Masu salmon (Oncorhynchus masou) zona pellucida protein B: cDNA cloning and tissue expression

A full-length cDNA clone encoding zona pellucida protein B (ZPB) was isolated for the ovary of masu salmon. The deduced amino acid sequence of ZPB contained two domains commonly observed in ZPB of both mammals and teleosts. Using gene-specific primers for ZPB in masu salmon, RT-PCR analyses revealed that expression of ZPB was isolated to the ovary. These results suggest involvement of an ovary-derived zona pellucida protein in formation of the chorion in masu salmon.     

The effect of cortisol administration on blood plasma immunoglobulin M (IgM) concentrations in masu salmon (Oncorhynchus masou)

Immunoglobulin M (IgM) is known as a main factor in the humoral immune system of teleosts. In the present study, the effect of cortisol on plasma IgM concentrations was investigated using a specific antibody to IgM in masu salmon (Oncorhynchus masou). Cortisol was orally administered each day for 2 weeks at a dose of 1 mg g⁻¹ in the diet, and for the following week the fish were fed a non-treated diet. Blood plasma samples were collected at 0, 1, 2 and 3 weeks after the initiation of treatment. Oral administration of cortisol elevated plasma cortisol concentrations to about 40 ng/ml for 2 weeks after administration and slightly reduced plasma IgM concentration; the suppression was statistically significant one week after the period of hormone administration. However, treatment with cortisol did not affect plasma concentrations of total protein or α1-protein, one of the major serum proteins, during the experimental period. These results indicate that cortisol specifically suppresses plasma IgM concentrations.     

Purification,characterization and immunoassay of striped bass (Morone saxatilis) vitellogenin

The egg yolk precursor, vitellogenin (VTG), was purified from blood plasma of striped bass by chromatography on hydroxylapatite or DEAE-agarose. The fish were first implanted with estradiol-17β (E₂), which induced vitellogenesis. A rabbit antiserum (a-FSPP) raised against plasma from mature female striped bass, and then adsorbed with mature male plasma, was used to detect female-specific plasma protein (FSPP) in the chromatography fractions. Striped bass VTG (s-VTG) was collected from the peak fraction that was induced by E₂, reacted with a-FSPP, and contained all detectable phosphoprotein. It appeared as a single band (M_r ≂ 170,000) in SDS-PAGE or Western blots using a-FSPP, and as a pair of closely-spaced phospholipoprotein bands in native gradient-PAGE, suggesting that there is more than one circulating form of s-VTG. The relationship of s-VTG to the yolk proteins was verified using a-FSPP. The antiserum reacted with the main peak from gel filtration of saline ovary extracts, and it specifically immunostained the two main bands in Western blots of the extracts and the yolk granules of mature oocytes. The amino acid composition of s-VTG was similar to that of VTG from other fish and Xenopus. A radial immunodiffusion assay for s-VTG was developed using a-FSPP and purified s-VTG as standard. The s-VTG was not detected in blood plasma of males, immature females, or regressed adult females, but plasma s-VTG levels were highly correlated with plasma E₂ and testosterone levels, and oocyte growth, in maturing females. The results indicate that the maturational status of female striped bass can be identified by s-VTG immunoassay.     

Lysine decarboxylase-negative Salmonella enterica serovar enteritidis: antibiotic susceptibility, phage and PFGE typing

One hundred twenty Salmonella Enteritidis isolates collected from 1992 to 2005 in Nagasaki prefecture (65 isolates from 40 outbreak cases, 44 from sporadic diarrhea patients, and 11 from chicken-related products) were investigated by their antibiotic susceptibility profiles, phage typing, and pulsed-field gel electrophoresis (PFGE) typing. Out of them, 18 were identified as lysine decarboxylase (LDC)-negative isolates, and 15 showed resistance toward streptomycin. Based on the PFGE typing, the isolates were classified into five clusters by UPGMA clustering method. Three LDC-negative isolates belonged to cluster A and were of phage type (PT) 4 and isolated between 2000 and 2004. Other 15 LDC-negative isolates belonged to cluster E. They were PT1, reacted but did not conform (RDNC), or untypable and were isolated between 2001 and 2004. LDC-negative isolates of the cluster A differed from LDC-negative isolates of the cluster E in antibiotic susceptibility profiles, phage typing, and PFGE typing. LDC-negative isolates of the cluster E were isolated after 2001 in Nagasaki prefecture.     

Gustatory detection of tetrodotoxin and saxitoxin, and its competitive inhibition by quinine and strychnine in freshwater fishes

Fish detect extremely low levels of marine toxins tetrodotoxin (TTX) and saxitoxin (STX) via the specialized gustatory receptor(s). Physiological and pharmacological studies show that receptor(s) for TTX and STX are distinct from those which detect feeding stimulant amino acids and bile acids, and that TTX and STX do not share the same receptor populations, while interacting with quinine and strychnine in a competitive fashion suggestive of an antidotal relationship.     

Relationship between wet deposition of sulfate and nitrate and rainfall amount in Japan

A regression model of wet deposition on rainfall amount for non-seasalt sulfate (nss-SO₄ ^2?) and nitrate (NO₃ ^?) was applied to a data set obtained through a nationwide survey from April 1989 to March 1993. Wet-only samples on a biweekly basis were collected at 29 sites over Japan. Reparameterized bivariate lognormal distribution was employed to describe the joint distribution of concentration (C) and rainfall amount (R) for each site. Ranges of geometric mean (μ_D) of biweekly deposition (D = C. R) for each site were 0.54–2.90 meq m^?2 for nss-SU₄ ^2?, and 0.21–1.36 meq m^?22 for NO₃ ^?; that of biweekly rainfall amount (μ_R) was 24.1–78.0 mm. Urban or industrialized areas had high values of μ_D for these ions. Ranges of estimates of the slope of the regression equation of log(D/μ_D) on log(R/μ_R), were 0.45–0.99 for nss-SO₄ ^2?, and 0.35–0.86 for NO₃ ^?; thus estimates of the slope for nss-SO₄ ^2? tend to be larger than those for NO₃ ^?. The present analysis, consequently, statistically clarified some differences between the two ions in deposition processes which is understood in the light of current knowledge of atmospheric chemistry.     

电阻抗分析法在海藻酸钙胶囊干燥中的应用

海藻酸钙胶囊是由大分子、水分子和离子组成的复杂网络结构,其水分含量很高(约3500%,以干基计)。在海藻酸钙胶囊干燥过程中,用常规分析方法确定干燥机理和硬化反应关键点等比较困难。电阻抗分析法在实际分析中有很多优点,该研究用于监控海藻酸钙胶囊的干燥进程。确定了电阻抗分析法的测定条件,测定并分析了几种干燥过程中电阻抗特性的变化     

Inhibition of radical reaction of apolipoprotein B-100 and alpha-tocopherol in human plasma by green tea catechins

(-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epigallocatechin gallate (EGCg), and Trolox inhibited the decreases of apolipoprotein B-100 (apoB) and alpha-tocopherol in a radical reaction of human plasma initiated by Cu(2+). The concentrations of EC, EGC, ECg, EGCg, and Trolox for 50% inhibition (IC50) of apoB fragmentation were 39.1, 42.2, 14.6, 21.3, and 36.2 microM, respectively. Similar IC50 values were observed for alpha-tocopherol consumption, indicating the close relationship between apoB fragmentation and alpha-tocopherol consumption. These results demonstrate that tea catechins serve as an effective antioxidant in plasma and that the gallate group has a strong antioxidative activity.