Effect of nonylphenol on the expression of hepatic vitellogenin mRNA in male Bombina orientalis (Boulenger).
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Animals↗
Biomedical subjects
H S Kang
Publications and source records attributed to H S Kang.
Kaposiform hemangioendothelioma arising from the internal auditory canal.
Kaposiform hemangioendothelioma is a rare vascular tumor and locally aggressive endothelial-derived spindle cell neoplasm, which occurs almost exclusively in infants and adolescents. Radiologically, hemangioendothelioma, including Kaposiform hemangioendothelioma, is seen as a highly vascularized well-enhancing tumor, but no characteristic findings differentiate Kaposiform hemangioendothelioma from other soft-tissue tumors, particularly when the tumor is too small to have any locally aggressive features or identifiable large vessels. We present a case of Kaposiform hemangioendothelioma in the internal auditory canal that had no differential features on initial MR images and rapidly grew into a huge mass in a few months.
Ear Neoplasms↗
Cellular responses to mild heat stress.
Since its discovery in 1962 by Ritossa, the heat shock response has been extensively studied by a number of investigators to understand the molecular mechanism underlying the cellular response to heat stress. The most well characterized heat shock response is induction of the heat shock proteins that function as molecular chaperones and exert cell cycle regulatory and anti-apoptotic activities. While most investigators have focused their studies on the toxic effects of heat stress in organisms such as severe heat stress-induced cell cycle arrest and apoptosis, the cellular response to fever-ranged mild heat stress has been rather underestimated. However, the cellular response to mild heat stress is likely to be more important in a physiological sense than that to severe heat stress because the body temperature of homeothermic animals increases by only 1-2 degrees C during febrile diseases. Here we provide information that mild heat stress does have some beneficial role in organisms via positively regulating cell proliferation and differentiation, and immune response in mammalian cells.
Animals↗
Effects of alachlor on survival and development of Bombina orientalis (Boulenger) embryos.
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Acetamides↗
Morphometric studies on the testis of Korean ring-necked pheasant (Phasianus colchicus karpowi) during the breeding and non-breeding seasons.
The purpose of this study was to obtain detailed quantitative information on all cell types in the testis interstitium of Korean ring-necked pheasants and to combine these data with changes in the steroidogenic function of the testis during the breeding and non-breeding seasons. For animals collected during the breeding season, their testis weights, sperm production, serum testosterone levels and leuteinizing hormone (LH)-stimulated testosterone secretion were significantly (p < 0.01) increased compared to the non-breeding season. Testes of the pheasants during the non-breeding season displayed a 98% reduction in testis volume that was associated with a decrease in the absolute volume of seminiferous tubules (98% reduction), tubular lumen (100%), interstitium (90%), blood vessels (84%), lymphatic spaces (97%), Leydig cells (79%), mesenchymal cells (51%) and myoid cells (61%) compared to the breeding season. The numbers of Leydig cells, mesenchymal cells and myoid cells per testis in the breeding season were much higher than in the non-breeding season. Although the mean volume of a Leydig cell was 74% lower in the non-breeding season, the mean volumes of myoid and mesenchymal cells remained unchanged. These results demonstrate that there are striking differences in the testicular structure of the Korean ring-necked pheasant during the breeding and non-breeding seasons. Every structural parameter of the Leydig cell was positively correlated with both testosterone serum levels and LH-stimulated testosterone secretion. The correlation of changes in hormonal status with the morphometric alterations of Leydig cells suggests that the Korean-ring necked pheasant may be used as a model to study structure-function relationships in the avian testis.
Animals↗
Transfer of 137Cs to rice plants from various paddy soils contaminated under flooded conditions at different growth stages.
Soil blocks from 18 paddy fields around three Korean nuclear power plant sites were put into lysimeters. Greenhouse experiments were carried out to investigate the (137)Cs transfer from these paddy soils to rice plants for its deposition at different growth stages. A solution of (137)Cs was applied to the flooded lysimeters at 2-3 different stages. The applied (137)Cs was mixed with the topsoil only at the pre-transplanting application. The transfer was quantified with a transfer factor based on the unit-area deposition (TF(a), m(2)kg(-1)-dry). The TF(a) in the pre-transplanting application showed a remarkable variation with the soils. However, the differences in the mean values among the study sites were not statistically significant. The straw TF(a) was 2-3 times higher than the corresponding seed value. The early-tillering stage and booting stage applications resulted in a higher transfer than the pre-transplanting application by factors of, on an average, 2 and 16 for the straws, and 3 and 25 for the hulled seeds, respectively. The (137)Cs transfer was found to correlate negatively with the soil pH and positively with the organic matter content. Based on the present results, the representative (137)Cs TF(a) values for the rice are proposed for use in the whole of Korea for the deposition at three different growth stages.
Cesium Radioisotopes↗
Risk factors of new compression fractures in adjacent vertebrae after percutaneous vertebroplasty.
PURPOSE: To evaluate the risk factors related to the development of new fractures in adjacent vertebrae after vertebroplasty. MATERIAL AND METHODS: The study was conducted on 106 patients in whom 212 vertebroplasties were performed during a period of 3 years. Evaluations of the five vertebrae superior and inferior to the treated vertebra were performed. Consequently, 913 vertebrae were evaluated and the fracture-free interval of the vertebral body adjacent to the treated vertebra was calculated. Survival analysis was performed using the Kaplan-Meier method and Cox proportional hazards regression analysis. RESULTS: Seventy-two (7.9%) new fractures were revealed. The Kaplan-Meier estimate of the 1-year fracture-free rate was 93.1%. The mean fracture-free interval was 32 months (95% CI, 32 to approximately 33 months). The greater degree of height restoration of the treated vertebra, the location of the adjacent vertebra in the TL junction, and the shorter distance between the treated and the adjacent vertebra increased the risk of new vertebral fractures. CONCLUSION: Thoracolumbar junction, shorter distance from the treated vertebrae, and greater degree of height restoration of the cemented vertebrae may increase the fracture risk of vertebrae adjacent to cement vertebrae after vertebroplasty.
Adult↗
A human model for road safety: from geometrical acquisition to model validation with radioss.
In order to investigate injury mechanisms, and to provide directions for road safety system improvements, the HUMOS project has lead to the development of a 3D finite element model of the human body in driving position. The model geometry was obtained from a 50th percentile adult male. It includes the description of all compact and trabecular bones, ligaments, tendons, skin, muscles and internal organs. Material properties were based on literature data and specific experiments performed for the project. The validation of the HUMOS model was first achieved on isolated segments and then on the whole model in both frontal and lateral impact situations. HUMOS responses were in good agreement with the experimental data used in the model validation and offers now a wide range of applications from crash simulation, optimization of safety systems, to biomedical and ergonomics.
Abdomen↗
Spine needle biopsy simulator using visual and force feedback.
OBJECTIVE: Biopsy with an inserted needle is an important procedure for lesion detection in the spine, but is difficult to perform due to the presence of many critical organs near the spine. This article presents a spine needle biopsy simulator, based on visual and force feedback, which can be used to plan the optimal path of a needle and to practice the procedure without risk. MATERIALS AND METHODS: The simulator is composed of a 3D human model, a visual-feedback component, a force-feedback component, and an evaluation module. The human model is based on 3D CT data. The visual-feedback component provides an oblique section, multiplanar reformatting images, and a volume-rendered image. Of these, the oblique section display is very useful for planning a 3D path for the needle. During simulation, the force-feedback component generates and provides realistic forces acting on the biopsy needle in real time by synchronizing them to visual feedback. After each simulation, the evaluation module provides a performance analysis for the trainee. RESULTS: For an XCT abdomen volume data set of 256 x 256 x 256, the update rate of image rendering due to needle movement is over 25 Hz, with a force-feedback rate of 1 kHz. This performance proved to be good enough for the trainee to learn the relationship between visual and force feedback. CONCLUSIONS: The simulator is useful for the planning of and training in complicated 3D spine needle biopsy procedures. It may be used as an educational tool for beginners, a practice tool to increase expertise, or a test bed for new procedures.
Algorithms↗
Interleukin-10 up-regulates tumour-necrosis-factor-alpha-related apoptosis-inducing ligand (TRAIL) gene expression in mammary epithelial cells at the involution stage.
Although interleukin-10 (IL-10) is known to contribute to inflammation and pathogenesis in mammalian organs, little is known about its precise role in the mammary gland. We found that IL-10 levels fluctuated during the mouse mammary cycle, showing little expression at the lactation stage and the highest expression at the involution stage. To reveal the effects of IL-10 on involution, expression profiles of apoptosis-related genes were examined in mice transgenic for IL-10 as well as in IL-10(-/-) mice. Mild inflammatory lesions by lymphocytes were observed in the mammary glands from four of seven transgenic lines at the lactation stage. It was striking that the expression of tumour-necrosis-factor-alpha-related apoptosis-inducing ligand (TRAIL) among the apoptosis-related genes was elevated approx. 7-fold in the transgenic mice, whereas others were almost unchanged. Furthermore, TRAIL was down-regulated 4-fold in the IL-10(-/-) mice at the involution stage. Elevated expression of TRAIL and of death receptor 4 (DR4) protein was identified at the involution stage of normal mammary glands as well as at the lactation stage of the IL-10 transgenic mice. These results indicate that the elevated expression of IL-10 at the involution stage recruits lymphocytes and induces the expression of TRAIL and DR4. These phenomena might partly contribute to apoptosis in the mammary epithelial cells for entering involution.
Animals↗
Protein phosphatase 2A modulates the proliferation of human multiple myeloma cells via regulation of the production of reactive oxygen intermediates and anti-apoptotic factors.
To understand the roles of reactive oxygen intermediates (ROI) in Fas-mediated apoptosis of myeloma cells, the effects of antioxidants were tested. Fas-mediated apoptosis was further increased in the presence of antioxidants such as N-acetyl-L-cysteine and glutathione, but it was decreased when hydrogen peroxide was added. The intracellular ROI level was significantly decreased in myeloma cells treated with okadaic acid, an inhibitor of protein phosphatases 1 and 2A (PP1/PP2A). To clarify the direct roles of PP2A in myeloma cell growth, the PP2A transfected cell lines, sense- or antisense-PP2A transfectants, were established. Spontaneous cell growth of antisense-PP2A transfectants was reduced compared with that of vector transfectants. The intracellular ROI level was significantly decreased in antisense-PP2A transfectants but increased in sense-PP2A transfectants compared with vector controls. In addition, anti-apoptotic factors such as bcl-2 and IL-6 were reduced in antisense-PP2A transfectants. Taken together, these results indicate that PP2A is an essential factor for survival and growth of myeloma cells via regulation of intracellular ROI and anti-apoptotic factors.
3T3 Cells↗
Molecular identification of IgE-dependent histamine-releasing factor as a B cell growth factor.
The culture supernatants of LK1 cells, murine erythroleukemia cells, showed B cell-stimulating activity. Purification and NH(2)-terminal sequence analysis revealed that one of the candidates was murine IgE-dependent histamine-releasing factor (IgE-HRF), which is known to induce histamine from basophils. Recombinant IgE-HRF (rHRF) obtained from Escherichia coli- or 293-transformed embryonal kidney cells was tested for B cell-stimulating activity. Both rHRFs stimulated B cell proliferation in a dose-dependent manner. However, boiling or anti-HRF Ab abolished the B cell stimulatory effects of rHRF. Recombinant HRF showed strong synergistic effects with IL-2, IL-4, and IL-5 for B cell activation, with maximal activity in the presence of anti-CD40 AB: Recombinant HRF increased MHC class II expression of B cells. It also increased Ig production from B cells. Treatment with polymyxin B, a neutralizing peptide antibiotic of LPS, did not reduce the activity of rHRF. In addition, FACS analysis using PE-conjugated rHRF showed that HRF bound to B cells. Recombinant HRF up-regulated the expression of IL-1 and IL-6 in B cells. In vivo administration of rHRF or the cDNA for rHRF increased total and Ag-specific Ig synthesis. Taken together, these results indicate that HRF stimulates B cell activation and function.
Animals↗
Intracardiac echocardiographic guidance and monitoring during percutaneous endomyocardial gene injection in porcine heart.
In an effort to develop a guiding and monitoring tool for transmyocardial gene transfer, we have evaluated the feasibility of intracardiac echocardiography (ICE) to guide percutaneous endomyocardial gene transfer (PEGT), and monitor complications, in a pig model. ICE (5.5-10 MHz), complemented by fluoroscopy, was utilized to guide a needle injection into the heart in 19 normal pigs. Using this system, we injected Evans blue dye into eight pigs (group I), a mixture of pCK-CAT plasmid and India ink into seven pigs (group II), and pCK-LacZ plasmid into four pigs (group III). In all pigs, ICE contributed to the injection procedure by guiding the catheter to anatomically distinct sites, and by assisting stabilization of the catheter-endocardial contact. ICE predicted the injection sites correctly in 56 of 64 sites (87.5%) in group I, and in 42 of 42 sites (100%) in group II. Leakage of injectate into the left ventricular cavity could be detected by the microbubbles generated. The sites of injections appeared as foci of bright myocardial echodensity, which persisted until the end of the procedure. The procedures were not associated with significant morbidity or mortality. The expression of the chloramphenicol acetyltransferase (CAT) gene was identified in 40 sites from 42 injections (95.2%) in group II. In group III, histology showed positive beta-galactosidase staining of myocytes limited around the needle track with low transfection efficiency (<1%). These results suggest that real-time ICE monitoring proves safe and useful during PEGT for guiding needle injection, monitoring leakage, ensuring delivery of injectate into the myocardium, and instantly diagnosing cardiac complications, resulting in successful gene transfer.
Animals↗
Molecular organization of the ribosomal RNA transcription unit and the phylogenetic study of Zymomonas mobilis ZM4.
Previously we reported that Zymomonas mobilis ZM4 contains three ribosomal transcription units (rrnA to C operons) which are clustered around the 50 min region, PacI fragments 13 and 6, on the physical map of Z. mobilis ZM4 [Kang, H. L. and Kang, H. S. (1998) Gene 206, 223-228]. The physical map reveals that the rrnA gene set is located on the 76 kb PacI fragment 13. The complete nucleotide sequence of the rrnA gene set has been determined. The total number of nucleotides of the rrnA gene set is about 6,250 bp. The structural genes of the 16S, 23S and 5S rRNA code for the 1,478 nt, 2,786 nt and 121 nt RNA chains, respectively. The length of the spacer regions between the 16S and 23S rRNA genes, and between the 23S and 5S rRNA genes, are 606 bp and 101 bp, respectively. Two tRNA genes, Ile-tRNA and Ala-tRNA, are found between the 16S and 23S rRNA genes and a fMet-tRNA gene is identified downstream of the 5S rRNA gene. Thus, the molecular organization of this rrnA gene set is the order of 5'-16S rRNA-tRNAIle-tRNAAla-23S rRNA-5S rRNA-tRNAfMet-3'. The secondary structure models of 16S, 23S and 5S rRNA are proposed. The phylogenetic tree, based on the 16S rRNA sequence, was constructed by neighbor-joining and maximum-parsimony methods. Zymomonas belongs to a group in which Aqorbacterium, Rhodobacter and Sphingomonas are included.
Base Sequence↗
Activation of heat shock factor 1 by pyrrolidine dithiocarbamate is mediated by its activities as pro-oxidant and thiol modulator.
Pyrrolidine dithiocarbamate (PDTC) is known to inhibit NF-kappa B, which plays a critical role(s) as an immediate early mediator of immune and inflammatory responses. Here we show that PDTC induces heat shock factor 1 (HSF1) activation and heat shock protein expression, while other antioxidants such as butylated hydroxytoluene (BHT), n-propylgallate (PG), ascorbic acid (AA), and N-acetyl-L-cysteine (NAC) do not. Since PDTC exerts other functions than antioxidant, e.g., a pro-oxidant, metal chelator, and thiol group modulator, we examined which of these activities is responsible for the PDTC-induced HSF1 activation. PDTC-induced HSF1 activation was not prevented by metal chelators, EDTAs, indicating that the metal chelating effect of PDTC is not linked to the HSF1 activation. PDTC increased intracellular GSSG level. In addition, PDTC-induced activation of HSF1 was significantly inhibited by NAC and a thiol-reducing agent dithiothreitol (DTT), while it was partially prevented by other antioxidants, AA, BHT, and PG. These results suggest that the activation of HSF1 by PDTC may be due to its activities as pro-oxidant and thiol group modulator rather than anti-oxidant.
Acetylcysteine↗
Extracellular signal-regulated kinase/90-KDA ribosomal S6 kinase/nuclear factor-kappa B pathway mediates phorbol 12-myristate 13-acetate-induced megakaryocytic differentiation of K562 cells.
Two signaling pathways, the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK)-dependent pathway and the nuclear factor-kappaB (NF-kappaB)-dependent pathway, have been known to mediate megakaryocytic differentiation of K562 cells induced by phorbol 12-myristate 13-acetate (PMA). In this study, we examined whether 90-kDa ribosomal S6 kinase (RSK), known as a substrate of ERK/MAPK and a signal-inducible IkappaBalpha kinase, would link two pathways during the differentiation. RSK1 was activated in a time- and dose-dependent manner during the PMA-induced differentiation. Overexpression of wild-type or dominant inhibitory mutant (D205N) of RSK1 enhanced or suppressed PMA-stimulated NF-kappaB activation and megakaryocytic differentiation as shown by morphology, nonspecific esterase activity, and expression of the CD41 megakaryocytic marker, respectively. In addition, overexpression of the dominant inhibitory mutant (S32A/S36A) of IkappaBalpha inhibited PMA-stimulated and RSK1-enhanced megakaryocytic differentiation, indicating that NF-kappaB mediates a signal for megakaryocytic differentiation downstream of RSK1. PMA-stimulated activation of ERK/MAPK, RSK1, and NF-kappaB and the PMA-induced megakaryocytic differentiation were prevented by pretreatment with PD98059, a specific inhibitor of the mitogen-activated ERK kinase (MEK). Therefore, these results demonstrate that the sequential ERK/RSK1/NF-kappaB pathway mediates PMA-stimulated megakaryocytic differentiation of K562 cells.
Amino Acid Substitution↗
Segmentation by evolution for visualization of the lower extremity of the Visible Man.
Medical image segmentation is the crucial process for three-dimensional (3D) modeling. Many studies have claimed to suggest more accurate ways of segmentation. However, such research seems to have the drawback that it works against the parsimony principle. These methods have to resegment the regions of interest (ROIs) for the already segmented data, without taking advantage of the vast amount of past segmentation results. The present report proposes a "segmentation by evolution" method. It is an advanced segmentation paradigm that incorporates the existing segmentation results. The "segmentation by evolution" paradigm was applied to the color images of the Visible Human data.
Anatomy, Cross-Sectional↗
The timing and characterization of p53 mutations in progression from atypical ductal hyperplasia to invasive lesions in the breast cancer.
The main reason for the recent interest in p53 is that almost 50% of human cancers contain p53 gene mutations. The majority of studies on p53 alterations in breast cancer have been limited to the isolated cases of ductal carcinoma in situ and infiltrating ductal carcinoma. The aims of this study were to determine the status and timing of p53 mutation in the progression from atypical ductal hyperplasia to invasive cancer, and to evaluate the patterns of p53 mutations in noninvasive and invasive lesions. Available lesions of invasive (n=88) and noninvasive (n=76) lesions were microdissected in 107 paraffin-embedded tissues (19 ductal carcinomas in situ, 57 invasive carcinomas with intraductal components, and 31 pure invasive carcinomas) and double-strand DNA sequencing was performed in exon 4-9 of the p53 gene. Among in situ cancers without invasive disease 36.8% had p53 mutations whereas in situ cancer with concurrent invasive disease showed p53 mutations in 33.3% of cases. In particular, two of seven atypical ductal hyperplasias harbored p53 alterations (one insertion and one missense mutation) in exon 8. The invasive component harbored p53 mutations in 30 of 88 cases (34.1%). We also discovered a novel deletion of 14 bp in exon 6 of two invasive lesions. The invasive component (1.33+/-0.13) carried a greater number of p53 mutations than its counterparts (1.19+/-0.10) and demonstrated more frequent multiple mutations (23.3% vs. 15.4%), but without statistical significance. Moreover, no statistical significance could be attached to the mutation frequency in the zinc-binding domains (26.7% vs. 15.4%), the directly DNA contact region (13.3% vs. 15.4%) and the missense mutation of p53 (50.0% vs. 57.7%) of the two groups. Based on our results, in spite of the small number of the lesions investigated, p53 mutation can occur at the stage of atypical ductal hyperplasia. The hypermutability and the specific p53 mutations involving the biologically functional domain (e.g., zinc binding domain or DNA contact region) have an insignificant influence on invasive progression in the breast cancer.
Base Sequence↗