Kinetics of systemic cytokine and brain chemokine gene expression in murine toxoplasma infection.

Toxoplasma gondii often migrates to the central nervous system in immunocompromised patients, where it induces a severe inflammation referred to as Toxoplasma encephalitis. The mechanisms involved in control of parasite multiplication and prevention of Toxoplasma encephalitis remain unclear. The objective of the present study was to characterize the inflammatory response in the brains of mice during acute T.

Effects of exposure of mice to hindlimb unloading on leukocyte subsets and sympathetic nervous system activity.

The hindlimb unloading (HU) rodent model was developed to simulate some of the aspects of spaceflight conditions. Our previous studies showed that exposure to HU for 48 h (h) followed by bacterial challenge, reduces the ability of mice to resist infection. The purpose of this study was to investigate the physiological changes in mice during the 48 h of exposure to HU to understand the mechanisms involved in the increased susceptibility to infection observed in mice subjected to these conditions.

Active hexose correlated compound activates immune function to decrease bacterial load in a murine model of intramuscular infection.

Background: Infection is a serious, costly, and common complication of surgery and constitutes the principal cause of late death in patients undergoing surgery. The objective of this study was to clarify the mechanisms by which active hexose correlated compound (AHCC) increases survival in a murine model of intramuscular infection.

Methods: Food-deprived mice receiving either AHCC or excipient were infected with bacteria.

Effect of the alpha3beta1 integrin on the IL-1 stimulated activation of c-Jun N-terminal kinase (JNK) in CACO-2 cells.

Intestinal epithelial cells (IEC) are capable of responding to IL-1 stimulation by producing a variety of pro-inflammatory cytokines. Recently, we have found that binding of the alpha3beta1 integrin may have a regulatory effect on IL-1 responses and intracellular signaling by suppressing cytokine secretion, mRNA expression and the downstream intracellular signaling events from IKK to NF-kappaB activation. In this study, we extend these findings by showing that treatment of the Caco-2 epithelial cells with a cross-linking anti-alpha3 integrin antibody resulted in a suppression in the levels of IL-1 induced AP-1 binding activity in nuclear extracts.

Active hexose correlated compound (AHCC) enhances resistance to infection in a mouse model of surgical wound infection.

Background: Infection is the most common postoperative complication within the surgical wound and during severe trauma. In spite of the use of modern sterile techniques and prophylaxis, infection continues to be a leading cause of death in these patients. Therefore, it has become crucial to develop new alternatives to prevent the effects of trauma and other complications on the immune system and improve resistance to infection.

Enhancement of in vitro growth of pathogenic bacteria by norepinephrine: importance of inoculum density and role of transferrin.

Norepinephrine is a stress hormone that enhances bacterial growth. We examined the effects of a small inoculum on the norepinephrine-induced growth of species previously reported to be unaffected by norepinephrine. The results indicated that a reduced inoculum density is essential for observing norepinephrine-induced effects.

Regulation of connexin43 protein complexes by intracellular acidification.

Ischemia-induced acidification of astrocytes or cardiac myocytes reduces intercellular communication by closing gap junction channels and subsequently internalizing gap junction proteins. To determine whether such coupling changes might be attributable to altered interactions between connexin43 (Cx43) and other proteins, we applied the nigericin/high K+ method to vary intracellular pH (pHi) in cultured cortical astrocytes. Intracellular acidification was accompanied by internalization of Cx43 with retention of Cx43 scaffolding protein Zonula Occludens-1 (ZO-1) at cell surfaces, suggesting that ZO-1 and Cx43 dissociate at low pHi.

Kinetics of protein-protein interactions of connexins: use of enzyme linked sorbent assays.

Determination of the protein-protein interactions of connexins has become a rapidly expanding field of research. While there are multiple methods of determining the identity of binding partners, determination of the strengths of interactions is not as simple. Here we describe the use of the in vitro method Enzyme Linked Sorbent Assay (ELSA) to compare binding affinities of known protein partners for Connexin43.

pH-dependent intramolecular binding and structure involving Cx43 cytoplasmic domains.

pH-induced closure of connexin43 (Cx43) channels involves interaction of the Cx43 carboxyl-terminal (Cx43CT) with a separate "receptor" domain. The receptor location and structure and whether the interaction is directly intramolecular are unknown. Here we show resonant mirror technology, enzyme-linked sorbent assays, and nuclear magnetic resonance (NMR) experiments demonstrating pH-dependent binding of Cx43CT to region 119-144 of Cx43 (Cx43L2), which we propose is the receptor.

The proximal promoter region is essential for lipopolysaccharide induction and cyclic AMP inhibition of mouse tumor necrosis factor-alpha.

Bacterial lipopolysaccharide (LPS) induces a rapid and transient increase in transcription of the tumor necrosis factor-alpha (TNF-alpha) gene in cells of monocyte/macrophage lineage. This study examines the role of potential regulatory elements within the proximal promoter region of the mouse TNF-alpha gene in LPS induction and cyclic AMP (cAMP)-mediated inhibition of TNF-alpha in RAW 264.7 murine macrophage-like cells.