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1.
Can J Anaesth ; 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38955983

RESUMEN

PURPOSE: We aimed to identify whether social determinants of health (SDoH) are associated with the development of sepsis and assess the differences between individuals living within systematically disadvantaged neighbourhoods compared with those living outside these neighbourhoods. METHODS: We conducted a single-centre case-control study including 300 randomly selected adult patients (100 patients with sepsis and 200 patients without sepsis) admitted to the emergency department of a large academic tertiary care hospital in Hamilton, ON, Canada. We collected data on demographics and a limited set of SDoH variables, including neighbourhood household income, smoking history, social support, and history of alcohol disorder. We analyzed study data using multivariate logistic regression models. RESULTS: The study included 100 patients with sepsis with a median [interquartile range (IQR)] age of 75 [58-84] yr and 200 patients without sepsis with a median [IQR] age of 72 [60-83] yr. Factors significantly associated with sepsis included arrival by ambulance, absence of a family physician, higher Hamilton Early Warning Score, and a recorded history of dyslipidemia. Important SDoH variables, such as individual or household income and race, were not available in the medical chart. In patients with SDoH available in their medical records, no SDoH was significantly associated with sepsis. Nevertheless, compared with their proportion of the Hamilton population, the rate of sepsis cases and sepsis deaths was approximately two times higher among patients living in systematically disadvantaged neighbourhoods. CONCLUSIONS: This study revealed the lack of available SDoH data in electronic health records. Despite no association between the SDoH variables available and sepsis, we found a higher rate of sepsis cases and sepsis deaths among individuals living in systematically disadvantaged neighbourhoods. Including SDoH in electronic health records is crucial to study their effect on the risk of sepsis and to provide equitable care.


RéSUMé: OBJECTIF: Nous avons cherché à déterminer si les déterminants sociaux de la santé (DSS) étaient associés à l'apparition de sepsis et à évaluer les différences entre les personnes vivant dans des quartiers systématiquement défavorisés et celles vivant à l'extérieur de ces quartiers. MéTHODE: Nous avons mené une étude cas témoins monocentrique portant sur 300 patient·es adultes sélectionné·es au hasard (100 personnes atteintes de sepsis et 200 témoins sans sepsis) admis·es au service des urgences d'un grand hôpital universitaire de soins tertiaires à Hamilton, ON, Canada. Nous avons recueilli des données démographiques et un ensemble limité de variables de DSS, y compris le revenu des ménages du quartier, les antécédents de tabagisme, le soutien social et les antécédents de troubles liés à l'alcool. Nous avons analysé les données de l'étude à l'aide de modèles de régression logistique multivariés. RéSULTATS: L'étude a inclus 100 patient·es atteint·es de sepsis avec un âge médian [écart interquartile (ÉIQ)] de 75 [58-84] ans et 200 patient·es sans sepsis avec un âge médian [ÉIQ] de 72 [60-83] ans. Les facteurs significativement associés au sepsis comprenaient l'arrivée en ambulance, l'absence de médecin de famille, un score Hamilton Early Warning Score plus élevé et des antécédents enregistrés de dyslipidémie. D'importantes variables de DSS, telles que le revenu individuel et du ménage et la race, n'étaient pas disponibles dans le dossier médical. Chez les personnes dont les DSS étaient disponibles dans leur dossier médical, aucun DSS n'était significativement associé au sepsis. Néanmoins, comparativement à leur proportion dans la population de Hamilton, le taux de cas de sepsis et de décès dus au sepsis était environ deux fois plus élevé chez les personnes vivant dans des quartiers systématiquement défavorisés. CONCLUSION: Cette étude a révélé le manque de données disponibles sur les DSS dans les dossiers de santé électroniques. Bien qu'il n'y ait pas d'association entre les variables disponibles et le sepsis, nous avons constaté un taux plus élevé de cas de sepsis et de décès dus à la septicémie chez les personnes vivant dans des quartiers systématiquement défavorisés. L'inclusion des DSS dans les dossiers de santé électroniques est cruciale pour étudier leur effet sur le risque de sepsis et pour dispenser des soins équitables.

2.
Thorax ; 78(12): 1248-1253, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37423763

RESUMEN

INTRODUCTION: Airway disease exacerbations are cyclical related to respiratory virus prevalence. The COVID-19 pandemic has been associated with reduced exacerbations possibly related to public health measures and their impact on non-COVID-19 respiratory viruses. We aimed to investigate the prevalence of non-COVID-19 respiratory viruses during the pandemic compared with prior in Ontario, Canada and healthcare utilisation related to asthma, chronic obstructive pulmonary disease (COPD) and respiratory tract infection. METHODS: This is a population-based retrospective analysis of respiratory virus tests, emergency department (ED) visits and hospitalisations between 2015 and 2021 in Ontario. Weekly virus testing data were used to estimate viral prevalence for all non-COVID-19 respiratory viruses. We plotted the %positivity and observed and expected counts of each virus to visualise the impact of the pandemic. We used Poisson and binomial logistic regression models to estimate the change in %positivity, count of positive viral cases and count of healthcare utilisation during the pandemic. RESULTS: The prevalence of all non-COVID-19 respiratory viruses decreased dramatically during the pandemic compared with prior. Comparing periods, the incidence rate ratio (IRR) for positive cases corresponded to a >90% reduction for non-COVID-19 respiratory viruses except adenovirus and rhino/enterovirus. Asthma-related ED visits and hospital admissions fell by 57% (IRR 0.43 (95% CI 0.37 to 0.48)) and 61% (IRR 0.39 (95% CI 0.33 to 0.46)). COPD-related ED visits and admissions fell by 63% (IRR 0.37 (95% CI 0.30 to 0.45)) and 45% (IRR 0.55 (95% CI 0.48 to 0.62)). Respiratory tract infection ED visits and admissions fell by 85% (IRR 0.15 (95% CI 0.10 to 0.22)), and 85% (IRR 0.15 (95% CI 0.09 to 0.24)). Rather than the usual peaks in disease condition, during the pandemic, healthcare utilisation peaked in October when rhino/enterovirus peaked. CONCLUSIONS: The prevalence of nearly all non-COVID-19 respiratory viruses decreased during the pandemic and was associated with marked reductions in ED visits and hospitalisations. The re-emergence of rhino/enterovirus was associated with increased healthcare utilisation.


Asunto(s)
Asma , COVID-19 , Enterovirus , Enfermedad Pulmonar Obstructiva Crónica , Infecciones del Sistema Respiratorio , Humanos , Pandemias , Estudios Retrospectivos , Prevalencia , COVID-19/epidemiología , COVID-19/complicaciones , Asma/epidemiología , Asma/terapia , Asma/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Enfermedad Pulmonar Obstructiva Crónica/terapia , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/terapia , Infecciones del Sistema Respiratorio/complicaciones , Aceptación de la Atención de Salud , Ontario/epidemiología , Servicio de Urgencia en Hospital
3.
Clin Pharmacol Ther ; 111(6): 1222-1238, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35098531

RESUMEN

Contrast-induced nephropathy (CIN) is a major complication of imaging in patients with chronic kidney disease (CKD). The publication of an academic randomized controlled trial (RCT; n = 83) reporting oral (N)-acetylcysteine (NAC) to reduce CIN led to > 70 clinical trials, 23 systematic reviews, and 2 large RCTs showing no benefit. However, no mechanistic studies were conducted to determine how NAC might work; proposed mechanisms included renal artery vasodilatation and antioxidant boosting. We evaluated the proposed mechanisms of NAC action in participants with healthy and diseased kidneys. Four substudies were performed. Two randomized, double-blind, placebo-controlled, three-period crossover studies (n = 8) assessed the effect of oral and intravenous (i.v.) NAC in healthy kidneys in the presence/absence of iso-osmolar contrast (iodixanol). A third crossover study in patients with CKD stage III (CKD3) (n = 8) assessed the effect of oral and i.v. NAC without contrast. A three-arm randomized, double-blind, placebo-controlled parallel-group study, recruiting patients with CKD3 (n = 66) undergoing coronary angiography, assessed the effect of oral and i.v. NAC in the presence of contrast. We recorded systemic (blood pressure and heart rate) and renal (renal blood flow (RBF) and glomerular filtration rate (GFR)) hemodynamics, and antioxidant status, plus biomarkers of renal injury in patients with CKD3 undergoing angiography. Primary outcome for all studies was RBF over 8 hours after the start of i.v. NAC/placebo. NAC at doses used in previous trials of renal prophylaxis was essentially undetectable in plasma after oral administration. In healthy volunteers, i.v. NAC, but not oral NAC, increased blood pressure (mean area under the curve (AUC) mean arterial pressure (MAP): mean difference 29 h⋅mmHg, P = 0.019 vs. placebo), heart rate (28 h⋅bpm, P < 0.001), and RBF (714 h⋅mL/min, 8.0% increase, P = 0.006). Renal vasodilatation also occurred in the presence of contrast (RBF 917 h⋅mL/min, 12% increase, P = 0.005). In patients with CKD3 without contrast, only a rise in heart rate (34 h⋅bpm, P = 0.010) and RBF (288 h⋅mL/min, 6.0% increase, P = 0.001) occurred with i.v. NAC, with no significant effect on blood pressure (MAP rise 26 h⋅mmHg, P = 0.156). Oral NAC showed no effect. In patients with CKD3 receiving contrast, i.v. NAC increased blood pressure (MAP rise 52 h⋅mmHg, P = 0.008) but had no effect on RBF (151 h⋅mL/min, 3.0% increase, P = 0.470), GFR (29 h⋅mL/min/1.73m², P = 0.122), or markers of renal injury. Neither i.v. nor oral NAC affected plasma antioxidant status. We found oral NAC to be poorly absorbed and have no reno-protective effects. Intravenous, not oral, NAC caused renal artery vasodilatation in healthy volunteers but offered no protection to patients with CKD3 at risk of CIN. These findings emphasize the importance of mechanistic clinical studies before progressing to RCTs for novel interventions. Thousands were recruited to academic clinical trials without the necessary mechanistic studies being performed to confirm the approach had any chance of working.


Asunto(s)
Enfermedades Renales , Insuficiencia Renal Crónica , Acetilcisteína/uso terapéutico , Antioxidantes , Medios de Contraste/efectos adversos , Creatinina , Estudios Cruzados , Humanos , Insuficiencia Renal Crónica/tratamiento farmacológico , Resultado del Tratamiento
4.
PLoS One ; 15(2): e0228544, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32027687

RESUMEN

BACKGROUND: The individual and combined contribution of viral prevalence in the community to Emergency Department (ED) visits and hospitalizations with respiratory tract infections (RTIs), chronic obstructive pulmonary disease (COPD) and asthma is unclear. METHODS: A retrospective analysis on daily viral positive tests and daily ED visits and hospitalizations between 01/01/2003 to 31/12/2013 in Ontario, Canada. Viral data was collected from the Centre for Immunization and Respiratory Infectious Diseases (CIRID). The Canadian Institute for Health Information reports daily ED visits and hospitalizations for RTIs, COPD and asthma as a primary diagnosis. RESULTS: There were 4,365,578 ED visits with RTIs of which 321,719 (7.4%) were admitted to hospital; 817,141 ED visits for COPD of which 260,665 (31.9%) were admitted and 649,666 ED visits with asthma of which 68,626 (10.6%) were admitted. The percentage of positive tests to influenza A and B, respiratory syncytial virus (RSV), parainfluenza and adenovirus prevalence explained 57.4% of ED visits and 63.8% of hospitalizations for RTI, 41.4% of ED visits and 39.2% of hospitalizations with COPD but only 1.5% of ED visits and 2.7% of hospitalizations for asthma. The further addition of human metapneumovirus, rhinovirus and coronavirus over the final 3 years accounted for 66.7% of ED visits and 74.4% of hospitalizations for RTI, 52.5% of visits and 48.2% of hospitalizations for COPD, and only 13.3% of visits and 10.4% of hospitalizations for asthma. CONCLUSIONS: Community respiratory viral epidemics are major drivers of ED visits and hospitalizations with RTIs and COPD but only a modest contributor to asthma.


Asunto(s)
Asma/epidemiología , Servicio de Urgencia en Hospital , Hospitalización/estadística & datos numéricos , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Infecciones del Sistema Respiratorio/epidemiología , Virosis/epidemiología , Asma/complicaciones , Infecciones Comunitarias Adquiridas/epidemiología , Servicio de Urgencia en Hospital/estadística & datos numéricos , Historia del Siglo XXI , Hospitalización/tendencias , Humanos , Ontario/epidemiología , Prevalencia , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Estudios Retrospectivos
5.
Can J Surg ; 62(2): 83-92, 2019 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-30697993

RESUMEN

Background: Studies have shown an association between socioeconomic status and breast cancer treatment. We examined the relation between socioeconomic status and the treatment of breast cancer (surgical, systemic and radiation) in a universal health care system. Methods: Data from a single urban Canadian centre were collected for consecutive patients who received a diagnosis of breast cancer from January 2010 to December 2011. Variables included patient and disease factors, surgery type, systemic and radiation treatment, and breast reconstruction. Socioeconomic variables were obtained from 2006 Canadian census data. We used multivariable logistic regression to identify predictors of breast cancer treatment. Results: A total of 721 patients were treated for breast cancer during the study period. Socioeconomic variables were not related to type of breast surgery for breast cancer. Age less than 50 years, having a first-degree relative with breast cancer and income status were predictors of breast reconstruction. Employment status was a consistent predictor of systemic and radiation treatment. Conclusion: Employment consistently predicted systemic and radiation treatment, and age and income were predictors of breast reconstruction in a universal health care system. Further research is required to determine precisely how socioeconomic factors affect care and to minimize possible disparities in delivery of health care services.


Contexte: Des études ont montré un lien entre la situation socio-économique et le traitement du cancer du sein. Nous avons analysé ce lien entre la situation socioéconomique et le traitement (chirurgie, chimiothérapie, radiothérapie) du cancer du sein dans un système de santé universel. Méthodes: Les données d'un seul centre urbain canadien ont été compilées pour les patientes consécutives ayant reçu un diagnostic de cancer du sein entre janvier 2010 et décembre 2011. Les variables incluaient des facteurs propres aux patientes et à la maladie, le type de chirurgie, la chimiothérapie, la radiothérapie et la reconstruction mammaire. Les variables socio-économiques proviennent des données du recensement canadien de 2006. Nous avons utilisé la régression logistique multivariée pour identifier les prédicteurs du traitement du cancer du sein. Résultats: En tout, 721 patientes ont été traitées pour un cancer du sein durant la période de l'étude. Les variables socio-économiques n'ont pas influé sur le type de chirurgie mammaire pour cancer du sein. L'âge inférieur à 50 ans, un cancer du sein chez une parente au premier degré et le revenu ont été des prédicteurs de la reconstruction mammaire. La situation professionnelle a été un prédicteur fiable du traitement systémique et de la radiothérapie. Conclusion: L'emploi a été un prédicteur fiable du traitement systémique et de la radiothérapie, et l'âge et le revenu ont été des prédicteurs de la reconstruction mammaire, dans un système de santé universel. Il faudra approfondir la recherche pour déterminer plus précisément l'influence des facteurs socio-économiques sur les soins et pour réduire les possibles disparités dans leur prestation.


Asunto(s)
Neoplasias de la Mama/terapia , Disparidades en Atención de Salud/estadística & datos numéricos , Factores Socioeconómicos , Atención de Salud Universal , Adulto , Factores de Edad , Anciano , Neoplasias de la Mama/patología , Canadá , Quimioradioterapia Adyuvante/estadística & datos numéricos , Femenino , Disparidades en Atención de Salud/economía , Hospitales Urbanos/estadística & datos numéricos , Humanos , Modelos Logísticos , Mamoplastia/estadística & datos numéricos , Mastectomía/estadística & datos numéricos , Persona de Mediana Edad , Estudios Retrospectivos
6.
Br J Nutr ; 110(12): 2234-41, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23702253

RESUMEN

Dietary polyphenols, such as those from grape products, may exert beneficial effects on cardiovascular health, including anti-hypertensive effects. We investigated the effect of a specific grape seed extract (GSE) rich in low-molecular-weight polyphenolic compounds on ambulatory blood pressure (ABP) in untreated subjects with pre- and stage I hypertension. In addition, potential mechanisms that could underlie the hypothesised effect of GSE on blood pressure (BP), and platelet aggregation, were explored. The study was designed as a double-blind, placebo-controlled, randomised, parallel-group intervention study including seventy healthy subjects with systolic BP between 120 and 159 mmHg. A 1-week run-in period was followed by an 8-week intervention period, during which subjects consumed capsules containing either 300 mg/d of GSE or a placebo (microcrystalline cellulose). Before and after the intervention, daytime ABP readings, 24 h urine samples and fasting and non-fasting blood samples were taken. The mean baseline systolic BP was 135.8 (SE 1.3) mmHg and diastolic BP was 81.5 (SE 0.9) mmHg. BP values were modestly, but not significantly, affected by the polyphenol-rich GSE treatment v. placebo with an effect of - 3.0 mmHg for systolic BP (95% CI - 6.5, 0.5) and - 1.4 mmHg for diastolic BP (95% CI - 3.5, 0.6). Vasoactive markers including endothelin-1, NO metabolites and asymmetric dimethylarginine, plasma renin activity and platelet aggregation were not affected by the GSE intervention. Our findings show that consumption of polyphenol-rich GSE does not significantly lower ABP in untreated subjects with pre- and stage I hypertension.


Asunto(s)
Presión Sanguínea/efectos de los fármacos , Hipertensión/fisiopatología , Extractos Vegetales/farmacología , Polifenoles/farmacología , Vitis/química , Femenino , Humanos , Hipertensión/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Extractos Vegetales/uso terapéutico , Polifenoles/uso terapéutico , Prehipertensión/tratamiento farmacológico , Prehipertensión/fisiopatología , Semillas/química
7.
BMC Clin Pharmacol ; 12: 3, 2012 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-22305183

RESUMEN

BACKGROUND: Contrast-induced nephropathy is a common complication of contrast administration in patients with chronic kidney disease and diabetes. Its pathophysiology is not well understood; similarly the role of intravenous or oral acetylcysteine is unclear. Randomized controlled trials to date have been conducted without detailed knowledge of the effect of acetylcysteine on renal function. We are conducting a detailed mechanistic study of acetylcysteine on normal and impaired kidneys, both with and without contrast. This information would guide the choice of dose, route, and appropriate outcome measure for future clinical trials in patients with chronic kidney disease. METHODS/DESIGN: We designed a 4-part study. We have set up randomised controlled cross-over studies to assess the effect of intravenous (50 mg/kg/hr for 2 hrs before contrast exposure, then 20 mg/kg/hr for 5 hrs) or oral acetylcysteine (1200 mg twice daily for 2 days, starting the day before contrast exposure) on renal function in normal and diseased kidneys, and normal kidneys exposed to contrast. We have also set up a parallel-group randomized controlled trial to assess the effect of intravenous or oral acetylcysteine on patients with chronic kidney disease stage III undergoing elective coronary angiography. The primary outcome is change in renal blood flow; secondary outcomes include change in glomerular filtration rate, tubular function, urinary proteins, and oxidative balance. DISCUSSION: Contrast-induced nephropathy represents a significant source of hospital morbidity and mortality. Over the last ten years, acetylcysteine has been administered prior to contrast to reduce the risk of contrast-induced nephropathy. Randomized controlled trials, however, have not reliably demonstrated renoprotection; a recent large randomized controlled trial assessing a dose of oral acetylcysteine selected without mechanistic insight did not reduce the incidence of contrast-induced nephropathy. Our study should reveal the mechanism of effect of acetylcysteine on renal function and identify an appropriate route for future dose response studies and in time randomized controlled trials. TRIAL REGISTRATION: Clinical Trials.gov: NCT00558142; EudraCT: 2006-003509-18.


Asunto(s)
Acetilcisteína/farmacología , Medios de Contraste/efectos adversos , Riñón/efectos de los fármacos , Riñón/fisiopatología , Circulación Renal/efectos de los fármacos , Insuficiencia Renal Crónica/fisiopatología , Proteínas de Fase Aguda/orina , Estudios Cruzados , Cistatina C/sangre , Tasa de Filtración Glomerular , Receptor Celular 1 del Virus de la Hepatitis A , Humanos , Lipocalina 2 , Lipocalinas/orina , Masculino , Glicoproteínas de Membrana/orina , Persona de Mediana Edad , Natriuresis/efectos de los fármacos , Proteínas Proto-Oncogénicas/orina , Receptores Virales
8.
J Pharmacol Exp Ther ; 334(3): 795-808, 2010 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-20507928

RESUMEN

Glucagon-like peptide-1 (GLP-1) mediates antidiabetogenic effects through the GLP-1 receptor (GLP-1R), which is targeted for the treatment of type 2 diabetes. Small-molecule GLP-1R agonists have been sought due to difficulties with peptide therapeutics. Recently, 6,7-dichloro-2-methylsulfonyl-3-N-tert-butylaminoquinoxaline (compound 2) has been described as a GLP-1R allosteric modulator and agonist. Using human embryonic kidney-293 cells expressing human GLP-1Rs, we extended this work to consider the impact of compound 2 on G protein activation, Ca(2+) signaling and receptor internalization and particularly to compare compound 2 and GLP-1 across a range of functional assays in intact cells. GLP-1 and compound 2 activated Galpha(s) in cell membranes and increased cellular cAMP in intact cells, with compound 2 being a partial and almost full agonist, respectively. GLP-1 increased intracellular [Ca(2+)] by release from intracellular stores, which was mimicked by compound 2, with slower kinetics. In either intact cells or membranes, the orthosteric antagonist exendin-(9-39), inhibited GLP-1 cAMP generation but increased the efficacy of compound 2. GLP-1 internalized enhanced green fluorescent protein-tagged GLP-1Rs, but the speed and magnitude evoked by compound 2 were less. Exendin-(9-39) inhibited internalization by GLP-1 and also surprisingly that by compound 2. Compound 2 displays GLP-1R agonism consistent with action at an allosteric site, although an orthosteric antagonist increased its efficacy on cAMP and blocked compound 2-mediated receptor internalization. Full assessment of the properties of compound 2 was potentially hampered by damaging effects that were particularly manifest in either longer term assays with intact cells or in acute assays with membranes.


Asunto(s)
Péptido 1 Similar al Glucagón/farmacología , Fragmentos de Péptidos/farmacología , Quinoxalinas/farmacología , Receptores de Glucagón/efectos de los fármacos , Sulfonas/farmacología , Biotransformación/efectos de los fármacos , Calcio/metabolismo , Línea Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Supervivencia Celular , AMP Cíclico/metabolismo , Interpretación Estadística de Datos , Proteínas de Unión al GTP/metabolismo , Péptido 1 Similar al Glucagón/biosíntesis , Receptor del Péptido 1 Similar al Glucagón , Proteínas Fluorescentes Verdes , Humanos , Ligandos , Fragmentos de Péptidos/biosíntesis , Receptores de Glucagón/biosíntesis , Transducción de Señal/efectos de los fármacos , Azul de Tripano
9.
Proc Am Thorac Soc ; 4(8): 591-6, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18073388

RESUMEN

The majority of chronic obstructive pulmonary disease (COPD) and asthma exacerbations in both children and adults are associated with respiratory viral infections and are cyclic in nature. Some variation in these cycles is associated with the timing of the appearance of respiratory viruses, particularly influenza and respiratory syncytial virus. Much more, however, is associated with signal events that are of either fixed or predictable timing. In children, asthma exacerbations reach epidemic levels following school return after the summer vacation and these are predominantly associated with rhinovirus infections. Although younger adults experience a rise in asthma exacerbations at this time, these are secondary to the epidemic in children. Older adults with either COPD or asthma experience only a slightly elevated risk of exacerbations after school return, and hospital presentations for pneumonia in any age group show only marginal increases at that time. Exacerbations of both COPD and adult asthma, with increasing risk with age, are at their highest average annual levels during the Christmas period. This effect appears to be independent of the timing of above average levels of influenza, RSV, parainfluenza, or adenovirus detections; however, hospitalization for respiratory tract infections in all age groups reaches high levels at the same time. Both the post-summer vacation asthma epidemic and the Christmas epidemic of COPD, asthma, and pneumonia are synchronous with the timing of signal events, the day of school return for the former and Christmas Day for the latter, and have been for several years. The agents responsible for the Christmas epidemic of respiratory diseases have not yet been identified. The differences between age and disease exacerbation patterns after school return and at Christmas suggest that either different agents are involved or that the response to a common agent is different between the two signal events.


Asunto(s)
Asma/epidemiología , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Estaciones del Año , Factores de Edad , Vacaciones y Feriados , Humanos , Infecciones por Picornaviridae/epidemiología , Infecciones del Sistema Respiratorio/epidemiología , Instituciones Académicas , Factores Sexuales
10.
Hypertension ; 44(6): 913-8, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15492133

RESUMEN

Angiotensin-converting enzyme and neutral endopeptidase (EC 3.4.24.11; neprilysin) are metallopeptidases present on the endothelium that metabolize bradykinin. Inhibitors of angiotensin-converting enzyme potentiate bradykinin-mediated vasodilatation and endothelial tissue plasminogen activator release. Combined angiotensin-converting enzyme and neutral endopeptidase inhibition may have additional beneficial cardiovascular effects mediated through bradykinin potentiation. We investigated the effects of local neutral endopeptidase inhibition on the vascular actions of bradykinin in heart failure patients maintained on chronic angiotensin-converting enzyme inhibition. Ten patients received intrabrachial infusion of thiorphan (30 nmol/min), a neutral endopeptidase inhibitor, in a randomized double-blind placebo-controlled crossover trial. Thiorphan was coinfused with Lys-des-Arg9-bradykinin (1 to 10 nmol/min), bradykinin (30 to 300 pmol/min), atrial natriuretic peptide (10 to 100 pmol/min), and sodium nitroprusside (2 to 8 mug/min). Bradykinin, atrial natriuretic peptide, and sodium nitroprusside caused dose-dependent vasodilatation (peak blood flow 14.4+/-2.2, 3.6+/-0.6, and 8.6+/-1.3 mL per 100 mL/min, respectively; P<0.0001). Bradykinin caused dose-dependent increases in tissue plasminogen activator antigen and activity (peak concentration 31.8+/-3.4 ng/mL and 21.9+/-7.6 IU/mL, respectively; P<0.001) and estimated antigen and activity release (peak release 152+/-46 ng per 100 mL/min and 154+/-22 IU/100 mL/min, respectively; P<0.005). Compared with placebo, thiorphan augmented bradykinin-mediated vasodilatation (1.4-fold; P<0.0001) and net tissue plasminogen activator release (1.5-fold; P<0.005). Neutral endopeptidase contributes to bradykinin metabolism in heart failure patients maintained on angiotensin-converting enzyme inhibitor therapy. Our findings may explain some of the clinical effects of combined angiotensin-converting enzyme and neutral endopeptidase inhibition, including the greater vasodepressor effect observed with combined therapy when compared with angiotensin-converting enzyme inhibition alone.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Bradiquinina/uso terapéutico , Insuficiencia Cardíaca/tratamiento farmacológico , Neprilisina/antagonistas & inhibidores , Inhibidores de Proteasas/uso terapéutico , Vasodilatadores/uso terapéutico , Anciano , Factor Natriurético Atrial/uso terapéutico , Estudios Cruzados , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Interacciones Farmacológicas , Quimioterapia Combinada , Femenino , Insuficiencia Cardíaca/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Nitroprusiato/uso terapéutico , Receptor de Bradiquinina B1/agonistas , Receptor de Bradiquinina B1/metabolismo , Tiorfan/uso terapéutico , Activador de Tejido Plasminógeno/metabolismo , Vasodilatación/efectos de los fármacos
11.
J Cardiovasc Pharmacol ; 44(1): 117-24, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15175566

RESUMEN

Blood flow and plasma fibrinolytic factors were measured on five occasions in both forearms of eight otherwise healthy male smokers during unilateral brachial artery infusion of the endothelium-dependent vasodilator, substance P (2 to 8 pmol/min), and the endothelium-independent vasodilator, sodium nitroprusside (2 to 8 microg/min). On the first occasion, intra-arterial vitamin C was co-infused at 25 mg/min. On subsequent occasions, subjects attended after 28 and 35 days treatment with oral vitamin C (1 g daily) or placebo in a double-blind randomized crossover design still smoking but with and without acute smoke inhalation (3 cigarettes over 30 minutes). Basal plasma ascorbate concentrations increased from 37 +/- 6 micromol/L to 105 +/- 11 micromol/L following oral vitamin C supplementation (P = 0.002). Substance P caused dose-dependent increases in forearm blood flow (P < 0.001, ANOVA) and t-PA release (P < 0.05, ANOVA) that was unaffected by acute recent smoke inhalation, intra-arterial vitamin C, or oral vitamin C administration (p = ns). Likewise there were no effects on sodium nitroprusside-induced vasodilatation (p = ns). Neither acute local intra-arterial nor prolonged oral vitamin C supplementation reverses smoking-related endothelial dysfunction and impaired endogenous t-PA release. We conclude that the adverse vascular actions of smoking are not principally mediated through oxidative stress.


Asunto(s)
Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Fibrinólisis/efectos de los fármacos , Nitroprusiato/farmacología , Fumar/metabolismo , Sustancia P/farmacología , Activador de Tejido Plasminógeno/efectos de los fármacos , Vasodilatadores/farmacología , Adulto , Ácido Ascórbico/sangre , Presión Sanguínea/efectos de los fármacos , Estudios Cruzados , Método Doble Ciego , Endotelio Vascular/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Vasodilatación/efectos de los fármacos
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