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Biomedical subjects

C Blais

Publications and source records attributed to C Blais.

53 records · Page 3Linked to original sources
PubMed1992

Noncontingent positive and negative feedback during maximal exercise.

A closed skill, maximal effort on a bicycle ergometer was used to study the effects of noncontingent external feedback on performance, perceived effort, and the subject's assessment of the quality and accuracy of the feedback. The 47 subjects included elite athletes as well as physical education majors. They were asked to perform a series of 5 60-sec. trials of maximal effort, trials which included positive, negative, positive and negative, and no-feedback conditions. Although there were no significant effects on performance for the various feedback conditions, subjects judged the positive feedback favourably and as accurate, but negative feedback was judged unfavourably and considered to be inaccurate. This result is seen as supportive of the 1982 McCarrey, et al. supposition that successful athletes may have less need to internalize attributions of effect.

Adult↗
PubMed1992

Informational feedback and self-esteem among male and female athletes.

The self-esteem of male and female competitive athletes was compared after each was provided either positive or negative (verbal) informational feedback on a nonathletic task, a series of single-solution anagrams. Subjects were 50 men and 50 women, aged 18 to 25 years, who were tested on the semantic differential to estimate athletes' self-esteem before and after receiving the informational feedback. Over-all, female athletes responded more strongly to both feedback conditions, with both groups being more influenced by negative rather than by positive feedback.

Achievement↗
PubMed1991

[Biosynthesis of ecdysteroids by prothoracic glands in Pieris brassicae (Lepidoptera insect). Conversion in vitro of radiolabelled precursor of 3-dehydroecdysone].

Ecdysteroids secreted by prothoracic glands of Pieris brassicae were measured by enzyme immunoassay, after HPLC separation. Both ecdysone and 3-dehydroecdysone, as a major product, are produced. Two radiolabelled putative precursors were converted by Pieris glands in vitro: [3H] ketodiol was converted into ecdysone at a low rate; [3H]3-oxoketodiol was efficiently converted, mainly into 3-dehydroecdysone. These data make 3-oxoketodiol a good candidate for an intermediate in ecdysteroid biosynthetic pathway.

Animals↗
PubMed1990

P1 gene expression in Drosophila larval fat body: induction by various ecdysteroids.

Using the developmental mutant ecd1, the biological activity of 20-hydroxyecdysone (20E) and 20E metabolites 3-dehydro-20-hydroxyecdysone (3D20E), 3-epi-20-hydroxyecdysone (3D20E), 3-epi-20-hydroxyecdysone-3-phosphate (20E'3P), 20,26-dihydroxyecdysone (20,26E), and 20-hydroxyecdysonoic acid (20Eoic) was tested for their ability to induce the transcription of the steroid-inducible gene P1 in the Drosophila larval fat body. 3D20E was the most efficient ecdysteroid in the initiation of P1 gene transcription therefore the formation of 3D20E and the 3-epimer could not be regarded as an inactivation pathway in Drosophila larvae. Formation of 20,26E and 20Eoic may be an inactivation pathway in this biological model.

Adipose Tissue↗
PubMed1990

Nonballistic coincident timing.

A nonballistic coincident timing task was used to assess to what extent retarded subjects could use spatial and temporal information to plan their movements. Subjects did not just respond to events but appeared able to modify/plan their responses, given sufficient time.

Adolescent↗
PubMed1988

Directional probability information and Down syndrome: a training study.

In previous studies we have found that subjects with Down syndrome did not respond to changes in directional probability within a complex motor task in the manner of other subjects with mental retardation (Blais & Kerr, 1986; Kerr & Blais, 1985). Only after extended practice were significant changes noted in their reaction time (RT) performance; however, movement time (MT) data remained relatively unchanged (Kerr & Blais, 1987). In the present study, subjects were given training relative to the directional probability component of the task (choice of direction). The subjects with Down syndrome did improve their subsequent performance, but primarily in terms of MT. Although they did adopt a pattern of responding to changes in directional probability (RT) similar to that of subjects without mental retardation, the nature of the change reflected the extent of previous exposure to the task.

Adolescent↗
PubMed1987

Down syndrome and extended practice of a complex motor task.

Mentally retarded subjects with and without Down syndrome made 2,400 responses on a discrete pursuit-tracking task. Both groups showed significant improvement on the task such that their performance was comparable to nonretarded subjects at the same functional level. Although the previously noted failure (Blais & Kerr, 1986; Kerr & Blais, 1985) of the subjects with Down syndrome to spontaneously use the directional probability information available in the task was moderated, differences remained that may reflect processing limitations.

Adolescent↗
PubMed1985

Motor skill acquisition by individuals with Down syndrome.

Motor skill acquisition of subjects with Down syndrome on a pursuit tracking task was assessed in comparison to groups of mentally retarded subjects without Down syndrome and nonretarded subjects matched for functional age and chronological age (CA). Thirty-seven male subjects performed eight trials on a subject-paced pursuit tracking task. The main finding was that subjects with Down syndrome did not respond to directional probability in the same manner shown by the retarded or the nonretarded subjects matched for CA or functional age. This difference in strategy was also reflected in their greater emphasis on accuracy rather than speed. Finally, these effects were consistent across the subjects with Down syndrome despite the large intersubject variability seen in their performance.

Adolescent↗
PubMed1984

Ecdysteroid metabolism by soluble enzymes from an insect. Metabolic relationships between 3 beta-hydroxy-, 3 alpha-hydroxy- and 3-oxoecdysteroids.

The formation and fate of 3-dehydroecdysteroids were studied in vitro in tissue extracts from Pieris brassicae (Lepidoptera). Three cytosolic enzymes are involved: an ecdysone oxidase converts 3 beta-hydroxyecdysteroids into 3-dehydroecdysteroids, and two different reductases, requiring NADPH as cofactor, transform 3-dehydroecdysteroids into the 3 alpha-hydroxy- or the 3 beta-hydroxy forms, respectively. 3 alpha-Hydroxyecdysteroid formation is only detected in the gut; all tissues contain the two other activities. It appears that conversion of 3 beta- to 3 alpha-hydroxyecdysteroids proceeds through 3-dehydro compounds. The biological significance of these reactions is discussed.

Animals↗
PubMed1984

Lymphangioma in children.

The topic of lymphangioma is reviewed. Included in the text are the embryology, classification, clinical presentation, and treatment. Eight case reports are included. One case involved the skin, two presented with a submandibular mass, one had both a facial lymphangioma and a cystic hygroma of the floor of the mouth, and there are two cases of involvement of the tongue, and two cases of classical cystic hygroma of the neck. The rate of involution is probably higher than previously thought. Indications for surgery are suggested. This diagnosis must be considered in the differential diagnosis of a mass presenting in the head and neck of a child.

Adolescent↗
PubMed1980

High-performance liquid chromatography of ecdysone metabolites applied to the cabbage butterfly, Pieris brassicae L.

HPLC allowed separation of twelve major labeled compounds after injection of 3H-ecdysone into Pieris pharate pupae. These compounds were identified as six pairs of metabolites (3 alpha and 3 beta epimers), comprising ecdysone, 20-hydroxyecdysone, 26-hydroxyecdysone, 20,26-dihydroxy-ecdysone and the polar metabolites P and 20-hydroxy-P. These last two products could not be enzymatically split by any hydrolase tested and are weak acids arising respectively from 26-hydroxyecdysone and 20,26-dihydroxyecdysone. They might be 26-oic compounds. Epimerization appears as a fundamental inactivation process in Pieris and could well be a general characteristic of closed systems (eggs and pupae). No significant amounts of hydrolyzable conjugates were detected in our biological system (pharate pupae and pupae).

Animals↗
PubMed1979

[Accidental hypothermia: treatment of a case using peritoneal irrigation].

A case of accidental hypothermia is reported. This patient was rewarmed by using a peritoneal irrigation. Rewarming was rapid and without complication. The patient was discharged from the hospital free from any sequellae. Peritoneal irrigation constitutes a fast and effective technique of core body rewarming in cases of moderate or severe hypothermia. Another advantage of this method is that it can be accomplished without complicated equipment and that it can be used even in small community hospitals.

Aged↗
PubMedDate not supplied

Acute lower respiratory infections among children hospitalized in Bangui, Central African Republic: toward a new case-management algorithm.

To measure the performance of the current WHO algorithm in identifying children at higher risk of death, children aged 2-59 months who presented with cough and/or difficult breathing and were admitted into the paediatric hospital of Bangui (Central African Republic) during a 1-year period (1996/97) were investigated. Among children with subcostal indrawing, mortality and severity of oxygen desaturation were identical whether or not they also had tachypnoea. Among children with a 'severe pneumonia', those who also fulfilled the 'very severe disease' definition had a higher risk of death (31/132, 23.5%) than those who did not (12/106, 11.3%, P = 0.02). However, this 'very severe disease' definition did not predict death when used in children who did not have severe pneumonia. To identify variables that would better predict death, combinations of symptoms and signs were examined among the subgroup of children with indrawing. Nine combinations had both a sensitivity and specificity over 60%. 'Grunting and/or nasal flaring' had a sensitivity of 72% and a specificity of 66% in predicting death, and might be easier to use by primary health care personnel than other combinations. A new algorithm is proposed for the management of children aged 2-59 months presenting with cough and/or difficult breathing. The definition of pneumonia would be unchanged (tachypnoea). Severe pneumonia would remain defined on indrawing regardless of respiratory rate, except that indrawing should be lower chest wall and/or intercostal. In health facilities where intravenous antibiotics, chloramphenicol and/or oxygen are available, entry into a 'very severe pneumonia' category would be based on 'grunting and/or nasal flaring' among children with indrawing. In our study population, the mortality rates in the categories based on these definitions were 0.8% (1/127) in children with no pneumonia, 0.9% (1/116) in children with pneumonia, 7.7% (12/156) in children with severe pneumonia and 31.1% (33/106) in children with very severe pneumonia.

Acute Disease↗