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Biomedical subjects

S H Hong

Publications and source records attributed to S H Hong.

At least 163 records · Page 9Linked to original sources

POEMS syndrome--a case report.

POEMS syndrome is a multisystem disorder associated with polyneuropathy, organomegaly, endocrinopathy, a monoclonal protein (M-protein), and skin changes. The authors describe a patient with POEMS syndrome who had osteosclerotic myeloma confirmed by open bone biopsy. Magnetic resonance imaging (MRI) showed discrete lesions of low signal intensity in both T1 and T2-weighted images. This patient is now being successfully treated with melphalan and prednisone with much improvement in skin thickening and sensory change in the lower extremities.

Adult↗

Prevalence of antibodies to hepatitis C virus in patients with various types of liver diseases.

BACKGROUND: Hepatitis C virus (HCV) is known to be a major cause of non-A, non-B hepatitis (NANBH) and is thought to be an important causative agent of serious liver disease. Recently the role of HCV in the development of various liver disease is suggested. METHODS: Sera from 222 patients with various liver diseases had been kept frozen at -20 degrees C until the test. Anti-HCV was detected using the ABBOTT HCV EIA Test System (ABBOTT Co., America) following the manufacturer's instructions. The assay uses a recombinant HCV antigen (C 100-3) synthesized in yeast. RESULTS: HCV antibodies (anti-HCV) were detected in 35 (31.5%) of 111 HBsAg-negative patients. The prevalence rate of anti-HCV was 61.9% (13 out of 21 patients) in chronic hepatitis, 29.1% (14 out of 48) in liver cirrhosis, 26.3% (5 out of 19) in hepatocellular carcinoma and 13% (3 out of 23) in acute hepatitis was far less (3 out of 111 patients, 2. 7%) than that of HBsAg-negative patients (p < 0.01). In this group, anti-HCV was detected in 2 (5.1%) out of 39 liver cirrhosis, 1 (1.9%) out of 52 chronic hepatitis, among them 47 were biopsy-proven chronic active hepatitis, and none of 20 hepatocellular carcinoma. CONCLUSIONS: These data suggest that, in Korea, 1) coinfection of HCV and HBV is infrequent, 2) HCV might be an important cause of HBsAg-negative chronic hepatitis, 3) HCV is seemed to be a less likely important factor associated with liver cirrhosis or hepatocellular carcinoma in HBsAg-negative patients, but further prospective study with a large population is necessary.

Female↗

A gene in Schizosaccharomyces pombe analogous to the RAD4 gene of Saccharomyces cerevisiae.

A gene, analogous to the RAD4 gene, which is required for nucleotide excision repair in Saccharomyces cerevisiae, also exists in Schizosaccharomyces pombe. RNA isolated from wild type S. pombe cells strongly cross-hybridized with the 1.2 kb PvuII DNA fragment of the S. cerevisiae RAD4 genomic clone (pPC1). Chromosomal DNA isolated from S. pombe had similar restriction patterns to those from S. cerevisiae, as determined by Southern blot analysis. Two species of mRNA, 3.1 and 1.8 kb, were identified by Northern hybridization. The level of these transcripts did not increase upon UV-irradiation, suggesting that the RAD4-like gene in S. pombe is not UV-inducible.

DNA Damage↗

Biochemical characteristics of glucose-6-phosphate dehydrogenase variants among the Malays of Singapore with report of a new non-deficient (GdSingapore) and three deficient variants.

Biochemical characteristics of one non-deficient fast G6PD variant (GdSingapore) and six different deficient variants (three new, two Mahidol, one each of Indonesian and Mediterranean) were studied among the Malays of Singapore. The GdSingapore variant had normal enzyme activity (82%) and fast electrophoretic mobilities (140% in TEB buffer, 160% in phosphate and 140% in Tris-HCl buffer systems respectively). This variant is further characterized by normal Km for G6P; utilization of analogues (Gal6P, 2dG6P; dAmNADP), heat stability and pH optimum. The other six deficient G6PD variants had normal electrophoretic mobility in TEB buffer with enzyme activities ranging from 1 to 12% of GdB+. The biochemical characteristics identity them to be 2 Mahidol, 1 Indonesian and 1 Mediterranean variants and three new deficient variants.

Electrophoresis↗

The effect of ageing on mucin contents in mouse submandibular glands.

There may be deleterious effects if there is an age-dependent reduction in mucin composition or content in salivary glands. To assess whether there was an effect of age in submandibular glands from male mice aged 3 months, 10 and 20 months and 27, 29 and 30 months, mucin, protein and sialic acid were quantitated. Changes in wet weight per gland and protein per gland were highly significant (p less than 0.001), as tested by analysis of variance, and the means for both were highest in middle aged glands. While sialic acid per gland showed no significant change from middle aged to old glands, mucin per gland showed an age-related decrease (p less than 0.01) when comparing either young or middle aged glands with old glands.

Aging↗

Age-related changes in mucins from human whole saliva.

The predominant mucins in human whole saliva, MG1 and MG2, serve to protect and to lubricate the oral cavity. In this study, both unstimulated and stimulated whole salivas were collected from two groups of subjects: young (18-35 years of age) and aged (65-83 years of age). The subjects were in apparent good health. Saliva samples from each subject were analyzed by SDS-PAGE. The gels were stained with Stains-all, and both MG1 and MG2 were quantitated by video-image densitometry. The protocol gave reproducible values for each mucin. The stimulated and unstimulated salivas from aged subjects showed significant reductions in concentrations of both MG1 and MG2, as quantitated in mucin dye-binding units. Possible associations of these reductions with the aging process are discussed.

Adolescent↗

In vitro activities of eight antibiotics against methicillin-resistant S. aureus and S. epidermidis strains isolated in Korea.

Staphylococcus aureus and Staphylococcus epidermidis strains isolated at eight large medical centers in Korea were examined for methicillin resistance and resistance to eight other antibiotics; cefazolin, cefamandole, cefuroxime, cefoxitin, cefotaxime, moxalactam, penicillin G and vancomycin. Methicillin resistance was found in 296 of 1225 strains (24.2%) of S. aureus and 126 of 348 strains (36.2%) of S. epidermidis. Methicillinresistant strains were isolated from all sources with the frequency of isolation ranging from 11% to 60%. From pleural effusion, throat swab and blood, methicillin-resistant strains of S. aureus were more frequently isolated with statistical significance (Chi-squared test, 95% confidence). Almost all of Methicillin-resistant S. aureus (MRSA) and S. epidermidis (MRSE) strains were multiply resistant to one or more tested eight antibiotics. However only 7(2.4%) of 296 MRSA strains and 2(1.6%) of 126 MRSE strains were resistant to vancomycin. Vancomycin was the most effective antibiotic against staphylococcal isolates as well as MRSA and MRSE.

Anti-Bacterial Agents↗

Upstream regulatory regions controlling the expression of the yeast maltase gene.

The expression of the maltase (MALS) and the maltose permease (MALT) genes in Saccharomyces species is coregulated at the transcriptional level; they are coordinately induced by maltose in the presence of a positively acting regulatory (MALR) gene and carbon catabolite repressed by glucose. We generated a series of deletions in the upstream region of the MAL6S gene to examine the regulatory elements in detail. The results showed that inducible expression by maltose was lost when the region between 320 and 380 base pairs upstream of the translation initiation codon was deleted. This region contained an imperfect inverted repeat sequence (-361 to -327) or four copies of short direct repeats that might serve as components of the upstream activation site (UASM) for the maltase gene, or both. When a stretch of T-rich sequence (-253 to -237) was deleted, the susceptibility of the maltase gene to carbon catabolite repression was affected.

Chromosome Deletion↗

Primary structure of the maltase gene of the MAL6 locus of Saccharomyces carlsbergensis.

We have determined the complete nucleotide (nt) sequence of a 2937-bp DNA fragment containing the yeast maltase (EC 3.2.1.20) gene (MAL6S) as well as part of the contiguous maltose permease gene (MAL6T) from the MAL6 locus of Saccharomyces carlsbergensis. The MAL6S gene encodes an alpha-glucosidase that is required for the utilization of maltose as a carbon source by yeast. The 5' transcription initiation sites for both MAL6S and MAL6T were determined by primer extension experiments using reverse transcriptase. The sequence data show one major open reading frame (ORF) of 584 amino acids (aa) for maltase with a calculated Mr of 68 107, somewhat larger than the value of 63 000 previously determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) analysis. The nucleotide sequences upstream of both the MAL6S and MAL6T genes, which are divergently transcribed, show common structural features for the transcription initiation of yeast genes as well as signals required for their translation. The codon bias index shows that the MAL6S gene is moderately expressed. The possible significance of two 17-bp dyad symmetric sequences, found in the intergenic region of MAL6S and MAL6T, for the control of expression of these genes is also discussed.

Amino Acid Sequence↗

Dysplastic nodules of the liver: imaging findings.

BACKGROUND: To verify characteristic features of hepatic dysplastic nodules at different imaging modalities. METHODS: Twenty-eight patients with 37 dysplastic nodules of the liver (0.8-3.0 cm) underwent sonography (28 patients), computed tomography (CT; 24 patients), magnetic resonance (MR; 11 patients), and angiography (12 patients). Each nodule was analyzed for echogenicity, attenuation, signal intensity, and vascularity. RESULTS: Echogenicity of nodules was high in 16 (43%), homogeneous in two (6%), and low in 19 (51%) of 37 nodules. Attenuation of nodules was high in one (7%), homogeneous in four (26%), and low in 10 (67%) of 15 nodules on the arterial-phase CT images; homogeneous in five (33%) and low in 10 (67%) of 15 nodules on the portal-phase CT images; and high in four (17%), homogeneous in six (26%), and low in 13 (57%) of 23 nodules on the delayed-phase CT images. Signal intensity of nodules was high in 15 (94%) and homogeneous in one (6%) of 16 nodules on T1-weighted MR images and was homogeneous in seven (44%) and low in nine (56%) of 16 nodules on T2-weighted MR images. Vascularity of nodules was avascular in 14 (88%) and slightly vascular in two (12%) of 16 nodules. CONCLUSIONS: Hepatic dysplastic nodules show diverse imaging characteristics with different imaging techniques; however, common imaging findings of hepatic dysplastic nodules are low echo, low attenuation, and high, low, or homogeneous intensity on T1- and T2-weighted MR, and avascularity.

Adult↗

Outpatient prescription drug use by children enrolled in five drug benefit plans.

This study examined prescription drug use among ambulatory children younger than 18 years of age enrolled in five drug benefit plans. Data for this study were obtained from the pharmacy benefit manager who administers the drug benefit plans. During the study period of December 29, 1992, through December 28, 1993, 3144 children younger than 18 years of age (34.0% of the total plan enrollment) were enrolled in the five drug benefit plans. A total of 8547 prescription drugs were dispensed to the study population. The mean prescription price was $16.38, and the mean duration of therapy was 11.7 days. The mean prescription price was $1.56 more for boys than for girls. The most frequently dispensed drugs were antibiotics (42.0%), followed by cold preparations (15.9%). The annual prevalence rate of prescription drug use was 59.1 cases per 100 children. The study population-based annual frequency rate was 3.2 prescriptions per child, and the drug user-based annual frequency rate was 5.5 prescriptions per child. The annual expenditures were $51.85 per child and $90.39 per drug users, with the out-of-pocket expenditures being $19.09 and $33.04, respectively. The prevalence rate varied little by sex. However, both frequency and expenditure rates differed by sex and decreased with age. Higher levels of cost sharing per prescription were associated with higher prevalence, frequency, and expenditure rates. Larger cost-sharing differentials between generic and brand name drugs were associated with higher rates of generic drug use but were not always associated with lower expenditure rates.

Adolescent↗

Red cell glucose-6-phosphate dehydrogenase phenotypes in several Mongoloid populations of eastern India: existence of a non-deficient fast variant in two Australasian tribes.

A total of 954 subjects of both sexes from nine Mongoloid tribes of eastern India were investigated for the distribution of red cell glucose-6-phosphate dehydrogenase (G6PD) phenotypes by starch-gel electrophoresis. The incidence of Gd- was found to be 8% in the Khasi, 6% in the Nishi, 5% in Apatani and 3% in Adi. The small group of Bodo and the mixed group of other Arunachal tribes had Gd- frequencies of 19% and 15%, respectively. Only one isolated incidence of Gd- was encountered in the Naga, while the Hmar lacked Gd-. The Khasi had a polymorphic frequency (about 4%) of a non-deficient fast variant (GdV) (105% mobility in TEB buffer of pH 8.6). Two heterozygotes of this allele with a combination of common GdB+ were detected in two females. Interestingly, the same allele was reported earlier in another Australasian tribe--the Korkus of central India.

Alleles↗

High resolution CT findings of miliary tuberculosis.

PURPOSE: The purpose of this study was to analyze high resolution CT (HRCT) findings of miliary tuberculosis and to assess the clinical utility of HRCT in the management of patients with miliary tuberculosis. METHOD: We reviewed retrospectively HRCT scans of 25 patients with histopathologically (n = 16) and/or microbiologically (n = 9) proven miliary tuberculosis. RESULTS: HRCT scans showed miliary nodules in 24 patients, which varied in size from 1 to 5 mm, with either sharply (n = 21) or poorly (n = 3) defined margins. The nodules had diffuse random distribution throughout both lungs and within the secondary pulmonary lobules. In 23 patients, areas of ground-glass opacities (GGOs) were observed with variable extent and distribution. The patients who had dyspnea showed large areas of GGOs, and two patients with impending adult respiratory distress syndrome revealed extensive GGOs. Both intralobular reticulation and interlobular septal thickening were seen in 10 patients. CONCLUSION: Miliary nodules and GGOs are the predominant HRCT findings in patients with miliary tuberculosis, and HRCT scans are helpful in the early diagnosis and proper management of patients with miliary tuberculosis.

Adult↗

The visible man: three-dimensional interactive musculoskeletal anatomic atlas of the lower extremity.

A personal computer-based interactive musculoskeletal anatomic atlas of the lower extremity has been created by using the Visible Human Male data set. A semiautomatic segmentation program was developed by using an intelligent scissors approach and shape-based interpolation, thus considerably reducing the laborious work of the segmentation and labeling process. Manual contour extractions at 3-mm section intervals and shape-based interpolations of intervening sections of the musculoskeletal structures of the lower extremity were performed. For interactive and realistic three-dimensional display, an efficient binary volume rendering method was developed that introduces the concept of shear-warp factorization and applies a newly developed normal calculation technique. Binary volume rendering reconstructs various structures from a series of two-dimensional sections in a few seconds, thus enabling real-time manipulations of the computerized atlas. All of the muscles, tendons, and bones of the lower extremity have been segmented and labeled. The volume-based three-dimensional interactive atlas supports various interactions including rotation, removal, highlighting with artificial colors, arbitrary cutting operation, transparent view, and descriptive knowledge representation. In addition, browsing through the two-dimensional images of transverse, coronal, and sagittal views with labeling and segmentation information is possible.

Anatomy, Cross-Sectional↗

Tumor angiogenesis as a prognostic predictor in colorectal carcinoma with special reference to mode of metastasis and recurrence.

Tumor angiogenesis has proved to be a useful prognostic determinant for patients with various solid tumors. In this study, we investigated the quantitative expression of angiogenesis in colorectal carcinoma to determine how angiogenesis correlates with clinicopathologic factors and prognosis. One hundred twenty-seven specimens resected from patients with primary colorectal carcinoma were investigated immunohistochemically using a polyclonal antibody against factor-VIII-related antigen, and areas with the highest vascular density at the invasive tumor margin were counted at 200 times magnification. The microvessel count, defined as angiogenesis density (AD), became significantly higher with increase in histologic grade (p = 0.02) and Dukes stage (p = 0.001). AD was also significantly higher in patients with lymph node metastasis (p = 0. 005), lymphatic invasion (p = 0.042), vascular invasion (p < 0.001), and liver metastasis (p = 0.0004) than in those without. In addition, patients with synchronous distant hematogenous metastasis in stage D disease showed significantly higher AD than patients with nonhematogenous metastasis (p = 0.006). When 27 cases of disease recurrence after surgical resection with curative intent were stratified according to mode of spread, AD in cases with a hematogenous pattern of relapse proved to be significantly higher than in cases with nonhematogenous spread (p < 0.001). No significant differences were, however, found in AD when they were subdivided as to operative nodal status (p = 0.39 and 0.08 in the node-negative and the node-positive group, respectively). Multivariate analysis indicated that AD was an independent prognostic factor (p = 0.0004) in colorectal carcinoma. Quantitative evaluation of tumor angiogenesis at the invasive tumor margin is suggested to be a good prognostic indicator and a useful predictor for hematogenous spread and recurrence in patients with colorectal carcinoma.

Colorectal Neoplasms↗

Biochemical characteristics of four common molecular variants in glucose-6-phosphate dehydrogenase-deficient Chinese in Singapore.

Biochemical characteristics were determined for four common molecular variants of glucose-6-phosphate dehydrogenase (G6PD) deficiency and 10 non-deficient Chinese males in Singapore. The variants included one Mediterranean (nt563 C-->T), two Canton (G-->T at nt1376) and one each of Kaiping (1388 G-->A) and Chinese-5 (1024 C-->T) variants. Molecular identification was carried out by amplication of genomic DNA with specific oligonucleotide primers followed by digestion with restriction enzymes that recognize artificially created or naturally occurring restriction sites. All the variants had low enzyme activity in red cells (0.2-0.6 IU/g Hb). All but the Chinese-5 variant (nt1024) had a normal Km for NADP (7-10 microM). The Mediterranean variant had a high utilization of deamino-NADP (296%), followed by the Canton variant 1376 substitution (131%). The Km for glucose-6-phosphate was low in the Mediterranean and 1376 variant (18-40 microM) but high in the 1024 substitution (104 microM). Electrophoretic mobility in TEB buffer (pH 8.6) was slightly faster (103%) for the 1376 mutation while 100% for all the others. All but the 1024 substitution had increased analogue utilization for galactose-6-phosphate and 2-deoxy-glucose-6-phosphate (58 and 68% for the Mediterranean mutation and 14-23% for the 1376 and 1388 substitutions, respectively), and reduced heat stability.

China↗