Objective To discuss microsurgical experience for transsuboccipital retrosigmoid sinus approach of large acoustic neuronomas,and improve the rate of tumor removing,and facial nerve and auditory nerve preserving Methods A retrospective analysis of 39 patients with acoustic neuronomas which were more than 4 cm in diameter were treated by microsurgery between January 1994 and December 2000 Tumor's excision was performed by transsuboccipital retrosigmoid sinus approach The surgical main points of transsuboccipital retrosigmoid sinus approach,and their experience of total removal,and rate of facial nerve and auditory nerve preservation were described Results The tumors were totally removed microsurgically in 34 patients,the total removal rate was 87 2%,and subtotal removal in 5 patients Facial nerve was anatomically preserved in 31 cases,the rate of facial nerve preservation was 79 5%,but the function of facial nerve was recovered in 22 cases (56 4%) The auditory nerve was preserved anatomically in 15 cases (38 5%) and functionally in 7 cases (17 95%) Conclusions An minimally invasive microsurgical treatment are crucial for increasing a satisfactory living quality of the patients It is considered that the total removal rate of tumor,the preservative rate of facial nerve and auditory depend upon microsurgical technique and intraoperative facial nerve monitoring in acoustic neuromas surgery

Objective To observre the change of plasma arginine vasopressin(AVP)in plasma and relationship of AVP with brain edema after traumatic brain injury(TBI).Methods The rat models of mild and severe degree local cerebral cortex injury were caused by free dropping.Radioimmunoassay was used to measure serial concentration of AVP in plasma in 45 rats with acute brain injuries at the 24th,48th,72th hour and the 5th day after brain injury.The content of injury brain water was measured by drying-wetting way.Results AVP levels had positive correlation with the severity of brain edema.The severer brain injury resulted in higher AVP level and longer persistent time of peak brain edema(P＜0.05).Conclusion AVP level is closely associated with edema after TBI.AVP may play a vital role in pathogenesis of brain edema.

Objective:To explore the clinical signiifcance of the protection of superior petrosal vein (SPV) in the microneurosurgery for acoustic neuroma. Methods:From January 2009 to July 2011, 149 cases of acoustic neuroma microsurgery were observed. hTe difference in hematoma in surgical area, cerebellar hematoma and cerebellar edema were compared between a SPV without protection group (SPVWP group, n=8) and a SPV protection group (SPVP group, n=141). Results:In the 149 patients with acoustic neuroma, the SPV was reserved in 141 patients. In the SPVWP group (8 patients), hematoma in the surgery area occurred in 4 patients, cerebellar edema in 5, and cerebellar hemorrhage in 3. In the SPVP group (141 patients), hematoma in the surgery area occurred in 40 patients, cerebellar edema in 56, and cerebellar hemorrhage in 12. hTere was signiifcant difference in the incidence of cerebellar hemorrhage (χ2=3.84, P=0.05), no signiifcant difference in the incidence of hematoma in the surgical area (χ2=0.646, respectively, P=0.422), and no significant difference in the incidence of cerebellar edema (χ2=0.611, P=0.434) between the SPVWP group and the SPVP group. Conclusion:In acoustic neuroma surgery, the SPV should be protected, which may reduce the risk of cerebellar hemorrhage.

Objective To explore the value of F wave recording in evaluating facial nerve function and its pathological changes in the pressure-induced rat models of acoustic neurinoma. Methods 58 rats in different groups were conducted F wave recording and biotinylated dextran amine(BDA) retrograde tracing for their right facial nerve one week after establishing models. Their latencies, amplitudes and F/M rates were analyzed first. 72 hours after BDA was injected into right whisker muscle, the rats were infused with 4% polyoxymethylene, then pontines and facial nerves in the CPA cistern were obtained. Pontiues were cut into frozen sections for histochemical staining with avidin-horseradish peroxidase (HRP)-DAB and Nissl 's counterstaining, calculating the positive BDA neurons ratio(BDA+-N%)in facial nuclear. Facial nerves were cut and stained with toluidine blue for light-micrescope inspection, and/or stained for transmission electron microscope observation. Correlating F/M with BDA+-N% and the facial nerve pathological findings. Results F/M are 97.66 % and 97.48 % in normal and pseudo-operation group, respectively, when stimulus are 1.4 mA; while 77.13 %, 48.91% and 11.54 % in from small to large tumor model groups because F waves were delayed in latencies or increasinglylost (P <0.001). Similarly, BDA+-N% are 98.37 % and 97.96 % in the above two control groups, while 77.28 %, 48.28 % and 11.55 % in from small to large tumor model groups (P < 0.001). Thus F/M are positively correlated with their BDA+-N% in all groups (r =0.996,P <0.001). Facial nerve examinations under light and electron microscope show increasing pathological changes along with increasing "tumor" size. Conclusion The findings of F wave recording in facial nerve may reflect its functional status and pathological changes. Therefore, F wave detection may help electrophysiological monitoring during acoustic neurinoma resection and facial nerve function evaluation after surgery.

Objective To discuss the preservation and clinical significance of petrosal vein in microsurgical operation of acoustic neuroma. Methods 147 patients with acoustic neuroma were operated, with internal decompression of the tumor firstly then dissected the tumor with surrounding structures, the petrosal vein were protected well in 143 cases and failed to protect in 4 cases. Results No hemorrhagic infarction in cerebellar was observed in 143 cases with intact petrosal vein. One case occurred with extensive cerebellar edema, which has gait disturbance after 18 months follow-up. The other three cases occurred with vein infarction and hemorrhagic edema after petrosal vein damage. One was dead and the other two were recovered well after decompression of posterior cranial fossa. One has no significant neurological deficit after 33 months follow-up, while the other has difficulty in line walking after 12 months follow-up. Conclusion Petrosal vein should be well protected in the operation of acoustic neuroma, the decompression of posterior cranial fossa should be considered if petrosal vein failed to protect.

ObjectiveTo investigate the relationship between tumor-infiltrating mast cell (TIM) and the clinicopathological and prognostic factors of patients with colorectal cancer.MethodsA total of 282 cases of paraffin-embedded colorectal cancer specimens were obtained from the First Affiliated Hospital of Sun Yat-sen University from January 2002 to December 2005.The density of TIM was determined by immunohistochemical staining.According to the mean TIM density detected [ ( 8.4 + 6.5 )/HPF ],all the patients were divided into low-TIM density group (mean TIM density ＜8.4/HPF) and high-TIM density group (mean TIM density ＞8.4/HPF).The clinicopathological factors and the prognosis of patients between high-TIM density group and low-TIM density group were compared.All data were analyzed using the t test or chi-square test.The survival curve was drawn using the Kaplan-Meier method,and the survival of the patients was analyzed by the Log-rank test.The clinicopathological factors were analyzed retrospectively with the univariate and multivariate COX regression model.ResultsTIM was detected in all the patients with colorectal cancer.Significant differences were observed in the number of patients in N stage and TNM stage between patients in the high-TIM density group and those in the lowTIM density group (x2 =6.025,7.410,P ＜ 0.05 ).All patients were followed up till September 2010,the 5-year overall and tumor-free survival rates of patients were 82.9％ and 63.1％ in the low-TIM density group,79.0％ and 59.3％ in the high-TIM density group,with significant difference between the 2 groups (P ＜ 0.05 ).COX proportional hazard regression model revealed that high density of TIM was associated with short overall survival time and tumor-free survival time of colorectal cancer patients ( RR =2.119,95 ％ CI 1.326- 3.386; RR =2.084,95 ％ CI 1.357-3.199,P ＜0.05).The resuhs of multivariate analysis showed that high density of TIM was the independent factor influencing the overall survival time and tumor-free survival time (RR =1.651,95％ CI 1.009-2.702; RR =1.680,95％ CI 1.074-2.629,P ＜ 0.05 ).ConclusionHigh density of TIM is correlated with the N stage and TNM stage of colorectal cancer,and it is an independent predictor of poor survival for patients with colorectal cancer.

Objective To analyze the clinicopathological factors on the prognosis and investigate the necessity of adjuvant chemotherapy for patients with stage Ⅱ colorectal cancer.Methods The clinical data of 255 patients with stage Ⅱ colorectal cancer who were admitted to the First Affiliated Hospital of Sun Yat-Sen University from January 2000 to December 2005 were collected.The survival curve was drawn by Kaplan-Meier method,and the survival rate of the patients were analyzed by Log-rank test.Factors influencing the survival were analyzed by Cox regression model.Results All patients were followed up till April 23,2010,and the mean time of follow-up was (63 ± 22)months.The median survival time was 63 months.The 5-year and tumor-free survival rates were 85.3％ and 83.7％,respectively.The 5-year overall and tumor-free survival rates of patients without preoperative bowel obstruction or perforation were 86.9％ and 85.6％,which were sigaificantly higher than 72.7％and 68.4％ of patients with preoperative bowel obstruction or perforation(x2 =4.546,4.573,P ＜ 0.05 ).The 5-year overall and tumor-free survival rates of patients with negative resection margin were 85.5％ and 83.9％,which were significantly higher than 75.0％ and 75.0％ of patients with positive resection margin(x2 =7.020,6.009,P ＜ 0.05 ).The result of multivariate analysis revealed that preoperative bowel obstruction or perforation were the independent risk factors for patients with stage Ⅱ colorectal cancer(Wald =4.477,relative risk =2.371,95 ％ confidence interval:1.066-5.275,P ＜ 0.05 ).The 5-year overall and tumor-free survival rates were 87.3％ and 86.0％ for patients who received adjuvant chemotherapy,and were 82.2％ and 80.3％ for patients who did not receive adjuvant chemotherapy (P ＞ 0.05 ).Conclusions Preoperative bowel obstruction or perforation are independent risk factors for the survival of patients with stage Ⅱ colorectal cancer.Adjuvant chemotherapy could not improve the prognosis of patients with stage Ⅱ colorectal cancer.

Objective To evaluate the efficacy of dural tenting suture and epidural drainage in craniotomy. Methods In 145 cases of intracranial lesions, dural tenting suture and epidural drainage were performed to prevent epidural hematoma. Results Postoperative computed tomography (CT) showed no epidural hematoma required surgery in both groups. Conclusion Both dural tenting suture and epidural drainage are effective in preventing epidural hematoma. Hemostasis is the key step. Dural tenting suture without epidural drainage relieves psychological stress. It decreases the risk of intracranial infection and avoids some unusual complications.

Objective To study the effects of γ-IFN on the expression of HLA-G mRNA in primary cultured astrocytoma cells. Methods Different concentrations of γ-IFN were added to primary cultured cells, and HLA-G mRNA were detected by RT-PCR. Results After γ-IFN treatment, HLA-G mRNA can not be determined from HLA-G originally negative astrocytoma cells. The expression of HLA-G are up - regulated in all original HLA-G positive astrocytoma cells in a dose-dependent manner. Conclusion γ-IFN can increase the ex-pression of HLA-G gene in the primary cultured astrocytoma cells which HLA - G are originally positive.

Objective To investigate the effects of different degrees of neuromuscular blockade (NMB) induced by rocuronium on facial nerve evoked-electromyographic (EEMG) monitoring in patients undergoing resection of acoustic neuroma.Methods Thirty-five ASA Ⅰ or Ⅱ patients of both sexes,aged 20-64 yr,with body mass index ≤30 kg/m2,scheduled for elective resection of acoustic neuroma under general anesthesia,were included in the study.Anesthesia was induced with midazolam,fentanyl and propofol.The patients were mechanically ventilated after tracheal intubation.Facial nerve EEMG monitoring and peripheral NMB monitoring were performed simultaneously during operation.Facial nerve EEMG was monitored using the Epoch XP2000 multichannel electrophysiological nerve monitoring system (Axon Co.,USA),facial nerve was stimulated and evoked potential of orbicularis oculi was recorded during operation.Peripheral NMB degrees were monitored with TOF-Watch SX monitor (Organon Co.Holland).After rocuronium 0.6 mg/kg was injected intravenously,the facial nerve EEMG responses were monitored when the degree of NMB (T1) was at 100％,75％,50％,25％ and 0 of the control height.The amplitude and latency of EEMG were recorded.The amplitude reservation ratio (the ratio of the amplitude of EEMG monitored to the baseline value) was calculated.Linear correlation of the amplitude reservation ratio or latency of EEMG with the degree of NMB was analyzed.Results No EEMG response was elicited when the degree of NMB was 100％ in 6 patients.The lirear regression equation of the interaction between the degree of NMB (X) and the amplitude reservation ratio (Y) was Y =1 - 0.787 X,the coefficient of determination was 0.898 ( P ＜ 0.05) and the correlation coefficient was - 0.947 ( P ＜ 0.05).The correlation coefficient between the latency of EEMG and the degree of NMB was 0.328 ( P ＜ 0.05).Conclusion When the degree of NMB is maintained at 25 ％-50％,facial nerve EEMG can be monitored effectively and body movement can be avoided during resection of acoustic neuroma.