Formation of trehalose from maltooligosaccharides by a novel enzymatic system.
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Amylose↗
Biomedical subjects
T Nakada
Publications and source records attributed to T Nakada.
Purification and properties of a novel enzyme, maltooligosyl trehalose synthase, from Arthrobacter sp. Q36.
Arthrobacter sp. Q36 produces a novel enzyme, maltooligosyl trehalose synthase, which catalyzes the conversion of maltooligosaccharide into the non-reducing saccharide, maltooligosyl trehalose (alpha-maltooligosyl alpha-D-glucoside) by intramolecular transglycosylation. The enzyme was purified from a cell-free extract to an electrophoretically homogeneous state by successive column chromatography on Sepabeads FP-DA13, DEAE-Sephadex A-50, Ultrogel AcA44, and Butyl-Toyopearl 650M. The enzyme was specific for maltooligosaccharides except maltose, and catalyzed the conversion to form maltooligosyl trehalose. The Km of the enzyme for maltotetraose, maltopentaose, maltohexaose, and maltoheptaose were 22.9 mM, 8.7 mM, 1.4 mM, and 0.9 mM, respectively. The enzyme had a molecular mass of 81,000 by SDS-polyacrylamide gel electrophoresis and a pI of 4.1 by gel isoelectrofocusing. The N-terminal and C-terminal amino acids of the enzyme were methionine and serine, respectively. The enzyme showed the highest activity at pH 7.0 and 40 degrees C, and was stable from pH 6.0 to 9.5 and up to 40 degrees C. The enzyme activity was inhibited by Hg2+ and Cu2+.
Amino Acid Sequence↗
Purification and characterization of a novel enzyme, maltooligosyl trehalose trehalohydrolase, from Arthrobacter sp. Q36.
A novel enzyme, maltooligosyl trehalose trehalohydrolase from Arthrobacter sp. Q36 was purified from a cell-free extract to an electrophoretically pure state by successive column chromatography on Sepabeads FP-DA13, Butyl-Toyopearl 650M, DEAE-Toyopearl 650S, and Toyopearl HW-55S. The enzyme specifically catalyzed the hydrolysis of the alpha-1,4-glucosidic linkage that bound the maltooligosyl and trehalose moieties of maltooligosyl trehalose. The Km of the enzyme for maltosyl trehalose, maltotriosyl trehalose, maltotetraosyl trehalose, and maltopentaosyl trehalose was 5.5 mM, 4.6 mM, 7.0 mM, and 4.2 mM, respectively. The enzyme had a molecular mass of 62,000 by SDS-polyacrylamide gel electrophoresis and a pI of 4.1 by gel isoelectrofocusing. The N-terminal amino acid of the enzyme was threonine. The enzyme showed the highest activity at pH 6.5 and 45 degrees C, and was stable from pH 5.0 to 10.0 and up to 45 degrees C. The activity was inhibited by Hg2+, Cu2+, Fe2+, and Zn2+.
Amino Acid Sequence↗
Magnetic resonance axonography of the rat spinal cord: postmortem effects.
The recent development of magnetic resonance (MR) axonography, which uses three-dimensional anisotropy contrast (3DAC), a new algorithm for the treatment of an apparent diffusion tensor, has provided an unprecedented opportunity for visualizing the anatomical details of the spinal cord in live animals. In this study, the authors investigated the sensitivity of the 3DAC method in detecting pathological conditions by obtaining chronological MR axonography of the rat spinal cord immediately after induction of cardiac arrest. The results clearly demonstrated that 3DAC is highly sensitive to any perturbation of physiological conditions. Trichromatic coefficient analyses indicated postmortem changes observed pictorially are indeed due to loss of anisotropy. The study further indicated the presence of at least two independent factors responsible for observed physiological anisotropy. Considering its rather simple implementation process and high anatomical resolution as well as its sensitivity to pathological alteration, MR axonography based on the 3DAC method appears to be the ideal noninvasive imaging technique for assessment of the spinal cord in biomedicine.
Animals↗
Ectopic sebaceous glands in the esophagus.
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Aged↗
A case of Chilaiditi's syndrome associated with strangulated volvulus of the sigmoid colon.
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Humans↗
In vivo 31P magnetic resonance spectroscopy for evaluation of testicular function in cryptorchid rats.
PURPOSE: To assess in vivo metabolism of rat testicles in experimental cryptorchidism, we used 31P magnetic resonance (MR) spectroscopy and compared testicular MR spectroscopic parameters with flow cytometric DNA analysis. MATERIALS AND METHODS: In vivo 31P MR spectroscopy and flow cytometric DNA analysis of rat testis were performed before and during 14 days of experimental cryptorchidism. RESULTS: The testicular phosphomonoester (PM)/ATP ratio showed a transient increase when multinuclear giant cells appeared in the seminiferous tubules. However, the ratio returned to the preoperative level when these cells disappeared. The phosphodiester (PD)/ATP ratio gradually decreased and the inorganic phosphate (Pi)/ATP ratio slowly increased. DNA flow cytometry showed a decrease in the percentage of haploid cells and an increase in the percentage of diploid cells from 7 days after cryptorchidism. The percentage of tetraploid cells did not change before and during cryptorchidism. CONCLUSION: This study indicates that in vivo 31P MR spectroscopy in combination with flow cytometric DNA analysis provides useful biochemical and histological information for evaluation of testicular function.
Animals↗
[Neutrophil elastase in postoperative pleural effusion of patients who had undergone pulmonary resections].
We determined whether activity of neutrophil elastase increases in pleural effusion after lobectomy for the neoplasm in the lung. Samples of pleural effusion were obtained 3 and 24 h postoperatively and samples of the peripheral blood were obtained preoperatively, 3 h, 24 h, and 1 w postoperatively, then the neutrophil counts, the levels of neutrophil elastase and alpha 1-antitrypsin by enzyme-linked immunosorbent assay, the activity of neutrophil elastase using succinyl-(L-alanine) 3-p-nitroanilide were measured. We found that the levels of neutrophil elastase increased 170 times greater in pleural effusion than in peripheral blood 3 h after lobectomy. However, the levels of alpha 1-antitrypsin did not increase in pleural effusion. The activity of neutrophil elastase increased to 0.54 +/- 0.1 mumol/min/l in pleural effusion 3 h after lobectomy, however the activity of neutrophil elastase was under the sensitivity level of detection in the peripheral blood after lobectomy. In conclusion, there is an imbalance between the levels of neutrophil elastase and alpha 1-antitrypsin in pleural effusion after lobectomy, the imbalance resulting in the increased activity of neutrophil elastase which probably is relating to tissue injury in the pleural spaces.
Aged↗
Remarkably suppressed manganese superoxide dismutase activity in malignant pheochromocytoma.
There are almost no special histopathological characteristics or criteria that exactly define a malignant pheochromocytoma. Tissue concentrations of catecholamine metabolites and superoxide dismutase activity have been proposed as possible candidates for discriminating between benign and malignant pheochromocytomas. Tissue concentrations of dihydroxyphenylalanine, metanephrine, normetanephrine, vanillylmandelic acid, and 3-methoxy-4-hydroxyphenylethylglycol were determined in 29 normal adrenal medullas, 13 benign pheochromocytomas and 6 malignant pheochromocytomas, respectively. The copper-zinc superoxide dismutase and manganese superoxide dismutase activities in remnants of these tissues were determined by interruption of nitric formation from hydroxylamines. Catecholamine metabolites and copper-zinc superoxide dismutase activity in benign and malignant pheochromocytomas were identical. Manganese superoxide dismutase activity in malignant pheochromocytoma was the lowest among the groups examined. These data suggest that the assay of catecholamine metabolites in removed specimens is not a reliable method for making a differential diagnosis of benign or malignant pheochromocytoma. However, a low level of manganese superoxide dismutase activity in malignant pheochromocytoma may be a marker for malignancy of this neoplasm.
Adrenal Gland Neoplasms↗
[Transport of ions across alveolar epithelial cells in resected human lungs].
Little information is available regarding the effect of ion transport agonists and antagonists on ion transport in the human lung. Therefore, we studied ion transport in lungs resected from patients with lung cancer. A test solution of 45 ml of isosmotic albumin was instilled into one segment of a resected lobe within 10 min of resection. Because protein leaves the air space very slowly, the concentration of alveolar protein over 4 h was used to quantify the volume of alveolar fluid. Ion transport was measured from the changes in ion concentrations and the volume of alveolar fluid. In the basal condition, the net efflux of Na+ and Cl- were 4.66 +/- 0.83 mEq/l/h and 3.52 +/- 0.84 mEq/l/h, respectively. In contrast, the net influx of K+ was 0.44 +/- 0.07 mEq/l/h. Amiloride (10(-5) M), an inhibitor of apical Na+ uptake, ouabain (10(-3) M), an inhibitor of Na(+)-K+ ATPase, and hypothermia (8 degrees C) reduced the efflux of Na+ and Cl-. Ouabain and hypothermia increased the net influx of K+. Terbutaline (10(-3) or 10(-4) M) increased the efflux of Na+ and Cl-, but did not affect the influx of K+. Propranolol (10(-4) M) and amiloride (10(-5) M) inhibited the terbutaline-induced increase in the transport of Na+ and Cl-. Alveolar fluid clearance was closely correlated with Na+ transport and with Cl- transport. However, the values of Na+ transport were greater than those of Cl- transport. These data suggest that Na+ transport is accompanied by Cl- transport and fluid movement out of the alveolar space in resected human lungs.
Adrenergic beta-Agonists↗
Inhibition by dexamethasone of human neutrophil apoptosis in vitro.
We investigated in this study the effect of a synthetic glucocorticoid hormone, dexamethasone (Dex), on apoptosis of human peripheral blood neutrophils. Dex inhibited spontaneous and tumor necrosis factor-alpha (TNF-alpha)-induced neutrophil apoptosis in a concentration- and time-dependent manner. This effect of Dex on neutrophil apoptosis was completely reversed by a glucocorticoid receptor antagonist, RU38486, and by cycloheximide. The decrease in sensitivity to TNF-alpha-induced apoptosis cannot be ascribed to a down-modulation of TNF receptors on these cells. These observations suggest that a glucocorticoid hormone participates in the regulation of neutrophil apoptosis and that inhibition of human neutrophil apoptosis by Dex is mediated through glucocorticoid-receptor-induced de novo synthesis of macromolecules. Possible mechanisms and implications of this phenomenon are discussed.
Apoptosis↗
Magnetic resonance axonography of the rat spinal cord.
In spite of dramatic advancement in biomedical imaging technologies, non-invasive visualization of anatomic detail of the spinal cord has remained a major challenge. Here, a novel color-coded contrast method for magnetic resonance imaging (MRI) which provides superb resolution of the spinal cord in live animals, comparable to that of histological preparations, is described. The method, referred to here as three dimensional anisotropy (3DAC) contrast MRI, displays cross-sectional images in the full visible color spectrum, encoding directional information regarding intravoxel anisotropic water motion in space. Since neuronal fibers, especially axons, possess significantly higher intravoxel anisotropic water motion compared with other elements in the nervous system, 3DAC is highly sensitive to axonal direction and density. Axonography of the spinal cord of rats obtained using this technique showed anatomic detail at a resolution hitherto unobtainable in live animals.
Animals↗
[Blood flow pattern in pulmonary atelectasis with color Doppler flow imaging].
Blood flow pattern in the lesion was evaluated in 4 patients with pulmonary atelectasis by color Doppler flow imaging synchronized electrocardiography. The pulsatile signal and triphasic signal were detected, whereas the continuous signal was not. It seemed that in pulmonary atelectasis the pulsatile signal was the blood flow signal in the pulmonary artery and the triphasic signal was the blood flow signal in the pulmonary vein.
Aged↗
Brain maturation and high-energy phosphate diffusivity: alteration in cytosolic microenvironment and effective viscosity.
Maturational changes in intracellular brain phosphocreatine (PCr) transport were investigated using 31P-nuclear magnetic resonance diffusion spectroscopy. The diffusivities of PCr showed significant maturational facilitation in rat brain in vivo. Physicochemical analysis of the cytosol microenvironment as a multicomponent solution, where one of the components is a dilute polymer, indicated that the observed developmental facilitation of PCr diffusivity is likely to be due to a decline in the concentration of the free amino acid taurine. Changes in the concentrations of biopolymers (i.e., proteins or lipids) have only little effect, if any, on PCr diffusivity. PCr diffusivity values of rat brain measured in vivo showed excellent quantitative agreement with the predicted values estimated using a model for multicomponent diffusion. The study confirmed that the taurine/N-acetylaspartate exchange observed during postnatal development of rat brain plays a major, it not unique, role in maturational facilitation of intracellular high-energy phosphate transport.
Albumins↗
[Comparison between MR imaging and pathological findings of the liver and VX2 carcinoma in rabbits after ethanol injection].
Ethanol injection was performed in the liver and VX2 carcinoma in rabbits and we evaluated changes with time by MR imaging, including dynamic study, and pathological findings. In the liver, the necrotic region was demonstrated as an area of low signal intensity on T1-weighted images and one of high intensity on T2-weighted images. Dynamic study after one and two weeks showed no enhancement in the necrotic region. But after a month, the pathologic analysis revealed growth of abundant fibrous stroma replacing the necrotic region, and progressive, concentric enhancement was seen in the necrotic region on dynamic study. On T1-weighted images obtained after the administration of contrast medium, delayed enhancement suggesting that the necrosis contained tissue with abundant interstitial space was seen. In VX2 carcinoma, the necrosis in the tumor was demonstrated as an iso or high signal intensity area on T1-weighted images and an area of low intensity on T2-weighted images, and did not show enhancement as in the dynamic study of the liver. From the pathological analysis, the presence or absence of space containing water among the necrotic cells was suggested to be responsible for these different findings on T1- and T2-weighted images between the liver and VX2 carcinoma after ethanol injection.
Animals↗
Localized proton spectroscopy of focal brain pathology in humans: significant effects of edema on spin-spin relaxation time.
Localized proton nuclear magnetic resonance (NMR) spectroscopy of human brain in two common focal pathologies producing brain edema (peritumor edema and acute edematous ischemic stroke) was performed utilizing point resolved spectroscopy (PRESS). The spectra obtained from the pathological tissues were characterized by a reduced N-acetyl-aspartate (NAA) to total creatine (Cr) ratio (NAA/Cr) and high level of lactate. While the spin lattice relaxation time (T1) of the main metabolite resonances, namely, those of NAA, Cr, and choline containing compounds (Cho), showed values similar to those of normal brain, the spin-spin relaxation time (T2) of these metabolites exhibited a dramatic shortening in pathological tissues. Serial postoperative measurements of T2 in two patients with peritumor edema showed a gradual recovery of the T2 shortening corresponding to improvement of the edema. The majority of localized spectroscopy studies in humans is performed using a sequence which utilizes spin echo signals with a fixed single echo time. Hence, the signal intensities of the metabolite resonances obtained are inherently T2 dependent. The current study underscores that cautious interpretation of clinical data with respect to metabolite quantification is warranted.
Adult↗
The granulocyte colony-stimulating factor produced in the human lung and its effect on liquid movement in the rabbit lung.
Levels of the granulocyte colony-stimulating factor (G-CSF) were determined in the plasma and resected lung tissue from patients who underwent pulmonary resection. Moreover, the effect of recombinant human (rh) G-CSF on the permeability of pulmonary endothelium and on liquid clearance from the alveolar spaces was investigated in rabbits. The plasma levels of G-CSF increased from 30 pg/ml preoperatively to 409 +/- 236 pg/ml 3 h postoperatively (P < 0.05), while the levels of G-CSF in the resected lung tissue were increased in the alveolar fluid, to 1,834 +/- 1,054 pg/ml, and in the pulmonary blood, to 5,466 +/- 2,019 pg/ml. It was found that rh G-CSF 25 micrograms administered into the subcutaneous tissue of rabbits increased extravascular lung water to 3.45 +/- 0.26 vs 2.98 +/- 0.20 in control experiments (P < 0.05); however, rhG-CSF 0.75 microgram/kg administered into the alveolar spaces did not affect liquid clearance from the alveolar spaces. The findings of this study led us to conclude that G-CSF is synthesized in the human lung and increases the permeability of pulmonary endothelium, but not liquid clearance across the alveolar epithelium.
Animals↗
Serum immunosuppressive acidic protein in haemodialysis patients with and without acquired cystic disease of the kidney.
Serum levels of immunosuppressive acidic protein (IAP) were measured in 20 haemodialysis patients with acquired cystic disease of the kidney (ACDK) and in 44 without it. Serum IAP levels in haemodialysis patients with and without ACDK were significantly elevated compared to that in controls. However, there was no considerable difference between haemodialysis patients with and without ACDK. A significant reduction in this marker was not found after dialysis treatment. This indicates that elevation of IAP may be related to an increased incidence of renal cell carcinoma in haemodialysis patients.
Adult↗