PubMed Health⌕ Search

Biomedical subjects

A Larouche

Publications and source records attributed to A Larouche.

9 recordsLinked to original sources
PubMed2006

Spontaneous recovery of hindlimb movement in completely spinal cord transected mice: a comparison of assessment methods and conditions.

STUDY DESIGN: To compare results obtained with a variety of locomotor rating scales in Th9/10 spinal cord transected (Tx) mice. OBJECTIVES: To assess spontaneous recovery with a variety of rating scales to find the most sensitive methods for assessing recovery levels in Tx mice and differences associated with gender and condition. SETTING: Laval University Medical Center, Neuroscience Unit & Laval University, Department of Anatomy and Physiology, Quebec City, Quebec, Canada. METHODS: Scales including the Basso, Beattie and Bresnahan (BBB), the Basso Mouse Score (BMS), the Antri, Orsal and Barthe (AOB), the Motor Function Score (MFS) and the Averaged Combined Score (ACOS) were used to assess, in open-field and treadmill conditions, spontaneous locomotor recovery in male and female Tx mice. RESULTS: The ACOS scale revealed a progressive increase of spontaneous recovery during 5-weeks post-Tx. The other methods detected a progressive increase for the first 2-3 weeks post-Tx without any significant progress in weeks 4 and 5. Generally, scores obtained with each method were nonsignificantly different between males and females or between open-field and treadmill conditions. CONCLUSION: These results further confirm the existence of a limited but significant increase of locomotor function recovery, occurring without intervention, in Tx animals. Although each method could detect small levels of recovery, the ACOS method was discriminative enough to detect progressive changes up to 5 weeks post-Tx. In conclusion, the ACOS rating scale was the most discriminative method for assessing the spontaneous return of hindlimb movements found in Tx mice, both in open-field and treadmill conditions.

Animals↗
PubMed1993

Anticipatory co-articulation in the speech of young normal and hearing-impaired French Canadians.

The anticipatory co-articulation in the speech of a group of 10 normal young French Canadians (5 boys, 5 girls) was compared to that found in age-matched groups of 10 moderately hearing-impaired and 10 profoundly hearing-impaired French Canadians. The speech stimuli were the syllables /ti/, /tu/, /ki/, and /ku/, elicited five times each in random order. Acoustic evidence (F2 and centroid frequency measures) of co-articulation was found for all groups; however, the degree of co-articulation was smaller and less consistent across consonants for the two hearing-impaired groups. In particular, the moderately hearing-impaired subjects exhibited a reversal of the expected pattern for [ki] and [ku] stimuli; the profoundly hearing-impaired subjects did not produce sufficient [ki] and [ku] stimuli to measure co-articulatory effects reliably. In general, the profoundly hearing-impaired subjects exhibited the smallest acoustic changes as a result of the vocalic influence on the preceding consonant. Results are considered in relation to theories of speech production deficits in hearing-impaired speakers.

Child↗
PubMed1992

Acoustic integrity of speech production in children with moderate and severe hearing impairment.

Ten normally hearing and 10 age-matched subjects with moderate-to-severe hearing impairment were recorded producing a protocol of 18 basic syllables [/pi/,/pa/,/pu/;/bi/,/ba/,/bu/; /ti/,/ta/,/tu/ ;/di/,/da/,/du/; /ki/,/ka/,/ku/; /gi/,/ga/,/gu/] repeated five times. The resulting 90 syllables were digitized and measured for (a) total duration; (b) voice-onset time (VOT) of the initial consonant; (c) fundamental frequency (F0) at midpoint of vowel; and (d) formant frequencies (F1, F2, F3), also measured at midpoint of vowel. Statistical comparisons were conducted on (a) average values for each syllable, and (b) standard deviations. Although there were numerical differences between normally hearing and hearing-impaired groups, few differences were statistically significant.

Belgium↗
PubMed1980

[Recurrent nasal polyposis and vidian neurectomy - preliminary report].

A short anatomical and physiological review of the vidian nerve is presented. The authors have described the surgical technique they use which is somewhat similar to the one described by Nomura. Eight cases are presented which had been unsuccessfully treated by multiple radical nasal polypectomies. The results are comparable to those published in the literature and it appears that vidian neurectomy has merit in the treatment of recurrent nasal polyposis but must be used in association with radical polypectomy.

Denervation↗
PubMed1979

Aminoglycoside antibiotic measurement by bioluminescence, with use of plasmid-coded enzymes.

We describe a bioluminescent assay for gentamicin in serum that is applicable to the measurement of other aminoglycosides as well. The assay is based on the measurement of residual ATP with the luciferase reaction after incubation of the antibiotic with a plasmid-coded enzyme. Two aminoglycoside-inactivating enzymes were used: an adenylytransferase and an acetyltransferase coupled to S-acetyl coenzymeA synthetase. We investigated the latter system further because of the good stability of the acetyltransferase, its recovery in high yield from bacteria, and its more favorable ATP/gentamicin mass ratio. Serum ATPases were inactivated at 60 degrees C for 20 min. The operating range of the assay was 0-15 mg of gentamicin per liter. The precision (CV) was 10.1% at a concentration of 2 mg/L and 1.1% at 10 mg/L. The method correlated well with a radio-enzymatic assay for mock unknown sera (r = 0.981). The results were available within 2 h.

Acetate-CoA Ligase↗
PubMedDate not supplied

Neuronal injuries induced by perinatal hypoxic-ischemic insults are potentiated by prenatal exposure to lipopolysaccharide: animal model for perinatally acquired encephalopathy.

We developed an original rat model for neonatal brain lesions whereby we explored the sequential effects of infectious and hypoxic-ischemic aggressions. We investigated the influence of combined exposure to prenatal infection with neonatal hypoxic-ischemic insult. Infectious effect was produced by administrating lipopolysaccharide (LPS) intraperitoneally to pregnant rats starting on embryonic day 17. Hypoxia-ischemia (H/I) was induced in the pups at postnatal day 1 (P1) by ligature of the right common carotid artery followed by exposure to hypoxia (8% O(2)) for 3.5 h. Animals were randomized into four groups: (1) control group: pups born to mothers subjected to intraperitoneal saline injection; (2) LPS group: pups exposed in utero to LPS; (3) H/I group: pups exposed to postnatal hypoxia after ligation of the right carotid artery, and (4) H/I plus LPS group: in utero exposure to LPS followed by postnatal hypoxia after ligation of the right carotid artery. Neuropathological findings in pups examined at P3 and P8 showed that groups 2, 3, and 4 presented a pattern of neuronal injury similar to those characterized as 'selective neuronal necrosis' within the context of human perinatal encephalopathy. Neuronal cellular injuries were particularly seen in the neocortex, mainly in parasagittal areas. The extent of neuronal cell injury in the brain of rats exposed to postnatal H/I was significantly increased by antenatal exposure to LPS. This animal model provides an experimental means to explore the respective roles of anoxic and infectious components in the pathogenesis of perinatal brain lesions and consequent cerebral palsy.

Animals↗