Tensegrity structure is comprised of compression-resis tant elements and a set of continuous tensile elements that are interconnected w ith each other. The stability of such system depends on maintenance of tensional integrity inside the structure, or what has come to be termed “tensegrity”. A ccording to studies on biology, cell structures are assembled on the basis of te nsegrity mechanism. Tensegrity of cytoskeleton can affect cell shape and functio n. Furthermore, some basic rules of mechanochemical transduction in cells can be well explained using tensegrity theory.

Objective To observe the survival,conversion and function preservation of mesenchymal stem cells(MSC) after transplantation.Methods MSCs from male Sprague-Dawley(SD) rats were isolated and cultured,then were transplanted to bone defect of female SD rats.Tissues were obtained at defferent periolds.Hybridization in situ was performed on the tissues using Y chromosome specific DNA probe labeled with digoxin to observe the transplanted cells on distribution,quantity and function.Results Allogeneic MSCs could survive and proliferate in the bone defect of recipients and formed bony callus with large quantity and good quality.After 90 days of graft,stem cells still survived and distributed in marrow and newly formed bone tissue.Conclusion After transplantation,allogeneic MSCs have a long-term surviving in marrow and new bone tissue and maintain the characteristic of ossification.

OBJECTIVE:To provide reference for standardizing the clinical use of carbapenem antibiotics and controlling drug-resistant bacteria infection. METHODS:The detection of 3 kinds of carbapenems-resistant Gram-negative bacillus in our hospi-tal during 2011-2016 were analyzed retrospectively. The consumption,target cure rate and treatment course of carbapenem antibiot-ics were analyzed statistically. The correlation between detection rate of drug-resistant bacteria with the consumption of carbapenem antibiotics was investigated by Pearson test. RESULTS:During 2011-2016,1222 strains of carbapenems-resistant Acinetobacter bauman (CRAB),655 strains of carbapenems-resistant Pseudomonas aeruginosa (CRPA) and 53 strains of carbapenem-resistant Escherichia coli (CRE) were detected in our hospital. The detection rates increased from 23.88%,8.92%,0.09% in 2011 to 80.34%,35.74%,0.97% in 2016. The types of carbapenem antibiotics in our hospital were mainly imipenem and meropenem. The consumption of them increased from 4222,145 g in 2011 to 7218,4387 g in 2016. The both target cure rates were all lower than 60%,and the proportion of the patients with treatment course >14 d was more than 65%. The detection rates of CRAB,CR-PA and CRE were positively correlated with the consumption of carbapenem antibiotics (r>0.9,P<0.05). CONCLUSIONS:The detection rate of carbapenems-resistant Gram-negative bacillus and drug consumption increase year by year in our hospital,and they have certain correlation. The target cure rate of carbapenem antibiotics in our hospital is in low level,and there is a long treatment course. They are should be standardized in the clinic. The selection of carbapenem antibiotics should be strictly followed clinical in-dications so as to reduce the generation of drug-resistant strains.

Objective To analyze the protein expression and subcellular distribution of mechanogrowth factor (MGF) in ostcoblasts under stretch stimulation. Methods Cyclic stretching was applied to osteohlasts by a mechanical stretching device. The whole-cell proteins were extracted from controlled and stretched osteoblasts for detecting the protcin expression level of MGF by Western blot and observing the intracellular distribution of MGF by fluorescent immunocytological method. Results Western blot showed significant increase of expression of MGF in osteoblasts under stimulation of cyclic stretching. The level of protein was increased by four folds after 12-hour stretching of osteohlasts, and then declined sharply. Immunofluorescence analysis showed that MGF was mainly distributed in the nuclei of osteoblasts. ConcinsionsUnder the cyclic stimulation, the expression of MGF reaches a short period of peak in osteoblasts, which may be related to the injury of osteoblasts caused by stretching. MGF is mainly distributed in the nuclei of osteoblasts, indicating that MGF may contain nuclear localization signal and modulate the expression of relative genes.

Objective: To explore aspirin resistance (AR) phenomenon in patients with coronary artery disease (CAD) for secondary prevention and to study the relationships between AR and COX1, COX2, TBXA2R gene polymorphisms. Methods: A total of 2881 CAD patients taken aspirin (100 mg/day) in 7 consecutive days were enrolled. Among them, 2 groups were established as AR group, n=166 and Control group, n=200 aspirin sensitive patients. Platelet aggregation function was induced by arachidonic acid (AA), COX1, COX2 and TBXA2R gene polymorphisms were examined by polymerase chain reaction-restricted fragment length polymorphisms (PCR-RFLP) method. Results: The occurrence rate of AR was 5.76% (166/2881). There were 8 tagSNPs locus in 3 genes as in COX1:(rs3842788), (rs4273915), (rs7866582); in: COX2 (rs3218625); in TBXA2R: (rs2238630), (rs2238631), (rs2238633), (rs3786989). The frequencies of wild type, heterozygous genotype and homozygous genotype were similar between 2 groups. Conclusion: The incidence rate of AR is not high in CHD patients with regular aspirin medication; single nucleotide gene polymorphisms of COX1, COX2 and TBXA2R have no obvious correlation to AR.

Mechano-growth factor (MGF) is one of IGF-1 isoforms. MGF is mechanosensitive and has important functions in muscle hypertrophy, regeneration and nerve injury recovery. In this study, MGF cDNA (330 bp) was cloned from stretched osteoblasts by RT-PCR. In order to avoid prolin residue inhibiting enterokinase cleavage, 9bp of MGF cDNA 5' end sequence was truncated by primer, then the obtained truncated MGF (des(1-3)MGF) cDNA (321 bp) was subcloned in pET32a(+) vector to construct a prokaryotic recombination expression plasmid. Trx/des(1-3)MGF fusion protein, existing in forms of solution, was expressed in transformed Escherichia coli strain BL21(DE3) by IPTG induction at 30 degres C. The supernatant of cell lysates was subjected to ion exchange chromatography and Ni2+ metal affinity chromatography, and the fusion protein was obtained with the purity over 95%. After the fusion protein was cleaved by enterokinase, Trx and des(1-3)MGF was isolated by reverse-phase HPLC. Through these procedures, des(1-3) MGF was obtained with the purity of 98%. The protein molecular mass was conformity to the theoretical value by SDS-PAGE and mass spectrometry analysis. The purified des(1-3)MGF was incubated with MC3T3-E1 for cell proliferation and migration assays. The results show that des(1-3)MGF exhibited more facilitative effects on proliferation and migration of MC3T3-E1 than that of des(1-3)IGF-1.
Cloning, Molecular ; DNA, Complementary ; genetics ; Escherichia coli ; genetics ; metabolism ; Humans ; Insulin-Like Growth Factor I ; Osteoblasts ; metabolism ; Protein Isoforms ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacology ; STAT5 Transcription Factor ; biosynthesis ; genetics ; Tumor Suppressor Proteins ; biosynthesis ; genetics

The stress environment regulates the factors of growth, resorption and remolding in bone tissue. Mechanical stimulation at cell physical level affects the physiological activity of osteoblasts, including proliferation, ALP activity and osteocalcin production. Mechanotransduction is a procedure which transduces the biophysical force into biochemical responses. It is also the basis of many physiological functions. The early response genes (c-fos, c-jun), the second message systems (Ca2+, NO, cAMP) and the mechano-sensitive cation channel are involved in the mechanotransduction course when osteoblasts respond to the mechanical stimulation.
Biomechanical Phenomena ; Calcium ; physiology ; Humans ; Mechanotransduction, Cellular ; Osteoblasts ; physiology ; Osteocalcin ; biosynthesis ; Proto-Oncogene Proteins c-fos ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-jun ; biosynthesis ; genetics ; Signal Transduction ; Stress, Mechanical

This experiment was designed to study the apoptosis and related mechanism of adherent liver tumor cells (SMMC-7721) and adherent normal liver cells (HL-7702) when they were exposed to the steep pulse generated by the steep pulse apparatus for tumor treatment. The results showed that the steep pulse of 200 V could induce tumor cells apoptosis. The tumor cells presented with their apoptosis when they were exposed to the steep pulse from 200 V to 250 V. Laser scanning confocal microscopy was used to make a real time study of calcium burst when the adherent tumor cells were exposed to the steep pulse. The results showed:On the condition of no extracellular Ca2+, the concentration of Ca2+ in tumor cells exposed to the steep pulse of 150 V did not change; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 200 V decreased; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 250 V decreased more evidently. On the condition of existing extracellular Ca2+, the concentration of Ca2+ in tumor cells exposed to the steep pulse of 150 V did not change; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 200 V decreased little; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 250 V reduced little, too. Maybe the change of calcium burst in the tumor cells is the mechanism of apoptosis when cells are exposed to the steep pulse.
Apoptosis ; radiation effects ; Calcium ; metabolism ; Electricity ; Electromagnetic Fields ; Hepatocytes ; cytology ; pathology ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Microscopy, Confocal ; Tumor Cells, Cultured

In the study of the relationship between cells overloading and the formation, regeneration and growth of bone, the text discussed osteoblasts express IGF-1 variation under overloading environment. The research of overloading on cellular level may elucidate the mechanical effect on the formation, regeneration and growth of bone and the mechanism of cell response in bone.
Animals ; Humans ; Insulin-Like Growth Factor I ; biosynthesis ; genetics ; Osteoblasts ; cytology ; metabolism ; Osteogenesis ; RNA, Messenger ; biosynthesis ; genetics ; Stress, Mechanical ; Weight-Bearing ; physiology

Objective To compare the image quality of chest low dose CT (LDCT) using automatic exposure control (AEC) and constant current control (CCC) and explore a more reasonable scanning protocol. Methods Two hundred and eighty participants were examined with 64 CT scanner at 7 centers in China. All were divided into 4 groups. Two groups underwent LDCT using AEC with standard deviation set at 25 (A1) and 30 (A2) respectively and the tube current ranged from 10 mA to 80 mA. The other two groups underwent LDCT using CCC with tube current set at 40 mA (C1) and 50 mA (C2) respectively. The axial and MPR images were evaluated by two radiologists who were blinded to the scanning protocols.The radiation dose, noise and the image quality of the 4 groups were compared and analyzed statistically.Differences of radiation dose and noise among groups were determined with variance analysis and t test,image quality with Mann-Whitney test and the consistency of diagnosis with Kappa test. Results There was a significant lower DLP in AEC group than in CCC group [(82.62±40.31)vs ( 110.81±18.21) mGy·cm (F =56. 88 ,P ＜ 0. 01 )], whereas no significant difference was observed between group A2 and group A1 0. 05]. The noisy of AEC group was higher than that of CCC group both on lung window(41.50±9.58 vs 40.86±7.03) and mediastinum window (41.19±7.83 vs 40.92±9.89), but there was no significant difference( Flung =0.835, P=0.476, Fmediastinum =1.910, P=0.128).The quality score of axial image in AEC group was higher than that in CCC group (superior margin of the brachiocephalic vein level: 4.49±0.56 vs4.38±0.64,superior margin of the aortic arch: 4.86±0.23 vs 4.81±0.32,the right superior lobar bronchus Level:4.87±0.27 vs 4. 84 ± 0. 22, the right middle lobar bronchus Level: 4.90±0.25 vs 4.88±0.21) except on the right inferior pulmonary vein level(4. 92 ±0. 25 vs 4. 93 ±0. 17) and superior margin of the left diaphragmatic dome level (4. 91±0.27 vs 4.93±0.22) on lung window, but no significant differences (F=0.076-1.748, P＞0.05) were observed. A significant higher score in AEC group was observed on mediastinum window compared with CCC group on superior margin of brachiocephalic vein level (2.57±0.77 vs 2. 46 ± 0. 59, F = 8. 459, P ＜ 0. 05 ), however, the score of AEC group was lower than that of CCC group on other levels without significant differences (superior margin of the aortic arch:3.36 ±0. 63 vs 3.45 ±0. 60,the right superior lobar bronchus level: 3.94 ±0. 56 vs 3. 95 ±0. 51 ,the right middle lobar bronchus Level: 3.80 ±0. 58 vs 3. 87 ±0. 50,the right inferior pulmonary vein level: 3.72 ±0. 56 vs 3.78 ±0. 53, superior margin of the left diaphragmatic dome level: 3.58 ± 0.63 vs 3.68±0.56,F=0.083-3.380,P ＞ 0.05 ). The MPR image quality of AEC group was better than that of CCC group both on lung window and mediastinum window (Zlung =-2.258, Zmedlastinum=-1.330, P＞0.05). For all participants including the underweighted group, the normal group and the overweighted group, the image quality of A1 group was better than that of A2 group without significant differences (the underweighted group: Zlung=0.000, P=1.000, Zmedastinum= 0.000, P=1.000;the normal group: Zlung =-0.062, P=0.950, Zmediastinum =-0.746, P = 0.456; the overweighted group: Zlung = - 1.177, P = 0.239,Zmediastinum =-1.715, P=0.144) both on lung and mediastinum windows, and for the higher BMI participants, a better image quality was obtained in A1 group than in A2 group on the mediastinum window (Z = -1. 715, P = 0. 144). Conclusions The total radiation exposure dose of AEC group is significantly lower than that of CCC group, but no statistical significant differences are observed between both groups in image quality and noise level. The AEC technique is highly recommended in thoracic LDCT scan for screening program, and the SD25 ( SD value = 25) scan protocol is suggested for higher BMI population while the SD30 (SD value = 30) scan protocol for lower BMI population.