• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.109-109
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• 2003

Taurine is present in a variety of tissue and exhibits many important physiological functions in many tissues. Although it is known that many tissues mediate taurine transport, its functions of taurine transport in bone have not been identified yet. In the present study, we investigated the expression of taurine transporter (TauT) and taurine uptake using mouse stromal ST2 cells and osteoblast-like MC3T3-El cells, which is bone related cells. Detection of TauT mRNA expression in these cells were performed by reverse transcription polymerase chain reaction (RT-PCR). The activity of TauT was assessed by measuring the uptake of ［$^3$H］taurine in the presence or absence of inhibitors. TauT mRNA was detected in these cells. ［$^3$H］Taurine uptake was dependent upon the presence of extracellular sodium, chloride and calcium ions, and inhibited by cold-taurine and ${\beta}$-alanine. These results suggest that taurine has biological functions in bone and some effect on the bone cells.

• Biomolecules & Therapeutics
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• v.22 no.1
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• pp.68-72
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• 2014

When chemotherapy is administered during pregnancy, it is important to consider the fetus chemotherapy exposure, because it may lead to fetal consequences. Paclitaxel has become widely used in the metastatic and adjuvant settings for woman with cancer including breast and ovarian cancer. Therefore, we attempted to clarify the transport mechanisms of paclitaxel through blood-placenta barrier using rat conditionally immortalized syncytiotrophoblast cell lines (TR-TBTs). The uptake of paclitaxel was time- and temperature-dependent. Paclitaxel was eliminated about 50% from the cells within 30 min. The uptake of paclitaxel was saturable with $K_m$ of $168{\mu}M$ and $371{\mu}M$ in TR-TBT 18d-1 and TR-TBT 18d-2, respectively. [$^3H$]Paclitaxel uptake was markedly inhibited by cyclosporine and verapamil, well-known substrates of P-glycoprotein (P-gp) transporter. However, several MRP substrates and organic anions had no effect on [$^3H$]paclitaxel uptake in TR-TBT cells. These results suggest that P-gp may be involved in paclitaxel transport at the placenta. TR-TBT cells expressed mRNA of P-gp. These findings are important for therapy of breast and ovarian cancer of pregnant women, and should be useful data in elucidating teratogenicity of paclitaxel during pregnancy.

• Journal of Life Science
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• v.8 no.2
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• pp.208-215
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• 1998

It was investigated the biosorption performances of copper by the immobilized biomass of nonliving marine brown alge h. fusiformis by each of the Ca-alginate method(Ca-ALG), Ba-alginate method(Ba-ALG), polyethylene glycol method(PEG), and carrageenan method (CARR). The copper removal performance increased but the copper uptake decreased as the biomass amount was increased. However, the copper uptake by the immobilized biomass increased with increasing initial copper concentration. The copper uptake by the immobilized biomass of the immobilization method decreased in the following sequence; Ca-ALG>Ba-ALG>PEG>CARR among the immoblization emthods. The copper uptake by the immobilized biomass followed the Langmuir isotherm better than the Freundlich isotherm.

• Applied Biological Chemistry
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• v.44 no.3
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• pp.185-190
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• 2001

Alginate, a well-known biopolymer, is universally applied for immobilization of microbial cells. Biosorption characteristics of lead by waste biomass of immobilized A. niger beads, used in fermentation industries to produce citric acid, were studied. The immobilized A. niger beads, prepared via capillary extrusion method using calcium chloride, were applied in the removal of lead. Pb uptake was the highest in A. niger beads cells grown for 3 days with medium producing citric acid (12% sucrose, 0.5% $NH_4NO_3$, 0.1% $KH_2PO_4$, and 0.025% $MgSO_4$). Lead uptake by the immobilized A. niger beads and free A. niger mycellia beads increased sharply with time. However, while uptake by the immobilized A. niger beads continued to increase slowly, that by free A. niger mycellia beads stopped after 30 min. The optimum pH and temperature of lead uptake were found to be 6 and $35^{\circ}C$, respectively. The maximum uptake of lead was achieved with $50{\sim}100$ beads and 50 ml lead solution in a 250-ml Erlenmeyer flask, while, at over 100 beads, uptake of the lead decreased. The order of biosorption capacity for heavy metals was Pb>Cu>Cd. Pb uptake capacity of the immobilized A. niger beads treated with 0.1 M $CaCI_2$, 0.1 M NaOH, and 0.1 M KOH decreased compared to the untreated beads. On testing the desorption of Pb from the immobilized A. niger beads, re-uptake of Pb was found possible after desorption of the binding metal with 0.1 M HCI.

• Journal of the korean society of oceanography
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• v.39 no.1
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• pp.20-25
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• 2004

The Yellow Sea is known to be a very productive region in terms of fisheries. However, its trophic status seems to be highly variable, ranging from oligotrophic to eutrophic, based on new production (NP) values. The NP and regenerated production (RP) values estimated from $^{15}N$-labelled nitrate and ammonium uptake in spring (April 1996) and winter (February 1997) during this study ranged from 0.05 to 19.8 mg $N m^{-2} d^{-1}$ and from 0.1 to 22.8 mg $N m^{-2}d^{-1}$, respectively. Our measurements and earlier observations suggested that NP in the Yellow Sea varied over the four orders of magnitude (range 0.05-180.9 mg $N m^{-2} d^{-1}$) temporally and spatially, and that RP (range 0.1-507.5 mg $N m^{-2}d^{-l}$) based on ammonium predominated during most period of the year, except in winter when both productions were low. The significant nitrogen uptake by phytoplankton below the euphotic zone and episodic entrainment of phytoplankton from below the euphotic zone into the euphotic zone, and nitrite excretion and dissolved organic nitrogen release during nitrate uptake might explain the apparent dominance of RP in the Yellow Sea.

• Journal of Environmental Science International
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• v.25 no.4
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• pp.473-481
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• 2016

We examined the effects of ocean acidification (OA) and eutrophication on the physiology of a red alga, Gracilariopsis chorda, using specimens collected at Wando Island, Korea, in July of 2015. The samples were transported to a laboratory and placed on growth media for treatments involving low or high levels of ammonium ($4{\mu}M$ or $60{\mu}M\;NH_4{^+}$) and low or high pH(7.5 or 8.2). The control treatment used filtered seawater (pH 8.2 and $4{\mu}M\;NH_4{^+}$). All experiments were conducted at $20^{\circ}C$ and under a lighting intensity of $80{\mu}mol\;photons\;m^{-2}\;s^{-1}$, with or without an injection of $CO_2$ (pH 7.5). In addition, we calculated rates of respiration under darkness, at a pH of 7.5 and $60{\mu}M\;NH_4{^+}$. Fluctuations in pH as well as the evolution of photosynthetic oxygen and $NH_4{^+}$ uptake rates were monitored for 6 h. The greatest increase in pH levels, from 7.50 to 8.65, occurred in response to $60{\mu}M\;NH_4{^+}$, whereas the largest decrease, from 7.50 to 7.42, was associated with elevated respiration rates. At a pH of 7.5, rates of oxygen evolution were higher (236% saturation) for samples treated with $60{\mu}M\;NH_4{^+}$ than for the control (121% saturation). Ammonium uptake was highest at pH 7.5 and $60{\mu}M\;NH_4{^+}$, with a rate of $0.526{\pm}0.002{\mu}mol\;g^{-1}\;FW\;h^{-1}$, followed in order by the treatments of $pH\;8.2/60{\mu}\;NH_4{^+}$, $pH\;7.5/4{\mu}M\;NH_4{^+}$, and the control ($pH\;8.2/4{\mu}M\;NH_4{^+}$). We speculated that the rates of photosynthesis and $NH_4{^+}$ uptake could be enhanced at a higher ammonium concentration and lower pH because $CO_2$ concentrations were increased through greater photosynthetic activity. Therefore, these findings suggest that the physiology of G. chorda populations can be improved by the interaction of optimized $CO_2$ concentrations and an adequate supply of essential nutrients such as ammonium.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.2
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• pp.72-79
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• 2017

Arbutin is a hydroquinone derivative with a glucose moiety. As a tyrosinase inhibitor, it is widely used as a skin-whitening cosmetic agent for the treatment of cutaneous hyperpigmentary disorders, such as melasma and freckles. In the medical field, many studies have addressed the use of arbutin in various tumors, but the mechanism for tumor uptake of arbutin is still unclear. In this paper, we radiolabeled arbutin using radioiodine and studied its pharmacokinetics and tumor uptake via biodistribution experiments and single-photon emission computed tomography (SPECT) imaging. Radiolabeled $^{131}I-arbutin$ was stable for up to 24 h in PBS and serum. Biodistribution studies and SPECT imaging indicated high uptake of the compound in the bladder and kidneys shortly after injection. Twenty-four hours post-injection, significant deiodination was observed. Apart from high thyroid uptake, selective tumor uptake was clearly observed. The tumor-to-muscle and tumor-to-blood ratios were 26 and 9, respectively.

• Journal of Nutrition and Health
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• v.32 no.4
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• pp.369-375
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• 1999

Hyperthroidism in known to alter the activity of a number of enzymes involved in the catabolism of histidine to CO2. 10-Formyltetrahydrofolate dehydrogenase(EC 1.5, 1.6, 10-formyl-THE dehydrogenase) catalyzes the NADP-dependent conversion of 10-formyltetrahydrofolate to tetrahydrofolate and CO2. In previous studies, 10-formyl-THF dehydrogenase purified from rat and pig liver was coidentified with the cytosolic folate-binding protein. In this study, we investigated the effects of feeding thyroid powder (TP) and thiouracil(TU) on the folate-binding properties of 10-formyl-THE dehydrogenase, the uptake of an injected dose of [3H] folate, and the metabolism of labeled folate to pteroylopoly-${\gamma}$-glutamate in rat liver. The initial hepatic uptake(24hr) of the labeled folate dose was higher in TU-rats and slightly higher in TP-rats in controls. With longer time periods, decreased hepatic uptake of labeled folate was observed in TP-animals compared to euthroid animals, and high levels of hepatic uptake of labeled folate were maintained in TU-animals. This data shows that high levels of thyroid hormone decreased the retention of folate in rat liver. Folate polygutamate chain length was shorter in TU-rats than controls, which suggests that thyroid states do not affect the ability to synthesize pteroylpolyglutamates and that folate polyglutamate might be modulated by altered folate pool size. The ability of 10-formyl-THE dehydrogenase to bind folate in rat liver was similar in both TP-and TU-rats although dehydrogenase activity was changed by thyroid sates.

• Toxicological Research
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• v.3 no.2
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• pp.73-80
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• 1987

Primary cultures of adult rat hepatocytes were used to study the cytotoxicity of D-galactosamine. Hepatocytes were isolated by a collagenase perfusion technique and maintained as monolayers in serum-free medium on collagen-coated culture dishes. Treatment of galactosamine to the culture markedly inhibited the uptake of ${\alpha}$-aminoisobutyric acid (AIB) inducible with glucagon and dexamethasone. At0.1 mM of galactosamine, AIB uptake was inhibited significantly when treated for 12 hr. At higher doses (0.25, 0.5 and 1.0mM), a significant inhibition was noticed after 1 hr exposure. Generally the magnitude of the inhibition was related to the dose and treatment time of galactosamine. Treatment of galactosamine also produced a dose- and treatment time-related suppression of the tyrosine aminotransferase (TAT) induction caused by dexamethasone. Meanwhile, uptake of ouabain was not affected by the treatment of galactosamine. The viability of the hepatocytes was decreased only slightly by the treatment of galactosamine; more than 87% of the cells excluded tryphane blue when treated 1 mM galactosamine for 12 hr. Galactosamine induced depressions of AIB uptake and TAT activity were prevented by the simultaneous addition of uridine to the culture. D-Galactosamine, cytotoxicity, hepatocytes culture, ${\alpha}$-aminoisobutyric acid uptake, tyrosine aminotransferase.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.108-115
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• 2002

The effects of long-term fertilization on soil properties and nutrient availability are not well documented for cassava cultivation in Vietnam. In 1990, a field research plots were established with 12 treatments to test the effect of different rates of nitrogen (N), phosphorus (P) and potassium (K) on soil properties in Acrisols at Thai Nguyen University in Northern Vietnam. In 1999, composite soil samples (0 to 20cm depth) were collected from eight selected plots for measurements of nutrient supply rates by ion exchange membrane probes and for growing corn and canola in a growth chamber with and without added lime. Generally, long-term nitrogen (N) fertilization increased available N supply rates but decreased available potassium (K) and magnesium (Mg). Long-term phosphorus(P) applications increased canola N, calcium (Ca) and Mg uptake. Canola P uptake increased with increased P rates only when lime was added. Long-term K applications increased canola N, K, Ca, Mg uptake but only significantly increased corn N uptake. Liming significantly increased uptake of N, P, K, Ca, Mg and S for both corn and canola. However, N $H_{4-}$N, K and Mg soil supply rates were reduced when lime was added, due to competition between Ca from the added lime and other nutrients.