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1.
Biomolecules ; 14(3)2024 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-38540696

RESUMEN

Calcification is a process of accumulation of calcium in tissues and deposition of calcium salts by the crystallization of PO43- and ionized calcium (Ca2+). It is a crucial process in the development of bones and teeth. However, pathological calcification can occur in almost any soft tissue of the organism. The better studied is vascular calcification, where calcium salts can accumulate in the intima or medial layer or in aortic valves, and it is associated with higher mortality and cardiovascular events, including myocardial infarction, stroke, aortic and peripheral artery disease (PAD), and diabetes or chronic kidney disease (CKD), among others. The process involves an intricate interplay of different cellular components, endothelial cells (ECs), vascular smooth muscle cells (VSMCs), fibroblasts, and pericytes, concurrent with the activation of several signaling pathways, calcium, Wnt, BMP/Smad, and Notch, and the regulation by different molecular mediators, growth factors (GFs), osteogenic factors and matrix vesicles (MVs). In the present review, we aim to explore the cellular players, molecular pathways, biomarkers, and clinical treatment strategies associated with vascular calcification to provide a current and comprehensive overview of the topic.


Asunto(s)
Calcio , Calcificación Vascular , Humanos , Calcio/metabolismo , Células Endoteliales/metabolismo , Sales (Química) , Transducción de Señal , Calcificación Vascular/metabolismo , Células Cultivadas
2.
Nat Ecol Evol ; 8(3): 536-551, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38200368

RESUMEN

The arrangement and morphology of the vertebrate skull reflect functional and ecological demands, making it a highly adaptable structure. However, the fundamental developmental and macroevolutionary mechanisms leading to different vertebrate skull phenotypes remain unclear. Here we exploit the morphological diversity of squamate reptiles to assess the developmental and evolutionary patterns of skull variation and covariation in the whole head. Our geometric morphometric analysis of a complex squamate ontogenetic dataset (209 specimens, 169 embryos, 44 species), covering stages from craniofacial primordia to fully ossified bones, reveals that morphological differences between snake and lizard skulls arose gradually through changes in spatial relationships (heterotopy) followed by alterations in developmental timing or rate (heterochrony). Along with dynamic spatiotemporal changes in the integration pattern of skull bone shape and topology with surrounding brain tissues and sensory organs, we identify a relatively higher phenotypic integration of the developing snake head compared with lizards. The eye, nasal cavity and Jacobson's organ are pivotal in skull morphogenesis, highlighting the importance of sensory rearrangements in snake evolution. Furthermore, our findings demonstrate the importance of early embryonic, ontogenetic and tissue interactions in shaping craniofacial evolution and ecological diversification in squamates, with implications for the nature of cranio-cerebral relations across vertebrates.


Asunto(s)
Cabeza , Cráneo , Animales , Cráneo/anatomía & histología , Osteogénesis
3.
BMJ Open ; 13(12): e071315, 2023 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-38070889

RESUMEN

INTRODUCTION: Cerebral palsy (CP) is one of the leading causes of childhood disability globally with a high burden in low-income and middle-income countries (LMICs). Preliminary findings from the global LMIC CP Register (GLM CPR) suggest that the majority of CP in LMICs are due to potentially preventable causes. Such data are lacking in the Latin American region. Generating comparable epidemiological data on CP from this region could enable translational research and services towards early diagnosis and early intervention. We aim to establish a Latin American multicountry network and online data repository of CP called Latin American Cerebral Palsy Register (LATAM-CPR). METHODS AND ANALYSIS: The LATAM-CPR will be modelled after the GLM CPR and will support new and emerging Latin American CP registers following a harmonised protocol adapted from the GLM CPR and piloted in Argentina (ie, Argentine Register of Cerebral Palsy). Both population-based and institution-based surveillance mechanisms will be adopted for registration of children with CP aged less than 18 years to the participating CP registers. The data collection form of the LATAM-CPR will include risk factors, clinical profile, rehabilitation, socioeconomical status of children with CP. Descriptive data on the epidemiology of CP from each participating country will be reported, country-specific and regional data will be compared. ETHICS AND DISSEMINATION: Individual CP registers have applied ethics approval from respective national human research ethics committees (HREC) and/or institutional review boards prior to the establishment and inclusion into the LATAM-CPR. Ethical approval for LATAM-CPR has already been obtained from the HREC in the two countries that started (Argentina and Mexico). Findings will be disseminated and will be made publicly available through peer-reviewed publications, conference presentations and social media communications.


Asunto(s)
Parálisis Cerebral , Personas con Discapacidad , Niño , Humanos , América Latina/epidemiología , Parálisis Cerebral/rehabilitación , Recolección de Datos , Países en Desarrollo
4.
PeerJ ; 11: e16542, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38144194

RESUMEN

Unlike the majority of sauropsids, which breathe primarily through costal and abdominal muscle contractions, extant crocodilians have evolved the hepatic piston pump, a unique additional ventilatory mechanism powered by the diaphragmaticus muscle. This muscle originates from the bony pelvis, wrapping around the abdominal viscera, extending cranially to the liver. The liver then attaches to the caudal margin of the lungs, resulting in a sub-fusiform morphology for the entire "pulmo-hepatic-diaphragmatic" structure. When the diaphragmaticus muscle contracts during inspiration, the liver is pulled caudally, lowering pressure in the thoracolumbar cavity, and inflating the lungs. It has been established that the hepatic piston pump requires the liver to be displaced to ventilate the lungs, but it has not been determined if the lungs are freely mobile or if the pleural tissues stretch ventrally. It has been hypothesized that the lungs are able to slide craniocaudally with the liver due to the smooth internal ceiling of the thoracolumbar cavity. We assess this through ultrasound video and demonstrate quantitatively and qualitatively that the pulmonary tissues are sliding craniocaudally across the interior thoracolumbar ceiling in actively ventilating live juvenile, sub-adult, and adult individuals (n = 7) of the American alligator (Alligator mississippiensis) during both natural and induced ventilation. The hepatic piston is a novel ventilatory mechanism with a relatively unknown evolutionary history. Questions related to when and under what conditions the hepatic piston first evolved have previously been left unanswered due to a lack fossilized evidence for its presence or absence. By functionally correlating specific characters in the axial skeleton to the hepatic piston, these osteological correlates can be applied to fossil taxa to reconstruct the evolution of the hepatic piston in extinct crocodylomorph archosaurs.


Asunto(s)
Caimanes y Cocodrilos , Humanos , Animales , Respiración , Diafragma , Músculos Abdominales , Hígado/diagnóstico por imagen
5.
Gels ; 9(11)2023 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-37998975

RESUMEN

Bone and cartilage tissue play multiple roles in the organism, including kinematic support, protection of organs, and hematopoiesis. Bone and, above all, cartilaginous tissues present an inherently limited capacity for self-regeneration. The increasing prevalence of disorders affecting these crucial tissues, such as bone fractures, bone metastases, osteoporosis, or osteoarthritis, underscores the urgent imperative to investigate therapeutic strategies capable of effectively addressing the challenges associated with their degeneration and damage. In this context, the emerging field of tissue engineering and regenerative medicine (TERM) has made important contributions through the development of advanced hydrogels. These crosslinked three-dimensional networks can retain substantial amounts of water, thus mimicking the natural extracellular matrix (ECM). Hydrogels exhibit exceptional biocompatibility, customizable mechanical properties, and the ability to encapsulate bioactive molecules and cells. In addition, they can be meticulously tailored to the specific needs of each patient, providing a promising alternative to conventional surgical procedures and reducing the risk of subsequent adverse reactions. However, some issues need to be addressed, such as lack of mechanical strength, inconsistent properties, and low-cell viability. This review describes the structure and regeneration of bone and cartilage tissue. Then, we present an overview of hydrogels, including their classification, synthesis, and biomedical applications. Following this, we review the most relevant and recent advanced hydrogels in TERM for bone and cartilage tissue regeneration.

6.
Medicina (Kaunas) ; 59(10)2023 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-37893470

RESUMEN

The RANK-RANKL-OPG system is a complex signaling pathway that plays a critical role in bone metabolism, mammary epithelial cell development, immune function, and cancer. RANKL is a ligand that binds to RANK, a receptor expressed on osteoclasts, dendritic cells, T cells, and other cells. RANKL signaling promotes osteoclast differentiation and activation, which leads to bone resorption. OPG is a decoy receptor that binds to RANKL and inhibits its signaling. In cancer cells, RANKL expression is often increased, which can lead to increased bone resorption and the development of bone metastases. RANKL-neutralizing antibodies, such as denosumab, have been shown to be effective in the treatment of skeletal-related events, including osteoporosis or bone metastases, and cancer. This review will provide a comprehensive overview of the functions of the RANK-RANKL-OPG system in bone metabolism, mammary epithelial cells, immune function, and cancer, together with the potential therapeutic implications of the RANK-RANKL pathway for cancer management.


Asunto(s)
Neoplasias Óseas , Resorción Ósea , Humanos , Receptor Activador del Factor Nuclear kappa-B/metabolismo , Osteoprotegerina , Ligando RANK , Osteoclastos , Neoplasias Óseas/secundario , Resorción Ósea/metabolismo , Homeostasis
7.
Anat Rec (Hoboken) ; 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37528640

RESUMEN

The vertebrate respiratory system is challenging to study. The complex relationship between the lungs and adjacent tissues, the vast structural diversity of the respiratory system both within individuals and between taxa, its mobility (or immobility) and distensibility, and the difficulty of quantifying and visualizing functionally important internal negative spaces have all impeded descriptive, functional, and comparative research. As a result, there is a relative paucity of three-dimensional anatomical information on this organ system in all vertebrate groups (including humans) relative to other regions of the body. We present some of the challenges associated with evaluating and visualizing the vertebrate respiratory system using computed and micro-computed tomography and its subsequent digital segmentation. We discuss common mistakes to avoid when imaging deceased and live specimens and various methods for merging manual and threshold-based segmentation approaches to visualize pulmonary tissues across a broad range of vertebrate taxa, with a particular focus on sauropsids (reptiles and birds). We also address some of the recent work in comparative evolutionary morphology and medicine that have used these techniques to visualize respiratory tissues. Finally, we provide a clinical study on COVID-19 in humans in which we apply modeling methods to visualize and quantify pulmonary infection in the lungs of human patients.

8.
Gels ; 9(8)2023 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-37623072

RESUMEN

The growing impact of infections and the rapid emergence of antibiotic resistance represent a public health concern worldwide. The exponential development in the field of biomaterials and its multiple applications can offer a solution to the problems that derive from these situations. In this sense, antimicrobial hydrogels represent a promising opportunity with multiple translational expectations in the medical management of infectious diseases due to their unique physicochemical and biological properties as well as for drug delivery in specific areas. Hydrogels are three-dimensional cross-linked networks of hydrophilic polymers that can absorb and retain large amounts of water or biological fluids. Moreover, antimicrobial hydrogels (AMH) present good biocompatibility, low toxicity, availability, viscoelasticity, biodegradability, and antimicrobial properties. In the present review, we collect and discuss the most promising strategies in the development of AMH, which are divided into hydrogels with inherent antimicrobial activity and antimicrobial agent-loaded hydrogels based on their composition. Then, we present an overview of the main translational applications: wound healing, tissue engineering and regeneration, drug delivery systems, contact lenses, 3D printing, biosensing, and water purification.

9.
J Exp Zool A Ecol Integr Physiol ; 339(6): 602-614, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37260090

RESUMEN

Understanding the locomotor characteristics of early diverging ground-walking chameleons (members of the genera Brookesia, Rhampholeon, Palleon, and Rieppeleon) can help to explain how their unique morphology is adapted to fit their environment and mode of life. However, nearly all quantitative studies of chameleon locomotion thus far have focused on the larger "true arboreal" chameleons. We investigated kinematics and spatiotemporal gait characteristics of the Brown Leaf Chameleon (Brookesia superciliaris) on different substrates and compared them with true arboreal chameleons, nonchameleon lizards, and other small arboreal animals. Brookesia exhibits a combination of locomotor traits, some of which are traditionally arboreal, others more terrestrial, and a few that are very unusual. Like other chameleons, Brookesia moved more slowly on narrow dowels than on broad planks (simulating arboreal and terrestrial substrates, respectively), and its speed was primarily regulated by stride frequency rather than stride length. While Brookesia exhibits the traditionally arboreal trait of a high degree of humeral protraction at the beginning of stance, unlike most arboreal tetrapods, it uses smaller shoulder and hip excursions on narrower substrates, possibly reflecting its more terrestrial habits. When moving at very slow speeds, Brookesia often adopts an unusual footfall pattern, lateral-sequence lateral-couplets. Because Brookesia is a member of one of the earliest-diverging groups of chameleons, its locomotion may provide a good model for an intermediate stage in the evolution of arboreal chameleons. Thus, the transition to a fully arboreal way of life in "true arboreal" chameleons may have involved changes in spatiotemporal and kinematic characteristics as well as morphology.


Asunto(s)
Lagartos , Locomoción , Animales , Marcha/fisiología , Lagartos/fisiología , Locomoción/fisiología
11.
Lancet Reg Health Am ; 16: 100366, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36185968

RESUMEN

Background: COVID-19 vaccines have proven safe and efficacious in reducing severe illness and death. Cuban protein subunit vaccine Abdala has shown safety, tolerability and efficacy (92·3% [95% CI: 85·7‒95·8]) against SARS-CoV-2 in clinical trials. This study aimed to estimate Abdala's real-world vaccine effectiveness (VE). Methods: This retrospective cohort study in Havana analyzed Cuban Ministry of Public Health databases (May 12-August 31, 2021) to assess VE in preventing severe illness and death from COVID-19 (primary outcomes). Cox models accounting for time-varying vaccination status and adjusting by demographics were used to estimate hazard ratios. A subgroup analysis by age group and a sensitivity analysis including a subgroup of tested persons (qRT-PCR) were conducted. Daily cases and deaths were modelled accounting for different VE. Findings: The study included 1 355 638 persons (Mean age: 49·5 years [SD: 18·2]; 704 932 female [52·0%]; ethnicity data unavailable): 1 324 vaccinated (partially/fully) and 31 433 unvaccinated. Estimated VE against severe illness was 93·3% (95% CI: 92·1-94·3) in partially- vaccinated and 98·2% (95% CI: 97·9-98·5) in fully-vaccinated and against death was 94·1% (95% CI: 92·5-95·4) in partially-vaccinated and 98·7% (95% CI: 98·3-99·0) in fully-vaccinated. VE exceeded 92·0% in all age groups. Daily cases and deaths during the study period corresponded to a VE above 90%, as predicted by models. Interpretation: The Cuban Abdala protein subunit vaccine was highly effective in preventing severe illness and death from COVID-19 under real-life conditions. Funding: Cuban Ministry of Public Health. Genetic Engineering and Biotechnology Centre.

12.
Biosensors (Basel) ; 12(7)2022 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-35884317

RESUMEN

Here we report a novel labeling strategy for electrochemical aptasensors based on enzymatic marking via supramolecular host-guest interactions. This approach relies on the use of an adamantane-modified target-responsive hairpin DNA aptamer as an affinity bioreceptor, and a neoglycoconjugate of ß-cyclodextin (CD) covalently attached to a redox enzyme as a labeling element. As a proof of concept, an amperometric aptasensor for a carcinoembryonic antigen was assembled on screen-printed carbon electrodes modified with electrodeposited fern-like gold nanoparticles/graphene oxide and, by using a horseradish peroxidase-CD neoglycoenzyme as a biocatalytic redox label. This aptasensor was able to detect the biomarker in the concentration range from 10 pg/mL to 1 ng/mL with a high selectivity and a low detection limit of 3.1 pg/mL in human serum samples.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Nanopartículas del Metal , Aptámeros de Nucleótidos/química , Técnicas Electroquímicas , Electrodos , Oro/química , Humanos , Límite de Detección , Nanopartículas del Metal/química
13.
Anat Rec (Hoboken) ; 305(10): 3037-3054, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35377558

RESUMEN

We imaged the lungs of five Cuvier's dwarf caiman (Paleosuchus palpebrosus) via computed tomography (CT) and micro-computed tomography (µCT) and compared these data to the lungs of the American alligator (Alligator mississippiensis). These data demonstrate anatomical commonalities between the lungs of P. palpebrosus and A. mississippiensis, and a few notable differences. The structural similarities are (a) a proximally narrow, distally widened, hook-shaped primary bronchus; (b) a cervical ventral bronchus that branches of the primary bronchus and immediately makes a hairpin turn toward the apex of the lung; (c) a sequential series of dorsobronchi arising from the primary bronchus caudal to the cervical ventral bronchus; (d) intraspecifically highly variable medial sequence of secondary airways; (e) sac-like laterobronchi; and (f) grossly dead-ended caudal group bronchi in the caudal and ventral aspects of the lung. The primary differences between the two taxa are in the overall number of large bronchi (fewer in P. palpebrosus), and the number of branches that contribute to the cardiac regions. Imaging data of both a live and deceased specimen under varying states (postprandial, fasting, total lung capacity, open to atmosphere) indicate that the caudal margin and position of the lungs shift craniocaudally relative to the vertebral column. These imaging data suggest that the smooth thoracic ceiling may be correlated to visceral movement during ventilation, but this hypothesis warrants validation. These results provide the scaffolding for future comparisons between crocodilians, for generating preliminary reconstructions of the ancestral crocodilian bronchial tree, and establishing new hypotheses of bronchial homology across Archosauria.


Asunto(s)
Caimanes y Cocodrilos , Animales , Pulmón/diagnóstico por imagen , Microtomografía por Rayos X
14.
Dev Dyn ; 251(9): 1576-1612, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-34927301

RESUMEN

BACKGROUND: Squamate reptiles (lizards, snakes, and amphisbaenians) exhibit incredible diversity in their locomotion, behavior, morphology, and ecological breadth. Although they often are used as models of locomotor diversity, surprisingly little attention has been given to muscle development in squamate reptiles. In fact, the most detailed examination was conducted almost 80 years ago and solely focused on the proximal limb regions. Herein, we present forelimb and hindlimb muscle morphogenesis data for three lizard species with different locomotion and feeding strategies: the desert grassland whiptail lizard, the central bearded dragon, and the veiled chameleon. This study fills critical gaps in our understanding of muscle morphogenesis in squamate reptiles and presents a comparative and temporospatial analysis of muscle development. RESULTS: Our results reveal a conserved pattern of early muscle development among lizards with different adult morphologies and ecologies. The variations that exist are concentrated in distal regions, particularly the specialized autopodia of chameleons, where differentiation of muscles associated with the digits is delayed. CONCLUSIONS: The chameleon autopod provides an example of major evolutionary modifications to the skeleton with only minor disruption of the conserved order and pattern of limb muscle development. This robustness of muscle patterning facilitates the evolution of extreme yet functional phenotypes.


Asunto(s)
Lagartos , Animales , Evolución Biológica , Extremidades , Miembro Anterior/anatomía & histología , Miembro Anterior/fisiología , Lagartos/genética , Filogenia , Serpientes
15.
Integr Org Biol ; 3(1): obab033, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34877473

RESUMEN

Every stage of organismal life history is being challenged by global warming. Many species are already experiencing temperatures approaching their physiological limits; this is particularly true for ectothermic species, such as lizards. Embryos are markedly sensitive to thermal insult. Here, we demonstrate that temperatures currently experienced in natural nesting areas can modify gene expression levels and induce neural and craniofacial malformations in embryos of the lizard Anolis sagrei. Developmental abnormalities ranged from minor changes in facial structure to significant disruption of anterior face and forebrain. The first several days of postoviposition development are particularly sensitive to this thermal insult. These results raise new concern over the viability of ectothermic species under contemporary climate change. Herein, we propose and test a novel developmental hypothesis that describes the cellular and developmental origins of those malformations: cell death in the developing forebrain and abnormal facial induction due to disrupted Hedgehog signaling. Based on similarities in the embryonic response to thermal stress among distantly related species, we propose that this developmental hypothesis represents a common embryonic response to thermal insult among amniote embryos. Our results emphasize the importance of adopting a broad, multidisciplinary approach that includes both lab and field perspectives when trying to understand the future impacts of anthropogenic change on animal development.

16.
Viruses ; 12(11)2020 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-33228135

RESUMEN

Serpentoviruses are an emerging group of nidoviruses known to cause respiratory disease in snakes and have been associated with disease in other non-avian reptile species (lizards and turtles). This study describes multiple episodes of respiratory disease-associated mortalities in a collection of juvenile veiled chameleons (Chamaeleo calyptratus). Histopathologic lesions included rhinitis and interstitial pneumonia with epithelial proliferation and abundant mucus. Metagenomic sequencing detected coinfection with two novel serpentoviruses and a novel orthoreovirus. Veiled chameleon serpentoviruses are most closely related to serpentoviruses identified in snakes, lizards, and turtles (approximately 40-50% nucleotide and amino acid identity of ORF1b). Veiled chameleon orthoreovirus is most closely related to reptilian orthoreoviruses identified in snakes (approximately 80-90% nucleotide and amino acid identity of the RNA-dependent RNA polymerase). A high prevalence of serpentovirus infection (>80%) was found in clinically healthy subadult and adult veiled chameleons, suggesting the potential for chronic subclinical carriers. Juvenile veiled chameleons typically exhibited a more rapid progression compared to subadults and adults, indicating a possible age association with morbidity and mortality. This is the first description of a serpentovirus infection in any chameleon species. A causal relationship between serpentovirus infection and respiratory disease in chameleons is suspected. The significance of orthoreovirus coinfection remains unknown.


Asunto(s)
Coinfección/veterinaria , Lagartos/virología , Enfermedades Pulmonares Intersticiales/veterinaria , Nidovirales/patogenicidad , Orthoreovirus/patogenicidad , Infecciones por Reoviridae/veterinaria , Animales , Animales de Zoológico/virología , Coinfección/virología , Brotes de Enfermedades/veterinaria , Femenino , Enfermedades Pulmonares Intersticiales/virología , Masculino , Metagenómica , Nidovirales/genética , Orthoreovirus/genética , Prevalencia
18.
Orthop Traumatol Surg Res ; 106(2): 325-328, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32192934

RESUMEN

Osteochondral injuries of the metacarpal head require anatomical restoration to prevent limitations in range of motion and osteoarthritis. Osteochondral bone grafting is a viable option, especially in younger patients. Central injuries allow for different types of grafting, but when the injured area is on the lateral portion of the metacarpal head, the graft must include both a cortical and a cartilaginous portion. We present here the pearls and pitfalls in the surgical technique of chondrocostal grating from the 6th rib and an example of its use within a case of comminuted fracture of the metacarpal head. This technique provides a graft with cortical bone that allows for a stable fixation, with few complications during its harvesting. The graft is viable in the long-term and shows similar magnetic resonance intensities in comparison to hand cartilage.


Asunto(s)
Fracturas Conminutas , Fracturas Intraarticulares , Huesos del Metacarpo , Trasplante Óseo , Humanos , Huesos del Metacarpo/diagnóstico por imagen , Huesos del Metacarpo/cirugía , Rango del Movimiento Articular
19.
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1408484

RESUMEN

RESUMEN El peligro de la ocurrencia de endemia por la COVID-19 es una preocupación del gobierno y epidemiólogos cubanos, pero conocer alguna métrica que influya en su surgimiento es de gran utilidad para evitarla. El objetivo de este trabajo es demostrar mediante modelos dinámicos y teoría cualitaiva de ecuaciones diferenciales, cómo el número reproductivo básico Ro constituye una métrica que incide en la ocurrencia de estos eventos. Se empleó un modelo de tipo SIR con demografía adaptado a las condiciones de Cuba. Los resultados demostraron que se consigue dar respuesta, desde el punto de vista matemático, a las condiciones que pueden causar un rebrote de la enfermedad. Recomendamos mantener activadas las medidas epidemiológicas que se relacionan en este trabajo y que ayudan a mantener controlados los casos confirmados que aparezcan y evitar de esta manera posibles rebrotes.


ABSTRACT The danger of the occurrence of endemic COVID-19 worries the Cuban government as well as epidemiologists. Knowledge about a metric that influences its emergence is a very useful tool to prevent it. The purpose of the study was to prove through dynamic models and the qualitative theory of differential equations that the basic reproduction number R0 is a metric influencing the occurrence of these events. A SIR model was used, which was adjusted to Cuban conditions. Results showed that a mathematical response may be provided to conditions potentially causing a fresh outbreak of the disease. We recommend to maintain activated the epidemiological measures referred to in the paper, which help keep under control the confirmed cases occurring, thus preventing possible fresh outbreaks.

20.
Rev. cuba. salud pública ; 46(supl.1): e2597, 2020. tab, graf
Artículo en Español | CUMED, LILACS | ID: biblio-1144568

RESUMEN

El modelo básico SIR (Susceptibles-Infectados-Recuperados) de Kermack y McKendrick, es un modelo de compartimentos donde la población bajo estudio se divide en clases epidemiológicas y se describe un flujo entre ellas. Un sistema sanitario robusto que proporcione al modelo datos confiables y aunados a políticas públicas de salud coherentes, contribuye a controlar los impactos de contingencias epidémicas. De ahí que el objetivo del presente estudio sea aplicar el modelo SIR, sin profundizar en el aparato matemático que lo acompaña, para conocer el impacto de la COVID-19 en Cuba, con énfasis en La Habana, como centro de la epidemia en el país en el período del 11 de marzo al 16 de julio de 2020. Para ello se muestra el modelo con coeficientes variables en el tiempo y su utilidad como modelo dinámico para hacer proyecciones en situaciones epidémicas; se aplica a regiones locales específicas y se manifiestan sus potencialidades para analizar rebrotes por la aparición de eventos locales que se alejan de las predicciones previstas. Este trabajo es parte de los esfuerzos que, en todos los órdenes, ha desarrollado el Ministerio de Salud Pública de Cuba para enfrentar la pandemia de la COVID-19(AU)


The basic SIR (Susceptible-Infected-Recovered) model of Kermack-McKendrick is a compartmental model in which the population under study is divided into epidemiological classes, in between which a flow is described. A robust health system that provides reliable data to the model and combined with coherent public health policies contributes to controlling the impacts of epidemic contingencies. Hence, the objective of this study is to apply the SIR model, without delving into the mathematical apparatus that accompanies it, to know the impact of COVID-19 in Cuba, with an emphasis on Havana, as the center of the epidemic in the country in the period from March 11 to July 16, 2020. To do this, the model is shown with variable coefficients over time, together with its usefulness as a dynamic model to make projections in epidemic situations. It is applied to specific local regions and its potentialities to analyze outbreaks are manifested by the onset of local events that are far from the foreseen predictions. This work is part of the efforts that, in all orders, the Cuban Ministry of Public Health has developed to confront the COVID-19 pandemic(AU)


Asunto(s)
Salud Pública , Modelos Estadísticos , Infecciones por Coronavirus/epidemiología , Cuba
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