Nest site choice by the three-spined stickleback, Gasterosteus aculeatus (form leiurus), in spring-fed waters

The nest site characteristics of the freshwater three-spined stickleback, Gasterosteus aculeatus (form leiurus ), were quantitatively investigated in springs and the main stream of the Yamayoke and the Tsuya River system, central Japan. Most nests (93·4%) were on a muddy or sandy substratum, at depths of 10–40 cm (84·3%), in water velocities less than 15 cm s⁻¹ (76·2%) and in the temperature range of 14 to 16° C (82·7%), Spring-fed localities provided more of these conditions than the main stream channel and hence contained more potential nesting areas. Thus, they were utilized by male sticklebacks both temporally (prolonged breeding season) and spatially (more nest sites).     

Subcellular Distribution of Calpain and Calpastatin Immunoreactivity and Fodrin Proteolysis in Rabbit Hippocampus After Hypoxia and Glucocorticoid Treatment

Abstract: Rabbits were subjected to hypoxia (5% O₂) for up to 90 min and allowed to recover for a maximum of 4 days. Hippocampus homogenate was assayed for fodrin breakdown product (BDP). After separation into a nuclear and mitochondrial fraction (NMF), a membrane and microsomal fraction (MMF), and a cytosolic fraction (CF), samples were assayed for μ-calpain, m-calpain, and calpastatin immunoreactivity. Calpain and calpastatin immunoreactivity decreased in the NMF and CF but increased in the MMF during hypoxia and short-term recovery. This translocation occurred in parallel with the increase in fodrin BDP. Because the increase in the MMF was not large enough to explain the decrease in the other two fractions, it was assumed that the translocation and activation was accompanied by a reduction in the total amounts of calpains and calpastatin. Glucocorticoid pretreatment (beta-methasone, 0.4 mg × kg⁻¹× day⁻¹) for 7 days produced a decrease in the ratio of activated μ-calpain in all three fractions in nearly all samples before, during, and after hypoxia, compared with untreated animals. Glucocorticoid pretreatment also prevented the increase in fodrin BDP that occurred in untreated animals during hypoxia and short-term recovery, indicating impairment of calpain activation.     

Non-systemic expression of a stress-responsive maize polyubiquitin gene (Ubi-1) in transgenic rice plants

We have used the promoter, 1st exon and 1st intron of the maize polyubiquitin gene (Ubi-1) for rice transformation experiments and revealed the characteristic expression of Ubi-1 gene: (1) Ubi-1 gene is not regulated systemically but rather individual cells respond independently to the heat or physical stress; (2) Ubi-1 gene changes its tissue-specific expression in response to stress treatment; (3) the expression of Ubi-1 gene is dependent on cell cycle.     

Enhanced Expression of an Endothelin ETA Receptor in Capillaries from Human Glioblastoma: A Quantitative Receptor Autoradiographic Analysis Using a Radioluminographic Imaging Plate System

Abstract: We identified and characterized ¹²⁵I-endothelin-1 (¹²⁵I-ET-1) binding sites in tumor capillaries isolated from human glioblastomas, using the quantitative receptor autoradiographic technique with pellet sections. Quantification was done using the computerized radioluminographic imaging plate system. High-affinity ET receptors were localized in capillaries from glioblastomas and the surrounding brain tissues (K_D = 4.7 ± 1.0 × 10^?10 and 1.6 ± 0.3 × 10^?10M, respectively; B_max = 161 ± 38 and 140 ± 37 fmol/mg, respectively; mean ± SEM, n = 5). BQ-123, a selective antagonist for the ET_A receptor, potently competed for ¹²⁵I-ET-1 binding to sections of the microvessels with IC₅₀ values of 5.1 ± 0.3 and 5.1 ± 1.5 nM, and 10^?6M BQ-123 displaced 84 and 58% of ET binding to capillaries from tumors and brains, respectively. In addition, competition curves obtained in the presence of increasing concentrations of ET-3 showed two components (IC₅₀ = 5.7 ± 2.5 × 10^?10 and 1.4 ± 0.2 × 10^?6M for tumor microvessels, 1.8 ± 0.6 × 10^?10 and 1.1 ± 0.3 × 10^?6M for brain microvessels, respectively). Our results indicate that (a) the method we used is simple and highly sensitive for detecting and characterizing various receptors in tumor capillaries, especially in the case of a sparse specimen, and (b) capillaries in glioblastomas express specific high-affinity ET binding sites, candidates for biologically active ET receptors, which predominantly belong to the ET_A subtype.     

A newCercophora with aChrysosporium-like anamorph

A new species ofCercophora, isolated from river sediment collected from Sakai River in Nagasaki Prefecture, Japan, is described and illustrated. It is distinguished from the other knwon species by the morphology of its ascomatal peridium and ascospores, and by itsChrysosporium-like anamorph.     

Lipopolysaccharide Isolated from a New O-Antigenic Form (O13) of Vibrio parahaemolyticus

The chemical properties of a lipopolysaccharide (LPS) isolated from a new O-antigenic form (O13) of Vibrio parahaemolyticus were investigated. The LPS contained glucose, galactose, L -glycero-D -manno-heptose and glucosamine. 2-Keto-3-deoxy-octonate (KDO) was not detected in the LPS by the periodate-thiobarbituric acid test (Weissbach's reaction) under conventional hydrolysis conditions. Instead, phosphorylated KDO (X1 and X2) was found in its strong-acid hydrolysate. This sugar composition was identical to that of V. parahaemolyticus O3, O5 and O11 LPS, indicating that, based on the sugar composition, O13 LPS belongs to Chemotype III to which O3, O5 and O11 belong. In addition, structural study demonstrated the presence of KDO 4-phosphate in its inner-core region.     

Processing inhibition of N-linked sugar chains associated with induction of Fc receptor-mediated phagocytosis in the mouse monocytoid cells

The concanavalin A staining of cellular glycoproteins and thedirect analysis of their sugar chains released by hydrazinolysisrevealed that the processing of N-linked sugar chains of someglycoproteins is suppressed by exposure of mouse monocytoidcells P388D1 to dimethyl sulphoxide, which can induce Fc receptor-mediatedphagocytosis. To elucidate the significance of altered glycosylationin inducing phagocytosis, the effects of exposure of the cellsto processing inhibitors (swainsonine and castanospermine) wereexamined and it was found that the cells are induced to acquirean ability to ingest IgG-coated sheep red blood cells, dependingon the dose of the inhibitors and incubation time. Analysisof the N-linked sugar chains liberated from cellular glycoproteinsby hydrazinolysis confirmed that the processing of the sugarchains is suppressed by the two inhibitors as expected. Sinceno significant alteration was induced in protein synthesis andDNA synthesis after exposure to the inhibitors, it is suggestedthat the altered glycosylation of cellular glycoproteins mayhave some direct role in the induction of Fc receptor-mediatedphagocytosis. The inhibitors did not affect the binding of theIgG-coated red blood cells to Fc receptors on the cells, non-specificphagocytosis of latex beads, and the contents of lysosomal enzymes,ß-glucuronidase and acid phosphatase. These resultssuggest that the glycosylation status of cellular glycoproteinsinfluences some specific processes involved in the ingestionof the ligands bound to Fc receptors. castanospermine macrophages phagocytosis swainsonine     

Effects of fenvalerate and esfenvalerate on hepatic gap junctional intercellular communication in rats

Effects of in vivo exposure with fenvalerate, esfenvalerate andDDT on hepatic gap junctional intercellular communication (GJIC) in Sprague-Dawley (SD) rats were examined by in vivolin vitro dye-transfer assay and by immunohistochemical staining of connexin 32 (C×32, major liver gap junction protein). Fenvalerate (75 mg/kg/day), esfenvalerate (25 mg/kg/day), DDT (50 mg/kg/day) and corn oil (vehicle control, 5mllkglday) were administered orally once a day. Animals were killed at weeks 1, 2, 4 and 6 after starting the experiment. In the fenvalerate- and esfenvalerate-groups, no compound-related changes in GJIC and C×32 expression were observed. On the contrary, in the DDT-group, average sizes of the dye spread after injection of Lucifer Yellow decreased at weeks 1, 2 and 4, and the area per GJ spot shown by C×32-immunohistochemical staining decreased at weeks 4 and 6. It is concluded that neither fenvalerate nor esfenvalerate inhibits hepatic GJIC with in vivo exposure.     

A novel monoantennary complex-type sugar chain found in octopus rhodopsin: occurrence of the Gal{beta}1->4Fuc group linked to the proximal N-acetylglucosaniine residue of the trimannosyl core

The N-linked sugar chains were liberated as oligosaccha-ridesfrom octopus rhodopsin by hydrazinolysis. Most of the oligosaccharideswere neutral, and separated into two major components by columnchromatography using immobilized lectins and Bio-Gel P-4. Structuralanalysis of the one major component by sequential exoglycosidasedigestion, chemical fragmentation in combination with meth-ylationanalysis revealed that it is a nonasaccharide; Man16(Gaiβ13GlcNAcβ12Man13)Manβ14GlcNAcβ14(Galβ14Fuc16)GlcNAcThis structure is quite unique in that a novel galactosylatedfucose residue is attached to the reducing terminal N-acetyl-glucosamineresidue. galactosylated Fuc N-linked sugar chain novel structure octopus rhodopsin