• Korean Journal of Weed Science
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• v.12 no.3
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• pp.261-270
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• 1992

Many herbicides that are applied at the soil before weed emergence inhibit plant growth soon after weed germination occurs. Plant growth has been known as an irreversible increase in size as a result of the processes of cell divison and cell enlargement. Herbicides can influence primary growth in which most new plant tissues emerges from meristmatic region by affecting either or both of these processes. Herbicides which have sites of action during interphase($G_1$, S, $G_2$) of cell cycle and cause a subsequent reduction in the observed frequency of mitotic figures can be classified as an inhibitor of mitotic entry. Those herbicides that affect the mitotic sequence(mitosis) by influencing the development of the spindle apparatus or by influencing new cell plate formation should be classified as causing disruption of the mitotic sequence. Sulfonylureas, imidazolinones, chloroacetamides and some others inhibit plant growth by inhibiting the entry of cell into mitosis. The carbamate herbicides asulam, carbetamide, chlorpropham and propham etc. reported to disrupt the mitotic sequence, especially affecting on spindle function, and the dinitroaniline herbicides trifluralin, nitralin, pendimethalin, dinitramine and oryzalin etc. reported to disrupt the mitotic sequence, particularly causing disappearence of microtubles from treated cells due to inhibition of polymerization process. An inhibition of cell enlargement can be made by membrane demage, metabolic changes within cells, or changes in processes necessary for cell yielding. Several herbicides such as diallate, triallate, alachlor, metolachlor and EPTC etc. reported to inhibit cell enlargement, while 2, 4-D has been known to disrupt cell enlargement. One potential danger inherent in the use of soil acting herbicides is that build-up of residues could occur from year to year. In practice, the sort of build-up that would be disastrous is unikely to occur for substances applied at the correct soil concentration. Crop injury caused by soil applied herbicides can be minimized by (1) following the guidance of safe use of herbicides, particularly correct dose at correct time in right crop, (2) by use of safeners which protect crops against injury without protecting any weed ; interactions between herbicides and safeners(antagonists) at target sites do occur probably from the following mechanisms (1) competition for binding site, (2) circumvention of the target site, and (3) compensation of target site, and another mechanism of safener action can be explained by enhancement of glutathione and glutathione related enzyme activity as shown in the protection of rice from pretilachlor injury by safener fenclorim, (3) development of herbicide resistant crops ; development of herbicide-resistant weed biotypes can be explained by either gene pool theory or selection theory which are two most accepted explanations, and on this basis it is likely to develop herbicide-resistant crops of commercial use. Carry-over problems do occur following repeated use of the same herbicide in an extended period of monocropping, and by errors in initial application which lead to accidental and irregular overdosing, and by climatic influence on rates of loss. These problems are usually related to the marked sensitivity of the particular crops to the specific herbicide residues, e.g. wheat/pronamide, barley/napropamid, sugarbeet/ chlorsulfuron, quinclorac/tomato. Relatively-short-residual product, succeeding culture of insensitive crop to specific herbicide, and greater reliance on postemergence herbicide treatments should be alternatives for farmer practices to prevent these problems.

• Journal of Oral Medicine and Pain
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• v.38 no.3
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• pp.221-233
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• 2013

Bile acids are polar derivatives of cholesterol essential for the absorption of dietary lipids and regulate the transcription of genes that control cholesterol homeostasis. Recently it have been identified the synthetic chenodeoxycholic acid (CDCA) derivatives HS-1200 and cisplatin showed apoptisis-inducing activity on various cancer cells in vivo and in vitro. This study was undertaken to investigate the synergistic apoptotic effect of co-treatment with HS-1200 and cisplatin on human tongue squamous cell carcinoma cells (SCC25 cells). To investigate whether the co-treatment with HS-1200 and cisplatin compared to each single treatment efficiently reduces the viability of SCC25 cells, MTT assay was conducted. The induction and augmentation of apoptosis were confirmed by DNA electrophoresis, Hoechst staining and an analysis DNA hypoploidy. Westen blot analysis and immunofluorescent staining were also performed to evaluate the expression levels and the translocation of apoptosis-related proteins following this co-treatment. Furthermore, proteasome activity and mitochondrial membrane potential (MMP) change were also assayed. In this study, co-treatment with HS-1200 and cisplatin on SCC25 cells showed several lines of apoptotic manifestation such as nuclear condensations, DNA fragmentation, reduction of MMP and proteasome activity, the increase of Bax and the decrease of Bcl-2, decrease of DNA content, the release of cytochrome c into cytosol, translocation of AIF and DFF40 (CAD) onto nuclei, and activation of caspase-9, caspase-7, caspase-3, PARP and DFF45 (ICAD) whereas each single treated SCC25 cells did not show these patterns. Although the single treatment of $25{\mu}M$ HS-1200 and $4{\mu}g/ml$ cisplatin for 24 h did not induce apoptosis, the co-treatment of these reagents prominently induced apoptosis. Therefore our data provide the possibility that the combination therapy with HS-1200 and cisplatin could be considered as a novel therapeutic strategy for human squamous cell carcinoma.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.228-236
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• 1999

Background: Thyrotoxic periodic paralysis is an uncommon illness characterized by intermittent flaccid paralysis of skeletal muscle, usually accompanied by hypokalemia, in patient with hyperthyroidism. However, the pathophysiology of thyrotoxic periodic paralysis remains largely unexplained and controversial. This report describes the clinical and biochemical findings in 19 patients with thyrotoxic periodic paralysis who were examined at the Yeungnam University Medical Center(YUMC) during the past decade. Methods: The medical records of 997 YUMC patients, seen between 1986 and 1996, with diagnosis of hyperthyroidism were reviewed. Nineteen patients out of 997 hyperthyroidism patients were diagnosed, and examined by history, physical examination, serum electrolyte value, and thyroid function test during paralysis. On the basis of these results, comparisons were made on age, sex, precipitating factors, timing, affected limbs, prognosis, serum potassium and serum phosphate and thyroid hormone levels. Results: The prevalence of periodic paralysis in hyperthyroidism was 1.9 percent and the male to female prevalence ratio was 30:1 and in all patients, the development of perodic paralysis was correlated with hyperfunctional state of the thyroid gland. Eleven cases of periodic paralysis were associated with hypokalemia and their thyroid hormone levels were significantly more increased than those of the patients without hypokalemia. Interestingly, our study shows the recurrence of paralysis after treatment. Conclusion: Although the precise pathophysiology of the disease is as yet undefined and controversial, it occurs primarily in Asians with an overwhelming male preponderance and prevalence of 2 percent in hyperthyroidism. The interactive roles of thyroid hormone, Na-K pump, and genetically inherited defect in the cellular membrane potential of the skeletal muscle can be speculated. Further investigation will be needed to firmly establish the mechanism of thyrotoxic periodic paralysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.184-190
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• 2016

We investigated the antioxidative and protective effects of corn silk (Zea mays L.) ethanol extracts on human HaCaT cells and erythrocytes. The NICS-2 fraction, extracted from corn silk, exhibited favorable 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging activities with $IC_{50}$valuesof$13.3{\pm}0.3{\mu}g/mL$ and $14.2{\pm}0.1{\mu}g/mL$ when compared with those of ${\alpha}$-tocopherol, a positive control, with $IC_{50}=10.4{\pm}02.2$ and $22.2{\pm}3.6{\mu}g/mL$, respectively. In addition, we investigated skin protection effects of NICS extracts of corn silk in HaCaT keratinocytes. To investigate the pharmacological potential of NICS-1 and NICS-2 extracts of corn silk on UV-B-induced damage in HaCaT cells, we measured the activity of interleukin (IL) 1a. Our results showed that all the corn silk extracts inhibited the UV-B-induced activity of IL-1a. In particular, NICS-1 extracts of corn silk significantly suppressed IL-1a activity in a dose-dependent manner without inducing cytotoxicity. These results indicate that the ethanol extracts of corn silk (Zea mays L.) could function as natural cytoprotective agents and antioxidants in biological systems, particularly the skin exposed to UV radiation, by protecting cellular membrane against reactive oxygen species (ROS).

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.452-460
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• 2018

This study was conducted to investigate the physiological activities of Houttuynia cordata extracts and fractions. H. cordata extracts were extracted with 50% ethanol and the ethyl acetate fractions were obtained from the extracts. Minimum inhibitory concentration (MIC) values of the ethyl acetate fraction for S. aureus and B. subtilis were $78{\mu}g/mL$ and $312{\mu}g/mL$, respectively, indicating the high activity against gram-positive bacteria. The free radical scavenging activity ($FSC_{50}$) for 1,1-diphenyl-2-picrylhydrazyl (DPPH) was higher in the ethyl acetate fraction with $12.00{\mu}g/mL$ compared to that of $27.15{\mu}g/mL$ for 50% ethanol extract. The total antioxidant activity ($OSC_{50}$) values for reactive oxygen species (ROS) produced in $Fe^{3+}-EDTA/H_2O_2$ system by a luminol-dependent chemiluminescence method were 2.91 and $0.983{\mu}g/ml$ for the 50% ethanol extract and ethyl acetate fraction, respectively. To investigate cellular protective effects on the HaCaT cell, the intracellular ROS scavenging activity was measured after UVB irradiation and the ethyl acetate fraction of H. cordata showed the activity in a concentration-dependent from $1.6{\mu}g/mL$ and a reduction rate of 54.3% at a maximum concentration of $12.5{\mu}g/mL$. Also, HaCaT cell protective effect against $H_2O_2$-mediated decreased the cell viability of the ethyl acetate fraction of H. cordata which significantly increased the cell viability from $0.8{\mu}g/mL$ and the maximum cell viability showed 86.9%. The ethyl acetate fraction of the H. cordata extracts was analyzed by TLC and HPLC. As a result, quercitrin, isoquercitrin, hyperoside, chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, rutin and afzelin were identified. From the above results, it was suggested that the extracts and fractions of H. cordata have a potential to be applied in the field of cosmetics as a natural antioxidant/preservative capable of protecting the cell membrane from the oxidative stress by eliminating ROS and exhibiting the antimicrobial effect.

• The Korean Journal of Physiology
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• v.18 no.2
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• pp.125-137
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• 1984

The effects of external $Ca^{2+}$ ana the inhibition of Na-pump on vanadate-induced contraction in isolated human and rat uterine smooth muscle were studied and the following results were observed. 1) Vanadate induced contraction in rat uterine muscle and showed maximal contraction at concentration of $5{\times}10^{-4}$M, and the contractile response to vanadate was more sensitive in human than rat uterine muscle. 2) Vanadate-induced contraction was not completely inhibited by $Ca^{2+}$ removal from PSS and the response to $Ca^{2+}$ removal was more sensitive in human than rat uterine muscle. 3) Vanadate-induced contraction decreased with increasing concentration of verapamil, but even in the presence of $3{\times}10^{-5}M$ verapamil which inhibited 100 K-induced contraction completely. about 40% of maximal contraction remained, and its amplitude was similar to that of contraction in $Ca^{2+}$-free solution. 4) Vanadate-induced contraction was increased by the inhibition of Na-pump and this increase also could be observed in the presence of $3{\times}10^{-5}M$ verapamil. 5) After pretreatment with $Ca^{2+}$-free PSS containing ouabain Vanadate-induced contraction was not increased, but the contractile response of these tissues to the addition of external $Ca^{2+}$ was remarkably increased in the presence of vanadate. 6) $3{\times}10^{-5}$M verapamil inhibited vanadate-induced $Ca^{45}$ influx completely, but after pretreatment with ouabain vanadate could induce remarkable $Ca^{45}$ influx even in the presence of verapmil. 7) With increasing the time of pretreatment with ouabain or $K^+$-free solution, the degree of increase in contraction by vanadate was more remarkable. 8) $10^{-4}M$ papaverine stowed a considerable inhibition of the increase in the vanadate-induced contraction by pretreatment with ouabain. 9) Acetylcholine-induced contraction increased with lengthening the duration of Na-pump inhibition even in the presence of verapamil. Considering above results it seems that the uterine muscle of human is more sensitive to vanadate than that of rat, and both internal and external $Ca^{2+}$ is utilized in vanadate·induced contraction. In the case of Na-pump inhibition several smooth muscle contracting agents seems to induce $Ca^{2+}$ influx which is not inhibited by verapamil. This $Ca^{2+}$ influx seems to be inhibited by papaverine and to be associated with membrane potential, although its precise characteristics is not certain.

• Journal of Life Science
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• v.21 no.7
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• pp.1032-1038
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• 2011

Recently identified Ciona intestinalis voltage sensor-containing phosphatase (Ci-VSP) consists of an ion channel-like transmembrane domain (VSD) and a phosphatase-like domain. Ci-VSP senses the change of membrane potential by its VSD and works as a phosphoinositide phosphatase by its phosphatase domain. In this study, we present the construction of His-tagged phosphatase-like domain of Ci-VSP, its recombinant expression and purification, and its enzymatic activity behavior in order to examine the biochemical behavior of phosphatase domain of Ci-VSP without interference. We found that Ci-VSP(248-576)-His can be eluted with an elution buffer containing 25 mM NaCl and 100 mM imidazole during His-tag purification. In addition, we found the proper measurement condition for kinetics study of Ci-VSP(248-576)-His against p-nitrophenyl phosphate (pNPP). We measured the kinetic constant of Ci-VSP(248-576)-His at $37^{\circ}C$, pH 5.0 or 5.5, under 30 min of reaction time, and less than $2.0\;{\mu}g$ of protein amount. With these conditions, we acquired that Ci-VSP(248-576)-His has $K_m$ of $354{\pm}0.143\;{\mu}M$, $V_{max}$ of $0.0607{\pm}0.0137\;{\mu}mol$/min/mg and $k_{cat}$ of $0.359{\pm}0.009751\;min^{-1}$ for pNPP dephosphorylation. Therefore, we produced a pure form of Ci-VSP(248-576)-His, and this showed a higher activity against pNPP. This purified protein will provide the road to a structural investigation on an interesting protein, Ci-VSP.

• Radiation Oncology Journal
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• v.22 no.2
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• pp.145-154
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• 2004

Purpose : To examine whether a synthetic bile acid derivatives (HS-1200) sensitizes the radiation-induced apoptosis in human breast cancer cells (MCF-7) and to investigate the underlying mechanism. Materials and Methods : Human breast cancer cells (MCF-7) in exponential growth phase were treated with HS-1200 for 24 hours at 37$^{\circ}C$ with 5$\%$ CO$_{2}$ in air atmosphere. After removal of HS-1200, cells were irradiated with 2$\~$8 Gy X-ray, and then cultured Ii drug-free media for 24-96 hours. The effect of radiation on the clonogenicity of MCF-7 cells was determined with clonogenic cell survival assay with 16$\mu$M of HS-1200. The induction of apoptosis was determined using agarose gel electrophoresis and Hoechst staining. The expression level of apoptosis-related molecules, such as PARP, Bax, Bcl-2, Bak and AIF, were assayed by Western blotting analysis with 40$\mu$M of HS-1200 combined with 8 Gy irradiation. To examine the cellular location of cytochrome c, bax and AIF immunofluorescent stainings were undertaken. Results : Treatment of MCF-7 cells with 40$\mu$M of HS-1200 combined with 8 Gy irradiation showed several changes associated with enhanced apoptosis by agarose gel electrophoresis and Hoechst staining. HS-1200 combined with 8 Gy irradiation treatment also enhanced production of PARP cleavage products and increased Bax/Bcl-2 ratio by Western blotting. Loss of mitochondrial membrane potential ($\Delta$$\psi$$_{m}$) and increased cytochrome c staining indicated that cytochrome c had been released from the mitochondria in HS-1200 treated cells. Conclusion : We demonstrated that combination treatment with a synthetic chenodeoxycholic acid derivative HS-1200 and irradiation enhanced radiation-induced apoptosis of human breast cancer cells (MCF-7). We suggest that the increased Bax/Bcl-2 ratio In HS-1200 co-treatment group underlies the increased radio sensitivity of MCF-7 cells. Further futures studies are remained elusive.

• Journal of Oral Medicine and Pain
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• v.32 no.3
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• pp.251-261
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• 2007

Bile acids and synthetic its derivatives induced apoptosis in various kinds of cancer cells and anticancer effects. Previous studies have been reported that the synthetic chenodeoxycholic acid (CDCA) derivatives showed apoptosis inducing activity on various cancer cells in vitro. It wasn't discovered those materials have apoptosis induced effects on YD9 human oral squamous carcinoma cells. The present study was done to examine the synthetic bile acid derivatives(HS-1199, HS-1200) induced apoptosis on YD9 cells and such these apoptosis events. We administered them in culture to YD9 cells. Tested YD9 cells showed several lines of apoptotic manifestation such as activation of caspase-3, degradation of DFF, production of poly (ADP-ribose) polymerase(PARP) cleavage(HS-1200 only), DNA degradation(HS-1200 only), nuclear condensation, inhibition of proteasome activity, reduction of mitochondrial membrane potential(HS-1200 only) and the release of cytochrome c and AIF to cytosol. Between two synthetic CDCA derivatives, HS-1200 showed stronger apoptosis-inducing effect than HS-1199. Therefore HS-1200 was demonstrated to have the most efficient antitumor effect. Taken collectively, we demonstrated that a synthetic CDCA derivative HS-1200 induced caspases-dependent apoptosis via mitochondrial pathway in human oral sqauamous carcinoma cells in vitro. Our data therefore provide the possibility that HS-1200 could be considered as a novel therapeutic strategy for human orall squamous carcinoma from its poweful apoptosis-inducing activity.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.141-152
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• 2020

The rapid on-site measurement of hydroponic nutrients allows for the more efficient use of crop fertilizers. This paper reports on the development of an embedded on-site system consisting of multiple ion-selective electrodes (ISEs) for the real-time measurement of the concentrations of macronutrients in hydroponic solutions. The system included a combination of PVC ISEs for the detection of NO₃, K, and Ca ions, a cobalt-electrode for the detection of H₂PO₄, a double-junction reference electrode, a solution container, and a sampling system consisting of pumps and valves. An Arduino Due board was used to collect data and to control the volume of the sample. Prior to the measurement of each sample, a two-point normalization method was employed to adjust the sensitivity followed by an offset to minimize potential drift that might occur during continuous measurement. The predictive capabilities of the NO₃ and K ISEs based on PVC membranes were satisfactory, producing results that were in close agreement with the results of standard analyzers (R² = 0.99). Though the Ca ISE fabricated with Ca ionophore II underestimated the Ca concentration by an average of 55%, the strong linear relationship (R² > 0.84) makes it possible for the embedded system to be used in hydroponic NO₃, K, and Ca sensing. The cobalt-rod-based phosphate electrodes exhibited a relatively high error of 24.7±9.26% in the phosphate concentration range of 45 to 155 mg/L compared to standard methods due to inconsistent signal readings between replicates, illustrating the need for further research on the signal conditioning of cobalt electrodes to improve their predictive ability in hydroponic P sensing.