Co-infection of human metapneumovirus with adenovirus or respiratory syncytial virus among children in Japan

Human metapneumovirus (hMPV) is one of the etiological agents of acute respiratory tract infections. From June 2005 to May 2006, we collected 185 clinical specimens from children in Osaka City, Japan, and detected 41 hMPV RNA. Of the 41 specimens, four (9.8%) also contained other viruses (3 with adenovirus [AdV] and 1 with respiratory syncytial virus [RSV]). The clinical symptoms of patients coinfected with AdV were indistinct from those of patients mono-infected with hMPV. The symptoms of the one patient co-infected with RSV were clinically severe. Further research is needed to clarify the effect of hMPV on other respiratory viruses or vice versa.     

AMSH, an ESCRT-III associated enzyme, deubiquitinates cargo on MVB/late endosomes

The appropriate sorting of vesicular cargo, including cell-surface proteins, is critical for many cellular functions. Ubiquitinated cargo is targeted to endosomes and digested by lysosomal enzymes. We previously identified AMSH, a deubiquitination enzyme (DUB), to be involved in vesicular transport. Here, we purified an AMSH-binding protein, CHMP3, which is an ESCRT-III subunit. ESCRT-III functions on maturing endosomes, indicating AMSH might also play a role in MVB/late endosomes. Expression of an AMSH mutant lacking CHMP3-binding ability resulted in aberrant endosomes with accumulations of ubiquitinated cargo. Nevertheless, CHMP3-binding capability was not essential for AMSH's in vitro DUB activity or its endosomal localization, suggesting that, in vivo, the deubiquitination of endosomal cargo is CHMP3-dependent. Ubiquitinated cargo also accumulated on endosomes when catalytically inactive AMSH was expressed or AMSH was depleted. These results suggest that both the DUB activity of AMSH and its CHMP3-binding ability are required to clear ubiquitinated cargo from endosomes.     

Degradation of longicorn beetle (Coleoptera,Cerambycidae, Disteniidae) fauna caused by conversion from broad-leaved to man-made conifer stands of <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> (Taxodiaceae) in central Japan

We studied the species richness and assemblages of longicorn beetles (Coleoptera, Cerambycidae, Disteniidae) in ten secondary broad-leaved stands and eight plantation stands of Japanese cedar (Cryptomeria japonica) of various ages after clear-cutting or plantation in Ibaraki, central Japan. The species richness of longicorns, which were collected with Malaise traps, was the highest in young stands, decreasing with the age of the stand for both broad-leaved and conifer stands. A canonical correspondence analysis divided the 18 plots into three groups based on longicorn assemblages and environmental variables. These three groups consisted of (1) very young (1–4 years old) stands after clear-cutting or plantation; (2) 12- to over 100 year-old broad-leaved stands; (3) 7- to 76-year-old conifer stands. The species richness of the longicorns was the highest in the young stands followed, in order of decreasing species richness, by broad-leaved stands and conifer stands. Possible causes of the high species richness in young stands include large amounts of coarse wood debris and flowers, which are resources for oviposition and nutrition for adults, respectively. The lower longicorn diversity in conifer stands than in broad-leaved stands may be due to the lower diversity of trees available as host plants in the former. Almost all species that occurred in conifer stands were also collected in young and/or broad-leaved stands, but the reverse was not true, suggesting that conifer plantations cannot replace broad-leaved stands in terms of longicorn biodiversity. We argue that an extensive conversion of broad-leaved forests into conifer plantations will lead to an impoverishment of the longicorn fauna, which may result in the degradation of ecosystem functions possibly carried out by them.     

Orally administered bisphenol A disturbed antigen specific immunoresponses in the naïve condition

Bisphenol A [2,2-bis(4-hydoxyphenyl)propane; BPA] is an endocrine disrupter widely used in polycarbonate plastics and epoxy resins. We investigated the effects of orally administered BPA on antigen-specific responses of the na?ve immune system.BPA was orally administered to T cell receptor transgenic mice, and the antigen-specific responses of immune cells were investigated. Administered BPA moderately reduced interleukin (IL)-2, 4, and interferon (IFN)-gamma secretion and increases in IgA and IgG2a production.Additionally, it was found that orally administered BPA increased antigen-specific IFN-gamma production of T cells and modified whole antigen presenting cells (APCs) to suppress antigen-specific cytokine production from T cells. These findings suggest that BPA can augment the Th1-type responses of na?ve immune systems, though the bioavailability of orally administered BPA was low in our experiments.     

Heat-triggered conversion of protofibrils into mature amyloid fibrils of beta2-microglobulin

Heat-triggered conversion of the salt-induced thin and flexible protofibrils into well-organized thick and straight mature amyloid fibrils was achieved with beta2-microglobulin, a protein responsible for dialysis-related amyloidosis. First, protofibrils that formed spontaneously at pH 2.5 in the presence of 0.5 M NaCl were aggregated by agitating the solution. Second, the aggregated protofibrils were heated in a cell of a differential scanning calorimeter (DSC). The DSC thermogram showed an exothermic transition with sigmoidal temperature dependence, resulting in a remarkably large decrease in the heat capacity of the solution. Third, on the basis of electron microscopy together with circular dichroism spectroscopy, seeding experiments, and a thioflavin T binding assay, the sigmoidal transition was found to represent the conversion of protofibrils into mature amyloid fibrils. Furthermore, DSC thermograms obtained at various heating rates revealed that the transition curve depends on the heating rate, implying that the effects of heat associated with the conversion to the mature fibrils are kinetically controlled, precluding an interpretation in terms of equilibrium thermodynamics. Taken together, these results highlight the importance of the change in heat capacity in addressing the biological significance of interactions between solvent water and amyloid fibrils and, moreover, in detecting the formation of amyloid fibrils.     

The cytotrophoblast layer of human chorionic villi becomes thinner but maintains its structural integrity during gestation

Chorionic villi in the human placenta serve as essential structures in fetomaternal exchanges. According to the embryology and placentology literature, during the first trimester, the cytotrophoblast (CTB) layer that is subjacent to the syncytiotrophoblast (STB) and supported by a basal lamina is nearly complete, but later, it becomes discontinuous. In the present study, we investigated the structural integrity of the CTB layer in the normal villous tree by advanced microscopy techniques using an antibody to hepatocyte growth factor (HGF) activator inhibitor type 1 (SPINT1), a potent inhibitor of HGF activators expressed exclusively on villous CTB. In full-term placenta, the cell surface of the CTB layer was spread over the basal lamina but was not interrupted. Morphometric analysis showed that throughout the villous tree, 80% of the continuity of the CTB layer of full-term placenta and 90% of that of first-trimester placenta were preserved. Gestation was accompanied by unique structural change in the basal domain of the trophoblast layer. The initially cuboidal-shaped CTB cells were transformed to flat cells with many cellular processes that, together with those of the adjacent STB, eventually covered the trophoblast basal lamina in a complex network of interdigitations. In addition, the expression levels of SPINT1, ST14, HGF, and MET mRNAs in the villous tree increased over the course of gestation. These results suggest that the structural integrity of the SPINT1-positive CTB layer may play an important role in villous differentiation and in maintenance of the villous tree via the HGF signaling system during gestation.     

Differentiation of murine B cells induced by chondroitin sulfate B

A two-step culture system was used to investigate the role of chondroitin sulfate (CS) B, which is mitogenic to B cells, in differentiation of B cells. Mouse spleen B cells were incubated for 3 days with CSB in the presence of interleukin (IL)-4 and IL-5. After washing, the cells were replated at 10(5) viable cells/well and recultured without CSB in the presence of IL-4 and IL-5. CSB dose-dependently increased IgM production, the greatest enhancement being 450%. Dextran sulfate had a similar effect, whereas other glycosaminoglycans, CSA, CSC, heparin and hyaluronic acid, were marginally effective. Treatment of B cells with CSB resulted in increases in the number of IgM-secreting cells and numbers of CD138-positive cells and CD45R/B220-negative cells. CSB-induced IgM production was inhibited by the protein kinase C (PKC) inhibitor GF109203X but not by the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin. These results demonstrated that CSB promoted differentiation of B cells in the presence of IL-4 and IL-5 and suggested that PKC but not PI3K is crucial for CSB-induced IgM production.     

Anti-apoptotic activity of porcine cFLIP in ovarian granulosa cell lines

In mammalian ovaries, more than 99% of follicles undergo atresia during growth and development. Recently, we found that the expression of cellular FLICE-like inhibitory protein long form (cFLIP(L)) decreased during follicular atresia in granulosa cells of porcine ovaries. In humans and other species, both the short (cFLIP(S)) and long (cFLIP(L)) forms of cFLIP are considered to function as cell survival factors that inhibit death ligand receptor-mediated apoptosis. Since the anti-apoptotic activity of porcine cFLIP (pcFLIP) in granulosa cells had not been determined, we examined the effect of pcFLIP on survival using granulosa-derived cell lines. A human cervix adenocarcinoma cell line, HeLa, human ovarian granulosa tumor cell line, KGN, and porcine granulosa-derived cell line, JC-410, were used. By Western blotting, internal cFLIP(L) was detected in all cell lines, but only trace levels of cFLIP(S) were found in HeLa and KGN cells. To examine the anti-apoptotic activity, pcFLIP(S) or pcFLIP(L) was overexpressed in HeLa and KGN cells. Transfected cells in which pcFLIP(S) or pcFLIP(L) was overexpressed, survived the induction of Fas-mediated apoptosis, while almost all of the cells transfected with empty vector died. Then, we suppressed the expression of porcine cFLIP(S) and/or cFLIP(L) in JC-410 cells using small interfering RNA (siRNA). When both cFLIP(S) and cFLIP(L), or only cFLIP(L) was suppressed, cell viability declined significantly. From the results, we conclude that porcine cFLIP(S) and cFLIP(L) exhibit anti-apoptotic activity in granulosa-derived cells. It was strongly suggested that pcFLIP acts as a survival-promoting factor in granulosa cells and determines whether porcine ovarian follicles survive or undergo atresia.     

Nocturnal emission and post-pollination change of floral scent in the leafflower tree,Glochidion rubrum,exclusively pollinated by seed-parasitic leafflower moths

Many insect-pollinated plants use floral scent signals to attract and guide the effective pollinators, and temporal patterns of their floral scent emission may be tuned to respond to the pollinator's activity and pollination status. In the intimate nursery pollination mutualism between monoecious Glochidion trees (Phyllanthaceae) and Epicephala moths (Gracillariidae), floral scent signals mediate species-specific interactions and influence the moth's efficient pollen-collecting and pollen-depositing behaviors on male and female flowers, respectively. We tested the hypotheses that both sexes of flowers of Epicephala-pollinated Glochidion rubrum exhibit a diel pattern of scent emission matching the activity period of the nocturnally active pollinator, and that female flowers change the chemical signal after pollination to reduce further visits and oviposition by the pollinator. We investigated the diel change of floral scent emissions during two consecutive days and the influence of pollination on the floral scent by conducting hand-pollinations in the field. The total scent emission of male and female flowers was higher at night than in the day, which would be expected from the nocturnal visitations of Epicephala moths. Some compounds exhibited a clear nocturnal emission rhythm. Hand-pollination experiments revealed that emission of two compounds, nerolidol and eugenol, drastically decreased in pollinated flowers, suggesting that these compounds may function as key attractants for the pollinator; however, the total scent emission of the female flower was not influenced by hand-pollination. The pattern of the floral scent emission of G. rubrum may be optimized to attract nocturnal pollinators and reduce oviposition.