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Biomedical subjects

J W Song

Publications and source records attributed to J W Song.

At least 19 recordsLinked to original sources
PubMed2006

Myocardial enhancement pattern in patients with acute myocardial infarction on two-phase contrast-enhanced ECG-gated multidetector-row computed tomography.

AIM: To evaluate the myocardial enhancement pattern of the left ventricle on two-phase contrast-enhanced electrocardiogram (ECG)-gated multidetector computed tomography (MDCT) images in patients with acute myocardial infarction (AMI). METHODS: Two-phase contrast-enhanced ECG-gated MDCT examinations were performed in 16 patients with AMI. The presence, location and pattern of myocardial enhancement were evaluated. MDCT findings were compared with the catheter angiographic results. RESULTS: Subendocardial (n = 9) or transmural (n = 6) area of early perfusion defects of the myocardium was detected in 15 of 16 patients (94%) on early-phase CT images. Variable delayed myocardial enhancement patterns on late-phase CT images were observed in 12 patients (75%): (1) subendocardial residual perfusion defect and subepicardial late enhancement (n = 6); (2) transmural late enhancement (n = 1); (3) isolated subendocardial late enhancement (n=1); and (4) isolated subendocardial residual perfusion defect (n = 2). On catheter angiography, 14 of 15 corresponding coronary arteries showed significant stenosis. CONCLUSION: Variable abnormal myocardial enhancement pattern was seen on two-phase, contrast-enhanced ECG-gated MDCT in patients with AMI. Assessment of myocardial attenuation on CT angiography gives additional information of the location and extent of infarction.

Adult↗
PubMed2005

Chronic tuberculous empyema: relationships between preoperative CT findings and postoperative improvement measured by pulmonary function testing.

AIMS: To evaluate whether preoperative computed tomography (CT) findings correlate with postoperative improvements in forced vital capacity (FVC) and forced expiratory volume during 1s (FEV1) in persons who have undergone unilateral decortication because of unilateral chronic tuberculous empyema. METHODS: A retrospective study was carried out of 67 individuals who had undergone decortication because of chronic tuberculous empyema between January 1996 and December 2000. Of these, 13 subjects who had had preoperative chest CT and preoperative and postoperative pulmonary function tests (PFTs) were included in the investigation. On preoperative CT, the degree of volume reduction of the affected side was compared with that of the contralateral normal lung. The relative volume of empyema was calculated by dividing the volume occupied by the empyema by the sum of the total volume of the ipsilateral lung and the empyema volume. The thicknesses of pleura and extrapleural fat in the involved hemithorax were measured by CT at their thickest points, and the degree of atelectasis adjacent to the empyema in the diseased lung was assessed and classified. These five CT parameters and the ages of the patients were compared with preoperative and postoperative FVC and FEV1 changes. RESULTS: A significant negative correlation was found between FVC changes and the relative volume of the affected lung (FVC: p = 0.039, RS = -0.58). FVC and FEV1 were found to be significantly and positively correlated with the relative volume of the empyema (FVC: p = 0.005, RS = 0.72; FEV1: p = 0.014, RS = 0.66) and the degree of atelectasis (FVC: p = 0.007, RS = 0.71; FEV1: p = 0.029, RS = 0.60) by Spearman's nonparametric correlation test. Other CT parameters and the ages of the patients were not found to be correlated with PFT changes. CONCLUSION: The relative volume of the affected side, the relative volume of empyema and the degree of atelectasis can predict improvements in FVC and FEV1 after decortication in patients with chronic tuberculous empyema.

Adult↗
PubMed2005

The genetic and phenotypic basis of blood group A subtypes in Koreans.

A serological and genetic study of Korean blood donors with phenotypic group A subtypes was performed. There were 176 donors with phenotypic A subtypes identified. Exons 6 and 7 from 57 representative donors were sequenced. The A(var) allele (784 G > A) was cloned and sequenced, and a family study demonstrating its inheritance and unusual serological characteristics was performed. The A102 allele was the most frequently identified allele in phenotypically A2 (58%, 11/19) and A2B (68%, 17/25) donors. Anti-A1 was rarely present amongst A2 and A2B donors. The family study revealed that the A(var) allele was expressed as phenotype A(weak)B in A(var)/B heterozygote members, but as phenotype O in A(var)/O heterozygotes. The most frequent allele in Korean donors with the A2 phenotype differs from its Caucasian counterpart, as does the frequency of anti-A1. The A(var) allele demonstrates allelic enhancement in A(var)/B heterozygotes.

ABO Blood-Group System↗
PubMed2004

Common crus aplasia: diagnosis by 3D volume rendering imaging using 3DFT-CISS sequence.

AIM: The purpose of this study was to evaluate the findings of three-dimensional (3D) volume rendering (VR) imaging in common crus aplasia (CCA) of the inner ear. MATERIALS AND METHODS: Using 3D VR imaging of temporal bone constructive interference in steady state (CISS) magnetic resonance (MR) images, we retrospectively reviewed seven inner ears of six children who were candidates for cochlear implants and who had been diagnosed with CCA. As controls, we used the same method to examine 402 inner ears of 201 patients who had no clinical symptoms or signs of sensorineural hearing loss. Temporal bone MR imaging (MRI) was performed with a 1.5 T MR machine using a CISS sequence, and VR of the inner ear was performed on a work station. Morphological image analysis was performed on rotation views of 3D VR images. RESULTS: In all seven cases, CCA was diagnosed by the absence of the common crus. The remaining superior semicircular canal (SCC) was normal in five and hypoplastic in two inner ears, while the posterior SCC was normal in all seven. One patient showed bilateral symmetrical CCA. Complicated combined anomalies were seen in the cochlea, vestibule and lateral SCC. CONCLUSION: 3D VR imaging findings with MR CISS sequence can directly diagnose CCA. This technique may be useful in delineating detailed anomalies of SCCs.

Child↗
PubMed2004

A novel B(var) allele (547 G>A) demonstrates differential expression depending on the co-inherited ABO allele.

BACKGROUND AND OBJECTIVES: Genetic analysis of group B donors in Korea was performed. MATERIALS AND METHODS: Exons 6 and 7 were sequenced in 12 phenotypically B3 donors 6 B3, 6 A1B3. RESULTS: Consensus sequences all B3 and 2/6 A1B3 donors were present. Four A1B3 donors demonstrated a novel B allele, B(var), in the context of A101/ or A102/B(var) genotypes. Family studies based on an A1B3 donor with the B(var) allele and on another unrelated subject with identical genotype and phenotype revealed B(var)/O01 genotypes with full B-antigen expression. CONCLUSIONS: B(var) allele is subject to differential expression, depending on the co-inherited ABO allele.

ABO Blood-Group System↗
PubMed2001

Homozygous VN (677C to T) and d/D (2756G to A) variants in the methylenetetrahydrofolate and methionine synthase genes in a case of hyperhomocysteinemia with stroke at young age.

Hyperhomocysteinemia is known to be associated with an increased risk of myocardial infarction, stroke, peripheral arterial disease, and venous thrombosis. Gene polymorphisms in methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MS) may account for reduced enzyme activity and hyperhomocysteinemia. A recent study has documented evidence of polygenic regulation of plasma homocyteine. We report here on a case of occlusive stroke at young age and hyperhomocysteinemia with homozygous VN (677C to T) variant in the MTHFR gene as well as homozygous D/D (2756G to A) variant in the MS gene.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed2001

The analysis of Plasmodium vivax Duffy receptor binding domain gene sequence from resurgent Korea isolates.

The Duffy binding domain gene structures of Plasmodium vivax facilitate the invasion of erythrocytes. Human erythrocytes that lack Duffy blood group antigens are resistant to invasion by P. vivax. We have sequenced the Duffy binding domain gene from eight P. vivax isolates collected from malaria cases in South Korea. When compared to isolates from other regions in the world, the amino acid sequences of the Korean isolates showed unique variations in region II. From 606 sequenced amino acids, 32 variations were found. Of these, three variations were regularly found in positions 424, 437 and 503 of the Sal-1 amino acid sequence. In region III, six isolates had a loss of the 30 bp (FAESTKSAE) insert. However, six isolates had 6 bp (SD) inserts at the end of region III. Two cases had a reverse pattern. Our results suggest that the P. vivax currently found in South Korea are unique when compared to other isolates and can be divided, by the analysis of their molecular structure, into two strains.

Amino Acid Sequence↗
PubMed2001

A dominant antigenic region of the hantaan virus nucleocapsid protein is located within a amino-terminal short stretch of hydrophilic residues.

The nucleocapsid (N) protein of the Hantaan virus (HTNV) is a major viral antigen that induces a strong antibody response during the acute phase of infection. By immunoblot analyses of the recombinant N proteins using human sera of the hemorrhagic fever with renal syndrome (HFRS), we have confirmed previous finding by other investigators of the presence of a highly antigenic region near the amino terminus of the HTNV N protein. We have further located the antigenic region within a short stretch of hydrophilic sequences between the 26 and the 46th amino acid residues. The recombinant glutathione S-transferase fusion proteins containing this region was expressed as a soluble form in a large quantity in Escherichia coli, and purified by a single-step affinity chromatography. The recombinant antigen also showed a similar, but a weaker reactivity with human antisera to Seoul virus (SEOV), the virus most closely related to HTNV.

Antigens, Viral↗
PubMed2001

Molecular epidemiology of hepatitis A virus in Korea.

BACKGROUND: The prevalence of antibodies for hepatitis A virus (anti-HAV) in adolescents and young adults has decreased remarkably following the economic growth in Korea. As a result, this age group has a high risk for HAV infection paradoxically, and over 1500 cases of clinically overt hepatitis A occurred in 1998. Human isolates of hepatitis A virus (HAV) are categorized within four genotypes (I, II, III, and VII). In some geographic regions, closely related isolates cluster, suggesting endemic spread of the virus, while in other regions multiple genotypes circulate. Virtually no data are available with regard to the genetic relatedness of Korean strains of HAV. METHODS AND RESULTS: A 168 base pair segment encompassing the putative VP1/2A junction of the HAV genome was amplified by RT-PCR and sequenced in sera of 18 Korean patients with a sporadic form of acute hepatitis A. Pairwise comparisons of the nucleic acid and amino acid sequences of 18 Korean isolates with one another revealed that the Korean isolates showed > 94.6% and > 96.4% identity, respectively. All of the 18 Korean isolates clustered within genotype IA, irrespective of the geographic locations and the time that hepatitis occurred. Unique amino acid sequence changes that had never been reported in genotype IA were found in nine of the 18 isolates. These changes were Gln-->Ser and Lys-->Arg in 2A-19 and 2A-10 amino acid positions. CONCLUSION: The presence of single genotype and unique mutations may be related with the circulation of endemic HAV over a long period of time in Korea.

Acute Disease↗
PubMed2001

The analysis of circumsporozoite-protein gene sequences from South Korean isolates of Plasmodium vivax.

The amino-acid sequences corresponding to the circumsporozoite protein (CSP) of Plasmodium vivax fall into two main types, VK210 and VK247, each of which has a characteristic tandem repeat. When the repetitive domains of the CSP gene from six isolates of P. vivax from South Korea were sequenced they were found to show a total of 20 tandem amino-acid repeats, and repeat patterns that are regular and distinct from those of other P. vivax isolates. The amino-acid sequences of the South Korean parasites were found to be most similar to those of three isolates from China (CH-3, CH-4, and CH-5) and, particularly, to one from North Korea. A sequence (AGGNAANKKAEDAGGNA) and two repeats of the sequence GGNA found in the North Korean parasites were found in all six isolates from South Korea. The South Korean parasites investigated appear phylogenetically identical and unique to the Korean peninsula.

Animals↗
PubMed2001

Electrophoretic karyotype analysis of sequential Candida parapsilosis isolates from patients with persistent or pecurrent fungemia.

We assessed the genetic relatedness of sequential isolates of Candida parapsilosis during persistent or recurrent fungemia and the effect of central venous catheter (CVC) removal. Serial isolates of C. parapsilosis were obtained from 17 patients with persistent or recurrent fungemia over periods of up to 5 months. Forty-eight C. parapsilosis isolates from the blood of 17 patients were analyzed by electrophoretic karyotyping (EK) with pulsed-field gel electrophoresis (PFGE), revealing 25 different karyotypes. The strains sequentially isolated from each of seven patients whose fungemia resolved following CVC removal had the same karyotype. Two patients with fungemia that cleared without CVC removal each had two sequential isolates with different karyotypes. In six (75%) of the eight patients whose fungemia was recurrent even after CVC removal, the karyotypes of the pre- and post-CVC removal isolates were different, implying the emergence of a new strain. Overall, the sequential strains from each patient had identical karyotypes in 53% (9 of 17) of the patients and two different karyotypes in 47% (8 of 17). This study shows that EK with PFGE is useful for investigating persistent or recurrent fungemia due to C. parapsilosis and that recurrent fungemia due to C. parapsilosis is more likely caused by reinfection with a second strain.

Adult↗
PubMed2001

Molecular genetic analysis of reovirus isolated in Korea.

Reovirus isolates from human, striped-field mouse (Apodemus agrarius) and Korean field mouse (A. peninsulae) in Korea showed extensive variability in the patterns of electrophoretic migration of the double-stranded RNA (dsRNA) genome segments. Hemagglutination inhibition (HI) test was performed for serotype determination of 12 reovirus isolates. To clarify genetic diversity and molecular phylogeny of Korean reoviruses, L1, S3 and S4 genomic segments of reoviruses were amplified by RT-PCR and directly sequenced. Among 12 reovirus strains, 9 strains were type 3 and 3 strains were type 2. The L1 was highly conserved showing 91.5-100%, 94.7-100% similarities among Korean isolates, and 77.5-97.9%, 92.6-96.8% similarities compared to other reference strains of each genotypes at nucleotide and amino acid levels, respectively. In S3 and S4 segments, 84.4-99.3%, 72.3-99% nucleotide sequence similarities and 92-99.3%, 89.1-98.4% amino acid sequence similarities among Korean isolates were observed, and 70.8-93.9%, 72.3-98.7% nucleotide sequence similarities and 81.8-100%, 88.3-97.7% amino acid sequence similarities compared with other reference strains of each genotype were observed, respectively. Phylogenetic analyses based on the S3 and S4 nucleotide sequences indicate that genotypes of reovirus are more related with geographic differences rather than host species or date of isolation.

Animals↗
PubMed2001

A novel silent substitution (C8516T) in exon 9 of the human PROC gene.

Protein C is a vitamin K dependent serine protease zymogen, which has a regulatory influence over the coagulation cascade via the inhibition of factors Va and VIIIa. Hereditary protein C deficiency is associated with an increased risk of thromboembolic disease. A multitude of families displaying protein C (PROC) gene defects have been reported, and a number of DNA sequence polymorphisms are known to occur in the PROC gene. We have identified a previously undescribed silent substitution (C8516T) by direct DNA sequencing in a Korean patient with thrombosis and protein C deficiency. In addition, a rare T allelic frequency (0.016) was determined in 123 patients with acquired or hereditary protein C deficiency.

Exons↗
PubMed2000

Genetic diversity of Apodemus agrarius-borne hantaan virus in Korea.

Hantaan (HTN) virus, the etiologic agent of clinically severe hemorrhagic fever with renal syndrome (HFRS), was first isolated in 1976 from lung tissues of striped field mice (Apodemus agrarius) captured in Songnae-ri, Kyungki-do, Korea. To clarify the genetic diversity and phylogenetic relationship among Korean strains of HTN virus, viral sequences of the partial S and M segments were amplified from lung tissues of 24 seropositive striped field mice captured between 1989 and 1998 at 11 sites in South Korea. The 771-nucleotide (nt) S segment sequences (coordinates 432 to 1202) of HTN virus strains from Yangju-kun differed by 10 to 40 nt (1.3 to 5.2%) from virus strains from Pocheon-kun, Songnae-ri and Nonsan-kun. Similar degrees of genetic variation were found in the G1 and G2 glycoprotein-encoding M segment. Phylogenetic trees, based on the partial S and M segments and generated by the maximum parsimony and neighbor-joining methods, demonstrated that virus strains from various geographic regions in South Korea showed a tendency to form two phylogenetic subgroups and were evolutionarily distinct from HTN virus strains from the People's Republic of China.

Animals↗
PubMed2000

Phylogenetic analysis of the small hydrophobic (SH) gene of mumps virus in Korea: identification of a new genotype.

Viral RNAs extracted from fifteen mumps virus isolated from throat swab, saliva, blood, urine or CSF during mumps epidemics between 1997-1998 in Korea were amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) and compared by nucleotide sequencing of the small hydrophobic (SH) gene. The deduced amino acid sequences of the SH gene were aligned with the published sequences of mumps virus isolated in different geographic areas. A comparison of the SH gene of mumps viruses in Korea indicated 96.2-100% and 91.2-100% similarity at the nucleotide and amino acid levels, respectively. Phylogenetic analysis, using the neighbor-joining method, showed that Korean mumps virus strains formed a genetically distinct monophyletic group from previously reported genotypes based on the 315-bp length nucleotide and 57 deduced amino acid sequences of the SH gene, and possibly be designated as a new genotype (I).

Adolescent↗
PubMed2000

Pseudochylous pleural effusion with fat-fluid levels: report of six cases.

The authors report the clinical and computed tomographic (CT) findings in six patients with chyliform pleural effusion. All six patients had a medical history of pleurisy before presentation; five of them had tuberculous pleural effusion. The CT scans of all six patients showed variable amounts of pleural fluid collection with a layering of fat at the nondependent site.

Adult↗
PubMed2000

Pulmonary vasculitis: the spectrum of radiological findings.

Pulmonary vasculitis includes various disease entities with a wide range of clinical presentations and overlapping imaging features. Radiological findings of vasculitis in the angiitis-granulomatosis group are nodular and patchy opacities, whereas the principal feature of those diseases causing widespread capillaritis is diffuse air space consolidation. Aneurysms or stenoses of pulmonary arteries are seen in patients with Takayasu arteritis or Behçet's disease.

Arteritis↗