Objective　To determine the optimized condition under which BMP expression vector will be constructed to transfect bone marrowstromal cells (MSCs), plasmid vector coding enhanced green fluorescence protein (EGFP) gene pEGFPwas transferred into MSCs. The transfer efficiency and transient expression were subsequently tested.Methods　pEGFP plasmid was amplified and tested by an enzyme cutting technique in vitro. MSCs, which were initially obtained from the bone marrow of rab- bits, were culturedin vitroand transferred with pEGFP by means of lipofectamine media methods. The ratio of plasmid and lipo- fectamine was varied according to the experiment design. Transfer efficiency and transient expressionwere evaluated by fluorescent microscopy.Results　Transfer efficiencywas correlatedwith the ratio of plamid and lipofectamine. The expression of EGFP began in 24 hours after transferring, reached maximum in 48-72 hours and decreased in 1 week, however there remained a weak expres- sion for more than 3 weeks.Conclusion　The efficiency of transferring pEGFP intoMSCs could achieve to 30% with proper ratio of plamid and lipofactamine. pEGFP was an ideal transient expression vector forMSCs gene transference.

Objective　Seed cell study is an essential area in the research of tissue engineering·To evaluate the potential- ity of marrow stromal cell(MSCs) as seed cell in the regeneration of tissue engineered cartilage, formation of cartilage nodules by culture expanded MSCs pellets under the induction of TGF-βwas investigated.Methods　MSCs were cultured and expandedin vitro. Cell pellets containing 1×106MSCswere obtained by centrifugingMSCs solution at 1 000 r/min in 5 ml centrifugation tube· Pellets were exposed to cell culture media containing 20 ng/mlTGF-βfor 7 days and then cultured for another 7 and 21 days·The nodules were moved out of the tube and cartilage formationwas observed by stereomicroscope, light microscope and electronic mi- croscope·Results　10 days after exposure to TGF-β, pellets contracted and formed small and round nodules on the bottom of the tubes·The nodules grewbigger slowly and reached maximal diameter of 1·8mm in 28 days·The surface of the noduleswas smooth and bright white·Histological examination showed that extra cellular matrix formed in 14 days and in some areas cells situated in lacuna·In 28 days′specimens, a lot of cells situated in lacuna could be observed and the histological appearance looked much similar to cartilage·Electronic microscope observation demonstrated that in 28 days′specimens a large amount of collagen fiber ex- isted·Conclusion　Under the induction of TGF-β, MSCs could differentiate into chondrogenesis cell and form cartilaginous nod- ulesin vitro. This indicated thatMSCs could be the potential seed cells in the regeneration of cartilage employing method of tissue engineering.

Objective　This study was intended to determine the salivary protein factors related to adult periodontitis. Methods　Twenty-five patientswith adult periodontitis (APgroup) and twenty-five normal controls (NC group, 25) were adopted in the study. Salivary protein composition in unstimulated whole saliva samples obtained before and after basic treatmentwas ana- lyzed by SDS-PAGE.Results　The volume of proteins with 66 kD, 18 kD, 15 kD, 13 kD in AP group before treatmentwere all remarkably higher than those in NC group. In addition, 51 kD, 34 kD, 19 kD, 17 kD protein bands were more frequently observed in AP group by comparison with NC group. However, after initial therapy, all the variables mentioned above decreased remarkably.Conclusion　The results demonstrated that protein bands with 18 kD, 15 kD, 13 kD might be closely related to the occurrence and recovery of periodontitis, and serum-derived proteins in saliva increased in patients with adult periodontitis.

Objective　To investigate the expression change of integrinα5during mandibular fracture healing.Methods　 Using rabbit mandibular fracture model, the fractured bone tissues were obtained and paraffin slices were made on the days of 1, 3,5,7,14,30,60 and 90 after surgery, respectively. Non-fractured mandibles were used as normal control. LsAB immunohisto- chemical methodwas used to detectthe expression of integrinα5in bone tissue, especially on osteoblasts and osteoclasts.Results　 Integrinα5was widely expressed in fractured bone and surrounding soft tissues. The expression of integrinα5increased 7 days after fracture, peaked in 14 to 30 days and returned to nearly normal in 60-90 days.Conclusion　During mandibular fracture healing, the expression of integrinα5in bone tissue increased clearly. It is estimated that integrinα5playes an important role in fracture healing.

Objective　To determine the influence of different surface conditioning methods on bonding strength of low fusing porcelain (La-Porcelain) and titanium.Methods　The surface of the sampleswere sandblasted for 2 minwith 80~250μm Al2O3or coated fortwotimeswith Si-couple agent or conditioned by pre-oxidation. The shear bond strengthwas examined by push- type shear test with a speed of 0·5 mm/min in a universal testing machine. Scanning electron microscopy (SEM) and electron probe micro-analyzer (EPMA) were employed to explore the relationship between bonding strength and microstructures, aswell as the element diffusion at the interface between porcelain coating and titanium when heated at 800℃.Results　Bonding strength was not statistically different (P>0·05) after sandblastingwith Al2O3in particle size ranged from 80μm to 250μm. When a Si- couple agent was used, bond of porcelain to titaniumwas significantly lower (P<0·05). The shear bond strength of the porcelain to the pre-oxidized titanium surface remained unchanged after heating (P>0·05). The SEMresults revealed integrity of porcelain and titanium.Conclusion　La-Porcelain showed a small effect of surface coarseness. Sandblastingthe titanium surfacewith 150~ 180μm Al2O3can be recommended as a method for better bonding between La-Porcelain and titanium. The Si-couple agent coating and pre-oxidation of titanium surface is unnecessary.

Objective　To investigate the effect of anti-ICAM-1/LAF-1 McAb on the cytotoxicity of tumor infiltrating lym- phocytes from oral squamous cell carcinoma.Methods　TILwere isolated from fresh tumor tissues in 15 patients with oral squa- mous cell carcinoma and culturedin vitro. The expression of ICAM-1/LAF-1 in fresh and activated TILwas examined by FACS. The cytotoxicity of TIL against auto tumor cells and the level ofTNF-αproduced byTILwere compared before and after interrupted with anti- ICAM-1/LAF-1 McAb.Results　The expression of ICAM-1and LAF-1 in the activatedTIL significantly increased com- paring with freshTIL (P<0·05). Interrupted by anti-ICAM-1 McAb, the cytotoxicity ofTIL against auto tumor cell was not sig- nificantly changed. Interrupted by anti-ICAM-1 and anti-LAF-1 McAb, the level ofTNF-αproduced byTIL showed no differences comparing with the control (P<0·05), but the cytotoxicity of TIL against auto tumor cells significantly decreased (P<0·05). Conclusion　The effect of anti-LAF-1 McAb may result from steric interference of antigen-nonspecific adhesion process.

Objective　To study and evaluate the clinical effects of combined preoperative chemotherapy and their rela- tionswith multi drug resistance (MDR).Methods　102 cases with oral squamous cell carcinoma(OSCC) were included in the study (63 males and 39 females,aged 22 to 67 years). Amongthe subjects therewere 57 caseswith cancer of tongue and 45 cases with cancer of buccal mucosa.27 cases in the groupwere classified as stageⅡ,55 as stageⅢand 20 cases as stageⅣaccording to TNMstandard.All cases accepted PYM+5-Fu+DDP combined chemotherapy pre-operatively.The total given dosewas PYM48 mg,5-Fu 7·5 g and DDP300 mg.Afterthe chemotherapy,radical surgerywere performedwithin 2 weeks.The diagnosis of all cases were proved as OSCC by biopsy.Results　Total effective rate of the combined chemotherapy was 82·4%. All of the cases were followed up and their 3 years′survival rate was 67·6%.Conclusion　The combined chemotherapy of PYM+5-Fu+DDP is ef- fective in using as one of comprehensive treatment for OSCC.

Objective　The purpose of this study was to investigate the cisplatin release in peripheral blood and tumor tissue after cisplatin-loaded albumin microspheres (CDDP-AMS) were infused through lingual artery for treating carcinoma of tongue.Methods 　Anticancer agent cisplatin was encapsulated with biodegradable and non-antigenic albumin. The cisplatin-loaded albumin microsph- eres, which were 56·3μm in diameter, were used for treating 7 patients with squamous carcinoma of tongue by infusing through lingual artery. The cisplatin in peripheral venous blood and carcinoma tissue were measured for analyzing the drug releasein vivo.Results　 Concentration of the drug in peripheral venous blood increased to the highest level in 90 minutes after CDDP-AMS was infused through lingual arterial and still could be detected until 10th day. The cisplatin concentration in tumor tissue kept considerably stable and could be detected until 17 days.Conclusion　CDDP-AMS had the effect of controlled releaseinvive. Effective and steady local drug concen- tration played the role of killing tumor cells, the low concentration in peripheral blood reduced the side effects of cisplatin tominimum as well. It is concluded that CDDP-AMS is a useful and recommendable method for treating the carcinoma of tongue.

Objective　The purpose of this studywas to investigate the effects of Fr¨ankelⅡappliance on the upper airway of children.Methods　The subjects consisted of 20 patients with Angle ClassⅡ, division I malocclusion (10 males and 10 fe- males). The ages of all caseswere ranged in 9~10 years. Each experimental subjectwas also served as self-control and cephalo- metric analysis was conducted.Results　Compared with the results of pretreatment, the distance of PNS-Ba, SPP-SPPW, P-T, V-LPW and theMcnamara line increased remarkably.Conclusion　The Fr¨ankelⅡappliance can improve the sagittal dimensions of the upper airway in children.

Objective　The aim of this study was to investigate the effects of preserving external jugular vein and cervical plexus in reducing intra-cranial pressure, face swelling as well as in avoiding shoulder arm syndrome in neck dissection.Methods 20 patients with oral cancer were divided into two groups. The facial interstitial pressure was examined before and after neck dis- section and lymph tubes were stained by immunochemical techniques.Results　The degree and lasting time of the increase of fa- cial interstitial pressure in groupwith external jugular vein and cervical plexus preserved was lower than that in control group. The density of lymphatic tubes around the internal jugular vein, accessory nerve and sternocleidomastoid muscleswas much higherthan that around the external jugular vein and cervical plexus.Conclusion　Preserving external jugular and cervical plexus during radi- cal treatment is effective not only in reducing the intra-cranial pressure and face swelling, but also in preventing shoulder arm syn- drome.

Objective　The aim of this studywas to observe the effects ofTip-Edge Differential Straight-ArchTechnique in treat- ing AngleⅡ1malocclusion.Methods　13 adults with AngleⅡ1malocclusion were treated with Tip-Edge appliance. The results of cephalometric measurements before and after treatment were statistically analyzed.Results　The average treatment time was 16·2 months. The results of cephalometric measurement showed that UIC-AP decreased by 3·72 mm (P<0·01), LIC-AP decreased by 1·03 mm (P<0·01), LIC-MP decreased by 1·59 mm(P<0·01), L6-MP increased by 0·99 mm (P<0·05), the over jet decreased by 3·73 mm (P<0·01).Conclusion　Tip-Edge appliance can effectively change the dento-alveolar position by means of the differen- tial mechanics.

Objective　The aim of the study was to evaluate the clinical efficacy of Oratest in detecting oral mucosal le- sions.Methods　Sixty patients with oral mucosal lesions that were suspected as carcinoma or premalignant lesions were divided into two groups randomly. The lesionswere stainedwithOratest bytopical application in one group and rinse application in another group. Staining results were recorded and compared with the pathological diagnosis.Results　The sensitivity of Oratest stain to oral carcinoma and dysplasia were 93·9% and 42·9%, respectively. The difference between rinse application and local applica- tion showed no significance(P>0·01).Conclusion　Oratest can be used as a method of diagnosing squamous cell carcinoma of oral mucosa, but its reliability in screening oral pre-malignant lesions is still uncertain.

Objective　The purpose of this study was investigate the effect of hyperthemia on multidrug resistance in K562/ADM cell.Methods　The MDR1 (mulitdrug resistance gene) andMRP (multidrug resistant associated gene) gene expres- sions in Tca8113 and K562/ADM cell lineswere analyzed by RT-PCR aftertreatedwith different cytotoxic drugs and different tem- perature (37℃and 41℃). The function and expression of Pgp andMRPwere detected by fluorescence photometeric assays.Re- sults　Inhibition rate of both cellswas significantly enhanced by exposure to chemotherapeutic drugs and 41℃temperature; Ex- posing to 41℃hyperthemia reduced MDR1 and MRP expression and enhanced intracellular drug concentration as well in K562/ ADM.Conclusion　41℃hyperthemia could effectively enhance the inhibition rate of chemotherapeutic drugs and partially re- verse the multidrug resistance. It is suggested that hyperthemia could be used as a method to overcome multidrug resistance.

Objective　To prepare the polyclonal antibody to amelogenin.Methods　The fetal porcine dental enamelwas collected. Enamel matrix protein was extracted in 4M guanidine HCl (pH 7·4) with protease inhibitors present. Polyacrylamide gel filtration was included to isolate amelogenin from the initial dissociated extraction. The purified amelogenin conjugated with or without complete/incomplete Freund′s adjuvantwas then used to immunize the rabbits subcutaneously or intravenously. The spe- cific IgG antibody was further purified by DE-52 cellulose. The working concentration of IgG antibody was determined through ELISA test.Results　The Gel filtration showed that amelogenin components is atmolecularweights of 15 kD and 13 kD apparent- ly, which was consistent with those described before. The ELISA results showed that the working concentration for IgG was 1∶ 1000.Conclusion　The antibody prepared in this study can be used for the detection of amelogenin.

Objective　The purpose of this study was to construct a eukaryotic expression vector for human amelogenin (AMG).Methods　PCR was performed to amplify the AMG encoding region. Amplified fragments for human AMG were recov- ered and inserted into eukaryotic expression vectors PsecTaq2A. The recombinant plasmid PsecTaq2A-AMG was constructed and their positive cloneswere identified.Results　①Amplified productswere checked by electrophoresis and the resultswere satisfac- tory.②The recombinant plasmid PsecTaq2A-AMG was analyzed by restriction endonuclease mapping and DNA sequencing. The results of sequencing were consistentwith those fromGenBank.Conclusion　The recombinant plasmid PsecTaq2A-AMGwas suc- cessfully constructed with properly inserted DNA sequence encoding mature amelogenin.

Objective　The purpose of this study was to compare the differences of craniofacial characteristics of adult high-angle and low-angle facial skeletal types.Methods　The subjects consisted of 37 yellowrace adults (17 high-angle, 20 low- angle). Fifty-three items of cephlometic radiographs were analyzed.Results　The angle of N-S-Ar and N-S-Ba, the distance of Ptm-A, Co-Go, Po-NB, and S-Go, and the thickness of the mandibular symphysis in high-angle groupwere smaller than these in low-angle group. The angles of SN-OP, FH-OP, PP-OP, SN-MP,FH-MP,PP-MP, S-Ar-Go, mandibular angle(Ar-Go-Me), Y- angle, and SUM, the distance of S-Co, N-Me, and ANS-Me in high-angle groupwere greater than these in low-angle group. The index of FHI, N-ANS/N-Me, and N-ANS/ANS-Me were smaller, and ANS-Me/N-Me larger in high-angle group. Although the means of Go-Po and FH-RPwere smaller in high angle group, but no statistical differencewere found.Conclusion　The craniofa- cial morphology of adult high-angle and low-angle facial skeletal types demonstrated significant differences, especially in lower fa- cial form.

Objective　The purpose of this study was to construct a eukaryote expression vector carrying human sIL-1R gene.Methods　Both sIL-1R gene and plasmid pcDNA3·1(+) DNAwere digestedwithKpnIandXhoI. After purification, the two fragments obtained were ligated by usingTakaRa DNALigation Kit. This recombinant DNAwas then transformed intoE.coli Competent Cells JM109 and positive cloneswere selected on the LB agarose plate containingAmpicillin (80μg/ml).Results　Six single clones were identified by double digestionwithKpnIandXhoI, and two fragmentswith the size of 5·4 kb and 1·0 kbwere produced as expected.Conclusion　The sIL-1R gene was successfully inserted into the eukaryote expression vector plasmid pcDNA 3·1(+) by the recombination techniquein vitro.

Objective　The studywas to investigate the circadian rhythm of the proliferation index (PI) of the mandibular osteoblast after distraction osteogenesis (DO) by a comparative study to explain the different rhythm characteristics.Methods　 Fourty-eight healthy goats were employed and divided randomly into DO group and control. Fourweeks after the right side mandi- ble of DO group was distracted, animals of the both groups were killed at 0:00, 4:00, 8:00, 12:00, 16:00, 20:00 time point subsequently. Samples of 2 cm×2 cm×0.5 cm bone tissue were excised from distracted zone of DO group and the right mental foramen zone of the control. Primary cell culture method was employed to isolate the osteoblast from bone tissue and a flow cyto- metric analysis was used to detect the PI of osteoblast. The data was analyzed with cosinor rhythmometry method and the different rhythm between the two groups were investigated.Results　The PI in the two groups demonstrated cosinorwaves. The mesor and amplitude in DOgroupwere significant higher comparedwiththe control(P<0·05), buttherewas no significant difference forthe acrophase between the two groups (P>0·05).Conclusion　The PI of osteoblast after DOshowed significant circadian rhythm. It is suggested that DO is helpful to promote osteoblast proliferation and bone regeneration.

Objective　The aim of this studywas to reveal the relations between expression and tumor behavior such as in- vasion, metastasis and prognosis in oral squamous cell carcinoma (SCC) through analyzing the expression of urokinase-type plas- minogen activator (UPA).Methods　With Labelled streptavidin biotin method (LsAB), the expression of UPAwas analyzed in 80 cases of oral squamous cell carcinoma, 10 cases of oral normal mucosa and 10 cases of oral leukoplakia.Results　Compared to oral normal mucosa and oral leukoplakia, the expression ofUPAwas significantly higher in SCC. The expression ofUPA in SCC cases with lymph node metastasiswas significantly higherthan in caseswithoutmetastasis. The expression in caseswith good prog- nosiswas significantly higher than in those with poor prognosis and the expression was significantly higher in cases with invasive growth than in those with ulcerative and papillary growth.Conclusion　The results obtained indicated that high expression ofUPA in SCC might be closely related to lymph node metastasis, invasive growth and poor prognosis.

Objective　The aim of this studywas to observe the expression of urokinase-type plasminogen activator (UPA) in human tongue squamous cell carcinoma cell line (Tca8113) after heat shockwith different dosage.Methods　The expression of UPA protein ofTca8113 after different heating temperatures(37℃、40℃、43℃and 45℃) treatmentwas examined by immuno- histochemical technique (IH) and flow cytometry (FCM).Results　Compared with 37℃group, the UPA protein expression in 40℃and 43℃groups decreased significantly (P<0·05); however, the UPA protein expression in 45℃group decreased but no statistical difference was found.Conclusion　Hyperthermia could inhibit invasion and metastasis of oral squamous cell carcino- ma and could be considered as a safe method in curing the tumor.

Objective　The expression ofKi-67 antigen of ameloblastomawas exmanied in orderto investigate the different proliferation activity of histological variants of ameloblastoma and its clinical significance.Methods　70 cases of different histolog- ical specimen of ameloblastoma were analyzed by immunohistochemical method using Ki-67 antibody. The Label Indexwas calcu- lated in percentage of Ki-67 positive cells after examinedwith an image analysis system.Results　The results showed that the La- beled Index in malignant ameloblastoma was the highest 14·72%±2·87%. The Labeled Index in solid ameloblastoma was in the middle, among which the follicular 4·42%±1·05% was higher than the plexiform 3·64%±1·23%. The Labeled Index in mono-cystic ameloblastoma was the lowest 2·21%±1·09%.Conclusion　The results demonstrated that the proliferation activity varied according to the histological pattern of ameloblastoma. The prognosis with different proliferation activitywas also varied ac- cordingly.

Objective　To investigate the effect of unilateral mastication on glenoid fossae bymeans of animal experiment. Methods　An animal model of unilateral mastication was established by extracting right mandibular molars of Wistar rats. The rats were sacrificed in different period to examine the location changes of glenoid fossae through sagittal and horizontal plane.Re- sults　The anterior points of glenoid fossae in non-masticatory side of experimental groupswere more anterior than those in masti- catory sides. The anterior points of the glenoid fossae of non-masticatory sides in experimental groupswere more anteriorthan those of the same sides in the control groups after inducing unilateral mastication fortwo and fourmonths. After inducing unilateral mas- tication for two and fourmonths, the anterior and the posterior points of the glenoid fossae of non-masticatory sides in experimental groups became closer to the midline by comparisonwith masticatory sides aswell as the same sides in control groups. Locations of glenoid fossae in masticatory sides showed no changes in comparison with the same side of the control groups.Conclusion　The forward and inward remodeling of the glenoid fassae can be observed after unilateral mastication was induce to the non-masticatory sides of experimental rats. It is concluded that unilateral mastication might be one of the etiologic factor of temporomandibular joint disorders.