• Biomedical Science Letters
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• v.15 no.2
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• pp.161-166
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• 2009

Human erythropoietin(EPO) is a glycoprotein that enhances red blood cell production by stimulating proliferation and differentiation of erythroid progenitor cells in the bone marrow. Patients with chronic kidney disease(CKD) suffer from anemia caused by reduced production of EPO in the kidney. Recombinant human EPO protein has been used successfully for the treatment of anemia associated with CKD. Recently, attention has been paid to the development of side effect of EPO, pure red cell aplasia(PRCA), in some patients with CKD. PRCA is a rare disorder of erythropoiesis that leads to a severe anemia due to an almost complete cessation of red blood cell production. EPO-related PRCA is caused by the production of EPO-neutralizing antibodies(Abs) that eliminate the biological activity of EPO as well as endogenous EPO in patients undergoing therapy. Since 1988, almost 200 cases worldwide have been reported with Ab-positive PRCA after receiving EPO therapeutics. The underlying mechanisms of the breaking of immune tolerance to self-EPO have been investigated. Modification of formulation, organic compounds of container closures, and route of administration has been suggested for the possible mechanism of increased immunogenicity of EPO. A number of assays have been used to detect Abs specific to EPO. These assays are generally grouped into two major categories: binding Ab assays and neutralizing Ab assays(bioassays). There are several types of binding Ab assays, including radioimmunoprecipitation assay, enzyme-linked immunosorbent assay, and the BIAcore biosensor assay. In vitro cell-based bioassays have been utilized for the detection of neutralizing Abs. Finally, the recent experience with anti-EPO Abs may have considerable implications for the future development and approval of EPO preparations. Also, considering that millions of patients are being treated with EPO, clinicians need to be aware of signs and consequences of this rare but severe clinical case.

• Toxicological Research
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• v.6 no.1
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• pp.63-73
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• 1990

Human exposure to environmental carcinogens can be detected by a number of methods including immunoassay, $^{32}P-postlabeling$ assay, and fluorescence technique. These assays have been applied to measure biological markers of carcinogen-adducts formed with macromolecules such as DNA, RNA and protein. In an attempt to investigate causal relationships between carcinogen exposure and tumor formation, specific carcinogen-adducts have been quantitated from human tissues and body fluids of cancer patients, occupational workers heavily exposed to certain carcinogens, smokers and controls. Carcinogens studied for biological human monitoring include benzo(a)pyrene, aflatoxin B1, UV light, ethylene oxide, 8-methoxypsoralen, 4-aminobiphenyl, vinyl choride, N-nitrosamine, cisplatin and other chemotherapeutic agents. Relevance of human monitoring for cancer research, progress in this field, methods to detect carcinogen-adducts are reviewed here. It is hoped that these approaches will be used for the risk assessment of carcinogen exposure, cancer etiology study and cancer prevention in humans.

• Toxicological Research
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• v.6 no.1
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• pp.61-61
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• 1990

Human exposure to environmental carcinogens can be detected by a number of methods including immunoassay, $^{32}P$-postlabeling assay, and fluorescence technique. These assays have been applied to measure biological markers of carcinogen-adducts formed with macromolecules such as DNA, RNA and protein. In an attempt to investigate causal relation ships between carcinogen exposure and tumor formation, specific carcinogen-adducts have been quantitated from human tissues and body fluids of cancer patients, occupational workers heavily exposed to certain carcinogens, smokers and controls. Carcinogens studied for biological human monitoring include benzo(a)pyrene, aflatoxin B1, UV light, ethylene oxide, 8-methoxypsoralen, 4-aminobiphenyl, vinyl chloride, N-nitrosamine, cisplatin and other chemotherapeutic agents. Relevance of human monitoring for cancer research, progress in this field, methods to detect carcinogen-adducts are reviewed here. It is hoped that these approaches will be used for the risk assessment of carcinogen exposure, cancer etiology study and cancer prevention in humans.

• Journal of Applied Biological Chemistry
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• v.48 no.4
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• pp.167-169
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• 2005

Crude extract of bioconverted linoleic acid using Pseudomonas aeruginosa PR3 was evaluated for its antibacterial activity against food-borne pathogenic bacteria. Crude extract showed antibacterial activity against four Gram-positive bacteria, Staphylococcus aureus (ATCC 6538), S. aureus (KCTC 1916), Listeria monocytogenes (ATCC 19166), and Bacillus subtilis (ATCC 6633), and one Gramnegative bacterium, Pseudomonas aeruginosa (KCTC 2004), with minimum inhibitory concentrations ranging from 750 to $1,500\;{\mu}g{\cdot}ml^{-1}$. S. aureus and B. subtilis were selected for growth inhibition assays with bioconverted linoleic acid. Major antibacterial effects occurred at lag phase.

• Development and Reproduction
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• v.25 no.4
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• pp.313-319
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• 2021

Hub cells comprise a niche for germline stem cells and cyst stem cells in the Drosophila testis. Hub cells arise from common somatic gonadal precursors in embryos, but the mechanism of their specification is still poorly understood. Here we find that RNA binding proteins Lin28 and Imp mediate transcript stability of Bowl, a known hub specification factor; Bowl transcripts were reduced in the testis of Lin28 and Imp mutants, and also when RNA-mediated interference against Lin28 or Imp was expressed in hub cells. In tissue culture Luciferase assays involving the Bowl 3'UTR, stability of Luc reporter transcripts depended on the Bowl 3'UTR and required Lin28 and Imp. Our findings suggest that proper Bowl function during hub cell specification requires Lin28 and Imp in the testis hub cells.

• Development and Reproduction
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• v.9 no.2
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• pp.65-83
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• 2005

The three important phases in the development of ligand immunoassays are identified and summarized. The competitive radiolabelled hormone measurement had been developed in the first and early in the second generations(1950s to 1960s), such as radioimmunoassays(RIA) or immunoradiometric(saturation) assays(IRMA), and used in all most of the hormone and also analyte in biological samples. In the second generation, ultrasensitive non-isotopic immunoassays(NIA) were developed using monoclonal antibodies(McAb), labelling the McAb and high specific activity non-isotopic labels. After their usefulness, advantages and disadvantages has been evaluated and non-competitive methods are discussed. The chip/microarray based multianalyte ligand assays(microspot or genechip methods) are developed and known as alternative ones in the third generation. We summarize the developments of NIAs and its usefulness, and then introduce briefly the new ligand assays.

• Journal of Applied Biological Chemistry
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• v.53 no.3
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• pp.139-146
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• 2010

The inhibitory effects of 25 polyphenols against in vitro allergic reactions were compared using biochemical and cell assays. Three polyphenols including curcumin, gallic acid, and quercetin suppressed the release of $\beta$-hexosaminidase from ionophore A23187-stimulated RBL-2H3 cells more effectively (>50% inhibition at $100{\mu}M$ concentration). They were found to have potencies in suppressing the release of histamine not only from ionophore A23187-, but also from immunoglobulin E (IgE)-stimulated RBL-2H3 cells. Moreover, such suppressive effects of the three polyphenols were also observed in A23187 plus PMA-costimulated rat peritoneal mast cells. The extent of inhibition were quantified as the respective polyphenol concentration that inhibit 50% ($IC_{50}$) of $\beta$-hexosaminidase or histamine release, showing an inhibition tendency with decreasing order of curcumin>gallic acid>quercetin. Down-regulation of $Ca^{2+}$ influx was suggested as the cause of the inhibition of $\beta$-hexosaminidase and histamine releases in these cells. The immune process inhibition was confirmed by the observed reduction in the gene expressions and release of pro-inflammatory cytokine tumor necrosis factor (TNF)-$\alpha$, interleukin (IL)-$1\beta$, and IL-4, due probably to antioxidant activity of the polyphenols. These findings illustrate that curcumin, gallic acid, and quercetin may be beneficial against allergic inflammatory diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2473-2481
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• 2015

Colon cancer is one of the leading causes of cancer-associated death worldwide. The prognosis for advanced colorectal cancers remains dismal, mainly due to the propensity for metastatic progression. Accordingly, there is a need for effective anti-metastasis therapeutic agents. Since a great body of research has indicated anticancer effects for curcumin, we investigated the effects of dendrosomal curcumin (DNC) on cellular migration and adhesion of human SW480 cells and possible molecular mechanisms involved. Different methods were applied in this study including MTT, Scratch and adhesion assays as well as real-time PCR and transwell chamber assays. Based on the results obtained, DNC inhibits metastasis by decreasing Hef 1, Zeb 1 and Claudin 1 mRNA levels and can reduce SW480 cell proliferation with $IC_{50}$values of 15.9, 11.6 and $7.64{\mu}M$ at 24, 48 and 72h post-treatment. Thus it might be considered as a safe formulation for therapeutic purpose in colorectal cancer cases.

• Journal of Radiation Industry
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• v.4 no.1
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• pp.39-45
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• 2010

The pollution of antibiotics is a major cause of spreading antibiotics resistant bacteria in the environment. Applications of ozonation, UV, and ${\gamma}-ray$ irradiations have been introduced to remove antibiotics in the effluents from wastewater treatment system. In this study, we compared the chemical (HPLC) and biological (antimicrobial susceptibility test, AMS) assays in measuring of the concentrations of residual antibiotics after ${\gamma}-ray$ and UV irradiation. Most samples were degraded by ${\gamma}-ray$ irradiation (1~2 kGy). However, lincomycin and tetracycline were not degraded by UV irradiation. The concentration of residual antibiotics, that was treated with ${\gamma}-ray$ and UV irradiation, measuring by bioassay was similar to HPLC. The concentrations of ${\gamma}-ray$ irradiated cephradine measured by AMS test were 2 times higher than that of HPLC assay, indicating AMS test is more sensitive than HPLC assay. These results indicate that ${\gamma}-ray$ irradiation technique is more useful than UV irradiation, and biological assay is more useful to detect the antibiotics and toxic intermediates in antibiotics degradation.

• Restorative Dentistry and Endodontics
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• v.41 no.3
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• pp.167-175
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• 2016

Objectives: Endodontically treated teeth with insufficient tooth structure are often restored with esthetic restorations. This study evaluated the cytotoxicity and biological effects of yttria partially stabilized zirconia (Y-TZP) blocks in combination with several dental cements. Materials and Methods: Pairs of zirconia cylinders with medium alone or cemented with three types of dental cement including RelyX U200 (3M ESPE), FujiCEM 2 (GC), and Panavia F 2.0 (Kuraray) were incubated in medium for 14 days. The cytotoxicity of each supernatant was determined using 3-(4,5-dimethylthiazole- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays on L929 fibroblasts and MC3T3-E1 osteoblasts. The levels of interleukin-6 (IL-6) mRNA were evaluated by reverse transcription polymerase chain reaction (RT-PCR), and IL-6 protein was evaluated by enzyme-linked immunosorbent assays (ELISA). The data were analyzed using one-way ANOVA and Tukey post-hoc tests. A p < 0.05 was considered statistically significant. Results: The MTT assays showed that MC3T3-E1 osteoblasts were more susceptible to dental cements than L929 fibroblasts. The resin based dental cements increased IL-6 expression in L929 cells, but reduced IL-6 expression in MC3T3-E1 cells. Conclusions: Zirconia alone or blocks cemented with dental cement showed acceptable biocompatibilities. The results showed resin-modified glass-ionomer based cement less produced inflammatory cytokines than other self-adhesive resin-based cements. Furthermore, osteoblasts were more susceptible than fibroblasts to the biological effects of dental cement.