• Korean Journal of Microbiology
• /
• v.28 no.3
• /
• pp.199-203
• /
• 1990

To study distribution of bacterial flora and their biochemical characteristics in the Antarctic soilecosystem, these experiments were performed during the austral summer(Feb., 1989) on the King George Island, Antarctica. The numbers of heterotrophic bacterial colonies and extracellular enzyme actibities were estimated from the Antarctic terrestrial soils which were sampled from 17 different locations near Sejong station (Korea) and Teniente Jubany station (Argentina) on the King George Island. The numbers of heterotrophic bacterial colonies were extremely variable with sampling sites and incubation temperatures. Arithmetric average numbers were $2.5\times 10^{4}$, $2.7\times 10^{7}$ , $6.9\times 10^{5}$ CFU/$cm^{3}$ soil at the incubation temperature of $37^{\circ}C$, $25^{\circ}C$ and $4^{\circ}C$, respectively. The activities of extracellular $\alpha$-glucosidase, $\beta$-glucosidase and N-acetyl-$\beta$-glucosaminidase were shown as similar mean percentage in the colonies obtained at different temperatures. Mean value of protease activities, however, was remarkably higher (92%) in the colonies grown at $4^{\circ}C$,.

• Radiation Oncology Journal
• /
• v.16 no.2
• /
• pp.99-106
• /
• 1998

Purpose : We conducted clonogenic assay using human cancer cell lines (MKN-45, PC-14, Y-79, HeLa) to investigate a correlation between the parameters of radiosensitivity. Materials and Methods : Human cancer cell lines were irradiated with single doses of 1, 2, 3, 5, 7 and 10Gy for the study of radiosensitivity and subrethal damage repair capacity was assessed with two fractions of 5Gy separated with a time interval of 0, 1, 2, 3, 4, 6 and 24 hours. Surviving fraction was assessed with clonogenic assay using $Sperman-H\"{a}rbor$ method and mathematical analysis of survival curves was done with linear-quadratic (LQ) , multitarget-single hit(MS) model and mean inactivation dose$(\v{D})$. Results : Surviving fractions at 2Gy(SF2) were variable among the cell lines, ranged from 0.174 to 0.85 The SF2 of Y-79 was lowest and that of PC-14 was highest(p<0.05, t-test). LQ model analysis showed that the values of $\alpha$ for Y-79, MKN-45, HeLa and PC-14 were 0.603, 0.356, 0.275 and 0.102 respectively, and those of $\beta$ were 0.005, 0.016, 0.025 and 0.027 respectively. Fitting to MS model showed that the values of Do for Y-79. MKN-45, HeLa and PC-14 were 1.59. 1.84. 1.88 and 2.52 respectively, and those of n were 0.97, 1.46, 1.52 and 1 69 respectively. The $\v{D}s$ calculated by Gauss-Laguerre method were 1.62, 2.37, 2,01 and 3.95 respectively So the SF2 was significantly correlated with $\alpha$, Do and $\v{D}$. Their Pearson correlation coefficiencics were -0.953 and 0,993. 0.999 respectively(p<0.05). Sublethal damage repair was saturated around 4 hours and recovery ratios (RR) at plateau phase ranged from 2 to 3.79. But RR was not correlated with SF2, ${\alpha}$, ${\beta}$, Do, $\v{D}$. Conclusion : The intrinsic radiosensitivity was very different among the tested human cell lines. Y-79 was the most sensitive and PC-l4 was the least sensitive. SF2 was well correlated with ${\alpha}$, Do, and $\v{D}$. RR was high for MKN-45 and HeLa but had nothing to do with radiosensitivity parameters. These basic parameters can be used as baseline data for various in vitro radiobiological experiments.

• Childhood Kidney Diseases
• /
• v.9 no.2
• /
• pp.175-182
• /
• 2005

Purpose : Interleukin 1 receptor antagonist(IL-1ra) is an endogenous antiinflammatory agent that binds to IL-1 receptor and thus competitively inhibits the binding of IL-1$\alpha$ and IL-1$\beta$. Allele 2 in association with various autoimmune diseases has been reported. In order to evaluate the influence of IL-1ra gene VNTR polymorphism on the susceptibility to HSP and its possible association with disease severity, manifested by severe renal involvement and renal sequelae, we studied the incidence of carriage rate and allele frequency of the 2 repeats of IL-1ra allele 2($IL1RN^{*}2$) of the IL-1ra gene in children with HSP with and without renal involvement. Methods : The IL-1ra gene polymorphisms were determined in children with HSP with(n=40) or without nephritis(n=34) who had been diagnosed at Busan Paik Hospital and the control groups(n=163). Gene polymorphism was identified by PCR amplification of the genomic DNA. Results : The allelic frequency and carriage rate of $IL1RN^{*}1$ were found most frequently in patients with HSP and in controls. The allelic frequency of $IL1RN^{*}2$ was higher in patients with HSP compared to that of controls($4.7\%\;vs.\;2.5\%$, P=0.794). The carriage rate of $IL1RN^{*}2$ was higher In patients with HSP compared to that of controls($8.1\%\;vs.\;6.8\%$, P=0.916). The allelic frequency of $IL1RN^{*}2$ was higher in patients with HSP nephritis compared to that of HSP($5.3\%\;vs.\;2.9\%$, P=0.356). The carriage rate of $IL1RN^{*}2$ was higher in Patients with HSP nephritis compared to that of HSP($10.0\%\;vs.\;5.9\%$, P=0.523). Among 13 patients with heavy proteinuria(>1.0 g), 11 had $IL1RN^{*}1$, 1 had $IL1RN^{*}2$ and the others had $IL1RN^{*}4$. At the time of last follow up 4 patients had sustained proteinuria and their genotype was $IL1RN^{*}1$. Conclusion : The allelic frequency and carriage rate of $IL1RN^{*}1$ were found most frequently in patients with HSP and in controls. Our study suggests that the carriage rate and allele frequency of the 2-repeats of IL-1lra allele 2($IL1RN^{*}2$) of the IL-1ra gene may not be associated with susceptibility and severity of renal involvement in children with HSP (J Korean Soc Pediatr Nephrol 2005;9:175-182)