Landmark of facial nerve in middle ear surgery / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To re-evaluate landmarks for facial nerve in middle ear surgery through temporal bone dissection and facial nerve surgery.</p><p><b>METHODS</b>Some relative landmarks were found through 44 facial nerves dissection in cadaver and 106 cases of facial nerve decompression surgery.</p><p><b>RESULTS</b>(1) Landmarks for vertical segment of the facial nerve: the vertical line in combined point between posterior and middle 1/3 horizontal semicircular canal clews the posterior edge of facial nerve; the prolong line of superior radian of incus short process clues to the anterior edge of the facial nerve, the facial nerve and horizontal semicircular canal are almost in the same plane. (2) Landmarks for horizontal segment of the facial nerve: the facial nerve tracks forward inferior to short process of incus and anterior to horizontal semicircular canal carina in 30 angel. The facial nerve, locating posterior and superior to cochleariform process and parallel with it, forms the step of middle-superior tympanic cavity and tracks forward to geniculate ganglion. (3) location of geniculate ganglion: The same distance prolong line of stapes head to cochleariform process clues to geniculate ganglion. (4) Location of the chorda tympani nerve: chorda tympani nerve, leaving tympanic sulcus at 3 clock of bone canaline left ear and at 9 clock of bone canaline right ear, tracks forward along tympani sulcus and then cross between long process of incus and manubrium. It lies in the border of pars tensa and pars flaccid and is about 5 - 8 mm from the stylomastoid foramen to where the chorda tympani nerve leaves the facial nerve. There is no difference of facial nerve structure in temporal bone dissection and in surgery.</p><p><b>CONCLUSIONS</b>The fixed landmarks of middle ear are the frame of reference of facial nerve, in which horizontal semicircular canal is most invariable; and the safety of surgery will be improved by the reference of the facial nerve.</p>

Significance of ceramide from precancerous lesion to carcinoma of larynx / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the expression of ceramide produced by sphingomyelin in normal laryngeal mucosa, laryngeal precancerous lesion and laryngeal carcinoma.</p><p><b>METHODS</b>One hundred and seventy-eight consecutive patients with leukoplakia larynx were identified from the archived pathology files of Eye Ear Nose and Throat Hospital of Fudan University from 1991 to 2001. Among them, 31 patients developed laryngeal carcinoma. Flow cytometry (FCM) and immunohistochemistry were performed to test DNA content and ceramide expression on normal tissue, precancerous lesions and laryngeal carcinoma</p><p><b>RESULTS</b>Among thirty-one patients with laryngeal carcinoma, thirty-one cases are all aneuploids, diploids in all normal laryngeal mucosa and three diploids, twenty-eight aneuploids in precancerous lesions. Expression of ceramide decreased gradually from normal tissue, precancerous lesions to laryngeal carcinoma Cell staining per high-power field: (400 +/- 30, 180 +/- 20, 10 +/- 10), t test: P < 0.01. The expression of ceramide in DNA diploid cell (400 +/- 20) is more than that in aneuploid cell (150 +/- 10), t test: P < 0.01.</p><p><b>CONCLUSIONS</b>Ceramide, the second messenger in apoptosis, plays a significant role from precancerous lesion to carcinoma of larynx. Reduction of ceramide may be the key factor contribution to laryngeal carcinogenesis.</p>

Mutual interaction of vestibular afferent nervous system and vestibular efferent nervous system in vestibular compensation / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To study the mutual interaction of vestibular afferent nervous system and vestibular efferent nervous system in vestibular compensation.</p><p><b>METHODS</b>Build up animal model of vestibular compensation by destroying single side vestibule of wistar rat. In the study the rats were divided into 3 groups: Group A 16 normal rats; Group B 15 rats, after 7 days of left vestibular damage; Group C 7 rats 3 months after left vestibular damage; and Group D 7 rats, after vestibular compensation. Electromyography of the rats was recorded and the expression of calcitonin gene relative peptide (CGRP), choline acetyltransferase (AChT) and Na-K-ATPase were investigated in efferent vestibular nervous system.</p><p><b>RESULTS</b>Electric potential activity of muscles of injury side decreased while that of the opposite side increased. In animals of vestibular compensation electric potential of bilateral musculus longus capitis at quiescent stage recovered symmetrically. CGRP positive cells of efferent vestibular nervous system increased bilaterally, and their activity enhanced, especially obvious at the acute stage. AChT positive cells of injury side of efferent vestibular nervous system decreased, but reaction degree of two sides enhanced. Reaction degree of the opposite side enhanced obviously at the stage of vestibular compensation. Expression of Na-K-ATPase mRNA of the same side was lower, but vestibular signal of the opposite side enhanced, clinically head and neck inclined obliquely by means of medial fasciculus of tractus vestibulospinalis. Months later, vestibular signal of the same side enhanced, and that of the opposite side enhanced also, clinical symptoms improved slightly. At the vestibular compensation stage, expression of Na-K-ATPase mRNA of the same side enhanced, and it was same as that of the opposite side or much higher, clinically it reached vestibular compensation.</p><p><b>CONCLUSION</b>Comprehensive effect of the above results maybe as follows: Efferent vestibular nervous system inhibited afferent signal of the opposite vestibule, and it modulated excitement of vestibular center of the same side, and it worked in the complicated mechanisms of vestibular compensation. CGRP may have facilitation function to the vestibular afferent signal of injury side. While Ach improved vestibule compensation by means of inhibition of vestibule excitement of the healthy side.</p>