Farm-scale evaluation of the impacts of transgenic cotton on biodiversity, pesticide use, and yield.

Higher yields and reduced pesticide impacts are needed to mitigate the effects of agricultural intensification. A 2-year farm-scale evaluation of 81 commercial fields in Arizona show that use of transgenic Bacillus thuringiensis (Bt) cotton reduced insecticide use, whereas transgenic cotton with Bt protein and herbicide resistance (BtHr) did not affect herbicide use. Transgenic cotton had higher yield than nontransgenic cotton for any given number of insecticide applications. However, nontransgenic, Bt and BtHr cotton had similar yields overall, largely because higher insecticide use with nontransgenic cotton improved control of key pests. Unlike Bt and BtHr cotton, insecticides reduced the diversity of nontarget insects. Several other agronomic and ecological factors also affected biodiversity. Nevertheless, pairwise comparisons of diversity of nontarget insects in cotton fields with diversity in adjacent noncultivated sites revealed similar effects of cultivation of transgenic and nontransgenic cotton on biodiversity. The results indicate that impacts of agricultural intensification can be reduced when replacement of broad-spectrum insecticides by narrow-spectrum Bt crops does not reduce control of pests not affected by Bt crops.

The in vitro effect of a low molecular weight heparin, nadroparin (Fraxiparine), on leukocytes obtained from patients with vascular diseases.

BACKGROUND: Both lymphocytes and granulocytes may play a role in the immune system-mediated inflammatory response associated with non-Q wave infarction and aortic aneurysms. METHODS: The purpose of this study was to establish the in vitro effects of a low molecular weight heparin (LMWH), nadroparin (Fraxiparine), on some functional parameters of peripheral granulocytes and lymphocytes isolated from control subjects and patients with aortic aneurysm or non-Q wave infarction. RESULTS: Nadroparin (0.06-600 AXaU/ml) exerted different in vitro effects on granulocytes and lymphocytes isolated from normal subjects and the patient groups. The following indices were assessed: superoxide anion release, lymphocyte proliferation, phagocytic activity and the cellular respiratory burst. The effects of nadroparin varied according to the patient group and the index of lymphocyte/granulocyte assessed. CONCLUSIONS: Since peripheral granulocytes isolated from these patients are activated, the observed inhibition exerted by nadroparin on superoxide anion release may be beneficial. LMWHs have additional effects that are independent of their anticoagulant activity. These effects may influence the "inflammatory component" of the atherosclerotic process.

Effects of synovial fluid on the respiratory burst of granulocytes in rheumatoid arthritis.

Neutrophil infiltration in the synovia is an important feature of the local inflammatory process associated with rheumatoid arthritis. The present study is focused on the effects exerted in vitro by the synovial fluid versus serum on the respiratory burst of granulocytes isolated either from blood or synovial fluid of rheumatoid arthritis patients. The respiratory burst was evaluated as superoxide anion release, by lucigenin-amplified chemiluminescence. Our data show that the respiratory burst of granulocytes isolated from rheumatoid arthritis patients might trigger a significant oxidative stress both in periphery and the inflamed joint. These cells show no pathological pattern when activated in vitro by the chemotactic peptide fMLP, heterologous synovial fluid or serum. Acellular synovial fluid amplifies the superoxide anion release induced by fMLP more than the corresponding serum, indicating that a bacterial infection in the joint might enhance the oxidative damage in the inflamed synovium.

Flow cytometry measurements of intracellular Ca2+ in K 562 cells.

The aim of this study is to show the intracellular Ca2+ changes induced by methotrexate, a cell cycle inhibitor, in order to prove the intracellular Ca2+ implication in cell proliferation processes. The fluorescent dye used to measure this parameter is Fluo-3, a fluorescein derivative useful for measuring the kinetics of Ca2+ transitions, waves and oscillations. The alterations of Ca2+ concentration proper to K562 cells have been studied, using methotrexate as a cell activation factor, both as direct effects on the cell response (1-15 minutes), and effects in time (24h.), using methotrexate in the culture medium. The K562 response at Ca2+ level in time remained constant for the cells grown in methotrexate medium, showing a slight increase in the control medium. We proved that methotrexate, a cell cycle inhibitor decreased the cytoplasmatic Ca2+ concentration in K562 cells, soon after adding methotrexate both to T0 and T1.

Peripheral leukocytes activation in aortic aneurysmal disease.

The pathogenesis of aneurysmal disease involves factors acting over time. A sustained chronic inflammatory reaction is observed in association with initiations, maintenance, rapid growth and rupture of aortic aneurysms. This study was designed to identify the possible pathogenic role of the inflammatory cells in the outcome of aneurysmal disease, testing the activation state of peripheral lymphocytes and neutrophils. Circulating activated lymphocytes and repeated peaks of neutrophils activation in sequential follow-up is associated with larger aneurysms, mural thrombosis, tendency to aneurysm extension and rupture.

The immune response induced by a split influenza vaccine. Studies on cellular immunity.

The aim of this study is to evaluate the effects exerted in vivo upon the general reactivity of the immune system by a commercial split influenza vaccine produced by the Cantacuzino Institute, Bucharest-Romania. The vaccine was intramuscularly administered to 14 volunteers with no precedent of influenza vaccination and no major immune disorders. We have investigated in vitro the polyclonal proliferation of peripheral lymphocytes and the phagocytosis developed by peripheral granulocytes, before and three weeks after vaccination. Our experimental results indicate that the vaccine might have a modulatory action on peripheral leukocyte concentration induces the activation of polyclonal lymphocyte proliferation and of the phagocytosis potential of granulocytes. These effects are not dependent on the age of the vaccinees.

Action of some proteic and carbohydrate components of Symphytum officinale upon normal and neoplastic cells.

The crude watery extract of Symphytum officinale and certain proteic and carbohydrate components isolated from it were studied for their effect upon the in vivo and in vitro proliferation of Ehrlich ascites cells, EL-4 cell line and of human T lymphocytes and upon the respiratory burst of human PMN granulocytes stimulated via Fc receptors. The results indicate that the crude extract and its proteic fraction stimulate the in vivo proliferation of the studied neoplastic cells and exert an antimitotic effect on human T lymphocytes in vitro stimulated with PHA. The vegetal preparations have remarkable effects on the respiratory burst of the granulocytes non-stimulated and stimulated via Fc receptors. The data underline the necessity to study thoroughly the effects of different phyto compounds through both pharmacological and immunological methods.

The in vitro action of a succussed substance on the proliferative response of human lymphocytes stimulated with phytohemagglutinin.

Human peripheral blood lymphocytes from healthy controls, immunodepressed patients presenting chronic bacterial infections or neoplasias and from allergic patients were stimulated in vitro with phytohemagglutinin (PHA) in culture medium supplemented or not with 1 x 10(-7), 1 x 10(-15) or 1 x 10(-30) succussed dilutions or bee venom or phosphorus in tridistilled water. The most significant inhibition due to DNA incorporation was noted in lymphocytes from allergic patients cultivated in media supplemented with 1 x 10(-30) succussed substance dilution in the presence of PHA. The cells from immunodepressed patients did not show a significant inhibition at 1 x 10(-30) dilution. Hypothetically, we try to explain these findings as the expression of the changes induced by the succussed solution on the water molecule which in turn, influences the chemical structure of the cellular membrane and implicitly, its functions.

In vivo and in vitro effect of Cantastim, an immunomodulatory agent extracted from a highly pathogenic Pseudomonas aeruginosa strain.

Cantastim is a biological product consisting of distinct molecules of phospholipids obtained from a peculiar Pseudomonas aeruginosa strain. It enhanced the IgM and especially the IgG responses of mice pretreated with Cantastim and then intraperitoneally inoculated with T-dependent antigens such as sheep erythrocytes; restored cellular immunocompetence as evidenced by an increase in the in vitro proliferative responses to T-cell mitogens and allogeneic stimuli of murine splenocytes from in vivo pretreated mice activated NK cytotoxicity, and inhibited in vivo growth of the Ehrlich ascites tumor. In vitro it stimulated the mitogenesis of mouse lymphocytes but did not exert such stimulatory effect on guinea pig or human lymphocytes. All these findings allow to define Cantastim as an immunomodulating agent influencing mainly the cell-mediated immune response.

[A nonspecific immunostimulant effect with Cantastim on the cellular and humoral immune responses in mice evaluated by in vivo and in vitro tests]. / Efectul imunostimularii nespecifice cu "Cantastim" asupra raspunsului imun mediat celular si umoral la soarece, apreciat prin teste in vivo si in vitro.

The stimulatory effect was evaluated, of an ethanol extraction obtained from a pathogenic strain of Pseudomonas aeruginosa type XV. It was noted that this extract, commercially known as "Cantastim" has mitogenic effects in vitro for mouse lymphocytes, but not for those of humans or of guinea pigs. It activates the cytostatic functions of macrophages. It is thermoresistant, nonimmunogenic and it is not allergic. A low amount of proteins and carbohydrates are contained in this extract, but it contains over 80% phospholipids. It has a transient stimulating effect of the cytotoxic effects of NK cells, and it also activates the synthesis of antibodies from the IgM and the IgG classes. It probably stimulates the expression of receptors for PHA in the membrane of T lymphocytes, and retards the development of the Ehrlich ascites tumour, protecting at the same time the animals from severe infections with conditionally pathogenic germs. These data suggests that "Cantastim" is a potent immunomodulating agent that could be used successfully in the fight against certain chronic diseases with a bacterial or neoplastic etiology of humans.