1.In vitro study evaluating the effect of different subgingival root exposure methods and ferrule designs on fracture resistance of residual root.
Qingfei MENG ; Lijuan CHEN ; Jian MENG
West China Journal of Stomatology 2014;32(1):75-79
OBJECTIVETo evaluate the effect of different subgingival root exposure methods, namely, crown lengthening or forced eruption, and different ferrule lengths on fracture resistance of a residual root restored with a carbon fiber post-and-core system.
METHODSFifty-six extracted endodontically-treated mandibular first premolars were sectioned 1.0 mm coronal to the buccal cementoenamel junction. All the models were divided randomly into seven groups that each consist of eight roots. Group A was given non-ferrule as control. Simulated crown lengthening was performed for the dentin ferrule design in the cervical tooth structure for Groups B, C, and D with a ferrule length of 1.0, 2.0, and 3.0 mm, respectively. Simulated forced eruption was performed with a ferrule length of 1.0, 2.0, and 3.0 mm in the cervical tooth structure for Groups E, F, and G, respectively. After restoration with prefabricated carbon fiber post-and-core system, each specimen was embedded in a self-cured acrylic resin block from 2.0 mm apical to the margins of a cast Ni-Cr alloy crown, then loaded at 150 degrees from the long axis in a universal testing machine at a crosshead speed of 1.0 mm min(-1) until fracture. Data of failure loads and fracture mode were recorded and analyzed.
RESULTSMean failure loads for Groups A to G were (1.13 +/- 0.15), (1.27 +/- 0.18), (1.02 +/- 0.11), (1.05 +/- 0.12), (1.63 +/- 0.14), (1.92 +/- 0.19), and (1.93 +/- 0.15) kN, respectively. The effects of root exposure method and ferrule design differed significantly, and two factors exhibited significant interaction (F=33.396, P<0.0001). When the ferrule lengths were the same, fracture loads in the simulated forced eruption groups were significantly higher than those of the simulated crown lengthening groups (P<0.001). No statistical differences in fracture mode were observed among all groups (P=1.00).
CONCLUSIONMore than 1.0 mm ferrule placement on the apical crown margin by using forced eruption significantly increases fracture resistance.
Bicuspid ; Crowns ; Dental Stress Analysis ; Humans ; In Vitro Techniques ; Post and Core Technique ; Tooth Fractures ; Tooth Root
2.Advances in effects and mechanisms of ADAMs in tumor progression
Qin CHEN ; Linghua MENG ; Jian DING
China Oncology 2001;0(02):-
ADAMs is a family of transmembrane proteins with multi domains and multiple functions,which play important roles in many(patho-)physiological processes.They are upregulated in a variety of tumors and possess protein shedding and adhesive activities,which showed that they could be useful as tumor biomarkers and promising targets for designing new anti-tumor drugs.This review focuses on the roles ADAMs play in the process of tumor development and the potential application in cancer therapy.
3.Treatment of nonsyndromic hereditary gingival fibromatosis:a case report
Zhiping LI ; Jian MENG ; Jie ZHANG ; Qianping GU ; Bin CHEN
Chinese Journal of General Practitioners 2014;(6):495-496
Nonsyndromic hereditary gingival fibromatosis ( HGF) was a rare hereditary condition characterized by a progressive increase in gingival tissue , simultaneously with hypertrichosis and mental retardation.The patients often had troubles with mastication , appearance and pronunciation.The measure include surgical therapy.One case of HGF was reported and its relevant literature reviewed.
4.CT and MRI findings of chorea associated with nonketotic hyperglycemia
Dongjin HU ; Weidong ZHANG ; Dingquan WU ; Lishi MENG ; Jian CHEN
Chinese Journal of Radiology 2008;42(7):720-723
Objective To explore the imaging diagnosis of chorea associated with nonketotic hyperglycemia by describing its CT and MR findings and correlating those findings with the clinical manifestations. Methods The imaging findings and clinical data from 6 patients with chorea associated with nonketotic hyperglycemia were retrospectively analyzed. All 6 patients had unenhanced CT scans, 1 also had MR imaging examination. Three of 6 patients had follow-up CT scans and 1 of 3 patients had follow-up MRimaging studies. Results CT studies of all 6 patients showed unilateral or bilateral hyperdense striatum.The putamen was involved in all 6 patients, the caudate nucleus or lateral portion of the globus pallidus were involved in 5 of all 6 patients. All 3 follow-up CT studies depicted a decreased or resolved hyperdensity of the abnormal striatum. T1-weighted MR images in 1 patient showed the hyperintense lesions of bilateral lentiform nuclei, T2-weighted MR images of the patient showed the hypointense lesions of the corresponding lentiform nuclei, and its follow-up MR images depicted invariable signal intensity of T1-weighted and T2-weighted images. In all patients, the chorea resolved within 2 to 6 days after treatment of the hyperglycemia. Conclusion The characteristic imaging findings of chorea associated with nonketotic hyperglycemia can suggest an accurate diagnosis.
5.Fast 3D Medical Image Segmentation Based on CUDA
Xiaolin MENG ; An QIN ; Jian XU ; Wufan CHEN ; Qianjin FENG
Chinese Journal of Medical Physics 2010;27(2):1716-1720
Objective: 3D segmentation is an important part of medical image analysis and visualization. It also continues to be large challenge in the medical image segmentation. While level sets have demonstrated a great potential for 3D medical image segmentation, these algorithms have a large computational burden thus are not suitable for real time processing requirement. To solve this problem, we propose a parallel accerelated method based on CUDA. Methods: We implement C-V level set algorithm in the CUDA environment which is the NVIDIA's GPGPU model.The segmentation speed can greatly improved by using independence of image pixel and concurrence of partial differential equation .The paper shows the flow chart of the parallel computing and gives the detailed introduction of the C-V level set algorithm which is implemented in the CUDA environment. Results: Realizing the C-V level set parallel accerelated algorithm. This method has faster segmentation speed while preserving the qualitative results, Conclusions: This method is viable and makes the fast 3D medical image segmentation come hue.
6.2D, 3D Rigid Registration Algorithm Base on CUDA
Jian XU ; An QIN ; Xiaolin MENG ; Wufan CHEN ; Qianjin FENG
Chinese Journal of Medical Physics 2010;27(2):1721-1725,1730
Objective: Real time medical image registration technique is one of the key techniques in image based surgery navi-gation system. While in medical image analysis, image registration is usually a very time-cousuming operation, and this is not conducive to clinical real-time requirements. This paper studies and realizes the acceleration of the process of image registra-tion. Methods: In order to improve the regisWation rate, in this paper, we propose a new technology which is based on CUDA (Compute Unified Device Architecture) programming model to accelerate the process of registration in hardware, using paral-lel methods to achieve pixel coordinate transformation, linear interpolation, and calculate the corresponding pixel gray value residuals. Results: The registration is up to the sub-pixel level and the GPU-based registration is dozens or even hundreds of times faster than CPU-based registration. Conclusions: This method greatly enhances the speed of rigid registration without changing the alignment accuracy.
7.Reversal of multidrug resistance and inhibition of DNA topoisomerase Ⅱ by emulsion of seed oil of Brucea Javanica
Tao TANG ; Linghua MENG ; Lingji CHEN ; Jian DING ;
Chinese Pharmacological Bulletin 1986;0(05):-
AIM To explore the reversal effect of multidrug resistance (MDR) and the influence on topoisomerase (TOPO) activity by emulsion of seed oil of Bbrucea Javanica (ESOBJ) in vitro . METHODS Cytotoxic effects of ESOBJ against sensitive and resistance tumor cells were deter mined by MTT assay. Influences of ESOBJ on the catalytic activities of TOPO Ⅰ and TOPO Ⅱ were measured by TOPO Ⅰ mediated negatively super coiled pBR322 relaxation and TOPOⅡ mediated kDNA decatenation. RESULTS 0 025 g?L -1 of ESOBJ could reverse MDR in various MDR cell lines such as K562/A02?MCF 7/ADM and KB/VCR. DNA TOPO Ⅱ mediated kDNA decatenation experiment showed marked inhibitory action of ESOBJ on TOPO Ⅱ activity at the concentration of 0 31 g?L -1 and TOPO Ⅱ activity was totally inhibited by ESOBJ at the concentration of 2 5 g?L -1 . On the other hand, ESOBJ exhibited no influence on DNA TOPO I mediated pBR322 relaxation and on DNA directly. CONCLUSION ESOBJ could reverse MDR to a certain extent in vitro , and inhibit the activity of TOPO Ⅱ significantly.
8.ZO-1 gene methylation status and its clinical significance in children with non-Hodgkin lymphoma.
Yu-Qiao DIAO ; Fan QU ; Ming-Juan YANG ; Jian-Hui MENG ; Xiu-Li ZHU ; Jian CHEN
Chinese Journal of Contemporary Pediatrics 2014;16(6):619-623
OBJECTIVETo investigate the methylation status of zonula occludens-1 (ZO-1) gene promoter and its clinical significance in children with stage IV non-Hodgkin lymphoma (NHL) and to provide a basis for further etiological study and early diagnosis of this disease.
METHODSFifty-five children with a confirmed diagnosis of stage IV NHL (40 cases of T-NHL and 15 cases of B-NHL) were selected as the case group, and 20 children with diseases other than hematologic malignancies were selected as the control group. Bone marrow samples were collected from these subjects. Methylation-specific PCR (MS-PCR) was applied to evaluate the methylation status of ZO-1 gene promoter, and the integrated optical density (IOD) was determined. RT-PCR was used to measure the mRNA expression of ZO-1.
RESULTSMS-PCR showed that the methylated bands of ZO-1 gene promoter were found in 39 (70.9%) of 55 patients in the case group before treatment, while no ZO-1 gene promoter methylation was detected in the control group. With close tracking of 47 cases in the study group, consisting of 32 cases of T-NHL and 15 cases of B-NHL, the rates of ZO-1 gene promoter methylation prior to treatment were 72% and 67%, respectively, (P>0.572). The cases of T-NHL and B-NHL showed no significant changes in methylation rate in the early and middle phases of chemotherapy (P>0.05), but they showed significant changes in methylation rate in the late phase of chemotherapy (P<0.05). RT-PCR showed that the NHL cases carrying methylated ZO-1 gene had no mRNA expression of ZO-1, while all children in the control group had mRNA expression of ZO-1. There was no linear relationship between the total number of peripheral blood leukocytes and ZO-1 gene IOD (r=0.093, P=0.575); a positive correlation was found between the number of malignant cells in bone marrow and ZO-1 gene IOD (r=0.669, P<0.001).
CONCLUSIONSZO-1 gene shows a hypermethylation status in children with NHL, and the methylation level is positively correlated with the number of malignant cells in bone marrow. ZO-1 may be used as a novel molecular marker in early diagnosis, outcome assessment, prognostic evaluation, and detection of minimal residual disease.
Adolescent ; Child ; Child, Preschool ; DNA Methylation ; Female ; Humans ; Infant ; Lymphoma, Non-Hodgkin ; genetics ; Male ; Promoter Regions, Genetic ; Zonula Occludens-1 Protein ; genetics
9.Design of a wireless ambulatory blood pressure monitoring system based on ARM.
Jian-guo ZENG ; Guang-meng CHEN ; Jian WANG
Chinese Journal of Medical Instrumentation 2006;30(6):424-427
A design of the wireless ambulatory blood pressure monitoring system has been presented based on ARM embedded microprocessor and GPRS module for the extention of native mobile telemedicine. The whole system framework and flow chart have been introduced in detail. Based on RBF neural networks, the ambulatory blood pressure data curve has been simulated, and the trend curve provides a reliable gist for the prevention, treatment, diagnosis and therapeutic efficacy of cerebrocardiac diseases.
Algorithms
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Blood Pressure Monitoring, Ambulatory
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instrumentation
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Computer Communication Networks
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Equipment Design
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Humans
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Neural Networks (Computer)
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Signal Processing, Computer-Assisted
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instrumentation
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Software
10.Antitumor activity of recombinant antimicrobial peptide penaeidin-2 against kidney cancer cells.
Ming-Xiang, MENG ; Jian-Fang, NING ; Jing-You, YU ; Dan-Dan, CHEN ; Xiao-Lin, MENG ; Jin-Ping, XU ; Jie, ZHANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2014;34(4):529-34
Penaeidin-2 (Pen-2) is an important antimicrobial peptide derived from the Pacific white shrimp, Penaeus vannamei, and possesses both antibacterial and antifungal activities. Recent studies suggest that recombinant penaeidins show similar activities to the native Pen-2 protein. Previous researches have shown that some antimicrobial peptides (AMPs) exhibit cytotoxic activity against cancer cells. To date, there have been no studies on the antitumor effects of Pen-2. This study evaluated the potential of recombinant pen-2 (rPen-2) in the selective killing of kidney cancer cell lines ACHN and A498, and its action mechanism. MTT assays found the maximal growth inhibition of HK-2, ACHN and A498 cells treated with 100 μg/mL rPen-2 at 48 h was 13.2%, 62.4%, and 70.4%, respectively. DNA-specific fluorescent dye staining showed a high percentage of apoptosis on cancer cells. Flow cytometry revealed that the apoptosis rate of HK-2, ACHN and A498 cells was 15.2%, 55.2%, and 61.5% at 48 h respectively, suggesting that rPen-2 induced higher apoptosis rate in cancer cells than in HK-2 cells. Laser confocal scanning microscopy demonstrated that the plasma membrane was the key site where rPen-2 interacted with and destroyed tumor cells. Scanning electron microscopy showed the morphologic changes of the cell membranes of kidney cancer cells treated with rPen-2. These results suggest that rPen-2 is a novel potential therapeutic agent that may be useful in treating kidney cancers.