Objective To design a novel strain loading device for studying the mechanical biology of adherent cells. Methods Based on the technology of substrate deformation loading, the device adopted controllable stepper to cause deformation of the silastic chamber, so as to realize cell loading with multiple units and large strain. The device was developed to test its loading functions. The three-dimensional (3D) models of the silastic chamber were established to simulate the loaded chamber by the finite element technology, and uniformity of the strain field was analyzed. The device applied 5% strain to bone marrow stromal cells (BMSCs) with 0.5 Hz stretch frequency at 2 hours per day for 5 days, and an inverted phase contrast microscope was used to observe the morphology of BMSCs. Results The developed strain loading device for adherent cells in vitro could provide mechanical unidirectional strain up to 50% with three groups of cell loading substrates; within the 10% stain range, the area of uniform strain filed on the silastic chamber remained above 50%, which ensured that the cells were loaded evenly; the morphology of BMSCs was obviously altered, and the direction of arrangement tended to be perpendicular to the loading direction of principal strain. Conclusions The device shows the advantages of reliable operation, wide strain range, adjustable frequency and convenient operation. It can be used to load multiple cell culture substrates at the same time, which provides convenient conditions for the study of cell mechanobiology.

Objective To investigate the effect and molecular mechanism of the combination of mechanical strain stimulation and icariin (ICA) on inhibiting the differentiation of osteoclasts induced by fatigue load stimulation. Methods The mouse mononuclear macrophage cell line RAW264.7 was cultured in vitro, and the blank control group was α-MEM complete medium. In the fatigue load group, RAW264.7 cells were treated with 5000 μεmechanical stretch strain, and then cultured in an osteoclast culture medium that was an α-MEM complete medium containing 40 ng/ml macrophage colony-stimulating factor and 40 ng/ml osteoclast differentiation factor. In the mechanical stimulation + ICA group, RAW264.7 cells were treated as the same procedure in the fatigue load group, and then cultured in an α-MEM complete medium containing 1 ×10 -5 mol/L ICA simultaneously with a 1000 μεtensile strain on the substrate. The activity of tartrate-resistant acid phosphatase (TRAP) was detected using a TRAP assay kit. The mRNA expression of the osteoclast marker genes, i.e. TRAP, cathepsin K(CTSK) and matrix metalloproteinase 9 (MMP-9) was detected by real-time RT-PCR. The nuclear translocation of nuclear factor kappa B (NF-κB) was analyzed by Western Blot. Results Compared with the fatigue load group, the combination of mechanical stimulation (1000 με substrate stretching) and ICA (1×10-5 mol/L) could significantly inhibit the activity of TRAP in osteoclasts (P<0.01) and reduce osteoclastosis. Moreover, that combination not only could down-regulate the mRNA expression of TRAP, CTSK and MMP-9 and the differences were statistically significant (all P<0.01), but also could inhibit the formation of osteoclasts by inhibiting the phosphorylation of P65, P50 and IκB-α in NF-κB signaling pathway. Conclusions The coupling of mechanical stimulation and ICA can effectively inhibit the osteoclast differentiation and the bone resorption induced by fatigue load, and the mechanism may involve regulating NF-κB signaling pathway.

Objective To investigate the effect of urinary training on urination control in infants using nappies after birth.Methods Stratified sampling method was used to investigate the daytime urination control and the using of diapers by children in kindergartens of 6 prefecture-level cities in Henan Province,China.The survey was conducted among parents of healthy children.Results In a total of 12 250 questionnaires,11 697 had response,and 10 562 valid questionnaires were collected,and the effective recovery rate was 86.22％.After the birth of infants,the age of toilet training was divided into 6 groups (0-＜ 3 months old group,3-＜ 6 months old group,6-＜ 12 months old group,12-＜ 18 months old group,18-＜ 24 months old group and no toilet training group).Results showed that toilet training within 12 months leads to higher urinary control rate compared with toilet training after 12 months and no toilet training till the age of 2 years old,70.56％ (4 831/6 847 cases) in contrast with 59.02％ (1 545/2 618 cases) and 42.48％ (466/1 097 cases),and the differences were statistically significant (x2 =114.76,335.48,all P ＜ 0.000 1).Within 12 months,there was no statistical difference in the urinary control rate between subgroups at 2 years of age(all P ＞0.05).After 12 months,the urination control rate decreased with the start time delayed till 2 years of age,and the urinary control rate at the age of 2 years old n different groups was 59.97％ (1 314/2 191 cases) and 54.10％ (231/427 cases) respectively.The results of other ages(0.5,1.0,1.5 years old) were similar to those of 2 years old.There was no difference between the groups of different genders (all P ＞ 0.05).Conclusions The use of diapers in infants before the age of 1 year to start urinary training is conducive to the development of urinary control in infants.

BACKGROUND: Minimally invasive percutaneous pedicle screw fixation possesses the advantages of less blood loss, less muscle and soft tissue dissection, and rapid recovery; however, accuracy of the screw positioning is the key to be successful.OBJECTIVE: To explore the application value of self-designed spinal localizer in the screw positioning for minimally invasive percutaneous pedicle screw fixation.METHODS: 428 patients with thoracolumber disorders were subjected to minimally invasive percutaneous pedicle screw fixation at the First Affiliated Hospital of University of South China, from March 2009 to March 2015, and randomly underwent the preoperative screw positioning by self-designed spinal localizer or one of traditional localizing methods (iliac crest, ribs, symptomatic vertebral appearance, skin marker, Kirscher wire, puncture needle localizations). The location accuracy, positioning time and radiographic times were compared among methods.RESULTS AND CONCLUSION: (1) Compared with the traditional localization methods, the self-designed spinal localizer was superior in accurate rate (P < 0.05), cost less positioning time (P < 0.05) and received less radiation (P < 0.05). (2) To conclude, the self-designed localizer exhibits a certain application value, which is an ideal method in preoperative localization for minimally invasive percutaneous pedicle screw fixation.

Objective To investigate the current situation of healthcare-associated infection(HAI)organization management systems in primary medical institutions.Methods 95 primary medical institutions in 5 provinces (au-tonomous regions,municipalities)in China were investigated.Results Of 95 primary medical institutions,82 (86.32%)established HAI management groups,65 (68.42%)set up antimicrobial management departments,87 (91.58%)assigned professionals for antimicrobial management.Before 2010,only 26 antimicrobial management departments were set up,which increased to 65(68.42%)in 2015.Hospitals established rules and regulations on medical waste management (n=93,97.89%),disinfection and sterilization(n = 87,91.58%),disposable sterile medical device (n=87,91.58%),HAI prevention and control measures (n=79,83.16%),occupational health and safety protection for health care workers(n=76,80.00%),outbreak reporting system (n=73,76.84%),hand hygiene (n=69,72.63%),and monitoring on HAI (n=56,58.95%).Conclusion Current situation of HAI or-ganization management systems in primary medical institutions needs to be improved,health administrative depart-ments should strengthen supervision to improve the level of HAI prevention and control.

Objective To understand the current situation of medical waste management in primary medical insti-tutions in China.Methods The management of medical waste in 95 primary medical institutions in 5 provinces of China in 2016 were investigated.Results Of 95 primary medical institutions,90(94.74%)dispose medical waste by centralized processing,92(96.84%)separately collect medical waste,89(93.68%)have specific locations for temporary waste storage and handover registration,46(48.42%)have wastewater treatment facilities,and are re-sponsible by full-time or part-time personnel.Before 2000,only 4 (4.21%)primary medical institutions carried out medical waste classification management and centralized disposal,which increased to 92(96.84%)and 90(94.74%) respectively in 2014;before 2000,only 5(5.26%)primary medical institutions conducted temporarily medical waste storage and treatment,which increased to 89(93.68%)in 2014.Conclusion Medical waste management in primary medical institutions has been improved significantly,but there still remain some problems,training relevant to waste management knowledge needs to be strengthened among health care workers,medical waste management procedures should be standardized,sound medical waste management and supervision system should be improved.

Benign Paroxysmal Positional Vertigo ; complications ; Humans ; Otologic Surgical Procedures ; adverse effects

PURPOSETo investigate the influence of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro.

METHODSPrimary osteoblasts, bone marrow-derived mesenchymal stem cells (BMSCs, cultured in osteoinductive medium) and RAW264.7 cells cultured in osteoclast inductive medium were all subjected to a 1000 μstrain (μs) at 1 Hz cyclic mechanical stretch for 30 min (twice a day).

RESULTSAfter mechanical stimulation, the alkaline phosphatase (ALP) activity, osteocalcin protein level of the osteoblasts and BMSCs were all enhanced, and the mRNA levels of ALP and collagen type I increased. Additionally, extracellular-deposited calcium of both osteoblasts and BMSCs increased. At the same time, the activity of secreted tartrate-resistant acid phosphatase, the number of tartrate-resistant acid phosphatase-positive multinucleated cells, matrix metalloproteinase-9 protein levels of RAW264.7 cells and the extracellular calcium solvency all decreased.

CONCLUSIONThe results demonstrated that 1000 μs cyclic mechanical loading enhanced osteoblasts activity, promoted osteoblastic differentiation of BMSCs and restrained osteoclastogenesis of RAW264.7 cells in vitro.

Animals ; Biomechanical Phenomena ; Cell Differentiation ; Cells, Cultured ; Mice ; Mice, Inbred C57BL ; Osteoblasts ; cytology ; Osteoclasts ; physiology ; Osteogenesis ; physiology ; Tartrate-Resistant Acid Phosphatase ; metabolism

Osteoporosis (OP) is one of the bone metabolic diseases which seriously harms the health and lives of people. The main cause of OP is that the balance between bone formation and bone absorption, i.e. the balance of the bone remodeling process,is no longer exist. When the bone absorption dominates the process, it will lead to osteopenia, destruction of bone microstructure and increased rate of fracture. Previous studies have shown that casein kinase 2-interacting protein-1 (CKIP-1) plays an important role in the process of bone tissue proliferation and differentiation. It mainly interacts with Smad ubiquitination regulatory factor 1 (Smurf 1) to affect bone metabolism. This review analyzes and summarizes the impact of CKIP-1 on bone tissue osteogenic differentiation direction and its mechanism, which may provide new idea and research orientation for future clinical treatment of osteoporosis.