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Abe S, Takahata Y, Miyakawa H. Daphnia uses its circadian clock for short-day recognition in environmental sex determination. Curr Biol 2024; 34:2002-2010.e3. [PMID: 38579713 DOI: 10.1016/j.cub.2024.03.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 02/12/2024] [Accepted: 03/14/2024] [Indexed: 04/07/2024]
Abstract
Some organisms have developed a mechanism called environmental sex determination (ESD), which allows environmental cues, rather than sex chromosomes or genes, to determine offspring sex.1,2,3,4 ESD is advantageous to optimize sex ratios according to environmental conditions, enhancing reproductive success.5,6 However, the process by which organisms perceive and translate diverse environmental signals into offspring sex remains unclear. Here, we analyzed the environmental perception mechanism in the crustacean, Daphnia pulex, a seasonal (photoperiodic) ESD arthropod, capable of producing females under long days and males under short days.7,8,9,10 Through breeding experiments, we found that their circadian clock likely contributes to perception of day length. To explore this further, we created a genetically modified daphnid by knocking out the clock gene, period, using genome editing. Knockout disrupted the daphnid's ability to sustain diel vertical migration (DVM) under constant darkness, driven by the circadian clock, and leading them to produce females regardless of day length. Additionally, when exposed to an analog of juvenile hormone (JH), an endocrine factor synthesized in mothers during male production, or subjected to unfavorable conditions of high density and low food availability, these knockout daphnids produced males regardless of day length, like wild-type daphnids. Based on these findings, we propose that recognizing short days via the circadian clock is the initial step in sex determination. This recognition subsequently triggers male production by signaling the endocrine system, specifically via the JH signal. Establishment of a connection between these two processes may be the crucial element in evolution of ESD in Daphnia.
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Affiliation(s)
- Shione Abe
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan
| | - Yugo Takahata
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan
| | - Hitoshi Miyakawa
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan.
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Takahata Y, Miyakawa H. Developmental Staging of Sexual Egg Formation in Daphnia pulex: Unmated Females Resorb Meiotic Oocytes to Resist Starvation. Zoolog Sci 2022; 39:407-412. [DOI: 10.2108/zs220010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/18/2022] [Indexed: 11/17/2022]
Affiliation(s)
- Yugo Takahata
- Center for Bioscience Research and Education, Utsunomiya University, 350 Mine-machi, Utsunomiya, Tochigi 321-8505, Japan
| | - Hitoshi Miyakawa
- Center for Bioscience Research and Education, Utsunomiya University, 350 Mine-machi, Utsunomiya, Tochigi 321-8505, Japan
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Yanai R, Takahata Y, Inomoto M. Development of new experimental setup focusing on long-pulse magnetic reconnection by using rotating magnetic field technique. Rev Sci Instrum 2018; 89:103506. [PMID: 30399850 DOI: 10.1063/1.5025714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 09/26/2018] [Indexed: 06/08/2023]
Abstract
A new closed-type experimental setup to achieve a long-pulse magnetic reconnection in weakly ionized plasmas was developed by using a rotating magnetic field (RMF) technique. The experimental setup has a cylindrical vacuum vessel in which two sets of four antennas are equipped to generate RMF which drives steady azimuthal electron current in two torus plasmas. This device provided a quasi-steady magnetic reconnection condition in weakly ionized plasmas with ionization fraction of less than 1%. The proposed experimental setup will extend the research area of laboratory reconnection experiments and be helpful to comprehend the reconnection process in weakly ionized plasmas such as solar chromosphere.
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Affiliation(s)
- R Yanai
- Graduate School of Engineering, The University of Tokyo, Bunkyo 113-8656, Japan
| | - Y Takahata
- Graduate School of Engineering, The University of Tokyo, Bunkyo 113-8656, Japan
| | - M Inomoto
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan
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Takahata Y. Estudos da instabilidade do íon H2O4+ pelo método CNDO/2. Eclet Quim J 2018. [DOI: 10.26850/1678-4618eqj.v4.1.1979.p17-28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Kusuda T, Hikino S, Ohga S, Kinjo T, Ochiai M, Takahata Y, Tokunaga S, Ihara K, Hata Y, Hara T. Genetic variation of vascular endothelial growth factor pathway does not correlate with the severity of retinopathy of prematurity. J Perinatol 2011; 31:246-50. [PMID: 20706192 DOI: 10.1038/jp.2010.111] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The aim of this study was to assess the genetic effects of the vascular endothelial growth factor (VEGF) pathway on retinopathy of prematurity (ROP). STUDY DESIGN A prospective study from a tertiary center that enrolled 204 Japanese infants (<35 weeks of gestational age (GA)) having no anomalies. ROP developed in 127, but not in 77 infants. The relative severity was defined as non-severe, moderate and severe ROP for GA, based on the staging criteria. VEGF (g.-634G>C, g.+13553C>T) and VEGF-receptor (KDR g.+4422(AC)11 to 14, Flt-1 c.+6724(TG)13 to 23) gene polymorphisms and clinical variables were assessed by uni/multivariate analyses. RESULT The frequency of polymorphisms did not differ between ROP and non-ROP patients. The TT genotype of g.+13553 showed a higher odds ratio for non-severe ROP than CC genotype (P=0.006). Multivariate analyses indicated that low birth weight, blood transfusion and respiratory distress syndrome, but not polymorphisms, were the risk factors of advanced ROP (≥ stage 3). CONCLUSION A genotype of the VEGF pathway weakly affects the severity of ROP compared with other clinical factors.
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Affiliation(s)
- T Kusuda
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Inoue H, Ihara K, Ochiai M, Takahata Y, Kohno H, Hara T. Congenital multiple pituitary hormone deficiency associated with hyperammonemia: a case report with a short review of the literature. J Perinatol 2011; 31:146-8. [PMID: 21283082 DOI: 10.1038/jp.2010.143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We herein report a case study of a female newborn with multiple pituitary hormone deficiencies who presented with generalized seizures, hypoglycemia and hyperammonemia at 18 h after birth. In addition, we review the association of hyperammonemia in neonates with multiple pituitary hormone deficiencies reported in the previous literature. This unrecognized association should be taken into account for the early diagnosis and treatment of these patients.
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Affiliation(s)
- H Inoue
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
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Takahata Y, Hiruma M, Shiraki Y, Tokuhisa Y, Sugita T, Muto M. Treatment of dermatophyte onychomycosis with three pulses of terbinafine (500 mg day−1for a week). Mycoses 2009; 52:72-6. [DOI: 10.1111/j.1439-0507.2008.01531.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wang KJ, Takahata Y, Kono Y, Kaizuma N. Allelic differentiation of Kunitz trypsin inhibitor in wild soybean (Glycine soja). Theor Appl Genet 2008; 117:565-73. [PMID: 18512041 DOI: 10.1007/s00122-008-0800-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Accepted: 05/12/2008] [Indexed: 05/26/2023]
Abstract
Soybean Kunitz trypsin inhibitor (SKTI) has several polymorphic types, which are controlled by co-dominant multiple alleles at a single locus. Of these types, Tia and Tib are predominant types, and there are nine differences in amino acids between Tia and Tib. Recently, an intermediate transitional type (Tibi5) between them was detected. However, other transitional types have not been detected despite surveys of many cultivated and wild soybeans. One of the reasons why other transitional variants have not been found is inferred to be due to the difficulty of the detection of SKTI protein variants by polyacrylamide gel electrophoresis (PAGE). To detect novel variants of SKTI, nucleotide sequence analysis in addition to PAGE was carried out. Four new variants were found from many Japanese wild soybeans. Of these variants, three (designated as Tiaa1, Tiaa2, Tiab1) were detected through gene sequence analysis on wild soybeans having the same electrophoretic mobility as Tia, and one (Tig) was detected through PAGE. The Tig variant showed a slightly lower electrophoretic mobility than Tic. The nucleotide sequences of Tig were identical to those of Tib except for one T-->C transitional mutation at position +340. The sequences of Tiaa1 and Tiaa2 genes were identical to those of Tia with the exception of a G-->A mutation at position +376 and a T-->C mutation at +404, respectively. The sequence of Tiab1 differed from Tia by three nucleotides: C-->A at position +331, T-->C at +459 and A-->G at +484. Of the three nucleotide changes, two were common to Tiab1, Tibi5 and Tib, suggesting that Tiab1 is an intermediate transitional type between Tia and Tib. Our results suggest that Tib type has been differentiated through a series of mutations from Tia before the domestication of cultivated soybean.
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Affiliation(s)
- K J Wang
- Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan
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Takahata Y, Sugita T, Kato H, Nishikawa A, Hiruma M, Muto M. Cutaneous Malassezia flora in atopic dermatitis differs between adults and children. Br J Dermatol 2007; 157:1178-82. [DOI: 10.1111/j.1365-2133.2007.08193.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Takahata Y, Sugita T, Hiruma M, Muto M. Quantitative analysis of Malassezia in the scale of patients with psoriasis using a real-time polymerase chain reaction assay. Br J Dermatol 2007; 157:670-3. [PMID: 17634085 DOI: 10.1111/j.1365-2133.2007.08090.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND It has been suggested that Malassezia is associated with the development of skin lesions in psoriasis because of the response of the scalp lesions in psoriasis to antifungal agents. Malassezia restricta and M. globosa are the two major members of the cutaneous Malassezia flora in patients with psoriasis, although they have not been analysed quantitatively. OBJECTIVES This study quantified the two major cutaneous Malassezia species in psoriatic scale from different body sites using a real-time polymerase chain reaction (PCR) assay. METHODS Scale samples were collected from lesional and nonlesional skin of 20 Japanese patients with psoriasis and fungal DNA was extracted from the samples directly. All the Malassezia species, including the two major species M. globosa and M. restricta, were quantified with high accuracy, using a real-time PCR assay. RESULTS Colonization by M. restricta was approximately five times higher at all body sites than colonization by M. globosa. Malassezia colonization was significantly lower in patients with hyperlipidaemia than in patients with normolipidaemia. CONCLUSIONS Malassezia restricta is the predominant species in psoriatic scale.
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Affiliation(s)
- Y Takahata
- Department of Dermatology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
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Toki S, Kagaya S, Shinohara M, Matsumoto T, Takahata Y, Saito H, Matsumoto K. Genome-wide Gene Expression Analysis of the Human Intestinal Epithelial Cells after Stimulation with Lactic Acid Bacteria. J Allergy Clin Immunol 2006. [DOI: 10.1016/j.jaci.2005.12.611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Wang KJ, Takahata Y, Kono Y, Kaizuma N. Entity evidence for differentiation between Tia and Tib types of soybean Kunitz trypsin inhibitor: detection of a novel transitional variant type between Tia and Tib in wild soybean (Glycine soja Sieb. & Zucc.). Theor Appl Genet 2005; 112:66-71. [PMID: 16228192 DOI: 10.1007/s00122-005-0105-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2005] [Accepted: 09/01/2005] [Indexed: 05/04/2023]
Abstract
Soybean Kunit trypsin inhibitor (SKTI) has several polymorphic types. Of these SKTI, there are large differences of nine amino acid substitutions between Tia and Tib. So far no transitional type between them has been found. A novel transitional intermediate variant between Tia and Tib was detected in 11 lines from 720 Japanese wild soybeans (Glycine soja Sieb. & Zucc.). This variant showed identical electrophoretic mobility to Tib in the Davis system polyacrylamide gel electrophoresis (PAGE), but higher electric points than other SKTI proteins (Tia, Tib, Tic) in isoelectric focusing PAGE. The genetic analysis of SKTI in F(2) seeds from a cross between the novel variant type and Tib showed that this variant type is inherited as codominant alleles in a multiple allelic system at an SKTI locus. This variant also showed inhibitory activity to trypsin. We propose the genetic symbol Ti b ( i5) for this novel variant. The sequence analysis of Tib ( i5) revealed that six nucleotides were different between Tib ( i5) and Tia, and the nucleotides of these mutated positions were identical to Tib. This causes substitution of five amino acids at the residue position 62 (Tyr-->Phe), 74 (Ser-->Arg), 114 (Met-->Val), 120 (Leu-->Ile) and 137 (Pro-->Thr). These substitutive amino acids are completely in accord with the amino acids of Tib, showing that Tib ( i5) is an intermediate between Tia and Tib types. Tib ( i5) type is widely distributed throughout seven separate areas from northeast to southwest Japan with a 1.5% frequency of total materials examined. This indicated that Tib ( i5) type did not originate from a recent mutation event, but had spread in wild soybean from ancient times.
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Affiliation(s)
- K J Wang
- Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan
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Takada H, Takahata Y, Nomura A, Ohga S, Mizuno Y, Hara T. Increased serum levels of interferon-gamma-inducible protein 10 and monokine induced by gamma interferon in patients with haemophagocytic lymphohistiocytosis. Clin Exp Immunol 2003; 133:448-53. [PMID: 12930373 PMCID: PMC1808805 DOI: 10.1046/j.1365-2249.2003.02237.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We measured serum interferon-gamma-inducible protein 10 (IP-10) and monokine induced by gamma interferon (MIG) levels to investigate the role of these molecules in the pathophysiology of haemophagocytic lymphohistiocytosis (HLH). Serum IP-10 and MIG levels were significantly increased in patients with active HLH compared with those of healthy controls. Serum MIG levels decreased gradually during the course of disease in a patient who recovered without therapy. On the other hand, rapid reduction of MIG and IP-10 levels was observed after chemotherapy in a patient with severe HLH. IP-10 and MIG mRNA expression was enhanced in liver and spleen, and IP-10 mRNA expression was enhanced in bone marrow in the patients, suggesting activated macrophages that infiltrated in these organs as one of the main producers of these cytokines. Serum IP-10 and MIG levels showed a significant correlation with serum IFN-gamma levels. In addition, these chemokines had a significant correlation with fever and serum LDH levels, which are clinical indicators of disease activity of HLH. These results suggest that IP-10 and MIG which are produced by activated macrophages by the stimulation of IFN-gamma, play an important role in the pathophysiology of HLH, by recruitment of activated Th1 cells into the tissues or organs.
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Affiliation(s)
- H Takada
- Department of Paediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
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15
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Abstract
AIM To assess the immunological role of human milk by analysing the concentrations of interferon-gamma-inducible protein of 10 kda (IP-10) and monokine induced by interferon-gamma (MIG) in human milk from mothers of preterm and term infants. METHODS IP-10 and MIG levels of colostrum, early milk, mature milk and sera were measured by enzyme-linked immunosorbent assay (ELISA). IP-10 and MIG mRNA expression levels in cellular components of human milk were determined by RT-PCR. IP-10 and MIG protein expression in mammary gland tissues was analysed by immunohistochemistry. RESULTS Significant amounts of IP-10 and MIG were detected in human milk. The concentrations of IP-10 and MIG in colostrum and early milk were significantly higher than those of sera from healthy controls or lactating mothers. These chemokine concentrations in colostrum and early milk were significantly higher than those of mature milk. Premature delivery or pregnancy complications of mothers had no significant correlation with these chemokine concentrations in breast milk. There were significant correlations between MIG and interferon-gamma (IFN-gamma) or IP-10 levels (p < 0.001) in human milk. Expression of IP-10 and MIG genes and proteins in the milk cells as well as in mammary gland epithelial tissues was detected by RT-PCR and immunohistochemistry. CONCLUSION IP-10 and MIG in human milk, probably derived from milk cells and mammary gland epithelial cells, may contribute to the migration and activation of intestinal T lymphocytes to enhance mucosal immunity during the early neonatal period.
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Affiliation(s)
- Y Takahata
- Department of Paediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
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Abstract
GH and IGF-I are important for physical growth. We measured serum levels of these factors in preterm infants. The study population (n = 81) was divided into three groups according to the gestational age. We evaluated differences in serum GH and IGF-I levels among groups with regard to physical growth and development of retinopathy of prematurity. Serum GH levels in extremely preterm infants born at <28 wk of gestational age were significantly higher than levels in those born between 28 and 34 wk at 1 and 2 mo of age. In contrast, serum IGF-I levels in extremely preterm infants remained low, whereas those in the other two groups gradually increased. Evaluation of the effects of GH and IGF-I on physical growth in very low birth weight infants (<1500 g) showed that IGF-I concentrations were positively related to physical growth for several months after birth, whereas no relationship was observed between GH and physical growth. Multivariate analysis demonstrated that high GH concentration at 1 mo of age was significantly associated with development of severe retinopathy of prematurity. In conclusion, persistent low serum IGF-I levels may explain the slow physical growth during neonatal life, and exposure of high GH may cause, at least in part, severe retinopathy of prematurity in preterm infants.
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Affiliation(s)
- S Hikino
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Takahata Y, Ohnishi-Kameyama M, Furuta S, Takahashi M, Suda I. Highly polymerized procyanidins in brown soybean seed coat with a high radical-scavenging activity. J Agric Food Chem 2001; 49:5843-7. [PMID: 11743772 DOI: 10.1021/jf010307x] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity of the 70% aqueous acetone extract from the seed coat of the brown soybean variety, Akita-Zairai, was investigated. The activity of the seed coat of Akita-Zairai was much higher than that of three other reddish-brown varieties, but lower than that of two black varieties, and was closely dependent on the content of phenolic compounds. In the LH20 column chromatography of Akita-Zairai, high DPPH radical-scavenging activities were detected in the fractions eluted with MeOH and 70% aqueous acetone. Proanthocyanidins were also detected in fractions showing high radical-scavenging activities. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry analysis showed that the degree of polymerization (DP) of the procyanidins contained in the brown or black soybean seed coat was as high as DP30.
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Affiliation(s)
- Y Takahata
- National Agricultural Research Center for Kyushu Okinawa Region, National Agricultural Research Organization (KONARC/NARO), Nishigoshi, Kumamoto 861-1192, Japan
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Takada Y, Ito A, Ninomiya C, Kakizaki T, Takahata Y, Suzuki G, Hatakeyama K, Hinata K, Shiba H, Takayama S, Isogai A, Watanabe M. Characterization of expressed genes in the SLL2 region of self-compatible Arabidopsis thaliana. DNA Res 2001; 8:215-9. [PMID: 11759841 DOI: 10.1093/dnares/8.5.215] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Self-incompatibility in Brassica species is regulated by a set of S-locus genes: SLG, SRK, and SP11/SCR. In the vicinity of the S-locus genes, several expressed genes, SLL2 and SP2/ClpP, etc., were identified in B. campestris. Arabidopsis thaliana is a self-compatible Brassica relative, and its complete genome has been sequenced. From comparison of the genomic sequences between B. campestris and A. thaliana, microsynteny between gene clusters of Arabidopsis and Brassica SLL2 regions was observed, though the S-locus genes, SLG, SRK, and SP11/SCR were not found in the region of Arabidopsis. Almost all genes predicted in this region of Arabidopsis were expressed in both vegetative and reproductive organs, suggesting that the genes in the SLL2 region might not be related to self-incompatibility. Considering the recent speculation that the S-locus genes were translocated as a single unit between Arabidopsis and Brassica, the translocation might have occurred in the region between the SLL2 and SP7 genes.
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Affiliation(s)
- Y Takada
- Faculty of Agriculture, Iwate University, Morioka, Japan
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Takahata Y, Hoaki T, Maruyama T. Starvation survivability of Thermococcus strains isolated from Japanese oil reservoirs. Arch Microbiol 2001; 176:264-70. [PMID: 11685370 DOI: 10.1007/s002030100318] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2000] [Accepted: 05/29/2001] [Indexed: 10/28/2022]
Abstract
The starvation survivability of seven Thermococcus strains isolated from four Japanese oil reservoirs was compared with that of Thermococcus strains from marine hydrothermal fields. 16S rDNA analyses showed the isolates to be closely related to Thermococcus litoralis. Growth of the isolates was dependent on amino acids, which were present at low concentrations in the oil reservoirs. At 80 degrees C in the formation water, strain CKU-1 from the oil reservoir showed a higher starvation survivability than strain KS-1 from the marine hydrothermal field. Crude oil did not affect the starvation survivability of strain CKU-1, but it reduced that of strain KS-1. These results indicate that strain CKU-1 could survive longer than stain KS-1 under the conditions of an oil reservoir. At 90 degrees C in artificial seawater without organic nutrients, the half-lives of the isolates were between 7.7 and 25.1 days. However, those of the strains from marine hydrothermal fields, except Thermococcus litoralis and Thermococcus chitonophagus, were less than 1.0 day. The higher starvation survivability is probably important for the hyperthermophiles to continue to exist in a hot subterranean oil reservoir where the supply of nutrients seems to be limited.
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Affiliation(s)
- Y Takahata
- Marine Biotechnology Institute, Kamaishi Laboratories, 3-75-1 Heita, Kamaishi, Iwate 026-0001, Japan.
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Takahata Y, Nishijima M, Hoaki T, Maruyama T. Thermotoga petrophila sp. nov. and Thermotoga naphthophila sp. nov., two hyperthermophilic bacteria from the Kubiki oil reservoir in Niigata, Japan. Int J Syst Evol Microbiol 2001; 51:1901-1909. [PMID: 11594624 DOI: 10.1099/00207713-51-5-1901] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two hyperthermophilic bacteria, strains RKU-1T and RKU-10T, which grew optimally at 80 degrees C, were isolated from the production fluid of the Kubiki oil reservoir in Niigata, Japan. They were strictly anaerobic, rod-shaped fermentative heterotrophs. Based on the presence of an outer sheath-like structure (toga) and 16S rDNA sequences, they were shown to belong to the genus Thermotoga. Cells of strain RKU-1T were 2-7 microm by 0.7-1.0 microm, with flagella. They grew at 47-88 degrees C on yeast extract, peptone, glucose, fructose, ribose, arabinose, sucrose, lactose, maltose, starch and cellulose as sole carbon sources. Cells of strain RKU-10T were 2-7 microm by 0.8-1.2 microm, with flagella. They grew at 48-86 degrees C on yeast extract, peptone, glucose, galactose, fructose, mannitol, ribose, arabinose, sucrose, lactose, maltose and starch as sole carbon sources. While strains RKU-1T and RKU-10T reduced elemental sulfur to hydrogen sulfide, their final cell yields and specific growth rates decreased in the presence of elemental sulfur. Thiosulfate also inhibited growth of strain RKU-1T but not strain RKU-10T. The G+C contents of the DNA from strains RKU-1T and RKU-10T were 46.8 and 46.1 mol%. Phenotypic characteristics and 165 rDNA sequences of the isolates were similar to those of Thermotoga maritima and Thermotoga neapolitana, both being hyperthermophilic bacteria isolated from hydrothermal fields. However, the isolates differed from these species in their minimum growth temperatures, utilization of some sugars, sensitivity to rifampicin and the effects of elemental sulfur and thiosulfate on growth. The low levels (less than 31%) of DNA reassociation between any two of these hyperthermophilic Thermotoga strains indicated that the isolates were novel species. Analysis of the gyrB gene sequences supported the view that the isolates were genotypically different from these reference species. The isolates were named Thermotoga petrophila sp. nov., with type strain RKU-1T (= DSM 13995T = JCM 10881T), and Thermotoga naphthophila sp. nov., with type strain RKU-10T (= DSM 13996T = JCM 10882T).
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Abstract
We analyzed IL-18 levels of human milk. Colostrum contained significantly higher levels of IL-18 compared with early milk and mature milk. By stepwise multiple linear regression analysis, preterm delivery and pregnancy complications of mothers significantly correlated with high levels of IL-18 in human milk (p = 0.0007 and 0.0018, respectively). There was a significant correlation between the levels of IL-18 and soluble Fas ligand in colostrum (p = 0.0003). IL-18 was detected in actively secreting epithelial cells in lactating mammary gland by immunohistochemical staining. These results suggest that IL-18 in colostrum plays an important role in host defense of high-risk neonates.
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Affiliation(s)
- Y Takahata
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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Ohga S, Nomura A, Takada H, Ihara K, Kawakami K, Yanai F, Takahata Y, Tanaka T, Kasuga N, Hara T. Epstein-Barr virus (EBV) load and cytokine gene expression in activated T cells of chronic active EBV infection. J Infect Dis 2001; 183:1-7. [PMID: 11106535 DOI: 10.1086/317653] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2000] [Revised: 09/18/2000] [Indexed: 11/04/2022] Open
Abstract
To identify the role of T cells in chronic active Epstein-Barr virus (EBV) infection, EBV and cytokine gene expression was quantified by use of real-time polymerase chain reaction (PCR) among 6 patients who fulfilled the diagnostic criteria for chronic active EBV infection. Four of these patients showed clonal expansion of EBV-infected T cells. Quantitative PCR for EBV DNA in peripheral blood of patients with symptomatic chronic active EBV infection showed higher copy numbers of virus (mean, 1.45 x 10(5) copies/mL) than were seen in blood from patients with infectious mononucleosis (3.08 x 10(3) copies/mL) or with EBV-associated hemophagocytosis (2.95 x 10(4) copies/mL). Fractionated CD3(+) HLA-DR(+) cells from patients with chronic active EBV infection contained higher copy numbers than did CD3(+) HLA-DR(-) cells. Quantitative PCR for cytokines revealed that interferon-gamma, interleukin (IL)-2, IL-10, and transforming growth factor-beta genes were expressed at higher levels in HLA-DR(+) than in HLA-DR(-) T cells. These results suggest that activated T cells in chronic active EBV infection expressed high levels of EBV DNA and both Th1 and Th2 cytokines. EBV-infected T cells may contribute to the unbalanced cytokine profiles of chronic mononucleosis.
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Affiliation(s)
- S Ohga
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
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25
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Jin CH, Takada H, Nomura A, Takahata Y, Nakayama H, Kajiwara M, Nakano H, Hara T. Immunophenotypic and functional characterization of CD33(+)CD34(+) cells in human cord blood of preterm neonates. Exp Hematol 2000; 28:1174-80. [PMID: 11027836 DOI: 10.1016/s0301-472x(00)00519-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To characterize CD33(+)CD34(+) cells, a major population in human cord blood (CB) CD34(+) cells of preterm neonates. MATERIALS The proportion of CD33(+) cells was analyzed on CB CD34(+) cells from preterm and full-term neonates. CD33(+)CD34(+) cells were purified by cell sorting and analyzed on their clonogenic activity, proliferative activity in short-time liquid suspension culture, and GATA-2 mRNA expression by RT-PCR and Southern blot. RESULTS The absolute numbers and proportion of CD34(+) cells in mononuclear cells inversely correlated with gestational age. CD33 was expressed on a majority of CB CD34(+) cells of preterm neonates but on only a minor population of them in full-term neonates. In addition, CD33 was dominantly expressed on CD38(-)CD34(+) cells or CD117(low)CD34(+) cells in CB of preterm neonates. CD33(+)CD34(+) cells of preterm cord blood had high proliferative and reproducible potentials compared with CD33(-)CD34(+) cells. CD33(+)CD34(+) cells as well as CD33(-)CD34(+) cells from preterm CB highly expressed GATA-2, in contrast to those from BM. CONCLUSIONS These results suggest that CD33(+)CD34(+) cells, which are a major population in CB CD34(+) cells of preterm neonates, do not simply represent relatively mature myeloid lineage hematopoietic progenitor cells as those in adult BM CD34(+) cells, and may contain hematopoietic stem cells or primitive progenitor cells as in fetal liver.
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Affiliation(s)
- C H Jin
- Departments of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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26
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Abstract
In order to study gene expression in a reproductive organ, we constructed a cDNA library of mature flower buds in Lotus japonicus, and characterized expressed sequence tags (ESTs) of 842 clones randomly selected. The EST sequences were clustered into 718 non-redundant groups. From BLAST and FASTA search analyses of both protein and DNA databases, 58.5% of the EST groups showed significant sequence similarities to known genes. Several genes encoding these EST clones were identified as pollen-specific genes, such as pectin methylesterase, ascorbate oxidase, and polygalacturonase, and as homologous genes involved in pollen-pistil interaction. Comparison of these EST sequences with those derived from the whole plant of L. japonicus, revealed that 64.8% of EST sequences from the flower buds were not found in EST sequences of the whole plant. Taken together, the EST data from flower buds generated in this study is useful in dissecting gene expression in floral organ of L. japonicus.
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Affiliation(s)
- M Endo
- Laboratory of Plant Breeding, Faculty of Agriculture, Iwate University, Ueda, Morioka, Japan
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Watanabe M, Ito A, Takada Y, Ninomiya C, Kakizaki T, Takahata Y, Hatakeyama K, Hinata K, Suzuki G, Takasaki T, Satta Y, Shiba H, Takayama S, Isogai A. Highly divergent sequences of the pollen self-incompatibility (S) gene in class-I S haplotypes of Brassica campestris (syn. rapa) L. FEBS Lett 2000; 473:139-44. [PMID: 10812061 DOI: 10.1016/s0014-5793(00)01514-3] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Self-incompatibility (SI) enables flowering plants to discriminate between self- and non-self-pollen. In Brassica, SI is controlled by the highly polymorphic S locus. The recently identified male determinant, termed SP11 or SCR, is thought to be the ligand of S receptor kinase, the female determinant. To examine functional and evolutionary properties of SP11, we cloned 14 alleles from class-I S haplotypes of Brassica campestris and carried out sequence analyses. The sequences of mature SP11 proteins are highly divergent, except for the presence of conserved cysteines. The phylogenetic trees suggest possible co-evolution of the genes encoding the male and female determinants.
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Affiliation(s)
- M Watanabe
- Laboratory of Plant Breeding, Faculty of Agriculture, Iwate University, 3-18-8, Ueda, Morioka, Japan.
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Zhang FL, Takahata Y, Watanabe M, Xu JB. Agrobacterium-mediated transformation of cotyledonary explants of Chinese cabbage (Brassica campestris L. ssp. pekinensis). Plant Cell Rep 2000; 19:569-575. [PMID: 30754819 DOI: 10.1007/s002990050775] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A procedure for producing transgenic Chinese cabbage plants by inoculating cotyledonary explants with Agrobacterium tumefaciens strain EHA101 carrying a binary vector pIG121Hm, which contains kanamycin-resistance and hygromycin-resistance genes and the GUS reporter gene, is described. Infection was most effective (highest infection frequency) when explants were infected with Agrobacterium for 15 min and co-cultivated for 3 days in co-cultivation medium at pH 5.2 supplemented with 10 mg/l acetosyringone. Transgenic plants of all three cultivars used were obtained with frequencies of 1.6-2.7% when the explants were regenerated in shoot regeneration medium solidified with 1.6% agar. A histochemical GUS assay and PCR and Southern blot analyses confirmed that transformation had occurred. Genetic analysis of T1 progeny showed that the transgenes were inherited in a Mendelian fashion.
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Affiliation(s)
- F-L Zhang
- Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan e-mail: , Fax. +81-19-6216177, , , , , , JP
| | - Y Takahata
- Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan e-mail: , Fax. +81-19-6216177, , , , , , JP
| | - M Watanabe
- Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan e-mail: , Fax. +81-19-6216177, , , , , , JP
| | - J-B Xu
- Beijing Vegetable Research Center, Beijing 100089, China, , , , , , CN
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Hajirezaei MR, Takahata Y, Trethewey RN, Willmitzer L, Sonnewald U. Impact of elevated cytosolic and apoplastic invertase activity on carbon metabolism during potato tuber development. J Exp Bot 2000; 51 Spec No:439-45. [PMID: 10938852 DOI: 10.1093/jexbot/51.suppl_1.439] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
During tuberization in Solanum tuberosum var. Desirée maximal catalytic activities of invertase(s) and sucrose synthase are inversely correlated. During the early stages, invertase activity is high and declines during maturation. The decrease in invertase activity is accompanied by a decrease in the hexose to sucrose ratio and an increase in sucrose synthase activity. This switch is paralleled by the onset of the storage phase as shown by the accumulation of starch and storage proteins. Biochemical and genetic evidence suggests that sucrose synthase activity is positively correlated with sink strength. To explore the possibility of enhancing sink strength in potato tubers by elevating the sucrolytic capacity, transgenic potato plants expressing either cytosolic or apoplastic yeast invertase in their tubers were made. Surprisingly, cytosolic invertase led to a decrease and apoplastic invertase to an increase in tuber yield. To understand the causes of the observed phenotypes, carbon metabolism in tubers of transgenic and control plants was analysed during different stages of tuber development. Both cytosolic and apoplastic invertase resulted in decreased sucrose and elevated glucose contents, indicating that sucrose is accessible in both compartments. Metabolic perturbation, however, was found to be compartment specific. Elevated cytosolic invertase activity led to increased carbon flux towards glycolysis and accumulation of phosphorylated intermediates. The phosphorylated intermediates were not used to build up starch. In contrast, apoplastic invertase does not lead to a significant increase in hexose phosphates compared to untransformed controls. Thus, hexoses originating in the apoplast are not efficiently phosphorylated during potato tuber development, which might be explained by an endocytotic uptake of sucrose and/or hexoses from the apoplast into the vacuole bypassing the cytosolic compartment.
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Affiliation(s)
- M R Hajirezaei
- Institut für Pflanzengenetik und Kulturpflanzenforschung, Gatersleben, Germany
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30
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Gaudio AC, Richards WG, Takahata Y. QSAR and molecular graphics analysis of N2-phenylguanines as inhibitors of herpes simplex virus thymidine kinases. J Mol Graph Model 2000; 18:33-41. [PMID: 10935205 DOI: 10.1016/s1093-3263(00)00032-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A quantitative structure-activity relationship study of N2-(substituted)-phenylguanines (PHG) as inhibitors of herpes simplex virus thymidine kinase (HSV TK) was performed. The activity of a set of PHG derivatives were analyzed against the thymidine kinase of herpes simplex virus types 1 (HSV1 TK) and 2 (HSV2 TK). Classic and calculated physicochemical parameters were included in the analysis. The results showed that there is an important difference in the activity of the meta substituted PHG derivatives against HSV1 TK and HSV2 TK. The activity of the meta derivatives against HSV2 TK is influenced by a steric effect, which is not observed against HSV1 TK. The superposition of the three-dimensional structures of the active sites of HSV1 TK (crystal structure) and HSV2 TK (homology model) revealed that the amino acid Ile97 is located near the meta position in the HSV1 TK active site, whereas the amino acid Leu97 is located near the meta position in the HSV2 TK active site. This single difference in the active sites of both enzymes can explain the source of the steric effect and serves as an indication that our previously proposed binding mode for the PHG derivatives is plausible. However, another observed mutation in the active site region, Ala168 by Ser168, suggests that an alternative binding mode, similar to that of ganciclovir, could be possible.
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Affiliation(s)
- A C Gaudio
- Departamento de Física, Centro de Ciências Exatas, Universidade Federal do Espírito Santo, Vitória, Brazil.
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31
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Takahata Y, Nishijima M, Hoaki T, Maruyama T. Distribution and physiological characteristics of hyperthermophiles in the Kubiki oil reservoir in Niigata, Japan. Appl Environ Microbiol 2000; 66:73-9. [PMID: 10618205 PMCID: PMC91787 DOI: 10.1128/aem.66.1.73-79.2000] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The distribution of culturable hyperthermophiles was studied in relation to environmental conditions in the Kubiki oil reservoir in Japan, where the temperature was between 50 and 58 degrees C. Dominant hyperthermophilic cocci and rods were isolated and shown to belong to the genera Thermococcus and Thermotoga, respectively, by 16S rDNA analyses. Using the most-probable-number method, we found that hyperthermophilic cocci were widely distributed in several unconnected fault blocks in the Kubiki oil reservoir. In 1996 to 1997, their populations in the production waters from oil wells were 9.2 x 10(3) to 4.6 x 10(4) cells/ml, or 10 to 42% of total cocci. On the other hand, hyperthermophilic rods were found in only one fault block of the reservoir with populations less than 10 cells/ml. Dominant Thermococcus and Thermotoga spp. grew at reservoir temperatures and utilized amino acids and sugars, respectively, as sole carbon sources. While organic carbon was plentiful in the environment, these hyperthermophiles were unable to grow in the formation water due to lack of essential nutrients. Concentrations of some organic and inorganic substances differed among fault blocks, indicating that the movement of formation water between fault blocks was restricted. This finding suggests that the supply of nutrients via fluid current is limited in this subterranean environment and that the organisms are starved in the oil reservoir. Under starved conditions at 50 degrees C, culturable cells of Thermococcus sp. remained around the initial cell density for about 200 days, while those of Thermotoga sp. decreased exponentially to 0. 01% of the initial cell density after incubation for the same period. The difference in survivability between these two hyperthermophiles seems to reflect their populations in the fault blocks. These results indicate that hyperthermophilic cocci and rods adapt to the subterranean environment of the Kubiki oil reservoir by developing an ability to survive under starved conditions.
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MESH Headings
- Colony Count, Microbial
- Culture Media
- DNA, Bacterial/analysis
- DNA, Bacterial/genetics
- DNA, Ribosomal/analysis
- DNA, Ribosomal/genetics
- Ecosystem
- Gram-Negative Anaerobic Straight, Curved, and Helical Rods/classification
- Gram-Negative Anaerobic Straight, Curved, and Helical Rods/growth & development
- Gram-Negative Anaerobic Straight, Curved, and Helical Rods/isolation & purification
- Hot Temperature
- Japan
- Microbial Sensitivity Tests
- Molecular Sequence Data
- Petroleum
- Polymerase Chain Reaction
- RNA, Ribosomal, 16S/genetics
- Thermococcus/classification
- Thermococcus/growth & development
- Thermococcus/isolation & purification
- Water Microbiology
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Affiliation(s)
- Y Takahata
- Marine Biotechnology Institute, Kamaishi Laboratories, Kamaishi, Iwate 026-0001, Japan.
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32
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Herbers K, Takahata Y, Melzer M, Mock HP, Hajirezaei M, Sonnewald U. Regulation of carbohydrate partitioning during the interaction of potato virus Y with tobacco. Mol Plant Pathol 2000; 1:51-9. [PMID: 20572950 DOI: 10.1046/j.1364-3703.2000.00007.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Abstract To test whether carbohydrates may play a signalling function during plant pathogenesis, we investigated the interaction between tobacco and potato virus Y (PVY(N)). Four days after PVY(N) infection, leaves started to accumulate soluble sugars and leaf photosynthesis decreased. The accumulation of soluble sugars was accompanied by an induction of cell wall invertase and a gradual decrease in the sucrose-to-hexose ratio. In parallel to changes in carbohydrate metabolism and photosynthesis, transcripts encoding PR-proteins accumulated. Based on this coincidence, it was hypothesized that elevated hexose levels may enhance the expression of defence-related functions and might possibly explain the phenomenon of high sugar resistance in plants. This notion has been supported by the fact that cell wall invertase-expressing transgenic tobacco plants were found to be resistant against PVY(N) (Herbers et al., 1996b). To exclude the possibility that salicylate, which accumulates in plants expressing invertase, may be responsible for the observed resistance, these transgenic plants were crossed with salicylate hydroxylase-expressing plants (nahG). The progeny were selected for high levels of sugar and low levels of salicylate. Necrotic lesions also developed, typically formed on the leaves of plants expressing invertase, and transcripts encoding PR-Q accumulated in the absence of salicylate. On the other hand, accumulation of PR-1b transcripts decreased, indicating that sugars are not sufficient for PR-1b induction. Infection experiments using these plants as hosts revealed resistance towards PVY(N). Thus, the mechanism of apoplastic invertase induced virus resistance is salicylate independent and most likely sugar mediated.
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Affiliation(s)
- K Herbers
- Institut für Pflanzengenetik und Kulturpflanzenforschung, Corrensstrasse 3, 06466 Gatersleben, Germany
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Vendrame R, Braga RS, Takahata Y, Galvão DS. Structure-activity relationship studies of carcinogenic activity of polycyclic aromatic hydrocarbons using calculated molecular descriptors with principal component analysis and neural network methods. J Chem Inf Comput Sci 1999; 39:1094-104. [PMID: 10614026 DOI: 10.1021/ci990326v] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recently a new methodology based on local density of state (LDOS) calculations using topological and semiempirical methods was proposed to identify the carcinogenic activity of polycyclic aromatic hydrocarbons (PAHs). In this work we perform a comparative study of this methodology with principal component analysis (PCA) and neural networks (NN). The PCA and NN results show that LDOS quantum chemical descriptors are relevant descriptors to identify the carcinogenic activity of methylated and non-methylated PAHs. Also, we show that the combination of these distinct methodologies can be an efficient and powerful tool in the structure-activity studies of PAHs compounds. We have studied 81 methylated and non-methylated PAHs, and our study shows that with the use of these methods it is possible to correctly predict the carcinogenic activity of PAHs with accuracy higher than 80%.
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Affiliation(s)
- R Vendrame
- Instituto de Física Gleb Wataghin and Instituto de Química, UNICAMP, SP, Brasil
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34
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Zhang FL, Takahata Y, Xu JB. Medium and genotype factors influencing shoot regeneration from cotyledonary explants of Chinese cabbage (Brassica campestris L. ssp. pekinensis). Plant Cell Rep 1998; 17:780-786. [PMID: 30736591 DOI: 10.1007/s002990050482] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Medium conditions for reliable shoot regeneration from cotyledonary explants of Chinese cabbage were examined. Maximum shoot regeneration was obtained in the presence of 5 mg/l BA and 0.5 mg/l NAA. Shoot induction was further improved by the addition of AgNO3 as well as higher concentrations (1.2-1.6%) of agar in the regeneration medium. When 123 genotypes were tested, a large variation in regeneration frequency was observed, ranging from 95% to 0%. Shoot regeneration frequency was not related to origin and days to maturity of the genotypes. Ethylene production from cultured explants seemed to play an important role in shoot regeneration. Explants of highly responsive genotypes or if cultured on the medium solidified with a higher concentration of agar generally showed low levels of ethylene production. However, AgNO3, which also enhanced shoot induction, resulted in an increase in ethylene production. The possible interaction between ethylene and shoot regeneration is discussed.
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Affiliation(s)
- F-L Zhang
- Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan Fax: 81-19-621-6177 e-mail: , , , , , , JP
| | - Y Takahata
- Faculty of Agriculture, Iwate University, Morioka 020-8550, Japan Fax: 81-19-621-6177 e-mail: , , , , , , JP
| | - J-B Xu
- Beijing Vegetable Research Center, Beijing 100081, China, , , , , , CN
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Sudo Y, Miyagawa R, Takahata Y. Method for the preparation of restricted access media by low-temperature plasma treatment. J Chromatogr B Biomed Sci Appl 1998; 705:55-62. [PMID: 9498670 DOI: 10.1016/s0378-4347(97)00496-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A new method for the preparation of restricted access media (RAM) was developed. A low-temperature plasma treatment removed octadecyl groups on the external surface of octadecylsilylated silica gel before those on the internal surface to produce silanol groups. The silanol groups produced were glycerylpropylsilylated to give RAM, DIOL-ODSs, consisting of internal octadecyl groups and external glycerylpropyl groups. DIOL-ODSs were inert to serum proteins and retained low-molecular-mass analytes adequately. Direct injection analysis of anticonvulsants in serum was accurately performed by column-switching high-performance liquid chromatography using a pre-column packed with DIOL-ODS.
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Affiliation(s)
- Y Sudo
- Chemicals Inspection and Testing Institute, Division of Research and Development, Tokyo, Japan
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36
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Gaudio AC, Takahata Y, Richards WG. Prediction of the binding mode of N2-phenylguanine derivative inhibitors to herpes simplex virus type 1 thymidine kinase. J Comput Aided Mol Des 1998; 12:15-25. [PMID: 9570086 DOI: 10.1023/a:1007930523818] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The probable binding mode of the herpes simplex virus thymidine kinase (HSV1 TK) N2-[substituted]-phenylguanine inhibitors is proposed. A computational experiment was designed to check some qualitative binding parameters and to calculate the interaction binding energies of alternative binding modes of N2-phenylguanines. The known binding modes of the HSV1 TK natural substrate deoxythymidine and one of its competitive inhibitors ganciclovir were used as templates. Both the qualitative and quantitative parts of the computational experiment indicated that the N2-phenylguanine derivatives bind to the HSV1 TK active site in the deoxythymidine-like binding mode. An experimental observation that N2-phenylguanosine derivatives are not phosphorylated during the interaction with the HSV1 TK gives support to the proposed binding mode.
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Affiliation(s)
- A C Gaudio
- Departamento de Física, Universidade Federal do Espírito Santo, Campus de Goiabeiras, Vitória, Brazil
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37
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Nitta T, Takahata Y, Kaizuma N. Scanning electron microscopy of microspore embryogenesis inBrassica spp. Plant Cell Rep 1997; 16:406-410. [PMID: 30727651 DOI: 10.1007/bf01146783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/1996] [Revised: 08/28/1996] [Accepted: 09/27/1996] [Indexed: 05/11/2023]
Abstract
Scanning electron microscopy was employed to study and compare microspore embryogenesis in vitro with pollen development in planta inBrassica napus andB. oleracea. An exine with its specific pattern had already been formed, when microspores were released from tetrads. During subsequent pollen development, microspores increased in size and continued to strengthen the exine. Upon in vitro culture, all microspores, i.e., embryogenic and nonembryogenic, initially showed the same morphological features. After 24 h in culture, the microspores had increased in size. Thereafter, embryogenesis was indicated in some microspores by two different morphological changes. One featured an expansion in volume of the cell cluster around the germination aperture (type I), the other showed cell cluster volume expansion over the entire microspore surface (type II). Two-thirds of embryogenic microspores in bothB. napus andB. oleracea demonstrated type I development. When followed by fluorescence microscopy, in vitro culture of microspores revealed cultures with a high embryo frequency were those with a high frequency of symmetrical division.
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Affiliation(s)
- T Nitta
- Faculty of Agriculture, Iwate University, Morioka 020, Japan
| | - Y Takahata
- Faculty of Agriculture, Iwate University, Morioka 020, Japan
| | - N Kaizuma
- Faculty of Agriculture, Iwate University, Morioka 020, Japan
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38
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Takahata Y, Komatsu H, Kaizuma N. Microspore culture of radish (Raphanus sativus L.): influence of genotype and culture conditions on embryogenesis. Plant Cell Rep 1996; 16:163-166. [PMID: 24177544 DOI: 10.1007/bf01890859] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/1996] [Revised: 05/15/1996] [Indexed: 06/02/2023]
Abstract
A number of factors influencing embryogenesis from isolated microspores of radish (Raphanus sativus) were examined. Of 11 genotypes evaluated, six produced embryos ranging from 8.3 embryos per 10(5) microspores for 'Chugoku-ao' to 0.2 for 'Tenshun', but five genotypes were not responsive. An initial culture period at elevated temperature before incubation at 25°C was essential for induction of microspore embryogenesis. However, the optimum period of the treatment varied among genotypes and/or experiments. Bud size also influenced microspore embryogenesis. Though optimum bud size was different between genotypes, the microspore populations represented in these buds contained uninucleate and binucleate microspores. Selection of embryogenic microspores using percoll density gradient resulted in up to 1.3-fold increase of embryo yield. Though almost all embryos failed to develop directly into plantlets, plants were obtained by multiple subcultures. The regenerated plants had hyperploid chromosome numbers.
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Affiliation(s)
- Y Takahata
- Faculty of Agriculture, Iwate University, 020, Morioka, Japan
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Nishimura H, Munakata N, Hayashi K, Hayakawa M, Iwamoto H, Terayama S, Takahata Y, Kodera Y, Tsurui H, Shirai T. Polyethylene glycol-modified avidin: a novel agent for the selective extraction of biotinylated immune-complex in an aqueous two-phase system. J Biomater Sci Polym Ed 1996; 7:289-96. [PMID: 7577831 DOI: 10.1163/156856295x00328] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Chicken avidin was chemically modified with 2,4-bis[O-methoxypoly(ethylene glycol)]-6-chloro-s-triazine (activated PEG2) to form PEG-avidin. The PEG-avidin, in which 78% of the amino groups were modified, retained 49% of the active biotin-binding sites. The modified avidin was partitioned preferentially into the PEG-phase in an aqueous two-phase system (PEG/dextran). Using PEG-avidin, the immune-complex formed between biotinylated anti-mouse IgG and its antigen IgG (mouse) molecules, was successfully transferred into the PEG-phase in an aqueous two-phase system. This finding leads to the effective isolation of a specific antigen among various kinds of antigens by partitioning with a two-phase system using PEG-avidin.
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Affiliation(s)
- H Nishimura
- Department of Material Science and Technology, Toin University of Yokohama, Japan
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Takahata Y, Nishizawa A, Kojima I, Yamanishi M, Toraya T. Synthesis, properties and microbiological activity of hydrophobic derivatives of vitamin B12. J Nutr Sci Vitaminol (Tokyo) 1995; 41:515-26. [PMID: 8750203 DOI: 10.3177/jnsv.41.515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Long chain alkylcobalamins and long chain acyl-cyanocobalamins, two types of hydrophobic derivatives of vitamin B12, were synthesized. It was shown by TLC and determination of the partition coefficient between organic and aqueous phases that the hydrophobicity of alkylcobalamins and acyl-cyanocobalamins increased with the chain length of the alkyl or acyl group introduced into cobalamin. Long chain alkylcobalamins were easily converted to aquacobalamin by photoirradiation, but the first-order rate constant of photolysis decreased with the length of an alkyl group. Long chain acyl-cyanocobalamins were gradually hydrolyzed to cyanocobalamin in neutral or alkaline solution with the pseudo-first order rate constant increasing with the pH of the solution. Stabilization of acyl-cyanocobalamins toward hydrolysis was achieved by introducing a methyl group into the alpha-position of an acyl group. All the long chain alkylcobalamins tested supported the growth of Escherichia coli 215, a cobalamin- or L-methionine-auxotroph, and Lactobacillus leichmannii, although their activity as cobalamin was at most 28% and 15% that of cyanocobalamin for E. coli 215 and L. leichmannii, respectively.
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Affiliation(s)
- Y Takahata
- Department of Biotechnology, Faculty of Engineering, Okayama University, Japan
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Takahata Y, Jomori H, Miyano S, Kunitake H, Mii M. Regeneration of Plants from Protoplasts of Gentiana Species (Gentian). Biotechnology in Agriculture and Forestry 1995. [DOI: 10.1007/978-3-642-57840-3_6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Ono Y, Takahata Y, Kaizuma N. Effect of genotype on shoot regeneration from cotyledonary explants of rapeseed (Brassica napus L.). Plant Cell Rep 1994; 14:13-17. [PMID: 24194219 DOI: 10.1007/bf00233290] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/1993] [Revised: 05/03/1994] [Indexed: 06/02/2023]
Abstract
Ability of shoot regeneration from cotyledonary explants of rapeseed (B. napus) was surveyed for 100 cultivars. Effects of explant age and plant growth regulators were determined before screening the genotypes. The optimal condition required 4-day-old cotyledons as explant and 4.0 mg/l benzylaminopurine as plant growth regulator. Gas-permeable tape as sealing material was more effective for shoot regeneration than Parafilm. When testing cultivars, shoot regeneration response was strongly influenced by genotype with a range of variation from 97% (percentage of explants regenerating shoots) in 'Arabella' and 'Norin 26' to 0% in 'Norin 18' and 'Norin 30'. The response was not dependent on origin and cropping type (spring vs. winter type). The ability of shoot regeneration was not related to that of microspore embryogenesis. The regenerants rooted on medium containing 2.0 mg/l indole-3-butyric acid and after planting in soil flowered and set seeds. Histological studies showed that shoot meristems developed in callus which had grown from the vascular bundle tissue within 8 days.
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Affiliation(s)
- Y Ono
- Faculty of Agriculture, Iwate University, 020, Morioka, Japan
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Gaudio AC, Korolkovas A, Takahata Y. Quantitative structure-activity relationships for 1,4-dihydropyridine calcium channel antagonists (nifedipine analogues): a quantum chemical/classical approach. J Pharm Sci 1994; 83:1110-5. [PMID: 7983594 DOI: 10.1002/jps.2600830809] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A quantum chemical (AM1) combined with a classical study of structure-activity relationships for 1,4-dihydropyridines (nifedipine analogues) was performed. The biological data were taken from the literature. The quantum chemical parameters tested were energies of HOMO and LUMO, dipole moment (total and partial), hardness, Mulliken electronegativity, frontier orbital indices, and others. Also tested were classical parameters like Hansch hydrophobic constant, tau; Hammett electronic constant for the meta position, sigma m; and the Verloop sterimol parameters, B1 and L. The van der Waals volume was also tested. The pharmacological activities of the para monoderivatives are negatively correlated with the molecular volume, i.e. a steric factor. The meta position of the phenyl ring is affected by steric and electronic parameters, whereas the ortho position seems to be affected by hydrophobic and electronic parameters.
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Affiliation(s)
- A C Gaudio
- Departamento de Fisica, CCEx., Universidade Federal do Espirito Santo, Brazil
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Sudo Y, Akeba M, Sakaki T, Takahata Y. Glycerylalkylsilylated Silica Gels for Direct Injection Analysis of Drugs in Serum by High-Performance Liquid Chromatography. ACTA ACUST UNITED AC 1994. [DOI: 10.1080/10826079408013455] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Fujii J, Inotsume N, Nakano M, Matsukane I, Higashi A, Matsuda I, Sudo Y, Takahata Y. Rapid determination of serum oxatomide levels with on-line precolumn solid-phase extraction. J Chromatogr 1990; 530:469-73. [PMID: 1981891 DOI: 10.1016/s0378-4347(00)82352-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- J Fujii
- Department of Pharmaceutical Services, Kumamoto University Hospital, Japan
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