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.

Immunological properties of lymphoblasts and lymphocytes in children with acute lymphatic or undifferentiated leukemia.

In 35 children with acute lymphatic or undifferentiated leukemia, immunological properties of normal lymphocytes and lymphoblasts were investigated. In most cases the number of circulating normal lymphocytes with surface or B markers and delayed type hypersensitivity was depressed. On the other hand, the response to mitogenic stimulation with PHA as well as the antibody and immunoglobulin serum concentrations were found to be normal.

Immunotherapy with tumor cells and BCG in the guinea pig, studied by immunological in vivo and in vitro experiments.

The effect of intradermal immunisation with viable line 1 hepatoma cells and BCG was studied in syngeneic strain 2 guinea pigs. Immunisation with 1.5 X 10(6) hepatoma cells admixed to 200 microgram BCG induced tumor regression in 7/8 animals.

The mixed lymphocyte response in whole blood: technical aspects.

Experiments were conducted to standardize the response of lymphocytes in whole blood in mixed culture with allogeneic lymphocytes. The following conditions were found suitable: (1) A culture period of 6-8 days. (2) The ratio of stimulator to responder lymphocytes should be 4-8, but may vary from one batch of stimulator cells to another.

[Cellular immunity during and after high-dose methotrexate therapy in patients with osteosarcoma (author's transl)].

Nine patients with osteogenic sarcoma and one patient with epitheloid sarcoma of bone undergoing treatment with high-dose methotrexate (MTX) therapy were studied immunologically. The following peripheral blood lymphocyte parameters were evaluated: 1-8 days after the intravenous infusion of 7.5 g MTX followed by leucovorin rescue: absolute count/mm3, the stimulatory response to the mitogens, phythemagglutinin (PHA) and pokeweed (PW) and the reactivity in the mixed lymphocyte culture (MLC).

Immunestimulation by 4-imino-1,3-diazabicyclo(3.1.0.)-hexan-2-on (BM 06.002).

The new cancerostatic substance 4-imino-1,3-diazabicycle- (3.1.0.

Tumor-specific immunity in sarcoma patients.

Stimulatory responses of 40 patients with bone [33] and soft tissue [7] sarcomas to autologous tumor cells were correlated with clinical data and prognosis. Although conclusive judgments for individual patients cannot be made, some genral features emerge: patients with stimulation indices greater than 1.5 have a 50 percent relapse-free interval after surgery of 22 months, patients with indices, below 1.

The immune-status in patients with bone and soft-tissue sarcomas.

The immunologic status of 50 sarcoma patients was established. It was possible to apply the DNCB test and the recall antigen test in most cases during the course of the illness. The PHA stimulation of the lymphocytes and their cytotoxicity on homologous sarcoma cell lines were also correlated with the course of the illness.

Immunocompetence of pinealectomized and simultaneously pinealectomized and thymectomized rats.

The cellular and antibody-mediated immune responsiveness was studied in adult rats which had the pineal and/or the thymus gland removed within 36 hours after birth. The immunolgical parameters measured were: Skin graft rejection, haemolytic plaque formation, and haemagglutinating antibody formation in response to sheep red blood cells and the stimulation of lymphoid cells from the spleen by phytohaemagglutinin in lipopolysaccharide. The removal of the pineal gland had little effect on the degree of immunocompetence in normal or immunosuppressed animals.

[Responsiveness of lymphocytes to stimulation by pha and autologous blasts in acute lymphatic leukemias during remission (author's transl)].

The paper deals with the question how far the lymphocytes of acute lymphatic leukemia patients in remission can be stimulated by PHA and autologous blasts in the MLC-Test. The lymphocyte stimulation by PHA showed considerable variation dependent on the phase of therapy. A significant reduction of the responsiveness to PHA stimulation was found during the prophylactic reinduction treatment with Vincristin and Prednisolon compared with the results during maintenance therapy.

Investigation of cell-vitality in tumor specimen after cryosurgical operations.

Carcinomas of the gastro-intestinal tract were resected in 6 patients either by cryosurgery or in the usual, conventional manner without freezing the tumor. Cells from the tumorsections in each case were isolated by the use of enzymes and were examined for vitality following trypan-blue vital staining. In 5 out of 6 cryosurgical cases fewer than 10% of the cells were vital compared with sections from nonfrozen specimen.