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1.
Can J Surg ; 64(2): E162-E172, 2021 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-33720676

RESUMEN

Background: There is currently no integrated data system to capture the true burden of injury and its management within Ontario's regional trauma networks (RTNs), largely owing to difficulties in identifying these patients across the multiple health care provider records. Our project represents an iterative effort to create the ability to chart the course of care for all injured patients within the Central South RTN. Methods: Through broad stakeholder engagement of major health care provider organizations within the Central South RTN, we obtained research ethics board approval and established data-sharing agreements with multiple agencies. We tested identification of trauma cases from Jan. 1 to Dec. 31, 2017, and methods to link patient records between the various echelons of care to identify barriers to linkage and opportunities for administrative solutions. Results: During 2017, potential trauma cases were identified within ground paramedic services (23 107 records), air medical transport services (196 records), referring hospitals (7194 records) and the lead trauma hospital trauma registry (1134 records). Linkage rates for medical records between services ranged from 49% to 92%. Conclusion: We successfully conceptualized and provided a preliminary demonstration of an initiative to collect, collate and accurately link primary data from acute trauma care providers for certain patients injured within the Central South RTN. Administration-level changes to the capture and management of trauma data represent the greatest opportunity for improvement.


Contexte: On ne dispose actuellement d'aucun système intégré de gestion des données pour évaluer le fardeau réel des traumatismes et de leur gestion dans les réseaux régionaux de traumatologie (RRT) en Ontario, en bonne partie en raison de la difficulté d'identifier les cas parmi la multiplicité des dossiers d'intervenants médicaux. Notre projet représente un effort itératif pour créer la capacité de cartographier le parcours de soin de tous les polytraumatisés du RRT de la région Centre-Sud. Méthodes: Grâce à l'engagement général des intervenants des grandes organisations de santé du RRT de la région Centre-Sud, nous avons obtenu l'approbation d'un comité d'éthique de la recherche et conclu des accords de partage des données avec plusieurs agences. Nous avons testé l'identification des cas de traumatologie du 1er janvier au 31 décembre 2017 et les méthodes de liaison des dossiers de patients entre les divers échelons de soin pour identifier les obstacles à la liaison et leurs solutions administratives possibles. Résultats: Au cours de 2017, les cas de traumatologie potentiels ont été identifiés auprès des services ambulanciers terrestres (23 107 dossiers), des services de transport médical aérien (196 dossiers), des hôpitaux référents (7194 dossiers) et du registre hospitalier principal de traumatologie (1134 dossiers). Les taux de liaison entre les différents services pour les dossiers médicaux variaient de 49 % à 92 %. Conclusion: Nous avons conceptualisé et présenté avec succès la démonstration préliminaire d'un projet visant à recueillir, colliger et relier avec justesse les données primaires des intervenants en traumatologie aiguë pour certains patients blessés du RRT du Centre-Sud. Des changements administratifs centrés sur la saisie et la gestion des données de traumatologie représentent la meilleure voie vers une amélioration.


Asunto(s)
Registro Médico Coordinado/normas , Mejoramiento de la Calidad , Centros Traumatológicos/organización & administración , Centros Traumatológicos/normas , Heridas y Lesiones , Humanos , Ontario , Heridas y Lesiones/terapia
2.
Phys Chem Chem Phys ; 21(29): 15974-15987, 2019 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-31294442

RESUMEN

Metal/semiconductor interactions affect electron transfer rates and this is central to photocatalytic hydrogen ion reduction. While this interaction has been studied in great detail on metal oxide semiconductors, not much is known of Au particles on top of polymeric semiconductors. The effects of gold nanoparticle size and dispersion on top of g-C3N4 were studied by core and valence level spectroscopy and transmission electron microscopy in addition to catalytic tests. The as-prepared, non-calcined catalysts displayed Au particles with uniform dimension (mean particle size = 1.8 nm) and multiple electronic states: XPS Au 4f7/2 lines at 84.9 and 87.1 eV (each with a spin-orbit splitting of 3.6-3.7 eV). These particles, which did not show localized surface plasmon resonance (LSPR), before the reaction, doubled in size after the reaction giving a pronounced LSPR at about 550 nm. The effect of the heating environment on these particles (in air or in H2) was further investigated. While heating in H2 gave Au nanoparticles of different shapes, heating under O2 gave exclusively spherical particles. Similar activity towards photocatalytic hydrogen ion reduction under UV excitation was seen in both cases, however. XPS Au 4f analyses indicated that an increase in deposition time, during catalyst preparation, resulted in an increase in the initial fraction of oxidized gold particles, which were easily reduced under hydrogen. The valence band region for Au/gC3N4 was further studied in an effort to compare it to what is already known for Au/metal oxide semiconductors. A shift of over 2 eV for the Au 5d doublets was noticed between reduced and oxidized gold particles with mean particle sizes between 2 and 6 nm, which is consistent with the final state effect. A narrow range of gold loading for optimal catalytic performance was seen, where it seems that a density of one Au particle per 10 × 10 nm2 is the most suitable. Particle size and shape had a minor effect on performance, which may indicate the absence of a plasmonic effect on the reaction rate.

3.
Faraday Discuss ; 190: 551-9, 2016 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-27483385

RESUMEN

Liquid salts comprising molten salts and ionic liquids offer important media to address both energy and materials challenges. Here we review topics presented in this Faraday Discussion volume related to improved electrowinning of metals, optimisation of processes, new electrochemical device concepts, chemistry in ionic liquids, conversion of biomass, carbon chemistry and nuclear applications. The underlying phenomenology is then reviewed and commentary given. Some future applications are then discussed, further exemplifying the high potential rewards achievable from these chemistries.

4.
Phys Chem Chem Phys ; 18(29): 19738-45, 2016 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-27384817

RESUMEN

The field of organo-lead halide perovskite solar cells has been rapidly growing since their discovery in 2009. State of the art devices are now achieving efficiencies comparable to much older technologies like silicon, while utilising simple manufacturing processes and starting materials. A key parameter to consider when optimising solar cell devices or when designing new materials is the position and effects of the energy levels in the materials. We present here a comprehensive study of the energy levels present in a common structure of perovskite solar cell using an advanced macroscopic Kelvin probe and UV air photoemission setup. By constructing a detailed map of the energy levels in the system we are able to predict the importance of each layer to the open circuit voltage of the solar cell, which we then back up through measurements of the surface photovoltage of the cell under white illumination. Our results demonstrate the effectiveness of air photoemission and Kelvin probe contact potential difference measurements as a method of identifying the factors contributing to the open circuit voltage in a solar cell, as well as being an excellent way of probing the physics of new materials.

5.
Phys Chem Chem Phys ; 17(21): 13929-36, 2015 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-25948234

RESUMEN

Loading of a co-catalyst on the surface of a semiconductor photocatalyst is often carried out without considering the effect of the loading procedure on the final product. The present study looks in detail at the effect that the loading method has on the morphology and final composition of platinum-based nanoparticles by means of XPS and TEM analysis. Additionally, reduction pre-treatments are performed to investigate how the coverage, crystallinity and composition of the NPs affect the photocatalytic H2 evolution. The activity of Pt-g-C3N4 can significantly be enhanced by controlling the properties of the co-catalyst NPs.

6.
Nat Commun ; 14(1): 4389, 2023 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-37474517

RESUMEN

Recently nitrogen-hydrogen compounds have successfully been applied as co-catalysts for mild conditions ammonia synthesis. Ca2NH was shown to act as a H2 sink during reaction, with H atoms from its lattice being incorporated into the NH3(g) product. Thus the ionic transport and diffusion properties of the N-H co-catalyst are fundamentally important to understanding and developing such syntheses. Here we show hydride ion conduction in these materials. Two distinct calcium nitride-hydride Ca2NH phases, prepared via different synthetic paths are found to show dramatically different properties. One phase (ß) shows fast hydride ionic conduction properties (0.08 S/cm at 600 °C), on a par with the best binary ionic hydrides and 10 times higher than CaH2, whilst the other (α) is 100 times less conductive. An in situ combined analysis techniques reveals that the effective ß-phase conducts ions via a vacancy-mediated phenomenon in which the charge carrier concentration is dependent on the ion concentration in the secondary site and by extension the vacancy concentration in the main site.

7.
Can J Rural Med ; 27(1): 16-21, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34975112

RESUMEN

INTRODUCTION: The HEART scoring system codifies the clinical gestalt used by physicians with 0-2 points assigned to 5 criteria (history, electrocardiography, age, risk factors and troponin). This scoring provides a prognostic tool that assists in disposition planning. The use of a truncated HEART score, minus the troponin data (HEAR score), was used for patients presenting with chest pain at one of four outpost nursing stations served by La Ronge Health Centre in northern Saskatchewan. These nursing stations have no onsite physician and no ability to obtain any troponin data. This study set out to determine if there was any utility in conducting point-of-care (PoC) troponins in these nursing outposts. MATERIALS AND METHODS: A retrospective analysis was conducted using the La Ronge regional electronic medical record by searching for all patients for whom an outpost nurse had called a physician regarding chest pain symptoms between 01 January 2011 and 31 December 2016. The HEAR and HEART score were then calculated for each individual presentation of patients with chest pain that met inclusion and exclusion criteria. RESULTS: By calculating both the patient's HEART score before evacuation from the outposts and after (i.e. with the troponin data), we were able to determine that, in 89.4% of cases (110/123 events), patients would require evacuation regardless of the troponin values due to a HEART score ≥4. In 10.6% (13/124 events) of cases, the patients who were evacuated had a HEART score ≤3, and in only one case did the troponin data increase this score. CONCLUSIONS: The majority of patients would continue to be evacuated regardless of the result of their PoC troponin due to an already elevated HEAR score. PoC troponin is unlikely to reduce the rate of evacuation of patients with chest pain from the nursing stations served by the La Ronge Health Centre.


Résumé Introduction: Le système de pointage HEART codifie la gestalt clinique utilisée par les médecins avec 0­2 points attribués à 5 critères (anamnèse, ECG, âge, facteurs de risque, troponine). Ce pointage est un outil pronostique qui aide à planifier les soins aux patients. Un score HEART tronqué, c'est-à-dire moins les données de troponine (score HEAR), a été utilisé chez les patients qui se présentaient pour douleur thoracique à 1 des 4 avant-postes de soins infirmiers servis par le centre La Ronge Health Centre au nord de la Saskatchewan. Il n'y a pas de médecin sur place à ces postes de soins infirmiers, et il est impossible d'obtenir des données sur la troponine. Cette étude voulait déterminer si le dosage ciblé de troponine est utile dans ces avant-postes de soins infirmiers. Méthodes: Une analyse rétrospective a été réalisée à l'aide du dossier médical électronique de la région de La Ronge après une recherche de tous les patients pour lesquels un avant-poste de soins infirmiers avait appelé un médecin pour des symptômes de douleur thoracique entre le 1er Janvier 2011 et le 31 Décembre 2016. Les scores HEAR et HEART ont alors été calculés pour chaque cas de douleur thoracique qui répondait aux critères d'inclusion et d'exclusion. Résultats: En calculant le score HEART (c.-à-d. avec les données sur la troponine) avant et après l'évacuation du patient de l'avant-poste, nous avons pu déterminer que dans 89,4% des cas (110/123 événements), les patients devraient être évacués sans égard aux valeurs de troponine en raison d'un score HEART ≤3 et la troponine a augmenté ce score dans un seul cas. Conclusions: La majorité des patients continueraient d'être évacués, peu importe les résultats de troponine ciblée en raison d'un score HEAR déjà élevé. La troponine ciblée ne réduirait probablement pas le taux d'évacuation des patients pour douleur thoracique des postes de soins infirmiers servis par le centre La Ronge Health Centre. Mots-clés: Maladie cardiaque, médecine rurale, score HEART, troponine.


Asunto(s)
Sistemas de Atención de Punto , Troponina , Dolor en el Pecho/diagnóstico , Electrocardiografía , Servicio de Urgencia en Hospital , Humanos , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo
8.
Epidemiol Infect ; 138(5): 730-7, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20092664

RESUMEN

In this case-control study, cases [community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), n=79] and controls [community-associated methicillin-susceptible S. aureus (CA-MSSA), n=36] were defined as a laboratory-confirmed infection in a patient with no previous hospital-associated factors. Skin and soft tissue were the predominant sites of infection, both for cases (67.1%) and controls (55.6%). Most of the cases (79.7%) and controls (77.8%) were aged <30 years. Investigations did not reveal any significant statistical differences in acquiring a CA-MRSA or CA-MSSA infection. The most common shared risk factors included overcrowding, previous antibiotic usage, existing skin conditions, household exposure to someone with a skin condition, scratches/insect bites, and exposure to healthcare workers. Similar risk factors, identified for both CA-MRSA and CA-MSSA infections, suggest standard hygienic measures and proper treatment guidelines would be beneficial in controlling both CA-MRSA and CA-MSSA in remote communities.


Asunto(s)
Infecciones Comunitarias Adquiridas/epidemiología , Resistencia a la Meticilina , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Antibacterianos/uso terapéutico , Estudios de Casos y Controles , Niño , Preescolar , Infecciones Comunitarias Adquiridas/microbiología , Aglomeración , Utilización de Medicamentos/estadística & datos numéricos , Salud de la Familia , Femenino , Humanos , Lactante , Mordeduras y Picaduras de Insectos/complicaciones , Masculino , Persona de Mediana Edad , Factores de Riesgo , Infecciones de los Tejidos Blandos/epidemiología , Infecciones de los Tejidos Blandos/microbiología , Infecciones Estafilocócicas/microbiología , Infecciones Cutáneas Estafilocócicas/epidemiología , Infecciones Cutáneas Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Adulto Joven
10.
Science ; 269(5231): 1714-8, 1995 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-17821643

RESUMEN

Independent domestication of sorghum, rice, and maize involved convergent selection for large seeds, reduced disarticulation of the mature inflorescence, and daylength-insensitive flowering. These similar phenotypes are largely determined by a small number of quantitative trait loci (QTLs) that correspond closely in the three taxa. The correspondence of these QTLs transcends 65 million years of reproductive isolation. This finding supports models of quantitative inheritance that invoke relatively few genes, obviates difficulties in map-based cloning of QTLs, and impels the comparative mapping of complex pheno-types across large evolutionary distances, such as those that separate humans from rodents and domesticated mammals.

11.
Psychoneuroendocrinology ; 93: 133-141, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29727810

RESUMEN

There is a need to identify new and more effective treatments for posttraumatic stress disorder (PTSD). Allopregnanolone and its stereoisomer pregnanolone (together termed ALLO) are metabolites of progesterone that positively and allosterically modulate GABA effects at GABAA receptors, thereby reducing anxiety and depression. Previous research revealed that women with PTSD had low cerebrospinal fluid (CSF) ALLO levels and a low ratio of ALLO to the allopregnanolone precursor 5α-DHP, consistent with deficient activity of the ALLO synthetic enzyme 3α-hydroxysteroid dehydrogenase (3α-HSD). The current study examined ALLO and the ratio of ALLO to 5α-DHP in plasma at rest and in response to psychophysiological stressors in trauma-exposed, medication-free women with and without PTSD. Participants were examined twice in random order during the early follicular phase (eFP) and mid-luteal phase (mLP) of the menstrual cycle. Plasma neurosteroids were measured using gas chromatography-mass spectrometry. Results indicate that the ALLO to 5α-DHP ratio in plasma increases between the eFP and mLP. In addition, women with PTSD have a lower ratio of ALLO to 5α-DHP than trauma-exposed healthy women, as well as blunted increases in this ratio in response to a moderately stressful laboratory procedure, i.e., differential fear conditioning, across the menstrual cycle. Clinically feasible testing for 3α-HSD dysfunction is critical to translating this line of research into clinical care. Measurement of this ratio in plasma could facilitate patient stratification in clinical treatment trials, as well as precision medicine targeting of treatments that address ALLO synthesis deficits in women with PTSD.


Asunto(s)
Pregnanolona/metabolismo , Progesterona/metabolismo , Trastornos por Estrés Postraumático/fisiopatología , 5-alfa-Dihidroprogesterona/metabolismo , Adulto , Femenino , Fase Folicular , GABAérgicos , Humanos , Hidroxiesteroide Deshidrogenasas/metabolismo , Fase Luteínica , Ciclo Menstrual , Neurotransmisores/análisis , Neurotransmisores/sangre , Neurotransmisores/metabolismo , Pregnanolona/análisis , Pregnanolona/sangre , Receptores de GABA/metabolismo , Receptores de GABA-A/metabolismo , Trastornos por Estrés Postraumático/metabolismo
12.
Nanoscale ; 8(12): 6623-8, 2016 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-26939617

RESUMEN

Device grade silicon nanocrystals (NCs) are synthesized using an atmospheric-pressure plasma technique. The Si NCs have a small and well defined size of about 2.3 nm. The synthesis system allows for the direct creation of thin films, enabling a range of measurements to be performed and easy implementation of this material in different devices. The chemical stability of the Si NCs is evaluated, showing relatively long-term durability thanks to hydrogen surface terminations. Optical and electrical characterization techniques, including Kelvin probe, ultraviolet photoemission spectroscopy and Mott-Schottky analysis, are employed to determine the energy band diagram of the Si NCs.

13.
Cell Death Differ ; 7(1): 80-8, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10713723

RESUMEN

Depending on the cellular context, the Myc oncoprotein is capable of promoting cell proliferation or death by apoptosis. These observations suggest that apoptosis in response to deregulated gene expression may represent a natural brake to tumour development. The pathways by which Myc induces apoptosis are as yet poorly characterised although recent observations on rat fibroblasts over-expressing Myc have demonstrated a requirement for the Fas pathway. To investigate the role of Fas in Myc-induced lymphomagenesis we backcrossed CD2-myc mice onto an lpr background. Rates of tumour development and phenotypic properties, including levels of apoptosis were indistinguishable from CD2-myc controls. Further, tumour cell lines derived from mice expressing a regulatable form of Myc showed inducible apoptosis at similar rates regardless of their lpr genotype. These results show that activation of c-myc and loss of Fas do not collaborate in T lymphoma development and that Myc-induced apoptosis in T-cells occurs by Fas-independent pathways.


Asunto(s)
Apoptosis , Antígenos CD2/metabolismo , Linfoma de Células T/patología , Proteínas Proto-Oncogénicas c-myc/metabolismo , Receptor fas/metabolismo , Animales , Antígenos CD2/genética , Transformación Celular Neoplásica , Femenino , Virus de la Leucemia Murina/genética , Linfoma , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Ratones Endogámicos MRL lpr , Fenotipo , Proteínas Proto-Oncogénicas c-myc/genética , Provirus/genética , Timo/citología , Transgenes , Células Tumorales Cultivadas , Integración Viral
14.
Genetics ; 150(4): 1663-82, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9832541

RESUMEN

The complex polyploid genomes of three Saccharum species have been aligned with the compact diploid genome of Sorghum (2n = 2x = 20). A set of 428 DNA probes from different Poaceae (grasses) detected 2460 loci in F1 progeny of the crosses Saccharum officinarum Green German x S. spontaneum IND 81-146, and S. spontaneum PIN 84-1 x S. officinarum Muntok Java. Thirty-one DNA probes detected 226 loci in S. officinarum LA Purple x S. robustum Molokai 5829. Genetic maps of the six Saccharum genotypes, including up to 72 linkage groups, were assembled into "homologous groups" based on parallel arrangements of duplicated loci. About 84% of the loci mapped by 242 common probes were homologous between Saccharum and Sorghum. Only one interchromosomal and two intrachromosomal rearrangements differentiated both S. officinarum and S. spontaneum from Sorghum, but 11 additional cases of chromosome structural polymorphism were found within Saccharum. Diploidization was advanced in S. robustum, incipient in S. officinarum, and absent in S. spontaneum, consistent with biogeographic data suggesting that S. robustum is the ancestor of S. officinarum, but raising new questions about the antiquity of S. spontaneum. The densely mapped Sorghum genome will be a valuable tool in ongoing molecular analysis of the complex Saccharum genome.


Asunto(s)
ADN de Plantas , Diploidia , Plantas Comestibles/genética , Poliploidía , Grano Comestible/genética , Duplicación de Gen , Reordenamiento Génico , Genoma de Planta , Polimorfismo Genético , Recombinación Genética
15.
Arch Intern Med ; 156(13): 1414-20, 1996 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-8678709

RESUMEN

BACKGROUND: Although current ideology suggests patients should be active participants in decision making about their care, the literature suggests that patients wish to be informed but not involved. OBJECTIVE: To test the hypothesis that most patients want their physicians to take the responsibility for problem solving (PS, identifying the one right answer), but that many want to be involved in decision-making (DM, selecting the most desired bundle of outcomes) tasks. METHODS: Survey responses from 300 patients undergoing angiogram at a Toronto, Ontario, hospital were analyzed (response rate, 72%). Survey items included scales to measure desire for information and participation, including Autonomy Preference Index, the Krantz Health Opinion Survey, and the Deber-Kraetschmer Problem-Solving Decision-Making Scale measured on a scale from, 1 (doctor only) to 5 (patient only). RESULTS: Patients had a relatively high desire for information. On the Problem-Solving Decision-Making Scale, they overwhelmingly wished the PS tasks to be performed by or shared with the physician (98.4% of the 12 PS scores are between 1 and 3), but wanted to be involved in DM (78% of the 6 DM scores are between 3 and 5). Preference for handing over control to the physician was significantly greater for the vignette involving potential mortality (chest pain) than for the vignettes involving mainly morbidity (urinary problems) or quality of life (fertility). CONCLUSIONS: Although patients do not wish to be involved in PS tasks, few wish to hand over DM control to their physician. These findings suggest 2 major roles for clinicians--assisting patients in PS to structure choices and supporting them in making often difficult decisions.


Asunto(s)
Actitud Frente a la Salud , Revelación , Participación del Paciente/estadística & datos numéricos , Relaciones Médico-Paciente , Toma de Decisiones , Femenino , Hospitales de Enseñanza , Humanos , Masculino , Persona de Mediana Edad , Ontario , Solución de Problemas , Medición de Riesgo , Valores Sociales , Encuestas y Cuestionarios
16.
Endocrinology ; 128(5): 2345-52, 1991 May.
Artículo en Inglés | MEDLINE | ID: mdl-2019254

RESUMEN

A putative prohormone-processing enzyme complex with specificity toward basic residues was partially purified from whole bovine pituitary glands. The complex is basic, binding to S-Sepharose at pH 8.2. The pH optimum of the enzyme is around 8.0. The enzyme is capable of cleaving proenkephalin and is present in at least three forms with relative molecular masses of about 36,000, 58,000, and 90,000 Da. The proteinase complex is inhibited by soybean trypsin inhibitor, limabean trypsin inhibitor, and aprotinin, but not by inhibitors of thiol proteinases or metal chelators. Our results indicate that this proteinase is a trypsin-like serine esterase with properties appropriate to that of a prohormone-processing enzyme.


Asunto(s)
Hormonas/metabolismo , Hipófisis/enzimología , Animales , Bovinos , Fraccionamiento Químico , Cromatografía , Electroforesis en Gel de Poliacrilamida , Métodos , Peso Molecular , Inhibidores de Proteasas/farmacología
17.
Hypertension ; 18(1): 72-8, 1991 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1860714

RESUMEN

Type A behavior has been associated with coronary heart disease as well as high cholesterol and smoking, major risk factors for coronary heart disease, but the data indicating a similar association with hypertension are inconsistent. Since past studies have usually based hypertension on a single blood pressure assessment or have often included treated hypertensive patients, this inconsistency is not surprising. The current study compared the prevalence of Type A behavior (assessed by Rosenman's structured interview) between 109 untreated hypertensive subjects and 109 age-, sex-, ethnic-, and occupation-matched normotensive subjects. Hypertension status was based on five repeated assessments over a 5-month period. Results indicated that Type A behavior is more prevalent in untreated, mildly hypertensive employed individuals than occupationally matched normotensive subjects. Type A component analysis confirmed the importance of hostility and certain vigorous voice stylistics in predicting cardiovascular conditions. These findings, taken together with the evidence linking Type A behavior with high cholesterol and cigarette smoking, further support the view that this behavior pattern is associated with increased risk of coronary heart disease.


Asunto(s)
Hipertensión/psicología , Personalidad Tipo A , Adulto , Presión Sanguínea , Femenino , Humanos , Masculino , Persona de Mediana Edad , Determinación de la Personalidad
18.
Invest Ophthalmol Vis Sci ; 17(10): 1005-18, 1978 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-100463

RESUMEN

Experimental histoplasmic choroiditis was produced in primates by intracarotid injections of living H. capsulatum organisms. The severity of the choroiditis varied with inoculum size, as well as with site of injection (common carotid vs. internal carotid artery). A reproducible model of histoplasmic choroiditis in primates was produced with an internal carotid injection of 5,000 to 10,000 organisms/lb. The clinical and histopathological course of this acute choroiditis over the first 30 days is presented.


Asunto(s)
Coroiditis/patología , Modelos Animales de Enfermedad , Histoplasmosis/patología , Enfermedad Aguda , Animales , Arterias Carótidas , Arteria Carótida Interna , Angiografía con Fluoresceína , Haplorrinos , Inyecciones Intraarteriales , Macaca , Macaca mulatta
19.
Br J Pharmacol ; 137(4): 538-44, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12359636

RESUMEN

1. The aim of the present study was to determine the relative contribution of prostanoids, nitric oxide and K(+) channels in the bradykinin-induced relaxation of bovine pulmonary supernumerary arteries. 2. In endothelium-intact, but not denuded rings, bradykinin produced a concentration-dependent relaxation (pEC(50), 9.6+/-0.1), which was unaffected by the cyclo-oxygenase inhibitor indomethacin. The nitric oxide scavenger hydroxocobalamin (200 micro M, pEC(50), 8.5+/-0.2) and the nitric oxide synthase inhibitor L-NAME (100 micro M, pEC(50), 8.9+/-0.1) and the combination of L-NAME and hydroxocobalamin (pEC(50), 8.1+/-0.2) produced rightward shifts in the bradykinin concentration response curve. 3. The guanylyl cyclase inhibitor ODQ (10 micro M, pEC(50), 9.6+/-0.4) did not affect the response to bradykinin. 4. Elevating the extracellular [K(+)] to 30 mM did not affect the response to bradykinin but abolished the response when ODQ or L-NAME was present. 5. The K(+) channel blocker apamin (100 nM), combined with charybdotoxin (100 nM), produced a small reduction in the maximum response to bradykinin but they abolished the response to bradykinin when ODQ, L-NAME or hydroxocobalamin were present. Apamin (100 nM) combined with iberiotoxin (100 nM) also reduced the response to bradykinin in the presence of hydroxocobalamin or L-NAME. 6. The concentration response curve for sodium nitroprusside-induced relaxation was abolished by ODQ (10 micro M) and shifted to the right by apamin and charybdotoxin. 7. These studies suggest that in bovine pulmonary supernumerary arteries bradykinin can stimulate the formation of nitric oxide and activate an EDHF-like mechanism and that either of these pathways alone can mediate the bradykinin-induced relaxation. In addition nitric oxide, acting through guanylyl cyclase, can activate an apamin/charbydotoxin-sensitive K(+) channel in this tissue.


Asunto(s)
Bradiquinina/farmacología , Óxido Nítrico/fisiología , Arteria Pulmonar/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Animales , Bovinos , Relación Dosis-Respuesta a Droga , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/fisiología , Inhibidores Enzimáticos/farmacología , Técnicas In Vitro , Óxido Nítrico/antagonistas & inhibidores , Bloqueadores de los Canales de Potasio/farmacología , Arteria Pulmonar/fisiología , Vasodilatación/fisiología
20.
Int J Parasitol ; 29(4): 567-79, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10428633

RESUMEN

Living in the high Arctic, the Svalbard reindeer (Rangifer tarandus platyrhynchus) and its trichostrongyle nematodes experience a long cold winter from October to late May/early June. Over this period, transmission would be expected to be low. However, in culled reindeer the abundance of infection increased from autumn to late winter, providing evidence for continued transmission within this period. To our knowledge this is the first time this has been demonstrated in a climate with temperatures consistently below 0 degrees C. In one winter (1996-1997), the average fraction of nematodes found as larvae in the abomasal mucosa increased from around 10% to 50% between October and March. This suggests that arrested development took place throughout the winter. We found no evidence for an efficient acquired immune response towards the nematodes. The abundance of infection did not tend to decrease with increasing host age after an earlier peak, but levelled off instead, as predicted by a simple immigration-death model. In the late winter when the nutritional plane is low, both adult reindeer and calves had high worm burdens at intensities that may affect their condition and fitness.


Asunto(s)
Infecciones por Nematodos/veterinaria , Reno/parasitología , Gastropatías/veterinaria , Abomaso/parasitología , Factores de Edad , Animales , Regiones Árticas , Femenino , Larva , Masculino , Infecciones por Nematodos/transmisión , Recuento de Huevos de Parásitos , Estaciones del Año , Gastropatías/parasitología
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