Iatrogenic Impairment of Hearing During Surgery for Acoustic Neuroma

Isolated or combined labyrinthine, neural, and vascular damage account for failure to preserve hearing during removal of acoustic neuromas. However, the specific mechanisms of auditory impairment remain unclear unless surgical maneuvers can be related to peri- and postoperative hearing on the basis of intraoperative monitoring of auditory function.

Among the different auditory monitoring techniques, recording of cochlear nerve action potentials (CNAPs) from the intracranial portion of the nerve has proven particularly useful for identifying the mechanisms of iatrogenic auditory injury.

The present investigation analyzes intra- and postoperative auditory impairment in relation to surgical steps in a group of 38 subjects with acoustic neuroma (size ranging from 5 to 24 mm) undergoing removal via a retrosigmoid approach.

Coagulation close to the cochlear nerve, drilling of the internal auditory canal, and removal of the intrameatal portion of the acoustic neuroma have prove to be the most critical surgical steps in hearing preservation.

Changes were correlated with intra- and extrameatal tumor size, the relationship between the internal auditory canal and vestibule, and internal auditory canal enlargement, anatomic involvement of the cochlear nerve, preoperative auditory level, and ABR and ENG test findings.

Changes in CNAP morphology and latency are detailed, and mechanisms of injury are analyzed and discussed as a function of these variables.

     

Endoscopic treatment of benign tumors of the nose and paranasal sinuses.

OBJECTIVE: The endoscopic approach can be successfully employed for the treatment of benign tumors such as fibroosseus and vascular lesions, pleomorphic adenomas, gliomas, and schwannomas. STUDY DESIGN AND SETTING: Nineteen patients diagnosed with benign tumors of the nasal cavity and paranasal sinuses and treated using an endoscopic approach were retrospectively reviewed. The endoscopic approach was used exclusively in 15 cases and was associated with an external approach in 4 cases (due to an intracranial extension of the tumor in 3 patients and its location at the level of the anterior wall of the frontal sinus in the last case). RESULTS: The resection of the lesions was radical in 18 patients and subtotal in 1 case. The mean follow-up was 27 months and only 1 recurrence (5%) was observed in the juvenile angiofibroma group 20 months postoperatively. CONCLUSION: and significance In selected cases, endoscopic surgery can be considered an effective treatment for the resection of benign tumors involving the sinonasal tract.     

Tissue polypeptide antigen (TPA) in pleural effusions

The usefulness of tumor marker assay in pleural effusions for differential diagnosis is still debated. From the observation of common antigens on tissue polypeptide antigen (TPA) and keratins 8, 18 and 19 and vimentin, all substances contained in normal and neoplastic mesothelium, we felt it opportune to evaluate the use of TPA assay in 105 pleural effusions (46 benign and 59 malignant). The values were much higher than those found in blood. In hydrothorax the median value was 454 U/l (range, 59-1923), in exudative effusions 846 U/l (range, 258-4485), in metastatic pleural effusions 1277 U/l (range, 58-32352) and in mesotheliomas 7705 (range, 759-16000). The maximum value found in nonmalignant effusions was 4485 U/l; this value was taken as a cutoff level, so only 29.9% of the tumors were positive to the test. Our results showed this assay to be not very important for a differential diagnosis of malignant and nonmalignant pleural effusions. Nevertheless, the different TPA patterns in mesotheliomas (66.6% positive) and metastatic pleural effusions (15.9%) suggest that further studies are warranted.     

转录因子Egr-1在失血性休克复苏后肝脏损伤中的作用

目的研究转录因子Egr-1在失血性休克复苏（HS/R）后肝脏损伤中的作用.方法利用Egr-1野生型（WT）和基因封闭型（KO）小鼠复制失血性休克复苏模型.取肝组织,RT-PCR法测定肝组织中TNF-α、IL-6、G-CSF、ICAM-1 mRNA的表达变化.通过检测肝组织中MPO的含量、血清ALT水平和组织学检查,评估肝脏炎症细胞浸润和损伤程度.结果失血性休克2.5 h＋复苏4 h后,Egr-1 KO小鼠肝组织中TNF-α、IL-6、G-CSF、ICAM-1 mRNA的表达水平明显低于Egr-1WT组;Egr-1 KO组失血性休克复苏后肝组织炎性浸润和损伤程度减轻,表现为血清ALT水平低,肝组织中MPO含量低,病理损伤轻.结论本实验结果表明转录因子Egr-1参与了失血性休克复苏后肝脏炎症反应基因表达的调节,在失血性休克复苏后的肝脏损伤中起一定的作用.