Combined intra-operative monitoring of hearing by means of auditory brainstem responses (ABR) and transtympanic electrocochleography (ECochG) during surgery of intra- and extrameatal acoustic neurinomas.

Background: Although being established as a standard procedure in intra-operative monitoring in acoustic neurinoma surgery, auditory brainstem responses (ABR) represent a far-field technique bearing some technical limitations. This prospective study was designed to evaluate electrocochleography (ECochG) as a supplementary tool for hearing preservation.

Method: 84 patients with unilateral intra-/extrameatal acoustic neurinomas (extrameatal diameter: 5-55 mm) preserving serviceable hearing, were operated on using a combined (neuro-/otosurgical) suboccipital approach.

[Diagnosis, treatment and results of malignant skull base tumours].

Background: Malignant tumours of the cranial base are rare and present usually in advanced tumour stage due to the lack of early clinical symptoms.

Patients And Methods: Sixty patients with malignant tumours infiltrating the skull base were treated at the Department of Otorhinolaryngology Head and Neck Surgery, University of Würzburg between 1987 and 1999. Most of the tumours (n = 51) originated from the nose or paranasal sinuses, the epipharynx, the outer ear canal or the middle ear.

Local retinoid signaling coordinates forebrain and facial morphogenesis by maintaining FGF8 and SHH.

Correlations between facial anomalies and brain defects are well characterized throughout the clinical literature, yet a developmental basis for this association has not been identified. We demonstrate that the frontonasal process, which gives rise to the mid- and upper face, and the forebrain are linked early in their morphogenesis by a local retinoid signaling event that maintains the expression of key regulatory molecules. First, we show that aldehyde dehydrogenase 6, which synthesizes the ligand, retinoic acid, is localized to the ventral epithelium of the presumptive frontonasal process of chick embryos.

Intra-operative electromyographic monitoring of the lower cranial motor nerves (LCN IX-XII) in skull base surgery.

The functional preservation of lower (motor) cranial nerves (LCN) is endangered during skull base surgery. Intra-operative EMG monitoring of the LCN IX-XII was investigated in 78 patients undergoing 80 operations on various skull base tumors with regard to technical feasibility and clinical efficacy. Ongoing 'spontaneous muscle activity' (SMA) and 'compound muscle action potentials' (CMAP) following supramaximal bipolar stimulation were intra-operatively recorded applying needle electrodes into the soft palate (CN IX: n=76), the vocal cord (CN X: n=72), the trapezius muscle (CN XI: n=18), and the tongue (CN XII: n=71).

Racial identity and reflected appraisals as influences on Asian Americans' racial adjustment.

J. E. Helms's (1990) racial identity psychodiagnostic model was used to examine the contribution of racial identity schemas and reflected appraisals to the development of healthy racial adjustment of Asian American university students (N = 188).

[Detection of loudness recruitment in patients with retrocochlear lesions using the "Würzburger Hörfeld" loudness scaling].

Background: The pathogenesis of hearing loss caused by cerebellopontine angle tumors such as acoustic neuromas is unknown. The lack of loudness recruitment is thought to be one of the features of retrocochlear hearing impairment. In contrast to conventional suprathreshold tests, the categorial loudness scaling using the "Würzburger Hörfeld" is a valuable tool to describe the individual perception of sound.

Sphingomyelin-enriched microdomains at the Golgi complex.

Sphingomyelin- and cholesterol-enriched microdomains can be isolated as detergent-resistant membranes from total cell extracts (total-DRM). It is generally believed that this total-DRM represents microdomains of the plasma membrane. Here we describe the purification and detailed characterization of microdomains from Golgi membranes.

Molecular aspects of healing in stabilized and non-stabilized fractures.

Bone formation is a continuous process that is initiated during fetal development and persists in adults in the form of bone regeneration and remodeling. These latter two aspects of bone formation are clearly influenced by the mechanical environment. In this study we tested the hypothesis that alterations in the mechanical environment regulate the program of mesenchymal cell differentiation, and thus the formation of a cartilage or bony callus, at the site of injury.

Organ culture of craniofacial primordia.

Organ culture systems have proven extremely useful techniques in studies that investigate the process of normal and abnormal development. The explant of tissues into an organ culture system is one of the few techniques that maintains three-dimensional cellular interactions under conditions that simultaneously permit controlled experimental manipulation in vitro. In this article we outline a procedure for growing "faces" in culture.

Comparison of the TEMPO+ ear-level speech processor and the cis pro+ body-worn processor in adult MED-EL cochlear implant users.

A study was conducted to compare the new MED-EL TEMPO+ ear-level speech processor with the CIS PRO+ body-worn processor in the COMBI 40/COMBI 40+ implant system. Speech tests were performed in 46 experienced subjects in two test sessions approximately 4 weeks apart. Subjects were switched over from the CIS PRO+ to the TEMPO+ in the first session and used only the TEMPO+ in the time between the two sessions.

A molecular analysis of matrix remodeling and angiogenesis during long bone development.

The replacement of cartilage by bone is the net result of genetic programs that control chondrocyte differentiation, matrix degradation, and bone formation. Disruptions in the rate, timing, or duration of chondrocyte proliferation and differentiation result in shortened, misshapen skeletal elements. In the majority of these skeletal disruptions, vascular invasion of the elements is also perturbed.

Evidence for segregation of sphingomyelin and cholesterol during formation of COPI-coated vesicles.

In higher eukaryotes, phospholipid and cholesterol synthesis occurs mainly in the endoplasmic reticulum, whereas sphingomyelin and higher glycosphingolipids are synthesized in the Golgi apparatus. Lipids like cholesterol and sphingomyelin are gradually enriched along the secretory pathway, with their highest concentration at the plasma membrane. How a cell succeeds in maintaining organelle-specific lipid compositions, despite a steady flow of incoming and outgoing transport carriers along the secretory pathway, is not yet clear.

Genetic and teratogenic approaches to craniofacial development.

Craniofacial malformations are the most common birth defects that occur in humans, with facial clefting representing the majority of these defects. Facial clefts can arise at any stage of development due to perturbations that alter the extracellular matrix as well as affect the patterning, migration, proliferation, and differentiation of cells. In this review, we focus on recent advances in the understanding of the developmental basis for facial clefting through the analysis of the effects of gene disruption experiments and treatments with teratogens in both chickens and mice.

["Vibrant Soundbridge" middle ear implant for auditory rehabilitation in sensory hearing loss. I. Clinical aspects, indications and initial results].

Background: The adequate therapy for patients suffering from a sensory hearing loss consists of fitting electronic hearing devices. Conventional hearing aids, however, present with significant inherent drawbacks such as insufficient amplification in the high frequency range, problems with the ear mold (feed back, occlusion, external otitis), or distortion of sound with an "unnatural" hearing impression.

Methods: The partially implantable middle ear device Vibrant Soundbridge provides a sound wave conversion into mechanical vibrations at the middle ear ossicles using the Floating Mass Transducer (FMT).

Mutations of PVRL1, encoding a cell-cell adhesion molecule/herpesvirus receptor, in cleft lip/palate-ectodermal dysplasia.

Cleft lip, with or without cleft palate (CL/P), is one of the most common birth defects, occurring in 0.4 to 2.0 per 1,000 infants born alive.

[Inner ear depression after middle ear interventions].

Background: Any type of otosurgical procedure involves the risk of inner ear damage. As middle ear surgery is also performed for functional reasons this risk should be taken into consideration. The aim of this study was to analyse the frequency and the nature of sensorineural hearing loss following chronic ear surgery.

Acoustic neuroma surgery as an interdisciplinary approach: a neurosurgical series of 508 patients.

Objectives: To evaluate an interdisciplinary concept (neurosurgery/ear, nose, and throat (ENT)) of treating acoustic neuromas with extrameatal extension via the retromastoidal approach. To analyse whether monitoring both facial nerve EMG and BAEP improved the functional outcome in acoustic neuroma surgery.

Methods: In a series of 508 patients consecutively operated on over a period of 7 years, functional outcome of the facial nerve was evaluated according to the House/Brackmann scale and hearing preservation was classified using the Gardner/Robertson system.

Quantitative parameters of intraoperative electromyography predict facial nerve outcomes for vestibular schwannoma surgery.

Objective: Facial nerve monitoring is an established method that is routinely used during cerebellopontine angle tumor surgery. The aim of this study was to determine quantitative electromyographic (EMG) parameters that were predictive of facial nerve outcomes.

Methods: In 137 patients with intra-/extrameatal vestibular schwannomas, the most proximal (the exit from the brainstem) and distal (the fundus of the internal auditory canal) parts of the facial nerve were stimulated after total tumor removal.

[Universal hearing screening of newborn infants with the BERA-phone].

Background: Unidentified and untreated early infant hearing loss leads to speech-language deficits as well as to cognitive, intellectual, emotional and psychosocial handicaps. Targeted hearing screening programs may miss approximately 50% of all hearing impaired children.

Methods: In an universal hearing screening program with a two stage protocol, 1349 newborns were examined using the CRESCENDO Newborn Hearing Screener according to Finkenzeller and a clinical ABR system operating with a time course step stimulus algorithm.