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Dumont M, Macchi MM, Carrier J, Lafrance C, Hébert M. Time course of narrow frequency bands in the waking EEG during sleep deprivation. Neuroreport 1999; 10:403-7. [PMID: 10203343 DOI: 10.1097/00001756-199902050-00035] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Electroencephalograms (EEGs) of 14 normal subjects were recorded every 2 h during 38 h constant routines. Adjacent narrow frequency bands (NFB) with similar temporal trends were grouped into frequency clusters. Clusters I (2.00-7.75 Hz) and III (11.00-14.75 Hz) exhibited similar time courses which may reflect both the duration of time awake and a circadian modulation. Cluster II (8.00-10.75 Hz) was characterized by a time course similar to the circadian modulation of core body temperature. Cluster V (18.00-24.75 Hz) was correlated with subjective sleepiness and may reflect the increasing effort made by subjects to perform the task as sleep deprivation lengthened. Various NFB in the waking EEG may reflect different physiological mechanisms underlying variations in vigilance states.
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Blondeau D, Valois P, Keyserlingk EW, Hébert M, Lavoie M. Comparison of patients' and health care professionals' attitudes towards advance directives. JOURNAL OF MEDICAL ETHICS 1998; 24:328-335. [PMID: 9800589 PMCID: PMC1377609 DOI: 10.1136/jme.24.5.328] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
OBJECTIVES This study was designed to identify and compare the attitudes of patients and health care professionals towards advance directives. Advance directives promote recognition of the patient's autonomy, letting the individual exercise a certain measure of control over life-sustaining care and treatment in the eventuality of becoming incompetent. DESIGN Attitudes to advance directives were evaluated using a 44-item self-reported questionnaire. It yields an overall score as well as five factor scores: autonomy, beneficence, justice, external norms, and the affective dimension. SETTING Health care institutions in the province of Québec, Canada. SURVEY SAMPLE The sampling consisted of 921 subjects: 123 patients, 167 physicians, 340 nurses and 291 administrators of health care institutions. RESULTS Although the general attitude of each population was favourable to the expression of autonomy, multivariate analysis of variance (MANOVA) indicated that physicians attached less importance to this subscale than did other populations (p < .001). Above all, they favoured legal external norms and beneficence. Physicians and administrators also attached less importance to the affective dimension than did patients and nurses. Specifically, physicians' attitudes towards advance directives were shown to be less positive than patients' attitudes. CONCLUSION More attention should be given to the importance of adequately informing patients about advance directives because they may not represent an adequate means for patients to assert their autonomy.
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Guillemette J, Hébert M, Paquet J, Dumont M. Natural bright light exposure in the summer and winter in subjects with and without complaints of seasonal mood variations. Biol Psychiatry 1998; 44:622-8. [PMID: 9787887 DOI: 10.1016/s0006-3223(97)00543-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Considering the success of bright light therapy in seasonal affective disorders, it was suggested that seasonal mood disorders are triggered by decreased exposure to bright light in the winter; however, no previous studies have used objective measures to assess seasonal patterns of bright light illumination in subjects with seasonal mood variations. METHODS Eleven subjects reporting seasonal mood variations and 8 control subjects had their levels of natural bright light (BL) exposure measured for 5-6 days with an ambulatory monitor during both the summer and winter, at a latitude of 45 degrees 31'N. RESULTS Both groups received significantly more BL in the summer than in the winter, but there was no difference between the two groups for the pattern of BL exposure, including total duration, daily distribution, and amplitude of seasonal variation. CONCLUSIONS These results suggest that complaints of seasonal mood variations are not caused by a differential pattern in bright light exposure compared to normals. It is possible, however, that some individuals are more sensitive than others to variations in natural bright light. Whether an increased vulnerability is due to a more fragile affective state or to a lower sensitivity to light remains to be determined.
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Lacoursière L, Langelier R, Hébert M. Diagnostic value of high-dose contrast-enhanced computed tomography of the postoperative lumbar spine. Clin Imaging 1998. [DOI: 10.1016/s0899-7071(98)00048-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Lacoursière L, Langelier R, Hébert M. Diagnostic value of high-dose contrast-enhanced computed tomography of the postoperative lumbar spine. Can Assoc Radiol J 1998; 49:42-5. [PMID: 9494463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Hébert M, Dumont M, Paquet J. Seasonal and diurnal patterns of human illumination under natural conditions. Chronobiol Int 1998; 15:59-70. [PMID: 9493715 DOI: 10.3109/07420529808998670] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Little is known about the natural pattern of seasonal and diurnal illumination to which normal people are exposed, especially in northern latitudes. In this study, ambient illumination of normal volunteers living at a latitude of 45 degrees 31' N was recorded with ambulatory photosensors worn for 5 to 6 days in winter and summer. Results from 12 normal subjects (6 men, 6 women) aged 18 to 35 years were included in the analyses. The mean daily duration of time awake was similar in both seasons: 14.6h in the summer and 14.9h in the winter. However, the phase of the sleep-wake cycle was advanced in the summer compared to the winter, as shown by an earlier average waketime and bedtime in the summer. Illumination recorded by the ambulatory monitor between waketime and bedtime was categorized according to four ranges of light intensities: very dim (< 1 lux), dim (1-100 lux), moderate (100-1000 lux), and bright (> 1000 lux) illumination. There was no seasonal difference for the time spent in illumination lower than 1000 lux, but the duration of daily exposure to bright light averaged 2.6h in the summer compared to only 0.4h in the winter (p = 0.0004). To evaluate the diurnal distribution of ambient illumination, time spent awake was divided into four time intervals: morning (waketime to 12:00), afternoon (12:00 to 16:00), early evening (16:00 to 20:00), and late evening (20:00 to bedtime). Except for late evening, the time spent in bright illumination was significantly longer during the summer for all time intervals, but the relative distribution of bright light exposure throughout the day was the same in both seasons. The subjects spent more than 50% of their time awake in illumination dimmer than 100 lux, even in the summer. More naturalistic studies are needed to determine whether very short exposure to bright light or longer exposure to light of moderate intensity (100-1000 lux) are sufficient to maintain circadian entrainment and euthymia in normal young subjects.
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Hébert M, Kant R, de Gennes PG. Dynamics and Thermodynamics of Artificial Muscles Based on Nematic Gels. ACTA ACUST UNITED AC 1997. [DOI: 10.1051/jp1:1997209] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Caillé A, Hébert M. Quasi-long-range order in columnar liquid crystals. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 54:R4544-R4547. [PMID: 9965801 DOI: 10.1103/physreve.54.r4544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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59
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Hébert M, Plumer ML. Thermal phase diagram of a model Hamiltonian for columnar phases of liquid crystals. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 54:550-558. [PMID: 9965099 DOI: 10.1103/physreve.54.550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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60
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Hébert M, Caillé A. Ground-state phase diagram of the ordered columnar phases of liquid-crystal materials. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 53:1714-1724. [PMID: 9964431 DOI: 10.1103/physreve.53.1714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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De Koninck GC, Hébert M, Carrier J, Lamarche C, Dufour S. Body temperature and the return of slow wave activity in extended sleep. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1996; 98:42-50. [PMID: 8689993 DOI: 10.1016/0013-4694(95)00215-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The time courses of slow wave sleep (SWS) and EEG slow wave activity (SWA) were examined in relation to core body temperature (CBT) during extended sleep periods of 15 h. Ten subjects (4 male, 6 female; aged 18-29 years) slept in the laboratory for 3 consecutive nights (2 of 8 h, and the last of 15 h). Bedtime was as close as possible to subjects' habitual bedtimes, but was always between 23.00 h and 1.00 h, and was the same on all nights. Standard polysomnographic measures as well as rectal temperature were collected continuously each night. Using 3 h blocks, SWS and SWA declined with time asleep, then showed a significant increase in the final 3 h. Using a more specific measure with 15 min means, 8 of the 10 subjects showed SWA returns late in sleep, that were not related to preceding amounts of waking after sleep onset (WASO), rapid eye movement sleep (REMS), or WASO+REMS. The timing and magnitude of the SWA return was significantly associated with the phase of CBT as indexed by delay from sleep onset to CBT minimum. The findings are consistent with a 12 h rhythm of SWS and SWA that is related to the phase of the CBT rhythm, with the minor pole of SWS/SWA occurring independently of WASO and/or REMS.
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Hébert M, Lachapelle P, Dumont M. Reproducibility of electroretinograms recorded with DTL electrodes. Doc Ophthalmol 1995; 91:333-42. [PMID: 8899303 DOI: 10.1007/bf01214651] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The purpose of this study was to examine whether the use of the DTL fiber electrode yields stable and reproducible electroretinographic recordings. To do so, luminance response function, derived from dark-adapted electroretinograms, was obtained from both eyes of 10 normal subjects at two recording sessions spaced by 7-14 days. The data thus generated was used to calculate Naka-Rushton Vmax and k parameters and values obtained at the two recording sessions were compared. Our results showed that there was no significant difference in the values of Vmax and k calculated from the data generated at the two recording sessions. The above clearly demonstrate that the use of the DTL fiber electrode does not jeopardize, in any way, the stability and reproducibility of ERG responses.
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Abstract
This article outlines a course on occupational therapy community practice offered at the University of Ottawa and discusses its assets and limitations in terms of preparing students for the shift to community-based health services. The shift to community services in the health care systems of Ontario and Québec is described. Then the curricular components needed to prepare students for community practice are summarized. Finally, the community practice course at the University of Ottawa including its goal, objectives, class topics and evaluations is outlined. The strength of the community practice course described is that it includes many of the curricular components needed for community practice. On the other hand, limitations include the lack of skill training in some areas, its place in the last year of the programme, and its optional nature. Changes planned for the course and other recommendations for curricula are also discussed.
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64
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Hébert M, Caillé A. Mean-field phase diagram of a coupled XY-Ising model for discotic liquid crystals. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 51:R1651-R1654. [PMID: 9962948 DOI: 10.1103/physreve.51.r1651] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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65
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Boutin Y, Jobin M, Bédard PM, Hébert M, Hébert J. Possible dual role of anti-idiotypic antibodies in combined passive and active immunotherapy in honeybee sting allergy. J Allergy Clin Immunol 1994; 93:1039-46. [PMID: 7516355 DOI: 10.1016/s0091-6749(94)70053-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Passive infusion of beekeepers' plasma was shown to protect patients against systemic reactions occurring during active immunotherapy by mechanisms still to be clarified. It is tempting to speculate that anti-idiotypic antibodies could play a role because they are found in beekeepers' plasma and are involved in the regulation of IgE synthesis. METHODS In this report we studied the effects of passive infusion of a beekeeper's plasma rich in anti-idiotypic antibodies to a patient who experienced systemic reactions to honeybee venom. RESULTS We reported, during the days after the infusion, a decrease of clinical sensitivity to the honeybee venom. Indeed, the patient tolerated a cumulative dose of 280 micrograms of venom without adverse reactions. We also observed decreases in skin mast cell and in basophil sensitivity. After the plasma infusion, a modified rush immunotherapy with honeybee venom was initiated in our patient. In the following 76 weeks, increased levels of anti-idiotypic antibodies in the serum of the patient were associated with a diminution of specific antibodies (IgG and IgE) to honeybee venom. CONCLUSION These results suggest a dual role of anti-id in our combined protocol of passive and active immunotherapy: an immediate action on clinical sensitivity along with a decrease of skin mast cell and basophil sensitivity and an immunoregulatory role on specific antibody production.
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66
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Caillé A, Hébert M, Plumer ML. Ground-state phase diagram of a one-dimensional discotic liquid crystal in a local anisotropy field. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:3104-3108. [PMID: 10011166 DOI: 10.1103/physrevb.49.3104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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67
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Hébert M, Caillé A. One-dimensional chiral discotic liquid crystal in a hexagonal field. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 49:55-63. [PMID: 10009257 DOI: 10.1103/physrevb.49.55] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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68
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Hébert M, Caillé A. Phase diagram at T=0 of the one-dimensional chiral planar model in a twofold-anisotropy field. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 48:3074-3078. [PMID: 10008727 DOI: 10.1103/physrevb.48.3074] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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69
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Abstract
Evaluation of the rectum by barium enema does not correlate well with rectometrographic studies and is not predictive of bowel function. The purpose of the present study was to describe clinical and functional data in patients with chronic idiopathic constipation, where a megarectum was diagnosed by a rectometrogram. Among 355 patients who underwent rectal elasticity studies, 35 were found to have a megarectum (maximum tolerable volume above 320 ml in women and 440 in men) for which no specific etiology was recognized. They, and a group of 11 healthy controls who were not sensitive to stress, underwent studies of stool frequency, colonic transit time of radiopaque markers, rectal elasticity, and anorectal pressures and reflexes. The elasticity coefficient of the rectal wall was decreased in patients as compared to controls (P less than 0.01). Seven patients had onset of symptoms at birth, with maximum tolerable volume in the rectum between 460 and 900 ml, and all were incontinent for feces. Studies of colonic transit times demonstrated normal function in the right and left colon, but there was rectosigmoid stagnation (transit time of 122 +/- 17 hr vs 8 +/- 2 in stress-free controls; X +/- SE; P less than 0.001). In the other 28 patients (late-onset megarectum), in contrast to the congenital group, there was a marked female preponderance, and their recorded stool frequency (4 +/- 0.7/week) was greater than the recalled frequency (1.4 +/- 0.2/week; P less than 0.001). Only half suffered from fecal incontinence. They did not have a greater rectal capacity when colonic transit times were prolonged (455 +/- 27 ml) than when normal (422 +/- 27). Rectal pressure was similar at the level of conscious sensation of filling, regardless of rectal capacity, suggesting a motor, rather than a sensory, abnormality. The amplitude of the rectoanal inhibitory reflex was decreased (P less than 0.001) as compared to controls, sometimes mimicking the findings of Hirschsprung's disease, but increasing rectal distension always induced a relaxation of the internal anal sphincter. The notion of a megarectum, which tolerates large amounts of fluid without sensation, lacks elasticity, and is accompanied by an abnormal rectoanal inhibitory reflex, provides an explanation for one of the mechanisms of constipation by outlet obstruction.
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Schang JC, Devroede G, Hébert M, Hémond M, Pilote M, Devroede L. Effects of rest, stress, and food on myoelectric spiking activity of left and sigmoid colon in humans. Dig Dis Sci 1988; 33:614-8. [PMID: 3359913 DOI: 10.1007/bf01798366] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The great variability which is known to affect colonic motility may partly be the result of changes in physiological conditions. In order to test this hypothesis, 40 subjects were sequentially put in conditions of vigilance, rest, stress, and feeding while colonic motility was monitored. The myoelectric spiking activity of the left colon was recorded with a 50-cm-long silastic tube equipped with four bipolar ring electrodes (located 10 cm apart) introduced into the left colon by flexible sigmoidoscopy. Tracings were performed while the subjects were kept awake (by conversation) for 1 hr, put at rest (quiet) for another 1 hr, submitted to a stress (by alternatively immersing and removing one hand from 2-4 degrees C cold water) for 20 min, and finally recorded for 2 hr after a 800-kcal meal. In 18 other subjects, the sequences of vigilance and rest were randomized. The results showed that colonic spiking activity was made of sporadic bursts that are known to be associated with intraluminal propulsion and of stationary bursts that probably play no role in colonic peristalsis. The duration of sporadic spiking activity was respectively 13.6 +/- 1.2 min/hr (mean +/- SEM) during the period of vigilance, 5.4 +/- 0.6 min/hr during the period of rest (P less than 0.001), 14.3 +/- 1.0 min/hr during the period of stress (NS), and 16.8 +/- 1.2 min/hr after a meal (P less than 0.05). The duration of stationary spiking activity did not change significantly throughout the four periods, respectively, 6.6 +/- 4.9, 4.4 +/- 3.7 (NS), 5.2 +/- 3.9 (NS), and 3.3 +/- 2.8 min/hr (NS).(ABSTRACT TRUNCATED AT 250 WORDS)
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Schang JC, Hémond M, Hébert M, Pilote M. Myoelectrical activity and intraluminal flow in human sigmoid colon. Dig Dis Sci 1986; 31:1331-7. [PMID: 3803135 DOI: 10.1007/bf01299811] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Myoelectric spike bursts were recorded in the sigmoid colon by means of an intraluminal silastic tube equipped with 3 Ag-AgCl ring electrodes fixed 15 cm apart on the tube that was introduced by flexible sigmoidoscopy. In six subjects, the tube was also equipped with three catheters whose tip opened 1 cm aborad from each electrode, for pressure recordings. In six other subjects, the tube was equipped with both electrodes and a catheter opening at the tip of the probe for infusing fluids at a rate of 12 ml/min into the colonic lumen. The fluid was collected with another tube inserted in the rectum and the volume was measured at 1-min intervals. Colonic spiking activity was made of rhythmic stationary bursts (RSB) and of sporadic bursts that were either propagating (SPB) or not propagating (SNPB). All sporadic bursts were associated with intraluminal pressure waves whose amplitude was significantly higher than that associated with rhythmic bursts. In the infusion experiments, the volume of fluid collected did not change significantly whether rhythmic bursts were present or not (3.9 +/- 1.7 ml/min and 3.3 +/- 1.9 ml/min respectively) (mean +/- SD). However, the volume was significantly higher when sporadic nonpropagating bursts were present (9.4 +/- 4.1 ml/min), and even higher when the sporadic bursts were propagating (21.6 +/- 8.8 ml/min). These results indicate that the occurrence of sporadic bursts, particularly when propagating, is associated with intraluminal pressure waves that lead to significant propulsive movements; and rhythmic bursts do not seem to be involved in colonic propulsive activity.
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Schang JC, Hémond M, Hébert M, Pilote M. How does morphine work on colonic motility? An electromyographic study in the human left and sigmoid colon. Life Sci 1986; 38:671-6. [PMID: 3951323 DOI: 10.1016/0024-3205(86)90580-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effect of morphine on colonic motility was investigated by recording the colonic myoelectric spiking activity by means of a 50 cm long silastic tube equipped with 4 bipolar AgAgCl ring electrodes fixed at 10 cm intervals that was introduced into the left colon in 8 healthy subjects by flexible sigmoidoscopy. Tracings were obtained for 1 hour in the fasting state and for another 1 hour after i.m. injection of morphine sulphate 0.15 mg/kg. The different types of spike bursts were compared before and after morphine injection. The control tracings showed that the spiking activity of the colon was made of 2 types: 1)- Rhythmic Stationary Spike Bursts (RSB), that were seen at only one electrode site; 2)- Sporadic Bursts, that were either propagating over all 4 electrodes (SPB) or non propagating (SNPB). Injection of morphine was followed by 1)- a considerable increase in the number of RSB from 107 +/- 43 bursts/hour (mean +/- SEM) to 491 +/- 23 bursts/hour; 2)- the complete disappearance of the SPB dropping from 7.3 +/- 2.0 bursts/hour to 0.3 +/- 0.2 bursts/hour; 3)- no significant change in SNPB (from 52 +/- 4 bursts/hour to 57 +/- 5 bursts/hour). These results indicate that 1)- stimulation of colonic smooth muscle activity by morphine seems to result from an increase in the number of rhythmic stationary bursts; 2)- however inhibition of colonic transit may be related to the decrease in the number of sporadic propagating bursts.
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73
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Schang JC, Hémond M, Hébert M, Pilote M. Changes in colonic myoelectric spiking activity during stimulation by bisacodyl. Can J Physiol Pharmacol 1986; 64:39-43. [PMID: 3955442 DOI: 10.1139/y86-005] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The purpose of this study was to determine some relationships between colonic myoelectric spiking activity and intraluminal propulsion when colonic peristalsis was stimulated by bisacodyl. Myoelectric recordings were obtained in 12 subjects by means of a 50 cm long Silastic tube equipped with four bipolar electrodes fixed at 10-cm intervals. The tube was introduced into the left colon by flexible sigmoidoscopy and the electrodes were located at 50, 40, 30, and 20 cm from the anal verge. A small polyethylene catheter opening at the proximal end of the Silastic tube was used for introducing the laxative into the colon. One hour recording sessions were obtained before and after bisacodyl administration (5 mL of 0.4% solution). The control tracings showed that colonic spiking activity was made of rhythmic stationary bursts that occurred at only one electrode site and of sporadic bursts that were either propagating over the whole colonic segment or nonpropagating. Administration of bisacodyl was followed by complete suppression of the rhythmic stationary activity; a considerable increase in the sporadic spiking activity, propagating as well as nonpropagating; the occurrence of abdominal cramps and urgency to defecate, both associated with the propagating sporadic spike bursts. It is concluded that colonic propulsion induced by bisacodyl may be dependent upon the production of the sporadic bursts, particularly the propagating ones, while the rhythmic stationary bursts do not seem to play a significant role in colonic transit.
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Schang JC, Devroede G, Duguay C, Hémond M, Hébert M. [Constipation caused by colonic inertia and distal obstruction: electromyographic study]. GASTROENTEROLOGIE CLINIQUE ET BIOLOGIQUE 1985; 9:480-5. [PMID: 4018482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Colonic motility was evaluated in 15 patients with chronic constipation and 12 healthy subjects by both measuring the transit time of 20 radiopaque markers and recording the colonic myoelectric signals by means of a silastic tube equipped with 4 ring contact electrodes. The tube was introduced by flexible sigmoidoscopy so as the electrodes be located at 50, 40, 30 and 20 cm from the anal verge. Constipation resulted from colonic inertia in 7 patients, the markers being delayed over the whole length of the colon. In the 8 other patients, constipation was due to distal obstruction, the markers accumulating electively in the rectum. The myoelectric tracings showed in the control subjects, on one hand rhythmical stationary spike potentials that occurred at only one electrode site at a mean rate of 10 per minute; on the other hand sporadic (non-rhythmic) spike potentials that were either propagating over the colonic segment (sporadic propagating potentials) or not (sporadic non-propagating potentials). In the constipated patients, the following changes were observed: 1) the number of sporadic propagating potentials was significantly decreased in colonic inertia (2.5 +/- 1.3 bursts of spikes per hour) compared to the controls (8.5 +/- 1.1 bursts/h) or distal obstruction (7.9 +/- 1.3 bursts/h); 2) sporadic propagating potentials usually moved aborally; however, 19.8 +/- 0.9 p. 100 moved orally in colonic obstruction, while 4.6 +/- 0.2 p. 100 in the controls and 4.7 +/- 0.1 p. 100 in colonic inertia.(ABSTRACT TRUNCATED AT 250 WORDS)
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Genest L, Hébert M. [Nutritional evaluation]. L'UNION MEDICALE DU CANADA 1980; 109:522-8. [PMID: 6779408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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76
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Hébert M. The dentist's role in high blood pressure detection. Why dentists. LE JOURNAL DENTAIRE DU QUEBEC 1977; 14:6. [PMID: 265949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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77
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Hébert M. [The shadow of the great Fauchard grows dim]. LE JOURNAL DENTAIRE DU QUEBEC 1976; 13:4. [PMID: 1069744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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78
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Hébert M. [The emergence of a real power by consumers of professional services]. LE JOURNAL DENTAIRE DU QUEBEC 1975; 12:4. [PMID: 1076377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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79
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Hébert M. [Interview with Dr. Paul Mercier. Atrophy of the jaws]. LE JOURNAL DENTAIRE DU QUEBEC 1974; 11:15-6. [PMID: 4529915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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80
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Hébert M. [The work force of dentists in Canada. Comparison between provinces]. LE JOURNAL DENTAIRE DU QUEBEC 1974; 11:4-5. [PMID: 4534995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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81
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Hébert M. [The word of Cambronne]. LE JOURNAL DENTAIRE DU QUEBEC 1973; 10:3. [PMID: 4534988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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82
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Hébert M. Schools must play role in teaching students dental care delivery. LE JOURNAL DENTAIRE DU QUEBEC 1973; 10:4. [PMID: 4534989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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83
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Hébert M. Editorial. LE JOURNAL DENTAIRE DU QUEBEC 1973; 10:4. [PMID: 4534892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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84
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Hébert M. Work simplification in dentistry. THE JOURNAL OF THE DENTAL ASSOCIATION OF SOUTH AFRICA = DIE TYDSKRIF VAN DIE TANDHEELKUNDIGE VERENIGING VAN SUID-AFRIKA 1966; 21:345-52. [PMID: 5225976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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