• Journal of Korean Society on Water Environment
• /
• v.26 no.1
• /
• pp.116-124
• /
• 2010

While groundwater is the major source for drinking and irrigation purposes, arsenic (As) contamination of groundwater is a serious issue in Bangladesh. With a view to reduce As contamination in drinking water the guideline value recommended for Bangladesh is 0.05 mg/L. We assessed groundwater As in an As-affected Sadar Upazilla (small administrative unit) in the District (administrative unit) of Chapai Nabwabganj during 2006, where 50% hand tube well water were above the recommended limit (0.05 mg/L) during dry season. Almost 20% tube well waters were above the recommended limit during rainy season, perhaps due to the dilution of water table. The groundwater in Bangladesh contaminates surface soils and plants thereby As entering the food chain. In 2005, we examined the As levels in different rice varieties grown in different Districts of Bangladesh and the As concentrations in rice grain ranged from 0.07~1.12 mg/kg while the concentrations in 3 rice varieties were above the recommended limit (1 mg/kg rice grain) and the maximum concentration was 1.12 mg/kg rice grain in the rice variety BR 11. With few exceptions, the As content of rice grain in Bangladesh is not considered to be concentration of greater health concern as yet. We also observed enhanced root uptake, efficient root-to shoot translocation, and a much elevated tolerance through internal detoxification all contribute to As hyperaccumulation in a plant, ladder brake fern (Pteris vittata L.). But the phytoremediation technique might not be an appropriate tool to reduce the As calamity in the vast areas of Bangladesh. To mitigate the As problem of Bangladesh, better coordination among governmental agencies and many other organizations will be required to combat the disaster.

• Journal of Chest Surgery
• /
• v.44 no.2
• /
• pp.99-107
• /
• 2011

Background: Calcification is the most frequent cause of clinical failure of bioprosthetic tissues fabricated from GA-fixed porcine valves or bovine pericardium. A multi-factorial approach using different mechanisms was recently developed to reduce the calcification of bioprosthetic tissues. The purpose of the present study was to evaluate the synchronized synergism of using L-arginine and $NaBH_4$, compared with ethanol and L-lysine, in glutaraldehyde treated porcine pericardium from the standpoint of calcification and tissue elasticity. Materials and Methods: Porcine pericardium was fixed at 0.625% GA (7 days at room temperature after 2 days at $4^{\circ}C$). An interim step of ethanol (80%; 1 day at room temperature) or L-lysine (0.1 M; 2 days at $37^{\circ}C$) or L-arginine (0.1 M; 2 days at $37^{\circ}C$) was followed by completion of the GA fixation. A final step of NaBH4 (0.1 M; 2 days at room temperature) was followed. Their tensile strength, thickness, and thermal stability were measured. Treated pericardia were implanted subcutaneously into three-week-old Sprague-Dawley rats for 8 weeks. Calcium content was assessed by atomic absorption spectroscopy and histology. Results: L-arginine and $NaBH_4$ pretreatment ($1.81{\pm}0.39$ kgf/5 mm p=0.001, $0.30{\pm}0.08$ mm p<0.001) significantly increased tensile strength and thickness compared with the control ($0.53{\pm}0.34$ kgf/5 mm, $0.10{\pm}0.02$ mm). In a thermal stability test, L-arginine and $NaBH_4$ pretreatment ($84.25{\pm}1.12^{\circ}C$, p=0.023) caused a significant difference from the control ($86.25{\pm}0.00^{\circ}C$). L-lysine and $NaBH_4$ pretreatment ($183.8{\pm}42.6$ ug/mg, p=0.804), and L-arginine and $NaBH_4$ pretreatment ($163.3{\pm}27.5$ ug/mg, p=0.621) did not significantly inhibit calcification compared to the control ($175.5{\pm}45.3$ ug/mg), but ethanol and $NaBH_4$ pretreatment did ($38.5{\pm}37.3$ ug/mg, p=0.003). Conclusion: The combined pretreatment using L-arginine and $NaBH_4$ after GA fixation seemed to increase the tensile strength and thickness of porcine pericardium, fixed with GA. Additionally, it seemed to keep thermal stability. However it could not decrease the calcification of porcine pericardium fixed with GA. $NaBH_4$ pretreatment seemed to decrease the calcification of porcine pericardium fixed with GA, but only with ethanol.

• Applied Biological Chemistry
• /
• v.37 no.3
• /
• pp.194-202
• /
• 1994

To study the metabolism and absorption of endosulfan in carp, $^{14}C-{\alpha}-endosulfan$ was treated with the $LC_{10}$ concentration $(4.5\;{\mu}g/L)$. In an in vivo test, endosulfan was metabolized $(65{\sim}80%)$ in tissues and endosulfan ether, endosulfan alcohol, endosulfan ${\alpha}-hydroxyether$, and endosulfan lactone were identified, indicating that those are the main metabolites of detoxification in carp. The maximum levels of $^{14}C-endosulfan$ in the head, muscle, and gut occurred after 8 hr exposure. However, the maxima reached in the liver and kidneys after 30 min and 4 hr, respectively. Radioactivity in the tissue decreased rapidly 8 hr after treatment. The total amount of $^{14}C-endosulfan$ recovered in the liver, kidneys and gut of fish was about $80{\sim}90%$ during the 8 hr treatment. The non-extractable radioactivity increased after 8 hr exposure $(27{\sim}31%)$. Endosulfan sulfate, the main degradation product in plant and mouse, was not detected during the test interval from tissues of the carp.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.46 no.1
• /
• pp.40-46
• /
• 2001

Ozone ($O_3$)-induced changes in chlorophyll content and specific activities of antioxidant enzymes, such as superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) were investigated in two rice cultivars (Oryza sativa L.) grown under variable nutrient treatments. For this study, two rice cultivars of Ilpumbyeo (IL) and Keumobyeo#l (KM), which were known as resistant and susceptible to $O_3$, respectively, were exposed to $O_3$at 0.15ppm for 30 days and investigated with 10 days interval. The available nutrient regimes were varied by doubling the supply of nitrogen (N), phosphorus (P) and potassium (K) Within a basic fertilizer status (N, P, K; 15, 12, 12kg/l0a$^{-1}$ ). In both cultivars and at all nutrient status, chlorophyll content in $O_3$-treated plants decreased with prolonged treatment period, although higher N, P and K supply with $O_3$ treatment alleviated the decrease in chlorophyll content. The activities of almost all enzymes investigated for this study were decreased during initial stages of $O_3$- exposure except GPX which maintained higher activity throughout the exposure period than the non-treated plant. However, the antioxidant enzymes in $O_3$-treated plants showed almost the same or higher activities on 30 days after $O_3$ - exposure. The most significant changes in activities were observed in GR of the $O_3$-treated leaves. With the prolonged treatment period, the activity of GR at 30 days was increased by 3-8 times compared to those in 10 days. Most of the investigated enzymes showed very similar tendency to $O_3$ treatment in all fertilizer status. There was no observed evidence for enhanced detoxification of $O_3$-derived activated oxygen species in plants grown under higher fertilizer status compared with that in plants grown under basic fertilizer status. The increase in the activities of SOD, APX and GR in rice leaves by relatively long-term treatment with $O_3$ at low concentration is considered to indicate that the plant became adapted to the $O_3$ stress and the protection system increased its capacity to scavenge toxic oxygen species. Our results in two rice cultivars indicated that there was little difference in the activities of antioxidant enzymes between IL and KM, which were known as resistant and susceptible cultivar to $O_3$

• Journal of Life Science
• /
• v.15 no.3 s.70
• /
• pp.397-405
• /
• 2005

Sulforaphane, an isothiocyanate derived from hydrolysis of glucoraphanin in broccoli and other cruciferous vegetables, was shown to induce phase II detoxification enzymes and inhibit chemically induced mammary tumors in rodents. Recently, sulforaphane is known to induce cell cycle arrest and apoptosis in human cancer cells, however its molecular mechanisms are poorly understood. In the present study, we demonstrated that sulforaphane acted to inhibit proliferation and induce morphological changes of human cervical carcinoma HeLa cells. Treatment of HeLa cells with $10{\mu}M\;or\;15{\mu}M$ sulforaphane resulted in significant G2/M cell cycle arrest as determined by flow cytometry. Moreover, $20{\mu}M$ sulforaphane significantly induced the population of sub-G1 cells (9.83 fold of control). This anti-proliferative effect of sulforaphane was accompanied by a marked inhibition of cyclin A and cyclin-dependent kinase (Cdk)4 protein and concomitant induction of Cdc2, Cdk inhibitor p16 and p21. However, sulforaphane did not affect the levels of cyelooxygenases and telomere-regulatory gene products. Although further studies are needed, the present work suggests that sulforaphane may be a potential chemoprevetive/ chemotherapeutic agent for the treatment of human cancer cells.

• Journal of Periodontal and Implant Science
• /
• v.31 no.4
• /
• pp.749-763
• /
• 2001

Osseointegrated titanium implants have become an integral therapy for the replacement of teeth lost. For dental implant materials, titanium, hydroxyapatite and alumina oxide have been used, which of them, titanium implants are in wide use today. Titanium is known for its high corrosion resistance and biocompatability, because of the high stability of oxide layer mainly consists of $TiO_2$. With the development of peri-implantitis, the implant surface is changed in surface topography and element composition. None of the treatments for cleaning and detoxification of implant surface is efficient to remove surface contamination from contaminated titanium implants to such extent that the original surface elemental composition. In this sights, the purpose of this study was to evaluate rough surface titanium implants by means of scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS) with respect to surface appearance and surface elemental composition. Moreover, it was also the aim to get the base for treatments of peri-implantitis. For the SEM and XPS study, rough surface titanium models were fabricated for control group. Six experimental groups were evaluated: 1) long-time room exposure, 2 ) air-powder abrasive cleaning for 1min, 3) burnishing in citric acid(pH1) for 1min, 4) burnishing in citric acid for 3min, 5) burnishing in tetracycline for 1min, 6) burnishing in tetracycline for 3min. All experimental treatments were followed by 1min of rinsing with distilled water. The results were as follows: 1. SEM observations of all experimental groups showed that any changes in surface topography were not detected when compared with control group. (750 X magnification) 2. XPS analysis showed that in all experimental groups, titanium and oxygen were increased and carbon was decreased, when compared with control group. 3. XPS analysis showed that the level of titanium, oxygen and carbon in the experimental group 3(citric acid treatment for 1min, followed by 1min of distilled water irrigation) reached to the level of control group. 4. XPS analysis showed that significant differences were not detected between the experimental group 1 and the other experimental groups except of experimental group 3. The Ti. level of experimental group 2, airpowder abrasive treatment for lmin followed by 1min of saline irrigation, was lower than the Ti. level of tetracycline treated groups, experimental group 5 and 6. From the result of this study, it may be concluded that the 1min of citric acid treatment followed by same time of rinsing with distilled water gave the best results from elemental points of view, and can be used safely to treat peri-implantitis.

• Clinical and Experimental Reproductive Medicine
• /
• v.43 no.4
• /
• pp.193-198
• /
• 2016

Objective: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect. G6PD plays a key role in the pentose phosphate pathway, which is a major source of nicotinamide adenine dinucleotide phosphate (NADPH). NADPH provides the reducing equivalents for oxidation-reduction reductions involved in protecting against the toxicity of reactive oxygen species such as $H_2O_2$. We hypothesized that G6PD deficiency may reduce the amount of NADPH in sperms, thereby inhibiting the detoxification of $H_2O_2$, which could potentially affect their motility and viability, resulting in an increased susceptibility to infertility. Methods: Semen samples were obtained from four males with G6PD deficiency and eight healthy males as a control. In both groups, motile sperms were isolated from the seminal fluid and incubated with 0, 10, 20, 40, 60, 80, and $120{\mu}M$ concentrations of $H_2O_2$. After 1 hour incubation at $37^{\circ}C$, sperms were evaluated for motility and viability. Results: Incubation of sperms with 10 and $20{\mu}M\;H_2O_2$ led to very little decrease in motility and viability, but motility decreased notably in both groups in 40, 60, and $80{\mu}M\;H_2O_2$, and viability decreased in both groups in 40, 60, 80, and $120{\mu}M\;H_2O_2$. However, no statistically significant differences were found between the G6PD-deficient group and controls. Conclusion: G6PD deficiency does not increase the susceptibility of sperm to oxidative stress induced by $H_2O_2$, and the reducing equivalents necessary for protection against $H_2O_2$ are most likely produced by other pathways. Therefore, G6PD deficiency cannot be considered as major risk factor for male infertility.

• Proceedings of the Botanical Society of Korea Conference
• /
• 2002.04a
• /
• pp.62-72
• /
• 2002

This study has investigated the biosynthesis and function of the heavy metal binding peptides, the phytochelatins, in plants. PCs are synthesised enzymatically from glutathione by the enzyme PC synthase in the presence of heavy metal ions. Using Arabidopsis thaliana as a model organism cadmium-sensitive, phytochelatin-deficient mutants have been isolated and characterised in previous studies. The cadl mutants have wildtype levels of glutathione, are PC deficient and lack PC synthase activity. Thus, the CADl gene has been proposed to encode PC synthase. The CADl gene was isolated by a positional cloning strategy The gene was mapped and a candidate identified. Each of four cadl mutants had a single base pair change in the candidate gene and the cadmium-sensitive, cadl phenotype was complemented by the candidate gene. This demonstrated the CADl gene had been cloned. A homologous gene in the fission yeast, Schizosaccharomyces pombe was identified through database searches. A targeted-deletion mutation of this gene was constructed and the mutant, like cadl mutants of Arabidopsis, was cadmium-sensitive and PC-deficient. A comparison of the redicted amino acid sequences reveals a highly conserved N-terminal region Presumed to be the catalytic domain and a variable C-terminal region containing multiple Cys residues proposed to be involved in activation of the enzyme by metal ions. Similar genes were also identified in animal species. The Arabidopsis CADl/AtPCSl and S. pombe SpbPCS genes were expressed in E. coli and were shown to be sufficient for glutathione-dependent, heavy metal activate PC synthesis in vitro, thus demonstrating these genes encode PC synthase enzymes. Using RT-PCR, AtPCSl expression appeared to be independent of Cd exposure. However, at higher levels of Cd exposure a AtPCSl-CUS reporter gene construct appeared to be more highly expressed. Using the reporter gene construct, AtPCSl was expressed most tissues. Expression appeared to be greater in younger tissues and same higher levels of expression was observed in some regions, including carpels and the base of siliques. AtPCS2 was a functional gene encoding an active PC synthase. However, its Pattern of expression and the phenotype of a mutant (or antisense line) have not been determined. Assuming the gene is functional then it has clearly been maintained through evolution and must provide some selective advantage. This implies that, at least in some cells or tissue, it is likely to be the dominant PC synthase expressed. This remains to be determined

• Journal of Life Science
• /
• v.22 no.11
• /
• pp.1507-1514
• /
• 2012

Oxidative stress leads to damage in all components of the cell, including proteins, lipids, and DNA due to imbalance between reactive oxygen species production and cellular detoxification. Phytochemicals are well-known to contain antioxidants, and their physiological role has been intensively studied. The fruit of Cornus officianalis has been used in oriental medicine and has been reported to have many functions. In this study, four different extraction techniques were applied to extract functional components from the fruit of Cornus officianalis, and the content of loganin, which is an antioxidant having DPPH radical and hydrogen peroxide scavenging activity and reducing power, was analyzed in each extract. Extraction techniques employed in this study were heat extraction by water, 70% ethanol extraction, enzyme treatment, and combination of enzyme treatment and heat extraction by water. All extracts contained 11.8-18.0 mg/g loganin and showed antioxidation function assayed by measuring DPPH radical and hydrogen peroxide scavenging activity and reducing power. Among them, heat extraction was the most effective technique, showing a maximum amount of loganin (18.0 mg/g) and antioxidative activity at 100 mg/ml concentration. Each extract showed very low cytotoxicity up to at 500 mg/ml but 10-20% cytotoxicity at 1,000 mg/ml by in vitro MTT assay.

• Korean Journal of Microbiology
• /
• v.36 no.4
• /
• pp.279-284
• /
• 2000

Simultaneous reduction of Cr(VI) and degradation of phenol was observed in batch and bench-scale continuous stirred tank reactors using Rhodococcus sp. CP01 isolated from leachate. The strain CP01, which was capable of utilizing phenol as a sole source of carbon and energy, completely reduced added hexavalent chromium (0.25 mM) to its trivalent form during 60 hr batch assay under optimal conditions (pH 7.0 and 1,000 mg/L of phenol concentration). The rates of Cr(VI) reduction and phenol degradation were estimated as 4.17 $\mu$M Cr(VI) and 38.4 mg phenol.$L^{-1}{\cdot}hr^{-1}$, respectively. The continuous culture experiment was conducted for 46 days using synthetic feed containing different levels of chromate (0.0625 to 0.25 mM) and phenol(1,000 to 4,000 mg/L). With a hydraulic retention time of 100 hr, Cr(VI) reduction efficiency was mostly 100% for influent Cr(VI) and phenol concentrations of 0.125 mM and 3,000 mg/L, respectively. During quasi-steady-state operation, specific rate of Cr(VI) reduction was calculated as 0.34 mg Cr(VI).g $protein^{-1}{\cdot}hr^{-1}$ which was comparable to reported values obtained by using glucose as growth substrate. The results suggest the potential application of biological treatment for detoxification of wastewater contaminated simultaneously with Cr(VI) and pheonol.