In this paper,the classification,application and advantages of three-dimensional (3D) printing in biomedical engineering are summarized.The working principles of 3D printing,stereolithography,fused deposition modeling,selective laser sintering and 3D spray printing,as well as merits,demerits and recent progress are reviewed.The 3D printing has been widely used in the synthetic of bone tissue engineering scaffolds,with biodegradable and bioactive materials in the scaffold.Synthetic bone materials and surgical simulation by 3D printing technology are increasingly common and has achieved satisfactory results in China.Although 3D printing technology has developed rapidly,development of suitable biomaterials and improving relevant techniques are still urgent issues.Up to now,the functionalization of bionic organs is the most difficult issue,in which the cell co-culture,vascularization and preparation of the scaffolds are problem to be solved.The 3D printing technology will make remarkable achievements for the regeneration and repair of human organ through our efforts.

AIM: The cytoplasm Ca 2+, expression of Bcl-2 and Bax and germ cell apoptosis of testes in adult male rats with varicocele were observed to investigate the relationship between apoptosis and infertility. METHODS: Thirty-five healthy male Wistar rats were divided into two groups randomly: varicocele group (VG, n=20) and sham operation group (SOG, n=15). Bilateral testes were removed after ten weeks. One part of it was homogenized, the other part was performed for tissue sectioning. The atomic absorption method was used to detect the cytoplasm Ca 2+. The germ cell apoptosis was detected by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) technique. The expression of Bcl-2/Bax was detected by immunohistochemical method. RESULTS: The cytoplasm Ca 2+ in testes of rats with varicocele was decreased obviously. The apoptosis indexes of germ cells and Bax expression in VG were significantly increased as compared with those in the SOG, while Bcl-2 expression was obviously decreased. CONCLUSION: The results showed that apoptosis was increased in testes of VG rats, suggesting that male infertility with varicocele may be caused by some apoptosis agents such as high temperature, testes toxin and oxygen free radical. The cytoplasm Ca 2+ and change of expression of Bcl-2/Bax may contribute to germ cell apoptosis and cause male infertility.

AIM: To investigate the effects of Scutellaria barbata flavonoids (SBF) on neurofibrillary tangle (NFT) aggregation, tau protein phosphorylation and the regulated mechanism of glycogen synthase kinase (GSK) 3βand protein phosphatase (PP) 2A in the rats induced by amyloid βprotein 25-35 (Aβ25-35) in combination with AlCl3 and re-combinant human transforming growth factor ( RHTGF)-β1( composited Aβ) .METHODS:The male SD rats were used to establish the simulated Alzheimer disease ( AD) model by intracerebroventricular injection of composited Aβ.The Morris water maze was applied for screening the successful model rats with learning and memory deficits .The successful model rats were daily and orally administrated with SBF at doses of 35, 70 and 140 mg/kg or positive control drug Ginkgo biloba leaves flavonoids ( GLF) at 140 mg/kg for 37 d.The silver nitrate staining was used to determine the cortical NFT .The protein levels of total tau, phosphorylated protein of tau at Ser199 and Ser214 sites, GSK3βand PP2A in hippocampus and cortex were determined by Western blot .The mRNA expression of GSK3βand PP2A in the hippocampus and cortex was detected by RT-PCR.RESULTS:Compared with sham group , the cell number of positive NFT with silver nitrate staining in model rat cerebral cortex was significantly increased .The protein levels of phosphorylated tau protein at Ser 199 and Ser214 sites, GSK3βin the hippocampus and cerebral cortex in the model rats dramatically elevated , and PP2A was marked decreased as compared with the sham group rats.Meanwhile, the mRNA expression of GSK-3βsignificantly increased but PP2A was de-creased.However, these above abnormalities were differently attenuated by treating with SBF at different doses or GLF at 140 mg/kg for 37 d.CONCLUSION: SBF suppresses the NFT aggregation by inhibition of the regulatory functions of GSK-3βand PP2A, thus reducing the phosphorylation of tau protein .

Purpose: To investigate the clinical effect of Yin-reinforcing and Blood-nourishing Drink plus electroacupuncture in the treatment of senile skin pruritus. Methods: Eighty patients were randomly divided into two groups. The treatment group was treated with Yin-reinforcing and Blood-nourishing Drink plus electroacupuncture and the control group, with Western medicine. Results: The total effective rate was 100.0% in the treatment group and 67.5% in the control group (P＜0.01). Conclusion: This therapy has a better effect on senile skin pruritus.

Objective To explore the effect of recombinant human tumor necrosis factor-α receptor Ⅱ:IgG Fc fusion protein injection (rhTNFR:FC) on the expression of cartilage oligomeric matrix protein (COMP) in the synovial fluid and peripheral blood of juvenile idiopathic arthritis (JIA); and to explore the clinical significance of COMP for JIA and the relationship between rhTNFR:FC and COMP in JIA.Methods Thirty-five patients with JIA (JIA group),30 patients with traumatic arthritis (trauma group) and 30 patients with indirect inguinal hernia hernioplasty (normal group) were included.Peripheral blood from all enrolled patients and synovial fluid from 15 JIA and 10 trauma arthritis were obtained for COMP detection before the treatment.Fifteen JIA (group A) patients were treated with combined rhTNFR:FC,diseasemodifying antirheumatic drugs (DMARDs) and non-steroid anti-inflammatory drugs (NSAIDs),20 JIA (group B) were treated with combined DMARDs and NSAIDs.After three to six months' treatment and when the disease were in remission,peripheral blood from group A and B were drawn for COMP detection.In group A,the synovial fluid from 5 patients were obtained for COMP detection after treatment.At the same time,such as tender joint count (TJC),swollen joint count (SJC),time for morning stiffness,blood routine,erythrocyte sedimentation rate (ESR),and C-reactive protein (CRP) and other parameters before and after treatment were measured.The level of COMP was tested by double antibody sandwich enzyme-linked immunosorbent assay.The measurement data were tested for variance and independent sample t-test; and the enumeration data were tested by chi-squared or Fisher's exact test.Pearson's correlation analysis was adopted to analyze the association among the variables.Results ① The blood COMP level before treatment was (0.77±0.29) ng/ml in the JIA group,(1.00±0.28) ng/ml in the traumatic arthritis group,and (1.33±0.37) ng/ml in the normal control group.The level in the former two groups was obviously lower than that in the normal control group.The variation was statistically significant (F=25.345,P＜0.05).The comparison between any two groups was statistically significant (P＜0.05).② The COMP level in the synovial fluid before treatment were (14.8±1.6) ng/ml in the JIA group,(15.1±1.0) ng/ml in the traumatic arthritis group.The variation was not stati-stically significant (t=0.523,P=0.606).③ The serum COMP level of the systemic JIA group was obviously lower than that of the oligoarticular JIA patients,and patients with enthesitis-related arthritis and polyarticular JIA (0.26± 0.03 vs.0.87±0.17,0.89±0.22 and 0.70±0.35 ng/ml,respectively; F=9.244,P＜0.05).④ The serum COMP level of JIA at the acute phase was negatively correlated with white blood cells count (WBC),CRP and ESR (r=-0.556,-0.582 and-0.684,respectively; P all＜0.05).By contrast,no correlation was detected between the serum COMP level and joint tenderness index,joint swelling index,morning stiffness duration,hemoglobin level and platelet count(r=0.06,-0.206,-0.107,0.15 and-0.185,respectively; P all ＞0.05).⑤ The serum COMP level was obviously lower in the JIA with joint destruction than that without joint destruction (0.52±0.22 vs.0.92±0.22 ng/ml; t=5.207,P＜0.05).⑥After treatment,the blood COMP level in group A was (1.33±0.21) ng/ml and (0.96±0.22) ng/ml in group B,which was obviously higher than that in the JIA group before treatment (0.77±0.29) ng/ml.In addition,the level in group A was higher than that in group B.The variation was statistically significant (F=24.681,P＜0.05).⑦ After treatment,the COMP level in the synovial fluid (18.4± 1.1) ng/ml (n=5) was higher than that before the treatment was (14.8± 1.6) ng/ml (n =15).The variation was of statistical significant (t=4.565,P＜0.05).Conclusion The COMP level in blood and synovial fluid declines before treatment and increases after treatment.The increase is more obvious after combined with rhTNFR:FC treatment.The serum COMP level is remarkably decreased in JIA at the acute phase,systemic JIA,and the JIA with destruction of joint,and showes a negative correlation with WBC,CRP and ESR.Serum COMP may be a useful marker of active disease,destruction of joint and growth inhibition for patients with JIA.rhTNFR:FC treatment for JIA can facilitate the recovery of COMP.

Objective To observe the changes in contrast sensitivity(CS) and color vision in patients with primary acute angle-closure glaucoma(PACG).Methods CS and color vision tests were performed in 35 patients(35 eyes) with preclinical stage of PACG,32 patients(32 eyes) with acute attack stage of PACG and 15 normal subjects(30 eyes).Then patients were followed up 1 month(31 eyes) and 3 months(28 eyes) after operation.Results The results of CS and color vision tests were abnormal in PACG patients when they were compared with those of normal people.The threshold of CS at 18.0 c/d was increased(P

Objective To observe the effect on Foxg1 gene expression in the subgranular zone (SGZ) of cerebral tissue from neonatal rats with hypoxic-ischemic brain damage (HIBD) after transplantation of neural stem cells (NSCs) derived from umbilical cord blood.Methods Mononuclear cells separated from umbilical cord blood by density gradient centrifugation were cultured with orientated induction to differentiate the NSCs.The neuronal phenotype was identified using immunocytochemical methods.A total of 150 Sprague-Dawley rats were randomly divided into a sham-operation group,an HIBD group and an HIBD-NSCs group.Rats in the HIBD group and the HIBD-NSCs group were subject to ligation of the left carotid artery and then kept in a box under 8％ oxygen and 92％ nitrogen for 2.5 hours to establish the HIBD animal model.The artery was separated but not ligated in the sham operation group,which was not subjected to hypoxia.Twenty-four hours after the operation,the cultivated NSCs were transplanted by caudal vein injection into the rats in the HIBD-NSCs group.Rats were then sacrificed on the 3rd,7th,14th,21st and 28th days after the operation.Foxg1 gene expression in the SGZ was examined using in-situ hybridization methods.Results The number of Nestin-positive cells peaked on the 6th day of cultivation and then decreased by the 9th day.The Foxg1 gene was expressed in the SGZs of each group.The expression increased by the 3rd day after surgery in the HIBD and HIBD-NSCs groups,and peaked on 7th day after the operation,then declined gradually.The average expression level of Foxg1 in the HIBD group was significantly lower than that in the HIBD-NSCs group on the 7th day and thereafter.Conclusions Human umbilical cord blood mesenchymal stem cells can be induced and differentiated into neural stem cells.Foxg1 genes can still be present in the SGZ after birth.HIBD can induce the expression of Foxg1 genes.Transplanting NSCs can promote the expression of Foxg1 genes and improve morphological and functional recovery after HIBD,at least in neonatal rats.

Objective To analyze the MSCT manifestations of septic pulmonary embolism(SPE)to explore the diagnosis value of MSCT.Methods The MSCT findings of eight patients with SPE were analyzed retrospectively.Results ① Of all 177 lesions,84 lesions located in both upper lobes,25 lesions located in right middle lobe and 68 lesions located in both lower lobes.② There were 106 nodules and 44 wedge shaped opacities in all the 8 cases,of which the 88 nodules (83.0%)and all of the wedge shaped opacities located in sub-pleural zones of the lung and the 18 nodules (1 7.0%)located in the inner and middle lung fields.In 6 cases,the 26 nodules (24.5%)and the 1 6 wedge shaped lesions (38.1%)had “feeding vessels”.③ There were 27 patchy shadows in 6 patients,of which 12 patchy shadows (44.4%)had air bronchogram.④ There were 18 cavities in 6 patients,of which 14 cavities (13.2%)located in nodules and 4 cavities (9.1%) in the wedge shaped lesions.There were 8 cysts in 4 patients,of which 6 cysts located in nodules (5.7%)and 2 cysts in the wedge shaped lesions (4.5%).⑤ The nodules and the wedge shaped lesions were enhanced slightly.⑥ Pleural effusion and pericardial effusion were found in 4 and 3 patients,repectively.⑦ Of 6 patients the follow-up MSCT scan in a short period showed the disease progressions. Conclusion SPE has characteristic manifestations in MSCT,and MSCT can provide valuable information for the diagnosis of SPE.

AIM: To observe the effect of ischemic preconditioning on contents of cytochrome C and mitochondrial calcium in rats after focal cerebral ischemic-reperfusion. METHODS: Focal cerebral ischemic model was made by occlusion of right middle artery in Wistar rats (ischemia for 2 h and reperfusion for 4 h). Rats were randomly divided into three groups: ischemia pretreatment, model and sham operation. Rats in ischemic pretreatment group were undergone transient ischemic preconditioning (30 min) and reperfusion (72 h). The contents of cytochrome C were measured according to Zhangjuntian's improved methods. The contents of mitochondrial calcium were detected by flame atom absorption. RESULTS: The contents of mitochondrial cytochrome C and calcium in model group were significantly lower than those in sham operation (P

BCG Purified Protein Derivative (BCG-PPD)was isolated and purified from BCG Culture filtrate by trichloroacetic acid and ammonium sulfate methods. The purity of BCG-PPD was Similar to PPD-S(international standard) and PPD-C(China), but more than that of PPD-CT68 (Canada)and PPD-RT23(Danish). The Delayed-Type Hyperseusitivity(DTH) to BCG-PPD was more sensitivity than other PPD on BCG vaccinated guinea pigs, but less sensitivity than other PPD on Mycobacterium tuberculosis infected guinea pigs. The conversion rate and induration diameter to BCG-PPD was higher than PPD in 333 of 12 weeks after BCG vaccination newborns, but lower than that of other PPD in 97 tuberculosis patients. It was shown that DTH reaction to PPD was more sensitivity in Mycobacteria homogeneous strain vaccinated individual than Mycobacteria heterogeneous strain vaccinated individual. It was demonstrated that BCG-PPD was better than other PPD on observation conversion rates and induration diameter of BCG vaccinated individual. It maybe help to identification BCG vaccinated or tuberculosis infected with DTH of BCG-PPD and PPD in same individual.