ABSTRACT
OBJECTIVE To observe the changes of synaptic ultrastructures in the rat auditory center after long-term salicylate administration and to elucidate the role of neuroplasticity in some areas of the CNS and its involvement in tinnitus. METHODS The rats were divided into 4 groups: the control group, the acute treatment group, the chronic treatment group, and the recovery group. We investigated ultrastructural alterations in the synapses of inferior colliculus (IC), auditory center (AC) and cerebellum (CRB) by transmission electron microscopy. RESULTS There were more synaptic vesicles (tIC=-4. 61, tAC=-7. 00, P＜0. 01), with greater postsynaptic densities(tIC=-4. 72,P＜0. 01; tAc=-3. 15, P＜0. 05), longer synaptic active zone (tIC=-4. 89, tAC=-3. 48, P＜ 0. 01), and increased synaptic interface curvature (tIC=-2. 32, tAC=-3. 17, P＜0. 05) in the chronic treatment group, as compared with the control group. There were more synaptic vesicles but no other changes in the acute salicylate-treatment group(tIC=-10. 57, tAC=-8. 34, tCRB=-9. 18,P ＜0. 01). CONCLUSION These findings showed that long-term salicylate administration have induced synaptic ultrastructural changes in the IC and AC because of neuroplasticity. These structural changes may result in increased speed and efficacy of chemical synaptic transmission. Alterations to neuroplasticity of the auditory center pathway may lead to tinnitus.
ABSTRACT
Objective To investigate the neural activity in the central auditory pathway by using a tinnitus an-imal model .Methods Twenty -four rats were randomly divided into the control ,acute salicylate treatment ,chronic salicylate treatment ,and recovery groups .The gap prepulse inhibition of acoustic startle test was used to confirm tinnitus -like behavior .After delivery of an intravenous bolus of fluorine -18 fluorodeoxyglucose (18F -FDG ) , small animal positron emission tomography scans were performed on rats .Results Only rats in chronic salicylate -treatment group showed evidence of experiencing tinnitus .The SUV ratios of the AC were significantly greater in the acute salicylate treatment group than in the control group (P<0 .01) ,suggesting relatively increased metabolism in the two brain regions of the rats in this group .The SUV ratios of the IC and AC (P<0 .01) ,but not of the CRB (P>0 .05) were greater in the chronic salicylate treatment group than in the control groups .There was a significant difference in whole brain SUVs between the control and acute salicylate treatment groups (P<0 .01) ,the whole brain SUVs in chronic salicylate treatment group were a little higher but showed no significant difference (P>0 .05) .There was no significant difference in the SUVs between the control and recovery groups (P>0 .05) .Conclu-sion These findings indicate that long -term salicylate administration induced tinnitus in rats and may have en-hanced neural activity corresponded to the up -regulated metabolic rate in our study .Alterations to neuroplasticity of the CNS may lead to tinnitus .
ABSTRACT
Presently, with the development of tissue engineering technology, medical workers have seen a more effective and safer therapy to repair and reconstruct tissue defects. Many domestic and abroad animal experiments have confirmed that it is feasible, effective and superior to use tissue-engineered bone and cartilage for repairing tissue defects. There have been achieved considerable results using tissue-engineered bone and cartilage to repair tissue defects and reconstruct tissue functions through the animal experiments and initial clinical studies. Compare with traditional operations, tissue engineering technology has a broader clinical application, especially in orthopedics, department of stomatology, cranio-facial surgery and ear, nose and throat, department. However, through the research, we recognize some deficiencies of tissue engineering, such as single tissue components, lack of biological activity, limited for scaffolds, tissue regeneration and productions.
ABSTRACT
OBJECTIVE To establish the isolation and identification system of human mesenchymal stem cells(hMSCs)in vitro, and then to establish a stable cultured system in which the hMSCs can be induced to osteoblasts, chondroblasts and lipoblasts in vitro. To study the possibility if hMSCs can be used as the seed cells in bone tissue engineering.This study would lay a foundation for the clinical application of tissue engineering. METHODS 5ml bone marrow of the patient was aspirated from iliac crest. The human MSCs were isolated using Percoll gradient centrifugation. The hMSCs were cultured in DMEM medium in vitro, FACS(fluorescence axtivated cell sorter)was used to identify the phenotype of hMSCs. The hMSCs were cultured in vitro, and induced to osteoblasts, chondrocytes and lipocytes. The changes of phenotype were tested by mmunohistochemisty and molecular biology technique. RESULTS The hMSCs were isolated by Percoll gradient centrifugation from patient’s bone marrow. The expression rate of MSC markers including CD105, CD166, CD29 were(78?6)%, (43?7)%, (69? 12)% respectively. The phenotype of osteoblasts induced from hMSCs was verified by the mineralized nodes formation when cultured in vitro and Col, and OCN expression showed by immunohistochemistryand RT-PCR. The phenotype of chondrocytes induced from hMSCs was verified by type, collagen, SOX9 expression with immunohistochemical staining technique and type, collagen, aggrecan mRNA expression with RT-PCR. The lipocytes’ phenotype was verified by positive result of oil red O staining and PPAR 2mRNA expression by RT-PCR. CONCLUSION The highly pure hMSCs can be harvested by means of density gradient centrifugation, and the hMSCs have multi-potentiality of cell differentiation via induced culture in vitro. The third passage of hMSCs can be induced to express osteoplast phenotype and meet the qualitative and quantitative demands of seed cells when bone tissue engineering was used in clinical practice.
ABSTRACT
Objective To report our experience in the embolization of the high-flow vascular lesion in the head and neck by direct percutaneous puncture. Methods Eleven cases of high-flow vascular lesion in the head and neck (8 cases of central hemangioma of the jaws and 3 cases of juvenile nasopharyngeal angiofibroma) were included in this study group. The patients of central hemangioma of the jaws were embolized with coils by a 14-gauge needle, and the fibered coils were placed directly into the center of the intraosseous AVM. The patients of juvenile nasopharyngeal angiofibroma were embolized with NBCA by a No.7 needle. The procedure was under the guidance of DSA machine (Philips V3000). Results The acute arterial bleeding in patients with central hemangioma of the jaws from the extraction of the tooth was controllable, and the pericoronal oozing of bleed disappeared in the 9-24 months follow-up. The juvenile nasopharyngeal angiofibromas were resected without blood transfusion after the embolization. Conclusion The embolization of the high-flow vascular lesion in the head and neck by direct percutaneous puncture was effective and safe, however the longer follow-up was expected.
ABSTRACT
Objective To evaluate the clinical value of pre-operative double embolization for nasopharyngeal angiofibroma. Methods Digital subtraction angiography(DSA) was carried out in 7 cases of nasopharyngeal angiofibroma. In six cases,the supplying arteries originated from the maxillary artery and the branches arising from internal carotid artery underwent double embolization-direct percutaneous puncture embolization and selective embolization of blood supplying arteries. In another case,the supplying artery originated from maxillary artery was only undertaken selective embolization for the feeding arteries. Results All the tumor masses reduced in vonlume obviously or even disappeared on the angiography after embolization. Conclusions Pre-operative double embolization for nasopharyngeal angiofibroma could be a necessary additional treatment method. (J Intervent Radiol,2006,15: 342-344)