The aim of this study was to determine and examine the relationship between red blood cell (RBC) membrane and serum lipid composition in type II diabetes subjects with and without nephropathy. METHODS: Trinidadian subjects aged 18-65 years were recruited for the study regardless of gender and ethnicity. Fasting blood samples were collected from 60 subjects of whom 20 were healthy individuals, 20 had type II diabetes without complications, and 20 were type II diabetics with nephropathy. Weight, height, waist/hip ratio, and blood pressure were recorded. All the blood samples were analysed to determine the serum lipid concentration, membrane lipid composition and plasma glucose concentration. RESULTS: The body mass index and the systolic blood pressure of the diabetics (28.17 +/- 4.98 kg/m2, 153.21 +/- 22.10 mmHg) and those with nephropathy (25.87 +/- 4.68, 158.60 +/- 22.49 mmHg) were higher when compared with controls (24.67 +/- 5.18, 119.15 +/- 13.03 mmHg). The diabetic (175.89 +/- 102.73 microg/mgprotein) and diabetic nephropathy (358.80 +/- 262.66) subjects showed significantly higher levels of RBC membrane cholesterol compared with controls (132.27 +/- 66.47). The membrane phospholipids, protein and Na+/K+ATPase concentrations were altered in diabetics and diabetic nephropathy patients when compared with controls. The trends of increased serum cholesterol and decreased high-density lipoprotein in diabetics and diabetic nephropathy patients were noted as compared with controls but they are not significant as expected. The low-density lipoprotein cholesterol was significantly higher in diabetics when compared with diabetic nephropathy and control subjects. CONCLUSIONS: Our data suggest that there is a relationship between RBC membrane and serum lipid composition in subjects with type II diabetes with and without nephropathy. This relationship shows that diet and lifestyle plays a significant role in the alterations of the lipids both in serum and RBC membrane. The membrane and serum lipid composition may be used as possible indicators for type II diabetic patients with and without nephropathy to control their diet in the beginning stages to prevent them from further complications.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Nefropatias Diabéticas/sangue , Membrana Eritrocítica/química , Lipídeos de Membrana/sangue , Adolescente , Adulto , Idoso , Glicemia/metabolismo , Pressão Sanguínea , Índice de Massa Corporal , Estudos de Casos e Controles , Colesterol/sangue , Diabetes Mellitus Tipo 2/etnologia , Diabetes Mellitus Tipo 2/fisiopatologia , Nefropatias Diabéticas/etnologia , Nefropatias Diabéticas/fisiopatologia , Dieta , Humanos , Estilo de Vida , Pessoa de Meia-Idade , Fosfolipídeos/sangue , Comportamento de Redução do Risco , ATPase Trocadora de Sódio-Potássio/sangue , Trinidad e Tobago , Relação Cintura-Quadril , Adulto Jovem
19.
J Natl Med Assoc ; 98(7): 1160-70, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16895288

RESUMO

PURPOSE: To explore attitudes and perceptions of obesity, and identify preferences for weight-management interventions by African-American and Caucasian women who were followed in general internal medicine clinics. PROCEDURE: Surveys exploring these issues were mailed to African-American (n=240) and Caucasian (n=240) women with a BMI of > or =30. MAIN FINDINGS: Caucasian women felt past weight-loss efforts were helped by weight-loss programs significantly more than African-American women (P<0.001); African-American women were more likely to feel that their cultural background contributed to their weight gain than did Caucasian women (P=0.001). African-American women expressed a higher need for one-on-one counseling with their physician (P<0.001) as well as group meetings with the dietician, physician and other women (P=0.004) than did Caucasian women. African-American women also felt it was more important for weight-loss programs to have information on food common to their culture than did Caucasian women (P<0.001). CONCLUSIONS: Differences in cultural background and preferences about weight loss interventions have important policy implications for how the U.S. healthcare system provides care to an ever-increasing multicultural population with a national epidemic such as obesity.


Assuntos
Negro ou Afro-Americano/psicologia , Obesidade/psicologia , Obesidade/terapia , Atenção Primária à Saúde , Redução de Peso , População Branca/psicologia , Saúde da Mulher , Índice de Massa Corporal , Comparação Transcultural , Feminino , Humanos , Pessoa de Meia-Idade
20.
J Transcult Nurs ; 17(3): 290-7, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16757669

RESUMO

Designing culturally relevant weight-reduction programs requires understanding of ethnic variations and illness beliefs. Preliminary data on the values and beliefs about obesity and weight reduction were obtained from women of different ethnic/racial backgrounds. Purposive sampling was used to recruit African American (AA) and Caucasian (C) women with a body mass index (BMI)>or= 30 from the general internal medicine clinics of a large tertiary care facility. Four focus groups (2 with AA women and 2 with C women) consisting of a total of 20 subjects were conducted in a 2-month period. AA women cited culture specific barriers to weight loss more so than did C women. AA women and C women also differed on how health care professionals could help them with weight loss. These findings have implications for nursing's role in the design of culturally relevant weight-loss programs.


Assuntos
Atitude Frente a Saúde/etnologia , Negro ou Afro-Americano/psicologia , Obesidade/etnologia , Obesidade/psicologia , Redução de Peso/etnologia , População Branca/psicologia , Adulto , Feminino , Grupos Focais , Humanos , Medicina Interna , Pessoa de Meia-Idade , Relações Médico-Paciente , Projetos Piloto , Saúde da Mulher/etnologia
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