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Biomedical subjects

I S Choi

Publications and source records attributed to I S Choi.

At least 19 recordsLinked to original sources
PubMed2007

Cerebellar peduncular myelinolysis in a patient receiving hemodialysis.

Here, we report the observation of extrapontine lesions, in addition to the pontine lesions previously documented in a diagnosed case of hemodialysis-associated osmotic demyelination syndrome due to end-stage renal disease. The patient exhibited lesions on bilateral middle cerebellar peduncles, and had been receiving regular hemodialysis as treatment for end-stage renal disease. He presented with progressive gait disturbance and postural instability. Accompanying symptoms included peduncular hallucinations and mild cognitive dysfunction. Brain MRI revealed high signal intensity in the area of bilateral cerebellar peduncles on the diffusion and T2-weighted images, with a decreased signal intensity noted on the ADC map. The ataxic form of osmotic myelinolysis syndrome is quite rare. The involvement of the cerebellar peduncles in extrapontine myelinolysis in a patient with end stage renal disease has not, to our knowledge, been previously reported. Here, we describe the MRI findings and clinical features associated with this unique case, and include a review of the relevant literature.

Aged↗
PubMed2005

Management of gastric lymphoma with chemotherapy alone.

PURPOSE: The optimal therapy for gastric lymphoma except MALToma has not yet been established. This study was undertaken to investigate whether gastric lymphoma can be managed effectively and safely with chemotherapy alone. PATIENTS AND METHODS: A total of 58 patients (median age 56 years) with newly diagnosed gastric lymphoma between 1989--2001 at Seoul National University Hospital and who were initially managed with chemotherapy alone were evaluated. MALToma was excluded from the pathologic review. RESULTS: All patients received initially anthracycline-containing chemotherapy. ECOG performance scale 0--1 was 88% and B symptoms were present in 41.4%. Diffuse large B cell type was the most common (74.1%). Stage IE, II1E accounted for 51.7% and II2E, IIIE, IV for 48.3%. The international prognostic index (IPI) of risk was low in 39.7%, low-intermediate in 22.4%, high-intermediate in 15.5% and high in 22.4%. The complete response rate after first-line chemotherapy was 71.4% and the partial response rate was 12.2%. (overall response rate: 83.6%). Among patients who did not reach the complete response, a further complete response was achieved by second-line chemotherapy including etoposide-based regimen. Ultimately, the maximum complete response rate by chemotherapy was 83.7% (92% in stage IE, II1E, 75% in stage II2E, IIIE, IV). Median overall survival was 47.4 months (84.7 months in stage IE, II1E, 32.5 months in stage II2E, IIIE, IV) and the 5-year survival rate was 46%. Bleeding as a complication occurred in 3 of 58 patients (5.6%) and these cases were controlled by embolization or conservative management. No perforation episode occurred and surgical intervention due to complication was not necessary. Organ preservation was possible in 57 of 58 patients (98%). The one gastrectomy was performed due to a partial clinical response to chemotherapy but the specimen showed pathologic CR. Multivariate analysis revealed that only IPI had a significant influence on survival. CONCLUSIONS: Gastric lymphoma except MALToma can be managed effectively and safely with chemotherapy alone.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

Quantitative analysis of interleukin-6 expression in porcine spleen cells and alveolar macrophages using real-time PCR.

Interleukin-6 (IL-6), a multifocal cytokine produced by lymphoid and non-lymphoid cells, regulates immune responses, acute-phase reactions against bacterial infections, and haematopoiesis. After cloning and sequencing of porcine IL-6, the expression pattern of porcine IL-6 mRNA was evaluated through real-time RT-PCR using porcine immune cells (spleen cells and alveolar macrophages) following stimulation with LPS. The sequence has been reported to GenBank with Accession no. AF 518322. The nucleotide sequence was different at the 89th and 205th positions in comparison with M80258, but only at the 205th with M86722. Comparison of porcine IL-6, Accession no. AF 518322, with IL-6 of human, canine, ovine, and mouse showed homologies of 78%, 81%, 82% and 73% in nucleotide sequence and 42%, 69%, 61% and 42% in amino acids. Expression of IL-6 mRNA was induced by stimulation with LPS. IL-6 mRNA expression in alveolar macrophages peaked at 2 h and decreased sharply to control levels at 4 h, whereas it peaked at 14 h and decreased at 24 h in spleen cells after stimulation with LPS (1 microg/ml). These results suggest that IL-6 mRNA expression in porcine immune cells is cell-type specific and the results of this study could be used as the basis for research on the porcine immune system.

Amino Acid Sequence↗
PubMed2004

Influence of mass transfer and chemical reaction on ozonation of azo dyes.

Azo dyes can be only mineralised by chemical oxidation. In this paper the oxidation of Reactive Black 5 (RB 5) and Reactive Orange 96 (RO 96) with concentrations between 35 and 5,700 mgL(-1) (RB 5) and between 20 and 2,050 mgL(-1) (RO 96) was investigated in a lab-scale bubble column. The reactor was modelled for two cases, a completely mixed and a plug flow gas phase. The oxidation rate was influenced by mass transfer for all dye concentrations used. For low dye concentrations mass transfer alone was decisive for the reaction rate showing no enhancement due to chemical reaction, E approximately equal to 1. However, in the region of high dye concentrations, the slope of the ozone concentration profile inside the liquid boundary layer increases more and more with increasing dye concentration as a result of a chemical oxidation. Therefore, the enhancement factor depends on the type and concentration of the azo dyes. For RB 5, a diazo dye, an enhancement factor of E = 5.5 was observed for cd = 2,000 mgL(-1), RO 96, a mono azo dye, with a remarkably higher chemical oxidation rate shows an E = 16 for cd = 2,050 mgL(-1).

Azo Compounds↗
PubMed2003

Effects of BCG revaccination on asthma.

In a study conducted 1 year ago, we found that Th1 immune enhancement following Bacille Calmette-Guérin (BCG) vaccination effectively suppressed human asthma. To investigate whether revaccination would further improve lung function, BCG vaccine was given again. Current lung function tended to improve in the Repeated BCG group (n = 9), but not in the Single BCG group (previously the placebo group) (n = 11), compared with that 1 year ago. The BCG vaccination improved lung function in both groups, and the Repeated BCG group showed a significant increase in the peripheral blood interferon gamma/interleukin 4 ratio. These findings suggest that repeated BCG vaccinations might be effective in asthma therapy.

Adult↗
PubMed2002

Atopy may be related to exercise-induced bronchospasm in asthma.

BACKGROUND: Recent studies suggest that atopy may be associated with exercise-induced bronchospasm (EIB) in asthma. However, it is not clear whether atopy is related to EIB, regardless of airway hyper-responsiveness (AHR) to methacholine, because asthmatic subjects often show AHR to exercise and methacholine simultaneously. OBJECTIVE: To investigate whether atopy is related to EIB in asthmatic subjects, independently of AHR to methacholine. METHODS: Fifty-eight male asthmatic subjects were studied. Initial spirometry was performed. Skin prick test was carried out, using 53 common allergens including mites dust antigen. Atopy score was defined as a sum of mean weal diameters to all allergens tested. Methacholine bronchial provocation testing was performed. Twenty-four hours later, free running test was performed. Positive EIB was defined as a 15% reduction or more in FEV1 from baseline after exercise. RESULTS: All subjects had AHR to methacholine. The degree of AHR to methacholine in asthmatics with EIB was similar to that in asthmatics without EIB. However, atopy score and skin reaction to Dermatophagoides pteronyssinus significantly increased in asthmatics with EIB compared with those without EIB (P < 0.05, respectively). Furthermore, the degree of EIB significantly correlated with atopy score in all subjects (r = 0.35, P < 0.01). This relationship was maintained even after the exclusion of EIB-negative asthmatic subjects. CONCLUSION: Atopy defined as skin test reactivity may contribute to the development of EIB in asthma, independently of AHR to methacholine.

Adult↗
PubMed2002

Relationship between changes in interferon-gamma production by peripheral blood T cells and changes in peak expiratory flow rate in patients with chronic stable asthma.

BACKGROUND: Cytokines production by T helper lymphocytes (Th cells), which orchestrate the interplay of the different cells involved in airway inflammation of asthma, may be reflected in peripheral blood. Some studies have suggested that the Th cell cytokines by peripheral blood T cells correlate with asthma severity. OBJECTIVE: To investigate the relationship between changes in IFN-gamma production by peripheral blood T cells and changes in lung function in chronic stable asthmatics. METHODS: Sixteen patients with chronic stable moderate asthma aged 35-65 years (nine women) were recruited. Morning and evening peak expiratory flow rates (PEFR) monitoring and blood sampling for peripheral blood T cell culture, total IgE and blood eosinophils were performed at baseline and week 12. Levels of IFN-gamma, IL-4 and IL-5 in culture supernatants of peripheral blood T cell were determined by using enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: Patients with increased IFN-gamma changes from baseline showed significantly increased changes in morning (P = 0.02) and evening (P < 0.05) PEFR compared with those with decreased IFN-gamma changes. The changes in IFN-gamma production and IFN-gamma: IL-4 ratio significantly correlated with the changes in morning PEFR (Rs = 0.59, P < 0.02; Rs = 0.63, P < 0.01, respectively) and tended to correlate with the changes in evening PEFR (Rs = 0.45, P = 0.08; Rs = 0.5, P = 0.05, respectively). The changes in IL-4 and IL-5 did not correlate with the changes in IgE and blood eosinophils, respectively. CONCLUSIONS: These findings suggest that IFN-gamma may be associated with the alteration of lung function in asthmatics and play a role in the pathophysiology of chronic stable asthma.

Adult↗
PubMed2002

Relationship between the perception of dyspnoea and airway inflammatory markers.

Poor dyspnoea perception in asthmatic patients seems to be associated with increased risk of asthma exacerbation. We have studied the relationship between basel ne dyspnoea perception and inflammatory markers in sputum in eight patients with mild asthma and in 13 patients with moderate to severe asthma. The perception of dyspnoea was scored on the Borg scale. Eosinophilic cationic protein (ECP) was measured by fluoroimmunoassay and by an interleukin (IL)-5 sandwich ELISA. The baseline Borg score was significantly higher in patients with severe asthma than in patients with mild to moderate asthma (4.1 +/- 0.29 vs. 2.28 +/- 0.28, P<0.05). The proportion of eosinophil and ECP levels in the sputum were significantly higher in patients with moderate to severe asthma. IL-5 in sputum was significantly increased in moderate to severe asthmatic patients compared to mild asthmatic patients. A significant relationship was found between the baseline perception score and FEV1/FVC (r = -0.53, P<0.01), sputum eosinophils (r = 0.70, P<0.01) and sputum ECP (r = 0.62, P<0.01). These findings suggest that the baseline perception score is related to inflammatory markers in sputum, and that the perception of dyspnoea as well as airway inflammatory markers may be considered to evaluate asthma severity.

Acute Disease↗
PubMed2001

Vascular effects of synthetic or natural progestagen combined with conjugated equine estrogen in healthy postmenopausal women.

BACKGROUND: Synthetic, not natural, progestagen may negate the favorable effects of estrogen. Nonetheless, observational studies report no differences in risk for clinical cardiovascular events between users of unopposed estrogen and users of estrogen combined with synthetic progestin. METHODS AND RESULTS: In a double-blind study, we randomly assigned 20 healthy postmenopausal women to micronized progesterone (MP) 200 mg or medroxyprogesterone acetate (MPA) 10 mg for 10 days with conjugated equine estrogen (CEE) 0.625 mg for 25 days and the remaining 5 days off cyclically during 2 months, followed by crossover to the alternate therapy. CEE+MP and CEE+MPA significantly improved the percent flow-mediated dilator response to hyperemia relative to baseline measurements (P=0.004 by ANOVA) by a similar degree (P=0.863). Both therapies significantly decreased E-selectin, intercellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule (VCAM)-1 levels from baseline values (P<0.001, P=0.048, and P=0.016 by ANOVA, respectively) by a similar degree (P=0.977 for ICAM-1 and P=0.541 for VCAM-1, respectively). CEE+MPA decreased E-selectin levels more than CEE+MP did (P=0.040). Both therapies significantly decreased monocyte chemoattractant protein-1 levels from baseline values (P<0.005 by ANOVA) by a similar degree (P=0.194). Both therapies significantly decreased tissue factor antigen and increased tissue factor activity levels from baseline values (P=0.003 and P<0.001 by ANOVA, respectively) by a similar degree (P=0.652 for antigen and P=0.173 for activity). Both therapies significantly lowered plasma plasminogen activator inhibitor-1 levels from baseline values (P<0.001 by ANOVA) by a similar degree (P=0.533). CONCLUSIONS: CEE+MP and CEE+MPA provide similar improvement in endothelium-dependent vasodilator responsiveness and effects on markers of inflammation, hemostasis, and fibrinolysis inhibition in healthy postmenopausal women.

Chemokine CCL2↗
PubMed2001

Efficacy of heparin-coated stent in early setting of acute myocardial infarction.

Primary stenting has been reported to be superior to balloon percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI) for recurrent ischemia, target lesion revascularization, and restenosis. However, concerns about early reocclusion or thrombosis after stenting in the very thrombotic environment of acute myocardial infarction still remain. Therefore, postprocedural short-term heparin or GpII(b)/III(a) receptor blockades has been used. The aim of our study was to evaluate the safety, feasibility, and long-term efficacy of heparin-coated stent in the early setting of AMI without postprocedural heparin or GpII(b)/III(a) receptor blockade infusion. We studied 102 consecutive patients presenting to cardiac catheterization laboratory < or = 6 hr from the onset of chest pain. No patients who were implanted with heparin-coated stents received heparin or GpII(b)/III(a) receptor blockade infusion after the procedures, not even patients who showed an angiographically large thrombus burden before stenting. Patients were evaluated for clinical endpoints at 30 days and 6 months. Coronary angiography was required for all patients at 2 weeks and 6 months after the procedure. Angiographic and procedural successes were 100% and 98%, respectively. Two patients (2%) died of heart failure without evidence of reocclusion of stented vessel during the hospitalization and 4 (4%) additional patients died of refractory heart failure within the first 6 months. Major bleeding complication occurred in one patient (1%). Recurrent myocardial infarction developed in one patient at 4 months. Early angiographic follow up at 2 weeks was performed in 88% of all patients, none of whom showed thrombotic stent occlusion. Six-month angiographic follow-up was completed in 71%(64/91) of eligible patients and binary restenosis was present in 17.2% of stented vessels. Eight(8%) patients underwent repeat PTCA. Cardiac event-free survival rate at 6 months was 86.3%. This study demonstrates that heparin-coated stents are safe in the early setting of acute myocardial infarction and no additional heparin infusion after stenting is necessary, which may reduce bleeding complications. Angiographic restenosis rate compares favorably to the binary restenosis rate from other studies with uncoated stents.

Adult↗
PubMed2001

Outdoor air pollutants derived from industrial processes may be causally related to the development of asthma in children.

BACKGROUND: There is no consistent evidence that outdoor air pollutants are involved in the development of asthma. OBJECTIVE: The aim of this study was to determine whether outdoor air pollutants derived from industrial processes were related to the prevalence of asthma, bronchial hyperresponsiveness, and atopy in exposed children. METHODS: A total of 7,511 children from 7 to 12 years of age were recruited in the study. Eight hundred eighty-eight of 1,009 (88%) of the subjects living around industrial factories and 5,998 of 6,502 (92%) living in a less polluted neighboring area responded to the ISAAC questionnaire. A total of 1,492 subjects 8 to 9 years old underwent skin prick tests for 11 common aeroallergens. A total of 732 of the subjects from 8 to 9 years of age underwent bronchial provocation tests with hypertonic saline (BPT-HS). RESULTS: The prevalence of ever experiencing wheezing and wheeze during the last 12 months was 25.6%, and 18.8% among the children living in the more polluted area. This was significantly higher than for those living in the less polluted area (14.2% and 9.0%, respectively). The positive rate of BPT-HS (the provocative dose of hypertonic saline causing 20% fall of FEV, < or = 23 mL) was higher among those in the more polluted area than in children living in the less polluted area (12.2% vs 7.5%). However, the rate of atopy based on the skin tests was the same in the two groups (28.3% vs 30.6%). CONCLUSIONS: The prevalence of asthma and bronchial hyperresponsiveness was higher among children living around the heavily industrial area compared with those living in the less polluted area, despite similar atopic sensitization.

Air Pollutants↗
PubMed2001

Desensitization to urine-derived gonadotropins in a woman with secondary infertility.

BACKGROUND: Urine-derived gonadotropins have been used to treat infertility but may cause allergic reactions. IgE-mediated hypersensitivity reactions can be treated with desensitization, especially when new therapies such as recombinant human gonadotropins are unavailable. OBJECTIVE: This case is described to highlight a successful intervention with desensitization in a woman with a complicated history of secondary infertility. She had been treated with ovulation-induction regimens, such as IVF-M (in vitro fertilization-human menopausal gonadotropin [hMG]) and IVF-C (human chorionic gonadotropin [hCG]), for intrauterine insemination. During treatment, however, she experienced reactions to IVF-M and IVF-C. Because she strongly wanted a baby and no alternative preparation was available, desensitization was attempted. METHODS: Intradermal tests with IVF-M and IVF-C using both negative and positive controls were performed on the patient and four normal control subjects. Immediate wheal-and-flare reactions occurred only in the patient. ELISA and ELISA inhibition tests showed positive responses to IVF-M and IVF-C, but not to highly purified hMG, hCG, or D-mannitol, a preservative in IVF-M and IVF-C. Desensitization to IVF-M and IVF-C was done with a protocol used for parenteral desensitization to penicillin. RESULTS: During the IVF-M desensitization, the intramuscular injections were well tolerated. For the next 2 days, daily administration of IVF-M was uneventful. Thirty-six hours later, desensitization to IVF-C was performed successfully. The patient had two intrauterine inseminations and became pregnant. CONCLUSIONS: Nongonadotropin proteins in urine-derived gonadotropins cause IgE-mediated hypersensitivity reactions. Acute desensitization to urine-derived gonadotropins can be performed effectively, as shown in our current case.

Adult↗
PubMed2001

Molecule-mimetic chemistry and mesoscale self-assembly.

Molecules are structured aggregates of atoms joined by chemical bonds; crystals are aggregates of molecules, interacting covalently or noncovalently. The work described in this Account uses molecules, crystals, and other forms of atomic/molecular matter to suggest principles that can be used in generating structured aggregates of millimeter-scale components, interacting through capillary interactions. The properties of these aggregates--that is, their "chemistry"--mimic aspects of the chemistry of molecules.

Crystallization↗