The adsorption of proteins on the surface of glass slides is essential for construction of protein chips. Previously, we prepared a nickel-coated plate by the spin-coating method for immobilization of His-tagged proteins. In order to know whether the structural factor is responsible for the immobilization of His-tagged proteins to the nickel-coated glass slide, we executed a series of experiments. First we purified a His-tagged protein after expressing the vector in E. coli BL21 (DE3). Then we obtained the unfolding curve for the His-tagged protein by using guanidine hydrochloride. Fractions unfolded were monitored by internal fluorescence spectroscopy. The delta G(H20) for unfolding was 2.27 kcalmol +/- 0.52. Then we tested if unfolded His-tagged proteins can be adsorbed to the nickel-coated plate, comparing with Ni2+ -NTA (nitrilotriacetic acid) beads. Whereas unfolded His-tagged proteins were adsorbed to Ni2+ -NTA beads, they did not bind to the nickel-coated plate. In conclusion, a structural factor is likely to be an important factor for constructing the protein chips, when His-tagged proteins will immobilize to the nickel-coated slides.
Adsorption ; Fibrinogen ; Glass* ; Guanidine ; Immobilization ; Protein Array Analysis ; Spectrometry, Fluorescence

A total of 221 patients were evaluated to be humidifier disinfectant associated with lung injury (HDLI) through two rounds of programs through April 2015. The humidifier disinfectant (HD) brands most often associated with HDLI were found to be Oxy (n=151, 68 %) and Cefu (n=26, 17 %). Polyhexamethylene guanidine used for disinfectant for four types of HD brands including Oxy was found to be associated with the highest number of HDLI cases (n=188). Further programs are operating to identify various health effects including lung injury which may be associated with the use of HD. Not only national agencies, but also pertinent environmental health societies should cooperate in the necessary investigations so that this tragedy can be properly addressed and future incidents concerning chemicals and chemical-containing products can be prevented.
Environmental Health ; Guanidine ; Humans ; Humidifiers* ; Lung Injury* ; Lung*

An analysis of patients and fatalities due to exposure to polyhexamethylene guanidine (PHMG) shows that PHMG causes mainly lung diseases such as pulmonary fibrosis. However, no research on the other organs has been conducted on this matter yet. So, an in-depth discussion on toxicological techniques is needed to determine whether or not PHMG is toxic to organs other than just the lungs. For the test of target organ toxicity by PHMG exposure, a toxicokinetic study must first be conducted. However, measurement method for PHMG injected into the body has not yet been established because it is not easy to analyze polymer PHMG, so related base studies on analytical technique for PHMG including radio-labeling chemistry must come first. Moreover, research on exposure-biomarker and effect-biomarker must also be conducted, primarily related to clinical application. Several limitations seem to be expected to apply the biomarker study to the patient because much time has passed after exposure to the humidifier disinfectant. It is why a more comprehensive toxicological researches must be introduced to the causality for the victims.
Chemistry ; Guanidine ; Humans ; Humidifiers* ; Lung ; Lung Diseases ; Methods ; Polymers ; Pulmonary Fibrosis

BACKGROUND: There is evidence that glycosaminoglycans (GAGs) are present in the hair shaft within the follicle but there are no studies regarding GAGs isolation and measurement in the human hair shaft over the scalp surface, it means, in the free hair shaft. OBJECTIVE: The purpose of our research was to isolate and measure the total GAGs from human free hair shaft. METHODS: Seventy-five healthy individuals participated in the study, 58 adults, men and women over the age of 50 and 17 children (aged 4~9). GAGs in hair samples, received from the parietal and the occipital areas, were isolated with 4 M guanidine HCl and measured by the uronic acid-carbazole reaction assay. RESULTS: GAGs concentration was significantly higher in the occipital area than in the parietal area, in all study groups. GAG levels from both areas were significantly higher in children than in adults. GAG levels were not associated with gender, hair color or type. CONCLUSION: We report the presence of GAGs in the human free hair shaft and the correlation of hair GAG levels with the scalp area and participants' age.
Adult ; Child ; Female ; Glycosaminoglycans* ; Guanidine ; Hair Color ; Hair* ; Humans* ; Male ; Proteoglycans ; Rabeprazole ; Scalp

We expressed anti-HBsAg human antibody fragment (B7 Fd) using pRSET-A vector and BL21(DE3)pLysS strain of E. coli. B7 Fd is composed only of variable domain (VH) and CH1 constant domain of IgG heavy chain molecule. This Fd molecule was solubilized using guanidine salt and then expressed in the form of inclusion body and successfully refolded into functional antibody molecule by rapid dilution in refolding buffer. B7 Fd reacted with d epitope of hepatitis B virus surface antigen (HBsAg). Its affinity was determined by competition enzyme-linked immunosorbent assay (competition ELISA). The K value of B7 Fd was 3.3 * 10.
Antigens, Surface ; Enzyme-Linked Immunosorbent Assay ; Guanidine ; Hepatitis B virus ; Humans* ; Immunoglobulin G ; Inclusion Bodies

Disinfectants including polyhexamethylene guanidine phosphate (PHMG) and mixtures of chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT) have been widely used in Korea to prevent microbial growth in the humidifier water, which triggered an outbreak of serious respiratory diseases. In addition to the respiratory syndrome, disease-related symptoms including liver toxicity, asthma, and skin allergies were also found after extensive survey of people exposed to the humidifier disinfectants (HDs). In this study, eye irritation tests were performed based on the Organization for economic co-operation and development (OECD) test guidelines 492 using EpiOcular™ which is a tissue model of reconstructed human cornea-like epithelium. As results, the raw materials of PHMG (26% as active ingredient) and CMIT/MIT (1.5% as active ingredient) were classified under UN globally harmonized system of classification and labeling of chemical (GHS) category 1 or category 2. However, aqueous dilutions of raw materials such as market products of HDs that contain 0.13% of PHMG and 0.03% of CMIT/MIT or further dilutions of the market products for humidifier that contain 0.0013% of PHMG and 0.0003% of CMIT/MIT were classified under any category, which suggested absence of eye irritation at the test concentration.
Asthma ; Classification ; Disinfectants ; Epithelium ; Guanidine ; Humans ; Humidifiers ; Hypersensitivity ; Korea ; Liver ; Skin ; United Nations ; Water

Several studies showed that the inflammatory and fibrotic responses induced by polyhexamethylene guanidine phosphate (PHMG-p) were similar to those observed for idiopathic pulmonary fibrosis in South Korea in 2011. “Omic” technologies can be used to understand the mechanisms underlying chemical-induced diseases. Studies to determine the toxicity of chemicals may facilitate understanding of the mechanisms underlying the development of pulmonary fibrosis at a molecular level; thus, such studies may provide information about the toxic characteristics of various substances. In this review, we have outlined the cellular and molecular mechanisms underlying idiopathic pulmonary fibrosis and described pulmonary fibrosis induced by various chemicals, including bleomycin, paraquat, and PHMG-p, based on the results of studies performed to date.
Bleomycin ; Epithelial Cells ; Guanidine ; Idiopathic Pulmonary Fibrosis ; Korea ; MicroRNAs ; Paraquat ; Pulmonary Fibrosis*

Several studies showed that the inflammatory and fibrotic responses induced by polyhexamethylene guanidine phosphate (PHMG-p) were similar to those observed for idiopathic pulmonary fibrosis in South Korea in 2011. “Omic” technologies can be used to understand the mechanisms underlying chemical-induced diseases. Studies to determine the toxicity of chemicals may facilitate understanding of the mechanisms underlying the development of pulmonary fibrosis at a molecular level; thus, such studies may provide information about the toxic characteristics of various substances. In this review, we have outlined the cellular and molecular mechanisms underlying idiopathic pulmonary fibrosis and described pulmonary fibrosis induced by various chemicals, including bleomycin, paraquat, and PHMG-p, based on the results of studies performed to date.
Bleomycin ; Epithelial Cells ; Guanidine ; Idiopathic Pulmonary Fibrosis ; Korea ; MicroRNAs ; Paraquat ; Pulmonary Fibrosis

Disinfectants including polyhexamethylene guanidine phosphate (PHMG) and mixtures of chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT) have been widely used in Korea to prevent microbial growth in the humidifier water, which triggered an outbreak of serious respiratory diseases. In addition to the respiratory syndrome, disease-related symptoms including liver toxicity, asthma, and skin allergies were also found after extensive survey of people exposed to the humidifier disinfectants (HDs). In this study, eye irritation tests were performed based on the Organization for economic co-operation and development (OECD) test guidelines 492 using EpiOcular™ which is a tissue model of reconstructed human cornea-like epithelium. As results, the raw materials of PHMG (26% as active ingredient) and CMIT/MIT (1.5% as active ingredient) were classified under UN globally harmonized system of classification and labeling of chemical (GHS) category 1 or category 2. However, aqueous dilutions of raw materials such as market products of HDs that contain 0.13% of PHMG and 0.03% of CMIT/MIT or further dilutions of the market products for humidifier that contain 0.0013% of PHMG and 0.0003% of CMIT/MIT were classified under any category, which suggested absence of eye irritation at the test concentration.
Asthma ; Classification ; Disinfectants ; Epithelium ; Guanidine ; Humans ; Humidifiers ; Hypersensitivity ; Korea ; Liver ; Skin ; United Nations ; Water

BACKGROUND: Rhinitis was the most frequently diagnosed disorder among users of humidifier disinfectants (HDs). The aim of our study was to investigate on the relationship between allergic rhinitis (AR) and HD uses.METHODS: Our study used the data from the eighth Panel Study on Korean Children; a total of 1,540 participants were enrolled. The χ² test and multiple logistic regression analyses were conducted to debunk the association between AR and HD uses.RESULTS: In our analysis, odds ratios (ORs) of doctor-diagnosed AR increased significantly when simply the response of whether HDs were used in the past was considered. When the brands of HD were considered, ORs of doctor-diagnosed AR were found to be increased significantly for those who have used polyhexamethylene guanidine phosphate/oligo(2-[2-ethoxy]-ethoxyethyl)guanidinium-containing HDs (model 3: 1.41, 95% confidence interval [CI]: 1.02–1.95). However, once duration of usage was additionally considered, ORs of doctor-diagnosed AR increased significantly only for those who have used chloromethylisothiazolinone/methylisothiazolinone-containing HDs for more than or equal to 3 months (model 3: 2.08, 95% CI: 1.17–3.69). Further, past use of HD was associated with significantly increased ORs of AR diagnosed before 2013 (model 3: 1.35, 95% CI: 1.02–1.79).CONCLUSIONS: Results of our study suggest that past uses of HDs may be associated with an increased risk of AR.
Child ; Cross-Sectional Studies ; Disinfectants ; Guanidine ; Humans ; Humidifiers ; Logistic Models ; Odds Ratio ; Rhinitis ; Rhinitis, Allergic