Effect of corticotomy techniques accelerating orthodontic tooth movement on root resorption / 北京大学学报(医学版)

In recent years, developing new methods to accelerate orthodontic tooth movement (OTM) has attracted extensive attention in the field of orthodontic clinical and scientific research. It reduces orthodontic treatment time and risks. Over the past, various approaches have been done to accelerate orthodontic tooth movement. Several forms of corticotomy techniques have been effective in inducing rapid tooth movement. These techniques activate regional acceleratory phenomenon and create a favorable microenvironment for accelerating tooth movement. Root resorption is one of most common side effects of orthodontic treatment. It affects the long-term viability and health of teeth. However, the effect of corticotomy techniques accelerating orthodontic tooth movement on root resorption still remains unclear. Accelerating tooth movement may have two-side effects on root resorption. Through shortening the treatment period and removing the hyalinized tissues, the acceleration of orthodontic tooth movement could reduce root resorption. The increase of root resorption might be due to the local inflammation and function of cementoclasts/odontoclasts. In this paper, we reviewed the effects of different corticotomy techniques accelerating orthodontic tooth movement on root resorption. Corticotomy techniques deal with mucoperio-steal flaps and bone tissues differently and develop towards minimally invasive. Previous studies on root resorption use two-dimensional images, including apical films and panoramic tomography, to evaluate the degree of root resorption. In recent years, researches measure the volume of root resorption accurately using cone-beam computed tomography (CBCT) and micro-CT. Most studies suggest that the root resorption during acceleration of orthodontic tooth movement through corticotomy techniques is not statistically different from that of traditional orthodontic treatment. Some studies using micro-CT have shown that the root resorption in the groups of corticotomy techniques increases compared with the control group without surgery. Because of the short duration of these studies, the clinical significance is controversial on the overall impact of corticotomy techniques on orthodontic treatment. Accelerating orthodontic tooth movement is still at its emerging phase and need further research in the form of clinical trials to illustrate the effect of corticotomy techniques accelerating orthodontic tooth movement on root resorption.

Acute toxicity mechanism of Panax notoginseng saponins in larvae zebrafish based on metabonomics / 中国中药杂志

Based on metabolomics,the metabolites of larvae zebrafish with overdose of Panax notoginseng saponins( PNS) were compared with those in normal group of larvae zebrafish to investigate the possible toxicity mechanism of overdose PNS in larvae zebrafish. An experimental animal model of long-term toxicity induced by PNS overdose was established by administering 1-6 dpf at low,medium and high doses of PNS,respectively. The ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry( UPLC-Q-TOF-MS) technique was combined with principal component analysis( PCA) and orthogonal partial least squares discriminant analysis( OPLS-DA) to screen and identify biomarkers associated with toxicity,and then the MetaboAnalyst database was used to analyze metabolism-related pathways. The results showed that the metabolites of each group could be distinguished distinctly,and they deviated more from the normal group in a time and dose dependent manner. Twenty-nine potential biomarkers related to toxicity( VIP>1,P<0. 05) were identified preliminarily,mainly involving six metabolic pathways. From the metabonomics point of view,the toxicity mechanism of overdose PNS may be related to the disorders of lipid metabolism,amino acid metabolism and energy metabolism.

Clinical and laboratory features of pediatric acute myeloid leukemia with inversion of chromosome 16 / 中华儿科杂志

<p><b>OBJECTIVE</b>To evaluate the clinical and laboratory features of pediatric inv(16) acute myeloid leukemia (AML) retrospectively.</p><p><b>METHOD</b>Dual color fluorescence in situ hybridization (D-FISH) using a LSI CBFβ inv(16) break apart probe labeled by Spectrum red and Spectrum green was performed in 15 acute myeloid leukemia cases, including 13 cases with or without abnormal eosinophils but with positive core binding factor β (CBFβ)-MYH11 fusion transcript detected by RT-PCR, and 2 cases with trisomy 8 (+8). The results were compared with the morphology, immunophenotype, karyotype and RT-PCR.</p><p><b>RESULT</b>Morphologically, 12 cases were diagnosed as M(4)EO, 2 as M(4), and 1 as M(2a). Immunophenotypically, all 13 AML cases with inv(16) showed positive expression of CD(13) and CD(33), but without the expression of any lymphoid lineage antigens. Karyotyping analysis with G-banding detected inv(16) in 10 AML cases, including 9 M(4)EO cases and 1 M(2a), but only 5 positive cases were detected using R-banding technique. Among them, 2 cases had simultaneous +8 and trisomy22 (+22), one had +22 only in addition to inv(16). D-FISH revealed a CBFβ-MYH11 rearrangement in 13 cases of AML with positive RT-PCR results, and the mean positive rate of cell detection was 55.15% (range 37.0% - 86.0%). The complete remission rate (CR) and median survival period in this series of inv(16) AML were 81.5%and 11 months, respectively, of whom, 8 cases were still in CR. Relapse and karyotypic evolution were seen in case 5 with +8, +22 in addition to inv(16).</p><p><b>CONCLUSION</b>AML with inv(16) is a special subtype. Most cases belong to M(4)EO. Its prognosis is good in general, but it seems to be an unfavorable feature for AML with inv(16) and +8, +22 simultaneously, especially with karyotypic evolution. For detection of inv(16), G-banding technique is evidently superior to R-banding technique. D-FISH combined with RT-PCR are more sensitive and reliable than chromosome banding analysis.</p>

The concern and preference of college students in Beijing Haidian district for female maxillary anterior tooth esthetic factors / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate Beijing college students' concern and preference for maxillary anterior tooth esthetic factors.</p><p><b>METHODS</b>Several images about lip and tooth were made through computer. A questionnaire was sent out to students in ten colleges and then collected. There were five factors to be evaluated: relationship of maxillary incisors and lower lip, numbers of tooth exposed, shape of centric incisor, crown width-length ratio, gingival margin. Concern of the beauty of anterior tooth, ie. tooth shape, tooth arrangement, shape of gingiva and so on, were then analyzed.</p><p><b>RESULTS</b>There were 408 responses collected, and 47.5% (194/408) of them preferred light contact between upper incisors and lower lip; 49.5% (202/408) preferred 8 tooth exposed when smile; 69.1% (282/408) preferred oval crown shape; 52.5% (214/408) preferred 0.85 as a crown width-length ratio; 49.5% (202/408)of responses chose the curve of gingiva runs horizontal. The average score of concern for male was 52.6% (100/190), for female was 59.6% (130/218).</p><p><b>CONCLUSIONS</b>Most results from this study accord with the classical principles of tooth esthetics. Sex affects the concern and preferences of maxillary anterior tooth esthetics factors.</p>

Clinical and experimental studies of childhood acute myeloid leukemia with 11q23/MLL rearrangements / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore clinical and experimental features of 28 cases of childhood acute myeloid leukemia (AML) with 11q23/MLL gene rearrangements.</p><p><b>METHODS</b>Karyotypes of 234 cases of de novo childhood AML were analyzed using short-term culture of bone marrow cells and R-banding. The fusion transcripts involving MLL gene and partial tandem duplication of MLL (MLL-PTD) were detected by multiple reverse transcription polymerase chain reaction (RT-PCR) assay. Two cases with 11q23 translocation by karyotypic analysis but with negative result of multiple RT-PCR were studied with MLL-dual-color fluorescence in situ hybridization (D-FISH).</p><p><b>RESULTS</b>R-banding karyotypic analysis has revealed 20 cases with 11q23 translocation (14 cases with M5, 4 cases with M4, 2 cases with M2), including 12 cases with t(9;11)(p22;q23), 3 cases with t(1;11)(q21;q23), 2 cases with t(6;11)(q27;q23), 1 case with t(11;19)(q23;p13), 1 with t(5;11)(q31;q23), and 1 with t(X;11)(q24;q23). Eighteen cases with 11q23 translocation having fusion transcripts involving MLL genes were confirmed with multiple RT-PCR; 2 cases showed negative results, but they were confirmed to have MLL rearrangements by D-FISH. MLL-PTD was also detected in 8 cases (4 cases M5, 2 cases M4, M2 and M6, one case each) from the other childhood AML cases. The total incidence of 11q23/MLL gene rearrangements was 11.97% (28/234), and most of patients(85.7%, 24/28) were M4/M5. The complete remission (CR) rate after treatment for the 28 cases with MLL rearrangements was 53.8%, the difference was significant by statistics (P< 0.05) compared with 90.5% for the control group (M4/M5 childhood AML with other karyotypic abnormalities or normal karyotype). Of them, 2 cases receiving intensive chemotherapy survived for 81 and 66 months, respectively, 4 cases receiving allogeneic stem cell transplantation survived for 21, 20, 16 and 11 months, respectively, and are still alive with CR. The medium survival (MS) time for 28 cases with 11q23/MLL rearrangements was 11 months, whereas the MS for control group was 15 months. The difference was not statistically significant(P> 0.05).</p><p><b>CONCLUSION</b>The 11q23/MLL rearrangements is highly correlated with the occurrence of monocytic leukemia (M4 and M5). The 11q23 translocation and MLL-PTD are mutually exclusive, though both are indicative of poor prognosis. Intensive chemotherapy and allogeneic stem cell transplantation may ameliorate the clinical outcome. Multiple RT-PCR combined with karyotypic analysis and D-FISH are useful for screening the 11q23/MLL rearrangements in childhood AML.</p>

Preliminary study of gene expression profile associated with risk classification of childhood patients with acute lymphoblastic leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore genes associated with risk classification of childhood acute lymphoblastic leukemia (ALL) by gene chip technology.</p><p><b>METHODS</b>Group A and B were both composed of three newly diagnosed ALL cases with standard risk. After re-evaluation, group B was relegated to high-risk. The control group was composed of three idiopathic thrombocytopenic purpura (ITP) patients. The gene expression profiles of group A and B were studied by Illumina Human-6 Beadchip. Eighty-two ALL patients were selected as the experimental group and 21 with normal bone marrow as control group for real-time quantitative RT-PCR (RQ-PCR).</p><p><b>RESULTS</b>(1) There were 19 genes expressed differently between group B and A, including 14 up-regulated as ABCC4 and BCL11A, 5 down-regulated genes as TOP2A. (2) ABCC4 and BCL11A were validated by RQ-PCR and their expression level was higher in the high risk group than in the standard risk group (P < 0.05). The gene expression level in the group A and B was higher than that in the normal control group (P < 0.01). TOP2A was also validated by RQ-PCR and its expression level in the high risk group was lower than that in the standard risk group (P < 0.05). The gene expression level in the groups A and B was lower than that in the normal control group and the difference was statistically significance (P < 0.01). (3) There was a significant difference in the expression level of ABCC4 between the remission and unremission patients (P < 0.05). There was no significant difference in the expression level of BCL11A between different clinical indicators (P > 0.05). There was significant difference in the expression level of TOP2A between remission and prednisone good responder groups (P < 0.05).</p><p><b>CONCLUSIONS</b>Fourteen genes studied were involved in the pathogenesis and drug resistance mechanism in childhood ALL patients. Investigation of gene expression profile will be helpful for predicting drug resistance, prognosis, early intervention and target therapy in childhood ALL.</p>

Epidemiological study on respiratory syncytial virus and its bronchopneumonia among children in Suzhou / 中华预防医学杂志

<p><b>OBJECTIVE</b>To probe the epidemiological trend of respiratory syncytial virus (RSV) and cellular immunological change of RSV bronchopneumonia among children in Suzhou in the past five years.</p><p><b>METHODS</b>10,205 children with acute respiratory tract infection from January 2001 to December 2005 were enrolled into the study. Nasopharyngeal aspirates were obtained from the respiratory tract by aseptic vacuum aspiration. Direct immuno-fluorescence assay was employed to detect seven kinds of virus antigens including RSV antigen. CD3, CD4, CD8, CD19, CD16 and CD56 in peripheral blood mononuclear cells of 30 patients with RSV bronchopneumonia (1.5-24.0 months old group) were analyzed by flow cytometry analysis, and 15 normal infants (1.5-24.0 months old group) were enrolled as control group.</p><p><b>RESULTS</b>The annual positive rate of RSV was 24.94%, 25.83%, 24.05%, 25.39% and 27.30% respectively from 2001 to 2005. It also found that the peak season for RSV infection was spring or winter (January to March or November to December). The positive rate of RSV was significantly higher in 1-12 months old group than that in > 12 months old group (chi2 = 97.320, P < 0.01), as well as the groups between 1-12 months old (chi2 = 7.804, P < 0.05, the highest positive rate was occurred at 3-6 months old group). The positive rate of RSV was significantly higher in boys than that in girls (chi2 = 9.693, P < 0.01). The percentages of CD3+, CD4+, CD8+ and NK (CD16 + 56)+ cells were significantly lower in RSV bronchopneumonia than those in control group (t = 3.199, P < 0.01; t = 2.215, P < 0.05; t = 2.619, P < 0.05 and t = 5.240, P < 0.01, respectively). While the percentage of CD19+ cells was significantly elevated in RSV bronchopneumonia than that in control group (t = 2.875, P < 0.01).</p><p><b>CONCLUSION</b>RSV infection is of obvious seasonal changes. The younger the patient, the higher positive rates of RSV infection is, while and the cellular immunity function is lower. The effective measures for preventing RSV infection are important, especially for the infants. Further investigation is necessary to understand the causes of the variations for RSV infections between boys and girls.</p>

Study on clinical and biological characteristics of childhood acute leukemia with MLL gene rearrangements / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the clinical and laboratory features of childhood acute leukemia (AL) with MLL gene rearrangements.</p><p><b>METHODS</b>Sixteen of 298 cases of childhood AL with MLL rearrangements were studied by using MLL dual-color FISH, multiplex RT-PCR with 13 pairs of primers in combination with R banding karyotype analysis and cell immunophenotyping by flow cytometry.</p><p><b>RESULTS</b>Sixteen cases of childhood AL with MLL rearrangements accounted for 5.4% of 298 AL patients, and 56.3% of infant ALs. Among 106 cases analyzed by multiplex RT-PCR, MLL gene rearrangements were found in 11 cases, including MLL/AF4 fusion gene in 2, MLL/AF6 fusion gene in 1, MLL/AF6 and MLL/ELL combined with MLL/ AFX or HOX11 in one case each, MLL/AF9 in 2, MLL/AF10 in 1, MLL/ELL in 2. MLL partial tandem duplication in 1 and activated HOX11 in 1. In 27 cases assayed by FISH, 9 cases (36.0%) were demonstrated MLL gene rearrangements. In 16 patients with MLL gene rearrangements, 14 (87.5%) exhibited clonal chromosome abnormalities involved chromosome 11 in 11 cases: being t(4;11) in 2, t(6;11), t(8;11), t(7;8;11), t(9;11) in each trisomy 11 in 2 and 11q--in 3 cases. Among these 16 patients, 11 were B-ALL, and 5 AML-M5, 3 of the latter were CD7+ and CD2+. Of these 16 patients, 8 received chemotherapy and 7 of them achieved complete remission, while the other 8 patients gave up treatment.</p><p><b>CONCLUSION</b>Multiplex RT-PCR combined with FISH provided a more accurate and sensitive method for detection of MLL gene rearrangements. Finding out MLL gene rearrangement is of most importance in guiding therapy and predicting prognosis in childhood AL.</p>

Detection of fusion genes resulting from chromosome abnormalities in childhood acute lymphoblastic leukemia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the expression of the fusion genes resulting from chromosome abnormalities in childhood acute lymphoblastic leukemia(ALL) and its conformity to WHO classification.</p><p><b>METHODS</b>Sixty-two children with ALL were investigated. The expression of fusion genes was determined by multiplex reverse transcription-polymerase chain reaction (RT-PCR), karyotyping (R band) and immunophenotyping (by flow cytometry) were also performed.</p><p><b>RESULTS</b>Of the 62 patients, 23(37.1%) were found to carry 13 different fusion genes. The patients with immunophenotype of Pre-B-ALL were found to carry: TEL/AML1(3 cases); E2A/PBX1, E2A/HLF, TLS/ERG, MLL/AF4, MLL/AF9, MLL/AF10, MLL/AFX-MLL/AF6-MLL/ELL, MLL/AF6-MLL/ELL, dupMLL (one case for each); and HOX11 (6 cases). The patients with immunophenotype of Pre-T-ALL were found to carry: TAL1D (4 cases, one is also found to have HOX11 expression); and HOX11 (2 cases). The multiplex RT-PCR in combination with chromosome analysis revealed genetic abnormalities in 69.4%(43/62) of childhood ALL.</p><p><b>CONCLUSION</b>Multiplex RT-PCR combined with chromosome analysis and immunophenotyping can provide reliable and helpful information for the diagnosis, therapy evaluation and prognosis prediction in childhood ALL, which may also serve as a basis on which to implement the criteria of WHO classification.</p>

A combined assay of multiplex RT-PCR and karyotypic analysis in childhood acute lymphoblastic leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the value of combination assay of multiplex RT-PCR and karyotypic analysis in the diagnosis and classification of childhood acute lymphoblastic leukemia (ALL).</p><p><b>METHODS</b>Fifty cases of childhood ALL patients were studied by multiplex RT-PCR in combination with R or G banding karyotype analysis.</p><p><b>RESULTS</b>Of the 50 childhood ALL patients, 18 (36.0%) carried 11 types of fusion genes including E2A/PBX1, TEL/AML1, TLS/ERG, MLL/AF4, MLL/AF9, MLL/AF10, MLL/AFX, MLL/AF6, MLL/ELL, TAL1D, and HOX11, revealed by multiplex RT-PCR, and in 48 cases, 24 (57.1%) had chromosome abnormalities. Among the latter, numeral chromosome abnormalities and chromosome deletions accounted for 75.0% (18/24), while translocations 25.0% (6/24). The multiplex RT-PCR in combination with chromosome analysis could detect genetic abnormalities in 70% (35/50) of childhood ALL.</p><p><b>CONCLUSIONS</b>Multiplex RT-PCR combined with chromosome analysis can enhance the detection rate of genetic abnormalities in childhood ALL. It provides reliable evidence for the diagnosis, classification and prognosis.</p>

Clinical and laboratory studies on childhood acute leukemia with 11q23 abnormalities / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the interrelations among morphology, immunology, cytogenetics and clinical outcome in childhood acute leukemia with 11q23 abnormalities.</p><p><b>METHODS</b>Eighteen patients with 11q23 abnormalities, from 320 childhood acute leukemia patients, were retrospectively analysed for cell morphology, flow cytometry, immunophenotyping, R-banding karyotype as well as clinical features and prognosis. Twenty cases of childhood AL with normal karyotype during the same period were used as control.</p><p><b>RESULTS</b>The incidence of 11q23 abnormalities in our childhood acute leukemia patients was 5.63% including 14 acute lymphoblastic leukemia (ALL) and 4 acute myeloid leukemia (AML). Of 16 cases immunophenotypically tested, 13 expressed lymphoid antigens and 3 CD(34) and other myeloid antigens. Karyotype analysis disclosed the following abnormalities: t(4; 11)(q21; q23) in 6 cases, t(10; 11)(p13; q23) in 3, t(11; 19)(q23; p13) in one and del(11)(q23) in 6. The complete remission rate for these patients with 11q23 abnormalities was comparable to that of the control (72.2% vs 80.0%, P > 0.05), while the mortality rate in the former was significantly higher than that in the latter (61.1% vs 25.0%, P < 0.05).</p><p><b>CONCLUSIONS</b>11q23 abnormalities were mainly seen in childhood ALL and acute monocytic leukemia with unique prognostic features.</p>