1.Tissue-engineered scaffold preparation using three-dimensional printing technology:a retrospective study on bone repair
Chinese Journal of Tissue Engineering Research 2017;21(10):1611-1616
BACKGROUND: The tissue-engineered scaffold, as a substitute of autogenous bone graft, plays an important role in bone repair. In the meanwhile, three-dimensional (3D) printing technology has obtained more attention because of its accurate adjustment.OBJECTIVE: To review the in vitro or in vivo studies on the 3D-printed scaffolds applied in bone repair, thus providing basis for clinical research.METHODS: The first author searched the PubMed database using the English keywords of tissue engineering, bone,three-dimensional printing, scaffold for pertinent articles addressing 3D-printed tissue-engineered scaffolds.RESULTS AND CONCLUSION: There are plenty of studies on 3D-printed tissue-engineered scaffolds, and recent research focuses on the material selection and surface modification. The appropriate porosity is vital, and with the development of manufacturing technology, each property of the scaffold is improved, and composite materials prevail gradually. All above improvements enhance the mechanical property and promote cell adhesion and proliferation.Furthermore, the surface modification promotes the implant-bone interaction. In vivo and in vitro research both indicate that composite materials with the surface coating of bone induction can improve the scaffold performance and osteogenesis.
2.Review on Biosorption of Heavy Metal by Saccharomyces cerevisiae
China Biotechnology 2006;0(01):-
Heavy metal pollution has become one of the most serious environmental problems today. Biosorption, regarded as a cost-effective biotechnology for treating heavy metal of low concentration in wastewater, has not been utilized at large scale successfully. It’s helpful to increase the knowledge of biosorption mechanism and decreasing the costs of biosorbents for the biosorption application. The yeast of Saccharomyces cerevisiae is an ideal biomaterial to be used for exploring the mechanism and for actual utilization because of its unique characteristics in spite of its relatively mediocre capacity of metal uptake to other fungi. The yeast can grow easily in cheap media, and is widely used in food and beverage manufacture. It’s also a safe by-product in large quantity as a waste of the fermentation industry, and easily manipulated at molecular level. The metal uptake specifically by S. cerevisiae was addressed. Firstly, it was discussed to use dead or live cells in biosorption . The yeast can absorb toxic heavy metals (Pb, Hg, Cd, etc), precious metals (Au, Ag, Pd, etc) and radionuclides (U, Am, etc). Secondry, metal-binding capacity of various heavy metals by S. cerevisiae in different conditions were compared. Lead and uranium, for instances, can be effectively removed from dilute solutions, while copper is not easily removed. Thirdly, various mechanism of metal uptake by S. cerevisiae were summarized in details according to the position in which metals are located. Metal uptake process is influenced by the ratio of the initial concentration of metal ions and the concentration of biomass. Cellular wall and its components are important for metal uptake. Functional groups for metallic ion fixation have been identified. Uptake is typically accompanied by ion exchange and complexation, sometimes with precipitation (for Pb) and redox (for Au or Ag). Intracellularly accumulated metal is associated with the cell membrane, vacuole and GSH, but may also be bound to other cellular organelles and biomolecules. The equilibrium and kinetic models used in the metal-yeast biosorption systems were also introduced. In most cases, classic Langmiur model and Freundlich model, widely used to describe single metal biosorption system of equilibrium, fit the experimental data very well. Pseudo-second order equation is often employed to describe biosorption process by S. cerevisiae. Finally, futher researches in metal biosorpiton by S. cerevisiae were proposed.
3.Investigation of drinking water fluoride and fluorosis in Shaanxi Province from 2005 to 2007
Can-sheng, ZHU ; Yan-fei, CHEN
Chinese Journal of Endemiology 2009;28(2):181-183
Objectives To investigate fluoride in drinking waters and fluorosis status and evaluate the effectiveness of fluoride-reducing projects in Shaanxi Province from 2005 to 2007. Methods In the Shaanxi province-wide, the 10 endemic areas of fluorosis were chosen according to historical data as focusing areas for investigation. The village was considered as investigation spot, 5 water samples were collected from each village for investigating of fluoride content. Four water samples were collected from each fluoride-reducing project for evaluating its effectiveness. Fluoride concentrations in drinking water were measured by fluoride-selective electrode method or speetrophotometry. When fluoride content in drinking water was greater than 1.00 mg/L, the epidemical study wasd conducted to investigate fluorosis patients, focusing on investigating of dental fluorosis prevalence in 8 to 12-year-old children and skeletal fluorosis prevalence in adults. Dental fluorosis of children was diagnosed by using Dean's method, and adult skeletal fluorosis was diagnosed according to National Standard for Clinical Diagnosis of Endemic Skeletal Fiuorosis(GB 16396-1996). Results The fluoride content in drinking water from 6390 villages was measured. The fluoride content of drinking water of 2619 villages ranged from 1.0 to<2.0 mg/L, where 1 654 998 people exposed. Additionally, the fluoride content of water of 845 villages ranged from 2.0 to<4.0 mg/L, where 355 623 people exposed. Moreover, the fluoride contents of water of 272 villages exceeded 4.0 mg/L, where 111 466 people exposed. The median of fluoride content in drinking water was 1.15% in the whole province, and fluoride content in drinking water exceeded 1.00 mg/L in Weinan, Xianyang and Yulin where were concentrated distribution areas of high fluoride water. Among 3115 fluoride-reducing projects, the fluoride content of drinking water of 1269 projects ranged from 1.0 to<2.0 mg/L, where 1 415 877 people exposed. Additionally, the fluoride content of drinking water of 120 projects ranged from 2.0 to<4.0 mg/L, where 43 888 people exposed. Moreover, the fluoride content of drinking water of 14 projects exceeded 4.0 mg/L, where 5960 people exposed. The detectable rate of dental fluorosis of 8 to 12 year-old children and skeletal fluorosis of adults reached 37.4%(16 489/44 081) and 5.1%(15 877/310 993), respectively. Conclusions The widely distribution of high-fluoride in drinking water still contributes to the prevalence of fluorosis in Shaanxi Province. The quality of fluoride-reducing projects should be further improved.
4.Application of Leucocyte Adherence Inhibition Test in Determining Immunological Activity of Ribonucleic Acid
Wang CAN ; Shao HONG ; Chen GANG
China Pharmacist 2015;(11):1848-1850
Objective:To establish a method for determining the immunological activity of ribonucleic acid. Methods: Leucocyte adherence inhibition test ( LAI) was applied, and the important parameters of LAI including the mouse strain, drug concentration, treatment time, content of buffer solution and cell density were researched. The immunological activity of RNAⅠ, Ⅱand Ⅲ was re-spectively determined by the method. Results:Stable and reliable parameters were obtained: the sample concentration was 10 mg· ml-1 , the treatment time was 2 hours, Ca2+ and Mg2+ were necessary for the buffer solution, and the cell density was about 4 × 107 cell·ml-1 . The strain of mouse showed no effect on the results. As a result, the determination method for immunological activity was established. Using the method, the immunological activity of RNA Ⅰ,Ⅱand Ⅲ was determined 3 times, and the results met the re-quirements with RSD below 20%. Conclusion:The method is suitable for determining the immunological activity of RNA.
5.Effect of dexmedetomidine on agitation during recovery from sevoflurane anesthesia in children
Xiufeng CAN ; Yanqing CHEN ; Conghua ZOU
Chinese Journal of Anesthesiology 2011;31(2):166-167
Objective To investigate the effect of dexmedetomidine on agitation during recovery from sevoflurane anesthesia in children. Methods Three hundred ASA Ⅰ or Ⅱ children, aged 4-7 yr, weighing 16-30kg, scheduled for elective ear-nose-throat operation under general anesthesia, were randomly divided into 2 groups ( n = 150 each) : control group (group C) and dexmedetomidine group (group D) . Dexmedetomidine 0.5 μg/kg in 20 ml was infused intravenously over 10 min before anesthesia induction in group D, while equal volume of normal Saline was infused in group C. Anesthesia was induced with inhalation of 8 % sevoflurane 5 min after the end of administration . The children were tracheal incubated and mechanically ventilated. Anesthesia was maintained with inhalation of 2 % -3 % sevoflurane. BIS was maintained at 40-60 during operation. The recovery time and agitation within 2 h after operation were recorded. Results There was no significant difference in the recovery time between the two groups ( P > 0.05) . The incidence of agitation was significantly lower in group D than in group C ( P <0.05 ) . Conclusion Dexmedetomidine can reduce the occurrence of agitation during recovery from sevoflurane anesthesia in children.
6.The correlation between YKL-40,sCD40L,AFP and coronary heart disease
Biao HE ; Haijian CHEN ; Can ZHANG
International Journal of Laboratory Medicine 2017;38(2):224-225,228
Objective To study the chitin enzyme protein(YKL-40),sCD40L,AFP and the correlation of hypertension with cor-onary heart disease(CHD).Methods 75 cases of elderly patients with CHD were selected as observation group,and then were di-vided into hypertension group and non hypertension group according to the blood pressure.103 cases of healthy elderly were select-ed as control group.ELISA method was used to detect YKL-40 and sCD40L,and AFP was detected by chemiluminescence immuno-assay.Results Clinical data comparison revealed that the relative risk of CHD with hypertension group and non hypertension of hy-perlipidemia,drinking,smoking,diabetes mellitus,were 1.56,1.33,1.23,1.15 times,data show that relative risk of CHD with hy-pertension were much greater than CHD without hyperlipidemia.The concentration of YKL-40 in CHD with hypertension(92.66± 12.04)ng/mL was significant higher than that in CHD without hypertension (57.08 ± 10.07 )ng/mL,and the concentration of sCD40L in CHD with hypertension (186.59 ± 69.63 )ng/mL was significant higher than that in CHD without hypertension (128.14±48.37)ng/mL(P <0.05).There was no significant difference in the concentration of AFP in patients with CHD with hy-pertension and non hypertension(P >0.05).Conclusion The levels of YKL-40,CD40L and AFP in the peripheral blood of elderly patients with CHD were significantly increased.And the concentration of sCD40L and YKL-40 was positively correlated with hy-pertension,which can be used to assess the stability and prognosis of CHD.
7.Mechanism of the reversibility of chronic cyclosporine nephrotoxicity after drug withdrawal
Can LI ; Ying CHEN ; Mingyu HONG
Chinese Journal of Nephrology 1997;0(05):-
Objective To explore the mechanism of the reversibility of chronic cyclosporine (CsA) nephrotoxicity in rats after long-term drug withdrawal. Methods Chronic CsA nephrotoxicity was induced in Sprague-Dawley rats by administering CsA(15 mg . kg-1. d-1) for 5 weeks,and then the effect of drug withdraw for 5 and 10 weeks was observed. Body weight,systolic blood pressure,and renal function were monitored. In addition,renal histopathology(arteriolopathy,ED-1-positive cells,and tubulointerstitial fibrosis) and expression of osteopontin(OPN) and transforming growth factor(TGF) -?1 mRNA was examined. Results Compared with the control rats,CsA-treated rats showed loss of body weight,deterioration in renal function and development of typical histopathology. All of these above parameters were significantly reversed,meanwhile,the upregulation of OPN and TGF-?1 mRNA expression decreased significantly at 5th and 10th week after CsA withdrawal. Of note,the decreased OPN and TGF-?1 mRNA expression was positively correlated with the reduction in the tubulointerstitial fibrosis score. Conclusion The established chronic CsA nephrotoxicity is reversible after long-term CsA discontinuation,and the mechanism may be associated with the down-regulation of OPN and TGF-?1 mRNA expression.
8.Expression of KAI1 protein and its clinicopathological significance in breast cancer
Meifu CAN ; Ying WU ; Hansong CHEN
China Oncology 2001;0(02):-
Purpose: To investigate the expression of KAI1 protein and its clinicopathological significance in breast cancer. Methods: Immunohistochemical staining ( S-P method) was used to detect the expression of KAI1 protein in specimens from 107 breast cancer and 30 adjacent normal breast tissues. Results: KAI1 protein positive rate in breast cancer tissues is significantly lower than that of adjacent nomal breast( P 0. 05). Conclusions: These data suggest that in advanced breast cancer, KAI1 is down-regulated and decrease in KAI1 ecpression plays an important role in the malignant progression of breast cancer. Therefore, detection of KAI1 protein might be a potentially valuable indicator for staging human breast cancer and predicting prognosis.
9.Loureirin B inhibits capsaicin-induced currents in rat dorsal root ganglion neurons
Can WANG ; Su CHEN ; Xiangming LIU
Chinese Pharmacological Bulletin 1987;0(02):-
Aim To investigate effects of loureirin B on capsaicin-evoked currents in rat dorsal root ganglion (DRG) neurons. Methods In acutely isolated rat DRG neurons, effects of loureirin B on capsaicin-evoked currents were observed using whole-cell patch-clamp technique. Results ① The holding potential was maintained at -60 mV and VR1 antagonist capsazepine inhibited capsaicin-evoked currents completely; ② Loureirin B concentration-dependently inhibited capsaicin-evoked currents. Loureirin B at the concentrations of 2.0, 4.0, 8.0 and 16.0 ?mol?L-1 reduced capsaicin-evoked currents by 15.36%?2.12%、36.41%?2.43%、76.26%?2.16% and 96.69%?3.21% (n=10, P
10.Exploration and Practice of the Reform of Pharmacochemistry Experiment Teaching for Pharmacy Major in Our School
Can CHEN ; Qinglin JIANG ; Zhihe ZANG
China Pharmacy 2015;(30):4301-4302,4303
OBJECTIVE:To improve the level of pharmaceutical experiment teaching for pharmacy major. METHODS:The ex-periment teaching of pharmacochemistry for pharmacy major in our school was taken as a pilot,and the teaching contents,teach-ing methods and appraisal system were explored. RESULTS:The teaching contents of“designing experiment”of pharmacochemis-try for pharmacy major in our school were added,multimedia teaching mode was introduced and scientific and comprehensive as-sessment mode was established. CONCLUSIONS:The reform of experiment teaching has cultivated the independent thinking and creative ability of students,improved enthusiasm and initiative,achieved good teaching quality and promoted the improvement of professional quality of teaching staff.