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Biomedical subjects

Sang-Woo Lee

Publications and source records attributed to Sang-Woo Lee.

9 recordsLinked to original sources
PubMed2007

Evaluation of hepatic function with (99m)Tc-galactosylated serum albumin scintigraphy in patients with malaria: comparison with (99m)Tc-colloid scintigraphy and liver ultrasonography.

OBJECTIVE: Malarial parasites injected by the mosquito rapidly target hepatocytes, and hepatomegaly is commonly observed during the progress of the disease in malaria patients. To evaluate the degree of hepatic damage and functional status of hepatocytes in malaria patients, we performed liver scintigraphy using (99m)Tc-galactosylated serum albumin (GSA) prospectively and the findings were compared with those of (99m)Tc-colloid scintigraphy, ultrasonography and clinical results in the same subject. METHODS: Eight malaria patients (all male, mean age 22 years) confirmed to be infected with Plasmodium vivax underwent (99m)Tc-GSA liver scintigraphy, followed by liver ultrasonography and (99m)Tc-colloid scintigraphy using phytate within 3 days. For hepatocyte scintigraphy, anterior images of cardiac blood-pool and liver were continuously acquired for 30 min after injection of 185 MBq (99m)Tc-GSA (3 mg). In addition to visual interpretation of the images, quantitative measurement of hepatic function was performed with several functional parameters, such as hepatic uptake index (LHL15), blood clearance index (HH15) and modified receptor index (LHL/HH) calculated from the radioactivity of the liver and heart. (99m)Tc-colloid images were assessed and graded visually. Severity of hepatic dysfunction or reticuloendothelial system activation was classified as normal, mild, moderate and severe on GSA or colloid images. RESULTS: Hepatomegaly was observed in five and splenomegaly in seven of the eight patients. Serum levels of transaminase and alkaline phosphatase were mildly elevated in two. Visual assessment of GSA scintigraphy revealed normal findings in all subjects, except for mild increases in size. The mean values of LHL15, HH15 and LHL/HH were 0.928+/-0.014, 0.537+/-0.031 and 1.732+/-0.106, respectively. They were graded as normal in five, and near-normal to mild dysfunction in three subjects. In contrast, (99m)Tc-colloid scintigraphy revealed abnormal findings in all of the subjects, and graded as moderate in three or severe reticuloendothelial system activation in five subjects. Liver ultrasonographic findings were normal for all subjects except mild hepatomegaly. CONCLUSIONS: Malaria-induced injury of the hepatocyte is likely to be minimal whereas hepatomegaly is commonly seen during disease process. This suggests that hepatic damage in malarial infection is mainly due to involvement of the reticuloendothelial system. (99m)Tc-GSA scintigraphy can be used in differentiating hepatocellular damage from reticuloendothelial system involvement in patients with infectious disease showing hepatomegaly.

Adult↗
PubMed2006

Human risk assessment for heavy metals and as contamination in the abandoned metal mine areas, Korea.

Cleanup goals for the contaminated sites are established on the basis of risk assessments and rely on the estimated toxicity of the chemicals of concern (COC). Toxicity estimates are based on bioavailability causing risk of adverse health effects on humans. In this study, bioavailability of As, Cu, Pb and Zn in soil was determined by SBET (Simple Bioavailability Extraction Test), and chemical analysis for groundwater and stream water collected from the abandoned mine areas (Dukeum, Dongil, Dongjung, Myungbong and Songchun mine areas) was conducted. High values of cancer risk for As (1.16x10(-5)) were detected through soil ingestion pathways in the Songchun mine area and assessed through water exposure pathways in the all mines except Dukeum. The hazard index value for As in the Songchun mine area (3.625) exceeded 1.0. The results indicated that the ingestion of As-contaminated soil and water by local inhabitants can pose a potential health threat in these mine areas.

Arsenic↗
PubMed2006

Direct comparison of adenosine and adenosine 5'-triphosphate as pharmacologic stress agents in conjunction with Tl-201 SPECT: Hemodynamic response, myocardial tracer uptake, and size of perfusion defects in the same subjects.

BACKGROUND: Adenosine 5'-triphosphate (ATP), a potent and inexpensive coronary vasodilator, was introduced as a pharmacologic stress agent for thallium 201 single photon emission computed tomography (SPECT). However, there has been no direct comparison of ATP and adenosine as myocardial stressors in the same subjects. METHODS AND RESULTS: Thirty-six patients underwent consecutive Tl-201 SPECT imaging with adenosine and ATP in a randomly assigned order. There were no changes in clinical status and no invasive procedures were performed between the two tests. The hemodynamic response and side effects were monitored, and myocardial tracer uptake was assessed by use of a visual grading system and quantitative analysis via a CEqual map. The hemodynamic changes and adverse effects did not differ significantly between the two groups. There were no changes in the detection of any perfusion defect on a per-subject basis, except in one. The exact agreement rate for the visual grading of the myocardial tracer uptake was 84.8%. However, the average extent of the perfusion defect and the severity score were higher with adenosine. CONCLUSION: The hemodynamic changes and the degree of myocardial uptake were similar between the adenosine and ATP infusion. However, quantitative analysis by use of a CEqual map revealed smaller perfusion defects and lower severity scores in subjects undergoing Tl-201 SPECT with ATP.

Adenosine↗
PubMed2005

The effects of different carbon sources on microbial mediation of arsenic in arsenic-contaminated sediment.

Changes in speciation and mobility of As by indigenous bacteria in As-contaminated sediments (339 mg/kg) from an abandoned Au-Ag mine area in Korea were investigated after biostimulation with a variety of carbon sources, including acetate, lactate and glucose in batch experiments. Sequential extraction analysis designed to determine the form of As occurrence revealed that 40 and 47% of As were present in the sediment as Fe-associated and residual fractions, respectively. After 22-day incubation with acetate and lactate, the presence of indigenous bacteria increased the amount of total dissolved As from both Fe-associated and residual fractions in the sediment. More than 99% of dissolved As existed as As(V) in biotic slurries in contrast to sterile controls (less than 50% of total dissolved As), which indicated that indigenous bacteria transformed some dissolved As(III) to As(V). In real environments, depending on the pH, microbially-produced aqueous As(V) may be either immobilized through adsorption or reduced to As(III) after migration to the anoxic subsurface.

Acetates↗
PubMed2004

Removal of arsenic in tailings by soil flushing and the remediation process monitoring.

In order to investigate the optimum conditions for the application of soil flushing of arsenic, a batch test was carried out using EDTA at various concentration and pH levels. Based on the optimum condition derived from the batch test, a column test was conducted to examine the feasibility of the soil-flushing technology under field-equivalent conditions. In this column test, a low flushing solution flow rate showed a significantly higher As removal efficiency (71.6%) than a high flow rate (56.3%). TCLP (toxicity characteristic leaching procedure) and a seed germination test were carried out to monitor the toxicity both during and after the treatment. The finally treated tailings were shown to be significantly remediated, having a reduced toxicity by both the TCLP and seed germination tests.

Agriculture↗
PubMed2004

Chorioretinal scar growth after 810-nanometer laser treatment for retinoblastoma.

PURPOSE: To determine the extent of expansion of laser scars after single treatment with transpupillary thermotherapy (TTT) for retinoblastoma. DESIGN: We retrospectively reviewed medical records and RetCam (Massie Industries, Dublin, CA) digital fundus photographs of patients with retinoblastoma who received TTT by use of an 810-nm diode laser with large-spot indirect ophthalmoscope. Digital images were measured by use of RetCam software beginning immediately after treatment. Lesions were measured in both linear size and area by 2 observers. In addition, optic disc diameters were also measured for each image. PARTICIPANTS: We identified 9 patients with hereditary retinoblastoma who were treated from 1997 to 2000. MAIN OUTCOME MEASURES: Linear and area expansion of laser scars as a function of time. RESULTS: Fourteen tumors in 10 eyes were treated successfully with 1 session of TTT. Follow-up for all eyes was at least 16 months. Scars of 12 of the 14 lesions increased beyond their original borders (mean starting linear diameter, 2.02 mm; range 1.46-2.59 mm; mean increase, 0.72 mm [36%]) over time, most within 6 months to 1 year after treatment. CONCLUSIONS: Scars from TTT for retinoblastoma may increase in size after treatment. This expansion must be considered when applying TTT to tumors near vital macular structures, such as the fovea and optic nerve.

Choroid Diseases↗
PubMed2002

Bone marrow immunoscintigraphy using technetium-99m anti-granulocyte antibody in multiple myeloma.

Conventional skeletal radiography and bone scan have certain limitations in the initial evaluation of bone and bone marrow lesions in multiple myeloma (MM). In this study we investigated the value of bone marrow immunoscintigraphy (BMIS) using anti-granulocyte monoclonal antibody (AGA) for the diagnosis of bone involvement of MM, in comparison with bone scan and skeletal radiography. Whole-body BMIS using technetium-99m-labelled AGA was performed in 22 MM patients (15 male, 7 female) and the imaging findings compared with those of skeletal radiography and (99m)Tc-methylene diphosphonate bone scan. The findings of bone marrow aspiration and serum biochemical findings were also compared with BMIS findings. Abnormal findings of BMIS were defined as presence of a focal photon defect in the axial skeleton or expansion of peripheral bone marrow. A total of 124 focal lesions were detected in 19 subjects (86%) by skeletal radiography, bone scan or BMIS. BMIS detected 92 lesions (74%) in 19 subjects, whereas skeletal radiography detected 58 focal lesions (47%) in 14 and bone scan 40 lesions (32%) in 11. Fifty-one (41%) of the 124 lesions were only seen on BMIS. Spine and pelvic lesions were better visualised by BMIS, whereas skull lesions were better seen with skeletal radiography, and bone scan detected more lesions in the ribs. Marrow expansion was noted in 15 subjects (68%) on BMIS, and its grade correlated with marrow cellularity and myeloma cell percentage in bone marrow aspirates ( P=0.0055 and P=0.0541, respectively). BMIS revealed abnormal lesions in one of three stage II patients and 17 out of 19 stage III patients. The number of lesions of the thoracolumbar vertebrae on BMIS was correlated with cellularity ( P=0.0393), but not with myeloma cell percentage ( P=0.1262). These findings suggest that the results of BMIS with (99m)Tc-labelled AGA correlate with clinical stage, and thus reflect the functional status of bone marrow in MM patients. BMIS might be useful for the detection of bone involvement of MM when skeletal radiography or bone scan is inconclusive, especially for vertebral lesions.

Adult↗