ATP activates non-selective cation channels and calcium release in inner hair cells of the guinea-pig cochlea.

1. ATP-evoked currents and Ca2+ signals were simultaneously recorded in isolated inner hair cells (IHC) of guinea-pig cochlea by combining conventional whole-cell or perforated patch clamp recording with indo-1 dual emission microfluorometry. 2.

Weighing contaminant risks and nutrient benefits of country food in Nunavik.

In view of the levels of human exposure to priority contaminants assessed in previous surveys in Nunavik, a series of risk reduction scenarios were produced to modelize the effects of different potential health advisories on limiting exposure of women of reproductive age to these contaminants, as well as on maximizing nutritional benefits derived from the consumption of country food. This paper presents part of the results, in particular as regards effects of reducing PCB intake by 46%, 65% and 86%.

Direct measurements of Ca(2+)-activated K+ currents in inner hair cells of the guinea-pig cochlea using photolabile Ca2+ chelators.

Intracellular photorelease of Ca2+ from caged Ca2+ (DM-nitrophen or nitr5) and the patch-clamp technique in the whole-cell configuration were used to investigate Ca(2+)-activated currents in inner hair cells (IHCs) of the mammalian cochlea. Photoliberation of intracellular Ca2+ activated outward currents with a mean amplitude of 260 +/- 110 pA when IHCs were voltage-clamped, near the resting membrane potential, at -50 mV. The photoactivated currents were reversibly blocked by extracellular application of tetraethylammonium (TEA, 10 mM), neomycin (1 mM) and charybdotoxin (1 microM), but not by apamin.

Photo-released intracellular Ca2+ evokes reversible mechanical responses in supporting cells of the guinea-pig organ of Corti.

Loaded under whole cell patch-clamp configuration, the caged Ca2+ molecule DM-nitrophen was used to increase [Ca2+]i rapidly and reversibly in isolated Deiters cells of the organ of Corti. Photolysis of DM-nitrophen increased [Ca2+]i from resting concentrations of 20-50 nM to values above microM, as measured with the fluorescent indicator Fluo-3. Immediately after the photoliberation of Ca2+, a movement of the head of the phalangeal process could be observed in 75% of cells (n = 28).

Mammalian cochlear outer hair cells density evaluated by means of an optical tweezer.

We report on the first individual measurements of guinea pig's cochlear outer hair cells densities. Cells were isolated in vitro and manipulated with an optical tweezer. They were levitated in an upward laser beam coaxially trapping the cells.

A randomized EORTC study on the effect of preoperative polychemotherapy in pyriform sinus carcinoma treated by pharyngolaryngectomy and irradiation. Results from 5 to 10 years.

226 patients with an operable epidermoid carcinoma of the pyriform sinus were entered in this clinical trial; 187 cases were considered evaluable, they were distributed as follows: 16 T2, 171 T3, 44 N0, 103 N1 and 40 N3 (UICC TNM Classification 1979). The 89 patients of the chemotherapy group received a 3 day course of Vincristine (1.5 mg/m2), Bleomycin (15 mg), Methotrexate (80 mg).

Histogenesis at the level of the basal forebrain: the entopeduncular nucleus.

This study shows that the neurons of the entopeduncular nucleus are derived from a longitudinal slab of isochronically generated neurons on day 11 and 15 h of gestation. Many neurons of this longitudinal slab which we have named the basal forebrain cell column, originate from an ependymal matrix closely associated with the ventral diencephalic sulcus and later become associated with the basal forebrain bundle. Other neurons also originate from the ependymal matrix at the site of emergence of the optic recess and keep close relationships with the optic chiasma through the following stages of development to form the retrochiasmatic nucleus.