Chymase participates in chronic dermatitis by inducing eosinophil infiltration

An epicutaneous application of 2,4-dinitrofluorobenzene (DNFB) to a mouse ear caused a transient skin swelling, and the repetition of the challenge enlarged the contact dermatitis. The repeated challenge with DNFB also induced eosinophil infiltration on the application site. Administration of a chymase inhibitor significantly inhibited the ear swelling as well as eosinophil accumulation. An intradermal injection of human chymase to the mouse ear also elicited transient skin swelling and eosinophil infiltration, both of which were augmented in proportion to the number of injections. Human serum albumin and heat-inactivated chymase failed to induce such skin reactions, suggesting the participation of proteolytic activity of the enzyme. In addition, chymase stimulated eosinophil migration in vitro in a concentration-dependent manner. Taken together, these observations suggest that mast cell chymase may contribute to development of the DNFB-induced dermatitis, probably by promoting eosinophil infiltration. It is therefore possible that chymase plays a role in pathogenesis of chronic dermatitis such as atopic dermatitis.     

Biological activities of Bacteroides forsythus lipoproteins and their possible pathological roles in periodontal disease

Bacteroides forsythus is a gram-negative, anaerobic, fusiform bacterium and is considered to be an etiological agent in periodontal disease. A lipoprotein fraction prepared from B. forsythus cells by Triton X-114 phase separation (BfLP) activated human gingival fibroblasts and a human monocytic cell line, THP-1, to induce interleukin-6 production and tumor necrosis factor alpha production. BfLP was found to be capable of inducing nuclear factor-kappaB translocation in human gingival fibroblasts and THP-1 cells. By using Chinese hamster ovary K1 cells transfected with Toll-like receptor genes together with a nuclear factor-kappaB-dependent CD25 reporter plasmid, it was found that signaling by BfLP was mediated by Toll-like receptor 2 but not by CD14 or Toll-like receptor 4. BfLP induced apoptotic cell death in human gingival fibroblasts, KB cells (an oral epithelial cell line), HL-60 cells (a human myeloid leukemia cell line), and THP-1 cells but not in MOLT4 cells (a T-cell leukemia cell line). Caspase-8, an initiator caspase in apoptosis, was found to be activated in these cells in response to BfLP stimulation. Thus, this study suggested that BfLP plays some etiological roles in oral infections, especially periodontal disease, by induction of cell activation or apoptosis.     

A NEW METHOD FOR VITAL STAINING OF CENTRAL NERVOUS TISSUES WITH NEUTRAL RED

A new vital staining method with neutral red has been established where by cerebral ganglion cells can be stained in vivo .     

Reduced blood BDCA-2+ (lymphoid) and CD11c+ (myeloid) dendritic cells in systemic lupus erythematosus

Type 1 IFN is thought to be implicated in the autoimmune process of SLE. Plasmacytoid dendric cells (DC), which are natural IFN-alpha producing cells, play a pivotal epipathogenic role in SLE. The present study was undertaken to investigate the phenotypic characteristics of peripheral blood DC in SLE patients in comparison with those of healthy controls. Samples from 20 SLE patients and 18 healthy controls were studied. Three-colour flow cytometry was performed to identify myeloid DC, as CD11c(+) lineage marker(-), and HLA-DR(+) cells and plasmacytoid DC, as BDCA-2(+) linage marker(-), and HLA-DR(+) cells. We used the whole blood 'lyse/no-wash' procedure, which allows precise counting of peripheral blood DC. BDCA-2(+) plasmacytoid DC and CD11c(+) myeloid DC were reduced in SLE patients compared with controls. Similarly, BDCA-3(+) DC were reduced in SLE patients. These results indicated that SLE patients had a reduced number of both BDCA-2(+) plasmacytoid DC and CD11c(+) myeloid DC. These alternations of the DC subset may drive the autoimmune response in SLE.     

Importance of a biofouling-resistant phospholipid polymer to create a heparinized blood-compatible surface

Heparinization is believed to be one of the methods to suppress thrombus formation on blood-contacting surfaces. However, this study hypothesizes that heparinization alone might not be sufficient to provide a blood-compatible surface; that is, a surface property that resists biofouling is necessary to obtain an effective heparin-modified surface. 2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers with 2-aminoethyl methacrylate (AEMA) were synthesized to immobilize heparin through ionic bonding. The primary amino groups of AEMA were considered to be the polymer surface because the zeta-potential of the surface was positive when the mole fraction of the AEMA units was above 0.2. The antithrombogenic character of the polymer surface modified with heparin was evaluated by both Lee-White and microsphere column methods. The coagulation period of human whole blood in the absence of anticoagulant in glass tubing coated with the MPC polymer was longer than that in the original glass tube. Cell adhesion was completely inhibited on the MPC polymer surface after contact with human whole blood without anticoagulant. However, many adherent blood cells were observed on poly(2-ethylhexyl methacrylate-co-AEMA) (no MPC unit) even after heparinization. These results strongly indicate that the MPC polymer is a useful substrate where the heparin works well and that the heparin-immobilized MPC polymer has superior blood compatibility to the simple MPC polymer.     

The ventilatory threshold gives maximal lactate steady state

Summary The purpose of this study was to examine whether the ventilatory threshold (Th _v) would give the maximal lactate steady state ([1a]_{ss, max}), which was defined as the highest work rate (W) attained by a subject without a progressive increase in blood lactate concentration [1a]_b at constant intensity exercise. Firstly, 8 healthy men repeated ramp-work tests (20 W·min^–1) on an electrically braked cycle ergometer on different days. During the tests, alveolar gas exchange was measured breath-by-breath, and theW atTh _v (W _{Th v}) was determined. The results of two-way ANOVA showed that the coefficient of variation of a singleW _{Th v} determination was 2.6%. Secondly, 13 men performed 30-min exercise atW _{Th v} (Th _v trial) and at 4.9% aboveW _{Th v} (Th _v + trial), which corresponded to the 95% confidence interval of the single determination. The [1a]_b was measured at 15 and 30 min from the onset of exercise. The [1a]_b at 15 min (3.15 mmol·1^–1, SEM 0.14) and at 30 min (2.95 mmol·1^–1, SEM 0.18) were not significantly different inTh _v trial. However, the [1a]_b ofTh _v+ trial significantly increased (P<0.05) from 15 min (3.62 mmol·1^–1, SEM 0.36) to 30 min (3.91 mmol·1^–1, SEM 0.40). These results indicate thatTh _v gives the [1a]_ss,max, at which one can perform sustained exercise without continuous [1a]_b accumulation.     

Evaluation of a Membrane Filter Assay System, Ortho HCV Ab Quik Pack, for Detection of Anti-Hepatitis C Virus Antibody

A simple membrane immunoassay assay system, Quik Pack, for the detection of hepatitis C virus antibody was compared with two enzyme-linked immunosorbent assays (ELISAs) in a study of 600 serum samples. Quik Pack exhibited excellent sensitivity and specificity: 96.0 and 99.7%, respectively, versus the ELISA-2 and 99.7 and 99.4%, respectively, versus the ELISA-3.     

An invasion-independent pathway of blood-borne metastasis: a new murine mammary tumor model

It is generally believed that active invasion by cancer cells is essential to the metastatic process. In this report, we describe a murine mammary tumor (MCH66) model of metastasis that does not require invasion into the vascular wall of both the primary tumor and the target organ, in this case, the lung. The process involves intravasation of tumor nests surrounded by sinusoidal blood vessels, followed by intravascular tumor growth in the lung, without penetration of the vascular wall during the process. Comparative studies using a nonmetastatic MCH66 clone (MCH66C8) and another highly invasive metastatic cell line (MCH416) suggested that high angiogenic activity and sinusoidal remodeling of tumor blood vessels were prerequisites for MCH66 metastasis. Differential cDNA analysis identified several genes that were overexpressed by MCH66, including genes for the angiogenesis factor pleiotrophin, and extracellular matrix-associated molecules that may modulate the microenvironment toward neovascularization. Our analyses suggest that tumor angiogenesis plays a role in the induction of invasion-independent metastasis. This model should prove useful in screening and development of new therapeutic agents for cancer metastasis.     

Identification of a novel adhesion molecule involved in the virulence of Legionella pneumophila

Legionella pneumophila is an intracellular bacterium, and its successful parasitism in host cells involves two reciprocal phases: transmission and intracellular replication. In this study, we sought genes that are involved in virulence by screening a genomic DNA library of an L. pneumophila strain, 80-045, with convalescent-phase sera of Legionnaires' disease patients. Three antigens that reacted exclusively with the convalescent-phase sera were isolated. One of them, which shared homology with an integrin analogue of Saccharomyces cerevisiae, was named L. pneumophila adhesion molecule homologous with integrin analogue of S. cerevisiae (LaiA). The laiA gene product was involved in L. pneumophila adhesion to and invasion of the human lung alveolar epithelial cell line A549 during in vitro coculture. However, its presence did not affect multiplication of L. pneumophila within a U937 human macrophage cell line. Furthermore, after intranasal infection of A/J mice, the laiA mutant was eliminated from lungs and caused reduced mortality compared to the wild isolate. Thus, we conclude that the laiA gene encodes a virulence factor that is involved in transmission of L. pneumophila 80-045 and may play a role in Legionnaires' disease in humans.