Construction of a multiple-scale implant surface with super-hydrophilicity / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To construct a multiple-scale organized implant surface with super-hydrophilicity.</p><p><b>METHODS</b>The SiC paper polished titanium disc was sandblasted and treated with HF/HNO₃ and HCl/H₂SO₄, then acid-etched with H₂SO₄/H₂O₂. The physicochemical properties of the surfaces were characterized by scanning electron microscope, static state contact angle and X-ray diffraction. MC3T3-E1 cells were used to evaluate the effects of the surface on the cell adhesion, proliferation and differentiation.</p><p><b>RESULTS</b>The acid-etching process with a mixture of H₂SO₄/H₂O₂ superimposed the nano-scale structure on the micro-scale texture. The multiple-scale implant surface promoted its hydrophilicity and was more favorable to the responses of osteoprogenitor cells, characterized by increased DNA content, enhanced ALP activity and promoted OC production.</p><p><b>CONCLUSION</b>A multiple-scale implant surface with super-hydrophilicity has been constructed in this study, which facilitates cell proliferation and adhesion.</p>

Study on the effects of overexpression of exogenous Notch1 in tongue squamous cell carcinoma cells on cell growth and expression of epidermal growth factor receptor in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of overexpression of exogenous Notch1 in human tongue squamous cell carcinoma (TSCC) cells on cell growth and expression of epidermal growth factor receptor (EGFR) in vitro.</p><p><b>METHODS</b>Human TSCC cell line Tca8113 cells were transiently transfected with the eukaryotic expression plasmid pRAMIC-IRES2-EGFP encoding exogenous intracellular fragment of Notch1 and control plasmid pIRES2-EGFP by Lipofectamine 2000, respectively. Untransfected parental Tca8113 cells served as control. The cell proliferation was evaluated by methyl thiazolyl tetrazolium(MTT) assay. The apoptosis was assessed by flow cytometry. The mRNA and protein levels of Notch1 and EGFR in Tca8113 cells were detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot. The expression of EGFR protein in Tca8113 cells was detected by immunocytochemistry.</p><p><b>RESULTS</b>MTT assay showed that the cell proliferation of Tca8113 cells transfected with pRAMIC-IRES2-EGFP was significantly inhibited as compared with controls (P < 0.05). After transfected with pRAMIC-IRES2-EGFP for 48 h, the apoptosis rate of Tca8113 cells was significantly higher than those of Tca8113 cells transfected with pIRES2-EGFP and untransfected Tca8113 cells (P < 0.05), and Notch1 expression was significantly increased at mRNA (P < 0.05) and protein (P < 0.05) levels, while EGFR expression was significantly decreased at mRNA (P < 0.05) and protein (P < 0.05) levels.</p><p><b>CONCLUSION</b>Overexpression of exogenous Notch1 may inhibit cell growth and down-regulate EGFR expression in TSCC cells.</p>

Expression of Notch1 and epidermal growth factor receptor in human tongue squamous cell carcinoma and precancerous lesion / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the expression of Notch1 in human tongue squamous carcinoma (TSCC) and precancerous lesion, and to explore the potential relation between Notch1 and epidermal growth factor receptor (EGFR).</p><p><b>METHODS</b>The expression of Notch1 and EGFR was detected in human TSCC (n = 41), tongue leukoplakia (LP) (n = 39) and normal tongue mucosa (n = 7) by immunohistochemistry.</p><p><b>RESULTS</b>In normal tongue mucosa and LP, the positive staining of Notch1 was mainly distributed in stratum corneum, partially in stratum granulosum and stratum spinosum, but not in stratum basale, while the positive staining of EGFR was mainly distributed in stratum basale, rarely in stratum spinosum, but not in stratum granulosum and stratum corneum. In TSCC, Notch1 expression was mainly distributed in locations of squamous metaplasia, but not in peripheral cells of carcinomas, while EGFR expression was detected mainly in peripheral cells of carcinomas, but not in locations of squamous metaplasia.</p><p><b>CONCLUSION</b>Notch1 promotes the differentiation of epithelial cells in tongue mucosa and acts as a tumor suppressor in TSCC. EGFR may act as a negative regulator of Notch1 expression in epithelium of tongue mucosa and TSCC, for maintaining cell proliferation and promoting the tumorigenesis and progression of TSCC.</p>

Effects of epidermal growth factor receptor gene silencing mediated by short hairpin RNA on proliferation and apoptosis of human tongue carcinoma cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of epidermal growth factor receptor (EGFR) gene silencing mediated by short hairpin RNA (shRNA) on proliferation and apoptosis of human tongue carcinoma cells.</p><p><b>METHODS</b>shRNA eukaryotic expression vector targeting the specific sequence of human EGFR gene was constructed and termed shEGFR. The control vector targeting the unrelated sequence was also constructed and termed shNC. The vectors were transiently transfected into Tca8113 cells of human tongue squamous cell carcinoma by Lipofectamine 2000, respectively. The mRNA and protein levels of EGFR in Tca8113 cells were detected by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. The cell proliferation of Tca8113 cells was evaluated by methyl thiazolyl tetrazolium (MTT) assay. The apoptosis of Tca8113 cells was assessed by flow cytometry.</p><p><b>RESULTS</b>EGFR expression in Tca8113 cells transfected with shEGFR were obviously decreased at mRNA level (81.6%) and protein level (72.0%) (P < 0.05) 48 h after transfection of shEGFR compared with untransfected Tca8113 cells. The proliferation activity of Tca8113 cells transfected with shEGFR was significantly lower than that of Tca8113 cells transfected with shNC and untransfected Tca8113 cells (P < 0.05). The early apoptotic rate of Tca8113 cells transfected with shEGFR was significantly higher than that of Tca8113 cells transfected with shNC and untransfected Tca8113 cells [(39.4 +/- 7.7)%, (4.3 +/- 1.2)%, (2.5 +/- 0.9)%, P < 0.05] 48 h after transfection of shEGFR.</p><p><b>CONCLUSIONS</b>EGFR gene silencing mediated by shRNA may inhibit cell proliferation and induce apoptosis in human tongue carcinoma cells.</p>

Expression of vascular endothelial growth factor, vascular endothelial growth factor receptor-3 and nm23-H1 in oral squamous cell carcinoma / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To explore the role of vascular endothelial growth factor C (VEGF-C), VEGFR-3 and nm23-H(1) in lymphatic metastasis of oral squamous cell carcinoma (OSCC).</p><p><b>METHODS</b>The expression of VEGF-C, VEGFR-3 and nm23-H(1) were examined by immunohistochemical SP method. The lymphatic vessels density (LVD) in tumors was counted and analyzed with clinicopathologic parameters.</p><p><b>RESULTS</b>VEGF-C, LVD and nm23-H(1) expressions were significantly different between OSCC and benign and precancerous lesions (P < 0.05). VEGF-C was correlated with lymph node metastasis and LVD (P < 0.01). nm23-H(1) was related to clinical stage, histological grade and lymphatic metastasis (P < 0.05).</p><p><b>CONCLUSIONS</b>The high expressions of VEGF-C/VEGFR-3 and inactivation of nm23-H(1) may play an important role in lymphatic metastasis in OSCC.</p>

Nitric oxide regulates c-fos expression in osteoblastic cells induced by wall-shear / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To observe regulation of nitric oxide on c-fos expression in osteoblastic cells in response to changes in wall-shear stress in vitro.</p><p><b>METHODS</b>Isolated and purified osteoblastic cells from the calvaria of newborn SD rats were cultured and passaged. The third generation cells, pre-treated with 10% FBS DMEM, 0.3 mmol/L L-NMMA DMEM and 0.1 mmol/L SNP DMEM separately, were subjected to wall-shear stress of 1.2 Pa. Gene expression of the c-fos and NOS activity were studied before (0 min) and 10 min, 15 min, 30 min, 60 min after treated with wall-shear stress.</p><p><b>RESULT</b>The expression of c-fos mRNA was increased transiently after application of 1.2 Pa wall-shear stress in osteoblastic cells and peaked at 15 min. The expression of c-fos mRNA was decreased after pre-application with L-NMMA and increased after use of SNP.</p><p><b>CONCLUSION</b>Changes in the osteoblastic cells mechanical environment may cause a dramatic induction of NO and c-fos expression.</p>

Effect of bicortical orthodontic microimplant on tooth movement in dogs / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate the potential anchorage of bicortical microimplant for tooth movement.</p><p><b>METHODS</b>Five bicortical microimplants were inserted in the interradicular area of the second premolar (P2) in one side of the mandible (test side), 5 monocortical microimplant in the contralateral region (control side) in 5 beagle dogs. A total of 100 g force was generated between the implant and the fourth premolar (P4) in two sides. M1-P4, CA-IB and CA-M1 were measured biweekly. At the end of loading, specimens with P4 segments were cut and grounded to 70 microm to calculate the bone-to-implant contact (BIC).</p><p><b>RESULT</b>All the bicortical microimplants remained stable during the treatment periods, while 1 monocortical microimplant was lost within 1 week. Mesial movement of P4 was ( 3.92+/-0.22) mm in the test side, (2.03+/-0.15) mm in the control side (P<0.05). Analysis showed no difference of the BIC between the bicortical microimplants and the monocortical microimplants.</p><p><b>CONCLUSION</b>The bicortical microimplant may be used as orthodontic anchorage for mesial movement of posterior tooth.</p>

A new local ablation for unresectable primary liver tumor: effect of electrothermal and electrochemical therapy on rat liver / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>BACKGROUND</b>Electrochemical therapy (ECT) has been used to treat unresectable hepatic tumor. In order to improve its efficacy, we combined ECT with hyperthermia induced by electrothermal needle (ETN) (ETECT). The aim of this study is to investigate the destructive effect of ETECT on normal rat liver.</p><p><b>METHODS</b>Twenty rats were randomized into 4 treatment groups (n=5 in each group): control, ECT alone, hyperthermia alone and ETECT. Following the treatment, sections of the livers were histologically examined by light microscopy and the destructive volumes were measured with micrometer.</p><p><b>RESULTS</b>We found that the destructive volumes in ETECT group were the largest (P<0.01). In ETECT group coagulative necrosis was found in both anode and cathode areas, around which transition zones existed. The transition zones can only be seen when coulomb was increased in ECT group.</p><p><b>CONCLUSION</b>ETECT was demonstrated to enhance the destructive effect of ECT. This study provides theoretical and experimental basis for a new local ablative treatment for unresectable primary liver tumor.</p>

Apoptosis induces by exogenous nitric oxide in Tca8113 cells / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To observe the apoptosis induced by exogenous NO in Tca8113 cells and to investigate the possible mechanism.</p><p><b>METHODS</b>SNP as NO donor was used to treat the tongue squamous cell carcinoma Tca8113 cells. Cytotoxic and apoptotic effects of NO on Tca8113 cells were examined by using MTT assay, acridine orange (AO) staining, Wright-Giemsa staining, agarose gel electrophoresis and flow cytometry. Western blot was performed for investigating the apoptotic mechanism.</p><p><b>RESULTS</b>NO had a remarkable proliferation inhibiting effect on Tca8113 cells. After being exposed to exogenous NO, Tca8113 cells showed series of apoptotic morphological changes such as cell shrinkage, nuclear condensation; and also showed DNA fragmentation, G2/M phase arrest as well as upregulation of the tumor suppressor P53 protein.</p><p><b>CONCLUSION</b>Exogenous NO has a proliferation inhibition and apoptosis induction effect on Tca8113 cells in a concentration and time-dependent manner, P53 protein may be involved in the apoptosis induced by NO.</p>

Relative quantification of cytokeratin 19 transcription in oral squamous cell carcinoma tissues by fluorescent quantitive real-time RT-PCR / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the relative quantification of cytokeratin 19 transcription in oral squamous cell carcinoma tissues by fluorescent quantitive real-time reverse transcription-polymerase chain reaction ((RT-PCR).</p><p><b>METHODS</b>CK19mRNA level was detected by fluorescent quantitive real-time RT-PCR in cancerous and para-cancerous tissues from 31 oral squamous cell carcinoma patients. According to the 2(-DeltaDeltaCt) equation, the relative quantification fold of CK19mRNA level was calculated in cancerous tissues compared with para-cancerous tissues.</p><p><b>RESULTS</b>CK19mRNA levels in cancerous tissues were 2.21 folds higher than those in para-cancerous tissues, and the amplicon was specific. CK19mRNA level in cancerous tissue correlated significantly with pathological differentiation degree, the poorer the differentiation was, the higher the CK19mRNA level became.</p><p><b>CONCLUSIONS</b>Fluorescent quantitive real-time RT-PCR is accurate and reliable in the detection of relative quantification of CK19 transcription in oral squamous cell carcinoma tissues.</p>

Activating protein-1 members in response to changes of wall-shear stress in osteoblastic cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To observe activating protein-1 (AP- 1) members in response to changes of wall-shear stress in osteoblastic cells in vitro.</p><p><b>METHODS</b>Isolated and purified osteoblastic cells from the calvaria of newborn SD rats were cultured and subcultured. The third generation cells were subjected to wall-shear stress of 0.8 Pa, 1.2 Pa, 1.4 Pa and 1.6 Pa separately. Gene expression of the seven AP-1 members were studied before (0 h) and 10 min, 15 min, 30 min, 60 min after treated with wall-shear stress.</p><p><b>RESULTS</b>The expression of FosB, c-Fos, c-Jun, JunD and JunB mRNA increased transiently after application of 1.2 Pa wall-shear stress in osteoblastic cells compared to 0.8 Pa , 1.4 Pa and 1.6 Pa stress, and peaked at 15 min.</p><p><b>CONCLUSION</b>Mechanical environment changes in osteoblastic cells induced a dramatic induction of most of the AP-1 members.</p>

Changes of taste bud and fungiform papillae after 60Co radiation in rat / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To observe the morphological changes and the regenerating ability of the fungiform papillae and taste buds after 60Co radiation with clinical doses in rats.</p><p><b>METHODS</b>The heads, faces and necks of 30 SD rats were radiated with a large dose and one time of 60Co in the clinical radiation. The general living condition and the number and shape of the fungiform papillae and taste buds of the tongues were observed after the radiation in rats.</p><p><b>RESULTS</b>In the group of 60Co radiation, the animals had wilting, decreasing appetite, losing weight. The heads, faces and necks of animals appeared redness, peeling of hair, increasing of secretions in 5 days after the 60Co radiation. The changes reached the summit in 10 days and the general living condition of the animals recovered in 60 days. The fungiform papillae and taste buds of the animals appeared degeneration, atrophy and collapsing in 5 days after the 60Co radiation. The injuries reached the summit in 10-20 days and the fungiform papillae and taste buds regenerated partially, and the some atrophied fungiform papillae and taste buds were not regenerated in 60 days.</p><p><b>CONCLUSION</b>The damage to fungiform papillae and taste buds of tongue following the 60Co radiation with the clinical doses was very serious. The damaged fungiform papillae and taste buds can regenerate partially, but not completely.</p>

Minimally invasive technique of parotidectomy for benign parotid tumors / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate a minimally invasive technique of parotidectomy in treatment of benign parotid tumors.</p><p><b>METHODS</b>This retrospective review included 49 patients with benign parotid gland tumors. The modified technique included incision, flap elevation, facial nerve dissection, the great auricular nerve preservation and postoperative disposal.</p><p><b>RESULTS</b>All tumors were resected completely. The operation lasted 1.5 approximately 2.5 h; the average length of incisions was from 5.5 cm to 7.5 cm, and the average postoperative hospital stay was 4 days. There were no permanent facial nerve injury, no obvious scars and no depressed deformity observed postoperatively. During the 6 months approximately 5 years following-up, no tumor recurrence was found.</p><p><b>CONCLUSION</b>The minimally invasive technique of parotidectomy reduces the disadvantages of the traditional procedure, and improves the quality of operation.T.</p>

Relationship of expression of inducible nitric oxide synthase to microvessel density in oral squamous cell carcinomas / 浙江大学学报·医学版

OBJECTIVE: To study expression of inducible nitric oxide synthase (iNOS) in oral squamous cell carcinomas (OSCC) and its relations to microvessel density (MVD) and lymphatic metastasis. METHODS: With 9 cases of normal oral mucosa as control, the expression rate of iNOS in 41 cases of OSCC was evaluated by immunohistochemstry SP staining. With CD34 as label, MVDs of these cases were also detected. RESULTS: The iNOS expression rate of OSCC cases was 63.41%(26/41), while no positive expression was seen in 9 cases of normal oral mucosa. Anymore, the expression rate of N+ group was 85.00% while that of N group 42.90%, the rate between them was significantly different (P<0.01). There was correlation between MVD and lymphatic metastasis (rs=0.51, P<0.01). MVDs in groups of different iNOS expression( approximate, equals +++) were 29.667+/-6.945, 34.833+/-4.579, 46.357+/-6.687, 54.167+/-5.565, respectively, and were significantly different with each other (P<0.001). CONCLUSION: There is high expression rate of iNOS in OSCC, and it has close relation to lymphatic metastasis; angiogenesis may facilitate lymphatic metastasis of OSCC, and expression of iNOS has positive relation to MVD in OSCC.