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Biomedical subjects

Y J Kim

Publications and source records attributed to Y J Kim.

At least 55 records · Page 3Linked to original sources
PubMed2004

Characteristics of ion components and trace elements of fine particles at Gosan, Korea in spring time from 2001 to 2002.

Size-segregated measurements of the composition of an aerosol are used to determine the transport of natural and anthropogenic aerosols to the Gosan site in springtime from 2001 to 2002. Although the transport of Asian dust is a well-known phenomenon in springtime, this study shows that not only is soil dust transported into Gosan each spring but so are anthropogenic aerosols, including sulfur, enriched trace metals such as Pb, Zn, Ni, K, S. This study also combines the size- and time-resolved aerosol composition measurements with isentropic, backward air-mass trajectories in order to identify some potential source regions of the anthropogenic aerosols. Finally, four types of transport episodes were identified: (1) anthropogenic pollutants, (2) dust storm mixed with the anthropogenic aerosols, (3) typical dust storms, (4) some sea salt with clean air mass. Overall, in addition to typical soil dust, a large amount of anthropogenic aerosols, whether mixed with the soil dust or not, are transported to Gosan each spring.

Aerosols↗
PubMed2004

Effects of the interaction between the C677T 5,10-methylenetetrahydrofolate reductase polymorphism and serum B vitamins on homocysteine levels in pregnant women.

OBJECTIVE: The purpose of this study was to investigate the effect of the interaction between the C677T mutation in the 5,10-methylenetetrahydrofolate reductase (MTHFR) genotypes and serum levels of B vitamins on serum homocysteine levels in pregnant women. DESIGN: A cross-sectional study. SETTING: Ewha Womans University Hospital, Seoul, Korea. SUBJECTS: A total of 177 normal pregnant women, 24.6+/-1.1 weeks of gestation, in a 6-month period during 2001-2002. INTERVENTIONS: Serum vitamin B2, vitamin B6, and homocysteine analyses were conducted using high-performance liquid chromatography methods. Serum folate and vitamin B12 concentrations were determined using a radioimmunoassay kit. MTHFR gene mutation was investigated by the polymerase chain reaction of a genomic DNA fragment. RESULTS: Serum homocysteine was higher in women with the T/T genotype than those with the C/T or C/C genotype of the MTHFR gene (P<0.05). Serum homocysteine was negatively correlated with serum folate in all MTHFR genotypes (P<0.001), and the correlation between the two serum levels was the strongest in the T/T genotype. Serum homocysteine was higher in the subjects with the T/T MTHFR genotype only when the serum folate was below the median level. Explanatory power of B vitamin status as predictors of serum homocysteine levels was more pronounced in the T/T genotypes (68.5%) compared with the C/T (37.9%) or C/C genotypes (20.6%). CONCLUSIONS: Serum homocysteine levels in pregnant women varied significantly with MTHFR genotype and the serum B vitamin status. Higher serum folate, vitamin B2, and vitamin B12 concentrations may lessen the MTHFR genotypic effect on serum homocysteine levels.

Adult↗
PubMed2004

Influence of maternal serum levels of vitamins C and E during the second trimester on birth weight and length.

OBJECTIVE: It has been known that maternal oxidative stress during pregnancy plays an important role in fetal growth. However, the association between antioxidant vitamin levels and birth outcomes is not conclusive. We investigated the relationship between maternal serum levels of vitamins C and E during the second trimester and birth weight and length. DESIGN: Prospective cohort study. SETTING: Outpatient-clinic of obstetrics, Ewha Womans University Hospital, South Korea. SUBJECTS AND METHODS: The study subjects were 239 healthy, pregnant women who visited an obstetric clinic for antenatal care, and their singleton live births, in Seoul, Korea, between August 2001 and March 2003. We measured the levels of vitamins C and E in maternal serum during the period 24-28 gestational weeks. Each woman was interviewed for dietary intake by trained interviewers during the second trimester. RESULTS: The serum concentration of maternal vitamin C during the second trimester was significantly associated with birth weight and length in the group of full-term deliveries. An increase of 1 microg/ml in the serum vitamin C level increased the birth weight by 27.2 g and the birth length by 0.17 cm. When we considered the levels of vitamins C and E together in the relationship with birth weight and length, we found that the heaviest birth weight and the longest birth length belonged to the group of upper vitamin C/upper vitamin E. However, dietary intake estimated by 24-h recall method was not a predictor of the levels of serum vitamins C and E. CONCLUSION: We found that maternal serum vitamin C levels during the second trimester were positively correlated with birth weight and length in full-term babies. We also found that birth weight and length were highest when the levels of both vitamins C and E were high. Our results indicate the importance of antioxidant nutrient balance for pregnant women who are exposed to various oxidants through food, drinking water, or inhaled air.

Antioxidants↗
PubMed2004

Re-circulation artefact at the carotid bulb can be differentiated from true stenosis.

Re-circulation artefact developing secondary to vortex flow at the bulb of the internal carotid artery is very difficult to distinguish from true stenotic defect on two-dimensional Fourier transformed time-of-flight magnetic resonance angiography (2D-FT TOF MRA). The purpose of our study is to identify appropriate distinguishing features of re-circulation artefact. We included 45 extracranial carotid arteries collected from 25 patients who underwent both 2D-FT TOF MRA and contrast medium based angiography. Review of the 45 vessels demonstrated re-circulation artefact in 21 vessels, true stenotic defect in 8 vessels, and no filling defect in 16 vessels on 2D-FT TOF MRA. We compared the findings of re-circulation artefact and true stenotic defect in 29 vessels excluding the 16 vessels without filling defect. The following were evaluated: (1) preservation of posterior wall contour; (2) marginal character of filling defect; (3) darkness of filling defect; (4) involvement of common carotid artery by filling defect; (5) size of filling defect. In four out of the five evaluated items, statistically significant difference was present between re-circulation artefact group and true stenotic defect group (p<0.01 in all four items, chi(2) analysis). Re-circulation artefact demonstrated the preservation of the posterior wall contour (19/21), ill-defined margin (19/21), less dark defect (18/21), and no involvement of the common carotid artery (19/21). On the contrary true stenotic defect demonstrated focal loss of posterior wall contour (8/8), sharp margin (8/8), dark defect (8/8), and involvement of common carotid artery (4/8). No significant difference was noted in the size of the defect between the two groups (p>0.05). The specificity of 2D-FT TOF MRA for carotid stenosis was markedly increased after application of above signs. These distinguishing signs are very helpful in differentiating re-circulation artefact from true stenotic defect.

Adult↗
PubMed2004

Vaccination as a control measure during the outbreak of foot-and-mouth disease in 2000 in Korea.

The Republic of Korea had been free from foot-and-mouth disease (FMD) for 66 years until 15 cases were confirmed between 24 March and 15 April in 2000. The FMD virus isolated in Korea was an O Pan Asia type, which was also responsible for the recent outbreaks in Japan and the U.K. Control measures including the stamping-out of infected animals on neighbouring farms, movement restrictions and emergency vaccination were implemented. The decision to vaccinate was made because the cattle affected were showing severe FMD lesions, there was significant possibility that a large amount of virus had already been shed and conditions at the time seemed to favour wind-borne spread. Also, because the spread was limited to cattle, it was assumed that the use of vaccinations would be more effective than if pigs had been affected. All susceptible animals within 10 km radius of the infected farms were vaccinated with inactivated, double-oil emulsion vaccines. Totals of 860,700 and 661,770 animals were vaccinated during the first and second round of booster vaccinations, and were completed within five months of the first outbreak. The government decided to adopt a let-live policy so that the vaccinated animals were not slaughtered. However, they were placed under movement restrictions and had to be identified and registered. Although there were concerns about the vaccinated animals becoming carriers, extensive serological surveillance using NSP ELISA found no evidence of FMD in the remaining vaccinated population. The use of emergency vaccinations in 2000 is regarded as being a major factor in limiting the spread of FMD and containing the outbreak within a month.

Animals↗
PubMed2003

Expression of a foot-and-mouth disease virus immunodominant epitope by a filamentous bacteriophage vector.

We described the construction of a recombinant filamentous phage displaying on its surface the immunodominant site of VP1 protein of foot-and-mouth disease virus (FMDV). The coding sequence was inserted at the amino-terminus of the major coat protein pVIII via a spacer. The hybrid phage proved to be antigenic as it was recognized by polyclonal and monoclonal anti FMDV sera. In two experiments involving immunisation of guinea-pigs with the recombinant phage, a low antibody response was generated. This suggests a possible role for phage displayed peptides in inducing anti FMDV immunity and the possibility of further development is discussed.

Amino Acid Sequence↗
PubMed2003

Clinicopathological characteristics of gastric carcinoma in young patients.

BACKGROUND AND AIMS: Gastric carcinoma is a common disease that usually affects older patients, rarely younger patients. Although the relationship between prognosis and the age of patients with gastric carcinoma is controversial, most investigators have suggested that young patients have a poorer prognosis. This study examined the clinicopathological features of young patients with gastric carcinoma. PATIENTS AND METHODS: We retrospectively reviewed the hospital records of 1,833 patients with gastric carcinoma to compare the clinicopathological findings in young (aged <36 years) and older (aged >/= 36 years) patients during the period 1988 to 1998 in a tertiary referral center in Gwangju City. Overall survival was the main outcome measure. RESULTS: Of the 1,833 patients, 137 (7.5%) were in the young age group. There were no significant differences in depth of invasion, lymph node invasion, hepatic metastasis, peritoneal dissemination, tumor stage or rate of curative resection. A significantly higher percentage of young patients had poorly differentiated histology ( P=0.0001). The young patients with curatively resected gastric carcinoma had a better survival rate than young patients with non-resected gastric carcinoma ( P<0.001). The 5-year survival rates of young and older patients did not differ statistically (39.6% vs 42.4%; P=0.254). CONCLUSION: Young patients with gastric carcinoma do not have a worse prognosis than older patients. The important prognostic factor was whether the patients underwent curative resection.

Adenocarcinoma↗
PubMed2003

Preferential elevation of Prx I and Trx expression in lung cancer cells following hypoxia and in human lung cancer tissues.

Transient/chronic microenvironmental hypoxia that exists within a majority of solid tumors has been suggested to have a profound influence on tumor growth and therapeutic outcome. Since the functions of novel antioxidant proteins, peroxiredoxin I (Prx I) and II, have been implicated in regulating cell proliferation, differentiation, and apoptosis, it was of our special interest to probe a possible role of Prx I and II in the context of hypoxic tumor microenvironment. Since both Prx I and II use thioredoxin (Trx) as an electron donor and Trx is a substrate for thioredoxin reductase (TrxR), we investigated the regulation of Trx and TrxR as well as Prx expression following hypoxia. Here we show a dynamic change of glutathione homeostasis in lung cancer A549 cells and an up-regulation of Prx I and Trx following hypoxia. Western blot analysis of 10 human lung cancer and paired normal lung tissues also revealed an elevated expression of Prx I and Trx proteins in lung cancer tissues. Immunohistochemical analysis of the lung cancer tissues confirmed an augmented Prx I and Trx expression in cancer cells with respect to the parenchymal cells in adjacent normal lung tissue. Based on these results, we suggest that the redox changes in lung tumor microenvironment could have acted as a trigger for the up-regulation of Prx I and Trx in lung cancer cells. Although the clinical significance of our finding awaits more rigorous future study, preferential augmentation of the Prx I and Trx in lung cancer cells may well represent an attempt of cancer cells to manipulate a dynamic redox change in tumor microenvironment in a manner that is beneficial for their proliferation and malignant progression.

Antioxidants↗
PubMed2003

Successful allogeneic hematopoietic stem cell transplantation using triple agent immunosuppression in severe aplastic anemia patients.

Graft rejection in patients with severe aplastic anemia (SAA) following allogeneic hematopoietic stem cell transplantation (HSCT) is strongly associated with a large number of prior transfusions and with prolonged disease duration before transplant. We retrospectively analyzed the outcomes and the factor affecting these multitransfused SAA patients, who had received triple agent immunosuppression and high doses of stem cells to overcome rejection. In total, 113 patients with SAA who had a median 16 months (range 1-216) of disease duration were transplanted using HLA-matched sibling donors after conditioning with cyclophosphamide (CY), procarbazine (PCB), and ATG. Graft failure occurred in 16 of the eligible 113 patients, and with a median follow-up of 30 months (range, 1-80), probability of overall rejection was 15%. Specifically, the multitransfused patients who received high doses of stem cells with T-cell depletion showed the lowest rejection rate, 5.6%, compared with 30.3% in multitransfused patients with bone marrow stem cells alone (P=0.0310). Disease duration (P=0.0338) and the number of infused CD34+cells (P=0.0101) were associated with a high risk of graft rejection on multivariate analysis. ABO mismatch and the number of CD34+ cells were significant factors in the incidence of acute graft-versus-host-disease (GVHD). The incidence of chronic GVHD among patients with sustained engraftment was 13/109 (11.9%). With the same follow-up period, probability of disease-free survival for the entire group of patients at 6 years was 89% and the only factor associated with long-term survival was rejection (P=0.0241). These results suggest that allogeneic HSCT conditioned with triple agent immunosuppression, and specifically with high-dose stem cell return is probably an effective treatment for successful engraftment in SAA patients with a high risk of rejection.

ABO Blood-Group System↗
PubMed2003

Toward an acoustic typology of motor speech disorders.

Acoustic methods have progressed to the point that an acoustic typology of the motor speech disorders can be constructed from a parameteric assessment of the speech subsystems (e.g., phonation, nasal resonance, vowel articulation, consonant articulation, intonation, and rhythm). The results of this analysis can be interpreted in respect to global functions in speech (e.g., voice quality, intelligibility, and prosody). This paper reviews studies showing that specific acoustic analyses have demonstrated or potential value toward the overall goal of constructing acoustic profiles of dysarthria and apraxia of speech. Several different acoustic measures are relevant to the study of the motor speech disorders, and these are increasingly supported by normative data and by guidelines for clinical application. Examples of these applications are discussed for a variety of specific neurologic diseases or perceptual types of disorder. Acoustic studies are useful in the study of motor speech disorders and recent progress points to a parametric analysis.

Humans↗
PubMed2003

Monitoring PAH-contaminated soil using laser-induced fluorescence (LIF).

The heterogeneity and opacity of soil matrices pose considerable challenges for the quantification of soil contaminants. In order to investigate the feasibility of applying the Laser-Induced Fluorescence technique to measure contamination levels of soils, statistical analyses of contaminant levels and intensity of fluorescence were investigated in relation to soil properties. A significant correlation (R2 > 0.97) between contaminant levels and intensity of fluorescence was shown under different matrix conditions, such as moisture content and particle size distribution. Higher fluorescence intensities were obtained from soils with higher sand and moisture content. The statistical results in relation to the interaction between fluorescence intensity and matrix properties rejected the hypothesis that all properties of the matrices and contaminants had an equal influence on fluorescence. This implied that the concentrations of contaminants had the greatest contribution to the fluorescence intensity, but other variables also showed a considerable influence.

Environmental Monitoring↗
PubMed2003

Application of advanced oxidation processes for the treatment of cyanide containing effluent.

Batch experiments were carried out for the removal of cyanide in the effluent of plating industry by the application of advanced oxidation processes. Four systems with different modes of oxidation in combination of ultra violet (UV) light with hydrogen peroxide and/or ozone were investigated. Of all the applied systems, UV-light with two oxidants, i.e. O3 (32 mg min(-1)), and H2O2 (1.36 g l(-1)) was found successful in bringing down the amount of cyanide from 157.32 mg l(-1) to 1.0 mg l(-1), which is the limit set by the Ministry of Environment of Korea for cyanide-containing discharges. Other systems, however, could not bring the cyanide abatement to the targeted value even with higher dosage of oxidants and an extended period of reaction time. Regardless of the oxidation modes applied, all the heavy metal ions in the treated effluent were reduced to 90%. Ultra violet light with the combination of two oxidants had the economic preference over the other systems since a relatively lower dosage of UV-light (2484 W-S cm(-2)) was found effective at achieving the targeted level of cyanide removal.

Cyanides↗
PubMed2003

Exposure to air pollution during different gestational phases contributes to risks of low birth weight.

BACKGROUND: Although there have been growing concerns about the adverse effects of air pollution on birth outcomes, little is known about which specific exposure times of specific pollutants contribute to low birth weight (LBW). METHODS: We evaluated the relationships between LBW and air pollution exposure levels in Seoul, Korea. Using the air pollution data, we estimated the exposure during each trimester and also during each month of pregnancy on the basis of the gestational age and birth date of each newborn. Generalized additive logistic regression analyses were conducted considering infant sex, birth order, maternal age, parental education level, time trend, and gestational age. RESULTS: The monthly analyses suggested that the risks for LBW tended to increase with carbon monoxide (CO) exposure between months 2-5 of pregnancy, with exposure to particles <10 micro m (PM(10)) in months 2 and 4, and for sulphur dioxide (SO(2)) and nitrogen dioxide (NO(2)) exposure between months 3-5. CONCLUSIONS: This study suggests that exposure to CO, PM(10,) SO(2) and NO(2) during early to mid pregnancy contribute to risks for LBW.

Air Pollutants↗