Application of the OmniLogTM microbial identification system in the detection of the host spectrum for wild-type plague phage in Qinghai Plateau / 中国人兽共患病学报

The growth of three plague phages from Qinghai Plateau in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,PTB5,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were detected through a micromethod based on the OmniLogTM microbial identification system and by the drop method,to provide a scientific basis for future ecological studies and classification based on the host range.For plague vaccine strains EV76 and 614F,successful phage infection and subsequent phage growth were observed in the host bacte-rium.Diminished bacterial growth and respiration and a concomitant decrease in color were observed with the OmniLogTM mi-crobial identification system at 33 ℃ for 48 h.Yersinia pseudotuberculosis PTB5 was sensitive to Yersinia pestis phage 476,but Yersinia pseudotuberculosis PST5 was insensitive to phage 087 and 072204.Three strains of non-Yersinia pestis(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were insensitive to Yersinia pestis pha-ges 087,072204,and 476 showed similar growth curves.The growth of phages 476 and 087,as determined with the drop method,in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersin-ia enterocolitica 52302-2)showed the same results at 37 ℃,on the basis of comparisons with the OmniLogTM microbial i-dentification system;in contrast,phages 072204 did not show plaques on solid medium at 37 ℃ with plague vaccine strains EV76 and 614F.Determination based on the OmniLogTM detection system can be used as an alternative to the traditional determination of the host range,thus providing favorable application val-ue for determining the interaction between the phage and host bacteria.

Wettability of titanium implants depending upon surface properties / 대한치과보철학회지

STATEMENT OF PROBLEM: When an implant is fixed, a fixture comes into contact with a tissue fluid. Adhesion of a tissue fluid to a surface of implant is various case by case. PURPOSE: The ultimate goal of this work is to analyze a correlation between a surface roughness and wettability of implant specimens. A measurement for wettability is performed considering 4 types of specimen implant with surface treatments different from each other to investigate the change of wettability with the elapse of time. MATERIAL AND METHODS: Firstly, 20 specimens of titanium were prepared. The specimen were made of a commercial Titanium Grade IV with the diameter of 10 mm and the thickness of 1 mm. According to the method of surface treatment, the specimens were classified into 4 groups of 5 specimens per group. Group A: Machined Surface Group B: Anodized surface Group C: RBM (HA blasting) surface Group D: CMP (calcium methaphosphate) coating surface. Surface roughness of specimen was measured using SV-3000S4 (Mituyoto, Japan). The measurement was based on the standard of JIS1994. Sessile drop method was used to measure the wettability, which measures contact angle between implant disc and saline with the time interval of 5, 10, and 15 seconds. SPSS 11.0 was used to analyze the collected data. In order to analyze the difference of wettability and surface roughness according to implant surface treatment method. The statistical significance was tested with the confidence level of 95 percent. Pearson's correlation coefficient was used to evaluate the correlation of surface roughness and wettability. RESULTS: The difference of surface roughness was statistically significant in the order of Group C (1.69 +/- 0.26), Group D (1.58 +/- 0.16), Group B (0.78 +/- 0.14) Group A (0.18 +/- 0.05). The wettability has also a statistically significant difference, which was in the order of group B (17.70 +/- 2.66), Group C (27.86 +/- 4.52), Group D (66.28 +/- 3.70) Group A (70.52 +/- 8.00). There was no difference in wettability with the passage of time. CONCLUSIONS: 1. The surface roughness was high in the order of RBM, CMP, Anodized, Machined group (P < .05). 2. The wettability was high in the order of Anodized, RBM, CMP, Machined group (P < .05). 3. There was no statistical significance in the correlation of surface roughness and wettability.

Effects of various surface treatments for titanium on surface micro roughness, static wettability, fibronectin adsorption / 대한치과보철학회지

Purpose: This study aims to get the fundamental data which is necessary to the development direction of implant surface treatment hereafter, based on the understanding the surface structure and properties of titanium which is suitable for the absorption of initial tissue fluid by researching effects of additional surface treatments for sandblasted with large grit and acid-etched(SLA) titanium on surface micro-roughness, static wettability, fibronectin adsorption. Materials and Method: In the Control groups, the commercial pure titanium disks which is 10mm in diameter and 2mm in thickness were treated with HCI after sandblasting with 50micrometer Al2O3. The experiment groups were made an experiment each by being treated with 1) 22.5% nitric acid according to SLA+ASTM F86 protocol, 2) SLA+30% peroxide, 3) SLA+NaOH, 4) SLA+Oxalic acid, and 5) SLA+600degree C heating. In each group, the value of Ra and RMS which are the gauges of surface roughness was measured, surface wettability was measured by analyzing with Sessile drop method, and fibronectin adsorption was measured with immunological assay. The significance of each group was verified by (SPSS, ver.10.0 SPSS Inc.) Kruskal-Wallis Test.(alpha=0.05) And the correlation significance between Surface micro-roughness and surface wettability, surface roughness and fibronectin adsorption, and surface wettability and fibronectin adsorption was tested by Spearman's correlation analysis. Result: All measure groups showed the significant differences in surface micro-roughness, surface wettability, and fibronectin adsorption.(p0.05) Conclusion: Surface micro-roughness and surface wettability rarely affected the absorption of initial tissue fluid on the surface of titanium.

Organotypic Culture of Organ of Corti with Floating Drop Method from Newborn Rat / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Organotypic culture of organ of Corti maintains the basic organization of the spiral lamina and can conserve several factors responsible for the neuronal growth of the nervous components. The explant culture technique has been widely used in organ culture system, however, the floating drop method using collagen gel was also developed as a simple and reliable method. In order to study the effect of growth factors on the regenerative and protective ability of cochlear hair cells, we first had to establish an in vitro model of the inner ear. MATERIALS AND METHODS: Organ of Corti was obtained from newborn rats and cultured with the floating drop method using collagen gel. Immunohistochemical staining was used to visualize the stereocilia and scanning electron microscopic study was also carried out. RESULTS: Explants were maintained up to 10 days without contamination. Morphologically, immunofluorescent staining with phalloidin showed well preserved outer and inner hair cells with stereocilia on the second day of culture. On the tenth day of culture, the staining result showed inner and outer hair cells, although the stereocilia were poorly stained. In scanning electron microscopic examination, an explant on the tenth day of culture showed preserved outer and inner hair cells and stereocilia, although damaged hair cells and stereocilia were also observed. CONCLUSION: The floating drop method was an appropriate method for maintaining the organ of Corti in vitro with the advantage being the easiness in its manual manipulation.