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C Allard

Publications and source records attributed to C Allard.

At least 19 recordsLinked to original sources
PubMed2001

Molecular and biochemical characterization of endo-beta-mannanases from germinating coffee (Coffea arabica) grains.

The activity of endo-beta-mannanase ([1-->4]-beta-mannan endohydrolase EC 3.2.1.78) is likely to be central to the metabolism of cell wall mannans during the germination of grains of coffee (Coffea spp.). In the present paper, we report the cloning and sequencing of two endo-beta-mannanase cDNAs (manA and manB) by different strategies from Coffea arabica L.. The manA cDNA was obtained by the use of oligonucleotides homologous to published sequences of other endo-beta-mannanases and manB by the use of oligonucleotides deduced from a purified enzyme from coffee. ManA and B proteins share about 56% sequence homology and include highly conserved regions found in other mannan endohydrolases. Purification of the activity by chromatography followed by separation by two-dimensional electrophoresis and amino acid sequencing demonstrated the existence of at least seven isomers of the ManB form. The existence of multiple manB genes was also indicated by Southern analysis, whereas only one or two gene copies were detected for manA. Northern hybridizations with manA- and manB-specific probes showed that mRNA transcripts for both cDNAs were present at the same periods of bean germination with transcript peaks at 20 days after imbibition of water (DAI). Transcripts were not detected during grain maturation or in the other tissues such as roots, stems, flowers and leaves. The peak endo-beta-mannanase activity occurred at approximately 28 DAI and was not detected in grains prior to imbibition. Activity and mRNA levels appeared to be tightly co-ordinated. Tests of substrate specificity with the purified ManB enzyme showed that activity required a minimum of five mannose units to function efficiently.

Amino Acid Sequence↗
PubMed2001

Disease knowledge in a high-risk population for cystic fibrosis.

Cystic fibrosis (CF) has high incidence (1/936 live births) and carrier rate (1/15 inhabitants) in Saguenay-Lac-Saint-Jean (SLSJ). One objective of a major enquiry among several subsets of individuals from this high-risk population for CF was to evaluate the knowledge of the disease and its genetic transmission. The overall score of correct answers pertaining to the clinical signs of CF among medical doctors (general practitioners and specialists) was 42.2 and 65.6%, respectively; it was 84.2% for questions regarding the genetic transmission of CF. The knowledge of the clinical signs was reasonable among CF patients and their parents (about 65% of correct answers), but it was much higher for the genetics (over 88% among parents). Aunts and uncles of CF children were poorly informed of the clinical signs (33.9% of correct answers) but well informed of the genetic transmission (73.8%). Specific subsets of the SLSJ population showed important gaps in the knowledge of the clinical signs of CF but, overall, they were well informed of its genetic transmission.

Adolescent↗
PubMed1998

Genetic determinants of Pseudomonas aeruginosa colonization in cystic fibrosis patients in Canada.

The present study was aimed at analyzing whether the rate of colonization and the age at colonization with Pseudomonas aeruginosa was genetically determined in cystic fibrosis (CF) patients. These two variables were calculated among 127 CF patients whose genotypes were known and who were monitored at the Clinique de Fibrose Kystique in Saguenay Lac-Saint-Jean. No statistically significant differences were found in the rate or the age at colonization when the patients were grouped by genotype; however, this result could be due to the small number of patients in each genotype group. The rate of colonization was significantly lower among CF patients carrying the A455E mutation, a "mild" allele with respect to exocrine pancreatic function, than among those carrying either the deltaF508 or the 621 + IG- > T mutation, both of which are "severe" alleles. The results confirm previous reports that the rate of colonization with Pseudomonas aeruginosa is, at least in part, genetically determined.

Adolescent↗
PubMed1998

Correlation of sweat chloride concentration with genotypes in cystic fibrosis patients in Saguenay Lac-Saint-Jean, Quebec, Canada.

OBJECTIVES: Saguenay Lac-Saint-Jean, a geographically isolated region of northeastern Quebec has a high incidence of cystic fibrosis (CF) and three mutations only account for 94% of the CF chromosomes. The objective of the present study was to determine whether different mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene had different effects upon the sweat chloride concentration. DESIGN AND METHODS: The sweat chloride concentration of 114 patients was measured by quantitative pilocarpine iontophoresis. RESULTS: CF patients carrying the A455E mutation, usually associated with pancreatic sufficiency, had lower sweat chloride concentrations than those carrying mutations associated with pancreatic insufficiency (delta F508 and 621 + 1G-->T). CONCLUSIONS: Our results confirm that mutations resulting in a reduction of the chloride current at the apical membrane of epithelial cells induce lower sweat chloride values. However, there are differences in the chloride current between genotypes, even if they are composed of mutations apparently having the same functional effect.

Chlorides↗
PubMed1998

Complete identification of cystic fibrosis transmembrane conductance regulator mutations in the CF population of Saguenay Lac-Saint-Jean (Quebec, Canada).

Over the past few years, we have conducted a systematic study of 230 cystic fibrosis (CF) chromosomes in the Saguenay Lac-Saint-Jean (SLSJ) population which has a high CF incidence (1/936 live births). We identified 11 mutations accounting for 100% of the CF chromosomes found in patients born in SLSJ. Our results indicate that denaturing gradient gel electrophoresis (DGGE) is a powerful method of identifying CF mutations. They have also considerable implications for genetic counselling and molecular characterization of doubtful patients. They make carrier screening technically feasible in this population.

Cystic Fibrosis↗
PubMed1997

Genotype-phenotype correlation in cystic fibrosis patients compound heterozygous for the A455E mutation.

Cystic fibrosis (CF) has a high incidence in the French-Canadian population of Saguenay Lac-Saint-Jean (Quebec). The A455E mutation accounts for 8.3% of the CF chromosomes. This mutation was shown to be associated with a milder lung disease in the Dutch population. Twenty two CF patients distributed in 17 families and compound heterozygotes for the A455E mutation have been followed at the Clinique de Fibrose Kystique de Chicoutimi. Fourteen patients also carried the delta F508 mutation while the remaining eight patients had the 621 + 1G-->T mutation. Each patient was matched by sex and age to a patient homozygous for the delta F508 mutation. The pairs were analyzed for several clinical and laboratory variables. The A455E compound heterozygotes were diagnosed at a later age (P = 0.003) and had chloride concentrations at the sweat test lower than those homozygous for the delta F508 mutation (P = 0.007). More patients were pancreatic sufficient (P = 0.004). They had a higher Shwachman score (P = 0.001) and better pulmonary function tests (P < 0.02). CF patients compound heterozygous for the A455E mutation have a milder pancreatic and lung disease than the delta F508 homozygotes. Therefore, the A455E should be associated with a better prognosis.

Adolescent↗
PubMed1997

Clinical features of cystic fibrosis patients with rare genotypes in Saguenay Lac-Saint-Jean (Quebec, Canada).

We describe the clinical features of six cystic fibrosis (CF) patients from Saguenay Lac-Saint-Jean who bear rare genotypes. Two patients with a delta F508/I148T genotype had pancreatic insufficiency, as did two patients compound heterozygous for the 621 + 1G-->T mutation who also had a major growth retardation. One CF adult who carried a delta F508/Q890X genotype had meconium ileus and bronchiectasis. The sixth patient (A455E/R117C) had borderline sweat chloride concentrations; the diagnosis of cystic fibrosis had remained doubtful until the molecular analysis showed the presence of two CF mutations. The seventh patient with a delta F508/R1158X genotype experienced several complications and is now 43 years old.

Adult↗
PubMed1995

Individual differences in stimulus intensity modulation and its relationship to two styles of depression in older adults.

Research comparing depressive persons with and without manic symptoms shows striking parallels with differences between augmenters and reducers on the Kinesthetic Aftereffect (KAE) task (A. Petrie, 1967). Twenty-three community-dwelling older adults identified by the Minnesota Multiphasic Personality Inventory (S. R. Hathaway & J. C. McKinley, 1951) as depressive without manic symptoms were compared with 24 older adults with manic symptoms on the KAE, the NEO Personality Inventory (NEO-PI; P. T. Costa & R. R. McCrae, 1985), and Strelau (J. Strelau, 1983) Temperament Inventory. As hypothesized, augmentation was related to depression without manic symptoms, and reduction was related to depression with manic symptoms. Stepwise discriminant analyses indicated that the KAE is a potent discriminator between the 2 types of depression. Three characteristics of Strelau's "strength of nervous system"--excitation, and inhibition and mobility--discriminate significantly between the 2 groups as well as NEO extraversion and conscientiousness. Results suggest that older depressive persons with and without manic symptoms may benefit from different therapeutic interventions.

Aged↗
PubMed1994

Disease knowledge and reproductive attitudes of parents having a child with cystic fibrosis.

Saguenay Lac-Saint-Jean (SLSJ), a geographically isolated region located in northeastern Quebec, has an incidence of cystic fibrosis (CF) of 1 in 902 live births and a carrier rate of 1 in 15 inhabitants. Forty two families among those registered at the local chapters of the Canadian CF Foundation were randomly selected. A multiple-choice questionnaire was applied during an interview. It included 102 questions pertaining to the sociodemographic status of the participants, their knowledge of the disease and their reproductive attitudes. All the educational and socioeconomic levels were represented in the sample; 76% of the respondents were married. Before answering the questionnaire, 86% estimated their knowledge of the transmission of CF to be good or excellent; in fact, the rate of good answers to various questions ranged from 71 to 95%. The birth of a child with CF had a major impact on further pregnancy planning (a 69% reduction or arrest). Seventy one percent of the respondents used a more effective contraception method (including vasectomy and tubal ligation) after the birth of the CF child; in 63% of them, the decision was a direct consequence of the presence of the disease in the family. Thirty four respondents (81%) knew that prenatal diagnosis was available; 90% were in favor of such a prenatal test but only 17% would have required an abortion should the fetus be affected.

Abortion, Induced↗
PubMed1989

Increased alveolar plasminogen activator in early asbestosis.

Alveolar macrophage-derived plasminogen activator (PA) activity is decreased in some chronic interstitial lung diseases such as idiopathic pulmonary fibrosis and sarcoidosis but increased in experimental models of acute alveolitis. Although asbestos fibers can stimulate alveolar macrophages (AM) to release PA in vitro, the effect of chronic asbestos exposure of the lower respiratory tract on lung PA activity remains unknown. The present study was designed to evaluate PA activity of alveolar macrophages and bronchoalveolar lavage (BAL) fluid in asbestos-exposed sheep and asbestos workers. Forty-three sheep were exposed to either 100 mg UICC chrysotile B asbestos in 100 ml phosphate-buffered saline (PBS) or to 100 ml PBS by tracheal infusion every 2 wk for 18 months. At Month 18, chest roentgenograms were analyzed and alveolar macrophage and extracellular fluid PA activity were measured in samples obtained by BAL. Alveolar macrophage PA activity was increased in the asbestos-exposed sheep compared to control sheep (87.2 +/- 17.3 versus 41.1 +/- 7.2 U/10(5) AM-24 h, p less than 0.05) as was the BAL fluid PA activity (674.9 +/- 168.4 versus 81.3 +/- 19.7 U/mg alb-24 h, p less than 0.01). Among the asbestos-exposed sheep, 10 had normal chest roentgenograms (Group SA) and 15 had irregular interstitial opacities (Group SB). Strikingly, whereas Group SA did not differ from the control group in BAL cellularity or PA activity, Group SB had marked increases in alveolar macrophages (p less than 0.005), AM PA activity (p less than 0.02), and BAL PA activity (p less than 0.001) compared to the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Occupational asthma due to various agents. Absence of clinical and functional improvement at an interval of four or more years after cessation of exposure.

We have previously shown that in some subjects with occupational asthma caused by various agents, there is no improvement approximately two years after exposure ended. These results could be explained by the short interval between diagnosis and follow-up. In the current study, we saw 28 subjects with occupational asthma at two intervals, 2.3 years (range, three months to 5.7 years) and 5.8 years (range, 4.3 to 10.9 years) after the cessation of exposure. Various causes of occupational asthma were included. The diagnosis was confirmed in 26 of the cases by specific inhalation challenges in the laboratory, and in the remaining two cases by combined monitoring of peak expiratory flow rates and bronchial responsiveness. All subjects had symptoms of asthma at both follow-up assessments. There were no changes in the need for medication, spirometry, or bronchial hyperresponsiveness. Depending on the interval of the follow-up, four to six subjects required inhaled steroid agents in addition to the usual bronchodilators, 11 had FEV1 less than 80 percent of predicted, and 26 or 27 had an abnormal PC 20 histamine. Only two subjects demonstrated sustained improvement in PC 20 at the first and second follow-ups, and one other showed changes during the second follow-up assessment which were not present at the first. We conclude that except for three subjects, the need for medication did not diminish, nor did airway obstruction and hyperresponsiveness improve in this group of subjects with occupational asthma long after exposure ended. These results differ from other studies, which demonstrated that some recovery takes place in a greater proportion of individuals.

Asthma↗
PubMed1988

Aldosterone nuclear receptors in kidneys of chick embryo.

We have studied the properties of the nuclear receptors for aldosterone in kidneys of chick embryo. Aliquots of 0.4 M KCl nuclear extracts were incubated with [3H]aldosterone with or without 1 microM RU28362, a potent glucocorticoid analog. Scatchard analyses of binding data revealed two classes of binding sites with Ka of 0.26 and 0.03 X 10(9) M-1 and Nmax of 330 fmol and 620 fmol/mg DNA respectively. In presence of RU28362, however, we observed only a single class of binding sites with a Ka of 1.02 X 10(8) M-1 and a Nmax of 90 fmol/mg DNA. Competition studies performed in presence of RU28362 showed that aldosterone was the more effective competitor followed by corticosterone, progesterone, deoxycorticosterone, dexamethasone, cortisol, triamcinolone acetonide and cortisone. The nuclear complexes had a sedimentation coefficient in the area of 8 S which changed to 4-5 S in the presence of 0.4 M KCl. This effect of KCl was prevented by the addition of 10 mM sodium molybdate. Always in the presence of the glucocorticoid analog, by DEAE-c chromatography we observed a major specific aldosterone-binding fraction which was eluted with 0.2 M KCl. This fraction sedimented at 8.4 S in the absence of sodium molybdate and KCl. In the absence of RU28362, DNA-c columns retained only a small portion of the nuclear complexes which were eluted with KCl. These complexes sedimented, on sucrose gradient, at 4.6 and 3.1 S, whereas those which did not bind to DNA-c had a sedimentation coefficient of 8 S. In the presence of RU28362, the majority of bound [3H]aldosterone remained in the column flow-through fraction; when this fraction was further analyzed on DEAE-c, complexes were eluted with 0.2 and 0.3 M KCl. These data indicate that nuclear receptors for aldosterone are present in small number in kidneys of chick embryo and that they are mostly in the 8 S form.

Aldosterone↗
PubMed1987

Adenosine deaminase, adenylate kinase and acid phosphatase polymorphism in a French-Canadian population.

Adenosine deaminase (ADA), adenylate kinase (AK1), and acid phosphatase (ACP1) red blood cell enzymes were studied for allelic variation in a French-Canadian population from Quebec City, Canada. Allele frequencies in 887 unrelated individuals were for ACP1, ACP1*A: 0.305; ACP1*B: 0.635 and ACP1*C: 0.060, for ADA, ADA*1: 0.969, ADA*2: 0.031, and for AK1, AK1*1: 0.976, AK1*2: 0.024. The allele frequencies for each enzyme were identical to those previously reported in other Caucasian populations.

Acid Phosphatase↗