Studies on interactions between aluminum compounds and cellulosic fibers in water by means of27Al-NMR

Interactions between pulp fibers and aluminum compounds in pulp suspensions were studied using fibrous cellulose (FC) and fibrous carboxymethylcellulose (FCMC) powders as models of pulp fibers by X-ray fluorescence analysis and²⁷Al nuclear magnetic resonance. When deionized water was used at pH 4–5, water-soluble cationic aluminum species (Al³⁺, aluminum oligomer, and polyaluminum species) were adsorbed on the solid FCMC, forming carboxylic acid aluminum salts by cation exchange. The formation of these nondissociated pulp-COOAl type structures in paper sheets may contribute to some decreases in hydrophilic property. On the other hand, the water-soluble cationic aluminum species had nearly no interactions with hydroxyl groups of solid cellulose in the suspensions at pH 4–5. When tap water was used at pH 5–7, some aluminum components were retained on not only FCMC but also the FC sample. Probably, water-insoluble Al(OH)₃ flocs are formed in the suspensions at pH 5–7 and retained on the FC sample by simple filtration effect. Therefore, two mechanisms of the aluminum retention (i.e., electrostatic interactions and a simple filtration effect) may exist between pulp fibers and aluminum components in the practical papermaking process.This research was presented in part at the 5th annual meeting of the Japan Cellulose Society, Kyoto, July 1998     

Effects of bisphenol-A on the growth of comb and testes of male chicken

Bisphenol-A (BPA) has been reported to have some xenoestrogenic effects on the reproductive system of male animals. In this study, we examined the growth of combs and testes of the male chickens exposed to BPA. White leghorn male chicks were administered 200 mg BPA orally every week from 2 wk of age. The combs and testes were examined at 16 wk of age. The body growth showed no significant difference between BPA-administered and control birds. However, the weight of the combs and testes were lower in the BPA-treated birds. Histologically, testes of the control birds were well matured; the seminiferous tubuli were filled with sperm. In contrast, the testes of most of the BPA-treated birds showed an immature appearance with smaller seminiferous tubuli and limited spermatogenesis. These findings suggest that the xenoestrogenic property of BPA might disturb the growth of the comb and testes of male chickens by a possible endocrine disrupting mechanism.     

母马生长激素细胞和催乳激素细胞的形态计测学研究

利用免疫组织化学和形态计测学的方法 ,观察了 1 8匹成熟雌性蒙古马的脑垂体前叶生长激素细胞和催乳激素细胞的数量和面积 ,同时利用放射免疫分析方法检测了这两种激素的血浆水平。结果表明 ,每个马脑垂体前叶中 ,生长激素细胞的平均数量为 6 .42× 1 8,每个细胞的平均面积为 82 .40μm2 ;催乳激素细胞的平均数量为 6 .0 7× 1 0 8,每个细胞的平均面积为 47.31μm2 。生长激素的血浆含量平均为 2 .84ng/ m L,但个体差异较大 ,变异系数高达 78.5 % ,催乳激素的血浆含量平均为 7.2 6 ng/ m L。本研究结果揭示 :母马脑垂体生长激素细胞和催乳激素细胞的数量和面积并不是决定母马这两种激素血中浓度的唯一重要因素 ;生长激素血中浓度上的个体差异 ,可能与其搏动性分泌形式有关     

Influence of dietary phosphorus level on growth performance in chicks given corn-soybean diet supplemented with amylase and acid protease

Two experiments were conducted to determine if dietary amylase and acid protease supplementation improves the nutritive value of corn-soybean diet, and whether the dietary inorganic phosphorus (P) level affects the growth-promoting effect induced by the enzyme supplementation in chicks. In the first experiment, 4-day-old Single Comb White Leghorn male chicks were given a corn-soybean diet supplemented with amylase and acid protease for 10 days. Dietary amylase addition produced a significant improvement in growth and food efficiency, whereas acid protease had no effect on these parameters. Although there was no significant interaction between amylase and acid protease, the combination of the two enzymes produced the greatest improvement in growth performance. In contrast, neither enzyme influenced the metabolizable energy value or nitrogen balance. In the second experiment, chicks were given corn-soybean diets having low, medium and high levels of inorganic P (3.5, 4.3 and 5.1 g/kg, respectively), supplemented with both enzymes. There were significant interactions between the dietary inorganic P level and enzyme supplementation on final bodyweight, bodyweight gain and food intake. Enzyme supplementation significantly improved chick growth at the medium inorganic P level, but not at the low or high levels. Although the thigh bone ash content and serum P concentration were improved as the dietary inorganic P level increased, enzyme supplementation had no influence on these parameters. In conclusion, the present results indicate that dietary amylase and acid protease have beneficial effects on growth performance in chicks given corn-soybean diet. The dietary inorganic P level affects the growth response to dietary amylase and acid protease supplementation.     

Microscopic detection of IgY‐Fc binding signal in the inner layers of ovarian follicular tissue in quail

In avian species, it has been assumed that an Fc receptor in the ovarian follicles mediates immunoglobulin Y (IgY) transport into the yolk. However, no such receptor responsible for IgY has been identified to date. To examine potential IgY binding activity in the entire ovarian follicle, whole‐mount sections of quail ovarian follicle were incubated with the Fc fragment of chicken IgY (cIgY). Whole‐mount frozen sections of the second largest ovarian follicle were prepared, and then the sections were incubated with digoxigenin‐labeled Fc or Fab fragments of cIgY. Microscopic observation revealed that incubation with the cIgY‐Fc fragment produced a binding signal in the inner layer of the ovarian follicular tissues, most likely in the granulosa cell layer. However, no such signal was detected when the sections were incubated with cIgY‐Fab. Coincubation of the ovarian sections with Alexa488‐labeled cIgY‐Fc and antiserum raised against ZP1, an envelope protein specifically localized in the perivitelline layer, demonstrated that the source of the Fc binding signals partly coincided with the perivitelline layer. In conclusion, our data suggest that potential IgY binding substances interacting with the Fc domain are present in the inner layers of ovarian follicular tissues, most likely in the granulosa cell layer and/or in the perivitelline layer.     

DNA fingerprinting of Pyricularia grisea by rep-PCR using a single primer based on the terminal inverted repeat from either of the transposable elements Pot2 and MGR586

We investigated the use of single primers complementary to sequences in the terminal inverted repeat (TIR) of either Pot2 or MGR586, transposable elements found in Pyricularia grisea, for DNA fingerprinting by repetitive-element-based polymerase chain reaction (rep-PCR). Under standard amplification conditions, rep-PCR with each single primer generated distinct fingerprint patterns among rice-infecting P. grisea isolates collected in Japan. With the Pot2-TIR primer, bands ranging in size from 0.2 to 8 kb and in number from 8 to 13 per isolate were amplified. Although fewer bands were amplified with the MGR586-TIR primer, this molecular technique should be more reliable to identify and classify P. grisea isolates by combining the data of fingerprint patterns from each TIR primer. In a cluster analysis based on DNA fingerprints from this rep-PCR with the Pot2-TIR primer, 10 reference isolates and 12 field isolates from Saga Prefecture in 2002 were separated into six clonal lineages. We also demonstrated that the 12 field isolates belonged to one clonal lineage. Thus, this rep-PCR method using the single primer Pot2-TIR will be useful for the analysis of the population structure of rice blast pathogens.     

Screening for condensed tannin-degrading fungi with a synthetic <Superscript>14</Superscript>C-labeled compound

To find fungi that are potent for degradation of condensed tannin, a two-step screening was used. This involved measurement of fungal growth rate on Japanese cedar (Cryptomeria japonica) bark, followed by determination of [¹⁴C]-labeled CO₂ generated from fungal degradation of synthetic [¹⁴C]-labeled condensed tannin model. In the first screening, 75 strains of wood rot fungi were tested, and 19 strains effectively decreased bark weight and/or the weight of the methanol-soluble fraction. For the second screening, [¹⁴C]-labeled condensed tannin model compound was synthesized in 11.8% yield based on radioactivity measurements. Over the incubation period, Coriolus hirsutus K-2671, Lentinus edodes Is, and Lampteromyces japonicus Nn showed higher cumulative [¹⁴C]-labeled CO₂ emissions than the other strains and mineralized the [¹⁴C]-labeled condensed tannin model compound by 3.7%, 3.0%, and 3.0%, respectively. Fractionation of the methanol extracts from the medium by gel permeation chromatography after fungal treatment suggested that fungi that can induce the emission of significant levels of [¹⁴C]-labeled CO₂ can extensively depolymerize condensed tannins.     

Adsorption behavior of aluminum compounds on pulp fibers at wet-end

Various aluminum compounds were added to pulp suspensions, and the adsorption behavior of their aluminum components on pulp fibers was studied. Aluminum contents in the handsheets were determined using an energy dispersive X-ray analyzer attached to a scanning electron microscope and an X-ray fluorescence analyzer. Although aluminum contents in the handsheets increased with increasing additions of the aluminum compounds, the detailed adsorption patterns varied among the aluminum compounds used. Their chemical structures and the pH values of the pulp suspensions greatly influence the adsorption behavior. When fines are present in the pulp suspensions, the aluminum components are predominantly adsorbed on the fines, probably due to their larger surface areas or the higher carboxyl contents compared to those of coarse fibers. Not only aluminum flocs but also far smaller components such as various aluminum cations seemed to be adsorbed on pulp fibers. Most aluminum flocs, which are formed in pulp suspensions by reacting with OH and entrapped in a fiber matrix by filtration effects, are removable by repeated mechanical agitation of the pulp suspensions.