Determining fitting ranges of various bone conduction hearing aids.

Objectives: To define fitting ranges for nine bone conduction devices (BCDs) over different frequencies based on the device's maximum power output (MPO) and to validate the assessment of MPO of BCDs in the ear canal.

Background: Maximum power output (MPO) is an important characteristic when fitting BCDs. It is the highest output level a device can deliver and is one of the major determinants of a device's fitting range.

Intraoperative auditory steady state response measurements during Vibrant Soundbridge middle ear implantation in patients with mixed hearing loss: preliminary results.

Objective: To optimize intraoperatively the coupling of the floating mass transducer (FMT) of the Vibrant Soundbridge middle ear implant to the round or oval cochlear window in patients with mixed hearing loss.

Study Design: Intraoperative measurement of objective hearing thresholds using auditory steady state responses (ASSRs).

Setting: Radboud University Nijmegen Medical Centre, tertiary referral hospital.

Gain and maximum output of two electromagnetic middle ear implants: are real ear measurements helpful?

We compared the output of two electronic middle ear implants: the Otologics MET device and the Vibrant Soundbridge device. Both devices were programmed in the linear amplification mode. Aided minus unaided sound pressure levels recorded in the ear canal (objective gain) were compared to unaided minus aided soundfield thresholds (functional gain) in 13 patients with severe sensorineural hearing loss.

Therapeutic drug monitoring.

The cytochrome P450 iso-enzyme system plays a key role in the biotransformation of many drugs, including psychotropics. Its activity is determined by both genetic and environmental factors. The most important iso-enzymes for psychiatry in general are P450 IID6, 3A4 and 1A2.

Het cytochroom P450 enzymsysteem: wat is de relevantie voor de praktijk? Deel II, interacties.

In man a great interindividual variability exists in the oxidative capacity to metabolize drugs. A major factor contributing to this phenomenon is the genetically determined hydroxyla-tion-capacity of the cytochrome P450 enzyme system. The cytochrome P450 system comprises of several isozymes.

Effects of alprazolam and lorazepam on catecholaminergic and cardiovascular activity during supine rest, mental load and orthostatic challenge.

Effects of oral alprazolam (0.5 and 1 mg) and lorazepam (2 mg) on sympathetic adrenomedullary activity and sedation were studied during supine rest, mental load (Color Word Test, CWT) and active standing (OCT), in 12 male volunteers in a randomized double-blind placebo-controlled cross-over design. Compared to placebo, alprazolam significantly increased subjective sedation, reduced plasma adrenaline and noradrenaline concentrations and mean blood pressure (MBP) during supine rest, and attenuated plasma adrenaline responses during the CWT and the OCT; these effects during the CWT and OCT appeared to be dose-dependent.

Pharmacological treatment strategies in mood, panic and obsessive compulsive disorders.

Since the introduction of the monoamine oxydase inhibitors and the first tricyclic antidepressant (TCA) imipramine in the late fifties, the treatment of depressive disorders has been changed dramatically. Althought a great variety of antidepressants such as TCA's, selective serotoninte-re-uptake inhibitors (SSRI's) mianserin, trazodone, mirtazapine, moclobemide and venlafaxine has become available, the exact mode of action is not revealed as yet, and classification should be done according to the interference of antidepressants with central monoaminergic processes. As to the potential of causing interactions, special attention has to be given to the SSRI's because of their interference with the CYP450 isozyme system.

Auditory abnormalities, including 'precocious presbyacusis', in myotonic dystrophy.

Auditory function tests were performed on 13 patients with myotonic dystrophy (MD). Seven patients had a sensorineural high-frequency hearing loss (HFL) of 30-85 dB at 8 kHz in their pure-tone audiogram, which was in excess of that expected for their age and could be attributed to MD. Their hearing loss resembled 'precocious presbyacusis', i.

Eighth cranial nerve dysfunction in hyperostosis cranialis interna.

Hyperostosis cranialis interna is a recently described autosomal dominant bone disorder characterised by hyperostosis and osteosclerosis confined to the skull, especially the calvarium and the skull base. In the affected family members, we found variable simultaneous involvement of cranial nerves I, II, VII and VIII from late childhood onwards, most likely due to nerve entrapment. Auditory and vestibular functions were followed in 3 young family members for 8 years.

Differential premature termination of transcription as a proposed mechanism for the regulation of coronavirus gene expression.

We propose that the different subgenomic mRNA levels of coronaviruses are controlled through differential premature termination of transcription, and are modulated by the relative strength of transcriptional initiation/blockage events. We present the complete set of sequences covering the leader encoding and intergenic regions of the MHV-A59 strain. A computer-assisted analysis of the two now complete sets of these sequences of strain IBV-M42 and MHV-A59 shows that, in contrast to the previous theory, differences amongst stabilities of intermolecular base-pairings between the leader and the intergenic regions are not sufficient to determine the mRNA gradients in both MHV and IBV infected cells.