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1.
Transfus Med ; 29(4): 231-238, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30666733

RESUMO

In this review, we explore how to assess potential harm related to neonatal transfusion practice. We consider different sources of information, including passive or active surveillance systems such as registries, observational studies, randomised trials and systematic reviews. Future research directions are discussed.


Assuntos
Transfusão de Eritrócitos , Sistema de Registros , Reação Transfusional/prevenção & controle , Humanos , Recém-Nascido , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco
2.
Clin Genet ; 93(2): 320-328, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29044489

RESUMO

Diamond-Blackfan anemia (DBA) features hypoplastic anemia and congenital malformations, largely caused by mutations in various ribosomal proteins. The aim of this study was to characterize the spectrum of genetic lesions causing DBA and identify genotypes that correlate with phenotypes of clinical significance. Seventy-four patients with DBA from across Canada were included. Nucleotide-level mutations or large deletions were identified in 10 ribosomal genes in 45 cases. The RPS19 mutation group was associated with higher requirement for chronic treatment for anemia than other DBA groups. Patients with RPS19 mutations, however, were more likely to maintain long-term corticosteroid response without requirement for further chronic transfusions. Conversely, patients with RPL11 mutations were less likely to need chronic treatment. Birth defects, including cardiac, skeletal, hand, cleft lip or palate and genitourinary malformations, also varied among the various genetic groups. Patients with RPS19 mutations had the fewest number of defects, while patients with RPL5 had the greatest number of birth defects. This is the first study to show differences between DBA genetic groups with regards to treatment. Previously unreported differences in the rate and types of birth defects were also identified. These data allow better patient counseling, a more personalized monitoring plan, and may also suggest differential functions of DBA genes on ribosome and extra-ribosomal functions.


Assuntos
Anemia de Diamond-Blackfan/genética , Proteínas Ribossômicas/genética , Adolescente , Adulto , Anemia de Diamond-Blackfan/epidemiologia , Anemia de Diamond-Blackfan/patologia , Canadá , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Mutação , Adulto Jovem
5.
Mol Oral Microbiol ; 31(4): 285-301, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26255984

RESUMO

Peri-implant diseases (peri-implantitis and peri-implant mucositis) are bacterially driven infections. Peri-implantitis leads to aggressive bone resorption and eventual loss of the implant. Traditionally, peri-implantitis was regarded as microbially similar to periodontitis, and translocation of periodontal pathogens into the peri-implant crevice was considered as a critical factor in disease causation. However, evidence is emerging to suggest that the peri-implant and periodontal ecosystems differ in many important ways. The purpose of this review is to examine the evidence supporting microbial congruence and discordance in these two communities. Current evidence suggests that osseointegrated implants truly create unique microenvironments that force microbial adaptation and selection. Further studies that revisit the "microbial reservoir" hypothesis and identify species that play an etiologic role in peri-implant disease and examine their transmission from teeth are needed.


Assuntos
Implantes Dentários/microbiologia , Consórcios Microbianos , Peri-Implantite/microbiologia , Periodontite/microbiologia , Biofilmes , Placa Dentária , Humanos , Peri-Implantite/etiologia , Periodontite/etiologia
6.
Vox Sang ; 110(2): 150-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26389829

RESUMO

BACKGROUND AND OBJECTIVES: Platelet concentrates (PCs) are associated with transfusion reactions involving hypotension, particularly bradykinin-mediated acute hypotensive transfusion reactions. This study aims to determine the incidence of hypotensive events and more specifically acute hypotensive transfusion reaction associated with PC transfusions. We also sought to ascertain whether these reactions are associated with elevated bradykinin levels. MATERIALS AND METHODS: This is a prospective descriptive study of PCs administered at Sainte-Justine Hospital over 28 months. All PCs administered during this period were screened for hypotension through review of all transfusion-associated reaction reports (TARRs) sent to the blood bank. All residual PC bags were returned to the blood bank. TARRs associated with hypotension were reviewed by adjudicators that established the imputability of the PC transfusion to the reaction. Bradykinin levels were sampled in the first 168 PC bags returned to the blood bank. Levels were compared between PCs associated with hypotension and control PCs not associated with hypotension. RESULTS: A total of 3672 PC bags were returned to the blood bank; 25 PCs were associated with hypotension. Adjudicators ascertained that five hypotensive events were imputable to PCs of which one was an acute hypotensive transfusion reaction (incidence: 0·03%). Bradykinin level in the latter PC was 10 pg/ml, whereas levels were 226·2 ± 1252 pg/ml in the 143 control PCs. CONCLUSION: Our results show a low incidence of hypotension after PC transfusion. We identified only one acute hypotensive transfusion reaction. No correlation between bradykinin level and the occurrence of acute hypotensive reactions could be observed given that only one event was identified.


Assuntos
Hipotensão/etiologia , Transfusão de Plaquetas/efeitos adversos , Reação Transfusional/etiologia , Bancos de Sangue/normas , Humanos
7.
Vox Sang ; 110(2): 199-201, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26383177

RESUMO

This study examined the prevalence of three human herpesviruses (HHV), namely HHV-4 (Epstein-Barr virus/EBV), HHV-6b and HHV-7 in leucoreduced blood products obtained from the Sainte-Justine Hospital blood bank. A total of 100 specimens, including 34 red blood cell concentrates, 33 platelet bags and 33 plasma units, were collected and screened by a sensitive PCR assay using virus-specific primers. Positive units were then retested by quantitative PCR. Of the 100 specimens, one platelet unit tested positive for EBV.


Assuntos
Bancos de Sangue/estatística & dados numéricos , Herpesvirus Humano 4/isolamento & purificação , Plasma/virologia , Bancos de Sangue/normas , Células Sanguíneas/virologia , Humanos
8.
Vox Sang ; 104(4): 342-9, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23294337

RESUMO

BACKGROUND AND OBJECTIVES: Plasma transfusions are commonly used in adult and paediatric intensive care units. Recent data suggest an association between plasma transfusions and worse clinical outcome in adult trauma patients. To date, no prospective paediatric study has addressed this issue. Our objective was to prospectively analyse the association between plasma transfusions and clinical outcome of critically ill children. MATERIALS AND METHODS: Prospective, observational and single centre study that includes all consecutive admissions to a tertiary level multidisciplinary paediatric critical care unit over a 1-year period. The primary outcome measure was the incidence after transfusion of new or progressive multiple organ dysfunction syndrome. Secondary outcome measures included nosocomial infections, intensive care unit length of stay and 28-day mortality. Odds ratios were adjusted for weight, severity of illness, coagulopathy, plasma transfusions prior to admission, need for extracorporeal life support and transfusion of other labile blood products. RESULTS: A total of 831 patients were enrolled, among which 94 (11%) received at least one plasma transfusion. In the latter group of patients, the adjusted odds ratio for an increased incidence of new or progressive multiple organ dysfunction syndrome was 3.2 (P = 0.002). There was also a significant difference in the occurrence of nosocomial infections and intensive care unit length of stay, but no significant difference in the 28-day mortality. CONCLUSIONS: In critically ill children, plasma transfusions seem to be independently associated with an increased occurrence of new or progressive multiple organ dysfunction syndrome, nosocomial infections and prolonged length of stay.


Assuntos
Transfusão de Componentes Sanguíneos/métodos , Estado Terminal/terapia , Plasma , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Humanos , Incidência , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Adulto Jovem
9.
J Clin Pharmacol ; 51(9): 1286-92, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21148050

RESUMO

The angiotensin-converting enzyme (ACE) gene is a candidate genetic locus for coronary artery disease (CAD). Studies investigating the relationship between the ACE-insertion/deletion (I/D) gene polymorphism and myocardial infarction (MI) have been inconsistent. The authors hypothesized that age may be an important modulating factor in this relationship. ACE-I/D allele and genotype distribution was determined in 3 groups: 104 men with a first MI at a young age (≤45 years old), 271 healthy young men (≤30 years old), and 28 healthy elderly men (>65 years old). All participants were French descendants from Quebec City, Canada. Frequency distribution of the ACE alleles and genotypes was similar among the healthy young, the healthy elderly, and the MI patients (P > .05). However, when considering the age at the time of the MI (≤40, ≤35, or ≤30 years old), a significant age-dependent effect with the prevalence of the ACE-DD genotype was found, as it increased by 22%, 61%, and 157%, respectively, compared with the healthy young group (P < .05). Similar observations were obtained versus the healthy elderly men (P < .05). The ACE-I/D polymorphism seems to be a genetic risk factor for MI in young men and becomes an important modulator of MI risk at a young age.


Assuntos
Envelhecimento/genética , Estudos de Associação Genética , Infarto do Miocárdio/enzimologia , Infarto do Miocárdio/genética , Peptidil Dipeptidase A/genética , Polimorfismo Genético/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Estudos de Associação Genética/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Mutagênese Insercional/genética , Fatores de Risco , Deleção de Sequência/genética , Adulto Jovem
10.
Vox Sang ; 99(2): 136-41, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20345516

RESUMO

BACKGROUND AND OBJECTIVES: IgA deficiency is common (1/500) and up to 40% of affected individuals will develop anti-IgA. A few studies suggested that passive transfusion of anti-IgA was not associated with an increased risk of allergic reactions. This study was designed to assess the safety of transfusing blood components containing anti-IgA. MATERIALS AND METHODS: IgA-deficient blood donors with and without anti-IgA were identified from Héma-Québec's (HQ) computerized database. IgA deficiency was confirmed by an ELISA method and the presence of anti-IgA by a passive hemagglutination assay. Blood donations from IgA-deficient donors issued to hospitals between March 1999 and December 2004 were retrieved. Medical charts of recipients were reviewed for the occurrence of a suspected transfusion reaction. Presence and nature of transfusion reactions were assessed blindly by an adjudicating committee. RESULTS: A total of 323 IgA-deficient blood products were issued by HQ to 55 hospitals. Of these, 48 agreed to participate [315 blood products (97.5%)]. A total of 272 products were transfused: 174 contained anti-IgA, and 98 did not. Only two minor allergic reactions occurred in each group. Incidence of allergic reactions was 1.15% in the anti-IgA group and 2.04% in the group without anti-IgA (P = 0.91). There was no anaphylactic reaction in either group. CONCLUSIONS: This study indicates that the proportion of allergic reactions does not appear to be greater in recipients of blood components containing anti-IgA compared to recipients of non-anti-IgA-containing components. Allowing donations from IgA-deficient donors with anti-IgA may therefore be contemplated.


Assuntos
Anticorpos Anti-Idiotípicos/sangue , Hipersensibilidade/sangue , Deficiência de IgA/sangue , Transfusão de Plaquetas/efeitos adversos , Reação Transfusional , Anticorpos Anti-Idiotípicos/imunologia , Feminino , Humanos , Hipersensibilidade/etiologia , Hipersensibilidade/imunologia , Deficiência de IgA/imunologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Doadores de Tecidos
11.
Brain Res ; 1187: 82-94, 2008 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-18005943

RESUMO

The present study investigated the spatial properties of cells in the postero-lateral lateral suprasylvian (PLLS) area of the cat and assessed their sensitivity to edges defined by motion. A total of one hundred and seventeen (117) single units were isolated. First, drifting sinusoidal gratings were used to assess the spatial properties of the cells' receptive fields and to determine their spatial frequency tuning functions. Second, random-dot kinematograms were used to create illusory edges by drifting textured stimuli (i.e. a horizontal bar) against a similarly textured but static background. Almost all the cells recorded in PLLS (96.0%) were binocular, and a substantial majority of receptive fields (79.2%) were end-stopped. Most units (81.0%) had band-pass spatial frequency tuning functions and responded optimally to low spatial frequencies (mean spatial frequency: 0.08 c./degree). The remaining units (19.0%) were low-pass. All the recorded cells responded vigorously to edges defined by motion. The vast majority (96.0%) of cells responded optimally to large texture elements; approximately half the cells (57.3%) also responded to finer texture elements. Moreover, 38.5% of the cells were selective to the width of the bar (i.e., the distance between the leading and the trailing edges). Finally, some (9.0%) cells responded in a transient fashion to leading and to trailing edges. In conclusion, cells in the PLLS area are low spatial frequency analyzers that are sensitive to texture and to the distance between edges defined by motion.


Assuntos
Potenciais de Ação/fisiologia , Sensibilidades de Contraste/fisiologia , Percepção de Movimento/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Córtex Visual/fisiologia , Animais , Gatos , Potenciais Evocados Visuais/fisiologia , Feminino , Masculino , Estimulação Luminosa , Especificidade da Espécie , Córtex Visual/anatomia & histologia , Campos Visuais/fisiologia , Vias Visuais/fisiologia
13.
Psychophysiology ; 43(4): 394-400, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16916436

RESUMO

A variant of the rapid serial visual presentation paradigm was used to display sequentially two lateral sequences of stimuli, one to the left and one to the right of fixation, embedding two pairs of target stimuli, T1 and T2. T1 was composed of a pair of alphanumeric characters, and subjects had either to ignore T1 or to encode T1 for a delayed response. T2 was a lateral square of a prespecified color. The square had a small gap in one side, and the task for this stimulus was to report which side had the gap. When subjects were required to ignore T1, the T2-locked ERP produced a clear N2pc, that is, a greater negativity at electrode sites contralateral to the position occupied by T2. This N2pc was followed by a sustained posterior contralateral negativity (SPCN). When subjects were required to monitor T1 in addition to T2, both the N2pc and the SPCN components amplitude depended on the difficulty of the task associated with T1. If T1 was composed of digits that had to be encoded for a delayed same/different judgment, both the N2pc and the SPCN components were entirely suppressed. Although attenuated, such components were present when T1 was composed of a pair of symbols that subjects could disregard. The results suggest that a set of mechanisms subserving the allocation of attention in the spatial domain, resulting in the N2pc, suffer significant interference from concurrent cognitive operations required to encode information into visual short-term memory.


Assuntos
Atenção/fisiologia , Piscadela/fisiologia , Percepção Espacial/fisiologia , Adulto , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Memória de Curto Prazo , Estimulação Luminosa , Desempenho Psicomotor/fisiologia
14.
Ther Drug Monit ; 26(5): 492-8, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15385831

RESUMO

Mexiletine is extensively metabolized in man, with less than 10% of the dose being excreted unchanged in urine. Clinical drug-drug interaction studies as well as in vitro drug metabolism studies suggest that CYP1A2, in addition to CYP2D6, is involved in the metabolism of mexiletine in man. Therefore, the objective of the study was to determine whether potential inhibition of CYP1A2 by the quinolone antibiotic agent ciprofloxacin would alter the stereoselective disposition of mexiletine. Nineteen healthy men (10 smokers and 9 nonsmokers) received a single 200-mg oral dose of racemic mexiletine hydrochloride on 2 occasions: once alone and once during concomitant administration of ciprofloxacin 750 mg BID (starting 3 days before and up to 2 days after the administration of mexiletine). Serial blood and urine samples were collected for 48 hours, and pharmacokinetic parameters were derived. Total clearances of R-(-)- and S-(+)-mexiletine were 42% and 63% higher in smokers compared with nonsmokers (P < 0.05). This observation is in agreement with increased clearance of mexiletine under conditions of increased CYP1A2 activity. On the other hand, ciprofloxacin administration only marginally decreased R-(-)- and S-(+)-mexiletine clearances (2 to 5 L/h; P < 0.05) secondary to a decrease in mexiletine nonrenal clearance. In conclusion, the increase in mexiletine nonrenal clearance in smokers and its decrease during the combined administration of ciprofloxacin confirm the role of CYP1A2 in the overall clearance of the drug. Nevertheless, results obtained in this study suggest that no major drug interaction is to be expected during the concomitant administration of ciprofloxacin and mexiletine in patients.


Assuntos
Antiarrítmicos/química , Antiarrítmicos/farmacocinética , Antibacterianos/farmacologia , Ciprofloxacina/farmacologia , Mexiletina/química , Mexiletina/farmacocinética , Adulto , Área Sob a Curva , Inibidores do Citocromo P-450 CYP1A2 , Interações Medicamentosas , Genótipo , Meia-Vida , Humanos , Masculino , Taxa de Depuração Metabólica , Fenótipo , Fumar/metabolismo , Estereoisomerismo
15.
Pharmacogenetics ; 10(5): 425-38, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10898112

RESUMO

The effects of gender, time variables, menstrual cycle phases, plasma sex hormone concentrations and physiologic urinary pH on CYP2D6 phenotyping were studied using two widely employed CYP2D6 probe drugs, namely dextromethorphan and metoprolol. Phenotyping on a single occasion of 150 young, healthy, drug-free women and men revealed that the dextromethorphan: dextrorphan metabolic ratio (MR) was significantly lower (P < 0.0001) in 56 female extensive metabolizers (0.008+/-0.021) compared to 86 male extensive metabolizers (0.020 +/-0.040). Urinary pH was a significant predictor of dextromethorphan: dextrorphan MRs in men and women (P < 0.001). Once-a-month phenotyping with dextromethorphan of 12 healthy young men (eight extensive metabolizers and four poor metabolizers) over a 1-year period, as well as every-other-day phenotyping with dextromethorphan of healthy, pre-menopausal women (10 extensive metabolizers and 2 poor metabolizers) during a complete menstrual cycle, did not follow a particular pattern and showed similar intrasubject variability ranging from 24.1% to 74.5% (mean 50.9%) in men and from 20.5% to 96.2% (mean 52.0%) in women, independent of the CYP2D6 phenotype (P = 0.342). Using metoprolol as a probe drug, considerable intrasubject variability (38.6+/- 12.0%) but no correlation between metoprolol: alpha-hydroxymetoprolol MRs and pre-ovulatory, ovulatory and luteal phases (mean +/- SD metoprolol: a-hydroxymetoprolol MRs: 1.086+/- 1.137 pre-ovulatory; 1.159+/-1.158 ovulatory and 1.002+/-1.405 luteal phase; P> 0.9) or 17beta-oestradiol, progesterone or testosterone plasma concentrations was observed. There was a significant inverse relationship between physiologic urinary pH and sequential dextromethorphan: dextrorphan MRs as well as metoprolol: alpha-hydroxymetoprolol MRs in men and women, with metabolic ratios varying up to six-fold with metoprolol and up to 20-fold with dextromethorphan (ANCOVA P < 0.001). We conclude that apparent CYP2D6 activity is highly variable, independent of menstrual cycle phases, sex hormones, time variables or phenotype. Up to 80% of the observed variability can be explained by variations of urinary pH within the physiological range. An apparent phenotype shift as a result of variations in urinary pH may be observed in individuals who have metabolic ratios close to the population antimode.


Assuntos
Citocromo P-450 CYP2D6/metabolismo , Hormônios Esteroides Gonadais/fisiologia , Metoprolol/análogos & derivados , Caracteres Sexuais , Urina/química , Administração Oral , Adulto , Análise de Variância , Biomarcadores/urina , Citocromo P-450 CYP2D6/genética , Dextrometorfano/administração & dosagem , Dextrometorfano/urina , Dextrorfano/urina , Ativação Enzimática/genética , Feminino , Hormônios Esteroides Gonadais/sangue , Humanos , Concentração de Íons de Hidrogênio , Masculino , Ciclo Menstrual/genética , Ciclo Menstrual/fisiologia , Metoprolol/urina , Fatores Sexuais , Especificidade por Substrato/genética , Fatores de Tempo
16.
Ther Drug Monit ; 21(2): 191-9, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10217339

RESUMO

Caffeine consumption is extensive in industrialized countries and its role in drug-drug interactions is often overlooked. CYP1A2, the major cytochrome P450 isoform involved in the metabolism of caffeine, has also been implicated in the formation of N-hydroxymexiletine, the major metabolite of mexiletine. Therefore, the objective of this study was to assess the effects of a clinically relevant dosage of caffeine on the stereoselective disposition of mexiletine. Fourteen healthy volunteers--10 extensive metabolizers (EMs) and 4 poor metabolizers (PMs) of CYP2D6--received a single 200 mg oral dose of racemic mexiletine hydrochloride on two occasions (1 week apart): once by itself and once during administration of caffeine (100 mg four times daily). Serial blood and urine samples were collected and pharmacokinetic parameters were estimated. Although the total clearance of mexiletine was not significantly altered by the coadministration of caffeine in EMs and PMs, a stereoselective decrease (16% in EMs and 14% in PMs) in the urinary recovery of N-hydroxymexiletine from the R-(-)-enantiomer was observed. Also, the partial metabolic clearance of R-(-)-mexiletine to N-hydroxymexiletine glucuronide was reduced from 126 +/- 48 mL/min to 106 +/- 32 mL/min and 152.6 (73.4-196.2) mL/min to 109 (77-127) mL/min by the coadministration of caffeine in EMs and PMs, respectively. Consequently, the R/S ratio for urinary recovery and the partial metabolic clearance of mexiletine to N-hydroxymexiletine were 28% lower during the coadministration of caffeine. In conclusion, data obtained in this study indicate that coadministration of caffeine does not lead to clinically significant changes in mexiletine plasma concentrations. However, results obtained suggest that CYP1A2 is involved in the formation of N-hydroxymexiletine.


Assuntos
Antiarrítmicos/farmacocinética , Cafeína/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Mexiletina/farmacocinética , Adulto , Antiarrítmicos/sangue , Antiarrítmicos/urina , Cafeína/sangue , Estimulantes do Sistema Nervoso Central/sangue , Citocromo P-450 CYP2D6/metabolismo , Interações Medicamentosas , Feminino , Humanos , Masculino , Mexiletina/sangue , Mexiletina/urina , Valores de Referência
17.
J Am Coll Cardiol ; 32(6): 1665-71, 1998 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-9822094

RESUMO

OBJECTIVES: This study characterized the attenuation of myocardial ischemia observed with re-exercise to determine whether: 1) a differing exercise intensity modifies this attenuation; 2) it could be explained by contractile down-regulation or stunning; 3) it is mediated by activation of ATP-sensitive potassium channels (K+-ATP). BACKGROUND: Subjects with ischemic heart disease (IHD) frequently note less angina with re-exercise after a brief rest. Potential mechanisms of this 'warm-up' phenomenon have been little explored. METHODS: IHD subjects with a positive exercise test were studied. Groups I and II (12 subjects each) underwent 2 successive Naughton protocol exercise echocardiography tests (with 1 min instead of 2 min stages for Group II). Group D (10 subjects) had type II diabetes, were on > or =10 mg daily of the K+-ATP blocker, glibenclamide, and underwent the group I exercise protocol. The ischemic threshold or rate-pressure product at 1 mm ST segment depression, ST depression corresponding to the peak rate-pressure product of the first exercise (maximum ST depression equivalent), and left ventricular wall motion indexes before and immediately after each exercise were analyzed. RESULTS: Exercise-induced myocardial ischemia with re-exercise was similarly attenuated in groups I, II, and D. The ischemic threshold was raised by nearly 20% with re-exercise (p=0.001, p=0.02, and p=0.02, respectively) and the maximum ST depression equivalent was nearly halved on re-exercise (p=0.005, p=0.006, and p=0.001, respectively). Exercise-induced wall motion dysfunction was attenuated with re-exercise. In group I, wall motion returned to the initial baseline score prior to exercise 2, whereas in the more intense protocol of group II, wall motion dysfunction persisted prior to exercise 2. CONCLUSIONS: Thus, the attenuation of myocardial ischemia observed with re-exercise appears to be independent of the intensity of the exercise protocol and is not explained by down-regulation of myocardial contractility induced by the initial ischemic stimulus. Since results were similar in diabetic subjects on robust doses of glibenclamide, this phenomenon does not appear to be mediated by K+-ATP activation.


Assuntos
Trifosfato de Adenosina/fisiologia , Angina Pectoris/complicações , Exercício Físico , Isquemia Miocárdica/complicações , Isquemia Miocárdica/fisiopatologia , Canais de Potássio/fisiologia , Fibras Adrenérgicas/fisiologia , Idoso , Doença Crônica , Estudos Cross-Over , Ecocardiografia , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica/fisiologia , Isquemia Miocárdica/diagnóstico , Método Simples-Cego
18.
Am Heart J ; 136(5): 884-93, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9812085

RESUMO

BACKGROUND: Several atherogenic, hemostatic, inflammatory, and genetic parameters and markers have been implicated as risk factors in coronary artery disease, although whether they are risk factors for acute as opposed to chronic coronary disease is unclear. METHODS AND RESULTS: Fifty subjects with an isolated myocardial infarction >3 months previously were compared with 50 subjects with a minimum 3-year history of stable angina, documented coronary artery disease, normal electrocardiogram and normal ventricular wall motion, and no episode suggesting infarction or unstable angina. Biologic variables analyzed included apolipoprotein B (apo B), lipoprotein (a), C-reactive protein (CRP), fibrinogen, factor VII, tissue plasminogen activator (TPA) and inhibitor (PAI-1), thrombin-antithrombin (TAT), fragment 1+2 (F1+2), von Willebrand factor (vWF), activated protein C resistance, homocyst(e)ine, anticardiolipin antibodies, blood group, and the angiotensin-converting enzyme insertion/deletion (I/D) and angiotensin II receptor gene polymorphisms. There were no significant differences between the 2 groups for any of the variables studied, although fibrinogen and F 1+2 tended to be slightly higher in the angina group (P = .09 for each). These significant correlations were present: age with fibrinogen, homocyst(e)ine, and vWF; factor VII with apo B, homocyst(e)ine, and TPA; apo B with TPA and CRP; CRP with fibrinogen, TPA, PAI-1, and factor VII; fibrinogen with vWF. CONCLUSIONS: Examination of atherogenic, hemostatic, inflammation, and genetic variables in the clinically quiescent state permitted no distinction between subjects with a previous isolated myocardial infarction in contrast to those with long-standing uncomplicated stable angina, favoring the notion that acute coronary events occur at random on a varying background of atherosclerosis. The multiple correlations found among these variables also underscore their complex interaction in the atherosclerotic process.


Assuntos
Angina Pectoris/complicações , Biomarcadores/sangue , Infarto do Miocárdio/etiologia , Adulto , Fatores Etários , Idoso , Angina Pectoris/sangue , Fatores de Confusão Epidemiológicos , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Estudos Prospectivos , Fatores de Risco
19.
J Am Coll Cardiol ; 29(7): 1497-504, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9180110

RESUMO

OBJECTIVES: We explored how the exercise electrocardiographic (ECG) indexes generally presumed to signify severe ischemic heart disease (IHD) correlate with coronary angiographic and scintigraphic myocardial perfusion findings. BACKGROUND: In exercise testing, it is generally assumed that the early onset of ST segment depression and its occurrence at a low rate-pressure product (ischemic threshold); the amount of maximal ST segment depression; and a horizontal or downsloping ST segment and its prolonged recovery after exercise signify more severe IHD. However, the relation of these indexes to coronary angiographic and exercise myocardial perfusion findings in patients with IHD is unclear. METHODS: We prospectively carried out a symptom-limited 12-lead Bruce protocol thallium-201 single-photon emission computed tomographic (SPECT) exercise test in 66 consecutive subjects with stable angina, > or = 70% stenosis of at least one coronary artery, normal rest ECG and left ventricular wall motion and a prior positive exercise ECG. The above ECG indexes, vessel disease (VD), a VD score and the quantitative thallium-SPECT measures of the extent, maximal deficit and redistribution gradient of the perfusion abnormality were characterized. RESULTS: Maximal ST segment depression could not differentiate the number of diseased vessels; was not related to VD score, maximal thallium deficit or redistribution gradient; but was related to the extent of perfusion abnormality (r = 0.29, 95% confidence interval [CI] 0.08 to 0.52, p = 0.02). Time of onset of ST segment depression correlated inversely only with VD (r = -0.22, 95% CI -0.44 to -0.05, p < 0.05), whereas the ischemic threshold had low inverse correlation only with VD score (r = -0.25, 95% CI -0.47 to -0.01, p < 0.05) and the redistribution gradient (r = -0.33, 95% CI -0.53 to -0.10, p < 0.01). A horizontal or downsloping compared with an upsloping ST segment did not demonstrate more severe angiographic and scintigraphic disease. Recovery time did not correlate with angiographic and scintigraphic findings, and correlations between angiographic and scintigraphic findings were also low or absent. CONCLUSIONS: In this homogeneous study group, the exercise ECG indexes did not necessarily signify more severe IHD by angiographic and scintigraphic criteria. Lack of concordance between the exercise ECG, angiography and myocardial scintigraphy suggests that these diagnostic modalities examine different facets of myocardial ischemia, underscoring the need for caution in the interpretation of their results.


Assuntos
Angiografia Coronária , Eletrocardiografia , Isquemia Miocárdica/diagnóstico , Índice de Gravidade de Doença , Idoso , Angina Pectoris/diagnóstico por imagem , Constrição Patológica , Estudos de Avaliação como Assunto , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/diagnóstico por imagem , Estudos Prospectivos , Sensibilidade e Especificidade , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Disfunção Ventricular Esquerda
20.
Can J Cardiol ; 12(10): 914-8, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9191480

RESUMO

Among 4371 men aged 35 to 64 in 1973 who were randomly selected, living in Quebec City suburbs, without clinical evidence of ischemic heart disease (IHD) at entry and followed for 16 years, 426 had a first acute IHD event; of these, 296 had a nonfatal myocardial infarction (MI), 50 a fatal MI (death within four weeks of the acute event) and 80 an early death, ie, they died before the diagnosis of MI was made. Among these 80 early deaths attributed to IHD in the absence of any other apparent cause, 55 men died within 1 h from the onset of symptoms or were found dead in their bed (group A) while 25 died more than 1 h after the onset of symptoms (group B). In this population, a first acute IHD event carried a 31% (130 of 426) case fatality within the first four weeks. Groups A and B accounted for 42% (55 of 130) and 19% (25 of 130) of the total acute ischemic mortality, respectively. As expected, fatal events increased with age, but the proportion of early deaths over the total IHD mortality was as frequent in younger men as in older men. Smoking, increased systolic and diastolic blood pressure and serum cholesterol were associated with increased nonfatal events. A similar association, except for serum cholesterol, was observed for all fatal events. No significant risk factor profile differentiated early from late fatal events. In conclusion, in this population, nearly a third of men with a first IHD event died, most of them outside the hospital. None of the main established risk factors differentiated men with a fatal MI from those with an early death.


Assuntos
Isquemia Miocárdica/mortalidade , Adulto , Pressão Sanguínea , Colesterol/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/mortalidade , Quebeque/epidemiologia , Fatores de Risco , Fumar/mortalidade
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