No abstract

Dietary supplementation with fish oil, which contains high amounts of long chain omega 3 ((n-3)) polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), has recently been shown to have protective and ameliorative effects on diseases characterized by chronic inflammatory reactions. Interactions between vascular endothelium, mononuclear cells, and cytokines are crucial steps in the course of inflammatory processes such as chronic graft rejection. We therefore studied the effects of DHA and EPA on both the adhesion of peripheral blood lymphocytes (PBL) to human endothelial cells (EC) in culture and the expression of EC-adhesion molecules and their counterreceptors on PBL. The addition of DHA or EPA to the adhesion assay significantly decreased the adhesion of PBL to untreated EC and tumor necrosis factor-alpha (TNF alpha)-, interleukin (IL) 4-, and lipopolysaccharide-stimulated EC. When EC were pretreated with (n-3) PUFAs for 18 hr, washed, and then stimulated by TNF alpha, IL-4, or lipopolysaccharide, PBL adhesion was also significantly reduced compared with controls. We also showed that PBL preincubated with DHA or EPA, and then washed and chromium radiolabeled, still exhibited an adhesion inhibition to TNF alpha- and IL-4-treated EC as well as untreated EC. Cytofluorometry and immunoenzymatic analyses indicated that pretreatment of EC with (n-3) PUFAs before their activation significantly reduced the EC-induced expression of vascular cell adhesion molecule 1, whereas the level of expression of intercellular adhesion molecule 1 and E-selectin was not modified. Furthermore, we showed that incubation of PBL with DHA or EPA moderately reduced the level of cell surface expression of L-selectin and leukocyte function-associated antigen 1, but not of very late antigen 4. In all cases, the inhibitory effect of (n-3) PUFAs was specific and dose dependent. In addition, DHA seems to be a more potent inhibitor than EPA, but the two compounds in association had an additive effect. Regardless of the mode of action, this inhibitory effect may explain the protective and ameliorative effects of (n-3) PUFAs on diseases involving chronic inflammatory reaction.

No abstract

SummaryDuring pregnancy, important modifications of hemostasis occur resulting in mothers in hypercoagulability and the role of placental cells such as trophoblast cells has been hypothesized. In this study, we first showed that syncytiotrophoblast plasma membranes, isolated from normal human placenta, expressed a strong tissue factor (TF) activity. We then studied TF activity of two continuous trophoblast cell lines (JEG-3 and BeWo) in comparison to human umbilical vein endothelial cells (HUVEC) and transformed human endothelial cells (ECV-304). TF assays were performed on intact detached confluent cells. Unstimulated JEG-3 and BeWo cells exhibited a very high TF activity which slightly increased after 2 to 4 h TNF-α stimulation. In contrast, HUVEC and ECV-304 had a lower basal TF activity which was mainly inducible by TNF-a, with a maximum effect after 4 to 6 h stimulation. For both cell types, TF activity was decreased to basal value after 16-hour TNF-α stimulation. These results support that trophoblast cells are able to express TF but the involvement of this property in the hemostatic physiological changes observed during pregnancy, remains to be demonstrated.

The effects of polyunsaturated fatty acids (PUFAs: docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids) on induced lymphocyte proliferation and expression of CD25alpha chain of interleukin-2 receptor, CD71 and HLA-DR were investigated. PUFAs had no effect on phytohaemagglutinin (PHA)-induced lymphocyte agglutination, but they strongly inhibited the lymphoproliferative response to PHA. This inhibitory effect is PUFA dose-dependent and seems to be more potent with DHA than EPA, Pre-incubation experiments showed that lymphocytes cultured with PUFAs for 6 h then washed and exposed to PHA, still inhibited lymphocyte proliferation. The authors also showed that this inhibitory activity was time dependent but became nonsignificant when PUFAs were added after 48 h lymphocyte culture. The addition of excess exogenous human recombinant rIL-2 partly restored PHA-lymphocyte proliferation inhibited by EPA but not by DHA. On the other hand, the authors showed that PUFAS did not inhibit IL-2 stimulated lymphocyte proliferation. The addition of PUFAs to cell culture medium had no inhibitory action on the PHA-induced lymphocyte expression of CD25, CD71 and HLA-DR. Furthermore, this effect appeared independent of eicosanoid synthesis or peroxide formation. Indeed, the inclusion of aspirin and vitamin E in the culture medium did not prevent the inhibitory effects of PUFAs on lymphocyte proliferation. Regardless of the mechanism of action, the inhibitory effect of PUFAs on activated lymphocytes may explain why some clinical trials of fish oil supplemented diets containing high amounts of DHA and EPA have been successful in improving the health status of patients suffering from inflammatory and autoimmune disorders.

Summary. Seminal fluid transferrin concentrations of proven fertile donors and normozoospermic patients were significantly higher (P < 0\m=.\001) than those in other groups examined. There were no significant differences in the transferrin values among vasectomized, azoospermic and very severe oligozoospermic subjects. Values were also similar in patients affected by secretory or excretory azoospermia. Regression analysis showed a positive correlation (P < 0\m=.\001,r = 0\m=.\72) between seminal fluid transferrin concentrations and sperm density. A negative correlation (P < 0\m=.\02, r = 0\m=.\28) existed between circulating FSH and seminal fluid transferrin concentrations. There were no significant differences between seminal fluid transferrin and the percentages of abnormal sperm cells or immature seminal line elements. These results indicate that the nature of seminiferous tubule dysfunction can be precisely defined by examining seminal fluid transferrin in combination with other biological values usually used to explore testicular function.

No abstract

The authors studied the effects of soluble syncytiotrophoblast extract (STE) on the proliferative responses of lymphocytes to different lectins (PHA and Con A) and to allogeneic cells in one-way mixed lymphocyte cultures. STE suppressed lymphocyte reactivity to lectins and to allogeneic cell cultures. The inhibitory effect was dose dependent. Increased concentrations of lectins failed to overcome the inhibitory effect of STE. Lymphocytes preincubated with STE for 18 hr, then washed and exposed to lectins still exhibited an inhibition of cellular proliferation. STE added to lymphocyte cultures at various times in the presence of both mitogens or of allogeneic cells continued to inhibit lymphoproliferative responses even when it was added after 43 hr of cell culture. Furthermore, STE was able to reduce the spontaneous proliferation of tumor cell lines K562 and LHN13 maintained in vitro culture prior to testing. In all cases, the inhibition observed was not due to lymphocytotoxicity or to tumor cell mortality. The inhibitory effect of STE on the proliferative responses of lymphocytes to stimulants may be due to a cytostatic effect that may represent a contributing factor in the nonrejection of the fetus by a competent immune system.