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O Vainio

Publications and source records attributed to O Vainio.

7 recordsLinked to original sources
PubMed1979

Germinal center formation in BSA-tolerant chickens.

In chickens rendered neonatally tolerant to BSA the germinal center formation was significantly decreased after stimulation with BSA at the age of 3 weeks. At the breakdown of tolerance after the age of 6 weeks the IgG antibody formations recovered before the IgM production. Stimulation of tolerant birds with unrelated antigens resulted in slightly decreased antibody response but the germinal center formation was on the same level as in normal controls.

Aging↗
PubMed1979

Maturation of bursal stem cells within allogeneic or syngeneic bursal microenvironment: surface determinants and capacity for germinal centre formation.

Maturation of bursal stem cells in an allogeneic environment was studied. The occurrence of surface IgM, surface IgG, and Ia-like antigens on B cells after differentiatoin within an allogeneic bursa was studied. Furthermore, the immediate capacity of B cells to form germinal centres after differentiation in an allogeneic bursa was studied by injecting them with histocompatible T cells into "test-tube" birds. The results indicate that the switch to surface-IgG-bearing cells occurs in an allogeneic bursa in a similar manner as in a syngeneic bursa. Studies of the occurrence of Ia-like antigens on bursa cells demonstrate that they retain their original Ia-like antigens, even during maturation in an allogeneic host. Third, the results demonstrate that after differentiation within an allogeneic environment bursa cells have acquired the ijmediate capacity to cooperate with histocompatible T cells as measured by germinal centre formation in "test-tube" birds.

Animals↗
PubMed1979

Maturation of bursal stem cells within allogeneic or syngeneic bursal microenvironment: acquisition of postbursal maturity.

Differentiation of bursal stem cells in an allogeneic or syngeneic bursal microenvironment was compared. Bursal stem cells were transplanted into CY-treated 4-day-old recipients and permitted to differentiate in these hosts for 6 weeks. Their maturity degree was thereafter assessed by transplanting them into secondary recipients by using morphologic and functional criteria. As the secondary recipients 4-day-old CY-treated or CY-treated and surgically bursectomized chicks were used. The results obtained demonstrate that bursal stem cells develop to mature postbursal cells also within an allogeneic bursa. They also indicate that although the interaction of different lymphoid cells requires histocompatibility, the interaction between stromal cells in the bursa and lymphoid progenitors is not genetically restricted.

Animals↗
PubMed1979

Formation of germinal centres during neonatal tolerance in the chicken.

Chickens were made tolerant to BSA at the time of hatching. During the tolerance, antigenic stimulation with BSA resulted in poor germinal centre formation as compared to normal immunized control birds. The tolerance persisted for at least 6 weeks. Its breakdown had hardly started at the age of 12 weeks, both IgM and IgG antibody responses against BSA remaining negligible. Stimulation with the unrelated antigens SRBC and Brucella abortus resulted in good antibody responses, but the number of germinal centres was smaller in the tolerant birds than in normal controls.

Animals↗
PubMed1978

Early ontogeny of germinal center formation in the chicken.

Germinal center formation was studied in the spleen of young chickens immunized in ovo and at the time of hatching. When immunization was performed on day 18 in ovo and on the day of hatching, the first germinal centers were observed at 4 days. This is markedly earlier than in unimmunized chickens, where the first germinal centers appear at the age of 10 days or later. Germinal center formation preceded significant antibody production. The possible role of germinal centers in the generation of immunological memory is discussed in the light of these and earlier observations.

Aging↗