In order to investigate in greater detail the two methods based on Hertz model for analyzing force-distance curve obtained by atomic force microscopy, we acquired the force-distance curves of Hela and MCF-7 cells by atomic force microscopy (AFM) indentation in this study. After the determination of contact point, Young's modulus in different indentation depth were calculated with two analysis methods of "two point" and "slope fitting". The results showed that the Young's modulus of Hela cell was higher than that of MCF-7 cell,which is in accordance with the F-actin distribution of the two types of cell. We found that the Young's modulus of the cells was decreased with increasing indentation depth and the curve trends by "slope fitting". This indicated that the "slope fitting" method could reduce the error caused by the miscalculation of contact point. The purpose of this study was to provide a guidance for researcher to choose an appropriate method for analyzing AFM indentation force-distance curve.
Actins ; Elastic Modulus ; HeLa Cells ; cytology ; Humans ; MCF-7 Cells ; cytology ; Microscopy, Atomic Force

Objective To explore the radiation dose from body γ-knife treatment to the nontargeted region's sensitive organs before and after shielding.Methods 20 patients suffering tumors less than 5 cm were selected.Calibrated thermoluminescence dosimeters (TLD) were placed above the sensitive organs,such as lens,thyroid gland and sexual gland,to measure the radiation dose received before shielding.Different plans were prepared for the patients with lung and renicapsule tumors using calibrators of different size.Radiation dose was measured by the aid of water phantom.For selected lungtumor treatment plan,the radiation doses were measured at the same location on the water phantom shielded with and without 1,2 and 4 cm lead,respectively.Results The maximum doses were 1 023.3 mGy for lens,1 235.7 mGy for thyroid gland and 1 176.8 mGy for sexual glands after treatment,respectively,being higher on the left site than the right.The radiation doses to the sensitive organs were higher for the water phatom with more tartgted points,decreasing by 55％-91％ after being covered with 1,2 and 4 cm lead shieldings.There were significant differences in doses received before and after lead shielding (t =14.4,12.9,13.3,P ＜ 0.05).Conclusions In the course of body γ-knife treatment,the additional factors would increase the dose to the sensitive organs.Therefore,it is necessary to provide lead shielding protection to the teenagers and adults with fertility when they undergo body γ-knife treatment.Trial registration Chinese Clinical Trial Registry,ChiCTR-OOC-16008259.

Objective To explore the nursing measures in blue laser endoscopy. Methods Endoscopy was performed in 102 patients. The nursing was done including preoperative preparation, nurse's coordination for different mode of endoscpy, postoperative nursing and so on. Result The endoscopy for the 102 patients was successfully done,the time ranging between 10~25 min,averaged 13.85 min.No complications were found. Conclusion The nursing measures including careful preoperative preparation,intraoperative cooperation and postoperative nursing are key to the successful detection and diagnosis of diseases by blue laser endoscopy.

Growth plate,the developmental center of endochondral osteogenesis,can be divided morphologically and functionally into a resting zone,a proliferative zone,a prehypertrophic zone and a hypertrophic zone.Injuries to growth plate often lead to bone growth defects including limb length discrepancy and angulation deformity in children.Currently,their orthopedic corrective surgeries are invasive and limitedly effective and no effective biotherapy has been available.Previous studies on animal models of growth plate damage have investigated the related cellular and molecular events in the repair of damaged growth plates in the 4 distinct inflammatory,fibrogenic,osteogenic and remodeling phases.Related molecules involved in the regulation of the above processes,such as inflammatory cytokines tumor necrosis factor alpha,mitogenic platelet-derived growth factor and bone morphogenetic protein,are found to participate in the regulation of growth plate injury.Exploration of the mechanisms may provide new targets for biotherapy.In addition,development of cartilage tissue engineering,especially application of mesenchymal stem cells,also provides potential interventions for growth plate injury.

Objective To observe the feasibility of inducible costimulatory(ICOS)target in mice adjuvant-induced arthritis(AIA)models.Methods Twenty BALB/c mice were injected with equal dose of complete Freund's adjuvant(AIA group,n=10)or phosphate buffered saline(control group,n=10)into the right back paws.The second day after injection,ICOS-IRD680 mAb probes were injected in AIA group,while IgG-IRD680 mAb probes were injected in control group through tail vein,respectively.The fluorescent intensity ratio of the right and left paw based on near-infrared fluorescence imaging 24 and 48 h later were compared between groups.The total RNA of mice were extracted for transcriptome sequencing,and differentially expressed genes(DEG)were screened and analyzed.Primary T cells were extracted from the spleen of mice in control group,then magnetic negative T cells were sorted.Activated T cells were stimulated and induced using phoboxylate/ionomycin,the expression level of ICOS protein on the surface of activated T cells were detected,and the safety of probe was also evaluated.Results The expression of ICOS gene in AIA group was significantly up-regulated,and the proportion of T cells was higher than that in control group.ICOS tented to distribute in FoxP3+ regulatory T cells,CD8+T cells and CD4+T cells.The purity of CD3+T cells before and after magnetic negative T cells was 65.31％ and 90.14％,respectively.The proportion of CD4+T cells before and after activated was 7.14％ and 31.20％,respectively,and the mean fluorescent intensity of ICOS protein in activated CD4+T cells(586±25)was significantly higher than that in non-activated CD4+T cells(161±31)(t=25.390,P＜0.001).Twenty-four and 48 h after probe injection,the fluorescent intensity ratio of the right paw/left paw in AIA group was higher than that in control group(t=34.600,P＜0.001;t=23.380,P＜0.001).Compared with control group,no significant pathological change of heart,liver nor kidney tissues of mice in AIA group was detected,while no significant difference of glutamic-pyruvic transaminase,glutamic-oxaloacetic transaminase nor creatinine was found between groups(all P＞0.05).Conclusion ICOS target was safe and feasible for mice AIA models.

OBJECTIVE: To analyze the tendency of incidence in coal workers' pneumoconiosis( CWP) in different time of dust exposure and different types of work in a mining enterprise in Huaibei City. METHODS: A total of 12 152 dust exposed workers who worked from 1970 to 2014 in a mining enterprise in Huaibei City were chosen as study subjects by judgment sampling method. They were divided into 2 cohorts were formed according to initial year of dust exposure( 1970-,1980-),and 4 group according to the type of work( tunneling,mining,combining and helping). Life table method was adopted to calculate cumulative life-incidence of CWP in each cohort. RESULTS: Among 12 152 workers,there were 594 of them diagnosed as CWP patients with a 4. 89% of incidence. During the same 34-year-observation period,the cumulative CWP incidence of 1970-cohort was higher than that of the 1980 s( 8. 03% vs 5. 45%,P < 0. 01). The cumulative CWP incidence of tunneling,mining,combining and helping workers were 69. 33%,40. 53%,36. 66% and 19. 70% by 2014,respectively. The cumulative incidence of CWP in tunneling group started to rise from the 14-year-observation window,mining's from 16-year-observation window,combining and helping workers from 18-year-observation window. Among the workers in 1970-cohort at the 34-year-observation window,the CWP cumulative incidence in mining group was the highest( 33. 83%,P < 0. 004),and combining's was the lowest( 2. 28%,P < 0. 004). Among the workers in 1970-cohort at the 44-year-observation window,the CWP cumulative incidence in tunneling group was the highest( 66. 66%,P < 0. 004),and helping's was the lowest( 27. 24%,P < 0. 004). Among the workers in 1980-cohort at the 34-year-observation window,the CWP cumulative incidence in tunneling group was the highest( 29. 87%,P < 0. 004). CONCLUSION: The cumulative incidence of CWP patients was slowed down with prolonged dust exposure starting time. There were differences among different types of workers with different starting time of dust exposure.

[Abstract] Objective: To develop a new type of CD7 chimeric antigen receptor modified T cell (CD7-CAR-T) for the treatment of CD7 positive acute myeloid leukemia (AML), and to observe its killing effect on CD7 positive AML cells. Methods: The CD7-CAR lentiviral vector was constructed based on the CD7 Nanobody sequence and costimulatory domain sequence of CD28 and 4-1BB. The lentiviral particles were packaged and used to co-transfect human T cells with protein expression blocker (PEBL), so as to prepare CD7- CAR-T cells. Real time cellular analysis (RTCA) was used to monitor the cytotoxicity of CD7-CAR-T cells on CD7 overexpressed 293T cells. Flow cytometry assay was used to detect the effect of CD7-CAR-T cells on proliferation and cytokine secretion of AML cells with high, medium and low CD7 expressions (KG-1, HEL and Kasumi-1 cells, respectively). Results: CD7-CAR-T cell was successfully constructed and its surface expression of CD7 was successfully blocked. Compared with T cells, CD7-CAR-T cells could significantly inhibit the proliferation of CD7-293T cells and promote the release of TNF, Granzyme B and INF-γ; in addition, CD7-CAR-T cells also significantly promoted the apoptosis (t=147.1, P<0.01; t=23.57, P<0.01) and cytokine release (P<0.05 or P<0.01) in CD7 positive KG-1 and HEL cells, but had little effect on Kasumi-1 cells that only expressed minimal CD7 antigen (t=0.7058, P>0.05). Conclusion: CD7-CAR-T cells can specifically kill CD7-positive AML cells in vitro.