Mitosis of maternal lymphocytes in the presence of fetal cells: possible implication in prenatal diagnosis from fetal blood samples

Histopathology of bile ducts in F1 rats hybridized from parents with different major histocompatibility antigens, undergoing inoculation with maternal strain lymphocytes during the fetal period

In 1979, Seemayer suggested that biliary atresia (BA) might represent maternal or postnatally induced graft-versus-host reactions in which the liver is the principal target for aggressor lymphocytes. We attempted to produce perinatal graft-versus-host disease (GVHD) models to clarify the causal relationship between BA and GVHD. F1 rats were hybridized from parents with different major histocompatibility antigens: inbred strain maternal Lewis (LEW) and paternal Brown Norway (BN). F1 hybrid rats between 16 and 18 days' gestational age (term: 21 days) were given a single intrahepatic inoculation of mixed lymphocytes (1 × 10(7)/ml) from spleen and peripheral blood of female LEW rats. Forty-seven (25.6%) of 184 F1 hybrid rats receiving lymphocyte inoculation were born alive. They were killed immediately after birth or between 1 and 65 days of age for histologic examination. Abnormalities of the intrahepatic bile ducts were noted in 16 (84.2%) of 19 rats, while 3 (60%) of 5 showed abnormalities of the extrahepatic bile ducts. Main histological features involved periductal lymphoid cell infiltration and intraepithelial lymphoid cell invasion as well as epithelial degeneration. The histologic changes corresponded to those in GVHD, and furthermore showed common findings observed in BA.

Human lymphocyte culture: intrinsic factors influencing the quality of chromosome preparations

In a cytogenetic study of the consecutive cell cycles (M1, M2 etc.) from human lymphocyte cultures after 5-bromodeoxyuridine incorporation followed by differential Giemsa staining, the metaphases of M2 and subsequent in vitro divisions have been found to spread better than those of M1 cells, as if the cells of in vitro generation suffer some membrane alterations. Moreover presence of S or G2 phase, leukocytes in a blood sample may result into early proliferation in a PHA stimulated culture system, so that the metaphase yield at 72 h will be larger than otherwise, a sizeable portion of which, being in M2 or subsequent cell cycles, will spread better. Thus such individual or transient intrinsic factors of haematologic state may influence the success of a leukocyte culture and the quality of chromosome preparation.