• The Korean Journal of Ceramics
• /
• v.5 no.2
• /
• pp.162-164
• /
• 1999

Microsotructure designed porous ceramics of calcium hydroxyapatite $(Ca_{10}(PO_4)_6(OH)_2)$ were prepared by hydrothermal method. The particle size, shape, and the micro-pore size of the porous hydroxyapatite ceramics could becontrolled. The hydroxyapatite was non-stoichiometric apatite with calcium deficient compositions (Ca/P ratio < 1.67). The composition of non-stoichiometric hydroxyapatite ceramics could be controlled from 1.50 to 1.63 in Ca/P ratio. The hydroxyapatite ceramics preparedc at $105^{\circ}C$ under the saturated vapor pressure for 20h were composed of rod-shaped crystals with about 10$\mu\textrm{m}$ in length with the mean aspect ratio of 40. The porous ceramics of calcium deficient hydroxyapatite had about 45% porosity with the inter-connecting pore structure. Porous hydroxyapatite ceramics prepared hydrothermally had the compressive strength of about 10 to 30 MPa. In addition, porous ceramics of $\beta$-tricalcium phosphate ($\beta-Ca_3(PO_4)_2$) were prepared from the calcium deficient hydroxyapatite.

• Biomolecules & Therapeutics
• /
• v.17 no.2
• /
• pp.144-150
• /
• 2009

Reactive oxygen species play a role in signal transduction and in many human diseases. B-cell activating factor (BAFF) plays a role for mature B cell generation and maintenance and for the incidence of autoimmune diseases. We previously reported that BAFF expression was induced by ROS. In this study, we investigated whether ROS-induced BAFF expression was affected by toll-like receptor (TLR) 4 or myeloid differentiation primary response gene (MyD) 88. BAFF expression was increased by serum deprivation that is an experimental modification to produce ROS. In contrast, TLR4 and MyD88 were decreased by serum deprivation. Although ROS production was decreased in TLR4-nonfunctional or MyD88-deficient splenocytes as compared to that in control mice, serum deprivation increased ROS production and augmented BAFF expression in both cells. $50{\mu}M\;H_2O_2$ also increased BAFF expression in TLR4-deficient or MyD88-deficient splenocytes. Collectively, results show that BAFF expression may be mediated by TLR4 or MyD88-independent manner and TLR4 or MyD88 may not be required in BAFF expression.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.20 no.5
• /
• pp.409-417
• /
• 1991

To investigate effects of chronic alcohol consumption and tocopherol on lipid peroxidation and mitochondrial respiration 48 male rats of Sprague-Dawley strain were divided into 4 groups. Each group received for 3 weeks one of 4 experimental diets: tocopherol deficient control (TDC), tocopherol deficient-ethanol (TDE), tocopherol-supplemented control (TSC) and tocopherol-supplemented-ethanol (TSE). Composition of the diets was based on the Lieber and Decarli liquid diet and $\alpha$-tocopherol was supplemented at the level of 30mg/liter of diet, and ethanol supplied 36kcal%. TDC and TSC were pair-fed to TDE and TSE, respectively. Increase of body weight of tocopherol deficient-ethanol group was the lowest and the effect was diminished with tocopherol supplementation. Respiration of liver mitochondria was depressed in ethanol-administered groups and the effect became larger with tocopherol deficiency. Hepatic lipid peroxide level was not influenced by ethanol, but hepatic tocopherol content decreased with ethanol treatment. The result indicated that, although lipid perroxide level was unchanged with chronic ethanol consumption, oxidative stress exists in tissues of rate administered ethanol and may be relieved by tocopherol supplementation.

• Molecules and Cells
• /
• v.44 no.8
• /
• pp.613-622
• /
• 2021

In vertebrate eyes, the retinal pigment epithelium (RPE) provides structural and functional homeostasis to the retina. The RPE takes up retinol (ROL) to be dehydrogenated and isomerized to 11-cis-retinaldehyde (11-cis-RAL), which is a functional photopigment in mammalian photoreceptors. As excessive ROL is toxic, the RPE must also establish mechanisms to protect against ROL toxicity. Here, we found that the levels of retinol dehydrogenases (RDHs) are commonly decreased in phosphatase tensin homolog (Pten)-deficient mouse RPE, which degenerates due to elevated ROL and that can be rescued by feeding a ROL-free diet. We also identified that RDH gene expression is regulated by forkhead box O (FOXO) transcription factors, which are inactivated by hyperactive Akt in the Pten-deficient mouse RPE. Together, our findings suggest that a homeostatic pathway comprising PTEN, FOXO, and RDH can protect the RPE from ROL toxicity.

• Korean Journal of Agricultural Science
• /
• v.48 no.1
• /
• pp.179-189
• /
• 2021

Plants need essential mineral elements to favorably develop and to complete their life cycle. Despite the irreplaceable roles of microelements, they are often ignored due to the relative importance of macroelements with their influence on crop growth and development. We focused on the changes in primary metabolites in the leaves and roots of bell pepper plants under 6 microelements-deficient conditions: Copper (Cu), Zinc (Zn), Iron (Fe), Manganese (Mn), Boron (B) and Molybdenum (Mo). Bell pepper plants were grown in hydroponic containers, and individual elements were adjusted to 1/10-strength of Hoagland nutrient solution. A remarkable perturbation in the abundance of the primary metabolites was observed for the Fe and B and the Mn and B deficiencies in the leaves and roots, respectively. The metabolites with up-accumulation in the Fe-deficient leaves were glucose, fructose, xylose, glutamine, asparagine and serine. In contrast, the Mn deficiency also resulted in a higher accumulation of glucose, fructose, xylose, galactose, serine, glycine, β-alanine, alanine and valine in the roots. The B deficiency noticeably accumulated alanine, valine and phenylalanine in the roots while it showed a substantial decrease in glucose, fructose and xylose. These results show that the primary metabolism could be seriously disturbed due to a microelement deficiency, and the alteration may be either the specific or adaptive responses of bell pepper plants.

• Microbiology and Biotechnology Letters
• /
• v.49 no.4
• /
• pp.594-602
• /
• 2021

The NLRP3 (nucleotide-binding domain, leucine-rich repeat family pyrin domain containing 3) inflammasome plays an important role in the initiation of inflammatory responses, through the recognition of pathogen-associated molecular patterns and tumor progression, including tumor growth and metastasis. In this study, we examined the effects of defective NLRP3 on the growth, migration, and invasiveness of hepatocellular carcinoma (HCC) SK-Hep1 cell. First, HCC SK-Hep1 cells were transfected with human NLRP3 targeting LentiCRISPRv2 vector using the CRISPR-Cas9 system, and NLRP3 deficiency was confirmed by RT-qPCR and western blotting. NLRP3 deficient SK-Hep1 cells showed delayed cell growth and decreased protein expression of PI3K, p-AKT, and pNF-κB when compared to NLRP3 complete SK-Hep1 cells. In addition, NLRP3 deficiency arrested the cell cycle at G1 phase through an increase in p21 and a reduction in CDK6. NLRP3 deficient SK-Hep1 cells also showed significantly delayed cell migration, invasion, and wound healing. The expression of epithelial-mesenchymal transition signaling molecules, such as N-cadherin and MMP-9, was found to be dramatically decreased in NLRP3 deficient SK-Hep1 cells compared to NLRP3 complete SK-Hep1 cells.

• BMB Reports
• /
• v.56 no.5
• /
• pp.296-301
• /
• 2023

Retinoic acid receptor-related orphan receptor α (RORα) plays a vital role in various physiological processes, including metabolism, cancer, circadian rhythm, cerebellar development, and inflammation. Although RORα is expressed in the skin, its role in skin physiology remains poorly elucidated. Herein, Rorα was expressed in the basal and suprabasal layers of the epidermis; however, keratinocyte-specific Rorα deletion did not impact normal epidermal formation. Under pathophysiological conditions, Rorα-deficient mice exhibited alleviated psoriasis-like symptoms, including relatively intact epidermal stratification, reduced keratinocyte hyperproliferation, and low-level expression of inflammatory cytokines in keratinocytes. Unexpectedly, the splenic population of Th17 cells was significantly lower in keratinocyte-specific RORα deficient mice than in the control. Additionally, Rorα-deficiency reduced imiquimod-induced activation of nuclear factor-κB and STAT3 in keratinocytes. Therefore, we expect that RORα inhibitors act on immune cells and keratinocytes to suppress the onset and progression of psoriasis.

• The Bulletin of The Korean Astronomical Society
• /
• v.45 no.1
• /
• pp.34.1-34.1
• /
• 2020

The recent discovery of diffuse dwarf galaxies that are deficient in dark matter appears to challenge the current paradigm of structure formation in our Universe. We describe the numerical experiments to determine if the so-called dark matter deficient galaxies (DMDGs) could be produced when two gas-rich, dwarf-sized galaxies collide with a high relative velocity of ~ 300km/s. Using idealized high-resolution simulations with both mesh-based and particle-based gravito-hydrodynamics codes, we find that DMDGs can form as high-velocity galaxy collisions separate dark matter from the warm disk gas which subsequently is compressed by shock and tidal interaction to form stars. Then using a large simulated universe ILLUSTRISTNG, we discover a number of high-velocity galaxy collision events in which DMDGs are expected to form. However, we did not find evidence that these types of collisions actually produced DMDGs in the ILLUSTRISTNG100-1 run. We argue that the resolution of the numerical experiment is critical to realize the "collision-induced" DMDG formation scenario. Our results demonstrate one of many routes in which galaxies could form with unconventional dark matter fractions.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.7
• /
• pp.4184-4190
• /
• 2014

The present paper examined the stress and ADL (activities of daily living) index in relation to the characteristics of the elderly in nursing homes. For this study, questionnaires were given to 110 seniors in the N-district of Seoul, and S-myeon, Hoengseong-gun, Gangwon Province from May 1 to September 30, 2013. For data analysis, t-test, correlation analysis, and multiple regression analysis were performed using the SPSSWIN18.0 program. The analysis of actual proof was made at a significance level of 5 percent. The findings from the analyses were as follows: first, the relocation syndrome into nursing homes has a positive correlation with the stress of deficient family visits in the category of daily stresses; second, depression has a positive correlation with the stresses of deficient private time and space and deficient family visits in the category of daily stresses; third, weight control has a positive correlation only with the stress of deficient private time and space in the category of daily stresses, whereas a nutrition deficiency has positive correlation with the stress of deficient family visits in the category of daily stresses. These findings may serve as ground source data for establishing policies regarding the stresses in relation to the characteristics and ADL index of the elderly in nursing homes.

• Journal of Nutrition and Health
• /
• v.2 no.4
• /
• pp.113-125
• /
• 1969

These experiments were designed to study the influence of early protein undernutrition on growth, behaviors toward food, general attitude toward a new environment, brain size and body composition of the experimental rats. The following experimental groups were studied. Lactation period (3 weeks) (Diets of mother rats) 25% Casein diet 12% Casein diet 25% Casein diet 25% Casein diet 12% Casein diet 12% Casein diet After-weaning protein deprivation period None deprivation (25% Casein diet) None deprivation (25% Casein diet) 5% Casein diet (4 weeks) 5% Casein diet (8 weeks) 5% Casein diet (4 weeks) 5% Casein diet (8 weeks) After a long period of rehabilitation with 25% casein diet the following results were obtained. 1. Growth rate during lactation period is closely related with the protein levels of the diet for mother rats. The average body weight of offsprings of the mother rat fed 25% casein diet is 46.0 grams at 21 days old. However, that of the mother rat fed 12% casein diet is only 25.0 grams. 2. The group of protein undernutrition during lactation (S weeks) (offsprings of mother rat fed low protein diet, 12% casein diet) could never catch up with the normal group in its growth even after twenty-four (24) weeks of rehabilitation. 3. However, the groups of protein undernutrition during either four (4) or even eight (8) weeks after weaning could catch up with the normal group in their growth after long period of rehabilitation. 4. The absolute amounts of carcass protein and fat of the normal group are larger than those of the protein deficient groups. In terms of percent carcass, however, the normal group showed higher body fat and lower body protein than the early deficient groups. However, there is no difference between preweaning (3 weeks) and postweaning (8 weeks) deficient groups. It is assumed, from these differences in body composition, that there might be any differences in physiological and metabolic functions among these various groups, and also that the basic formation of various metabolic regulators (protein-nature) might be fixed mostly during lactation and postweaning period. 5. The groups of protein undernutrition during either three (3) weeks lactation or four (4) weeks after weaning are not so remarkably different from the normal group in their amounts of food intake and spillage. However, the groups of undernutrition during either eight (8) weeks postweaning or eleven (11) weeks (3 weeks lactation period plus 8 weeks postweaning period) showed higher amounts of food intake and spillage. In these respects, it seems that desire for food is closely related with the degree of early hunger in protein and also seems that the longer be deficient in early life the more food spillage is found. 6. Both preweaning and postweaning deficient groups showed generally nervous and restless. The normal group is staid and showed less mobilities. 7. The average size of the brains of the group subjected to protein deficiency during three (3) weeks lactation period is smaller than that of the group of the eight (8) weeks postweaning deficiency. This means that the development of the brain is made mostly during lactation period. The group of the eleven (11) weeks postnatal deficiency is significantly different from the normal group in its brain development. It is assumed, in connection with the results of various maze tests reported, that the brain size is closely related with the intellectual ability.