SERPINE2 is a possible candidate promotor for lymph node metastasis in testicular cancer

Testicular germ cell tumors (TGCTs) commonly metastasize to the lymph node or lung. However, it remains unclear which genes are associated with TGCT metastasis. The aim of this study was to identify gene(s) that promoted human TGCT metastasis. We intraperitoneally administered conditioned medium (CM) from JKT-1, a cell-line from a human testicular seminoma, or JKT-HM, a JKT-1 cell sub-line with high metastatic potential, into mice with JKT-1 xenografts. Administration of CM from JKT-HM significantly promoted lymph node metastasis. A cDNA microarray analysis showed that JKT-HM cells highly expressed the Serpine peptidase inhibitor, clade E, member 2 (SERPINE2), which encodes a secreted protein. Administration of CM from SERPINE2-silenced JKT-HM cells inhibited lymph node metastasis in the xenograft model, compared with administration of CM from JKT-HM cells. There was no significant difference in xenograft volume. Moreover, administration of CM from SERPINE2-over-expressing JKT-1 was likely to promote lymph node metastasis in the xenograft model. There was no difference in the in vitro proliferation or migration of JKT-1 cells cultured with CM from JKT-HM cells, compared to that with CM from JKT-1. There was no promotion of proliferation or lymphangiogenesis in the xenografts, as measured by Ki-67 and LYVE-1 immunohistochemistry, respectively. Although we could not clarify how SERPINE2 promoted lymph node metastasis, it may be a promoter in the development of lymph node metastasis in the human seminoma cells in a mouse xenograft model.     

Biological control by two exotic parasitoids: eight-year population dynamics and life tables of the arrowhead scale

To determine the process of regulation of Unaspis yanonensis (Kuwana) (Hemiptera: Diaspididae) by the two introduced parasitoids, Aphytis yanonensis DeBach et Rosen and Coccobius fulvus (Compere et Annecke) (Hymenoptera: Aphelinidae), the temporal changes in the population density of U. yanonensis as well as the parasitism rates were monitored for eight years before and after the release of the two parasitoids in a Satsuma mandarin orange (Citrus unshiu Marc. (Rutaceae)) orchard. From 2–4 years after the release, the parasitism rate by C. fulvus gradually increased, eventually reaching 70%, while that by A. yanonensis showed a weak increase, remaining under 12%. During this period, the host density decreased to about 1/100 of the initial density. After the drastic decrease, the host density remained under 1/60 of the level previous to the release for at least 2 years with the populations of both parasitoids persisting. To estimate the ability of the two parasitoids to regulate the populations of U. yanonensis, life tables of U. yanonensis under natural conditions and predator/parasitoid-exclusion (bagged) conditions were compared. It was demonstrated that C. fulvus and A. yanonensis impose about 70% mortality rate on the host at mature adult stages and about 30% on the host at immature adult stages. The results have strongly confirmed the high capability of the two parasitoids as biological control agents for U. yanonensis, which was suggested by earlier studies. However, contrary to those studies, the present study did not support the complementarity of the two parasitoids in regulating the host population, suggesting that the effectiveness of C. fulvus alone in regulating the host population at low levels.     

Properties of the Plastidial Acyl-(Acyl-Carrier-Protein): Glycerol-3-Phosphate Acyltransferase from the Chilling-Sensitive Plant Squash (Cucurbita moschata)

To determine whether the plastidial acyl-(acyl-carrier-protein(ACP)): glycerol-3-phosphate acyltransferase from chilling-sensitiveplants exhibits fatty acid selectivities different from thoseof resistant plants, we characterized this enzymic activityfrom the chilling-sensitive plant Cucurbita moschata. In squashcotyledons, the glycerol-3-phosphate acyltransferase (AT) occurredas three isomeric forms: one with an isoelectric point at pH6.6 (ATI) and two at about pH 5.5 (AT2 and AT3). These isomershad approximately equal total activities in plastids. All threeforms specifically directed acyl groups to the C-l positionof glycerol-3-phosphate. However, ATI differed from the twoother isomeric forms on the basis of kinetic data determinedwith different acyl-ACPs as substrates. These kinetic differenceswere reflected in the different fatty acid selectivities ofthe acyltransferases. ATI preferably utilized oleoyl groupsin comparison to palmitoyl and stearoyl groups while AT2 andAT3 hardly discriminated between the acyl-ACP thioesters. However,the observed selectivity of ATI was significantly reduced byincreasing the pH of the reaction mixture from 7.4 to 8.0, whichis the stroma pH of illuminated chloroplasts. Consequently,the glycerol-3-phosphate acyltransferases from squash cotyledonscould account for the high proportion of saturated acyl groupsfound at the C-l position of the plastidial phosphatidylglycerolfrom this plant. (Received April 7, 1987; Accepted July 8, 1987)     

A Modified Murine Embryonic Stem Cell Test for Evaluating the Teratogenic Effects of Drugs on Early Embryogenesis

Mammalian fetal development is easily disrupted by exogenous agents, making it essential to test new drug candidates for embryotoxicity and teratogenicity. To standardize the testing of drugs that might be used to treat pregnant women, the U.S. Food and Drug Administration (FDA) formulated special grade categories, labeled A, B, C, D and X, that define the level of risk associated with the use of a specific drug during pregnancy. Drugs in categories (Cat.) D and X are those with embryotoxic and/or teratogenic effects on humans and animals. However, which stages of pregnancy are affected by these agents and their molecular mechanisms are unknown. We describe here an embryonic stem cell test (EST) that classifies FDA pregnancy Cat.D and Cat.X drugs into 4 classes based on their differing effects on primitive streak formation. We show that ~84% of Cat.D and Cat.X drugs target this period of embryogenesis. Our results demonstrate that our modified EST can identify how a drug affects early embryogenesis, when it acts, and its molecular mechanism. Our test may thus be a useful addition to the drug safety testing armamentarium.     

Feeding behaviour of the ladybeetle,Pseudoscymnus kurohime

A laboratory study was made of the feeding behaviour of the ladybeetlePseudoscymnus kurohime (Miyatake) when attacking the sugar cane woolly aphidCeratovacuna lanigera Zehntner. The 1st-instar ladybeetle larva was smaller than the 1st instar aphid nymph. All larval stages of the ladybeetle sucked out the body fluids of aphids and left their emptied corpses. The 1st, 2nd, and 3rd instar ladybeetle larvae mostly attacked 1st instar aphids, whereas the 4th-instar ladybeetle larvae attacked all stages of aphids. Ladybeetle adults ate mostly 1st-instar aphids. Young larvae attacked aphids in several different ways: (1) They crawled under an aphid, seized it by its underside and lifted it up. (2) They attacked new born nymphs at birth or shortly afterwards. (3) They fed on an aphid that had been captured by an older larva. The larvae preferred to seize with their mandibles the head or thorax of an aphid, while adults seized their prey by the abdomen. When attacked by an adult, 82% of the aphids secreted droplets from their abdominal cornicles, whereas only 7.2–12% secreted droplets when attacked by larvae. The 4th instar larvae more voracious than the younger larvae.