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Biomedical subjects

E Saksela

Publications and source records attributed to E Saksela.

At least 109 records · Page 6Linked to original sources
PubMed1979

Human natural killer cell activity is augmented by interferon via recruitment of 'pre-NK' cells.

Contact with various cell-line targets increases the natural killer (NK) activity of human lymphocytes. Supernatants of such 20 h co-cultures augment the NK activity of virgin lymphocyte populations, and the augmenting factor penetrates 0.2 micrometer Millipore filters. The supernatants also contain interferon, and partially purified human leucocyte interferon increases NK activity when added to 20 h assays with 51Cr-labelled K-562 target cells. Potent anti-interferon antiserum added to the co-cultures inhibits the target-cell-induced augmentation phenomenon. Both the target-cell contact and interferon-induced augmentation affect a population of human lymphocytes, from which the 'mature' NK cells have been removed by adsorption-elution using fetal fibroblasts as adsorbents. The activity of 'mature' NK cells is not enhanced, and we conclude that the augmentation is mediated by recruitment of 'pre-NK' cells.

Adsorption↗
PubMed1979

Genital Chlamydia trachomatis infections in patients with cervical atypia.

Of 177 gynecologic outpatients with cervical dysplasia studied, 29 (16%) were found to excrete Chlamydia trachomatis from their urogenital tract. Sera collected from 93 of these patients were significantly more often positive for and showed higher levels of antichlamydial micro-complement fixation (CF) and immunofluorescence (IF) antibodies than sera obtained from the controls. However, when the sera were tested for anti-herpesvirus type II (HSV-II) and cytomegalovirus (CMV) antibodies, no difference between the cases and the controls were encountered.

Adolescent↗
PubMed1978

Genital chlamydial infections in patients attending a gynaecological outpatient clinic.

Investigation for genital chlamydial infections was carried out on 160 patients of fertile age attending a gynaecological outpatient clinic. Thirteen (9%) of the 144 patients with valid specimens were found to be Chlamydia-positive. Seven (54%) of them had antichlamydial antibodies by the complement-fixation test, and 11 (85%) antichlamydial antibodies by a single-antigen immunofluorescence test compared with 21 (16%) and 70 (53%), respectively, of the 131 Chlamydia-negative patients. Patients with overt genital chlamydial infection often complained of ocular and urethral symptoms. Usually there was clinical evidence of cervical infection as well as of inflammation on cervicovaginal smears. Colposcopical and histological examinations did not show any specific alterations.

Antibodies, Bacterial↗
PubMed1978

Malignant histiocytosis. A clinical and morphological study of four cases.

Four patients with malignant histiocytosis are described. Major clinical signs were fever, lymphadenopathy, hepatomegaly and splenomegaly. Laboratory studies showed leukopenia, thrombocytopenia, low leukocyte alkaline phosphatase (LAP) score, normal erythrocyte sedimentation rate (ESR) and elevated serum triglycerides. There was evidence of bone marrow involvement in all four cases. Typical changes were seen in the histological study.

Adult↗
PubMed1978

Ectopic pregnancy. Relationship to the preceding contraception.

The incidence of extrauterine pregnancies in all the deliveries in this clinic has increased from 1.3% in 1968 to 2.5% in 1976. Of 163 consecutive extrauterine pregnancies during a ten month period in 1976, 40% had an intrauterine contraceptive device in situ at the time of conception. 650 healthy women who had had an IUD inserted in 1973 were follow-up for an average of 3 years and all extrauterine and intrauterine pregnanices registered while the device was in situ. 27 intrauterine and 4 extrauterine pregnancies occurred over 1,572 women-years of use. From these data it was calculated that 99.5% of all possible intrauterine implantation and 93.5% of tubal implantations were inhibited by the device. This difference is apparently the reason for the increased risk of extrauterine pregnancies in IUCD users.

Abortion, Legal↗
PubMed1977

Spontaneous, augmentable cell-mediated cytotoxicity with limited target cell specificity in human blood.

Nonadherent and nonphagocytic lymphoid cells from human peripheral blood became strongly cytotoxic against 51Cr-labeled chicken red blood cells and cells from an established human myeloma cell line when subjected to repeated cycles of washing in phosphate buffered saline or treated with trypsin or lecithinase. Prior to augmentation the effector cells pass nylon wool columns that remove practically all surface IgG-positive cells, but after augmentation they are retained in such columns. Augmentation does not make them phagocytic or adherent to plastic surfaces. Incubation at 37 degrees C of augmented cells prior to addition on the target cells restores the original nonaggressive state. Morphologically the cells making contact with the target cells are small or intermediate-sized mononuclear cells.

Animals↗
PubMed1977

Identification of the effector cells in human blood displaying spontaneous cytotoxicity to chicken erythrocytes.

By combining velocity and linear density fractionations as well as target cell rosetting techniques we have isolated and morphologically identified the human effector cell type responsible for spontaneous, trypsin-augmentable cytotoxicity against chicken red cells and human myeloma cell line targets. This cell is a large lymphoid cell with strong alpha-naphthyl esterase activity concentrated in a limited area in the cytoplasm usually at the indentation site of a slightly reniform nucleus. Cells with this morphology also formed plaques on chicken erythrocyte monolayers. The cell is nonphagocytic and nonadherent, it carries Fc receptors but no complement receptors on its surface, and shows a weak affinity to sheep red blood cells (SRBC). The frequency of these cells based on morphological analysis is 3 x 10(4)--6 x 10(4)/ml in normal human blood. This cell shows similarities (surface Ig-, Fc+, C3-) with the human natural killer (NK) cells lytic to hematopoetic target cell lines but differs in that the cytotoxicity is augmentable by trypsin and the affinity to SRBC is lower. Therefore, we postulate that these two killer populations represent different subpopulations of human NK cells.

Animals↗
PubMed1977

A simplified isotope release assay for cell-mediated cytotoxicity against anchorage dependent target cells.

An assay for cell-mediated cytotoxicity has been developed in which anchorage-dependent target cells are cultured on small plastic beads in suspension. Confluent target cells on the beads are handled by methods appropriate to suspension-grown cells and labelled with chromium-51, iodine-125 and [3H]proline. Fetal human lung fibroblasts and HeLa cells were used as targets in model experiments measuring human natural killer cell activity. In 20 h experiments, chromium-51 was the most suitable isotope. In 40 h experiments, [3H]proline release assay was superior to chromium-51 and iodine-125 assays. The bead cytotoxicity assay offers a rapid and simple isotope release technique for anchorage dependent cells because no trypsinization and re-seeding of target cells is needed.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1977

Antibody-dependent cell-mediated cytotoxicity in various orders of vertebrates.

By using chicken antibodies and chicken lymphoid cells, we could demonstrate antibody-dependent cytotoxicity (ADCC) against haptenated chicken erythrocytes. ADCC could be demonstrated either by treating the target cells with antibody (sensitization) or by treating the effector cells (arming). Approximately ten times higher antibody concentrations were required for arming than for sensitization. Chicken lymphoid cells did not co-operate with mammalian antibodies in either type of ADCC, and thus the situation was reciprocal to that observed earlier with mammalian lymphoid cells. In a further attempt to characterize the arming phenomenon we used biofiltered (aggregate-free) mouse antibodies for the arming of rat spleen cells. They were as efficient as nonfiltered antibodies, and this confirms that individual antibody molecules are efficient in arming.

Animals↗