Routine exposure of recurrent laryngeal nerve in thyroid surgery can prevent nerve injury

To determine the value of dissecting the recurrent laryngeal nerve during thyroid surgery with respect to preventing recurrent laryngeal nerve injury, we retrospectively analyzed clinical data from 5 344 patients undergoing thyroidectomy. Among these cases, 548 underwent dissection of the recurrent laryngeal nerve, while 4 796 did not. There were 12 cases of recurrent laryngeal nerve injury following recurrent laryngeal nerve dissection （injury rate of 2.2%） and 512 cases of recurrenl laryngeal nerve injury in those not undergoing nerve dissection （injury rate of 10.7%）. This difference remained statistically significant between the two groups in terms of type of thyroid disease, type of surgery, and number of surgeries. Among the 548 cases undergoing recurrent laryngeal nerve dissection, 128 developed anatomical variations of the recurrent laryngeal nerve （incidence rate of 23.4%）, but no recurrent laryngeal nerve injury was found. In addition, the incidence of recurrent laryngeal nerve injury was significantly lower in patients with the infedor parathyroid gland and middle thyroid veins used as landmarks for locating the recurrent laryngeal nerve compared with those with the entry of the recurrent laryngeal nerve into the larynx as a landmark. These findings indicate that anatomical variations of the recurrent laryngeal nerve are common, and that dissecting the recurrent laryngeal nerve during thyroid surgery is an effective means of preventing nerve injury.

Changes in Endolymphatic Hydrops Visualized by Magnetic Resonance Imaging after Sac Surgery

The purpose of the study was to observe changes in endolymphatic hydrops by using intratympanic injection of gadolinium and magnetic resonance imaging（MRI） before and after endolymphatic sac surgery in patients with unilateral Meniere＇s disease. Thirteen patients with unilateral Meniere＇s disease undergoing endolymphatic sac surgery were retrospectively and prospectively analyzed. Three-dimensional fluid-attenuated inversion recovery or three-dimensional real inversion recovery MRI was performed 24 h after an intratympanic injection of gadolinium to grade the presence of endolymphatic hydrops. Among the 13 patients with hydrops confirmed by preoperative MRI, vestibular hydrops had no significant change in all patients; cochlear hydrops became negative in 2 patients, and remained unchanged in the other 11 patients after surgery. Definite vertigo attacks were substantially controlled in one patient and completely controlled in 12 patients during a follow-up period of 8-34 months after surgery. The hearing levels were improved in 3 patients, remained unchanged in 7 patients, and decreased in 3 patients. In conclusion, endolymphatic sac surgery does not always alleviate endolymphatic hydrops in patients with Meniere＇s disease. Relief from vertigo cannot always be attributed to the remission of hydrops. A change in hearing levels cannot be explained by hydrops status alone.

Effects of gamma-aminobutyric acid receptors on muscarinic receptor-mediated free calcium ion levels in the facial nucleus following facial nerve injury

Muscarinic receptors and nicotine receptors can increase free calcium ion levels in the facial nucleus via different channels following facial nerve injury. In addition, γ-aminobutyric acid A （GABAA） receptors have been shown to negatively regulate free calcium ion levels in the facial nucleus by inhibiting nicotine receptors. The present study investigated the influence of GABAA, γ-aminobutyric acid B （GABAB） and C （GABAc） receptors on muscarinic receptors in rats with facial nerve injury by confocal laser microscopy. GABAA and GABAB receptors exhibited significant dose-dependent inhibitory effects on increased muscarinic receptor-mediated free calcium ion levels following facial nerve injury. Results showed that GABAA and GABAB receptors negatively regulate muscarinic receptor effects and interplay with cholinergic receptors to regulate free calcium ion levels for facial neural regeneration.

Analysis of Epstein-Barr viral DNA load, EBV-LMP2 specific cytotoxic T-lymphocytes and levels of CD4^＋CD25^＋ T ceils in patients with nasopharyngeal carcinomas positive for IgA antibody to EBV viral capsid antigen

Background Epstein-Barr virus （EBV） is a herpesvirus commonly associated with several malignant diseases including nasopharyngeal carcinoma （NPC）, which is a common cancer in Southeastern Asia. Previous studies showed that plasma levels of EBV-DNA might be a sensitive and reliable biomarker for the diagnosis, staging and evaluating of therapy for NPC. There are a few analyses of the levels of EBV-latent membrane protein 2 （LMP2）-specific cytotoxic T-lymphocytes （CTLs） in patients with NPC. This study was conducted to investigate the levels of EBV-LMP2-specific CTLs, EBV-DNA load and the level of CD4^＋CD25^＋T cells in such patients. Methods From February 2006 to April 2006, 62 patients with NPC, 40 healthy virus carriers positive for EBV viral capsid antigen （EBV-IgA-VCA） and 40 controls were enrolled in the study. We used a highly sensitive ELISPOT assay, real-time polymerase chain reaction （PCR） and flow cytometry to measure the EBV-LMP2-specific CTL response, the EBV DNA load and the level of CD4^＋CD25^＋T cells, respectively. Results The EBV-LMP2-specific CTL responses of the samples from the control, healthy virus carriers and patients with NPC were significantly different from the LMP2 epitopes, with the control and healthy virus carrier samples displaying a stronger response in three cases. There were significant differences in EBV DNA load in serum between NPC and the healthy groups; patients with NPC at stages Ⅲ or Ⅳ had significantly higher viral loads compared with those at stages Ⅰ or Ⅱ. A significantly higher percentage of CD4^＋CD25^＋ T lymphocytes were detected in the patients, compared with healthy virus carriers and healthy controls. Moreover, patients with advanced stages of NPC （Ⅲ and Ⅳ） had significantly higher percentages than the patients with early stages （Ⅰ and Ⅱ）. Conclusions Patients with NPC are frequently unable to establish or maintain sufficient immunosurveillance to control proliferating B cells harboring EBV and to destroy the tumor cells that express immunodominant LMP2 proteins. Controlling the activity of CD4^＋CD25^＋T cells and elevating CD8^＋ cells specific for LMP2 epitopes could be an effective immunotherapy for patients with NPC.