Simultaneous exposure to ethyl benzene and noise: Synergistic effects on outer hair cells

The effects on hearing of simultaneous exposure to the ototoxic organic solvent ethyl benzene and broad-band noise were evaluated in rats. The effects of three ethyl benzene concentrations (0, 300 or 400 ppm) and three noise levels (95 or 105 dBlin SPL or background noise at 65 dBlin SPL) and all their combinations were investigated for a 5 day...

Ethyl benzene-induced ototoxicity in rats: A dose-dependent mild-frequency hearing loss

Rats were exposed to ethyl benzene at 0, 300, 400 and 550 ppm for 8 hours/day for 5 consecutive days. Three to six weeks after the exposure, auditory function was tested by measuring compound action potentials (CAP) in the frequency range of 1-24 kHz and 2f1-f2 distortion product otoacoustic emissions (DPOAEs) in the frequency range of 4-22.6...

An analysis of the possibility for health implications of joint actions and interactions between food additives

The possibility that structurally unrelated food additives could show either joint actions or interactions has been assessed based on their potential to share common sites and mechanisms of action or common pathways of elimination. All food additives approved in the European Union and allocated numerical acceptable daily intake values were...

The bovine protein -lactalbumin increases the plasma ratio of tryptophan to the other large neutral amino acids and in vulnerable subjects raises brain serotonin activity reduces cortisol concentration and improves mood under stress

Background: Increased brain serotonin may improve the ability to cope with stress, whereas a decline in serotonin activity is involved in depressive mood. The uptake of the serotonin precursor, tryptophan, into the brain is dependent on nutrients that influence the cerebral availability of tryptophan via a change in the ratio of plasma...

Anion channels in Chara corallina tonoplast membrane: Calcium dependence and rectification

Tonoplast K+ channels of Chara corallina are well characterized but only a few reports mention anion channels, which are likely to play an important role in the tonoplast action potential and osmoregulation of this plant. For experiments internodal cells were isolated. Cytoplasmic droplets were formed in an iso-osmotic bath solution according to...

Stochastic modelling of extreme action events in structural engineering

The design for extreme actions, like impact and explosions, should ideally be based on advanced mechanics in combination with risk analysis and decision making principles. In present practice, however, the design for these important actions is often very simple and quite unsatisfactory. For instance, in the case of truck or ship impact loading...

Effect of oral contraceptives on haemostasis variables

Combined oral contraceptives (COCs) have effects on a large number of haemostasis variables. We have summarised literature data on effects of COCs containing 30-35 μg ethinyl estradiol for the third generation of progestogens (PGs): desogestrel, gestodene and norgestimate. It is concluded that about 15 variables show a shift in distribution of...

Lack of interaction between orlistat and oral contraceptives

Objectives: Orlistat, a potent and selective inhibitor of gastrointestinal lipases, is designed for the treatment of obesity. A double-blind, randomised, placebo-controlled, 2-way crossover study investigated the possible influence of orlistat on the ovulation-suppressing action of combination oral contraceptives (OC). Methods: After an 8-day...

Insulin suppresses bile acid synthesis in cultured rat hepatocytes by down-regulation of cholesterol 7α-hydroxylase and sterol 27-hydroxylase gene transcription

Evidence from in vivo studies indicates that the bile acid pool and bile acid excretion are increased in humans with diabetes mellitus and in experimental diabetic animals, and that both parameters return to normal levels after administration of insulin. To investigate the biochemical background of these changes, the effects of insulin on bile...

Improved color fundamentals offer a new view on photometric additivity

New action spectra are derived for the foveal cones on the basis of three assumptions: (1) the Stiles-Burch (1959) colorimetric data are better than CIE 1931; (2) the long wavelength flanks of the dichromatic luminosity functions offer better anchorage than the confusion loci; and (3) the relative mutual heights per receptor can be derived from...

The absorption of a new sustained release furazolidone formulation from the digestive tract of piglets and calves.

Chyme concentrations and total recoveries of furazolidone (5 mg/kg body-weight) were determined by a HPLC-method, after oral administration of two different furazolidone formulations to piglets (n = 6) and pre-ruminant calves (n = 8), provided with an ileal re-entrant canula. Additional blood samples were taken from the calves to measure the...

Effects of acute noise traumata on whole-nerve and single-unit activity

Some preliminary results of a research program on the effects of noise traumata on cochlear functioning are given. Measurements reported here include: the latency of the whole-nerve (compound) action potential (AP), the selectivity of frequency-tuning curves (e.g., the Q10-values) measured for the AP (with a forward-masking technique) and for...