• Journal of Electrochemical Science and Technology
• /
• 제3권2호
• /
• pp.90-94
• /
• 2012

A simple and sensitive electrochemical sensor for simultaneous and quantitative detection of ranitidine (RT) and metronidazole (MT) was developed, based on a poly(thionine)-modified anodized glassy carbon electrode (PTH/GCE). The modified electrode showed the excellent electrocatalytic activity towards the reduction of both RT and MT in 0.1M phosphate buffer solution (PBS, pH 7.0). The peak-to-peak separations (${\Delta}E_p$) for the simultaneous detection of RT and MT between the two reduction waves in CV and DPV were increased significantly from ca. 100 mV at anodized GCE, to ca. 550 mV at the PTH/GCE. The reduction peak currents of RT and MT were linear over the range from 35 to $500{\mu}M$ in the presence of 200 and $150{\mu}M$ of RT and MT, respectively. The sensor showed the sensitivity of 0.58 and $0.78{\mu}A/cm^2/{\mu}M$ with the detection limits (S/N = 3) of 1.5 and $0.96{\mu}M$, respectively for RT and MT.

• KSBB Journal
• /
• 제17권1호
• /
• pp.38-43
• /
• 2002

중금속 결합 단백질인 metallothionein (MT)를 발현하는 CUP1 유전자를 다중으로 함유하는 재조합 Saccharomyces cerevisiae의 균체성장과 중금속 제거특성을 조사하였다. CUP1 유전자를 다중으로 함유하는 재조합 효모는 중금속을 포함한 배지에서의 균체성장과 중금속 흡착능이 중금속에 대하여 내성을 가지고 있는 야생효모나 숙주세포에 비하여 우수하였다. 서로 다른 플라스미드를 함유하는 중금속을 함유하는 배지에서의 균체성장과 중금속 흡착능의 차이는 중금속에 대한 내성과 중금속 흡착에 MT 단백질의 발현 수준이 중요한 영향을 미치는 것으로 추정되었다. 구리를 함유하지 않고 고농도의 아연과 망간을 함유하는 배지에서 재조합 효모는 높은 균체 농도와 중금속 제거능을 나타내었는데, 이는 MT 단백질을 발현하는 CUP1 promoter가 아연과 망간에 의해서도 발현이 유도된다는 것을 알 수 있었다. MT 단백질을 효율적으로 발현하여 재조합 효모에 의한 중금속 흡착을 최대화 할 수 있는 최적의 구리농도는 0.31 mM로 결정되었으며, 비이온계 계면활성제인 Triton X-100은 재조합 효모의 균체성장과 중금속 흡착을 증가시켰지만, 대사 저해제는 균체성장과 중금속 흡착을 모두 저해하였다.

• Animal cells and systems
• /
• 제5권3호
• /
• pp.263-266
• /
• 2001

Metallothionein (MT) is induced in the regenerating rat liver. We have investigated expression of MT gene by RT PCR as well as specific localization of MT by immunocytochemistry in regenerating rat liver after partial hepatectomy (PH). MT mRNA level started to increase from 1 h and reached the peak at 8 h after PH. The level decreased gradually by 24 h, and became similar to that of control group. In the immunocytochemical study, in all groups treated with primary antibody, immunogold particles indicating the presence of MT were evenly distributed throughout both cytoplasm and nucleus of the rat hepatocytes. Within the nucleus, the gold particles appeared to be intensely localized in the areas of euchromatin and nucleolus. Within the cytoplasm, gold particles did not seem to adhere to mitochondria or Iysosomes, but were freely distributed. However, rough endoplasmic reticulum was the obvious compartment on which the gold particles were localized. Time course of MT immunoreactivity revealed that distribution of gold particles in hepatocytes increased gradually by 24 h, and decreased at 48 h after PH. Briefly, PH resulted in the sharpest increase in the expression of MT mRNA at 8 h and in the immunoreactivity of MT at 24 h, respectively. It is suggested that the increase of MT mRNA expression, the intensity of immunoreactivity and the specific localization of MT may be associated with the compensatory cell proliferation followed by PH.

• Korean Journal of Radiology
• /
• 제23권11호
• /
• pp.1055-1066
• /
• 2022

Objective: The clinical relevance of myosteatosis has not been well evaluated in patients with pancreatic ductal adenocarcinoma (PDAC), although sarcopenia has been extensively researched. Therefore, we evaluated the prognostic value of muscle quality, including myosteatosis, in patients with resectable PDAC treated surgically. Materials and Methods: We retrospectively evaluated 347 patients with resectable PDAC who underwent curative surgery (mean age ± standard deviation, 63.6 ± 9.6 years; 202 male). Automatic muscle segmentation was performed on preoperative computed tomography (CT) images using an artificial intelligence program. A single axial image of the portal phase at the inferior endplate level of the L3 vertebra was used for analysis in each patient. Sarcopenia was evaluated using the skeletal muscle index, calculated as the skeletal muscle area (SMA) divided by the height squared. The mean SMA attenuation was used to evaluate myosteatosis. Diagnostic cutoff values for sarcopenia and myosteatosis were devised using the Contal and O'Quigley methods, and patients were classified according to normal (nMT), sarcopenic (sMT), myosteatotic (mMT), or combined (cMT) muscle quality types. Multivariable Cox regression analyses were conducted to assess the effects of muscle type on the overall survival (OS) and recurrence-free survival (RFS) after surgery. Results: Eighty-four (24.2%), 73 (21.0%), 75 (21.6%), and 115 (33.1%) patients were classified as having nMT, sMT, mMT, and cMT, respectively. Compared to nMT, mMT and cMT were significantly associated with poorer OS, with hazard ratios (HRs) of 1.49 (95% confidence interval, 1.00-2.22) and 1.68 (1.16-2.43), respectively, while sMT was not (HR of 1.40 [0.94-2.10]). Only mMT was significantly associated with poorer RFS, with an HR of 1.59 (1.07-2.35), while sMT and cMT were not. Conclusion: Myosteatosis was associated with poor OS and RFS in patients with resectable PDAC who underwent curative surgery.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권7호
• /
• pp.3409-3416
• /
• 2012

Aim: It is well known that polycyclic aromatic hydrocarbons (PAHs) such as benzo (a) pyrene have carcinogenic properties and may cause many types of cancers in human populations. Genetic susceptibility might be due to variation in genes encoding for carcinogen metabolizing enzymes, such as cytochrome P-450 (CYP450). Our study aimed to investigate the effect of genetic polymorphisms of CYP1A1 (m1 and m2) on genetic damage in 115 coal-tar workers exposed to PAHs at their work place. Methods: Genetic polymorphisms of CYP1A1 were determined by the PCR-RFLP method. Comet and buccal micronucleus assays were used to evaluate genetic damage among 115 coal tar workers and 105 control subjects. Results: Both CYP1A1 m1 and CYP1A1 m2 heterozygous and homozygous (wt/mt+mt/mt) variants individually as well as synergistically showed significant association (P<0.05) with genetic damage as measured by tail moment (TM) and buccal micronuclei (BMN) frequencies in control and exposed subjects. Conclusion: In our study we found significant association of CYP1A1 m1 and m2 heterozygous (wt/mt)+homozygous (mt/mt) variants with genetic damage suggesting that these polymorphisms may modulate the effects of PAH exposure in occupational settings.

• 한국미생물·생명공학회지
• /
• 제21권1호
• /
• pp.59-65
• /
• 1993

방선균 분리주 GMT 1153로부터 ts/NRK 세포의 형태를 변형된 세포형태에서 정상세포의 형태로 전환하는 활성물질을 분리, 정제하였다. 활성물질 MT 1155는 UV, IR, 1H-NMR, 13C-NMR, mass,원소분석 등의 기기분석을 통하여 항진균성 항암물질인 toyocamycin으로 동정되었다. MT 1155는 ts/NRK 세포의 형태전환에 대한 활성외에도 PKA 효소활성 저해와 CTLL 세포에 대한 세포독성이 있으나 K562 소포형성 억제 및 PKC 효소활성에 대한 저해효과도 없었다.

• Journal of Plant Biology
• /
• 제12권4호
• /
• pp.19-29
• /
• 1969

This study investigated the vertical distribution of the vegetation in Mt. Hanla of Quelpart Island from 1967 to 1969. According to the physiognomy and life form of plants, the following plant communities are observed and arranged tentatively from the foot to the top. A. North-facing slope. (1) Grass land(0∼600m) (2) Deciduous broad-leaved forest(600∼1200m) (3) Mixed forest(broad and needle leaved forest : 1200∼1300m) (4) Evergreen coniferous forest(1300∼1700m) (5) Scrub communities(1700∼1950m) B. South-facing slope. (1) Grass land(0∼700) (2) Deciduous broad-leaved forest(700∼1300m) (3) Mixed forest(1300∼1550m) (4) Evergreen coniferous forest (1550∼850m) (5) Scrub communities(1850∼1950m) D. West-facing slope. (1) Grass land(0∼650) (2) Deciduous brod-leaved forest(650∼1400m) (3) Mixed forest(1400∼1500m) (4) Evergreen coniferous forest(1500∼1750m) (5) Scrub communities(1750∼1950m) The relation of the geological map and vegetation are as follows: (1) In the region of lava of Mt. Hanla are mainly distribut4ed deciduous broad-leaved forest. (2) In the region of Mt. Hanla are mainly distributed scrub. (3) In the region of lava of Gogun-san are involved deciduous broad-leaved forest, scrub and grass land of Gaimi-Dung.

• Journal of Radiation Protection and Research
• /
• 제36권3호
• /
• pp.119-126
• /
• 2011

Mitochondrial DNA (mtDNA) deletion is a well-known marker for oxidative stress and aging, and contributes to harmful effects in cultured cells and animal tissues. mtDNA biogenesis genes (NRF-1, TFAM) are essential for the maintenance of mtDNA, as well as the transcription and replication of mitochondrial genomes. Considering that oxidative stress is known to affect mitochondrial biogenesis, we hypothesized that ionizing radiation (IR)-induced reactive oxygen species (ROS) causes mtDNA deletion by modulating the mitochondrial biogenesis, thereby leading to cellular senescence. Therefore, we examined the effects of IR on ROS levels, cellular senescence, mitochondrial biogenesis, and mtDNA deletion in IMR-90 human lung fibroblast cells. Young IMR-90 cells at population doubling (PD) 39 were irradiated at 4 or 8 Gy. Old cells at PD55, and H2O2-treated young cells at PD 39, were compared as a positive control. The IR increased the intracellular ROS level, senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal) activity, and mtDNA common deletion (4977 bp), and it decreased the mRNA expression of NRF-1 and TFAM in IMR-90 cells. Similar results were also observed in old cells (PD 55) and $H_2O_2$-treated young cells. To confirm that a increase in ROS level is essential for mtDNA deletion and changes of mitochondrial biogenesis in irradiated cells, the effects of N-acetylcysteine (NAC) were examined. In irradiated and $H_2O_2$-treated cells, 5 mM NAC significantly attenuated the increases of ROS, mtDNA deletion, and SA-${\beta}$-gal activity, and recovered from decreased expressions of NRF-1 and TFAM mRNA. These results suggest that ROS is a key cause of IR-induced mtDNA deletion, and the suppression of the mitochondrial biogenesis gene may mediate this process.

• Environmental Analysis Health and Toxicology
• /
• 제18권1호
• /
• pp.15-19
• /
• 2003

Metallothionein gene expression activity of cadmium was investigated in a human lung epithelial cell line. Cells, grown to near confluence, were exposed to 0∼10 ${\mu}$M Cd metal for 6 hours. Cadmium did not cause morphological alteration in lung epithelial cells that are characteristic of cell damages such as cell shrinkage, detachment of the cell from its neighbors, cytoplasmic and chromatic condensation. However, metallothionein genes of MT-1 and MT-2 were rapidly induced in the treated cell measured by RT-PCR. Regarding the induction pattern of motallothionein mRNA, MT-1 mRNA was induced in a dependent manner. MT-2 mRNA induction, which was measured using oligo primers based on cDNA of human reticulocytes, seemed to be slightly increased in low doses but decreased at high concentration used in the experiment.

• Preventive Nutrition and Food Science
• /
• 제9권3호
• /
• pp.276-282
• /
• 2004

Marginal Zn deficiency is prevalent through the world and yet human zinc status has not been properly assessed due to the lack of a reliable diagnostic indicator. One potential possibility for zinc status assessment using Zn-binding protein, metallothionein (MT)-mRNA, has been proposed. The purpose of the present study was aimed to show whether measurement of mononuclear cell (MNC) MT mRNA, using a competitive-reverse transcriptase-polymerase chain reaction (competitive-RT-PCR) assay, could indicate zinc status in human subjects. In this study, MNC MT-mRNA expression was measured using a competitive-RT-PCR to compare before and after 14 days of zinc supplementation (50 mg Zn/das zinc gluconate). RT-PCR oligonucleotide primers which were designed to amplify both a 278 bp segment of the human MT-2A cDNA and a 198 bp mutant competitor cDNA template from MNCs, were prepared. MT-2A mRNA was normalized by reference to the housekeeping gene, $\beta$-actin, mRNA for which was also measured by competitive-RT-PCR. There was considerable inter-individual variation in MT-mRNA concentration and yet, the mean MT-2A mRNA level increased 4.7-fold after Zn supplementation, as compared to before Zn supplementation. This MT-2A mRNA level was shown as the same pattern and, even more sensitive assay, compared to the conventional plasma and red blood cells (RBCs) Zn assessment in which plasma and RBCs zinc levels increased 2.3- and 1.2-fold, respectively (p<0.05). We suggest that MT competitive-RT-PCR can be a useful assessment tool for evaluating human zinc status.