Sylviane Sapir

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OBJECTIVES To assess long term (24 months) effects of the Lee Silverman voice treatment (LSVT), a method designed to improve vocal function in patients with Parkinson's disease. METHODS Thirty three patients with idiopathic Parkinson's disease were stratified and randomly assigned to two treatment groups. One group received the LSVT, which emphasises high(More)
Cyclic di-GMP (c-di-GMP) is the specific nucleotide regulator of beta-1,4-glucan (cellulose) synthase in Acetobacter xylinum. The enzymes controlling turnover of c-di-GMP are diguanylate cyclase (DGC), which catalyzes its formation, and phosphodiesterase A (PDEA), which catalyzes its degradation. Following biochemical purification of DGC and PDEA, genes(More)
This study assessed the impact of the Lee Silverman Voice Treatment (LSVT) on vocal loudness [sound pressure level (SPL)] in a group of dysarthric individuals with idiopathic Parkinson's disease (IPD). Pre- to post-treatment changes in SPL in the treated group were compared with changes in voice SPL during the same time in two control groups: individuals(More)
This study examined the effect of aging on respiratory and laryngeal mechanisms involved in vocal loudness control. Simultaneous measures of subglottal pressure and electromyographic (EMG) activity from the thyroarytenoid (TA), lateral cricoarytenoid (LCA), and cricothyroid (CT) muscles were investigated in young and old individuals while they attempted to(More)
Nineteen healthy young adult males with normal voice and speech attempted to sustain the vowel /u/ at a constant pitch (target: 180 Hz) and a constant and comfortable loudness level while receiving a sudden mechanical perturbation to the larynx (thyroid prominence) via a servo-controlled probe. The probe moved toward or away from the larynx in a(More)
A protein which specifically binds cyclic diguanylic acid (c-di-GMP), the reversible allosteric activator of the membrane-bound cellulose synthase system of Acetobacter xylinum, has been identified in membrane preparations of this organism. c-di-GMP binding is of high affinity (KD 20 nM), saturable and reversible. The equilibrium of the reaction is markedly(More)
In spite of various claims for the presence and functional significance of brainstem reflexes in phonatory control, very little is known about these reflexes in humans. The present study was aimed at studying auditory-laryngeal reflexes in human subjects during sustained phonation. Fourteen subjects sustained phonation at constant voice pitch and voice(More)
Vocalizations were elicited in three anesthetized rhesus macaques by electrical stimulation of a site in the brain stem. At the same, the laryngeal muscles--cricothyroid (CT), geniohyoid (GH) and sternothyroid (ST)--were electrically stimulated to assess their effect on the elicited phonation. Analysis of the recorded vocalizations indicated that(More)
The objective of this investigation was to describe the electrophysiological properties of short-latency reflexive pathways existing between the auditory system and the motoneurons involved in the control of lower lip movements for speech. The general procedure involved binaural presentation of auditory clicks (60--75 dB SL) at constant rates while subjects(More)