Biomedical subjects

So-Young Kang

Publications and source records attributed to So-Young Kang.

7 recordsLinked to original sources

PubMed2006

Soluble glucocorticoid-induced tumor necrosis factor receptor stimulates osteoclastogenesis by down-regulation of osteoprotegerin in bone marrow stromal cells.

Soluble glucocorticoid-induced tumor necrosis factor receptor (sGITR) is a potent stimulator of osteoclastogenesis. The mechanism by which it induces osteoclastogenesis was studied by culturing bone-marrow-derived macrophages (BMM) with conditioned medium from mouse bone marrow stromal cells. GITR and GITR ligand (GITRL) were expressed on the surface of bone marrow stromal cells, and sGITR-induced osteoclastogenesis was inhibited by anti-GITRL Ab, indicating that stimulatory effect of osteoclastogenesis by sGITR involved signaling via GITRL. Bone marrow stromal cells up-regulated cyclooxygenase-2 (COX-2) and produced prostaglandin E(2) (PGE(2)) early in their response to sGITR, and the stimulation of osteoclastogenesis was markedly inhibited by NS398, a COX-2 inhibitor. Later, sGITR markedly reduced the steady-state level of osteoprotegerin (OPG) mRNA and increased receptor activator of nuclear factor-kappaB ligand (RANKL) mRNA. NS398 blocked the sGITR-induced reduction of OPG mRNA but did not significantly affect the sGITR-induced rise in RANKL mRNA. This suggests that down-regulation of OPG by PGE(2) is involved in sGITR-induced osteoclast (OC) formation in the presence of conditioned medium from mouse bone marrow stromal cells.

Animals↗

PubMed2006

Monitoring metal ion binding in single-layer Pseudomonas aeruginosa biofilms using ATR-IR spectroscopy.

The binding of metal ions to Pseudomonas aeruginosa PAO1 cells attached to a ZnSe surface has been observed in this research through cation exchange experiments using ATR-IR spectroscopy. A biofilm consisting of a single layer of Pseudomonas aeruginosa PAO1 cells was formed on a ZnSe prism by flowing a bacterial suspension in a 0.03 mol L(-)(1) NaNO(3) solution at pH 5.0 across its surface. Exposure of the biofilm to chromium(III) nitrate solution resulted in increases in all band absorbances. This absorbance increase has been attributed to the binding of chromium(III) to the bacterial exopolymers associated with the prism surface. The chromium(III) binding causes the exopolymers to contract and move the bacterial cell closer to the ZnSe surface. Further study of chromium(III) ion exchange using a mutant P. aeruginosa with a truncated lipopolysaccharide (LPS) chain resulted in much smaller absorbance changes. This observation supports the view that the extension of bacterial exopolymers and hence the distance of the bacterial cell from the surface is strongly influenced by environmental factors such as the presence of metal cations. Following chromium(III) cation exchange, the bacterial band absorbances remained constant even when the bacteria were washed with a 0.03 mol L(-)(1) NaNO(3) solution, indicating that the chromium(III) was irreversibly bound. Ion exchange with nickel(II) and cobalt(II) nitrate solutions within identical biofilms showed that these cations caused relatively small increases in absorbances that were reversible, indicating that nickel(II) and cobalt(II) are less strongly bound than chromium(III) within P. aeruginosa biofilms. The absence of discernible IR spectral changes with metal binding appears to indicate a predominantly electrostatic mechanism for binding of Cr(III), Ni(II), and Co(II) ions by bacteria in the early stages of biofilm formation.

Bacterial Adhesion↗

PubMed2005

Sulforaphane inhibits osteoclastogenesis by inhibiting nuclear factor-kappaB.

We show that sulforaphane inhibits osteoclastogenesis in the presence of macrophage colony-stimulating factor (M-CSF) and receptor for activation of nuclear factor-kB ligand (RANKL) in osteoclast (OC) precursors. Sulforaphane, an aliphatic isothiocyanate, is a known cancer chemo-preventative agent with anti-oxidative properties. Nuclear factor-kB (NF-kB) is a critical transcription factor in RANKL-induced osteoclastogenesis, and electrophoretic mobility shift assays (EMSAs) and assay of NF-kB-mediated secreted alkaline phosphatase (SEAP) revealed that sulforaphane selectively inhibited NF-kappaB activation induced by RANKL. Inhibition may involve interaction of sulforaphane with thiol groups, since it was prevented by reducing agents.

Alkaline Phosphatase↗

PubMed2005

Clinical usefulness of free light chain concentration as a tumor marker in multiple myeloma.

Monoclonal immunoglobulin, as a marker for monoclonal gammopathy, is evaluated by protein electrophoresis (PEP) and immunofixation electrophoresis (IFE). However, PEP and IFE are not satisfactory in sensitivity, objectivity, and facility. Recently, a highly sensitive, automated immunoassay for measurement of free light chain (FLC) concentrations in serum and urine has been developed for the identification and monitoring of patients with monoclonal gammopathy. To explore the clinical usefulness of measurement of FLC concentrations, we measured the kappa and lambda FLC concentrations and calculated the kappa/lambda FLC ratios for three groups [multiple myeloma (MM), other diseases, and control] and compared the results of the FLC assay with the results of PEP or IFE. The concentrations of serum kappa and lambda FLCs and the kappa/lambda FLC ratios for the MM group and non-MM groups were distinct. In the MM group, some sera and urine samples had no evidence of M protein on PEP and IFE, but FLC assay showed abnormal concentrations of FLCs and abnormal kappa/lambda FLC ratios in most cases. As compared with the PEP, the kappa/lambda FLC ratio revealed higher sensitivity in all diagnostic ranges with different cutoff values. Particularly, when the cutoff value 2.0 for kappa/lambda FLC ratio was used, specificity and positive predictive value were largely improved than when the cutoff values 1.2 and 1.5 were used. These findings indicated that FLC assay enables to detect myeloma patients with very low M protein due to early stage or after therapy and to distinguish patients with monoclonal increase of FLC from patients with polyclonal increase of FLC due to other conditions, particularly using kappa/lambda FLC ratio 0.3-2.0 as a diagnostic range. Despite some technical limitations of the assay, the incorporation of kappa/lambda FLC ratios with FLC concentrations is useful in the detection of M protein, particularly with negative serum or urine IFE results, and differentiation of monoclonal gammopathies from patients with polyclonal increase in FLC due to other conditions.

Adult↗

PubMed2005

[A professional nursing practice environment and its impact on nurses' task motivation].

PURPOSE: This study was aimed at (a) describing professional nursing practice environments embedded in nursing care units and (b) examining its relationships to nurses' task motivation. METHOD: Using the Nursing Work Index Revised (NWI-R) and the Work Preference Inventory (WPI), a descriptive study was conducted with a sample of 320 registered nurses on 26 nursing care units in one University hospital in Korea. RESULT: Mean scores were 12.9 on a 5-20 score range of an autonomous environment scale, 7.3 on a 3-12 score range of a collaborative environment, and 15.8 on a 7-28 score range of control over nursing practice. Nurses' age, educational level, job position, working period at the hospital and employment status were significantly related to the degree of a professional practice environment. The extent to which a professional practice environment accounted for task motivation was 19.5%. CONCLUSION: There is a certain degree of professionalism in the workplace environment that nurses perceived within the nursing care units. When nurses care for patients, the degree of task motivation depends on the work environment supporting the professional nursing practice.

Adult↗

PubMed2004

Competitive adsorption characteristics of Co2+, Ni2+, and Cr3+ by IRN-77 cation exchange resin in synthesized wastewater.

Adsorption properties of Co2+, Ni2+, and Cr3+ on an Amberlite IRN-77 cation exchange resin were investigated in batch systems. Levels of adsorption rapidly approached an equilibrium state within 1 h. The adsorption characteristics of each metal onto the resin were accurately represented by Langmuir isotherms. Co2+ and Ni2+, which have an equivalent electrovalence, displayed similar levels of adsorption onto the resin when they coexisted in the solution. However, when Cr3+ was added to the solution it competitively replaced Co2+ and Ni2+ ions that had been previously adsorbed onto the resin, resulting in the desorption of these metals into the solution. The result was likely due to a higher adsorption affinity of Cr3+ relative to Co2+ and Ni2+. This implies that interactively competitive adsorption of multi-cations onto the resin should be thoroughly considered when contemplating the efficient operation of an ion exchange process in the treatment of industrial wastewater.

Adsorption↗

PubMed2002

Arithmetic operation and working memory: differential suppression in dual tasks.

The relationship between arithmetic function and working memory was examined using a dual-task paradigm for either phonological or visuo-spatial suppression. Simultaneous phonological rehearsal significantly delayed the performance of multiplication but not subtraction, whereas holding an image in the mind delayed subtraction but not multiplication. This result indicates that arithmetic function is related to working memory in a subsystem-specific manner: multiplication is more closely linked to phonological loop and subtraction to visuo-spatial sketchpad. Whereas this is not compatible with the notion that arithmetic is done on a unitary, amodal representation of numbers, it provides support for the triple-code and/or the modular processing models on human numerical cognition in which number representations are specific for input/output modality and arithmetic types.

Adult↗