J. C. Gern

Medicinal mushroom Ganoderma lucidum (Leyss: Fr) Karst. triggers immunomodulatory effects and reduces nitric oxide synthesis in mice.

This study investigated the effect of Ganoderma lucidum supplementation on lymphocytes and peritoneal macrophages from mice. Our results show that G. lucidum in vivo was able to increase interferon-gamma (IFN-gamma) concentration but reduced CD3(+) and CD8(+) spleen lymphocytes. Ex vivo, IFN-gamma; and interleukin-10 levels were increased and the tumor necrosis factor-alpha (TNF-alpha) level was reduced by peritoneal macrophages from mice fed with G. lucidum. In the absence of stimuli nitric oxide production was reduced in mice fed with G. lucidum, and with lipopolysaccharide stimulation nitric oxide production was increased but was lower than control values (P < .05). G. lucidum was grown by solid-state culture in wheat grain, and a chow containing 10% G. lucidum mycelium was formulated (G10). Swiss male mice were divided into two groups, termed G10 and control groups according to the diet, and were fed for 3 months. Peritoneal macrophages were obtained and investigated with regard to phagocytosis, lysosomal volume, hydrogen peroxide, superoxide anion, and cytokines ex vivo. In the plasma we investigated concentrations of cytokines, and in the spleen we determined subsets of CD3(+), CD4(+), CD8(+), and CD19(+) lymphocytes.

Direct and indirect toxic effects of cotton-derived cellulose nanofibres on filamentous green algae

Recently, cellulose nanofibers (CNFs) have attracted considerable attention as natural, abundant polymers with excellent mechanical properties and biodegradability. CNFs provide a new materials platform for the sustainable production of high-performance nano-enable products for various applications. Given the increasing rates of CNF production, the potential for their release to the environment and the subsequent impact on ecosystem is becoming an increasing concern that needs to be addressed. Here, we used the Klebsormidium flaccidum as a bioindicator organism of terrestrial and freshwater habitats pollution using a battery of biomarkers. Our results show that cotton CNFs inhibit the proliferation of algae and induce morphological changes in them. The two main toxicity mechanisms induced by cotton CNFs are: (i) a direct contact of CNFs with the cell wall and cellular membrane and (ii) an indirect effect through the generation of reactive oxygen species (ROS).

Agaricus brasiliensis mycelium supplementation in Sarcoma 180tumour-bearing mice reverses the immune response induced by the tumour

Abstract The biological properties of Agaricus brasiliensis mycelium, including their immuno-stimulating and anti-tumour activities, have previously been investigated. The aim of this study was to evaluate the effects of long-term intake of A. brasiliensis mycelium cultivated on wheat grains by solid-state culture on tumour growth and immune response in Sarcoma 180 tumour-bearing mice. Mice received dietary supplementation with 100% or 50% Agaricus mycelium cultivated on wheat grains for 14 weeks and were inoculated with Sarcoma 180 tumours. We found that A. brasiliensis had anti-tumour activity, and that dietary supplementation with a 50% concentration (A50S) prevented loss of body weight, inhibited tumour growth, induced the increase of CD4+ T cells and CD25+ CD4+ T subsets in peripheral organs and downregulated Tumor necrosis factor alpha production in plasma. Our results confirm that dietary supplementation with Agaricus may offer immuno-modulatory activity and protection against tumour growth.

SHORT-COMMUNICATION Evaluation of perfused bovine udder for gene expression studies in dairy cows

Intramammary infections are one of the main causes of productivity loss in dairy cows. To better understand the immune system response and to avoid the use of live animals, we validated the use of isolated bovine udder as an ex situ model. Six mammary glands were collected from cows ready for culling. Three udders were perfused with Tyrodes solution and three were not-perfused. During six hours, we collected perfusate samples for biochemical analysis. We also collected alveolar and teat canal tissue to evaluate gene expression. The biochemical parameters indicated that the perfused udders remained viable for the entire period of the experiment. A real-time polymerase chain reaction showed an increase in 18S rRNA gene expression in the alveolar tissue at 3 and 4 h after perfusion. There was also an increase in the Ubiquitin gene in the teat canal from not-perfused udders at 1, 3, and 4 h after slaughter. In general, gene expression was stable during the experiment. Our results indicated that the isolated perfused bovine udder model is appropriate for genetic studies, opening a new perspective in animal experimentation methods.

Carbon Nanotubes as a DNA Delivery Agent for Generation of Genetically Modified Mammals Embryos

Several research centers and pharmaceutical corporations routinely use genetically modified animals (GMAs) in the development of new drugs, in the identification of new drug targets and to test drugs’ efficacy and safety. The most usual methods to produce GMAs are pronuclear microinjection, somatic cell nuclear transfer, retroviral vectors, and recently, embryonic stem cell transgenesis. These methods make use of DNA vectors and present several limitations. Recently, nanomaterials have been applied as an alternative vector for delivery of exogenous DNA into mammalian cells. This chapter addresses the use of carbon nanotubes (CNTs) as a DNA delivery agent for the generation of genetically modified mammals embryos. CNTs can be easily bound to DNA by non-covalent attachement. The DNA strand spontaneously wraps around the carbon nanotubes and DNA molecules can be encapsulated within or around them. The process of interaction of DNA/RNA with CNT favors their protection from degradation by cytoplasmic nucleases, increasing the integration of the transgene into cell nucleus. Thus, the use of CNTs can be far simpler and less laborious when compared to other techniques to produce GMAs.