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Biomedical subjects

Y S Shim

Publications and source records attributed to Y S Shim.

At least 55 records · Page 3Linked to original sources
PubMed1997

Isoniazid resistance and the point mutation of codon 463 of katG gene of Mycobacterium tuberculosis.

It has long been known that almost all isoniazid (INH) resistant mycobacteria lose the catalase and peroxidase activities along with reduced or no virulence for guinea pigs. Recently resistance to INH has become known to be associated with mutations of katG gene encoding the HPI (Hydroperoxidase I) type catalase and peroxidase. Among these mutations, the point mutation of codon 463 of katG gene is found frequently, and is suggested as being associated with INH resistance. Therefore we performed this study in order to confirm the correlation between the point mutation of codon 463 of the katG gene and INH resistance of M. tuberculosis in Korea. Fifty isolates, 32 of which were resistant to INH, and 18 of which were sensitive to INH, were selected for this study. We used PCR-SSCP and RFLP analysis to detect the point mutation of the codon 463 of katG gene and confirmed the CGG (arginine) to CTG (leucine) mutation by direct sequencing analysis. Among 32 resistant isolates, 7 isolates (22%) had the same restriction pattern compared with that of the reference strain (H37Rv), and 25 isolates (78%) showed a different restriction pattern. Among 18 sensitive isolates, 7 isolates (39%) had the same restriction pattern compared with that of H37Rv, and 11 isolates (61%) showed a different restriction pattern. These results suggest that the CGG to CTG change of codon 463 of katG gene of M. tuberculosis may be a polymorphism not related with INH resistance.

Antitubercular Agents↗
PubMed1996

Identification of the DNA damage-responsive elements of the rhp51+ gene, a recA and RAD51 homolog from the fission yeast Schizosaccharomyces pombe.

The Schizosaccharomyces pombe rhp51+ gene encodes a recombinational repair protein that shares significant sequence identities with the bacterial RecA and the Saccharomyces cerevisiae RAD51 protein. Levels of rhp51+ mRNA increase following several types of DNA damage or inhibition of DNA synthesis. An rhp51::ura4 fusion gene was used to identify the cis-acting promoter elements involved in regulating rhp51+ expression in response to DNA damage. Two elements, designated DRE1 and DRE2 (for damage-responsive element), match a decamer consensus URS (upstream repressing sequence) found in the promoters of many other DNA repair and metabolism genes from S. cerevisiae. However, our results show that DRE1 and DRE2 each function as a UAS (upstream activating sequence) rather than a URS and are also required for DNA-damage inducibility of the gene. A 20-bp fragment located downstream of both DRE1 and DRE2 is responsible for URS function. The DRE1 and DRE2 elements cross-competed for binding to two proteins of 45 and 59 kDa. DNase I footprint analysis suggests that DRE1 and DRE2 bind to the same DNA-binding proteins. These results suggest that the DRE-binding proteins may play an important role in the DNA-damage inducibility of rhp51+ expression.

Base Sequence↗
PubMed1996

Endobronchial tuberculosis.

Endobronchial tuberculosis (EBTB) is a highly infectious disease that remains a diagnostic challenge in the developed countries. It also presents as a troublesome therapeutic problem due to its sequelae of cicatrical stenosis. Due to the worldwide decrease of tuberculosis, diagnosis of EBTB is frequently delayed until the onset of serious bronchial stenosis with resultant atelectasis and bronchiectasis. The exact pathogenesis of EBTB is not yet completely understood and the course of EBTB differs according to the type. The prognosis of actively caseating type and edematous-hyperemic type EBTB is grave, resulting fibrostenosis in two thirds of patients. Fibrostenotic type EBTB shows no change or worsening of stenosis. The prognosis is good for granular and non-specific bronchitic type EBTB; however, the prognosis of tumorous type is poor, frequently resulting in bronchial stenosis despite adequate treatment. Antituberculous chemotherapy is effective in controlling the infection, but does not prevent residual bronchostenosis. Early treatment with steroid therapy is effective in certain groups of EBTB. Balloon dilatation and stent insertion is an effective treatment of bronchial stenosis id obstruction of the stent by granulation tissue overgrowth can be prevented. Future research should focus on the pathogenesis of bronchial inflammatory reaction and resulting fibrosis to prevent bronchial stenosis at the early stage.

Adolescent↗
PubMed1996

Prognostic factors of patients with thymoma.

OBJECTIVES: To analyze the prognostic factors influencing the survival of patients with thymoma, clinical characteristics, treatment modalities and survival of patients were evaluated. The efficacy of chemotherapy was also determined. METHODS: Retrospective study was done on one hundred patients whose diagnosis was confirmed pathologically at Seoul National University Hospital from 1981 to 1994. The staging was carried out according to the Masaoka system. Survival rate was calculated by the Kaplan-Meier method and prognostic factors were analyzed by a multivariate analysis (Weibull model). RESULTS: The stage of 100 patients was as follows: Stage I-50, II-6, III-27, IV A-10, IV B-7. The overall survival rates at 5 and 10 years after diagnosis were 73.1% and 58.7%, respectively. The 5-year survival differences, according to various prognostic factors, were as follows: 1) Stage: I-92.8%, II-100%, III-71.6%, IVA-25.9% and IVB-32.9% (p = 0.0029). 2) Age: < 60 years-79.5% and > or = 60 years-41.5% (p = 0.0489). 3) Extent of resection: Total patients: complete resection-87.6% and incomplete resection-50.5% (p > 0.05) Stage III: complete resection-66.7% and incomplete resection-75.5% (p > 0.05) 4) Myasthenia gravis: present-71.6% and absent-74.9% (p > 0.05) Seventeen patients were treated with a combination chemotherapy of Cyclophosphamide, Adriamycin and cisplatin(CAP). Two complete responses and seven partial responses (overall response rate of 53%) were observed with a median response duration of fourteen months. Combination chemotherapy with CAP was effective. CONCLUSIONS: Stage and age were the independent prognostic factors in patients with thymoma. However, the presence of myasthenia gravis or the extent of resection in stage III patients was not associated with the survival time.

Adolescent↗
PubMed1996

An adult case of pulmonary sling with complete tracheal ring.

Pulmonary sling is a rare congenital condition in which the left pulmonary artery arises from the right pulmonary artery forming a sling around the trachea causing tracheal compression. Many cases are associated with cardiovascular and tracheo-bronchial anomalies. When combined with complete tracheal ring, it is called "ring-sling complex". The average onset of symptoms is 2 months and about half have symptoms from birth. The anomaly, if not corrected, can be fatal within the first year of life. In an adult, it is most often asymptomatic and usually found incidentally. We report an adult case who was diagnosed as pulmonary sling with complete tracheal ring by CT and bronchoscopy along with a literature review.

Adult↗
PubMed1995

Giant lymph node hyperplasia (Castleman's disease) in the chest.

We have experienced 7 cases of giant lymph node hyperplasia in the chest from 1981 to 1992. The ages of the 1 male and 6 female patients ranged from 9.9 to 40.4 years (mean age, 29.2 +/- 10.4 years). In 4 patients, a mass was discovered in routine radiographs. Focal calcification suggesting continual enlargement over a long time was noted in 1 patient. The sites of lesions were unusual in 2 patients (intercostal space and intrapulmonary fissure). All patients underwent surgical removal of the mass. Five cases had typical features of the hyaline-vascular type, and 2 cases revealed a mixture of the hyaline-vascular type and the plasma-cell type. Follow-up was available in all patients (mean follow-up, 31.9 months). In 1 patient, recurrence was observed 9 years after surgical removal. In general, giant lymph node hyperplasia can occur anywhere in the chest, grow without symptoms, and recur in spite of complete resection. Surgical resection and close follow-up are advised.

Adult↗
PubMed1995

Evidences for possible involvement of Rhp51 protein in mitotic events including chromosome segregation.

To understand the role of the Rhp51 protein in Schizosaccharomyces pombe, we examined the phenotypes of the null mutant for the rhp51+ gene. Unlike Saccharomyces cerevisiae rad51 mutants, S. pombe rhp51 mutants (rhp51delta cells) displayed slow growth and heterogeneity in cell size, indicating perturbation of the cell cycle. Furthermore, many aberrant nuclear structures found in 4',6'-diamidino-2-phenylindole (DAPI)-stained rhp51delta cells and the caffeine hypersensitivity of the mutant cells suggested an involvement of the Rhp51 protein in normal chromosome segregation. These data suggested that the Rhp51 proteins were required for normal cell growth as well as a DNA repair pathway. Moreover, rhp51delta mutants showed a considerable sensitivity to ultraviolet (UV) light-irradiation as well as methyl methanesulfonate (MMS) treatment, indicating that the Rhp51 proteins are involved in both the active excision mechanism of UV-induced DNA damage and recombinational repair in S. pombe. Taken together, we suggest that the role(s) of the Rhp51 protein in S. pombe may be different from those of Rad51 in S. cerevisiae.

DNA Damage↗
PubMed1993

Pulmonary tuberculosis: CT findings--early active disease and sequential change with antituberculous therapy.

To evaluate findings of active pulmonary tuberculosis on computed tomographic (CT) scans and their sequential changes before and after antituberculous chemotherapy, 29 patients with newly diagnosed pulmonary tuberculosis and 12 patients with recent reactivation were studied prospectively. The diagnosis of active pulmonary tuberculosis was based on positive acid-fast bacilli in sputum (n = 29) and changes on serial radiographs obtained during treatment (n = 12). Twenty-six patients were followed up with CT during treatment for 1-20 months. Lungs from the cadavers of nine other patients, who died of pulmonary tuberculosis, were studied to provide a pathologic basis for diagnosis. At examination with CT, centrilobular lesions (nodules or branching linear structures 2-4 mm in diameter) were most commonly seen (n = 39 [95%]); in the 26 patients with follow-up, most of these lesions disappeared within 5 months after the start of treatment. In 11 of 12 patients with recent reactivation, CT clearly differentiated old fibrotic lesions from new active lesions. Lesions in and around the small airways appear to be the most characteristic CT feature of early active tuberculosis and may be a reliable criterion for disease activity.

Adult↗
PubMed1992

The first report of diffuse panbronchiolitis in Korea: five case reports.

Diffuse panbronchiolitis (DPB), which is prevalent in Japan, is known to be rare outside Japan. Although a case of diffuse panbronchiolitis in a second generation Korean was reported in Japan in 1986, no case has been reported in Korea. Recently we found 5 cases of diffuse panbronchiolitis in Korea, two histologically proven and three clinically and radiologically suspected. All 5 cases had the typical respiratory symptoms and signs and a history of chronic sinusitis. In three clinically and radiologically suspected cases, high resolution computed tomography showed the typical findings of DPB and other diseases such as pulmonary emphysema, bronchial asthma, chronic bronchitis and bronchiectasis could be ruled out. More cases of DPB are expected to be found in Korea in the near future.

Adult↗
PubMed1992

Pleuropulmonary paragonimiasis: radiologic findings in 71 patients.

Pleuropulmonary paragonimiasis is a disease caused by lung flukes characterized by migration of a juvenile worm in the early stage and by formation of cysts around the worm later on. The purpose of this study was to describe the radiologic manifestations of pleuropulmonary paragonimiasis, with special emphasis on the worm cyst and worm migration track. We retrospectively studied 71 patients who had evidence of pleuropulmonary paragonimiasis on chest radiographs (n = 71) and CT scans (n = 17). The diagnosis was based on the detection of eggs or on positive antibody tests. On chest radiographs, 59 patients (83%) had pulmonary lesions and 43 patients (61%) had pleural lesions. Pulmonary findings included patchy air-space consolidation (n = 37) with or without cystic changes; ring shadows (n = 16); and peripheral linear opacities (n = 29), which were more prominent in patients with pleural effusion. Twelve patients (17%) had bilateral pleural effusions or pneumothoraces. On CT scans, round low-attenuation cystic lesions (5-15 mm), filled either with fluid (n = 5) or gas (n = 5), were characteristically seen within the consolidation. Peripheral linear opacities seen on radiographs were suggestive of worm migration tracks on CT scans. CT may reveal an intracystic worm. Although the findings vary depending on the stage of the disease, findings on chest radiographs are usually typical of paragonimiasis. CT provides more specific information about the worm cyst and the worm migration track.

Adult↗
PubMed1992

Bronchial stenosis due to endobronchial tuberculosis: successful treatment with self-expanding metallic stent.

Endobronchial tuberculosis is present in 10-40% of patients with active pulmonary tuberculosis, and more than 90% of the patients with endobronchial tuberculosis have some degree of bronchial stenosis. The primary treatment for tuberculous bronchial stenosis is antituberculous chemotherapy combined with steroids, but some patients do not respond well, and more aggressive treatment is needed to restore the patency of the involved bronchus. Balloon dilatation of tuberculous bronchial stenosis has been reported to be successful. However, in our experience, balloon dilatation of the stenotic segment has not significantly improved patients' clinical symptoms except in those with very short segmental stenosis. We describe a case of tuberculous bronchial stenosis that was successfully treated with Gianturco self-expanding metallic stents.

Adult↗
PubMed1992

Small airway disease in rheumatoid arthritis.

Variety of pulmonary lesions are thought to be associated with rheumatoid arthritis (RA). These lesions traditionally have included pleurisy with or without effusion, Caplan's syndrome, pulmonary rheumatoid nodules, diffuse interstitial fibrosis, and pulmonary arteritis and hypertension. But little attention has been paid to the airways in RA. Recently, several reports have suggested an association between airflow limitation and RA, but its incidence is not known. Also whether there exists a parameter of disease activity of RA, suggesting the presence of small airway disease (SAD) is not clear. To answer these questions, the serologic parameters which reflect the disease activity of RA and pulmonary function tests which reflect small airway dysfunction were performed on 36 lifetime nonsmokers with RA who had normal chest x-ray findings. The prevalence of SAD and the relationships between the disease activity parameters of RA and pulmonary function were observed. The results were as follows. The percentages of patients with abnormal values for diffusing capacity, frequency dependence of compliance (C1.0/C0.0), forced expiratory flow 25-75%, Vmax50% and Vmax 75% were 45.5%, 62.5%, 40%, 22.8% and 11.4%, respectively. There was statistically significant negative correlation between C1.0/C0.0 and ESR. But consistent correlation between other pulmonary function tests and clinical and serologic parameters of RA, and differences in pulmonary function between patients who were serologically positive and negative for CRP and FANA, were not found. In conclusion, SAD, without the influence of smoking, is frequently associated with RA, but the presence of SAD cannot be predicted from any clinical and serologic parameters of RA currently in use.

Adult↗
PubMed1992

Malocclusion, body posture, and temporomandibular disorder in children with primary and mixed dentition.

Occlusal factors, body posture and TM disorders were examined in forty children with primary dentition and forty children with mixed dentition. The purpose of the study was to test the hypothesis that there is a relationship between TM disorders and malocclusion, as well as that there is a relationship between body posture and TM disorders in the examined population. Clinical examination was done by two investigators, who used a stethoscope to detect TMJ sounds. The results showed that forward head position had a significant relationship to TM disorders in the mixed dentition. Also many of the occlusal factors were closely related to TM disorders in the population examined. The prevalence of TM disorders in primary dentition was 2.5% and in the mixed dentition it was 90% in the population studied.

Bruxism↗
PubMed1992

[New classification of endobronchial tuberculosis and balloon dilatation of bronchial stenosis].

Endobronchial tuberculosis frequently leaves bronchial stenosis as the complication despite of modern efficacious chemotherapy, and it may be misdiagnosed as bronchial asthma or bronchogenic carcinoma. When bronchial stenosis involves major airway, its treatment needs such special measures as steroid therapy, surgical intervention and/or laser therapy, but the therapeutic result is often disappointing. We have introduced a new classification of endobronchial tuberculosis, analyzing bronchoscopic findings in 166 cases of endobronchial tuberculoses. Namely, endobronchial tuberculosis was classified into seven subtypes as stenotic type with fibrosis, stenotic type without fibrosis, actively caseating type, tumorous type, ulcerative type, granular type, and nonspecific bronchitic type. Actively caseating type (48 cases: 28.9%), stenotic type without fibrosis (44 cases: 26.5%), nonspecific bronchitic type (31 cases: 18.7%) and stenotic type with fibrosis (30 cases: 18.1%) were predominant in the order of frequency, but tumorous type (9 cases: 5.4%), ulcerative type (2 cases: 1.2%) and granular type (2 cases: 1.2%) were relatively uncommon. Stenotic type with or without fibrosis, actively caseating type and tumorous type of endobronchial tuberculosis were closely related to bronchial stenosis. In these cases, it is necessary to apply specific measures for preventing or minimizing bronchial stenosis. To consider the therapeutic effect of steroid on the alleviation of bronchial stenosis in endobronchial tuberculosis, it may be very effective when the interval between symptom-onset and treatment with steroid is less than 6 months. To exploit a new treatment modality for bronchial stenosis, balloon dilatation was also carried out in 12 patients with endobronchial tuberculosis. Under local anesthesia, 4F-Fogarty balloon was inserted via bronchofiberscope in ten cases and 10F-Gruentzig balloon was introduced under fluoroscopic guide in two others.(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchial Diseases↗
PubMed1991

Fluoride levels and fluoride contamination of fruit juices.

Increasing consumption of beverages as a replacement for water have made fluoride content in beverages an important issue. In this study, forty-three ready-to-drink fruit juices were examined for fluoride ion concentration. It was found that 42% of the samples had more than 1 ppm of fluoride. It was also determined that "pure" fruit juices, often grape juices, contained high levels of fluoride. Juice made from grapes separated from the skin did not contain any fluoride. Since it is common practice to use fluoride-containing insecticide in growing grapes, it is believed that contamination of these juices is occurring. Washing of grape skins produced appreciable quantities of fluoride. Given that increasing numbers of people are consuming beverages instead of water, fluoride supplementation should not be based solely upon the concentration of the drinking water, but should also consider the amount of different beverages consumed and their fluoride content.

Beverages↗
PubMed1989

Antibody changes in paragonimiasis patients after praziquantel treatment as observed by ELISA and immunoblot.

To observe antibody changes after praziquantel treatment in paragonimiasis, a total of 46 serum samples from 13 serologically diagnosed patients was collected for 4-28 months. The specific antibody (IgG) levels were measured by enzyme-linked immunosorbent assay (ELISA). All but one patient who needed retreatment became symptom-free within a week. Antibody levels were dropped near to or below a cut-off absorbance (abs.) of 0.25 in varying intervals from 4 to 18 months. Of 9 patients who were retested within 3 months, 5 revealed temporary elevation of antibody level. After the elevation, the levels began to decline slowly to negative ranges. If treated earlier after symptoms developed, the temporary elevation did not occur and intervals to negative conversion were shorter. By sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE)/immunoblot, antigen-antibody reactions in individual patient faded gradually without significant changes in reacting antigen bands.

Animals↗
PubMed1989

Transbronchial catheter drainage via fiberoptic bronchoscope in intractable lung abscess.

The use of the fiberoptic bronchoscope as a drainage procedure for lung abscess has become more and more widespread. We have recently adopted the technique of inserting a simple polyethylene catheter through the flexible fiberoptic bronchoscope into the abscess cavity of 11 patients with lung abscess. All cases had not responded to aggressive postural drainage and adequate antibiotic therapy for at least a week. The results were as follows: 1) Among 11 patients, the therapeutic response was dramatic in 6 patients. 2) In the successful group, the abscess sizes were greater than 8cm in diameter and the airfluid levels were higher than two-thirds of the cavity. 3) Additional diagnoses, other than bacterial lung abscess, could be made in 2 cases when otherwise the diagnosis would have remained in doubt. The authors suggest that catheter drainage via fiberoptic bronchoscope is an effective treatment modality in the large lung abscess with a high air-fluid level which is intractable to other medical approaches, and it is also a safe procedure.

Adult↗