Influence of magnification and superimposition of structures on cephalometric diagnosis

OBJECTIVE: The purpose of this study was to assess the influence of magnification and superimposition of structures on CBCT-generated lateral cephalometric radiographs (LCR) using different segments of the cranium. METHODS: CBCT scans of 10 patients were selected. Four LCR were generated using Dolphin Imaging(r) software: full-face, right side, left side and center of the head. A total of 40 images were imported into Radiocef Studio 2(r), and the angles of the most common cephalometric analyses were traced by the same observer twice and within a 10-day interval. Statistical analyses included intraexaminer agreement and comparison between methods by means of intraclass correlation coefficient (ICC) and Bland-Altman agreement tests. RESULTS: Intraexaminer agreement of the angles assessed by ICC was excellent (> 0.90) for 83% of measurements, good (between 0.75 and 0.90) for 15%, and moderate (between 0.50 and 0.75) for 2% of measurements. The comparison between methods by ICC was excellent for 68% of measurements, good for 26%, and moderate for 6%. Variables presenting wider confidence intervals (> 6o) in the Bland-Altman tests, in intraexaminer assessment, were: mandibular incisor angle, maxillary incisor angle, and occlusal plane angle. And in comparison methods the variables with wider confidence interval were: mandibular incisor, maxillary incisor, GoGn, occlusal plane angle, Frankfort horizontal plane (FHP), and CoA. CONCLUSION: Superimposition of structures seemed to influence the results more than magnification, and neither one of them significantly influenced the measurements. Considerable individual variability may occur, especially for mandibular and maxillary incisors, FHP and occlusal plane. .

OBJETIVO: o objetivo do presente estudo foi avaliar a influência da sobreposição estrutural e da magnificação nas radiografias cefalométricas laterais (RCL) geradas por meio de tomografias computadorizadas de feixe cônico (TCFC), usando diferentes segmentos do crânio. MÉTODOS: foram selecionadas 10 tomografias de pacientes. Quatro RCL foram geradas usando Dolphin Imaging, sendo face total, lado direito, lado esquerdo e o centro da cabeça. Um total de 40 imagens foi importado para o Radiocef Studio, e os ângulos das análises cefalométricas mais comuns foram medidos pelo mesmo observador, duas vezes, em um intervalo de 10 dias. As análises estatísticas incluíram concordância intraexaminador e comparação entre os métodos por meio do coeficiente de correlação intraclasse (ICC) e testes de concordância de Bland-Altman. RESULTADOS: a concordância intraexaminador dos ângulos avaliados pelo ICC foi excelente (> 0,90) para 83% das medições, boa (entre 0,75 e 0,90) para 15%, e moderada (entre 0,50 e 0,75) para 2% das medições. A comparação entre os métodos por ICC foi excelente para 68% das medições, boa para 26% e moderada para 6%. As variáveis que apresentaram intervalos de confiança mais amplos (> 6°) nos testes de Bland-Altman, na avaliação intraexaminador, foram: incisivo superior, incisivo inferior e plano oclusal, enquanto nos métodos de comparação, as variáveis com intervalos de confiança mais amplos foram: incisivo inferior, incisivo superior, GoGn, ângulo do plano oclusal, plano horizontal de Frankfort e CoA. CONCLUSÃO: a sobreposição estrutural pareceu influenciar os resultados mais do que a magnificação, mas os métodos não influenciaram significativamente as medições. Considerável variabilidade individual pode ocorrer especialmente para os incisivos superiores e inferiores, plano horizontal de Frankfort e plano oclusal. .

Analysis of genomic copy number variation for a Chinese patient with split hand/split foot malformation / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To employ single nucleotide polymorphisms (SNP) microarray to detect copy number variations (CNVs) for the diagnosis of disease and molecular classification.</p><p><b>METHODS</b>For a patient with split-hand/split-foot malformation, genome-wide copy number variants SNP microarray was applied. Tiny copy number variations were verified by real-time fluorescent quantitative PCR.</p><p><b>RESULTS</b>The results of SNP microarray has revealed that the patient has carried a 0.39 Mb duplication in 10q24.31-24.32 (102 955 122-103 348 688), which has encompassed genes including LBX1, BTRC and POLL. By real-time fluorescent quantitative PCR, duplicate area encompassing the pathogenic genes have been verified. The results for LBX1, BTRC, POLL genes were all consistent with the SNP microarray test. Moreover, a duplication was detected in exon 9 of FBXW4 gene which is in nearby.</p><p><b>CONCLUSION</b>SNP chips can efficiently identify tiny CNVs (< 1.0 Mb). In combination with real-time fluorescence quantitative PCR, this may provide valuable information for prenatal diagnosis.</p>

Effects of DNA polymerase beta on the genotoxicity and genetic instability induced by benzo(a)pyrene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the effects of DNA polymerase β expression level on the genotoxicity and genetic instability induced by benzo(a)pyrene (BaP),and provide experimental the basis for further study on the carcinogenic molecular mechanism of BaP.</p><p><b>METHODS</b>Three kinds of cell lines with the identical genetic background, polβ wild-type cells (polβ+/+), polβ null cells (polβ-/-) and polβ overexpression cells (polβ oe) were applied as cellular models. The oxidative damage, genotoxicity and genetic instability induced by BaP were analyzed by using different methods respectively.</p><p><b>RESULTS</b>Cell viability and colony forming ability of 3 kinds of cell lines exposed to BaP decreased with BaP. After treated with 5 and 20 µmol/L concentration of BaP, fluorescence intensity of polβ-/- cell line was significantly higher than that of other two cell lines (P < 0.05). When treated with 5.00 µmol/L and 20.00 µmol/L concentration of BaP, the SOD activities (76.56 ± 2.84 and 62.78 ± 4.28 U/mg pro) of polβ-/- cell line were significantly lower than that (84.85 ± 3.59) of control group and those (85.21 ± 3.20 and 76.90 ± 3.38 U/mg pro) of polβ+/+ cell line. In 20.00 µmol/L BaP group. SOD activity (82.59 ± 4.64 U/mg pro) of polβ oe cell line was lower than that (88.58 ± 6.77 U/mg pro) of control but higher than that of polβ+/+ cell line (P < 0.05). In 1.25, 5.00 and 20.00 µmol/L concentration BaP groups, the micronucleus rates of polβ-/- cell line were much higher than those of polβ+/+ cell line (P < 0.05). In 5.00 and 20.00 µmol/L concentration BaP groups, the micronucleus rates of polβ oe cell line were significantly lower than those of polβ+/+ line (P < 0.05). In 5.00 and 20.00 µmol/L concentration BaP groups, HPRT gene mutation frequencies (26.16 × 10(-6) and 37.51 × 10(-6); 27.68 × 10(-6) and 38.63 × 10(-6)) in polβ-/- cells and polβ oe cells were significantly higher than those (19.76 × 10(-6) and 24.78 × 10(-6)) of polβ+/+ cells (P < 0.05).</p><p><b>CONCLUSION</b>Polβ could play a role in protecting the cells from the genotoxicity and genetic instability induced by BaP, and the normal expression level of polβ was indispensable for maintaining genome stability.</p>

Effect of DNA polymerase beta on apoptosis and mitochondrial membrane potential induced by hydroquinone, a metabolite of benzene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the effect and mechanism of DNA polymerase β expression level on cell apoptosis and mitochondrial membrane potential induced by hydroquinone.</p><p><b>METHODS</b>Polβ wild-type cells (polβ+/+), polβ overexpressed cells (polβ oe) and polβ null cells (polβ-/-) were applied as a model cell system, The effect of cell apoptosis and mitochondrial membrane potential induced by different doses of hydroquinone were analyzed by flow cytometry. The ROS and ·OH assay kit were used to examine the cellular ROS and ·OH level. The activity of cellular SOD and GSH-Px were tested by Chemiluminescence method after exposed to different concentrations of hydroquinone.</p><p><b>RESULTS</b>With the dose of hydroquinone increased, the rate of apoptosis and falling of mitochondrial membrane potential (ΔΨm) in cells were increased compared with the control. When compared with polβ+/+ cells, the rate of apoptosis in polβ-/- cells exposed to 20.00, 40.00, 80.00 µmol/L hydroquinone increased and the rate of apoptosis in polβ oe cells exposed to 10.00, 20.00, 40.00, 80.00 µmol/L hydroquinone decreased (P < 0.05). Compared with polβ+/+ cells (20.60% ± 0.57%, 37.95% ± 0.64%, 44.50% ± 1.27%, 57.55% ± 1.06%), the rate of cell which undergone mitochondrial depolarization in polβ-/- cells treated with 10.00, 20.00, 40.00, 80.00 µmol/L hydroquinone (33.60% ± 1.55%, 46.05% ± 1.77%, 52.75% ± 2.05%, 75.20% ± 0.56%) increased. The rate of cell which undergone mitochondrial depolarization in polβ oe cells exposed to 10.00, 20.00, 40.00, 80.00 µmol/L hydroquinone (16.05% ± 1.20%, 29.80% ± 1.21%, 35.15% ± 1.06%, 53.80% ± 0.85%) decreased (P < 0.05). When compared with polβ+/+ cells, fluorescent intensity of polβ-/- cells treated with different dosages of hydroquinone increased, while which of polβ oe cells decreased (P < 0.05). Compared with polβ+/+ cells, ·OH level of polβ-/- cells treated with 20.00, 40.00 µmol/L hydroquinone significantly enhanced, while which of polβ oe cells decreased sharply (P < 0.05). Under the same concentrations of hydroquinone, the activity of SOD and GSH-Px were decreased most rapidly in polβ-/- cells. The activity of SOD and GSH-Px in polβ oe cells decreased slower than in the polβ-/- cells.</p><p><b>CONCLUSION</b>Hydroquinone could induced apoptosis by the generation of ROS and decrease of ΔΨm; polβ could protect cells from apoptosis induced by hydroquinone through decrease of ROS level and depolarization of mitochondria.</p>

Specific up-regulation of DNA polymerase by human papillomavirus 16 / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To analyze how the infection of human papillomavirus 16 (HPV16) affects expression of DNA polymerase beta (DNA polB) with the aim of probing the mechanism of over-expression of DNA polB in human cancers.</p><p><b>METHODS</b>Four fragments of human DNA polB promoter were amplified and constructed into luciferase reporter vector pGL-Basic, generating pGL-BP, pGL-BMH, pGL-BMS, and pGL-BAT constructs respectively, and co-transfected with HPV16 or HPV6 into Hep2 cells. Luciferase activity was assayed 48 hours after transfection. Semi-quantitative RT-PCR was used to measure mRNA expression of endogenous DNA polB. Immunohistochemistry and in situ hybridization were used to analyze DNA polB expression and HPV16 or HPV6 infection in 38 cases of cervical lesions respectively.</p><p><b>RESULTS</b>With co-transfection of HPV16 and DNA polB promoter-driving reporters into Hep2 cells, pGL-BP reporter in full-length DNA polB promoter presented markedly elevated luciferase activities (P < 0.05). However, the other three mutant reporters: pGL-BMH, pGL-BMS, and pGL-BAT, generated no reporting activities in the presence of HPV16 (P > 0.05). On the contrary, all of polB promoter reporters were little stimulated in co-transfection of HPV6 (P > 0.05). The transfection of HPV16 could enhance the endogenous polB mRNA expression compared with that of HPV6 (3.42 vs. 0.80, P < 0.05). The DNA polB expression was found in 8 of 10 HPV16-positive cervical intraepithelial neoplasia grade III (CIN III) cases, while was only found in 3 of 11 HPV6-positive condyloma accuminatum cases, but was negative in all chronic cervicitis cases. The correlation of DNA polB expression with HPV16 infection in cervical lesions was significant (P < 0.05).</p><p><b>CONCLUSIONS</b>HPV16 is able to specifically stimulate the expression of DNA polB in human epithelial cells through interaction with the core upstream regulatory sequences of DNA polB promoter. Over-expression of DNA polB might be an explanation for the molecular mechanism underlying HPV-related human cancers.</p>

Preliminary study of DNA polymerase beta gene silencing by small interfering RNA in human gastric cancer BGC-823 cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the influence of DNA polymerase beta (polbeta) gene silencing by small interfering RNA on biological behavior of human gastric cancer cell line BGC-823.</p><p><b>METHODS</b>The siRNA eukaryotic expression vectors targeting polbeta gene were constructed and transfected into BGC-823 cells by liposome. Stable cell lines were screened with G418. The expression levels of polbeta mRNA and protein were detected by real time PCR and Western blot in the cells of each group. The proliferation of each group was detected by flow cytometry and tumorigenicity was determined in nude mice.</p><p><b>RESULTS</b>The siRNA expression vector targeting polbeta gene was successfully constructed. The expression levels of polbeta mRNA and protein were significantly reduced in the experimental group transfected with siRNA expression vectors targeting polbeta, and the silencing effect of pRNAT-U6.1-sipolbeta2 (suppression degree was 83%) was stronger than that of pRNAT-U6.1-sipolbeta1 (depression degree is 56%). Compared with irrelevant siRNA control group, empty vector control group and untransfected group, the ratio of G0/G1 cells was increased, proportion of S phase cells and cell proliferation were decreased in the experimental group 1 cells transfected with pRNAT-U6.1-sipolbeta1 (P < 0.05). On the contrary, the ratio of G1/G0 was decreased, proportion of S phase cells and cell proliferation was increased in the experimental group 2 cells transfected with pRNAT-U6.1-sipolbeta2 (P < 0.05).</p><p><b>CONCLUSION</b>The siRNA expression vectors targeting DNA polymerase beta gene can significantly inhibit the expression of polbeta mRNA. Neither high nor extremely low expression of polbeta is beneficial to maintain the cellular physiological functions. The expression of polbeta silenced to a proper level by siRNA may play an important role in inhibiting tumorigenesis.</p>

Possible role of DNA polymerase beta in protecting human bronchial epithelial cells against cytotoxicity of hydroquinone / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To explore the toxicological mechanism of hydroquinone in human bronchial epithelial cells and to investigate whether DNA polymerase beta is involved in protecting cells from damage caused by hydroquinone.</p><p><b>METHODS</b>DNA polymerase beta knock-down cell line was established via RNA interference as an experimental group. Normal human bronchial epithelial cells and cells transfected with the empty vector of pEGFP-C1 were used as controls. Cells were treated with different concentrations of hydroquinone (ranged from 10 micromol/L to 120 micromol/L) for 4 hours. MTT assay and Comet assay [single-cell gel electrophoresis (SCGE)] were performed respectively to detect the toxicity of hydroquinone.</p><p><b>RESULTS</b>MTT assay showed that DNA polymerase beta knock-down cells treated with different concentrations of hydroquinone had a lower absorbance value at 490 nm than the control cells in a dose-dependant manner. Comet assay revealed that different concentrations of hydroquinone caused more severe DNA damage in DNA polymerase beta knock-down cell line than in control cells and there was no significant difference in the two control groups.</p><p><b>CONCLUSIONS</b>Hydroquinone has significant toxicity to human bronchial epithelial cells and causes DNA damage. DNA polymerase beta knock-down cell line appears more sensitive to hydroquinone than the control cells. The results suggest that DNA polymerase beta is involved in protecting cells from damage caused by hydroquinone.</p>

Atividade clastogênica e genotóxica de altas concentrações do extratoaquoso de Agaricus brasiliensis e diferentes respostas quando associadoaos inibidores de reparo de DNA, ARA-C e 3DEOT, in vitro / Clastogenic and genotoxic activity of high concentrations of Agaricus

O Agaricus brasiliensis Wasser & Didukh – Ab (=Agaricus blazei Murrill ss. Heinemann) é um basidiomiceto que vem sendo consumido em diversas partes do mundo no combate e tratamento de muitas doenças. Neste estudo, foram testados, em células de ovário de hamster chinês (CHO-k1), os efeitos clastogênicos e genotóxicos de altas concentrações de Ab e seu potencial protetor, por meio dos ensaios de aberração cromossômica (AC) e cometa (SCGE), associados a dois bloqueadores de reparodo DNA (citosina arabinoside trifosfato - Ara-C - inibidor de DNA polimerase α e 3’deoxitimidina5’trifosfato - 3DeoT - inibidor de DNA polimerase β), na presença ou não de um agente alquilante(metilmetanosulfonato). No teste de clastogenicidade, verificou-se que as concentrações 0,2 e 0,4 não se mostraram indutoras de dano, ao contrário da maior concentração (0,6). Nos tratamentos de genotoxicidade no SCGE, a concentração de 0,2 do extrato não mostrou atividade genotóxica, ao contrário das concentrações de 0,4 e 0,6, as quais foram efetivas indutoras de danos no DNA. Os resultados de anticlastogenicidade indicaram que, na maioria dos tratamentos realizados, o extrato aquoso de Ab não apresentou atividade protetora contra danos no DNA, induzidos pela Ara-C e Ara-C + MMS. Pelo SCGE, Ab, nas três concentrações testadas, não mostrou atividade antigenotóxica. Os dados sugerem cuidado no consumo e ingestão de Ab por seres humanos, principalmente em altas concentrações.

Effects of overexpression of human pol-beta on cellular response to DNA damage / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the biological effects of overexpression of the human DNA polymerase (pol-beta) on cellular response to DNA damage.</p><p><b>METHODS</b>The cell strain HLFbeta from the stable overexpression of the human pol-beta was contaminated with methyl methanesulfonate (MMS) for investigating the effects of the pol-beta on the cellular responses to DNA damage on the aspects such as the DNA damage, the cell cycle and the induced mutation rate.</p><p><b>RESULTS</b>The cell HLFbeta from the stable overexpression of the human pol-beta was obtained through the screening. The cellular response to DNA damage of HLFbeta induced by the MMS in the intermediate and high dosage group (ranging from 0.5 to 0.8 mmol/L) was significantly lower than that in the control group. The analysis for the cell cycle distribution showed that both the two types of cells contaminated by MMS had retardation at G(2) phase. In the HLFbeta group, the cells had the obvious G(2) phase retardation and 49.0% of the cells were retarded at G(1) phase as well when the MMS was increased to 0.5 mmol/L while in the control, only 20.1% of the cells were retarded at the G(1) phase when the same dosage of MMS was administered. Moreover, the MMS-induced mutagenesis in HLFbeta was increased from 4.5 x 10(-6) to 8.2 x 10(-6), significantly higher than that in the control group (P < 0.05).</p><p><b>CONCLUSION</b>High Pol-beta level decreases cellular DNA damage induced by MMS. Nevertheless, the overexpression of Pol-beta can also increase error-prone DNA synthesis during DNA repair process.</p>