The developing inner ears of mice (CBAKBA), ages ranging from gestational day 12 through postnatal day 21, were examined using scanning electron microscopy following the epoxy-embedding/ freeze-fracture technique. This technique provides unique three-dimensional views of surface and fractured structures of the developing inner ear, thus allowing excellent preservation of the relationships between the developing sensory epithelium and the overlying membranes (i.e. the tectorial membrane and cupula) during their development.The tectorial membrane is formed of two distinct parts: the major (medial) and the minor (distal). The major portion is produced by the cells of the greater epithelial ridge prior to the formation of the minor part, which is produced largely by the primordial supporting cells of the lesser epithelial ridge. The developing tectorial membrane has two types of fibers: radial (found mainly in the major part) and slanted (found mainly in the minor part). The slanted fibers become the cover net, which fuses with the marginal band. The marginal zone of the developing tectorial membrane is completely sealed during development by the third row of Deiters' cells. The surfaces of cells that produce the tectorial membrane are characterized by numerous long microvilli which are largely lost when the tectorial membrane completely forms and separates from the supporting cells.The surface of developing auditory sensory cells is initially covered with numerous microvilli, some of which become future stereocilia. Stereocilia form stepped rows in the shape of a "W", with the tallest row located at the periphery of the cell. As the sensory cell matures, the short transitional stereocilia gradually disappear. Kinocilia on hair cells are still seen in the 14-day-old mouse (even though the organ of Corti is morphologically mature) but not in the 21-day-old mouse, indicating that complete maturation of the sensory cells in all turns is attained by 21 days of age. The mouse has upper radial tunnel fibers and basal tunnel fibers. Neural contacts of the upper radial tunnel fibers with the outer hair cells at the apical portions are frequent in the developing organ of Corti.The external sulcus cells undergo drastic changes during development, forming numerous pits that are often covered with mucus-like droplets or grape-like spherical structures of varying sizes. This phenomenon was observed only during postnatal days 6 and 14.The developing cupula starts as a thin amorphous membrane, which later becomes compact and fibrotic-like as the mass increases. By the 6th postnatal day well-developed cupular canals occur. In some canals in the central zone of the crista, the tall stereociliary bundles are in contact with a part of the canal wall, but short stereociliary bundles are free-standing in the subcupular space. In the periphery of the crista, the cupular canals are smaller in diameter or are not seen at all at the extreme periphery. Consequently, only the tall ciliary bundles are directly in contact with the cupula. The on...
Our data shows that the majority of anastomotic failures occur within the first 24 h. Thereafter, the frequency of failures decreases. We also found that the time between initial reconstruction and start of the salvage procedure influences the outcome of the revision negatively.
The median LF was 7 Newtons (N) (range 0-27) before treatment and 18.5 N (range 7-44) after treatment (p < 0.001). The median SC was 0 ml/s (range 0-9.1) before treatment and 12.1 ml/s (range 0-36.7) at follow-up (p < 0.001). There was no significant difference in swallowing improvement between patients with versus those without facial paresis. The interval between stroke attack and start of treatment, ranging from a few days up to 10 years, had no significant influence on the treatment results, nor did age or sex. The facial paresis was improved or at least ameliorated in all patients after the lip training period.
A prefabricated oral screen has shown promising results as a muscle self-training device to improve the lip function of stroke patients affected by oropharyngeal dysphagia. However, a technique for the measurement of lip muscle force, whether in healthy individuals or in stroke patients, is lacking. The present study was designed to (1) test the intra- and interreliability of lip force measurements by means of a newly devised Lip Force Meter, LF100, (2) determine a normal lower limit for lip force in newtons (N), and (3) ascertain the instrument's sensitivity and specificity. LF100 is a modified strain gauge for recording the ability of lips to withstand pressure from a predentally placed oral screen. Forty-two healthy controls and 22 stroke patients agreed to participate in the trial. The controls and patients were examined three times with the LF100, with 2-min rest intervals, twice by investigator MH and once by investigator MO. Intrainvestigator reliability with the LF100 proved excellent in both controls and patients: ICC was 0.83 and 0.90, respectively. Interinvestigator reliability was good or excellent in both groups: ICC was 0.71 and 0.91. There was a significant difference in lip force between controls and stroke patients (mean = 24.7 +/- 6.3 N and 9.5 +/- 5.5 N, p < 0.001). The sensitivity of LF100 was 91% and the specificity 95%. The cutoff level for normal lip force was 15 N. The LF100 showed itself to be a suitable and reliable instrument for measuring lip force.
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