1.Sintering character of nanocrystal calcium-deficient apatite
Yantao ZHAO ; Dagang GUO ; Yumei ZHANG
Journal of Practical Stomatology 1996;0(02):-
Objective:To study the sintering character of calcium-deficient apatite.Methods:Calcium-deficient apatite synthesised by wet chemical method was sintered at different temperature and then its chemical composition, phase structure and morphology were examined by FT-IR spectroscopy, X-ray diffraction (XRD) and field emission scanning microscopy (FESEM) respectively.Results:When the heating temperature is below 500 ℃, apatite crystal kept a stable size with a diameter of 12-26 nm and a length of 30-66 nm. After sintered at 600 ℃ for 2 h, apatite crystal were with a diameter of 25-40 nm and a length of 75-100 nm. Around 800 ℃ for 2 h, apatite was decomposed into Ca_3(PO_4)_2.The crystal size of the Ca_3(PO_4)_2 surpassed 200 nm in diameter and length. NH_4+ ion could be removed at temperature beyond 300 ℃.Conclusion: Calcium-deficient apatite has it's specific sintering character.
2.Microencapsulation of immortalized mandibular condylar chondrocytes.
Xiaohong DUAN ; Dagang GUO ; Kewei XU ; Junzheng WU ; Bin LIU
Journal of Biomedical Engineering 2002;19(4):639-641
To explore the possibility of microencapsulation of chondrocytes in cartilage tissue engineering, immortalized manibular condylar chondrocytes (IMCCs) were microencapsuled by Alginate-polylysine-alginate (APA) method, according to air pressure shearing model. Phase contrast microscopy, trypan blue staining exclusion, cell number counting, HE staining and immunohistochemistry method were used to observe the morphology of the microencapsules, the growth character of cells, cartilage characteristics, and so on. The results showed that IMCC could survive and grow in microencapsule, and the viability rate of cells is more than 80 per cent. The diameter of microcapsule is 779 microns in average. The number of cell increased with time, and cells went into platform in about 20 days. Cells grew in clusters and cartilage specific proteoglycans and type II collagen were highly expressed. It was concluded that IMCC could form cartilage-like tissue within microencapsulation, implying that microencapsule technique might be applicable to cartilage tissue engineering.
Alginates
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Animals
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Cell Culture Techniques
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methods
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Cells, Cultured
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Chondrocytes
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cytology
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Drug Compounding
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Mandibular Condyle
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cytology
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Polylysine
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analogs & derivatives
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Rabbits
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Tissue Engineering
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methods
3.Application of polyvinyl alcohol in biomedical engineering.
Journal of Biomedical Engineering 2005;22(3):602-605
This paper explicated the present application of poly- vinyl alcohol (PVA) in the field of biomedical engineering, such as artificial cartilage, drug delivery systems, microorganism enwrapping, cell micro-capsulation, anti-thrombin materials, and biomedical sponges. And a preliminary study of the good dispersion of PVA as a surfactant on nano-particles of hydroxyapatite was presented.
Artificial Organs
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Biocompatible Materials
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Biomedical Engineering
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Drug Compounding
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Drug Delivery Systems
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Durapatite
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chemistry
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Materials Testing
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Nanoparticles
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chemistry
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Polyvinyl Alcohol
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chemistry
4.Effect of extract from Tripterygium hypoglaucum on proliferation and apoptosis of vascular smooth muscle cells.
Zhuo YU ; Lei MENG ; Yan-hong GUO ; Dagang WU ; Wei GAO
Chinese Journal of Integrated Traditional and Western Medicine 2004;24(9):827-830
OBJECTIVETo study the effect of THW-4, an extract from Trypterygium hypoglaucum on proliferation and apoptosis of vascular smooth muscle cells (VSMC).
METHODSVSMC derived from rabbit aorta were cultured in vitro and different concentrations of THW-4 were added in experimental groups. Cell proliferation was evaluated by MTT and apoptosis by transmission electron microscopy (TEM), TUNEL assay and Annexin V-FITC/PI double labelled assay.
RESULTSThe inhibitory effects of THW-4 on proliferation of VSMC displayed dose-time dependently, with the IC50 value of 15.6 microg/L at 48 hrs. Incubated with THW-4 (10-100 microg/L) for 56 hrs, VSMC mainly appeared early stage apoptosis and the percentage of apoptosis was found to raise along with the increase of the THW-4 concentration. Typical images of apoptosis could be observed under TEM and TUNEL assay showed increase of DNA segments with karyorrhexis and pyknosis after THW-4 treatment for 72 hrs. Analysis of cell cycle indicated the THW-4 mainly lead to the blockage of VSMC in G2/M stage.
CONCLUSIONTHW-4 could inhibit the proliferation and induce the apoptosis of VSMC in vitro, suggesting that THW-4 is a potential agent for prevention of restenosis following angioplasty.
Animals ; Aorta ; cytology ; Apoptosis ; drug effects ; Cell Division ; drug effects ; Cells, Cultured ; Coronary Restenosis ; prevention & control ; Drugs, Chinese Herbal ; pharmacology ; Male ; Muscle, Smooth, Vascular ; cytology ; Rabbits ; Tripterygium ; chemistry
5.Clinical values of laboratory inflammation indicators for diagnosis and treatment of COVID-19 patients
Dagang WANG ; Weijie LI ; Fangfang JIN ; Shuang WANG ; Jiyun SUN ; Chun ZHOU ; Fei XU ; Jingjing GUO ; Yajie WANG
Chinese Journal of Experimental and Clinical Virology 2020;34(4):347-351
Objective:To investigate the clinical values of laboratory inflammation indicators including lymphocyte count, C reactive protein (CRP), serum amyloid A protein (SAA), and procalcitonin (PCT) in the diagnosis and treatment of 2019 novel corona virus disease (COVID-19) patients.Methods:The data of clinical characteristics of 77 hospitalized COVID-19 patients were collected from February to March 2020. According to the guidelines for diagnosis and management of COVID-19, these patients were divided into moderate type (49 cases) and severe type (28 cases). Among them 19 cases were discharged. The differences of lymphocyte count, CRP, SAA and PCT among moderate, severe and discharged groups were compared. The indicators with better predictive value for disease development and prognosis were screened out by logistic regression and receiver operating characteristic curve (ROC) analysis.Results:The severe patients had lower lymphocyte count compared to the moderate patients ( P=0.000), while their CRP ( P=0.000), SAA ( P=0.000) and PCT positive rate ( χ2=11.003, P=0.001) were significantly higher; The lymphocyte count of discharged patients was much higher than that of moderate ( P=0.001) and severe ( P=0.000) patients, while CRP ( P=0.036, P=0.000) and SAA ( P=0.002, P=0.000) were dramatically lower; Although the discharged patients had much lower PCT positive rate than severe patients ( χ2=6.891, P=0.009), they were not significantly different from moderate patients ( χ2=0.169, P=0.681). Logistic regression analysis showed that the increased SAA and CRP were both risk factors for predicting severe illness, but the decreased SAA were demonstrated as an independent indicator for discharge. The ROC curve analysis showed that the sensitivity and specificity of SAA for diagnosis of severe patients were 85.71% and 87.76%, whereas CRP were 82.14% and 93.88%. Further, the sensitivity and specificity of SAA for predicting discharge were 100% and 57.89%. Conclusions:The laboratory inflammation indicators such as lymphocyte count, CRP, SAA and PCT had important clinical significance for the diagnosis and treatment of COVID-19 patients. Among them, SAA was demonstrated as an independent indicator with high sensitivity for evaluating the disease progression and prognosis.
6.The association of pre?pregnancy body mass and weight gain during pregnancy with macrosomia:a cohort study
Ping FENG ; Xiaoyu WANG ; Zhiwen LONG ; Shufang SHAN ; Danting LI ; Yi LIANG ; Mengxue CHEN ; Yunhui GONG ; Rong ZHOU ; Dagang YANG ; Ruonan DUAN ; Tian QIAO ; Yue CHEN ; Jing LI ; Guo CHENG
Chinese Journal of Preventive Medicine 2019;53(11):1147-1151
Objective To examine the association of pre?pregnancy body mass and weight gain during pregnancy with macrosomia. Methods From January 2015 to December 2015, a total of 20 477 pregnant women were recruited by probabilistic proportional scale sampling with simple randomization in Sichuan, Yunnan and Guizhou Provinces. Basic information of pregnant women, weight gain during pregnancy and weight of newborn were collected. A multiple logistic regression model was used to assess the association between the pre?pregnancy body mass and gestational weight gain indicators with macrosomia. Results 20 321 mother?infant were included in the final analysis. 20 321 pregnant women were (30.09 ± 4.10) years old and delivered at (39.20 ± 1.29) weeks, among which 12 341 (60.73%) cases were cesarean delivery. The birth weight of 20 321 infants were (3 292.26 ± 431.67) grams, and 970 (4.77%) were macrosomia. The multiple logistic regression model showed that after adjusting for the age of women, compared to the normal weight group in the pre?pregnancy, the overweight and obesity group elevated the risk of macrosomia, with OR (95%CI) about 1.99 (95%CI: 1.69-2.35) and 4.05 (95%CI: 3.05-5.39), respectively. After adjusting for the age, the pre?pregnancy BMI, delivery weeks, delivery mode and infant's gender, compared to the weight?gain appropriate group, higher weight gain rate in the mid?pregnancy and excessive total gestational weight gain elevated the risk of macrosomia, with OR (95%CI) about 1.99 (95%CI:1.66-2.39) and 1.80 (95%CI: 1.55-2.08), respectively. Conclusion The overweight before pregnancy, obesity before pregnancy, the rate of weight gain in the second trimester and the high total weight gain during pregnancy could increase the risk of macrosomia.
7.The association of pre?pregnancy body mass and weight gain during pregnancy with macrosomia:a cohort study
Ping FENG ; Xiaoyu WANG ; Zhiwen LONG ; Shufang SHAN ; Danting LI ; Yi LIANG ; Mengxue CHEN ; Yunhui GONG ; Rong ZHOU ; Dagang YANG ; Ruonan DUAN ; Tian QIAO ; Yue CHEN ; Jing LI ; Guo CHENG
Chinese Journal of Preventive Medicine 2019;53(11):1147-1151
Objective To examine the association of pre?pregnancy body mass and weight gain during pregnancy with macrosomia. Methods From January 2015 to December 2015, a total of 20 477 pregnant women were recruited by probabilistic proportional scale sampling with simple randomization in Sichuan, Yunnan and Guizhou Provinces. Basic information of pregnant women, weight gain during pregnancy and weight of newborn were collected. A multiple logistic regression model was used to assess the association between the pre?pregnancy body mass and gestational weight gain indicators with macrosomia. Results 20 321 mother?infant were included in the final analysis. 20 321 pregnant women were (30.09 ± 4.10) years old and delivered at (39.20 ± 1.29) weeks, among which 12 341 (60.73%) cases were cesarean delivery. The birth weight of 20 321 infants were (3 292.26 ± 431.67) grams, and 970 (4.77%) were macrosomia. The multiple logistic regression model showed that after adjusting for the age of women, compared to the normal weight group in the pre?pregnancy, the overweight and obesity group elevated the risk of macrosomia, with OR (95%CI) about 1.99 (95%CI: 1.69-2.35) and 4.05 (95%CI: 3.05-5.39), respectively. After adjusting for the age, the pre?pregnancy BMI, delivery weeks, delivery mode and infant's gender, compared to the weight?gain appropriate group, higher weight gain rate in the mid?pregnancy and excessive total gestational weight gain elevated the risk of macrosomia, with OR (95%CI) about 1.99 (95%CI:1.66-2.39) and 1.80 (95%CI: 1.55-2.08), respectively. Conclusion The overweight before pregnancy, obesity before pregnancy, the rate of weight gain in the second trimester and the high total weight gain during pregnancy could increase the risk of macrosomia.
8. The association of pre-pregnancy body mass and weight gain during pregnancy with macrosomia: a cohort study
Ping FENG ; Xiaoyu WANG ; Zhiwen LONG ; Shufang SHAN ; Danting LI ; Yi LIANG ; Mengxue CHEN ; Yunhui GONG ; Rong ZHOU ; Dagang YANG ; Ruonan DUAN ; Tian QIAO ; Yue CHEN ; Jing LI ; Guo CHENG
Chinese Journal of Preventive Medicine 2019;53(11):1147-1151
Objective:
To examine the association of pre-pregnancy body mass and weight gain during pregnancy with macrosomia.
Methods:
From January 2015 to December 2015, a total of 20 477 pregnant women were recruited by probabilistic proportional scale sampling with simple randomization in Sichuan, Yunnan and Guizhou Provinces. Basic information of pregnant women, weight gain during pregnancy and weight of newborn were collected. A multiple logistic regression model was used to assess the association between the pre-pregnancy body mass and gestational weight gain indicators with macrosomia.
Results:
20 321 mother-infant were included in the final analysis. 20 321 pregnant women were (30.09±4.10) years old and delivered at (39.20±1.29) weeks, among which 12 341 (60.73%) cases were cesarean delivery. The birth weight of 20 321 infants were (3 292.26±431.67) grams, and 970 (4.77%) were macrosomia. The multiple logistic regression model showed that after adjusting for the age of women, compared to the normal weight group in the pre-pregnancy, the overweight and obesity group elevated the risk of macrosomia, with