Search PubMed⌕ Search

Biomedical subjects

J Grégoire

Publications and source records attributed to J Grégoire.

At least 19 recordsLinked to original sources
PubMed2006

Predictors of self-reported noncompliance with antihypertensive drug treatment: a prospective cohort study.

BACKGROUND: Persistence and compliance are different aspects of the broader concept of adherence to drug treatment. In a prior study, determinants of nonpersistence in a group of patients newly prescribed antihypertensive medications were examined. OBJECTIVE: To determine noncompliance among those who were persistent with therapy. METHODS: A prospective cohort study was conducted, in which individuals prescribed a new antihypertensive monotherapy were identified through a network of 173 pharmacies. Participants were interviewed by telephone twice during a three-month period. At the end of this period, individuals who reported still taking the medication initially prescribed were included in the analysis. Self-reported noncompliance was measured at three months. Data were analyzed using a multivariate logistic regression model. RESULTS: Of 509 eligible participants, 118 (23.2%) reported noncompliance with their drug treatment. Noncompliance was significantly associated with the use of angiotensin-converting enzyme inhibitors (adjusted OR [AOR] 3.0; 95% CI 1.17 to 7.92) compared with the angiotensin II receptor blocker losartan, and with the belief that hypertension is not a risk factor for cardiovascular diseases (AOR 2.0; 95% CI 1.21 to 3.33). On the other hand, noncompliance was inversely associated with the use of more than four pills of medication per day (AOR 0.3; 95% CI 0.15 to 0.64). CONCLUSIONS: Compliance with drug treatment could be improved by proper selection of medication, and by attempts to correct the false perceptions patients may have about hypertension. Further research is needed to better understand the clinical significance of a higher number of pills as a predictor of good compliance. Further research is also needed using different means of measuring noncompliance.

Antihypertensive Agents↗
PubMed2004

Adaptation of the diaphragm and the vastus lateralis in mild-to-moderate COPD.

The chronology of diaphragm and vastus lateralis adaptation in chronic obstructive pulmonary disease (COPD) has not been studied. The hypothesis of this study was that muscle changes would occur earlier in the diaphragm than in the vastus lateralis in COPD, a finding that would suggest that local factors would be more important than systemic factors in determining the muscle phenotypic expression, at least in mild-to-moderate disease. The adaptation of the vastus lateralis and diaphragm muscles was evaluated in patients with mild-to-moderate COPD and in subjects with normal pulmonary function. In both groups, the oxidative potential and the number of lipofuscin inclusions were higher in the diaphragm than in the vastus lateralis. Compared to control, the diaphragm in COPD had a higher oxidative capacity and a higher proportion of type I fibres, with a reciprocal decrease in type IIA fibres, while there was no difference in diaphragmatic cross sectional areas, capillarisation and lipofuscin inclusions. No significant differences were found in the vastus lateralis from both groups. In conclusion, these data indicate that the diaphragm in controls and in chronic obstructive pulmonary disease has a higher oxidative potential than the vastus lateralis, and that muscle adaptation occurs earlier in the diaphragm than in the vastus lateralis in mild-to-moderate chronic obstructive pulmonary disease.

Adaptation, Physiological↗
PubMed2001

Impact of residual plaque burden after balloon angioplasty in the MultiVitamins and Probucol (MVP) trial.

BACKGROUND: It has been shown in the MultiVitamins and Probucol (MVP) trial that probucol reduces angiographic lumen loss by 68% after percutaneous transluminal coronary angioplasty (PTCA). Restenosis occurred in 40% of patients not treated with probucol and in 20% of those in the probucol alone group. OBJECTIVE: To determine the morphological predictors of restenosis in patients treated with probucol. PATIENTS AND METHODS: Beginning 30 days before angioplasty, 317 patients were randomly assigned to receive probucol, multivitamins, the combined treatment or placebo. Patients were then treated for six months after angioplasty. Intravascular ultrasound (IVUS) examination was performed immediately after angioplasty and at follow-up in 94 patients (108 segments). The angioplasty operator was blinded to the IVUS results. The cross-section selected for serial analysis was the one at the angioplasty site with the smallest lumen area at follow-up. Receiver operating characteristic curves were used to determine the performance of criteria to predict angiographic restenosis at follow-up. RESULTS: In probucol-treated patients, the cross-sectional area (CSA) narrowing of 67.6% or less was the best IVUS predictor for the absence of restenosis (P=0.03). Diameter stenosis of 35% or less almost reached significance as a predictor in these patients (P=0.056). The restenosis rate when either of these predictors was met was less than 13%. Rates of repeat PTCA in patients treated with probucol were 9.7% when CSA narrowing was 67.6% or less on IVUS and 3.1% with a post-PTCA stenosis of 35% or less on quantitative coronary angiography (QCA). No predictor of the absence of restenosis in patients not treated with probucol was identified. CONCLUSIONS: The presence after balloon angioplasty of a CSA narrowing of 67.6% or less on IVUS or a diameter stenosis of 35% or less on QCA is associated, in patients treated with probucol, with extremely low rates of coronary restenosis and repeat angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed2000

Long-term results of sleeve lobectomy for lung cancer.

OBJECTIVE: Sleeve lobectomy is a lung saving procedure indicated for central tumors for which the alternative is a pneumonectomy. Current controversies relate to the safety of the procedure and adequacy as a cancer operation. The aim of the study is to analyze long-term survival after sleeve lobectomy, particularly in relation with nodal status and histological type. The incidence and patterns of recurrences were reviewed. METHODS: From 1972 to 1998, 184 patients (male 152, female 32) underwent sleeve resection for lung cancer. The mean age was 60+/-10 years (11-78 years), and the indications for operation were a central tumor (79%), peripheral tumor with nodal involvement (13%) and compromised pulmonary function (8%). The histological type was predominantly squamous (n=125, 68%), followed by non-squamous (n=50, 27%) and carcinoid tumors (n=9, 5%). Resection was complete in 161 patients (87%). RESULTS: The operative mortality was 1.6% (n=3). Follow-up was complete for the remaining 181 patients (mean, 5.7 years; range, 1 month-26 years). The survival at 5 and 10 years of all patients was 52 and 33%, respectively. Theses rates for patients with N0 status (n=97) were 63 and 48%, and 48 and 27% for those with N1 status (n=68; N0 vs. N1, P<0.05). An 8% survival rate was observed with N2 status (n=19) at 5 years, with no survivors after 7 years of follow-up. The 5 and 10 year survival was 56 and 34% for squamous carcinoma vs. 33 and 22% for non-squamous carcinoma (P<0.05). These rates were 58 and 38% for complete resection vs. 11 and 6% for incomplete resection at 5 and 10 years, respectively (P<0.05). Local recurrences occurred in 22% of cases, and the prevalence was statistically different between patients with N0 disease (14%) and N1 disease (23%; P=0.03), but not between N1 and N2 disease (42%; P=0.2). When local and distant recurrence were pooled together, the differences were highly significant between N0 (22%) and N1 (41%) disease (P=0.007), and between N0 and N2 (63%) disease (P=0.0002), but not between N1 and N2 disease (P=0.09). CONCLUSION: Sleeve lobectomy is a safe and effective therapy for patients with resectable lung cancer. The presence of N1 and N2 disease, or of non-squamous carcinoma significantly worsen the prognosis.

Adenocarcinoma↗
PubMed2000

Reliability of mechanical and phased-array designs for serial intravascular ultrasound examinations--animal and clinical studies in stented and non-stented coronary arteries.

BACKGROUND: Both mechanical and multi-element intravascular ultrasound designs have potential advantages and limitations that may impact on their value for clinical and research purposes. Determination of the reproducibility of measurements is critical before a given system can be used in studies such as regression of atherosclerosis trials. METHODS: We performed serial intravascular ultrasound imaging with catheters using mechanical and phased-array designs in stented and non-stented coronary arteries in dogs and in patients. RESULTS: Both systems correlated well for areas (r > or = 0.90, p < 0.0001) and diameters (r > or = 0.84. p < 0.0001) in dogs and in patients. There was a slight difference between multi-element and mechanical designs for measurements of area (mean difference in dogs and in patients: -0.24 and 0.96 mm2, p < 0.055) and diameter (-0.08 and 0.16 mm, p < 0.0001). The reproducibility of the multi-element system for reanalysis of the same frames and for analysis of serial pullbacks was similar to the same measurements with the mechanical system (r > or = 0.96 for all measurements). The differences in absolute and relative variability between the mechanical and phased-array designs, both for reanalysis of same frames and serial pullbacks, were very small. CONCLUSIONS: Although multi-element and mechanical intravascular ultrasound designs are not strictly interchangeable, their similar reproducibility and the small differences in measurements demonstrate that both designs are acceptable alternatives for trials of regression of atherosclerosis. Determination of the variability for serial pullbacks of both designs was also important to assess the statistical power of such trials.

Animals↗
PubMed2000

Surgical therapy of early non-small cell lung cancer.

Approximately 45% of all lung carcinomas are limited to the chest, where surgical resection is not only an important therapeutic modality, but in many cases, the most effective method of controlling the disease. Patients with T1N0 and T2N0 tumors have early lung cancer, and most are curable by resection, with 5-year survival rates in the range of 75 to 80% for patients with T1N0 status. Patients with smaller tumors do better than patients with larger ones, while visceral pleural invasion does not seem to influence survival. Histologic type is also a significant prognostic variable, with squamous tumors having a better prognosis than tumors of nonsquamous histology. Other known prognostic factors are age and gender of the patient and completeness of resection. The "gold standard" of surgery remains lobectomy, regardless of tumor size at presentation. Stage T1N1 and T2N1 carcinomas represent a group of patients where the disease involves hilar and bronchopulmonary nodes. This group is best treated by complete resection with mediastinal lymphadenectomy. Tumor size and histology are significant prognostic variables, and 5-year survival after complete resection is in the range of 40 to 50%. Postoperative radiation therapy may improve local control, while chemotherapy results in a slightly reduced risk of death.

Carcinoma, Non-Small-Cell Lung↗
PubMed2000

Clinical and surgical staging of non-small cell lung cancer.

The necessity for a compulsive attitude toward preoperative assessment of lung cancer is to be emphasized, since rational treatment and prognosis depend largely on the stage of disease at the time of diagnosis. In the preoperative setting, the techniques used should be sequential, logical, and help to identify patients suitable for treatment with curative intent. With regard to the primary tumor (T status), the accuracy of CT or MRI to predict the need for extended resections is limited. Similarly, all noninvasive methods to determine the nodal status (N) are valuable, but mediastinoscopy has a greater sensitivity and specificity than either CT or MRI. The role of routine organ screening for the detection of distant occult metastasis in the asymptomatic patient is still controversial. Ultimately, the prognosis of the resected patient with lung cancer is based on complete intraoperative staging, which can be done by either systematic node sampling or complete lymphadenectomy. At present, neither of these techniques has been shown to improve the quality of staging or survival.

Carcinoma, Non-Small-Cell Lung↗
PubMed1999

Sauna-induced myocardial ischemia in patients with coronary artery disease.

PURPOSE: Sauna bathing is a popular recreational activity that is generally considered to be safe. However, there have been case reports of adverse cardiac events. We sought to determine whether sauna use caused myocardial ischemia in patients with coronary artery disease. METHODS: Sixteen patients with proven coronary artery disease were submitted to three conditions (rest, exercise, and sauna bathing) with continuous electrocardiographic (ECG) monitoring and regular blood pressure measurements. During each condition, patients were injected with Tc-99 sestamibi followed by nuclear scintigraphic imaging. Perfusion defect scores were calculated in 15 patients. RESULTS: Sauna bathing was well tolerated. There was a mean (+/- SD) increase in heart rate of 32% +/- 20% in the sauna (resting mean heart rate = 60 +/- 9 beats per minute vs sauna mean heart rate = 79 +/- 11 beats per minute, P <0.001) and a 13% +/- 6% drop in systolic blood pressure (resting mean systolic blood pressure = 142 +/- 14 mm Hg vs sauna mean systolic blood pressure = 123 +/- 15 mm Hg, P <0.001). There were no arrhythmias or ECG changes in the sauna. Compared with rest, there was significant ischemia during sauna bathing (average perfusion defect score at rest = -0.44 vs average sauna score = -0.93, P <0.001). The perfusion defect score in the sauna was worse than the resting score in 14 of the 15 patients. Sauna-associated perfusion defect scores were highly correlated with exercise-induced scores (R2 = 0.65, P <0.001). CONCLUSION: In patients with stable coronary artery disease, sauna use is clinically well tolerated but is associated with scintigraphically demonstrated myocardial ischemia.

Aged↗
PubMed1999

Techniques of pneumonectomy. Completion pneumonectomy.

Completion pneumonectomy refers to an operation intended to remove what is left of a lung partially resected during previous surgery. Completion pneumonectomy is a technically demanding procedure, which carries an increased operative mortality and morbidity. If the planning and the surgical technique are done meticulously, the good prospect for long-term survival justifies the higher risk.

Adolescent↗
PubMed1999

Techniques of pneumonectomy. Drainage after pneumonectomy.

After most pneumonectomies, the pleural space can be safely closed without drainage. If a chest tube must be used, a balanced drainage system is recommended. This article specifically addresses some of the controversial issues in the early management of the postpneumonectomy space. It also describes the indications, advantages, and disadvantages of drainage and the methods commonly used for this purpose.

Chest Tubes↗
PubMed1999

Physiologic consequences of pneumonectomy. Consequences on the pulmonary function.

When pneumonectomy is done in children, there is some speculation that lung growth occurs. In the adult population, volume response is incomplete and attributable to alveolar distention rather than multiplication. Stretch is widely regarded as the initial stimulus for compensatory growth. The authors review data pertaining to the physiology of the various adjustments that occur after pneumonectomy gathered both from observations on human response and from experimental findings in animals. Mechanisms and mediators of this adaptive response are discussed.

Adolescent↗
PubMed1998

Intravenous diltiazem in acute myocardial infarction. Diltiazem as adjunctive therapy to activase (DATA) trial.

OBJECTIVES: This study was defined as a pilot investigation of the usefulness and safety of intravenous diltiazem as adjunctive therapy to tissue plasminogen activator in acute myocardial infarction, followed by oral therapy for 4 weeks. BACKGROUND: Experimental studies have documented that calcium antagonists protect the myocardial cell against the damage caused by coronary artery occlusion and reperfusion, yet no benefits have been conclusively demonstrated in acute myocardial infarction (AMI) in humans. METHODS: In this pilot study, 59 patients with an AMI treated with tissue-type plasminogen activator (t-PA) were randomized, double blinded, to intravenous diltiazem or placebo for 48 h, followed by oral therapy for 4 weeks. The primary objective was to detect an effect on indices of regional left ventricular function and perfusion. Patients were also closely monitored for clinical events, coronary artery patency and indices of infarct size and of left ventricular function. RESULTS: Creatine kinase elevation, Q wave score, global and regional left ventricular function and coronary artery patency at 48 h were not significantly different between the diltiazem and placebo groups. A greater improvement observed in regional perfusion and function with diltiazem was likely explained by initial larger defects. Diltiazem, compared to placebo, reduced the rate of death, reinfarction or recurrent ischemia at 35 days from 41% to 13% (p=0.027) and prevented the need for an urgent intervention. The rate of death or myocardial infarction was reduced by 65% (p=0.15). These benefits could not be explained by differences in baseline characteristics such as age, site and extent of infarction, time of inclusion or concomitant therapy. Heart rate and blood pressure were reduced throughout the study with active diltiazem treatment. Side effects of diltiazem were bradycardia and hypotension that required transient or permanent discontinuation of the study drug in 27% of patients, vs. 17% of patients with placebo. CONCLUSIONS: A protective effect for clinical events related to early postinfarction ischemia and reinfarction was suggested in this study, with diltiazem administered intravenously with t-PA followed by oral therapy for 1 month, with no effect on coronary artery patency and left ventricular function and perfusion.

Administration, Oral↗
PubMed1998

Clinical patterns and trends of outcome of elderly patients with bronchogenic carcinoma.

OBJECTIVE: To investigate the clinical characteristics and determinants of operative mortality and long-term survival of elderly patients submitted to pulmonary resection for intended cure of lung cancer. METHODS: Retrospective analysis of 500 consecutive pulmonary resections performed in patients aged over 70 years from 1975 to 1996. Predictors of in-hospital mortality were identified by univariate and multivariate analyses. Determinants of long-term outcome were investigated in all survivors, with no patient being lost to follow-up. RESULTS: Mean age was 74 +/- 3 years (maximum: 90), and 36 patients were octogenarians. The sex-ratio M:F was 5:3. History of combined cardiovascular or previous neoplastic disease was noted in 193 and 63 patients, respectively. The predominant histology was squamous cell carcinoma (n = 243), with a significantly higher incidence in male than in female. Most patients received standard procedures, while 103 patients underwent extended resections for tumors involving the mediastinum (n = 44), the chest wall (n = 33), the carina (n = 2) or had a sleeve resection of the main bronchus (n = 24). Procedures were considered to be complete and curative in 459 patients, among whom 294 had a stage I disease. There were 37 (7.4%) in-hospital deaths. Mortality rates following pneumonectomy, bilobectomy, lobectomy and lesser resection were 11:136, 4:34, 22:291, and 0:39, respectively. Age, male gender, hypertension, low FEV1 and extended procedure were identified as independent predictors of early mortality. Overall survival rates were 33.7 and 12% at 5 and 10 years, respectively. Multivariate analysis demonstrated that the disease stage was the main prognosticator. During the follow-up period, cancer recurrence (n = 183; 39.5%) or second primary lung cancer (n = 20; 4.3%) occurred in 203 patients, among whom 18 (9%) had a second lung resection. Carcinoma in other systems occurred in 25 patients (5.3%), and major cardiovascular event in 51 (11%). CONCLUSIONS: Male and squamous cell carcinoma are characteristic of elderly patients with resected lung cancer. Operative mortality is acceptable for standard resection, and survival figures are concordant with those reported in other series which include younger patients.

Aged↗
PubMed1998

Postpneumonectomy pulmonary edema.

The adult respiratory distress syndrome seen after pneumonectomy is an uncommon but usually lethal complication. Its etiology remains unknown, although several factors such as fluid overload, endothelial damage, lymphatic interruption, and hyperinflation are thought to be involved in its pathogenesis.

Aged↗
PubMed1997

Short wave ultraviolet laser energy in porcine coronary arteries: medial cell death and neointimal formation.

BACKGROUND AND OBJECTIVE: Smooth muscle cell migration and proliferation from arterial media into the neointima are major factors in the restenosis process following coronary angioplasty. Because short wave ultraviolet (UV) radiation is cytotoxic for rat carotid artery smooth muscle cells, the aims of this study were to determine the effects of short wave UV irradiation on normal pig coronary arteries and to evaluate the efficacy of UV laser energy for reducing neointimal hyperplasia (NI). STUDY DESIGN/MATERIALS AND METHODS: In 13 pigs fed a normal diet, 37 coronary arteries were studied. UV laser light (275 nm) was applied in escalating doses from 0-16,353 mJ/cm2 via fiberoptic through a 20 mm PTCA balloon catheter. The pigs were euthanized at 21 days and histologic analysis performed. Arterial media was rendered acellular (ACM) in 20 of 33 irradiated coronary arteries (61%). The minimum UV energy density inducing ACM was 1348 mJ/cm2. The fraction of acellular media to internal elastic lamina length (ACM/IEL) was 0.79 +/- 0.29. RESULTS: No statistically significant difference was found between NI thickness at normal media sites (NM) vs. ACM sites (0.17 +/- 0.14 mm vs. 0.16 +/- 0.17 mm). No correlation was found between UV dose and NI formation (r = 0.307, P = 0.08). CONCLUSION: Short wave UV irradiation induces ACM in normal porcine coronary arteries. Induction of acellular media is not associated with a reduction of NI formation in this porcine coronary model.

Angioplasty, Balloon, Coronary↗
PubMed1997

Myocardial distribution of cardioplegia administered by antegrade and retrograde routes to ischemic myocardium.

OBJECTIVE: To study the distribution of a cardioplegic solution delivered by antegrade and retrograde routes to ischemic myocardium. Retrograde administration has been suggested to improve protection of the ischemic myocardium. However, there are insufficient data on perfusion of ischemic and necrotic zones by the retrograde route. DESIGN: A laboratory study in dogs. METHOD: In 12 dogs, 500 mL of hyperkalemic crystalloid cardioplegia containing 0.5 mCi of thallium-201 was injected antegradely or retrogradely through the coronary sinus after 3 hours of occlusion and 2 hours of reperfusion of the left anterior descending coronary artery. Myocardial distribution of the cardioplegic solution was measured by computer planimetry in the normally perfused zone, in the ischemic area and in the necrotic zone. RESULTS: The mean (and standard deviation) area at risk of ischemia (% of the left ventricle) delimited by Evans blue perfusion was smaller in dogs receiving a retrograde injection than in those receiving an antegrade injection (34% [3%] v. 42% [4%], p = 0.15). The infarct size (% of the area at risk indicated by triphenyltetrazolium dye) averaged 25% (11%) and 20% (7%) respectively (p = 0.36). The ratio of thallium-201 activity in ischemic to normal myocardium averaged 76% (13%) in the retrograde and 89 (12%) in the antegrade groups (p = 0.75). The ratio of thallium activity of infarct to normal myocardium averaged 56% (8%) in the retrograde group and 93% (19%) in the antegrade group (p = 0.18). Large areas of hypoactivity in the left ventricular myocardium were noted on scintigraphic imaging in all dogs that received retrograde perfusion. CONCLUSIONS: The retrograde injection of cardioplegia through the coronary sinus does not improve the distribution of cardioplegic solution in the acutely ischemic myocardial area nor in the zone of acute infarction in the dog. Because some cells may remain viable in the border zone and into the necrotic area, retrograde cardioplegia may result in suboptimal protection and incomplete prevention of further damage to the myocardium.

Animals↗
PubMed1996

The Drug Utilization Review Network of Quebec.

Drug utilization review programs have been recognized as an effective way to control health care spending while maintaining quality services. This article describes the structure, mandate and activities of Quebec's Drug Utilization Review Network. This 112-member network, which represents 45% of health care facilities in the province, was established to promote the optimal utilization of drugs through the provision of support to pharmacology committees, therapeutic committees and pharmacy departments. The network's main role is to coordinate multi-centre drug utilization studies. Future challenges include maintaining member interest and evaluating the clinical and economic impact of the network's efforts.

Cost Control↗