204 research outputs found

    Localization of (+)-Catechin in Picea abies Phloem : Responses to Wounding and Fungal Inoculation

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    To understand the positional and temporal defense mechanisms of coniferous tree bark at the tissue and cellular levels, the phloem topochemistry and structural properties were examined after artificially induced bark defense reactions. Wounding and fungal inoculation withEndoconidiophora polonicaof spruce bark were carried out, and phloem tissues were frequently collected to follow the temporal and spatial progress of chemical and structural responses. The changes in (+)-catechin, (-)-epicatechin, stilbene glucoside, and resin acid distribution, and accumulation patterns within the phloem, were mapped using time-of-flight secondary ion mass spectrometry (cryo-ToF-SIMS), alongside detailed structural (LM, TEM, SEM) and quantitative chemical microanalyses of the tissues. Our results show that axial phloem parenchyma cells of Norway spruce contain (+)-catechins, the amount of which locally increases in response to fungal inoculation. The preformed, constitutive distribution and accumulation patterns of (+)-catechins closely follow those of stilbene glucosides. Phloem phenolics are not translocated but form a layered defense barrier with oleoresin compounds in response to pathogen attack. Our results suggest that axial phloem parenchyma cells are the primary location for (+)-catechin storage and synthesis in Norway spruce phloem. Chemical mapping of bark defensive metabolites by cryo-ToF-SIMS, in addition to structural and chemical microanalyses of the defense reactions, can provide novel information on the local amplitudes and localizations of chemical and structural defense mechanisms and pathogen-host interactions of trees.Peer reviewe

    Effect of the GSTM1 Null Genotype on Glutathione S-Transferase (GST) Activity in Patients with Non-Viral Liver Tumors 

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    Glutathione S-transferase (GST) is a major phase II drug-metabolizing enzyme. Several isoforms of human GST as well as different GST genetic polymorphisms are known, but limited data exists concerning the relationship between GST polymorphisms and GST activity using 1-chloro-2,4-dinitrobenzene in human liver. To resolve this query, we analyzed the genetic polymorphisms of four main GST isoforms [GST mu 1 (GSTM1), GST theta 1 (GSTT1), GST alpha 1 (GSTA1), GST pi 1 (GSTP1)] and measured hepatic GST activity isolated from the same patients. We found that GSTM1 null individuals have significantly lower (P=0.0082) GST activity compared with GSTM1 positive individuals. No significant changes in GST activity were observed in individuals with GSTT1, GSTA1, and GSTP1 genotypes. Interestingly, the levels of GST activity exhibited were similar when compared with GSTA1*A/*A and GSTA1*A/*B, and GSTP1*A/*A and GSTP1*A/*B, respectively, if the genotype was GSTM1 null. Therefore, the genotypes of GSTA1*A/*B and GSTP1*A/*B individuals do not significantly affect the level of hepatic GST activity. An examination of the correlation between GST mRNA expression and GST activity subsequently revealed a significant correlation between GSTM1 mRNA levels and GST activity (r=0.626, P=0.007). These data are expected to facilitate research on the prediction of efficacy and safety of GSTM1 null-mediated drug metabolism and may establish whether genetic polymorphisms of the GST gene, specifically GSTM1, can act as a biomarker

    Localization, regulation, and function of metallothionein-III/growth inhibitory factor in the brain.

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    The metallothionein (MT) family is a class of low molecular, intracellular, and cysteine-rich proteins with a high affinity for metals. Although the first of these proteins was discovered nearly 40 years ago, their functional significance remains obscure. Four major isoforms (MT-I, MT-II, MT-III, and MT-IV) have been identified in mammals. MT-I and MT-II are ubiquitously expressed in various organs including the brain, while expression of MT-III and MT-IV is restricted in specific organs. MT-III was detected predominantly in the brain, and characterized as a central nervous system-specific isomer. The role of MTs in the central nervous system has become an intense focus of scientific research. An isomer of MTs, MT-III, of particular interest, was originally discovered as a growth inhibitory factor, and has been found to be markedly reduced in the brain of patients with Alzheimer's disease and several other neurodegenerative diseases. MT-III fulfills unique biological roles in homeostasis of the central nervous system and in the etiology of neuropathological disorders.</p

    A novel PCOS rat model and an evaluation of its reproductive, metabolic, and behavioral phenotypes

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    Background: Although animal models of PCOS have been used in many studies, none of them can reproduce both the reproductive and metabolic phenotypes of PCOS. In addition, behavioral parameters have not been evaluated in PCOS animal models. Purpose: We tried to produce an improved rat model of PCOS, and the reproductive, metabolic, and behavioral phenotypes of the model rats were evaluated. Methods: Female rats were implanted with silicon tubes containing oil-dissolved dihydrotestosterone (Oil-DHT) as a new PCOS model. Their phenotypes were compared with those of conventional PCOS model rats (DHT), into which tubes containing crystalline DHT were implanted, and non-DHT-treated rats (control). Results: Both the Oil-DHT and DHT rats showed greater body weight gain, food intake, and fat depot weight than the control rats. Furthermore, these groups showed fewer estrous stages and increased numbers of cystic follicles. The DHT rats exhibited lower ovarian and uterine weights than the control rats, whereas no such changes were observed in the Oil-DHT rats. The Oil-DHT and DHT rats showed less locomotor activity in the light phase than the control rats. Conclusions: Our proposed PCOS model reproduced both the reproductive and metabolic phenotypes of PCOS and may have potential for PCOS research

    Effects of land use on trophic states and multi-taxonomic diversity in Japanese farm ponds

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    金沢大学環日本海域環境研究センターFarm ponds are among the most biodiverse anthropogenic freshwater habitats because of their small size, shallow water depth, and aquatic vegetation. Land-use changes, such as converting riparian vegetation to human use or changing the management practices of farm ponds, are assumed to be major factors that change such ecosystems from a clear-water state to a turbid state, leading to deterioration of water quality and biodiversity in such ponds. Using the database of a large-scale pond survey, we evaluated the effects of surrounding land use (landscape factors and modern pond management practices), fish abundance, and other environmental variables on total phosphorus concentration and taxonomic richness patterns of six biological indicators associated with changes in the trophic state. Local- and landscape-level vegetation structure associated with land use and total fish abundance were among the factors influencing the total phosphorus concentration of farm ponds, a main driver of trophic state changes. In addition, a transition from a clear-water state to a turbid state was associated with lower taxonomic richness of aquatic plants, macroinvertebrates, and adult Odonata, and a higher taxonomic richness of phytoplankton and fish. Based on these results, we discuss potential land-use and pond management strategies for conserving and/or restoring the water quality and biodiversity of farm ponds through maintenance of a clear-water state. © 2017 Elsevier B.V.Embargo Period 24 month

    Biotin levels in blood and follicular fluid

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    It has been shown that biotin, a water-soluble vitamin (B7), plays roles in reproductive functions, such as oocyte maturation and embryo development, in experimental animals. On the other hand, little is known about the clinical effects of biotin on human reproduction. In this study, serum and follicular fluid biotin levels were measured in patients who underwent in vitro fertilization / intracytoplasmic sperm injection (IVF / ICSI), and their associations with reproductive outcomes were evaluated. As a result, biotin was detected in follicular fluid, as well as serum, and the biotin levels of follicular fluid were found to be positively correlated with those of serum. The biotin levels of serum were higher than those of follicular fluid, suggesting that biotin may be taken up into the follicular fluid from the blood. Although serum and follicular fluid biotin levels tended to be higher in pregnant patients than in non-pregnant patients, these data did not show the significant statistical difference. These findings indicate that biotin does not contribute to the maintenance of oocyte quality, and hence, it does not increase fertilization and pregnancy rates
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