Biomedical subjects

R Menzies

Publications and source records attributed to R Menzies.

At least 37 records · Page 2Linked to original sources

PubMed1994

The booster effect in two-step tuberculin testing among young adults in Montreal.

OBJECTIVES: No consensus exists regarding the definition and interpretation of a significant boosting reaction after sequential tuberculin testing. The booster phenomenon is thought to represent remote tuberculous infection where tuberculin reactivity has waned, but it has also been described among persons with previous exposure to other mycobacteria or Bacille Calmette-Guérin (BCG) vaccine. We studied the factors affecting the booster phenomenon among Canadian-born young adults to determine the definition that would maximize sensitivity and specificity of a positive booster reaction in these persons. DESIGN: Point-prevalence survey of initial tuberculin reactions and response to repeated tuberculin testing after 1 to 4 weeks. SETTING: Community-based study of all students entering health professional training programs at six post-secondary institutions. MEASUREMENTS: In 1989, 1990, and 1991, students completed self-administered questionnaires, underwent two-step tuberculin testing with purified protein derivative-tuberculin (PPD-T), and had their childhood BCG vaccination status verified. In 1991, students were also tested with purified protein derivative-Battey (PPD-B) (for Mycobacterium intracellulare). RESULTS: Overall, 74 students (5.2%) had positive booster reactions, which were significantly associated with older age (P < 0.001), larger initial tuberculin reactions (P < 0.001), previous BCG vaccination (P < 0.001), older age when vaccinated (P < 0.02), longer interval from vaccination to testing (P < 0.01), and sensitivity to PPD-B (P < 0.001). Boosting was not associated with the number of BCG vaccinations, sex, or risk factors for tuberculous infection. The pattern, mean, and mode of the frequency distributions of booster reactions among those with BCG vaccination and sensitivity to PPD-B were similar to those with assumed tuberculous infection. CONCLUSIONS: In young adults, booster reactions due to previous tuberculous infection are uncommon and cannot be distinguished from false-positive reactions due to past exposure to other mycobacteria.

Adolescent↗

PubMed1994

The effect of war on tuberculosis. Results of a tuberculin survey among displaced persons in El Salvador and a review of the literature.

SETTING: During wartime, civilian populations usually experience a drop in caloric intake, disruption of housing, and a diminution in availability of medical services. These disturbances might be expected to result in increased reactivation of tuberculosis, which may result in increased transmission. Such privations occurred in El Salvador during its 1980-92 civil war, particularly among the 20% of the population, or over 1 million people, who were displaced. OBJECTIVE: (1) To estimate the rate of transmission of tuberculosis among displaced Salvadorians prior to and during the war, and (2) to compare this result with experience in the literature. DESIGN: (1) A tuberculin survey was conducted in El Salvador in July 1992 among all residents aged 1-30 years in 12 communities of formerly displaced persons. (2) The English language literature on tuberculosis during wartime was reviewed. RESULTS: (1) Overall, 21.2% of the non-BCG vaccinated had significant tuberculin reactions, equivalent to an annual risk of infection of 2.3%. The trend in the annual risk of infection was upward over the latter 6 years of the war, stable over the first 6 years, and was downward prior to the war years. The estimated incidence of smear positive pulmonary tuberculosis was 125 per 100,000 or 3 times the reported rate for El Salvador. (2) A review of the literature showed consistent evidence for increased morbidity and mortality from tuberculosis during wartime. Increased transmission was suggested by those studies showing a rise in both incidence of tuberculous meningitis during war years and excess morbidity and mortality many years after a war. Two major population-based studies found no evidence of increased transmission based on the calculated annual risk of infection; however other studies examining younger or more severely affected populations, or following more prolonged wars, detected an apparent increase in the transmission of tuberculosis. CONCLUSIONS: Conditions of war are associated with a rapid increase in morbidity and mortality from tuberculosis, which appears to result in increased transmission among populations most severely affected by war. This increased transmission will result in increased morbidity and mortality for many years, underscoring the need for improved tuberculosis control in the post-war period in countries such as El Salvador that have been devastated by war.

Adolescent↗

PubMed1994

Factors affecting compliance with preventive treatment for tuberculosis at Mistassini Lake, Quebec, Canada.

Non-compliance is the most important cause of failure of anti-tuberculous therapy throughout the world. In 1990 and 1991, an outbreak of tuberculosis occurred on the Mistassini Cree territory in Northern Quebec, Canada, and a number of cases of active tuberculosis occurred among known tuberculin-positive contacts who were non-compliant with preventive therapy. To better understand the factors affecting compliance with preventive treatment, a review of patients prescribed preventive treatment over the past 10 y was conducted. A freely-translated, interviewer-administered questionnaire was used to measure personal/lifestyle factors and knowledge/attitudes about tuberculosis. Clinic dossiers were reviewed to assess compliance. One hundred and two (102) subjects prescribed preventive treatment between 1981 and 1991 were interviewed, of whom 33.7% were judged to have been compliant. The most significant factor associated with compliance with preventive therapy was year of therapy. Between 1981 and 1985, 78% completed treatment, compared to less than 20% since 1986 (p < .0001). The major factor identified as associated with this sudden change was a shift in responsibility for tuberculosis treatment follow-up from native community health workers to non-native nurses in 1985/86. We conclude that tuberculosis control programs must be tailored to take into account the importance of cultural factors in promoting compliance with therapy.

Adult↗

PubMed1993

The effect of varying levels of outdoor-air supply on the symptoms of sick building syndrome.

BACKGROUND: The sick building syndrome is the term given to a constellation of symptoms reported by workers in modern office buildings, hypothesized to occur when the supply of outdoor air is reduced, because of the accumulation of contaminants arising from within the building. We undertook this study to determine the effect of changing the supply of outdoor air in four office buildings on the symptoms reported by workers and their perception of the indoor environment. METHODS: Within each of three consecutive two-week blocks, the ventilation systems in each building were manipulated, in random order, to deliver to the indoor environment an intended 20 or 50 ft3 (0.57 or 1.4 m3) of outdoor air per minute per person for one week at a time. Each week, the participants, unaware of the experimental intervention, reported symptoms and the indoor environment was thoroughly evaluated. RESULTS: Of 1838 eligible workers in the four buildings, 1546 (84 percent) participated in the study. The supply of outdoor air averaged 7 percent and 32 percent in the ventilation systems and 30 and 64 ft3 (0.85 and 1.8 m3) per minute per person in the work sites at the lower and higher ventilation levels, respectively. These changes in the supply of outdoor air were not associated with changes in the participants' ratings of the office environment or in symptom frequency (crude odds ratio, 1.0; 95 percent confidence interval, 0.9 to 1.1). After work-site measures of ventilation, temperature, humidity, and air velocity were included in the regression analysis, the adjusted odds ratio was also 1.0 (95 percent confidence interval, 0.8 to 1.2). CONCLUSIONS: Increases in the supply of outdoor air did not appear to affect workers' perceptions of their office environment or their reporting of symptoms considered typical of the sick building syndrome.

Adult↗

PubMed1993

A longitudinal study of the relationships between psychometric test scores, offence history and the plasma concentrations of phenylacetic and 5-hydroxyindoleacetic acids in seven inmates of a prison for the psychiatrically disturbed.

1. The plasma concentrations of phenylacetic (PAA) and 5-hydroxyindoleacetic (5HIAA) acids in seven inmates incarcerated in the Regional Psychiatric Centre (Prairies), Correctional Service of Canada, were assessed each weekday for four weeks (i.e., 20 samples each). Psychometric assessments for hostility, anger, depression and anxiety were also performed daily. Mean differences between subjects in psychometric and biochemical measures were subjected to tests of statistical significance. 2. The subject who was clearly most aggressive by offence history/institutional behavior scored significantly highest on scales of anger and hostility and significantly lowest with respect to PAA concentration. It was concluded that PAA may be a trait marker for aggression. 3. Plasma 5HIAA concentrations were invariant between subjects. 4. The psychometric measures were intercorrelated, thus confounding the variables of interest. They also varied little, proving insensitive to subtle mood changes.

Adult↗

PubMed1993

Factors associated with compliance in treatment of tuberculosis.

The most important cause of failure of antituberculosis therapy is that the patient does not take the medication as prescribed. To assess this problem, a retrospective review was conducted, using medical and nursing records, of adult patients treated at the tuberculosis clinic of the Montreal Chest Hospital in 1987-1988. In all, 352 patients were identified, of whom 59% were judged to have completed therapy. Completion of therapy was recorded in 92% of those with culture-positive disease, 76% of those with active but culture-negative disease and 54% among the 300 prescribed preventive therapy (P < 0.001). Compliance with preventive therapy was highest among those who had been in contact with an active case, and lowest among those identified through a workforce screening survey (P < 0.01). At the time of the first follow-up visit, patients identified to have suboptimal compliance were more likely to fail to complete therapy (P < 0.001). Compliance was higher among those initially hospitalized, those assessed to have better understanding (P < 0.05), those prescribed 6-9 rather than 12 months of therapy (P < 0.01), and those who returned for follow-up within 4 weeks of initiation of therapy (P < 0.01). Compliance could be improved by enhancing patient understanding, closer follow-up, and shorter therapy, particularly for those at lower risk of reactivation. As well, additional compliance enhancing interventions can be targeted to those patients with suboptimal compliance who can be accurately identified early in the course of therapy.

Adult↗

PubMed1992

Effect of bacille Calmette-Guérin vaccination on tuberculin reactivity.

The effect on tuberculin reactivity of bacille Calmette-Guérin vaccination (BCG-V) given 10 to 25 yr earlier was measured among schoolchildren and young adults in Montreal. Of a total eligible population of 8,264 persons, 5,952 were tuberculin tested (72%). The BCG-V status could be verified for 4,629 of 4,969 (93%) participants born in Quebec. Of these, 1,511 (33%) had received BCG-V, 66% of whom had been vaccinated once only in infancy, 23% of whom had been vaccinated once but after infancy, and 11% of whom had been vaccinated twice. Among those vaccinated in infancy, 7.9% had significant tuberculin reactions, compared with 18% among those vaccinated between 1 and 5 yr of age, and 25.4% among those vaccinated after the age of 5 (p less than 0.001). Among those receiving BCG-V in infancy, the prevalence of tuberculin reactions of 10 mm was similar to the nonvaccinated subjects, after accounting for differences in age and socioeconomic status. Among those vaccinated after infancy, tuberculin reactivity was not significantly affected by interval from BCG-V until tuberculin testing nor by repeat BCG-V. We conclude that after an interval of 10 to 25 yr the most important determinant of effect of BCG-V on tuberculin reactivity is age when vaccinated. A significant tuberculin reaction among those who have received BCG-V should be interpreted in light of the age when vaccinated and the expected prevalence of tuberculous infection in the population tested.

Adolescent↗

PubMed1992

Factors associated with tuberculin reactivity among the foreign-born in Montreal.

Because tuberculosis among the foreign-born is of increasing importance in North America, it has recently been recommended that newly arriving immigrants be tuberculin tested and preventive therapy given to all those with significant reactions. The factors affecting the prevalence of tuberculin reactions were assessed in a community-based tuberculin survey among foreign-born schoolchildren and young adults. Of 1,198 foreign-born who were tuberculin tested, 32.4% had significant tuberculin reactions. False-positive tuberculin reactions due to sensitivity to purified protein derivative (PPD)-B (for Mycobacterium avium) were uncommon and those due to BCG vaccination of importance only among immigrants from countries with low tuberculosis rates. Tuberculin reactions of 10+ mm were associated with tuberculosis rates in the country of origin (p less than or equal to 0.001), age when immigrated (p less than or equal to 0.001), bacillus Calmette-Guérin (BCG) vaccination (p less than or equal to 0.01), and residence in poorer neighborhoods in Montreal (p less than or equal to 0.001), but not with number of years resident in Canada. The booster phenomenon, seen in 16% of those undergoing two-step testing, was most strongly associated with prior BCG vaccination (p less than or equal to 0.001) and also with tuberculosis rates in the country of origin (p less than or equal to 0.08), age of immigration (p less than or equal to 0.01), and number of years resident in Canada (p less than or equal to 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

PubMed1992

Images of law and disorder: a survey of forensic mental health professionals in Ontario, Canada.

In this article we report on a survey that was organized to expand knowledge across a range of medicolegal issues and pragmatic applications. We wanted to provide forensic professionals with an opportunity to express their views on these various forensic trends, and on their relevance for expert identities, statuses and activities across a broad spectrum of contexts and concerns. In an exploratory framework, the intention was to operationalize many of these developments in systems, laws, ideas and practices, and to present them as structured questions for the consideration of respondents representing the full complement of mental health disciplines connected to the criminal court apparatus in one Canadian province. In what follows we set out to sketch their images of law and disorder, and their specific opinions about the role of forensic practitioners, the nature of forensic assessment and decision-making, the relationship between mental disorder and crime, the application of treatment and punishment, and the overall process of criminal court adjudication and sentencing.

Attitude of Health Personnel↗

PubMed1991

Thoracoscopy for the diagnosis of pleural disease.

OBJECTIVE: To assess the accuracy and safety of thoracoscopy for the evaluation of pleural disease. DESIGN: Prospective evaluation of patients referred for thoracoscopy. SETTING: University hospital specializing in chest diseases. PATIENTS: We studied 102 patients with pleural disease, the cause of which had not been determined after initial investigation, including thoracentesis and needle biopsy. Eighty-six patients had pleural effusion, 11 had pleural mass, and 5 had pleural effusion in association with a known primary lung carcinoma. INTERVENTION: All patients had thoracoscopy under local anesthesia with mild sedation. Visually directed biopsies were done of parietal pleura. MEASUREMENTS: We recorded clinical characteristics, laboratory data, findings and duration of thoracoscopy, and any complications associated with the procedure. Hospital and clinic follow-up records were reviewed, and patients were contacted by telephone 12 and 24 months after thoracoscopy to assess their health status. MAIN RESULTS: One hundred and four thoracoscopies were done in 102 patients. A definitive diagnosis was established in 95 patients: 42 had malignant pleural disease and 53 had benign pleural disease. A diagnosis of benign pleural disease using thoracoscopy could not be confirmed in the remaining 7 patients because of insufficient follow-up information. Overall, thoracoscopy was 96% accurate with a sensitivity of 91%, a specificity of 100% and a negative predictive value of 93% for the diagnosis of pleural malignancy. Thoracoscopy was well tolerated under local anesthesia and entailed hospitalization for less than 24 hours in most cases. No deaths occurred, although 1.9% of patients had major complications, and 5.5% had minor complications. CONCLUSIONS: Among patients with pleural disease remaining undiagnosed after usual initial investigation, thoracoscopy done under local anesthesia is a rapid, safe, and well-tolerated procedure with an excellent diagnostic yield that is equivalent to that of thoracotomy.

Aged↗

PubMed1991

Longitudinal study of inmates of a prison for the psychiatrically disturbed: plasma concentrations of biogenic amine metabolites and amino acids.

Plasma concentrations of eight large and neutral amino acids and 10 acidic metabolites of biogenic amines in seven inmates incarcerated in the Regional Psychiatric Centre (Praries), Correctional Service of Canada, were assessed each week day for 4 weeks (i.e., 20 samples each). Measures of central tendency and dispersion of the variables were calculated. The measures are distinctively different in their variability and their normality of distribution. The large and neutral amino acid (LNAA) measures are somewhat less variable, but also less likely to be normally distributed than most acid metabolites. Acid metabolites tend to show consistent interindividual differences that persist over time, with the notable exception of 5-hydroxyindoleacetic acid. LNAA measures tend to show differences across time but not between individuals. The distributional properties of LNAA measures are largely accounted for by the observation of a downward convergence of values of these variables over the 4 weeks of the study.

Adult↗

PubMed1991

Investigation of nosocomial prosthetic valve endocarditis due to antibiotic-resistant Staphylococcus epidermidis.

A reservoir of antibiotic-resistant Staphylococcus epidermidis strains in our cardiac surgery unit appeared to be the source of organisms responsible for three cases of early prosthetic valve endocarditis. Staphylococcus epidermidis isolates recovered from the skin of 13 patients before and after surgery were compared. All were typed by plasmid profile, antimicrobial susceptibility and slime production. The three strains from early prosthetic valve endocarditis resembled the antibiotic-resistant nosocomial strains recovered from the skin of eight patients following surgery and the environment of the operating theatres. These strains expressed resistance to oxacillin, gentamicin, kanamycin and tobramycin and most produced slime, whereas those isolated from the skin of patients at the time of admission were predominantly susceptible to antibiotics and few produced slime.

Adult↗

PubMed1991

The behavioural properties of CI-988, a selective cholecystokininB receptor antagonist.

1. The behavioural effects of a selective cholecystokininB (CCKB) receptor antagonist CI-988 were investigated in rodents. 2. In three rodent tests of anxiety (rat elevated X-maze, rat social interaction test and mouse light/dark box) CI-988 over the dose range 0.001-10.0 mg kg-1, (i.p.) produced an anxiolytic-like action. The magnitude of this effect was similar to that of chlordiazepoxide (CDP). In contrast, the selective CCKA receptor antagonist, devazepide, was inactive. CI-988 also showed anxiolytic-like action in the rat conflict test but the magnitude of this effect was about 2.5 fold less than that of CDP. 3. Central but not peripheral administration of the selective CCKB receptor agonist, pentagastrin, like FG 7142, produced an anxiogenic-like action. 4. The pentagastrin-induced anxiety was dose-dependently antagonized by CI-988, whereas devazepide was inactive. However, ten times higher doses of CI-988 were required to block a similar action of FG 7142. 5. In contrast to CDP, CI-988 up to 3000 fold higher doses than those inducing anxiolysis was inactive in tests measuring sedation and ataxia. It also failed to antagonize pentylenetetrazol-induced tonic seizures. Furthermore, CI-988 did not interact with alcohol or barbiturates. Thus, CI-988 appears to be an anxioselective compound. 6. The anxiolytic-like action of CDP in the rat elevated X-maze was dose-dependently antagonized by flumazenil. In contrast, the benzodiazepine receptor antagonist failed to block a similar effect of CI-988. 7. Thus, CI-988 shows anxiolytic-like activity in several animal models of anxiety. The anxiolytic-like effect of CI-988 involves a novel mechanism of action, that is likely to be mediated by selective antagonism of the brain CCKB receptor. It is suggested that CI-988 should have a better side-effect profile in man than the benzodiazepines.

Animals↗

PubMed1990

The discriminative stimulus properties of (+)-HA-966, an antagonist at the glycine/N-methyl-D-aspartate receptor.

Using a two-lever operant drug discrimination paradigm, rats have been trained to discriminate between the administration of saline and R-(+)-HA-966 (R-(+)-3-amino-1-hydroxypyrrolid-2-one, 30 mg/kg i.p.) an antagonist at the glycine modulatory site on the N-methyl-D-aspartate (NMDA) receptor/ion channel complex. Drug-appropriate responding was not induced in stimulus generalisation experiments when the non-competitive NMDA receptor antagonist, phencyclidine (PCP, 1-8 mg/kg i.p.) was substituted for (+)-HA-966. Similarly, (+)-HA-966 (6-50 mg/kg i.p.) did not induce drug-appropriate responding in animals trained to discriminate PCP (3 mg/kg i.p.) from saline. The results suggest that the behavioural profile of compounds attenuating the actions of NMDA via blockade of the glycine modulatory site may be substantially different from those acting at the ion channel of the NMDA receptor complex.

Animals↗

PubMed1989

Determinants of weaning and survival among patients with COPD who require mechanical ventilation for acute respiratory failure.

The decision to institute MV in patients with COPD and ARF is difficult because the risk of complications is high and the long-term prognosis is poor. We reviewed our experience with 95 COPD patients with ARF requiring MV. Fifty-five patients required MV for more than two weeks, 72 were weaned successfully, and 59 died within one year of follow-up. Survival was associated with premorbid level of activity (p less than .001), FEV1 (p less than .01), serum albumin level (p less than .05), and severity of dyspnea (p less than .01). Cor pulmonale on ECG, premorbid hypercarbia, and history of left ventricular failure were also more common among those who died. Weaning from MV was associated with premorbid level of activity (p less than .001), FEV1 (p less than .001), albumin level (p less than .05), and negative inspiratory pressure (p less than .001) and respiratory rate during T-piece trial (p less than .01). The duration of intubation was associated only with premorbid level of activity (p less than .01). Predictive models for the weaning success and the one-year survival were developed.

Actuarial Analysis↗

PubMed1988

Chylothorax associated with tuberculous spondylitis.

A patient is described with bilateral chylothorax which was associated with tuberculous spondylitis. The tuberculous spondylitis appeared at two widely separated thoracic levels. A similar association has not been reported previously. Anti-tuberculous treatment resulted in healing of the spondylitis and resolution of the chylothorax.

Chylothorax↗

PubMed1987

VEPs in normal full-term and premature neonates: longitudinal versus cross-sectional data.

VEPs have been shown to change with CNS maturation in children, yet few studies had documented maturational changes in the premature infant. Using LED goggles, VEPs were studied in 75 neurologically normal infants of 22-42 weeks gestational age (GA) within the first 3 days of life. Twenty of these (22-32 weeks GA) were also followed longitudinally. The 22-23 week GA neonates had no identifiable waves. In all infants greater than 24 weeks a large negative wave is seen with a latency around 300 msec (N300). After 27 weeks GA a late positive wave was present (P400), but with more variable latency and morphology. Between 30 and 35 weeks GA a small positive wave (P200) was seen in over one-third of the neonates; this component was present in all infants greater than 36 weeks GA. The consistency of the N300 across the ages studied suggests that it might arise from the basilar dendrites in the visual cortex, which are well developed by 24 weeks GA and undergo relatively little further development between 24 weeks and term. The P200 is suggested to arise from the apical dendrites which develop in the last trimester, explaining the emergence of P200 after 30 weeks GA. The infants followed longitudinally showed the same components, emerging in the same order, but with more rapid development (particularly of P200) compared to the cross-sectional studies. These data suggest that there are differences in the maturation of the visual system in the extrauterine versus intrauterine environment.

Evoked Potentials, Visual↗

PubMed1987

Round atelectasis. Pathologic and pathogenetic features.

Round atelectasis is an uncommon pulmonary condition usually presenting in an asymptomatic individual as a peripheral parenchymal opacity on a chest roentgenogram. Pathologic examination of eight cases revealed localized fibrosis of the visceral pleura overlying the roentgenographic abnormality in all instances. Beneath the region of fibrosis, the pleura showed extensive wrinkling and folding, occasionally with deep invaginations into the pulmonary parenchyma. No discrete mass corresponding to the roentgenographic opacity was identified; however, lung parenchyma adjacent to the fibrotic and folded pleura appeared compressed, and in some cases, showed interstitial fibrosis. These findings support the hypothesis that round atelectasis is due to contraction of a focus of visceral pleural fibrosis that results in buckling of the pleura and collapse of underlying lung parenchyma.

Female↗