[The expression of neuraminidase-1 in Ewing sarcoma and its impact on sarcoma cell proliferation and migration].

Objective: To investigate the expression of neuraminidase-1 (NEU1) in Ewing sarcoma (ES) tissue and its effect on the proliferation and migration of ES cells. Methods: To obtain datasets of ES from the National Center for Biotechnology Information's High-Throughput Gene Expression Omnibus (GEO) for the analysis of NEU1 expression in ES; to acquire ES patient dataset from the International Cancer Genome Consortium (ICGC) database and apply Kaplan-Meier survival analysis to investigate the relationship between NEU1 and the prognosis of ES patients; adopting both univariate and multivariate Cox regression analysis to determine whether NEU1 is a prognostic factor for ES; adopting the Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation to analyze the potential mechanism of NEU1 in regulating the malignant biological behavior of ES; adopting the real-time fluorescence quantitative polynucleotide chain reaction (RT-qPCR) to verify the expression of NEU1 in the human bone marrow mesenchymal stem cells (hBMSC) and the ES cell line RD-ES; adopting the transfection technology to knock down the expression of NEU1 in ES cell lines and divide them into two groups: shRNA-NEU1 and shRNA-NC to explore the effects of altered NEU1 expression on ES malignant behavior; adopting the cell counting kit (CCK-8) and cell clone formation experiment to detect the proliferation ability of two groups of cells; adopting the scratch healing experiment to test the cell migration ability of the two groups. Results: We retrieved and analyzed data from the GEO database, including GSE17674 (44 ES tissues and 18 normal tissues) and GSE17679 (87 ES tissues and 18 normal tissues), and found that NEU1 expression was significantly higher in ES tissues compared to normal control tissues (P<0.001). The complete gene expression and clinical information of 56 ES patients obtained from the ICGC database revealed that the ES patients with high NEU1 expression (n=28) had a significantly lower overall survival rates at different time points compared to those with low NEU1 expression (n=28) (HR=2.830, 95%CI:1.324-6.051, P=0.005). Univariate analysis indicated that NEU1 could impact ES patient prognosis (HR=1.049, 95%CI: 1.008-1.092, P=0.019), and multivariate analysis further suggested that NEU1 could serve as a risk factor for ES prognosis (HR=1.087, 95%CI: 1.028-1.148, P=0.003). KEGG results show that MAPK signaling pathway and cell adhesion molecule signaling pathway were potential mechanisms regulating the malignant process of ES. The RT-qPCR results showed that the expression level of NEU1 in the RD-ES cell line is significantly higher than that in the control cell hBMSC (2 184.23±527.32 vs 1.00±0.08, P<0.001). The CCK-8 experiment results show that the proliferation of RD-ES cells in the NEU1 knockdown group was lower than that in the control group at 24, 48, and 72 hours (0.494±0.126 vs 0.696±0.118, 0.657±0.096 vs 1.142±0.182, 1.053±0.064 vs 1.980±0.146, all P<0.001). The results of single cell clone formation experiment show that the number of colony formation in the low expression NEU1 group was significantly lower than that in the control group (184.2±123.9 vs 362.8±78.0, P=0.021). The cell scratch healing experiment finds that the average scratch distance of the NEU1 knockdown group was significantly lower than that of the control group (19.6%±5.7% vs 56.0%±7.6%, P<0.001). Conclusion: NEU1 may be a prognostic factor in ES, and its abnormal expression in ES can affect the proliferation and migration ability of the ES cells, leading to poor prognosis in ES patients.

Aberrantly high DEPDC1B expression leads to poor prognosis in patients with lower-grade gliomas.

OBJECTIVE: DEPDC1B, which encodes DEP domain-containing protein 1B, exerts pathogenic effects in diverse cancers, but no such effect has been reported in the case of lower-grade glioma (LGG). Therefore, we sought to investigate the relationship between DEPDC1B expression and the prognosis of patients with LGG and reveal the underlying molecular mechanism. MATERIALS AND METHODS: First, RT-qPCR and immunohistochemical staining were used to examine DEPDC1B mRNA and protein expression in LGG. Second, transcriptomic data were collected from The Cancer Genome Atlas and Chinese Glioma Genome Atlas databases to investigate the impact of DEPDC1B expression on LGG patients by using the Kaplan-Meier survival analysis, receiver operating characteristic analysis and Cox models. Third, the effects of DEPDC1B on LGG cell proliferation and migration were revealed using wound-healing and Cell Counting Kit-8 assays and Ki67 immunofluorescence staining. Fourth, the Tumor Immune Estimation Resource database was used to examine how DEPDC1B affects the LGG immune microenvironment, and gene set enrichment analysis was used to uncover the signaling pathways in which DEPDC1B is involved in LGG. RESULTS: DEPDC1B was significantly upregulated in both LGG cells and tissues, and high expression of DEPDC1B contributed to poor prognosis of LGG patients and represented an independent risk factor for LGG. Moreover, DEPDC1B knockdown reduced the proliferation and migration abilities of LGG cells. Lastly, DEPDC1B was found to be positively associated with multiple immune infiltrates and immune-checkpoint markers. CONCLUSIONS: Our findings indicate for the first time that DEPDC1B is a pathogenic gene in LGG. More importantly, we provide a new biomarker and immunotherapeutic target for improving the diagnosis and treatment of LGG patients.

LncRNA SNHG1 attenuates neuropathic pain following spinal cord injury by regulating CDK4 level.

OBJECTIVE: Neuropathic pain (NP) is one of the most intractable complications of spinal cord injury (SCI). This study aims to explore the role of long non-coding RNA (lncRNA) SNHG1 in influencing SCI-induced NP. MATERIALS AND METHODS: After establishment of the spinal nerve ligation (SNL) model in rats, spinal tissues were extracted. SNHG1 level in rat spinal tissues was determined by quantitative real-time polymerase chain reaction (qRT-PCR). The role of SNHG1 in the development of NP was explored by assessing paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) in model rats. The interaction between SNHG1 and CDK4 was explored by Luciferase assay and RIP (RNA-Binding Protein Immunoprecipitation). Enzyme-linked immunosorbent assay (ELISA) and qRT-PCR were conducted to determine inflammatory factor levels in rat spinal tissues. RESULTS: SNHG1 was upregulated in rats undergoing SNL. Knockdown of SNHG1 alleviated the development of NP and overexpression of SNHG1 was capable of inducing NP symptoms in uninjured rats. SNHG1 induced NP by directly regulating CDK4 level. CONCLUSIONS: SNHG1 is a novel target in the treatment of NP associated with neuroinflammation.

[Early efficacy of percutaneous endoscopic cervical discectomy with multimodal neurophysiological monitoring].

Objective: To explore the clinical efficacy of percutaneous endoscopic cervical discectomy (PECD) assisted by neurophysiology monitoring (NM) in the treatment of cervical spondylotic radiculopathy (CSR). Methods: The clinical data of 55 patients with CSR treated in the Department of Spinal Surgery of Henan Provincial People's Hospital from April 2015 to May 2018 were analyzed retrospectively. Among them, 29 patients were treated with multi-mode NM-assisted PECD (NM group) and 26 patients with PECD alone (PECD group). The gender, age, operation time, bleeding volume, average hospital stay and complications between the two groups were recorded and compared. In addition, the visual analogue score (VAS) of neck and upper limb pain and the score of Japanese Orthopedic Association (JOA) were compared between the two groups before operation, 1 month after the operation and at the last follow-up. These data between groups were compared by independent sample t test. Results: All patients in both groups were followed-up for at least 18 months. Neck VAS and upper limb VAS scores of two groups at 1 month post operation (neck: 2.1±1.2, 2.0±1.1; upper lamb: 2.4±1.2, 2.2±0.8) and the last follow-up (neck:0.8±0.5, 0.7±0.5; upper lamb: 0.8±0.7, 0.8±0.5) decreased significantly when compared with those before the operation (neck: 6.0±1.0, 5.9±1.0; upper lamb: 7.1±0.9, 7.4±0.9) (t=12.670-27.305, all P<0.05). However, there was no significant difference between the two groups (t=-1.107-0.917, all P>0.05). JOA scores of two groups at 1 month after the operation (12.7±0.8, 12.6±0.8), and at the last follow-up (14.6±0.7, 14.4±0.8) were all improved significantly from those before the operation (11.1±1.0, 10.9±0.8) (t=-11.074, -14.829, -9.603, -13.086, all P<0.05); however, there was no significant difference between the two groups (t=0.842, 0.003, both P>0.05). There was also no significant difference in bleeding volume, and operation time between the two groups, (t=-0.615, -0.922, P>0.05) but the average hospital stay and incidence of complications in the NM group were significantly lower than those in the PECD group (t=-2.815, χ(2)=4.755, both P<0.05). Conclusion: Multimode NM-assisted PECD in the treatment of CSR achieves satisfactory results, reducing the average hospital stay, reducing complications and improving surgical safety.

Prognostic model for identifying candidates for hepatectomy among patients with hepatocellular carcinoma and hepatic vein invasion.

BACKGROUND: Hepatic vein tumour thrombus (HVTT) is a major determinant of survival outcomes for patients with hepatocellular carcinoma (HCC). An Eastern Hepatobiliary Surgery Hospital (EHBH)-HVTT model was established to predict the prognosis of patients with HCC and HVTT after liver resection, in order to identify optimal candidates for liver resection. METHODS: Patients with HCC and HVTT from 15 hospitals in China were included. The EHBH-HVTT model with contour plot was developed using a non-linear model in the training cohort, and subsequently validated in internal and external cohorts. RESULTS: Of 850 patients who met the inclusion criteria, there were 292 patients who had liver resection and 198 who did not in the training cohort, and 124 and 236 in the internal and external validation cohorts respectively. Contour plots for the EHBH-HVTT model were established to predict overall survival (OS) rates of patients visually, based on tumour diameter, number of tumours and portal vein tumour thrombus. This differentiated patients into low- and high-risk groups with distinct long-term prognoses in the liver resection cohort (median OS 34·7 versus 12·0 months; P < 0·001), internal validation cohort (32·8 versus 10·4 months; P = 0·002) and external validation cohort (15·2 versus 6·5 months; P = 0·006). On subgroup analysis, the model showed the same efficacy in differentiating patients with HVTT in peripheral and major hepatic veins, the inferior vena cava, or in patients with coexisting portal vein tumour thrombus. CONCLUSION: The EHBH-HVTT model was accurate in predicting prognosis in patients with HCC and HVTT after liver resection. It identified optimal candidates for liver resection among patients with HCC and HVTT, including tumour thrombus in the inferior vena cava, or coexisting portal vein tumour thrombus.

ANTECEDENTES: La trombosis tumoral de la vena hepática (hepatic vein tumour thrombus, HVTT) es un determinante importante de los resultados de supervivencia en pacientes con carcinoma hepatocelular (hepatocellular carcinoma, HCC). Se desarrolló el modelo llamado Eastern Hepatobiliary Surgery Hospital (EHBH)-HVTT para predecir el pronóstico de los pacientes con HCC y HVTT después de la resección hepática (liver resection, LR), con el fin de identificar los candidatos óptimos para LR entre estos pacientes. MÉTODOS: Se incluyeron pacientes con HCC y HVTT de 15 hospitales en China. El modelo EHBH-HVTT con gráfico de contorno se desarrolló utilizando un modelo no lineal en la cohorte de entrenamiento, siendo posteriormente validado en cohortes internas y externas. RESULTADOS: De 850 pacientes que cumplieron con los criterios de inclusión, hubo 292 pacientes en el grupo LR y 198 pacientes en el grupo no LR en la cohorte de entrenamiento, y 124 y 236 en las cohortes de validación interna y externa. Los gráficos de contorno del modelo EHBH-HVTT se establecieron para predecir visualmente las tasas de supervivencia global (overall survival, OS) de los pacientes, en función del diámetro del tumor, número de tumores y del trombo tumoral de la vena porta (portal vein tumour thrombus, PVTT). Esto diferenciaba a los pacientes en los grupos de alto y bajo riesgo, con distinto pronóstico a largo plazo en las 3 cohortes (34,7 versus 12,0 meses, 32,8 versus 10,4 meses y 15,2 versus 6,5 meses, P < 0,001). En el análisis de subgrupos, el modelo mostró la misma eficacia en la diferenciación de pacientes con HVTT, con trombo tumoral en la vena cava inferior (inferior vena cava tumour thrombus, IVCTT) o en pacientes con PVTT coexistente. CONCLUSIÓN: El modelo EHBH-HVTT fue preciso para la predicción del pronóstico en pacientes con HCC y HVTT después de la LR. Identificó candidatos óptimos para LR en pacientes con HCC y HVTT, incluyendo IVCTT o PVTT coexistente.

MicroRNA-765 targets MTUS1 to promote the progression of osteosarcoma via mediating ERK/EMT pathway.

OBJECTIVE: Previous studies have shown that microRNA-765 (miR-765) is involved in certain biological behaviors of human cancers. However, abnormal expression and function of miR-765 have not been reported in osteosarcoma (OS). PATIENTS AND METHODS: Changes in the expression of miR-765 and MTUS1 (Microtubule-associated tumor suppressor 1) were examined via Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. The function of miR-765 was investigated through Cell Counting Kit-8 (CCK-8) and transwell assays in OS. The target of miR-765 was identified using a Dual-Luciferase reporter assay. RESULTS: MiR-765 was upregulated in OS tissues. And upregulation of miR-765 promoted cell proliferation, migration and invasion in OS. In addition, MTUS1 was confirmed as a direct target gene of miR-765. Moreover, miR-765 promoted the progression of OS through targeting MTUS1. Furthermore, miR-765 was involved in tumorigenesis of OS through activating extracellular-signal-regulated kinase/ epithelial-mesenchymal transition (ERK/EMT) pathway. CONCLUSIONS: MiR-765 targets MTUS1 to promote the progression of OS via mediating the ERK/EMT pathway. Therefore, miR-765 may be used as a novel biomarker for the diagnosis of OS.

[Characteristics of exercise ventilation and gas exchange in obese and extremely obese patients].

Objective: To evaluate the characteristics of exercise ventilation and gas exchange in obese and extremely obese patients by Cardiopulmonary exercise test (CPX). Methods: Restrospective anal-ysis of subjects who underwent CPET in Shengjing Hospital of China Medical University from June 2014 to June 2017. A total of 74 subjects were enrolled. According to the body mass index (BMI), 74 subjects were divided into control group(18.5 kg/m(2)≤BMI<23.9 kg/m(2)) (n=21), obese group (28.0 kg/m(2)≤BMI<40.0 kg/m(2)) (n=30) and extremely obese group(BMI≥40.0 kg/m(2))(n=23), respectively. V(O2max), V(O2max)/kg, anaerobic thresh-old(AT), oxygen pulse(V(O2)/HR), breath reserve(BR), inhale time (VTin), expiratory time(VTex) and ventilato-ry equivalent for CO(2)(EqCO(2))were measured by CPX and compared by using one-way ANOVA. Results: Compared to the control group (1 620±400) L/min, the maximal oxygen uptake(V(O2max)) in obese group(1 905±592) L/min and extremely obese group (2 131.09±541.86) L/min were significance higher (F=5.14, P<0.01). The V(O2max)/kg in obese group (19±5) L·min(-1)·kg(-1) and extremely obese groups (16±4) L·min(-1)·kg(-1) were sig-nificant lower than those in control group(27±5)L·min(-1)·kg(-1) (F=35.37,P<0.01). Compared to the control group (9.3±1.4)L·min(-1)·W(-1), the change of oxygen uptake required under certain exercise load (ΔV(O2)/ΔWR) in obese group(9.0±1.7) L·min(-1)·W(-1)and extremely obese group (8.7±2.2) L·min(-1)·W(-1) were no significant difference (F=0.67,P=0.51). The AT in obese group (1 114±391) L/min and extremely obese group (1 348±349) L/min were significant higher than those in control group (832±223) L/min (F=12.85,P<0.01). Com-pared to the control group(10±4) L·min(-1)·b(-1), V(O2)/HR in obese group (12±3) L·min(-1)·b(-1) and extremely obese group(14±3) L·min·b(-1) were significance higher (F=8.16, P<0.01). No significant difference was found between the three groups in BR, VTin, VTex and EqCO(2). Conclusion: obese and extremely obese individu-als have a decreased ablity to exercise when the body requires anaerobic metabolism to provide energy. As exercise power increases, the heart oxygen consumption per stroke and the amount of volume and oxygen re-quired for gax exchange does increase.

[Posterior debridement combined with atlantoaxial fusion to upper cervical tuberculosis].

Objective: To explore clinical results of posterior debridement combined with atlantoaxial fusion for upper cervical Tuberculosis. Methods: From March 2007 to April 2012, 8 patients with upper cervical Tuberculosis underwent posterior debridement combined with atlantoaxial fusion in our hospital were selected for retrospective analysis. 3 cases were males and 5 females, aged 29-65 (43.5±13.2) years. According to the pedicle destruction, using different screws (pedicle screw or laminar screw) fixation.In the preoperative and final follow-up, Japanese Orthopaedic Association score (JOA) and neck disability index (NDI) were used to evaluate neurological function and calculate improvement rate JOA score. At final follow-up, clinical efficacy was evaluated by Odom's grade. situation of internal fixation, fusion of upper cervical were assessed by imaging examination. During follow-up, complications were documented and analyzed. Results: Postoperatively 12 months, all bony fusion were achieved. Tuberculosis were reached clinical cure in 12-18 months. The JOA score increased from 10.5±2.0 preoperatively to 15.6 ±1.1 in final follow-up(P<0.05), and the NDI decreased from 29.9 ± 6.2 preoperatively to 8.6±1.6 (P<0.05). At last follow-up, according to Odom's standard, excellent were obtained in 6 cases (75.0%), good 1 cases (12.5%) and ordinary 1 case (12.5%). No severe complications was documented during follow-up. Conclusions: The treatment of posterior debridement combine with atlantoaxial fusion, and structure grafting and local anti-Tuberculosis drug using intraoperative, not only could obtain reliable clinical efficacy, completely removal of lesions, but also obtain strong stability, which plays an important role in the treatment of cervical tuberculosis.

[A cross-sectional survey of the knowledge on chronic obstructive pulmonary disease in physicians of tertiary hospitals in Northern China].

To investigate physicians' knowledge about chronic obstructive pulmonary disease (COPD) in tertiary hospitals in northeast China. Physicians from 77 tertiary hospitals in northeast China were surveyed with a questionnaire, which included questions such as risk factors, symptoms, exacerbations, comorbidities and diagnostic criteria of COPD. Besides cigarette smoking, air pollution and pulmonary infections, only 22.5%(40/178) physicians recognized that the biomass fuels may induce COPD. Totally 59.0%(105/178) physicians recognized the importance of spirometry to the diagnosis of COPD. Besides dyspnea, cough, sputum production, wheezing and chest tightness, only 23.7%(42/177) of physicians considered that limitation of activity was an important symptom of COPD. 65.5%(116/177) physicians believed that recurrent lung infections was one of the most important comorbidities of COPD. However, less than 30%[20.9%(37/177)-28.8%(51/177)] physicians were aware of the other important comorbidities. The physicians of tertiary hospitals in northeast China need to be systematically educated on COPD to meet the new guideline.

[Anterior retropharyngeal debridement combined with posterior atlantoaxial fusion for atlantoaxial Tuberculosis].

OBJECTIVE: To evaluate the clinical efficacy of anterior debridement combined with posterior atlantoaxial fusion for atlantoaxial Tuberculosis. METHODS: From February 2005 to February 2013, 7 patients, 3 males and 4 females, with atlantoaxial Tuberculosis underwent anterior debridement combined with posterior atlantoaxial fusion in Department of Orthopedics Zhengzhou University People's Hospital were selected.In the preoperative and final follow-up, Japanese Orthopaedic Association score (JOA), neck disability index (NDI) and Frankel Classification were used to evaluate neurological function and calculate improvement rate.At final follow-up, clinical efficacy was evaluated by Odom's grade.Situation of internal fixation, fusion of upper cervical were assessed by X-ray, CT scan and MRI scan. RESULTS: Bony fusion were achieved in 7 cases after operation in 12 months. Tuberculosis were reached clinical cure between 17 and 21 months. At follow The JOA score increased from (11.1±0.7) preoperatively to (15.3±0.5) in final follow-up(P<0.05), and the NDI decreased from (34.0±4.6) preoperatively to (10.1±1.3) in final follow-up (P<0.05). At last follow-up, according to Odom's standard, excellent were obtained in 5 cases, good 1 cases and ordinary 1 case. Frankel Classification of all cases improved from D class to E. CONCLUSIONS: The treatment of anterior retropharyngeal debridement combine with atlantoaxial fusion, and local anti-tuberculosis drug using intraoperative, not only could obtain reliable clinical efficacy, completly removal of lesions, but also obtain strong stability, which plays an important role in the treatment of atlantoaxial Tuberculosis.

Microsurgery for ruptured cerebellar arteriovenous malformations.

OBJECTIVE: To summarize the clinical features of ruptured cerebellar arteriovenous malformations (AVMs) and to explore surgical methods and outcomes in ruptured cerebellar AVM patients. PATIENTS AND METHODS: In the past 14 years, 67 patients with cerebellar AVMs were treated at our institution, accounting for 14.9% of the total vascular malformation patients in our department. In this study, we retrospectively analyzed the clinical characteristics, operation indication, surgery techniques, and prognoses of these cases. RESULTS: Among the 67 AVM cases, the distribution of Spetzler-Martin grades was 32 Grade I, 14 Grade II, 13 Grade III, 5 Grade IV, and 3 Grade V cases. Microsurgical treatment was carried out via the retrosigmoid approach or suboccipital midline approach. After the surgery, the distribution of GOS grades was 60 Grade V, 3 Grade IV, 1 Grade III, 2 Grade II, and 2 Grade I cases. CONCLUSIONS: Microsurgical removal should be performed in ruptured cerebellar AVM patients as early as possible once the preoperative and postoperative preparations were done. Good surgical effects were obtained by using proper surgery techniques and the right protection of critical cerebral structures. Patients with a GCS grade of ≥ 8 showed good recovery, but patients with a grade of < 8 had poor prognoses.

Clinical results of the transoral operation for lesions of the craniovertebral junction and its abnormalities.

BACKGROUND: We treated 20 cases of craniovertebral junction lesions via a transoral approach. Developmental abnormalities of the craniovertebral junction accounted for 15 cases; there were 3 cases of tumor, 1 case of osteomyelitis, and 1 case of rheumatoid arthritis. METHODS: The transoral transpharyngeal approach was used in all cases. In 17 non-tumoral patients the anterior margin of the atlas and the odontoid process were resected. In one patient with a ventral clivus chordoma, both a transoral and a transnasal transsphenoidal approach was used for partial resection of the tumor mass. In two cases the median transpharyngeal approach was combined with a jaw-facial incision. In one case a metastatic adenocarcinoma, and in another a neurinoma of the accessory nerve straddling the posterior fossa and the pharyngeal region were removed. RESULTS: After operation four cases developed craniovertebral joint instability and required posterior cervical fusion or external fixation with a halo brace. Follow-up ranged from 2 to 44 months. In most patients neurologic function slowly improved. One worsened, and one died of respiratory failure after operation. Two patients with malignant tumors died during the follow-up period. CONCLUSION: In patients with developmental malformations, transoral decompression will result in some neurologic improvement and arrest the progress of symptoms. Patients with tumors are likely to show a good neurologic outcome when transoral surgery is performed in the early stage of the condition.

[Treatment of the lesions at anterolateral area of the brain stem via far-lateral approaches].

Based on our 12 cases of lesions located at anterolateral area of brain stem which were successful operated upon via far-lateral approaches, the study and progress of the far-lateral approaches were reviewed. In our cases, there were 4 intramedullary lesions including 3 vascular malformations, and 1 glioma. The other 8 lesions were located at extramedullary anterolateral area of brain stem including 2 large acoustic neuromas, 2 meningiomas at clivus and 2 neurofibromas at anterolateral areas of the medulla oblongata and upper spinal cord, 1 teratoma at the anterolateral area of pone-medulla and 1 large aneurysm at the junction of vertebrobasilar artery. During the operations, 8 lesions were totally removed. 1 meningioma was subtotally removed. 2 (1 vascular malformation and 1 glioma) were subtotally removed too, the aneurysm was only given a decompression of increased intracranial pressure, because the patient's interrupted respiration during the operation. There were nooperative mortality and morbidity and good results were obtained in this group. The details of our modified far-lateral approach was also described in this paper.

[Cavernomas of the central nervous system].

18 cases of pathological cavernoma of the central nervous system were reported. The took 11.25 per cent of verified vascular malformations in our department in the same period. 15 cases located intracranially, and 3 cases were within the vertebral canal. Repeated small amount hemorrhages in the lesions were the major cause of the clinical symptoms of these patients. MRI was the most reliable method for making a correct diagnosis of cavernomas before operation. Cavernomas usually had clear border and surrounded with gliotic tissues, so that extirpation of tumor with microsurgical technique was the best choice.

An acute experimental model of saccular aneurysms in the rat.

A new and reproducible saccular aneurysm model has been developed at the bifurcation of the common carotid artery in rats. The details of the experimental methods and results are described. It is strongly suggested that the internal elastic lamina is a critical layer in saccular aneurysm formation, because an experimental saccular aneurysm can be produced immediately by transluminally damaging the inside of the arterial wall at the bifurcation of the common carotid artery. This saccular aneurysm model has several advantages: (i) it can be induced quickly and the success rate approaches 100% in rats; (ii) this technique can produce satisfactory experimental saccular aneurysms for other aneurysm studies, and in the future it will also be possible to use this technique to produce experimental saccular aneurysms in cerebral arteries of large animals.

Arachnoid cyst in the internal auditory canal.

An arachnoid cyst of the internal auditory canal causing compression atrophy of nerve trunks was found in each of three human temporal bones. Arachnoid cysts are found in about 0.5% of operations for suspected neoplasm of the internal auditory canal. There is no current method for differentiating intracanalicular neoplasm from arachnoid cysts.