• Korean Journal of Applied Biomechanics
• /
• v.19 no.2
• /
• pp.297-309
• /
• 2009

The study analyzed the mechanism of plantar foot pressure distribution during pitching wedge swinging on a flat, an up hill lie and a down hill lie to provide the fundamental information regarding biomechanical motion data by using plantar foot pressure measuring instrument. In the results, time factor spanning according to slope differences, plantar foot pressure factor and swing motion on the slope could have negative effect on the coiling of lower limbs during back swing, as well as the blocking of the lower limbs to minimize the dispersion of the weight and the release of the lower limbs after the impact during the down swing process. Moreover, since slope is one of many external factors affecting swing motion, address motion on an up hill lie limits the lower limbs movement, therefore, a relatively narrow stance is better on a down hill lie. It is estimated that a relatively wide stance would be better in order to limit the bigger activation of the lower limbs. Not only for the address motion but also during the down swing on an up hill lie it is concluded that the weight should be on the left foot in order to keep the body balance.

• Food Science of Animal Resources
• /
• v.26 no.3
• /
• pp.402-409
• /
• 2006

Although microorganisms are, in fact, the most diverse and abundant type of organism on Earth, the ecological functions of microbial populations remains poorly understood. A variety of bacteria including marine Vibrios encounter numerous ecological challenges, such as UV light, predation, competition, and seasonal variations in seawater including pH, salinity, nutrient levels, temperature and so forth. In order to survive and proliferate under variable conditions, they have to develop elaborate means of communication to meet the challenges to which they are exposed. In bacteria, a range of biological functions have recently been found to be regulated by a population density-dependent cell-cell signaling mechanism known as quorum-sensing (QS). In other words, bacterial cells sense population density by monitoring the presence of self-produced extracellular autoinducers (AI). N-acylhomoserine lactone (AHL)-dependent quorum-sensing was first discovered in two luminescent marine bacteria, Vibrio fischeri and Vibrio harveyi. The LuxI/R system of V. fischeriis the paradigm of Gram-negative quorum-sensing systems. At high population density, the accumulated signalstrigger the expression of target genes and thereby initiate a new set of biological activities. Several QS systems have been identified so far. Among them, an AHL-dependent QS system has been found to control biofilm formation in several bacterial species, including Pseudomonas aeruginosa, Aeromonas hydrophila, Burkholderia cepacia, and Serratia liquefaciens. Bacterial biofilm is a structured community of bacterial cells enclosed in a self-produced polymeric matrix that adheres to an inert or living surface. Extracellular signal molecules have been implicated in biofilm formation. Agrobacterium tumefaciens strain NT1(traR, tra::lacZ749) and Chromobacterium violaceum strain CV026 are used as biosensors to detect AHL signals. Quorum sensing in lactic acid bacteria involves peptides that are directly sensed by membrane-located histidine kinases, after which the signal is transmitted to an intracellular regulator. In the nisin autoregulation process in Lactococcus lactis, the NisK protein acts as the sensor for nisin, and NisR protein as the response regulator activatingthe transcription of target genes. For control over growth and survival in bacterial communities, various strategies need to be developed by which receptors of the signal molecules are interfered with or the synthesis and release of the molecules is controlled. However, much is still unknown about the metabolic processes involved in such signal transduction and whether or not various foods and food ingredients may affect communication between spoilage or pathogenic bacteria. In five to ten years, we will be able to discover new signal molecules, some of which may have applications in food preservation to inhibit the growth of pathogens on foods.

• Microbiology and Biotechnology Letters
• /
• v.35 no.2
• /
• pp.118-127
• /
• 2007

Germanium-fortified yeast (GY) is a organic germanium-fortified yeast with potent immune modulating activities including anti-inflammatory effect. Through cell line studies, we observed that GY can modulate the diverse immune activity but little evidence was provided on the mechanism of GY in modulating immune activities in other higher animals. In this study, we investigated the effect of GY on modulation of immune function in mice. GY was administered in normal mice or tumor-bearing mice and then effect of GY on modulation of host immune system was analyzed by using ex vivo isolated macrophages, B cells, NK cells. Admistration of GY in mice induced macrophage activation thereby increased effector function of macrophage such as increased phagocytosis, chemotaxis, adherence, $O_2-release$, NO, $TNF-{\alpha}$ production. In addition, GY administration Increased B lymphocyte activation and plaque forming cells. Furthermore, GY administration increased NK-cell mediated cytotoxicity. Furthermore, GY administration suppressed progression of tumor in mice by increasing $TNF-{\alpha}$ production and effector function of NK cells. Our results showed that GY has a potent immunostimulatory function in vivo mice model. Proper modulation and administration of GY in human could be helpful to maintaining immunological homeostasis by modulating host immune system.

• Journal of Acupuncture Research
• /
• v.22 no.1
• /
• pp.155-164
• /
• 2005

Objective : Chemokines are important for the recruitment of leukocytes, which is essential in host defense to the sites of infection. The thymus and activation-regulated chemokine (TARC) is a CC chemokine which potentially plays a role via a paracrine mechanism in the development of allergic respiratory diseases. Methods : The objective of this study is to investigate the effect of Pinelliae Rhizoma Herbal Acupuncture Solution (PHS) on the secretion of TARC of human bronchial epithelial cell. Methods : Enzyme-linked immunosorbent assay (ELISA) was performed to detect the secretion of TARC. The cytotoxicity was measured by MTT assay. Results : PHS significantly inhibited the secretion of TARC with a dose-dependant manner. The effective dosage did not have the cytotoxicity on human bronchial epithelial cell by MTT assay. Conclusion : Results of our study imply that PHS would play an important role in modulation of TARC in Human bronchial epithelial cells.

• International Journal of Oral Biology
• /
• v.34 no.1
• /
• pp.7-14
• /
• 2009

Nitric oxide (NO) acts as an intracellular messenger at the physiological level but can be cytotoxic at high concentrations. The cells within periodontal tissues, such as gingival and periodontal fibroblasts, contain nitric oxide syntheses and produce high concentrations of NO when exposed to bacterial lipopolysaccharides and cytokines. However, the cellular mechanisms underlying NO-induced cytotoxicity in periodontal tissues are unclear at present. In our current study, we examined the NO-induced cytotoxic mechanisms in human gingival fibroblasts (HGF). Cell viability and the levels of reactive oxygen species (ROS) were determined using a MTT assay and a fluorescent spectrometer, respectively. The morphological changes in the cells were examined by Diff-Quick staining. Expression of the Bcl-2 family and Fas was determined by RT-PCR or western blotting. The activity of caspase-3, -8 and -9 was assessed using a spectrophotometer. Sodium nitroprusside (SNP), a NO donor, decreased the cell viability of the HGF cells in a dose- and time-dependent manner. SNP enhanced the production of ROS, which was ameliorated by NAC, a free radical scavenger. ODQ, a soluble guanylate cyclase inhibitor, did not block the SNP-induced decrease in cell viability. SNP also caused apoptotic morphological changes, including cell shrinkage, chromatin condensation, and DNA fragmentation. The expression of Bax, a member of the proapoptotic Bcl-2 family, was upregulated in the SNP-treated HGF cells, whereas the expression of Bcl-2, a member of the anti-apoptotic Bcl-2 family, was downregulated. SNP augmented the release of cytochrome c from the mitochondria into the cytosol and enhanced the activity of caspase-8, -9, and -3. SNP also upregulated Fas, a component of the death receptor assembly. These results suggest that NO induces apoptosis in human gingival fibroblast via ROS and the Bcl-2 family through both mitochondrial- and death receptor-mediated pathways. Our data also indicate that the cyclic GMP pathway is not involved in NO-induced apoptosis.

• Journal of Ginseng Research
• /
• v.39 no.4
• /
• pp.354-364
• /
• 2015

Background: Intracellular $Ca^{2+}$($[Ca^{2+}]_i$) is a platelet aggregation-inducing molecule. Therefore, understanding the inhibitory mechanism of $[Ca^{2+}]_i$mobilization is very important to evaluate the antiplatelet effect of a substance. This study was carried out to understand the $Ca^{2+}$-antagonistic effect of total saponin from Korean Red Ginseng (KRG-TS). Methods: We investigated the $Ca^{2+}$-antagonistic effect of KRG-TS on cyclic nucleotides-associated phosphorylation of inositol 1,4,5-trisphosphate receptor type I ($IP_3RI$) and cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) in thrombin (0.05 U/mL)-stimulated human platelet aggregation. Results: The inhibition of $[Ca^{2+}]_i$ mobilization by KRG-TS was increased by a PKA inhibitor (Rp-8-BrcAMPS), which was more stronger than the inhibition by a cyclic guanosine monophosphate (cGMP)- dependent protein kinase (PKG) inhibitor (Rp-8-Br-cGMPS). In addition, Rp-8-Br-cAMPS inhibited phosphorylation of PKA catalytic subunit (PKAc) ($Thr^{197}$) by KRG-TS. The phosphorylation of $IP_3RI$ ($Ser^{1756}$) by KRG-TS was very strongly inhibited by Rp-8-Br-cAMPS compared with that by Rp-8-BrcGMPS. These results suggest that the inhibitory effect of $[Ca^{2+}]_i$ mobilization by KRG-TS is more strongly dependent on a cAMP/PKA pathway than a cGMP/PKG pathway. KRG-TS also inhibited the release of adenosine triphosphate and serotonin. In addition, only G-Rg3 of protopanaxadiol in KRG-TS inhibited thrombin-induced platelet aggregation. Conclusion: These results strongly indicate that KRG-TS is a potent beneficial compound that inhibits $[Ca^{2+}]_i$ mobilization in thrombin-platelet interactions, which may result in the prevention of platelet aggregation-mediated thrombotic disease.

• Archives of Pharmacal Research
• /
• v.29 no.5
• /
• pp.375-383
• /
• 2006

The anti platelet effects of a novel guanidine derivative, KR-32570 ([5-(2-methoxy-5-chlorophenyl) furan-2-ylcarbonyl]guanidine), were investigated with an emphasis on the mechanisms underlying its inhibition of collagen-induced platelet aggregation. KR-32570 significantly inhibited the aggregation of washed rabbit platelets induced by collagen $(10{\mu}g/mL)$, thrombin (0.05 U/mL), arachidonic acid $(100{\mu}M)$, a thromboxane (TX) $A_2$ mimetic agent U46619 (9,11-dideoxy-9,11-methanoepoxy-prostaglandin $F_2,\;1{\mu}M$) and a $Ca^{2+}$ ATPase inhibitor thapsigargin $(0.5{\mu}M)$ ($IC_{50}$ values: $13.8{\pm}1.8,\;26.3{\pm}1.2,\;8.5{\pm}0.9,\;4.3{\pm}1.7\;and\;49.8{\pm}1.4{\mu}M$, respectively). KR-32570 inhibited the collagen-induced liberation of $[^3H]$arachidonic acid from the platelets in a concentration dependent manner with complete inhibition being observed at $50{\mu}M$. The $TXA_2$ synthase assay showed that KR-32570 also inhibited the conversion of the substrate $PGH_2$ to $TXB_2$ at all concentrations. Furthermore, KR-32570 significantly inhibited the $[Ca^{2+}]_i$ mobilization induced by collagen at $50{\mu}M$, which is the concentration that completely inhibits platelet aggregation. KR-32570 also decreased the level of collagen $(10{\mu}g/mL)$induced secretion of serotonin from the dense-granule contents of platelets, and inhibited the NHE-1-mediated rabbit platelet swelling induced by intracellular acidification. These results suggest that the antiplatelet activity of KR-32570 against collagen-induced platelet aggregation is mediated mainly by inhibiting the release of arachidonic acid, $TXA_2$ synthase, the mobilization of cytosolic $Ca^{2+}$ and NHE-1.

• Journal of Life Science
• /
• v.20 no.5
• /
• pp.736-744
• /
• 2010

The root of Playtcodon grandiflorum, called Platycodi radix, has been a favorite edible plant in Asia and contains a large amount of saponins. Melanoma cells (B16F10) were used to investigate the inhibitory effect of aged black Platycodi radix extract (ABPRE) on oxidative stress and matrix metalloproteinases (MMPs). Platycodon radix has been known to have a variety of medicinal effects such as prevention of gastric ulcers, antiallergenic activities, histamine release inhibition, and antioxidant effects. However, the mechanism of its action remains unclear in humans. ABPRE was prepared using ethanol extraction of aged black Platycodi radix. In an antioxidant effect study of ABPRE, it was observed that ABPRE specifically exhibited the scavenging activity of DPPH radical, but did not inhibit the production of malondialdehyde from lipid peroxidation. DNA oxidation was also blocked in the presence of ABPRE. In addition, ABPRE decreased the expression and activation of MMP-2 stimulated by phenazine methosulfate. Furthermore, ABPRE revealed the inhibitory effect on melanin production induced by L-dopa via antioxidant effect and the reduction of tyrosinase expression. Especially, the expression of antioxidant enzymes such as SOD-1 and SOD-2 regulated by Nrf2 was increased in the presence of ABPRE. Therefore, it appears that ABPRE may be a possible chemopreventive agent for the prevention of metastasis related to oxidative stress.

• Korean Journal of Clinical Pharmacy
• /
• v.12 no.1
• /
• pp.22-28
• /
• 2002

Aceclofenac, 2-[(2',6'-dichlorphenyl)amino]phenylacetoxiacetic acid, is a new nonsteroidal anti-inflammatory drug that belongs to the family of phenylacetic acids. It shows good tolerance and potent analgesic/antiinflammatory properties, and acts on cartilaginous chondriocytes, stimulating their repair mechanism. The purpose of the present study was to evaluate the bioequivalence of two aceclofenac products, $Airtal^{TM}$ tablet (Daewoong Pharmaceutical Co.) and $Acer^{TM}$ capsule (Kyungdong Pharmaceutical Co.), according to the guideliner of Korea Food and Drug Administration (KFDA). The aceclofenac release from the two aceclofenac products in vitro was tested using KP VII Apparatus II method at pH 7.8 dissolution media. Sixteen normal male volunteers, $23.13\pm2.03$ years in age and $66.33\pm7.08$ kg in body weight, were divided into two groups and a randomized $2\times2$ cross-over study was employed. After one tablet or capsule containing 100 mg of aceclofenac was orally administered, blood was taken at predetermined time intervals and the concentrations of aceclofenac in serum were determined using HPLC with UV detector. The dissolution profiles of the two aceclofenac products were very similar at pH 7.8 dissolution media. The pharmacokinetic parameters such as $AUC_t,\;C_{max}\;and\;T_max$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters. The results showed that the differences in $AUC_t,\;C_{max}\;and\;T_{max}$ between two products were $6.50\%,\;-1.06\%\;and\;11.96\%$ respectively, when calculated against the $Airtal^{TM}$ tablet. The powers $(1-\beta)\;for\;AUC_t,\;C_{max}\;were\;89.82\%\;and\;82.84\%$, respectively. Minimum detectable differences $(\Delta)\;at\;\alpha=0.05\;and\;1-\beta=0.8$ were less than $20\%\;(e.g.,\;17.51\%\;and\;19.30\%\;for\;AUC_t,\;C_{max}$, ). The $90\%$ confidence intervals were within $\pm20\%\;(e.g.,\;-3.73\%\sim16.73\%\;and\;-12.34\%\sim10.22\%\;for\;AUC_t,\;C_{max},\;respectively)$. Two parameters met the criteria of KFDA for bioequivalence, indicating that $Acer^{TM}$ capsule is bioequivalent to $Airtal^{TM}$ tablet.

• Journal of Korean Society for Atmospheric Environment
• /
• v.24 no.1
• /
• pp.16-29
• /
• 2008

Nitrous acid (HONO) can be produced by heterogenous reactions of nitrogen dioxide on surface materials and direct emission from combustion sources. However, a little is known of indoor HONO levels or the relationship between residential HONO, NO, and $NO_2$ concentrations in occupied houses. Therefore, we measured simultaneously NO, $NO_2$, and HONO concentrations in living room of an apartment using continuous analyzers to study the production of HONO (June $22{\sim}30$, 2006). The 4-min average concentrations of indoor NO, $NO_2$, and HONO were 4.3 (range: $0.4{\sim}214.3$), 10.3 ($2.0{\sim}87.3$), and 1.8 ppb ($0.3{\sim}7.7$), respectively. Peak levels of HONO up to 7.7 ppb and 24-hr averages as high as 1.7 ppb were measured. In agreement with previous studies, indoor HONO concentrations increased during operation of an unvented gas range. Examination of the observed kinetics suggests that the secondary production of indoor HONO, possibly as a result of heterogeneous reactions involving $NO_2$ and $H_2O$ is associated with $[NO_2]^2[H_2O]\;(r^2=0.88)$ rather than with $[NO][NO_2][H_2O]\;(r^2=0.75)$. Three combustion experiments at nighttime were also carried out to investigate the effects of vented combustion on the HONO, NO, and $NO_2$ concentrations. It was found to release HONO for $10{\sim}15$ minutes after NO and $NO_2$ source was turned off, and peak values were finally attained. Compared to unvented combustion, peak $NO_2$ and HONO concentrations were 3.2 and 2.0 times lower at weak vented combustion (air flow: $340\;m^3/hr$) and 4.9 and 2.4 times lower at strong vented combustion (air flow: $540\;m^3/hr$), respectively, emphasizing importance of operating ventilation hood fan during combustion to improve indoor air quality.