Formation of trehalose from maltooligosaccharides by a novel enzymatic system.
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Amylose↗
Biomedical subjects
T Sugimoto
Publications and source records attributed to T Sugimoto.
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↗
Xenotransplantation and high tumorigenicity of feline tumors in SCID mice.
Nine feline tumors resected at surgery were subcutaneously xenotransplanted into SCID mice. The primary take rate of the benign and malignant tumors was 50% (1/2) and 100% (7/7) respectively. Six of the eight primary tumor xenografts transplanted and grown in the first recipient were successfully transplanted serially. One feline mammary adenocarcinoma xenograft metastasized to the lung of a SCID mouse. The primary take rate of feline tumors to SCID mice was high and the established xenografts appear to be valuable tools for investigating growth and metastasis mechanisms, and various therapies for feline neoplasms.
Adenocarcinoma↗
Effects of 22-oxacalcitriol on bone metabolism in vitro: comparison with calcitriol--effects of 22-oxacalcitriol on osteoclast-like cell formation and bone-resorbing activity.
22-Oxacalcitriol (OCT), a synthetic vitamin D3 analog, can mimic the ability of calcitriol to differentiate leukemia and skin cells, to enhance the immune response and to suppress parathyroid hormone secretion, but has much less calcemic activity than that of calcitriol. The mechanism of this selective action remains not fully understood, and the actions of OCT on bone metabolism are little known. The present study was, therefore, designed to investigate the effects of OCT and calcitriol on: the proliferation and functions of osteoblastic MC3T3-E1 cells; osteoclast-like cell formation from hemopoietic blast cells in the absence of stromal cells as well as from unfractionated bone cells in the presence of stromal cells; bone resorption; and the proliferation of MC3T3-E1 cells via monocytes. 22-Oxacalcitriol and calcitriol inhibited [3H]thymidine (TdR) incorporation, alkaline phosphatase activity and collagen synthesis of MC3T3-E1 cells to a similar degree. Both OCT (10(-10)-10(-8) mol/l) and calcitriol significantly and similarly stimulated osteoclast-like cell formation from both hemopoietic blast cells and unfractionated bone cells. 22-Oxacalcitriol (10(-10) and 10(-8) mol/l) significantly stimulated bone resorption, although to a slightly lesser degree than did calcitriol. Human monocyte-conditioned medium (CM) significantly stimulated TdR incorporation into MC3T3-E1 cells. On the other hand, CM obtained from monocytes treated with calcitriol (10(-10)-10(-8) mol/l) significantly inhibited TdR incorporation in a dose-related fashion, whereas CM obtained from monocytes treated with OCT (10(-10)-10(-8) mol/l) significantly stimulated TdR incorporation in a dose-related fashion.(ABSTRACT TRUNCATED AT 250 WORDS)
Alkaline Phosphatase↗
Expression of mRNA encoding the prostaglandin F2 alpha receptor in bovine corpora lutea throughout the oestrous cycle and pregnancy.
The abundance of mRNA encoding the PGF2 alpha receptor in bovine corpora lutea at different phases of the oestrous cycle and pregnancy was examined in relation to the number of [3H]PGF2 alpha binding sites. Corpora lutea were removed from cyclic (early: 3-5 days after ovulation; mid-cycle: 8-12 days after ovulation; late: 15-18 days after ovulation; and regressed: 20-21 days after ovulation) and pregnant (early: fetal size 9-13 cm (2-3 months); mid-cycle: fetal size 42-43 cm (5-6 months); and late: fetal size 78-80 cm (8 months)) cows and subjected to total RNA preparation, in situ hybridization and membrane preparation for [3H]PGF2 alpha binding assay. Northern blot analysis demonstrated that expression of PGF2 alpha receptor mRNA progressively increased from the early phase to the late phase of the oestrous cycle, and was markedly reduced at the regressed phase; while constant amounts of mRNA were observed in early and middle pregnant corpora lutea, and there was a significant reduction at late pregnancy. Specific high affinity [3H]PGF2 alpha binding sites with Kd values of 18.3-31.1 nmol-1 were observed in the luteal membrane during the oestrous cycle and pregnancy; this is consistent with the expression of PGF2 alpha receptor mRNA. The number of receptors decreased at the regressed phase and in early pregnancy. These results strongly suggest that PGF2 alpha is involved in not only luteolysis but also luteal functions in both pregnant and nonpregnant cows.
Animals↗
Endothelin-1 stimulates tyrosine phosphorylation of p125 focal adhesion kinase in mesangial cells.
Endothelin-1 (ET-1) is known to induce the contraction and proliferation of glomerular mesangial cells. Because ET-1 was found to stimulate the tyrosine phosphorylation of unidentified cellular proteins in cultured mesangial cells, protein tyrosine kinase might serve as one of the important signals leading to various functions of ET-1. Focal adhesion kinase (p125FAK) is a newly identified cytoplasmic protein tyrosine kinase that is activated by the phosphorylation of its own tyrosine residue. Because p125FAK was found to play a role in the signal transduction of not only integrins but also various neurotransmitters, including bombesin, endothelin, and vasopressin in Swiss 3T3 cells and Rat-1 fibroblasts, whether ET-1 could stimulate the tyrosine phosphorylation of p125FAK in glomerular mesangial cells was examined. ET-1 stimulated the tyrosine phosphorylation of p125FAK by threefold to fourfold in cultured mesangial cells. This effect of ET-1 was detected at 1 min and reached a maximum within 5 min and was blocked by BQ-123, an antagonist for ETA receptor. A23187, a calcium ionophore, failed to stimulate the tyrosine phosphorylation of p125FAK, and ET-1 was able to stimulate the tyrosine phosphorylation of p125FAK, even in a calcium-free medium. The activation of protein kinase C (PKC) by phorbol 12, 13-dibutyrate resulted in a stimulation of the tyrosine phosphorylation of p125FAK, and an inhibition of PKC by calphostin C or staurosporine significantly reduced the effect of ET-1. Furthermore, prolonged treatment of the cells with phorbol 12, 13-dibutyrate markedly inhibited the ET-1-induced tyrosine phosphorylation of p125FAK. These results indicate that p125FAK might play a role in a signal transduction system of ET-1 in glomerular mesangial cells and that the ET-1-induced tyrosine phosphorylation of p125FAK is largely dependent on the PKC pathway.
Animals↗
Prospective study of lipoprotein(a) as a risk factor for atherosclerotic cardiovascular disease in patients with diabetes.
OBJECTIVE: To assess whether lipoprotein(a) [Lp(a)] is a risk factor for atherosclerotic cardiovascular disease in diabetes. RESEARCH DESIGN AND METHODS: We studied 221 patients with non-insulin-dependent diabetes mellitus (NIDDM) without diabetic complications who were followed for 2.2-3.1 years. Their serum Lp(a) levels were semiquantified by a rapid electrophoretic method that accurately discriminates high from low serum Lp(a) at the 20 mg/dl level. RESULTS: Seven of 105 diabetic patients with a high serum Lp(a) experienced a clinical event related to atherosclerotic cardiovascular disease. This incidence was significantly higher than that of the 110 diabetic patients with a low serum Lp(a). The logistic regression analysis revealed that Lp(a) was an independent risk factor for the event. CONCLUSIONS: Lp(a) is a significant risk factor for atherosclerotic cardiovascular disease in NIDDM.
Adult↗
[Analysis of patients with excellent motor recovery after large infarction in the middle cerebral artery territory including the cortex].
We reported 6 cases of excellent motor recovery after a large infarction in the middle cerebral artery territory including the cortex. All patients were men (aged 67 to 80); 4 had left hemiplegia and 2 had right hemiplegia. They had abrupt onset of focal neurologic symptoms and signs, suggesting embolic stroke. The consciousness level, according to the Japan coma scale, was grade II in 4 patients and normal in the other 2. Atrial fibrillation was present in 4 patients and premature atrial and ventricular contractions were seen in 1 each. Hypertension was present in 3 patients and diabetes mellitus in 1. The motor plegia gradually improved after 1 to 3 days and almost completely disappeared at 12 days after onset. All patients were eventually able to walk alone without any aids. However, aphasia persisted in 2 patients with left hemispheric damage and left unilateral spatial neglect in 3 patients with right hemispheric damage. A cerebral blood flow analysis by single photon emission computed tomography, using [123I] isopropyliodoamphetamine or technetium 99m hexamethylpropylenamine oxime, demonstrated increased blood flow in the frontal lobe cortex surrounding the infarcted region in 5 patients. These patients showed good recovery from motor deficit, even though, motor symptoms did not begin to improve until 1 to 3 days after onset of stroke. We suggest that there is a subgroup of stroke patients, whose severe motor deficit starts to improve even 3 days after onset of a large infarction in the middle cerebral artery territory including the cerebral cortex.
Aged↗
[Three cases of postoperative laryngopharyngeal edema following nonsimultaneous bilateral radical neck dissection].
Three cases of postoperative laryngopharyngeal edema following nonsimultaneous radical neck dissection are presented. Case 1 was a 65-year-old male with tongue cancer and left cervical lymph node metastases. Hemiglossectomy, reconstruction of the floor of the mouth with a free rectus abdominis flap, and left radical neck dissection had been performed. Postoperatively, the tongue and left upper neck were irradiated. Seven months later, right cervical lymph node metastases were observed. Right radical neck dissection was performed, and immediately after extubation, upper airway stenosis due to severe laryngopharyngeal edema occurred. Emergent tracheostomy saved his life. Case 2 was a 55-year-old female with tongue cancer and right cervical lymph node metastases. Radium needles had been implanted in the tongue, and right radical neck dissection was performed. Three months later, left cervical lymph node metastases were found. Left radical neck dissection was performed and, as in Case 1, upper airway stenosis revealed immediately after extubation. Since the situation was anticipated, an immediate tracheostomy was done. Case 3 was a 43-year-old male with laryngeal cancer and left cervical lymph node metastasis. Irradiation of the larynx and the bilateral upper neck followed by left radical neck dissection and partial laryngohypopharyngectomy had been performed. Five years later, right cervical lymph node metastasis was observed. Right radical neck dissection was performed, and laryngoscopic examination before extubation revealed severe laryngopharyngeal edema. In this case, tracheostomy was performed before extubation. To our knowledge, there have been only five cases of postoperative laryngopharyngeal edema, following nonsimultaneous radical neck dissection, reported in the literature.
Adult↗
[Angiotrophic lymphoma in the paranasal sinuses].
Angiotrophic lymphoma (neoplastic angioendotheliosis) is a peculiar disease which increases large extraordinary sized cells originating from B lymphocytes, in the small blood vessels and the capillary vessels of each viscera of the whole body, including brain. This disease, which was first reported by Pfleger and Tappeiner in 1959, has many clinical manifestations. CNS, skin, lung, kidney, and adrenal gland are often damaged by the disease. A case of this disease appearing in the paranasal sinus with successful remission following chemotherapy is reported. The patient was a 78-year-old woman with bilateral occulomotor nervous paralysis. Ethmosphenoidectomy was conducted under a working diagnosis of pansinusitis following CT. The surgical specimens were studied histopathologically and diagnosed as angiotrophic lymphoma. Six courses of chemotherapy (THP-COP) were applied. This disease is not necessarily rare, but the possibility of its being overlooked without enough diagnosis and treatment is very high. If we detect and treat it at an early stage, recovery of the disease can be expected, as in the case described above.
Aged↗
[A case of type A acute aortic dissection successfully treated with a ringed intraluminal graft: a new technique of graft insertion].
A-77-year old woman was hospitalized at our hospital presenting with severe chest and back pain. A computed tomographic scan revealed acute type A aortic dissection and intraoperative ultrasound showed an entry near the brachiocephalic artery. Selective cerebral perfusion using flexible 12 Fr balloons was performed for brain protection. The distal aorta was trimmed just proximal to the entry using felt strips and a 24 mm ringed intraluminal graft (ILG) was inserted under it successfully. The patient did well after the operation. Insertion of a ringed ILG is a simple and easy technique, however if an entry is located near the aortic arch, insertion is difficult because of intimal retraction to the arch. And an additional intimal tear sometimes occurs at the site of tape ligation. The method which we presented seemed to provide safer insertion of the proximal ring without these problems.
Acute Disease↗
[Hemodynamics in obesity].
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Hemodynamics↗
Signal transduction mechanisms of parathyroid hormone- and parathyroid hormone-related-peptide-stimulated osteoclast-like cell formation from hemopoietic blast cells.
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Animals↗
A surgical case of Takayasu's arteritis with bilateral pulmonary artery stenosis.
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Adult↗
Return of spontaneous respiration in an infant who fulfilled current criteria to determine brain death.
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Brain Death↗
[Hematologic improvement by alpha-interferon in a case of the 5q- syndrome with basophilia and eosinophilia].
An 82-year-old female was diagnosed as having 5q- syndrome accompanied by basophilia, eosinophilia and thrombocytosis. Since cytogenetic abnormalities other than 5q- were also detected, she was considered to be type B of 5q- syndrome. According to the FAB classification a diagnosis of refractory anemia with excess of blasts (RAEB) was made. She was treated with recombinant interferon alpha 2b, because peripheral blood findings resembled those of chronic myelogenous leukemia. Interferon was effective, and resulted in disappearance of peripheral blasts, normalization of platelet numbers, and improvement of basophilia. These changes were interferon-dependent. After 1 year, cytogenetic studies revealed that about 2/3 of metaphases showed normal karyotype. Twenty months after diagnosis, myeloid blastic crisis occurred and eventually the patient died. However, treatment with interferon in this case might support the usefulness of the drugs for this kind of disease.
Aged↗
[MAP kinase cascade in cultured rat mesangial cells].
In order to evaluate the intracellular signaling pathway of endothelin 1 (ET-1), we examined mitogen-activated protein kinase (MAPK) cascade in cultured rat glomerular mesangial cells. Treatment of quiescent mesangial cells with ET-1 increased kinase activities toward bovine myelin basic protein (MBP). Maximal activation was at 10 min and ED50 was about 5 nM. The 44- and 42-kDa kinases were activated in MBP containing gel kinase assay. These kinases were identified as extracellular signal regulated kinase (ERK) 1 and ERK2 with immunoblotting, respectively. MAPK or ERK kinase (MEK), one of the MAPK kinases, was present in rat mesangial cells and ET-1 also activated this MAPK kinase. These results indicate that MAPK kinase and MAP kinase are rapidly activated by ET-1 and may modulate cellular functions in rat mesangial cells.
Animals↗