Coffee and metabolic syndrome: A systematic review and meta-analysis / 한국영양학회지

PURPOSE: Coffee is the most frequently consumed food item in South Korea after rice and cabbage. Coffee contains various substances, including caffeine, cafestol, kahweol, chlorogenic acid, and many other known and unknown ingredients with some health benefits. Especially, cumulative evidence has shown that regular coffee use is associated with lower risk of type 2 diabetes, although limited and inconsistent data are available regarding metabolic syndrome. METHODS: This study reviewed all available scientific and epidemiologic evidence on coffee consumption, metabolic syndrome, and the association between them. Most epidemiologic research regarding this association was of a cross-sectional design, and a few case-control and cohort studies were available. We conducted meta-analysis with 11 observational studies investigated in Europe, America, and Asia. Summary odds ratios (OR) were calculated using a random-effects model. RESULTS: The overall OR of metabolic syndrome was 0.90 (95% Confidence Interval (CI), 0.81-0.99) for the highest category of coffee intake compared with the lowest intake category. These associations were stronger in populations of US and Europe (OR 0.84, 95% CI 0.76-0.94), whereas no association was observed in the Asian population (OR 1.00, 95% CI 0.81-1.23). CONCLUSION: The review results indicate that frequent coffee consumption may be beneficial to metabolic syndrome, but the association between coffee consumption and metabolic syndrome may differ by nations or continents.

Primary Malignant Melanoma of the Esophagus Treated by Early Diagnosis and Surgical Resection

Primary malignant melanoma of the esophagus is an extremely rare disease and accounts for approximately 0.1~0.2% of all esophageal malignancies. It is also a very aggressive disease with 5 year survival rates ranging from 2.2% to 37.5%. A 51-year-old woman with no previous medical history visited the hospital complaining of mild epigastric discomfort and belching. Endoscopy revealed a dark pigmented, polypoid lesion which was later diagnosed as primary malignant melanoma of the esophagus. Here we report a case of primary malignant melanoma of the esophagus that was diagnosed in a very early phase and successfully resected with an Ivor-Lewis procedure.

Silver Nanoparticles as a Smart Antimicrobial Agent

In modern medicine the resistance to conventional antibiotics is becoming a serious concern due to high instances of mortality. Several metallic nanoparticles are suggested as promising anti-microbial agents against multidrug-resistant bacteria and some viruses. Among the nanoparticles mentioned, we review the recent finding which demonstrate the impact of silver nanoparticles on antimicrobial activities and recommend them as a potential candidate for restraining infections.

The Effects of Silica Nanoparticles in Macrophage Cells

Silica nanoparticles, which are applicable in many industrial fields, have been reported to induce cellular changes such as cytotoxicity in various cells and fibrosis in lungs. Because the immune system is the primary targeting organ reacting to internalized exogenous nanoparticles, we tried to figure out the immunostimulatory effect of silica nanoparticles in macrophages using differently sized silica nanoparticles. Using U937 cells we assessed cytotoxicity by CCK-8 assay, ROS generation by CM-H2DCFDA, intracellular Ca++ levels by staining with Fluo4-AM and IL-8 production by ELISA. At non-toxic concentration, the intracellular Ca++ level has increased immediately after exposure to 15 nm particles, not to larger particles. ROS generation was detected significantly in response to 15 nm particles. However, all three different sizes of silica nanoparticles induced IL-8 production. 15 nm silica nanoparticles are more stimulatory than larger particles in cytotoxicity, intracellular Ca++ increase and ROS generation. But IL-8 production was induced to same levels with 50 or 100 nm particles. Therefore, IL-8 production induced by silica nanoparticles may be dependent on other mechanisms rather than intracellular Ca++ increase and ROS generation.

The Impact of Nanomaterials in Immune System

As a nanotechnology has been actively applied to the overall areas of scientific fields, it is necessary to understand the characteristic features, physical behaviors and the potential effects of exposure to nanomaterials and their toxicity. In this article we review the immunological influences induced by several nanomaterials and emphasize establishment of the animal models to estimate the impact of these nanomaterials on development of immunological diseases.