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Biomedical subjects

H Choi

Publications and source records attributed to H Choi.

At least 145 records · Page 8Linked to original sources
PubMed1994

Urinary methamphetamine concentration following famprofazone administration.

A 37-year-old man had a considerable concentration of methamphetamine in his urine, but he denied taking any abused drug. It was found that he took a pain killer that contains famprofazone, a relatively strong analgesic whose metabolites include methamphetamine and amphetamine. The human urinary metabolism of famprofazone was investigated. Immunoassay was used as a preliminary test, and gas chromatography with flame-ionization detection and gas chromatography-mass spectrometry were used for quantitation and confirmation.

Adult↗
PubMed1994

Latex antigens induce IgE and eosinophils in mice.

Hypersensitivity to latex proteins has been reported with increasing frequency in recent years. Elevated levels of latex specific IgE have been detected in the majority of these patients. Severe anaphylaxis and death resulting from latex exposure has also been reported. Nevertheless, the immune mechanism of latex allergy is not fully understood. In this report, we describe a model of latex allergy developed in mice exposed to latex proteins. Animals exposed to latex proteins demonstrated enhanced levels of total IgE, peripheral blood and lung eosinophilia, and elevated levels of serum IL-4 and IL-5. mRNA transcripts of IL-4 and IL-5, but not IFN-gamma, could be demonstrated in spleen lymphocytes. Antibodies to latex belonging to all IgG subclasses were detected in the sera of mice exposed to latex antigens. The histology of the lung showed non-necrotizing granulomas and extensive interstitial chronic inflammatory infiltrates, particularly around bronchioles and small blood vessels. Although this model of latex allergy demonstrates a heterogeneous immunological response, the CD4-positive Th2 cell-mediated response predominated.

Animals↗
PubMed1994

Genetic mapping of a locus for multiple epiphyseal dysplasia (EDM2) to a region of chromosome 1 containing a type IX collagen gene.

Multiple epiphyseal dysplasia (MED) is a dominantly inherited chondrodysplasia characterized by mild short stature and early-onset osteoarthrosis. Some forms of MED clinically resemble another chondrodysplasia phenotype, the mild form of pseudoachondroplasia (PSACH). On the basis of their clinical similarities as well as similar ultrastructural and biochemical features in cartilage from some patients, it has been proposed that MED and PSACH belong to a single bone-dysplasia family. Recently, both mild and severe PSACH as well as a form of MED have been linked to the same interval on chromosome 19, suggesting that they may be allelic disorders. Linkage studies with the chromosome 19 markers were carried out in a large family with MED and excluded the previously identified interval. Using this family, we have identified an MED locus on the short arm of chromosome 1, in a region containing the gene (COL9A2) that encodes the alpha 2 chain of type IX collagen, a structural component of the cartilage extracellular matrix.

Child↗
PubMed1993

Aspergillus fumigatus antigen induced eosinophilia in mice is abrogated by anti-IL-5 antibody.

A murine model of allergic bronchopulmonary aspergillosis (ABPA), developed by exposure to Aspergillus fumigatus antigens, demonstrated eosinophilia of peripheral blood (PB), bone marrow (BM), and lung. The eosinophilia was abrogated by monoclonal anti-interleukin-5 (IL-5) antibody (TRFK-5) and not by an isotype control antibody (GL 113). Eosinophils in PB were enumerated from stained smears and their relative increase or decrease in cells from BM and lung was determined by an eosinophil peroxidase (EPO) assay (measured in optical density). Intraperitoneal injection of TRFK-5 in mice exposed to A. fumigatus antigen produced a significant reduction in eosinophils (PB 6.6 +/- 1.14% vs. 3.8 +/- 0.8%, P < .01) and EPO production in BM (0.935 +/- 0.03 vs. 0.615 +/- 0.02, P < .001). A similar reduction in EPO production in the lung (0.691 +/- 0.12 vs. 0.495 +/- 0.05, not significant) was also reflected in the histopathology for the different groups of mice. These findings confirming the role of IL-5 in eosinophilia, although not surprising, are significant in elucidating the immunopathogenesis of ABPA in the murine model. We conclude that in this model, eosinophilia may be due largely to the Th2 cytokine -IL-5 induced by A. fumigatus antigens.

Animals↗
PubMed1993

Cardiopulmonary resuscitation without intermittent positive pressure ventilation.

The purpose of this study was to examine whether tracheal insufflation of oxygen (TRIO) could be used as a substitute for intermittent positive pressure ventilation (IPPV) during cardiopulmonary resuscitation (CPR) in dogs with orotracheal intubation. Twenty-seven anesthetized, paralyzed and intubated dogs were used. The tip of the insufflation catheter was placed 1 cm distal to the top of the endotracheal tube. The effects of TRIO at a flow rate of 10 l/min with or without a continuous positive airway pressure (CPAP) of 5 cmH2O during external cardiac compressions were compared with those managed under the standard CPR. During CPR, TRIO without CPAP maintained adequate gas exchange. Peak airway pressures in the TRIO groups were significantly lower than that in the standard CPR group. No significant differences were observed in arterial, pulmonary artery and diastolic right atrial pressures during CPR among the three groups. However, the coronary perfusion pressures in the TRIO group with CPAP always tended to be low during CPR. The present study suggests that TRIO without CPAP should be a promising substitute for IPPV during CPR when IPPV is not feasible.

Animals↗
PubMed1993

The alterations of cellular metabolism in the contralateral testis following spermatic cord torsion in rats.

Cellular metabolic study was performed on the contralateral testis after torsion to delineate early testicular changes. In 9-week-old Sprague-Dawley rats the left testicle was rotated and fixed to the scrotum for 3, 8 and 24 hours in 3 groups (I, II and III). Each group was divided into 3 subgroups (a, b and c) by the length of detorsion of 0, 4 hours and 14 days. We measured adenosine triphosphate, total adenosine nucleotides and adenylate energy charge of the contralateral testis by high performance liquid chromatography. Compared to controls, no subgroups showed differences in the histological parameters. Also in subgroups Ia, Ib, Ic and IIa none of the metabolic parameters were significantly altered. However, subgroups IIb and IIc, and group III and its subgroups showed significantly decreased levels of all metabolic parameters. Therefore, it appears that unilateral testicular torsion (greater than 8 hours) and detorsion affect the contralateral testicular metabolism without gross histological changes in rats, and these changes seem to be reversible in terms of cellular recoverability because the maximally decreased level of adenylate energy charge among all subgroups is only 13% compared to controls. These findings suggest that some systemic mechanisms rather than an immunological or local inflammatory process is involved in this early period after torsion.

Adenine Nucleotides↗
PubMed1993

Cultural and noncultural factors as determinants of caregiver burden for the impaired elderly in South Korea.

This study investigated the determining variables of caregiver burden in caring for impaired older relatives in South Korea. Economic factors, daily caregiving hours, and caregiver's health status emerged as the most important determinants of caregiver burden in Korea. Though not a powerful predictor, caregivers' congruency with the traditional caregiver selection norms remained a statistically significant predictor of certain dimensions of caregiver burden.

Adolescent↗
PubMed1993

Comparison of methods for the Fmoc solid-phase synthesis and cleavage of a peptide containing both tryptophan and arginine.

A major side reaction which can occur during the synthesis of Trp-containing peptides is modification of the Trp indole by reactive carbonium ion species released during acidolytic cleavage. [Asn2,Trp4]Dynorphin A-(1-13), a sequence which is very susceptible to Trp modification, was chosen as a model peptide to compare the effectiveness of various methods proposed to minimize Trp modification during Fmoc solid-phase synthesis. The peptide was synthesized with the side chain of Trp unprotected and cleaved by Reagent K [82.5% trifluoroacetic acid (TFA)/5% phenol/5% water/5% thioanisole/2.5% ethanedithiol (EDT)] [King, D.S. et al. (1990) Int. J. Peptide Protein Res. 36, 255-266], Reagent R [90% TFA/5% thioanisole/3% EDT/2% anisole] [Albericio, F. et al. (1990) J. Org. Chem. 55, 3730-3743], TFA containing 20% EDT and 4% water [Riniker, B. & Hartmann, A. (1990) in Peptides: Chemistry, Structure, and Biology (Rivier, J.E. & Marshall, G.R., eds.), pp. 950-952, Escom, Leiden], and TFA containing trialkylsilane, MeOH, and ethylmethyl sulfide [Chan, W.C. & Bycroft, B.W. (1992) in Peptides: Chemistry, Structure, and Biology, Op. cit., pp. 613-614]. Cleavage with Reagent K, Reagent R and TFA containing 20% EDT and 4% water yielded similar results; in addition to the desired peptide, the crude product contained 22-30% of a side product which appeared to result from Trp modification by a Pmc group. Cleavage with the trialkylsilane-containing mixture gave the lowest recovery of the desired peptide and the highest levels of Pmc-containing peptides.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

Experimental results using nafamostat mesilate as anticoagulant during extracorporeal lung assist for 24 hours in dogs.

We report on the experimental application of nafamostat mesilate (NM, 6-amidino-2-naphthyl p-guanidinobenzoate dimethanesulfonate, FUT), a new anticoagulant, to extracorporeal lung assist (ECLA) with an artificial membrane lung. Venovenous ECLA, from the jugular vein to the femoral vein, was performed with a hollow-fiber membrane lung at a blood flow rate of approximate 82 ml kg-1 min-1 for 24 h in 7 dogs under anesthesia and hypoventilation. Heparin (10 U ml-1 in a priming lactated Ringer solution of 140 ml, and 200 U kg-1) was administered before blood access cannulation. After start of ECLA, however, no heparin was used, and nafamostat mesilate was continuously infused into the drainage line of the bypass circuit to control activated coagulation time (ACT) at about 150 to 200 s. To maintain the prolonged ACT, 8.0 +/- 1.7 mg kg-1 h-1 of NM was required. Arterial blood pressure and pulse rate decreased significantly. Though fibrin monomer test revealed hypercoagulability after 6 h of ECLA, platelet counts did not significantly decrease. Total blood loss remained less than 40 g. The artificial membrane lung sustained a good gas exchange and low flow resistance throughout ECLA. Macroscopic examination revealed small spotty thrombi in the artificial lung but no major pathologic changes of the visceral organs in the all dogs at autopsy. High-dose NM administration could control blood coagulation and decrease blood loss during ECLA for 24 h without deterioration of the artificial lung and systemic complication other than mild hypotension and bradycardia.

Animals↗
PubMed1993

The effect of glucose on proteoglycans produced by cultured mesangial cells.

Altered proteoglycan metabolism may play a role in the development of diabetic glomerulopathy. This study was conducted to examine the effects of glucose on the production and physical characteristics of proteoglycans generated by rat mesangial cells in culture. Rat mesangial cells were exposed to elevated glucose media (500 mg/dl) or standard glucose media (200 mg/dl) for 8-10 days, and proteoglycan synthesis was determined using 35S-labeling in conjunction with anion exchange and sizing chromatography. Rat mesangial cells generated predominantly chondroitin/dermatan sulfate proteoglycans, with small amounts of heparan sulfate proteoglycans. High glucose did not alter the number of rat mesangial cells after 24 h or after 8-10 days, compared with cells grown under standard glucose conditions. The total amount of glycosaminoglycan generated and the sizes of the major proteoglycans were not different between cultures grown in standard and elevated glucose medium. Levels of mRNA for the proteoglycan, biglycan (as assessed by Northern blot analysis), also were comparable between the standard and elevated glucose conditions. Exposure to media high in glucose did not change the rate of secretion of proteoglycans from the cell layer to the medium, but did result in a greater quantity of radiolabeled proteoglycan deposited in the extracellular matrix. The cell, extracellular matrix and medium proteoglycans isolated from the elevated glucose cultures, consistently eluted from the anion exchange column at a lower [NaCl] compared with those generated under standard glucose conditions, indicating a loss of anionic charges.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Urodynamic evaluation in pediatric neurogenic bladder.

Urodynamic evaluation in pediatric neurogenic bladder is prerequisite for accurate prediction of prognosis and selection of appropriate treatment modality. We classified normal, hyperreflexic and areflexic bladders by cystometry. Hyperreflexic bladder was subdivided into two groups with or without detrusor sphincter dyssynergia and areflexic bladder into low pressure and high pressure. Among 36 patients with myelodysplasia on whom we performed a videourodynamic study vesicoureteral reflux was found in three of 7 patients with hyperreflexia with detrusor sphincter dyssynergia, two of 6 patients with hyperreflexia without detrusor sphincter dyssynergia and five of 10 patients with areflexia with high pressure. Low pressure areflexic bladder didn't show vesicoureteral reflux. When we evaluated 39 pediatric neurogenic bladder patients with a mean 25.5 follow-up months period, upper tract deterioration was improved and normal findings persisted in all the compliant patients to treatment. In the noncompliant group initial abnormal upper tract findings persisted or aggravated, especially in hyperreflexic bladder with dyssynergia and high pressure areflexic bladder. One of the three hyperreflexic bladders with dyssynergia and two of six high pressure areflexic bladders received augmented cystoplasty. These data show that urodynamic evaluation in pediatric neurogenic bladder provides excellent criteria for selecting high risk groups in pediatric neurogenic bladder.

Adolescent↗
PubMed1992

A murine model of allergic bronchopulmonary aspergillosis with elevated eosinophils and IgE.

A model of allergic bronchopulmonary aspergillosis was developed by exposing BALB/c mice to Aspergillus fumigatus (AF) Ag. Animals immunized intranasally (i.n.) with soluble AF Ag produced low levels of serum IgE compared to animals given alum precipitated AF Ag i.p. The latter treatment also produced higher levels of serum IgG1 and AF-specific IgG1 than soluble AF given i.p. or i.n.. Blood and lung eosinophilia was detected in mice repeatedly exposed to AF by i.n. but not in the groups injected i.p. Particulate AF Ag-induced striking blood and lung eosinophilia and elevated levels of serum IgE in mice preexposed to AF Ag. The results indicate that route of inoculation and physical nature of Ag determine the immune response and can be manipulated to obtain enhanced IgE, eosinophils, or both in the animal model.

Administration, Intranasal↗
PubMed1992

Structural analysis on the single-stranded genomic DNAs of the virus newly isolated from silkworm: the DNA molecules share a common terminal sequence.

Recently, a parvo-like virus was newly isolated from silkworm larvae and the two viral DNAs (VD1 and VD2) with different electro-mobilities were identified. We cloned the viral DNAs in a plasmid pUC119 and demonstrated that these two DNAs were not a bimorphic molecules though they shared a common terminal sequence of 53 nucleotides. In addition, the sequence at the 5' terminus of each strand of the viral DNA was located in inverted form at its 3' terminus. On the other hand, the nucleotide sequences of VD1 and VD2 were different from that of the Bombyx densovirus (Ina isolate) DNA.

Animals↗
PubMed1992

Gas-exchange function of a preprimed pediatric oxygenator stored for one year for emergency cardiopulmonary bypass.

To save priming time and perform more rapid initiation of emergency cardiopulmonary bypass for acute cardiopulmonary failure, an extracorporeal circuit with a hollow-fiber oxygenator (EL-2000 for pediatric use; Kurary Co. Ltd., Osaka, Japan) was preprimed, and the gas-exchange function was evaluated after 1 year of storage. EL-2000 has a dense polyolefin membrane with a surface area of 0.3 m2. When the bypass flow rates were 250, 500, 1,000, and 1,500 ml/min with 100% oxygen at the same flow rate as the bypass blood flow (namely, V/Q = 1) to the oxygenator, oxygen transport rates of the stored oxygenator were 19.6 +/- 0.3, 38.3 +/- 0.41, 64.4 +/- 0.9, and 76.4 +/- 2.7 ml/min (n = 5, mean +/- SD), respectively. PCO2 differences between pre- and postoxygenator blood (delta PCO2) were 18.6 +/- 1.4, 12.0 +/- 1.6, and 4.4 +/- 1.2 mm Hg at V/Q = 1 and the same bypass blood flow rates, respectively, excluding 1,500 ml/min, the data for which were excluded because of preparatory failure. PCO2 removal indices (defined as the ratio of delta PCO2 to PCO2 in preoxygenator blood) were 0.45 +/- 0.03, 0.29 +/- 0.12, and 0.10 +/- 0.03, respectively. Though the evaluation was done using only a single oxygenator, we feel strongly that the gas-exchange function of the preprimed dense-membrane hollow fiber oxygenator will be preserved even after 1 year of storage.

Cardiopulmonary Bypass↗
PubMed1992

Incidence estimation of genitourinary cancer in Korea.

A nation-wide study was performed to estimate the incidence of bladder, kidney, renal pelvis and ureter, prostate, testicular and other genitourinary cancer among Koreans in Korea using medical records of the inpatients of the beneficiaries of the Korea Medical Insurance Corporation (KMIC) from Jan. 1, 1989 to Dec. 31, 1989. The crude incidence rate of bladder cancer (ICD-9 188) is estimated to be 4.43 and 0.98 per 100,000 in males and females, respectively. Around 1,093 new cases of bladder cancer (895 male and 198 female) are estimated to occur in a year. The adjusted rate for the world population is 7.76 in males and 1.19 in females which is similar to that of Japanese in Osaka and Chinese in Shanghai, but lower than in American whites and blacks. The crude incidence of kidney, renal pelvis and ureteral cancer (ICD-9 189) is estimated to be 1.61 and 0.87 in males and females, respectively. Around 507 new cases of kidney, renal pelvis and ureteral cancer (332 male and 175 female) are estimated to occur in a year. The adjusted rate for the world population is 2.69 in males and 1.04 in females. In the prostate (ICD-9 185), the crude incidence rate of cancer is estimated to be 1.36. Around 274 new cases of prostate cancer are occurring in a year. The adjusted rate for the world population is 2.98 which is similar to the Chinese rate. The incidence of genitourinary cancer continuously increases with age.

Adult↗