Potential Migration and Health Risks of Heavy Metals and Metalloids in Take-Out Food Containers in South Korea.

The consumption of take-out food has increased worldwide; consequently, people are increasingly being exposed to chemicals from food containers. However, research on the migration of metals from containers to food is limited, and therefore, information required to determine the health risks is lacking. Herein, the amount of transfer of nine metals and metalloids (Pb, Sb, Cd, Ge, Co, Mn, Sn, As, and Hg) from food containers to food in South Korea was assessed from take-out food containers classified into paper and plastic container groups. The sample containers were eluted over time by either warming with 4% acetic acid at 70 °C or cooling with 4% acetic acid at 100 °C /deionized water at 25 °C. It was analyzed using an inductively coupled plasma mass spectrometer and a direct mercury analyzer. The reliability of the quantitative results was verified by calculating the linearity, limit of detection, and limit of quantification. We found that the amount of metals and metalloids (Pb, Sb, Cd, and Co) eluting over time was highly significant in the plastic group. Regardless of the food simulant and elution time, the amount of Sb transferred from the food containers to food was substantially higher in the plastic (average concentration: 0.488-1.194 µg/L) than in the paper group (average concentration: 0.001-0.03 µg/L). Fortunately, all food containers were distributed at levels safe for human health (hazard index: 0.000-64.756%). However, caution is needed when warm food is added to food containers. Overall, our results provide baseline data for the management and use of take-out containers.

Hepatitis B Virus-X Downregulates Expression of Selenium Binding Protein 1.

Selenium binding protein 1 (SELENBP1) has been known to be reduced in various types cancer, and epigenetic change is shown to be likely to account for the reduction of SELNEBP1 expression. With cDNA microarray comparative analysis, we found that SELENBP1 is markedly decreased in hepatitis B virus-X (HBx)-expressing cells. To clarify the effect of HBx on SELENBP1 expression, we compared the expression levels of SELENBP1 mRNA and protein by semi-quantitative RT-PCR, Northern blot, and Western blot. As expected, SELENBP1 expression was shown to be reduced in cells expressing HBx, and reporter gene analysis showed that the SELENBP1 promoter is repressed by HBx. In addition, the stepwise deletion of 5' flanking promoter sequences resulted in a gradual decrease in basal promoter activity and inhibition of SELENBP1 expression by HBx. Moreover, immunohistochemistry on tissue microarrays containing 60 pairs of human liver tissue showed decreased intensity of SELENBP1 in tumor tissues as compared with their matched non-tumor liver tissues. Taken together, our findings suggest that inhibition of SELENBP1 expression by HBx might act as one of the causes in the development of hepatocellular carcinoma caused by HBV infection.

Factors Influencing Lower Urinary Tract Symptoms in Advanced Cancer Patients With Chemotherapy-Induced Peripheral Neuropathy.

PURPOSE: This study aimed to investigate the severity of lower urinary tract symptoms (LUTS) and to identify factors that influenced LUTS in advanced cancer patients with chemotherapy-induced peripheral neuropathy (CIPN). METHODS: This cross-sectional study included a total of 158 advanced cancer patients with CIPN. A structured questionnaire including the International Prostate Symptom Score and the Functional Assessment of Cancer Therapy/Gynecology Oncology Group/Neurotoxicity scale was used. Data were analyzed using the Pearson correlation coefficient and multiple regression analysis. RESULTS: Nocturia was the most prevalent LUTS. A positive relationship was found between CIPN symptoms and LUTS. The duration of cancer diagnosis and the severity of CIPN were key factors that influenced LUTS. CONCLUSION: The severity of CIPN symptoms was the most important predictor of LUTS. Nurses' care for advanced cancer patients should incorporate a comprehensive health assessment, which includes a history of treatment and physical neuropathic symptoms, for any patient complaining of CIPN symptoms.

Effect of alendronate on bone remodeling around implant in the rat.

PURPOSE: The purpose of this study was to evaluate the effect of alendronates on bone remodeling around titanium implant in the maxilla of rats. MATERIALS AND METHODS: The maxillary first molars were extracted and customized-titanium implants were placed immediately in thirty male Sprague-Dawley rats. The rats were divided into experimental (bisphosphonate) group and control group. At 4 weeks after implantation, the rats in the bisphosphonate group were subcutaneously injected with alendronate three times a week for 6 weeks where as the rats in control group were injected with saline. The rats were sacrificed at 1, 2, 3, 4, or 6 weeks after starting of injection and maxillary bones were collected subsequently. Alveolar bone remodeling around the implants were evaluated by radiographic and histologic analysis. Microarray analysis and immunohistomorphologic analysis were also performed on one rat, sacrificed at 6 weeks after starting of injection, from each group. Statistical analysis was performed using repeated measures analysis of variance and independent t test at a significance level of 5%. RESULTS: There was no statistically significant difference in the bone area (%) around implant between the bisphosphonate group and the control group. However, the amount of empty lacuna was significantly increased in the bisphosphonate group, especially in the rats sacrificed at 4 weeks after starting of injection compared to that of the corresponding control group. The bisphosphonate group showed the same level of TRAP positive cell count, osteocalcin and angiopoietin 1 as the control group. CONCLUSION: Alendronate may not decrease the amount of osteoclast. However, the significantly increased amount of empty lacuna in the bisphosphonate group may explain the suppression of bone remodeling in the bisphosphonate group.

Corrosion behavior and cytotoxicity of Mg-35Zn-3Ca alloy for surface modified biodegradable implant material.

This study was conducted to investigate the biocompatibility of Mg-Zn-Ca ternary alloy as a biodegradable material. The casting alloy underwent anodization in an alkaline electrolyte at current density 300 mA/cm(2) and frequency 50 Hz to obtain porous oxide layer. Plasma anodization film using pulse was shown to form irregular porous oxide film. As a result of corrosion test, the corrosion current was shown to decrease and the corrosion voltage was shown to increase in the anodized group, which showed the improvement of corrosion resistance after surface treatment. Sodium silicate (0.1 M) was directly oxidized due to high charges caused by spark and then formed SiO(2), and the compounds produced inside the film were shown MgO, Mg(2) SiO(4), and SiO(2.) In the histological examination in rats, all samples of the untreated group were shown to be absorbed 3 weeks later into the body. After the magnesium alloy was implanted, blood vessel expansion and tissue change were shown in the adjacent tissues. However, the changed tissues were shown to return to normal muscle tissues 4 weeks later when the alloy was completely absorbed. These results suggest that anodized Mg-35Zn-3Ca alloy has good biocompatibility in vivo and controls the absorption rate of biomaterials.

Helicobacter pylori infection and development of gastric cancer in Korea: long-term follow-up.

BACKGROUND AND AIM: Infection of Helicobacter pylori is viewed as a major driver of progression to the precancerous state or to gastric cancer. This study was performed to investigate the effect of H. pylori infection on gastric cancer development and to determine to what extent H. pylori eradication is likely to reduce the prevalence of gastric cancer. METHODS: Gastric cancer development was investigated in 1790 Korean subjects who underwent gastroscopy and H. pylori testing between 1992 and 1998. The effects of H. pylori-positive and eradicated states on gastric cancer development were analyzed. RESULTS: Gastric cancer developed in 5 of the study cohort during a mean follow-up period of 9.4 years. All of these patients were positive for H. pylori infection, and 4 of the 5 had antral intestinal metaplasia (IM) at the time of study enrollment. One of these 5 patients was in an eradicated state when the gastric cancer was diagnosed, and had histologic IM before eradication therapy was performed. Gastric cancer was found to develop 10.9 times more frequently in the presence of IM than in its absence. CONCLUSIONS: The present study shows a close relationship between H. pylori infection and IM, and between IM and the development of gastric cancer. In addition, our finding suggests that chronic H. pylori infection looks like an important risk factor for the development of gastric cancer in Korea, where the prevalence of H. pylori remains high. This study indicates that to prevent gastric cancer H. pylori eradication is best performed before the development of IM.

Neuroprotective effects of 3,5-dicaffeoylquinic acid on hydrogen peroxide-induced cell death in SH-SY5Y cells.

Oxidative stress plays an important role in the pathological processes of a variety of neurodegenerative diseases. The neuroprotective effects of 3,5-diCQA and 3,4-diCQA, two caffeoylquinic acid derivatives present in Dipsacus asper, on hydrogen peroxide (H2O2)-induced neuronal cell damage were evaluated in this study.SH-SY5Y cells treated with H2O2 exhibited a decrease in survival and intracellular glutathione and also an increase in the caspase-3 activity. However, pretreatment of cells with 3,5-diCQA attenuated the neuronal death and caspase-3 activation induced by H2O2. In addition, 3,5-diCQA restored H2O2-induced depletion of intracellular glutathione. 3,5-diCQA showed significant protective effects although it could not completely suppress H2O2-induced cell injury to control levels. The data suggest that 3,5-diCQA might be a potential therapeutic agent for treating or preventing neurodegenerative diseases implicated with oxidative stress.

No Association between Catalase Gene Polymorphism and Gastric Carcinoma and Hepatocellular Carcinoma in Koreans.

PURPOSE: Oxidative stress has been implicated in the pathogenesis of various diseases. Catalase is one of the main defense mechanisms against oxidative stress. To examine the possible relationship between oxidative stress, and gastric and hepatocellular carcinomas, HinfI restriction length polymorphism (RFLP) in the human catalase gene was assessed. MATERIALS AND METHODS: The genotype and allele frequencies in the promoter region of the catalase gene were studied by PCR-RFLP in 108 Korean controls, 80 Korean gastric carcinoma (GC) and 106 Korean hepatocellular carcinoma (HCC) patients. RESULTS: No statistically significant differences were found in the genotypic distribution and allelic frequencies between the controls and both types of carcinoma patient. CONCLUSION: To address the possible contribution of oxidative stresses to the pathogenesis of gastric and hepatocellular carcinomas, the associations between the catalase gene polymorphism and GC and HCC susceptibilities were studied. As a result, the catalase gene polymorphism was found not to be determinant of GC and HCC susceptibilities. Further studies are required on various other oxidative stress related genes to elucidate the mechanisms of GC and HCC.