Biomedical subjects
Publications and source records attributed to J Ueda.
The copper ions in the imidazole-clusters of histidine-oligopeptide, His(His)nGly (n = 18) and N-acetyl-His(His)nGly(n = 8 and 18), showed the d-d transition bands at 520 nm and 630 nm and oxidase-like activities. Those with the d-d bands at 480 nm and 550 nm did not have the activity.
Plants have evolved on the earth, indicating the morphology, growth and development, and life cycle of plants are highly influenced by gravity as well as other environmental stimuli. Indeed, simulated microgravity on a clinostat or hypergravity on a centrifuge has recently been reported to change the growth and development of plants (Hoson et al. 1992, 1993, 1995, Rasmussen et al. 1994, Kasahara et al. 1995). Senescence is a final drastic phenomenon in life cycle of plants, which is characterized by the loss of total chlorophyll and protein, and/or the formation of the abscission (Osborne 1973, Thimann 1977, Addicott 1982). Many environmental stimuli as well as the qualitative and quantitative changes of plant hormones have been reported to affect plant senescence. Among those stimuli, light is the most important factor to regulate plant senescence (Leopold 1964). Dark condition promotes leaf senescence due to the decrease in endogenous level of cytokinin and/or the increase in that of abscisic acid or ethylene (Tetley and Thimann 1974, Gepstein and Thimann 1980). However, there are few reports concerning the effect of gravity on leaf senescence. Strenuous effort to learn leaf senescence under microgravity condition has been done using a three-dimensional (3-D) clinostat. In this paper, we report that simulated microgravity condition on a 3-D clinostat promoted the senescence of oat leaf segments in the dark. A possible mechanism of microgravity condition on promoting the senescence is also discussed.
The morphology, growth and development of higher plants are strongly influenced by environmental stimuli on the earth, which affect the changes in the dynamics of plant hormones in plants. Qualitative and quantitative changes in plant hormones are the most important internal factor to regulate plant growth and development. Among them, auxin (IAA) is of most significant. There are numerous reports concerning the physiological roles of auxin in plant growth and development (Matthysse and Scott 1984). One of the characteristics of auxin is to have the ability of polar transport along the vector of gravity on the earth (Schneider and Wightman 1978), suggesting that the activity of auxin polar transport is also important for the growth and development of plants. It has recently been reported that the normal activity of auxin polar transport in inflorescence axis of Arabidopsis thaliana was required for flower formation (Okada et al. 1991, Ueda et al. 1992). Considering the above evidence together with the fact that gravity affects the morphology, growth and development of higher plants, gravity might affect the qualitative and quantitative changes in plant hormones including the activity of auxin polar transport. In this paper, we report the effect of microgravity condition simulated by a three-dimensional (3-D) or a horizontal clinostat on the activity of auxin polar transport in inflorescence axis of Arabidopsis thaliana.
The reactivities of copper(II) complexes with cimetidine (Cim) and cyclo(histidylhistidyl) (CyHH), both of which are SOD model compounds, toward active oxygen species such as superoxide (O2-) and hydrogen peroxide (H2O2) were investigated by electron spin resonance-spin trapping and thiobarbituric acid methods. At physiological pH values, low concentrations of Cu(II) complexes (0.025 mM) with Cim and CyHH could scavenge O2-, but high concentrations of these compexes (0.25 mM) yielded hydroxyl radicals (.OH) during dismutation of O2-. These Cu(II) complexes could directly react with H2O2 to yield .OH. From these results, it is indicated that .OH formed during the dismutation of O2- by high concentration of SOD model compounds may be caused by the reaction of H2O2 generated form dismutation of O2- with Cu(II) complexes. Further, DNA single-stranded breakage was observed during the reactions of H2O2 with these Cu(II) complexes.
The reactivities of copper(II) complexes with histidine-containing oligopeptides towards active oxygen species such as hydrogen peroxide (H2O2) and superoxide ion (O2-) were investigated by electron spin resonance (ESR)-spin trapping and thiobarbituric acid (TBA) methods. At physiological pH values, Cu(II) complexes with oligopeptides containing histidyl residue at the N-terminal could more easily activate H2O2 to yield hydroxyl radical (.OH) than other Cu(II)-oligopeptide complexes containing histidyl residue in the second or third position. Further, it was suggested that since all Cu(II)-oligopeptide complexes examined could scavenge O2-, these complexes have SOD-like activities.
OBJECTIVE: To clarify the relationship between the noninvasive evaluation of hepatic mitochondrial function, the redox tolerance test, and cytochrome c oxidase activity of the liver, focusing on surgical risk in hepatic resection. DESIGN: Six-month randomized clinical trial. SETTING: Inpatients in surgical department. STUDY PARTICIPANTS: Forty patients who underwent hepatic resection (n = 36) and other abdominal operations (n = 4). INTERVENTION: Preoperative, noninvasive: The redox tolerance test, which measures the changes in arterial ketone body ratio in response to 75 g of oral glucose loading. Intraoperative, invasive: Cytochrome c oxidase activity and energy charge of the liver. MAIN OUTCOME MEASURE: Correlation of the index in the redox tolerance test (RTI) with cytochrome c oxidase activity, both of which predict the postoperative course. RESULTS: The RTI values were negatively correlated with the maximal velocity (Vmax) and Michaelis constant (Km) values of cytochrome c oxidase activity. The maximal velocity and Michaelis constant values in patients with RTI values above or equal to 0.5 (group A, n = 29) were significantly lower than those in patients with RTI values below 0.5 (group B, n = 11). Eight (72.7%) of 11 patients in group B experienced postoperative complications. CONCLUSION: The RTI is a noninvasive method of assessing the hepatic energy metabolism and can be a useful index for evaluating surgical risk in hepatectomy.
The roles and characteristics of the ventricle were examined using mean ventricular pressure (MVP) in ventricular-vascular association. One hundred and two patients with congenital heart diseases who had undergone cardiac catheterization were studied. They were divided into five groups: Group 1, atrial septal defect without pulmonary hypertension (PH); Group 2, ventricular septal defect (VSD) without PH; Group 3, VSD with PH; Group 4, pulmonary valvular stenosis; and Group 5 as a control group. Then, we examined the relationships between mean pulmonary artery pressure (MPAP) and mean right ventricular pressure (MRVP), and also between mean systemic arterial pressure (MSAP) and mean left ventricular pressure (MLVP) among the five groups. Furthermore, we defined new indicators to express the ease of blood flow through each ventricle. They were referred to as a conductance of the right ventricle (CDR) and a conductance of the left ventricle (CDL), respectively. Then they were compared among the five groups. The values of MPAP/MRVP and MSAP/MLVP were kept constant to be about 1.3 and 1.7, respectively. Furthermore, CDR was different between each group according to the property of the pulmonary vascular bed, whereas CDL took almost the same value among the five groups. The ventricle works as a converter of atrial blood flow so that it can achieve efficient blood transport.
Studies were conducted to determine if the amniotic fluid of a developing chick embryo (CEAm) could be used as a co-culture system for the maturation of pig oocytes. In Exp. 1, the pig oocytes were cultured in mTCM-199 (control) or day 3, 4 and 5 CEAm. The maturation rate of pig oocytes in the control vs CEAm was significantly higher (P < 0.001). The maturation rate of pig oocytes cultured in day 3 vs day 4 and 5 CEAm was significantly higher (P < 0.001). In Exp. 2, the pig oocytes were cultured in day 3 CEAm maintained either in a conventional incubator with 40-70% relative humidity or incubator with 5% CO2 in air atmosphere at 37 degrees C or 39 degrees C. A significantly lower maturation rate (P < 0.001) was obtained when CEAm were maintained in an incubator with 5% CO2 gas atmosphere regardless of the temperature. In Exp. 3, pig oocytes cultured in day 3 CEAm and mTCM-199 (control) were fertilized in vitro (IVF). The penetration and male pronucleus (MPN) formation of pig oocytes cultured in day 3 CEAm was significantly lower (P < 0.01) than those cultured in mTCM-199 medium. The results presented here demonstrate that CEAm could be used to induce maturation of pigs oocytes, however its efficacy is influenced by factors such as developmental stages of chick embryos, temperature and gas atmosphere.
The reactivities of new synthetic oligopeptides containing cysteine or histidine towards active oxygen species such as superoxide (O2-) and hydroxyl radical (.OH) were investigated by an electron spin resonance (ESR)-spin trapping method. At physiological pH values, these oligopeptides greatly suppressed the generation of .OH from the reaction of Cu(en)2 (en: ethylenediamine) with hydrogen peroxide (H2O2), although these oligopeptides did not scavenge O2-. The antioxidant mechanism of these oligopeptides is discussed.
At physiological pH values, Cu(II)-tetraglycine and Cu(II) complexes with peptides containing a histidyl residue at the N-terminal caused DNA strand breakage in the presence of H2O2, whereas Cu(II) complexes with peptides containing histidyl residue in the second or third position did not. Because of the correlation between the generation of hydroxyl radical and DNA strand scission, a mechanism for the reaction is proposed.
By means of the immunocytochemical method, the level of cytoplasmic lysozyme in leukocytes from healthy volunteers (n = 50) and from patients with uremia (n = 50), leukocytosis (n = 50), various forms of leukemia (n = 36) and myelodysplastic syndrome (MDS) (n = 7) were analysed, and compared with that of simultaneously assayed serum lysozyme. Both the cytoplasmic and serum levels of lysozyme in uremia and leukocytosis were significantly higher than normal subjects (p < 0.001). No correlation, however, was found between their cytoplasmic and serum levels of lysozyme. Morphological analysis for various kinds of leukemia and MDS indicated that myelocytic and monocytic cells became highly positive for lysozyme staining with maturation, and that lymphocytes, leukemic myeloblasts and monoblasts were negative. The cytoplasmic and serum lysozyme levels of leukemias or MDS having a number of lysozyme-positive cells were elevated as compared with those of normal individuals. Among them acute myelocytic leukemia (FAB M4) revealed an excellent correlation between the lysozyme levels in cytoplasm and in serum. The rest whose serum lysozyme level tend to be lower than the cytoplasmic one gave poor correlation. Thus, serum lysozyme level is not fully reflected by the cytoplasmic level. The dual determination of cytoplasmic and serum lysozyme is suggested to be helpful on estimating leukemia types, the degree of cellular maturation and total cell mass, and might also provide a valuable tool for prediction of prognosis for these disorders.
The adult mature fetal, but not immature fetal, lung is capable of actively transporting Na+ from the alveolar space. The reason for the impaired Na+ transport in the immature lung is not known; however, the apical membrane Na+ channel is the rate-limiting step for epithelial Na+ transport. This study determined whether transcripts coding for the adult rat colonic epithelial Na+ channel (alpha rENaC) were present in the fetal and adult lung and whether they were developmentally regulated. Similarly sized alpha rENaC transcripts were identified in RNA isolated from fetal and adult whole rat lung, primary cultures of fetal and adult alveolar epithelium, and adult rat whole kidneys, suggesting that the lung alpha rENaC is a similar transcript to that found in the salt-deprived rat colonic epithelium. There were low mRNA levels in 17- to 18-day gestational age (GA) fetal lungs and epithelium (term GA = 22 days), but these levels increased markedly during the saccular stage of lung development (20 days GA) and remained high in adult lungs. The combined administration of thyroid-releasing hormone and dexamethasone to pregnant rats between 16 and 18 days GA induced the expression of lung alpha rENaC in their fetuses. We conclude that alpha rENaC is expressed in mature fetal and adult alveolar epithelium and that it is influenced by hormones known to alter maturation of the fetal lung.
A simple method using ion-pair high-performance liquid chromatography was established for the rapid and precise determination of honokiol(3',5-di-2-propenyl-1,1'-biphenyl-2,4'-diol) and magnolol(5,5'-di-2-propenyl-1,1'-biphenyl-2,2'-diol) in eighteen species of oriental pharmaceutical decoctions containing Magnolia bark. An ODS column and a mixed solvent system of water involving 10 mM tetra-n-amyl-ammonium bromide (TAA) and acetonitrile (4:6) as a mobile phase were used for the separation. Honokiol and magnolol were eluted without interference of other coexisting components within 12 min.
A simple method using ion-pair high-performance liquid chromatography was established for the rapid and precise simultaneous determination of honokiol (3', 5-di-2-propenyl-1, 1'-biphenyl-2,4'-diol) and magnolol (5,5'-di-2-propenyl-1,1'-biphenyl-2,2'-diol) in oriental pharmaceutical decoctions containing Magnolia bark. An ODS column and a mixture of water involving 10 mM tetra-n-amylammonium bromide (TAA) and acetonitrile (4:6) as a mobile phase were used for the separation. Honokiol and magnolol were eluted without interference of other co-existing components within 12 min.
Early-stage pig embryos were collected from superovulated donor gilts (60-72 hr post hCG injection) and co-cultured in modified Brinster medium for ovum culture (mBMOC-2) + porcine oviduct epithelial cells (POEC) or in the amniotic fluid of a developing chick embryo (CEAm). The development rate to the compacted morulae or blastocyst stage was significantly higher (P < 0.01) in embryos co-cultured in CEAm (60.0%) than those co-cultured in mBMOC-2 + POEC (18.0%). The results indicate that CEAm could be used for production of compacted morulae or blastocysts from early-stage pig embryos. This culture system could also be valuable in situations where a CO2 controlled incubator is not available.
Seedlings of rice, maize, cress, pea, and azuki bean were grown on a three-dimensional clinostat and changes in their vegetative growth processes were analyzed. A balanced relationship among the length or the weight of each organ was observed in these species even on the clinostat. Growth of pea second internodes is supported by the transport of sugars from the cotyledons, which was not influenced by the clinostat rotation. Thus, growth correlation and the translocation of sugars normally occurred even under simulated microgravity conditions. In contrast, morphogenesis was clearly changed by the clinostat rotation. The axiality along the gravity vector disappeared and so seedlings formed themselves into a sphere-like shape on the clinostat. The dorsiventrality was indistinct in growth of maize coleoptiles on the surface of the earth, but the clinostat rotation induced a clear dorsinventral bending. These changes in morphogenesis may influence the long-term growth phenomena and modify the life cycle of higher plants under a microgravity environment.
The conversion of the closed circular double stranded supercoiled DNA (pBR322) to the nicked circular form and linear form was used to investigate DNA nicking induced by the reactions of Cu(II) complexes with hydrogen peroxide (H2O2). As a result, the dose-response curve for the CuII(en) (en:ethylenediamine) mediated H2O2 dependent DNA nicking was observed. For a fixed concentration of CuII(en)2 (1 mM), the concentration of H2O2 producing a maximum extent of DNA nicking was 100 mM. On the other hand, for a fixed concentration of H2O2 (100 mM), the concentration of CuII(en)2 was 1 mM. That is, when the concentration ratio of H2O2 to CuII(en)2 was 100, a maximum extent of DNA nicking was observed. This result is a good accordance with that observed by thiobarbituric acid (TBA) and ESR-spin trapping methods. This result gives first experimental evidence that Cu(II) complex did cause the DNA damage in the presence of H2O2. On the other hand, CuII(edta) (edta: ethylenediaminetetraacetic acid) did not cause the DNA strand breaks with the reaction of H2O2, but it was activated by addition of the biological reductant such as ascorbic acid in the presence of H2O2 to cause the DNA strand breaks.
Copper(II)-albumin complex did not directly react with hydrogen peroxide (H2O2). However, Cu(II)-albumin complex was easily reduced to Cu(I) complex by some biological reductants such as L-cysteine and L-ascorbic acid. Cu(I) complex thus formed could react with H2O2 to give hydroxyl radical (.OH) which was detected by electron spin resonance (ESR) spectroscopy using some water-soluble spin-traps. This result gives the first ESR evidence for the formation of OH radical by the reaction of Cu(II)-albumin with H2O2 in the presence of biological reductants.