RESUMEN
Antimicrobial resistance continues to grow and antimicrobial use in food animal production and to a lesser extent in human patients is under fire. Much of the criticism has to do with the misapplication of these drugs in both settings. Research indicates that patients, food animal producers, physicians and veterinarians have all played a part in misusing antimicrobials, often because of mistaken beliefs. This paper reviews this research and introduces a theoretical perspective, the Theory of Planned Behavior (TPB), which broadens our understanding of the motivations for misuse. In particular this approach shows that individuals making decisions about antimicrobial use take into account social pressures from and a sense of obligation to significant others in their social networks. Our own work summarized in this paper indicates that both feedlot veterinarians and feedlot managers' antimicrobial decisions are influenced by both expectations from and obligations to a variety of actors in the feedlot network (other veterinarians, feedlot clients, consumers, pharmaceutical companies, and regulatory bodies). Generally across 4 circumstances of antimicrobial use (for acutely sick cattle, chronically-sick cattle, at-risk cattle, high-risk cattle), it is largely the perception that peers and clients expect feedlot veterinarians to use antimicrobials and feedlot veterinarians sense of obligation to these groups that have the most influence on their decisions to recommend antimicrobials. Based on these findings, the question of engaging in changing the choices made by those working with food animals must start with those who influence the decision to proscribe or use antimicrobials. As our data come from the United States and may be unique relative to other countries, these efforts should begin by ascertaining who influences these decisions. The next step is to then change the beliefs of these significant others.
Asunto(s)
Crianza de Animales Domésticos/métodos , Antiinfecciosos/efectos adversos , Actitud del Personal de Salud , Farmacorresistencia Microbiana , Mal Uso de Medicamentos de Venta con Receta , Veterinarios/psicología , Animales , Actitud Frente a la Salud , Bovinos , Enfermedades de los Bovinos/tratamiento farmacológico , Toma de Decisiones , Humanos , Percepción , Médicos/psicología , Estados UnidosRESUMEN
Understanding the prevalence of cattle producers' beliefs regarding disease reporting can help officials improve surveillance programs with passive data collection. A cross-sectional survey was conducted in Texas in 2008 and 2009 to determine beliefs about reporting cattle with clinical signs consistent with foot-and-mouth disease (FMD) either prior to (scenario 1) or during an on-going outbreak of FMD (scenario 2). Two questionnaires were developed and distributed to Texas cow-calf producers in order to evaluate their behavioral, control, and normative beliefs related to disease reporting. The context for each behavior was provided through the use of scenarios, and belief strength was measured using a 7-point Likert-like scale. Beliefs were compared across scenarios and demographic categories, and the effect of scenario on belief examined using ordinal logistic regression. Respondents agreed that reporting clinically suspect cases would have positive economic and emotional consequences; however, when an outbreak was known to be present, producers were less likely to agree with many of the positive outcomes of reporting. Important barriers to disease reporting indicated by producers included a lack of knowledge related to clinical signs of highly contagious cattle diseases and which cattle are at risk of contracting FMD. In general, beliefs about barriers to reporting did not differ based on scenario. Veterinarians and regulatory authorities were the groups perceived to most strongly expect disease reporting, regardless of the scenario. Risk education for producers related to clinical signs of reportable livestock diseases, post-reporting procedures, and an understanding of FMD introduction and spread may improve the reporting of cattle with clinical signs consistent with FMD.
Asunto(s)
Crianza de Animales Domésticos/métodos , Enfermedades de los Bovinos/epidemiología , Brotes de Enfermedades/veterinaria , Fiebre Aftosa/epidemiología , Conocimientos, Actitudes y Práctica en Salud , Animales , Bovinos , Enfermedades de los Bovinos/virología , Control de Enfermedades Transmisibles , Estudios Transversales , Fiebre Aftosa/virología , Prevalencia , Encuestas y Cuestionarios , Texas/epidemiologíaRESUMEN
The voluntary cooperation of producers with disease control measures such as movement restrictions and gathering cattle for testing, vaccination, or depopulation is critical to the success of many disease control programs. A cross-sectional survey was conducted in Texas in order to determine the distribution of key beliefs about obeying movement restrictions and gathering and holding cattle for disease control purposes. Two questionnaires were developed and distributed to separate representative samples of Texas cow-calf producers, respectively. The context for each behavior was provided through the use of scenarios in the questionnaire. Belief strength was measured using a 7-point Likert-like scale. Producers surveyed were unsure about the possible negative consequences of gathering and holding their cattle when requested by authorities, suggesting a key need for communication in this area during an outbreak. Respondents identified a lack of manpower and/or financial resources to gather and hold cattle as barriers to their cooperation with orders to gather and hold cattle. Producers also expressed uncertainty about the efficacy of movement restrictions to prevent the spread of foot-and-mouth disease and concern about possible feed shortages or animal suffering. However, there are emotional benefits to complying with movement restrictions and strong social expectations of cooperation with any movement bans put in place.
Asunto(s)
Crianza de Animales Domésticos/métodos , Enfermedades de los Bovinos/epidemiología , Brotes de Enfermedades/veterinaria , Fiebre Aftosa/epidemiología , Conocimientos, Actitudes y Práctica en Salud , Animales , Bovinos , Enfermedades de los Bovinos/virología , Control de Enfermedades Transmisibles , Estudios Transversales , Fiebre Aftosa/virología , Prevalencia , Encuestas y Cuestionarios , Texas/epidemiología , TransportesRESUMEN
The objective of this study was to ascertain current teaching methods for antimicrobial resistance (AMR) in veterinary professional curricula and to find out what veterinary instructors consider to be prioritized subtopics related to AMR. The sampling frame was instructors in veterinary professional programs at US colleges of veterinary medicine who provide instruction about antibiotics or AMR in the disciplines of microbiology, pharmacology, public health, epidemiology, internal medicine, surgery, or related subjects. Identified instructors were invited to participate in an online survey of current teaching methods related to subtopics of AMR. From 1,207 invitations, 306 completed surveys were available for analysis (25% response rate) with the largest number of respondents stating their contact hours about antibiotics occur in the discipline of "medicine-food animal." The median contact time suggested for AMR in the core veterinary curriculum was 3-5 hours, and for antibiotics in general, 16-20 hours. Subtopics of AMR were prioritized based on respondents' indication that they use or would use various teaching tools. The most common teaching tool for all topics was projected text (i.e., slides or PowerPoint slides) and the least common were video clips, non-course Web sites, online modules, and laboratory experiments. Recommendations for identifying the priorities of AMR content coverage and learning outcomes are made.
Asunto(s)
Antiinfecciosos/farmacología , Farmacorresistencia Microbiana , Educación en Veterinaria/métodos , Curriculum , Encuestas y Cuestionarios , Estados UnidosRESUMEN
The effective control of an outbreak of a highly contagious disease such as foot-and-mouth disease (FMD) in the United States will require a strong partnership between the animal agriculture industry and the government. However, because of the diverse number of economic, social, and psychological influences affecting livestock producers, their complete cooperation during an outbreak may not be assured. We conducted interviews with 40 individuals involved in the Texas cattle industry in order to identify specific behaviors where producer participation or compliance may be reduced. Through qualitative analysis of these interviews, we identified specific factors which the participants suggested would influence producer behavior in regard to FMD detection and control. Using the Theory of Planned Behavior (TPB) as an initial guide, we developed an expanded theoretical framework in order to allow for the development of a questionnaire and further evaluation of the relative importance of the relationships indicated in the framework. A 2-day stakeholder workshop was used to develop and critique the final survey instruments. The behaviors which we identified where producer compliance may be reduced included requesting veterinary examination of cattle with clinical signs of FMD either before or during an outbreak of FMD, gathering and holding cattle at the date and time requested by veterinary authorities, and maintaining cattle in their current location during an outbreak of FMD. In addition, we identified additional factors which may influence producers' behavior including risk perception, trust in other producers and regulatory agencies, and moral norms. The theoretical frameworks presented in this paper can be used during an outbreak to assess barriers to and social pressures for producer compliance, prioritize the results in terms of their effects on behavior, and improve and better target risk communication strategies.
Asunto(s)
Crianza de Animales Domésticos/normas , Enfermedades de los Bovinos/prevención & control , Recolección de Datos/métodos , Fiebre Aftosa/prevención & control , Crianza de Animales Domésticos/economía , Animales , Bovinos , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/epidemiología , Industria Lechera , Femenino , Fiebre Aftosa/diagnóstico , Fiebre Aftosa/epidemiología , Virus de la Fiebre Aftosa/fisiología , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Medición de Riesgo , Encuestas y Cuestionarios , Texas/epidemiologíaRESUMEN
This study aimed to understand mothers' everyday food choices using one type of visual method-participant-driven photo-elicitation (PDPE). The sample consisted of 12 low/moderate income mothers (26-53 years) living in Bryan/College Station, Texas. Each mother completed a photography activity, where she created photographs of her food experience, and an in-depth interview using the mother's photographs. Interview transcripts were analyzed using a grounded theory approach and coded using qualitative data analysis software ATLAS.ti. Mothers emphasized their identities related to food and eating as they described food-related decisions and activities. These identities influenced a mother's food choices for herself and those she made for her children. Analysis revealed that mothers with a more defined health identity made healthier choices for themselves and similar food choices for their children. In addition, they exhibited behaviors that positively influenced their children's food choices. Mothers who struggled to see themselves as healthy indulged with more junk food and indicated feelings of anxiety and guilt; these mothers' food choices were more disconnected from their children's. These findings underscore the importance of understanding how identities related to food and eating can influence food choices. Encouraging mothers to develop and maintain health identities may be one way to improve food and eating habits in families.
Asunto(s)
Conducta de Elección , Conducta Alimentaria , Preferencias Alimentarias , Adulto , Recolección de Datos , Ingestión de Alimentos , Femenino , Alimentos Orgánicos , Promoción de la Salud , Humanos , Conducta Materna , Persona de Mediana Edad , Relaciones Madre-Hijo , Madres , Fotograbar , Encuestas y Cuestionarios , TexasRESUMEN
Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth's orbital geometry control the ice ages, fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles. Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the 'warmer-than-present' early-Pliocene epoch ( approximately 5-3 Myr ago) is needed to better constrain the possible range of ice-sheet behaviour in the context of future global warming. Here we present a marine glacial record from the upper 600 m of the AND-1B sediment core recovered from beneath the northwest part of the Ross ice shelf by the ANDRILL programme and demonstrate well-dated, approximately 40-kyr cyclic variations in ice-sheet extent linked to cycles in insolation influenced by changes in the Earth's axial tilt (obliquity) during the Pliocene. Our data provide direct evidence for orbitally induced oscillations in the WAIS, which periodically collapsed, resulting in a switch from grounded ice, or ice shelves, to open waters in the Ross embayment when planetary temperatures were up to approximately 3 degrees C warmer than today and atmospheric CO(2) concentration was as high as approximately 400 p.p.m.v. (refs 5, 6). The evidence is consistent with a new ice-sheet/ice-shelf model that simulates fluctuations in Antarctic ice volume of up to +7 m in equivalent sea level associated with the loss of the WAIS and up to +3 m in equivalent sea level from the East Antarctic ice sheet, in response to ocean-induced melting paced by obliquity. During interglacial times, diatomaceous sediments indicate high surface-water productivity, minimal summer sea ice and air temperatures above freezing, suggesting an additional influence of surface melt under conditions of elevated CO(2).
Asunto(s)
Cubierta de Hielo , Regiones Antárticas , Atmósfera/análisis , Atmósfera/química , Calibración , Dióxido de Carbono/análisis , Diatomeas/química , Diatomeas/aislamiento & purificación , Fósiles , Historia Antigua , Isótopos de Oxígeno , TemperaturaRESUMEN
Twenty-seven patients undergoing treatment in a high-secure forensic facility participated in focus group interviews to elicit their perceptions of (1) the factors leading to aggressive behaviour; and (2) strategies to reduce the risk of such behaviour. The focus group interviews were audiotaped, transcribed and analysed using content analysis. The participants identified that a combination of patient, staff and environmental factors contributed to violence in the study wards. The cause of aggressive behaviour centred around five major themes: the environment; empty days; staff interactions; medication issues; and patient-centred factors. Potential strategies identified by patients to reduce aggressive behaviour included: early intervention; the provision of meaningful activities to reduce boredom; separation of acutely disturbed patients; improved staff attitudes; implementation of effective justice procedures; and a patient advocate to mediate during times of conflict. Findings suggested that social and organizational factors need to be addressed to change the punitive subculture inherent in forensic psychiatric facilities, and to ensure a balance between security and effective therapy.
Asunto(s)
Agresión/psicología , Actitud Frente a la Salud , Psiquiatría Forense/métodos , Trastornos Mentales/psicología , Relaciones Enfermero-Paciente , Enfermería Psiquiátrica/métodos , Actitud del Personal de Salud , Tedio , Causalidad , Conflicto Psicológico , Femenino , Grupos Focales , Ambiente de Instituciones de Salud , Hospitales Psiquiátricos , Humanos , Masculino , Trastornos Mentales/enfermería , Negativismo , Negociación/métodos , Negociación/psicología , Investigación Metodológica en Enfermería , Cultura Organizacional , Defensa del Paciente , Participación del Paciente/métodos , Participación del Paciente/psicología , Prisioneros/psicología , Gestión de RiesgosRESUMEN
Correct cell cycle regulation and terminal mitosis are critical for nervous system development. The retinoblastoma (Rb) protein is a key regulator of these processes, as Rb-/- embryos die by E15.5, exhibiting gross hematopoietic and neurological defects. The extensive apoptosis in Rb-/- embryos has been attributed to aberrant S phase entry resulting in conflicting growth control signals in differentiating cells. To assess the role of Rb in cortical development in the absence of other embryonic defects, we examined mice with telencephalon-specific Rb deletions. Animals carrying a floxed Rb allele were interbred with mice in which cre was knocked into the Foxg1 locus. Unlike germline knockouts, mice specifically deleted for Rb in the developing telencephalon survived until birth. In these mutants, Rb-/- progenitor cells divided ectopically, but were able to survive and differentiate. Mutant brains exhibited enhanced cellularity due to increased proliferation of neuroblasts. These studies demonstrate that: (i) cell cycle deregulation during differentiation does not necessitate apoptosis; (ii) Rb-deficient mutants exhibit enhanced neuroblast proliferation; and (iii) terminal mitosis may not be required to initiate differentiation.
Asunto(s)
Proteínas del Tejido Nervioso/fisiología , Proteína de Retinoblastoma/fisiología , Telencéfalo/embriología , Alelos , Animales , Apoptosis , Biomarcadores , Ciclo Celular , Diferenciación Celular , División Celular , Corteza Cerebral/anomalías , Corteza Cerebral/embriología , Cruzamientos Genéticos , Proteínas de Unión al ADN/deficiencia , Proteínas de Unión al ADN/genética , Muerte Fetal/genética , Factores de Transcripción Forkhead , Genes Letales , Genes de Retinoblastoma , Ratones , Ratones Noqueados , Mutagénesis Insercional , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/genética , Neuronas/patología , Especificidad de Órganos , Proteína de Retinoblastoma/deficiencia , Telencéfalo/anomalías , Tubulina (Proteína)/biosíntesis , Tubulina (Proteína)/genéticaRESUMEN
Between 34 and 15 million years (Myr) ago, when planetary temperatures were 3-4 degrees C warmer than at present and atmospheric CO2 concentrations were twice as high as today, the Antarctic ice sheets may have been unstable. Oxygen isotope records from deep-sea sediment cores suggest that during this time fluctuations in global temperatures and high-latitude continental ice volumes were influenced by orbital cycles. But it has hitherto not been possible to calibrate the inferred changes in ice volume with direct evidence for oscillations of the Antarctic ice sheets. Here we present sediment data from shallow marine cores in the western Ross Sea that exhibit well dated cyclic variations, and which link the extent of the East Antarctic ice sheet directly to orbital cycles during the Oligocene/Miocene transition (24.1-23.7 Myr ago). Three rapidly deposited glacimarine sequences are constrained to a period of less than 450 kyr by our age model, suggesting that orbital influences at the frequencies of obliquity (40 kyr) and eccentricity (125 kyr) controlled the oscillations of the ice margin at that time. An erosional hiatus covering 250 kyr provides direct evidence for a major episode of global cooling and ice-sheet expansion about 23.7 Myr ago, which had previously been inferred from oxygen isotope data (Mi1 event).
RESUMEN
This paper presents the results of an action research study into the acute care experience of Dissociative Identity Disorder. The study, which was grounded in principles of critical social science, utilized focus group interviews and narrative construction. Nurses and patients are under-represented in all clinical evaluation and their voices need to be heard if services are to be truly collaborative. Findings of the study extend intrapsychic theories of trauma to emphasize the interpersonal relationship between nurse and person who can work together to facilitate recovery from trauma, make connections both intra and interpersonally and build resilience.
Asunto(s)
Actitud del Personal de Salud , Actitud Frente a la Salud , Trastornos Disociativos/enfermería , Trastornos Disociativos/psicología , Relaciones Enfermero-Paciente , Personal de Enfermería en Hospital/psicología , Enfermería Psiquiátrica/métodos , Enfermedad Aguda/enfermería , Enfermedad Aguda/psicología , Adaptación Psicológica , Conducta Cooperativa , Femenino , Grupos Focales , Investigación sobre Servicios de Salud , Conducta de Ayuda , Humanos , Maquiavelismo , Masculino , Investigación Metodológica en Enfermería , Enfermería Psiquiátrica/normas , Teoría Psicológica , Apoyo Social , Transferencia PsicológicaRESUMEN
People differ with respect to their beliefs about the consequences of attaining goals. Some people (linkers) believe that attaining certain goals will make them happy, whereas others (nonlinkers) see their happiness as more contingent upon the inherent quality of their actions than upon the outcomes of those actions. Because of the importance linkers place on goal attainment, linkers should be likely to seek information indicative of their progress toward their goals. Because of the importance nonlinkers place on enjoyment, nonlinkers should be likely to seek information indicative of the pleasurableness of their current task. Because negative affect can signal a lack of goal progress, whereas positive affect can signal task enjoyment, linkers may place more weight on their negative than their positive affect, whereas nonlinkers may do the opposite. Consistent with these hypotheses, the results of this study showed that linkers reported more negative affect when exposed to sad videos than when exposed to happy videos but did not report different amounts of positive affect. Nonlinkers, on the other hand, reported more positive affect when exposed to happy videos than when exposed to sad videos but did not report different amounts of negative affect. The implications of this pattern for a number of theoretical perspectives on goals and affect are discussed.
Asunto(s)
Afecto , Actitud , Objetivos , Adulto , Cognición , Femenino , Humanos , Masculino , Encuestas y CuestionariosRESUMEN
Photopolymerizing hydrogel systems provide a method to encapsulate cells and implant materials in a minimally invasive manner. Controlled release of growth factors in the hydrogels may enhance the ability to engineer tissues. IGF-I and TGF-beta1 were loaded in PLGA microspheres using a double emulsion technique. 125 ng and 200 pg of active IGF-I and TGF-beta, respectively, as measured by ELISA, were released over 15 days. The growth factor containing microspheres were photoencapsulated with bovine articular chondrocytes in PEO-based hydrogels and incubated in vitro for two weeks. Statistically significant changes in glycosaminoglycan (GAG) production compared to control gels either without microspheres or with blank spheres were observed after a 14 day incubation with IGF-I and IGF-I/TGF-beta microspheres combined, with a maximum density of 8.41+/-2.5% wet weight GAG. Total collagen density was low and decreased with the IGF-I/TGF-beta microspheres after two weeks incubation, but otherwise remained unchanged in all other experimental groups. Cell content increased 10-fold to 0.18+/-0.056 x 10(6) cells/mg wet weight and extracellular matrix (ECM) staining by H&E increased in hydrogels with IGF-I/TGF-beta microspheres. In conclusion, photoencapsulation of microspheres in PEO-based hydrogels provides a method to deliver molecules such as growth factors in porous hydrogel systems.
Asunto(s)
Cartílago/efectos de los fármacos , Factor I del Crecimiento Similar a la Insulina/administración & dosificación , Ingeniería de Tejidos , Factor de Crecimiento Transformador beta/administración & dosificación , Animales , Bovinos , Condrocitos/efectos de los fármacos , Hidrogel de Polietilenoglicol-Dimetacrilato , Ácido Láctico/administración & dosificación , Microesferas , Ácido Poliglicólico/administración & dosificación , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , Polímeros/administración & dosificaciónRESUMEN
OBJECTIVE: To demonstrate that the recent decline in egg consumption in the United States was, in part, the result of a food scare that began in the 1960's. METHODS: Using the Reader's Guide to Periodical Literature, the frequency of articles about eggs, dietary cholesterol and heart disease in popular magazines was obtained. A content analysis was performed on a random sample of these articles. RESULTS: The increased trend in magazine articles and public statements by groups such as the American Heart Association linking eggs, blood cholesterol and heart disease is associated with the downward trend in egg consumption. CONCLUSIONS: Public exposure to negative messages about particular foods can contribute to a decline in their consumption. Exposure to more consistently positive messages about foods can bring about an increase in the consumption of those foods.
Asunto(s)
Colesterol en la Dieta/efectos adversos , Huevos , Promoción de la Salud/tendencias , Cardiopatías/prevención & control , Publicaciones Periódicas como Asunto/tendencias , Medio Social , Cultura , Conocimientos, Actitudes y Práctica en Salud , Cardiopatías/etiología , Humanos , Medios de Comunicación de Masas/estadística & datos numéricos , Medios de Comunicación de Masas/tendencias , Publicaciones Periódicas como Asunto/estadística & datos numéricos , Formulación de Políticas , Simbolismo , Factores de Tiempo , Estados UnidosRESUMEN
Intravascular papillary endothelial hyperplasia is a benign lesion of vascular origin that is caused by an excessive proliferation of endothelial cells in normal blood vessels or vascular malformations. We report the case of a 26-year-old man who had such a lesion deep within the soft tissues of his neck. Imaging studies revealed a 6-cm-diameter mass, with its epicenter in the right retromandibular space. The mass extended into the right parapharyngeal space and compressed the pharynx. The mass was excised, and the patient recovered uneventfully. We discuss the management of this lesion, with emphasis on radiologic and histologic assessment and the differential diagnosis.
Asunto(s)
Endotelio Vascular/patología , Neoplasias de Cabeza y Cuello/diagnóstico , Hemangioendotelioma/diagnóstico , Adulto , Biopsia , Diagnóstico Diferencial , Humanos , Hiperplasia , Imagen por Resonancia Magnética , Masculino , Pronóstico , Tomografía Computarizada por Rayos XRESUMEN
A photopolymerizing hydrogel system provides an efficient method to encapsulate cells. The present work describes the in vitro analysis of bovine and ovine chondrocytes encapsulated in a poly(ethylene oxide)-dimethacrylate and poly(ethylene glycol) semi-interpenetrating network using a photopolymerization process. One day after encapsulation, (3-[4,5-dimethylthiazol-2-y1]-2, 5-diphenyl-2H-tetrazolium bromide) (MTT) and light microscopy showed chondrocyte survival and a dispersed cell population composed of ovoid and elongated cells. Biochemical analysis demonstrated proteoglycan and collagen contents that increased over 2 weeks of static incubation. Cell content of the gels initially decreased and stabilized. Biomechanical analysis demonstrated the presence of a functional extracellular matrix with equilibrium moduli, dynamic stiffness, and streaming potentials that increased with time. These findings suggest the feasibility of photoencapsulation for tissue engineering and drug delivery purposes.
Asunto(s)
Materiales Biocompatibles , Cartílago Articular/citología , Polietilenglicoles , Animales , Cápsulas , Cartílago Articular/fisiología , Bovinos , Colágeno/análisis , Fémur , Glicosaminoglicanos/análisis , Cinética , Rótula , Polietilenglicoles/efectos de la radiación , Rayos UltravioletaRESUMEN
Many hospitals today struggle to remain competitive through the adoption of medical technology or expansion of hospital services. This article presents a case study of one hospital's attempt to remain viable through the adoption of telemedicine. Through a 17-year analysis of local hospital-related news reports, it is argued that a hospital's relationship to the local community can affect the success and potential of such innovations. Establishing a pattern of trust and support between the local community and hospital should therefore be an important step in increasing hospital viability.
Asunto(s)
Hospitales Rurales/organización & administración , Transferencia de Tecnología , Telemedicina , Relaciones Comunidad-Institución , Difusión de Innovaciones , Competencia Económica , Educación Continua , Eficiencia Organizacional , Hospitales Rurales/economía , Medios de Comunicación de Masas , Estudios de Casos Organizacionales , TexasRESUMEN
Photopolymerizations are widely used in medicine to create polymer networks for use in applications such as bone restorations and coatings for artificial implants. These photopolymerizations occur by directly exposing materials to light in "open" environments such as the oral cavity or during invasive procedures such as surgery. We hypothesized that light, which penetrates tissue including skin, could cause a photopolymerization indirectly. Liquid materials then could be injected s.c. and solidified by exposing the exterior surface of the skin to light. To test this hypothesis, the penetration of UVA and visible light through skin was studied. Modeling predicted the feasibility of transdermal polymerization with only 2 min of light exposure required to photopolymerize an implant underneath human skin. To establish the validity of these modeling studies, transdermal photopolymerization first was applied to tissue engineering by using "injectable" cartilage as a model system. Polymer/chondrocyte constructs were injected s.c. and transdermally photopolymerized. Implants harvested at 2, 4, and 7 weeks demonstrated collagen and proteoglycan production and histology with tissue structure comparable to native neocartilage. To further examine this phenomenon and test the applicability of transdermal photopolymerization for drug release devices, albumin, a model protein, was released for 1 week from photopolymerized hydrogels. With further study, transdermal photpolymerization potentially could be used to create a variety of new, minimally invasive surgical procedures in applications ranging from plastic and orthopedic surgery to tissue engineering and drug delivery.
Asunto(s)
Sistemas de Liberación de Medicamentos , Polímeros , Implantación de Prótesis/métodos , Animales , Materiales Biocompatibles , Dimerización , Femenino , Humanos , Luz , Piel , PorcinosRESUMEN
Transdermal photopolymerization, a minimally invasive method for implantation, was used to subcutaneously place a mixture of polymer and isolated chondrocytes to regenerate cartilage tissue in vivo. Semi-interpenetrating networks of varying proportions of poly(ethylene oxide)-dimethacrylate and poly(ethylene oxide) and primary bovine articular chondrocytes were implanted in athymic mice. Four mice (12 implants) were harvested at 2, 4, and 7 weeks. Chondrocytes survived implantation and photopolymerization and formed neocartilage containing 1.5 to 2.9% wet weight collagen and 4 to 7% glycosaminoglycan. Thirty-five percent of the total collagen was type II collagen. Histologic analysis exhibited tissue structure resembling neocartilage, and safranin O staining demonstrated glycosaminoglycan distribution throughout the hydrogels. This study demonstrates the potential use of transdermal photopolymerization for minimally invasive subcutaneous implantation of hydrogels and chondrocytes for in vivo cartilage regeneration.
Asunto(s)
Materiales Biocompatibles/síntesis química , Cartílago Articular , Hidrogeles/síntesis química , Polietilenglicoles/síntesis química , Animales , Bovinos , Dimerización , Femenino , Hidrogeles/administración & dosificación , Inyecciones Subcutáneas , Ratones , Ratones Desnudos , PolímerosRESUMEN
We examined how smokers were depicted in 100 popular films spanning 5 decades. Smokers were depicted as more romantically and sexually active than nonsmokers and as marginally more intelligent than nonsmokers. Smokers and nonsmokers did not differ in terms of attractiveness, goodness, socioeconomic status, aggression, friendliness, or outcome at film's end. Thus, if anything, smokers are depicted a bit more positively than nonsmokers. We compared Hollywood's depiction of smokers to real-world demographics on smoking and found that Hollywood's depiction of smoking tends to ignore the negative consequences and correlates (e.g., ill health, low socioeconomic status, aggressive behavior) of smoking.