• Polymer(Korea)
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• v.28 no.6
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• pp.478-486
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• 2004

Small intestinal submucosa (SIS) is consisted with collagen and glycosaminoglycan as well as some growth factors which can stimulate cell activity. Recently, it has been recognized that SIS has been successfully examined in the bio-medical application as biomaterials without xenograft immune-rejection response. We prepared native SIS sheets and acid treated SIS sheets by acetic acid with 1 or 5-layered sheets, respectively. The water uptake ability of native and acid treated SIS sheets was examined to evaluate the possibility as wound dressings. Morphologies of SIS sheets were characterized by SEM and the effects of various buffer solutions and different pH solutions on the water uptake ability were observed for 16 days. We observed that the acid treated SIS sheets had higher water uptake ability than native SIS sheets. Also, the water uptake ability of these was slightly higher in various buffers than distilled water. In conclusion, this study suggests that native and acid treated SIS sheets could be useful for the applications of wound dressing and biodegradable injectable materials.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.1
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• pp.83-91
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• 1999

Angiotensin II (ANG II) has a biphasic effect on $Na^+$ transport in proximal tubule: low doses of ANG II increase the $Na^+$ transport, whereas high doses of ANG II inhibit it. However, the mechanisms of high dose ANG II-induced inhibition on $Na^+$ uptake are poorly understood. Thus the aim of the present study was to investigate signal transduction pathways involved in the ANG II-induced inhibition of $Na^+$ uptake in the primary cultured rabbit renal proximal tubule cells (PTCs) in hormonally defined serum-free medium. ANG II $(10^{-9}\;M)-induced$ inhibition of $Na^+$ uptake was blocked by losartan $(10^{-8}\;M,\;AT_1\;antagonist),$ but not by PD123319 $(10^{-8}\;M,\;AT_2\;antagonist)$ (P<0.05). ANG II-induced inhibition of $Na^+$ uptake was also completely abolished by neomycin $(10^{-4}\;M,$ PLC inhibitor), W-7 $(10^{-4}\;M,$ calmodulin antagonist), and $AACOCF_3\;(10^{-6}\;M,\;PLA_2\;inhibitor)$ (P<0.05). ANG II significantly increased $[^3H]arachidonic$ acid (AA) release compared to control. The ANG II-induced $[^3H]AA$ release was blocked by losartan, $AACOCF_3,$ neomycin, and W-7, but not by PD123319. ANG II-induced $[^3H]AA$ release in the presence of extracellular $Ca^{2+}$ was greater than in $Ca^{2+}-free$ medium, and it was partially blocked by TMB-8 $(10^{-4}\;M,$ intracelluar $Ca^{2+}$ mobilization blocker). However, in the absence of extracellular $Ca^{2+},$ it was completely blocked by TMB-8. In addition, econazole $(10^{-6}\;M,$ cytochrome P-450 monooxygenase inhibitor) and indomethacin $(10^{-6}\;M,$ cyclooxygenase inhibitor) blocked ANG II-induced inhibition of $Na^+$ uptake, but NGDA $(10^{-6}\;M,$ lipoxygenase inhibitor) did not affect it. In conclusion, $PLA_2-mediated$ AA release is involved in ANG II-induced inhibition of $Na^+$ uptake and is modulated by $[Ca^{2+}]_i$ in the PTCs.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.65-70
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• 2010

The blood-brain barrier (BBB) transport of acetylcholinesterase (AChE) inhibitors, donepezil and tacrine suggested to be mediated by choline transport system in our previous study. Therefore, in the present study, we investigated the interaction of other AChE inhibitors, rivastigmine and galantamine with choline transporter at the BBB. The effects of rivastigmine and galantamine on the transport of choline by conditionally immortalized rat brain capillary endothelial cell lines (TR-BBB cells) were characterized by cellular uptake study using radiolabeled choline. The uptake of [$^3H$]choline was inhibited by rivastigmine and galantamine, with $IC_{50}$ values (i.e. concentration necessary for 50% inhibition) for 1.13 and 1.15 mM, respectively. Rivastigmine inhibited the uptake of [$^3H$]choline competitively with $K_i$ of 1.01 mM, but galantamine inhibited noncompetitively. In addition, the efflux of [$^3H$]choline was significantly inhibited by rivastigmine and galantamine. Our results indicated that the BBB choline transporter may be involved in a part of the influx and efflux transport of rivastigmine across the BBB. These findings should be therapeutically relevant to the treatment of Alzheimer's disease (AD) with AChE inhibitors, and, more generally, to the BBB transport of CNS-acting cationic drugs via choline transporter.

• Environmental Mutagens and Carcinogens
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• v.17 no.1
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• pp.7-11
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• 1997

Variations in adriamycin uptake and cytotoxicity were studied in tumor cells that were grown in different growth states and microenvironments. RIF-1 tumor cells were maintained in an RPMI 1640 medium, and grown in either a monolayer or multicell spheroids. For exponentially growing cells, adriamycin cytotoxicity increased with increased dosage up to 2.5 $\mu$g/ml, and this cytotoxicity was reduced when the cells were grown in a plateau phase or in an acidic microenvironment (pH 6.6). This reduced cytotoxicity was correlated with the uptake of the drug. For multicell spheroids, the cytotoxicity of the drug was reduced dramatically, and this reduction was also correlated with a reduced uptake of the drug and an acidic pH inside of the spheroids. When the drug cytotoxicity was evaluated at different locations within the spheroids, the cells in the inner regions were least affected by the drug, suggesting that both an acidic microenvironment and noncycling plateau phase cells are contributing factors in decreasing the efficacy of the drug in an organized tissue, such as multicell spheroids.

• The Korean Journal of Nuclear Medicine
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• v.36 no.1
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• pp.87-89
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• 2002

A 30 year-old female patient with papillary thyroid carcinoma received her fifth radioiodine ablation therapy after the subtotal thyroidectomy. The scan, which was peformed one week after the last therapy, revealed residual uptake in the thyroid bed and uptake in the anterior mediastinum suggesting metastasis. However, further evaluation of the thorax with chest CT and camera-based FDG PET confirmed normal thymus without metastatic focus. Occasionally thymus remains intact in adult and has avidity for I-131 and FDG. Therefore, normal thymus (instead of metastasis) should be considered in patients with well differentiated thyroid carcinoma and anterior mediastinal radioiodine uptake.

• The Korean Journal of Nuclear Medicine
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• v.36 no.2
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• pp.143-145
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• 2002

A 49-year-old male patient with a carcinoma of the right pyriform sinus had a whole-body bone scan and gamma camera based F-18 FDG-PET for staging. Tc-99m MDP bone scan depicted diffuse increased uptake in the left femur due to chronic osteomyelitis but no skeletal metastasis. F-18-FDG-PET revealed increased focal bone uptake and uptake in the draining sinus due to chronic osteomyelitis in addition to visualization of the right pyriform sinus carcinoma and right neck nodal uptake. Fluorine-18 fluorodeoxyglucose-positron emission tomography is significantly more accurate than the bone scan in pinpointing chronic osteomyelitis focus and draining soft tissue infection.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.158.2-159
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• 2003

Cadmium is well known as a toxic metal and has insulin mimicking effects in rat adipose tissue. To investigate the effect of CdCl2 on glucose transport and its mechanism, this study was performed in 3T3-L1 adipocytes. 10 and 25mM of CdCl2 exposed to cells for 12 hours increased 2-deoxyglucose uptake to 2.2 and 2.8 fold, respectively. Nifedipine, a calcium channel blocker, inhibited the 2-deoxyglucose uptake stimulated by CdCl2. (omitted)

• Journal of Plant Biology
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• v.37 no.3
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• pp.271-276
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• 1994

The possibility that 1-aminocyclopropane-1-carboxylic acid (ACC)-uptake may be dependent on the H+-gradient established across the plsma membrane was tested in protoplasts isolated from 2.5 day old mungbean hypocotyls. The ACC-induced ethylene production was inhibited when the H+-gradient was collapsed by the treatment with carbonycyamide-p-trifluro-methoxy-phenylhydrazone (FCCP). Moreover, the treatment with o-vanadate, a specific inhibitor of plasma membrane H+-ATPase, caused the inhibition of ethylene production. The ACC-induced ethylene production was inhibited by the treatemnt with verapamil (Ca2+-channel blocker), or ethylene glycol-bis($\beta$-aminoethyl ether) N, N, N', N'-tetraacetic acid (EGTA) (Ca2+-chelator). In contrast, the ehtylene production was stimulated by the application of A23187 (Ca2+ ionophore). The inhibitory effect of EGTA in the ethylene producton was magnified in the presence of A23187. From these results, we suggest that the external Ca2+ influx to the cytosol resulted in the stimulatin of ACC oxidase activity after ACC-uptake resulting from a H+-gradient across the plasma membrane.

• Korean Journal of Human Ecology
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• v.5 no.2
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• pp.119-127
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• 2002

Dyeing properties of the colorants extracted from acorn on wool fabric were investigated. Effects of dyeing temperature, dyeing time, repeating, and pH on dye uptake and colorfastness were explored. Acorn colorants showed very good affinity to wool fiber and produced bright to dark brown color ranged 4.81-8.97YR, 4.46-7.47/1.79-3.35. ,Higher temperature increased dye adsorption, so did longer time and more repeating. Washfastness was fairly good. The Dyed wool fabric had deeper color after irradiation to light. pH had an effect on the development of color, also. Dye uptake and washfastness were higher in acidic and alkaline pH than in neutral pH solution.

• Journal of Environmental Science International
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• v.8 no.1
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• pp.69-74
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• 1999

Soil properties which affect the retention of Pb(I) were investigated in the laboratory. It was determined, through selective removal, that organic matter and Fe-oxides are of lesser importance in influencing Pb retention than are soil clay minerals. The following trend : clays ＞ organic matter ＞ Fe-oxides represents the relative importance of each constituent in the adsorption of Pb by soils. The consistently greater Pb uptake by surface over subsurface samples was apparently due to differences in organic matter content, inasmuch as organic matter removal from both resulted in similar adsorption characteristics. All five soils stooled exhibited a pH-dependent trend of adsorption. The extent of Pb adsorption was least at low pH values(4~5), was maximum in the neutral pH range, and leveled off or diminished under more alkaline conditions. There was no strong correlation between Pb uptake and soil cation exchange capacity as routinely measured by the NH$_4$OAc method. A knowledge of clay mineralogy in conjunction with soil pH is suggested as being the most reliable guide to predicting Pb retention by soils.