Publications by authors named "Miguel Arriaga"

7 Publications

  • Page 1 of 1

Membrane curvature and connective fiber alignment in guinea pig round window membrane.

Acta Biomater 2021 Dec 24;136:343-362. Epub 2021 Sep 24.

Department of Mechanical Engineering, Columbia University, 220 Mudd Building 500 West 120th Street, New York, NY 10027, USA; Department of Otolaryngology - Head and Neck Surgery, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA. Electronic address:

The round window membrane (RWM) covers an opening between the perilymph fluid-filled inner ear space and the air-filled middle ear space. As the only non-osseous barrier between these two spaces, the RWM is an ideal candidate for aspiration of perilymph for diagnostics purposes and delivery of medication for treatment of inner ear disorders. Routine access across the RWM requires the development of new surgical tools whose design can only be optimized with a thorough understanding of the RWM's structure and properties. The RWM possesses a layer of collagen and elastic fibers so characterization of the distribution and orientation of these fibers is essential. Confocal and two-photon microscopy were conducted on intact RWMs in a guinea pig model to characterize the distribution of collagen and elastic fibers. The fibers were imaged via second-harmonic-generation, autofluorescence, and Rhodamine B staining. Quantitative analyses of both fiber orientation and geometrical properties of the RWM uncovered a significant correlation between mean fiber orientations and directions of zero curvature in some portions of the RWM, with an even more significant correlation between the mean fiber orientations and linear distance along the RWM in a direction approximately parallel to the cochlear axis. The measured mean fiber directions and dispersions can be incorporated into a generalized structure tensor for use in the development of continuum anisotropic mechanical constitutive models that in turn will enable optimization of surgical tools to access the cochlea. STATEMENT OF SIGNIFICANCE: The Round Window Membrane (RWM) is the only non-osseous barrier separating the middle and inner ear spaces, and thus is an ideal portal for medical access to the cochlea. An understanding of RWM structure and mechanical response is necessary to optimize the design of surgical tools for this purpose. The RWM geometry and the connective fiber orientation and dispersion are measured via confocal and 2-photon microscopy. A region of the RWM geometry is characterized as a hyperbolic paraboloid and another region as a tapered parabolic cylinder. Predominant fiber directions correlate well with directions of zero curvature in the hyperbolic paraboloid region. Overall fiber directions correlate well with position along a line approximately parallel to the central axis of the cochlea's spiral.
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http://dx.doi.org/10.1016/j.actbio.2021.09.036DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8627469PMC
December 2021

Are beliefs and attitudes about COVID-19 associated with self-perceived changes in food consumption? Results from a nationwide survey during lockdown.

Appetite 2021 Sep 7;168:105681. Epub 2021 Sep 7.

EnviHeB Lab, Instituto de Saúde Ambiental, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisbon, Portugal; Laboratório Associado TERRA, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisbon, Portugal; Unbreakable Idea Research, Estrada Nacional 115, Sítio da Caniceira, nº 1, Casarão, 2550-426, Painho, Portugal.

This study aimed to understand how beliefs and attitudes regarding COVID-19 are associated with self-perceived changes in food consumption during lockdown between March 19 and May 2, 2020. We conducted a cross-sectional study with a non-probabilistic weighted sample of the Portuguese population. Data were collected using an online survey and telephone interviews. The association between agreement with sentences about food and COVID-19 and perceived changes in food consumption were assessed by multinomial logistic regression models. Overall, 5858 citizens were included, with a mean age of 38.2 (17.3) years. Exclusive agreement with the belief "SARS-CoV-2 can be transmitted by food" (27.5%) was associated with decreased odds of perceived positive changes (e.g., increased consumption of fruit and vegetables). Agreement only with the attitudinal sentence "I started to consume foods that may protect against COVID-19" (11.9%) was associated with positive perceived consumption changes (e.g., increasing fruit and vegetables, and decreasing soft drinks and snacks). Cumulative agreement (with both sentences; 10.6%) was also associated with mostly positive food consumption changes. Specific beliefs and attitudes regarding COVID-19 and food are associated with self-perceived changes in food consumption. Longitudinal research is needed to understand how beliefs and/or attitudes about the role of food in infectious diseases act as determinants of eating behavior modification.
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http://dx.doi.org/10.1016/j.appet.2021.105681DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8421078PMC
September 2021

Towards an In-Depth Understanding of Physical Activity and Eating Behaviours during COVID-19 Social Confinement: A Combined Approach from a Portuguese National Survey.

Nutrients 2021 Aug 2;13(8). Epub 2021 Aug 2.

Direção-Geral da Saúde, 1049 Lisboa, Portugal.

Rapid worldwide decreases in physical activity (PA), an increase in sedentary behaviour (SB) and poorer dietary patterns have been reported during COVID-19 confinement periods. However, as national variability has been observed, this study sought to describe PA, SB and eating patterns, and to explore their gender as well as other socio-demographic correlates and how they interrelate in a representative sample of Portuguese adults during the COVID-19 first mandatory social confinement. The survey was applied online and by telephone to 5856 adults (mean age = 45.8 years; 42.6% women). The majority reported high (46.0%) or moderate (20.5%) PA levels. Men, younger participants, those with higher education levels and a favourable perception of their financial situation reported higher PA levels, with the opposite pattern for SB. Physical fitness activities and household chores were more reported by women, with more strength training and running activities reported by men. Regarding eating behaviours, 45.1% reported changes, positive (58%) and negative (42%), with 18.2% reporting increases in consumption of fruit, vegetables, and fish and other seafood consumption, while 10.8% (most with lower educational level and less comfortable with their income) reported an increase in consumption of ready-to-eat meals, soft drinks, savoury snacks, and take-away and delivered meals. Two clusters-a health-enhancing vs. risky pattern-emerged through multiple correspondence analysis characterized by co-occurrence of high vs. low PA levels, positive vs. negative eating changes, awareness or not of the COVID-19 PA and dietary recommendations, perceived financial situation, higher vs. lower educational level and time in social confinement. In conclusion, while in social confinement, both positive and negative PA and eating behaviours and trends were displayed, highlighting the role of key sociodemographic correlates contributing to healthy vs. risky patterns. Results may inform future health interventions and policies to be more targeted to those at risk, and also advocate the promotion of PA and healthy eating in an integrated fashion.
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http://dx.doi.org/10.3390/nu13082685DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8399723PMC
August 2021

Active and Healthy Aging After COVID-19 Pandemic in Portugal and Other European Countries: Time to Rethink Strategies and Foster Action.

Front Public Health 2021 2;9:700279. Epub 2021 Jul 2.

Instituto de Saúde Ambiental (ISAMB), Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.

The population aging in Europe imposes challenges to societies that require adaptations and responses at various levels to minimize impacts and figuring out opportunities. Portugal has been committed to the World Health Organization and European Union's values and policy frameworks concerning active and healthy aging. In 2017, an inter-ministerial working group developed the National Strategy for Active and Healthy Aging. In the face of the COVID-19 pandemic that exposed the vulnerabilities of older populations, the launch of the Decade of Healthy Aging 2021-2030 and its baseline report and the 2018 Active Aging Index Analytical Report may constitute an opportunity to strategically think about the aging of the population as a national purpose in Portugal and in the other European countries that face similar challenges.
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http://dx.doi.org/10.3389/fpubh.2021.700279DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8283528PMC
July 2021

Shaping Policy on Chronic Diseases through National Policy Dialogs in CHRODIS PLUS.

Int J Environ Res Public Health 2020 09 28;17(19). Epub 2020 Sep 28.

School for Policy Studies, University of Bristol, Bristol BS8 1TZ, UK.

Policy dialogs are deliberative dialogue that gather policy makers and relevant stakeholders from across disciplines to discuss a topic of mutual interest. They typically serve as a single element in a broader policymaking cycle, either informing the content of new policy or forming a component of policy evaluation and review. In the joint action CHRODIS PLUS, national policy dialogs were conducted in fourteen EU Member States. The aim of the dialogs was to identify new policies or changes to existing policies and legislation that are capable of tackling major risk factors for chronic disease, to strengthen health promotion and prevention programs and to ensure health systems are equipped to respond to priority issues within the chronic diseases field. In this paper, we present the CHRODIS PLUS policy dialog methodology, as well as results and lessons learnt from three national policy dialogs held in Ireland, Portugal and Spain. After discussion of the results, we conclude that the CHRODIS PLUS methodology is an effective mechanism to provoke deliberative discussion around chronic disease prevention and management in different countries. However, it is essential to ensure adequate human and financial resources-as well as political commitment-to accomplish objectives set out during the policy dialogs. We argue that priority-setting across sectors can improve the resilience of health systems and opportunities for investment in Health in All Policies (HiAP), both at European Union and Member State levels.
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http://dx.doi.org/10.3390/ijerph17197113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7579029PMC
September 2020

European Collaborative and Interprofessional Capability Framework for Prevention and Management of Frailty-a consensus process supported by the Joint Action for Frailty Prevention (ADVANTAGE) and the European Geriatric Medicine Society (EuGMS).

Aging Clin Exp Res 2020 Apr 22;32(4):561-570. Epub 2020 Jan 22.

Hospital Universitario de Getafe, Getafe, Spain.

Background: Interprofessional collaborative practice (ICP) is currently recommended for the delivery of high-quality integrated care for older people. Frailty prevention and management are key elements to be tackled on a multi-professional level.

Aim: This study aims to develop a consensus-based European multi-professional capability framework for frailty prevention and management.

Methods: Using a modified Delphi technique, a consensus-based framework of knowledge, skills and attitudes for all professions involved in the care pathway of older people was developed within two consultation rounds. The template for the process was derived from competency frameworks collected in a comprehensive approach from EU-funded projects of the European Commission (EC) supported best practice models for health workforce development.

Results: The agreed framework consists of 25 items structured in 4 domains of capabilities. Content covers the understanding about frailty, skills for screening and assessment as well as management procedures for every profession involved. The majority of items focused on interprofessional collaboration, communication and person-centred care planning.

Discussion: This framework facilitates clarification of professionals' roles and standardizes procedures for cross-sectional care processes. Despite a lack of evidence for educational interventions, health workforce development remains an important aspect of quality assurance in health care systems.

Conclusions: The multi-professional capability framework for frailty prevention and management incorporated interprofessional collaborative practice, consistent with current recommendations by the World Health Organization, Science Advice for Policy by European Academies and the European Commission.
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http://dx.doi.org/10.1007/s40520-019-01455-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7170812PMC
April 2020

In-vitro perforation of the round window membrane via direct 3-D printed microneedles.

Biomed Microdevices 2018 06 8;20(2):47. Epub 2018 Jun 8.

Department of Mechanical Engineering, Columbia University, 220 Mudd Building 500 West 120th Street, New York, NY, 10027, USA.

The cochlea, or inner ear, is a space fully enclosed within the temporal bone of the skull, except for two membrane-covered portals connecting it to the middle ear space. One of these portals is the round window, which is covered by the Round Window Membrane (RWM). A longstanding clinical goal is to reliably and precisely deliver therapeutics into the cochlea to treat a plethora of auditory and vestibular disorders. Standard of care for several difficult-to-treat diseases calls for injection of a therapeutic substance through the tympanic membrane into the middle ear space, after which a portion of the substance diffuses across the RWM into the cochlea. The efficacy of this technique is limited by an inconsistent rate of molecular transport across the RWM. A solution to this problem involves the introduction of one or more microscopic perforations through the RWM to enhance the rate and reliability of diffusive transport. This paper reports the use of direct 3D printing via Two-Photon Polymerization (2PP) lithography to fabricate ultra-sharp polymer microneedles specifically designed to perforate the RWM. The microneedle has tip radius of 500 nm and shank radius of 50 μ m, and perforates the guinea pig RWM with a mean force of 1.19 mN. The resulting perforations performed in vitro are lens-shaped with major axis equal to the microneedle shank diameter and minor axis about 25% of the major axis, with mean area 1670 μ m. The major axis is aligned with the direction of the connective fibers within the RWM. The fibers were separated along their axes without ripping or tearing of the RWM suggesting the main failure mechanism to be fiber-to-fiber decohesion. The small perforation area along with fiber-to-fiber decohesion are promising indicators that the perforations would heal readily following in vivo experiments. These results establish a foundation for the use of Two-Photon Polymerization lithography as a means to fabricate microneedles to perforate the RWM and other similar membranes.
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http://dx.doi.org/10.1007/s10544-018-0287-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6091873PMC
June 2018
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