Validity of sleep nasendoscopy in the investigation of sleep related breathing disorders.

OBJECTIVE: To validate the technique of sleep nasendoscopy using target controlled infusion in symptomatic patients and a control group of asymptomatic individuals. DESIGN: Prospective cohort study. SETTING: Department of otolaryngology-head and neck surgery and anesthesia in a teaching hospital. PARTICIPANTS: Two groups of patients were compared and matched for their body mass index. The first group consisted of 53 patients with a history suggestive of obstructive sleep apnea. The second group consisted of 54 patients with partner-confirmed history of no snoring. These patients were undergoing anesthesia for other reasons. Both groups of patients were free of associated otorhinolaryngologic symptoms. MAIN OUTCOME MEASURE: Assessment of production of snoring or obstruction in patients with no documented history of snoring when sedation was administered as part of general anesthesia using target controlled infusion with propofol. RESULTS AND CONCLUSIONS: None of the patients in the asymptomatic group snored or obstructed at any level of propofol, and this was clearly significant on comparison with the symptomatic group (P < .001). All of the symptomatic patients were induced to become symptomatic (snoring/obstruction).

Regulation of a plant plasma membrane sucrose transporter by phosphorylation.

The protein phosphatase inhibitor okadaic acid (OA) either provided directly to sugar beet (Beta vulgaris L.) leaf discs or infiltrated in the leaf blade rapidly inhibited sucrose uptake. Methyl okadaic acid, a biologically inactive analogue of OA, had only a marginal effect on uptake. OA inhibited proton-motive force-driven uptake of sucrose into plasma membrane vesicles, without affecting their proton permeability. OA did not significantly affect the amount of sucrose transporters present in the vesicles, as estimated by ELISA with specific antibodies. It is concluded that OA directly inhibits the activity of a H+-sucrose cotransporter of the plant plasma membrane, likely by maintaining it in a phosphorylated form.

Effects of Compounds Affecting Calcium Channels on Phytochrome- and Blue Pigment-Mediated Pulvinar Movements of Cassia fasciculata.

Verapamil and nifedipine, known as calcium channel blockers, inhibited the phytochrome-mediated movements induced on Cassia fasciculata leaflets by a light-off signal, whereas they had no effect on the ;blue' pigment-mediated movements induced by a light-on signal. LaCl(3) inhibited both types of reactions, but the inhibition of light-induced opening needed a 10 times higher concentration than that of dark-induced closure. Bay K 8644, an activator of calcium channels, increased the rate of dark-induced closure, whereas it had no effect on the light-induced opening. These data suggest that calcium ions are not mobilized in the same way in the two types of movements: possibly from external stores in the phytochrome-mediated reaction and from internal stores in the ;blue' pigment-mediated reaction.

Redistribution of potassium, chloride and calcium during the gravitropically induced movement of Mimosa pudica pulvinus.

When the leaves of Mimosa pudica are changed from their normal position in the gravitational field, they perform reversible compensatory movements by means of pulvini. These movements are not the result of growth processes but involve reversible turgor variations. These variation are concomitant with ion migrations within pulvini: during the gravitropic movement, K(+) and Cl(-) shift towards the adaxial half of the motor organ whereas Ca(2+) shifts towards the abaxial half. Compounds known to affect K(+) transport, tetraethylammonium chloride and valinomycin, do not hinder the gravitropic movement but inhibit strongly the seismonastic reaction. The same general result is obtained with compounds affecting anion transport, disulfonic stilbenes and 9-anthracene carboxylic acid. Calcium chelators inhibit the gravitropic movement more efficiently than the seismonastic reaction and the calcium ionophore A 23 187 increases both movements. The data obtained with these various compounds indicate that ions do not have the same functional importance in the regulation of the two different pulvinar movements.

Effects of Respiration Inhibitors and Uncouplers on Dark- and Light-Induced Leaflet Movements of Cassia fasciculata.

Respiration inhibitors, in particular KCN and NaN(3), inhibited slightly the dark-induced (scotonasty) as well as the light-induced (photonasty) leaflet movements of Cassia fasciculata: they act only at concentrations higher than 1 millimolar and 0.1 millimolar, respectively. Amytal induced a stronger inhibitory effect on scotonasty. Salicylhydroxamic acid, which inhibits the cyanide-insensitive respiration pathway, was also poorly effective when applied alone. KCN and salicylhydroxamic acid applied together increased the inhibition. Uncouplers of oxidative phosphorylation were very effective: 2,4-dinitrophenol and carbonylcyanide-m-chlorophenylhydrazone inhibited the scotonastic movements at concentrations higher than 10 mum and 1 mum, respectively. Although uncouplers reduced the photonastic movements at higher concentrations, they promoted leaflet opening at other concentrations in an unexpected way.

A visual technique of chemotactic assessment for pharmacological studies.

A visual assay of chemotactic response was performed by measuring the extent of the migration of polymorphonuclear leukocytes (PMN) collected from the rat pleural cavity toward a dying cell. Various types of cells (erythrocytes, PMN, or monocytes) may be destroyed by means of an argon laser, and the process may be visualized under a phase-contrast microscope (necrotactic phenomenon). This experimental model may simulate pathological events that occur in damaged tissues, and it permits the study of cellular migration during inflammatory diseases. This method did not seem to involve chemokinetic effects, but instead represented a true measure of chemotaxis. A numeration of the migrating PMNs at t = 0 and t + 10 min after cell lysis allowed a statistical analysis and the use of this phenomenon for pharmacological studies. The modification of rat PMN chemotaxis by cholera toxin, substance P, and a synthetic muramyl dipeptide are presented as examples of the use of this technique.

Effects of Ethephon, 1-Aminocyclopropane-1-carboxylic Acid, and Inhibitors of Ethylene Synthesis on the Gravitropically Induced Movement of Mimosa pudica Pulvinus.

Primary pulvini of Mimosa pudica L. displaced from their position display gravitropic movements beginning about 15 minutes after their reorientation. Ethephon, an ethylene-releasing compound, and 1-aminocyclopropane-1-carboxylic acid, an intermediate in ethylene biosynthesis, enhance these movements at a concentration as low as 10 nanomolar. Inhibitors of ethylene synthesis (l-alpha-(2-aminoethoxyvinyl)glycine, (aminooxy)acetic acid, and Co(2+)) reduce the amplitude of the movements. The promotive action of 1-aminocyclopropane-1-carboxylic acid is abolished by l-alpha-(2-aminoethoxyvinyl)glycine. These results permit one to conclude that ethylene may modify the curvature movement but not the initiation of the gravitropic reaction. With reference to the pulvinus functioning based on turgor variations and ion migrations inside the organ, namely K(+) acting as the osmoticum, the data suggest that ethylene may act by increasing the membrane permeability to water and/or by altering an ion pump.

Effects of Salicylic and Acetylsalicylic Acids on the Scotonastic and Photonastic Leaflet Movements of Cassia fasciculata.

Salicylic and acetylsalicylic acids applied on excised leaves of Cassia fasciculata modify the dark-induced (scotonastic) and light-induced (photonastic) leaflet movements. They inhibit the scotonastic movements in a dose-dependent manner from 1 x 10(-4) to 1 x 10(-3) molar and they promote the photonastic movements at an optimum concentration of 5 x 10(-4) molar. These results suggest that these phenolic compounds do not act specifically on the K(+) uptake, which was shown to be inhibited by their action on other materials.

Effects of glycine on dark-and ligh-induced pulvinar movements and modifications of proton fluxes in the pulvinus of Mimosa pudica during glycine uptake.

Glycine (1-50 mM) increases the rate of the dark-induced (scotonastic) movements and decreases the amplitude and the rate of the light-induced (photonastic) movements of the secondary pulvini of Mimosa pudica leaves. The uptake of glycine is accompanied by a long-lasting dose-dependent increase in the alkalinity of the bathing medium of the excised pulvini. The data are in agreement with a H(+)-glycine co-transport mechanism within the pulvinar cells. Fusicoccin (50 µM), known to promote H(+)-K(+) exchange, antagonizes the effects of glycine on the movements and the alkalization of the bathing medium of the excised pulvini. The present results argue for the hypothesis that proton fluxes mediate the scotonastic and photonastic pulvinar movements.

Effects of prostaglandins E, precursors and some inhibitors of prostaglandin biosynthesis on dark- and light-induced leaflet movements in Cassia fasciculata Michx.

Prostaglandin E1 and prostaglandin E2 speed up the dark-induced (scotonastic) and light-induced (photonastic) leaflet movements of Cassia fasciculata. The precursors of prostaglandin biosynthesis, homo γ-linolenic and arachidonic acids, and an intermediary product, prostaglandin-interm-5, act in the same manner on these movements. Inhibitors of prostaglandin biosynthesis, indomethacin and phenylbutazone, inhibited the scotonastic but promoted the photonastic movements in an unexpected way. Since the pulvinar movements are mediated by water and ion migrations, the observed modifications of these movements indicate that prostaglandins and their precursors may affect, as in animal cells, processes linked to a variation of membrane permeability.

Méthode de traitement des intérferogrammes à deux ondes pour accroître leur sensibilité.

Two-beam interference fringes are not always able to give sufficient information to determine the topography of very weakly deformed wave surfaces. The process described allows us to intercalate several intermediate levels, which vary linearly in terms of the phase, between the brightness extrema of a fringe. The interference pattern is submitted to an optoelectronics treatment where the photoelectric signal is compared with an adjustable electric reference signal.

Restoration of the complex amplitude of a phase object in microscopy by phase modulation interferometry.

Observations of phase objects with a microscope generally involve interferometric methods. However, visual or photometric analysis of the interferogram interprets in the same way the information corresponding to the advance and retardation of the wave front transmitted or reflected by an object. Hence, no information about the direction of relief of the object is obtained. An experimental process is described here that is capable of restoring both sign and magnitude of the phase throughout the field. This method, based on modulation interferometry using a microscope and a scanning device, provides the user with different information about the object, such as a display of an intensity image of the interference pattern and its photometric analysis as well as the equal phase contours inside the scanned area, a display of the complex amplitude components and-extending the use of the instrument to the phase measurement technique to complete the data-measurement of the phase for an array of points in the object area.