Biomedical subjects
Publications and source records attributed to W Mann.
Using a pressure chamber for differenatiation of naso-sinal and sino-nasal ventilatory ostial resistance, we examined 300 patients with pathology of the frontal and maxillary sinuses, stimulating physiological conditions. The analysis of the different obstructing factors--before and after washouts--hints to the presence of a surface--active substance in human sinus secretions.
The conditions for RNA- and protein synthesis in toluenized E. coli B are investigated. The kinetics of RNA- and protein synthesis indicate that a coupled synthesis of both macromolecules takes place in these preparations. Treatment with 1% Brij 58 alters the permeability of toluenized E. coli in such a way that the protein synthesis depends on the addition of supernatant proteins (chromotographed S100 from E. coli) and tRNA.
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Outer hair cells could be protected during intense noise exposure by the application of the calcium channel blocker diltiazem given before and after noise treatment. After various experimental approaches, the ultrastructural morphology was analysed for the different animal populations in the basal part of the second turn of the cochlea, which was the most destroyed area after an acute noise trauma caused by a gun shot (sound pressure at the ear drum 156 dB, frequency maximum between 4 and 6 kHz). Compared to untreated control specimens (experimental animal group I), the outer hair cells in the basal part of the second turn of the cochlea were mostly destroyed without any diltiazem application but after intense noise exposure (group II) or when the calcium channel blocker was given only before (group III) or only after an intense noise exposure (group IV). Only cellular debris of these receptor cells could be identified within this region of the cochlea at the electron-microscopic level. After diltiazem application before and after the intensive noise exposure (group V), the general morphology of the tissue was much better conserved and almost no destroyed outer hair cells were found. But nevertheless, the electron-microscopic analysis revealed that the cellular fine structure was altered. Compared to untreated control specimens, small invaginations were sometimes seen in the basolateral membranes of outer hair cells, and also the cuticular structures of the Deiters cells forming the lamina reticularis bulged into the outer hair cells. To get more information about possible physiological alterations, the amounts of precipitable calcium within the outer hair cells were determined by an image-processing system for the five different populations (groups I-V). The values obtained were compared to the calcium content in specimens which had received diltiazem without any additional noise exposure (group VI) and with an animal population which was exposed to a pure tone for 5 min at 90 dB (group VII). The results are discussed in respect of outer hair cell protection preventing morphological damage and/or physiological alterations.
Calcium ions are known to be important to the process of signal transduction across the apical and basal sides of the inner hair cells. Calcium channel antagonists have been demonstrated by light microscopy to provide protection against acoustic trauma. To evaluate the protective effect of calcium channel blocker on the inner ear cells to noise exposure, the amount of the histochemical reaction products formed in the cytoplasm of the inner hair cells of the guinea pig after application of pyroantimonate was measured by an image processing system connected to an energy-filtering transmission electron microscope (EFTEM). Compared to untreated control specimens (experimental animal group I) the amount of precipitable calcium had clearly increased in the inner hair cells of noise-exposed cochleae 60 h after an acute noise trauma (group III). In addition, small electron- lucent areas could be identified in the cytoplasm of the hair cells probably representing damage to the cellular fine structure. When the calcium channel blocker diltiazem was administered without any additional noise exposure the calcium content was drastically reduced in the inner hair cells (group II), but when the antagonist was given before and after acute noise trauma (group IV), the calcium content in the inner hair cells was nearly compared to the amount determined in the untreated group of animals. The role of diltiazem is discussed in respect of tissue protection and to the maintenance of the calcium-dependent physiological processes in the inner hair cells during signal transduction.
In this prospective study, 82 patients (40 males, 42 females, aged between 15 and 80 years) with benign paroxysmal positioning vertigo (BPPV) were treated with different positioning manoeuvres using video-oculographic control. The maximum age for females and males was 31 and 40 years respectively. After an interview about the special history related to vertigo imbalance symptoms and using video-oculographic control, we diagnosed 79 patients with BPPV of the posterior semicircular canal and 3 of the horizontal semicircular canal. The Dix-Hallpike and Cawthorne manoeuvres were used for the diagnosis of BPPV of the posterior semicircular canal and the McClure manoeuvre for the diagnosis of BPPV of the horizontal semicircular canal. 72% of the patients had an idiopathic BPPV and 12.2% were post-traumatic. 3.7% had BPPV after ear surgery and 2.4% were pregnant. 39 patients with posterior BPPV were treated with Semont's manoeuvre and 40 with Epley's. The 3 patients with horizontal BPPV were treated with Baloh's manoeuvre. More than half of the patients (52.5%) were free of symptoms after one session of Epley's manoeuvre and all of them after four sessions. 51.3% had no further symptoms after one session of Semont's manoeuvre and all of them after four sessions. These results, in agreement with the literature, show that the success rate of Semont's and Epley's manoeuvres is approximately the same. Video-oculographic control is helpful for the diagnosis and for the registration of the eye movements during the therapeutic manoeuvres.
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.
Synaptophysin has been localized previously in the mammalian cochlea at the light-microscopic level and in few reports by electron microscopy using either a preincubation procedure or the avidin-biotin reaction. Here we present results of the electron-microscopic analysis for postembedding immunoreactivity of synaptophysin in the cochlea of the guinea pig of LR-White-embedded samples. Strong synaptophysin immunoreactivity is located in the cytoplasm of the efferent nerve endings at the base of inner and outer hair cells. Besides this, some antibodies to synaptophysin were also identified in the cytoplasm of outer hair cells. To get more information about the cellular content of synaptophysin, the density of the immunoreaction per square micrometer was determined for the outer hair cells of the second turn of the cochlea counting the gold particles in numerous ultrathin sections. The role of synaptophysin identified in the cytoplasm of outer hair cells is discussed.
Twenty-six children requiring surgical intervention for orbital complications of acute sinusitis were treated at our institutions between 1985 and 1995. Twenty patients were successfully treated surgically utilizing endoscopic/microscopic endonasal surgery, or traditional external ethmoidectomy. However, six patients failed to respond to initial surgical attempts and ultimately required a revision. In one of these six patients the development of an intracranial abscess also necessitated a craniotomy for surgical drainage. Analysis of these six failures was performed with special attention given to the reasons for initial surgical failure and possible means for preventing revision surgeries.