Parasitoid spectrum (Hymenoptera: Braconidae; Aphelinidae) of the soybean aphid Aphis glycines (Homoptera: Aphididae) in Japan and Indonesia (Java and Bali)

Aphidiine and aphelinid parasitoids collected from the soybean aphid, Aphis glycines, on Glycine max in Japan and Indonesia (Java and Bali) were identified to clarify the parasitoid spectrum of the aphid there. Nine parasitoid species from Japan (Aphidiinae: Aphidius gifuensis, Aphidius sp., Binodoxys communis, Diaeretiella rapae, Lipolexis gracilis, Lysiphlebia japonica; Aphelinidae: Aphelinus asychis, A. gossypii, A. varipes) and two parasitoid species from Indonesia (B. communis, A. gossypii) were found to be associated with A. glycines.     

Interaction between Brucella abortus and cellular prion protein in lipid raft microdomains

A wide variety of pathogens employ lipid raft microdomains to infect host cells. Here, we review selected aspects of interaction between Brucella abortus and cellular prion protein, one of the lipid raft-associated molecules on the plasma membrane, when bacteria infect macrophages, and discuss the correlates of proliferation in mice.     

Brucella abortusd-alanyl-D-alanine carboxypeptidase contributes to its intracellular replication and resistance against nitric oxide

Brucella spp. are facultative intracellular pathogens that have the ability to survive and multiply in professional and nonprofessional phagocytes, and cause abortion in domestic animals and undulant fever in humans. However, the mechanism and factors of virulence are not fully understood. In the present study, a D-alanyl-D-alanine carboxypeptidase (DAP) mutant of Brucella abortus failed to replicate in mouse macrophages and HeLa cells, and showed less virulence than the wild type in mice. Under nitric oxide (NO) stress, the growth of the DAP mutant in vitro decreased and it also had less capability to reduce NO than the wild type. Intracellular replication of the DAP mutant was partially restored by pretreatment of macrophages with the NO synthase inhibitor, 1-phenyl-imidazole, and the level of expression of the NO reductase gene, norB, in the DAP mutant was lower than that in the wild type. These results suggest that DAP contributes to resistance against NO and that it is required for the intracellular growth of the bacterium.     

Insulinlike Growth Factor (IGF)-1 Administration Ameliorates Disease Manifestations in a Mouse Model of Spinal and Bulbar Muscular Atrophy

Spinal and bulbar muscular atrophy is an X-linked motor neuron disease caused by polyglutamine expansion in the androgen receptor. Patients develop slowly progressive proximal muscle weakness, muscle atrophy and fasciculations. Affected individuals often show gynecomastia, testicular atrophy and reduced fertility as a result of mild androgen insensitivity. No effective disease-modifying therapy is currently available for this disease. Our recent studies have demonstrated that insulinlike growth factor (IGF)-1 reduces the mutant androgen receptor toxicity through activation of Akt in vitro, and spinal and bulbar muscular atrophy transgenic mice that also overexpress a noncirculating muscle isoform of IGF-1 have a less severe phenotype. Here we sought to establish the efficacy of daily intraperitoneal injections of mecasermin rinfabate, recombinant human IGF-1 and IGF-1 binding protein 3, in a transgenic mouse model expressing the mutant androgen receptor with an expanded 97 glutamine tract. The study was done in a controlled, randomized, blinded fashion, and, to reflect the clinical settings, the injections were started after the onset of disease manifestations. The treatment resulted in increased Akt phosphorylation and reduced mutant androgen receptor aggregation in muscle. In comparison to vehicle-treated controls, IGF-1–treated transgenic mice showed improved motor performance, attenuated weight loss and increased survival. Our results suggest that peripheral tissue can be targeted to improve the spinal and bulbar muscular atrophy phenotype and indicate that IGF-1 warrants further investigation in clinical trials as a potential treatment for this disease.     

Clostridium perfringens alpha-toxin induces the release of IL-8 through a dual pathway via TrkA in A549 cells

A characteristic feature of gas gangrene with Clostridium perfringens (C. perfringens) is the absence of neutrophils within the infected area and the massive accumulation of neutrophils at the vascular endothelium around the margins of the necrotic region. Intravenous injection of C. perfringens alpha-toxin into mice resulted in the accumulation of neutrophils at the vascular endothelium in lung and liver, and release of GRO/KC, a member of the CXC chemokine family with homology to human interleukin-8 (IL-8). Alpha-toxin triggered activation of signal transduction pathways causing mRNA expression and production of IL-8, which activates migration and binding of neutrophils, in A549 cells. K252a, a tyrosine kinase A (TrkA) inhibitor, and siRNA for TrkA inhibited the toxin-induced phosphorylation of TrkA and production of IL-8. In addition, K252a inhibited the toxin-induced phosphorylation of extracellular regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK). PD98059, an ERK1/2 inhibitor, depressed phosphorylation of ERK1/2 and nuclear translocation of nuclear factor kappa B (NF-κB) p65, but SB203580, a p38 MAPK inhibitor, did not. On the other hand, PD98059 and SB203580 suppressed the toxin-induced production of IL-8. Treatment of the cells with PD98059 resulted in inhibition of IL-8 mRNA expression induced by the toxin and that with SB203580 led to a decrease in the stabilization of IL-8 mRNA. These results suggest that alpha-toxin induces production of IL-8 through the activation of two separate pathways, the ERK1/2/NF-κB and p38 MAPK pathways.     

Effect of turpentine oil on C-reactive protein (CRP) production in rainbow trout (Oncorhynchus mykiss)

The effect of turpentine oil on C-reactive protein (CRP) production was studied in rainbow trout (Oncorhynchus mykiss). Serum CRP concentration was estimated by sandwich enzyme-linked immunosorbent assay using anti-rainbow trout CRP monoclonal antibody (mAb) AC4 and polyclonal antibody. Intracellular CRP was demonstrated by flow cytometry using anti-trout CRP mAb. Hepatocytes, head kidney macrophages, spleen lymphocytes and peripheral blood lymphocytes showed reaction against AC4, but RTG-2 fibroblastic line cells, derived from rainbow trout gonad did not. This is the first report on the detection of intracellular CRP in fish. CRP levels decreased significantly 1 day after intramuscular injection of turpentine oil and remained low for 14 days. Significant decreases in the expression of CRP in hepatocytes, head kidney macrophages and spleen lymphocytes after injection of turpentine oil were found. The reduction of serum CRP concentration after turpentine oil injection may be attributed to decreases in intracellular CRP synthesis.     

Food habit of the juvenile of the Japanese newt Cynops pyrrhogaster

The previous study showed that the red coloration of the ventral skin of the Japanese newt Cynops pyrrhogaster was associated with the number of carotenoid vesicles and the content of carotenoid in the pigment cell of the skin. To elucidate the mechanism for the red coloration of the skin of the newt, we studied the food habit of the juvenile from the Japanese newt Cynops pyrrhogaster. Sixty-two juveniles were collected in Fukue Island in Nagasaki Prefecture from November 2000 to May 2002 and divided into 2 groups according to the snout-vent length (SVL). Over 400 prey animals were obtained from the juveniles by stomach flushing. In the larger group (SVL>30.0mm), Collembola (45.4%) and Acari (12.6%), which are very common species of soil animals, were the prey animals dominant in number. In the group with the smaller SVL (<29.9mm), Collembola (30.4%) and Acari (25.4%) were in number as well. We also studied the food habit of the Japanese clouded salamander, Hynobius nebulosus. In the salamander, Doratodesmidae (56.5%) and Amphipoda (13%) were the prey animals dominant in number. Our results, taken together, suggest that the Japanese juvenile C. pyrrhogaster does not change its food habit as it grows, and that it eats soil animals common in its habitat. Moreover, the food habit of juvenile C. pyrrhogaster differs from that of H. nebulosus, although the juveniles of both species live in the same area.     

RCAI-17, 22, 24-26, 29, 31, 34-36, 38-40, and 88, the analogs of KRN7000 with a sulfonamide linkage: their synthesis and bioactivity for mouse natural killer T cells to produce Th2-biased cytokines

RCAI-17, 22, 24-26, 29, 31, 34-36, 38-40, and 88, the analogs of KRN7000 with a sulfonamide linkage instead of an amide bond, were synthesized to examine their bioactivity for mouse natural killer (NK) T cells. RCAI-17, 22, 24-26, 29, 31, 34-36, and 88 are the aromatic sulfonamide analogs, while RCAI-39 and 40 are the aliphatic ones. RCAI-38 is a C-galactoside analog of RCAI-26, which is the p-toluenesulfonamide analog of KRN7000. According to their bioassay, these sulfonamide analogs were shown to be the stimulants of mouse NKT cells to induce the production of Th2-biased cytokines in vitro, while RCAI-38 did not induce any cytokine production.     

Distinctiveness of the genomic sequence of Shiga toxin 2-converting phage isolated from Escherichia coli O157:H7 Okayama strain as compared to other Shiga toxin 2-converting phages

Shiga toxin 2-converting phage was isolated from Escherichia coli O157:H7 associated with an outbreak that occurred in Okayama, Japan in 1996 (M. Watarai, T. Sato, M. Kobayashi, T. Shimizu, S. Yamasaki, T. Tobe, C. Sasakawa and Y. Takeda, Infect. Immun. 61 (1998) 3210-3204). In this study, we analyzed the complete nucleotide sequence of Shiga toxin 2-converting phage, designated Stx2phi-I, and compared it with three recently reported Stx2-phage genomes. Stx2phi-I consisted of 61,765 bp, which included 166 open reading frames. When compared to 933W, VT2-Sakai and VT2-Sa phages, six characteristic regions (regions I-VI) were found in the Stx2 phage genomes although overall homology was more than 95% between these phages. Stx2phi-I exhibited remarkable differences in these regions as compared with VT-2 Sakai and VT2-Sa genes but not with 933W phage. Characteristic repeat sequences were found in regions I-IV where the genes responsible for the construction of head and tail are located. Regions V and VI, which are the most distinct portion in the entire phage genome were located in the upstream and downstream regions of the Stx2 operons that are responsible for the immunity and replication, and host lysis. These data indicated that Stx2phi-I is less homologous to VT2-Sakai and VT2-Sa phages, despite these three phages being found in the strains isolated at the almost same time in the same geographic region but closely related to 933W phage which was found in the E. coli O157 strain 933W isolated 14 years ago in a different geographic area.