Does levonorgestrel emergency contraceptive have a post-fertilization effect? A review of its mechanism of action.

Background: Recent studies have identified that levonorgestrel administered orally in emergency contraception (LNG-EC) is only efficacious when taken before ovulation. However, the drug does not consistently prevent follicular rupture or impair sperm function.

Objective: The present systematic review is performed to analyze and more precisely define the extent to which pre-fertilization mechanisms of action may explain the drug's efficacy in pregnancy avoidance.

MLC-activation by acute lymphatic leukemia blasts.

The MLC-activating potential of 25 ALL blasts (16 "common" ALL, 6 T-ALL, 3 not identified) was investigated. Mitomycin-treated leukemic blasts or X-irradiated lymphocytes were cultured with heparinized whole blood from different healthy donors. MLC activation by blast cells was expressed as percentage of MLC activation by X-irradiated lymphocytes.

Influence of thymosin on E-rosette formation of lymphoid cells in leukemic and nonleukemic children.

The influence of two thymosin and two spleen control preparations on the E-rosette formation of peripheral blood lymphocytes and leukemic cells from non-leukemic children with depressed T cell values and leukemic children was investigated. Both thymosin preparations but also one of the control preparations induced a significant increase in the mean percentage of E-rosette forming PBL in the non-leukemic children with depressed T cell values. Thymosin and spleen preparations, however, did not convert the non-erythrocyte binding blasts to erythrocyte binding cells in either common or pre-T-ALL.

[The prognostic value of lymphocyte transformation by phytohemagglutinin in children with acute lymphatic leukemia].

The response to phytohemagglutinin (PHA) of lymphocytes from 62 children with acute lymphoblastic leukemia (ALL) was tested before and during cytostatic therapy. Nineteen patients were tested as well for reactivity in autologous mixed lymphocyte-blast cell cultures. The prognostic value of the results obtained has been assessed.