1.Evaluation of GeneXpert MTB/RIF assay in diagnosing pulmonary tuberculosis
Aimei LIU ; Yu SU ; Qi ZHANG ; Liusheng TANG ; Guangfu LIAO
Chinese Journal of Postgraduates of Medicine 2017;40(6):500-504
Objective To evaluate the value of GeneXpert MTB/RIF assay in the clinical diagnosis of tuberculosis and tuberculosis associated rifampin resistance. Methods A total of 851 patients admitted to the Guangxi Longtan Hospital from September 22, 2015 to May 25, 2016 were enrolled. The smear microscopic examination, solid culture test, and GeneXpert MTB/RIF assay was performed on each patient. Drug sensitivity test of rifampicin using proportion method was done on patients infected with mycobacterium tuberculosis isolated by solid culture, and rifampicin resistance detection was performed on GeneXpert MTB/RIF positive patients. Bacteriological positive consistency test was performed on GeneXpert MTB/RIF and solid culture, and rifampicin resistance detection was compared bwtween GeneXpert MTB/RIF and drug sensitivity using proportion method. Culture and drug susceptibility testing were used as the gold standard, and the MTB sensitivity and specificity of smear microscopic examination, solid culture, and GeneXpert MTB/RIF assay was compared. Results Culture was used as the gold standard. Compared with culture, the sensitivity, specificity, positive predictive value, and negative predictive value of GeneXpert MTB/RIF was 95.48%(211/241), 94.91%(559/569), 87.55%(211/241), and 98.24%(559/569) respectively. The sensitivity of Xpert MTB/RIF for culture positive smear positive specimens and culture positive smear negative specimens was 98.78% (162/164) and 85.96%(49/57) respectively. Drug susceptibility testing was used as the gold standard. Compared with drug susceptibility testing, the sensitivity, specificity, positive predictive value, and negative predictive value of rifampin resistance measured by GeneXpert MTB/RIF was 98.70%(152/154), 92.98%(53/57), 97.44%(152/156) and 96.36%(53/55) respectively. The consistency rate of GeneXpert MTB/RIF and solid culture was 93.83% (Kappa = 0.847), and that of GeneXpert MTB/RIF rifampin resistance detection and proportion method for drug sensitivity was 96.38% (Kappa = 0.904). Conclusions The GeneXpert MTB/RIF detection is easily operated with high sensitivity and specificity compared with smear microscopic examination and solid culture, and it also possesses good consistency with solid culture and traditional drug sensitivity. Moreover, it could also be applied to diagnose the resistance to rifampin, which is very promising in application.
2.Application of 3D printing technology in the second staged revision of infection after hip replacement
Guangfu ZHOU ; Weimin ZHU ; Bensen TANG ; Xulin WU
Chongqing Medicine 2018;47(13):1746-1748
Objective To explore the application of 3D printing technology in the second staged revision of infection after hip replacement.Methods From July 2014 to July 2016,21 patients with postoperative infection after hip replacement needed for phase Ⅱ revision surgery were selected as the 3D printing group,while 21 patients who underwent hip replacement without 3D printing technique were selected as the control group.The acetabulum,femoral and other related data were obtained by CT scanning,using computer simulation and modeling in vitro,3D printing technology was used to print the model,showed the hip joint model and done the operation,after 2 to 3-year-follow-up,compared the effect and the Harris hip joint function score.Results Compared the operation time of the two groups,3D printing group average operation time was (86.4±31.5) min,while the control group was (131.7±29.6) min,the difference was statistically significant (P<0.05);the Harris hip joint function score of 3D printing group was (41.4±7.8) point before operation,and after three years follow-up the score was (91.2 ± 6.9) point,the difference was statistically significant (P<0.05).Conclusion 3D printing technology can be applied in the second stage revision surgery of infection after hip replacement,which has effective result.
3.Mechanical environment of rotating bioreactor and its effect on cell growth.
Yanfang ZHANG ; Huaiqing CHEN ; Hua HUANG ; Xiujuan XU ; Xiaohong TANG ; Guangfu YIN ; Jiang WU
Journal of Biomedical Engineering 2006;23(2):400-404
In this paper is presented an analysis of the mechanical effect of horizontal rotating bioreactor on cell culture. Getting the microgravity of the bioreactor and the shear stress on canine mesenchymal stem cells (cMSCs) with theoretic calculating model and differential equations, we have validated the density,growth rate and modality of cultured cell by scanning electron microscopy. The horizontal rotating bioreactor which we developed could create the mechanic environment of microgravity (K<8.38 X 10(-2))and low shear stress(r<1.62 dyn/cm2) in theory. The results of scanning electron microscopy indicated that the cells' growth-speed, quantity and modality in bioreactor were better than those of cells cultured in static 24-well plate. The mechanical environment of the rotating bioreactor is propitious for keeping better modality and more rapid proliferation of cMSCs. The rotating bioreactor is a novel approach and technique it is superior to static culture.
Animals
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Bioreactors
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Bone Marrow Cells
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cytology
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Cell Culture Techniques
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instrumentation
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methods
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Cell Proliferation
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Cells, Cultured
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Dogs
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Mechanotransduction, Cellular
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physiology
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Mesenchymal Stromal Cells
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cytology
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Rotation
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Tissue Engineering
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methods
4.Research of osteoblast-induced rat mesenchymal stem cells cocultured with beta-TCP/PLLA composite of different ratio.
Qiaofeng WU ; Yanjuan TANG ; Huaiqing CHEN ; Jiang WU ; Guangfu YIN
Journal of Biomedical Engineering 2005;22(2):242-246
There are three key factors in tissue engineering: seeding cells, scaffold and their interaction. Although mesenchymal stem cells (MSCs) are potential seeding cells, the problem of what phase MSCs should be used is not yet solved. On the other hand, degradable porous scaffolds which have good mechanics and good biocompatibility are preferred. To choose the optimum seeding cells and the suitable ratio of beta-TCP/PLLA porous scaffold, we observed the phenotype of the male SD rat's osteoblastic MSCs and detected the amount of alkaline phosphatase, osteocalcin and type I collagen secreted by the osteoblastic rMSCs in different phase. About 10, 14 and 20 days after induction, the induced cells came into proliferative phase, matrix synthesis phase and mineralization phase, respectively. Then we chose the suitable cells and seeded them on beta-TCP/PLLA composite scaffolds with different ratios (beta-TCP/PLLA = 1:1; beta-TCP/PLLA = 1:2; and beta-TCP/PLLA = 2:1). Fluorescence microscope, scanning electron microscope and MTT assay were used to observe and to detect the biocompatibility of the scaffolds. The results indicated that all of these materials have biocompatibility to some extent. Cells can grow well on all of the scaffolds. However, scaffold beta-TCP/PLLA = 2:1 seems to be a more suitable tissue engineering scaffold on account of its minimal influence on cell growth and differentiation.
Animals
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Biocompatible Materials
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Calcium Phosphates
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pharmacology
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Cell Differentiation
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Cells, Cultured
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Coculture Techniques
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Lactic Acid
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pharmacology
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Male
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Mesenchymal Stromal Cells
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cytology
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Osteoblasts
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cytology
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Polyesters
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Polymers
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pharmacology
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Porosity
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Rats
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Rats, Sprague-Dawley
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Tissue Engineering
5.Growth and osteogenesis characteristics of cultured canine mesenchymal stem cells under osteogenic induction.
Yanjuan TANG ; Yi LI ; Huaiqing CHEN ; Qiaofeng WU ; Guangfu YIN ; Dali ZHOU
Journal of Biomedical Engineering 2006;23(1):142-146
To investigate the growth and osteogenesis characteristics of cultured canine mesenchymal stem cells (cMSCs) under osteogenic induction. We found the cMSCs were isolated from adult canine using density gradient separation method. The cMSCs attachment formed soon after seeding and grew into colonies with the appearance of fibroblastic cells. The osteogenic induction compound of Dexamethasone (Dex), beta-sodium glycerphosphate (beta-GP), ascorbic acid (AA) was added to passaged cMSCs and the proliferation and osteogenic differentiation of them was studied. The morphology of cells was observed by light micrograph and transmission electron microscope. The proliferation and growth characteristics of cMSCs were observed during primary and passage cultures through MTT. The differentiation were assayed by alkaline phophatase (ALP) and osteocalcin (OCN). We found the cMSCs have an active proliferative ability in primary and passage culture, and cMSCs under osteogenic induction have the typical characteristic of a secretory cell; the osteogenic induction compound may induce cMSCs to differentiate to osteoblasts. There are higher expression of ALP and OCN in passage 3 cMSCs under osteogenic induction than that of the osteoblasts osteogenic induction condition. Our research suggest the cMSCs in our culture system are mainly undifferentiated osteoprogenitors and can differentiate to osteoblast under osteogenic induction.
Animals
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Bone Marrow Cells
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cytology
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Cell Differentiation
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physiology
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Cells, Cultured
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Dogs
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Mesenchymal Stromal Cells
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cytology
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Osteoblasts
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cytology
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Osteogenesis
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Tissue Engineering
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methods
6.Transportation of citrinin is regulated by the CtnC gene in the medicinal fungus Monascus purpureus.
Yanling GUI ; Guangfu TANG ; Haiqiao MAN ; Jiao WANG ; Jie HAN ; Jiehong ZHAO
Journal of Zhejiang University. Science. B 2023;24(6):543-548
Monascus is one of the most essential microbial resources in China, with thousands of years of history. Modern science has proved that Monascus can produce pigment, ergosterol, monacolin K, γ-aminobutyric acid, and other functionally active substances. Currently, Monascus is used to produce a variety of foods, health products, and pharmaceuticals, and its pigments are widely used as food additives. However, Monascus also makes a harmful polyketide component called citrinin in the fermentation process; citrinin has toxic effects on the kidneys such as teratogenicity, carcinogenicity, and mutagenicity (Gong et al., 2019). The presence of citrinin renders Monascus and its products potentially hazardous, which has led many countries to set limits and standards on citrinin content. For example, the citrinin limit is less than 0.04 mg/kg according to the Chinese document National Standard for Food Safety Food Additive Monascus (GB 1886.181-2016) (National Health and Family Planning Commission of the People's Republic of China, 2016), and the maximum level in food supplements based on rice fermented with Monascus purpureus is 100 µg/kg in the European Union (Commission of the European Union, 2019).
Citrinin
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Dietary Supplements
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Fungi
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Monascus