• The Korean Journal of Physiology and Pharmacology
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• v.25 no.3
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• pp.239-249
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• 2021

The present study explored the therapeutic potential of hydrogen sulfide (H2S) in restoring aging-induced loss of cardioprotective effect of remote ischemic preconditioning (RIPC) along with the involvement of signaling pathways. The left hind limb was subjected to four short cycles of ischemia and reperfusion (IR) in young and aged male rats to induce RIPC. The hearts were subjected to IR injury on the Langendorff apparatus after 24 h of RIPC. The measurement of lactate dehydrogenase, creatine kinase and cardiac troponin served to assess the myocardial injury. The levels of H2S, cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), nuclear factor erythroid 2-related factor 2 (Nrf2), and hypoxia-inducible factor (HIF-1α) were also measured. There was a decrease in cardioprotection in RIPC-subjected old rats in comparison to young rats along with a reduction in the myocardial levels of H2S, CBS, CSE, HIF-1α, and nuclear: cytoplasmic Nrf2 ratio. Supplementation with sodium hydrogen sulfide (NaHS, an H2S donor) and l-cysteine (H2S precursor) restored the cardioprotective actions of RIPC in old hearts. It increased the levels of H2S, HIF-1α, and Nrf2 ratio without affecting CBS and CSE. YC-1 (HIF-1α antagonist) abolished the effects of NaHS and l-cysteine in RIPC-subjected old rats by decreasing the Nrf2 ratio and HIF-1α levels, without altering H2S. The late phase of cardioprotection of RIPC involves an increase in the activity of H2S biosynthetic enzymes, which increases the levels of H2S to upregulate HIF-1α and Nrf2. H2S has the potential to restore aging-induced loss of cardioprotective effects of RIPC by upregulating HIF-1α/Nrf2 signaling.

• Journal of the Korean Society of Food Culture
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• v.23 no.4
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• pp.521-528
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• 2008

This study examined the effects of 2% Lycii fructus powder (LFP) supplementation on lipid metabolism in rats. Male Sprague-Dawley rats were administered 1% cholesterol and 0.25% sodium cholate to induce hypercholesterolemia. Then, 40 rats were divided into four diet groups: a normal diet group (NC), high cholesterol diet group (HC), normal diet plus 2% Lycii fructus powder (NC-LFP) group, and high cholesterol diet plus 2% Lycii fructus powder (HC-LFP) group. The HC group presented higher growth rates and liver weights than NC and NC-LFP however, growth rates and liver weights in the 2% LFP administered groups gradually decreased. HC also showed increased serum triglyceride, total cholesterol, free cholesterol, and LDL-cholesterol levels and decreased atherogenic index values, HDL-cholesterol, and phospholipid levels, whereas LFP group showed decreased serum triglyceride, total cholesterol, free cholesterol, and LDL-cholesterol levels as compared to HC. There were no differences in serum triglyceride, phospholipid, LDL-cholesterol, HDL-cholesterol, and free cholesterol concentrations between the normal diet groups (NC and NC-LFP). The high cholesterol diet groups (HC and HC-LFP) had significant increases in serum alanine aminotransferase (ALT), asparate aminotransferase (AST), alkaline phosphatase (ALP), and lactate dehydrogenase (LDHase) activities. And the 2% LFP administered groups had lower hepatic concentrations of total cholesterol and triglycerides than the HC groups. Overall, the results suggest that Lycii fructus powder has hypochloesterolemic effects by reducing serum and liver cholesterol contents.

• Korean Journal of Agricultural Science
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• v.8 no.2
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• pp.238-243
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• 1981

This experiment was carried out to study the availability of Korean peat as a main carrier material of rhizobial inoculant, using the alfalfa strain Rhizobium meliloti M 14 which was isolated in the previous report. Modification of powdered peat with calcium carbonate and other materials was studied; inoculation of the peat with culture broth, maturation of the mixture under different conditions, and survival of the strain in the peat culture was examined. The results obtained were as follows. 1. Peat produced in Pyongtak was highly acidic, pH 3.8, and addition of calcium carbonate by 14% was required for pH adjustment to 6.4. However the amount of calcium carbonate could be reduced by 4 to 8% when carbon or charcoal was mixed with the peat. 2. Viable number of the strain reached to $7-9{\times}10^9cells/g$ after 3 days, when inoculated with the culture broth of early stationary growth phase and matured in unsteriled peat of open trays; and the number in steriled peat was $1.1-6.2{\times}10^{10}cells/g$ after 5 days, when matured in closed bottles. 3. Survival of the strain was affected markedly by storage temperature, and positive effect of D-sorbitol on the viability was recognized at elevated temperatures, when added as an additional carbon source and moistening agent. Glycerol, sorbitol, or sodium lactate was utilized by the strain as a sole source of carbon, and the decimal reduction time of viable number in the peat culture was was found to be 8 to 9 weeks at $25^{\circ}C$ when these agents were added by 0.5%.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.4
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• pp.343-351
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• 2001

This study was undertaken to investigate the mechanism of lipopolysaccharide (LPS) and nitric oxide (NO) as a regulator of vascular smooth muscle cell (VSMC) proliferation. VSMC was primarily cultured from rat aorta and confirmed by the immunocytochemistry with anti-smooth muscle myosin antibody. The number of viable VSMCs were counted, and lactate dehydrogenase (LDH) activity was measured to assess the degree of cell death. Concentrations of nitrite in the culture medium were measured as an indicator of NO production. LPS was introduced into the medium to induce the inducible nitric oxide synthase (iNOS) in VSMC, and Western blot for iNOS protein and RT-PCR for iNOS mRNA were performed to confirm the presence of iNOS. Inhibitors of iNOS and soluble guanylate cyclase (sGC), sodium nitroprusside (SNP) and L-arginine were employed to observe the action of LPS on the iNOS-NO-cGMP signalling pathway. LPS and SNP decreased number of VSMCs and increased the nitrite concentration in the culture medium, but there was no significant change in LDH activity. A cell permeable cGMP derivative, 8-Bromo-cGMP, decreased the number of VSMCs with no significant change in LDH activity. L-arginine, an NO substrate, alone tended to reduce cell count without affecting nitrite concentration or LDH level. Aminoguanidine, an iNOS specific inhibitor, inhibited LPS-induced reduction of cell numbers and reduced the nitrite concentration in the culture medium. LY 83583, a guanylate cyclase inhibitor, suppressed the inhibitory actions of LPS and SNP on VSMC proliferation. LPS increased amounts of iNOS protein and iNOS mRNA in a concentration-dependent manner. These results suggest that LPS inhibits the VSMC proliferation via production of NO by inducing iNOS gene expression. The cGMP which is produced by subsequent activation of guanylate cyclase would be a major mediator in the inhibitory action of iNOS-NO signalling on VSMC proliferation.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.4
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• pp.275-281
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• 2013

Astrocytes are reported to have critical functions in ischemic brain injury including protective effects against ischemia-induced neuronal dysfunction. Na-K ATPase maintains ionic gradients in astrocytes and is suggested as an indicator of ischemic injury in glial cells. Here, we examined the role of the Na-K ATPase in the pathologic process of ischemic injury of primary cultured astrocytes. Chemical ischemia was induced by sodium azide and glucose deprivation. Lactate dehydrogenase assays showed that the cytotoxic effect of chemical ischemia on astrocytes began to appear at 2 h of ischemia. The expression of Na-K ATPase ${\alpha}1$ subunit protein was increased at 2 h of chemical ischemia and was decreased at 6 h of ischemia, whereas the expression of ${\alpha}1$ subunit mRNA was not changed by chemical ischemia. Na-K ATPase activity was time-dependently decreased at 1, 3, and 6 h of chemical ischemia, whereas the enzyme activity was temporarily recovered to the control value at 2 h of chemical ischemia. Cytotoxicity at 2 h of chemical ischemia was significantly blocked by reoxygenation for 24 h following ischemia. Reoxygenation following chemical ischemia for 1 h significantly increased the activity of the Na-K ATPase, while reoxygenation following ischemia for 2 h slightly decreased the enzyme activity. These results suggest that the critical time for ischemia-induced cytotoxicity of astrocytes might be 2 h after the initiation of ischemic insult and that the increase in the expression and activity of the Na-K ATPase might play a protective role during ischemic injury of astrocytes.

• Food Science of Animal Resources
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• v.31 no.5
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• pp.710-718
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• 2011

The effects of organic acids mix (0.4%) and modified atmosphere packaging (MAP) on the storage quality of sliced bacon were investigated. Pork bellies were treated with or without organic acids at the curing stage. The organic acids mix comprised 35% sodium acetate, 25% salt, 15% calcium lactate, 11% trisodium citrate, 7% ascorbate, and 7% citric acid. The cured pork bellies were smoked and packaged with 50% $CO_2$ + 50% $N_2$ (50% $CO_2$-MAP) and 100% $N_2$ (100% $N_2$-MAP), and stored at $5^{\circ}C$ for 14 d. The 50% $CO_2$-MAP showed a higher pH value (p<0.05) up to 10 d, a lower protein deterioration (p<0.05) as measured by volatile basic nitrogen (VBN) from 6 to 14 d, and a higher color value of lightness (CIE $L^*$) compared to 100% $N_2$-MAP. The development of lipid oxidation measured by thiobarbituric acid reactive substance (TBARS) values seemed to be effectively controlled throughout the storage period in both 50% $CO_2$-MAP and 100% $N_2$-MAP regardless of the application of organic acids. The 50% $CO_2$-MAP inhibited the growth of aerobic and anaerobic bacteria (p<0.05) both in non-added and bacon added with organic acids mix. The 50% $CO_2$-MAP alone seemed to be effective in delaying the growth of bacteria since the use of organic acids mix gave no additional effects. The addition of organic acids mix lowered the pH value (p<0.05), effectively retarded the protein deterioration (p<0.05), and showed a higher color value of lightness (CIE $L^*$) value (p<0.05) and lower color value of redness (CIE $a^*$) value (p<0.05). In conclusion, 50% $CO^2$-MAP showed better quality and self-life of sliced bacon during storage. However, the beneficial effect of organic acids mix was not noticed in the concentration used in this experiment.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.325-329
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• 2002

This study was carried out to investigate the effect of porphyran on enzyme activity in rats and immunity in mice. Animals were divided into 5 groups, and were given porphyran diet for 4 weeks. Porphyran was extracted from Porphyra yezoensis: Diet groups were normal diet, control diet fed high fat, cholesterol and sodium cholate, control and 1% porphyran diet (1% PD), control and 5% porphyran diet (5% PD), control and 10% of porphyran diet (10% PD). Also Balb/c female mouse were injected i.p. with porphyran extract every other day for 20 days at levels of 1%, 2% and 5%. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) activities were lower in the porphyran diet group than those in control group. Superoxide dismutase and catalase activities in liver homogenates were reduced in porphyran diet group compared to those of control group. Also, the level of liver thiobarbituric acid reactive substance (TBARS) was lower in porphyran group than that of control group. Porphyran increased IL-1 production in a dose-dependent manner, however, interleukine-2 production was reduced as the amount of porphyran increases. These results showed that supplementation of porphyran lowered antioxidant enzyme activities and has possibility of modulating immunological function.

• Journal of Gastric Cancer
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• v.17 no.2
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• pp.132-144
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• 2017

Purpose: To identify baseline prognostic factors for survival in patients with disease progression, during or after chemotherapy for the treatment of advanced gastric or gastroesophageal junction (GEJ) cancer. Materials and Methods: We pooled data from patients randomized between 2009 and 2012 in 2 phase III, global double-blind studies of ramucirumab for the treatment of advanced gastric or GEJ adenocarcinoma following disease progression on first-line platinum- and/or fluoropyrimidine-containing therapy (REGARD and RAINBOW). Forty-one key baseline clinical and laboratory factors common in both studies were examined. Model building started with covariate screening using univariate Cox models (significance level=0.05). A stepwise multivariable Cox model identified the final prognostic factors (entry+exit significance level=0.01). Cox models were stratified by treatment and geographic region. The process was repeated to identify baseline prognostic quality of life (QoL) parameters. Results: Of 1,020 randomized patients, 953 (93%) patients without any missing covariates were included in the analysis. We identified 12 independent prognostic factors of poor survival: 1) peritoneal metastases; 2) Eastern Cooperative Oncology Group (ECOG) performance score 1; 3) the presence of a primary tumor; 4) time to progression since prior therapy <6 months; 5) poor/unknown tumor differentiation; abnormally low blood levels of 6) albumin, 7) sodium, and/or 8) lymphocytes; and abnormally high blood levels of 9) neutrophils, 10) aspartate aminotransferase (AST), 11) alkaline phosphatase (ALP), and/or 12) lactate dehydrogenase (LDH). Factors were used to devise a 4-tier prognostic index (median overall survival [OS] by risk [months]: high=3.4, moderate=6.4, medium=9.9, and low=14.5; Harrell's C-index=0.66; 95% confidence interval [CI], 0.64-0.68). Addition of QoL to the model identified patient-reported appetite loss as an independent prognostic factor. Conclusions: The identified prognostic factors and the reported prognostic index may help clinical decision-making, patient stratification, and planning of future clinical studies.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.2
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• pp.117-124
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• 2006

The analytical measurement range (AMR) is the range of analyte values that a method can directly measure on a specimen without any dilution, concentration, or other pretreatment not part of the usual assay process. The linearity of the AMR is its ability to obtain test results which are directly proportional to the concentration of analyte in the sample from the upper and lower limit of the AMR. The AMR validation is the process of confirming that the assay system will correctly recover the concentration or activity of the analyte over the AMR. The test specimen must have analyte values which, at a minimum, are near the low, midpoint, and high values of the AMR. The AMR must be revalidated at least every six months, at changes in major system components, and when a complete change in reagents for a procesure is introduced; unless the laboratory can demonstrate that changing the reagent lot number does not affect the range used to report patient test results. The AMR linearity was total protein (0-16.6), albumin (0-8.1), total bilirubin (0-18.1), alkaline phosphatase (0-1244.3), aspartate aminotransferase (0-1527.9), alanine aminotransferase (0-1107.9), gamma glutamyl transpeptidase (0-1527.7), creatine kinase (0-1666.6), lactate dehydrogenase (0-1342), high density lipoprotein cholesterol (0.3-154.3), sodium (35.4-309), creatinine (0-19.2), blood urea nitrogen (0.5-206.2), uric acid (0-23.9), total cholesterol (-0.3-510), triglycerides (0.7-539.6), glucose (0-672.7), amylase (0-1595.3), calcium (0-23.9), inorganic phosphorus (0.03-17.0), potassium (0.1-116.5), chloride (3.3-278.7). We are sure that materials for the AMR affect the evaluation of the upper limit of the AMR in the process system.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.408-414
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• 2008

Low-fat sausages (LFS) containing various levels (0, 0.3, and 0.6%) of activated lactoferrin (ALF) which was prepared by dialysis to chelate irons of native lactoferrin, were manufactured and measured the physicochemical and textural properties, and shelf-life effect during refrigerated storage ($8^{\circ}C$). LFSs contained 72-16% moisture, 1-2% fat, 12-14% protein and a pH range of 6.04-6.08. No differences in physico-chemical and textural properties were observed with the increased ALF (p>0.05). Microbial growth of Listeria monocytogenes (LM), which inoculated at the levels of $10^4$ CFU/g, was increased with increased storage time. ALF at the amount of 0.6% slightly inhibited the microbial growth on the LFS (p<0.05), as compared to those of LFSs without ALF, however it had lower antimicrobial activity than those of 3.3% sodium lactate. These results indicated that the addition of ALF at the level of 0.6% affected the antibacterial activity of LFSs, resulting in the suppression of microbial growth in LFSs without quality defects.