Copper oxide nanoparticles synthesized from an endophytic fungus Aspergillus terreus: Bioactivity and anti-cancer evaluations.

The mycofabricated metal nanoparticles (NPs) plays a significant role in cancer therapeutics and imparts a strategy in medicine. The current investigation focused to synthesize the Copper Oxide Nanoparticles (CuONPs) using an endophytic fungus isolated from Aegle marmelosa medicinal tree located in Western Ghats, India. The endophytic fungus FCBY1 explored the highest antagonistic and antioxidant activities among the 16 pigmented endophytic fungal strains which were isolated from the collected samples. The fungus FCBY1 was identified for its morphological and molecular characteristics where the (Internal Transcribed Spacer) ITS 1, 5.8 ribosomal gene and ITS 2 were sequenced; and the organism FCBY1 is Aspergillus terreus. The endophyte was put through for the synthesis of CuONPs and the size and structure of the synthesized particles were characterized by Scanning Electron Microscope (SEM). The confirmation of the CuONPs was characterized by FT-IR, EDAX and XRD analyses. The CuONPs exhibited the maximized antibacterial and antifungal activities against the human clinical pathogens; moreover the particles also explicated the free radicals/ROS scavenging at minimum concentration, which was assessed through DPPH, nitric oxide radical scavenging assays, and reductive power ability. The anti-cancer activity of CuONPs on colon cancer cell lines (HT-29) was evaluated by MTT (IC50: 22 µg/mL) and FACS analyses (32.11% cells gated in S phase of cell cycle). Angiogenesis inhibition in tumor cells was estimated through in vivo HET- CAM assessment and the highest concentration 60 µL tested inhibited the blood vessels at the percentage of 31.36% and 81.81%. The CuONPs explicated the anti-cancer activities in a concentration - dependent manner and the results of this investigation manifest the significant role of the CuONPs in cancer therapeutics.

Dynamical theory of strongly coupled two-dimensional Coulomb fluids in the weakly degenerate quantum domain.

We study the problem of dynamical response and plasma mode dispersion in strongly coupled two-dimensional Coulomb fluids (2DCFs) in the weakly degenerate quantum domain. Adapting the nonlinear response function approach of Golden and Kalman [Phys. Rev. A 19, 2112 (1979)] to the 2DCF, we construct a self-consistent approximation scheme for the calculation of the density response functions and plasma mode dispersion at long wavelengths. The basic ingredients in the construction are (i). the first kinetic equation in the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy, (ii). the velocity-average-approximation (VAA) hypothesis, (iii.) the quadratic fluctuation-dissipation theorem, and (iv). the dynamical superposition approximation (DSA) closure hypothesis. The reliability of the VAA-DSA theory can be assessed by observing that the principal coupling correction to the 2D temperature-dependent Lindhard function is identified as being precisely the part of the third-frequency-moment sum-rule coefficient proportional to the potential energy.

Compressibility sum rule for the two-dimensional electron gas.

The authors establish formulas for the isothermal compressibility and long-wavelength static density-density response function of a weakly correlated two-dimensional electron gas in the 1<

IL-10 is critical in the regulation of autoimmune encephalomyelitis as demonstrated by studies of IL-10- and IL-4-deficient and transgenic mice.

Experimental autoimmune encephalomyelitis (EAE) and other organ-specific autoimmune diseases are induced by autoantigen-specific Th1 cells. In contrast, transfer of autoantigen-reactive Th2 cells that produce IL-4 and IL-10 can prevent and/or reverse EAE. The relative roles of these two Th2 cytokines in the regulation of EAE has not been evaluated. Utilizing IL-4 and IL-10 knockout mice deficient for these cytokines and IL-10 and IL-4 transgenic mice overexpressing these cytokines, we demonstrate that IL-10-deficient mice (IL-10(-/-)) are more susceptible and develop a more severe EAE when compared with IL-4-deficient mice (IL-4(-/-)) or wild-type mice. T cells from IL-10(-/-) mice exhibit a stronger Ag-specific proliferation, produce more proinflammatory cytokines (IFN-gamma and TNF-alpha) when stimulated with an encephalitogenic peptide, and induce very severe EAE upon transfer into wild-type mice. In contrast, while IL-4 transgenic mice develop similar disease compared with their nontransgenic littermates, mice transgenic for IL-10 are completely resistant to the development of EAE. Taken together, our data suggest that IL-10 plays a more critical role in the regulation of EAE by regulating autopathogenic Th1 responses.

Autopathogenic T helper cell type 1 (Th1) and protective Th2 clones differ in their recognition of the autoantigenic peptide of myelin proteolipid protein.

We previously generated a panel of T helper cell 1 (Th1) clones specific for an encephalitogenic peptide of myelin proteolipid protein (PLP) peptide 139-151 (HSLGKWLGHPDKF) that induces experimental autoimmune encephalomyelitis (EAE) upon adoptive transfer. In spite of the differences in their T cell receptor (TCR) gene usage, all these Th1 clones required W144 as the primary and most critical TCR contact residue for the activation. In this study, we determined the TCR contact residues of a panel of Th2/Th0 clones specific for the PLP peptide 139-151 generated either by immunization with the PLP 139-151 peptide with anti- B7-1 antibody or by immunization with an altered peptide Q144. Using alanine-substituted peptide analogues of the native PLP peptide, we show that the Th2 clones have shifted their primary contact residue to the NH2-terminal end of the peptide. These Th2 cells do not show any dependence on the W144, but show a critical requirement for L141/G142 as their major TCR contact residue. Thus, in contrast with the Th1 clones that did not proliferate to A144-substituted peptide, the Th2 clones tolerated a substitution at position 144 and proliferated to A144 peptide. This alternative A144 reactive repertoire appears to have a critical role in the regulation of autoimmune response to PLP 139-151 because preimmunization with A144 to expand the L141/G142-reactive repertoire protects mice from developing EAE induced with the native PLP 139-151 peptide. These data suggest that a balance between two different T cell repertoires specific for same autoantigenic epitope can determine disease phenotype, i.e., resistance or susceptibility to an autoimmune disease.

B7-2 (CD86) is essential for the development of IL-4-producing T cells.

The CD28/CTLA-4 ligands, B7-1 (CD80) and B7-2 (CD86), provide a co-stimulatory signal necessary for optimal T cell activation. We have examined the effect of blocking B7-1 and B7-2 in an in vitro system using ovalbumin-specific T cells from alpha beta TCR-transgenic mice. This system allowed us to examine the interaction of B7 co-stimulators on physiologic antigen-presenting cells (APC) with antigen-specific T helper precursor (ThP) cells. We report that blocking Thp/B7-1 or B7-2 interactions in a primary response differentially affects the cytokine profile observed in a secondary stimulation, even in the absence of additional anti-B7 antibody. Engagement of B7-2 in the primary stimulation was found to be essential for production of the Th2 cytokine, IL-4, but not the Th1 cytokines, IL-2 and IFN-gamma, in a secondary stimulation. Conversely, inclusion of the anti-B7-1 mAb in cultures using highly purified naive T cells increased levels of IL-4 and significantly depressed levels of IFN-gamma, upon re-stimulation. The effect of the anti-B7-2 mAb in reducing IL-4 production could be overcome by the addition of recombinant IL-4 in the primary stimulation. The effects of the anti-B7-2 mAb appear to be due to blocking and not cross-linking, as F(ab) fragments mimicked the intact antibody. Taken together, our data demonstrate that the interaction between Thp and B7-2 favors the development of Th2 cells.

B7-1 and B7-2 costimulatory molecules activate differentially the Th1/Th2 developmental pathways: application to autoimmune disease therapy.

CD4 T helper precursor cells mature along two alternative pathways, Th1 and Th2. Here we show that these pathways are differentially activated by two costimulatory molecules, B7-1 and B7-2. Using anti-B7 antibodies, this developmental step was manipulated both in vitro and in vivo in experimental allergic encephalomyelitis (EAE). Anti-B7-1 reduced the incidence of disease while anti-B7-2 increased disease severity. Neither antibody affected overall T cell induction but rather altered cytokine profile. Administration of anti-B7-1 at immunization resulted in predominant generation of Th2 clones whose transfer both prevented induction of EAE and abrogated established disease. Since co-treatment with anti-IL-4 antibody prevented disease amelioration, costimulatory molecules may directly affect initial cytokine secretion. Thus, interaction of B7-1 and B7-2 with shared counterreceptors CD28 and CTLA-4 results in very different outcomes in clinical disease by influencing commitment of precursors to a Th1 or Th2 lineage.

Oral tolerance: a biologically relevant pathway to generate peripheral tolerance against external and self antigens.

OT is a relevant biological pathway for generating peripheral tolerance against both self and external antigens with minimal side effects (fig. 3). This route might, therefore, contain promising potential for the treatment of autoimmune and allergic diseases in the human (fig. 3). Thus, oral administration of autoantigens suppresses experimental autoimmune diseases (EAE, EAU, AA, collagen-induced arthritis, NOD diabetes) in a disease- and antigen-specific manner, and oral administration of alloantigens has led to increase of allograft survival. OT might be important in treatment of immune complex diseases and food allergies. OT is mediated by T lymphocytes using at least two nonmutually exclusive mechanisms: suppression and anergy. Suppression can be adoptively transferred by CD8+ T lymphocytes which act by releasing TGF-beta and IL-4 following antigen-specific triggering. Antigen-driven tissue-directed suppression occurs following oral administration of an antigen from the target organ, even if it is not the disease-inducing antigen (bystander suppression). Thus, synthetic peptides can induce OT, and tolerogenic epitopes of antigen may be different from the autoreactive epitope. Due to the promising results in animal models, OT is being tested in clinical trials in multiple sclerosis, rheumatoid arthritis and uveitis [193, 194].

Epitopes of myelin basic protein that trigger TGF-beta release after oral tolerization are distinct from encephalitogenic epitopes and mediate epitope-driven bystander suppression.

We have been studying the suppression of experimental autoimmune encephalomyelitis in the Lewis rat after oral administration of myelin basic protein (MBP). Suppression is mediated by CD8+ T cells that adoptively transfer protection and suppress immune responses in vitro. This suppression is mediated by secretion of TGF-beta following triggering by the fed antigen. In the present study, we tested the ability of overlapping 20 amino acid peptides from MBP to trigger suppression mediated by spleen cells from Lewis rats orally tolerized to MBP. Using a transwell system, we found that spleen cells from MBP orally tolerized animals stimulated by residues 21-40, 51-70 and 101-120 of MBP suppress proliferative responses of an ovalbumin specific cell line. This suppression correlated with secretion of TGF-beta by cells stimulated with the peptide. In addition, T cells from animals fed the tolerogenic peptide 21-40 alone secreted TGF-beta whereas no TGF-beta release or in vitro suppression was observed in animals fed the MBP encephalitogenic determinant 71-90. The 71-90 peptide triggered proliferation of MBP primed cells from animals immunized with MBP/CFA whereas the suppressor epitopes identified above did not. Furthermore, oral administration of peptide 21-40 suppressed disease induced by peptide 71-90. DTH responses to 71-90 were not affected by oral administration of peptide 21-40 whereas DTH responses to whole MBP were suppressed. These results demonstrate that distinct suppressor determinants exist on MBP which are separate from encephalitogenic determinants, and that epitope-driven bystander suppression plays an important role in down-regulation of tissue specific autoimmune processes following oral tolerization. These findings have important implications for the design of tissue specific targeted immunotherapy by oral tolerization in humans.

Medical students' attitude towards psychiatry.

The attitudes of medical students are important as they influence recruitment to psychiatry. In order to better understand the attitudes of medical students towards psychiatry and the impact of psychiatric clerkship, the authors administered a questionnaire eliciting information regarding demographic data, attitudes and career choices to third year medical students of the University of Ottawa, at the beginning and end of their four week psychiatric clerkship. The data suggests that the students found their clerkship experience valuable and rewarding and expressed an interest in knowing more about psychiatry. The students' perception of the various aspects of their clinical practice of psychiatry became more positive after the clerkship. The authors have identified the positive and negative experiences the students had during their clerkship and postulate that the change in attitude is directly due to their clerkship experience.