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Biomedical subjects

V Jahnke

Publications and source records attributed to V Jahnke.

103 records · Page 6Linked to original sources

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. Speech tests included monosyllabic word tests and sentence tests via the telephone. An adaptive noise method was used to adjust each subject's scores to approximately 50%. Additionally, subjects had to complete a questionnaire based on their 4 weeks of experience with the TEMPO+. The speech test results showed a statistically significant improvement in the monosyllabic word scores with the TEMPO+. In addition, in the second session, subjects showed a significant improvement when using the telephone with the TEMPO+, indicating some learning in this task. In the questionnaire, the vast majority of subjects found that the TEMPO+ allows equal or better speech understanding and rated the sound quality of the TEMPO+ higher. All these objective and subjective results indicate the superiority of the TEMPO+ and are mainly attributed to a new coding strategy called CIS+ and its implementation in the TEMPO+. In other words, based on the results of this study, it appears that after switching over from the CIS PRO+ to the TEMPO+, subjects are able to maintain or even improve their own speech understanding capability.

Adult↗

Substance-P-induced histamine release from human nasal mucosa in vitro.

There is growing evidence that substance P (SP) is one of the main neuropeptides involved in neurogenic inflammation of the airways. However, a number of studies were not able to demonstrate histamine release from human mucosal mast cells after SP administration. Since cultures of isolated cell systems provide only a partial picture of the inflammatory processes in vivo, organ culture models promise to offer physiologically relevant assay systems for studying tissue interactions. Thus, we examined the influence of SP on histamine release and its morphological effects on human nasal mucosa using a previously described histoculture technique. Compared to controls, the histamine content in the culture bath was significantly elevated after SP stimulation (p < 0.05). Histomorphometry showed a decreased density of mast cells and an increased percentage of degranulated mast cells. These findings were dose and time dependent and support the hypothesis of a close interaction between C-sensory nerves and mast cells implying that these interactions are of pathogenetic importance in nasal mucosa inflammation.

Culture Media, Conditioned↗

Electron microscopic and functional aspects of the human vomeronasal organ.

The vomeronasal organ or Jacobson's organ is essential for pheromone detection and reproductive behavior in most mammals. The purpose of this article is to describe the fine structure of the adult human vomeronasal organ in 14 specimens and to discuss functional aspects. Our studies show a duct-like invagination of the epithelium, surrounded by numerous exocrine glands with short ducts; their fine structure suggests serous secretion. In the depth of the invagination, pseudostratified columnar epithelial cells are seen, with plump processes, kinocilia, and microvilli at the apical cell membrane. There are several cell types that differ regarding their organelles and electron density; the light sensory cells exhibit neurofilaments. Underneath the typical basement membrane, in the very vascular lamina propria, numerous myelinated and unmyelinated axons are present. These morphologic findings, which are unique in the human body, suggest that a chemosensory epithelium corresponding to a vomeronasal organ may exist. Its central connections and the possible functional significance for pheromone detection are unknown. Preservation of the vomeronasal organ in endonasal surgery could become important both clinically and medicolegally, should function be demonstrated in humans.

Adolescent↗