Biomedical subjects

M Cyr

Publications and source records attributed to M Cyr.

At least 37 records · Page 2Linked to original sources

PubMed1999

Localization of somatosensory function by using positron emission tomography scanning: a comparison with intraoperative cortical stimulation.

OBJECT: To investigate the utility of [15O]H2O positron emission tomography (PET) activation studies in the presurgical mapping of primary somatosensory cortex, the authors compared the magnitude and location of activation foci obtained using PET scanning with the results of intraoperative cortical stimulation (ICS). METHODS: The authors used PET scanning and vibrotactile stimulation (of the face, hand, or foot) to localize the primary somatosensory cortex before surgical resection of mass lesions or epileptogenic foci affecting the central area in 20 patients. With the aid of image-guided surgical systems, the locations of significant activation foci on PET scanning were compared with those of positive ICS performed at craniotomy after the patient had received a local anesthetic agent. In addition, the relationship between the magnitude and statistical significance of blood flow changes and the presence of positive ICS was examined. In 22 (95.6%) of 23 statistically significant (p < 0.05) PET activation foci, spatially concordant sites on ICS were also observed. Intraoperative cortical stimulation was positive in 40% of the PET activation studies that did not result in statistically significant activation. In the patients showing these results, there was a clearly identifiable t-statistic peak that was spatially concordant with the site of positive ICS in the sensorimotor area. All PET activation foci with a t statistic greater than 4.75 were associated with spatially concordant sites of positive ICS. All PET activation foci with a t statistic less than 3.2 were associated with negative ICS. CONCLUSIONS: Positron emission tomography is an accurate method for mapping the primary somatosensory cortex before surgery. The need for ICS, which requires local anesthesia, may be eliminated when PET foci with high (> 4.75) or low (< 3.20) t-statistic peaks are elicited by vibrotactile stimulation.

Craniotomy↗

PubMed1998

Factors related to utilization of services for mental health reasons in Montreal, Canada.

This study examines factors related to the utilization of services for mental health reasons by Montreal residents. Data were drawn from telephone interviews. A random sample of 893 respondents completed a questionnaire on service utilization and the Diagnostic Interview Schedule Self Administered to assess DSM-III-R psychiatric disorders. Results indicate that 12.8% of the population had used such services in the past year. Medical doctors and psychiatrists, whose services are free of charge under universal health coverage, were consulted, respectively, by 4.1% and 2.0% of respondents. Psychologists, whose services are not free, were seen by 3.4% of respondents. In all, 42.0% of respondents who presented a current diagnosis used services in the past year. The highest proportion of users (48.0%) was found among respondents who presented both current and lifetime diagnoses and among respondents with comorbidity. The choice of caregiver was related also to pattern of disorders: respondents with current and comorbid disorders tended to consult general practitioners, while respondents with lifetime disorders or with lifetime and current disorders favoured specialized care. In line with other studies, self-perception of mental health, gender and marital status were related to utilization; unlike other studies, attitudes and age were not. It is argued that particularities found in this study stem not only from methodological considerations, but also from the configuration of the mental health system in Quebec, where the greater availability of psychologists may facilitate service utilization.

Adolescent↗

PubMed1998

The evaluation of Franco-Quebec victims of child sexual abuse and their mothers: the implementation of a standard assessment protocol.

OBJECTIVE: There were two aims: first, to evaluate the feasibility of applying a standard assessment protocol to Franco-Quebec victims of child sexual abuse and nonoffending mothers; and second, to compare results from an initial sample with available data from English-speaking samples. METHOD: A standard individual case study design was used for victims and mothers; and the satisfaction of the nine participating youth workers was assessed. Four self-report instruments for victims and five for mothers were chosen on the bases of workers' priorities, sensitivity to the impact of CSA, and the availability of published norms on English-speaking samples. Results are reported on 48 confirmed victims and 40 nonoffending mothers. RESULTS: The protocol was favorably received by the CPS workers, supervisors and all mothers and victims. Percentages of clinically distressed victims varied from highs of 68% on the externalization difficulties of the Child Behavior Checklist and 67% for 2- to 6-year-olds on the Child Sexual Behavior Inventory, to lows of 10% on hostility symptoms and 13% on the Dissociation Scale of the Trauma Symptom Check for Children. The rate of symptom-free children was lower (19%) and that of revictimization higher (30%) than most published estimates (Kendall-Tackett, Williams, & Finkelhor, 1993). Most mothers reported elevated emotional distress (depression, 59%) and symptoms of post-traumatic stress (intrusiveness, 67%). Although 87% of mothers believed the allegations, only 45% offered adequate emotional support. CONCLUSION: The implementation phase of this research was successful, given the positive reactions of workers and clients. Results on standard instruments from this French-speaking sample were similar to profiles of English-speaking victims and their mothers but firm conclusions on appropriate norms will require larger samples, cross cultural contrasts, and the evaluation of additional variables.

Canada↗

PubMed1998

Gonadal hormones modulate 5-hydroxytryptamine2A receptors: emphasis on the rat frontal cortex.

The effect of short-term (Sprague-Dawley rats, two weeks) and long-term ovariectomy (Sprague-Dawley and Fischer rats, three months) on serotonin 5-hydroxytryptamine2A receptors in different regions of the brain and its possible correction with an 17 beta-estradiol treatment (10 micrograms, b.i.d., two weeks) were studied in comparison to intact rats. Saturation binding assays were performed using [3H]ketanserin to estimate 5-hydroxytryptamine2A receptor density and affinity in tissue homogenates of frontal cortex of Fischer rats and quantitative autoradiography was performed to evaluate receptor specific binding in frontoparietal cortex, nucleus accumbens, striatum and dorsal raphe nucleus of Fischer rats, and in frontal cortex of the two strains of rats. Messenger RNA levels of 5-hydroxytryptamine2A receptors were measured by in situ hybridization in frontal cortex of the two strains of rats. An overall decrease of 5-hydroxytryptamine2A receptor densities was found in all the brain regions of ovariectomized Fischer rats assayed, and this could be restored towards control levels by estradiol treatment. No change in the 5-hydroxytryptamine2A receptor affinity was measured in the frontal cortex. A similar pattern of changes was observed for the messenger RNA levels encoding the 5-hydroxytryptamine2A receptors and receptor density, suggesting the implication of a genomic mechanism. Experiments in Sprague-Dawley rats confirmed and extended the results obtained with Fischer rats. By analogy, in humans, this 5-hydroxytryptamine2A receptor modulation may underlie the mood and movement disorders associated with menopause.

Animals↗

PubMed1998

Current drug therapy recommendations for the treatment of attention deficit hyperactivity disorder.

Attention deficit hyperactivity disorder (ADHD) is characterised by symptoms of inattentiveness and/or hyperactivity-impulsivity which are not appropriate to the child's age. This disorder usually manifests by age 3 and affects up to 5% of school-age children. Although the aetiology is unknown, ADHD appears to have a strong genetic component and to involve dysregulation of the CNS dopaminergic system. Psychostimulants are the mainstay of therapy. The majority of patients will respond to an adequate trial of one of the 3 available stimulants, methylphenidate, dexamphetamine or pemoline. Use of the tricyclic antidepressants as second-line agents is supported by substantial literature. Third-line agents include amfebutamone (bupropion) and clonidine. Other modalities have been studied, but sufficient research is not available to recommend their use over the abovementioned treatments. Assessment of response is best achieved by objective rating scales which allow for input from various environments.

Antidepressive Agents, Tricyclic↗

PubMed1998

Maternal education and fetal and infant mortality in Quebec. Fetal and Infant Mortality Study Group of the Canadian Perinatal Surveillance System.

OBJECTIVES: This article examines differences in fetal and infant mortality by maternal education in the province of Quebec, where the rates are among the lowest in Canada. DATA SOURCE: The data are from linked birth and infant death records (including stillbirths) for the 1990-1991 birth cohorts in Quebec. MAIN RESULTS: Fetal and infant mortality rates were greater for the offspring of mothers with less than 12 years of education, compared with mothers with at least 14 years, even after adjusting for maternal age, parity, marital status and infant's sex. When intermediate factors such as birthweight or both gestational age and fetal growth were taken into account, the differentials in mortality by education diminished. If all education groups had experienced the low rates attained by the higher education group, the number of fetal and infant deaths would have been reduced by approximately 20%.

Adolescent↗

PubMed1997

Decreased hypoprothrombinemic effect of warfarin associated with furosemide.

The authors describe a case of furosemide possibly inhibiting the hypoprothrombinemic effect of warfarin. The initiation of furosemide dosing in a patient receiving a stable dose of warfarin was associated with an 28% decrease in the international normalized ration (INR). Using normal volunteers, two previous controlled studies of an interaction between warfarin and chlorthalidone, and between warfarin and spironolactone, assert that volume depletion produced by forced diuresis results in the inhibition of warfarin's hypoprothrombinemia. Consistent with this hypothesis, the authors found that their patient's hematocrit (believed to reflect hydration status) correlated with the INR: r2 = 0.78, p < 0.05. This case provides further evidence suggesting that acute diuresis can decrease the hypoprothrombinemic effect of warfarin.

Anticoagulants↗

PubMed1997

Telephone surveys as an alternative for estimating prevalence of mental disorders and service utilization: a Montreal catchment area study.

BACKGROUND: Large-scale mental health surveys have provided invaluable information regarding the prevalence of specific mental disorders and service use for mental health reasons. Unfortunately, because vast surveys conducted face to face are very costly, many countries and provinces do not embark upon this path of research, thus depriving themselves of a rich source of data useful for service planning. METHOD: As an alternative, the authors undertook a telephone survey with a sample of 893 residents from a Montreal catchment area. Mental disorders were assessed by the Composite International Diagnostic Interview Simplified (CIDIS), an instrument especially designed to be used in mail or telephone surveys. Service utilization was measured by an instrument similar to those used in recent large Canadian or American surveys. RESULTS: The prevalence rate for any mental disorder was lower in this study than in some large-scale epidemiological surveys reviewed. This could be explained by methodological differences, such as number of disorders covered and period of reference. With regard to specific mental disorders, results appeared very similar to those of other studies. Concerning service utilization, rates tended to be higher than in other studies, and this finding could reflect real differences between Quebec and other Canadian provinces or the United States. CONCLUSIONS: Aside from being lower in cost, telephone surveys can yield results comparable to those obtained in large-scale epidemiological surveys conducted by means of face-to-face interviews.

Adolescent↗

PubMed1996

The reliability of the community version of the MRC Needs for Care Assessment.

One hundred and nine adults were screened in the community using the abridged version of the CIDI (CIDIS). The subjects comprised DSM-III-R current cases (N = 48), lifetime cases (N = 31) and non-cases (N = 30). The interviews with the 109 subjects were conducted by one of two pairs of clinicians and videotaped. Each interviewer-pair included a psychiatrist and a clinical psychologist. They rated the community version of the Needs for Care (NFCAS-C) by consensus. The other pair of judges then viewed the video and rated the NFCAS-C independently. The agreement on overall needs was excellent (kappa = 0.75), and very good for four of the seven specific sections (from kappa = 0.61 to 0.81). One section could not be rated because of low prevalence, and agreement was less good for the remaining two sections. Agreement was good on specific interventions (medication, kappa = 0.60; specific psychotherapy, kappa = 0.55), but poor on non-specific interventions. The majority of disagreements were due to differences in clinical judgement rather than to technical errors. A new instruction manual has been produced and should help training as well as stabilizing reliability. In devising reliable and valid instruments based on clinical judgement, a balance must be achieved between enhancing reliability with more precise rules and constraining clinical judgement so tightly that validity is lost.

Adult↗

PubMed1996

Nefazodone: its place among antidepressants.

OBJECTIVE: To review the pharmacology, pharmacokinetics, efficacy, adverse effects, and drug interactions of nefazodone as well as to determine its place among currently available antidepressants. DATA SOURCES: A search of European and American literature using EMBASE and MEDLINE was completed. Nefazodone was the search term. DATA SYNTHESIS: Nefazodone is an antidepressant that blocks serotonin type 2 (5-HT2) receptors in addition to inhibiting the reuptake of serotonin and norepinephrine. In double-blind, placebo-controlled studies, nefazodone demonstrates antidepressant activity at dosages ranging from 400 to 600 mg/d. Sedation, dry mouth, nausea, and dizziness are the more common adverse effects of nefazodone. Nefazodone, an analog of trazodone, has not been associated with priapism at this time, and may have fewer sexual adverse effects than other antidepressants. More studies are needed to determine the potential role of nefazodone in treating anxiety, pain, and premenstrual syndrome. STUDY SELECTION: Only double-blind, placebo-controlled studies designed to establish the efficacy of nefazodone as an antidepressant were reviewed. CONCLUSIONS: Based on placebo-controlled, double-blind, comparative trials, nefazodone demonstrates greater efficacy than placebo, and equivalent efficacy to imipramine. Somnolence, dry mouth, nausea, dizziness, and constipation are the most common adverse effects. Nefazodone appears to have a milder adverse effect profile than the tricyclic antidepressants, causes fewer sexual dysfunctions than the serotonin selective reuptake inhibitors, and may cause less dizziness than trazodone. Nefazodone at dosages of at least 300 mg/d provides another option for the treatment of depression.

Antidepressive Agents, Second-Generation↗

PubMed1995

Changes in effectiveness of psychotherapeutic drug level monitoring program after lessening pharmacy involvement.

The psychotherapeutic drug monitoring policy established by the medical, laboratory, and psychopharmacy departments at Austin State Hospital allowed for psychopharmacists to schedule, interpret, and monitor antidepressant and antipsychotic plasma concentrations. A recent policy change eliminated the psychopharmacists' role in scheduling blood draws for plasma drug concentration determinations. A comparison of the use of psychotropic plasma drug concentrations before and after implementation of the policy change, with regards to appropriate disease states, indication, scheduling, and choice of drug was conducted. Despite a fourfold increase in the number of plasma drug concentrations obtained after the policy change, the physicians appeared to be aware of the steady state requirements and situations in which monitoring plasma drug concentrations was justified. The number of plasma drug concentrations that were obtained to verify a suspected drug interaction, or adverse effect, increased after the new policy was implemented. This seemingly indicates physician uncertainty in determining the clinical implication of potential drug-drug interactions and recognizing which adverse effects may be dose related.

Drug Interactions↗

PubMed1994

Problems and needs for care of patients suffering from severe mental illness.

Recently, evaluative research has yielded a procedure, the Needs for Care Assessment Schedule (NFCAS), which articulates the problems and the corresponding interventions required by psychiatric patients in a systematic and reproducible manner that is of interest to both administrators and clinicians. Although the NFCAS decisions are ultimately subjective and there is no absolute standard, the procedure limits variation and offers a framework for comparison and further elaboration. A group of 98 patients who were receiving treatment at the Louis-Hippolyte Lafontaine Psychiatric Hospital in Montréal, Québec and who were suffering from severe mental disorders were assessed with the NFCAS procedure. Subjects were selected from four treatment settings representing different levels of problems and needs: long-term in- and outpatients and short-term in- and outpatients. Results of the NFCAS were examined, along with those of standardized questionnaires. The NFCAS allowed a comprehensive understanding of the clinical realities for problem and need assessment. There was an average of 3.9 clinical problems and 4.5 social problems per patient. Long-term patients and patients residing in the hospital had more problems. A total of 76% of the problems assessed were rated as receiving appropriate interventions, whereas 17% of the problems assessed were considered in need of an assessment or in need of treatment. A greater need for intervention was found for social problems than for clinical problems.

Activities of Daily Living↗

PubMed1994

Further reliability and validity studies of a procedure to assess the needs for care of the chronically mentally ill.

The Needs for Care Assessment Schedule (NFCAS; Brewin et al. 1987) is an itemized and systematic procedure that aims to evaluate the needs for care of long-term mentally ill patients. The present study pursues reliability and validity related issues with the NFCAS in a different cultural context applying the procedure to 98 severely mentally ill patients belonging to different patient groups: short-term, long-term, in-patient and out-patient. Inter-rater reliability was found to be excellent. The results suggest that a clinician with little practical experience and adequate training may effectively use the procedure. The assessment of clinical relevance suggested that the procedure is both applicable and pertinent to all the patients in the study. Additional guidelines were developed for its use with long-term in-patients.

Adolescent↗

PubMed1994

Assessment of independent living skills for psychotic patients. Further validity and reliability.

It is well known that psychotic patients have severe social and life-skill deficits. Psychiatric rehabilitation programs are designed to teach these skills to patients. Before implementing such a program, patient deficits should be evaluated with reliable measures. The present study assessed the psychometric properties of the French version of the "Independent Living Skills Survey" (ILSS) developed by Wallace, Kochanowicz and Wallace (Wallace C J, Kochanowicz N, Wallace J [1985] Independent living skills survey. Unpublished manuscript, Mental Health Clinical Research Center for the Study of Schizophrenia, West Los Angeles Veterans Administration Medical Center, Rehabilitation Medicine Service [Brentwood Division], Los Angeles, CA). Although widely used, the patient version of this scale has unknown psychometric properties. The ILSS was composed of 75 items, rated as present or absent and distributed in 10 scales. The French version was administered to 145 patients with a psychotic diagnosis who were living in the community. All scales had very good psychometric qualities with the exception of the job-maintenance scale. The test-retest reliability varied from .48 to .85, and alpha coefficients were good for seven of the nine scales. Various aspects of construct validity were explored. The scales discriminated between patients as a function of their subgroups, sex, and diagnosis. Concurrent validity confirmed the specificity of the ILSS dimensions. Factor analysis revealed two factors, one for basic skills and one representing higher order skills. Recommendations for future development of the ILSS are proposed.

Activities of Daily Living↗

PubMed1993

The Canadian Birth Data Base: a new research tool to study reproductive outcomes.

A new tool for epidemiological, demographic, and genetic research--the Canadian Birth Data Base-is being developed at Statistics Canada. Over a million live birth and stillbirth records for the period 1987-89 received from all provincial and territorial offices of vital statistics are being processed in a form suitable for linkage with other files. Maternal, child health, occupational, and environmental concerns, as well as some of the consequences and possible risks involved in new reproductive technologies, could be investigated. Associations between socio-economic indicators (e.g., parental income, education, and occupation) and unfavourable birth outcomes could also be studied in the future. Approved statistical studies can be carried out within Statistics Canada on a cost-recovery basis. It is planned to update the data base annually.

Birth Certificates↗

PubMed1991

Reliable use of the Present State Examination by psychiatric nurses for clinical studies of psychotic and nonpsychotic patients.

Four psychiatric nurses were trained with the French version of the Present State Examination, 9th edition (PSE-9). Reliability was tested on 18 cases of psychotic and nonpsychotic patients. The reliability indexes were comparable to those reported for the English version of PSE-9. These preliminary results indicate that further training may improve reliability for the nurses. It also warrants other trials in which psychiatric nurses will be used as interviewer with instruments that require clinical judgement.

Hospitalization↗

PubMed1991

In vitro photodynamic inactivation of herpes simplex virus with sapphyrins: 22 pi-electron porphyrin-like macrocycles.

The photodynamic inactivation of HSV-1, a virus having a membranous envelope, with both a decaalkyl sapphyrin and its dicarboxy-substituted analog was studied. The decaalkyl sapphyrin was as efficient in the inactivation of HSV-1 on a per macrocycle basis as DHE, whereas the efficiency of the dicarboxy-substituted sapphyrin was approximately two orders of magnitude less. Fluorescence studies of sapphyrin's binding to liposomes and VSV suggested that the decaalkylsapphyrin bound monomerically to cholesterol-rich regions of the viral envelope, whereas its charged analog localized in a more polar environment.

Animals↗

PubMed1990

Impact of supervised apartments on the functioning of mentally disordered adults.

The impact on the mentally disordered of living in supervised residences remains unclear. The present investigation followed a group of supervised apartment residents and a matched comparison group for two years. Symptomatology, psychosocial functioning, stress, social support, quality of life, and life satisfaction were measured at six month intervals. Readmission and consultations in the emergency room were documented for all subjects for the two year period. Neither readmission rates, emergency room consultations, nor measures of functioning, other than symptomatology, differed for the two groups. It is argued that supervised apartments are stressful environments that may lead to deterioration in mentally disordered persons.

Adolescent↗