PubMed HealthSearch

Biomedical subjects

T Timonen

Publications and source records attributed to T Timonen.

81 records · Page 5Linked to original sources

Blocking effect of rheumatoid factor on the in vitro cytotoxicity of lymphoid cells from carcinoma patients.

Human cryo-IgM rheumatoid factor (RF) preparations blocked the tumor-specific in vitro cytotoxicity of ovarian or bladder carcinoma patients' lymphoid cells in microcytotoxicity assays. The effect was mediated by pretreatment of the effector cells. Cryo-IgM RF free of detectable IgG blocked in a dilution-dependent manner, and immunosorbent purification of contaminating IgG from another preparation did not abrogate the blocking effect. Control IgM preparations lacking RF activity did not block the cytotoxicity, and normal human serum preincubation of the RF preparations rendered them inactive, indicating that the blocking effect was due to the anti-IgG activity of the RF.

Cryoglobulins

Cell-mediated anti-embryo cytotoxicity in human pregnancy.

The microcytotoxicity assay has been used to study human maternal cell-mediated immunity against foetal lung cells derived from foetal autopsies and amnion cells from full-term deliveries. Cytotoxicity against semi-allogeneic foetal lung cells but not against adult skin fibroblasts was detected in fourteen cases. No cytotoxicity was detected in six mothers tested during the first 15 weeks of gestation whereas 58% of mothers in the 15-17 weeks of gestation (twelve cases) and 88% with more advanced pregnancies (eight cases) were specifically cytotoxic. Cross-reactions against allogeneic foetal lung cells were mainly produced by effector cells from patients with 16-17-week-old pregnancies. No cytotoxicity was detected against semi-allogeneic amnion cells by effector cells from mothers after full-term deliveries. Cytotoxicity was blocked by autologous post-abortum sera in two out of seven cases. The effect of autologous post-abortum sera on non-cytotoxic effector cells was nonspecifically arming in four out of ten cases.

Amniotic Fluid