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An analysis of the daily radial activity of 7 boreal tree species, northwestern Quebec.

In the 'Des Vieux Arbres' ecological reserve situated within northwestern Quebec, 40 band dendrometers were installed on 7 of the major boreal tree species. The late Spring-early Summer daily radial activity registered in 1997 was related to daily weather variables. For each tree species, the daily mean i) cumulative radial increment and ii) radial activity indexed series obtained by first-difference standardization were analyzed. The results indicate the existence of strong similarities among the 7 species. All showed strong synchronous fluctuations in radius during late winter and early spring. This period ended with a short but sharp increase in radial increments that marked the passage of water into the stem. This initial swelling, less obvious in Pinus species was followed by a prolonged period of little change in radial activity. Meteorological data indicated that air temperature was positively related to stem swelling during the late winter-early spring period. Both air and soil temperatures became negatively related to radial expansion once the passage of water has occurred in the stem. Starting in early June, all species registered a sustained increase in radial increments possibly associated with active cell division. After this, radial expansion was negatively related to air temperature and positively to rainfall.

Climate↗

Interactions among the alpha2-, beta2-, and beta3-adrenergic receptor genes and obesity-related phenotypes in the Quebec Family Study.

The gene-gene interactions between markers in the alpha2-, beta2-, and beta3-adrenergic receptor (ADR) genes and obesity-related phenotypes were studied in the Quebec Family Study (QFS) cohort. The prevalence of the Arg allele of the Arg16Gly polymorphism in the beta2-ADR gene was higher (49%) in males with a body mass index (BMI) of 35 kg/m2 or higher versus those with a BMI less than 35 kg/m2 (33%; P = .010). The beta2-ADR gene Arg16Gly and Gln27Glu polymorphisms were associated with plasma total and low-density lipoprotein (LDL) cholesterol concentrations. In addition, the homozygotes for the 6.3-kb allele of DraI polymorphism in the alpha2-ADR gene had the lowest mean abdominal subcutaneous fat area (P = .012) and total fat area (P = .003), as well as insulin area, under the curve during an oral glucose tolerance test ([OGTT] P = .004). Several ADR gene-gene interaction effects on abdominal fat distribution and plasma lipids were detected. First, significant interactions between alpha2- and beta3-ADR genes were observed on total (P = .015) and subcutaneous (P = .004) abdominal fat. Second, interaction effects between alpha2- and beta2-ADR gene variants influenced total, high-density lipoprotein (HDL), and LDL cholesterol concentrations. Finally, there were interactions between markers within the beta2-ADR gene affecting plasma triglyceride concentrations and subcutaneous abdominal fat. From these results, we conclude that polymorphisms in the ADR genes contribute to body fat and plasma lipid variability in men. Gene-gene interactions among the ADR genes contribute to the phenotypic variability in abdominal obesity and plasma lipid and lipoprotein, but not in visceral fat levels.

Abdomen↗

Reliability, validity, and applicability of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0) for adults with multiple sclerosis.

PURPOSE: To investigate the measurement properties of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0) with respect to test-retest stability, alternate form reliability, construct validity and applicability. METHOD: Data on satisfaction and quality of life impacts of mobility devices were obtained from 81 community-based adults with Multiple Sclerosis, using the QUEST 2.0 and the Psychosocial Impact of Assistive Devices Scale (PIADS). Subjects were assigned to four groups and a second QUEST 2.0 was administered one week later. Groups differed with respect to the format and the order in which alternate forms were presented. Measures of association were calculated between QUEST 2.0 and PIADS (n = 81) and between QUEST 2.0 alternate forms (n = 48). Respondents' reactions were considered. RESULTS: The device subscale, services subscale, and total QUEST 2.0 scores achieved good test-retest stability (ICC 0.82, 0.82, 0.91). Alternate-form equivalence (ICC 0.89, 0.76, 0.91) was lower for services. The positive correlations between QUEST 2.0 and the three PIADS dimensions were fair to moderate for device and total QUEST 2.0 (r(p) 0.34 to 0.45) and fair with services (r(p) 0.27 to 0.30). The tool was positively received, with some restrictions for the services subscale. CONCLUSIONS: These findings on the psychometric properties of the QUEST 2.0 reinforce the relevance of the device subscale as an important outcome measure for assistive technology MS users. Further assessment of the services subscale is needed.

Female↗

Reliability and validity of the Dutch adaptation of the Quebec Back Pain Disability Scale.

BACKGROUND AND PURPOSE: The purposes of this study were to determine whether a Dutch translation of the Quebec Back Pain Disability Scale (QBPDS) retains the high levels of reliability and validity of the original English version and to determine whether it is therefore more practical to translate this scale, and possibly other scales, than to generate language- and culture-specific instruments. SUBJECTS: Subjects were 120 individuals with chronic low back pain. METHODS: The QBPDS was filled out at the beginning of the study, after 1 week, and after 4 months. Reliability was determined by calculating Pearson correlation coefficients and intraclass correlation coefficients in addition to Cronbach's alpha and item-total correlation at the beginning of the study and after 4 months. Validity was examined by correlating the QBPDS scores to external criteria scores at a single point in time (cross-sectional) and over a period of time (longitudinal). RESULTS: Pearson and intraclass correlation coefficients for test-retest reliability were .90. Cronbach's alpha was .95. The cross-sectional construct validity coefficients were .80 (RDQ) and .70 (pain severity). The longitudinal construct validity coefficients were .60 (RDQ), .53 (pain severity), and .35 (course of the complaint). CONCLUSION AND DISCUSSION: Our results support previous findings of the English and French versions of the QBPDS. Whether this instrument can be used as an evaluative instrument remains unknown.

Adult↗

A comparison of a modified Oswestry Low Back Pain Disability Questionnaire and the Quebec Back Pain Disability Scale.

BACKGROUND AND PURPOSE: The quality of a disability scale should dictate when it is used. The purposes of this study were to examine the validity of a global rating of change as a reflection of meaningful change in patient status and to compare the measurement properties of a modified Oswestry Low Back Pain Disability Questionnaire (OSW) and the Quebec Back Pain Disability Scale (QUE). SUBJECTS: Sixty-seven patients with acute, work-related low back pain referred for physical therapy participated in the study. METHODS: The 2 scales were administered initially and after 4 weeks of physical therapy. The Physical Impairment Index, a measure of physical impairment due to low back pain, was measured initially and after 2 and 4 weeks. A global rating of change survey instrument was completed by each subject after 4 weeks. RESULTS: An interaction existed between patients defined as improved or stable based on the global rating using a 2-way analysis of variance for repeated measures on the impairment index. The modified OSW showed higher levels of test-retest reliability and responsiveness compared with the QUE. The minimum clinically important difference, defined as the amount of change that best distinguishes between patients who have improved and those remaining stable, was approximately 6 points for the modified OSW and approximately 15 points for the QUE. CONCLUSION AND DISCUSSION: The construct validity of the global rating of change was supported by the stability of the Physical Impairment Index across the study period in patients defined as stable by the global rating and by the decrease in physical impairment across the study period in patients defined as improved by the global rating. The modified OSW demonstrated superior measurement properties compared with the QUE.

Activities of Daily Living↗

Prevalence and risk behaviours for HIV infection among inmates of a provincial prison in Quebec City.

OBJECTIVE: To assess HIV prevalence and related risk factors among inmates at the Quebec Detention Centre (QDC). DESIGN: Cross-sectional prevalence study. METHODS: Inmates incarcerated at the QDC in September 1994 were asked to participate in an anonymous survey concerning HIV infection. Volunteers answered a questionnaire and provided a saliva sample during a meeting with an interviewer. RESULTS: The overall participation rate was 95% (618 out of 651). HIV prevalence was 2% (11 out of 499) in men. All HIV-infected men were injecting drug users (IDU) with an HIV prevalence of 9% (11 out of 129) in this group. HIV prevalence was 14% (9/63) among male IDU admitting previous needle-sharing and 3% (two out of 66) among the other IDU (odds ratio, 5.3; P = 0.028). Twelve male inmates admitted injecting drugs during imprisonment, of whom 11 shared needles and three were HIV-positive. HIV prevalence in men reporting sexual intercourse with men prior to incarceration was 10% (five out of 52). Nine of the 119 women were HIV-infected (8%), seven of whom were IDU (prevalence of 16% in female IDU). One of the two non-IDU had sexual contacts with male IDU, and the other with men who had sex with men. Tattooing was not associated with HIV infection in either men or women. CONCLUSIONS: Prisoners constitute a group at high risk of HIV infection mainly because of the high proportion of them who are IDU. Imprisonment offers a good opportunity to provide education and preventive programs to this specific group that might otherwise be difficult to reach.

Female↗

The Oswestry Disability Index, the Roland-Morris Disability Questionnaire, and the Quebec Back Pain Disability Scale: translation and validation studies of the Iranian versions.

STUDY DESIGN: Cross-cultural translation and psychometric testing were performed. OBJECTIVES: To cross-culturally translate the Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RDQ), and Quebec Back Pain Disability Scale (QDS) into Persian, and then investigate the psychometric properties of the Persian versions produced. SUMMARY OF BACKGROUND DATA: To the authors' knowledge, there is no validated instrument to measure functional status in Persian-speaking patients with low back pain (LBP) in Iran. To our knowledge, the widely used back-specific measures, the ODI, RDQ, and QDS, have not been translated and validated for Persian-speaking patients with LBP. METHODS: The translation and cross-cultural adaptation of the original questionnaires were performed in accordance with published guidelines. A total of 100 patients with chronic LBP were asked to complete a questionnaire booklet (the Persian versions of the ODI, RDQ, QDS, Short Form Health Survey (SF-36), and visual analog scale measure of pain). There were 31 randomly select patients with chronic LBP asked to complete the second questionnaire booklet 24 hours later. RESULTS: The Cronbach-alpha for the ODI, RDQ, and QDS was 0.75, 0.83, and 0.92, respectively. The ODI, RDQ, and QDS showed excellent test-retest reliability (intraclass correlation coefficient = 0.91, 0.86, and 0.86, respectively) (P < 0.01). The correlation among the ODI, RDQ, QDS and physical functioning scales of the SF-36 was -0.66, -0.62, and -0.69, respectively (P < 0.001). The correlation among the ODI, RDQ, and QDS and visual analog scale was 0.54, 0.36, and 0.46, respectively (P < 0.001). CONCLUSIONS: The Persian versions of the ODI, RDQ, and QDS are reliable and valid instruments to measure functional status in Persian-speaking patients with LBP. They are simple and fast scales, and the use of them can be recommended in a clinical setting and future outcome studies in Iran.

Adolescent↗

Classification of bacteria nodulating Lathyrus japonicus and Lathyrus pratensis in northern Quebec as strains of Rhizobium leguminosarum biovar viciae.

The diversity of two populations of rhizobia isolated from Lathyrus japonicus (30 strains) and Lathyrus pratensis (49 strains) growing in northern regions of Quebec, Canada, was determined on the basis of phenotypic characteristics, multilocus enzyme electrophoresis, DNA-DNA homology, and 16S ribosomal DNA sequencing. According to numerical analysis of phenotypic characteristics, strains were divided into four groups. Strains isolated from L. pratensis fell in groups I to III; the latter included reference strains of Rhizobium leguminosarum. All strains isolated from L. japonicus were included in group IV. All strains had nodulation characteristics similar to those of R. leguminosarum bv. viciae. Strains isolated from L. japonicus originating from an arctic region were usually able to grow at 5 degrees C and were more likely to be tolerant to copper (CuCl2.H2O, 100 micrograms/ml) and lead [Pb(CH3COO)2, 500 micrograms/ml] than strains isolated from L. pratensis from a boreal zone. However, both populations of Lathyrus strains were adapted to the cold in comparison to reference strains from temperate regions. Each population had similar genetic diversity (H = 0.45), determined by multilocus enzyme electrophoresis of the loci encoding eight enzymes, but the diversity obtained by analyzing all strains including the reference strains (H = 0.58) was higher. Representative strains of both populations showed high levels of DNA homology among themselves and with R. leguminosarum. Partial sequences of the 16S ribosomal RNA genes were similar to those reported for R. leguminosarum bv. viciae. We conclude that the strains isolated from L. japonicus and L. pratensis belong to R. leguminosarum bv. viciae but are distinguishable by growth at 5 degrees C, which is a characteristic related to their geographic origin.

Base Sequence↗

Antimicrobial resistance of clinical strains of Campylobacter jejuni subsp. jejuni isolated from 1985 to 1997 in Quebec, Canada.

The antimicrobial resistance of 158 Campylobacter jejuni strains isolated from humans in Quebec, Canada, from 1995 to 1997 was compared to the resistance of 47 and 86 strains of C. jejuni isolated in 1985 and 1986 and in 1992 and 1993, respectively. Of the 291 C. jejuni strains tested, no strain was resistant to erythromycin. Compared to the C. jejuni strains isolated in 1985 and 1986, the C. jejuni strains isolated in 1992 and 1993 were more resistant to tetracycline (40.7 versus 19.1%, respectively; P = 0. 01) but not to nalidixic acid or ciprofloxacin (P > 0.05). Compared to the C. jejuni strains isolated in 1992 and 1993 and in 1985 and 1986, the C. jejuni strains isolated from 1995 to 1997 were more resistant to tetracycline (55.7% versus 40.7 and 19.1%, respectively; P = 0.03 and P < 0.001, respectively) to nalidixic acid (13.9% versus 4.7 and 0%, respectively; P = 0.02 and P = 0.007, respectively), and to ciprofloxacin (12.7% versus 3.5 and 0%, respectively; P = 0.02 and P = 0.009, respectively).

Campylobacter jejuni↗

Comparison of blood smear, antigen detection, and nested-PCR methods for screening refugees from regions where malaria is endemic after a malaria outbreak in Quebec, Canada.

The importation of malaria into a region where it is not endemic raises many concerns, including the timely delivery of appropriate care, safety of the blood supply, and the risk of autochthonous transmission. There is presently no consensus on the best way to screen mobile populations for malaria. Between August 2000 and March 2001, 535 refugees arrived in Quebec, Canada, from Tanzanian camps. Within 4 weeks of resettlement of the first group of 224, the McGill University Centre for Tropical Diseases noted an outbreak of malaria across the province (15 cases over a 3-week period). This group (group 1) was traced and screened for malaria between 3 and 4 months after arrival in Canada. Subsequent groups of 106 and 205 refugees were screened immediately upon arrival in Canada (group 2) and immediately prior to their departure from refugee camps (group 3), respectively. A single EDTA-blood sample was obtained from 521 refugees for testing by thick and thin blood smears (groups 1 and 2), antigen detection (ICT Malaria Pf and OptiMAL; group 1 only), and nested PCR (all groups). Overall, 98 of 521 refugees were found to be infected (18.8%). The vast majority of infections (81 of 98) were caused by Plasmodium falciparum alone. Using PCR as the "gold standard," both microscopy (sensitivity, 50%; specificity, 100%) and antigen detection (ICT sensitivity, 37.5%; ICT specificity, 100%; OptiMAL sensitivity, 29.1%; OptiMAL specificity, 95.6%) performed poorly. None of the PCR-positive subjects were symptomatic at the time of testing, and only two had recently had symptoms compatible with malaria (with or without diagnosis and treatment). Active surveillance of migrants from regions of intense malaria transmission can reduce the risk of morbidity in the migrant population and mitigate against transmission to the host population. Our data demonstrate that PCR is, by far, the most powerful tool for such surveillance.

Adolescent↗

Two types of mouse (Mus musculus domesticus) Y chromosomes in Quebec.

A Y chromosomal repetitive sequence identified two types of Y chromosomes in mice (Mus musculus domesticus) caught near Ste. Anne de Bellevue, Quebec. One type is apparently identical to the Y chromosome found in Maryland, Delaware, and California, whereas the other type is similar, but not identical, to the Y chromosome present in M.m. poschiavinus, an Alpine race of M.m. domesticus. These findings suggest that the domesticus Y chromosome is highly polymorphic and thus useful for elucidating the relationships among American and European house mouse populations.

Animals↗

Entomopathogenic fungi of the order Entomophthorales (Zygomycotina) in adult black fly populations (Diptera: Simuliidae) in Quebec.

Infections by insect-pathogenic fungi of the order Entomophthorales in two adult black fly populations were studied in the Réserve Faunique du Saint-Maurice (Quebec). Entomophaga near limoniae infected Simulium verecundum/rostratum in June whereas Erynia curvispora predominantly parasitized Simulium decorum from the 2nd week of July to September and Erynia conica attacked the Simulium venustum complex, Simulium verecundum/rostratum, and the Simulium vittatum complex from May to September. The fungi did not infect the adult stage of Prosimulium species. Possible evidence of host specificity for Erynia conica is discussed.

Animals↗

Intracellular activation of the fibrinolytic cascade in the Quebec Platelet Disorder.

The Quebec Platelet Disorder (QPD) is an unusual bleeding disorder associated with increased platelet stores of urokinase-type plasminogen activator (u-PA) and proteolysis of platelet alpha-granule proteins. The increased u-PA and proteolyzed plasminogen in QPD platelets led us to investigate possible contributions of intracellular plasmin generation to QPD alpha-granule proteolysis. ELISA indicated there were normal amounts of plasminogen and plasmin-alpha(2)-antiplasmin (PAP) complexes in QPD plasmas. Like normal platelets, QPD platelets contained only a small proportion of the blood plasminogen, however, they contained an increased amount of PAP complexes compared to normal platelets (P < 0.005). The quantities of plasminogen stored in platelets were important to induce QPD-like proteolysis of normal alpha-granule proteins by two chain u-PA (tcu-PA) in vitro. Moreover, adding supplemental plasminogen to QPD, but not to control, platelet lysates, triggered further alpha-granule protein proteolysis to forms that comigrated with plasmin degraded proteins. These data suggest the generation of increased but limiting amounts of plasmin within platelets is involved in producing the unique phenotypic changes to alpha-granule proteins in QPD platelets. The QPD is the only known bleeding disorder associated with chronic, intracellular activation of the fibrinolytic cascade.

Blood Platelet Disorders↗

Impact of waist circumference on the relationship between blood pressure and insulin: the Quebec Health Survey.

Hyperinsulinemia has been suggested to be involved in the etiology of obesity-associated hypertension. The objective of the present study was to quantify, in a population-based study, the respective contributions of excess adiposity (body mass index [BMI]), waist circumference (WC), fasting insulin levels, and insulin sensitivity to the variation of resting blood pressure. The Quebec Health Survey was used to obtain fasting plasma insulin and glucose levels and resting blood pressure as well as anthropometric measurements in a representative sample of 907 men and 937 women. When the sample was divided into tertiles of BMI and further stratified on the basis of the 50th percentile of WC (88 cm in men), nonobese men in the first BMI tertile (<23.2 kg/m2) but with abdominal obesity were characterized by an increased systolic blood pressure (SBP) compared with nonobese men with low WC (130+/-18 versus 120+/-11 mm Hg; mean+/-SD; P=0.075). The SBP was comparable to SBP values measured among men in the top BMI tertile (129+/-14 mm Hg for BMI > or =26.6 kg/m2). When subjects were classified into tertiles of fasting insulin and WC, no association between insulin levels and blood pressure was noted, once the variation in WC was considered. Insulin sensitivity (estimated with homeostasis model assessment [HOMA]) did not explain variation in blood pressure in men, whereas the contribution of HOMA in women was of marginal clinical significance (R2 of <1.3%; P<0.0001). These results suggest that the documented association between obesity, fasting insulin, insulin sensitivity, and blood pressure is largely explained by concomitant variation in WC.

Abdomen↗

Lung structure as a risk factor in adverse pulmonary responses to asbestos exposure. A case-referent study in Quebec chrysotile miners and millers.

To investigate the hypothesis that lung structure may predispose to the development of asbestos-related pulmonary fibrosis, we carried out a case-referent study using data gathered in a cross-sectional study of Quebec chrysotile asbestos miners and millers. Tracheal and thoracic measurements were derived from the routine chest radiographs of 44 men with established radiologic fibrosis and compared with similar measurements for 88 men matched for age and cumulative exposure in the same industry who had not developed pulmonary fibrosis. Intrathoracic tracheal lengths were, on the average, shorter, and transthoracic diameters narrower in cases compared with those in referents. In addition, cases were shorter than the referents, suggesting that height might be an indirect measure of the structural characteristics relevant to the response to inhaled asbestos particles. Our findings are thus consistent with the hypothesis outlined, and they suggest a line of investigation that might be useful in relation to other inhaled pollutants.

Adult↗

Pilot study for the Quebec Child Mental Health survey: Part I. Measurement of prevalence estimates among six to 14 year olds.

A pilot study for a Quebec Child Mental Health Survey was completed in 1990 with 139 children aged six to 14 years from the general population. Six month prevalence estimates for seven disorders were established using DSM-III-R criteria alone and in combination with an impairment index related to the diagnoses. Prevalence estimates were studied separately for parents and children. Each age group (six to 11, 12 to 14) was also studied separately. The impairment index, working as a severity scale, lowered prevalence estimates and allowed identification of impairing and non impairing diagnoses. Little overlap was found between informants.

Adolescent↗

Pilot study for the Quebec Child Mental Health Survey: Part II. Correlates of DSM-III-R criteria among six to 14 year olds.

A pilot study for a Quebec Child Mental Health Survey was completed in 1990 with 139 six to 14 year olds from the general population. The following variables, which were correlated with child psychopathology, were studied for each age group (six to 11 years, 12 to 14 years) and informant (parent, child): child's gender and stressful life events, respondent parent's psychiatric illness, family structure, parent-child relationships, parents' relationship, socioeconomic status, respondent parent's social desirability. Correlations obtained are consistent with those found in the literature. Correlations between the parent's mental health, parent-child relationships and the children's mental health are the most important results of the study.

Age Factors↗

Bleeding risks associated with inheritance of the Quebec platelet disorder.

Quebec platelet disorder (QPD) is an autosomal dominant bleeding disorder associated with increased urokinase-type plasminogen activator in platelets and alpha-granule protein degradation. To determine bleeding risks and common manifestations of QPD, a history questionnaire was developed and administered to 127 relatives in a family with QPD. Data entry was done blinded to affected and unaffected status, determined by assays for platelet urokinase-type plasminogen activator (u-PA) and fibrinogen degradation. Odds ratios (ORs), with 95% confidence intervals (CIs), were determined for items queried. Summative bleeding scores for each individual were calculated using items with OR more than 1. Mean ages (34 years; range, 1-89 years) were similar for affected (n = 23) and unaffected (n = 104) family members. Affected individuals had higher mean bleeding scores (P <.0001) and a much higher likelihood (OR > 20) of having bleeding that led to lifestyle changes, bruises that spread lower or as large or larger than an orange or both, joint bleeds, bleeding longer than 24 hours after dental extractions or deep cuts, and received or been recommended other treatments (fibrinolytic inhibitors) for bleeding. Individuals with QPD and exposure(s) to hemostatic challenges had experienced excessive bleeding only when fibrinolytic inhibitors had not been used. These data illustrate that QPD is associated with increased risks of bleeding that can be modified by fibrinolytic inhibitors.

Adolescent↗