Biomedical subjects

E C Kim

Publications and source records attributed to E C Kim.

At least 37 records · Page 2Linked to original sources

PubMed1998

Korean Nationwide Surveillance of Antimicrobial Resistance of bacteria in 1997.

Antimicrobial-resistant bacteria are known to be prevalent in tertiary-care hospitals in Korea. Twenty hospitals participated to this surveillance to determine the nationwide prevalence of resistance bacteria in 1997. Seven per cent and 26% of Escherichia coli and Klebsiella pneumoniae were resistant to 3rd-generation cephalosporin. Increased resistance rates, 19% of Acinetobacter baumannii to ampicillin/sulbactam, and 17% of Pseudomonas aeruginoa to imipenem, were noted. The resistance rate to fluoroquinolone rose to 24% in E. coli, 56% in A. baumannii and 42% in P. aeruginosa. Mean resistance rates were similar in all hospital groups: about 17% of P. aeruginosa to imipenem, 50% of Haemophilus influenzae to ampicillin, 70% of Staphylococcus aureus to methicillin, and 70% of pneumococci to penicillin. In conclusion, nosocomial pathogens and problem resistant organisms are prevalent in smaller hospitals too, indicating nosocomial spread is a significant cause of the increasing prevalence of resistant bacteria in Korea.

Bacterial Physiological Phenomena↗

PubMed1998

Epidemiological typing of methicillin-resistant Staphylococcus aureus outbreak isolates by pulsed-field gel electrophoresis and antibiogram.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial pathogens. In April 1997, there were five MRSA-infected patients among 16 patients in the Neonatal Intensive Care Unit (NICU), Seoul National University Hospital, which is a tertiary-care hospital with 1,500 beds. The infections had spread from twin patients with MRSA who had transferred from Hospital C. MRSA was isolated from the axilla of 15 (94%) of the 16 patients, including the two patients with obvious infections. Three (19%) of 16 doctors and nine (30%) of 30 nurses had MRSA colonization of the anterior nares. Six different PFGE patterns (A through F) were identified in the 53 isolates of MRSA tested. Twelve of 13 isolates from infected sites of five patients showed pattern F. Three MRSA strains obtained from hospital C showed closely or possibly related pattern F. MRSA of type F was isolated from three of 16 patients' axilla, and one of 3 doctors' and three of 30 nurses' nasal swabs. The antibiogram code for 12 of 13 MRSA isolates from five infected patients was 66,754. PFGE patterns of these isolates were either F, F1, F2 or Fa. Only one of three strains isolated from clinical specimens of patients in Hospital C showed the antibiogram code 66754, although they were all PFGE types F1 and Fa. In conclusion, the presumptive sources of the outbreak of MRSA infection in NICU were the twin patients transferred from hospital C. Antibiogram correlated reasonably well to the PFGE type. An effective notification system is needed when a MRSA-infected patient is transferred to another hospital to control the spread of the infection.

Bacterial Typing Techniques↗

PubMed1997

Colorectal polyps and their relationship to cancer.

Autosomal dominant, familial forms of colorectal adenocarcinoma are recognized, but more than 90% of cases are sporadic. Most familial and sporadic cases arise through malignant transformation of benign adenomas in a process known as the adenoma-to-carcinoma sequence. Adenomas are classified histologically as tubular, tubulovillous, or villous. As a neoplasm, adenomas all manifest mild, moderate, or severe dysplasia. The majority (> 90%) of adenomas are small (< 1 cm in diameter) and do not progress. Risk factors for carcinomatous progression include the presence of multiple adenomas, size greater than or equal to 1 cm, and villous histology or severe dysplasia in adenomas of any size. The adenoma-to-carcinoma sequence advances through the accumulation of lesions involving multiple genes. It appears that similar molecular genetic mechanisms are involved in familial and sporadic forms of colorectal neoplasia.

Colonic Polyps↗

PubMed1997

Positive and negative regulation of the human thymidine kinase promoter mediated by CCAAT binding transcription factors NF-Y/CBF, dbpA, and CDP/cut.

The proximal CCAAT element located 38 bp upstream of the transcription initiation site contributes to the human thymidine kinase (htk) promoter activity, because site-directed mutagenesis of a 10-bp region containing this CCAAT motif (TKC1) reduced the promoter activity by 55%. Through binding site competitions and antigenic cross-reactivity, the major factor that binds TKC1 from both HeLa and hamster nuclear extracts is identified as NF-Y/CBF. In serum-stimulated cells, the binding of NF-Y/CBF to TKC1 increased gradually, reaching a plateau at the S phase. In cell transfection assays, a dominant-negative mutant of NF-Y/CBF inhibited the htk promoter in a dosage-dependent manner, providing direct evidence that NF-Y/CBF is required for maximal htk promoter activity. Recently, it has been demonstrated that the site occupied by NF-Y/CBF also binds the serum-inducible dbpA and dpbB. We show here that recombinant dbpA interacts with the htk promoter, and overexpression of dbpA can stimulate htk promoter activity mediated through TCK1. In contrast, CDP/cut, the CCAAT displacement protein with known repressor property, binds the htk promoter through both the proximal and distal CCAAT elements. Our discovery that CDP/cut binds the htk promoter primarily in quiescent cells and that overexpression of CDP/cut inhibits htk promoter activity provides an explanation for the reported dramatic increase in htk promoter activity in serum-starved cells when both CCAAT elements were mutated. Thus, a combination of suppression in quiescent cells and activation in serum-stimulated cells mediated through various CCAAT-binding proteins may account in part for the induction of htk promoter activity as quiescent cells reenter the cell cycle.

Animals↗

PubMed1996

Diagnosis of Yersinia pseudotuberculosis infection by polymerase chain reaction.

BACKGROUND: The diagnosis of Yersinia pseudotuberculosis infection is usually based on serologic and/or bacteriologic tests. However, successfully culturing Y. pseudotuberculosis is difficult, and serologic tests in many cases require at least two serial sera obtained during 1-week intervals to confirm rising agglutination antibody titers. METHODS: We applied a nested polymerase chain reaction method for rapid diagnosis of Y. pseudotuberculosis infection. The DNAs extracted from the peripheral blood and urine of patients and from mountain water, a suspected source of infection, were used as templates for the polymerase chain reaction with consequent amplification of a fragment of the inv gene in the chromosomal DNA of Y. pseudotuberculosis. RESULTS: The overall rate of diagnosis with the polymerase chain reaction, which was based on a positive result with a single blood sample or one or more positive results with serial samples, was 93.3%. The polymerase chain reaction was also positive in two mountain water samples that were thought to be a source of infection. CONCLUSION: Based on our results the nested polymerase chain reaction method can be used clinically for rapid and precise diagnosis of Y. pseudotuberculosis infection.

Base Sequence↗

PubMed1996

Comparison of M-serotypes of Streptococcus pyogenes isolated from healthy elementary school children in two rural areas.

Serotypings have been used as markers for epidemiological surveys of Streptococcus pyogenes infections. Seventy-seven strains of S. pyogenes isolated from the throats of elementary school children in Kangwon Province in Korea in March and April 1992 were serotyped with M and/or opacity factor (OF) antisera. Sixty-eight strains of S. pyogenes from healthy school children in Chungnam Province in March 1993 were also serotyped and the distribution of serotype was compared with the isolates from those living in Kangwon Province. The distributions of M types were quite different between the two areas. M-78 (46.8%) and M-28 (22.1%) were most frequently encountered in Kangwon Province, while M-5 (20.6%), M-12 (16.2%), M-3 (13.2%), M-1 (11.8%) and M-62 (11.8%) were frequently isolated in Chungnam Province. Eighty-seven percent of strains in Kangwon produced OF while 33.2% of those in Chungnam produced OF (P < 0.0001). The difference in the distribution of serotypes and of OF production in the isolates from the children in the two provinces may be responsible for differences in the epidemiology of group A streptococcal infections and their sequelae.

Child↗

PubMed1996

Identification of a set of protein species approximately 40 kDa as high-affinity DNA binding factor(s) to the cell cycle regulatory region of the human thymidine kinase promoter.

Promoter elements that are important for the G1-S induction of the human thymidine kinase (htk) promoter reside within the core of the cell cycle regulatory unit, positioned between -110 and -84 upstream of the TATA element. Within this 27-bp region are three GC-rich motifs, which resemble the E2F binding site. By site-directed mutagenesis, we identified a 14-bp region, between -97 and -84, critical for the htk promoter transcriptional activity. Methylation interference studies indicate that the sequences between -97 and -84 are major protein contact points, correlating with the functional significance of this sequence in vivo. Although the core of the cell cycle regulatory unit contains three E2F-like sites and can form minor S-phase-specific complexes containing p107, cyclin A, and cdk2, the major complex that binds to this region is not competed by E2F binding sites. Through DNA affinity chromatography, we identified a set of protein species of approximately 40 kDa that copurified with the htk DNA binding activity. From gel shift assays and Western blot analysis, this protein species is antigenically distinct from E2F-1, E2F-2, E2F-3, and E2F-4. Our studies raise the possibility that other members of the E2F protein family or a novel protein(s) with preferred binding affinity for the htk promoter exert(s) control on the G1 to S regulation of the htk promoter through their interactions with cyclins and kinases.

Animals↗

PubMed1995

High incidence of resistance to multiple antimicrobials in clinical isolates of Streptococcus pneumoniae from a university hospital in Korea.

One hundred thirty-one strains of Streptococcus pneumoniae isolated from clinical specimens between January 1991 and April 1993 were serotyped and tested for susceptibility to 10 antimicrobials by the agar dilution method. Five serotypes (6A, 6B, 14, 19F, and 23F) accounted for 67% of all isolates. Seventy percent of isolates were not susceptible to penicillin, exhibiting either intermediate resistance (37%) or high-level resistance (33%); 82% of isolates from children and 59% of those from normally sterile body fluids were resistant to penicillin. A significantly increased rate of penicillin resistance (P < .01, Fisher's exact or chi 2 test) was associated with hospitalization, an age of < or = 15 years, ongoing antimicrobial therapy at the time of isolation of the organism, nosocomial acquisition, and several specific serotypes (6, 14, 19F, and 23F). No penicillin-resistant strain showed beta-lactamase activity. Various proportions of the penicillin-resistant strains also displayed resistance to cefaclor (89%), cefotaxime (82%), chloramphenicol (65%), erythromycin (52%), and ciprofloxacin (15%), but none was resistant to teicoplanin or vancomycin. The prevalence of pneumococcal resistance documented in Korea in this study is among the highest figures published to date.

Adolescent↗

PubMed1995

Development of monoclonal antibodies against Hantaan virus nucleocapsid protein.

Forty-five hybridoma cell lines producing monoclonal antibodies against Hantaan virus, the etiologic agent of hemorrhagic fever with renal syndrome, were generated by fusion of P3-X63-Ag8.V653 myeloma cells with spleen cells of mice immunized with inactivated Hantaan virus vaccine. Among these, 38 antibodies were identified as binding to the 48-kDa nucleocapsid protein by immunoblot assay or radioimmunoprecipitation. Twenty-six of them were of the immunoglobulin G1 (IgG1), nine were of the IgG2a, and three were of the IgA isotype. According to cross-reactivities with other serotypes of the genus Hantavirus, the antibodies were classified into three groups: 6 antibodies specific to the Hantaan serotype (group I), 20 antibodies cross-reacting with Hantaan and Seoul serotypes (SR-11, Tchoupitoulas, and R22) (group II), and 12 antibodies cross-reacting with Hantaan, Seoul, and Prospect Hill serotypes (group III). None of the antibodies cross-reacted with the Puumala serotype. With a panel of antibodies of different cross-reactivities, serotypes of Hantavirus could be differentiated. Thirty-eight monoclonal antibodies against Hantaan virus nucleocapsid protein which have different cross-reactivities between serotypes were developed. These results confirmed the presence of multiple serotype-specific epitopes on the nucleocapsid protein of Hantaan virus, which can be utilized in differentiation of serotypes.

Animals↗

PubMed1995

The role of serology in the diagnosis of Helicobacter pylori infection in children.

The aim of this study was to evaluate the diagnostic accuracy of serologic tests and to verify whether specific IgG antibody can be used in the diagnosis of Helicobacter pylori infection in children without endoscopy. Serologic and endoscopic examinations were performed in 310 children (1 month-15 years) with gastrointestinal symptoms. Serologic outcomes were compared with the results of rapid urease test, histologic examination, and culture. The prevalence of H. pylori infection was 21.0% and the seropositivity of H. pylori was 24.2% in these symptomatic children. Serologic examination for diagnosis of H. pylori showed a sensitivity of 94.9% and a specificity of 92.4%, diagnostic reliability equal to the rapid urease test and histologic examination in children. The serum IgG test is a useful tool for the diagnosis of H. pylori infection, especially in children.

Adolescent↗

PubMed1994

Rapid differentiation between Hantaan and Seoul viruses by polymerase chain reaction and restriction enzyme analysis.

The majority of causative strains of hemorrhagic fever with renal syndrome (HFRS) are known as Hantaan and Seoul viruses in Korea. The clinical manifestations may be indistinguishable between both viruses, although the clinical course of Hantaan virus infection is more severe than that of the Seoul virus. Therefore, the differentiation of Hantaan or Seoul virus may be important for predicting the prognosis. The primers were selected from the published sequences of the S segments of Hantaan virus strain 76-118 and Seoul virus strain SR-11, which made it possible to obtain the same size of 403 bp amplified product by reverse transcriptase polymerase chain reaction (RT-PCR) and nested PCR from both viral strains. The differentiation of the amplified products was carried out by restriction enzyme digestion. With HindIII, the 403 bp amplified product from Hantaan virus strain 76-118 was cleaved into two segments of 175 bp and 228 bp. By contrast, the 403 bp product from Seoul virus strain SR-11 was not cut by HindIII. With HinfI, the 403 bp amplified product from Hantaan virus strain 76-118 was divided into two bands of 280 bp and 60 bp on the electrophoresis. In the case of the digestion of 403 bp PCR product from Seoul virus strain SR-11 with HinfI, more than four bands (155 bp, 115 bp, 60 bp, and 32/29 bp) were observed on the 2% agarose gel electrophoresis. This rapid technique may be useful for the differential diagnosis of Asian HFRS in Korea.

Animals↗

PubMed1994

Chemiluminescent microwell hybridization assay for direct detection of human parvovirus B19 DNA.

A method for the direct detection of human parvovirus DNA in serum samples that uses a digoxigenin-labeled RNA probe to hybridize with target B19 DNA, followed by capture of the hybrid onto a microtiter plate wells previously coated with a second oligonucleotide probe was developed. The captured hybrid is then detected with anti-digoxigenin-alkaline phosphatase conjugate and chemiluminescent substrate and the reaction read on a scintillation counter. The relative sensitivities of the microwell and standard dot blot hybridization assays were compared. The chemiluminescent microwell hybridization assay was more sensitive than dot-blot hybridization and could be performed in a few hours. This format, therefore, permits rapid and sensitive detection of parvovirus DNA suitable for the clinical setting.

Base Sequence↗

PubMed1994

Serotypes of Streptococcus pyogenes isolated from healthy school children in Kangwon-do.

Seventy-seven Streptococcus pyogenes strains isolated of children of three elementary schools located in Kangwon-do in spring, 1992 were serotyped with M, opacity factor (OF) and T typing antisera. In the M/OF typing results, M-78 (46.8%) and M-28 (22.1%) were most frequently encountered, while M-4 (6.5%), M-12 (5.2%), M-3 (1.3%), M-5 (1.3%) and M-6 (1.3%) were rarely observed. Twelve strains (15.6%) were not typable with M or OF typing system. In the T typing results, T-11 (35.1%) and T-28 (27.3%) were most common. We were able to identify 77.9% of S. pyogenes strains by T typing, 94.8% with T typing and OF typing. With the addition of M typing, 97.4% were typable. Through the serotypings, we could know the basic distribution of serotypes of S. pyogenes of healthy children which could be comparable to those of rheumatic fever, poststreptococcal glomerulonephritis and other severe streptococcal disease.

Adolescent↗

PubMed1993

Immunohistochemical detection of S-100, S-100 alpha, S-100 beta proteins, glial fibrillary acidic protein, and neuron specific enolase in the prenatal and adult human salivary glands.

Developing human fetal salivary glands of gestational age from 10 to 40 weeks (n = 100) and normal adult glands (n = 10) were examined for immunoreactivity to S-100 protein and its subunits S-100 alpha, S-100 beta, glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE). In the early intermediate developmental stage (19-32 weeks) some acinar basal cells showed immunoreactivity to S-100 protein which rapidly disappeared in the late developmental stage (33-40 weeks). Adult salivary glands were negative for S-100 protein. The S-100 alpha subunit was strongly positive in the glandular ducts and acini of both fetal and adult glands. The S-100 beta, although present in some acini and ductal cells during the late intermediate developmental stage, was rarely seen in the adult glands. GFAP and NSE was positive at the developing salivary epithelium in the early developmental stage (15-18 weeks). The above findings indicated that the developing salivary epithelia showed transient appearance of the neuronal phenotype during active cytodifferentiation stage of glandular acini and ducts. Therefore, after evaluation of normal developmental and neoplastic transformation of the salivary glands a suggestion that neuronal differentiation of ductal reserve cells is responsible for the production of modified myoepithelial cells in both normal developmental salivary gland and neoplastic transformation is made.

Adult↗

PubMed1988

Primary carcinoma of the gallbladder.

Forty four patients with primary carcinoma of the gallbladder diagnosed during 12 years were reviewed. Nineteen patients had histologically proven cancer and the remaining 25 patients were diagnosed by laparotomy and/or the several diagnostic procedures. The female to male ratio was 1.6 to 1. The mean age was 65.7 years in resected cases and 63.5 years in unresected cases. The mean survival times in curative, noncurative resection and unresected cases were 49.8, 7.9 and 2.9 months, respectively. Although early diagnosis is difficult due to the lack of specific symptoms and signs, our results suggested that the measurement of serum CA 19-9 is a useful marker for detection and ultrasonography is helpful in the early assessment of disease. These tests, together with more aggressive surgery, may extend the survival of patients with primary carcinoma of the gallbladder.

Aged↗

PubMed1987

A case of leukemia-associated arthritis--identification of leukemic cells in synovial fluid by light microscopy.

One case of arthritis complicating leukemia is described in which leukemic cells were identified in synovial fluid by light microscopy. Although arthritis is a well-known manifestation of leukemia with an incidence of 13.5%, the pathogenesis often is unclear, and the direct demonstration of leukemic cells in synovial fluid has been very uncommon. A 16 year-old male patient was admitted due to left elbow joint pain and swelling. Synovial fluid examination revealed blast cells and this finding has directed to a final diagnosis of acute lymphoblastic leukemia.

Adolescent↗

PubMedDate not supplied

Osteoporosis.

Explore the source record for details and available documents.

Calcitonin↗

PubMedDate not supplied

Ultrasound for the early diagnosis of tibial fracture healing after static interlocked nailing without reaming: histologic correlation using a canine model.

OBJECTIVE: Ultrasound is thought to be clinically useful in evaluating bone formation through its presumed identification of fracture callus. However, documentation of the actual histology of the tissue identified by ultrasound has been lacking. The purpose of this study was to determine the histologic composition of the hyperechoic tissue "seen" by ultrasound. STUDY DESIGN: Unilateral fractures were created in eight canine tibias and then fixed by using locked intramedullary nailing without reaming. The limbs were studied at two, three, four, six, and eight weeks postoperatively with plain radiographs, ultrasound, and ultrasound-directed needle biopsy. RESULTS: The presence of a hyperechoic ultrasound signal was found to have a 100 percent correlation with the presence of hard fracture callus biopsy tissue. In addition, fracture union by ultrasound criteria significantly predated radiographic fracture union (5.6 vs. 7.3 weeks, p = 0.05). CONCLUSIONS: These results support and provide a scientific basis for the clinical use of ultrasound to assess tibial fracture healing following static interlocked nailing without reaming.

Animals↗