BACKGROUND: The complicated localization of intramedullary nails and osteotomy more dependent on surgeons' experience limit the application of conventional total knee arthroplasty (TKA). The occurrence of three-dimensional (3D) printing technology can achieve precise localization and osteotomy in TKA.OBJECTIVE: To explore the effectiveness of 3D printing technology-aided TKA versus conventional TKA for genu varum.METHODS: Thirty-four patients with genu varum undergoing primary unilateral TKA were recruited and were then divided into two groups (n=17 per group) in accordance with the random number table. One group was treated with TKA with 3D printing guild plate (3D printing group), while the other group received the conventional TKA (conventional group).The intraoperative and postoperative blood loss, operation time, as well as the Hospital for Special Surgery score, range of motion, and lower limb mechanical alignment at 2 weeks postoperatively were compared between two groups.RESULTS AND CONCLUSION: (1) The range of motion of knee in the 3D printing group was larger than that in the conventional group, but had no significant difference at 2 weeks postoperatively (P=0.744). (2) There was no significant difference in the Hospital for Special Surgery scores between two groups at 2 weeks postoperatively (P= 0.532). (3) The postoperative lower limb mechanical alignment showed no significant difference between two groups (t=0.218, P=0.632).(4) The operation time in the 3D printing group was significantly shorter than that in the conventional group (P=0.000). (5) The blood loss in the 3D printing group was significantly less than that in the conventional group (P=0.000). (6) Our findings indicate that 3D printing technology-aided TKA exhibits similar results to the conventional TKA in the Hospital for Special Surgery scores, range of motion, and lower limb mechanical alignment, but it shortens the operation time,reduces the blood loss, and achieves precise osteotomy, which is available for the elderly with poor basic condition, and weak tolerance of surgery.

AIM:To explore the effect of homocysteine (Hcy)-mediated endoplasmic reticulum stress on lipid metabolism in hepatocytes.METHODS: HepG2 cells used in the study were treated with 5 mmol/L Hcy. The concentrations of Hcy, triglycerides (TGE) and cholesterol (CHO) in the cells were measured. In high methionine diet-induced hyperhomocysteinemia C57BL/6 mice, the concentrations of TGE and CHO in hepatocytes were analyzed. The mRNAs and proteins expressions of glucose-regulated protein 78 (GRP-78) and sterol regulatory element binding protein (SREBP-1) were also assessed.RESULTS: The concentrations of Hcy and lipids (TGE, CHO) in HepG2 cells at different time point were elevated after treated with 5 mmol/L Hcy (P0.05,vs 0 week). The mRNAs and proteins expressions of GRP-78 and SREBP-1 in mice at different time point after high methionine diet were higher than that at 0 week (P

Objective To explore the expression of sterol regulatory element binding protein 1C (SREBP-1C) and glucose-regulated protein 94(GRP-94)in hyperhomocysteinmia and to evaluate the effects of endoplasmic reticulum stress proteins on hepatocytes lipids metabolism. Methods After hyperhomocysteinmia C57BL/6 mice model being induced by high methionine diet, TGE and CHO of Hepatocytes were determined, and the expression of SREBP-1C and GRP-94 was assessed by RT-PCR and Western blot. All data were compared to those in control group′s. Results The level of plasmic homocysteine(Hcy) and hepatocytes TGE or CHO of high methionine diet mice at different time point significantly ascended(P

The paper deals with a portable analyzing monitor system with liquid crystal display (LCD), which is low in power consumption and suitable for China's specific conditions. Apart from the development of the overall scheme of the system, the paper introduces the design of the hardware and the software. The 80196 single chip microcomputer is used as the central microprocessor to process and real-time electrocardiac signal data. The system have the following functions: five types of arrhythmia analysis, alarm, freeze, and record of automatic paperfeeding. The portable system can be operated by alternate-current (AC) or direct-current (DC). Its hardware circuit is simplified and its software structure is optimized. Multiple low power consumption and LCD unit are adopted in its modular designs.
Arrhythmias, Cardiac ; diagnosis ; Computers ; Electrocardiography, Ambulatory ; instrumentation ; Equipment Design ; Humans ; Microcomputers ; Software

The improvement of diagnostics teaching system,including the establishment of curriculum system and evaluation system,is the base of promoting clinical- medicine teaching.Our study showed that the theoretical knowledge and clinical skill of medical students could be improved by constructing clinical diagnostics curriculum system and improving organization management and assessment system,which could pave the way for the transition from medical students to clinicians.

Objective To investigate the long-term prognosis and possible risk factors of acute kidney injury(AKI)following cardiac surgeries. Methods Clinical data of 941 patients undergoing open heart surgery from January 2004 to June 2007 were retrospectively analyzed.Survival and renal function of above patients were informed through telephone or clinic follow-up till February 2010.Long-term survival was analyzed using risk-adjusted Cox proportional hazards regression model. Results Of the 941 patients after cardiac surgery,275(29.2%)developed AKI and 666(70.8%)did not.Survival was worse in patients with AKI(67.8%vs 85.6%,P<0.01)and was proportional to its severity (AKIN 1,2 and 3 stages:70.7%,62.3%and 58.6%,P<0.01).Although 90.5% of patients had complete renal recovery after AKI at discharge of hospital,they still had an increased risk for death during follow-up compared with patients without AKI (69.6% vs 85.6%,P<0.01).In the Cox proportional hazards regression model,age(HR=2.238),anemia (HR=1.625),prolonged operation time (HR=1.153),AKI severity (HR=1.473)were independent risk factors for long-term prognosis after cardiac surgery.At the end of the follow-up,patients with AKI had statistically higher Scr than non-AKI patients(107.6 μmol/L vs 83.0 μmol/L,P=0.014),and among those AKI patients,34.0%progressed into CKD 3-5 stages,34.8%developed double serum creatinine. Conclusions AKI is a risk factor for the long-term prognosis of cardiac surgery.Patients with complete renal recovery after AKI still has an increased risk for death and poor renal function compared with patients without AKI.

Objective To study DNA quantification and STR typing of samples pre-treated with pyrami-don. Methods The blood samples of ten unrelated individuals were anticoagulated in EDTA. The blood stains were made on the filter paper. The experimental groups were divided into six groups in accor-dance with the storage time, 30 min, 1 h, 3 h, 6 h, 12 h and 24 h after pre-treated with pyramidon. DNA was extracted by three methods: magnetic bead-based extraction, QIAcube DNA purification method and Chelex-100 method. The quantification of DNA was made by fluorescent quantitative PCR. STR typing was detected by PCR-STR fluorescent technology. Results In the same DNA extraction method, the sample DNA decreased gradually with times after pre-treatment with pyramidon. In the same storage time, the DNA quantification in different extraction methods had significant differences. Sixteen loci DNA typing were detected in 90.56% of samples. Conclusion Pyramidon pre-treatment could cause DNA degradation, but effective STR typing can be achieved within 24 h. The magnetic bead-based extrac-tion is the best method for STR profiling and DNA extraction.

Objective To observe the expression of phosphoinositide 3-kinase(PI3K) and protein kinase B1 (Akt1) in PI3K/Akt signaling pathway in rat bones with fluorosis, and to reveal the mechanisms of the skeletal fluorosis. Methods Thirty-six SD rats were randomly divided into 3 groups (control group, low-dose fluorosis group, high-dose fluorosis group) and 12 rats were in each group according to body weight. The rats were fed with different concentrations of fluoride (NaF) to establish fluorosis models. Controls were fed with tap water( < 0.5 mg/L), experimental animals in low- or high-dose groups were fed with water containing NaF 5.0,50.0 mg/L, respectively. Rats were sacrificed after 6 months of treating with fluoride and the serum was kept for testing the bone metabolic markers of none gla protein(BGP) and cathepsin K(Cath-K) by enzyme-linked immunosorbent assay(ELISA), the proteins and mRNA levels of PI3K and Akt1 in rat bones were detected by immunohistochemistry and real time PCR, respectively. Results Each group of serum BGP and Cath-k were compared, the difference was statistically significant(F = 73.45,39.36, all P < 0.05). The contents of BGP[(1.99 ± 0.62), (2.38 ± 0.16)μg/L] and Cath-K [(89.07 ± 19.66), (110.16 ± 9.81)pmol/L] in the low-and high-dose fluorosis groups were higher than those in the control group[(0.15 ± 0.03)μg/L,( 18.32 ± 2.27)pmol/L], and the high fluorosis group was obviously higher than the low fluorosis group (all P < 0.05). Each group of serum PI3K and Akt1 protein and mRNA were compared, the difference was statistically significant(F- 178.16,118.08,38.81,52.31, all P< 0.05). Compared to the control group (181.55 ± 4.24,188.46 ± 2.18,3.84 ± 1.69,4.33 ± 0.89), the protein and mRNA expressions of PI3K(171.66 ± 2.85,154.12 ± 4.15,11.31 ± 4.18,20.54 ± 6.68), Akt1(177.47 ± 3.16,156.42 ± 3.18,12.52 ± 3.13,19.43 ± 5.36) were higher in the low- and high-dose fluorosis groups (all P < 0.05), and the high fluorosis group was obviously higher than the low fluorosis group (all P < 0.05). Conclusions BGP and Cath-K contents could be used as bone metabolic indices in the endemic fluorosis disease. Fluoride can increase the expression of PI3K and Akt1 mRNA and protein in bone tissue of fluorosis rats, and PI3K/Akt1 signaling pathway may be involved in the pathogenesis of bone injury caused by fluoride.

ObjectiveTo investigate the expression of nuclear factor kappa B(NF-kB)-related mRNA and protein in bone tissue of rats with chronic fluorosis.MethodsThirty-six healthy SD rats,weighting 100 - 120 g,were randomly divided into three groups (twelve in each group ).Rats of control group were fed with tap water (NaF ＜ 1 mg/L) and the experimental rats were exposed to NaF(low-dose group:5 mg/L,high-dose group:50mg/L) through drinking water.All rats were killed at the eight month and metaphysic of femoral was collected.Bone tissues were stained with hematoxylin-eosin and observed under optical microscope.Bone fluorine was detected by ashing-fluorin ion selective electrode method.Serum content of tartrate-resistant acid phosphatase 5b(TRACP 5b)was detected by enzyme-linked immunosorbent assay(ELISA).The expressions of p50,p65 and IkBα's mRNA and protein in bone tissue was detected by real-time PCR and immunohistochemistry.ResultsBone sclerosis was observed under optical microscope.The contents of bone fluorine in both the low and high doses fluoride groups [(6.32 ± 1.23),( 10.89 ± 1.56) mg/kg] were significantly higher than that of the control [(3.06 ± 1.01 ) mg/kg,all P ＜ 0.05],and of that the high fluoride group was significantly higher than that of the low fluoride group(P ＜ 0.05).Serum content of TRACP 5b of the low fluoride group[(3.45 ± 1.85)U/L] was significantly higher than that of the control[(1.26 ± 0.23)U/L,P ＜ 0.05],but that of the high fluoride group[(2.74 ± 1.85)U/L] was lower than that of the low dose group(P ＜ 0.05).The mRNA expressions of p50 and IkBα in the low fluoride group(4.41 ± 0.44,1.15 ± 0.25) were significantly higher than that of the control(1.46 ± 0.10,0.26 ± 0.07,all P ＜ 0.05),but that of the high fluoride group(0.69 ± 0.09,0.14 ± 0.03) was lower than that of the low dose group(all P ＜ 0.05).The protein expressions of p50 and IkBα in the low fluoride group(152.96 ± 7.87,156.20 ± 9.75) were significantly higher than that of the control( 125.63 ± 9.85,118.97 ± 6.94,all P ＜ 0.05),but the high fluoride groups' ( 120.56 ±9.57,114.50 ± 7.61 ) was significantly lower than that of the low dose group(all P ＜ 0.05).ConclusionFluoride can lead to altered gene expression of NF-kB pathway,and the latter may be involved in fluoride induced bone damage.

Objective To investigate the relationship between change of relevant gene of nuclear factor kappa B(NF-κB) and osteoclast apoptosis in bone injury of rats with chronic fluorosis,and to reveal the mechanism of skeletal fluorosis.Methods Thirty-six healthy SD rats,weighting 100-120 g,were randomly divided into three groups(twelve in each group).Rats of control group were fed with tap water(NaF ＜ 1 mg/L) and the experimental rats were exposed to NaF(low-dose group:5 mg/L,high-dose group:50 mg/L) through drinking water to established chronic fluorosis model.All rats were killed at the eight month and metaphysic of femoral was collected.Bone tissues were stained with hematoxylin-eosin and observed under optical microscope.Serum content of tartrateresistant acid phosphatase 5b (TRACP 5b) was detected by enzyme-linked immunosorbent assay (ELISA).Osteoclast was identified and counted by tartrate-resistant acid phosphatase staining(TRAP).The expression of p50,IκBα,Bcl-2 and Bax's mRNA and protein of bone tissue was detected by Real-time PCR and immunohistochemistry.Results Bone sclerosis was observed under optical microscope.The content of TRACP 5b in serum and the number of osteoclast in the low fluoride group[(3.45 ± 1.85)U/L,(6.75 ± 1.29)/slice]were significantly higher than that of the control[(1.26 ± 0.23)U/L,(3.92 ± 1.38)/slice,all P ＜ 0.05],but that of the high fluoride group [(2.74 ± 1.85)U/L,(3.33 ± 1.07)/slice]were lower than that of the low dose group(all P ＜ 0.05).The mRNA expressions of p50,IκBα,Bcl-2 and Bax in low fluoride group(4.41 ± 0.44,1.15 ± 0.25,2.02 ± 0.11,1.25 ± 0.22) were significantly higher than that of the control(1.46 ± 0.10,0.26 ± 0.07,1.00 ± 0.06,0.74 ± 0.09,all P ＜ 0.05),but the high fluoride groups' (0.69 ± 0.09,0.14 ± 0.03,0.95 ± 0.08,0.62 ± 0.08) were lower than that of the low dose group(all P ＜ 0.05).The protein expressions of p50 and IκBα in the low fluoride group (152.96 ± 7.87,156.20 ± 9.75) were significantly higher than that of the control(125.63 ± 9.85,118.97 ± 6.94,all P ＜ 0.05),but the high fluoride group(120.56 ± 9.57,114.50 ± 7.61) were lower than the low dose group(all P ＜ 0.05).The protein expressions of Bcl-2 and Bax(170.61 ± 6.60,160.77 ± 7.66) and the ratio of Bcl-2/Bax (1.07 ± 0.08) were higher than the control(l10.73 ± 5.27,114.64 ± 5.83,0.96 ± 0.04,all P＜ 0.05),but the high fluoride group(81.70 ± 8.00,99.93 ± 3.83,0.81 ± 0.08) were lower than that of the control and the low dose group (all P ＜ 0.05).There was a significant positive correlation between protein expression of p50,IκBα and Bcl-2/Bax (r =0.587,0.676,all P ＜ 0.05).Conclusions Chronic fluorosis can cause change of the relevant gene of NF-κB in rat bone tissues and osteoclast apoptosis.The mechanism of skeletal fluorosis might be related to the abnormal of osteclast apoptosis caused by changes of NF-κB p50 and IκBα.