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Biomedical subjects

G Tajima

Publications and source records attributed to G Tajima.

35 records · Page 2Linked to original sources

Autoxidation of oxymyoglobin. An overall stoichiometry including subsequent side reactions.

Oxymyoglobin (MbO2) is oxidized easily to metmyoglobin (metMb) with generation of the superoxide anion, which can be converted by the spontaneous dismutation into H2O2, this being also a potent oxidant of MbO2. In the presence of sodium azide in stoichiometric amounts, however, the rate of autoxidation of MbO2 increased rapidly with increasing concentration of the anion, but soon reached a saturating level, the extent of which was about twice that of the normal autoxidation in buffer alone. Quantitative analysis has revealed that this enhancement is not due to the nucleophilic displacement of O2- from MbO2 by the anion (Satoh, Y., and Shikama, K. (1981) J. Biol. Chem. 256, 10272-10275), but is due to the additional oxidation of MbO2 by H2O2 freed from the metMb being occupied by the anion at the sixth coordination position. Based on these novel results and stoichiometric considerations, it is possible to propose a new view that H2O2 produced from O2- can be eliminated or decomposed mostly, if not completely, by the metMb resulting from the normal autoxidation reaction of MbO2, presumably via the formation of the ferryl species.

Animals↗

A study of intracytoplasmic inclusions in myeloma cells from two patients with multiple myeloma.

Two cases of multiple myeloma which showed inclusions within the cytoplasma of myeloma cells were reported. One contained crystalline inclusions which were not stained by May-Grünwald and Giemsa, and the other contained Auer rod-like spindle shaped inclusions which were stained by May-Grünwald and Giemsa and PAS. Both cases were stained intensively by acid phosphatase but they were not stained by Congo red or by thioflavine-T. Moreover, they reacted only with anti-kappa sera in the immunofluorescent study and showed the same structure on electron microscopic observation. Although they showed different staining behaviors according to their compositions, they were considered to be essentially the same. It appears that light chains produced in excess are concentrated and form inclusions through the addition of sugar or digestion by lysosomal enzymes.

Aged↗

Postoperative bronchopleural fistula: clinical and experimental study.

It is a well-known fact that in pulmonary tuberculosis patients treated by resection, the quality of the suture material used for closing the bronchial stump plays an important role in the pathogenesis of postoperative bronchopleural fistula. Of 426 cases treated surgically and in whom silk suture thread was used, 23 developed bronchopleural fistula, whereas none of the 220 cases sutured with nylon monofilament developed abnormality. Statistical analysis of 100 surgical cases with silk thread suture and of 100 cases with nylon monofilament suture showed that the two groups had no marked differences as to background factors. Howevers, as compared with the silk-thread suture group, the nylon-monofilament suture group revealed more consistently favorable postoperative bronchoscopic findings. Experimental studies with dogs showed a similar lack of complications when the monofilament suture material was used, as contrasted were conducted in hospital by the same surgical personnel using the same procedures, it can be said that, to insure prevention of complications, the suture material for bronchial stump closure should be of non-irritating nature and preferably of monofilament strength and quality, such as nylon monofilament.

Animals↗