Development of a particle agglutination assay system for detecting Japanese encephalitis virus-specific human IgM,using hydroxyapatite-coated nylon beads

Japanese encephalitis virus-specific IgM is a reliable indicator for serodiagnosis of Japanese encephalitis. A particle agglutination (PA) assay system was developed to detect anti-Japanese encephalitis virus IgM in human serum samples. The newly developed PA assay consisted of hydroxyapatite-coated nylon beads and V-bottom 96-well microplates. Hydroxyapatite-coated nylon beads were coated with Japanese encephalitis virus antigens. Japanese encephalitis virus antigen-coated, hydroxyapatite-coated nylon beads agglutinated in the IgM-captured wells when anti-Japanese encephalitis virus IgM-positive serum samples were used. A button pattern was formed at the bottom of the wells when anti-Japanese encephalitis virus IgM-negative serum samples were used. Thirty anti-Japanese encephalitis virus IgM-positive serum samples from Japanese encephalitis-confirmed cases were tested by the PA assay. All these serum samples were determined to be Japanese encephalitis virus IgM-positive. IgM titers determined by the PA assay corresponded to those determined by enzyme-linked immunosorbent assay. The titers were consistent in two independent PA assays. These results indicate that the newly developed PA assay is a reliable method for detecting anti-Japanese encephalitis virus IgM in human serum samples and that this assay will be a suitable diagnostic system especially in rural areas of Asia.     

Histamine downregulates CD14 expression via H2 receptors on human monocytes

Lipopolysaccharide (LPS) binds to LPS-binding protein (LBP) in plasma and is delivered to the cell surface receptor CD14 on human monocyte. LPS is transferred to the transmembrane signaling receptor toll-like receptor (TLR) 4. In the present study, the effect of histamine on the expression of CD14 on human monocytes was investigated. Histamine concentration- and time-dependently decreased the expression of cell surface CD14, whereas histamine did not decrease mRNA for CD14 nor increase soluble CD14 (sCD14). The inhibitory effects of histamine on CD14 expression were antagonized by H2-receptor antagonist, but not by H1 and H3/H4 antagonist. The effects of selective H2-receptor agonists, 4-methylhistamine and dimaprit, on CD14 expression mimicked that of histamine indicating that histamine regulated CD14 expression through the stimulation of H2-receptors. The pretreatment with histamine partially inhibited the LPS-induced TNF-alpha production in human peripheral blood mononuclear cells (PBMC). Such inhibition might be due to the down-regulation of CD14 expression on monocytes by histamine.     

Mevalonic acidemia: First case of Japan

Summary Mevalonic acidemia is a rare metabolic disorder due to mevalonate kinase deficiency which affects the biosynthesis of cholesterol and nonsterol isoprenes. We report the first case of Japan. The clinical course is characterized by intrauterine growth retardation, postnatal growth failure, intractable diarrhea, liver dysfunctions and death at three months of age. Dysmorphic features including triangular face, protrusion of forehead, hypertelorism, low set ears and micrognathism were noted. High mevalonic acid level was found by GC/MS.     

Cytokines and lipopolysaccharide induce nitric oxide synthase in cultured rat pulmonary artery smooth muscle.

In the current study, we describe cytokine and Escherichia coli lipopolysaccharide (LPS) induction of nitric oxide (NO) synthase mRNA levels in cultured smooth muscle from rat pulmonary artery (RPASM). Exposure of RPASM to interleukin-1 beta, interferon-gamma, or LPS alone did not significantly affect NO synthesis, as determined by nitrite concentrations in media. Exposure to tumor necrosis factor-alpha caused a modest (2x) increase in nitrite production. In contrast, exposure to a combination of the above three cytokines and LPS caused a large increase in NO synthesis. Exposure of RPASM to this combination caused an increase in mRNA levels of NO synthase (as described by Northern blot analysis with 32P-cDNA probe to an inducible form of NO synthase present in murine macrophages) that was apparent as early as 4 h. Expression of the induced gene product after exposure to the cytokine and LPS mixture was evident by significant increases in nitrite production at 12 h. Production of nitrite was completely abolished in the presence of NG-monomethyl-L-arginine (NMA), and this inhibition was reversible by the addition of excess L-arginine. NO synthase mRNA levels were not affected by NMA. The nitrite production induced by the combination of cytokines and LPS was abolished by pretreating cells with cycloheximide. These data indicate that a combination of cytokines and LPS affect expression of the gene for the inducible form of NO synthase in cultured RPASM.     

Phase stability after aging and its influence on pin-on-disk wear properties of Ce-TZP/Al2O3 nanocomposite and conventional Y-TZP

Recently zirconia/alumina composites have been examined by many researchers as the new generation of bearing materials in total joint replacements. In this study, the phase stability of a Ce-TZP/Al(2)O(3) nanocomposite and conventional Y-TZP after aging, and its influence on wear resistance, were investigated. Very slight phase transformation was observed in both types of ceramics 18 months after the implantation of Ce-TZP/Al(2)O(3) or Y-TZP samples into rabbit tibiae. However, Y-TZP showed marked phase transformation (approximately 80%) after aging in an autoclave (121 degrees C) for 190 h or in physiological saline at 62 degrees C for 18 months, whereas the new composite remained almost resistant to degradation. According to the results of self-pairing pin-on-disk wear tests using ceramic specimens with or without autoclave aging, the wear factor was almost the same between Ce-TZP/Al(2)O(3) samples with and without aging (6.74 +/- 0.36 x 10(-8) and 6.04 +/- 0.95 x 10(-8) mm(3)/Nm, respectively). In contrast, although non-aged Y-TZP had the lowest wear factor (4.88 +/- 0.51 x 10(-8) mm(3)/Nm) of all specimens tested, aged Y-TZP showed 10-fold greater wear than nonaged Y-TZP. The present study suggests that Ce-TZP/Al(2)O(3) nanocomposite has much greater phase stability than Y-TZP, and that its wear properties are not influenced by aging.     

Membrane orientation of the precursor 74-kDa form of L-histidine decarboxylase

Objective We previously demonstrated that, when expressed in COS-7 cells, L-histidine decarboxylase (HDC), which has neither an amino terminal signal sequence nor a hydrophobic membrane anchor, was localized in the endoplasmic reticulum (ER), although its orientation in the membrane remains to be clarified. Methods & Results Protease digestion and immunofluorescence analyses of the cells, of which plasma membrane was selectively permeabilized, revealed that the amino terminal 50-kDa portion of HDC is hardly accessible to proteases and antibodies added exogenously from the cytosolic side. Green fluorescent protein fused with the carboxyl terminal 20-kDa region of HDC at its carboxyl terminus exhibited the same characteristics as native HDC. Conclusion These results indicate that HDC is tightly associated with the ER membrane with its carboxyl terminal region exposed on the cytosolic side. Received 22 November 2005; returned for revision 28 December 2005; accepted by A. Falus 22 January 2006     

Laboratory-scale mass production of a multi-micropatterned grafted surface with different polymer regions

In this article, we demonstrate laboratory-scale mass production of a regionally precise multi-micropatterned surface photo-graft-copolymerized with three water-soluble monomers based on the photochemistry of an iniferter, which means that it acts as an initiator, a transfer agent and a terminator, benzyl N, N-diethyldithiocarbamate. The surface was semi-automatically prepared using a combination of a custom-designed irradiation apparatus installed with a motor-controlled stage for a substrate and three photomasks with different line-patterned slits (number of slits 20, width 500 microm, length 10 mm), and carbon dioxide laser cutting apparatus. A particular region of poly(styrene-co-vinylbenzyl N,N-diethyldithiocarbamate) coated on a PET film was irradiated in a particular aqueous monomer solution while moving the irradiated portion stepwise after irradiation through each line of the photomask. Photo-graft-copolymerization was carried out sequentially with acrylic acid sodium salt (AANa), N-[3-(dimethylamino)propyl]acrylamide methiodide (DMAPAAm), and acrylamide (AAm) using differently patterned photomasks. Characterization of surface elemental distribution by X-ray photoelectron spectroscopy (XPS), and light microscopic visualization by dye staining revealed a microprocessed surface with 20 sets of micropatterns, each of which had three line regions grafted with three different polymers. The irradiation of a carbon dioxide laser manipulated via computer-aided design (CAD) software onto the microprocessed surface resulted in automatic circular cutting for each set of micropatterns to mass-produce multi-micropatterned substrates for the study of substrate-dependent endothelial cell responses.     

Effects of current intensity on behavioral and autonomic heat-loss responses in intracranial self-stimulating rats

We investigated the effects of current intensity on behavioral and autonomic heat-loss responses in intracranial self-stimulating (ICSS) rats. At an ambient temperature (Ta) of 22 degrees C, the tail vasodilation during ICSS behavior began at higher hypothalamic temperature (Thy) at higher current intensity. At a Ta of 36 degrees C, body extension, a typical heat-loss response in rats, appeared during ICSS behavior and frequently interrupted lever pressing. When the body extension first began, Thy was elevated if current intensity was high. In experiments in which current intensity was varied between two levels at a Ta of 22 degrees C, if current intensity was lowered after tail vasodilation began and Thy reached a steady level, the rat interrupted pressing the lever to lose heat through grooming or body extension. Rectal temperature (Tre) dropped in the process. If, on the other hand, current intensity was raised, the rate of lever pressing increased and Tre rose with tail vasoconstriction. The data suggest that the magnitude of the reward, as reflected in current intensity, affects both behavioral and autonomic heat-loss responses.