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H Ohki

Publications and source records attributed to H Ohki.

42 records · Page 3Linked to original sources
PubMed1987

Tolerance induced by thymic epithelial grafts in birds.

Grafts of the anterior limb bud introduced at embryonic day 4 between histoincompatible chick embryos were subject to chronic, mild rejection beginning from several weeks to several months after birth. In contrast, quail wing buds similarly grafted into chickens started to be rejected at the first or second week after birth and finally autoamputated. Embryonic thymus epithelium from donor quail (before it had been colonized by hemopoietic cells) was grafted into chicks. A chimeric thymic epithelial stroma was generated in which the lymphocytes of the chick acquired the capacity to recognize the grafted limb as self either permanently or for a protracted period of time. In such thymic chimeras the grafted wings were not rejected.

Animals↗
PubMedDate not supplied

Characterization of a pyridoxalated hemoglobin-polyoxyethylene conjugate as a physiologic oxygen carrier.

A pyridoxalated hemoglobin-polyoxyethylene conjugate (PHP) is an oxygen carrier prepared from outdated human red cells through chemical modifications of hemoglobin (Hb). PHP was evaluated as a physiologic oxygen carrier. PHP was synthesized from a pyridoxalated hemoglobin (PLP-Hb) and an activated diester of polyoxyethylene (POE). The average numbers of molecules of PLP and POE conjugated to a Hb molecule were 3.3 and 6.2, respectively. The p50 of PHP was 20.4 torr, which was much higher than the 14.0 torr of stroma-free Hb. At a Hb concentration of 6 g per dL, PHP had a physiologic colloid osmotic pressure (29 torr) and a lower viscosity (2.6 cP at 37 degrees C) than whole blood (4.2 cP at 37 degrees C). At temperatures below 20 degrees C, the p50 of PHP was higher than that of the red cells. PHP, which had an average molecular weight of 90,000, consisted of 83 percent monomeric PLP-Hb-POE conjugate, 12 percent dimeric PLP-Hb-POE, and 4 percent trimeric PLP-Hb-POE. The consistency of the relative contents of the components was well controlled through seven lots, and each component had sufficient oxygen-carrying capacity. The dimeric and trimeric components contributed to the prolongation of the residence of PHP in the circulation. The results indicate that PHP has favorable properties as an oxygen-carrying blood substitute and perfusate.

Animals↗