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Biomedical subjects

J Caron

Publications and source records attributed to J Caron.

At least 37 records · Page 2Linked to original sources
PubMed2000

Dose-response evaluation of levalbuterol versus racemic albuterol in patients with asthma.

Albuterol, in all marketed forms, is sold as a racemate, composed of a 50:50 mixture of (R)- and (S)-isomers. Racemic albuterol and the single isomer version (R)-albuterol (levalbuterol) were compared in a randomized, double-blind, dose-ranging five-way crossover study in patients (n = 20) with mild persistent to moderate persistent asthma. Placebo, racemic albuterol (2.50 mg), or levalbuterol (0.31, 0.63, or 1.25 mg) were delivered as single, nebulized doses to 5 male and 15 female nonsmoking patients with asthma aged 18-50 years. Serial pulmonary function was assessed at 15-min intervals and mean time to onset of activity and duration of improvement of forced expiratory volume in 1 sec (FEV1) were measured. In addition, blood chemistries, electrocardiogram (ECG) readings, and patient subjective assessment of adverse symptoms were recorded. Levalbuterol was found to provide significant bronchodilatory activity and was well tolerated. Levalbuterol 1.25 mg provided the greatest increase and duration in FEV1 improvement, whereas racemic albuterol (2.50 mg) and levalbuterol 0.63 mg provided comparable effects. The lower doses of levalbuterol were associated with a less marked effect on heart rate and potassium than racemic albuterol or high-dose levalbuterol. These data suggest that 0.63 mg levalbuterol provides bronchodilation equivalent to 2.50 mg racemic albuterol with less beta-mediated side effects.

Adolescent↗
PubMed2000

[Suicide in Abitibi-Temiscamingue region: epidemiological data for the period of 1992-96].

A permanent register of suicide cases has been established and has made it possible to produce a quantitative description of the suicide phenomenon in Abitibi-Témiscamingue for the period 1992-1996. This study reviews 211 suicide cases reported by the Chief Coroner Office of Quebec. A content analysis grid was applied to the coroners' files and has facilitated the study of 87 variables potentially related to suicide. The results show the evolution of suicide rates in this region in relation to those in other parts of Quebec, and the differences among various parts of the region. Several variables are shown to be significantly related to suicide (sex, age, method used, suicide site, etc.). A review of recent literature on suicide throughout the world indicates that patterns of suicide in Abitibi-Témiscamingue follow present trends in North America and Europe, but with aspects particular to the region.

Adolescent↗
PubMed1999

An evaluation of psychometric properties of the client's questionnaire of the Wisconsin Quality of Life Index-Canadian version (CaW-QLI).

Psychometric properties of Client's questionnaire from the Canadian version of the Wisconsin Quality of Life-Index (CaW-QLI) were assessed with two groups, 89 English (E) and 94 French (F) individuals with schizophrenia or schizoaffective disorder. Sub-samples of 40 E and 36 F were re-interviewed within a 2-week period. Spearman correlations-SC between each domain and CaW-QLI global Score ranged from 0.39 to 0.76, while interdomain correlations were low, confirming the multi-dimensional properties of the scale. Cronbach's alpha (internal consistency) were 0.78 (E) and 0.70 (F) for the CaW-QLI global scores and, from 0.45 to 0.88 among seven of eight domains. Test-retest (Concordance Correlation Coefficient--CCC) ranged from 0.36 to 0.80 among the domains, and from 0.80 (E) and 0.85 (F) between CaW-QLI global scores. Regarding convergent validity, SC between CaW-QLI global score and Spitzer's QOL-Index were 0.72 (E) and 0.58 (F). As hypothesized, there were higher correlations between CaW-QLI global scores (E and F) and SF-36 scales related to mental health than those related to physical health. Minor changes in the scoring are proposed to enhance face and content validity.

Adolescent↗
PubMed1999

[Toxic dermatitis caused by tramadol].

BACKGROUND: Tramadol chlorhydrate (Topalgic) is a powerful analgesic recently introduced in France where its use has spread rapidly. We report a case where this drug induced a maculopapulous toxic skin reaction with secondary erythrodermia. CASE REPORT: A 47-year-old man was treated for lower back pain with tramadol chlorhydrate (50 mg b.i.d.). Otherwise, he was in good general health and was taking no other medications. Shortly after beginning the treatment, he developed a highly pruriginous maculopapulous eruption involving the entire skin surface, hyperthermia and general degradation. There was no skin exfoliation, mucosal involvement nor nodal enlargement. Tramadol was withdrawn and the patient was given corticosteroid therapy. Secondary erythrodermia developed after termination of the corticosteroids. The lesions regressed after tramadol withdrawal. DISCUSSION: Tramadol-induced skin reactions are uncommon and usually benign. In our case, the delay from onset of tramadol and the development of the maculopapulous eruption was very short (four days). The patient was taking no other medication. We hypothesize that the patient had been sensitized by cross-reaction with another compound and recall the fundamental aspects of tramadol and opiate drugs.

Analgesics, Opioid↗
PubMed1998

Quality of life of severely mentally ill individuals: a comparative study.

This survey compared the subjective quality of life (SQOL) of severely mentally ill patients (n = 59) receiving community support services with a random sample from the general population members (n = 253) and welfare recipients (n = 79). Research participants lived in two cities of Northwest Quebec. The Satisfaction with Life Domain Scale (Baker & Intagliata, 1982) was used in face to face interviews, and also administered as a mail-in questionnaire for the general population. Results show that patients' subjective quality of life as-a-whole is lower than the general population. Mentally ill patients were more satisfied with material domains (e.g., housing and finances) than welfare recipients. However, mentally ill patients were less satisfied with interpersonal relationships, including people they live with, family members and their love life.

Adolescent↗
PubMed1998

Components of social support and quality of life in severely mentally ill, low income individuals and a general population group.

Satisfaction with social support and quality of life (QOL) were assessed for 60 psychiatric patients, 79 welfare recipients and 266 people of the general population using the Social Provisions Scale (SPS) and the Satisfaction with Life Domains Scale (SLDS). Psychiatric patients reported less satisfaction than the general population on all components of social support. They have a comparable level of satisfaction with welfare recipients on most of the components, with the exception of emotional integration and opportunity for nurturance. However, patients satisfaction with QOL was quite similar to the general population, although higher than welfare recipients on some dimensions. Their lower satisfaction with the personal-intimate dimension suggest deficiencies in social support. All components of social support were consistently related to QOL in the general population. Attachment and reassurance of worth was significant for psychiatric patients but only attachment was related to QOL for the welfare recipients group. The pairing of SPS and SLDS scales seem to be good instruments for discriminating the majority of psychiatric patients.

Adult↗
PubMed1998

Risk and penetrance of primary hyperparathyroidism in multiple endocrine neoplasia type 2A families with mutations at codon 634 of the RET proto-oncogene. Groupe D'etude des Tumeurs à Calcitonine.

Germline mutations of the RET proto-oncogene are responsible for multiple endocrine neoplasia type 2, including multiple endocrine type 2A (MEN 2A), type 2B (MEN 2B), and familial medullary thyroid carcinoma. The relationship between specific mutations and syndromic features has been established. In particular, the risk for pheochromocytoma and hyperparathyroidism (HPT) in MEN 2A patients is clearly associated with the presence of the RET mutation at a specific position, i.e. at codon 634. Also, a correlation between a specific mutation, C634R, and the development of HPT has been suggested but is still controversial. To further investigate the relationship between specific mutations of codon 634 and the development of HPT, we studied a population of 188 individuals, carrying mutations at codon 634, namely C634R (65 patients belonging to 10 families), C634Y (80 patients belonging to 11 families), or the less frequent codon 634 mutations [i.e. C634S, C634F, C634G, or C634W (43 patients belonging to 9 families)]. In this series of patients, we defined an overall HPT prevalence of 19.1% and found that this prevalence did not vary significantly, with respect to the nature of the mutation. However, irrespective of the particular mutation, the prevalence of HPT showed a high interfamilial variability. The statistical model that best fitted with the observed data was in favor of the heterogeneity of the risk for HPT, with 40% of the families showing an HPT risk of 34% and 60% of the families showing an HPT risk of 9%. In addition, our study clearly demonstrated that HPT could be an early component of the disease and provided the first estimate of age-specific and mutation-specific HPT penetrance in individuals with mutations of codon 634 of the RET proto-oncogene.

Adult↗
PubMed1998

[Von Hippel-Lindau disease: recent genetic progress and patient management. Francophone Study Group of von Hippel-Lindau Disease (GEFVH)].

Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder, predisposing to the development of central nervous system (CNS) and retinal hemangioblastomas, endolymphatic sac tumors, renal cell carcinoma and/or renal cysts, pheochromocytomas, pancreatic cysts and/or tumors. Incidence of the disease is 1/36,000. CNS hemangioblastomas and renal cell carcinoma are the main causes of death. The VHL gene, located on 3p25-26, is a tumor-suppressor gene which plays a major role in regulation of VEGF expression. Germline mutations of the VHL gene are identified in about 70-99% of the patients. Mutations associated with VHL type 2 (with pheochromocytoma) are mainly missense mutations with hot-spot at codon 167. Somatic mutations of the VHL gene are found in both sporadic central nervous system hemangioblastomas and sporadic renal cell carcinoma. For endocrinologists search for VHL disease (as for MEN) should be imperative in presence of a patient with pheochromocytoma and neuroendocrine pancreatic tumor.

Carcinoma, Renal Cell↗
PubMed1998

[Electrophysiologic effects and arrhythmogenic potential of diphemanil methylsulfate on rabbit purkinje fibers. Correlations with clinical observations of QT prolongation in pediatrics].

Serious undesirable cardiac side effects have been reported with treatment with diphemanil methylsulfate (Prantal) in premature babies or neonates. To understand the origin of this problem, the authors undertook an electrophysiological study of the effects of this product in vitro on rabbit Purkinje fibres. In three separate series (N = 5 to N = 8), the effects of increasing concentrations (0.1 microM-30 microM) of diphemanil methylsulfate, different frequencies of stimulation (0.2 Hz, 1 Hz, 2 Hz) and duration of exposition (60 min followed by 120 min washout) were observed on the properties of the action potential. The results show a clearcut antiarrhythmic Class III type action characterised by a concentration-dependent prolongation of the action potential duration with an inverse frequency dependency without significant changes of the other parameters. During stimulation at 0.2 Hz, early post-depolarizations and induced activity were observed in 3/8 of the fibres exposed to 10 microM and 8/8 fibres exposed to 30 microM. The effect did not attain a steady state after 60 min of exposition. It was not reversed by 120 min of washout of the preparation. These results were compatible with the reported cardiac arrhythmic effects of prolongation of the QT interval and torsades de pointe.

Action Potentials↗
PubMed1997

Effect of ramipril on heart rate variability in digitalis-treated patients with chronic heart failure.

The aim of this study was to evaluate the effect of an angiotensin-converting enzyme (ACE) inhibitor, ramipril, on heart rate variability in patients with heart failure simultaneously treated with digitalis. This study was a multicentric, randomized, double-blind, placebo-controlled study including 50 patients with chronic heart failure (CHF). All patients were in NYHA functional class II and III. The etiology of CHF was mainly idiopathic dilated cardiomyopathy and ischemic heart disease. After a 4-week placebo run-in period with digoxin and diuretics, patients were randomized to receive additional ramipril or placebo. To assess heart rate variability (HRV) and arrhythmias, 24-hour ECGs were recorded at the end of the placebo run-in period, 8 and 24 weeks after randomization. Spectral analysis of HRV was performed during one diurnal and one nocturnal 5-minute time period. No statistically significant differences in HRV within low-, high-, and total-frequency bands were induced by ramipril in either the diurnal or nocturnal periods, both at 8 and 24 weeks after randomization. Ramipril produced a significant decrease in nonsustained ventricular tachycardia at 24 weeks of treatment (p = 0.01). These results run against previous observations showing an increase in parasympathetic tone with ACE inhibitors in heart failure. The present study thus suggests that the effects of ACE inhibitors in CHF are variable and depend on the patient and concomitant treatment that might influence HRV such as digoxin treatment.

Adult↗
PubMed1997

Adverse effects of class I antiarrhythmic drugs.

Class I antiarrhythmic drugs are characterised by their ability to block the fast inward sodium current in cardiac muscle tissue. However, at the same time, they can be responsible for various effects involving other organs and systems. Although some of these effects can be helpful in specific situations, most of them, such as their pro-arrhythmic propensity, are deleterious. Some of the adverse effects of class I antiarrhythmic drugs are directly linked to sodium-channel blockade (conduction disorders haemodynamic perturbations, and digestive and neurological effects), while others are linked to other specific pharmacological properties (e.g. atropinic, or alpha- or beta-adrenergic blockade) or to nonspecific properties (idiosyncratic hypersensitivity, and haematological, dermatological or hepatic reactions). Other adverse effects are associated with complex interactions between class I antiarrhythmics and individual predisposing factors, trigger mechanisms and physiological factors (including concomitant drug treatment). These numerous variations and interactions within a specific environment and underlying disorder might be of pharmacological or/and pharmacokinetic origin, making analysis of the true liability of the class I drugs very difficult when adverse effects occur.

Anesthesia, Local↗
PubMed1997

Quality of life and social integration of severely mentally ill patients: a longitudinal study.

The quality of life concept serves to measure functional changes and program outcome. Patients with schizophrenia have an improved prognosis. Is quality of life improving over time, and if so, over what period? These questions were addressed in a longitudinal study where subjective quality of life (SQOL) was rated by severely mentally ill patients living in the community and using support services located in an outlying area of Quebec. The Satisfaction for Life Domains Scale (SLDS) (Baker and Intagliata 1982) measuring SQOL as a whole and in specific domains (for example, housing, finances, social relationships) was repeated over a period of 7 y. Results show that SQOL ratings received the same scores after 7 y. Functional status was decreased, while social integration improved and more services were used. The results could be due to sample characteristics or to the ambiguity of the SQOL construct. In our opinion, extensive community-based support services may have played a key role in the maintenance of patient's quality of life.

Adult↗