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Biomedical subjects

S H Cho

Publications and source records attributed to S H Cho.

At least 127 records · Page 7Linked to original sources
PubMed1999

Management of foreign bodies in the gastrointestinal tract: an analysis of 104 cases in children.

BACKGROUND AND STUDY AIMS: Ingested foreign bodies may be managed by endoscopy, observation, or surgery. The aim of the study was to investigate the methods of removal of foreign bodies according to type and location, success rates, and complications. PATIENTS AND METHODS: The charts of 104 children who had ingested foreign bodies were retrospectively reviewed. RESULTS: Of the patients, 80 (76.9%) were managed endoscopically. The overall success rate for endoscopic management was 98.8%. There were no complications during endoscopic interventions. In 23 cases the foreign bodies spontaneously passed through the gastrointestinal tract (22.1%). Surgical removal of a foreign body was done in only one case (0.96%). The majority of the foreign bodies which were located in the upper gastrointestinal tract could be removed endoscopically regardless of the nature of the material. Foreign bodies in the small and large intestine tended to pass through spontaneously without complications. CONCLUSIONS: It appears that the endoscopic approach is the preferable method for the extraction of upper gastrointestinal foreign bodies in child patients because of its high success rate, and that foreign bodies in the small and large intestine tend to be passed spontaneously without complications.

Adolescent↗
PubMed1999

Monte Carlo calculations of the dose backscatter factor for monoenergetic electrons.

Recently, there has been growing interest in beta emitters for therapeutic uses, especially in connection with so-called endovascular (or intravascular) brachytherapy. Since accurate dose estimation is necessary for the success of such applications, some problems in beta-ray dosimetry need further study. Among these problems, we have investigated the effect of electron backscattering on dose, which has significance not only for accurate dose estimation but also for new source design. In this study, an empirical measure of electron backscattering, known as the dose backscatter factor, was calculated using EGS4 Monte Carlo calculations for monoenergetic electrons and various scattering materials. Electron energies were 0.1, 0.5, 1.0, 2.0 and 3.0 MeV in combination with Al (Z = 13), Ti (Z = 22), Sr (Z = 38), Ag (Z = 47) and Pt (Z = 78) scatterers. The dose backscatter factor ranged from 10% to 60%, depending on electron energy and material, and was found to increase with the atomic number Z by a log(Z + 1) relationship. A method is presented for calculating the beta-ray dose backscatter factors using the results of this study. To demonstrate the efficacy of this method, a dose backscatter factor depth profile for 32P near a water/aluminium interface was calculated and these calculated results were found to generally reproduce the depth profile obtained from direct EGS4 calculations using the 32P spectrum. The data presented in this study can be used to calculate dose backscatter factors for any combination of beta emitter/scatterer whose atomic number ranges from 13 to 78.

Beta Particles↗
PubMed1999

Primary total hip arthroplasty with the AML total hip prosthesis.

Primary total hip arthroplasty using an uncemented AML total hip prosthesis (trispiked cup and a 4/5 porous coated stem) was performed in 50 patients (52 hips). The average age of the patients at the time of surgery was 47.6 years (range, 19-68 years), and the diagnosis was osteonecrosis of the femoral head in 18 hips, osteoarthritis in 16, fracture of the femoral neck in 14, osteoarthrosis secondary to childhood pyogenic arthritis in two, childhood tuberculous arthritis in one, and traumatic arthritis in one. The average followup was 11.3 years (range, 11-12 years). The average preoperative Harris Hip Score was 59 points, which improved to 90 points. Twenty-five (48%) hips had excellent results, 14 (27%) had good results, three (6%) had fair results, and 10 (19%) had poor results. The overall rate of revision was 15% (eight hips). The rate of revision of the femoral component was 2% (one hip), and the rate of revision of the acetabular component was 15% (eight hips). Twenty (38%) hips had acetabular and femoral osteolysis. Nine (17%) hips had femoral osteolysis only. Thirty-four (65%) hips had an average of 3.3 mm (range, 2-12 mm) of wear in the polyethylene liner. The average wear rate was 0.29 mm (range, 0.17 to 1.04 mm) per year.

Adult↗
PubMed1999

Fatty marrow conversion of the proximal femoral metaphysis in osteonecrotic hips.

To determine whether fatty marrow conversion of the proximal femoral metaphysis is related to osteonecrosis of the femoral head using a marrow conversion index ([signal intensity of the proximal femoral metaphysis/signal intensity of the greater trochanter] x 100 in T1 weighted magnetic resonance images), a case control study was conducted on 42 osteonecrotic hips in 28 patients. The 28 patients (42 osteonecrotic hips) were matched with 84 control patients (84 normal hips) for gender, age (5-year range), and time of presentation (1-year range). The marrow conversion index was measured in each hip studied. The index was 90.2% (standard deviation, 8.2%) in osteonecrotic hips and 75.1% (standard deviation, 9.1%) in matched controls. By conditional logistic regression, a 5% increase in the index was associated with 3.6 times increase of the odds ratio of osteonecrosis and a 10% increase with a 12.9 times increase of the odds ratio. The marrow conversion index, which reflects the ratio of fatty marrow conversion of the proximal femoral metaphysis to that of the greater trochanter measured on T1 weighted magnetic resonance images, is increased in osteonecrotic hips.

Adipose Tissue↗
PubMed1999

Determination of the tissue attenuation factor along two major axes of a high dose rate (HDR) 192Ir source.

Quantitative information on photon scattering around brachytherapy sources is needed to develop dose calculation formalisms capable of predicting dosimetric parameters with minimal empiricism. Photon absorption and scatter around brachytherapy sources can be characterized using the tissue attenuation factor, defined as the ratio of dose in water to water kerma in free space. In this study, the tissue attenuation factor along two major axes of a high dose rate (HDR) 192Ir source was determined by TLD measurements and MCNP Monte Carlo calculations. A calculational method is also suggested to derive the tissue attenuation factor along the longitudinal source axis from the factor along the transverse axis, using published anisotropy data as input. TLD and Monte Carlo results agreed with each other for both source axes within the statistical uncertainty (approximately +/- 5%) of Monte Carlo calculations. Comparison with published data, available only for the transverse source axis, also showed good agreement within +/- 5%. The shape and magnitude of the tissue attenuation factor are found to be remarkably different between the two axes. The tissue attenuation factor reaches a maximum value of about 1.4 at 8 cm from the source along the longitudinal source axis, while a maximum value of about 1.04 occurs at 3-4 cm from the source along the transverse axis. The calculated tissue attenuation factor along the longitudinal source axis generally reproduced the TLD and Monte Carlo results within +/- 5% at most radial distances.

Anisotropy↗
PubMed1999

Bone marrow edema and associated pain in early stage osteonecrosis of the femoral head: prospective study with serial MR images.

PURPOSE: To determine whether the marrow edema around focal osteonecrosis on magnetic resonance (MR) images is associated with clinical symptoms. MATERIALS AND METHODS: Thirty-three patients with 37 hips showing early stage osteonecrosis of the femoral head were followed up at 3-month intervals with clinical evaluation, conventional radiography, and serial MR imaging. RESULTS: Seven (50%) of 14 symptomatic hips showed marrow edema around focal osteonecrosis on initial MR images, whereas only one (4%) of 23 asymptomatic hips showed edema (P < .01). Six (86%) of seven hips that were moderately to severely painful were associated with surrounding marrow edema. All eight hips showing osteonecrosis with marrow edema at the initial MR examination had joint effusion and exhibited intense radionuclide uptake in the proximal femur, which corresponded to the extent of edema on MR images. In all eight hips, the marrow edema resolved on follow-up MR images, and the pain subsided with the resolution of edema. CONCLUSION: The results of this study suggest that the combination of marrow edema of the proximal femur and focal osteonecrosis of the femoral head are strongly associated with hip pain in early stage osteonecrosis, even prior to collapse. Pain improvement usually parallels the resolution of edema.

Adolescent↗
PubMed1999

Lavender oil inhibits immediate-type allergic reaction in mice and rats.

We studied the effects of lavender oil on mast cell-mediated immediate-type allergic reactions in mice and rats. Lavender oil (1:500, 1:100, 1:10, 1:1, 1:0) inhibited concentration-dependently mast cell-dependent ear swelling response induced by compound 48/80 in mice by both topical and intradermal application. Lavender oil (1:500, 1:100, 1:10, 1:1, 1:0) inhibited concentration-dependently passive cutaneous anaphylaxis induced by anti-dinitrophenyl (DNP) IgE in rats by both topical and intradermal application. Lavender oil (1:500, 1:100, 1:10, 1:1, 1:0) also inhibited concentration-dependently the histamine release from the peritoneal mast cells by compound 48/80 or anti-DNP IgE. Moreover, lavender oil (1:1000, 1:100, 1:10, 1:0) had a significant inhibitory effect on anti-DNP IgE-induced tumour necrosis factor-alpha secretion from peritoneal mast cells. These results indicate that lavender oil inhibits immediate-type allergic reactions by inhibition of mast cell degranulation in-vivo and in-vitro.

Anaphylaxis↗
PubMed1999

Preparation of antibodies directed to the Babesia ovata- or Theileria sergenti-parasitized erythrocytes.

To investigate the surface antigens of the bovine red blood cells (RBCs) parasitized by Babesia ovata or Theileria sergenti, attempts were made to produce monoclonal antibodies (mAbs) with BALB/c mice. Comparable numbers of hybridomas producing anti-piroplasm mAbs, as well as anti-bovine RBC mAbs, were obtained from the mice immunized with B. ovata- or T. sergenti-PRBCs. However, mAbs directed to the surface of parasitized RBCs (PRBCs) were obtained only from the mice immunized with B. ovata-PRBCs, but not from those immunized with T. sergenti-PRBCs. When serum samples from the immunized mice and the infected cattle were examined, antibodies recognizing B. ovata-PRBC surface were detected in the sera against B. ovata, but analogous antibodies were undetectable in the sera against T. sergenti, despite that the sera showed substantial antibody titers to T. sergenti piroplasms. The results suggest that significant antigenic modifications occur on the surface of B. ovata-PRBCs, but not on the surface of T. sergenti-PRBCs.

Animals↗
PubMed1999

Total knee arthroplasty in bony ankylosis in gross flexion.

Between June 1993 and December 1994, we performed total knee arthroplasty (TKA) on 27 knees in 24 patients with spontaneous bony ankylosis in severe flexion. The mean age at operation was 43.5 years (30 to 60). No patient had preoperative pain. Three were unable to walk and 21 could manage less than five blocks. The mean duration of the ankylosis was 18.7 years (13 to 25) and its mean position was 105 degree flexion (75 to 135). The preoperative Hospital for Special Surgery Knee Score of 60 points was improved to 87 at the final follow-up three to five years later. All knees were free from pain. The mean range of active flexion in 24 knees was 97 degrees (78 to 115) and the mean arc of movement 91 degrees (78 to 98). The mean fixed flexion deformity was 6 degrees (0 to 25) and the extension lag 8 degrees (0 to 25). Angular deformity was corrected to between 0 degrees and 10 degrees of valgus. Four patients were able to walk one block and 20 five to seven blocks. Thirteen knees (48%) showed some necrosis at the skin edge; one knee required arthrodesis and another resection arthroplasty. One had a recurrence of tuberculous infection requiring arthrodesis. One patient had a rupture of the quadriceps tendon. To date no prosthesis has required revision for loosening. Radiolucency of 1 mm or less about the tibial prosthesis was observed at follow-up in four of the 24 knees. Our results have shown that one-stage TKA and skeletal traction after operation can achieve correction of severe flexion deformity of the knee with marked improvement in the function and quality of life.

Adult↗
PubMed1999

Exposure to hexavalent chromium does not increase 8-hydroxydeoxyguanosine levels in Korean chromate pigment workers.

This study was performed to determine whether chromium exposure increased 8-hydroxydeoxyguanosine levels in respiratory epithelial and white blood cells of chromate pigment workers. The subjects of this study were 22 chromium pigment workers and 16 controls in a chromate pigments factory. To estimate the level of exposure, hexavalent chromium concentrations in the factory air were measured. Chrominum concentrations of venous blood and spot urine, and 8-hydroxydeoxyguanosine levels in DNA extracted from sputum and white blood cells were determined. Correlation coefficients were calculated between them and their statistical significance was tested. Hexavalent chromium concentration in the factory air ranged from below limit of detection to 0.5150 mg/m3. Chromium levels in blood and 8-hydroxydeoxyguanosine levels in DNA extracted from venous blood and sputum were not statistically different between the two groups. Urine chromium level was significantly higher among workers. Among the correlation coefficients between blood chromium concentration, urine chromium concentration, blood 8-OH-dG level, and sputum 8-OH-dG level, none was statistically significant for workers, controls, and total subjects. Duration of employment did not show any significant correlation with those four variables, either. These results suggest that neither the hydroxyl radical nor 8-hydroxydeoxyguanosine is formed by the reduction of hexavalent chromium, or that one or both of these is formed and then effectively removed by oxygen free radical scavengers or 8-hydroxydeoxyguanosine repair enzymes. Since increased exposure to hexavalent chromium did not result in increased 8-hydroxydeoxyguanosine levels, it is unlikely that hexavalent chromium induces lung cancer through 8-hydroxydeoxyguanosine formation.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1999

Comparison of basophil histamine releasability between atopic and nonatopic asthmatics.

To compare the mediator releasability between atopic and nonatopic asthmatics, we measured basophil histamine releasability (BaHR) using a calcium-ionophore A23187 and anti-IgE in 137 subjects who were treated at Seoul National University Hospital. Subjects were categorized into atopic (group AA, n=77) or nonatopic asthmatics (group NA, n=32), or normal controls (group NC, n=28). Serum total IgE levels were determined and correlation with BaHR was assessed. Anti-IgE-induced maximal BaHR in groups AA, NA, and NC was 41.0+/-3.2, 23.1+/-4.5, and 16.8+/-3.8, respectively (mean+/-SE, %). Anti-IgE-induced BaHR in group AA was significantly higher than that in groups NA and NC (p<0.05). Calcium ionophore A23187-induced maximal BaHR was 43.1+/-2.8, 40.8+/-4.4, and 50.5+/-5.2, respectively (mean+/-SE, %), and there was no significant difference among the groups. Serum total IgE level correlated significantly with anti-IgE-induced maximal BaHR (r=0.281, p<0.01) but not with that induced by calcium ionophore A23187. In conclusion, IgE receptor-related BaHR is higher in atopic asthmatics than in nonatopic asthmatics, and this increased BaHR in atopics is significantly associated with increased serum total IgE level.

Asthma↗
PubMed1999

Comparison of CD34+ subsets and clonogenicity in human bone marrow, granulocyte colony-stimulating factor-mobilized peripheral blood, and cord blood.

To compare the clonogenicity and distribution of CD34+ subsets in bone marrow (BM), granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood (PB) and cord blood (CB), we analyzed in vitro colony formation and CD34+ cells co-expressing differentiation molecules (CD38, HLA-DR), myeloid associated molecules (CD13, CD33), a T-cell associated molecule (CD3), and a B-cell associated molecule (CD19) from mononuclear cells (MNCs) in the three compartments. The proportions of CD34+CD38- cells (BM: 4.4+/-2.8%, PB: 5.3+/-2.1%, CB: 5.9+/-3.9%) and CD34+HLA-DR cells (BM: 4.7+/-3.4%, PB: 5.5+/-2.3%, CB: 6.1+/-3.7%) did not differ significantly among the compartments. In contrast, a significantly higher proportion of CD34 cells of PB and CB co-expressed CD13 (75.0+/-11.4%, 77.7+/-17.3%) and CD33 (67.1 +/-5.7%, 56.8+/-10.3%) compared with those of BM (43.0+/-6.3%, 27.6+/-5.1%) and a significantly higher number of granulocyte-macrophage colony-forming units (CFU-GM) and erythroid burst-forming units (BFU-E) were detected in MNCs derived from PB and CB compared with those from BM (p<0.01). The proportion of CD34+CD19+ cells was higher in BM (34.9+/-11.9%) than those in PB (5.6+/-3.0%) and CB (4.7=2.1%) (p<0.05). The proportion of CD34+CD3+ was comparable in all three compartments. In conclusion, our findings show that MNCs of mobilized PB and CB display similar phenotypic profiles of CD34+ subsets and clonogenicity, different from those of BM.

Adult↗
PubMed1999

Large subcutaneous calcification in systemic lupus erythematosus: treatment with oral aluminum hydroxide administration followed by surgical excision.

A 32-year-old woman with a long-standing systemic lupus erythematosus had multiple subcutaneous nodules on her axillae, iliac crests and limbs. Three years ago, these nodules began to appear and slowly became larger. Some of them amassed to form a large, fungating, lobulated mass on her right iliac crest. Roentgenographic and histological examination showed that they were calcium deposits. She was initially treated with aluminum hydroxide administration for nine months, which resulted in moderate decrease in size and softening in consistency, but not complete resolution. Then, the mass on the right iliac crest was excised, with an excellent early result.

Administration, Oral↗
PubMed1999

Effects of BCG, lymphotoxin and bee venom on insulitis and development of IDDM in non-obese diabetic mice.

To investigate whether BCG, lymphtoxin (LT) or bee venom (BV) can prevent insulitis and development of diabetes in non-obese diabetic (NOD) mice, we measured the degree of insulitis and incidence of diabetes in 24 ICR and 96 female NOD mice. NOD mice were randomly assigned to control, BCG-, LT-, and BV-treated groups. The BCG was given once at 6 weeks of age, and LT was given in 3 weekly doses from the age of 4 to 10 weeks. The BV was injected in 2 weekly doses from the age of 4 to 10 weeks. Diabetes started in control group at 18 weeks of age, in BCG group at 24 weeks of age, and in LT- or BV-treated group at 23 weeks of age. Cumulative incidences of diabetes at 25 weeks of age in control, BCG-, LT-, and BV-treated NOD mice are 58, 17, 25, and 21%, respectively. Incidence and severity of insulitis were reduced by BCG, LT and BV treatment. In conclusion, these results suggest that BCG, LT or BV treatment in NOD mice at early age inhibit insulitis, onset and cumulative incidence of diabetes.

Adjuvants, Immunologic↗
PubMed1999

Assessment of myocardial metaiodobenzylguanidine uptake and its relation to left ventricular systolic and diastolic functional parameters in dilated cardiomyopathy.

The purpose of this study was to assess the relation between myocardial metaiodobenzylguanidine (MIBG) uptake and left ventricular systolic and diastolic functional parameters, both of which are known as predictors of prognosis in patients with dilated cardiomyopathy. Echocardiography and iodine-123-MIBG myocardial scintigraphy were performed in 35 patients of dilated cardiomyopathy with normal sinus rhythm. Mean myocardial MIBG uptake in the patient group at early and delayed images were significantly lower than those in normal control subjects (10.6 +/- 1.1, 9.8 +/- 1.2 vs 12.4 +/- 1.0, 12.1 +/- 1.0, p < 0.01). There were, however, no significant differences of mean MIBG uptake in the lung and mediastinum between the two groups (p > 0.05). There were no significant correlations between myocardial MIBG uptake, expressed as the ratio of heart/mediastinum MIBG activity at delayed image, and left ventricular systolic and diastolic functional parameters [left ventricular ejection fraction, left ventricular end-diastolic dimension, peak velocity of early diastolic filling (E velocity), deceleration time of E wave, cardiac output, left ventricular end-diastolic pressure]. In conclusion, the myocardial uptake of MIBG is decreased in patients with dilated cardiomyopathy assessed by iodine-123-MIBG myocardial scintigraphy. There were, however, no significant correlations between myocardial MIBG uptake and left ventricular systolic and diastolic functional parameters derived from echocardiography.

3-Iodobenzylguanidine↗
PubMed1999

A case of parenchymal pulmonary endometriosis.

Pulmonary Endometriosis is a rare disease entity and we report a 23-year-old single woman with a history of hemoptysis in association with menstruation. She was previously treated effectively with hormone therapy for 3 months, but decided to undergo surgical resection because of the high cost of hormone therapy. Radiographic finding of the chest showed haziness in the right lower lung field, and chest CT showed a ground-glass appearance in the posterobasal and laterobasal segment. The patient underwent basal segmentectomy of the right lower lobe. There was no incidence of hemoptysis during her menstruation following the operation.

Adult↗
PubMed1998

Identification and characterization of the inducible murine mast cell gene, imc-415.

Activation of mast cells results in the generation and release of bioactive mediators which in turn initiate allergic inflammation. Mast cell function is enhanced following stimulation in part because of the induction of specific genes and their products. To identify additional genes induced in mast cells that support this process, we thus constructed an activation-specific mast cell subtraction library. To date, we have isolated 26 novel inducible murine mast cell (imc) cDNA clones. Among them, a full-coding region of the murine gene imc-415 was found to have a greater than 90% nucleotide sequence homology and a 97.5% amino acid sequence homology to both a human beta4 integrin-binding protein (p27(BBP)) and a human translation initiation factor 6 (eIF6), which in turn are identical. In vitro translation of the imc-415 gene yielded a band of an approximately 26 kDa. This is the same as the calculated molecular weight of murine IMC-415 protein based on the predicted amino acid sequence and is the molecular weight of p27(BBP)/eIF6. Murine imc-415 message was also induced in inflamed lung tissues in a mouse model of asthma. These results suggest a role for murine imc-415 in allergic inflammation where it may enhance protein synthesis. Human eIF6/p27(BBP) may also play a role in allergic diseases based on the similarities in sequence and in gene expression patterns.

Amino Acid Sequence↗