To study the antagonistic action of acanthopanax senticosus injection (ASS) on gentamicin ototoxicity.Guinea pigs were randomly divided into control group, GM group, ASS group, and ASS + GM group. The changes of hearing threshold, cochlear morphology, expression of caspases-3 were determined by ABR, TEM, and Western blot, respectively.The ABR threshold in GM group increased markedly. There was no significant difference in ABR threshold between ASS group and control group, but the ABR threshold in ASS group was much lower than that both in GM group and ASS + GM group. Severely injured hair cells with morphological characteristics of apoptosis were found under TEM in GM group, and the hair cells were less injured in ASS + GM group. The results of Western blot showed that the expression of caspase-3 increased markedly in GM group, but it increased slightly in ASS + GM group.ASS may antagonize the GM ototoxicity by inhibiting the expression of caspases-3.

High doses of acetylsalicylic acid (ASS) induce tinnitus and hearing loss. This ototoxic side effect of ASS is characterized by a decrease in spontaneous and evoked otoacoustic emissions. A decrease in otoacoustic emissions is found not only in mammals, but also in non-mammalian ears without electromotile outer hair cells. The molecular mechanism underlying ASS ototoxicity seems to be competitive binding to and a block of the motor molecule prestin. In non-mammalian species, ASS ototoxicity is possibly explained by an effect on the hair bundle.The present data from the outer hair cells of the adult guinea pig cochlea show a reduction in the membrane capacitance by maximally 42%, probably as a result of ASS binding competitively to the motor molecule. However, spontaneous and evoked receptor currents were not modulated by ASS.The results suggest an influence of ASS on outer hair cell somatic electromotility, without a concomitant effect on hair-bundle function.

To assess the treatment outcome, late toxicity, and prognostic factors for radiotherapy (RT) of carcinoma of the pinna.The charts of 313 patients treated between 01/82 and 12/93 were retrospectively reviewed. There were 334 lesions treated: 201 basal cell carcinoma (BCC), 122 squamous cell carcinoma (SCC), and 11 basosquamous carcinoma. RT was most commonly given by orthovoltage X-rays (278 lesions) or electrons (39 lesions). The most frequently used dose prescriptions were 35 Gy in 5 fractions (123 treatments with median field size = 4.9 cm(2)), 42. 5-45 Gy in 10 fractions (67 treatments with median field size = 10.5 cm(2)), and 50-65 Gy in 20-30 fractions (42 treatments with median field size = 81 cm(2)).2 cm. RESUL TS: The actuarial 2- and 5-year local control rates were 86.6% and 79.2 %. Multivariate analysis revealed two factors to be statistically signi ficant for increased local failure: tumor size > 2 cm (hazard ratio [HR] = 2.66, 95% confidence interval [CI] = 1.16-6.08), and a low biological effective dose (BED) (for each decrease of 5 BED units, HR = 1.76, 95% CI = 1.07-2.88). The 5-year actuarial rate of significant Grade 4 late toxicity was 7.3%. Factors statistically significant for this endpoint on univariate analysis were tumor size (p = 0.035), T-stage (p = 0.02), field size (p = 0.05), fraction size (p = 0.003), and BED (p = 0.05).RT is an eff ctive treatment option for epithelial skin cancer of the pinna. Large t umor size and low BED were independently statistically significantly ass ociated with increased local failure. Dose-fractionation schedules usin g fraction sizes < 4 Gy may reduce the risk of necrosis and ulceration, particularly for field sizes > 5 cm2.

Neuronal responses to electrical stimulation at the horizontal ampulla (HA), vestibular nerve (at the windows) and corpus callosum (CC) were investigated in neurons in the anterior suprasylvian gyrus of the cat. The field potentials to HA stimulation had short latency: 2.9 +/- 0.3 (mean +/- SD) ms from the stimulus to the onset and 5.6 +/- 1.9 ms to the peak. The focus of the evoked potentials was located in the anterior suprasylvian (ASS) gyrus or near the ASS sulcus. HA stimulation activated 6 neurons out of 674 examined, with the mean latency of 4.3 +/- 1.1 ms. Of these 6, four neurons also responded to window stimulation. Fifty-six neurons responded to window stimulation with the mean latency of 6.1 +/- 2.4 ms. The mean latency for CC stimulation was 1.9 +/- 0.9 ms (n = 76). Four neurons responded to CC stimulation antidromically (mean = 0.9 +/- 0.3 ms) and one of them also responded orthodromically. The convergence of CC inputs in relation to HA or window stimulation was examined. One (17%) of the 6 HA-activated cells responded to CC stimulation, compared with 8 (14%) of the 56 neurons activated by window stimulation. The other 612 neurons did not respond to either HA or window stimulation, and 80 (13%) of the 612 responded to CC stimulation. Therefore, it is concluded that neurons in the ASS gyrus received callosal input equally irrespective of the presence or absence of responses to ampulla or window stimulation. WGA-HRP was injected in the ASS gyrus to identify the passing callosal fibers in the CC. Fibers from the ASS area passed at the rostral third of the CC. The present results indicate that the ASS area received vestibular projection with short latency, but responses of this projection did not seem to be very strong, at least from the present unit study, to HA stimulation. Discussion was made on the poor neuronal responses to electrical HA stimulation in comparison with previous studies. Also consideration was made on neuronal activity to CC stimulation.

Single cell activity was recorded from the Anterior Suprasylvian (ASS) gyrus of cats trained to orient their gaze toward visual or auditory stimuli. Sixty-five fixation cells were activated or suppressed as long as the animals were attentive to a particular region of space in the tangential or in the radial direction. Most of these fixation cells were neither light nor sound sensitive. Fifty-five cells were activated in relation to saccades. Fourteen neurons were active before and 41 after the onset of saccades. Nineteen neurons were also active with spontaneous eye movements in the dark. Fifteen neurons were seemingly related to vergence. They were not light-sensitive. They were preferentially activated by visual stimuli moving in the radial direction either towards or away from animal's face. Fifty light-sensitive neurons responded to moving stimuli. Only two neurons responded to onset of eccentric stationary light-stimuli. Fifty-one neurons showed a modulation in relation to vestibular stimulation. A majority showed, in addition, a vestibulo-collic response. These data suggest that the ASS gyrus in cats has a major role in the construction of the behavioral space.

The present study provides evidence that during whole-body rotation and during isolated rotation of either the head or the trunk, essentially the same processing of labyrinthine and neck afferent inputs takes place in neurons of the cat's ASS cortex and in humans who try to distinguish these stimulus conditions. This processing includes, among others (1) measurement of angular velocity and displacement during labyrinthine stimulation (whole-body rotation); (2) indication of trunk rotation as well as of an apparent head rotation in the opposite direction during neck stimulation (isolated trunk rotation); and (3) subtraction as well as addition of labyrinthine and neck afferent inputs during combined stimulation (isolated head rotation). Subtraction provides a basis for the discrimination between whole-body rotation and isolated head rotation; addition may optimize the indication of movement and position of the head in space.