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AIM: To determine whether obesity information obtained via imaging techniques is desirable for clinicians and patients, and to investigate whether it impacts clinical decision-making. MATERIALS AND METHODS: Parallel surveys were designed to assess patient and clinician attitudes to the medical utility and social stigma of reporting obesity on radiology reports performed for other reasons. RESULTS: Where obesity was noted at medical imaging performed for any reason, clinicians and patients strongly agreed that it should be included in the radiology report (5.9 and 5.8, respectively, on a seven-point preference score ranging from strongly disagree [1] to strongly agree [7]). Clinicians and patients indicated a preference for a quantitative report. Clinicians somewhat disagreed and patients disagreed that a radiology report describing obesity would be considered insulting (3 and 2.1, respectively). Clinicians and patients agreed that they would be more likely to discuss overweight/obesity if it was described in a radiology report (5.3 and 6.1 respectively). Clinicians and patients agreed that radiology reports describing obesity would influence future management/behaviour (4.5 and 6.2, respectively). Clinicians strongly disagreed that they would avoid sending patients for scans if obesity was reported (1.3). Patients also disagreed that including such information on a report would result in imaging avoidance (1.9). CONCLUSION: Both clinicians and patients indicate a clear preference for obesity-related information on radiology reports for examinations performed for any reason. Surveyed attitudes suggest including such information is not considered insulting, and is unlikely to result in avoidance of imaging.
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Actitud del Personal de Salud , Documentación , Obesidad/epidemiología , Servicio de Radiología en Hospital , Humanos , Prevalencia , Estigma Social , Encuestas y CuestionariosRESUMEN
Aim We aimed to determine the prevalence of smoking and smoking cessation advice received by inpatients in Beaumont Hospital and compared results to previous similar studies. Method Cross-sectional survey where we interviewed eligible in-patients over a two-week period. Results 14.8% (30/203) of participants were current smokers, which is lower than the smoking prevalence found by previous studies. The rate of cessation advice delivery was 53.3% (16/30). An increasing socioeconomic gap between smokers and non-smokers over time was found. Discussion There remains limited provision of smoking cessation advice to inpatients.
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Hospitalización/estadística & datos numéricos , Cese del Hábito de Fumar/métodos , Cese del Hábito de Fumar/estadística & datos numéricos , Prevención del Hábito de Fumar/métodos , Fumar/epidemiología , Adulto , Anciano , Actitud Frente a la Salud , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Cese del Hábito de Fumar/psicología , Clase Social , Factores de TiempoRESUMEN
BACKGROUND AND PURPOSE: Revascularisation treatment with thrombolysis must be initiated within 4.5â h following ischaemic stroke symptom onset. Despite its proven benefits, thrombolysis therapy is underused, with patient delay in presenting to hospital with symptoms identified as the leading barrier. This study aimed to examine help-seeking behaviour at stroke onset, in order to understand delays in accessing acute medical care for stroke symptoms. METHODS: 149 consecutive patients hospitalised with ischaemic stroke were interviewed at 72â h poststroke with the Stroke Awareness Questionnaire and the Response to Symptoms Questionnaire. RESULTS: Sixty per cent of stroke cases presented to the ED within 3.5â h of stroke onset. Knowledge of stroke symptoms and risk factors was poor, with 40% unable to correctly define a stroke. Bystander recognition of symptoms (p=0.03) and bystander initiation of Emergency Medical Services was associated with ED presentation within 3.5â h (p=0.03). CONCLUSIONS: This study provides insights into patient response when a stroke occurs, with the presence and action of others highlighted as critical in fast response to stroke symptoms. Knowledge of stroke warning signs and risk factors was low among stroke survivors. Findings highlight the complexity of changing help-seeking behaviour during stroke onset, and provide directions for public education efforts to reduce prehospital delay.
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Conocimientos, Actitudes y Práctica en Salud , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/tratamiento farmacológico , Terapia Trombolítica , Tiempo de Tratamiento , Anciano , Estudios Transversales , Femenino , Humanos , Irlanda , Masculino , Factores de Riesgo , Encuestas y Cuestionarios , Factores de TiempoRESUMEN
BACKGROUND: In recent years, the management of synchronous colorectal liver metastasis has changed significantly. Alternative surgical strategies to the classical colorectal-first approach have been proposed. These include the liver-first and combined resections approaches. The objectives of this review were to compare the short- and long-term outcomes for all three approaches. METHODS: A systematic review of comparative studies was performed. Evaluated endpoints included surgical outcomes (5-year overall survival, 30-day mortality, and post-operative complications). Pair-wise and network meta-analysis (NMA) were performed to compare survival outcomes. RESULTS: Eighteen studies were included in this review, reporting on 3,605 patients. NMA and pair-wise meta-analysis of the 5-year overall survival did not show significant difference between the three surgical approaches: combined versus colorectal-first, mean odds ratio (OR) 1.02 (95% CI 0.8-1.28, P = 0.93); liver-first versus colorectal-first, mean OR 0.81 (95% CI 0.53-1.26, P = 0.37); liver-first versus combined, mean OR 0.80 (95% CI 0.52-1.24, P = 0.41). In addition NMA of the 30-day mortality among the three approaches also did not observe statistical difference. Analysis of variance showed that mean post-operative complications of all approaches were comparable (P = 0.51). CONCLUSION: There are considerable differences in the peri-operative management of synchronous CLM patients. This meta-analysis demonstrated no clear statistical surgical outcome or survival advantage towards any of the three approaches.
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Neoplasias Colorrectales/cirugía , Hepatectomía/mortalidad , Neoplasias Hepáticas/cirugía , Neoplasias Primarias Múltiples/cirugía , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Humanos , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/secundario , Estadificación de Neoplasias , Neoplasias Primarias Múltiples/mortalidad , Neoplasias Primarias Múltiples/patología , Pronóstico , Tasa de SupervivenciaRESUMEN
A large body of empirical research shows that psychosocial risk factors (PSRFs) such as low socio-economic status, social isolation, stress, type-D personality, depression and anxiety increase the risk of incident coronary heart disease (CHD) and also contribute to poorer health-related quality of life (HRQoL) and prognosis in patients with establishedCHD. PSRFs may also act as barriers to lifestyle changes and treatment adherence and may moderate the effects of cardiac rehabilitation (CR). Furthermore, there appears to be a bidirectional interaction between PSRFs and the cardiovascular system. Stress, anxiety and depression affect the cardiovascular system through immune, neuroendocrine and behavioural pathways. In turn, CHD and its associated treatments may lead to distress in patients, including anxiety and depression. In clinical practice, PSRFs can be assessed with single-item screening questions, standardised questionnaires, or structured clinical interviews. Psychotherapy and medication can be considered to alleviate any PSRF-related symptoms and to enhance HRQoL, but the evidence for a definite beneficial effect on cardiac endpoints is inconclusive. A multimodal behavioural intervention, integrating counselling for PSRFs and coping with illness should be included within comprehensive CR. Patients with clinically significant symptoms of distress should be referred for psychological counselling or psychologically focused interventions and/or psychopharmacological treatment. To conclude, the success of CR may critically depend on the interdependence of the body and mind and this interaction needs to be reflected through the assessment and management of PSRFs in line with robust scientific evidence, by trained staff, integrated within the core CR team.
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BACKGROUND: The association between depression after myocardial infarction and increased risk of mortality and cardiac morbidity may be due to cardiac disease severity. AIMS: To combine original data from studies on the association between post-infarction depression and prognosis into one database, and to investigate to what extent such depression predicts prognosis independently of disease severity. METHOD: An individual patient data meta-analysis of studies was conducted using multilevel, multivariable Cox regression analyses. RESULTS: Sixteen studies participated, creating a database of 10 175 post-infarction cases. Hazard ratios for post-infarction depression were 1.32 (95% CI 1.26-1.38, P<0.001) for all-cause mortality and 1.19 (95% CI 1.14-1.24, P<0.001) for cardiovascular events. Hazard ratios adjusted for disease severity were attenuated by 28% and 25% respectively. CONCLUSIONS: The association between depression following myocardial infarction and prognosis is attenuated after adjustment for cardiac disease severity. Still, depression remains independently associated with prognosis, with a 22% increased risk of all-cause mortality and a 13% increased risk of cardiovascular events per standard deviation in depression z-score.
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Enfermedades Cardiovasculares/mortalidad , Trastorno Depresivo/mortalidad , Infarto del Miocardio/mortalidad , Anciano , Causas de Muerte , Comorbilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Riesgo , Índice de Severidad de la Enfermedad , Encuestas y CuestionariosRESUMEN
Using the (slow-scale) linear noise approximation, we give parameter-independent bounds to the substrate and product intrinsic noise variance for the stochastic Michaelis-Menten approximation at steady state.
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Modelos Químicos , Cinética , Procesos EstocásticosRESUMEN
This study examined the spatio-temporal reproductive patterns, population structure, maturity and growth of Acanthopagrus hybrid complexes, which comprise mainly black bream Acanthopagrus butcheri and the hybrids they form with yellowfin bream Acanthopagrus australis, in two Australian estuaries (Coila and Brou Lakes, NSW). There were no differences between pure A. butcheri and hybrids in terms of their population structure, growth and maturity, suggesting that these two breeds have similar life histories and may therefore be managed as single, naturally cohesive units. Sexual variation in size structure was only observed for the complex in Coila Lake. Although there was significant variation in age structure between estuaries, both complexes exhibited dominance of only a few year classes indicating episodic recruitment and high fishing mortality. Acanthopagrus eggs occurred in higher numbers within upstream creek habitats compared to lake habitats, thereby highlighting the need to protect these spawning habitats. Although maturity in the complexes was not influenced by gender or estuary, differences in growth were detected between the genders and estuaries.
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Hibridación Genética , Perciformes/fisiología , Animales , Australia , Tamaño Corporal , Conservación de los Recursos Naturales , Estuarios , Femenino , Modelos Logísticos , Masculino , Perciformes/crecimiento & desarrollo , Reproducción/fisiología , Factores Sexuales , Razón de MasculinidadRESUMEN
A multi-parametric model predictive control (mpMPC) algorithm for subcutaneous insulin delivery for individuals with type 1 diabetes mellitus (T1DM) that is computationally efficient, robust to variations in insulin sensitivity, and involves minimal burden for the user is proposed. System identification was achieved through impulse response tests feasible for ambulatory conditions on the UVa/Padova simulator adult subjects with T1DM. An alternative means of system identification using readily available clinical parameters was also investigated. A safety constraint was included explicitly in the algorithm formulation using clinical parameters typical of those available to an attending physician. Closed-loop simulations were carried out with daily consumption of 200 g carbohydrate. Controller robustness was assessed by subject/model mismatch scenarios addressing daily, simultaneous variation in insulin sensitivity and meal size with the addition of Gaussian white noise with a standard deviation of 10%. A second-order-plus-time-delay transfer function model fit the validation data with a mean (coefficient of variation) root-mean-square-error (RMSE) of 26 mg/dL (19%) for a 3 h prediction horizon. The resulting control law maintained a low risk Low Blood Glucose Index without any information about carbohydrate consumption for 90% of the subjects. Low-order linear models with clinically meaningful parameters thus provided sufficient information for a model predictive control algorithm to control glycemia. The use of clinical knowledge as a safety constraint can reduce hypoglycemic events, and this same knowledge can further improve glycemic control when used explicitly as the controller model. The resulting mpMPC algorithm was sufficiently compact to be implemented on a simple electronic device.
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The present review evaluated health-related quality of life (HR-QoL) outcomes in surgical breast cancer survivors who received breast reconstruction (BR), breast-conservation surgery (BCS) or mastectomy (M), and whether HR-QoL domains across generic and disease/surgery-specific questionnaires are compatible. Six electronic databases were searched for appropriate observational studies. Standardized scores for different HR-QoL domains in the BR, BCS, and M treatment groups were extracted from each study for the purpose of a meta-analysis. Using Stata version 14.0, a random-effects meta-analysis model was adopted for each outcome variable to estimate the effect size, 95% CI-confidence intervals, and statistical significance. Sixteen of the 18 eligible studies with BR (n = 1474) and BCS (n = 2612) or M (n = 1458) groups were included in the meta-analysis. The BR group exhibited a better physical health (k = 12; 0.1, 95% CI 0.04, 0.24) and body image (k = 12; 0.50, 95% CI 0.10, 0.89) than the M group. However, the two groups exhibited comparable social health (k = 13; 0.1, 95% CI -0.07, 0.37), emotional health (k = 13; -0.08, 95% CI - 0.41, 0.25), global health (k = 7; 0.1, 95% CI - 0.01, 0.27), and sexual health (k =11; 0.2, 95% CI - 0.02,0.57). There was no clear evidence of the superiority of BR to BCS for all the six domains. These results suggest that HR-QoL outcomes in BR and BCS groups are better than the M group. Therefore, women opting for BR or BCS are likely to report fairly better HR-QoL outcomes than M. However, due to the significant heterogeneity observed in most BR versus BCS outcomes, developing a unified questionnaire incorporating both breast/surgery-specific and generic HR-QoL domains is warranted.
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Neoplasias de la Mama/cirugía , Supervivientes de Cáncer/psicología , Mamoplastia/psicología , Mastectomía Segmentaria/psicología , Mastectomía Simple/psicología , Calidad de Vida , Imagen Corporal , Mama , Neoplasias de la Mama/psicología , Supervivientes de Cáncer/estadística & datos numéricos , Femenino , Humanos , Mamoplastia/estadística & datos numéricos , Mastectomía Segmentaria/efectos adversos , Mastectomía Segmentaria/estadística & datos numéricos , Mastectomía Simple/efectos adversos , Mastectomía Simple/estadística & datos numéricos , Encuestas y Cuestionarios/estadística & datos numéricosRESUMEN
BACKGROUND: Globally the older population is increasing rapidly. As a result there is an increase in frail older persons living within the community, with increased risks of a hospital admission and higher mortality and morbidity rates. Due to complexity of care, health care professionals face challenges in providing effective case management and avoiding unplanned admissions to hospital. A community virtual ward (CVW) model was developed to assist health care professionals to support older persons at home during periods of illness and/or functional decline. METHODS: A quantitative observational study was conducted to examine if a CVW model of care reduced unplanned hospital admissions and emergency department (ED) presentations in 54 patients over a 12-month period. The sign-rank test examined matched data on bed days, ED presentations, and unplanned hospital admissions pre- and post-CVW implementation. Other risk factors for admission to hospital were examined using the Mann-Whitney test pre-and post-CVW admission, including falls, living alone, and cognition. Correlations between hospital admission avoidances and unplanned hospital admissions and ED presentations were tested using Spearman's ρ test. RESULTS: There was a reduction in ED presentations post-CVW admission (P<0.001), and median unscheduled admissions were reduced (P=0.001). Those living alone had a lower number of ED presentations (median 0.5, interquartile range 0-1) prior to admission in comparison to those living with a caregiver, with no differences observed during admission to CVW. For those who experienced a fall during CVW admission, the odds ratio (OR) of requiring long-term care doubled for each extra fall (OR =2.24, 95% CI 1.11 to 4.52, P=0.025). Reduced cognition was associated with an increased risk of ED presentations (ρ=0.292, P<0.05) but not associated with increased risks of unplanned hospital admissions (ρ=0.09, P=0.546). There were no significant correlations seen between admission avoidance and the number of unplanned hospital admissions or ED presentations. CONCLUSION: Through an integrated approach to care, a CVW model in the care of older persons can reduce ED presentations and unplanned hospital admissions.
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Manejo de Caso/organización & administración , Servicio de Urgencia en Hospital/estadística & datos numéricos , Vida Independiente , Telemedicina/organización & administración , Accidentes por Caídas/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , Cognición , Femenino , Anciano Frágil , Humanos , Masculino , Oportunidad Relativa , Factores de RiesgoRESUMEN
Emerging knowledge suggests that post-traumatic stress disorder (PTSD) pathophysiology is linked to the patients' epigenetic changes, but comprehensive studies examining genome-wide methylation have not been performed. In this study, we examined genome-wide DNA methylation in peripheral whole blood in combat veterans with and without PTSD to ascertain differentially methylated probes. Discovery was initially made in a training sample comprising 48 male Operation Enduring Freedom (OEF)/Operation Iraqi Freedom (OIF) veterans with PTSD and 51 age/ethnicity/gender-matched combat-exposed PTSD-negative controls. Agilent whole-genome array detected ~5600 differentially methylated CpG islands (CpGI) annotated to ~2800 differently methylated genes (DMGs). The majority (84.5%) of these CpGIs were hypermethylated in the PTSD cases. Functional analysis was performed using the DMGs encoding the promoter-bound CpGIs to identify networks related to PTSD. The identified networks were further validated by an independent test set comprising 31 PTSD+/29 PTSD- veterans. Targeted bisulfite sequencing was also used to confirm the methylation status of 20 DMGs shown to be highly perturbed in the training set. To improve the statistical power and mitigate the assay bias and batch effects, a union set combining both training and test set was assayed using a different platform from Illumina. The pathways curated from this analysis confirmed 65% of the pool of pathways mined from training and test sets. The results highlight the importance of assay methodology and use of independent samples for discovery and validation of differentially methylated genes mined from whole blood. Nonetheless, the current study demonstrates that several important epigenetically altered networks may distinguish combat-exposed veterans with and without PTSD.
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Metilación de ADN , Trastornos por Estrés Postraumático/genética , Adulto , Campaña Afgana 2001- , Islas de CpG , Epigénesis Genética , Humanos , Guerra de Irak 2003-2011 , Masculino , Persona de Mediana Edad , Regiones Promotoras Genéticas , Veteranos , Salud de los Veteranos , Adulto JovenRESUMEN
The in-cement technique for revision hip arthroplasty involves retaining the original cement-bone interface. This has been proven to be a biomechanically stronger method than recementing after complete removal of the original cement mantle. This study reviewed a series of 54 consecutive revision hip arthroplasty procedures, using the in-cement technique, between November 1999 and November 2003. Clinical and radiological follow-up included functional assessment. There were 54 procedures performed in 51 patients, whose mean age at surgery was 70.3 years (45 to 85). A total of 42 were available at a mean follow-up of 29.2 months (6 to 51). There was no radiological evidence of loosening. Functional assessments were available for 40 patients who had a mean Harris hip score of 85.2 (51.9 to 98.5), a mean Oxford hip score of 19.6 (12 to 41), a mean UCLA activity profile score of 5.9 (3 to 8) and a mean SF-36 score of 78.0 (31.6 to 100). The in-cement technique provides consistent, high functional outcomes and should be considered in appropriately selected cases.
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Artroplastia de Reemplazo de Cadera/métodos , Cementos para Huesos , Acetábulo/cirugía , Actividades Cotidianas , Anciano , Anciano de 80 o más Años , Femenino , Fémur/cirugía , Articulación de la Cadera/diagnóstico por imagen , Articulación de la Cadera/fisiopatología , Articulación de la Cadera/cirugía , Humanos , Masculino , Persona de Mediana Edad , Falla de Prótesis , Radiografía , Reoperación/métodos , Resultado del TratamientoRESUMEN
(1) In the bovine renal epithelial cell line NBL-1, transport of alanine and glutamine is highly Na(+)-dependent while the transport of leucine and phenylalanine is also stimulated by Na+ although to a much lesser extent. (2) Na(+)-dependent alanine transport is insensitive to inhibition by methyl AIB, lysine and glutamate but is inhibited by a range of other neutral amino acids. (3) Inhibition of Na(+)-dependent alanine transport by glutamine, phenylalanine and leucine is competitive indicating that these amino acids are transported on a common carrier. (4) Amino acid transport in these cells appears to be localised preferentially on the basolateral membrane. (5) The results are consistent with the presence in confluent cells of a broad-specificity Na(+)-dependent neutral amino acid transport system (System Bo) similar to that in bovine BBMV. An Na(+)-independent system with high activity similar to System L is also present. (6) It is argued that previous results in the literature are consistent with the occurrence of this broad-specificity system in other renal cell lines.
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Aminoácidos/metabolismo , Riñón/metabolismo , Microvellosidades/metabolismo , Sodio/metabolismo , Animales , Transporte Biológico , Bovinos , Línea Celular , Epitelio/metabolismo , CinéticaRESUMEN
The development of control-relevant models for a variety of biomedical engineering drug delivery problems is reviewed in this paper. A summary of each control problem is followed by a review of relevant patient models from literature, an examination of the control approaches taken to solve the problem, and a discussion of the control-relevance of the models used in each case. The areas examined are regulating the depth of anesthesia, blood pressure control, optimal cancer chemotherapy, regulation of cardiac assist devices, and insulin delivery to diabetic patients.
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Antineoplásicos , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Sistemas de Liberación de Medicamentos , Insulina/administración & dosificación , Neoplasias , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapéutico , Ingeniería Biomédica , Hemodinámica , Humanos , Modelos Biológicos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismoRESUMEN
We have used confocal microscopy to analyze the vagal afferent innervation of the rat heart. Afferents were labeled by injecting 1,1'-dioleyl-3,3,3',3'-tetramethylindocarbocyanine methanesulfonate (DiI) into the nodose ganglia of animals with prior supranodose de-efferentations, autonomic ganglia were stained with Fluoro-gold, and tissues were examined in whole mounts. Distinctively different fiber specializations were observed in the epi-, myo-, and endocardium: Afferents to the epicardium formed complexes associated with cardiac ganglia. These ganglia consisted of four major ganglionated plexuses, two on each atrium, at junctions of the major vessels with the atria. Ganglionic locations and sizes (left > right) were consistent across animals. In addition to principal neurons (PNs), significant numbers of small intensely fluorescent (SIF) cells were located in each of these plexuses, and vagal afferents provided dense pericellular varicose endings around the SIF cells in each ganglionic plexus, with few if any terminations on PNs. In the myocardium, vagal afferents formed close contacts with cardiac muscles, including conduction fibers. In the endocardium, vagal fibers formed "flower-spray" and "end-net" terminals in connective tissue. With three-dimensional reconstruction of confocal optical sections, a novel polymorphism was seen: Some fibers had one or more collaterals ending as endocardial flower sprays and other collaterals ending as myocardial intramuscular endings. Some unipolar or pseudounipolar neurons within each cardiac ganglionic plexus were retrogradely labeled from the nodose ganglia. In conclusion, vagal afferents form a heterogeneity of differentiated endings in the heart, including structured elements which may mediate chemoreceptor function, stretch reception, and local cardiac reflexes.
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Corazón/inervación , Ratas Sprague-Dawley/fisiología , Nervio Vago/fisiología , Vías Aferentes/fisiología , Animales , Carbocianinas , Colorantes Fluorescentes , Ganglios Autónomos/citología , Ganglios Autónomos/fisiología , Atrios Cardíacos/inervación , Atrios Cardíacos/ultraestructura , Masculino , Microscopía Confocal , Miocardio/ultraestructura , Terminaciones Nerviosas/fisiología , Neuronas/ultraestructura , Ratas , Reflejo/fisiología , Vagotomía , Nervio Vago/citología , Nervio Vago/cirugíaRESUMEN
We injected the anterograde fluorescent tracer 1,1'-dioleyl-3,3,3',3'-tetramethylindocarbocyanine methanesulfonate (DiI) into the dorsal motor nucleus of the vagus (DmnX), counterstained the cardiac ganglia with Fluorogold (FG), and used confocal microscopy to examine the distributions and different types of DmnX fibers in wholemounts of the atria. We also quantified the number of DmnX cardiac axons and the number of innervated cardiac principal neurons (PNs). Rats with unilateral DiI injections were used in three different experiments, including unilateral FG soaking of cervical vagal trunks, intracranially rhizotomizing the vagal afferent roots, or contralaterally sectioning the cervical vagus. These manipulations indicated that DiI-labeled cardiac fibers were exclusively from the DmnX. Our observations established that: (1) three major ganglionic plexuses were localized in the epicardium; (2) both sides of the DmnX supplied significant fibers to each of the plexuses; (3) these cardiac efferents formed dense basket terminals around individual PNs; (4) collaterals of individual DmnX fibers diverged, producing calyx endings on multiple PNs; (5) small intensely fluorescent (SIF) cells in the cardiac plexuses were innervated pericellularly; (6) individual axons could innervate both PNs and SIF cells; (7) the total number of DmnX fibers were in the range of [68, 96; left] and [67, 115; right]; (8) these fibers innervated 709 (left) and 494 (right), or at least 18% and 12%, of the PNs, respectively; and (9) vagal preganglionics exhibited a degree of lateralization: Significantly more PNs were contacted by fiber varicosities in the sinoatrial plexus than in the atrioventricular plexus after right DmnX injections. In summary, the present observations suggest that the DmnX plays a significant role(s) in controlling the heart.
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Función Atrial , Ganglios Autónomos/fisiología , Corazón/inervación , Neuronas Motoras/fisiología , Vías Nerviosas/fisiología , Neuronas Eferentes/fisiología , Nervio Vago/fisiología , Animales , Colorantes Fluorescentes , Ganglios Autónomos/citología , Atrios Cardíacos/citología , Masculino , Neuronas Motoras/citología , Fibras Nerviosas/fisiología , Vías Nerviosas/citología , Neuronas Eferentes/citología , Ratas , Ratas Sprague-Dawley/fisiología , Sensibilidad y Especificidad , Nervio Vago/citologíaRESUMEN
For over 30 years, nuclear magnetic resonance (NMR) spectroscopy has been used for chemical analysis and for studying molecular behavior, but NMR imaging is a recent addition to the methods available to radiologists for investigating the interior of the body. It uses radiofrequency radiation in the presence of a magnetic field to produce anatomical cross sections. The images may be simple maps of the concentration of the hydrogen nucleus, or they may depend on tissue relaxation times, which describe how rapidly hydrogen nuclei exchange energy with their surroundings. In this article, the basic concepts and physical principles of conventional NMR spectroscopy are introduced. In subsequent articles, the various approaches to producing NMR images will be outlined, and the types of information obtainable from NMR scanners will be discussed.
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Espectroscopía de Resonancia MagnéticaRESUMEN
Poly(diethylaminoethyl-g-ethylene glycol) microparticles were prepared by suspension polymerization of diethylaminoethyl methacrylate, poly(ethylene glycol) monomethacrylate and the crosslinking agent tetra(ethylene glycol) dimethacrylate in silicone oil using redox initiators. Particles of different sizes, crosslinking ratios and graft molecular weights were prepared. The changes in the swelling of the particles were studied as the pH was changed between 3.0 and 7.4. The particles showed rapid swelling/deswelling dynamics in response to changes in pH. It was evident that faster response could be obtained from smaller particles. Changing the crosslinking ratio resulted in changes in the extent of swelling, as well as the speed of response. It was also found that longer graft lengths were responsible for increasing the effect of relaxation of the swelling of the network.
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Materiales Biocompatibles , Glucosa Oxidasa , Hidrogeles/química , Metacrilatos/química , Polietilenglicoles/química , Portadores de Fármacos , Concentración de Iones de Hidrógeno , Cinética , Microesferas , Relación Estructura-ActividadRESUMEN
Glucose oxidase and catalase were immobilized on poly(diethylaminoethyl methacrylate-g-ethylene glycol) gels by copolymerization of the constituent monomers and the functionalized enzyme solutions. The hydrogels were prepared in the form of discs and microparticles. The amount and the activity of enzymes immobilized in the matrix were determined. The hydrogels were tested for their response to glucose by exposing microparticles to varying concentrations of glucose. The generation of gluconic acid as a result of the reaction of glucose with oxygen was investigated as a function of polymer parameters, such as crosslinking ratio and enzyme loading. Pulsatile variation of the glucose concentration was used to confirm the glucose-dependent swelling properties of these hydrogels.