• The Journal of Pediatrics of Korean Medicine
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• v.20 no.1
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• pp.109-135
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• 2006

Objective : In the present study, the author tried to investigate whether six oriental medical prescriptions named gamisingitang (SGT), gamijungtang (IJT), gamicheongpyetang (CPT), galhwengchihyosan (CHS), chwiyeontong (CYT), sigyoungcheongpyetang (SCPT) significantly affect mucin release from cultured hamster tracheal surface epithelial (HTSE) cells. Methode : Confluent HTSE cells were inetabolically radiolabeled with $^{3}H-glucosamine$ for 24 hrs and chased for 30 min in the presence of drugs aforementioned, respectively, to assess the effect of each drug on $^{3}H-mucin$ release. Possible cytotoxicities of effective drugs were assessed by measuring lactate dehydrogenase(LDH) release. Additionally, total elution profiles of control spent media and treatment sample (CPT, CHS, SCPT and CYT) through Sepharose CL-4B column were analysed and effect of CPT, CHS and CYT on MUC5AC mRNA expression in cultured HTSE cells were invsetigated. Results : (1) SGT and IJT did not affect mucin release without cytotoxicity; (2) CPT, SCPT and CHS significantly stimulated mucin release from cultured HTSE cells, with significant cytotoxicity; (4) CPT, CHS, SCPT and CYT chiefly affected the 'mucin' release and did not affect significantly the release of the releasable glycoproteins with less molecular weight than mucin. This result suggests that the four herbal prescriptions specifically affect the release of mucin ; (5) CTP and CHS did not significantly affect the expression levels of MUC 5AC mRNA, however, CYT significantly inhibit the expression levels of MUC 5AC mRNA. Conclusion : CYT can decrease the synthesis of mucin at gene level in cultured HTSE cells.

• Archives of Pharmacal Research
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• v.28 no.4
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• pp.493-501
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• 2005

Effect of solvents on physical characteristics and release characteristics of monolithic acetaminophen (APAP) hydroxypropylmethylcellulose (HPMC) matrix granules and tablets were examined. Various types and amounts of solvents were employed for granulation and coating. APAP and other excipients were mixed and were then wet-granulated in a high-speed mixer. The dried granules were then directly compressed and film-coated with low viscosity grade HPMC. As the amount of water increased, the size of granules also increased, showing more spherical and regular shape. However, manufacturing problems such as capping and lamination in tableting occurred when water was used alone as a granulating solvent. The physical properties of HPMC matrix granules were not affected by the batch size. The initial release rate as well as the amount of APAP dissolved had a tendency to decrease as the water level increased. Addition of nonaqueous solvent like ethanol to water resulted in good physical properties of granules. When compared to water/ethanol as a coating solvent, the release rate of film-coated HPMC matrix tablets was more sensitive to the conditions of coating and drying in methylene chloride/ethanol. Most of all, monolithic HPMC matrix tablet when granulated in ethanol/water showed dual release with about $50\%$ drug release immediately within few minutes followed by extended release. It was evident that the type and amount of solvents (mainly water and ethanol) were very important for wet granulation and film-coating of monolithic HPMC matrix tablet, because the plastic deforming and fragmenting properties of material were changed by the different strengths of the different solvents.

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.81-91
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• 2012

In this study, it is grasped the status of nutrients through an investigation of release characteristics and physicochemical properties of sediments on reservoir. And then the effect of sediments is evaluated on the water quality in reservoir. In the results of physicochemical analysis, the pollution level of midstream is the highest, which shows the traits that the water is more deeper and takes place a deposition consistently. Then, the pollution level of upstream is higher than downstream's because inflow has influence on the upstream directly. The downstream is located near tidal gate so that the soil particles can be moved easily and are difficult to be deposited due to the distribution of seawater by control of tidal gate. Therefore, the downstream is showed the lowest pollution level than the others. Also, the concentration of SOD(Sediment Oxygen Demand) in the upstream which is influenced on the effect of inflow is highest than the others. When it analyzes under anaerobic and aerobic condition to understand the release characteristic of sediment, it shows that the release rate is low or negative under the aerobic condition. Whereas the release rate is usually positive under the unaerobic condition relatively. According to these results, it is necessary to maintain the proper environmental factors of water body for decreasing the release rate of sediment. Because the release rate is changeable under the different condition of water body. Therefore, proper strategies are required for increasing the self-purification of water as well as keeping the aerobic condition of sediment and managing a sediment layer directly to control the inner-pollution by the sediment of reservoir.

• YAKHAK HOEJI
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• v.31 no.1
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• pp.25-32
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• 1987

The effect of loading dose, plasticiser and PVA molecular weight on naproxen release from hydrophilic polymer matrix was examined. Hydrophilic polymer matrix was prepared with PVA and PVP by adding glycerine as plasticiser. The release of naproxen from polymer matrix was determined in phosphate buffer medium. The release rate of naproxen from the polymer matrix increased as drug loading dose and plasticiser percentage increased. Raproxen released from the polymer matrix showed the time square root kinetics. Without changing the release-pattern, the release rate of naproxen could not be changed by varying molecular weight of PVA. Linearly released time range increased as drug loading dose increased, whereas decreased as plasticiser percentage increased up to 30%.

• International Journal of Air-Conditioning and Refrigeration
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• v.17 no.1
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• pp.25-31
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• 2009

Supercooled type ice storage system with aqueous solution (or water) may have trouble with non-uniform release of supercooling even though it contributes to the simplicity of system and ecological improvement. The non-uniform release increases the instability of the system because it may cause an ice blockage in pipe or cooling part. In order to suppress the release of the supercooling, a cooling experiment was tried to an ethylene glycol(EG) 3 mass% solution corresponding with pressurization. Also, the frequency ratio of the release of the supercooling was measured to the pressurization from 101 to 505 kPa. At results, the frequency ratio of supercooling release tends to decrease as the pressure of the aqueous solution increased in each cooling rate. Moreover, it tends to decrease as the cooling rate of the solution decreased in each pressure.

• Macromolecular Research
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• v.12 no.1
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• pp.71-77
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• 2004

We have synthesized various types of poly(ethylene glycol) (PEG)-ibuprofen conjugates by nucleophilic substitution of bromo-terminated PEG with ibuprofen-Cs salt. The conversion of the terminal hydroxyl groups to bromo-termini was quantitative, as was the drug conjugation process, which suggests that the present synthetic method is very useful for the preparation of PEG-based prodrugs from pharmaceuticals having carboxyl functionalities. The drug-release behavior of the prodrugs was examined in both phosphate buffer (PBS, pH 7.4) and rat plasma. From the drug-release behavior in PBS, we determined that each prodrug has high storage stability. The drug-release rate was observed to be much faster in rat plasma than in buffer solution as a result of the acceleration effect provided by enzymes present in the plasma. The drug-release rate in rat plasma depends on the degree of molecular aggregation of the prodrugs, which can be changed effectively by the nature of their spacer groups or by the use of Pluronic as the polymer carrier.

• YAKHAK HOEJI
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• v.31 no.5
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• pp.286-295
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• 1987

The relationship between in vitro release and in vivo bioavailability of acetaminophen from suppositories was investigated. Effect of glycyrrhizin on the drug release and rectal absorption in rats was also examined. Suppositories containing 25mg of acetaminophen were prepared with Wecobee FS (fatty base) or PEG (water-soluble base) bases. The release from the suppositories were determined with USP rotating basket dissolution apparatus and with the suppository release tester. The temperature of the dissolution medium was very critical for the dissolution of acetaminophen from Wecobee FS suppositories. The bioavailability of acetaminophen was calculated from the plasma concentration-time curve after rectal administration of the suppositories to the rats. There were no significant differences in AUC following rectal administration of Wecobee FS and PEG suppositories, but the release and absorption from the Wecobee FS suppositories were faster than those from PEG suppositories. The dissolution rate obtained by the suppository release tester was better correlated with in vivo absorption rate constant than that by the USP dissolution apparatus. It suggests that the partitioning between rectal fluid and suppository base is the rate-limiting step in the rectal absorption of acetaminophen from suppositories. Glycyrrhizin was found not to affect in vitro dissolution and rectal absorption of acetaminophen.

• Journal of Korean Society on Water Environment
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• v.18 no.2
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• pp.213-220
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• 2002

In this study the effects of initial pH, temperature, dissolved oxygen concentration, and sediment depth on the release of phosphorus from sediment in Lake Sihwa were investigated. No phosphorus release occurred at $10^{\circ}C$ for all pH values. DO concentrations were decreased and equilibrium was obtained 4-8 days after phosphorus release started. The DO concentrations were less than 1 mg/L. Sediment depth had little effect on phosphorus release rate. In order to control the released phosphorus, raw sludge and chalk were used. Results showed that a portion of phosphorus was removed by adsorption to chalk and raw sludge. About 90 % phosphorus removal was observed using sludge and calcinated chalk from the water sample in Lake Sihwa.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.379-388
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• 2011

The mechanism by which gonadotropin-releasing hormone (GnRH) and dopamine (DA) control gonadotropin (GTH) release was studied in male and female rainbow trout using cultured pituitary cells obtained at different reproductive stages. The mechanisms of follicle-stimulating hormone (FSH) release by GnRH and DA could not be determined yet. However, basal and salmon-type GnRH (sGnRH)- or chicken-II-type GnRH (cGnRH-II)- induced luteinizing hormone (LH) release increased with gonadal maturation in both sexes. LH release activity was higher after sGnRH stimulation than cGnRH-II stimulation at maturing stages in both sexes. The GnRH antagonist ([Ac-3, 4-dehydro-$Pro^1$, D-p-F-$Phe^2$, D-$Trp^{3,6}$] GnRH) suppressed LH release by sGnRH stimulation in a dose-dependent manner, although the effect was weak in maturing fish. The role of DA as a GTH-release inhibitory factor differs during the reproductive cycle: the inhibition of sGnRH-stimulated LH release by DA was stronger in immature fish than in maturing, ovulating, or spermiated fish. DA did not completely inhibit sGnRH-stimulated LH release, and DA alone did not alter basal LH release. Relatively high doses ($10^{-6}$ or $10^{-5}M$) of domperidone (DOM, a DA D2 antagonist) increased LH release, which did not change with reproductive stage in either sex. The potency of DOM to enhance sGnRH-stimulated LH release was higher in maturing and ovulated fish than in immature fish. These data suggest that LH release from the pituitary gland is controlled by dual neuroendocrine mechanisms by GnRH and DA in rainbow trout, as has been reported in other teleosts. The mechanism of control of FSH release, however, remains unknown.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.5
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• pp.573-580
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• 1997

In this report, the inhibitory action of eupatilin was investgated by using leukotriene $D_4$ in the human neutrophils and Kato III cells (Gastric adenoma cells as a substitute for gastric mucosal cells) stimulated by Helicobacter pylori. Leukotriene $D_4$ ($LTD_4$) was released from both neutrophils and Kato III cells when these cells were incubated with H. pylori. The release of $LTD_4$ increased time-dependently and the maximum release of $LTD_4$ was $2.3{\sim}2.5$ pmol. But in the presence of eupatilin, the release of $LTD_4$ from these cells was inhibited in a dose-dependent manner. In the neutrophils, the release of $LTD_4$ was suppressed to 70% and 50% of the control levels when neutrophils was incubated with 0.01 and 0.1 mM of eupatilin. In the Kato III cells, the release of $LTD_4$ was suppressed to 59% and 27% of the control levels by adding 0.01 and 0.1 mM of eupatilin. We estimated the intracellular $Ca^{2+}$ levels when Kato III cells and neutrophils were stimulated by H. pylori using $^{45}Ca$. But the suppressive effect of eupatilin on $Ca^{2+}$ influx into these cells was not significant. We also obtained the results that H. pylori induced $Ca^{2+}$ influx into these cells by confocal microscopy, however there was no differences in the dose level of eupatilin. These results were confirmed by 1H Nuclear Magnetic Resonance(NMR) spectroscopy. The NMR patterns of eupatilin in the absence of $Ca^{2+}$ was changed compare with when $Ca^{2+}$ was present, but its effect was not strong.