Copper in rice and in soils according to soil type in Japan, Indonesia, and China: a baseline study.
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China↗
Biomedical subjects
Y Lee
Publications and source records attributed to Y Lee.
Purification of ornithine carbamoyltransferase from kidney bean (Phaseolus vulgaris L.) leaves and comparison of the properties of the enzyme from canavanine-containing and -deficient plants.
Kidney bean (Phaseolus vulgaris L.) ornithine carbamoyltransferase (OCT; EC 2.1.3.3) was purified to homogeneity from leaf homogenates in a single-step procedure, using delta-N-(phosphonoacetyl)-L-ornithine-Sepharose 6B affinity chromatography. The 8540-fold-purified OCT exhibited a specific activity of 526 micromoles citrulline per minute per milligram of protein at 35 degrees C and pH 8.0. The enzyme represents approximately 0.01% of the total soluble protein in the leaf. The molecular mass of the native enzyme was approximately 109 kDa as estimated by Sephacryl S-200 gel filtration chromatography. The purified protein ran as a single band of molecular mass 36 kDa when subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and at a single isoelectric point of 6.6 when subjected to denaturing isoelectric focusing. These results suggest that the enzyme is a trimer of identical subunits. Among the tested amino acids, L-cysteine and S-carbamoyl-L-cysteine were the most effective inhibitors of the enzyme. The OCT of kidney bean showed a very low activity towards canaline. The OCTs of canavanine-deficient plants have very low canaline-dependent activities, but the OCTs of canavanine-containing plants showed high canaline-dependent activities. It was assumed that the substrate specificity of this enzyme determines the canavanine synthetic activity of the urea cycle.
Animals↗
Expression of Bfl-1 in normal and tumor tissues: Bfl-1 overexpression in cancer is attributable to its preferential expression in infiltrating inflammatory cells.
Bfl-1, a member of the Bcl-2 gene family, blocks p53-mediated apoptosis and has oncogenic transforming activity. In normal tissues, the transcript of Bfl-1 is expressed abundantly in bone marrow and at a low level in several other tissues. In previous experiments, elevated expression of Bfl-1 was observed by Northern analysis of stomach cancer samples. To study the role of Bfl-1 in normal cell development and in tumorigenesis, we have analyzed the expression of Bfl-1 in normal and tumor tissues by the in situ hybridization technique. The Bfl-1 transcript was detected in the white pulp of the spleen and in the germinal center of lymphatic tissues. In tumor tissues, its expression was preferentially detected in infiltrating inflammatory cells rather than in cancer cells, suggesting that Bfl-1 is not involved in tumorigenesis.
Colonic Neoplasms↗
Inhibition of immediate type allergic reactions by the aqueous extract of Kum-Hwang-San.
We studied the effect of aqueous extract of Kum-Hwang-San (KHS) on mast cell-mediated immediate type allergic reactions. KHS (1-100 microg/site) inhibited concentration-dependently mast cell-dependent ear swelling response induced by compound 48/80 (200 microg/site) in mice by both topical and intradermal application. KHS (0.1-100 microg/site) inhibited concentration-dependently passive cutaneous anaphylaxis induced by anti-dinitrophenyl (DNP) IgE in rats by both topical and intradermal application. KHS also inhibited concentration-dependently the histamine release from the rat peritoneal mast cells (RPMC) by compound 48/80 and anti-DNP IgE. Moreover, KHS had a significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-alpha (TNF-alpha) secretion from RPMC. These results indicate that KHS inhibits immediate type allergic reactions by inhibition of histamine release and TNF-alpha secretion from mast cells in vivo and in vitro.
Animals↗
Estrogen causes cell death of estrogen receptor stably transfected cells via apoptosis.
We examined the effect of estrogen on the growth of estrogen receptor (ER) stably transfected cells (Rat1 + ER). 17-Beta-estradiol (E2, 10 nM) inhibited approximately 35-50% of Rat1 + ER growth after 3 d of treatment. The half-maximal growth inhibition occurred at 0.5-0.75 nM of E2 concentration and was saturated above 10 nM. This E2-induced antiproliferative effect was mediated through the ER since E2 did not cause any change in ER-negative parental Rat1 cells. Cells started to detach from plates and the adherent cells exhibited nuclear condensation. Apoptotic cell populations showed a 25% increase at 2 d of E2 treatment over controls that were quantified by fluorescence-activated cell sorter analysis. This indicates that E2 induced apoptosis in Rat1 + ER cells.
Animals↗
High-resolution harmonic gray-scale imaging of normal and abnormal vessels and tissues in animals.
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Animals↗
A rearrangement of the CDD gene at the 5' UTR produces two types of transcripts that contain a natural antisense region.
In order to study the regulatory region for transcription, the genomic DNA of the human CDD gene was cloned and analyzed. In contrast to previously reported CDD cDNA sequence, the sequence of the isolated genomic clone was rearranged at the 5' untranslated region (UTR) by a 30 bp inversion and a 57 bp insertion. Polymerase chain reaction (PCR) of chromosomal DNA and mRNA, and sequencing analysis of the PCR products revealed that sequences corresponding to both the genomic clone and the cDNA clone were present in the chromosomal DNA and were also transcribed into mRNA. Because of the 30 base inversion, the two types of CDD transcripts contain antisense sequences in their 5' UTR. Their role in the regulation of CDD expression is discussed.
5' Untranslated Regions↗
Phase I/II trial of PIXY321 (granulocyte-macrophage colony stimulating factor/interleukin-3 fusion protein) for treatment of inherited and acquired marrow failure syndromes.
Fourteen paediatric patients with advanced amegakaryocytic thrombocytopenia (AMT) or other bone marrow (BM) failure syndromes were enrolled on one of two phase I/II dose escalation studies of PIXY321. PIXY321 was administered subcutaneously in doses ranging from 250 to 750 mg/m2/d. No dose-limiting toxicity was observed. Peak absolute neutrophil count (ANC) was higher than baseline in all patients. Most transfusion-independent patients demonstrated elevation in haematocrit and/or platelet count. Trilineage haemopoietic responsiveness was evident in the three transfusion-independent patients. In these paediatric populations PIXY321 is well tolerated and merits consideration as a potential therapy.
Adolescent↗
Antimicrobial activity of magnolol and honokiol against periodontopathic microorganisms.
Magnolol (1) and honokiol (2), main compounds from the stem bark of Magnolia obovata Thunb., were evaluated for an antimicrobial activity against periodontopathic microorganisms, Porphyromonas gingivalis, Prevotella gingivalis, Actinobacillus actinomycetemcomitans, Capnocytophaga gingivalis, and Veillonella disper, and a cytotoxicity against human gingival fibroblasts and epithelial cells. Our results indicate that magnolol and honokiol, although less potent than chlorhexidine, show a significant antimicrobial activity against these microorganisms, and a relatively low cytotoxic effect on human gingival cells. Thus, it is suggested that magnolol and honokiol may have a potential therapeutic use as a safe oral antiseptic for the prevention and the treatment of periodontal disease.
Aggregatibacter actinomycetemcomitans↗
Complementation of the growth defect of an rnpA49 mutant of Escherichia coli by overexpression of arginine tRNA(CCG).
We previously found that overexpression of arginine tRNA(CCG) from Brevibacterium albidum complements the rnpA49 mutation, which is responsible for the thermosensitivity of Escherichia coli RNase P function. In this present work, we show that the E. coli homologue tRNA also complements the same mutation, but other tRNAs do not. These results suggest that the rnpA49 mutation causes a major cellular defect in an RNase P reaction to generate the mature arginine tRNA(CCG).
Base Sequence↗
Susceptibility of penicillin-susceptible and -resistant pneumococci to CFC-222, a new fluoroquinolone.
The in-vitro activity of 12 antibacterial agents against 98 clinical isolates of Streptococcus pneumoniae, including 54 penicillin-resistant strains, was determined by a standardized broth microdilution method. CFC-222, vancomycin and imipenem were the most active agents, with an MIC90 of 0.5 mg/L for the test strains. CFC-222 was 16-fold more potent than ciprofloxacin and ofloxacin against all strains tested, including both penicillin-susceptible and -resistant strains. The anti-pneumococcal activity of fluoroquinolones was not affected by penicillin susceptibility. These results indicate that CFC-222 is potentially useful for treating infection caused by penicillin-resistant strains of S. pneumoniae.
Anti-Infective Agents↗
Cloning and expression of human adenylate kinase 2 isozymes: differential expression of adenylate kinase 1 and 2 in human muscle tissues.
A cDNA clone coding for adenylate kinase 2B was isolated from fetal liver, and the expression of AK2 was investigated in human tissues. The ORF in the cDNA clone for human AK2B predicted a protein comprising 232 amino acids (25.6 kDa). The features of AK2A and AK2B sequences in human were the same as those in the bovine system. Each of the recombinant proteins, AK2A and AK2B, was expressed in Escherichia coli cells, and the purified recombinant proteins were enzymatically active. The distribution of AK2 transcripts in various human tissues was examined by Northern analysis. Unlike in the bovine system, it was found that the AK2A transcript was the major form of AK2 mRNA species in all human tissues. The transcripts of AK2 isozymes were relatively abundant in heart, liver, and also in skeletal muscle, where the expression level of AK2 was known to be low. Western blot analysis of AK isozymes in human heart and skeletal muscle revealed that AK2 protein was found only in heart, whereas AK1 was detected in both tissues. These tissue-specific expressions of the AK isozymes in human might suggest the presence of organ-specific regulation of the AK2 gene including a post-transcriptional control in skeletal muscle.
Adenylate Kinase↗
An experimental study on thrombogenicity of various metallic microcoils with or without thrombogenic coatings.
RATIONALE AND OBJECTIVES: Various metallic microcoils have been used as effective embolic materials (stainless steel, tungsten, and platinum). It also has been reported in several articles that the thrombogenicity of coils increased after soaking in thrombin solutions. To compare the thrombogenicity, the authors performed in vitro study, measuring whole blood clotting time (WBCT) of the various microcoils with and without coating with thrombin, gelatin, or both gelatin and thrombin. METHODS: Stainless steel, tungsten, and platinum microcoils were used in the study. For thrombin coating, the microcoils were soaked in 4 U/mL thrombin solution for 5 minutes, dried for 30 minutes, then soaked and dried again. For gelatin coating, the microcoils were soaked in 10% gelatin solution for 15 minutes, dried for 30 minutes, then soaked and dried again. For dual coating with both gelatin and thrombin, they were soaked in 10% gelatin solution first for 15 minutes, dried for 45 minutes, and soaked in 4 U/mL thrombin solution for 5 minutes, and dried. The authors introduced 1 mL of fresh blood immediately into the test tube containing the microcoil, and measured the time taken for complete coagulation of the 1 mL blood (WBCT). RESULTS: Untreated stainless steel, tungsten, and platinum microcoils reduced WBCT from 15.76 minutes to 7.15, 5.64, and 7.27 minutes, respectively. Stainless steel microcoils after soaking in thrombin, gelatin, and both gelatin and thrombin solutions showed WBCT of 5.77, 5.82, and 4.44 minutes, respectively. Tungsten microcoils after soaking in thrombin, gelatin, and both gelatin, and thrombin solutions showed WBCT of 3.25, 4.95, and 3.67 minutes, respectively. Platinum microcoils after soaking in thrombin, gelatin, and both gelatin and thrombin solutions showed WBCT of 5.70, 10.01, and 6.27 minutes, respectively. CONCLUSIONS: Untreated tungsten microcoils showed superior clot promoting activity compared with untreated stainless steel and platinum microcoils. Clot promoting activity of microcoils was increased after coating with thrombin, or both gelatin and thrombin compared with untreated microcoils.
Embolization, Therapeutic↗
The cardiac tissue-restricted homeobox protein Csx/Nkx2.5 physically associates with the zinc finger protein GATA4 and cooperatively activates atrial natriuretic factor gene expression.
Specification and differentiation of the cardiac muscle lineage appear to require a combinatorial network of many factors. The cardiac muscle-restricted homeobox protein Csx/Nkx2.5 (Csx) is expressed in the precardiac mesoderm as well as the embryonic and adult heart. Targeted disruption of Csx causes embryonic lethality due to abnormal heart morphogenesis. The zinc finger transcription factor GATA4 is also expressed in the heart and has been shown to be essential for heart tube formation. GATA4 is known to activate many cardiac tissue-restricted genes. In this study, we tested whether Csx and GATA4 physically associate and cooperatively activate transcription of a target gene. Coimmunoprecipitation experiments demonstrate that Csx and GATA4 associate intracellularly. Interestingly, in vitro protein-protein interaction studies indicate that helix III of the homeodomain of Csx is required to interact with GATA4 and that the carboxy-terminal zinc finger of GATA4 is necessary to associate with Csx. Both regions are known to directly contact the cognate DNA sequences. The promoter-enhancer region of the atrial natriuretic factor (ANF) contains several putative Csx binding sites and consensus GATA4 binding sites. Transient-transfection assays indicate that Csx can activate ANF reporter gene expression to the same extent that GATA4 does in a DNA binding site-dependent manner. Coexpression of Csx and GATA4 synergistically activates ANF reporter gene expression. Mutational analyses suggest that this synergy requires both factors to fully retain their transcriptional activities, including the cofactor binding activity. These results demonstrate the first example of homeoprotein and zinc finger protein interaction in vertebrates to cooperatively regulate target gene expression. Such synergistic interaction among tissue-restricted transcription factors may be an important mechanism to reinforce tissue-specific developmental pathways.
Animals↗
Pharmacological characteristics of MJ-451, a new benzopyran- derived ATP-sensitive potassium channel opener, in guinea pig isolated trachea.
In this study, we determined the pharmacological activities of MJ-451 (6-cyano-3S,4R-dihydro-2, 2-dimethyl-2H-3-hydroxy-4-[2-oxo-5S-1-hydroxmethyl)-1-pyrrolidinyl ]-1 -benzopyran) in guinea pig isolated trachea and compared its effects with those of cromakalim. MJ-451 (0.1-10 micromol/l) and cromakalim (0.01-1 micromol/l) produced concentration-dependent relaxation of guinea pig isolated trachea precontracted with carbachol (0.5 micromol/l) or histamine (1 micromol/l). MJ-451 (0.03-30 micromol/l), as well as cromakalim (0.03-30 micromol/l), caused a complete and concentration-dependent relaxation of guinea pig isolated trachea precontracted with 20 mmol/l KCl, but did not inhibit the spasmogenic effect of 80 mmol/l KCl. However, theophylline (30-3,000 micromol/l) caused a complete and concentration-dependent relaxation of guinea pig isolated trachea precontracted with either 20 or 80 mmol/l KCl. Propranolol (0.1 micromol/l) markedly antagonized the relaxant action of isoprenaline, but not that of MJ-451 in carbachol-contracted isolated trachea. 8-(p)-sulfophenyltheophylline (150 micromol/l), a selective P1 purinoceptor antagonist, had no effect against the tracheal relaxation induced by MJ-451, but markedly depressed the concentration-response curve of 5'-N-ethylcarboxamidoadenosine. Charybdotoxin (10 micromol/l), a large-conductance Ca2+-activated K+ channel blocker, failed to modify the relaxant activity of MJ-451 in carbachol-contracted isolated trachea. The ATP-sensitive K+ channel blocker, glibenclamide (0.1, 1 and 10 micromol/l) concentration-dependently antagonized the relaxant activity of MJ-451 in carbachol-contracted isolated trachea. It is concluded that MJ-451 is a selective ATP-sensitive K+ channel opener in the tracheal smooth muscle of the guinea pig.
Animals↗
Semicircadian rhythms of c-Fos expression in several hypothalamic areas during pregnancy in the rat: relationship to prolactin secretion.
Prolactin (PRL) serves an important luteotrophic function in the rat during early pregnancy, expressed as a nocturnal surge in the early morning and a diurnal surge in the late afternoon. Several areas of the hypothalamus, including the preoptic area (POA), the suprachiasmatic nucleus (SCN) and the ventromedial and dorsomedial nuclei (VM-DM) have been implicated in PRL surges. We investigated the temporal relationship between neuronal activity as measured by c-Fos immunocytochemistry in these areas and PRL secretion during early and late pregnancy. Brains were collected at nine time points (24:00, 02:00, 04:00, 06:00, 10:00, 14:00, 16:00, 18:00 and 20:00 h) on days 6-7 and three time points (02:00, 14:00 and 18:00 h) on days 14-15 of pregnancy. Plasma PRL levels determined by radioimmunoassay revealed two surges with peaks at 02:00 and 18:00 h and a trough at 14:00 h on days 6-7, which were absent on days 14-15 of pregnancy. The number of neurons expressing c-Fos in the anterior medial preoptic nucleus, the medial preoptic area and the medial preoptic nucleus, but not the anteroventral preoptic nucleus of the POA, and the VM-DM, showed a semicircadian rhythm which was maximal at 02:00 h or/and 04:00 and 18:00 h and reached the lowest value at 14:00 h, in parallel with the PRL surges in early pregnancy. However, the temporal pattern of c-Fos in these areas was reversed during late pregnancy, with a peak at 14:00 h and low levels at 02:00 and 18:00 h. PRL surges were absent and levels were uniformly low during these times. Neuronal activity in the SCN did not show any correlation with PRL surges. The dorsomedial subdivision of the SCN showed high neuronal activity during the daytime in both stages of pregnancy. Neuronal activity in the ventrolateral subdivision of the SCN was high during the nighttime in early pregnancy, however it exhibited high levels during the daytime in late pregnancy. These results suggest that the two daily surges of PRL secretion during the first half of pregnancy might be related to the temporal rhythm of neuronal activity in the POA and the VM-DM, and a major change in the pattern of neuronal activity in these hypothalamic areas might result in termination of the PRL surges at midpregnancy.
Animals↗
Enhanced de novo lipogenesis in the leptin-unresponsive pancreatic islets of prediabetic Zucker diabetic fatty rats: role in the pathogenesis of lipotoxic diabetes.
Overaccumulation of fat in pancreatic islets of obese ZDF fa/fa rats is believed to cause beta-cell failure and diabetes. Previously, we demonstrated that ZDF islets have an increased capacity to esterify fatty acids imported via the circulation. Here we examine the capacity of ZDF islets to synthesize fatty acids de novo. Compared with age-matched wild-type (+/+) control islets, acetyl CoA carboxylase (ACC) mRNA was fivefold and sixfold higher and fatty acid synthetase (FAS) was fourfold and sevenfold higher in prediabetic and diabetic ZDF islets, respectively. Incorporation of label from [14C]glucose into lipids was 84% higher in ZDF islets and was not suppressed normally by fatty acids. Chronic hyperleptinemia, induced by adenoviral transfer of leptin cDNA, reduced ACC and FAS mRNA in +/+ islets by 93 and 80%, respectively, but did not decrease the high ACC and FAS expression in islets of fa/fa rats. Recombinant leptin cultured with islets isolated from +/+ rats lowered ACC and FAS expression by 66 and 47%, respectively, but had no effect in fa/fa islets. We conclude that de novo lipogenesis in islets is controlled by leptin and remains low in leptin-responsive islets. It is increased in leptin-insensitive fa/fa islets, contributing to the fat overload that leads to beta-cell dysfunction and diabetes.
Acetyl-CoA Carboxylase↗
Sex differences in naturally occurring leg muscle pain and exertion during maximal cycle ergometry.
This investigation examined the role of sex in perceptions of leg muscle pain during exercise. Males (N = 26; age = 23.2 +/- 3.9) and females (N = 26; age = 21.9 +/- 3.5) matched on weekly energy expenditure completed a ramped maximal cycle ergometry test. Leg muscle pain thresholds were determined and pain intensity ratings as well as ratings of perceived exertion were obtained during and after exercise. The power output at pain threshold was lower in females (129.9 +/- 46.5 watts) compared to males (148.2 +/- 56.6 watts). Peak power output and peak pain intensity ratings were lower (P < 0.001) in females (211.3 +/- 39.1 watts; 5.5 +/- 2.9) compared to males (303.6 +/- 27.5 watts; 8.5 +/- 2.3). A Sex X Relative Intensity (i.e., % peak power output) ANOVA revealed that females reported lower pain ratings at each relative intensity examined (F = 17.7; df = 1.50; p < 0.001). The primary conclusion of this investigation is that females rate naturally occurring leg muscle pain as less intense than males when data are relativized to peak power output.
Adult↗