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1.
Anticancer Res ; 43(11): 5051-5059, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37909949

ABSTRACT

BACKGROUND/AIM: Chemotherapy is the standard treatment for patients with unresectable gastric cancer (UGC); however, the survival outcomes are poor. This study investigated the predictive values of skeletal muscle mass (SMM) index (SMI) before second-line chemotherapy and the survival outcomes of patients with UGC. PATIENTS AND METHODS: A total of 79 patients diagnosed with UGC at our hospital who received at least second-line palliative chemotherapy were included. The cross-sectional SMM at the third lumbar vertebra was obtained before second-line chemotherapy. SMI was defined as the muscle area normalized by height squared (m2), and SMI before second-line chemotherapy was defined as 2ndSMI. RESULTS: Using 2ndSMI for men and women (35.4 and 31.7 cm2/m2, respectively) as the cutoff value, patients were divided into high (2ndSMIHigh; n=54) and low (2ndSMILow; n=25) 2ndSMI groups. The number of patients receiving fourth-line chemotherapy was significantly higher in the 2ndSMIHigh group than in the 2ndSMILow group (p=0.039). The overall survival time after the start of second-line chemotherapy was significantly higher in the 2ndSMIHigh group than in the 2ndSMILow group (p=0.008). The incidence of grade 3 or 4 side effects was significantly higher in the 2ndSMILow than in the 2ndSMIHigh group (p=0.028). The multivariate analysis identified 2ndSMI as independent prognostic factor after the start of second-line chemotherapy. CONCLUSION: The 2ndSMILow group had a significantly worse prognosis and significantly less conversion to fourth-line chemotherapy than the 2ndSMIHigh group. Moreover, 2ndSMILow was associated with grade 3 or 4 side effects of second-line chemotherapy.


Subject(s)
Drug-Related Side Effects and Adverse Reactions , Stomach Neoplasms , Male , Humans , Female , Cross-Sectional Studies , Stomach Neoplasms/drug therapy , Prognosis , Muscle, Skeletal
2.
In Vivo ; 37(6): 2662-2668, 2023.
Article in English | MEDLINE | ID: mdl-37905614

ABSTRACT

BACKGROUND/AIM: Preoperative osteopenia, defined as low bone mineral density, is a prognostic factor in patients with digestive tract cancers, including gastric cancer (GC). However, the correlation between preoperative osteopenia and GC in elderly patients is unclear. PATIENTS AND METHODS: We enrolled 251 patients who had undergone curative surgery for histopathologically diagnosed gastric adenocarcinoma from January 2008 to December 2012. Patients were classified into the non-elderly group (n=169) and the elderly group (n=82). Bone mineral density was calculated as the average pixel density (Hounsfield units) within a circle of the mid-vertebral core at the bottom of the 11th thoracic vertebra on preoperative computed tomography. RESULTS: Although overall survival was significantly shorter in the elderly compared to the non-elderly group (p=0.0062), there was no significant difference in disease-specific survival between the two groups (p=0.71) because of the higher rate of death from other diseases. In addition, the elderly group had a significantly higher incidence of osteopenia (p<0.001) and a significantly lower prognostic nutritional index (p<0.001). Multivariate analysis revealed that preoperative osteopenia and a low preoperative prognostic nutritional index were significant risk factors for death from other diseases after gastrectomy in elderly patients. CONCLUSION: In elderly patients with GC, preoperative osteopenia is an important factor to consider in terms of both curability and death from other diseases.


Subject(s)
Adenocarcinoma , Bone Diseases, Metabolic , Stomach Neoplasms , Humans , Aged , Middle Aged , Prognosis , Adenocarcinoma/surgery , Stomach Neoplasms/pathology , Gastrectomy/adverse effects , Bone Diseases, Metabolic/etiology , Bone Diseases, Metabolic/surgery , Risk Factors , Retrospective Studies
3.
Anticancer Res ; 43(8): 3665-3672, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37500136

ABSTRACT

BACKGROUND/AIM: Preoperative osteopenia, defined as low bone mineral density (BMD), has been reported as a prognostic factor in patients with digestive tract cancers. However, the correlation between preoperative osteopenia and the prognosis of gastric cancer (GC) remains unclear. The aim of this study was to reveal the importance of preoperative osteopenia as a prognostic factor in patients undergoing gastrectomy for GC. PATIENTS AND METHODS: We enrolled 251 patients who had undergone curative surgery for histopathologically diagnosed gastric adenocarcinoma from January 2008 to December 2012. BMD was calculated as the average pixel density (Hounsfield units) within a circle of the mid-vertebral core at the bottom of the 11th thoracic vertebra on preoperative computed tomography. RESULTS: Osteopenia had a high area under the curve and predictive value for both overall survival (OS) and disease-specific survival (DSS). The study cohort was categorized into an osteopenia group and non-osteopenia group based on the optimal BMD cutoff values for OS (157.5) and DSS (195) determined by receiver operating characteristic analysis. The multivariate analysis revealed that OS (hazard ratio=3.607, p<0.001) and DSS (hazard ratio=2.797, p=0.03) were significantly worse in patients with than without preoperative osteopenia. CONCLUSION: Preoperative osteopenia is associated with poor OS and DSS in patients undergoing gastrectomy for GC.


Subject(s)
Bone Diseases, Metabolic , Stomach Neoplasms , Humans , Stomach Neoplasms/complications , Stomach Neoplasms/surgery , Retrospective Studies , Prognosis , Risk Factors , Gastrectomy/adverse effects
4.
Psychol Rep ; 118(1): 5-22, 2016 Feb.
Article in English | MEDLINE | ID: mdl-29693520

ABSTRACT

Behavioral activation is a validated intervention for depression, which helps depressed people re-engage overt behaviors to facilitate contacts with reinforcing environmental contingencies and subsequent reductions in depression. Moreover, behavioral activation deals with values that are based on acceptance and commitment therapy. However, there is no empirical study that examines the role of behavior in line with values in behavioral activation. This study examined the role of behavior in line with values in behavioral activation by examining the association between behavior in line with values and variables of behavioral activation intervention targets, as well as the mediating effect of behavioral commitment. Japanese versions of the Personal Values Questionnaire II, the Behavioral Activation for Depression Scale, the Environmental Reward Observation Scale, and the Center for Epidemiological Studies Depression were completed by 292 Japanese undergraduate students ( M age = 19.2 yr., SD = 1.7; 65 men, 226 women, 1 unknown). Results indicated that behavior in line with values was associated with focused, goal-directed activation and completion of scheduled activities, which were mediated by behavioral commitment to values.

5.
Radiat Prot Dosimetry ; 167(1-3): 219-22, 2015 Nov.
Article in English | MEDLINE | ID: mdl-25956780

ABSTRACT

Due to releases of radionuclides in the Fukushima Daiichi Nuclear Power Plant accident, radiocesium ((134)Cs and (137)Cs) has been incorporated into large varieties of plant species and soil types. There is a possibility that radiocesium taken into plants is being diffused by pollen. Radiocesium concentrations in cedar pollen have been measured in Ome City, located in the Okutama area of metropolitan Tokyo, for the past 3 y. In this research, the variation of radiocesium concentrations was analysed by comparing data from 2011 to 2014. Air dose rates at 1 m above the ground surface in Ome City from 2011 to 2014 showed no significant difference. Concentration of (137)Cs contained in the cedar pollen in 2012 was about half that in 2011. Between 2012 and 2014, the concentration decreased by approximately one-fifth, which was similar to the result of a press release distributed by the Japanese Ministry of Agriculture, Forestry and Fisheries.


Subject(s)
Cedrus/chemistry , Cesium Isotopes/analysis , Fukushima Nuclear Accident , Pollen/chemistry , Radiation Monitoring/methods , Soil Pollutants, Radioactive/analysis , Air Pollutants, Radioactive/analysis , Biological Assay/methods , Japan , Radiation Dosage , Radioactive Fallout/analysis , Reproducibility of Results , Sensitivity and Specificity , Spatio-Temporal Analysis
6.
Kyobu Geka ; 60(10): 903-5, 2007 Sep.
Article in Japanese | MEDLINE | ID: mdl-17877009

ABSTRACT

This study reports on a 57-year-old woman who underwent a 3rd mitral valve replacement and presented with complaints of fatigue. Laboratory examination revealed severe hemolytic anemia, and trans-esophageal echocardiography revealed a paravalvular leak (PVL) around the prosthetic valve at the posterior trigone in the mitral position. PVL was regarded as the cause of hemolytic anemia. At surgery, a small tissue defect was detected around the calcified posterior trigone of the mitral annulus with no evidence of infective endocarditis. The mitral PVL was successfully repaired with suture closure of the annular defect. The postoperative course was uneventful: postoperative echocardiography revealed no evidence of PVL, and the hemolytic anemia subsided.


Subject(s)
Heart Valve Prosthesis Implantation , Heart Valve Prosthesis , Mitral Valve Insufficiency/surgery , Mitral Valve Stenosis/surgery , Mitral Valve/surgery , Prosthesis Failure , Anemia, Hemolytic/etiology , Female , Humans , Middle Aged , Reoperation , Suture Techniques
7.
Kyobu Geka ; 59(12): 1103-5, 2006 Nov.
Article in Japanese | MEDLINE | ID: mdl-17094550

ABSTRACT

A 60-year-old woman had previously undergone aortic valve replacement for aortic regurgitation. As the aortic wall was elastic hard, inflammatory change was suspected; therefore, we undertook a partial biopsy of the ascending aortic wall and the intraoperative pathological specimens were compatible with aortitis syndrome. As there was no active inflammatory change, she was diagnosed as inactive aortitis syndrome and steroid therapy was not applied. Seven years later, a follow-up computed tomography (CT) showed an ascending aortic aneurysm of 65 mm in diameter. Aortic root replacement was planned based on a clinical diagnosis of an aneurysm of the ascending aorta. The patient was discharged without complication 21 days after surgery. It is possible that an inactive stage of aortitis may lead to late dilatation of the ascending aorta; therefore, careful postoperative follow-up is necessary in such cases.


Subject(s)
Aortic Aneurysm/surgery , Aortic Arch Syndromes/complications , Aortic Valve/surgery , Blood Vessel Prosthesis Implantation , Heart Valve Prosthesis Implantation , Aorta/pathology , Aortic Aneurysm/etiology , Aortic Valve Insufficiency/surgery , Dilatation, Pathologic , Female , Humans , Middle Aged , Reoperation
8.
Kyobu Geka ; 58(13): 1163-5, 2005 Dec.
Article in Japanese | MEDLINE | ID: mdl-16359018

ABSTRACT

We report 2 cases of cardiac papillary fibroelastomas in adults. Case 1: A 61-year-old man was admitted because echocardiography showed a 1 cm pedunculated papillary tumor in the left atrium. In an operation, it was located in the left atrium near the mitral valve and was resected along with a 5 mm margin of endocardium. Case 2: A 60-year-old woman had a 1 cm mobile tumor in the right ventricle near the tricuspid valve located by echocardiography in a preoperative examination of a ventricular septal defect. In an operation, a pedunculated tumor located in the right ventricle was resected. In these 2 cases, histopathology showed the tumor to be a papillary fibroelastoma. Almost all cardiac papillary fibroelastoma are closely related to the cardiac valve, but in these cases, the tumors were located in the left atrium, and the right ventricle, respectively, which is quite rare.


Subject(s)
Fibroma/surgery , Heart Neoplasms/surgery , Cardiac Surgical Procedures/methods , Female , Fibroma/diagnostic imaging , Heart Atria , Heart Neoplasms/diagnostic imaging , Heart Ventricles , Humans , Male , Middle Aged , Ultrasonography
9.
Kyobu Geka ; 57(4): 325-8, 2004 Apr.
Article in Japanese | MEDLINE | ID: mdl-15071868

ABSTRACT

A 62-years old man had plural aneurysms from the aortic arch to the descending aorta. Y-grafting had been performed twice for an abdominal aortic aneurysm. We performed the first operation which involved aortic valve and arch replacement under deep hypothermia with selective cerebral perfusion. During the operation, hemodynamics was stable, but after the operation he developed paraplegia due to ischemic change in the spinal cord. It was considered that the cause of the ischemia might have been the changing of the blood supply to the spinal cord. In patients with severe atherosclerosis, the blood supply for the spinal cord needs to be very strictly determined.


Subject(s)
Aorta, Thoracic/surgery , Aortic Aneurysm, Thoracic/surgery , Aortic Valve/surgery , Postoperative Complications/etiology , Spinal Cord Ischemia/etiology , Arteriosclerosis/complications , Blood Vessel Prosthesis Implantation , Heart Valve Prosthesis Implantation/methods , Humans , Hypothermia, Induced , Male , Middle Aged , Paraplegia/etiology , Perfusion/methods , Spinal Cord/blood supply
10.
Behav Res Ther ; 42(5): 601-12, 2004 May.
Article in English | MEDLINE | ID: mdl-15033504

ABSTRACT

The purpose of this study was to compare the frequency of anxiety symptoms and their association with gender and age in Japanese and German children using the Spence Children's Anxiety Scale (SCAS). A total of 1837 children (862 from Germany and 975 from Japan) between the age of 8 and 12 years were investigated. Results revealed that German children reported significantly higher symptoms of separation anxiety, social phobia, obsessive compulsive disorder, and generalized anxiety disorder than Japanese children. Conversely, Japanese children reported significantly higher scores on symptoms related to physical injury fear. In both countries, girls scored higher than boys on all the scales of the SCAS. Symptoms of separation anxiety and panic decreased with age, whereas social phobia increased with age. The findings underscore the impact of culture on children's anxiety.


Subject(s)
Anxiety Disorders/ethnology , Child , Cross-Cultural Comparison , Female , Germany/epidemiology , Humans , Japan/epidemiology , Male , Psychiatric Status Rating Scales
11.
Appl Microbiol Biotechnol ; 56(3-4): 465-73, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11549021

ABSTRACT

A region downstream of the gene for pullulan-hydrolyzing alpha-amylase, TVA II, of Thermoactinomyces vulgaris R-47 was sequenced, and an open reading frame encoding an enzyme homologous to glucoamylase was found. The nucleotide sequence of this enzyme, designated TGA, consists of 1,953 base pairs corresponding to a protein of 651 amino acid residues. The TGA gene was subcloned and expressed in Escherichia coli. Enzymatic analyses showed that, like other glucoamylases, TGA produced beta-D-glucose from its substrate. However, TGA hydrolyzed maltooligosaccharides such as maltotetraose and maltose more efficiently than starch, while fungal glucoamylases preferred starch to maltooligosaccharides. The primary structure of TGA resembled a putative glucoamylase from the hyperthermophilic archaeon Methanococcus jannaschii (MGA), while homologies between TGA and the fungal glucoamylases were low. The enzymatic properties of recombinant MGA produced in E. coli cells were similar to those of TGA. These findings indicate that TGA and MGA are novel glucoamy-lase-type enzymes with oligosaccaharide-metabolizing activity.


Subject(s)
Glucan 1,4-alpha-Glucosidase/genetics , Methanococcus/enzymology , Micromonosporaceae/enzymology , alpha-Amylases/genetics , Amino Acid Sequence , Base Sequence , Cloning, Molecular , Glucan 1,4-alpha-Glucosidase/chemistry , Glucans/metabolism , Methanococcus/genetics , Micromonosporaceae/genetics , Molecular Sequence Data , Restriction Mapping , Sequence Alignment , Sequence Analysis, DNA , Substrate Specificity , alpha-Amylases/chemistry
12.
Carbohydr Res ; 334(4): 309-13, 2001 Sep 07.
Article in English | MEDLINE | ID: mdl-11527532

ABSTRACT

Phe286 located in the center of the active site of alpha-amylase 2 from Thermoactinomyces vulgaris R-47 (TVAII) plays an important role in the substrate recognition for cyclomaltooligosaccharides (cyclodextrins). The X-ray structures of mutant TVAIIs with the replacement of Phe286 by Ala (F286A) and Tyr (F286Y) were determined at 3.2 A resolution. Their structures have no significant differences from that of the wild-type enzyme. The kinetic analyses of Phe286-replaced variants showed that the variants with non-aromatic residues, Ala (F286A) and Leu (F286L), have lower enzymatic activities than those with aromatic residues, Tyr (F286Y) and Trp (F286W), and the replacement of Phe286 affects enzymatic activities for CDs more than those for starch.


Subject(s)
Amino Acid Substitution/genetics , Cyclodextrins/chemistry , Micromonosporaceae/enzymology , Micromonosporaceae/genetics , Phenylalanine/chemistry , alpha-Amylases/chemistry , alpha-Amylases/genetics , Alanine/genetics , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Binding Sites/genetics , Crystallography, X-Ray , Kinetics , Mutagenesis, Site-Directed , Phenylalanine/genetics , Tyrosine/genetics
13.
Biosci Biotechnol Biochem ; 65(3): 619-26, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11330677

ABSTRACT

The structures of Thermoactinomyces vulgaris R-47 alpha-amylase II mutant (d325nTVA II) complexed with substrate analogues, methyl beta-cyclodextrin (m beta-CD) and maltohexaose (G6), were solved by X-ray diffraction at 3.2 A and 3.3 A resolution, respectively. In d325nTVA II-m beta-CD complex, the orientation and binding-position of beta-CD in TVA II were identical to those in cyclodextin glucanotransferase (CGTase). The active site residues were essentialy conserved, while there are no residues corresponding to Tyr89, Phe183, and His233 of CGTase in TVA II. In d325nTVA II-G6 complex, the electron density maps of two glucosyl units at the non-reducing end were disordered and invisible. The four glucosyl units of G6 were bound to TVA II as in CGTase, while the others were not stacked and were probably flexible. The residues of TVA II corresponding to Tyr89, Lys232, and His233 of CGTase were completely lacking. These results suggest that the lack of the residues related to alpha-glucan and CD-stacking causes the functional distinctions between CGTase and TVA II.


Subject(s)
Cyclodextrins/chemistry , Oligosaccharides/chemistry , alpha-Amylases/chemistry , beta-Cyclodextrins , Glucosyltransferases/chemistry , Micromonosporaceae/enzymology , Models, Molecular , Protein Structure, Tertiary , Substrate Specificity , alpha-Amylases/physiology
14.
J Psychiatr Res ; 35(2): 95-104, 2001.
Article in English | MEDLINE | ID: mdl-11377438

ABSTRACT

The combined dexamethasone/CRH test (DEX/CRH test) is reported to produce augmented ACTH and cortisol responses in various psychiatric disorders as well as in some non-psychiatric conditions. To examine whether stress affects the outcome of DEX/CRH test, two stress groups in a repeated measures design were compared to an age-matched control group with regard to the psychological, autonomic and neuroendocrine responses after the combined dexamethasone and CRH challenge. Cold pressor (4 degrees C, total 10 min) produced stronger subjective distress than mental arithmetic (15 min). Cold exposure, but not the mental test, elevated systolic and diastolic blood pressure, whereas the mental test increased pulse rate and skin conductance level more markedly than cold exposure. Neither stressor produced a significantly enhanced response of ACTH and cortisol in DEX/CRH test, and there was no correlation between psychological and neuroendocrine responses. These findings suggest that different stressors induce different patterns of sympathetic activation and that acute stress is unlikely to affect the results of DEX/CRH test.


Subject(s)
Adrenocorticotropic Hormone/blood , Arousal/physiology , Corticotropin-Releasing Hormone , Dexamethasone , Hydrocortisone/blood , Adult , Blood Pressure/physiology , Galvanic Skin Response/physiology , Heart Rate/physiology , Humans , Hypothalamo-Hypophyseal System/physiology , Male , Pituitary-Adrenal System/physiology , Reference Values , Sympathetic Nervous System/physiology
15.
Biosci Biotechnol Biochem ; 65(2): 401-8, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11302176

ABSTRACT

Thermoactinomyces vulgaris R-47 alpha-amylases, TVA I and TVA II, have a domain N, which is an extra structure in the family 13 enzymes. To investigate the roles of domain N in TVAs, we constructed TVAs-deltaN mutants which are deleted in domain N, and Y14,16,68A and Y41,82,95A mutants of TVA II. TVAs-deltaN were unstable under alkaline conditions, and their thermal stabilities were 10 degrees C lower than that of wild-types. The specific activities of TVAs-deltaN for pullulan, starch, cyclodextrins, and oligosaccharides were drastically decreased, being about 1,500- to 10,000-fold smaller than those of wild-types. The kcat values of Y14,16,68A and Y41,82,95A for all tested substrates were markedly decreased, and the Km value of Y14,16,68A for alpha-CD and maltotriose were 25- and 3-fold larger, and that of Y41,82,92A for starch was 10-fold larger than that of the wild-type. TVA I and TVAs-deltaN in solution are a monomer, while TVA II is a homo-dimer, calculated by their molecular masses. These results suggest domain N in TVAs is an important structure for stabilization of enzymes, recognition and hydrolysis of substrates, and dimerization of TVA II.


Subject(s)
Micromonosporaceae/enzymology , Micromonosporaceae/genetics , alpha-Amylases/chemistry , alpha-Amylases/metabolism , Base Sequence , DNA Primers/genetics , Dimerization , Enzyme Stability , Isoenzymes/chemistry , Isoenzymes/genetics , Isoenzymes/metabolism , Kinetics , Models, Molecular , Molecular Weight , Protein Structure, Tertiary , Sequence Deletion , Substrate Specificity , alpha-Amylases/genetics
16.
J Biochem ; 129(3): 423-8, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11226882

ABSTRACT

Crystals of the mutant E354A of Thermoactinomyces vulgaris R-47 alpha-amylase 2 (TVAII) complexed with beta-cyclodextrin were prepared by a soaking method, and the diffraction data were collected at 100 K, using Synchrotron radiation (SPring-8). The crystals belong to an orthorhombic system with the space group P2(1)2(1)2(1) and cell dimensions a = 111.1 A, b = 117.7 A, c = 113.3 A, which is almost isomorphous with crystals of the wild-type TVAII, and the structure was refined to an R-factor = 0.208 (R(free) = 0.252) using 3.0 A resolution data. The refined structure shows that the interactions between Phe286 and two C6 atoms of beta-cyclodextrin at the hydrolyzing site are important for TVAII to recognize cyclodextrins as substrates. This observation from the X-ray structure was supported by kinetic analyses of cyclodextrins using the wild-type TVAII, the mutant F286A and F286L. These studies also suggested that the TVAII-hydrolyzing mechanism for cyclodextrins is slightly different from that for starch.


Subject(s)
Amino Acid Substitution/genetics , Cyclodextrins/metabolism , Micromonosporaceae/enzymology , alpha-Amylases/chemistry , alpha-Amylases/metabolism , Binding Sites , Crystallography, X-Ray , Cyclodextrins/chemistry , Hydrolysis , Kinetics , Micromonosporaceae/metabolism , Models, Molecular , Mutagenesis, Site-Directed/genetics , Protein Binding , Protein Conformation , alpha-Amylases/genetics
17.
Shinrigaku Kenkyu ; 72(4): 290-7, 2001 Oct.
Article in Japanese | MEDLINE | ID: mdl-11797329

ABSTRACT

The purpose of this study was to investigate the relationship between coping behavior and stress response of undergraduates as they experienced over time prior to an examination. One hundred forty eight undergraduates were asked to complete a set of questionnaires on coping behavior and stress response at a month (T1), a week (T2), and immediately (T3) prior to an important examination. Cluster analysis showed that there were four clusters of coping behavior at each period of time. Regardless of their effort level, students with high distress showed higher stress score than those with low distress. In hierarchical regression analysis of stress response change, an interaction effect of effort change and distress change over T1 to T2 was significant. Stress responses lessened for students whose effort score increased but distress score decreased. The opposite was true for those whose effort score decreased but distress score increased. From T2 to T3, a main effect of distress was significant: For students whose stress response increased, distress score also increased.


Subject(s)
Adaptation, Psychological , Educational Measurement , Stress, Psychological/psychology , Adult , Female , Humans , Individuality , Male , Sex Factors , Time Factors
18.
Biosci Biotechnol Biochem ; 64(12): 2692-5, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11210138

ABSTRACT

To confirm that the catalytic residues (Asp325, Glu354, and Asp421) are necessary for the hydrolysis of starch, pullulan, and cyclodextrins, we constructed TVA II mutated by site-directed mutagenesis. The mutated enzymes (D325N, E354Q, and D421N) had markedly reduced levels of activity, less than 0.006% of the wild type, indicating that these three residues are the catalytic sites for these substrates. Even E354D had reduced levels of activity, less than 0.05% of wild type. These four mutated enzymes retained a trace of activity. From the result of hydrolysis patterns for maltohexaose, in particular, D421N, unlike D325N and E354Q, catalyzed transglycosylation rather than hydrolysis. The results suggest that Asp421 could function to capture water molecules.


Subject(s)
Catalytic Domain , Micromonosporaceae/enzymology , alpha-Amylases/genetics , alpha-Amylases/metabolism , Glucose/metabolism , Glycosylation , Hydrolysis , Maltose/metabolism , Mutagenesis, Site-Directed , Oligosaccharides/metabolism , Sequence Homology, Amino Acid
19.
Med Electron Microsc ; 33(4): 246-57, 2000.
Article in English | MEDLINE | ID: mdl-11810482

ABSTRACT

Degeneration of proteoglycans and abnormalities in their metabolism have been assumed to be critical at an early stage of osteoarthritis. To clarify a trigger mechanism of osteoarthritis, anionic sites of knee articular cartilage were blocked by intracapsular injection of cationic polyethyleneimine of 2000 or 70,000 molecular weight (MW) into rat knee joints. Experimental or normal rats were examined by gross observation, roentgenography, cytokine interleukin-1beta (IL-1beta) assay, and light or electron microscopy. In both groups with the polyethyleneimine injection, the rats showed temporarily limping and swelling of their knee joints. By light or electron microscopic studies, knee articular cartilage was found to be degenerated at an early stage, but IL-1beta was within normal levels. At 2, 4, or 6 months, the deformity of the knee joints was obvious by roentgenography. Degeneration and hypofunction of proteoglycans might be related to the ultrastructural changes of articular cartilage at an early stage, though the inflammatory cytokine was not involved. At later stages the pathophysiology of the knee joints advanced chronically to typical osteoarthritis, which was more radically induced by the large molecular polyethyleneimine (70,000 MW). The functional impairment of anionic sites is a key point for elucidating the mechanism of osteoarthritic development in this animal model.


Subject(s)
Cartilage, Articular/pathology , Knee Joint/pathology , Osteoarthritis/pathology , Polyethyleneimine/toxicity , Animals , Cartilage, Articular/ultrastructure , Collagen/analysis , Interleukin-1/analysis , Knee Joint/ultrastructure , Male , Microscopy, Electron , Osteoarthritis/chemically induced , Osteoarthritis/diagnostic imaging , Proteoglycans/metabolism , Radiography , Rats , Rats, Inbred F344
20.
J Biochem ; 125(6): 1115-9, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10348914

ABSTRACT

RNA ligands (RNA aptamers) to a protease subtilisin were selected from pools of random RNA by SELEX (systematic evolution of ligands by exponential enrichment) and by use of a subtilisin-immobilized Sepharose column. After eight rounds of selection, RNA aptamers were isolated by cloning to a plasmid vector. We characterized one of the selected RNA molecules. This RNA aptamer displayed specific inhibition toward the subtilisin activity, even when the assay for subtilisin was performed using the chromogenic small peptide as substrate, and almost no inhibitory activity toward trypsin and chymotrypsin, although these enzymes are serine proteases similar to subtilisin. These findings indicate that this RNA can differentially recognize the surfaces of similar proteases. Kinetic analysis of the RNA aptamer revealed that the inhibition constant (Ki) toward subtilisin was 2.5 microM.


Subject(s)
RNA/chemistry , RNA/pharmacology , Serine Proteinase Inhibitors/chemistry , Serine Proteinase Inhibitors/pharmacology , Subtilisins/antagonists & inhibitors , Animals , Base Sequence , Cattle , DNA Primers/genetics , Directed Molecular Evolution , In Vitro Techniques , Kinetics , Ligands , Molecular Sequence Data , Nucleic Acid Conformation , RNA/genetics , Serine Proteinase Inhibitors/genetics
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