Modulating effect of acorn barnacle C-type lectins on the crystallization of calcium carbonate

ABSTRACT:   The modulating effect of invertebrate C-type lectins on the crystallization of calcium carbonate was investigated. The multiple C-type lectins, named BRA-1, -2 and -3, isolated from the acorn barnacle Megabalanus rosa inhibited the nucleation and growth of calcium carbonate crystals. Among BRA, BRA-2 most efficiently inhibited the crystal nucleation of aragonite and calcite at the concentrations of > 3.3 and > 26 μg/mL, respectively. The inhibitory activities of BRA were enhanced by the addition of various biomolecules such as D-glucosamine, D-galactosamine, chitosan oligosaccharides, L-arginine and L-aspartic acid. Although the crystals of aragonite and calcite were formed in the presence of lower concentrations of BRA, the shape and size of the crystals were changed. These results further indicate the participation of the lectins in biomineralization.     

Antioxidant activity of flavonoids isolated from young green barley leaves toward biological lipid samples

Natural plant flavonoids, saponarin/lutonarin=4.5/1, isolated from young green barley leaves were examined for their antioxidant activity using cod liver oil, omega-3 fatty acids, phospholipids, and blood plasma. The saponarin/lutonarin (S/L) mixture inhibited malonaldehyde (MA) formation from cod liver oil by 76.47+/-0.11% at a level of 1 micromol and 85.88+/-0.12% at a level of 8 micromol. The S/L mixture inhibited MA formation from the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by 45.60+/-1.08 and 69.24+/-0.24%, respectively, at a level of 8 micromol. The S/L mixture inhibited MA formation from the phospholipids lecithin I and II by 43.08+/-0.72 and 69.16+/-2.92%, respectively, at a level of 8 micromol. It also inhibited MA formation from blood plasma by 62.20+/-0.11% at a level of 8 micromol. The antioxidant activities obtained from the S/L mixture were comparable to those obtained from alpha-tocopherol and butylated hydroxy toluene (BHT) in all lipids tested.     

Comparative study of the plasma globulin level, CD21(-) B-cell counts and FOXP3 mRNA expression level in CD4(+) T-cells for different clinical stages of feline immunodeficiency virus infected cats

Feline immunodeficiency virus (FIV) infection leads to hypergammaglobulinemia through mechanisms that remain poorly understood. We investigated changes in plasma globulin level, B cells, and T cells with progression of the clinical stage of FIV-infected cats. We classified FIV-infected cats into the stage of Asymptomatic carrier (AC) and AIDS-related complex (ARC) based on the clinical symptoms, and measured the plasma globulin level, the CD4(+) T-cell counts, and analyzed surface markers of B cells. We investigated the relationship between the plasma globulin level and regulatory T cells (Tregs) using the Forkhead box P3 (FOXP3) mRNA expression level. In FIV-infected cats, the plasma globulin level and the surface immunoglobulin (sIg)(+) CD21(-) B-cell counts were increased, whereas the CD4(+) T-cell counts were decreased compared with specific-pathogen free (SPF) cats. The mRNA expression of Blimp-1 (master gene of plasma cells) was increased in peripheral blood, and the FOXP3 mRNA expression level was decreased in CD4(+) T-cells. These immunological changes were marked in the ARC stage. These data indicate that the decrease of Tregs and the increase of plasma cells lead to hypergammaglobulinemia.     

鸬鹚幽门区内分泌细胞的免疫组织化学研究

用免疫组织化学方法在食鱼的鸬鹚幽门区中发现了胃泌素、生长抑素、5-羟色胺、禽胰多肽和神经降压素细胞等五种内分泌细胞。其密度和种类大于食谷性和杂食性鸟类,且幽门区的长度为这些鸟类的3—4倍。这些特点可能是食肉性鸟类适应其生态习性的一种选择。     

Simple and rapid determination of thiabendazole,imazalil, and o-phenylphenol in citrus fruit using flow-injection electrospray ionization tandem mass spectrometry

A simple and rapid analytical method for thiabendazole (TBZ), imazalil (IMA), and o-phenylphenol (OPP) in citrus fruit has been developed by using flow-injection electrospray ionization tandem mass spectrometry for the first time. The method involves the combined use of stable isotopically labeled internal standards (thiabendazole-(13)C(6), imazalil-d(5), and p-phenylphenol-d(9)) and a multiple reaction monitoring technique. The average recoveries for the fungicides at the tolerance levels (TBZ and OPP, 10 mg/kg; IMA, 5 mg/kg) ranged from 77 to 101%, with the coefficients of variation (CVs) ranging from 0.7 to 4.2% (n = 5). At half the tolerance levels (TBZ and OPP, 5 mg/kg; IMA, 2.5 mg/kg), the average recoveries ranged from 62 to 112%, with the CVs ranging from 0.7 to 8.4% (n = 5). The CVs of the average recoveries, obtained from lemon samples fortified with three fungicides at the tolerance levels, obtained on three different days over two weeks, ranged within 2%. The analysis time, including sample preparation and determination, is only 15 min.     

Nitrogen transport and transformation in packed soil columns from paddy fields

Our understanding of nitrogen transformation in paddy fields or wetlands is limited due to the complex interactions between soil, water, and biomass. Therefore, we studied transformation patterns resulting from the oxic level in the soil, and studied saturated (anoxic) and unsaturated (oxic) flow conditions. We present a model designed to predict concentrations of nitrate and ammonium at several soil depths resulting from the processes of nitrification, denitrification, and ammonification. Model equations were obtained that describe NO₃-N and NH₄-N concentrations in terms of position, rate constant, and average flow velocity. Although many parameters were included in the model equations, some were determined from the literature and others were derived from experiments. A sensitivity analysis of the rate coefficients for NO₃-N and NH₄-N revealed that they are extremely sensitive to denitrification and ammonification respectively. Experimental results show that there were large differences in the transformations of NO₃-N and NH₄-N, the water pressure distributions, and the oxygen reduction potentials (ORP) between saturated and unsaturated pore water flow conditions. The performance of the model for sequential transformations during the transport of NO₃-N is well documented under both saturated and unsaturated flow conditions.     

Stimulatory effect of cold acclimation on skeletal muscle branched-chain α-keto acid dehydrogenase in rats

The effects of cold-acclimation (3 weeks at 4°C) on the actual activities of branched-chain α-keto acid dehydrogenase (BCKDH) and pyruvate dehydrogenase (PDH) complexes in the skeletal muscle and liver of normal 6-week-old rats were studied. The activities of BCKDH and PDH complexes were assayed using [1–¹⁴C] α-ketoisocaproate and [1-¹⁴C]pyruvate, respectively. Cold-acclimation markedly stimulated the activity of BCKDH, and slightly but significantly increased the activities of PDH and citrate synthase (CS) in the skeletal muscle, but did not alter PDH, BCKDH or CS activities in the liver. The increase in muscle BCKDH activity (control rats, 1.45 ± 0.54 mU/g wet wt; cold-acclimated rats, 2.54 ± 0.50 mU/g wet wt; 75% increase: P  = 0.001) was much greater than the increases in PDH activity (84 ± 16 mU/g wet wt and 111 ± 25 mU/g wet wt; 32% increase: P  = 0.020) or CS activities (27 ± 3 μmol/min per g wet wt and 31 ± 2 μmol/min per g wet wt; 14% increase: P  = 0.046). These results suggest that, unlike PDH, BCKDH is not directly associated with the mitochondrial oxidative activity of the skeletal muscle of cold-acclimated rats. This study provides the first evidence that BCKDH in skeletal muscle responds selectively to cold-acclimation.     

Pipecolic acid in rumen fluid and plasma in ruminant animals

A survey was conducted to investigate the physiological levels of pipecolic acid (Pip) in rumen fluid and plasma of ruminants such as goats and cattle in the presence or absence of rumen protozoa. The concentration of Pip was determined using HPLC. Basal Pip levels in the rumen fluid and plasma of normal faunated animals were 21 ± 8 and 2.3 ± 1.3 µM, respectively, and levels increased 1–2 h after feeding. The Pip levels in the rumen fluid and plasma of faunated goats and cattle were significantly higher than those of defaunated goats and unfaunated cattle. A small amount of Pip was also found in the rumen fluids of the defaunated and unfaunated animals; this appeared to be derived from feeds such as hay cube and corn silage. The results obtained in the present study suggest that a significant amount of rumen‐produced Pip is likely to be absorbed into the plasma of the host animals and that rumen protozoa significantly enhance the concentration of Pip in the rumen fluid and plasma of ruminant animals.     

Effect of supplementation of soy sauce oil and Ca salts of fatty acids on rumen fermentation,milk production and conjugated linoleic acid in milk of dairy cows

Eight cows were used to evaluate the effects of supplementation of soy sauce oil (SO) or Ca salts of fatty acids (FA) on rumen fermentation and milk production. The control diet (CO) consisted mainly of hay, corn silage and a concentrate. In the experimental diets, 400 g/day per cow of SO or FA (soybean oil and rapeseed oil) was supplemented to the CO diet. Experimental period for the three treatments was 14 days, and milk samples were taken during the last 2 days and rumen sample was taken on the last day. Dry matter intake was not affected by the treatments. The number of rumen protozoa at 0 h increased by SO and FA diets. Total volatile fatty acids at 2 h after feeding of SO diet was decreased compared to CO. The milk composition yield did not differ among treatments, although the percentages of fat and protein were decreased by SO and FA diets. The proportions of C8–C16 fatty acids in milk fat decreased, and those of C18 increased by SO and FA diets. The proportion of cis‐9, trans‐11 conjugated linoleic acid in milk fat by SO and FA diets increased by 120% and 135%, respectively. In spite of the slight suppression of rumen fermentation by SO diet, negative effects on feed intake and milk production were not detected.