Biomedical subjects

Seung-Hun Lee

Publications and source records attributed to Seung-Hun Lee.

7 recordsLinked to original sources

PubMed2005

Rapid identification of potentially probiotic Bifidobacterium species by multiplex PCR using species-specific primers based on the region extending from 16S rRNA through 23S rRNA.

This study aimed at developing a novel multiplex polymerase chain reaction (PCR) primer set for identification of the potentially probiotic Bifidobacterium species B. adolescentis, B. animalis subsp. animalis (B. animalis), B. bifidum, B. breve, B. longum biovar infantis (B. infantis), B. animalis subsp. lactis B. lactis, B. longum biovar longum (B. longum) and B. pseudolongum. The primer set comprised specific and conserved primers and was derived from the integrated sequences of 16S and 23S rRNA genes and the rRNA intergenic spacer region (ISR) of each species. It could detect and identify type strains and isolates from pharmaceuticals or dairy products corresponding to the eight Bifidobacterium species with high specificity. It was also useful for screening of the related strains from natural sources such as the gastro-intestinal tract and feces. We suggest that the assay system from this study is an efficient tool for simple, rapid and reliable identification of Bifidobacterium species for which probiotic strains are known.

Base Sequence↗

PubMed2005

Spin chirality on a two-dimensional frustrated lattice.

The collective behaviour of interacting magnetic moments can be strongly influenced by the topology of the underlying lattice. In geometrically frustrated spin systems, interesting chiral correlations may develop that are related to the spin arrangement on triangular plaquettes. We report a study of the spin chirality on a two-dimensional geometrically frustrated lattice. Our new chemical synthesis methods allow us to produce large single-crystal samples of KFe3(OH)6(SO4)2, an ideal Kagomé lattice antiferromagnet. Combined thermodynamic and neutron scattering measurements reveal that the phase transition to the ordered ground-state is unusual. At low temperatures, application of a magnetic field induces a transition between states with different non-trivial spin-textures.

Beryllium↗

PubMed2004

Clinical findings in patients with cardiac troponin T elevation and end-stage renal disease without acute coronary syndrome.

Clinical, echocardiographic, and carotid ultrasound parameters were compared according to the level of cardiac tropopin T (cTnT) (cTnT <0.04 vs > or =0.04 microg/L; cTnT <0.1 vs > or =0.1 microg/L) in patients with end-stage renal disease without acute coronary syndrome. Left atrial size, left ventricular mass index, the ratio of transmitral early left ventricular filling velocity to early diastolic Doppler tissue imaging velocity of the mitral annulus, and the prevalence of left ventricular dysfunction and diabetes mellitus were higher in the groups with cTnT > or =0.04 and > or =0.1 microg/L. Diabetes was an independent correlate of cTnT elevation of > or =0.04 and > or =0.1 microg/L. Left ventricular mass index and left atrial size were independent predictors of cTnT elevations of > or =0.04 and > or =0.1 microg/L, respectively.

Acute Kidney Injury↗

PubMed2004

Expression of epidermal growth factor in the developing rat kidney.

Epidermal growth factor (EGF) is important in mammalian renal development. In our study, we investigated the detailed distribution and the time of the first appearance of EGF in developing rat kidney. Kidneys from embryonic 18 (E18)- and 20-day-old (E20) fetuses, postnatal 1 (P1)-, 3 (P3)-, 7 (P7)-, 14 (P14)-, and 21-day-old (P21) pups, and adults were processed for immunohistochemistry and electronmicroscopy. In adult rat kidney, EGF immunoreactivity was found in distal tubule including the thick ascending limb (TAL) and portion 1 of distal convoluted tubule (DCT1), whereas no EGF immunoreactivity was seen in portion 2 of distal convoluted tubule (DCT2) and connecting tubule. In developing kidney, EGF-positive cells first appeared at P3 and were localized in the middle portion of the differentiating TAL of the corticomedullary junction. By P7, the abundance of EGF expression had dramatically increased in the medullary TAL. Between P14 and P21, EGF immunoreactivity was found in the TAL and the DCT for the first time. However, EGF-positive and EGF-negative cells were in the TAL in developing rat kidney. EGF-positive cells did not differ from negative cells in the expression of sodium transport proteins or in the proliferation rate at P3 and P7. In the TAL, smooth-surfaced cells had strong EGF immunoreactivity, but no EGF immunoreactivity was seen in the rough-surfaced cells with well-developed microvilli. Our results suggest that the expression of EGF in developing kidney plays an important role in the regulation of growth and differentiation of the loop of Henle during kidney development and that this may act in the paracrine mode.

Animals↗

PubMed2004

Effect of epidermal growth factor on the developing rat renal papilla.

BACKGROUND: Apoptosis plays an important role in the morphogenesis of the renal papilla. During kidney development, ATL is derived from the TAL in the inner medulla by apoptotic deletion of a fraction of TAL cells and the transformation of the remaining TAL cells. EGF is an important regulator of apoptosis in the kidney. HYPOTHESIS: Exogenously administered EGF in postnatal rat affects renal papilla growth with cell proliferation and apoptosis in the loop of Henle. METHODS: Rat pups received subcutaneous injections of EGF (0.3 microg/g body weight) or saline four times a day from after birth. Rats were sacrificed and the kidneys were preserved for immunohistochemistry on day 4 and day 7. The TAL was identified with antibody directed against Na-K-ATPase or BSC1, and type A intercalated cells were identified with antibody to anion exchanger 1 (AE1). Apoptosis was detected with TUNEL method, and cell proliferation with immunostaining for PCNA. RESULTS--PRIMARY AND SECONDARY: EGF treatment resulted in the following: (1) reduced kidney weight; (2) shortened length of renal papilla; (3) delayed transformation of the cuboidal epithelium into the squamous epithelium of the ATL; (4) delayed elimination of type A intercalated cells in the medullary collecting duct; (5) decreased both apoptotic index and PCNA-positive cells in the TAL and the collecting duct of the renal medulla. CONCLUSION: These findings suggest that exogenous EGF delays the development of loop of Henle in the renal papilla by reducing both apoptosis and cell proliferation.

Animals↗

PubMed2004

Influence of thermocycling on the optical properties of laboratory resin composites and an all-ceramic material.

The purposes were to determine the difference of color and translucency of dental laboratory resin composites and an all-ceramic material, and to compare the changes in optical properties after thermocycling. Three shades for enamel appearance of two laboratory resin composites (ART; Artglass, TES; Tescera) and all-ceramic material (EMP; Empress 2) were chosen, and three disk specimens for each shade and thickness (0.8, 1.3 and 1.8 mm) were made. Color and spectral reflectance were measured before and after thermocycling over white and black backgrounds. Contrast ratio (CR) and translucency parameter (TP) were calculated. Before and after thermocycling, CR of 1.8 mm specimens did not differ between the materials. After thermocycling, CR and TP of TES were not changed significantly; however, ART and EMP showed increased CR and decreased TP in some shades (p = 0.05). Color change of three materials after thermocycling was not significant. CR increased in inverse proportion to TP (r = - 0.93, p < 0.01). In TES, change of translucency after thermocycling was lower than those of other materials regardless of the specimen thickness. TES seemed to yield more predictable curing performance.

Cementation↗

PubMed2003

Cyclosporine A in the treatment of a patient with immune thrombocytopenia accompanied by myelodysplastic syndrome and nephrotic syndrome.

We describe a complete remission with cyclosporine A in a myelodysplastic syndrome (MDS) patient who had a 9-year history of nephrotic syndrome (NS) due to autoimmune nephritis. A 72-year-old woman with MDS and NS rapidly developed thrombocytopenia with multiple spontaneous bleeding episodes and profound proteinuria. She showed persistent platelet refractoriness to platelet transfusions. A flow cytometry examination strongly detected antiplatelet autoantibodies on the surface of her platelets. The treatment with high-dose corticosteroids and intravenous immunoglobulin did not lead to complete improvement in the platelet count, bleedings and proteinuria. However, a low dose of cyclosporine A resulted in a sustained normal range of blood platelet count and negative proteinuria. This finding suggests that, in selected cases, cyclosporine A can be an attractive alternative for MDS patients who also have immune-mediated diseases.

Aged↗