Assessment of species specificity of moulting accelerating compounds in Lepidoptera: comparison of activity between Bombyx mori and Spodoptera littoralis by in vitro reporter and in vivo toxicity assays

BACKGROUND: Dibenzoylhydrazine analogues have been developed successfully as a new group of insect growth regulators, called ecdysone agonists or moulting accelerating compounds. A notable feature is their high activity against lepidopteran insects, raising the question as to whether species‐specific analogues can be isolated. In this study, the specificity of ecdysone agonists was addressed through a comparative analysis in two important lepidopterans, the silkworm Bombyx mori L. and the cotton leafworm Spodoptera littoralis (Boisd.). RESULTS: When collections of non‐steroidal ecdysone agonists containing different mother structures (dibenzoylhydrazine, acylaminoketone, tetrahydroquinoline) were tested, in vitro reporter assays showed minor differences using cell lines derived from both species. However, when compounds with high ecdysone agonist activity were examined in toxicity assays, larvicidal activity differed considerably. Of note was the identification of three dibenzoylhydrazine analogues with > 100‐fold higher activity against Bombyx than against Spodoptera larvae. CONCLUSION: The present study demonstrated that species‐specific ecdysone‐agonist‐based insecticides can be developed, but their species specificity is not based on differences in the activation of the ecdysone receptor but rather on unidentified in vivo parameters such as permeability of the cuticle, uptake/excretion by the gut or metabolic detoxification. Copyright © 2010 Society of Chemical Industry     

Local convergence zones or discontinuous lines in the Taklimakan Desert, Northwest China

In order to study convergence zones or discontinuous lines formed locally in the Taklimakan Desert,we analyzed available MODIS images onboad TERRA or AQUA satellite for ten cases:29 March 2002,14 April 2002;2 January 2003;21 April 2003;26 March 2004;28 April 2004;30 January 2005;25 June 2005;3 December 2005;and 26 July 2006.We used weather maps published by the Japan Mete-orological Agency for the Asia and Pacific region at 500 hPa,700 hPa and 850 hPa,at 00Z and 12Z to analyze the meteorological conditions occurring in each case.We estimated the positions of air streams,convergence zones or discontinuous lines between them,and thermal conditions on the maps and con-firmed the presence of cumulus and cumulonimbus clouds through satellite images in particular.After a review of previous studies,this paper introduced the results of the present study.Closed warm areas in the Taklimakan Desert and on the Tibetan Plateau and local convergence zones or discontinuous lines in the Taklimakan Desert were discussed together with their diurnal changes,using composite maps of the ten cases.Along the long axis of the desert the convergence zones or discontinuous lines normally extend 70-80 km in a west-east direction,but are suspected to exceed 100 km in extreme cases.On the other hand,the convergence zones or discontinuous lines extending in a north-south direction on the southern fringe of the desert have a length of 40-60 km.The closed warm areas show clear diurnal changes,but they were not detected at the 500 hPa level.An example of a clear convergence zone running in a north-south direction on 26 July 2006 was presented in detail with corresponding satellite images.     

Purinergic P2X7 receptor antagonist ameliorates intestinal inflammation in postoperative ileus

Postoperative ileus (POI) is a postsurgical gastrointestinal motility dysfunction caused by mechanical stress to the intestine during abdominal surgery. POI leads to nausea and vomiting reduced patient quality of life, as well as high medical costs and extended hospitalization. Intestinal inflammation caused by macrophages and neutrophils is thought to be important in the mechanism of POI. Surgery-associated tissue injury and inflammation induce the release of adenosine triphosphate (ATP) from injured cells. Released ATP binds the purinergic P2X7 receptor (P2X7R) expressed on inflammatory cells, inducing the secretion of inflammatory mediators. P2X7R antagonists are thought to be important mediators of the first step in the inflammation process, and studies in chemically induced colitis models confirmed that P2X7R antagonists exhibit anti-inflammatory effects. Therefore, we hypothesized that P2X7R plays an important role in POI. POI models were generated from C57BL/6J mice. Mice were treated with P2X7R antagonist A438079 (34 mg/kg) 30 min before and 2 hr after intestinal manipulation (IM). Inflammatory cell infiltration and gastrointestinal transit were measured. A438079 ameliorated macrophage and neutrophil infiltration in the POI model. Impaired intestinal transit improved following A438079 treatment. P2X7R was expressed on both infiltrating and resident macrophages in the inflamed ileal muscle layer. The P2X7R antagonist A438079 exhibits anti-inflammatory effects via P2X7R expressed on macrophages and therefore could be a target in the treatment of POI.     

Expression profiles of interferon gamma genes in response to immunostimulants and alloantigen in ginbuna crucian carp Carassius auratus langsdorfii

Interferon gamma (IFNγ), a Th1-derived cytokine is one of the key molecules inducing cell-mediated immune responses in mammals. The expression of 2 distinct IFNγ (ifng1 and ifng2) and IFNγrel (ifngrel) genes was examined in kidney leukocytes from clonal ginbuna crucian carp Carassius auratus langsdorfii. The expression of IFNγ and IFNγrel genes was induced in kidney leukocytes by stimulation with lipopolysaccharide or phytohemagglutinin in a dose-dependent manner. The expression levels of IFNγ and IFNγrel genes in kidney leukocytes from allo-sensitized fish cocultured with allogeneic cells were higher than those from fish cocultured with isogeneic cells. The highest expression of ifng1 was observed at day 1, whereas that of ifng2 and ifngrel was detected at day 2 after cocultivation with allogeneic cells. However, the expression pattern of ifng2 and ifngrel in kidney leukocytes from allo-sensitized fish by scale-grafting was similar to those from non-sensitized fish. These results indicate that ifng1 is a major isoform of IFNγ related to antigen-specific cell-mediated immunity (CMI), and will be a useful marker to evaluate induction of CMI in ginbuna crucian carp. In addition, IFNγ would be a crucial type-II interferon compared to IFNγrel, relevant to cell-mediated immunity in fish as in mammals.     

Rearing conditions to develop seawater tolerance in underyearling sockeye salmon smolt

ABSTRACT:   In order to confirm the conditions required to produce underyearling smolts, juvenile sockeye salmon Oncorhynchus nerka were reared under different photoperiod and temperature conditions. The level of smoltification was assessed by plasma sodium concentration 24 h after transfer to sea water (plasma-Na), gill Na⁺,K⁺-ATPase activity (gill-ATPase), and plasma thyroxine (plasma-T4) and growth hormone (plasma-GH) concentrations. Mean fork length of all groups reached more than approximately 8.5 cm at the end of the experiment. The fish that experienced an alteration in photoperiod from short day (8:16 h light–dark cycle) to long day (16:8 h light–dark cycle) showed significant elevation in gill-ATPase from 9 to 16 µmol inorganic phosphate per milligram protein per hour (µmol Pi/mg pro/h) and reduction in plasma-Na from 194 to 154 mM. This group displayed distinct pigmentation on their fin margins. However, in groups reared under constant short day and constant long day, changes in gill-ATPase and plasma-Na occurred vaguely at each different time and pigmentation on fin margins were not observed. The observed photoperiod-induced changes were greater at 7°C than at 11°C. Further, the alteration of the photoperiod induced two–threefold increases in plasma-GH and plasma-T4. These results suggest that lengthening of photoperiod from short to long daylight at 7°C causes smoltification accompanied by active secretion of growth hormone and thyroxine in underyearling sockeye salmon when the fish are larger than 8.5 cm in fork length.     

Three distinct groups of isolates of <Emphasis Type="Italic">Tomato yellow leaf curl virus</Emphasis> in Japan and construction of an infectious clone

Complete nucleotide sequences of eight Japanese isolates of Tomato yellow leaf curl virus (TYLCV) were determined and compared with four TYLCV isolates already reported. These isolates separated into three groups – Shizuoka (Sz), Aichi (Ai), Nagasaki (Ng) – and had 99% identities within the groups. Full-length molecules of DNA-A of group Sz consist of 2791nt and those of group Ai contain 2787nt. Both were closely related to TYLCV-Is.M, although those of group Ng had 2793nt and were more closely related to TYLCV-Is. Comparison of common sequences of isolates belonging to groups Sz and Ai had substitutions of 4nt in the intergenic region and nonsynonymous substitutions at open reading frames between the groups. None of the isolates tested had DNA molecules. Agroinfection of four plant species with a DNA-A dimeric infectious clone of TYLCV-SzY, a member of group Sz, resulted in systemic infection. Tomato plants then developed typical yellow leaf curl symptoms.The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession numbers AB116629, AB116630, AB116631, AB116632, AB116633, AB116634, AB116635, and AB116636     

Effects of methoxychlor exposure during perinatal period on reproductive function after maturation in rats

Methoxychlor (MXC) is a non-steroidal pesticide that is known to possess estrogenic activity, and therefore may be potentially hazardous to the development and/or reproduction. The present study assessed the effects of perinatal exposure to MXC on reproductive function after maturation in both male and female rats. Pregnant rats were fed a phytoestrogen-free diet containing different doses of MXC (24, 240, and 1200 ppm) from day 15 of gestation to day 10 after parturition, and reproductive functions of offspring were examined after maturation. In males, MXC exposure during the perinatal period decreased serum LH and FSH, but not testosterone levels, but it did not affect copulatory behavior. In females, MXC exposure prolonged the days exhibiting cornified vaginal smears during the estrous cycle. In addition, both the lordosis reflex and preovulatory LH surge on the presumptive proestrous evening were suppressed in MXC-exposed females. These results suggest that perinatal exposure to MXC exerts permanent effects on several aspects of the reproductive function in both male and female rats.     

Production of a transgenic pig expressing human albumin and enhanced green fluorescent protein

We introduced a fusion gene of human albumin and enhanced green fluorescent protein (EGFP) into porcine oocytes using the sperm vector method, and produced a piglet that showed clear expression of GFP in the hooves and skin. PCR and Southern blotting analysis of genomic DNA extracted from the piglet's tissues, including the liver, showed that the tissues carried the transgene. RT-PCR analysis demonstrated that both the human albumin and EGFP genes were expressed in the tissues. The fact that human albumin gene was integrated and expressed in the liver of the transgenic pig opened a way for us to achieve our goal, which was the use of transgenic pigs for the bioartificial liver support system.     

γ-Oryzanol reduces adhesion molecule expression in vascular endothelial cells via suppression of nuclear factor-κB activation

γ-Oryzanol (γ-ORZ) is a mixture of phytosteryl ferulates purified from rice bran oil. In this study, we examined whether γ-ORZ represents a suppressive effect on the lipopolysaccharide (LPS)-induced adhesion molecule expression on vascular endothelium. Treatment with LPS elevated the mRNA expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin in bovine aortic endothelial cells (BAECs). Pretreatment with γ-ORZ dose-dependently decreased the LPS-mediated expression of these genes. Western blotting also revealed that pretreatment with γ-ORZ dose-dependently inhibited LPS-induced VCAM-1 expression in human umbilical vein endothelial cells. Consistently, pretreatment with γ-ORZ dose-dependently reduced LPS-induced U937 monocyte adhesion to BAECs. In immunofluorescence, LPS caused nuclear factor-κB (NF-κB) nuclear translocation in 40% of BAECs, which indicates NF-κB activation. Pretreatment with γ-ORZ, as well as its components (cycloartenyl ferulate, ferulic acid, or cycloartenol), dose-dependently inhibited LPS-mediated NF-κB activation. Collectively, our results suggested that γ-ORZ reduced LPS-mediated adhesion molecule expression through NF-κB inhibition in vascular endothelium.