Biomedical subjects

Jian Ma

Publications and source records attributed to Jian Ma.

45 records · Page 3Linked to original sources

PubMed2003

Gelatinase B is associated with peri-implant bone loss.

The aim of this study was to clear whether gelatinase B is associated with peri-implant bone loss (PBL). Peri-implant sulcus fluid was collected from 46 implant sites in 12 patients. These sites were also characterized using modified Gingival Index (mGI). Activated and total gelatinase B levels, measured using a modified urokinase assay, showed correlation with PBL (n = 46, Spearman's rank correlation test). Activated and total gelatinase B values were significantly higher in PBL > 3 mm group (n = 6) compared to PBL < 1 mm (n = 29) and 1 < PBL < 3 mm (n = 11) groups (rank sum test). Activated gelatinase B level in mGI > 0.5 group (n = 24) was clearly higher compared to mGI = 0 (n = 13) and < or = 0.5 (n = 9) groups (Rank sum test). We conclude that gelatinase B is associated with PBL. Activation of gelatinase B together with elevated mGI eventually reflect active phases of peri-implantitis and may prove to be diagnostically useful.

Adult↗

PubMed2003

Chronic inflammation around painless partially erupted third molars.

OBJECTIVES: We sought to assess the histologic host response in chronic, symptomless pericoronitis. STUDY DESIGN: Gingival mucosal (n = 20) and dental follicle (n = 20) samples were collected during extraction from patients with pericoronitis and clinically healthy control subjects. Antibodies-recognizing macrophages (CD68), natural killer cells (CD56), T cells (CD2), helper T cells (CD4), suppressor/cytotoxic T cells (CD8), and neutrophils (lactoferrin) were applied in a labelled streptavidin-biotin method by using a DAKO TechMate staining robot. RESULTS: Macrophage was the most numerous kind of cell in pericoronitis, but CD2+ T lymphocytes, with a normal CD4/CD8 ratio, were also increased (P < .01). Neutrophils were not increased and did not show signs of activation. Dental follicles did not contain increased numbers of inflammatory cells. CONCLUSION: This type of pericoronitis is a chronic/smoldering, rather than an acute/purulent, infection. Because of the chronic and often symptomless nature of pericoronitis, various long-term sequelae may result, which may lead to the need for extraction.

Adult↗

PubMed2003

The shock formation distance in a bounded sound beam of finite amplitude.

This paper investigates the shock formation distance in a bounded sound beam of finite amplitude by solving the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation using frequency-domain numerical method. Simulation results reveal that, besides the nonlinearity and absorption, the diffraction is another important factor that affects the shock formation of a bounded sound beam. More detailed discussions of the shock formation in a bounded sound beam, such as the waveform of sound pressure and the spatial distribution of shock formation, are also presented and compared for different parameters.

Journal Article↗

PubMed2003

Unipolar electrogram in identification of successful targets for radiofrequency catheter ablation of focal atrial tachycardia.

OBJECTIVE: To analyze the unipolar electrogram from successful and unsuccessful ablation sites of focal atrial tachycardia (AT), and to evaluate its value in the identification of successful targets. METHODS: Fifteen consecutive patients with focal AT were referred for radiofrequency catheter ablation (RFCA). Both unipolar (from the tip electrode of ablating catheter) and bipolar (from the distal pair of electrode of ablating catheter) electrograms were used to identify the ablation targets of focal AT. RESULTS: Successful ablation was echieved in 14 patients. Radiofrequency energy was delivered at a total of 27 sites. The bipolar electrograms associated with successful ablation sites showed earlier atrial deflection relative to P wave onset (36 ms +/- 15 ms vs 30 ms +/- 11 ms, P < 0.05) than the electrograms associated with failed ablation sites. At the 14 successful ablation sites, the unipolar electrograms displayed a completely negative atrial wave ("QS" morphology) beginning with intrinsic deflection. However, at the 13 unsuccessful ablation sites, a "rS" morphology of atrial wave was shown on the unipolar electrogram. CONCLUSION: The "QS" morphology of the atrial wave on unipolar electrograms appears to represent a reliable marker for identifying the successful ablation targets of focal AT, with a high sensitivity and specificity.

Adolescent↗

PubMed2002

Profiling genes differentially expressed in NGX6 overexpressed nasopharyngeal carcinoma cells by cDNA array.

PURPOSE: To investigate the role of the NGX6 gene in carcinoma proliferation and profile the downstream genes regulated by NGX6 in a nasopharyngeal carcinoma (NPC) cell line. METHODS: We established a NPC cell line with NGX6 overexpression by gene transfection. Subsequently, a high-density cDNA array was used to identify differentially expressed genes in NGX6-overxepressed cells. Four differentially expressed genes or EST(expressed sequence tags) were examined using Northern blot. Furthermore, flow cytometry was employed to analyze the percentages of cells in the G(0)-G(1), S, and G(2)-M phase of the cell cycle in a NGX6 overexpression cell line. RESULTS: Fifty-five genes and ESTs were differentially expressed after NGX6 transfection in a cDNA array assay. Several genes related to cell cycle and transcription regulation were identified using this technique. Flow cytometry analysis showed NGX6 overexpression can increase the length of the G(1) phase of the cell cycle in NPC cells. CONCLUSION: We demonstrated the existence of a panel of genes that can be regulated by NGX6. Overexpression of NGX6 can influence the distribution of the cell cycle in NPC cells. Further studies are necessary to elucidate the exact function of these genes and their relationship to NGX6 expression.

Carcinoma↗

PubMed2002

Protective effect of verbascoside on 1-methyl-4-phenylpyridinium ion-induced neurotoxicity in PC12 cells.

The neuroprotective effects of verbascoside, one of phenylpropanoid glucoside isolated from the Chinese herbal medicine Buddleja officinalis Maxim, on 1-methyl-4-phenylpyridinium ion (MPP(+)) induced apoptosis and oxidative stress in PC12 neuronal cells were investigated. Treatment of PC12 cells with MPP(+) for 48 h induced apoptotic death as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, the activation of caspase-3 measured by the caspase-3 activity assay kit, the reduction in mitochondrial membrane potential with laser scanning confocal microscopy and the increase in the extracellular hydrogen peroxide level. Simultaneous treatment with verbascoside markedly attenuated MPP(+)-induced apoptotic death, increased extracellular hydrogen peroxide level, the activation of caspase-3 and the collapse of mitochondrial membrane potential. These results strongly indicate that verbascoside may provide a useful therapeutic strategy for the treatment of oxidative stress-induced neurodegenerative disease such as Parkinson's disease.

1-Methyl-4-phenylpyridinium↗

PubMed2002

[Mechanical research on effects of yishenqing on membranous nephropathy].

OBJECTIVE: To investigate the therapeutic effect and mechanism of Yishenqing on rabbit membranous nephropathy. METHOD: The rabbit membranous nephropathy model was induced by cationic bovine serum albumin, and the immunity of mice together with urine volume and haemorheological property of rats were also estimated. RESULT: Yishenqing could significantly reduce the urinary protein content, preserve the renal function and pathologically restore the glomeruli. Moreover, its effects also include immunity enhancement, diuretic property and blood stasis amelioration. CONCLUSION: Yishenqing has good effects on the rabbit membranous nephropathy, which is probably due to the effects of diuretic property, immunity enhancement and blood stasis amelioration.

Animals↗

PubMed2002

[Unilateral tonsillar enlargement and malignant tonsillar lymphoma].

OBJECTIVE: To study clinic characters of malignant lymphoma in patients with unilateral tonsillar enlargement for early discover and synthetic therapy clinic characters of malignant lymphoma patients with unilateral tonsillar enlargement for early discover and synthetic therapy. METHOD: 10 cases of non-Hodgkin's lymphoma (NHL) out of 100 unilateral tonsillar enlargement patients given tonsillectomy were treated with combined chemotherapy. 8 cases of 10 underwent local radiotherapy after operation. RESULT: 5 years survival rate was 60% in 10 patients with NHL. CONCLUSION: Progressing unilateral swollen tonsil found in a short time with suspicious appearance should be given tonsillectomy for histopathology; upper airway and systematic symptoms such as fever and rigors, night sweats; lymphatic enlargement in cervical, axillary, inguinal region; hepatosplenomegaly should be thought of main traits of malignant lymphoma, and hyposensitivity to medicine should be taken malignant lymphoma into account.

Adolescent↗

PubMedDate not supplied

Cellular fibronectin in failing dental implants.

PURPOSE: Cellular fibronectin staining is decreased in adult periodontitis, which implies elastase-mediated degradation of periodontal tissues. The purpose of this study was to determine whether failing dental implants display similar changes. MATERIALS AND METHODS: Cellular fibronectin and its integrin receptors were identified by immunohistochemistry and quantified by computerized image analysis. RESULTS: Cellular fibronectin was found in blood vessel walls, epithelial basement membranes, and fibroblasts. Quantitative results of cellular fibronectin staining were as follows: failing dental implants, median 26.5% (Q3-Q1 = 23%); adult periodontitis, median 5.5% (Q3-Q1 = 5.6%); normal controls, median 12.2% (Q3-Q1 = 7.5%). Cellular fibronectin staining was increased around failing dental implants but decreased in adult periodontitis compared to healthy controls. DISCUSSION: The distribution of integrin receptor subunits alpha4, alpha5, and beta1 of cellular fibronectin was similar in failing dental implants. The pathomechanisms in adult periodontitis and failing dental implants seem to differ. CONCLUSIONS: Adult periodontitis is characterized by proteolysis/loss of cellular fibronectin, whereas failing dental implants are characterized by increased cellular fibronectin deposition, probably as a result of titanium-induced local synthesis and relatively modest degradation.

Adolescent↗