• Korean Journal of Microbiology
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• v.34 no.3
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• pp.108-114
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• 1998

Salmonella Pathgenicity Island 2 plays an important role in Salmonella pathogenicity, especially invasion into host cell. We have investigated the effect of various environmental factors, such as oxygen level, osmolarity, pH, carbon starvation and glycerol addition on the expression of SPI2. For this research, we constructed the reporter plasmids, in which the promoter-less lac operons are fused with the regulatory regions (including promoter) of ssaJ and ssaK, major genes in SPI2. The study using the reporters showed that low oxygen, low osmolarity, or weak alkali conditions increased the expression levels of ssaJ and ssaK and when these three conditions exist simultaneously, the expression levels of ssaJ and ssaK are the highest. However carbon starvation and glycerol addition did not affect the expression of ssaJ and ssaK. These environmental effects on the expression levels of ssaJ and ssaK are the same in three Salmonella typhimurium wild types, LT2, UK1, and SL1344. In addition, we confirmed that the mutation in hilA, a regulatory gene encoding a transcriptional activator of SPI1, had no effect on the expression of ssaJ and ssaK. Thus, these results strongly suggest that the expressions of SPI2 and SPI1 are regulated by different control systems.

• The Korean Journal of Physiology
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• v.21 no.1
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• pp.23-33
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• 1987

This study was carried out to investigate the characteristics of lithium concentration difference between maternal and fetal plasma and the effect of previous lithium loading on rapid transplacental transport of large amounts of lithium. Pregnant rabbits at $20{\sim}22\;days$ of gestation were divided into two groups: chronic $Li^+$ injection group and chronic plus acute $Li^+$ injection group. Small amounts of LiCl (1 mmol/kg per day) were given intraperitoneally to all rabbits of both group, for 5 days before sacrifice. The rabbits of chronic plus acute injection group, received additional intravenous injections of large amounts of LiCl (2 mmol/kg) one hour before sacrifice. Maternal arterial blood, placental sinus blood, fetal blood and amniotic fluid were drawn and analyzed for the plasma concentrations of $Li^+$, $Na^+$ and $K^+$ and for osmolartiy. Followings are the results obtained. 1) There was no difference in the $Li^+$ concentration between maternal plasma and placental sinus plasma in chronic lithium group, although the $Li^+$ concentration of placental sinus plasma was slightly lower than that of maternal arterial plasma in the chronic plus acute lithium group. 2) The $Li^+$ concentration of fetal plasma was much lower than that of placental sinus plasma in both groups, the ratio being $0.76{\pm}0.250$ ($mean{\pm}95%$ confidence interval) for the chronic $Li^+$ group and $0.78{\pm}0.366$ for the chronic plus acute $Li^+$ group. 3) The ratio of $Li^+$ concentration of fetal plasma to maternal arterial plasma was $0.71{\pm}0.196$ in the chronic group and $0.59{\pm}0.261$ in the chronic plus acute group. 4) $Li^+$ concentration of amniotic fluid was much higher than that of fetal plasma in the chronic $Li^+$ group but not significantly different in the chronic plus acute $Li^+$ group. 5) An acute loading of $Li^+$ did not produce any detectable changes in $Na^+$ and $K^+$ concentrations and osmolarity of the maternal plasma. The above results may suggest that: (a) The placental barrier maintains steady state lithium concentration gradient between placental sinus plasma and fetal plasma. (b) In rabbits chronically treated with $Li^+$ the steady state $Li^+$ gradient is established within one hour after an acute $Li^+$ loading, provided that the $Li^+$ concentration in the maternal plasma is less than 4 mmole/l.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.3
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• pp.325-335
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• 1997

Evidence for the existance of at least two subclasses of renal adenosine receptors has been presented. N-6-cyclohexyladenosine (CHA) is a relatively selective $A_1$ adenosine agonists, whereas 5'-N-ethylcarboxamidoadenosine (NECA) acts as a preferential agonist of $A_2$ adenoisne receptor. N6-(L-2-phenylisoproryl)-adenosine (PIA) almost unselectively activates both $A_1\;and\;A_2$ adenosine receptors at micromolar concentrations. During the characterization of adenosine receptor in the kidney, we have discovered a novel phenomenon, that is, an intramuscular administration of CHA for 3 days caused a diuresis and a suppression of urinary concentrating ability. To further characterize this novel phenomenon, an intramuscular administration of adenosine and other adenosine angonists, PIA and NECA, and prior treatment of adenosine antagonists, caffeine, theophylline and 1,3-diethyl-8-phenyl-xanthine (DPX) were performed. Systemic administration of CHA, PIA, and NECA for 3 days caused a suppression in heart rate, blood pressure and general motor activity without change in rectal temperature. Systemic administration of CHA, 0.5, 1 and 2 mg/kg/day, for 3 days caused a dose-dependent increase in urine volume and decrease in urinary osmolarity and free water reabsorption. This phenomenon was reversible and repeatable. Administration of adenosine (40 mg/kg/day) produced no apparent effect on the renal function, whereas PIA (2 mg/kg/day) produced an similar effect to CHA on the renal function. Systemic adminstration of NECA, 0.025, 0.05 and 0.25 mg/kg/day, for 3 days caused a dose-dependent increase in urine volume and dose-dependent increases in excreted amount of creatinine, urinary osmolarity and free water reabsorption. These renal effects of adenosine agonist were maximum at second day during the drug administration. In terms of increase in urine volume and the suppression of urinary concentrating ability, NECA was potent than CHA. Prior treatment of caffeine (50 mg/kg/day) or theophylline (50 mg/kg/day) abolished the diuretic effect of CHA, whereas DPX (50 mg/kg/day) did not affect the CHA effect. CHA, 0.5 mg/kg/day, produced no change in plasma renin activity and plasma levels of aldosterone, epinephrine, and norepinephrine. These results suggest that this novel phenomenon produced by an activation of renal adenosine receptors plays an important role in urinary concentrating mechanism.

• Journal of Life Science
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• v.19 no.6
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• pp.728-734
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• 2009

In this work, a simple, inexpensive and reproducible technique of flotation density gradient centrifugation was developed to isolate monocytes with high purity and yield from peripheral blood mononuclear cells (PBMC) using Histopaque solution, density and osmolarity of which were modified to 1.072 g/ml and 335 mOsm with phosphate-buffered saline (PBS) and sodium chloride (NaCl) solution, respectively. The average purity of monocytes was 74.75${\pm}$3.84%, with the individual purity ranging from 71.44% to 82.38%. The average yield of monocytes was 32.62${\pm}$11.16%, with the individual yields ranging from 21.02 to 53.63%. The monocytes isolated by floatation density gradient centrifugation could be successfully cultured into morphologically, phenotypically and functionally dendritic cells in vitro. In conclusion, the entire procedure seemed to be faster and more convenient, simple and cost-effective than other monocyte isolation methods, including plastic adherence and density gradient methods, and has the potential to be developed as a closed system for clinical scale generation of dendritic cells.

• Journal of Chest Surgery
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• v.16 no.2
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• pp.213-220
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• 1983

Pulmonary function is the determinant of blood gas tension. However, Acid-Base disturbances can also alter partial pressures of oxygen and carbon dioxide in arterial blood. During respiratory acidosis $PO_2$ will be lowered and reverse changes will be produced during respiratory alkalosis. On the other hand, in metabolic acidosis $PO_2$ will be elevated and $PCO_2$ will be lowered by the respiratory compensation, and reverse response will be induced in metabolic alkalosis. Urinary gas tension has many influencing factors than arterial blood and difficult to estimate the tendency of its alterations. Urinary $PO_2$ and $PCO_2$ are not always identical level as venous blood. It is to be altered by blood gas tension, flow rate of urine, metabolic rate of kidney, and Acid-Base status of blood. Particularly countercurrent exchange of oxygen and carbon dioxide in the renal medulla will make larger alteration of gas tension than venous blood. After induction of Acid-Base disturbances [disturbances] arterial and urinary $PCO_2$, $PO_2$, urinary volume, and osmolarity were determined in dogs, and the relationships between arterial and urinary $PCO_2$ , $PO_2$ Acid-Base disturbances, urinary volume, and osmolarity were investigated. 1. During the acute Metabolic and Respiratory disturbances urinary pH did not respond on respiratory origin. However, there were immediate urinary response in pH on metabolic origin. 2. Urinary $PO_2$, $PCO_2$, did not always follow arterial or venous gas tension and Acid-Base disturbance. Urinary $PCO_2$, correlate well with the urinary volume. The larger the urinary volume, $PCO_2$ lowered to the venous level. The smaller the urinary volume, urinary $PCO_2$ tends to be higher. However urinary $PO_2$ did not have any particular correlation with urinary volume. 3. Correlation between urinary $PCO_2$ and $PO_2$ were inversely proportional to arterial blood. Differences of $PCO_2$ between arterial blood and urine also did not have any particular correlation with urinary volume. This may suggest that changes on blood gas tensions can influence on urinary $PCO_2$. 4. There were eminent clear inverse correlation between urinary $PCO_2$ and osmolar concentrations of urine. Above results strongly suggest that partial pressure of gas in urine primarily depend upon counter-current exchanges in renal medullary tissues.

• The Korean Journal of Zoology
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• v.18 no.4
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• pp.181-196
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• 1975

Rabbit follicular oocytes were cultured in a basic medium containing 0.4% bovine serum albumin (BSA), carbohydrates and amino acids in various combinations. Osmolarity of the medium was maintained at 308 mOsm. The carbohydrates, pyruvate, lactate and glucose were all about equally beneficial, but not essential for rabbit oocyte maturation. Glutamine and proline, but not methionine or phenylalanine stimulated oocyte develoment. Glutamine stimulated more follicular oocytes to develop to prophase and metaphase II than did any of the three carbohydrates tested alone or in combination. Ammonia production after 24 hours of culture was highest in medium containing glutamine(15.2$\\mu$g/ml) but this was not inhibitory to maturation. Negligible amounts of ammonia were found with the other amino acids added. The optimum level of osmolarity for rabbit oocyte maturation appears to be ranged from 250$\\sim$310 mOsm with the maximum level of 270 mOsm. With 0, 0.08, 0.4, 2, 10 and 50 mM of glutamine in the medium, plus BSA but without carbohydrates, 30, 73, 70, 71, 59, 45% of the oocytes developed to prophase or metaphase II respectively. This indicates that no carbohydrate is required of the maturation of rabbit oocytes when 0.08$\\sim$2 mM of glutamine is included, which are the optimum range. Follicular oocytes could develop in the medium containing $^14 C$-glutamine and BSA but without carbohydrates or other organic compound. From the $^14 CO_2$ produced and TCA precipitable material isolated, it is suggested that glutamine probably is utilized by oocytes and cumulus cells as a source of energy as well as for protein synthesis.

• Journal of Sasang Constitutional Medicine
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• v.10 no.2
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• pp.565-588
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• 1998

1. Background and Purpose : I intended to investigate the effects of Taeumin Yuldahansotang and Jowisokmyungtang experimentally to hypertension and renal function and contrived to approach these diseases by constitutional medicine. 2. Methods : I adapted two groups, normal rats and spontaneously hypertensive rats, to the same environment for more than 2 weeks and adminstrated water extracts of Yuldahansotang and Jowisokmyungtang. After adminstration of water extracts, I observed significant changes of values of the blood pressure and the urinary excretion of creatininine, electrolytes, osmolarity, renin, atrial natriuretic peptide and the plasma level of aldosterone, triglyceride, phospholipid, cholesterol. 3. Results : Yuldahansotang and Jowisokmyungtang decrease the blood pressure in the spontaneous hypertensive rats, the one by increasing the plasma level of atrial natriuretic peptide and decreasing the plasma level of aldosterone, the other by decreasing the plasma level of aldosterone, from which we could detect the therapeutic difference between Yuldahansotang and Jowisokmyungtang.

• Molecules and Cells
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• v.26 no.2
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• pp.200-205
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• 2008

The mitogen-activated protein kinase (MAPK) signaling pathway is activated in response to extracellular stimuli and regulates various activities in eukaryotic cells. Following exposure to stimuli, MAPK is known to be activated via dual phosphorylation at a conserved TxY motif in the activation loop; both threonine and tyrosine residues are phosphorylated by an upstream kinase. However, the mechanism underlying dual phosphorylation is not clearly understood. In the budding yeast Saccharomyces cerevisiae, the Hog1 MAPK mediates the high-osmolarity glycerol (HOG) signaling pathway. Tandem mass spectrometry and phosphospecific immunoblotting were performed to quantitatively monitor the dynamic changes occurring in the phosphorylation status of the TxY motif of Hog1 on exposure to osmotic stress. The results of our study suggest that the tyrosine residue is preferentially and dynamically phosphorylated following stimulation, and this in turn leads to the dual phosphorylation. The tyrosine residue was hyperphosphorylated in the absence of a threonine residue; this result suggests that the threonine residue is critical for the control of signaling noise and adaptation to osmotic stress.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.6
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• pp.1482-1486
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• 2008

The antihypertensive effects of the Wild Mountain Ginseng Cultured Root Extract (WMGCE) were investigated in spontaneously hypertensive rats (SHR). Daily oral administration of the WMGCE (100 and 200 mg/kg) exhibited a significant decrease in blood pressure in SHR rats during for 8 weeks. The systolic blood pressure was dose- and time-dependently decreased significantly from the second weeks (p < 0.05) to the end of WMGCE treatment in SHR. The WMGCE decreased the plasma levels of sodium, potassium, chlorides, urea and osmolarity in SHR rats but no statistically significant change was observed. Furthermore, no significant changes were noted on heart weight, heart rate and diameter of aorta after WMGCE treatment in SHR. Our results suggest that daily oral administration of WMGCE at the dose of 100 and 200 mg/kg for 8 weeks exhibited antihypertensive activities.

• Plant Biotechnology Reports
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• v.2 no.3
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• pp.171-177
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• 2008

This paper reports an improved protocol for isolation, culture and regeneration of Lotus corniculatus protoplasts. A range of parameters which influence the isolation of L. corniculatus protoplasts were investigated, i.e., enzyme combination, tissue type, incubation period and osmolarity level. Of three enzyme combinations tested, the highest yield of viable protoplasts was achieved with the combination of 2% Cellulase Onozuka RS, 1% Macerozyme R-10, 0.5% Driselase and 0.2% Pectolyase. The use of etiolated cotyledon tissue as a source for protoplast isolation proved vital in obtaining substantially higher protoplast yields than previously reported. Culture of the protoplasts on a nitrocellulose membrane with a Lolium perenne feeder-layer on the sequential series of PEL medium was highly successful in the formation of microcolonies with plating efficiencies 3-10 times greater than previous studies. Shoot regeneration and intact plants were achieved from 46% of protoplast-derived cell colonies.