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Biomedical subjects

Hae Kyung Lee

Publications and source records attributed to Hae Kyung Lee.

At least 19 recordsLinked to original sources

High-resolution sonography for nasal fracture in children.

OBJECTIVE: We describe the sonographic findings of nasal fracture in children, and we evaluate the diagnostic value of sonography as compared with conventional radiography and clinical findings to determine whether sonography can be a primary technique for evaluating nasal fracture in children. MATERIALS AND METHODS: Conventional radiographs and sonographic scans were obtained in 26 consecutive children with nasal trauma who were seen at our hospital from March 2003 to March 2005. There were five girls and 21 boys, and their ages ranged from 1 year 9 months to 15 years 11 months (mean age, 9.9 years). The following sonographic scans (HDI-5000 unit with a 7-15-MHz linear array transducer) were used to evaluate the nasal bone at different levels: a midline longitudinal image; axial scans of the nasal bones at the upper, middle, and lower levels; images of the nasal septum; and transverse and longitudinal scans of both lateral walls. Ten children also underwent CT. RESULTS: Conventional radiographs depicted 14 (54%) of 26 fractures. Sonographic scans were able to show all the fracture lines. One case was diagnosed as an old nasal fracture on the basis of a physical examination, even though a visible fracture line was seen on sonography. The sonographic findings of nasal fracture were disruption of the bone continuity with or without separation of the fractured segment (7/26), displacement of the bone segment as being depressed or overriding (20/26), associated septal deviation (7/26), and separation of the pyriform aperture of the maxilla and nasal bone (2/26). The associated findings were soft-tissue edema and hypoechoic hematoma near the fracture lines in 25 cases. The fractures involved both sides of the nasal bones in 11 of 26 cases, the midline part of the bones in six of 26 cases, and the unilateral paramedian or lateral part of the bones in 12 of 26 cases. Among the 10 CT scans, one CT scan did not depict the fracture, showing only soft-tissue swelling, and one scan showed fractures of the orbital floor and maxilla. CONCLUSION: Sonography can be a primary diagnostic technique for evaluating nasal fracture in children. It inflicts no radiation, provides various imaging planes without positional change, and can be used to evaluate the cartilaginous septum. Potential pitfalls are the nasofrontal suture, the junction between the nasal bone and the pyriform aperture of the maxilla, the vascular groove, and the presence of an old fracture. CT can be used in addition to sonography in cases of suspected complex facial bone trauma.

Adolescent↗

Tyrosine 311 is phosphorylated by c-Abl and promotes the apoptotic effect of PKCdelta in glioma cells.

In this study we characterized the phosphorylation of tyrosine 311 and its role in the apoptotic function of PKCdelta in glioma cells. We found that c-Abl phosphorylated PKCdelta on tyrosine 311 in response to H2O2 and that this phosphorylation contributed to the apoptotic effect of H2O2. In contrast, Src, Lyn, and Yes were not involved in the phosphorylation of tyrosine 311 by H2O2. A phosphomimetic PKCdelta mutant, in which tyrosine 311 was mutated to glutamic acid (PKCdeltaY311E), induced a large degree of cell apoptosis. Overexpression of the PKCdeltaY311E mutant induced the phosphorylation of p38 and inhibition of p38 abolished the apoptotic effect of the PKCdelta mutant. These results suggest an important role of tyrosine 311 in the apoptotic function of PKCdelta and implicate c-Abl as the kinase that phosphorylates this tyrosine.

Apoptosis↗

The effects of infant massage on weight, height, and mother-infant interaction.

PURPOSE: The purpose of this study was to test the effects of infant massage (auditory (mother's voice), tactile/kinesthetic (massage) and visual (eye to eye contact) stimulation) on weight and height of infant and mother-infant interaction with normal infants over a period of 4 weeks. METHOD: This study was designed as a nonequivalent control group pretest-posttest design. The experimental group infants (aged 2-6 months) participated in one of the infant massage programs at the health district center for 4 weeks. The control group (N=26) was paired with the experimental group (N=26) by matching the infant's age and sex. Infant weight, height, and mother-infant interaction were measured two times and recordings of the mother-infant interaction were done using the video equipment in a room at the health center for 10 minutes. RESULTS: After 4 weeks of massage, there were no significant differences weight gain and height increase between the two groups. Comparison of the total scores for the mother-infant interaction between the two groups showed a significant difference (t=5.21, p=.000). There were also significant differences on maternal response (t=3.78, p=000), infant response (t=5.71, p=000) and dyadic response (t=4.05, p=000) in the mother-infant interaction between the two groups. CONCLUSION: Overall, the results of this study reassure that infant massage facilitates the mother-infant interaction for infants and mothers who give massage to their baby.

Anthropometry↗

Characterization of erythromycin resistance of Streptococcus pyogenes isolated from pharyngitis patients in Korea.

Six hundred fifteen isolates of Streptococcus pyogenes were collected over a 6-year period from patients with pharyngitis in Korea. All isolates were characterized in terms of their antibiotic resistance, the phenotypes of erythromycin resistance, the frequencies of erm(B), erm(A), and mef(A) genes, and the emm genotype. The prevalent emm genotypes were emm12 and emm4. Moreover, the emm12 genotype was found to be the most resistant strain to erythromycin. Among the 126 strains demonstrating resistance to erythromycin, those with erm(B) were the most prevalent, accounting for 64.3% of the total. In summary, it is suggested that the S. pyogenes pathogen isolated from pharyngitis patients in Korea developed resistant gene acquisition, as well as a resistant phenotype, according to the annual prevailing emm type. It is also suggested that the emm genotype distribution of erythromycin-resistant strains is correlated to the acquisition of resistant genes.

Anti-Bacterial Agents↗

[Intraductal ultrasonography for the selection of self expandable metal stent in extrahepatic bile duct carcinoma].

BACKGROUND/AIMS: Endoscopic stent insertion with self expandable metal stent (SEMS) is one of the standard palliative treatments for the patients with unresectable bile duct carcinoma. The aim of this study was to determine whether detection of longitudinal spread of extrahepatic bile duct carcinoma by intraductal US (IDUS) would be helpful in the selection of metal stent for the palliative drainage in bile duct carcinoma. METHODS: Seventeen patients with histologically proven unresectable extrahepatic bile duct carcinoma who underwent endoscopic retrograde cholangiography with IDUS were included. Longitudinal cancer extension along the bile duct was determined and, then, compared with the cholangiographic image. The type and length of SEMS was selected based on IDUS findings. RESULTS: IDUS demonstrated more extensive tumor spread than ERC in 7 of 17 (41.2%) patients with the hepatic side of strictures and in 7 of 16 (43.8%) patients with the duodenal side of strictures. Five of 17 (29.4%) patients have changed the plan of endoscopic biliary drainage with SEMS after IDUS. There was no early dysfunction associated with endoscopic biliary drainage. CONCLUSIONS: IDUS prior to biliary drainage would be useful in demonstrating longitudinal extension of extrahepatic bile duct carcinoma. It has a potential role in helping stent selection and identifying factors which predict early stent dysfunction.

Bile Duct Neoplasms↗

Narrow-band UVB induces apoptosis in human keratinocytes.

Narrow-band ultraviolet (NB-UVB) phototherapy emits mostly 311/312 nm light and is commonly used in the treatment of inflammatory skin disorders. As a source of UVB irradiation, NB-UVB causes apoptosis in T lymphocytes but its effects on keratinocytes are unknown. Herein, we have investigated the ability of NB-UVB to induce apoptosis in keratinocytes. Two types of human keratinocytes, primary and immortalized, were exposed to NB-UVB and broad-band UVB (BB-UVB; 315-280 nm) and tested for apoptosis. Both UVB light sources induced apoptosis in keratinocytes as determined by the presence of DNA ladders, although NB-UVB required approximately ten fold higher doses; NB-UVB (1000 mJ/cm2) and BB-UVB (125 mJ/cm2). By comparison, lower doses of NB-UVB (750 mJ/cm2) induced apoptosis in T lymphocytes, suggesting cell type specificity for NB-UVB induced apoptosis. Approximately, 50% or more of the cells underwent apoptosis when exposed to NB-UVB or BB-UVB as revealed by TUNEL assay. Electron micrographs showed that NB-UVB irradiated keratinocytes contained marked chromatin condensation, extensive cytoplasmic vacuolization and fragmentation of the nuclear envelope. Furthermore, Western blot analysis confirmed the presence of activated products of caspase 3 in keratinocytes that received apoptotic doses of NB-UVB. This study defines conditions by which NB-UVB irradiation causes apoptosis in keratinocytes.

Apoptosis↗

Prevalence of Ambler class A and D beta-lactamases among clinical isolates of Pseudomonas aeruginosa in Korea.

OBJECTIVES: Recently, resistance to extended-spectrum cephalosporins due to acquired beta-lactamases has been reported in Pseudomonas aeruginosa. The aim of this study was to investigate the prevalence of Ambler class A and D beta-lactamases and their extended-spectrum derivatives and antimicrobial susceptibilities of P. aeruginosa isolated from various parts of Korea. METHODS: A total of 252 consecutive, non-duplicate isolates of P. aeruginosa were studied for the presence of class A or D beta-lactamase. Antibiotic susceptibility tests and PCR amplification of genes encoding class A (bla(PSE-1), bla(PER-1), bla(VEB-1), bla(TEM), bla(SHV), bla(CTX-M) and bla(GES-1)) and class D beta-lactamases (bla(OXA-groupI), bla(OXA-groupII) and bla(OXA-groupIII)) were performed. For PCR-positive isolates, isoelectric focusing (IEF) analysis, sequencing and pulsed-field gel electrophoresis (PFGE) were performed. RESULTS: In 64 (25.4%) isolates, structural genes for PSE-1 (6.3%), OXA-10 (13.1%), OXA-4 (4.3%), OXA-30 (2.0%), OXA-2 (2.3%) and OXA-17 (0.4%) were found; their distribution varied between provinces. None harboured bla(PER-1), bla(VEB-1), bla(TEM), bla(SHV), bla(CTX-M) and bla(GES-1). The cross-class resistance rates to other antibiotics was significantly higher in class A and D beta-lactamase producers than in non-producers (P < 0.001 for aminoglycosides, ciprofloxacin and meropenem). CONCLUSIONS: OXA-type beta-lactamases are widespread, but their extended-spectrum derivatives are rare among P. aeruginosa in Korea. To our knowledge, this is the first report of OXA-17, an extended-spectrum derivative of OXA-10, outside the Middle East. In addition, combined resistance to ticarcillin and aminoglycosides was a useful indicator for P. aeruginosa producing PSE- or OXA-type beta-lactamases in this study.

Drug Resistance, Bacterial↗

Prevalence of decreased susceptibility to carbapenems among Serratia marcescens, Enterobacter cloacae, and Citrobacter freundii and investigation of carbapenemases.

Between March and July 2002, total of 612 clinical isolates of Serratia marcescens, Enterobacter cloacae, and Citrobacter freundii (201 S. marcescens, 228 E. cloacae, and 183 C. freundii) were collected from 13 clinical laboratories in a nationwide distribution. Imipenem and meropenem minimum inhibitory concentrations (MICs) were determined using the agar dilution method according to the National Committee for Clinical Laboratory Standards guidelines. For the isolates with a decreased susceptibility to carbapenems (MICs of >or=2 microg/mL), isoelectric focusing, polymerase chain reaction (PCR) amplification of the carbapenemase genes (bla(IMP-1), bla(VIM-2), bla(SME-1), bla(OXA-23), bla(OXA-25), bla(KPC-1)), and sequencing were performed. The prevalence of S. marcescens, E. cloacae, and C. freundii with a decreased susceptibility to imipenem was 17.9% (36/201), 0.4% (1/228), and 0.5% (1/183), respectively, and to meropenem, it was 11.4% (23/201), 0% (0/228), and 0.5% (1/183), respectively. The bla(VIM-2) was the only carbapenemase detected, and was found in 0.5% (1/201) of S. marcescens and 0.5% (1/183) of C. freundii isolate.

Anti-Bacterial Agents↗

The detection of bile duct stones in suspected biliary pancreatitis: comparison of MRCP, ERCP, and intraductal US.

OBJECTIVES: Early ERCP and endoscopic sphincterotomy for stone extraction can benefit the prognosis in patients with severe biliary pancreatitis, but are associated with complications. The ability to identify choledocholithiasis by noninvasive means in biliary pancreatitis is limited. The aim of this study was evaluation of the ability of MRCP to detect choledocholithiasis in patients with acute biliary pancreatitis. In addition, we investigated whether intraductal US (IDUS) could help manage these patients. METHODS: Thirty-two patients with suspected biliary pancreatitis were studied prospectively. MRCP was performed immediately before ERCP by separate blinded examiners within 24 h of admission. Wire-guided IDUS was performed during ERCP within 72 h of admission, regardless of the results of MRCP. Using endoscopic extraction of a stone as the reference standard, the diagnostic yield of MRCP was compared with transabdominal US, CT, ERCP, and IDUS. RESULTS: The sensitivity of US, CT, MRCP, ERCP, and IDUS for identifying choledocholithiasis was 20.0%, 40.0%, 80.0%, 90.0%, and 95.0%, respectively. The overall agreement between MRCP and ERCP was 90.6% for choledocholithiasis (kappa= 0.808, p < 0.01). The sensitivity of MRCP for detecting choledocholithiasis decreased with dilated bile ducts (bile duct diameter > 10 mm, 72.7% vs 88.9%). The combination of ERCP and IDUS improved accuracy in the diagnosis of choledocholithiasis. CONCLUSIONS: MRCP can be used to select patients with biliary pancreatitis who require ERCP. IDUS may be applied in the management of biliary pancreatitis if ERCP is performed.

Adult↗

Diagnosis of pelvic congestion syndrome using transabdominal and transvaginal sonography.

OBJECTIVE: We prospectively evaluated transabdominal and transvaginal sonographic findings of patients with pelvic congestion syndrome and compared them with those of healthy volunteers. SUBJECTS AND METHODS. We examined 32 patients with pelvic congestion syndrome and 35 control subjects. Using transabdominal sonography, we evaluated the ovarian veins for diameter and flow direction, presence of pelvic varicocele, diameter of the pelvic veins, change of the duplex waveform during the Valsalva's maneuver, volume of the uterus, and presence of polycystic changes in the ovaries. We compared and statistically analyzed each parameter in the pelvic congestion syndrome group and in the control group. RESULTS: The mean (+/- SD) diameter of the left ovarian vein was 0.79 +/- 0.23 cm in the pelvic congestion syndrome group and 0.49 +/- 0.15 cm in the control group (p = 0.000). Reversed caudal flow in the left ovarian vein was present in 22 of 22 patients and in four of 16 control subjects. Pelvic varicoceles were present in all patients with pelvic congestion syndrome and in six control subjects. The mean diameter of the left pelvic vein was 0.68 +/- 0.21 cm in the pelvic congestion syndrome group and 0.42 +/- 0.19 cm in the control group; the mean diameter of the right pelvic vein was 0.64 +/- 0.24 cm in the pelvic congestion syndrome group and 0.35 +/- 0.14 cm in the control group (p = 0.000). Polycystic changes of the ovary were present in 13 patients with pelvic congestion syndrome (40.6%) and four control subjects (11.4%). CONCLUSION: Sonographic findings of pelvic congestion syndrome were dilated left ovarian vein with reversed caudal flow, presence of varicocele, dilated arcuate veins crossing the uterine myometrium, polycystic changes of the ovary, and variable duplex waveform during the Valsalva's maneuver. Combined transabdominal and transvaginal sonography are potentially useful as a noninvasive screening tool for determining which patients with chronic pelvic pain may benefit from selective ovarian venography and transcatheter embolization.

Adult↗

Evaluation of Vitek system for susceptibility testing of Enterococcus faecium isolates.

Although imipenem is not a first-line drug for treating enterococcal infection, it could well become a useful drug for treating mixed infections that include enterococci. However, there is no NCCLS guideline for susceptibility testing of imipenem versus enterococci. Moreover, there are no statements to indicate that in vitro susceptibility results for other antimicrobial agents can be used to predict the in vitro activity of imipenem against enterococci. In this study, 52 Enterococcus faecium isolates were collected from patients hospitalized at Kangnam St. Mary's Hospital between March 2002 and December 2002. The sources of the isolates were mainly urine specimens and wounds. For ampicillin, the "major" and "very major" error rates observed with the Vitek system were 0% and 2.0%, respectively. For penicillin, the major and very major error rates observed with the Vitek system were both 0%. For imipenem, the major and very major error rates observed with the Vitek system were 0% and 36.5%, respectively. The MICs of ampicillin and penicillin obtained using the Vitek system were reliable, but that of imipenem was unreliable. In the 52 E. faecium isolates, the in vitro activity of penicillin and ampicillin versus enterococci accurately predicted that of imipenem. Therefore, the MIC of imipenem obtained with the Vitek system must be retested by the agar dilution method, when it disagrees with those of penicillin and ampicillin.

Ampicillin↗

Diagnosis of occult thyroid carcinoma by ultrasonography.

The increased sensitivity of many imaging devices has increased the identification of asymptomatic nodules in the thyroid gland. In this study we investigated the actual incidence of nonpalpable thyroid nodules and occult carcinoma in women. Between January and June 2003, among the women who were scheduled to undergo breast ultrasonography, 697 without palpable thyroid nodules were screened for thyroid nodules. They were classified into four categories according to ultrasonographic findings: negative, benign, indeterminate and malignant. Ultrasound-guided fine-needle aspiration biopsy (FNAB) was carried out for all malignant lesions and for some of the benign and indeterminate ones. The nodule detection and malignancy rates were determined and the effectiveness of ultrasonography as a diagnostic tool was also investigated. Out of the 697 subjects, 246 (35.3%) were found to have thyroid nodules. The malignancy detection rate based on the FNAB results, including both suspicious and malignant groups, was 3.6% (25/697) for all subjects. In addition, 3.0% (21/697) of all the women were confirmed to have thyroid cancer by surgery. The sensitivity of sonographic classification was increased from 80% to 100% when the indeterminate class was added to the malignant one, although this decreased the specificity from 91.7% to 33.3%. In conclusion, high-resolution ultrasonography detected a high percentage of malignant nodules. Ultrasonography can augment its value by guiding FNAB, in addition to providing diagnostic images.

Adult↗

Mosaic structure of pathogenicity islands in Legionella pneumophila.

A gene complex, dot/icm, located in two independent chromosomal loci of L. pneumophila, the causative agent of Legionnaires' disease, is related to virulence. To investigate the evolutionary pattern of these pathogenicity islands of L. pneumophila, portions of four genes in the dot/icm complex, namely, dotA, dotB, icmB, and icmT, were amplified, sequenced, and phylogenetically analyzed, in addition to rpoB, which encodes an RNA polymerase beta-subunit. The nucleotide sequences and phylogenetic analyses of these five genes of 96 L. pneumophila strains revealed that several subgroups of L. pneumophila proliferated clonally. However, incongruent gene tree topologies and the results of statistical testing (Templeton Willcoxon signed-ranked and incongruence length differences tests) indicated that the evolutionary histories of these genes within the pathogenicity islands are not uniform, and that they constitute a mosaic structure. In addition, the nonuniform grouping of some reference strains suggests that intraspecific recombination might be still occurring in nature or in the laboratory.

Animals↗

Detection and identification of Legionella pneumophila by PCR-restriction fragment length polymorphism analysis of the RNA polymerase gene (rpoB).

The partial RNA polymerase beta-subunit coding gene (rpoB) sequences of 38 Legionella species (59 reference strains) were used to select both Legionella genus-specific and Legionella pneumophila species-specific primers to amplify the 347-bp and 217-bp DNAs, respectively. Enzyme restriction sites for PCR-restriction fragment length polymorphism (PCR-RFLP) analysis were also generated by a computer program. Thirty-eight Legionella species were well differentiated by the identification scheme for Legionella genus-specific PCR-RFLP using HaeIII, AluI, CfoI, PstI, and MaeII. The most common and important pathogenic species, L. pneumophila, was differentiated into two subspecies (L. pneumophila subsp. pneumophila and L. pneumophila subsp. fraseri) by both Legionella genus-specific PCR-RFLP and L. pneumophila species-specific PCR-RFLP using BamHI. Eighty-two Korean culture isolates could also be easily identified by both PCR-RFLP methods as 68 strains of L. pneumophila subsp. pneumophila, 11 strains of L. pneumophila subsp. fraseri, and three novel strains that were separately confirmed by 16S rDNA and rpoB sequence analysis. These results suggest that the rpoB PCR-RFLP for Legionella is a simple and convenient method, not only for specific detection, but also for the rapid identification of Legionella species.

DNA, Bacterial↗

Legionella busanensis sp. nov., isolated from cooling tower water in Korea.

Three Legionella-like micro-organisms, isolated from cooling tower water of a building in Busan, Korea, were characterized by a variety of biochemical and molecular phylogenetic tests. Analyses of whole-cell fatty acids and results of biochemical tests revealed that these three isolates are distinct from previously described Legionella species. Furthermore, results of comparative analyses of 16S rDNA (1476-1488 bp), mip (408 bp) and rpoB (300 bp) sequences also confirmed that these strains represent a novel species within the genus Legionella. The 16S rDNA sequences of the three Korean isolates had similarities of less than 95.8% to other Legionella species. Phylogenetic trees formed by analysis of the 16S rRNA, rpoB and mip genes revealed that the isolates formed a distinct cluster within the genus Legionella. Based on the evaluated phenotypic and phylogenetic characteristics, it is proposed that these Korean isolates from water be classified as a novel species, Legionella busanensis sp. nov.; the type strain is strain K9951T (=KCTC 12084T =ATCC BAA-518T).

Bacterial Proteins↗

Molecular evolution of the dotA gene in Legionella pneumophila.

The molecular evolution of dotA, which is related to the virulence of Legionella pneumophila, was investigated by comparing the sequences of 15 reference strains (serogroups 1 to 15). It was found that dotA has a complex mosaic structure. The whole dotA gene of Legionella pneumophila subsp. pneumophila serogroups 2, 6, and 12 has been transferred from Legionella pneumophila subsp. fraseri. A discrepancy was found between the trees inferred from the nucleotide and deduced amino acid sequences of dotA, which suggests that multiple hits, resulting in synonymous substitutions, have occurred. Gene phylogenies inferred from three different segments (the 5'-end region, the central, large periplasmic domain, and the 3'-end region) showed impressively dissimilar topologies. This was concordant with the sequence polymorphisms, indicating that each region has experienced an independent evolutionary history, and was evident even within the same domain of each strain. For example, the PP2 domain was found to have a heterogeneous structure, which led us hypothesize that the dotA gene of L. pneumophila may have originated from two or more different sources. Comparisons of synonymous and nonsynonymous substitutions demonstrated that the PP2 domain has been under strong selective pressure with respect to amino acid change. Split decomposition analysis also supported the intragenic recombination of dotA. Multiple recombinational exchange within the dotA gene, encoding an integral cytoplasmic membrane protein that is secreted, probably provided increased fitness in certain environmental niches, such as within a particular biofilm community or species of amoebae.

Bacterial Proteins↗

Clinical significance of glucose transporter 1 (GLUT1) expression in human breast carcinoma.

Glucose uptake and glycolytic metabolism are enhanced in cancer cells compared to normal cells and tissues. Increased expression of glucose transporter 1 (GLUT1) has been reported in human malignant cells. The aim of this study is to determine the expression of the facilitative glucose transporter protein GLUT1 in human breast carcinomas and a possible correlation between GLUT1 expression and clinical outcome including disease-free or overall survival. One hundred consecutive formalin-fixed, paraffin-embedded sections of invasive breast carcinomas were evaluated by means of immunohistochemical staining of GLUT1. Forty-seven (47%) of 100 breast carcinomas showed positive staining for GLUT1. Expression of GLUT1 correlated significantly with nuclear grade (P < 0.001), estrogen receptor status (P = 0.002), and progesterone receptor status (P = 0.001). The mean disease-free survival periods of GLUT1-positive and -negative patients were 47 +/- 2.4 months and 54.3 +/- 1.3 months, respectively (P = 0.017). The mean overall survival periods of GLUT1-positive and -negative patients were 48.7 +/- 2.2 and 56.1+/- 1.3 months, respectively (P = 0.043). In the multivariate analysis, disease-free survival correlated significantly with GLUT1, tumor size, and lymph node involvement (P = 0.043, P = 0.014, and P = 0.045, respectively). In analysis of overall survival, however, lymph node involvement, tumor size, and nuclear grade were statistically significant (P = 0.024, P = 0.023, and P = 0.003, respectively). Our data suggest that absence of GLUT1 expression significantly increases disease-free survival. These findings demonstrate that GLUT1 expression in breast carcinoma can be a marker of aggressive biological behavior and identifies a worse prognosis in breast carcinoma patients.

Adult↗