A new species, Gazza squamiventralis, from the East Coast of Africa (Perciformes: Leiognathidae)

Gazza squamiventralis sp. nov. is described as the fifth species of the genus, based on the holotype and eight paratypes, 42–96 mm in standard length, collected along the east coast of Africa, from Kenya to Mozambique. The species is similar to other congeners in general appearance, differing clearly from them in having the ventrolateral surface of the body scaled anterior to a line from the pectoral fin base to the pelvic fin origin (vs naked) and a smooth supraorbital ridge (vs finely serrated). Additionally, the species differs from G. dentex, G. rhombea, and G. achlamys in having the dorsolateral surface of the body scaled anterior to a vertical through the tip of the posterior branch of the supratemporal canal (vs corresponding region naked), and from G. minuta in having the first dorsal fin pterygiophore narrowly expanded anteriorly, with a concave margin (vs broadly expanded, with a convex or linear margin), and a short antrorse extension of the first anal fin pterygiophore (vs long). A key to the five species of the genus Gazza is provided. Received: May 30, 2000 / Revised: September 16, 2000 / Accepted: January 16, 2001     

Rapid degradation of the silkworm diapause hormone by trypsin and its suppression by VAP-map, a synthetic analog of the cuticular peptide of silkworm, Bm ACP-6.7 (VAP-peptide).

Very fast tryptic degradation of the silkworm diapause hormone was found and the degradation pathway was analyzed by moderating the reaction conditions. It proceeded via cleavage at Arg23 and finally at Arg15 of DH. As the C-terminal structure of DH was essential for exhibiting bioactivity, the first cleavage caused rapid inactivation of the hormone. This tryptic digestion was strongly suppressed by adding VAP-map, a synthetic analog of the cuticular peptide of silkmoths, Bm ACP-6.7 (VAP-peptide), which is a natural synergist of DH. VAP-map suppressed the enzymic reaction by interacting with the substrate, but not with the enzyme.     

Regional differences in the morphology of a shrub Damnacanthus indicus: An induced resistance to deer herbivory?

We report here the possibility of an induced resistance of a spiny shrub Damnacanthus indicus against deer herbivory. Six characters of D. indicus were compared between regions with and without deer herbivory on the Boso Peninsula. We found that D. indicus in browsed areas produced smaller leaves, thicker spines, and shorter internode distances between spines than those in unbrowsed areas whereas the length of spines and the angle of a pair of spines did not differ significantly. It is likely that D. indicus shows an induced resistance by producing smaller leaves, and by increasing stoutness of spines and spine density.     

Detection of HbA1c by boronate affinity immunoassay using bacterial magnetic particles

We have developed a boronate affinity immunoassay system using m-aminophenylboronic acid (mAPB) coupling to bacterial magnetic particles (BMPs). Homobifunctional crosslinker, Bis-(succcimidyl)suberate (BS3), was employed for preparation of mAPB-BMPs conjugates (mAPB-BMPs). Quantities of HbA_1c on mAPB-BMPs were evaluated based on luminescence from alkaline phosphatase-conjugated anti-Hb antibody (ALP–antibody) binding to HbA_1c on the BMP surface. The binding of HbA_1c to mAPB-BMPs occurred gradually and was almost completed within 10 mm. The coupling reaction is enhanced due to static electric interaction between the positive charges on HbA_1c and negative charges on BMPs. The amount of HbA_1c binding to mAPB-BMPs increased with increasing sodium chloride concentrations in the range of 0–100 mM. However, the amount of Hb binding to mAPB-BMPs also increased in high concentration of sodium chloride. The Hb binding to mAPB-BMPs was detached from mAPB-BMPs when Hb–mAPB-BMPs were washed with low salt buffer. This indicates that Hb is nonspecifically adsorbed onto the surface of mAPB-BMPs in high concentration of sodium chloride. These results suggest that selective separation of HbA_1c using mAPB-BMPs can be achieved with these conditions. A dose–response curve was obtained between luminescence intensity and HbA_1c concentration using a fully automated boronate affinity immunoassay. A linear relationship between luminescence intensity and HbA_1c concentration was obtained in the range of 10–10⁴ ng/ml.     

Synthesis and evaluation of bioactive naphthoquinones from the Brazilian medicinal plant, Tabebuia avellanedae

A series of naphthoquinones based on the naphtho[2,3-b]furan-4,9-dione skeleton such as (−)-5-hydroxy-2-(1′-hydoxyethyl)naphtho[2,3-b]furan-4,9-dione (1) and its positional isomer, (−)-8-hydroxy-2-(1′-hydoxyethyl)naphtho[2,3-b]furan-4,9-dione (2), which are secondary metabolites found in the inner bark of Tabebuia avellanedae, were stereoselectively synthesized and their biological activities were evaluated in conjunction with those of their corresponding enantiomers. Compound 1 exhibited potent antiproliferative effect against several human tumor cell lines, but its effect against some human normal cell lines was much lower than that of mitomycin. On the other hand, its enantiomer (R)-1 was less active toward the above tumor cell lines than 1. The antiproliferative effect of 2 against all tumor cell lines was significantly reduced. These results indicated the presence of the phenolic hydroxy group at C-5 is of great important for increasing antiproliferative effect. In addition, 1 also showed higher cancer chemopreventive activity than 2, while there were no significant differences between 1 and 2 in antimicrobial activity. Both compounds displayed modest antifungal and antibacterial activity (Gram-positive bacteria), whereas they were inactive against Gram-negative bacteria.     

Heterogeneous mechanisms of human cytotoxic T lymphocyte generation. I. Differential helper cell requirement for the generation of cytotoxic effector cells from CD8+ precursor subpopulations.

The subpopulations of CD8+ T cells defined by CD45RA Ag expression have been hypothesized to represent cells varying in their relative maturation along a common, activation-dependent differentiation pathway. Previous studies have shown that both the CD8+CD45RA+ and CD8+CD45RA- subsets contain precursor cells capable of developing into alloreactive CTL. In the current study, we have examined the mechanisms involved in the generation of CTL effector cells from these two CD8+ subsets. Purified CD8+CD45RA+ or CD8+CD45RA- cells were stimulated with allogeneic non-T cells, either alone or in the presence of CD4+ Th cells. Although the generation of CTL from CD8+CD45RA- precursor cells consistently required the presence of CD4+ Th cells, cytotoxic effector cells could be generated from CD8+CD45RA+ precursor cells in the absence of CD4+ cells. Several lines of evidence indicated that the helper cell-independent generation of cytotoxic effector cells from CD8+CD45RA+ precursors resulted from the unique ability of this subset to produce and use IL-2 in an autocrine fashion: 1) exogenous IL-2 could replace the effects of CD4+ helper cells for either CD8+ subset; 2) the helper cell-independent functional maturation of CD8+CD45RA+ cells could be blocked by anti-CD25 or anti-IL-2 antibodies; and 3) CD8+CD45RA+ cells produced IL-2 after activation with allogeneic cells. The finding that precursors for helper cell-independent CTL generation are restricted to the CD8+CD45RA+ subset suggests that this capability may vary as a function of the maturation of CD8+ cells.     

Plant Growth Inhibitory Activities of Synthetic α-Methylene-γ-butyrolactones

Some α-methylene-β-butyrolactones and congeners were synthesized and their growth inhibitory activities were assayed on rice seedlings and Avena coleoptile sections. In the latter bioassay, the inhibitory activities of the synthetic α-methylene-γ-lactones were comparable to those of heliangine and pyrethrosin, the natural inhibitors possessing α-methylene-γ-lactone moiety.     

Characterization of an antiserum to guinea pig antithrombin III (AT III). II. Stimulation of T lymphocyte proliferation

A goat antibody specific for an antigenic determinant shared between guinea pig antithrombin III (AT III) and thymocytes was shown to be mitogenic for lymph node T lymphocytes in the presence of macrophages. Although the antiserum was not mitogenic for purified populations of B lymphocytes, B lymphocytes were as efficient as T lymphocytes in absorbing the mitogenic activity of the serum. The shared antigenic determinant appeared to be carbohydrate in nature in that native and guanidine-treated AT III, but not periodate oxidized AT III, were capable of inhibiting the mitogenic activity of the serum when added continuously to the cultures. The possibility that the plasma protease inhibitor AT III or an antigenically related membrane protein are involved in the regulation of T cell activation is discussed.