ObjectiveTo establish multidrugresistance cell substrain of human hepatocellular carcinoma and to investigate its characteristics.MethodsSMMC7721 cell strain was cultured in Adriamycin(ADM). The multidrugresistance cell substrain SMMC7721/ADM was harvested after a long period of culture by gradually increasing the concentration of ADM and its characteristics were investigated. Results①The drug resistance of SMMC7721/ADM to ADM increased by 33.3 times, to Vincristine 16.8 times, to Diamminedichloroplatinum 2.8 times. ②The drug resistance cell substrain had almost the same growth velocity as its parental generation. The doubling time was 32.0 hours and 30.5 hours respectively. They had the analogous growth curves. ③The obvious difference between the drug resistance cell substrain and its parental generation was that the former’s microvilli became thick, short and scattered by scanning and transmitting electron microscopy. ④The multidrug resistance cell substrain kept the characteristics of hepatocellular carcinoma, it could be transplanted into the subcutaneous tissue of nude mice. ⑤The drug resistance of the cell substrain reduced to 28.0% and 9.2%after removal of the drug for 1 month and 2 months respectively, its drug resistance could remain stable (35.4 times) after 2 months of culture in ADM (0.04 μg/ml).ConclusionThe SMMC7721/ADM cell substrain has the stable fundamental characteristics of a drug resistance cell strain.
Objective To set up the experimemtal model with superior segmentalbone defect in acetabulum and implant the three-fin acetabular component, and examine the Von Mises stresses of pelvis bone with simulating single leg position in vitro using rosette strain gages method(RSGD). Methods Four kinds of three-fin components were made based on measurement of diameter, depth and roof thickness of acetabular specimens. These kinds of threefin acetabular components based on spreaded degrees of lateral fins(0,36,45 and 60°). The superiorsegmental bone defect of acetabulum in 4 cadaver pelvis specimens was made,then simulated the actual position to place implant into acetabular bone.A blank control group was set up.After being fit up the 7 sets of rosette strain gages,then specimen to test the pelvic Von Mises stresses simulating the static load of single leg on the mechanic machine.Progressive load was graded into 150, 300,450, 600, 750 and 900 N.We obtained the strains informations about loaded andun-loaded pelvis bone. Results Based on computed the strains informations,we were informed the Von Mises stresses about pelvis bone.The maximal Von Mises stresses of selected local position was 6.93 MPa and the minimal Von Mises stresses of selected local position was 1.08 MPa. Conclusion Providing the data about the mainpart of threefin acetabular component to optimize spreaded degrees of lateral fins.
By using Urist s method four types of BMG from the long bones of the rabbit、 pig、sheep、 and human being were prepared. Each of them was implanted into the pectoralis and thigh muscles in 25 adult rats, respectiely. Two-eight weeks after implantation, the unoreaction and inductive osteogensis potential in the tissues were observed under mieroscope. The result showed that aBMG had inductive osteogenesis potential. However, rejection in varying digree existed around aBMG. It was important to further decrease the antingenicity digree exised around a BMG . and enhance its osteogennic potential before the possibility of its clinical application.
Bone marrow-derived mesenchymal stem cells (BMSCs) are multipotent stem cells that differentiate into a variety of cell types and widely used in tissue regeneration engineering. The purpose of this study is to investigate whether the cyclic biaxial stretching strain could promote the rat BMSCs (rBMSCs) to differentiate into cardiomyocyte-like cells in vitro. The second or third generation of rBMSCs were randomly divided into the cyclic stretching stain group, the control group and the blank group. Those rBMSCs in the cyclic stretching strain group were seeded on a silicone membrane with complete medium were exposed to biaxial stretching strain of 10% of membrane at a frequency of 1 Hz lasting for 6 h, 12 h and 24 h. Those in the control group were seeded on silicone membrane with complete medium. Those in the blank group were seeded in the 6-wells plates with complete medium. The mRNA expression of GATA4 and myocyte-specific enhancer factor 2C (MEF-2C) were detected by the real-time fluorescent quantification PCR and the protein expression of connexin 43 (Cx43) was detected by using the Western blot method. The results showed that the mRNA expression level of the GATA4 and MEF-2C, and the protein expression level of Cx43 were significantly higher in the cyclic stretching strain groups, compared with those in the relative control groups (P<0.05). It suggests that cyclic biaxial stretching strain could play a part in the induction of rBMSCs to differentiate into cardiomyocyte-like cells in vitro, but the differentiation mechanism is still unclear.
Objective To investigate whether the biomechanical effect of mushroom shaped surface prosthesis on femoral neck is in the scope of safety after the replacement. Methods Four donated fresh-adult specimens of upper femur under the age of 55 years old were used. The strains of detecting points A (lateral) and B (medial) on the narrow place of femoral neck in the standing position were simulated for three stages before or after the prosthesis replacement, namely the pre-replacement, the initial stage during which the interspace of the prosthesis was filled with cancellous bone, and laterstage during which the interspace of the prosthesis was filled with bone cement. Then they were compared by using l inear regression analysis in Excel and rel iabil ity analysis. Results The regression analysis showed that the values of correlation coefficient r were all more than 99% at the different stages, indicating the strain of femoral neck’s cortical bone was proportional to the load and there was no occurrence of the plastic deformation of the femoral neck. For point A, the slope of the trend l ine of strain was 0.671 9 at the pre-replacement stage. The value of the initial stage after replacement was 0.619 2 and its change rate was —7.8%; while corresponding value was 0.662 7 and —1.4% at the later stage after replacement. For point B, the slope of the trend l ine of strain was —1.056 1 at the pre-replacement stage. The value of the initial stage after replacement was — 1.129 2 and its change rate was 6.9%; while corresponding value was —1.085 1 and 2.7% at the later stage after replacement. Conclusion The mechanical strength of femoral neck is in the scope of safety after surface replacement of the femoral head. The change rate of strain at the later stage is smaller than the initial stage.
ObjectiveTo evaluate myocardial segmental motion function in left ventricular of patients with rheumatic mitral stenosis by using the technology of real-time three-dimensional echocardiography (RT-3DE). MethodsWe retrospectively analyzed the clinical data of 14 patients with rheumatic mitral stenosis between October and November 2014 in our hospital as a trial group. There were 4 males and 10 females with a mean age of 50.9±9.0 years ranging from 34 to 64 years. We chose 11 healthy individuals as a control group. There were 7 males and 4 females with a mean age of 49.5±9.7 years ranging from 32 to 67 years. Both the two groups were subjected to myocardial performance evaluation using two-dimensional echocardiography (2DE) and real-time three-dimensional echocardiography (RT-3DE) to examine the left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end systolic volume (LVESV), longitudinal strain, circumferential strain, area strain, and lateral strain of each left ventricular myocardial segments. Result RT-3DE detected that the trial group had significantly lower values of LVEF, LVEDV and LVESV than those of the control group (P < 0.05). RT-3DE also revealed that the trial group had a significantly weaker longitudinal strain than the control group (P < 0.05). ConclusionRT-3DE is an accurate technology for assessing myocardial motion and function in patients with rheumatic mitral valve disease.
Percutaneous pulmonary puncture guided by computed tomography (CT) is one of the most effective tools for obtaining lung tissue and diagnosing lung cancer. Path planning is an important procedure to avoid puncture complications and reduce patient pain and puncture mortality. In this work, a path planning method for lung puncture is proposed based on multi-level constraints. A digital model of the chest is firstly established using patient's CT image. A Fibonacci lattice sampling is secondly conducted on an ideal sphere centered on the tumor lesion in order to obtain a set of candidate paths. Finally, by considering clinical puncture guidelines, an optimal path can be obtained by a proposed multi-level constraint strategy, which is combined with oriented bounding box tree (OBBTree) algorithm and Pareto optimization algorithm. Results of simulation experiments demonstrated the effectiveness of the proposed method, which has good performance for avoiding physical and physiological barriers. Hence, the method could be used as an aid for physicians to select the puncture path.
Intraocular pressure detection has a great significance for understanding the status of eye health, prevention and treatment of diseases such as glaucoma. Traditional intraocular pressure detection needs to be held in the hospital. It is not only time-consuming to doctors and patients, but also difficult to achieve 24 hour-continuous detection. Microminiaturization of the intraocular pressure sensor and wearing it as a contact lens, which is convenient, comfortable and noninvasive, can solve this problem because the soft contact lens with an embedded micro fabricated strain gauge allows the measurement of changes in corneal curvature to correlate to variations of intraocular pressure. We fabricated a strain gauge using micro-electron mechanical systems, and integrated with the contact lens made of polydimethylsiloxane (PDMS) using injection molding. The experimental results showed that the sensitivity was 100.7 μV/μm. When attached to the corneal surface, the average sensitivity of sensor response of intraocular pressure can be 125.8 μV/mm Hg under the ideal condition.
Objective To evaluate the significance of the ultrasound elastography (UE) strain ratio (SR) in the diagnosis of breast nodule by meta-analysis. Methods A computer-based online search was conducted in PubMed, The Cochrane Library (Issue 6, 2017), EMbase, CNKI, VIP, CBM, WanFang data databases, and so on (establishment time to June 2017), to collect the relevant diagnostic trials of the SR for breast nodules. Two reviewers independently screened literatures, extracted data, and evaluated the methodological quality of included studies. The meta-analysis was performed by using Stata 12.0 and Meta-Disc 1.4 software, and the combined indexes included sensitivity (Sen), specificity (Spe), positive likelihood ratio (LR+), negative likelihood ratio (LR–), and diagnostic odds ratio (DOR). Results A total of 26 studies were finally included. The results of meta-analysis showed that, the pooled Sen, Spe, LR+, LR–, and DOR was 0.88 (95% CI was 0.87 to 0.90), 0.85 (95% CI was 0.84 to 0.86), 6.66 (95% CI was 5.26 to 8.43), 0.14 (95% CI was 0.11 to 0.17), and 53.37 (95% CI was 34.96 to 81.49), respectively, P<0.000 1. Conclusion SR has high diagnostic accuracy in the differential diagnosis of benign and malignant breast nodules, it is worthy of widely utilized in the clinic.
ObjectiveTo explore the value of ultrasound real-time tissue elastography in the differential diagnosis between benign and malignant breast lesions.Methods A total of 131 cases of patients with breast lesions who underwent ultrasound examination in the People’s Hospital of Guangan City between December 2010 and December 2015 were enrolled as the research object. The patients took conventional color Doppler ultrasound diagnosis firstly, and then took ultrasound real-time tissue elastography diagnosis. The lesions were scored with improved 5-scoring system respectively. By the strain ratio measure method equipped with the ultrasonic machine, strain ratio of the lesion was calculated, with 3.08 as the cut-off pont. The results were campared with the pathologic diagnosis.ResultsThere were 182 breast lumps in the 131 patients. The conventional ultrasound examination detected 128 benign lesions and 54 malignant lesions. By ultrasound real-time tissue elastography examination, there were 121 benign tumors and 61 malignant tumors. For the benign tumors, the elasticity imaging score was 1.74±0.81, and the elastic strain rate ratio was 1.83±1.22; for the malignant tumors, the elasticity imaging score was 4.45±0.59, and the elastic strain rate ratio was 8.68±5.58. The 182 breast lumps were all removed by surgical resection, and the pathologic examination showed there were 121 benign lesions and 61 malignant lesions. The accuracy, sensitivity and specificity of conventional ultrasonic diagnosis of breast malignant lesions was 76.4%, 59.0% and 85.1%, respectively; while the indexes of ultrasound real-time tissue elastography diagnosis of breast malignant lesions was 96.7%, 95.1% and 97.5%, respectively, and the differences were statistically significant (P<0.05).ConclusionReal-time tissue elastography is helpful in the differential diagnosis between malignant and benign breast lesions.