Development of a large-sized dredge ‘Beni-Zuwai Type 1’ for deep sea bottom sampling

A large-sized dredge ‘Beni-Zuwai Type 1 (BZ-1)’ was designed for sampling mainly in sea bottom deeper than 1000m. The width and height of the BZ-1 were 8.2 and 1m, respectively. Its weight was 1150kg (890kg in water). Sea trial was conducted at a depth of 500-2000m. The BZ-1 was towed at the speed of 2 knots for 15minutes with a single warp which was shorter than that required for an otter trawl. For example, for trawling at 2000m depth the warp length and the total operating time was 2720m and about 2 hours, respectively. The catch ability of the BZ-1 was compared with that of an otter trawl. The BZ-1 collected large individuals of many species as well as the otter trawl, and small individuals which were not caught by the otter trawl. Catch number and weight per swept area of the BZ-1 were more than those of the otter trawl. From these results, the BZ-1 was an effective sampling gear in deep sea.水深1000m を超える深海においても，オッタートロールよりも短いワープ長で安定した曳網ができ，分布調査として十分な採集量を確保できる生物用採集器具を目指し，桁網を開発した。実際の調査に用いたところ，桁網は深海でも安定した曳網が可能であった。また，大型個体に関してはトロールと同等の採集能力を持ち，さらに小型個体も多く採集できることから，生活史を通した分布，生態調査に使用可能であると考えた。departmental bulletin pape

Identity of the elusive IgM Fc receptor (FcμR) in humans

Although Fc receptors (FcRs) for switched immunoglobulin (Ig) isotypes have been extensively characterized, FcR for IgM (FcμR) has defied identification. By retroviral expression and functional cloning, we have identified a complementary DNA (cDNA) encoding a bona fide FcμR in human B-lineage cDNA libraries. FcμR is defined as a transmembrane sialoglycoprotein of ∼60 kD, which contains an extracellular Ig-like domain homologous to two other IgM-binding receptors (polymeric Ig receptor and Fcα/μR) but exhibits an exclusive Fcμ-binding specificity. The cytoplasmic tail of FcμR contains conserved Ser and Tyr residues, but none of the Tyr residues match the immunoreceptor tyrosine-based activation, inhibitory, or switch motifs. Unlike other FcRs, the major cell types expressing FcμR are adaptive immune cells, including B and T lymphocytes. After antigen-receptor ligation or phorbol myristate acetate stimulation, FcμR expression was up-regulated on B cells but was down-modulated on T cells, suggesting differential regulation of FcμR expression during B and T cell activation. Although this receptor was initially designated as Fas apoptotic inhibitory molecule 3, or TOSO, our results indicate that FcμR per se has no inhibitory activity in Fas-mediated apoptosis and that such inhibition is only achieved when anti-Fas antibody of an IgM but not IgG isotype is used for inducing apoptosis

Inverse Correlation of Serum Leptin Levels and Platelet Counts in Patients with Menstruation-Associated Cyclic Thrombocytopenia.

Abstract The platelet counts of patients with cyclic thrombocytopenia (CT) are occasionally associated with menstruation, yet its mechanism is unknown. Leptin has been shown to stimulate the production of Th1 cytokines (Nature1998;27:897), which dominate in idiopathic thrombocytopenic purpura (ITP) (Blood2004;103:2645), and a recent study showed that the serum levels of leptin, whose secretion is menstruation-related, are high in ITP (Eur J Haemataol2004;72:348). Here we examined the serial serum levels of leptin in 3 patients with CT by radioimmunoassay. Case 1 is a 29-year-old woman with ITP who had repeated spontaneous abortion at an early phase of pregnancy accompanied by transient severe thrombocytopenia. Case 2 is a 37-year-old woman diagnosed as having ITP and autoimmune neutropenia during her second pregnancy, whose platelet counts became cyclic after delivery. Case 3 is a 28-year-old woman, who developed CT after splenectomy performed for refractory ITP two years before. The serum leptin levels were inversely correlated with the platelet counts in case 1 (r = −0.573, P =0.047, n=13) and case 3 ( r = −0.771, P =0.029, n=9), and a similar inverse correlation was observed in case 2, although the correlation was statistically not significant (r = −0.524, P=0.116, n=10). These findings suggest that leptin might play an important role in the pathogenesis of menstruation-associated CT. Further interventional studies to give leptin and its antagonists to the patients with CT, as well as to ITP model mice, will be warranted.</jats:p