Objective:The aim of this study was to investigate the relationship between loss of heterozygosity (LOH) on chromosome 9p and the pathogenesis of oral squamous cell carcinoma (OSCC).Methods: Atotal of 24 humanOSCC specimenswere analyzed for LOHon chromosome 9p using 8 microsatellite markers by means of polymerase chain reaction.Results: In 24 cases of OSCC, LOH on chromosome 9pwas identified in 10 of 24 cases (41167%) with at least one marker. The main LOHwere found on 9p21 at locus D9S171 (21105%) and D9S304 (10.00%). There were also a deletion on 9p22-23 at locus D9S168 (22122%) and D9S162 (15138%). However, there was no statistically significant correlation between LOH at these loci with such clinical pa- rameters as pathological types, tumor size and lymph-node metastasis. Microsatellite instability (MSI) is rare for any of the 8 markers in 24 OSCC, No MSI could observed using the common criteria for defining MSI-its detection in two or more markers. Conclusion: We found that high frequency of LOH occurred at 9p21-23 band. Their results indicate that more than one tumor suppressor genes at chromosome 9p21-23 region related to a subset of OSCC, while MSI might not be a crucial event.

Objective:The aim of this study is to evaluate of Bromodeoxyuridine (BrdU) label in the proliferation of the tongue cancer. Methods:The authors used 80LgPml BrdUoriododeoxyuridine (IdU) to label three cases of fresh tissue of tongue cancer and four bottles of Tca8113 cells in logarithmic growth period in vitro. Theywere fixed and embedded in the routine procedure, and then in serial sections. These specimenswere labeled with BrdUpolyclonal antibody (1B200), and PCNAmonoclonal antibody (1B100), stained using immunohistochemical ABC method. The authors observed the shapes and sizes of those positive cells, counted their label indexes (LI) of BrdU- or IdU-positive cells and PCNA- positive cells respectively. Four bottles of Tca8113 cells were cul- tured for 1~4 days. One bottle of the cells was every day used in the experimental study about comparing the cells labeled BrdU with those of the S phase of FCMin same cultural time.Results:The positive cells generally owned a larger round nucleus, some- times in company with sister cells. There was no difference of positive cells in these two kinds of labeling methods between the in- corporation of BrdUor IdUand the expression of proliferating cell nuclear antigen (P>0.05). The cells of S phase with FCM method were much more than thatmethod with BrdUincorporation (P<0.001).Conclusion: The method of BrdUlabeling could be used in tumor cellular proliferation studies.

Objective:The aim of this study is to compare activities of phospholipase ofCandida albicansisolatesfrom oral cavities of two groups of patients, including oral pre-malignant lesions and oral cancers.Methods:A total of 55 isolates, including oral pre-ma- lignant lesions (21), oral cancers (15), and normal health control (19), were studied using the precipitate zone assay on the egg yolk agar.Results:No significant difference was found in phospholipase activities between these isolates from normal controls and oral pre-malignant lesions, while the activities of phospholipase of isolates from oral cancers were higher than those of the normal controls.Conclusion:Candida albicansmay play different roles in different manners in these two closely related diseases.

Objective:The aims of this study are to analyze the surface stress of the periodontal supporting bone of the bilateral distol extension removable partial denture which is retained by using intra_coronal or extra_coronal semi-precision attachment, and to characterize the biomechanics of these two designs by using a strain gauge.Methods:A fresh human mandible specimen with \{76│67\} missing and six bilateral partial removable denture retained with six semi-precision attachments were made, including three attachments with intra_coronal studs and three attachments with extra_coronal vertical bars. A total of six 45° rosette strain gauges were bonded at six prepared points on the surface of the mandible to measure the surface stress, including the middle point between 76 of the buccal edentulous alveolar crest area under the denture base verge(point 1), the distal buccal cervix of 5 (point 2), the buccal apical area of 5 (point 3), the buccal middle area of 34 roots (point 4,5), the lingual middle area of 5 root (point 6). The static loads of 14N, 28N and 42N were applied vertically, buccally 45°, lingually 45° at the middle point of the \{6│6\} occlusal surface. The micro_strain was recorded, and the maximal/minimal principle stresses were calculated for each RPD and each point. The stress characteristics of these two types of attachments were compared and analyzed.Results:In most situations, the stress of these two semi_precision attachments showed significant differences. The vertical load: The stress values of these intra_coronal and extra_coronal attachments at points 1,2,3,4,6 differed significantly(P<0 05), including points 1,2,(σ\-\{intra\}<σ\-\{extra\}) and points 3,4,6(σ\-\{intra\}>σ\-\{extra\}). Buccal loads: The stress values of these intra_coronal and extra_coronal attachments at points 1,2,3,4,5 differed significantly(P<0 05), including points 1,2(σ\-\{intra\}<σ\-\{extra\}) and points 3,4,5(σ\-\{intra\}>σ\-\{extra\}). Lingual loads: The stress values of these intra_coronal and extra_coronal attachments at points 2,3,4,6 differed significantly (P<0 05,σ\-\{intra\}>σ\-\{extra\}). The intra_coronal attachment generally produced higher stress at the site of the alveolar bone around the abutment than the extra_coronal attachment, but extra_coronal attachment produced higher stress at the edentulous alveolar crest\ and\ the distal cervical alveolar bone of the distal abutment than the intra_coronal attachment.\ Conclusion:The intra_coronal attachment is suggested to be applied in some cases that the periodontal condition of distal abutment was good, and the extra_coronal attachment is suggested to be used in some cases that the condition of the edentulous alveolar crest is fairly good, while the periodontal condition of the distal abutment was relatively weak.

Objective:The aim of this study is to investigate the relationship between cyclinAand cycle regulation of squamous cells car- cinoma of tongue, and to provide basisfor cancergene therapy.Methods: Eukaryocyte expression vector(pAS-A) containing anti- sense and the full-length human cyclin A complementary DNA (cDNA) (1.77 kb) was constructed and was transferred into squa- mous carcinoma of the tongue cell line (Tca8113) by LipofectAMINETMintroduction. The positive cell cloneswere selected with G418. Transcription of Neo gene mRNA and cyclin A mRNA were determined by in situ hybridization. The stable expression of anti-sense cyclin A in the Tca8113 cell line was determined using immunohistochemical methods.Results: After G418 selection, cells transferred anti-sense cyclin Awere obtained successfully. The positive cells of in situ hybridization of specific-stained Neo- probe were observed in cells transferred eukaryocyte expression vector. The positive cells of in situ hybridization of cyclin A in cells transferred anti-sense cyclin Awere significantly fewer than those in cells transferred cyclin A. The positive rate of cyclin A immunohistochemical stain in cells transferred anti-sense cyclin A was significantly lower than that in cells transferred cyclin A. Conclusion:Human anti-sense cyclin A gene is stably expressed in the Tca8113 cell lines.

Objective:The aim of this studywas to investigate effects of lowenergy laseron the experimental toothmovement and the re- modeling of alveolar bone in rabbits.Methods:A total of 42 white rabbits were chosen and randomized into one control group and six experimental groups, with 6 rabbits in each group. After anesthesia with 2% pentobaritone sodium, orthodontic appliances consisting of a coil spring connected bilaterally the upper firstmolarwith the upper incisor by using a ligature wire. The force ex- erted at the time of insertion was approximately 80 g. The left side served as the control side, and the right side was the experi- mental side treated by receiving irradiation of lowenergy laser. The treatmentperiods of differentgroups lasted separately for1, 3, 5, 7, 14, 21 days respectively. The displacement extent of teeth was measured by employing the computer image analyzing sys- tem. The resultswere analyzed statistically. ThroughHE staining, the histomorphological characterof tissue around firstmolarwas also investigated, and numbers of osteoclasts were counted.Results:The displacement extent of teeth on the experimental side, which was irradiated by low energy laser, was more obvious than that of the normal control side. The difference was statistically significant 1, 3, 14, 21 days after the beginning of the treatment. Through histological observation under a lightmicroscope, the osteoclasts and osteoblasts on the experimental side remained more active than those of the control side. There is significant differ- ence in amount of osteoclasts between the experimental and the control sides, 3,5 or 7 days after the treatment (P<0.01, P<0.05).Conclusion:The irradiation of low energy laser promote tooth movement and remodeling of alveolar bone.

Objective:The objective of this study is to obtain the optimized separating conditions of formic acid, acetic acid, propionic acid, butyric acid, valeric acid, lactic acid, succinic acid from bacteria using reversed-phase high performance liquid chromato- graph (RP-HPLC), and to set up a reliable progress in identifying the end-products of oral bacteria.Methods: The conditions of separating seven short-chain fat acidswere optimized using the method of gradient RP-HPLC.Results: The study showed that the optimal chromatographic parameters were: 110 mlPmin and 210 mlPmin of flow rates, and the wavelength of ultraviolet detection was 217 nm. The composition of eluent: the ratio of phosphate buffer(pH218) tomethanol is95B5 (vPv), gradient5%~50%. The liner gradientwash will be performed in 10 minutes at room temperature. The average recovery rate was 92%, and RSDwas 118%.Conclusion:The results of this paperwill be helpful to determine acid composition of end products of oral bacteria.

Objective:The aim of this study is to obtain the general information of post-operation malignant oral-maxillofacial tumor pa- tients in forty-seven years.Methods: A total of 6539 patientswith malignant oral-maxillofacial tumors in the hospital of stomatolo- gy, west china university of medical sciences, from 1953 to 2000 were retrospected.Results: The average age of patientswithma- lignant oral-maxilloficial tumor is 48.7 years old. The ratio of male to female is 2.31B1. The most common original malignant tu- mors in this oral-maxillofacial region are malignant oral tumors, malignant maxillary tumors, malignant mandibular tumors, and malignant sialoma successively. As to the original tissues of tumors, there were 5869 cases of epithelial tumors, and made up 89.75% of all the investigated patients. Tumors came from lymphatic and hematopoietic systems and mesoderm were much less those came from epithelia. There were 4177 cases of squamous cell carcinomas and the percentage was 63.88%.ConclusionBThe incidence rate of malignant tumors in oral-maxillofacial region tends to increase, and the average age of patients also rose. The ra- tio of male to female decreasesgradually. Epithelial tumors, especially squamous cell carcinomas are very common tumors happen- ing in this region.

Objective:The objective of the study is to evaluate the nutritional status of patientswith oral maxillofacial cancer.Methods: The nutritional statuswas evaluated using seven easily determined variables and multi-factor nutritional indexin 50 hospitalized pa- tients with oral maxillofacial cancerfrom 1990 to 1992.Results: Fifty-six percentof patients had protein-energy malnutrition. The high incidence of protein-energy malnutrition was found in those patients without adequate dietary intake.Conclusion: Patients with oral maxillofacial cancer usually have protein-energy malnutrition. The reason is that the patients always have an inadequate dietary intake.

Objective: The aim of this studywas to estimate the expression of vascularendothelial growth factor(VEGF) and intratumoral microvessel density (IMVD) in oral squamous cell carcinoma(SCC).Methods: A total of 60 cases of oral squamous carcinoma were immunohistochemically stained with a SP method by using monoclonal antibodies of VEGF and CD34.Results: There was no significant difference in the expression of VEGF in differentTNMstages and lymphe node metastases of oral squamous cell carcino- ma. The expression of VEGF showed no relation with pathologic grades, but IMVD expression differed significantly in SCC. The carcinoma in grade I and IV of IMVD differed significantly in expression of VEGF.Conclusion: It indicates the change of IMVD may resulted from the change of VEGF in oral SCC.

Objective:This study aim at comparing anatomical and functional recovery from surgical and non-surgical treatmentof condy- lar process fractures.Methods: Totally Forty-nine patients, 22 treated by performing operation, and 27 using non-surgical meth- ods, were included in this study. Displaced angle of condylar, maximal mouth opening, lateral deviation on opening and mastica- tory function were analyzed using radiological and clinical examinations 6 weeks and 1 year after treatment.Results: Patients treat- ed by surgical method had significantly greaterinitial displaced angle of condyles than did the group treated non-surgically, butpa- tients treated non-surgically had significantly greaterdisplaced angle of condylar and lateral deviation on opening than did the group treated surgically 6 weeks and 1 year after the therapy finished. Patients treated surgically had significantly greater masticatory function than did the group treated non-surgically 6 weeks and 1 year after treatment. Six weeks later, patients treated surgically had significantly greater maximal mouth opening than did the group treated non-surgically.Conclusion:Surgical treatment may be helpful in anatomical and functional recovery of mandibular condyles for patients with displaced condylar process fractures.

Objective:The aim of this study is to evaluate advantages and disadvantages of two types of appliances for maxillary molar distalization. Methods: Totally, 28 patientswith classÒmalocclusion resulting frommolars shiftingmesiallywere treated using two differentmolar distaliza- tion methods, including suing removable and fixed appliances. An intra-oral removable acrylic appliance with headgear for extra-oral traction resulted in tipping the maxillary firstmolars distally. The modified rapid helix expansion appliance (MRHEA), which consisted of bands, an- chorage teeth, Nance palatine bases, helix bars and connecting rods, made the maxillary firstmolarsmove parallel distally.Results: The de- sired efforts were gained in 7 or 9 months by using removable appliances, but only 2 or2.5 months if usingMRHEA. The treatment results of using removable appliances were dependent on patients.cooperation, however, the method of using fixed appliance overcame some shortcom- ings of othermolardistalization techniques, and this appliance would not lead to the distal inclination of the crown of the shifted teeth.Conclu- sion:These two methods could convert the classÒmolar relationship to classÑ. The MRHEA can save much chair-side time, and shorten the period of treatment, move molars distally parallel.

Objective:The aim of this study is to examine effects of para-aminobenzoic acid (PABA) on the growth ofStreptococcus mu- tans(S.mutans).Methods:Different concentrations of PABA (10-10~10-3gPL) were separately transferred to modified Carlsson medium.S.mutans(ATCC 25175) grew in modified Carlsson mediumwith different concentrations of PABA. All cultureswere incubated at 37eanaerobically in an atmosphere of 80% of nitrogen (vPv), 10% of hydrogen (vPv) and 10% of carbon dioxide (vPv) for 48 hours. The absorbance values ofS.mutanswere measured by using a spectrometer (UV-1601). The colony forming units (CFU) were obtained by growingS.mutansinmediawith different concentrations of PABA(10-10~10-3gPL).Results:Dif- ferent concentrations of PABAhad different stimulating effects on the growth ofS.mutans(P<0.05). But this kind of stimulat- ing effects declined when the concentration of PABAwas 10-3gPL.Conclusion:This experiment indicates PABAhas stimulating ef- fects on the growth ofS.mutans, and PABA can promote growth ofS.mutans.

Objective:The aim of this study is to examine effects of para-aminobenzoic acid (PABA) on the growth ofLactobacillus aci- dophilus(L.acidophilus).Methods:Different concentrations of PABA (10-10~10-3gPL) were separately transferred to the modi- fied Carlsson medium.L.acidophilus(ATCC4356) grew in these Carlsson media. All cultureswere incubated at 37eanaerobi- cally in atmosphere of 80% of nitrogen, 10% of hydrogen, and 10% of carbon dioxide for 48 hours. Absorbance values (K= 540nm) of bacterial suspensions were measured using a spectrometer (UV-1601). Colony forming units (CFU) were obtained by growingL.acidophilusin Carlsson media with different concentration of PABA (10-10~10-3gPL).Results:Different concentra- tions of PABA (10-10~10-4gPL) had different stimulating effects on the growth ofL.acidophilus(P<0.05). But stimulating ef- fects declined, when PABA concentrationwas 10-5gPL, andwhen the concentration of PABA reached 10-3gPL, the stimulating ef- fect disappeared.Conclusion:This study indicates PABA stimulates the growth ofL.acidophilus, and PABA can promote growth ofL.acidophilus.

Objective:The aim of this study was to examine interleukin-1 beta (IL-1B) mRNA and tumor necrosis factor alpha (TNF-A) mRNA expression in gingival tissues of patientswith adultperiodontitis.Methods: Atotal of 19 patients, including 10 patientswith adult periodontitis and 9 healthy individuals as the control, were evaluated forwere selected forevaluating IL-1BmRNAand TNF-A mRNA expression, using reverse transcription polymerase chain reaction (RT-PCR) technique.Results: The relative amountof IL- 1BmRNA expression of gingival samples from patientswith adult periodontitis (01819?01045)(P<0101) wasmuch higher than that from the normal control (01306?01087)(P<0101). The relative amount of TNF-AmRNA expression, gingival samples from AP patients (01696?01098) was also much higher than that from the normal control (0)(P<0101).Conclusion: As the inflammatory and bone absorption mediators, IL-1Band TNF-Amight play important roles in the pathogenesis and development of adult periodontitis.

Objective:The aim of this study is to investigate temporal and spatial change patterns of osteocalcin in serum of young grow- ing SD rats, in conditions of different functional treatment time spans.Methods:Totally, 72 SD rats are randomly divided into 3 groups, including the control group, the 24-hourwearing group (wearing functional appliance 24 hours a day), and the 12-hour wearing group (wearing appliance for 12 hours in daylight). One week after the experiment, rats were sacrificed and osteocalcin level in serumwasmeasured by using radioimmunoassy. Date was processed using macroscopic and microscopic analysis.Results: Serum osteocalcin had circadian rhythm and the peakwas about12:00 in a day. Afterwearing the functional appliance, serum os- teocalcin level increased with treatment time, and serum osteocalcin level in the 24-hour wearing group rose more obviously than that in the 12-hourwearing group.Conclusion: Forthe functional appliance, better results can be achieved in the 24-hourwearing group.

Objective:The aim of this study is to investigate relationship between the concentration of human growth hormone in urine (HGH-U) and puberty, and to find a simple, accurate, and acceptable way of judging puberty of patients.Methods: The concen- tration of HGH-Uwas measured by using radioimmunoassay in 277 students of Chengdu, and studentswere divided into three dif- ferent groups, according to their ages (9, 13, 17 years old). Half of them are male. In order to evaluate the relationship between the concentration ofHGH-Uand puberty, the information of age, height, weight, growth velocity and sex characterof all individu- als were obtained, and analyzed their relationwith the concentration of individuals.HGH-U.Results:¹There was no significant difference in the concentration of HGH-Ubetween the 9-year-old group and the 13-year-old group, but there is significant differ- ence between the concentration of HGH-Uin the 9-year-old, 13-year-old groups and that of the 17-year-old group, and the con- centration in the lattergroup is lowerthan those of the formertwo groups.ºThe concentration ofHGH-Uwas negatively correlated with height, body weight, age, sex character and growth velocity (P<0.05), but the correlation coefficient is low.»The coef- ficients of variation of HGH-Uin all groupwere higher than 30%, which indicated a low dispersion degree.Conclusion:The con- centration of HGH-U cannot be used as an independent indicator to evaluate puberty of children.

Objective:This studywas designed to examine whether the neonatal conditonmightbe related to the caries of deciduous teeth in pre-school children.Methods:1000 children from 3 years old to 6 years old in Chengdu were surveyed, and 260 children with dmft\6 and 260 caries-free childrenwere chosen. Data was collected by 200 pairs of useful questionnaire from their parents and analyzed by using logistic regression analysis andV2test.Results:The neonatal conditionwas closely relatedwith incidence rates of deciduous caries in pre-school children (P<0.05). The incidence rate of children with premature delivery was higher than that with full-term normal delivery (P<0.05). No significant difference was showed in children with full-term normal delivery and childrenwith dystrophy (P<0.05).Conclusion:There should be emphasis on the childrenwith premature delivery in caries pre- ventive cares.