• Development and Reproduction
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• v.4 no.1
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• pp.45-52
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• 2000

Membrane type matrix metalloproteinases(MT-MMPs) have been suggested to play an important role during structural remodeling of various tissue. Expression patterns of MT1-MMP and MT2-MMP mRNAs were investigated in oocytes, embryos, ovary and oviduct of mouse during their differentiation or periovulatory period using RT-PCR technique. Both cDNA products of MT1- and MT2-MMP of immature oocytes were barely discernable with a minimum amount but the expressions were distinct in mature oocytes regardless that they were matured in vivo or in vitro. MT2-MMP was not expressed by 2-cell embryos but was expressed by 4-cell stage embryos. From the morula stage untill hatched blastocyst stage, embyos showed intesnse expression of MT2-MMP with a sudden increase at blastocyst stage. While mouse ovarian tissues showed both expression of MT1- and MT2-MMP, there was no stage-specific difference throughout the estrous cycle. Mouse oviducts also exhibit constant amount of both MT1- and MT2-MMP expressions throughout periovulatory period, i.e., before or after ovulation. These observations lead to suggest that the differential expressions of maternal MT1- and MT2-MMP during meiotic resumption of mouse oocytes and embryonic expression of MT2-MMP particularly at blastocyst stage might play a role in the differentiation of mouse oocytes and／or embryos. The precise function of MT1- and MT2-MMP with regards to their participation in the remodeling of ovarian and oviductal tissues remains in a question.

• Journal of Aquaculture
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• v.8 no.3
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• pp.183-193
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• 1995

Blue tilapia, Oreochromis aureus swim-up fry were fed,0, 1, 10, or 60 ppm $17\alpha-methyltestosterone$(MT) for 30 days (sex reversal period). Fish that had been fed 0 ppm MT during the sex reversal period were subsequently fed 0 ppm MT (0-0), 10 ppm MT (0-10) or 60 ppm MT (0-60) for the next 57 days (post sex reversal period) ; fish that had been fed 60 ppm MT during the sex reversal period were subsequently fed 0 ppm MT (60-0), 10 ppm MT (60-10), or 60 ppm MT (60-60) during the post sex reversal period. One group was fed 1 ppm MT (1-1), while another group was fed 10 ppm MT (10-10) during the entire 87-day experiment. There was a significant inverse relationship between concentration of MT and percentage body protein and percentage body fat at the end of the sex reversal period, while there was a significant positive relationship between concentration of MT and percentage body moisture. MT treatment during the post sex reversal period had greater effects on body composition of males at the end of the post sex reversal period than did MT treatment during the sex reversal period. There was a significant inverse relationship between MT concentrations, during both the sex reversal and post sex reversal periods, and gonosomatic indices (GSI) in males. In females, there was a significant inverse relationship between MT concentrations during the post sex reversal period and GSI.

• Journal of Pharmaceutical Investigation
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• v.23 no.3
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• pp.9-18
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• 1993

Sugar spheres loaded with melatonin (MT) were coated with $Aquacoat^{\circledR}$ to control the release rate of MT over 8 hours. A zero-order release pattern over 8 hours was obtained with 20% coating on 8-10 mesh beads in USP basket dissolution studies. MT in 20% coated beads was quite stable at room temperature with less than 5% MT degraded during 6 months' storage. Dissolution profiles were also unchanged after 6 months. An oral preparation containing MT-loaded uncoated beads for immediate release and 20% coated beads with $Aquacoat^{\circledR}$ for controlled release over 8 hours was evaluated in six human subjects. When total 0.5 mg MT as low dose (immediate release portion of MT, 0.1 mg) was administered to four subjects, average peak plasma MT concentration was reached at about 600 pg/ml and maintained at about 10 pg/ml over 8 hours. Plasma MT concentration-time profiles were similar in shape to computer-simulated profiles. However, maximal plasma MT concentrations were three times greater compared to computer simulated curve. These results suggest that MT dose, ratio of immediate and controlled release MT, and pharmacokinetic parameters selected are adjusted to mimic endogenous MT concentration-time curve. In another study, 0.2 mg MT having 10% of immediate release portion and 80% controlled release portion produced plasma MT concentration-time curve which is more similar to endogenous profiles. A low bioavailability (<20%) may result from extensive first pass metabolism and remaining amounts of MT from controlled beads. A good correlation between plasma MT concentration and urinary excretion rate of 6-sulphatoxymelatonin (6-STMT), a major metabolite of MT was observed. As plasma MT concentration increased, urinary excretion rate of 6-STMT increased concomitantly. The linear relation between plasma MT and urinary excretion rate of 6-STMT was statistically significant. This result suggests that urinary 6-STMT may be used as an index of circadian rhythms of MT in humans.

• Animal Bioscience
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• v.34 no.3_spc
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• pp.405-416
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• 2021

Objective: This study evaluated the effects of feeding diets naturally contaminated with deoxynivalenol (supplemental 2 mg/kg) on health, growth, and the effects of a mycotoxin-detoxifying additive in newly-weaned pigs. Methods: Thirty-six pigs (27 day-old) were housed individually and assigned to 3 treatments for 5 weeks: CON (diet containing minimal deoxynivalenol), MT (diet with supplemental 1.9 mg/kg of deoxynivalenol), and MT+D (MT + mycotoxin-detoxifying additive, 0.2%, MegaFix, ICC, São Paulo, Brazil). The mycotoxin-detoxifying additive included bentonite, algae, enzymes, and yeast. Blood was taken at week 2 and 5. Jejunal tissue were taken at week 5. Data were analyzed using the MIXED procedure of SAS. Results: Pigs fed MT+D tended to have decreased (p = 0.056) averaged daily feed intake during week 1 than MT. At week 2, serum aspartate aminotransferase/alanine aminotransferase in MT tended to be lower (p = 0.059) than CON, whereas it was increased (p<0.05) for MT+D than MT, indicating hepatic damages in MT and recovery in MT+D. Pigs fed MT had lower (p<0.05) blood urea nitrogen/creatinine than CON, supporting hepatic damage. At week 5, pigs fed MT tended to have reduced (p = 0.079) glucose than CON, whereas it was increased (p<0.05) for MT+D than MT, indicating impaired intestinal glucose absorption in MT, which was improved in MT+D. Pigs fed CON tended to have increased (p = 0.057) total glutathione in jejunum than MT, indicating oxidative stress in MT. Pigs fed MT+D had a reduced (p<0.05) proportion of Ki-67-positive cells in jejunum than MT, indicating lower enterocyte proliferation in MT+D. Conclusion: Feeding supplemental 1.9 mg/kg of deoxynivalenol reduced growth and debilitated hepatic health of pigs, as seen in leakage of hepatic enzymes, impaired nitrogen metabolism, and increase in oxidative stress. The mycotoxin-detoxifying enhanced hepatic health and glucose levels, and attenuated gut damage in pigs fed deoxynivalenol contaminated diets.

• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.149-160
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• 2002

Analysis of benthic macroinvertebrate community structure and biological estimation of water quality by the benthic macroinvertebrates from the Mt. Myungji(1267m), Mt. Kalbong(840m), Mt. Daegeum(704m) and Mt. Jubal(489m) region of Gapyung-gun, Kyunggi-do were investigated from April to November, 2001. Total taxa of benthic macroinvertebrates were 105 species, 38 families, 13 orders, 5 classes in 4 phyla. Aquatic insects were 33 species in ephemeroptera, 5 species in odonata, 13 species in plecoptera, 2 species in hemiptera, 1 species in megaloptera, 27 species in trichoptera, 3 species in coleoptera and 13 species in diptera, respectively. Non-insects were 1 species in platyhelminthes, 5 species in gastropoda, 1 species in oligochaeta, 1 species in crustacea, respectively. Ephemeroptera, trichoptera and plecoptera as indicators in clean water were very abundantly. Occurrence species at each survey area was 67 species at Mt. Myungji and 69 species at Mt. Kalbong, 48 species at Mt. Daege.um and 47 species at Mt. Jubal, respectively. Mean species diversity indices at Mt. Myungji, Mt. Kalbong, Mt. Daegeum and Mt. Jubal were 3.30, 3.33, 2.59 and 3.43, respectively. According to the saprobic system based on the species diversity indices of benthic macroinvertebrates, Mt. Myungji, Mt. Kalbong and Mt. Jubal are determined as Limnosaprobic area, respectively, but Mt. Daegeum is determined as $\beta$-mesosaprobic area.

• Journal of Life Science
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• v.27 no.12
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• pp.1415-1420
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• 2017

The metallothionein (MT) gene (IbMT3) was selected from an EST library of suspension-cultured sweet potato cells. The MT gene, which is one of abundant ESTs in the library, is involved in stress regulation of cells and tissues. A full-length IbMT3 cDNA was obtained and analysis of its nucleotide sequence revealed that IbMT3 encoded a type 3 MT protein, based on its structural characteristics. The function of type 3 MT in plants is not yet known. Northern blot analysis showed stronger expression of IbMT3 in suspension-cultured cells than in sweet potato plant leaves. Since cell culture is known to impose a state of oxidative stress on cells, sweet potato plants were subjected to oxidative stress to investigate the transcriptional regulation of IbMT3. When the herbicide methyl viologen (MV) was administered for 6, 12, and 24 hr, IbMT3 transcription rapidly increased at 6 hr and then decreased. A cold treatment at $15^{\circ}C$ for 24 and 48 hr resulted in a gradual increase in IbMT3 expression. These findings indicate that IbMT3 expression is regulated in response to environmental and oxidative stress. IbMT3 isoform is expected to have antioxidant effects in sweet potato plants and may play an important role in cellular adaptation to oxidative stress.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.2
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• pp.126-140
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• 2011

Genetic determinants of two metallothionein isoforms (MT-A and MT-B) were isolated and characterized from the perciform species, rockbream (Oplegnathus fasciatus). Rockbream MT-A and MT-B shared a high degree of homology at amino acid levels with representative orthologs from other perciform species, especially with respect to the conserved cysteine residues. At the genomic level, both MT-A and MT-B genes represent a tripartite structure typical of vertebrate MT genes. However, rockbream MT-B showed unusually large introns (1.2 kb and 0.8 kb for intron I and II, respectively), a phenomenon that has rarely been seen in other vertebrate MT genes. MT-A and MT-B transcripts were ubiquitously detected in a wide array of tissues, wherein brain and eye showed the highest basal expression levels, and the fin exhibited the lowest expression of both isoforms. The basal expression of MT-A in most tissues was significantly higher (ranging from 4- to 10-fold) than that of MT-B. Upon heavy metal exposures to Cd, Cu or Zn at 25 ppb for 48 h, MT-A and MT-B transcripts in the liver were significantly activated by Cd and moderately by Zn. On the other hand, exposure to Cu did not result in alterations of MT-A, nor in the significant suppression of MT-B. Following bacterial challenges with Escherichia coli, Edwardsiella tarda or Streptococcus iniae, MT isoforms in the liver, kidney and spleen were highly modulated and exhibited a pattern that was dependent on the bacterial species, tissues and isoforms. These results suggest that the two MT isoforms could be taken into account as potential indicators of metal toxicity and immune perturbations of this aquaculture-relevant species.

• Journal of Plant Biology
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• v.4 no.2
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• pp.33-40
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• 1961

The moss flora and it's geoecological study were made on Mt. Odae which is situated in the easterm part(37$^{\circ}$43'N. Lat., 128$^{\circ}$30' E. Long) of Korea. The total number ofmosses collected on Mt. Odae in the autumn of 1960 is 50 species, 1 varieties and 1 subspecies, belonging to 23 families. For climate index, Warmth index and Humidity index were calculaterd on Mt. Odae. From the result, it was known that the climate of Mt. Odae is Humid temperate climate and that it's vegetation zone is Deciduous broad-leaf forest zone. Moss Quotient of this mountain is 1.21 and it indicates that the plant climate of Mt. Odae is Hemicryptophytic climate. The moss flora of this mountain was discussed from the pnytogeographical point of view. The flora consists of the following elements: Holarctic element : 20 species (38.5%) North Pacific element: 1 (1.9%) Cosmopolian element: 6 (11.6%) Tropical element: 1 (1.9%) East Asiatic element: 12 (23.05%) Korean-Japan element: 12 (23.05%) Coefficient of closeness was also calculated between the moss flora of Mt. Odae and that of Mt. Sulak and Mt. Kwanak. It was known, therefore, that the flora relation between Mt. Odae and the Mt. Sulak was closer than that between Mt. Odae and Mt. Kwanak.

• Journal of Life Science
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• v.31 no.12
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• pp.1057-1065
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• 2021

Alterations in mitochondrial DNA (mtDNA) copy numbers have been reported in patients with stomach cancer and suggested to play a role in gastric carcinogenesis or gastric cancer progression. However, changes in the levels of mitochondrial proteins or mtDNA-encoded oxidative phosphorylation (OXPHOS) proteins in gastric cancer remain unclear. In this study, we investigated mtDNA contents, mitochondrial protein levels, and mtDNA-encoded OXPHOS protein levels in gastric cancer tissues and cell lines. We correlated mtDNA copy numbers with clinicopathologic features of the gastric cancer samples used in this study and used quantitative PCR to analyze the mtDNA copy numbers of the gastric cancer tissues and cell lines. Western blot analysis was used for assessing the amounts of mitochondrial proteins and mtDNA-encoded OXPHOS proteins. Among the 27 gastric cancer samples, 22 showed a reduction in mtDNA copy numbers. The mtDNA content was increased in the other five samples relative to that in normal matched gastric tissues. Mitochondrial protein and OXPHOS protein levels were reduced in some gastric cancer tissues. However, mitochondrial protein and OXPHOS protein levels in gastric cancer cell lines were not always in line with their mtDNA contents. The mtDNA copy numbers were reduced in five gastric cancer cell lines tested in this study. In summary, this study reports a common reduction in mtDNA contents in gastric carcinoma tissues and cell lines, pointing to the possible involvement of mtDNA content alterations in tumorigenesis of the stomach.

• Geophysics and Geophysical Exploration
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• v.18 no.4
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• pp.232-240
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• 2015

Magnetotelluric (MT) survey investigates electrical structure of subsurface by measuring natural electromagnetic fields on the earth surface. For the accurate interpretation of MT data, the precise three-dimensional (3-D) modeling algorithm is prerequisite. Since MT responses are affected by electrical anisotropy of medium, the modeling algorithm has to incorporate the electrical anisotropy especially when analyzing time-lapse MT data sets, for monitoring engineered geothermal system (EGS) reservoir, because changes in different-vintage MT-data sets are small. This study developed a MT modeling algorithm for the simulation MT responses in the presence of electrical anisotropy by improving a pre-existing staggered-grid finite-difference MT modeling algorithm. After verifying the developed algorithm, we analyzed the effect of vertical transversely isotropic (VTI) anisotropy on MT responses. In addition, we are planning to extend the applicability of the developed algorithm which can simulate not only the horizontal transversely isotropic (HTI) anisotropy, but also the tiled transversely isotropic (TTI) anisotropy.