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Biomedical subjects

K Ogata

Publications and source records attributed to K Ogata.

At least 343 records · Page 19Linked to original sources
PubMed1989

[Evaluation of CT images in pulmonary tuberculosis].

Characteristics of CT images of 40 patients with pulmonary tuberculosis were compared with those of chest radiograms of the same patients, and the clinical usefulness of CT was evaluated. CT findings in pulmonary tuberculosis could be classified as follows. (1) centrilobular shadow, (2) lobular shadow, (3) multilobular shadow, (4) small nodular shadow, (5) pneumonic shadow, (6) cavitary shadow, (7) shadow showing, broncho-vascular dilatation. It was concluded that CT could express far more precisely the location, extension and stage of the tuberculous lesions and could give more informations on the clinical and pathological natures of the lesions than ordinary chest radiograms. Further, CT was superior for the radiological analysis of the detail of the lesions and their distributions.

Adolescent↗
PubMed1989

A simple method for ultrastructural observation of in vitro hematopoietic and leukemic colonies formed in fibrin- and plasma-clots.

A simple method has been developed for the ultrastructural study of in vitro hematopoietic and leukemic colonies formed in fibrin- or plasma-clots. A technique for selective embedding of the target colony in situ into Epon without picking it up from the semi-solid culture medium was developed. Using this technique, not only the intracellular structure of the cells composing the colonies but also the ultrastructural details of the colonies can be examined without destroying their native structure in situ.

Animals↗
PubMed1989

[Unilateral pulmonary venous obstruction: a case report].

A 3-month-old girl with right common pulmonary venous obstruction and severe pulmonary hypertension underwent pulmonary venous reconstruction (venoplasty). However, pulmonary hypertension persisted and she died on the 69th postoperative day. Autopsy revealed a widely opened pulmonary vein at the site of the venoplasty. Histological examination showed thickened alveolar walls, thromboembolism in pulmonary arterioles and venous hypoplasia in the right lung. The venoplasty for unilateral pulmonary venous obstruction with severe pulmonary hypertension may not be the proper treatment, since pulmonary hypertension usually continues or progresses postoperatively. Pneumonectomy may be a better choice to be applied.

Child, Preschool↗
PubMed1989

[Successful treatment of secondary erythroleukemia with androgen].

A case of secondary erythroleukemia treated with apparent success with androgen is reported. The patient is 63-year-old Japanese female. She had a history of multiple myeloma and had been treated with melphalan, vincristine and prednisolone. She developed erythroleukemia 88 months after the initiation of chemotherapy, while her myeloma was a complete remission. She was treated first with vitamin D3 with no beneficial effect and subsequently with 0.5 mg/kg of mepitiostane. A hematologic improvement began two months from the initiation of androgen therapy, and a complete remission of erythroleukemia was attained thereafter. A chromosomal abnormality of bone marrow cells, which was observed at the time of developing erythroleukemia, also disappeared after the treatment. She remained in good condition and hematologic remission under the androgen therapy at the latest follow-up, 1-year after the development of erythroleukemia. Androgen therapy may be considered as a useful treatment for secondary erythroleukemia.

Androstanols↗
PubMed1989

The first record of a confirmed human case of Gnathostoma doloresi infection.

The first case of Gnathostoma doloresi infection in a human was found in Miyazaki Prefecture, Japan. A whole length of the parasite was dissected out from biopsied skin and was identified as the third-stage larva of G. doloresi based on the morphological characteristics of the hooklets of the head bulb and also on the number of nuclei in the intestinal epithelial cells of the parasite.

Animals↗
PubMed1989

Acute volar compartment syndrome during skeletal traction in distal radius fracture. A case report.

Fractures of the distal end of the radius rarely cause acute compartment syndrome of the forearm. Acute compartment syndrome of the forearm occurred after a fracture of the distal end of the radius in a 17-year-old boy who developed symptoms after application of skeletal traction. Satisfactory recovery was obtained by early decompressive fasciotomy. In this case a combination of traction and elevation of the forearm appeared to have increased the susceptibility of the limb to acute compartment syndrome.

Adolescent↗
PubMed1988

Ricin and alpha-sarcin alter the conformation of 60S ribosomal subunits at neighboring but different sites.

The effects of ricin and alpha-sarcin separately or in combination on the conformation of rat liver ribosomes were investigated by measuring the relative accessibility of individual ribosomal proteins to N-ethylmaleimide after 80S ribosomes were treated with these toxins. By using a double-labelling technique in which ribosomes were incubated with the toxins and then treated with 3H-labelled or 14C-labelled N-ethylmaleimide, it was found that labelling of protein L14 was specifically reduced by treatment with ricin, and that of proteins L3 and L4 by treatment with alpha-sarcin, suggesting that the toxins alter the conformation of ribosomes in the vicinity of these proteins. When ribosomes were treated with both ricin and alpha-sarcin, the extent of labelling of protein L3 was reduced compared to that observed after treatment with alpha-sarcin alone. These results are discussed in relation to previous observations showing that these three proteins are neighbours in the 60S ribosomal subunit and probably play important roles in protein biosynthesis, and in the actions of ricin and alpha-sarcin on 28S rRNA.

Animals↗
PubMed1988

Monoclonal antibodies to proliferating cell nuclear antigen (PCNA)/cyclin as probes for proliferating cells by immunofluorescence microscopy and flow cytometry.

Proliferating cell nuclear antigen (PCNA)/cyclin is an intranuclear polypeptide antigen that is found in both normal and transformed proliferating cells. We have recently described two mouse monoclonal antibodies reacting with PCNA. In this report we describe the application of these antibodies to the study of proliferating human cells by indirect immunofluorescence microscopy and by flow cytometry. A fixation/permeation procedure was developed in order to obtain satisfactory binding of monoclonal PCNA-specific antibodies to proliferating cells. This method involved fixation with 1% paraformaldehyde followed by methanol treatment. For the staining of cells in suspension with the IgM type monoclonal antibodies lysolecithin was added to the paraformaldehyde solution to achieve a better permeation by the antibody molecules. This procedure gave a good ratio of specific staining relative to the background staining. It also preserved the shape and normal architecture of the cells as judged by visual microscopic observation and by light scatter measurements using a flow cytometer. Furthermore, this fixation technique permits simultaneous labeling of DNA by propidium iodide and PCNA by monoclonal antibodies. PCNA was detected in various types of normal and transformed proliferating cells by indirect immunofluorescence. Quiescent peripheral blood mononuclear cells were PCNA-negative whereas a fraction of lectin-stimulated lymphocytes became PCNA-positive. Similarly, early passages of fetal skin fibroblasts were PCNA-positive but non-proliferating senescent fibroblasts of later passages were PCNA-negative. The association of PCNA-staining by monoclonal antibodies with cell proliferation was confirmed by flow cytometry. Simultaneous labeling of PCNA and DNA showed that the PCNA signal increased during the G1 phase of the cell cycle, reached its maximum in the S-phase, and declined during the G2/M phase. Using cell sorting we demonstrated that mitotic cells had a very low PCNA signal. Thus, monoclonal PCNA-specific antibodies offer a convenient tool for the detection of human cell proliferation by immunofluorescence microscopy and by flow cytometry.

Animals↗
PubMed1988

Nucleotide sequence of cloned cDNA specific for rat ribosomal protein L27.

We constructed cDNA libraries from 8-9-S poly(A)-rich RNA from regenerating rat liver, isolated clones specific for ribosomal protein L27 and determined the nucleotide sequences of the cDNA clones. The longest cDNA consists of 15 base pairs from the 5' leading sequence, the entire coding sequence of 411 base pairs, and the 3' trailing sequence of 59 base pairs including the poly(A) tail. The primary structure of protein L27 was deduced from the sequence of nucleotides. Protein L27 contains 135 amino acids and has a molecular mass of 15,666 Da. The amino-terminal sequence agreed well with the published partial amino acid sequence and the calculated amino acid composition is also consistent with the reported composition determined for the hydrolyzate of L27.

Amino Acid Sequence↗
PubMed1988

A comparative study on 40S ribosomal proteins of Artemia salina and rat liver: micro analysis of amino acid composition by high-performance liquid chromatography.

The amino acid compositions of 24 proteins of 40S ribosomal subunits of Artemia salina cysts were determined and compared with those of rat liver. The basic proteins of A. salina 40S ribosomes were separated by two-dimensional polyacrylamide gel electrophoresis and extracted with 70% formic acid. Samples were freed from contaminants by gel-filtration through a high-performance liquid chromatography column. Amino acid compositions were determined for individual proteins by pre-column derivatization with N,N-dimethylaminoazobenzenesulfonyl chloride followed by reverse phase high-performance liquid chromatography. The similarity of amino acid compositions between A. salina and rat liver 40S ribosomal proteins was evaluated by the method of Cornish-Bowden (Cornish-Bowden, A. (1980) Anal. Biochem. 105, 233-238), and possible relationships between A. salina and rat were detected for 16 protein species (S2, S3, S4, S6, S7, S8, S15a, S16, S17, and S18, strongly related and S14, S15, S20, S23, S24, and S26, weakly related), indicating a conservative nature of eukaryotic ribosomal proteins.

Amino Acids↗
PubMed1988

In vitro sequence-specific cleavage in transcribed spacer of mouse precursor ribosomal RNA.

When we compared the sequences near four terminal sites of transcripts including two endoribonucleolytic cleavage sites in external transcribed spacer 1 upstream of the 5' end of the mouse 18S rRNA (Mishima, Y., Mitsuma, T., & Ogata, K. (1985) EMBO J. 4, 3879-3886), a seven-nucleotide consensus sequence, GGPyUUGPy (Py is C or U), was obtained. The results of both in vitro pulse-chase experiments and S1 nuclease mappings using the mouse rDNA fragment of the transcription initiation region indicated that ribonucleolytic cleavages take place in the sequence matching the consensus sequence at more than five nucleotides out of the seven positions. Furthermore, effective ribonucleolytic cleavages in vitro were observed in a sequence, GGCUUGU, in the internal transcribed spacer 2 located between 5.8S and 28S rRNA. These results demonstrate that the ribonucleolytic cleavages occur preferentially in the sequence of GGPyUUGPy in the transcribed spacer regions of the mouse pre-rRNA. From this information, we infer the existence of processing steps for the pre-rRNA maturation involving the sequence-specific ribonucleolytic cleavages.

Animals↗
PubMed1988

Identification of a protein factor and the nucleotide sequence required for processing of mouse precursor rRNA.

We have studied the protein components and nucleotide sequence involved in the endonucleolytic cleavage at 105 bp upstream of the 5' end of mouse 18S rRNA. By fractionating the mouse S100 extract into four fractions by phosphocellulose chromatography, we separated and characterized the processing factor which participated in in vitro coupled and uncoupled transcription-processing systems. Processing activity was recovered in the flow-through fraction (fraction A), while the transcription initiation was supported by the combination of fractions C and D. This endonucleolytic cleavage activity was heat-labile and resistant to micrococcal nuclease. By constructing deletion fragments, we found that the sequence between 219 bp upstream and 26 bp downstream of the processing site was required for the processing. This sequence does not include the 18S rRNA coding region and can form a stem-loop secondary structure.

Animals↗
PubMed1988

Lateral forces exerted on the abutment tooth of complete mandibular overdentures.

The purpose of this study was to analyse the magnitude and direction of lateral forces exerted on the abutment tooth of a complete mandibular overdenture. A newly developed transducer was used for measuring forces. It was small enough to be embedded in the lower denture base, and could detect the magnitude and direction of forces. Five subjects, 38 to 77 years of age, with an edentulous maxilla and one or two canines remaining in the mandible were selected for this experiment. An upper complete denture and a lower complete overdenture with only one abutment tooth were fabricated for each subject. Forces exerted on the abutment tooth were measured during tapping and chewing of kamaboko (a Japanese cooked fish paste with soft consistency) and also peanuts, a few days and about 20 days after the denture insertion. The following results were obtained: (i) the average magnitude of lateral forces ranged from 0.5 to 2.0 kgf, and there were significant differences of the mean value between subjects; (ii) lateral forces were mainly observed on an imaginary line drawn through the experimental tooth (lower canine) and the opposite retromolar pad. There were no significant differences between the first and the second measurement.

Adult↗