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J Oda

Publications and source records attributed to J Oda.

At least 73 records · Page 4Linked to original sources
PubMed1992

Purification, molecular cloning, and expression of lipase from Pseudomonas aeruginosa.

An extracellular lipase secreted by Pseudomonas aeruginosa TE3285 was purified. A genomic library of this strain was constructed in lambda EMBL3, and a DNA fragment 2.7 kb long containing the lipase gene, lipA, was isolated with an oligonucleotide probe synthesized on the basis of the partial amino acid sequence of a purified preparation of the enzyme. Nucleotide sequence analysis showed an open reading frame of 933 bases, and the deduced amino acid sequence agreed well with the molecular mass and partial amino acid sequences of mature lipase. The results of alignment of the amino acid sequences of five lipases from Pseudomonas species considered together with the published crystal structure studied with human pancreatic lipase showed that Ser82, His251, and Asp209 were catalytic residues and that a surface loop from residues 172 to 204 was responsible for the substrate specificity. About 50 bases downstream of lipA, there was another gene, lipB. The sequence of lipB was highly homologous to that of putative modulators of the production of active lipases in other Pseudomonas species. Expression plasmids encoding lipA followed by the complete or incomplete lipB gene downstream of the lac promoter of pUC18 were constructed. lipA was expressed in Escherichia coli 1100 only in the presence of the complete lipB gene.

Amino Acid Sequence↗
PubMed1992

[Magnetic resonance (MR) imaging of chordoma and chondroma in the skull base--differential diagnosis by IR sequence].

Differential diagnosis of chordoma and chondroma in the skull base is sometimes difficult. We retrospectively reviewed the MR images of 14 patients with skull base tumors (nine chordomas, four chondromas and one chondrosarcoma). MR imaging was performed with a 0.5 Tesla system (Picker International). Inversion recovery (IR) (2500-2100/600-500/40), T1-weighted spin echo (SE) (800-600/40), and T2-weighted SE (2500-1800/120) images were obtained. On IR images, seven of eight chordomas showed heterogeneous low signal intensity, and one chordoma and all chondromas showed markedly low signal intensity similar to that of CSF. Calcified or ossified portions of the chondromas were demonstrated as areas of moderately low intensity on IR images. Chondrosarcoma showed moderately low intensity similar to that of chordoma. T1-weighted SE images of chordoma and chondroma showed no difference in signal intensity. On T2-weighed SE images, six of nine chordomas and all chondromas showed markedly high signal intensity. Three chordomas and one chondrosarcoma showed moderately high signal intensity. In the diagnosis of skull base tumors, the IR sequence seems to be useful for differentiating chondroma from chordoma.

Adolescent↗
PubMed1992

Mutational and proteolytic studies on a flexible loop in glutathione synthetase from Escherichia coli B: the loop and arginine 233 are critical for the catalytic reaction.

The function of the flexible loop which is disordered in crystal structure analysis of glutathione synthetase from Escherichia coli B has been investigated by limited proteolysis and kinetic measurements for the wild-type and mutant enzymes. Proteolysis of the intact enzyme using arginyl endopeptidase or trypsin brought about a time-dependent decrease in the enzymatic activity and the production of protein fragments. SDS-polyacrylamide gel electrophoresis and peptide sequence analysis showed that only a peptide bond between arginine 233 and glycine 234 in the loop was cleaved. Further, native polyacrylamide gel electrophoresis revealed that the cleaved enzyme retained almost the same quaternary structure as that of the wild-type enzyme. Upon protease treatment, the presence of substrates, ATP and/or gamma-L-glutamyl-L-cysteine (gamma-Glu-Cys), protected the loop from cleavage, but the presence of glycine was not capable of protecting it. In addition, replacement of arginine 233 in the loop with lysine by site-directed mutagenesis increased the Michaelis constants for gamma-Glu-Cys and glycine by factors of 28 and 213, respectively. The protection against cleavage on a similar protease incubation of this mutant enzyme was also observed in the presence of ATP and/or gamma-Glu-Cys, but the effect in the presence of both substrates was half as large as that for the wild-type enzyme. These results suggest that the loop covers the active site while ATP and gamma-Glu-Cys bind there and that it protects the unstable gamma-Glu-Cys phosphate intermediate from decomposition by bulk water.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1992

Palmoplantar pustulotic arthro-osteitis of the peripheral joints with no sternocostoclavicular lesions.

A 45 year old woman presented with swelling and pain on joint movement of her knees, although joint movement was relatively well maintained. Five years previously the patient had been diagnosed as having pustulosis palmoplantaris by a dermatologist. Treatment with non-steroidal anti-inflammatory drugs (NSAIDs) had no effect, but treatment with 5 mg/day prednisolone caused remission of both the joint pain and swelling and the pustulosis palmoplantaris. There were no sternocostoclavicular lesions at any time during treatment. Clinical findings in this patient were different from previous reports and she was diagnosed as having palmoplantar pustulotic arthro-osteitis affecting the peripheral joints.

Arthritis, Psoriatic↗
PubMed1992

Intramedullary spinal cord tumors: significance of associated hemorrhage at MR imaging.

Magnetic resonance (MR) images obtained in 35 patients with intramedullary spinal tumors were reviewed. Hypointense areas on both T1- and T2-weighted images were seen within or around eight tumors, all of which were in the cervical cord. Hypointensity at the tumor margin was seen in seven cases. Hypointensity within the tumor was seen in two cases. (One case had both types of hypointensity). In seven surgically confirmed cases, hypointensity at the tumor margin was found to be a relatively firm pseudocapsule, and hypointensity within the tumor corresponded to intratumoral hematoma. All of the tumors with hypointensity were ependymomas at histologic examination. When MR imaging shows an intramedullary tumor with hypointensity at the tumor margin, it is suggestive, but not pathognomonic, of an ependymoma.

Adult↗
PubMed1992

Overexpression and purification of asparagine synthetase from Escherichia coli.

Overexpression of the asnA gene from Escherichia coli K-12 coding for asparagine synthetase (EC 6.3.1.1) was achieved with a plasmid, pUNAd37, a derivative of pUC18, in E. coli. The plasmid was constructed by optimizing a DNA sequence between the promoter and the ribosome binding region. The enzyme, comprising ca. 15% of the total soluble protein in the E. coli cell, was readily purified to apparent homogeneity by DEAE-Cellulofine and Blue-Cellulofine column chromatographies. The amino-terminal sequence, amino acid composition, and molecular weight of the purified protein agreed with the predicted values based on the DNA sequence of the gene. Furthermore the native molecular weight measured by gel filtration confirmed that asparagine synthetase exists as a dimer of identical subunits.

Amino Acid Sequence↗
PubMed1992

Osteonecrosis of the femoral head in spontaneously hypertensive rats. Relation to ossific nuclei during growth.

We observed the distribution of the ossific nuclei and the occurrence of osteonecrosis in the femoral capital epiphysis of spontaneously hypertensive rats. In 270 femoral heads, the ossific nuclei were seen in the following sites of the epiphysis: Type 1, the lateral portion in 150 femoral heads; Type 2, the central portion in 5 heads; Type 3, both lateral and central portions in 12 heads; and Type 4, throughout the epiphysis in 62 heads. The number of femoral heads with osteonecrosis in Types 1-4 was 61, 0, 5, and 17, respectively.

Aging↗
PubMed1992

[Quantitative evaluation of deglutition in the upper esophagus by scintigraphy].

To evaluate the function of deglutition quantitatively, radionuclide transit in the and upper esophagus was examined. Ten ml of water containing 185 MBq 99mTc pertechnetate was put into the mouth and isotopic counts were measured every 0.2 second in the oral cavity, upper and lower cervical esophagus, and upper mediastinum. The subjects were studied twice, once while sitting and once supine. Esophageal transit was evaluated with time-activity curves obtained in each region of interest. In twelve healthy volunteers transit of the radionuclide was significantly delayed in supine position compared with sitting position. Even while the subject was supine, the radionuclide was propelled into the lower cervical esophagus in 0.8 second and upper mediastinum in 1.4 second in the healthy volunteers. In the patient, who had reconstruction of the esophagus through posterior mediastinum, radionuclide transit was not different from that of healthy volunteers. Whereas in the patient, who had the reconstruction through retrosternal space, the transit was remarkably delayed. The esophageal scintigraphy was safe and sensitive enough to evaluated the function of deglutition quantitatively.

Adult↗
PubMed1992

Synovial osteochondromatosis of the sole of the foot. A case report.

Synovial osteochondromatosis of the foot is a rare disorder. We present the first report of synovial osteochondromatosis of the intermetatarsal/tarsometatarsal joints. When a mass develops in the sole of the foot and heterotopic ossifications are revealed radiographically, synovial osteochondromatosis should be considered in the differential diagnosis.

Adult↗
PubMed1991

Similarity graphing and enzyme-reaction database: methods to detect sequence regions of importance for recognition of chemical structures.

We developed a new method which searches sequence segments responsible for the recognition of a given chemical structure. These segments are detected as those locally conserved among a sequence to be analyzed (target sequence) and a set of sequences (reference sequences). Reference sequences are the sequences of functionally related proteins, ligands of which contain a common chemical substructure in their molecular structures. 'Similarity graphing' cuts target sequences into segments, aligns them with reference sequence pairwise, calculates the degree of similarity for each alignment, and shows graphically cumulative similarity values on target sequence. Any locally conserved regions, short or long in length and weak or strong in similarity, are detected at their optimal conditions by adjusting three parameters. The 'enzyme-reaction database' contains chemical structures and their related enzymes. When a chemical substructure is input into the database, sequences of the enzymes related to the input substructure are systematically searched from the NBRF sequence database and output as reference sequences. Examples of analysis using similarity graphing in combination with the enzyme-reaction database showed a great potentiality in the systematic analysis of the relationships between sequences and molecular recognitions for protein engineering.

Algorithms↗
PubMed1991

[Bone metastases in breast cancer and its risk factor--follow up study by bone scintigraphy].

Breast cancer is considered to often involve bone metastasis. Early detection and treatment of bone metastasis are essential in improving the prognosis of this disease. In 47 patients with bone metastasis confirmed with bone scintigraphy, we examined the appearance time of bone metastasis; bone metastasis was frequently observed with the progress of stage, but no association with the appearance time was found. Age was not associated with the incidence of bone metastasis but was found to be closely related to its appearance time. That is to say, patients with breast cancer below 40 years of age showed relatively early bone metastasis. Bone scintigraphy is required every 6 months at least for 3 years after the operation. In patients over 40 years of age, on the other hand, bone scintigraphy is required only once a year but has to be continued for 5 years or more, because they often show relatively late bone metastasis.

Adult↗
PubMed1991

[Aging effects on blood biochemical parameters in aged women: a longitudinal study using principal component analysis].

In order to examine the aging effects on blood biochemical parameters, 25 aged females (70 +/- 8 years old at the beginning of this investigation) were studied prospectively for 7 years. Biochemical parameters were measured in 1982, 1985, 1987, and 1989. Component scores were obtained by principal component analysis applied to all of these 100 data. The data of 13 biochemical parameters and 4 component scores were analyzed for aging, cohort, and time effects by utilizing 3 types of approach i.e., longitudinal, cross-sectional, and time-series. Positive aging effects were observed on blood urea nitrogen and 4th component score. Fourth component score had positive relations to blood urea nitrogen and total bilirubin, and a negative relation to total protein. This 4th component score increased with longitudinal age changes among all cohorts divided by decade, and it increased markedly over 70 years old. These results suggest that the aging effects on biochemical parameters are related with both the decrease in glomerular and hepatocellular functions and the increase in breakdown of tissue protein.

Aged↗
PubMed1990

[The experimental and clinical evaluation of digital chest radiography using FCR (Fuji Computed Radiography)].

Image quality of digital chest radiography using FCR (Fuji Computed Radiography) was evaluated experimentally and clinically, comparing with the conventional radiography using regular film-screen system (F-S system). 1. In experimental study, Burger's phantom and Hawlet chart were used. The results were as follows: 1) Almost same amount of incident X-ray exposure was necessary for FCR to obtain the same resolution power as F-S system. 2) Contrast enhancement processing did not improve resolution power in FCR. It was improved by the processing of spatial frequency enhancement in the range of lower than 0.5 c/mm, but was decreased by the same processing in the range of higher than 0.5 c/mm. 2. In clinical study, chest radiograms of FCR and F-S system which were taken at the same day were evaluated. The results were as follows. 1) Firstly, the visibility of abnormal shadows which were classified into nine types was evaluated subjectively by two chest-radiologists. As the results, FCR was superior to F-S system in visibility of the lesions overlapping mediastinum and diaphragm, calcifications and bone lesions. FCR was, however, inferior to F-S system in visibility of ground glass shadows, fine reticular shadows and granular shadows. 2) In the second step, the detectability of those interstitial shadows was evaluated using ROC curve analysis. As the results, FCR was statistically inferior to F-S system in detectability of those interstitial shadows.

Evaluation Studies as Topic↗
PubMed1990

Ultraviolet action spectrum for intracellular free Ca2+ increase in human epidermal keratinocytes.

Effects of UV on normal human epidermal keratinocytes were studied by measuring the intracellular free Ca2+ concentration ([Ca2+]i) using fluorescence ratio imaging (fura-2-AM). Upon UV irradiation the [Ca2+]i increased sharply after a certain lag time, and the UV sensitivity was higher at lower temperatures. Statistically the distribution of [Ca2+]i became broader as the mean values became larger, and the number of affected cells increased sharply above a certain fluence (light intensity x time [photons/cm2]) at all wavelengths studied (200-400 nm). The action spectrum showed a single peak at about 230 nm and decreased gradually toward longer-wavelength UV regions.

Calcium↗