The study to estimate the floating population in Seoul, Korea

Traffic-related pollutants have been reported to increase the morbidity of respiratory diseases. In order to apply management policies related to motor vehicles, studies of the floating population living in cities are important. The rate of metro rail transit system use by passengers residing in Seoul is about 54% of total public transportation use. Through the rate of metro use, the people-flow ratios in each administrative area were calculated. By applying a people-flow ratio based on the official census count, the floating population in 25 regions was calculated. The reduced level of deaths among the floating population in 14 regions having the roadside monitoring station was calculated as assuming a 20% reduction of mobile emission based on the policy. The hourly floating population size was calculated by applying the hourly population ratio to the regional population size as specified in the official census count. The number of people moving from 5 a.m. to next day 1 a.m. could not be precisely calculated when the population size was applied, but no issue was observed that would trigger a sizable shift in the rate of population change. The three patterns of increase, decrease, and no change of population in work hours were analyzed. When the concentration of particulate matter less than 10 μm in aerodynamic diameter was reduced by 20%, the number of excess deaths varied according to the difference of the floating population. The effective establishment of directions to manage the pollutants in cities should be carried out by considering the floating population. Although the number of people using the metro system is only an estimate, this disadvantage was supplemented by calculating inflow and outflow ratio of metro users per time in the total floating population in each region. Especially, 54% of metro usage in public transport causes high reliability in application.

Withdrawal: Specific nephrotoxicity and cardiotoxicity of BT-CAL®, Sigma Anti-bonding Molecule Calcium Carbonate, in mice / 한국실험동물학회지

This article has been retracted.

Perilla oil improves blood flow through inhibition of platelet aggregation and thrombus formation / 한국실험동물학회지

The inhibitory effects of perilla oil on the platelet aggregation in vitro and thrombosis in vivo were investigated in comparison with aspirin, a well-known blood flow enhancer. Rabbit platelet-rich plasma was incubated with perilla oil and aggregation inducers collagen or thrombin, and the platelet aggregation rate was analyzed. Perilla oil significantly inhibited both the collagen- and thrombin-induced platelet aggregations, in which the thromboxane B2 formation from collagen-activated platelets were reduced in a concentration-dependent manner. Rats were administered once daily by gavage with perilla oil for 1 week, carotid arterial thrombosis was induced by applying 35% FeCl3-soaked filter paper for 10 min, and the blood flow was monitored with a laser Doppler probe. Perilla oil delayed the FeCl3-induced arterial occlusion in a dose-dependent manner, doubling the occlusion time at 0.5 mL/kg. In addition, a high dose (2 mL/kg) of perilla oil greatly prevented the occlusion, comparable to the effect of aspirin (30 mg/kg). The results indicate that perilla oil inhibit platelet aggregation by blocking thromboxane formation, and thereby delay thrombosis following oxidative arterial wall injury. Therefore, it is proposed that perilla oil could be a good candidate without adverse effects for the improvement of blood flow.

An ethanolic extract of Angelica gigas improves atherosclerosis by inhibiting vascular smooth muscle cell proliferation / 한국실험동물학회지

The effects of an ethanolic extract of Angelica gigas (EAG) on the vascular smooth muscle cell (VSMC) proliferation and high-cholesterol diet-induced hypercholesterolemia and atherosclerosis were investigated. Rat aortic VSMCs were stimulated with platelet-derived growth factor-BB (25 ng/mL) for the induction of DNA synthesis and cell proliferation. EAG (1-10 microg/mL) significantly inhibited both the thymidine incorporation and cell proliferation in a concentration-dependent manner. Hypercholesterolemia was induced by feeding male New Zealand white rabbits with 0.5% cholesterol in diet for 10 weeks, during which EAG (1% in diet) was given for the final 8 weeks after 2-week induction of hypercholesterolemia. Hypercholesterolemic rabbits exhibited great increases in serum total cholesterol and low-density lipoproteins (LDL) levels, and finally severe atheromatous plaque formation covering 28.4% of the arterial walls. EAG significantly increased high-density lipoproteins (HDL), slightly decreased LDL, and potentially reduced the atheroma area to 16.6%. The results indicate that EAG attenuates atherosclerosis not only by inhibiting VASC proliferation, but also by increasing blood HDL levels. Therefore, it is suggested that EAG could be an alternative or an adjunct therapy for the improvement of hypercholesterolemia and atherosclerosis.

Molecular Epidemiology of Clostridium perfringens Isolated from Food Poisoning in Seoul, 2013

Clostridium perfringens food poisoning ranks among the most common gastrointestinal diseases in developed countries. In Korea, C. perfringens food poisoning gradually increases. Using PCR, 72 strains of C. perfringens isolated in Seoul, 2013 were tested for the presence of toxin genes. Of the tested strains, 32 isolates carried the cpe gene, 37 isolates carried the cpb2 gene and 3 isolates carried the cpe and cpb2 genes, respectively. 32 cpe-positive strains were isolated from the food poisoning patient, whereas among 37 cpb2-positive strains, 22 strains were isolated from asymptomatic person. To investigate epidemiological relationship between the isolates, Pulsed-filed gel electrophoresis (PFGE) was performed. The genetic relatedness of the isolates ranged from 55.9% to 100% and 47 distinct PFGE profiles were observed. The results show that the cpe-positive outbreak strains showed close genetic relation, whereas the cpb2-positive isolates revealed a wide genetic diversity.

Nattokinase improves blood flow by inhibiting platelet aggregation and thrombus formation / 한국실험동물학회지

The effects of nattokinase on the in vitro platelet aggregation and in vivo thrombosis were investigated in comparison with aspirin. Rabbit platelet-rich plasma was incubated with nattokinase and aggregation inducers collagen and thrombin, and the platelet aggregation rate was analyzed. Nattokinase significantly inhibited both the collagen- and thrombin-induced platelet aggregations. Nattokinase also reduced thromboxane B2 formation from collagen-activated platelets in a concentration-dependent manner. Rats were orally administered with nattokinase for 1 week, and their carotid arteries were exposed. Arterial thrombosis was induced by applying 35% FeCl3-soaked filter paper for 10 min, and the blood flow was monitored with a laser Doppler probe. Nattokinase delayed the FeCl3-induced arterial occlusion in a dose-dependent manner, doubling the occlusion time at 160 mg/kg. In addition, a high dose (500 mg/kg) of nattokinase fully prevented the occlusion, as achieved with aspirin (30 mg/kg). The results indicate that nattokinase extracted from fermented soybean inhibit platelet aggregation by blocking thromboxane formation, and thereby delay thrombosis following oxidative arterial wall injury. Therefore, it is suggested that nattokinase could be a good candidate without adverse effects for the improvement of blood flow.

Specific nephrotoxicity and cardiotoxicity of BT-CAL(R), Sigma Anti-bonding Molecule Calcium Carbonate, in mice / 한국실험동물학회지

According to a high anti-osteoporotic efficacy of Sigma Anti-bonding Molecule Calcium Carbonate (SAC), repeated-dose toxicities of SAC were investigated to assess its feasibility as drug or functional food ingredient. Male ICR mice were given drinking water containing 0.006, 0.02 or 0.06% SAC for 4 weeks. SAC feeding decreased the body weights and feed and water consumptions of mice in a dose-dependent manner, especially, leading to severe emaciation and 70% death in 3 weeks in the high-dose (0.06%) group. Not only kidney and heart weights, but also the levels of blood urea nitrogen, creatinine, aspartate transaminase, and creatine phospokinase significantly increased after SAC administration, indicative of nephrotoxicity and cardiotoxicity. Such renal and cardiac toxicities were also confirmed by microscopic findings, exhibiting renal crystals and cardiac fibrosis, which may be due to the insoluble crystal formation and calcium overload, respectively. In conclusion, it is suggested that no observed adverse effect level of SAC is lower than 0.006% in mice, and that a long-term intake may cause serious adverse effects on renal and cardiac functions.