Biomedical subjects

Ho-Jang Kwon

Publications and source records attributed to Ho-Jang Kwon.

4 recordsLinked to original sources

PubMed2003

Ischemic stroke associated with decrease in temperature.

BACKGROUND: Some studies suggest low temperatures can affect mortality, especially deaths associated with circulatory and respiratory conditions. METHODS: We investigated the association between ischemic stroke onset and decrease in temperature in 545 patients over a 3-year period (January 1998 to December 2000) in Incheon, Korea. We used a case-crossover study design to assess changes in the risk of ischemic stroke during a brief hazard period after exposure to decrease in temperature. For each subject, the case period was matched to 2 control periods exactly 1 week before and after onset of the ischemic stroke. RESULTS: Decreased ambient temperature was associated with risk of acute ischemic stroke. The strongest effect was seen on day after exposure to cold weather. The odds ratio (OR) for an interquartile range decrease in temperature was 2.9 (95% confidence interval [CI] = 1.5-5.3). The risk period was 24-48 hours after cold exposure. Risk estimates associated with decreased temperature were greater in the winter than in the summer. Women, persons greater than 65 years of age, nonobese persons, and those with previous hypertension or hypercholesterolemia were more susceptible to cold-induced ischemic stroke. CONCLUSIONS: These results suggest that stroke occurrence rises with decreasing temperature, and that even a moderate decrease in temperature can increase the risk of ischemic stroke. Susceptible people should take steps to protect themselves from cold, especially in the winter.

Age Factors↗

PubMed2003

Health survey on workers and residents near the municipal waste and industrial waste incinerators in Korea.

Hazardous substances, such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) also have been detected in Municipal Solid Waste (MSW) and industrial waste incinerators in Korea. In this study, we estimated the exposure status of these hazardous substances and their heath effects in workers and residents near the MSW incinerators and residents near the industrial waste incinerators. We interviewed 13 workers and 16 residents from the area around the two MSW incinerators, and further 10 residents from the area around one industrial waste incinerator, which is suspected to emit higher hazardous substances. During the interview we collected information including sociodemographic information, personal habits, work history, detailed gynecologic and other medical history. Blood samples from 45 subjects were also collected for analysis of PCDDs and PCDFs, which were analyzed by HRGC-HRMS (High Resolution Gas Chromatography-High Resolution Mass Spectrometer). In addition to a questionnaire survey, urinary concentrations of 8-hydroxydeoxyguanosine (8-OH-dG) and malondialdehyde (MDA) were measured as oxidative injury biomarkers. Urinary concentrations of 8-OH-dG were determined by in vitro ELISA (JAICA, Fukuroi, Japan). MDA were determined by HPLC using adduct with TBA (thiobarbituric acid). The PCDD/F concentrations in residents from the area around industrial waste incinerator were higher than those in workers and residents from the area around MSW incinerator. The average toxic equivalency (TEQ) concentrations of PCDD/Fs in residents from the area around industrial waste incinerator were 53.4 pg I-TEQs/g lipid. The average TEQ concentrations of PCDD/Fs in workers and residents near MSW incinerator were 12.2 pg I-TEQs/g lipid. Estimated daily intake (EDI) of each person was calculated, and the EDI of all workers and residents near MSW incinerator were within the tolerable daily intake range. But for only 30% of 10 people near the industrial waste incinerator were the EDI within the tolerable daily intake range (1-4 pg I-TEQ/kg bw/day) suggested by WHO (1997). The oxidative stress of residents near the industrial waste incinerator was higher than that in workers and residents from the area around MSW incinerator. This oxidative stress may have been caused by hazardous substances, such as PCDD/Fs emitted by incinerators. The residents from the area around industrial waste incinerator were exposed to hazardous substances such as PCDD/ Fs. Proper protection strategies against these hazardous chemicals are needed.

Benzofurans↗

PubMed2002

Effects of the Asian dust events on daily mortality in Seoul, Korea.

The Korean peninsula has a long history of dust clouds blown by winds from the arid deserts of Mongolia and China in springtime; these are called Asian dust events. Public concern about the possible adverse effects of this dust has increased, because the dust arrives in Korea after having passed over heavily industrialized eastern China. The present study explored the effect of Asian dust events on daily mortality in Seoul, South Korea, during the period 1995-1998. We evaluated the association between daily death counts and the dust events using Poisson regression analysis, adjusted for time trends, weather variables, and the day of the week. Between 1995 and 1998, we identified 28 Asian dust days in Seoul. The estimated percentage increase in the rate of deaths from 3-day moving averages of exposure was 1.7% (95/ confidence interval: -1.6 to 5.3) for all causes, 2.2% (95% confidence interval: -3.5 to 8.3) for deaths of persons aged 65 years and older, and 4.1% (95% confidence interval: -3.8 to 12.6) for cardiovascular and respiratory causes. Our results provide weak evidence that the Asian dust events are associated with risk of death from all causes. However, the association between the dust events and deaths from cardiovascular and respiratory causes was stronger and it suggests that persons with advanced cardiovascular and respiratory disease may be susceptible to the Asian dust events.

Age Factors↗

PubMed2002

Air pollution: a new risk factor in ischemic stroke mortality.

BACKGROUND AND PURPOSE: Air pollution is known to be associated with cardiovascular disease, but little is known about the occurrence of stroke in relation to air pollution. We investigated the association between acute stroke mortality and air pollution over a 7-year period (January 1991 through December 1997) in Seoul, Korea. METHODS: A generalized additive model was used to regress daily stroke death counts for each air pollutant, controlling for time trends, day of the week, and meteorological influences such as temperature, relative humidity, and atmospheric pressure. Ischemic and hemorrhagic stroke deaths were examined separately. RESULTS: The effects of air pollutants on ischemic stroke mortality were statistically significant, whereas this was not the case for hemorrhagic stroke mortality. We observed estimated relative risks of 1.03 (95% CI, 1.00 to 1.06) and 1.04 (95% CI, 1.01 to 1.08) for ischemic stroke mortality for each interquartile range increase in total suspended particulates and sulfur dioxide concentrations on the same day. We also found significantly increased relative risks of 1.04 (95% CI, 1.01 to 1.07) for nitrogen dioxide with a 1-day lag, of 1.06 (95% CI, 1.02 to 1.09) for carbon monoxide with a 1-day lag, and of 1.06 (95% CI, 1.02 to 1.10) for ozone with a 3-day lag for each interquartile range increase. CONCLUSIONS: These findings indicate that air pollutants are significantly associated with ischemic stroke mortality, which suggests an acute pathogenetic process in the cerebrovascular system induced by air pollution.

Air Pollution↗