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Biomedical subjects

W Arnold

Publications and source records attributed to W Arnold.

At least 595 records · Page 33Linked to original sources
PubMedDate not supplied

Human leukocyte antigens in patients with inner ear diseases of unknown etiology.

The immune response genes that control the immune response and recognition of 'self' from 'nonself' are closely linked with the human leukocyte antigen (HLA) complex. Sixty-six HLA antigens were typed in 42 Caucasian patients with inner ear diseases of unknown etiology. All of these patients had positive serum antibodies against the inner ear structures as detected by an indirect immunofluorescence assay. Results revealed that none of the 66 HLA antigens was associated with the inner ear diseases. Reviewing results from other studies on HLA association in inner ear diseases shows that the findings are inconsistent with each other. The conclusion that HLA associations occur with inner ear diseases cannot be reached.

Adult↗
PubMedDate not supplied

Evidence of measles virus RNA in otosclerotic tissue.

By use of the very sensitive polymerase chain reaction technique, evidence is given that otosclerosis is a measles-virus-associated disease of the otic capsule. These results support recent observations which demonstrated the expression of measles antigen within active otosclerotic foci by immunohistochemical methods. Thus it is hypothesized that the viral infection acts as at least one pathogenetic factor during the development of this obscure, locally restricted inflammatory bone disease.

Blotting, Southern↗
PubMedDate not supplied

Role of adhesion molecules for the immunological defense of the inner ear.

Previous experiments demonstrated an organ-specific migration of sensitized lymphocytes to the inner ear and enabled us to establish an animal model for an autoimmunological labyrinthitis in the guinea pig. For a nonrandom emigration from capillaries into tissues of their immunological destination, memory lymphocytes need homing receptors on their cell surface to interact with specialized postcapillary venules, the so-called high endothelial venules. These molecules were already demonstrated in organs of the mucosa-associated lymphatic system (MALT). This study was performed to demonstrate these adhesion molecules on endothelial cells and lymphocytes of the inner ear by using two monoclonal antibodies: MECA-325 and MEL-14. Special interest was directed to the posterior spiral modiolar vein as a known port of entry for lymphocytes during an immune response. Emphasis was placed on the development of new or additional binding sites for lymphocytes on the above-mentioned structures using immunohistochemistry during an immune response of the inner ear. The results suggest a constant recirculation of memory lymphocytes through the endolymphatic sac as known for other organs of the MALT. The acquisition of high endothelial venules in the cochlea during an immune response could serve for the cellular requirements of a sympathetic cochleolabyrinthitis with the spiral modiolar vein as port of entry for lymphocytes. Furthermore, this study supports the hypothesis of the endolymphatic sac as central immunological control organ of the inner ear and as the primary place for antigen processing.

Animals↗
PubMedDate not supplied

Cytoskeletal basis for contractility of outer hair cells in the normal adult human organ of Corti: comparisons with vestibular hair cells.

The present study is the first consecutive analysis of the adult normal human organ of Corti and vestibular hair cells with regard to the expression of F-actin, actin-associated proteins (alpha-actinin, alpha- and beta-spectrins, vinculin and tropomyosin), beta-tubulin and the calcium-binding protein synaptophysin. The expression of these cytoskeletal and their associated proteins in man is largely similar to, although not identical with, that previously described for several other mammalian species. However, a few very unusual staining patterns were found. In several long outer hair cells a rod of F-actin extended from the infracuticular area to the cell nucleus. Fluorescence for tropomyosin occurred both in the cuticular plates of the outer and inner hair cells, and in the area of close apposition between the base of the outer hair cell and the apical part of Deiter's cell. In contrast, the vestibular hair cells showed immunoreactivity for tropomyosin only in the cuticular plates.

Actinin↗
PubMedDate not supplied

The human spiral ganglion.

The adult normal human spiral ganglion (SG) was analyzed with regard to ultrastructure and immunohistochemistry. The cytoskeleton of the SG cells was found to comprise F-actin, intermediate filaments (IFs) and microtubules (MTs). The IF subgroups (cytokeratins, Cks; neurofilaments, NFs, vimentin, glial fibrillary acidic proteins, GFAP; desmin) displayed characteristic staining patterns. Ck No. 8 was found in all SG cells, whereas vimentin was lacking. GFAP stained only a small subpopulation of SG cells (type 2?). The light (68 kD) and medium-sized chains of NFs occurred in all SG cells and axons, whereas the 200-kD NF subunit was only found in the axonal hillock of (type 2?) SG cells, but in no other part of the cytoplasm, and regionally in nerve fibres. MAP-1 and MAP-2 occurred in all SG cells but only MAP-1 was found in the nerve fibres. The calcium-binding protein synaptophysin (SY) was expressed only in SG cells, in contrast to the S-100 which occurred more generally in the labyrinth. The neuropeptides VIP and substance P were identified in all SG cells, in contrast to NPY which was expressed in a small subpopulation of SG cell (type 2?). Staining for neuron-specific enolase (NSE) identified most (type 1?) but not all SG cells. The cell surface glycoprotein Thy-1 was expressed in SG cells in a way similar to that described for neurons in the CNS. The SG cells express a high degree of cytoskeletal complexity, allowing one to distinguish between type 1 and type 2 cells. The cell bodies and their adjacent nerve fibres show characteristic features of calcium-binding proteins, surface membrane glycoproteins, NSE and neuropeptides but the basic pattern is still similar to neurons in the CNS.

Actins↗
PubMedDate not supplied

Microtubule-associated proteins in adult human sensory organs.

The distribution of microtubule-associated proteins MAP-1 and MAP-2 was analysed with immunomorphological techniques in the serially sectioned adult human membranous labyrinth. In the organ of Corti, monoclonal antibodies to MAP-1 did not stain. Positivity for MAP-2 occurred in the entire outer hair cell cytoplasm, in the inner hair cells (?), in the nerve fibres and in the cytoplasm of epithelial cells of the spiral prominence. In addition, staining for MAP-2 was identified in many (but not all) cells or Reissner's membrane. Immunofluorescence for MAP-1 occurred in the supporting cells of the cristae and maculae interpreted to be localized in the apical region adjacent to the sensory cells. Thus, the distribution of MAP-1 and MAP-2 in the adult human membranous labyrinth was the same as described for several animal species with regard to the cochlea. In contrast to such a pattern, both MAP-1 and MAP-2 were identified in the human vestibular organs, thus identifying a subpopulation of centrally located nerve calyces and possibly also the apical portion of vestibular hair cells.

Acoustic Maculae↗
PubMedDate not supplied

Hyaluronic acid as a molecular filter and friction-reducing lubricant in the human inner ear.

Immunofluorescence for hyaluronic acid occurred intracellularly in morphologically highly specialized areas in the adult human inner ear, for instance in the cuticular plates of all types of hair cells, at the apposition between outer hair cells and Deiter's cell bodies and in the near-surface area of Hensen's cells. The cytoskeletal organization in these regions is characterized by tightly packed filamentous proteins. Under physiological stimulus these regions undergo micromechanical change, either actively moving (force generation) or passively vibrating with changes in elasticity. Hyaluronic acid might therefore act as a friction-reducing molecular lubricant. In the lateral wall of the cochlea an accumulation of hyaluronic acid occurred in the loose connective tissue of the spiral ligament, in particular close to the stria vascularis. Due to its complex molecular network, hyaluronic acid offers considerable resistance to bulk flow of water and may exclude molecules. The basal cell region of the stria vascularis is thus given additional support to minimize (seal?) the stria vascularis towards all other areas except the endolymphatic space. Here, hyaluronic acid could act as a molecular filter.

Adolescent↗
PubMedDate not supplied

Comparative cytoskeletal analyses of the inner ear in man and the squirrel monkey.

Serially sectioned human and squirrel monkey labyrinths were analyzed with high-resolution light microscopy after using 25 different monoclonal antibodies (mAbs) identifying all three main classes of cytoskeletal proteins. A high degree of similarity was found in labyrinths from man and squirrel monkey. Only 1 of 25 mAbs stained differently between the two species. In the squirrel monkey but not in the human the mAbs identifying S-100 proteins stained subpopulations of type I vestibular hair cells in the striola of the two macula and the summit of the cristae as compared to the same type of hair cells in the periphery of vestibular organs. Such an establishment of subpopulations of hair cells with the same ultrastructure has previously not been described in higher vertebrates. In contrast to the species differences in the distribution of neuroactive substances, the cytoskeletal architecture seems to be relatively unchanged and stable during evolution. Since each species has its own hearing and equilibrium function, neurotransmitters (neuropeptides, amino acids, etc.) could contribute to such species-specific functions.

Acoustic Maculae↗
PubMedDate not supplied

Speech understanding in quiet and in noise with the CIS speech coding strategy (MED-EL Combi-40) compared to the multipeak and spectral peak strategies (nucleus).

This study compares sentence understanding in quiet and in noise with 3 different speech coding strategies for cochlear implants. The results show that the spectral-peak (SPEAK) and continuous-interleaved-sampling (CIS) coding strategies, based on spectral signal analysis, allow for better speech understanding in quiet as well as in noise, than the multipeak (MPEAK) coding strategy, which relys on speech feature extraction. In the intrasubject comparison of the MPEAK and SPEAK strategies, the SPEAK coding strategy provided a considerable improvement in quiet and in noise for the majority of patients using the Nucleus 22 Mini-implant. In the intersubject comparisons, the mean results in noise with the CIS strategy were superior to both the MPEAK and the SPEAK strategies. The difference was greatest for the most difficult tests in noise. Understanding in noise was least reduced for the CIS strategy. Understanding in quiet was not significantly different between the CIS and the SPEAK strategies; both strategies were significantly better than the MPEAK strategy in quiet. These results are still preliminary, due to the relatively small number of patients and the great inherent intersubject variability of results.

Adolescent↗
PubMedDate not supplied

The drainage of cerebrospinal fluid into the lymphatic system of the neck in humans.

A histo- and immunohistochemical examination of the superior deep cervical lymph nodes was performed in a group of 19 patients who died from intracerebral haemorrhage. For comparison two control groups without cerebral lesions were studied (n = 17, n = 13). Free iron deposits as shown within the lymph nodes by Prussian blue reaction were seen significantly more often following intracerebral haemorrhage than without bleeding. The expression of CD 68 (a marker for macrophages) or CR 3/43 (microglia) gave a strong reaction, but there are no significant differences between the three groups. Glial fibrillary acidic protein was rarely seen in the three groups. Raising the CSF pressure results in increased CSF drainage into the cervical lymph nodes. The clinical importance of this lymphatic drainage suggests a communication between the brain and the immune system of the head and neck, with a possible selective up- and down-regulation.

Carcinoma↗
PubMedDate not supplied

Focal metabolic activation in the predominant left auditory cortex in patients suffering from tinnitus: a PET study with [18F]deoxyglucose.

Eleven patients suffering from chronic disabling tinnitus underwent an FDG-PET study (positron emission tomography with [18F]deoxyglucose). Nine tinnitus patients revealed a significantly increased metabolic activity in the left, 1 in the right primary auditory cortex (PAC, Brodmann area 41). These results were statistically significant when compared to 14 healthy control individuals without tinnitus. A negative result was obtained from a chronic tinnitus patient but who had no subjective complaints during the period of PET investigation. One patient was first investigated during a disabling tinnitus period, later during a period with tinnitus relief and again when suffering from severe tinnitus. The metabolic activity of his left PAC was in good accordance with the subjective degree of tinnitus complaints present during each PET investigation. Although for the first time these results give objective evidence of tinnitus sensation and localization, they are difficult to interpret because of the limited research data available that combine functional brain imaging and acoustic stimuli.

Acoustic Stimulation↗
PubMedDate not supplied

Expression of vasoactive intestinal peptide, substance P and bombesin-flanking peptide in nasal polyps.

The presence of neuropeptide-containing sensory, parasympathetic and sympathetic nerves in human nasal mucosa is well established. However, information regarding the neuropeptide distribution in nasal polyps is still lacking. The aim of this study was to compare immunohistologically the presence and distribution of substance P (SP), vasoactive intestinal peptide (VIP) and bombesin-flanking peptide (BFP) in normal nasal mucosa and nasal polyps. The expression was studied using Formalin-fixed and paraffin-embedded biopsy sections from 20 patients with nasal polyps and 10 controls with normal nasal mucosa from the anterior part of the inferior turbinate. Indirect immunohistochemistry (APAAP method) with mono- and polyclonal antibodies was used. None of the control group but 5 patients of the nasal polyp group had an atopic disease. Comparing localization and intensity of the immunohistological reaction in nasal mucosa and nasal polyp tissue, there was no difference in the expression of the three neuroendocrine substances. There was no difference of expression in the polyposis group itself concerning allergic and nonallergic subjects. The results indicate that VIP, SP and BFP have an equal distribution in nasal polyps and normal nasal mucosa.

Adult↗
PubMedDate not supplied

Evaluation of performance with the COMBI40 cochlear implant in adults: a multicentric clinical study.

The present multicentric clinical study involves 19 centres, 16 of them in German-speaking countries, 1 British, 1 Polish and 1 Hungarian. 60 postlingually deafened adults with a mean age of 47.5 years (20-70) and mean duration of deafness of 5.3 years (0.5-20) have been evaluated with the MED-EL COMBI 40 cochlear implant which implements a high-rate continuous-interleaved-sampling strategy with 8 channels. Safety and effectiveness data have been collected. Speech perception tests include a 16-consonant, an 8-vowel, a sentence and a monosyllabic-word test in all languages and a 2-digit figure test in all languages but English. Test intervals are 1, 3, 6 months and 1 year after first fitting. 41 of the 60 postlingually deafened adult study patients have completed their 6-month evaluation. While their pre-operative monosyllabic-word score was 0%, their mean monosyllabic-word score 6 months after first fitting was 48% (8-90) with a median of 50%. The mean sentence understanding was 84% (24-100) with a median of 90%. The respective values for the 1-year evaluations with 25 patients are a mean of 50% (5-85), with a median of 60% for the monosyllables and a mean of 89% (30-100), with a median of 97%, for the sentences.

Adult↗
PubMedDate not supplied

Effectiveness of hyperbaric oxygen therapy in patients with acute and chronic cochlear disorders.

Over the course of 18 months 359 patients with defined acute and chronic inner ear disorders who had not responded to treatment with medication were given hyperbaric oxygen (HBO) therapy. The inner ear diseases of the patients were divided, based on the duration of their conditions, into four symptomatic groups. Of the patients who had had hearing loss for less than 3 months, noticeable improvement or complete recovery was seen in 13% (20 dB in at least three test frequencies); 25.2% showed an improvement between 10 and 20 dB. Changes up to 10 dB or less were not considered to be positive. Patients with a pretreated hearing loss for more than 3 months had markedly less benefit from HBO therapy. Two percent regained normal hearing function. In 30% an improvement of more than 10 dB was achieved. For patients who had suffered from tinnitus for less than 3 months excellent improvement was seen in 6.7% and noticeable improvement in 44.3% expressed by means of a visual analog scale. In 44.3% the tinnitus was described as unchanged. Patients who had had tinnitus for more than 3 months before HBO therapy showed a less favorable response to HBO. In none of the patients did the tinnitus disappear; 34.4% of the patients described a noticeable improvement in their complaints.

Acute Disease↗
PubMedDate not supplied

Inner ear and renal diseases.

Certain conditions (Alport's syndrome, kidney transplantation, dialysis) are followed by a progressive inner ear hearing loss. On the other hand, pharmacological substances that act on the transport mechanisms of the tubular epithelium may also produce inner ear disturbance. Experimental data on the possible pathomechanisms are discussed in reference to results reported in the literature.

Animals↗
PubMedDate not supplied

[Considerations on the pathogenesis of the cochleo-renal syndrome (author's transl)].

The histological findings in two cases of Alport's syndrome are presented. Damage within the inner ear is mainly represented in the vascular stria region and it seems that the inner ear damage pattern tallies with the renal alterations. Glomerular basement thickening and splitting are the first and pathognomonic findings together with confluence of the epithelial feet. Later on, the increase in volume in the epithelial cells and the tremendous enlargement of the glomerular basement membranes leads to an obliteration of glomerular capillaries. In the first described case a subtotal loss of stria vascularis seems to be the reason for a degeneration of the inner and outer hair cells as well as of some spiral ganglion cells. The second case revealed only a slight edema of the stria vascularis and apical protrusions of cytoplasm, sometimes vacuolated. Whereas in the basal turn most of the inner hair cells had disappeared, in the upper turns we observed a slight degeneration of the inner hair cell but intact outer hair cell system. Although in Alport's syndrom there are--according to the literature--no constant findings, our observations allow us to assume that inner ear damage in the cochleo-renal syndrome is secondary to the kidney disease.

Adult↗