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Biomedical subjects

K Nishimoto

Publications and source records attributed to K Nishimoto.

At least 145 records · Page 8Linked to original sources
PubMed1982

[Diagnostic value of radioisotope cisternography combined with intranasal pledgets in CSF rhinorrhea].

The experience with the radioisotope cisternography in 17 cases without CSF rhinorrhea for control study and one with CSF rhinorrhea at Tokyo Medical and Dental University Hospital is reported. In addition to the usual cisternography, we used intranasal pledgets for identification and localization of CSF rhinorrhea. The cotton pledgets are placed in the following regions; 1) sphenoethmoid recess, 2) middle meatus and 3) cribriform region. The radioisotope (111In-DTPA, 1mCi) is introduced by lumbar puncture. After scintiphoto is taken at 4 hours, the pledgets are removed and the radioactivity are counted by well-type scintillation counter. The radioactivity of 1 ml of blood is also counted. There is close correlation between the radioactivity of nasal pledget and blood. The ratio of radioactivity of a pledget to that of blood was less than 0.3. The ratio of radioactivity in patient with CSF rhinorrhea is much greater than 0.3. The usefulness of these combined method for identifying the fistulous tract so that surgeon can carry out a direct operation is emphasized.

Adult↗
PubMed1981

Evaluation of the dye-protein tracers in pathophysiology of the blood-brain barrier.

1. Sodium fluorescein and Evans Blue, commonly used tracers in the study of blood-brain barrier disturbances, revealed considerable differences in their respective protein binding capacity in the plasma, passage through the barrier and in the rate of their elimination from the brain parenchyma. 2. In the plasma a considerable portion of the sodium fluorescein remains free and behaves like a micromolecular barrier tracer. On the other hand, almost complete binding of the Evans Blue to albumin confers to it properties of a protein tracer. 3. Following the extravasation of the tracers, the sodium fluorescein is relatively soon eliminated, whereas Evans Blue remains in the cellular elements of the brain parenchyma for a considerable time, although the protein moiety of the tracer is removed much sooner from the cytoplasm of glial cells, presumably by the lysosomal digestion.

Animals↗
PubMed1980

Effect of hydrogen bonding on electronic spectra and reactivity of flavins.

Riboflavin tetrabutyrate undergoes characteristic spectral changes, in both the first and second absorption band regions, upon hydrogen bonding with trichloroacetic acid of trifluoroacetic acid. On the basis of the calculated electron densities, hydrogen bonding at the heteroatoms of the isoalloxazine nucleus is considered to occur with increasing concentrations of the proton donor, first at N(1), then at O(12), O(14), and N(3)H, and finally at N(5). The idea that the major effect of the hydrogen bonding at the N(1), N(3)H, and oxygen atoms of the flavin nucleus is to facilitate the electrophilicity of the N(5) position, which was predicted by molecular orbital calculations, was supported by the observation that the hydrogen-bonded flavin in its triplet state abstracts hydrogen from the donor N-benzyl-n,n'-dimethylethylenediamine at a faster rate than do the non-hydrogen-bonded species in CCI4. The implications of the present study in the spectroscopic and catalytic properties of flavoproteins are briefly discussed.

Hydrogen Bonding↗
PubMed1978

Hydrogen bonding of flavoprotein. I. Effect of hydrogen bonding on electronic spectra of flavoprotein.

The effect of hydrogen bonding on the transition energy and the oscillator strength of the isoalloxazine nucleus of flavins was studied by the molecular orbital method. Among the possible hydrogen bondings examined, characteristic spectral shifts were found for the hydrogen bondings at N(1) and N(5) of the nucleus. The hydrogen bonding at N(1) resulted in the shift of the first absorption band towards blue and that of the second one towards red. On the other hand, the hydrogen bonding at N(5) resulted in the shifts of both the first and the second band towards red. The spectral characteristics reported on Clostridium MP and Desulfovibrio vulgaris flavodoxin coincided with the calculated results. The application of the calculated results to D-amino acid oxidase (D-amino acid: oxygen oxidoreductase (deaminating), EC 1.4.3.3) led to the conclusion that hydrogen bonding occurs at O(12), N(3)H, O(14) and N(5) of the isoalloxazine nucleus. The occurrence of hydrogen bondings at O(12), N(3)H, and O(14) is favorable for N(5) of the isoalloxazine nucleus to accept electron from an electron donor.

Clostridium↗
PubMed1978

[Significance of computed tomography in therapeutic diagnosis of brain tumors (author's transl)].

Because of its noninvasive property of direct imaging of the size and shape of the lesion, CT scan is significant not only for the diagnosis of the brain tumors, but also for the assessment of its chronological and/or therapeutic change in size. Contrary to the conventional cerebral angiography and contrast encephalography, CT scan is feasible to detect the tumor repeatedly at short intervals. From March 1976 to October 1977, 197 cases of brain tumors were examined by CT, 6 tumors (1 pineal tumor, 2 cerebellar vermian tumors and 3 supratentorial tumors) of which were radiated after the initial CT scan and re-examined by CT at every 400-1,000 rads radiation, and their grade of radiosensitivity could be evaluated. Immediately after the radiation of 400 rads for five days to the large pineal tumor of a 16-year-old boy, CT exactly showed the markedly diminished size of the tumor, and the tumor disappeared on CT after the 4,000 rads radiation. Cerebellar vermian tumors suspected of medulloblastoma were also diminished in size on CT after the 600 rads radiation. One supratentorial tumor was radiosensitive and disappeared at the end of radiation therapy. Other supratentorial tumors were not changed on CT during the radiation. Procedures for the therapeutic diagnosis, when combined with CT, can easily indicate whether the tumor is radiosensitive or not, without any invasive examination and/or operation.

Adolescent↗