Significance of Vestibular Testing on Distinguishing the Nerve of Origin for Vestibular Schwannoma and Predicting the Preservation of Hearing.

BACKGROUND: Determining the nerve of origin for vestibular schwannoma (VS), as a method for predicting hearing prognosis, has not been systematically considered. The vestibular test can be used to investigate the function of the superior vestibular nerve (SVN) and the inferior vestibular nerve (IVN). This study aimed to preoperatively distinguish the nerve of origin for VS patients using the vestibular test, and determine if this correlated with hearing preservation. METHODS: A total of 106 patients with unilateral VS were enrolled in this study prospectively. Each patient received a caloric test, vestibular-evoked myogenic potential (VEMP) test, and cochlear nerve function test (hearing) before the operation and 1 week, 3, and 6 months, postoperatively. All patients underwent surgical removal of the VS using the suboccipital approach. During the operation, the nerve of tumor origin (SVN or IVN) was identified by the surgeon. Tumor size was measured by preoperative magnetic resonance imaging. RESULTS: The nerve of tumor origin could not be unequivocally identified in 38 patients (38/106, 35.80%). These patients were not subsequently evaluated. In 26 patients (nine females, seventeen males), tumors arose from the SVN and in 42 patients (18 females, 24 males), tumors arose from the IVN. Comparing with the nerve of origins (SVN and IVN) of tumors, the results of the caloric tests and VEMP tests were significantly different in tumors originating from the SVN and the IVN in our study. Hearing was preserved in 16 of 26 patients (61.54%) with SVN-originating tumors, whereas hearing was preserved in only seven of 42 patients (16.67%) with IVN-originating tumors. CONCLUSIONS: Our data suggest that caloric and VEMP tests might help to identify whether VS tumors originate from the SVN or IVN. These tests could also be used to evaluate the residual function of the nerves after surgery. Using this information, we might better predict the preservation of hearing for patients.

The PD-1/B7-H1 pathway modulates the natural killer cells versus mouse glioma stem cells.

PURPOSE: Glioblastoma multiforme (GBM) is the most malignant primary type of brain tumor in adults. There has been increased focus on the immunotherapies to treat GBM patients, the therapeutic value of natural killer (NK) cells is still unknown. Programmed death-1 (PD-1) is a major immunological checkpoint that can negatively regulate the T-cell-mediated immune response. We tested the combination of the inhibiting the PD-1/B7H1 pathway with a NK-cell mediated immune response in an orthotopic mouse model of GBM. METHODS AND MATERIALS: Mouse glioma stem cells (GL261GSCs) and mouse NK cells were isolated and identified. A lactate dehydrogenase (LDH) assay was perfomed to detect the cytotoxicity of NK cells against GL261GSCs. GL261GSCs were intracranially implanted into mice, and the mice were stratified into 3 treatment groups: 1) control, 2) NK cells treatment, and 3) PD-1 inhibited NK cells treatment group. Overall survival was quantified, and animal magnetic resonance imaging (MRI) was performed to determine tumor growth. The brains were harvested after the mice were euthanized, and immunohistochemistry against CD45 and PCNA was performed. RESULTS: The mouse NK cells were identified as 90% CD3- NK1.1+CD335+ by flow cytometric analysis. In the LDH assay, the ratios of the damaged GL261GSCs, with the E:T ratios of 2.5:1, 5:1, and 10:1, were as follows: 1) non-inhibited group: 7.42%, 11.31%, and 15.1%, 2) B7H1 inhibited group: 14.75%, 18.25% and 29.1%, 3) PD-1 inhibited group: 15.53%, 19.21% and 29.93%, 4) double inhibited group: 33.24%, 42.86% and 54.91%. In the in vivo experiments, the mice in the PD-1 inhibited NK cells treatment group and IL-2-stimulated-NK cells treatment group displayed a slowest tumor growth (F = 308.5, P<0.01) and a slower tumor growth compared with control group (F = 118.9, P<0.01), respectively. The median survival of the mice in the three groups were as follows: 1) conrol group: 29 days, 2) NK cells treatment group: 35 days (P = 0.0012), 3) PD-1 inhibited NK cells treatment group: 44 days (P = 0.0024). Immunologic data of PCNA-positive cell ratios and CD45-positive cell ratios of the tumor specimens in the three groups were as follows: 1) control group: 65.72% (PCNA) and 0.92% (CD45), 2) NK treatment group: 27.66% (PCNA) and 13.46% (CD45), and 3) PD-1 inhibited NK cells treatment group: 13.66% (PCNA) and 23.66% (CD45) (P<0.001). CONCLUSION: The results demonstrated that blockade of PD-1/B7H1 pathway could promote mouse NK cells to kill the GL261GSCs, and the PD-1-inhibited NK cells could be a feasible immune therapeutic approach against GBM.

[Experiences of transcallosal-interforniceal approach for resection of the third ventricle and the pineal region tumors: report of 24 cases].

OBJECTIVE: To discuss the advantages and disadvantages of transcallosal-interforniceal approach for resection of the third ventricle and the pineal region tumors. METHODS: The clinical data of 24 cases from July 2008 to March 2011 were retrospectively analyzed. All 24 patients operated by transcallosal-interforniceal approach, among them, there were 14 males and 10 females, with a average age of 32 years ranged from 17 to 65 years and with medical history from 1 month to 10 years. Issues of managements were analyzed and discussed, including reasonable incision design, the managements of draining vein, the site and the length of the incision of the corpus callosum, tumor exposure in increased intracranial pressure, prevention of complications, skills of surgery, treatments of obstructive hydrocephalus, and postoperative managements. RESULTS: In the 24 cases, there were 5 cases of pineal parenchymal tumors, 4 cases of germinoma, 3 cases of astrocytoma, 2 cases of hypothalamus hamartomas, 2 cases of ependymoma, 2 cases of mixed germ cell tumour, 2 cases of malignant lymphomas, 1 case of pineoblastoma, 1 case of dermoid cyst, 1 case of chordoid glioma and 1 case of craniopharyngioma. After surgeries, total removal achieved in 9 cases, and subtotal removal in 10 cases and partial removal in 5 cases. Operative mortality was 0. Combined third ventriculostomy were performed in 13 cases. Postoperative complications occurred in 5 cases, including frontoparietal epidural hematoma in 1 case; postoperative short-term memory loss in 3 cases, postoperative memory loss within 1 month in 2 cases and within 3 months in 1 case; frontoparietal subdural effusion in 1 case and the effusion disappeared without any treatment. Ventriculoperitoneal shunt was performed in 1 case. CONCLUSIONS: The transcallosal-interforniceal approach is ideal for the removal of tumors in third ventricle as well as majority tumor in posterior of third ventricle in a skillful hand. Tumor resection combined with third ventriculostomy is the significant advantages in the approach.

[Effects of VCAM-1 siRNA on restenosis following carotid endarterectomy: experiment with rats].

OBJECTIVE: To evaluate the inhibitory effects of VCAM-1 siRNA on VCAM-1 protein expression and restenosis following carotid endarterectomy in rats. METHODS: Lentivirus-based VCAM-1 siRNA was constructed and its efficacy of blocking VCAM-1 protein expression in endothelial cells and carotids was identified by Western blot. Doppler ultrasonography and morphometric analysis were performed to measure the degree of restenosis. RESULTS: VCAM-1 siRNA decreased the protein expression of VCAM-1 in cultured endothelial cells and carotids. Treatment of VCAM-1 siRNA showed a significant reduction in the restenosis and manifested as an increased blood velocity and linear diameter as compared with control siRNA (P < 0.05). Morphometric analysis showed that the ratio of intima to media area (I/M) increased significantly in CEA group (3.99 +/- 0.65) versus sham-operated group (0.35 +/- 0.13) (P < 0.05). Furthermore, VCAM-1 siRNA resulted in an evident decrease in the neointimal area (1.79 +/- 0.43) as compared with that of the control siRNA (4.33 +/- 0.59) (P < 0.05). CONCLUSION: VCAM-1 plays an important role in pathogenesis of restenosis after carotid endarterectomy. VCAM-1 siRNA blocks VCAM-1 protein expression and alleviates the restenosis following carotid endarterectomy in rats.

[Study on influence between activated carbon property and immobilized biological activated carbon purification effect].

By means of immobilizing five kinds of activated carbon, we studied the influence between the chief activated carbon property items and immobilized bioactivated carbon (IBAC) purification effect with the correlation analysis. The result shows that the activated carbon property items which the correlation coefficient is up 0.7 include molasses, abrasion number, hardness, tannin, uniform coefficient, mean particle diameter and effective particle diameter; the activated carbon property items which the correlation coefficient is up 0.5 include pH, iodine, butane and tetrachloride. In succession, the partial correlation analysis shows that activated carbon property items mostly influencing on IBAC purification effect include molasses, hardness, abrasion number, uniform coefficient, mean particle diameter and effective particle diameter. The causation of these property items bringing influence on IBAC purification is that the activated carbon holes distribution (representative activated carbon property item is molasses) provides inhabitable location and adjust food for the dominance bacteria; the mechanical resist-crash property of activated carbon (representative activated carbon property items: abrasion number and hardness) have influence on the stability of biofilm; and the particle diameter size and distribution of activated carbon (representative activated carbon property items: uniform coefficient, mean particle diameter and effective particle diameter) can directly affect the force of water in IBAC filter bed, which brings influence on the dominance bacteria immobilizing on activated carbon.