Preliminary exploration of Gd-DTPA enhanced inner ear image of guinea pig using magnetic resonance scan / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To observe the distribution of Gd-DTPA in the inner ear of guinea pig by MRI at different time points after intratympanic administration, explore the optical time for observing the whole inner ear. To study the pharmacokinetic feature of Gd-DTPA in the inner ear, and find out whether discrimination of endolymph and perilymph can be obtained under current conditions.</p><p><b>METHODS</b>Sixty-five guinea pigs were randomly divided into 13 groups, after diluted Gd-DTPA intratympanic injection, each group of guinea pigs were scanned through MRI (3D-T1 FSE sequence) at different time points (0 h, 0.5 h, 1 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 24 h, 48 h, 72 h, 96 h). Pixel intensity values of some locations in the inner ear were analyzed using e-Film software, then pixel intensity was converted into concentration using the results of previous in-vitro study. ABR thresholds of bilateral ears before, 1 d and 7 d after intratympanic injection were compared.</p><p><b>RESULTS</b>Six hours after transtympanic Gd-DTPA injection was the time point when contrast agent was distributed all over the inner ear, and reached a high concentration: 589.29, 552.54, 570.17, 255.08, 107.09 and 139.18 µmol/L in the vestibule, scala vestibuli and scala tympani of basal turn, the 2(nd), the 3(rd) and the apical turn individually, that was also the optimal time for observing the whole inner ear by MRI. Perilymph appeared to be preferentially enhanced relative to the endolymph, resulting in a distinction between the scales of the inner ear. There was no significant difference between the experimental ear (diluted GD-DTPA injected ear) and contrast ear (physiological saline injected ear) on 1 d and 7 d.</p><p><b>CONCLUSIONS</b>The best time getting MRI imaging after intratympanic diluted GD-DTPA injection is 6 h. After diluted agent injection perilymph can be enhanced so as to be differentiated with endolymph by MRI, diluted agent have no obvious effect on the ABR threshold. The pharmacokinetic feature of Gd-DTPA in the inner can be studied using MRI.</p>

Study on discrepant protein expression in rat auditory cortex under impulse noise exposure / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>Impulse noise was adopted in adult rats to built acute deafferent animal model. Differential proteomics techniques were applied to detect the changes of protein expression in the auditory cortex before and after the noise exposure.</p><p><b>METHODS</b>Thirty adult SD rats were divided into three groups: normal group, rats with acute noise exposure and rats 28 days recovery after noise exposure (n=10/group). All animals were exposed to impulse noise at 156 dB for 50 pulses with a rise-time of 100 µs and duration of around 0.25 ms. ABR was used to evaluate the auditory function. The two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF-MS) were used to identified the differential protein expression.</p><p><b>RESULTS</b>Compared with the normal group, ABR thresholds were found significantly increased at 2, 4, 8, 16, 32 kHz (P<0.05) in the acute and recovery groups. There was a 40-60 dBSPL ABR threshold shift at all tested frequencies immediately after impulse noise exposure. There was a partial recovery of ABR thresholds at 7 day to 28 days after impulse noise exposure. In addition, it seemed that the thresholds were rather stable and no further ABR threshold recovery was observed from 14 day to 28 days after the impulse noise exposure. Using differential proteomic techniques, 36 spots containing 27 proteins were revealed and identified in auditory cortex. Those proteins are related to cytoskeleton, neurotransmission, energy supply, mitochondrial function and synaptic remolding.</p><p><b>CONCLUSIONS</b>Impulse noise may influence the function of microtubule transport and cell metabolism, there after affect the neurotransmission of auditory neurons. The compensatory changes such as pre- and postsynaptic or such related functional changes may also happen in auditory cortex after the deafferentation treatment.</p>

Activation of nuclear factor-kappaB and aberrant gene expression of interleukin 6 in middle ear cholesteatoma / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To establish the activation of NF-kappaB in middle ear cholesteatoma, discuss the relationship of NF-kappaB and the gene expression of IL-6 and explore the pathogenesis of middle ear cholesteatoma.</p><p><b>METHODS</b>Ten cases of cholesteatoma and 6 cases of normal external meatal skin were obtained from middle ear surgery. The NF-kappaB DNA binding activity and the mRNA level of IL-6 in these two kinds of tissues were detected by electrophoretic motility shift assay (EMSA) and Reverse transcription polymerase chain reaction (RT-PCR) respectively. The relationship of NF-kappaB DNA binding activity and the mRNA level of IL-6 were analyzed.</p><p><b>RESULTS</b>The NF-kappaB DNA binding activities of cholesteatoma [(15.9 +/- 8.2)%] were higher than those in normal skin [(1.36 +/- 0.94)%, t = 3.502, P < 0.05]. The expression of IL-6 mRNA was increased significantly in patients with cholesteatoma, as compared with that in the control specimens (t = 2.166, P < 0.05) and had a significant positive correlation with NF-kappaB DNA binding activity (r = 0.752, P < 0.05).</p><p><b>CONCLUSIONS</b>The IL-6 mRNA expression in cholesteatoma is closely related with the activity of NF-kappaB. It is tempting to speculate that NF-kappaB play a key role in the activation of cytokine in cholesteatoma.</p>

Maxillary swing approach in the management of tumors in the central and lateral cranial base / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>A retrospective review of seventeen patients who were operated through the maxillary swing approach was carried out to assess the efficacy of this approach in the management of tumors of the central and lateral cranial base.</p><p><b>METHODS</b>From May 2000 to January 2005, 17 patients with primary or recurrent neoplasms involving the central cranial or lateral base underwent surgical resection via maxillary swing approach. Ten patients were male, and other seven patients were female, and age range was 7 to 58 years, with a mean age of 42. 6 years. Eight patients had tumors originally involving lateral cranial base, and nine patients had tumors originated from central cranial base. The pathology spectrum was very wide. Among them, five suffered from chordoma, two had rhabdomyosarcoma, two had squamous cell carcinoma, one had malignant fibrous histiocytoma, one had malignant melanoma, one had esthesioneuroblastoma, one had invaded hypophysoma, two had schwannoma, one had pleomorphic adenoma, and one had angiofibroma. Three patients had received previous surgery, two patients had previous radiation therapy and nine patients received postoperative radiotherapy.</p><p><b>RESULTS</b>Sixteen of all seventeen patients had oncologically complete resection, one had near-total resection. This group patients was followed up from 10 to 60 months, with a median follow-up time of 28 months. Two patients died 14 and 26 months after surgery respectively, as a result of local recurrence and metastasis. One patient defaulted follow-up at 12 months after operation, and the other 14 patients were alive at the time of analysis. Of the 12 malignant tumors, the 1-and 2-year survival rate were 91.67% and 72.92%, respectively. The facial wounds of all patients healed primarily, and there were no necrosis of the maxilla, damage of the temporal branch of the facial nerve, lower-lid ectropion, and facial deformity. Epiphora and facial hypoesthesia were detected in all patients. Four patients (23.5%) developed palatal fistula, ten patients developed serous otitis media (58.8%), and four patients developed a certain degree of trismus (23.5%). Cerebrospinal fluid leak occurred in two patients. They subsequently healed with conservative management.</p><p><b>CONCLUSIONS</b>The maxillary swing approach is a proven method for access to the central and lateral skull base with good exposure and acceptable morbidity. Complications and sequelae associated with this approach include facial scarring, transaction of the infraorbital nerve, impaired lacrimal drainage, eustachian tube dysfunction and serous otitis, palatal fistula, trismus etc. Some procedures should be performed for reducing the incidence and severity of complications in the maxillary swing approach.</p>

Expression and activation of nuclear factor-kappaB in middle ear cholesteatoma / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To explore the expression and activation of NF-kappaB in middle ear cholesteatoma.</p><p><b>METHODS</b>The protein expression of NF-kappaB p65 in 21 middle ear cholesteatoma tissues and 8 normal external ear canal skin obtained in middle ear surgery were examined by immunohistochemistry; NF-kappaB DNA binding activity in these two kinds of tissues were also detected by electrophoretic motility shift assay (EMSA). The influence of cholesteatoma debris on the NF-kappaB DNA binding activity of HaCat cell were further analyzed.</p><p><b>RESULTS</b>All epithelial cell of cholesteatoma revealed a relatively abundant plasma expression of NF-kappaB p65 protein, among which 12 cases showed nuclear positive expression. In contrast,the normal skin epithelium only revealed a sparse plasma distribution of NF-kappaB protein. The levels of NF-kappaB p65 protein expression in the epithelium of middle ear cholesteatoma tissue and normal skin were 0.168 +/- 0.051, 0.088 +/- 0.019 (t = 4.211, P < 0.01), respectively. The NF-kappaB DNA binding activities of cholesteatoma [(16.5 +/- 10.1)%] were also higher than those in normal skin [(1.38 +/- 1.24)%, t = 3. 600, P = 0.014]. The NF-kappaB DNA binding activity of HaCat cell increased when exposed to cholesteatoma debris in a dose dependent manner.</p><p><b>CONCLUSION</b>NF-kappaB might be an important factor which was involved in the occurrence and development of cholesteatoma.</p>

Establishment of a HPV-negative cell line derived from xenografted human laryngeal squamous cell carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To establish a human laryngeal carcinoma cell line unassociated with human papillomavirus (HPV).</p><p><b>METHODS</b>Viable tissue of a well-differentiated laryngeal squamous cell carcinoma was obtained and tested negative for the presence of HPV by polymerase chain reaction. Minced tissue fragments were then transplanted subcutaneously into nude mice. After two successive passages, the tumor tissue was seeded into culture flasks and incubated in a medium containing 10% fetal bovine serum, insulin and epidermal growth factor. Tumor cell phenotype and molecular features were determined by various methods.</p><p><b>RESULTS</b>A stable cell line, designated as Lscc-02, was successfully established after 86 culture passages. The cells grew as a monolayer with epithelioid features. The cell doubling time was approximately 39.1 hours. The human origin of the tumor cells was confirmed by karyotype analysis. The squamous epithelial phenotype was demonstrated by the immunopositivity of anti-cytokeratin antibodies and ultrastructural presence of tonofilaments and desmosomes. The malignant nature of the cells was documented by their clonal formation in soft-agar and tumorigenicity in nude mice. Lscc-02 cells expressed carcinoembryonic antigen (CEA) and were negative for HPV DNA.</p><p><b>CONCLUSION</b>This newly established Lscc-02 laryngeal squamous cell carcinoma cell line may be a useful model for investigating laryngeal carcinoma unrelated to HPV infection, and the role of HPV in the progression of human laryngeal carcinoma.</p>