Maturation-associated changes in the non-specific immune response against Flavobacterium psychrophilum in Ayu Plecoglossus altivelis

In this study, we investigated maturation-associated changes in non-specific immune responses of ayu against Flavobacterium psychrophilum. The gonadosomatic index was minimum on 16 June, began to increase on 17 July, and reached the maximum value during August. The highest phagocytic rate (16.3%) was observed on 16 June, which decreased significantly to 5.6% on 26 August. The number of viable bacteria after the serum treatment was highest during August, suggesting that bactericidal activity of the serum decreased along with the sexual maturation. Gene expression levels of interleukin-8, and tumor necrosis factor-α in the spleen did not change significantly during this period, whereas the level of suppressor of cytokine signaling (SOCS)3 was significantly higher on 26 August than that on 16 July (p < 0.05). These results suggest that phagocytic activity of trunk kidney leukocytes and serum bactericidal activity against F. psychrophilum decreased with sexual maturation, and that SOCS3 may be related to the decrease in non-specific immune activity in ayu

Passive immunisation of goldfish with the serum of those surviving a Cyprinid herpesvirus 2 infection after high temperature water treatment

Herpesviral haematopoietic necrosis of goldfish caused by cyprinid herpesvirus 2 (CyHV-2) can be controlled by raising water temperature to a virus non-permissive temperature of 34℃. Consequently, the goldfish can survive and acquire resistance to the disease; the underlying mechanism of acquired resistance, however, remains unclear. In this study, we investigated serological changes in the surviving goldfish, with a focus on their humoral immunity, and examined whether sera of the surviving goldfish conferred passive immunity to naive goldfish. Levels of the anti-CyHV-2 antibodies in 8 of the 9 survivors measured via ELISA were higher than those in control fish. Neutralising antibodies were detected in the sera of 2 survivors, but no direct correlation was observed between ELISA optical density value and neutralising antibody titer. Passive immunisation tests showed that recipients injected with the serum containing neutralising antibodies showed higher survival rates than the control group. The sera from 6 other survivors showed no effect on the recipient\u27s mortality regardless of anti-CyHV-2 antibody levels. These results suggest that neutralising antibodies can contribute to acquired immunity in survivors, and other protective factors, including cell-mediated immunity, may work in the survivors that show no detectable neutralising antibodies

Characterization of Aquimarina hainanensis isolated from diseased mud crab Scylla serrata larvae in a hatchery

Mass mortality due to necrosis signs occurred in hatchery‐reared zoea stage larvae of the mud crab Scylla serrata in Okinawa, Japan, and a causative bacterium was isolated. In this study, we identified and characterized the bacterium by genome analysis, biochemical properties and pathogenicity. The bacterium was a Gram‐negative, non‐motile, long rod, forming yellow colonies on a marine agar plate. It grew at 20–33°C (not at 37°C) and degraded chitin and gelatin. Phylogenetic analysis of the 16S rRNA gene sequence identified the bacterium as Aquimarina hainanensis. Genome sequence data obtained from Illumina MiSeq generated 29 contigs with 3.56 Mbp in total length and a G + C content of 32.5%. The predicted 16 chitinase genes, as putative virulence factors, had certain homologies with those of genus Aquimarina. Experimental infection with the bacterium conducted on larvae of four crustacean species, brine shrimp Artemia franciscana, freshwater shrimp Caridina multidentata, swimming crab Portunus trituberculatus and mud crab S. serrata, revealed that this bacterium was highly virulent to these species. The present study suggests that the bacterium caused mass mortality in mud crab seed production was A. hainanensis and can be widely pathogenic to crustaceans

A Case of Benign Schwannoma of the Transverse Colon with Granulation Tissue

Schwannomas occurring in the gastrointestinal tract are rare, and among them, schwannomas of the large intestine are extremely rare. In this paper, we report a case of a macroscopically atypical schwannoma of the transverse colon. The case is a female aged 67. Stool occult blood test was positive, and colonoscopy revealed a protruded lesion resembling a type 1 carcinoma measuring 4 cm with a reddish and uneven surface on the transverse colon. The surface was smooth and lobulated in observation with indigo carmine spray, and granulation tissue was revealed by biopsies. CT of the abdomen showed an irregular mass, and clinical examinations could not rule out malignancy. Therefore, partial transverse colectomy with peripheral lymph node dissection was performed. Histologically, proliferation of spindle cells was observed originating from the muscularis propria, and most of the upper part of the lesion was replaced by granulation tissue. In immunohistochemical staining, S-100 protein and NSE were positive while KIT, CD34, desmin and smooth muscle actin were negative, and the tumor was therefore diagnosed to be a schwannoma. In addition, since the MIB-1 labeling index was low and virtually no mitosis was observed, it was diagnosed as benign tumor

High-Field Magnetization Process in R_2Fe_<14>B and R_2Fe_<17>N_x Compounds(Magnetism)

General method of calculating magnetization curves in ternary system R-Fe-X is given, where R is a rare-earth element and X a non-magnetic element such as B. In this method the ferromagnetism of Fe sublattice is treated phenomenologically, while exchange and crystal field acting on R ions are exactly taken into account. Experimental data on R_2Fe_B and R_2Fe_N_x systems are summarized in comparison with the calculated curves. Detailed analyses have shown that in the light R compounds the inter-multiplet mixing via the R-Fe exchange interaction is important especially for the first-order magnetization process, which often occurs at low temperatures with external fields along the hard direction

Local Resection by Combined Laparoendoscopic Surgery for Duodenal Gastrointestinal Stromal Tumor

Combined laparoendoscopic surgery is a novel surgical method which consists of both endoscopic surgery from inside the gastrointestinal tract and laparoscopic surgery from the outside. We report a case of duodenal GIST, in which combined laparoendoscopic local resection was attempted. The lesion was resected endoscopically using endoscopic submucosal dissection technique under laparoscopic assistance. Laparoscope was used for originating the orientation of the tumor, intra-operative EUS, and monitoring serosal injury from the peritoneal cavity. Postoperative hemorrhage occurred; however, precise orientation of the lesion helped us to manage the patient with minimal invasive reoperation. And thus, the bowel integrity was completely preserved, by avoiding segmental duodenal resection and pancreaticoduodenectomy. This novel, less invasive surgical procedure may become an attractive option for the lesions originating in the anatomically challenging portion of the GI tract for endoscopic or laparoscopic surgery alone

A Novel Antigen-Sampling Cell in the Teleost Gill Epithelium With the Potential for Direct Antigen Presentation in Mucosal Tissue

In mammals, M cells can take up antigens through mucosal surfaces of the gut and the respiratory tract. Since M cells are deficient of lysosomes and phagosomes, the antigens are directly delivered to the mucosa-associated lymphoid tissue (MALT) without degradation. In teleost fish, the entire body surface (gills, skin, and intestinal system) is covered by mucus; however, specific antigen-sampling cells have not yet been identified in their mucosal tissues. Here, we show that two phenotypes of antigen-sampling cells take up antigens through epithelial surfaces of the rainbow trout gill. One phenotype of antigen-sampling cells has features of monocyte/macrophage/dendritic cell-type cells; they have large vacuoles in the cytoplasm and express PTPRC (CD45), CD83, IL-1β, and IL-12p40b. The second phenotype exhibits similar characteristics to mammalian M cells; the corresponding cells bind the lectin UEA-1 but not WGA and show expression of M cell marker gene Anxa5. In contrast to mammalian M cells, teleost M-type cells were found to exhibit small vacuoles in their cytoplasm and to express almost all genes related to the “phagosome”, “lysosome,” and “antigen processing and presentation” pathways. Furthermore, MHC class II was constitutively expressed on a fraction of M-type cells, and this expression was significantly increased after antigen uptake, suggesting that the MHC class II is inducible by antigen stimulation. Here, we suggest that teleost M-type cells play a role in the phylogenetically primitive teleost immune system, similar to bona-fide M cells. In addition, the presence of MHC class II expression suggests an additional role in antigen presentation in the gills, which are an organ with high T cell abundance, especially in interbranchial lymphoid tissue. The present results suggest an unconventional antigen presentation mechanism in the primitive mucosal immune system of teleosts, which generally lack highly organized lymphoid tissues. Moreover, the results of this work may be valuable for the development of mucosal vaccines that specifically target M-type cells; mucosal vaccines significantly reduce working costs and the stress that is usually induced by vaccination via injection of individual fish

Inhibition of EP4 Signaling Attenuates Aortic Aneurysm Formation

BACKGROUND: Aortic aneurysm is a common but life-threatening disease among the elderly, for which no effective medical therapy is currently available. Activation of prostaglandin E(2) (PGE(2)) is known to increase the expression of matrix metalloproteinase (MMP) and the release of inflammatory cytokines, and may thus exacerbate abdominal aortic aneurysm (AAA) formation. We hypothesized that selective blocking of PGE(2), in particular, EP4 prostanoid receptor signaling, would attenuate the development of AAA. METHODS AND FINDINGS: Immunohistochemical analysis of human AAA tissues demonstrated that EP4 expression was greater in AAA areas than that in non-diseased areas. Interestingly, EP4 expression was proportional to the degree of elastic fiber degradation. In cultured human aortic smooth muscle cells (ASMCs), PGE(2) stimulation increased EP4 protein expression (1.4 ± 0.08-fold), and EP4 stimulation with ONO-AE1-329 increased MMP-2 activity and interleukin-6 (IL-6) production (1.4 ± 0.03- and 1.7 ± 0.14-fold, respectively, P<0.05). Accordingly, we examined the effect of EP4 inhibition in an ApoE(-/-) mouse model of AAA infused with angiotensin II. Oral administration of ONO-AE3-208 (0.01-0.5 mg/kg/day), an EP4 antagonist, for 4 weeks significantly decreased the formation of AAA (45-87% reduction, P<0.05). Similarly, EP4(+/-)/ApoE(-/-) mice exhibited significantly less AAA formation than EP4(+/+)/ApoE(-/-) mice (76% reduction, P<0.01). AAA formation induced by periaortic CaCl(2) application was also reduced in EP4(+/-) mice compared with wild-type mice (73% reduction, P<0.001). Furthermore, in human AAA tissue organ cultures containing SMCs and macrophages, doses of the EP4 antagonist at 10-100 nM decreased MMP-2 activation and IL-6 production (0.6 ± 0.06- and 0.7 ± 0.06-fold, respectively, P<0.05) without increasing MMP-9 activity or MCP-1 secretion. Thus, either pharmacological or genetic EP4 inhibition attenuated AAA formation in multiple mouse and human models by lowering MMP activity and cytokine release. CONCLUSION: An EP4 antagonist that prevents the activation of MMP and thereby inhibits the degradation of aortic elastic fiber may serve as a new strategy for medical treatment of AAA