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Biomedical subjects

T Yagi

Publications and source records attributed to T Yagi.

At least 595 records · Page 33Linked to original sources
PubMed1985

Comparative study of biochemical characteristics of the fluids in otitis media with effusion and postoperative maxillary cysts.

The biochemical characteristics and smears of the fluids in M-OME, S-OME, AOM, POMC, and AMS were studied. The fluids in S-OME and POMC had the character of transudate rather than exudate. On the other hand, M-OME, AOM, and AMS showed a more exudative or secretive nature. The character of the product from the inflammatory process of the specific condition was particularly seen in M-OME, AOM, and AMS. Thus we speculate that the chronic inflammatory process has a close relationship to the pathogenesis of OME, especially in mucoid types.

Acute Disease↗
PubMed1985

Limitation of long term ventilation tube: in view of complications and hearing restoration.

The silicon-rubber T-tube was applied to 181 ears in 116 patients with chronic otitis media with effusion within last 5 years. Among the 181 ears, 81 (46%) accepted the T-tube without problems. In the remaining 97 ears, complications such as otorrhea, occlusion of the tube, extrusion of the tube, enlarged perforation and cholesteatoma occurred. However, in 161 ears (89%), the tube could be stabilized in the middle ear and functioned as ventilating tube beyond 3 months. Based on the incidence and prognosis of the ears with the complications and the results of hearing, we conclude that insertion of the T-tube is valuable and reliable method of treatment in the ears with retractions or atelectasis but in the ears with adhesion or granulation, this method of treatment has only limited value.

Adolescent↗
PubMed1985

Studies on the mechanism of oxidative phosphorylation: effects of specific F0 modifiers on ligand-induced conformation changes of F1.

Aurovertin is a fluorescent antibiotic that binds to the catalytic beta subunits of the mitochondrial F1-ATPase and inhibits ATP synthesis and hydrolysis. ATP, ADP, and membrane energization in submitochondrial particles (SMP) alter the fluorescence of F1-bound aurovertin. These fluorescence changes are considered to be in response to the conformation changes of F1-ATPase. This paper shows that the ATP-induced fluorescence change of aurovertin bound to SMP or complex V (purified ATP synthase complex F0-F1) is inhibited when these preparations are pretreated with oligomycin or N,N'-dicyclohexylcarbodiimide (DCCD). This inhibition is not seen with isolated F1-ATPase. These and other results have suggested that modifications of the DCCD-binding protein in the membrane sector (F0) of the ATP synthase complex are communicated to F1, thereby altering the binding characteristics of ATP to the beta subunits. By analogy, it is proposed that modifications (e.g., protonation/deprotonation) of the DCCD-binding protein effected by protonic energy alter the conformation of F1 and bring about the substrate/product binding changes that appear to be essential features of the mechanism and regulation of oxidative phosphorylation.

Adenosine Triphosphate↗
PubMed1985

Human tumor cell strains both unable to repair O6-methylguanine and hypersensitive to killing by human alpha and beta interferons.

Human brain tumor cell strains were previously found by others to be sensitive to growth inhibition by human interferon-beta (HuIFN-beta). We noticed that the sensitive strains were some that we had found deficient in the repair of O6-methylguanine (O6MeG), a characteristic of 20% of the human tumor cell strains we have studied. We confirmed this sensitivity to HuIFN-beta, and have further shown that human brain tumor cells which repair O6MeG are resistant to the growth inhibitory effects of HuIFN-beta. In addition, treatment with HuIFN-alpha or HuIFN-beta resulted in more killing (reproductive inactivation) of six human tumor cell strains deficient in repairing O6-methylguanine in DNA than did such treatment of six strains of cells proficient in such repair. Further, we found two human lines, altered to become O6MeG repair deficient after establishment of the primary tumor cell culture, that were resistant to interferon. IFN treatment produced no DNA damage detectable by either chemical or biological assays. It is suggested that the genes responsible for resistance to IFN treatment and to agents that produce O6MeG are often coordinately shut down.

Brain Neoplasms↗
PubMed1985

Analysis of the active center of hydrogenase from Desulfovibrio vulgaris Miyazaki by magnetic measurements.

Hydrogenase [hydrogen: ferricytochrome c3 oxidoreductase, EC 1.12.2.1] solubilized and purified from the particulate fraction of Desulfovibrio vulgaris Miyazaki F (IAM 12604) contains 8 iron and 8 labile sulfide ions in one molecule which is composed of two unequal subunits (Mr: 60,000 + 29,000). It does not contain nickel atoms. The EPR (electron paramagnetic resonance) spectrum has an isotropic signal at g = 2.017 which is independent of the temperature. The peak-to-peak width of the signal is about 20 G. The signal intensity is nearly equivalent to 1 unpaired electron per molecule. No other signals can be detected in the field range between 2,240 and 4,240 G (which corresponds to g-values between 2.91 and 1.54). Ferricyanide has only a little effect on the shape and intensity of the EPR signal. The hydrogenase reduced under H2 is EPR silent. The Mössbauer spectrum has no hyperfine splitting at 4K. The isomer shift and quadrupole splitting at 77K are 0.38 and 0.87 mm/s, respectively. Based on these magnetic measurements, the structure of the active center of hydrogenase was suggested to be [4Fe-4S]3+ + [4Fe-4S]2+.

Desulfovibrio↗
PubMed1985

Magnetic susceptibility of hydrogenase from Desulfovibrio vulgaris.

Magnetization and magnetic susceptibility measurements revealed that the hydrogenase [EC 1.12.2.1] from Desulfovibrio vulgaris Miyazaki F has an independent unpaired electron in its iron-sulfur cluster. The paramagnetic center of the Desulfovibrio hydrogenase is, therefore, different from that in the Chromatium hydrogenase which interacts with another paramagnetic center, probably nickel.

Desulfovibrio↗
PubMed1985

Non-divergence theory of evolution: sequence comparison of some proteins from snakes and bacteria.

A "non-divergence theory" is proposed for the mechanism of evolution. The theory is based on the observation that comparison of the amino acid sequences of related proteins in various organisms gives inconsistent results from one type of protein to another, and on the occurrence of significant gene transfer among living organisms. Special attention is focused on the sequence comparisons of short- and long-chain neurotoxins and phospholipases A2 from the venoms of proteroglyphous snakes and those of microbial ferredoxins, rubredoxins, and flavodoxins.

Amino Acid Sequence↗
PubMed1985

A simple preparation method for apoaspartate aminotransferase from Escherichia coli B, and its application for the assay of pyridoxal and pyridoxamine 5'-phosphate.

A simple and rapid preparation method for apoaspartate aminotransferase from Escherichia coli B was developed. A crude extract of the bacterial cells was treated batchwise with DEAE-cellulose. The enzyme fraction obtained was then applied to a pyridoxamine-Sepharose column. Apoaspartate aminotransferase was eluted with 50 mM potassium phosphate buffer (pH 7.0), and found to be electrophoretically homogeneous. The apoenzyme preparation thus obtained showed very low holoenzyme activity (only 0.4% of the activity seen in the fully saturated condition with pyridoxal 5'-phosphate) and was successfully used for assaying pyridoxal and pyridoxamine 5'-phosphate.

Apoenzymes↗
PubMed1985

Enhanced bioavailability of insulin after rectal administration with enamine as adjuvant in depancreatized dogs.

Rectal absorption of insulin by depancreatized dogs was significantly enhanced by the coadministration of enamine as a suppository adjuvant and if this was followed by a further suppository containing enamine alone, the insulin absorption was even further enhanced. The additional enamine suppository resulted in high serum insulin concentrations for a longer time and effected a significant decrease in serum glucose concentrations. To decrease serum glucose concentrations effectively in depancreatized dogs, serum insulin levels had to remain high for a long period of time, rather than be transient.

Adjuvants, Pharmaceutic↗
PubMed1985

[Muscle exercise after the anterior cruciate ligament reconstruction of the knee--Part I: The force given to the anterior cruciate ligament by separate isometric contraction of the quadriceps or the hamstrings].

UNLABELLED: An attempt was made to investigate the force of the anterior cruciate ligament (ACL) in separate isometric contraction (IMC) of the quadriceps and the hamstrings by means of the analysis of two-dimensional models. In IMC of the quadriceps, the average value of the anterior drawer force (ADF) was equal to 14% of the quadriceps tension at the knee flexion of 5 degrees. The ADF decreased as the flexion angle increased. The average value of the angles, where the ADF became zero, was 45.3 degrees, and the standard deviation was 12.5 degrees. In IMC of the hamstrings, the posterior drawer force was given at the every flexion angle. CLINICAL RELEVANCE: In the early stage of the rehabilitation after the ACL reconstruction, the quadriceps exercise by IMC should be performed at the knee flexion of more than 70 degrees (average + 1.96 X S.D.). The hamstrings exercise by IMC can be carried out regardless of flexion angle.

Adult↗
PubMed1985

[Muscle exercise after anterior cruciate ligament reconstruction of the knee--Part II: The development of the exercise method by simultaneous isometric contraction of the quadriceps and the hamstrings, and its biomechanics].

UNLABELLED: An attempt was made to investigate the stress of the ACL in the simultaneous isometric contraction (IMC) of the quadriceps and the hamstrings by means of analysis of two-dimensional models, and to estimate electromyographically the forces of those muscles in that contraction. The anterior drawer force (ADF) in the simultaneous IMC decreased as the flexion angle of the knee increased. The average value of the angles, where the ADF became zero, was 7.4 degrees. The integrated EMGs of the quadriceps and the hamstrings in the simultaneous maximum IMC were equal to 30-60% of those in separate maximum IMC. CLINICAL RELEVANCE: In the early stage of the rehabilitation after the ACL reconstruction, the simultaneous IMC of the quadriceps and the hamstrings is useful as one of the muscle exercise method, because that can be performed at the knee position near the full extension and can generate sufficient muscle force for exercise.

Adult↗
PubMed1985

[A histological study on osteosarcoma. Part II: The mode of local extension of osteosarcoma].

The survival rate of patient with osteosarcoma has been increasing, owing to the development of adjuvant chemotherapy. Recently, the limb saving procedure in osteosarcoma has been attempted in many countries. Although we need knowledge about the mode of local extension of osteosarcoma in the planning of this surgery, there are few reports concerning the matter. The purpose of this paper is to make clear, morphologically, how tumor tissue extends across the epiphyseal plate, periosteum and bone marrow. The materials were 26 amputated extremities of osteosarcoma which had not received any chemotherapy or radiotherapy. Paraffin embedded macrosections were prepared and stained with HE and Masson stain. When epiphyseal plate was open or closing, 13 out of 14 cases (93%) showed transphyseal extension of tumor. Tumor extension along the vessels at the center of the plate and the epiphyseal artery was most common. Transmedullary extension showed three different types, infiltrative type (18 cases), lobular type (5 cases), and "skip" type (one case). None had capsule or pseudocapsule surrounding the tumor. As to the relationship between periosteal reaction and tumor involvement of cortex or medulla, periosteal reaction was located more proximally than cortical or medullary involvement in some cases. In other cases, however, cortical or medullary involvement was located more proximally than periosteal reaction. The gaps between the tips of the periosteal reaction and cortical or medullary involvement ranged from 0.5 to 1.5 cm. In the transperiosteal extension, it was confirmed that tumor cells had invaded the periosteum along the vessels penetrating the periosteum.

Adolescent↗