The combined impacts of selenium and phosphorus on the fate of arsenic in rice seedlings (Oryza sativa L.).

Although the single role of selenium (Se) or phosphorus (P) in regulating the As contamination of rice plants has been reported in some studies, the combined impacts of Se and P on the fate of As and the underlying mechanisms are poorly understood. To address this knowledge gap, the uptake, translocation, and biotransformation of As mediated by Se were investigated in rice (Oryza sativa L.) seedlings hydroponically cultured with P-normal and P-deficient conditions. The results showed Se addition stimulated the uptake of arsenite and arsenate by 15.6% and 30.7%, respectively in P-normal condition, and such effect was more profound in P-deficient condition with the value of 43.8% and 70.8%. However, regardless of Se addition, P-deficiency elevated the As uptake by 47.0%-92.1% for arsenate but had no obvious effects for arsenite. Accompanying with the As transfer factorShoot/Root reduced by 74.5%-80.2% and 71.1%-85.7%, Se addition decreased the shoot As content by 65.8%-69.7% and 59.6%-73.1%, respectively, in the arsenite- and arsenate-treated rice plants. Relative to the corresponding treatments of P-normal condition, P-deficiency reduced the As transfer factorShoot/Root by 38.9%-52.5% and thus decreasing the shoot As content by 35.2%-42.5% in the arsenite-treated plants; while the opposite impacts were observed in the arsenate-treated plants, in which the shoot As content was increased by 22.4%-83.7%. The analysis results of As species showed As(III) was dominant in both shoots (68.9%-75.1%) and roots (94.9%-97.2%), and neither Se addition nor P-deficiency had obvious impacts on the interconversion between As(III) and As(V). Our results demonstrate the regulating roles of Se in As accumulation mainly depend on P regimes and the specific rice tissues, but the effects of P-deficiency on the fate of As were influenced by the form of As added to the culture.

Anti-inflammatory effect of dialysable leucocyte extract in a rat model of osteoarthritis: histopathological and molecular characterization.

OBJECTIVES: To evaluate the effect of dialysable leucocyte extract (DLE) on pro- and anti-inflammatory profiles in a rat model of osteoarthritis (OA). METHOD: Forty-eight male Wistar rats were divided into three groups: normal rats without treatment, OA rats treated with placebo, and OA rats treated with DLE. After treatment, the animals were killed to obtain cartilage for histological analysis and to determine the expression of pro- and anti-inflammatory cytokines by reverse transcription multiplex polymerase chain reaction (RT-MPCR) and immunohistofluorescence analyses. RESULTS: Histological analysis revealed that OA cartilage from rats treated with DLE displayed similar characteristics to non-OA cartilage from the control group. The OA cartilage treated with placebo showed alterations in the cellular architecture and in chondrocyte cluster formation. Analysis of cytokine expression by RT-MPCR showed that OA cartilage from DLE-treated rats expressed platelet-derived growth factor (PDGF), interferon (IFN)-γ, and fibroblast growth factor (FGF)-2, similar to non-OA cartilage from the control group. However, OA cartilage from rats treated with placebo expressed interleukin (IL)-1, PDGF, and I kappa B (IκB). Confocal immunodetection of FGF-2, PDGF, and non-phosphorylated IκB showed that they were distributed in the cytoplasm of most chondrocytes in OA cartilage from DLE-treated rats whereas no nuclear factor kappa B (NF-κB) expression was observed in the nuclei. Instead, in OA cartilage from the placebo group, only weak FGF-2 staining was observed, PDGF and IκB were not detected, and NF-κB was strongly observed in both cytoplasm and nuclei. CONCLUSIONS: Our findings suggest that DLE treatment modifies the OA process, promoting the expression of anti-inflammatory cytokines and diminishing the inflammatory effects, avoiding the nuclear translocation of NF-κB in chondrocytes.

A low-molecular-weight dialysable leukocyte extract selectively enhances development of CD4⁺RORγt⁺ T cells and IL-17 production.

A low-molecular-weight (under 10 kDa) dialysable leukocyte extract (called transfer factor, TF) has been shown to be a prospective substance to improve or modulate immune response in autoimmunity, inflammation, infectious diseases or cancers. However, the use of TF has been limited by the absence of any data on the mechanism of its action. Here we show that TF prepared from peripheral blood leukocytes of healthy human donors displays multiple regulatory effects on individual parameters of the immune system. TF decreases proliferation of T and B lymphocytes and partially alters the production of cytokines and nitric oxide by activated macrophages. TF also inhibits production of T helper 1 (Th1) cytokines interleukin 2 (IL-2) and interferon γ, slightly stimulates production of Th2 cytokine IL-10 and considerably enhances the secretion of IL-17 by activated mouse spleen T cells. At the molecular level, TF enhances expression of genes for transcription factor RORγt and for IL-17. The enhanced expression of the RORgt gene corresponds with an increase in the number of RORγt⁺CD4⁺ Th17 cells and with enhanced IL-17 production. In contrast, the expression of the Foxp3 gene and the proportion of CD4⁺CD25⁺Foxp3⁺ regulatory T cells are not significantly changed in the presence of TF. These results suggest that the activation of pro-inflammatory Th17 cells, which have multiple immunoregulatory properties, could be the main mechanism of the immunomodulatory action of a low-molecular-weight leukocyte extract.

[The immune reactivity transfer factor as a modulator of lymphocyte functional activity in rats]. / Faktor perenosu imunnoï reaktyvnosti iak moduliator funktsional'noï aktyvnosti limfotsytiv shchuriv.

The transplantation of the thyroid tissue is one of the perspective methods for rehabilitation of thyroid gland functional disorders that appear due to the influence of insufficient environmental conditions on organism. By means of micromethod of lymphocyte blast transformation reaction on the base of [3H]-thymidine shift the functional activity of the Wistar rat's splenocytes was studied in case of radiation induced hypothyroidism with or without xenotransplantation of newborn pig thyroid gland organ culture. It was found that the level of thyroxine and triiodothyronine significantly decreased in serum of irradiated animals, the lymphocyte proliferation level was also reduced (by means of radioiodine introduction in dose of 8,325 MBk/mmole). Application of thyroid gland tissue xenotransplantate in this model of hypothyroidism helped to achieve the increasing of thyroid hormones levels in serum and rehabilitation of lymphocytes functional activity. The opportunities for correction of immunological disorders with the help of transfer factor of immune reactivity preparates were investigated. Transfer factor--is a low-molecular weight leukocyte extract (J 10 kD) with immunomodulating activities. This preparates activated the proliferation of splenocytes from animals with hypothyroidism and animals with hypothyroidism after xenotransplantation.

[A neuromorphological analysis of the motor area of the cerebral cortex in rat pups subjected to prenatal exposure to normal and pathological blood serum]. / Neiromorfologicheskii analiz motornoi oblasti kory mozga krysiat, podvergshikhsia prenatal'nomu vozdeistviiu normal'noi i patologicheskoi syvorotki krovi.

Morphological quantitative and qualitative analysis of the pyramidal neurones in the motor cortex of rat puppies after administration of the blood serum from human donors with central motor disorders reveals the dependence of the quality and quantity of neurones from the effect of corresponding blood sera. Pathologic blood serum decreases the number and induces degradation of dendritic organization of the pyramidal neurones. The effect of the blood sera on quantitative and qualitative properties of the pyramidal neurones in rat puppies depends on the age of donor infants with central motor disorders. Blood serum from newborn babies with motor dysfunctions significantly decreases the number of labeled pyramidal neurones and results in degradation of dendritic organization, whereas sera from 11-13-year infants only insignificantly affect these characteristics.

De novo initiation of specific cell-mediated immune responsiveness in chickens by transfer factor (specific immunity inducer) obtained from bovine colostrum and milk.

Transfer factors (TF) were prepared from colostrum and milk of bovines previously immunized with antigens obtained from Coccidioides immitis, infectious bovine rhinotracheitis virus, or from the viral agents responsible for avian Newcastle disease, laryngotracheitis disease or infectious bursal disease. The ability of bovine TF to transfer specific cell-mediated immune responsiveness to a markedly xenogenic species was studied using specific pathogen free (SPF) and standard commercial (SC) chickens as model recipients. Cell-mediated immune responsiveness was documented using one or more of the following for each antigen (organism) studied: (a) an in vitro chicken leukocyte (heterophil) migration inhibition assay; (b) delayed-wattle reactivity; or (c) protection from clinical disease. Chicken TFs obtained from spleens of immune donors were evaluated in parallel to bovine TF's in selected comparative studies. Bovine TF also referred to as specific immunity inducer (SII), and chicken TF were found to initiate antigen-specific cell-mediated immunity de novo in previously non-immune SPF chickens as well as in SC chickens despite the presence of maternally acquired humoral antibody which may serve as a "barrier" to immunization of SC chickens when commercially available vaccines are administered by parenteral routes. Bovine TF's specific for laryngotracheitis virus or infectious bursal disease virus afforded protection equal to that found for commercially available vaccines. Bovine TF's action was rapid (less than a day) and of relatively long duration at least 35 days.

Effect of immuno-modulating agents on murine IL-2 production.

The effect of two Chinese traditional drugs, Dang Gui injection prepared from Angelica sinensis and C 21 Ester glucoside (GB) extracted from Cynanchus auriculatus on in vitro production of IL-2 has been studied. The IL-2 was produced by Con A stimulation of mouse spleen mononuclear cells. The IL-2 activity was assayed using Con A stimulated blast cells as the target. It was found that Dang Gui increased and GB decreased the production of IL-2. In the control experiments for immuno-modulating effect, prostaglandin E2 (PGE2) was found to suppress and indomethacin to increase IL-2 production. The stimulatory effect of Dang Gui was totally abrogated by PGE2.