Application of pathological feature clustering in oral pathology teaching / 中华口腔医学杂志

To propose a new student-guided teaching method, in which students carried out the clustering of different diseases with the same pathological characteristics, and differentiated diagnosis of these diseases. This method was named pathological feature clustering (PFC). Seventy-seven undergraduates of School of Stomatology, Wuhan University were enrolled. Stratified random sampling method was adopted to divide the students into 4 groups with 18-20 students in each group. Each group of students selected a disease from the following four topics as the theme and summarize the histological characteristics of the disease: ①oral mucosal disease;②odontogenic tumors and tumor-like lesions, oral and maxillofacial cysts; ③salivary gland diseases;④epithelial-derived tumors and tumor-like lesions (referred to as topics 1, 2, 3, and 4, respectively). When discussing a specific type of disease, the group which select the topic was the summary group (SG), and the other groups were the non-summary group (NSG). After summarizing, students shared the summary results through PPTs, and teachers made comments and supplements. The teaching effect was evaluated by comparing the results of the pre-class test and the final examination. Students' acceptance of PFC teaching method was evaluated through a questionnaire, which included 8 objective questions and 1 subjective question. Likert-scale was used to design the questionnaire, with 1 to 5 points for each question. Students rated each question according to their own situation. Differences among groups were compared by Mann-Whitney U nonparametric test. The pre-class test results showed that the scores of students in SG group in subjects 1, 2, 3 [(5.6±0.8), 5.0(1.0) and (2.9±1.0) points for subjects 1, 2 and 3, respectively] were higher than those in NSG group [(5.1±1.0), 4.0(2.5) and 1.5(2.5) points] (U=402.50, P=0.047; U=392.00, P=0.026; U=295.00, P=0.003). The final examination results showed that there was no significant difference between the scores of the SG group and the NSG group in subjects 1, 2, 3 and 4 (P>0.05). These results showed that the differences between SG and NSG groups were reduced after the summarizing and share between groups, further demonstrating the effectiveness of the PFC teaching method. The results of questionnaire showed that 81.8%(63/77) students were completely satisfied with PFC teaching method, 13.0%(10/77) students were satisfied and 5.2%(4/77) students were basically satisfied. According to the feedback of Likert scale objective evaluation questionnaire, the mean score of each question ranged from 4.19 to 4.77, indicating that students believed that PFC teaching method had a positive impact on the learning of oral pathology. The PFC teaching method proposed in this study could improve the ability of pathological differential diagnosis of undergraduates.

Analysis of dental caries and the impact factors of caries in children aged 3-5 years old in Changdu, Xizang / 华西口腔医学杂志

OBJECTIVES@#To investigate caries status and its impact factors in preschool children in plateau and to provide reference for caries prevention in highlands.@*METHODS@#Examination of caries was performed on 1 597 children aged 3-5 years old in 11 kindergartens in Changdu, Xizang, in accordance with the 4th National Oral Health Survey standards and methods. Their parents were surveyed with the questionnaire regarding oral hygiene habit and consciousness about oral health and related factors. All the data were collected and analyzed.@*RESULTS@#The prevalence of caries among children aged 3-5 years old in Changdu was 52.85%, with dmft index of 2.44. The caries rate and dmft of children aged 3 years old were lower than those of children aged 4 and 5 years old (@*CONCLUSIONS@#The prevalence of ca-ries in children aged 3-5 years old in Changdu increases with aging. Good oral hygiene and eating habits and regular oral examination can reduce the rate of caries.

Construction and immunocompetence of recombinant DNA E.coli ghosts expressing Treponema pallidum adhesin Tp0751 / 中国免疫学杂志

Objective:To construct the recombinant DNA E.coli ghosts (EBGs) expressing Treponema pallidum adhesin Tp0751 (pcD/Tp0751-BG) and determine its immunocompetence in immunized mice,and provide a potential novel method for syphilis vaccine developing.Methods:The recombinant eukaryotic expression plasmid pcDNA3.1(+)/Tp0751 was constructed and loaded into empty EBGs to create pcD/Tp0751-BG.The loading rate was determined accordingly.Macrophages cell line RAW264.7 was transfected with pcD/Tp0751-BG,and the expression of recombinant Tp0751(rTp0751) protein was detected by Western blot(WB).For immuno-competence in mice,the female BALB/c mice were randomly divided into 6 groups,including three control groups,A (PBS),B (EBG),C (empty pcDNA),and experimental group D(naked pcD/Tp0751),E (pcD/Tp0751-BG) and F (pcD/Tp0751-BG+rTp0751).All the mice were immunized as indicated for three times by intramuscular injection at two weeks intervals.The levels of specific IgG in sera and SIgA in genital tract lavage fluid were measured by ELISA.Levels of lymphocyte proliferation and IFN-γ secretion in spleen cells were measured by CCK-8 Cell Counting Kit and ELISA as well,respectively.Results:The loading rate of pcD/Tp0751 to EBGs was 76.1%.WB showed that the target recombinant protein pcD/Tp0751 expressed in RAW264.7 cells was active with Tp-infected rabbit sera.The titers of specific IgG and SIgA in group D,E,F gradually increased to significantly higher level as compared to the control groups (P<0. 01),which reached its peak at wk 8 after last immunization(the titers of IgG and SIgA were 1 :102 400 and 1 :12 800 in group F,respectively). Higher levels of specific IgG and SIgA were observed in groups E and F as compared to group D after first boost (P<0. 01),with groups F higher than group E after last boost(P<0. 01). At wk 8 after the last boost,the stimulation index (SI) and levels of IFN-γ in group D,E,F were all significant higher than the control groups (P<0. 01), with group E and F higher than group D (P<0. 01),and group E higher than group F (P<0. 05). Conclusion: The recombinant DNA EBGs of T. pallidum adhesin Tp0751 (pcD/ Tp0751-BG) possesses the immunocompetence to induce not only strong mucosal and systemic humoral immune response but also systemic cellular immune response in BALB/ c mice. The heterologous boost can be more efficient than homologous boost during immunization process.

A study on the growth effects of SD rats by repeated restraint in dermal exposure test / 预防医学

Objective To analysis the effects on the growth of rats by repeated restraint in dermal exposure test. Methods SD rats in the restraint group was bound for 6 hours per day for 91 days according the way by dermal exposure, while SD rats in the control group didn't receive the treatment. Clinical signs, body weight and food consumption changes were observed for 91 days. When the study was terminated, hematology, clinical biochemistry, urinalyses, gross necropsy, and histopathology were carried out. Statistical methods such as the generalized estimating equation were used to compare the differences between two groups. Results The statistical results of generalized estimating equation showed that there was an interaction between the group and test time for male and female rats in body weight changes (P<0.05), and the body weight of male rats in the restraint group was lower than the control group (P<0.05) . Further analysis showed that for male rats there was significant difference between groups since the forth week (P<0.05), and the interaction was found between groups and test time (P<0.05) . For female rats, the interaction was found since the eighth week between the group and test time (P <0.05) .There was no significant differences in other parameters between two groups (P>0.05) . Conclusion Repeated restraint during dermal exposure affected the body weight gain of rats, and the sensitivity of male rats was higher than that of female rats.

Study on fatigue of pilots during simulated flight training based on electroencephalogram / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study EEG during simulated flight training, then to explore the situational character of mental fatigue of the pilots.</p><p><b>METHODS</b>Fifty male pilots were randomly choice to be recorded their EEG including rest,flight and recovery phase. Then the band waves of EEG were analysed among the three phase.</p><p><b>RESULTS</b>(1) During flight, the amplitude of alpha, beta, SMR, theta, gamma waves tended to increase. These changes seemed obviously in SMR, theta waves. (2) After flight, all the amplitude of the waves declined except for beta wave of the right lobe,and most of them were still higher than those before flight (P < 0.05); (3) The right brain showed a higher cerebration than the left, especially in theta wave.</p><p><b>CONCLUSION</b>Mental fatigue is started during the flight training, and the right lobe has a severe mental fatigue than the left. After flight, mental fatigue showed a slow recovery.</p>

Contrasting study of erythritol and xylitol on Streptococcus mutans / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the inhibitory effect of erythritol by contrast to xylitol on growth and acid production of Streptococcus mutans (S. mutans).</p><p><b>METHODS</b>S. mutans were incubated respectively in 0.5%, 1%, 2%, 4%, 8%, 12%, 16% erythritol or xylitol culture medium under anaerobic conditions. The A and pH value of the mediums were measured at 0, 2, 4, 6, 8, 10, 12, 18, 24 hours, following the profile plots by SPSS.</p><p><b>RESULTS</b>The data of A were higher in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while lower in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration. The data of pH were lower in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while higer in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration. It indicated that the growth and acid production of S. mutans were higer in 0.5%, 1%, 2% erythritol culture medium than in xylitol culture medium at the same concentration, while lower in 8%, 12%, 16% erythritol culture medium than in xylitol culture medium at the same concentration.</p><p><b>CONCLUSION</b>Compared with xylitol, erythritol in low concentration has weaker effort on the growth and acid production of S. mutans, while having stronger effort in high concentration.</p>

Evaluation on parallel HER-2 testing using in situ hybridization and immunohistochemistry in breast cancer tissues / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the application of the immunohistochemistry (IHC) and the fluorescence in situ hybridization (FISH) in detecting the amplification and the expression of HER-2 gene in the breast cancer patients.</p><p><b>METHODS</b>Sixty-six cases of paraffin-embeded breast cancer samples with overexpression, low or no expression of HER-2 gene as detected by IHC were analyzed for HER-2 gene amplification using FISH.</p><p><b>RESULTS</b>Among the 42 samples with HER-2 gene overexpression (3+/2+) detected by IHC, 31 showed positive HER-2 gene amplification and 11 showed negative HER-2 gene amplification in FISH. In the 24 samples with low or no HER-2 gene expression (1+/-) detected by IHC, no HER-2 gene amplification was detected by FISH. The results of the two testing methods showed a good consistency with the kappa coefficient of 0.672 (P<0.001). We also found that the 17 chromosome polysomy in 42% of the samples and the incidence of 17 polysomy was significantly higher in the HER-2 gene overexpression (3+/2+) group than in low or no HER-2 gene expression (1+/-) group (chi(2)=4.688, P=0.03).</p><p><b>CONCLUSION</b>IHC can be used as a screening method for detecting HER-2 gene amplification, and FISH should be performed in cases of HER-2 gene overexpression (3+/2+) as detected by IHC.</p>

Influence of chronic unpredictable emotional stress on the ultrastructures of temporomandibular joint in rats / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the influence of emotional stress on the ultrastructures of temporomandibular joint in rats.</p><p><b>METHODS</b>Sixteen male Wistar rats, aged 12 weeks, were divided into 2 groups randomly, experimental group and control group. Animal model of chronic unpredictable stress was established in the experimental group. After 6 weeks, all rats in both groups were killed and their condyles and articular discs were dissected, taken out and observed by scanning electron microscope.</p><p><b>RESULTS</b>Under scanning electron microscope, the surface gelatum of the condyles in experimental group were cracked, and collagen fibrils in disorder and broke, and deep layer collagen fibrils were exposed. The articular discs' surface gelatum were still integrated, but the gyri dispose were irregular. In control group, there were no such changes in condyles and articular discs.</p><p><b>CONCLUSIONS</b>The long-term emotional chronic unpredictable stress could induce the injuries of temporomandibular joint in rats in ultrastructure level.</p>

Effects of surface potentials of tooth hard tissue on bone remodeling in rabbit tibiae / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the influence of surface potentials of tooth hard tissue on bone remodeling.</p><p><b>METHODS</b>After insured the surface potentials of human extracted teeth with electrochemical methods, teeth sections and artificial hydroxyapatite were implanted into 25 rabbits' tibiae. The rabbits were sacrificed at 1, 2, 4, 6 and 8 weeks after implantation, respectively. The bone regeneration was compared between opposite two sides (cathode side and anode side) of tooth sections using hematoxylin-eosin (HE) staining, tartrate-resistant acid phosphatase (TRAP) activity detecting and tetracycline tracing method.</p><p><b>RESULTS</b>Resorption lacunae was seen in the tibiae facing to the enamel anode and new bone density in the implant bed near the cathode of tooth samples was much higher than that near the anode, while the number of TRAP positive cells near the cathode was smaller than that near the anode (P < 0.01). The fluorescent area of tetracycline tracing near the cathode was larger than that near the anode (P < 0.05).</p><p><b>CONCLUSIONS</b>The cathode of tooth hard tissue (cementum) could improve or trigger new bone formation, while the other side, anode (enamel), could improve the bone resorption. This study suggests that tooth hard tissue's electrochemical characteristic might affect the remodeling of alveolar bone, and tooth supraeruption and the alveolar bone loss after tooth extraction might result from the redundant or lack of root electrochemical stimulation to bone.</p>

The relation of nuclear factor kappa B to angiogenesis and clinical outcomes in adenoid cystic carcinoma of salivary glands / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the expression of nuclear factor kappa B (NF-kappaB) p65 in relation to angiogenesis microvessel density (MVD) and clinical outcomes in adenoid cystic carcinoma of salivary glands (ACCs).</p><p><b>METHODS</b>Immunohistochemical staining method was used to quantify the protein expression levels of NF-kappaB p65 in 80 surgically resected salivary gland ACC and normal salivary tissues. In all cases of ACCs, microvessel density was evaluated by counting any CD(34)-reactive endothelial cell or endothelial-cell cluster. The patients with ACCs were followed up from 1992 to 2002.</p><p><b>RESULTS</b>NF-kappaB p65 was detected in the cytoplasm of normal and ACC cells, but was only in the nucleus of tumor cells; while there was no NF-kappaB p65 nuclear staining in all the controls. The mean value of MVD was (47.07 +/- 13.44), which had significant correlations with NF-kappaB p65 expression (P < 0.01). In three histological types of salivary gland ACC, the expressions of NF-kappaB and MVD were significantly higher in solid type than in cribriform type and tubular type (P < 0.01). NF-kappaB p65 expression and MVD were significantly correlated to clinical stage, tumor size, perineural and vascular invasion, recurrence and metastasis (P < 0.05), but there were no correlations between those three factors and patient age, gender and tumor site (P > 0.05). Multivariate analysis showed NF-kappaB (P < 0.05) expression, MVD (P < 0.01), histotypes (P < 0.01), and perineural invasion (P < 0.05) had an independent prognostic impact on overall survival.</p><p><b>CONCLUSIONS</b>The expression of NF-kappaB p65 was related to MVD, and the correlation between those two factors and clinico-pathological factors and prognosis of ACCs are significant.</p>