Animal Experiment on Functional Features of Eggs Stated to be Hypoallergenic for People with Food Allergies

Functional features concerned with low proallergic natures were examined using an allergy-inducible rat strain (Brown Norway rat; BN rat) on hen's eggs which have been empirically mentioned as hypoallergenic for patients suffering from food allergies (experimental eggs). BN rats were fed on feed containing whole experimental eggs (feed E) and whole normal eggs (control feed, feed C). The densities of immunoglobulin E (IgE)-positive cells, have reported to be IgE-bearing mast cells, in the jejunum and ileum of BN rats fed on experimental-egg-containing feed were lower than those of BN rats fed on normal-egg-containing feed. The number of blood eosinophils was also lower in BN rats fed on feed E. Serum IgE levels were no different between BN rats fed on feed E and feed C. These results indicate that the low proallergic nature of hen's eggs studied in the present study is due to the dereased ability of experimental eggs to facilitate the proliferation and induction of mast cells in the intestinal tissue.食物アレルギーを持つ消費者の経験に基づいて低アレルギー誘発性であることが言及されている鶏卵について，低アレルギー誘発性の有無と科学的な根拠を明らかにするために動物を用いた実験をおこなった．実験にはアレルギーを発症することが知られているラットの系統であるBrown Norway rat（BNラット）を用い，この鶏卵を混ぜ込んだ飼料で飼育した．対照として，市販の鶏卵（普通卵）で同様に飼育した．試験卵で飼育したBNラットでは，空腸と回腸組織のIgE陽性細胞の密度は普通卵で飼育した場合に比較して大きく低下した．組織中のIgE陽性細胞の大部分は肥満細胞であることが知られていることから試験卵群における小腸組織の肥満細胞密度は低下した．さらに，血中の好酸球数は同様に試験卵による飼育で低下した．一方，血清のIgE濃度には摂取させた卵による違いは認められなかった．以上の結果は，試験卵を摂取した場合，通常の卵の摂取に比較して即時型アレルギー症状の発生に直接的に関与する肥満細胞と好酸球の誘導や増殖が促進されにくいと考えられ，このことが，試験卵がアレルギーを引き起こしにくい一因であると推察される

ニワトリ胚のファブリシウス嚢におけるＢリンパ球の発達に対する sIgM 誘導因子の役割

　The bursa of Fabricius plays essential roles in the establishment of immune functions of avian species as a primary site for differentiation and proliferation of B lymphocytes. The bursa of chick embryos is colonized by lymphoid cell precursors only between the days 7th of embryogenesis (E7) and E14. Susceptibility to the sIgM-inducing factor may fluctuate in bursal lymphoid cells during the lymphoid precursor cell-receptive period. In the present study, the dynamic changes in the sIgM-positive ratio and responsiveness to sIgM-inducing factor were examined in lymphoid cells sampled from the bursa during the B precursor cell-receptive period (E10 to E13) and findings suggest that responsiveness to sIgM-inducing factor varies with the development of the chick embryos. E11 is suggested to be a critical stage of B-lymphocytegenesis in the bursa of chick embryos.ファブリシウス嚢はＢリンパ球分化と増殖のための中枢リンパ組織として鳥類の免疫機能の発達において重要な役割を演じている．培養ファブリシウス嚢上皮細胞は胚のファブリシウス嚢リンパ球に膜の IgM 分子（sIgM）の発 現を誘導する因子を産生することが報告されている．ファブリシウス嚢リンパ球の sIgM 発現誘導因子に対する感受性はファブリシウス嚢における分化の時期において変動する可能性が考えられる．ニワトリの胚では，リンパ球系の前駆細胞は胚発達の７日目から14日目の間においてのみファブリシウス嚢に進入・定着することが知られている．そこで本研究では，リンパ球系前駆細胞がファブリシウス嚢に定着するこの時期（10日胚から13日胚）におけるファブリシウス嚢リンパ球の sIgM 発現の変動を調べるとともに，これらの細胞における sIgM 発現誘導因子に対する感受性の変動について測定した．sIgM 陽性細胞の割合は11日胚で有意に上昇した．sIgM 発現誘導因子に対する反応性はこの時期の胚発達に伴って変動し，11日胚で高い傾向を示した．これらの結果から，11日胚齢はニワトリ胚のファブリシウス嚢におけるＢリンパ球の発達に関して重要な時期であることが示唆された

Enhancement of norepinephrine-induced transient contraction in aortic smooth muscle of diabetic mice.

Changes in norepinephrine-induced transient contractions in Ca2+-deficient solution were investigated in the aortic smooth muscles of diabetic ALS (alloxan-induced diabetes susceptible) mice. The transient contractions in diabetic mice were significantly larger than those in normal mice. The longer incubation of the muscle preparations in Ca2+-deficient solution made the transient contractions smaller, probably due to the leakage and decrease in norepinephrine-releasable stored Ca2+. The rate of this reduction in contraction was slower in diabetic mice. These results suggest that the leakage of intracellular stored Ca2+ caused by extracellular Ca2+ deficiency is attenuated in diabetic mice, contributing to enhanced norepinephrine-induced transient contractions.</p

Induction of Atherosclerosis in Aorta and Coronary Artery of Chicken by Orally Administered Cholesterol

Hypercholesterolemia and hyperlipidemia have been important in human health as factors that induce atherosclerotic lesions in brain and heart blood vessel. Various experimental studies have been done to prevent and treat atherosclerotic lesions in animals. In the present study, we assessed the suitability of chickens as experimental animal for atherosclerosis. Newly hatched chicks were fed on 1.0%-or 0.1%-cholesterol(CHO) containing feed. After 3 and 6 months, total cholesterol levels in the sera and histological changes in the aorta and coronary artery of chicks fed on 1.0%-CHO-containing feed for 3 and 6 months, intimal thickening and marked accumulation of foam cells were observed. Endothelial cells had disappeared in the aorta of these chicks. A slight accumulation of foam cells was observed in the aortic intima of chicks fed on 0.1%-CHO-containing feed. In the coronary artery, a remarkable thickening of intima with accumulation of foam cells and a marked stenosis of coronary space were observed in chicks fed on 1.0%-CHO-containing feed. The results of present study indicate that the chicken can be a useful experimental animal in the study of hypercholesterolemia, hyperlipidemia and atherosclerosis

Effects of Estrogen Treatment During the Embryogenic Period on Chick Antibody Production

Antibody production against a T cell-dependent antigen (goat red blood cell) and a T cell-independent antigen (killed Brucella abortus) was examined in chicks treated with estrogen in which eggs were dipped into ethyl alcohol solution containing &beta;-estradiol. Relative weights (organ weights/body weight) of the primary lymphoid organs of chicks were also determined. Secondary antibody production against goat red blood cells (GRBC) was significantly increased by treating chick embryos with high doses of estrogen (1.0% solution) on the 4th day of embryogenesis. Primary and secondary antibody responses against killed Brucella abortus (BA) were dose-dependently increased with estrogen treatment on the 4th day of embryogenesis. In contrast, primary and secondary responses against BA of chicks treated with estrogen on the 14th day of embryogenesis were significantly suppressed. Thymus weight significantly increased in chicks treated with estrogen on the 4th day of embryogenesis. The rate of CD4-positive cells in the chick thymocytes significantly increased with estrogen treatment on the 4th day of embryogenesis. On the other hand, the weight of the bursa of Fabricius significantly decreased when treating chick embryos with high doses of estrogen (1.0%) on the 14th day of embryogenesis. Results from the present study indicated that estrogen treated at different stages of embryogenesis exerts discrete effects on B cell differentiation in the bursa and helper T cell differentiation in the thymus of chick embryos

Serum-free Culture of Chicken Bursal Epithelial Cells

We developed a method of culturing bursal epithelial cells under serum-free condition. Bursal cells sampled from 14 days of embryogenesis were cultured in DMEM/Ham&rsquo;s F12 1 : 1 mixture medium supplemented with epidermal growth factor, insulin, transferrin, sodium selenite, hydrocortisone and 2-aminoethanol. A monolayer, in which polygonal cells were extensively observed, entirely covered the well after 2 to 3 weeks of incubation. The cultured cells were maintained for 5 months without any apparent morphological abnormalities. Polygonal cells in wells cultured for 3 weeks or 5 months were reacted with anti-keratin antibody, indicating these cells are cytokeratin-positive cells. These results suggest that most cells proliferated under a serum-free condition are epithelial cells. It seems possible to precisely analyze presumable factors in the supernatant of bursal epithelial cell culture

Intracellular Calcium Ion Elevation in Chicken Phagocytes Treated with Activating Agents

Cytoplasmic calcium ion concentrations [Ca2+]i were measured for the first time in chicken heterophils and macrophages stimulated with Leukotriene B4 (LTB4), phorbol myristate acetate (PMA), formyl-methionyl-leucyl-phenylalanine (fMLP) and lipopolysaccharide (LPS) which are known to be activating factors of phagocyte functions. [Ca2+]i in rat neutrophils and macrophages was also measured after stimulation with these activating factors. [Ca2+]i was measured by the Fura-2-AM-loading method using an intracellular ion analyzer. Resting levels of [Ca2+]i in chicken phagocytes were similar to those reported previously in rats. [Ca2+]i of chicken phagocytes was elevated by treatment with LTB4, PMA and LPS, and the patterns and duration times of the elevation of [Ca2+]i by these factors resembled those in rat phagocytes. However, fMLP did not elevate [Ca2+]i in chicken phagocytes, although the agent elevated [Ca2+]i of rat phagocytes. The degree of elevation of [Ca2+]i in chicken heterophils and macrophages stimulated by LTB4, PMA and LPS was significantly higher than that in the same kinds of rat phagocytes (neutrophils and macrophages) stimulated with the corresponding factors. The degree of elevation of [Ca2+]i in granulocytes treated with these factors was significantly higher than that in macrophages in chickens and rats. The reasons for these differences are unclear at the present time. It is valuable to examine the reason for these differences