Search

The ability of a hydrophilic extract prepared from edible mushroom ( Flammulina velutipes) to stabilize fresh color of bigeye tuna ( Thunnus obesus) meat was evaluated to compare it with certain other antioxidants. The fresh color shelf life of bigeye tuna meats, to which were added as 1, 3, or 5 mL of mushroom extract to 100 g of minced bigeye tuna meat, prolonged duration of ice storage by more than 2, 4, and 6 d, respectively, in comparison with the control tuna meat without mushroom extract. The addition of 5 mL of mushroom extract to 100 g of minced bigeye tuna meat was more effective than adding ascorbic acid sodium salt (500 ppm) or α-tocopherol (500 ppm) with regard to oxidation of lipid in the tuna meat. The color changes significantly correlated with lipid oxidation as well as metmyoglobin formation in the tuna meat. These results clearly show that the mushroom extract is a potential antioxidant, which has the ability to stabilize fresh color of tuna meat during ice storage. [ABSTRACT FROM AUTHOR]

The article discusses a study which evaluated the effects of chilling and hypoxia treatments on skin color of Japanese common squid Todarodes pacificus and spear squid Loligo bleekeri to prevent highly fresh squids from abnormal fading skin color with inappropriate commercial value losses. Results of chromatophores expansion measurements suggest that skin color can be maintained well after death by keeping the bodies well-oxygenated and avoiding direct contact with ice.

SUMMARY:In order to clarify the effects of habitat temperatures on crustacean myofibrillar ATPase activities, the activities were measured in the muscle of American lobster Homarus americanus and Japanese spiny lobster Panulirus japonicus. Magnesium (Mg2+)-ATPase activities of the Japanese spiny lobster in the presence and absence of calcium (Ca2+) were lower than the corresponding activities of the American lobster. The American lobster lost Ca2+ sensitivities in myofibrillar Mg2+-ATPase activities over 35°C, while the Japanese spiny lobster lost sensitivities over 40°C. Inactivation profiles in Mg2+- and Ca2+-ATPase activities showed that myofibrillar thermal stability of the American lobster was lower than that of the Japanese spiny lobster. No seasonal change in Mg2+-ATPase activity was observed in either species. These results suggest that the myofibrils of both lobster species would adapt to their habitat temperatures. [ABSTRACT FROM AUTHOR]

We studied the mechanism of eosinophilia in BALB/c-nu/ + (nu/+) and BALB/c-nu/nu (nu/nu) mice infected with Toxocara canis. Eosinophilia with two peaks on days 11 and 21 of infection was observed in infected nu/+ mice, and with a peak on day 11 in nu/nu mice. Interleukin-5 (IL-5) mRNA was expressed on day 5 of infection in the lung and spleen of nu/+ mice and in the lung of nu/nu mice, but not in the spleen of nu/nu mice. Large numbers of eosinophils and lymphocytes infiltrated the lung of both mice I week after infection. The number of larvae in the lung was the largest on day 5. Anti-IL-5 monoclonal antibody (mAb) treatment completely inhibited eosinophilia of both mice, with no change of larval distribution. Administration of anti-CD4 or anti-CD3 mAb markedly reduced the second peak of eosinophilia on day 21 of infection in nu/+ mice, and slightly reduced the first peak of eosinophilia on day 11 in both mice. Anti-CD8 mAb had no effect on the eosinophilia. These results suggest that eosinophilia in both mice is caused by IL-5, and that IL-5 is produced by cells other than CD4+ T cells, in addition to CD4+ T cells. [ABSTRACT FROM AUTHOR]

Background The skin has evolved an epithelial defence mechanism which is characterized by antimicrobial peptides that inactivate various microorganisms and exhibit stimulatory activities bridging innate and adaptive immunity. Dermcidin (DCD) is a newly isolated antimicrobial peptide produced by the eccrine sweat glands in the skin. Recently, the DCD peptides DCD-1 and DCD-1L have been shown to display in vitro microbicidal activities against bacteria and viruses. Objectives Because some skin-derived antimicrobial peptides activate keratinocytes, we investigated whether DCD-1L would also trigger keratinocyte activation. Methods Normal human keratinocytes were used in this study. The ability of DCD-1L to induce the production of cytokines/chemokines by keratinocytes was determined by enzyme-linked immunosorbent assay, and various inhibitors were used to investigate the stimulatory mechanism of DCD-1L. Mitogen-activated protein kinase (MAPK) phosphorylation and NF-κB activation were analysed by Western blotting. Results DCD-1L stimulated keratinocytes to generate cytokines and chemokines including tumour necrosis factor-α, interleukin-8 (CXCL8), interferon-inducible protein 10 (CXCL10) and macrophage inflammatory protein-3α (CCL20). To determine the molecular mechanism involved, we showed that DCD-1L-mediated cytokine/chemokine production was controlled by both G-protein and MAPK pathways, as evidenced by the inhibitory effects of pertussis toxin and specific inhibitors for p38 and ERK, but not for JNK, on DCD-1L-induced keratinocyte activation. Furthermore, we confirmed that DCD-1L could induce phosphorylation of p38 and ERK, and noticeably upregulated NF-κB activation. Conclusions Taken together, the new activity of DCD-1L to stimulate the production of cytokines/chemokines by keratinocytes provides novel evidence for the implication of DCD, beyond its microbicidal ability, in skin immunity. [ABSTRACT FROM AUTHOR]

Background Psoriasis is characterized by epidermal infiltration of neutrophils that destroy invading microorganisms via a potent antimicrobial arsenal of oxidants and antimicrobial agents. In contrast to atopic dermatitis, psoriasis exhibits low levels of skin infections due to the presence of antimicrobial agents, including cathelicidin LL-37. LL-37 kills a broad spectrum of microbes, and activates neutrophil chemotaxis. Objective To determine whether or not LL-37 could regulate additional neutrophil functions such as production of cytokines/chemokines, reactive oxygen species and release of neutrophil antimicrobial peptides. Methods Human peripheral blood neutrophils were used in this study. The production of interleukin (IL)-8 and release of α-defensins were analysed by enzyme-linked immunosorbent assay, and real-time polymerase chain reaction (PCR) was used to quantify α-defensin gene expression. Phosphorylation of mitogen-activated protein kinase (MAPK) was determined by Western blotting. The generation of reactive oxygen species was examined using flow cytometry, and intracellular Ca2+ mobilization was measured using a calcium assay kit. Results LL-37 enhanced the production of IL-8 under the control of MAPK p38 and extracellular signal regulated kinase (ERK), as evidenced by the inhibitory effects of p38 and ERK1/2 inhibitors on LL-37-mediated IL-8 production. Furthermore, LL-37 induced phosphorylation of p38 and ERK. We also revealed that LL-37 stimulated the generation of reactive oxygen species dose- and time-dependently, most probably via NADPH oxidase activation and intracellular Ca2+ mobilization. Finally, LL-37 induced both mRNA expression and protein release of α-defensins, known as human neutrophil peptide 1–3. Conclusion Taken together, we suggest that in addition to its microbicidal properties, LL-37 may contribute to innate immunity by enhancing neutrophil host defence functions at inflammation and/or infection sites. [ABSTRACT FROM AUTHOR]

It is well known that ayu ( Plecoglossus altivelis) die after spawning. Their lifespan is known to be only 1 year; possibly one contributing factor to post-spawning mortality in ayu is the enhanced oxidative stress, probably inducing DNA damage and subsequent DNA repair systems (i.e. phosphorylated p53), which in turn may cause apoptosis and a shortened lifespan. To examine this possibility, we surveyed p53 and its phosphorylation state, oxidative DNA damage by measuring the levels of 8-hydroxy-2′-deoxyguanosine, and the induction of apoptosis by measuring levels of caspase-3, -9/6 in the brain at different stages. Accumulation of oxidative stress in brain DNA was accompanied by caspase-3, -9/6, and stimulates p53 through the phosphorylation of this p53 (specifically residue Ser 15) in ayu brain with aging. [ABSTRACT FROM AUTHOR]

Seafood allergy is a common and major cause of food allergy in adults. In recent years, seafood allergy has become a serious problem with the increase of seafood consumption. To develop a rapid allergen detection method based on the affinity of antigen-antibody interaction, fish major allergen, parvalbumin, was used for kinetic analysis by a surface plasmon resonance (SPR) biosensor. Anti-parvalbumin murine monoclonal antibody (MAb) EG8 was immobilized onto a carboxymethyl dextran (CMD) surface. By the injection of various concentrations of purified carp parvalbumin (CPa), a standard curve and the affinity constants (K and k) for the MAb EG8-CPa model system were determined. In addition, kinetic data were also obtained by the injection of serial dilutions of extracts from seafood products: sardine fish cake ( tsumire) and dried skipjack tuna (katsuonut). Sardine tsumire and katsuonut contained 0.11 mg/kg and 0.39 mg/kg parvalbumins, respectively, where affinity constants K and k were almost similar among paralbumins from different sources. In the SPR system, the allergen can be detected only for 5 min according to the allergen-MAb binding interaction. Consequently, by the use of a SPR biosensor, kinetic analysis based on the allergen specific MAb would be a rapid and powerful tool for allergen detection and quantification. [ABSTRACT FROM AUTHOR]

The viscosity of (Fe1-XNiX)83B17 (X=0, 0.25, 0.5, 0.75 and 1.0 atomic fractions) and (Fe0.25Ni0.75)78Al5B17 liquid alloys has been measured by an oscillating crucible method in the temperature range from melting temperature (Tm) up to about 1400 °C. In the (Fe1-XNiX)83B17 liquid alloys, the viscosity decreased with increasing Ni content up to about X=0.5 and then increased to a maximum value at X=0.75. The activation energy for viscous flow decreased to the minimum value of about 37 kJ/mol at X=0.75. This composition is well consistent with those of the Fe–Ni–B alloys having a large glass-forming ability. When Al is added in the (Fe0.25Ni0.75)83B17 alloy, the liquid viscosity further increased while the activation energy for viscous flow decreased to about 33 kJ/mol. [Copyright &y& Elsevier]

Sweet smelt Plecoglossus altivelis (Temminck et Schlegel) were fed with diets containing 0.01% or 1% α-tocopherol for 14 weeks to investigate whether an excess dose of α-tocopherol effected several biological functions of fish. The different concentrations of α-tocopherol in fish diets did not affect fish body weight or length, or fatty acid composition of fish blood. However, the accumulation of hydroperoxides in plasma and erythrocytes of fish fed 1% α-tocopherol was significantly higher than those of fish fed 0.01% α-tocopherol. The osmotic fragility of fish erythrocytes showed the opposite result. These results suggest that an excess dose of dietary α-tocopherol promoted lipid peroxidation, increasing the accumulation of hydroperoxides in fish blood but reducing the erythrocyte osmotic fragility. [ABSTRACT FROM AUTHOR]

Background and purpose:We have recently reported that phytosteryl ferulates isolated from rice bran inhibit nuclear factor-κB (NF-κB) activity in macrophages. In the present study, we investigated the effect of γ-oryzanol (γ-ORZ), a mixture of phytosteryl ferulates, cycloartenyl ferulate (CAF), one of the components of γ-ORZ, and ferulic acid (FA), a possible metabolite of γ-ORZ in vivo, on a model of colitis in mice.Experimental approach:We induced colitis with dextran sulphate sodium (DSS) in mice and monitored disease activity index (DAI), histopathology score, tissue myeloperoxidase (MPO) activity, mRNA expressions of cytokines and COX-2, colon length, antioxidant potency and NF-κB activity in colitis tissue.Key results:Both DAI and histopathology score revealed that DSS induced a severe mucosal colitis, with a marked increase in the thickness of the muscle layer, distortion and loss of crypts, depletion of goblet cells and infiltration of macrophages, granulocytes and lymphocytes. MPO activity, pro-inflammatory cytokines and COX-2 levels, NF-κB p65 nuclear translocation and inhibitory protein of nuclear factor-κB-α degradation levels were significantly increased in DSS-induced colitis tissues. γ-ORZ (50 mg kg−1 day−1 p.o.) markedly inhibited these inflammatory reactions and CAF had a similar potency. In vitro assay demonstrated that γ-ORZ and CAF had strong antioxidant effects comparable to those of α-tocopherol.Conclusions and implications:Phytosteryl ferulates could be new potential therapeutic and/or preventive agents for gastrointestinal inflammatory diseases. Their anti-inflammatory effect could be mediated by inhibition of NF-κB activity, which was at least partly due to the antioxidant effect of the FA moiety in the structure of phytosteryl ferulates.British Journal of Pharmacology (2008) 154, 812–824; doi:10.1038/bjp.2008.137; published online 21 April 2008 [ABSTRACT FROM AUTHOR]

Bee-collected pollen (bee pollen [BP]) has been used as a folk medicine for centuries against various diseases, including allergy. There is no study elucidating how BP exerts such an anti-allergic effect. Since mast cells play a central role in the pathogenesis of various allergic diseases, we investigated the effect of BP on mast cell activation elicited by the Fc immunoglobulin E (IgE) receptor (Fc epsilon RI)-mediated pathways. The in vivo effect of orally administered BP on cutaneous mast cell activation was examined by passive cutaneous anaphylaxis reaction. In vitro mast cell degranulation and IgE binding to mast cells and the status of protein tyrosine phosphorylation were examined using bone marrow-derived mast cells. Daily oral administration of BP to mice significantly reduced the cutaneous mast cell activation elicited by IgE and specific antigens. BP also reduced in vitro mast cell degranulation and tumor necrosis factor-alpha production by inhibiting IgE binding to Fc epsilon RI on mast cells. The inhibitory effect of BP on mast cell degranulation by preventing IgE binding was confirmed by the reduced levels of protein tyrosine phosphorylation, which occurred as downstream events in activated mast cells via Fc epsilon RI. These results first revealed that the anti-allergic action of BP was exerted by inhibiting the Fc epsilon RI-mediated activation of mast cells, which plays important roles, not only in the early phase, but also in the late phase of allergic reactions. [ABSTRACT FROM AUTHOR]

Background Atopic dermatitis is a chronic, relapsing inflammatory disorder characterized by pruritic and eczematous skin lesions. Transforming growth factor (TGF)-β1 has been implicated in the suppression of inflammatory responses. Objective The purpose of this study is to determine whether TGF-β1 suppresses skin lesions in a mouse model of atopic dermatitis. Methods We used the NC/Nga strain of mice as an in vivo model of atopic dermatitis. The effects of exogenous TGF-β1 on atopic dermatitis-like skin lesions in NC/Nga mice were evaluated clinically, histologically and immunologically. Results Subcutaneous injection of recombinant TGF-β1 macroscopically suppressed eczematous skin lesions in NC/Nga mice associated with reduced serum immunoglobulin E (IgE) levels. Histological analysis showed that TGF-β1 significantly inhibited the infiltration of inflammatory cells such as mast cells and eosinophils into the skin of NC/Nga mice. Spontaneous interferon (IFN)-γ production from splenocytes of NC/Nga mice was down-regulated by the treatment with TGF-β1 and neutralizing antibody against IFN-γ inhibited skin lesions in NC/Nga mice. The inhibitory effect of TGF-β1 on the skin lesions lasted at least 1 week after cessation of the treatment. Conclusion These findings indicate that TGF-β1 suppressed atopic dermatitis-like skin lesions in NC/Nga mice at least in part through down-regulation of IFN-γ. These results suggest that TGF-β1 may have a therapeutic potential for atopic dermatitis. [ABSTRACT FROM AUTHOR]

Examines tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) expression in atopic dermatitis. Observance of expression of TRAIL in skin samples; Technique used to diagnose atopic dermatitis; Observance of TRAIL-positive mononuclear cells in skin lesions of psoriasis.