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Biomedical subjects

S K Kang

Publications and source records attributed to S K Kang.

At least 127 records · Page 7Linked to original sources
PubMed1993

Biological exposure indices of organic solvents for Korean workers.

Biological exposure indices (BEIs) of toluene, perchloroethylene (PCE) and methyl ethyl ketone (MEK) for Korean workers were studied respectively. Exposure in workplace to organic solvents were measured by personal sampling. Blood toluene, blood PCE, urinary trichloroacetic acid and urinary MEK were determined by headspace GC. Urinary hippuric acid was determined by HPLC and corrected for creatinine. BEIs for Korean workers were calculated with the levels of the determinants corresponding to permissible exposure limits in Korea which were the same with TLV of ACGIH. Blood toluene level of 2.2 mg/l and urinary hippuric acid level of 1.7 g/g creatinine corresponded to exposure of 100 ppm toluene. Blood PCE concentration of 1.6 mg/l and urinary trichloroacetic acid concentration of 2.9 mg/l corresponded to exposure to 50 ppm PCE. Urinary MEK concentration of 1.4 mg/l corresponded to exposure to 200 ppm of MEK. In conclusion, BEIs for Korean workers determined in this study were different to ACGIH's BEI as urinary determinants were lower and blood determinants were higher than ACGIH's BEI.

Adult↗
PubMed1992

Microleakage of new crown and fixed partial denture luting agents.

This study measured the in vitro microleakage of conventional and new FPD luting agents. Standardized preparations were made on 42 freshly extracted premolars. Facial and lingual chamfer margins were placed in enamel, mesial and distal in dentin and cementum, and castings were made in Rexillium III alloy and were then cemented with a standardized technique. Six groups of seven samples were tested, (1) polycarboxylate, (2) zinc phosphate, (3) glass ionomer, (4) Den-Mat Thin Film cement, (5) Panavia Ex, and (6) Den-Mat Thin Film cement with Tenure. The ranking of groups for stain ingress was from the greatest (1) to the least (6). A one-way analysis of variance and Tukey-Student range analysis revealed significantly similar groups, p less than 0.05:(1,2,3,4) (5,6).

Adhesives↗
PubMed1992

Molecular cloning and characterization of an alkalophilic Bacillus sp. C125 gene homologous to Bacillus subtilis sec Y.

A 1.8 kb HindIII DNA fragment containing the secY gene of alkalophilic Bacillus sp. C125 has been cloned into plasmid pUC119 using the B. subtilis secY gene as a probe. The complete nucleotide sequence of the cloned DNA indicated that it contained one complete ORF and parts of two other ORFs. The similarity of these ORFs to the sequences of the B. subtilis proteins indicated that they were the genes for ribosomal protein L15-SecY-adenylate kinase, in that order. The gene product of the alkalophilic Bacillus sp. C125 secY homologue was composed of 431 amino acids and its M(r) value has been calculated to be 47,100. The distribution of hydrophobic amino acids in the gene product suggested that the protein was a membrane integrated protein with ten transmembrane segments. The total amino acid sequence of alkalophilic Bacillus sp. C125 secY homologue showed 69.7% homology with that of B. subtilis secY. Regions of remarkably high homology (78% identity) were present in transmembrane regions, and cytoplasmic domains (73% identity) with less homologous regions present in extracellular domains (43% identity).

Amino Acid Sequence↗
PubMed1991

Porcelain-composite interface microleakage with various porcelain surface treatments.

This study evaluated the effects of various porcelain surface treatments on the microleakage of the porcelain-composite interface. The experimental model isolated and evaluated only the porcelain-composite interface without the presence of a bond to tooth structure. Four types of porcelain were fired into circular porcelain tabs 1.0 mm thick by 8.5 mm in diameter. The groups of porcelain were divided into subgroups for treatment with hydrofluoric acid-etching and silane. A jig standardizing composite thickness to 0.2 mm was used to photopolymerize composite to porcelain. The margins were finished and polished with burs and disks. Samples were stored in 37 degrees C water thermocycled 1000X, placed in AgNO3 solution, embedded in epoxy, and cross-sectioned every 90 degrees for measurement of stain penetration at the composite-porcelain interface. Occasional crazing of porcelain from composite polymerization shrinkage was observed. Porcelain surface treatment significantly increased the specimens' ability to withstand water storage and thermal-cycling procedures. Porcelain surface treatment with silane alone did not reduce microleakage, but, in combination with etching, reduced microleakage significantly.

Acid Etching, Dental↗
PubMed1991

Changes of lactate dehydrogenase and its isoenzyme activity in renal diseases.

Analysis of the five different serum isoenzymes of lactate dehydrogenase (LDH) is of great value in the differential diagnosis of various diseases. In order to investigate the changes of serum LDH isoenzymes in several renal diseases, 44 patients with Korean hemorrhagic fever, 10 patients with chronic renal failure, 10 patients with nephrotic syndrome, and 15 healthy subjects were studied. The isoenzymes of LDH were determined by the Helena LDH isoenzyme electrophoresis procedure. LDH1 was 22.3 +/- 2.8, LDH2 29.4 +/- 5.1, LDH3 20.8 +/- 4.5, LDH4 9.0 +/- 2.7 and LDH5 8.8 +/- 3.2 mU/ml in healthy subjects. In patients in the oliguric stage of Korean hemorrhagic fever, LDH1 was 63.4 +/- 28.5, LDH2 99.7 +/- 40.7, LDH3 107.5 +/- 39.0, LDH4 41.9 +/- 32.8 and LDH5 37.2 +/- 26.3 mU/ml, while LDH1 was 23.8 +/- 11.7, LDH2 38.9 +/- 14.6, LDH3 36.0 +/- 18.7, LDH4 13.8 +/- 13.0 and LDH5 12.7 +/- 7.6 mU/ml in nonoliguric patients. In patients with chronic renal failure LDH1 was 33.2 +/- 10.8, LDH2 41.9 +/- 13.3, LDH3 27.7 +/- 8.5, LDH4 12.1 +/- 6.2 and LDH5 12.3 +/- 5.8 mU/ml. In patients with nephrotic syndrome, LDH1 was 25.1 +/- 4.3, LDH2 33.5 +/- 4.9, LDH3 23.1 +/- 6.2, LDH4 8.4 +/- 3.7 and LDH5 8.4 +/- 3.4 mU/ml. In summary, LDH3 activity was elevated in the oliguric stage of Korean hemorrhagic fever and LDH2 was elevated in chronic renal failure; those values were correlated with the BUN level.

Adolescent↗
PubMed1991

Pulmonary lymphangioleiomyomatosis in a male.

Pulmonary lymphangioleiomyomatosis has been observed almost exclusively in women, usually in their reproductive years. Exacerbations with pregnancy and after hormonal manipulation have been documented, and it has been suggested that its pathogenesis is due to the influence of hormonal(estrogenic) stimulus. The clinical, roentgenographic, and histopathologic features of this case of pulmonary lymphangioleiomyomatosis in a 22-year-old male are all characteristic of those described in prior reports, except for the patient's sex. With the following case of pulmonary lymphangioleiomyomatosis in a male, we suggest the possibility of the existence of an additional pathogenetic mechanism.

Adult↗
PubMed1990

Toxic acute renal failure and hepatitis after ingestion of raw carp bile.

The raw carp bile has both nephrotoxic and hepatotoxic effects which are not well known. Recently, we studied 13 patients who had toxic acute renal failure and toxic hepatitis after ingestion of raw bile of carp in 3, grass carp in 8 and silver carp in 2 cases. The purpose of this report is to alert physicians to this very rare cause of toxic acute renal failure and hepatitis. All patients presented initially with gastrointestinal upset after eating. These symptoms were followed by oliguria in 7 patients (54%), hematuria was noted in 10 (77%) and jaundice in 8 patients (62%). Elevation of blood urea nitrogen, creatinine and transaminases lasted for about 3 weeks. The severity of the symptoms depended on the amount of bile ingested. All the patients recovered with conservative therapy and hemodialysis. Biopsy of the kidney revealed findings compatible with acute tubular necrosis similar to that produced by other nephrotoxins. Biopsy of the liver revealed findings consistent with acute toxic hepatitis. Both suggest toxic effects of carp bile as a cause of toxic acute renal failure and hepatitis.

Acute Kidney Injury↗
PubMed1990

Leptospirosis in Chonbuk Province of Korea in 1987.

Leptospirosis is a zoonosis with protean clinical manifestations. Its diagnosis requires a high index of suspicion and is confirmed by isolation of the organism or, more commonly, by serologic tests. In the fall of 1987, after severe flooding, we saw 93 patients with leptospirosis, confirmed by a microagglutination test. Thirteen percent of the patients had no clinical or laboratory findings except fever and headache, but the rest had mild to severe manifestations. Jaundice, renal failure, and aseptic meningitis were not common, but pulmonary symptoms, when present, were striking. The mortality rate was 5%. The main cause of death was asphyxiation due to massive hemoptysis from pulmonary hemorrhage and acute respiratory failure.

Adolescent↗
PubMed1989

Red cell sodium and ionic fluxes in patients with hyper- and hypothyroidism.

To investigate the status of the Na+ concentrations [Na+]i, K+ concentrations [K+]i and ionic fluxes in red cells of human subjects with abnormal thyroid function, we measured the Na(+)-K+ pump activity as well as Na(+)-K+ cotransport (CoT), Na(+)-Li+ countertransport (CTT) and Na+ passive permeability in erythrocytes of 37 normal subjects, 19 untreated hyperthyroid patients, 12 treated hyperthyroid patients and 9 hypothyroid patients with T4 replacement. The mean [Na+]i value in the untreated hyperthyroidism group was significantly higher than that in the normal subjects (p less than .05), but not significantly different from that in the treated hyperthyroidism group. The mean [Na+]i value in the hypothyroidism with T4 replacement group, however, was significantly lower than that in the normal group (p less than .01). We did not find any significant difference of [K+]i in comparing each group. It was found that the Na(+)-K+ pump activity in erythrocytes was significantly increased in untreated hyperthyroidism (mean; 23.4% above control, p less than 10(-5], but there was no significant difference in treated hyperthyroidism and hypothyroid patients with T4 replacement. The rate constant for ouabain-sensitive Na+ efflux in the hypothyroidism with T4 replacement group was markedly higher than that in normal subjects (p less than .01), but not significantly different in the untreated hyperthyroidism group. We observed a significant increase of the Na+ CoT value in the patients with untreated hyperthyroidism as compared with that of the normal subjects (p less than .05), but there was no significant difference in the patients treated for hyperthyroidism and the hypothyroidism with T4 replacement group. However, the rate constant for Na(+)-CoT in the patients with hypothyroidism with T4 replacement was significantly higher than that in normal subjects (p less than .05). We observed a marked decrease of Na(+)-Li+CTT value in the patients with untreated hyperthyroidism versus that in the normal group (p less than .01). Passive Na+ permeability in the patients with untreated hyperthyroidism was markedly increased (p less than .05), and was markedly decreased in the patients with hypothyroidism with T4 replacement compared to normal subjects (p less than .01). It can be concluded from these studies that an increase in Na(+)-K+ pump activity in the patients untreated for hyperthyroidism might then be regarded as a secondary adaptive cellular response to higher [Na+]i values due to enhanced passive Na+ permeability, rather than a direct effect of the thyroid hormone.

Adult↗
PubMed1989

Effects of cyclosporin A on insulin binding and action in isolated fat cells of rat.

To study the effect of cyclosporin A (CsA) on glucose metabolism in peripheral insulin target cells, we studied the intraperitoneal glucose tolerance test (i.p. GTT), insulin binding, glucose transport and lipogenesis in isolated adipocytes of CsA-treated male Wistar rats. The rats were treated for 7 days with an intramuscular injection of vehicle (control group), or 5 (group I) or 50 mg/kg body weight (group II) of CsA dissolved in ethanol. The results of i.p. GTT in group II showed markedly impaired glucose tolerance with significantly decreased basal and glucose-stimulated serum insulin levels. In isolated adipocytes of CsA-treated rats, the insulin bindings were decreased by 26% in group I and 32% in group II. The maximum insulin-stimulated glucose transports were decreased by 34% in group I and 41% in group II. The maximum insulin-stimulated lipogenesis was decreased by 33% in group I and 37% in group II. There was a right shift of the dose response curves for insulin of glucose transport and lipogenesis of both CsA-treated groups. In conclusion, these results suggest that CsA produces significant functional changes of pancreatic B cells and also induces insulin resistance in adipocytes due to combined receptor and postreceptor defects in insulin action.

Adipose Tissue↗
PubMed1989

[Clinical and histopathologic study of salivary mucoceles].

Mucoceles are commonly occurring lesions of the oral mucous membrane and the most common lesion involving minor salivary tissue. The incidence of mucoceles is understandable since accessary salivary gland tissue is widely distributed throughout the oral mucous membrane and trauma to the mucosa, which causes their formation, occurs frequently. But only a few studies have been reported that describe its detailed features. This is a retrospective study on the salivary mucoceles in the oral mucous membrane and based on clinical chart, biopsy request and photomicroscopic finding of 112 patients treated by Dept. of Oral Surgery in Seoul National University Hospital, during the period of last 10 years. The results were as following. 1. The age range of the 112 patients was 2 to 60 years, with a peak incidence in the second decade and a gradual decline thereafter. Of the 112 patients, 49 (44%) were males and 63 (56%) were females, the male-to-female ratio being 1:1.29. 2. The majority of these lesions were located on the lower lip but occurred with lesser frequently on the buccal mucosa, floor of the mouth, tongue, retromolar region, upper lip. 3. Of the 112 patients, 107 (95%) were treated by excision and only 5 were treated by marsupialization. 18 of 112 cases had recurrence and the recurrence rate in this study was 16%. 4. Only 3 of the 112 cases revealed an epithelial lining. This incidence indicates that the mucus-extravasation by the damage of excretory duct rather than the ductal dilatation by mucus-retention may play a critical role in the production of these lesions. 5. In 81 cases (72.3%) minor salivary gland were included in the excision biopsy, specimen. Changes observed in the glandular tissue were atrophy and infiltration of chronic inflammatory cell, but the secretory function of gland was thought to be normal in most cases because the changes were mild.

Adolescent↗
PubMed1989

Leptospirosis in Chonbuk Province of Korea in 1987: a study of 93 patients.

Leptospirosis is a zoonosis with protean clinical manifestation. Diagnosis requires a high index of suspicion and is confirmed by isolation of the organism or, more commonly, by serologic studies. In the fall of 1987, after severe flooding, we saw 93 patients with leptospirosis, confirmed by a microagglutination test. Thirteen percent of the patients had no clinical or laboratory findings except fever and headache, but the rest had mild to severe manifestations. Jaundice, renal failure, and aseptic meningitis were not common, but pulmonary symptoms, when present, were striking. The mortality rate was 5%. The main cause of death was asphyxiation due to massive hemoptysis from pulmonary hemorrhage and acute respiratory failure.

Agglutination Tests↗