Studies on the Prevention of Leucocytozoon Infection of the Chicken. : VI. The Observation of the Gametocytes of Leucocytozoon caulleryi in the Unstained Wet Blood Film.

Usually the diagnosis of the infected chickens with leucocytozoon disease has been made by finding gametocyte of Leucocytozoon caulleryi in the blood smear stained by Giemsa's or May-Grunwald's method. But, as the inner part of the gametocyte can be observed in the unstained wet film of blood, the feature of the gametocyte considerably differs from that of the fixed sample. Method: One drop of blood from an affected chicken is placed on a cover-glass. This is inverted on a slide and the preparation is rimmed with paraffin. Then it is examined with phase-contrast microscopy at 37℃. Results and considerations: In macrogametocyte, the nucleus is rather small, usually have a curved or twisted rod shape and is suspended in protoplasm. The protoplasm is rich and filled with the immense number of fine granules. But in an usual smear sample, the nucleus shrinks and is covered with the granules at the time of smearing, and yet the granules are stained in dark purple by Giemsa's method, and hence it is considered that the shape of the nucleus is obscured. In microgametocyte, the nucleus is globular or oval, rather large in size compared with the size of the gametocyte itself, and placed at the nearly central point of the cell. The granules of protoplasm are a little larger in size and less in number than that of the macrogametocyte, and as the most of the granules are attached around the nucleus, these look like a pearl necklace in an optical section. As the nucleus expands at the time of smearing, it extends on nearly the whole surface of gametocyte and the protoplasm is seen indistinctly around it. As the granules are attached to the nucleus, they scatter on the surface of the nucleus as it expands. Most of the macro- and microgametocyte are covered with the membrane of the host cell. These cell membranes contain semifluid thinner than the protoplasm of the parasite. Some of which contain the granules of various sizes and they present the vivid Brownian motion. But these granules cannot be stained with Giemsa's dye

Studies on the Prevention of Leucocytozoon Infection of the Chicken : III. The Preventive Effect of Diaveridine.

1.diaveridineを飼料に最高0.01%から最低0.0001%までの各種の濃度になるように添加して,これを連続投与して本病の感染予防試験を行なった.その結果0.01%ならびに0.005%添加区においては感染が認められなかったが0.0025%以下の添加濃度では感染鶏が高率に認められた.従って本剤の最低有効濃度は一応0.005%の附近にあると思われる.しかしながら1964年度は,全国的に本病の予防剤としてpyrimethamineが発売されたため,岡山県下でも本病の発生が少なく,岡山大学農学部構内の鶏舎でも本病の感染率が一般に低かった.すなわち第1区の無添加対照区の感染率は35.0%であり,同時に行なった他の試験でも,薬剤無添加区での感染率は20～30%が普通であって,第1試験でみられたような濃厚感染は認められなかった.第2試験の0.001%添加区で81.3%の感染率を示したのはむしろ例外的現象と考えられる.従って第2試験の0.005%添加区がもしさらに濃厚な感染に曝された場合,果して完全に本病の感染を防ぎ得るか否かは疑問であるので,本剤を実地に応用する場合,最低有効濃度は0.005%より上にあると考えた方が安全と思われる.2.試験期間中における試験鶏の体重,産卵率,卵重等の推移を各区別の平均値で図示したように,いずれの場合も本剤がニワトリに対して毒性を示しているとは認められなかった.ただし第1図で,8月1日以後第3区および第4区の平均体重曲線が降下しているのは,第3区で2羽第4区で1羽がそれぞれ内臓型淋巴腫症に罹患し,体重が900gないし660gに減少したものが出たためであるが,8月29日現在の体重で,無添加対照区との間でF検定を行なっても5%の水準において有意の差は認められていない.第2図の平均産卵率の曲線についても,同様な傾向が見られるが,これも前記と同じ理由によるものと考えられ,期間中の総産卵個数について,対照区と各区の間でF検定を行なったが,いずれの場合も有意の差は認められなかった.3.ニワトリのcoccidium症に対するdiaveridineの効果は,前記の通りM. L. Clark3)によれば,sulfa剤と混じた場合0.001%であるといい,同じくpyrimethamineの効果は,S. B. Kendall&L. P. Joyner5)によると,sulfa剤と混合した場合0.004%が適当と認めている.従って,この両者はニワトリのcoccidiim症に対してはほぽ同等の効力を有しているものと見られるが,ニワトリのleucocytozoon病に対するpyrimethamineの最低有効濃度は著者ら2)の成績では0.00005%であるのに反し,diaveridineは前記の通り0.005%であるとすると,本病の予防効果では両者の間に100倍の開きが認められるわけであって興味深いことである.4.以上の試験により本剤単味の場合の最低有効濃度がほぼ0.005%であると判明したが,この濃度では実際の野外での応用の場合薬価の点で問題を生ずる恐れがある.したがってsulfa剤と混合投与した場合その相乗効果によりさらに投与濃度をさげる研究が行なわれないと本剤単味では応用範囲が限定されると考えられる

Studies on the Prevention of Leucocytozoon Infection of the Chicken. : V. The Leucocytozoon Infection in the Yearling Hen.

The investigations were carried out about the reinfection with leucocytozoon disease in yearling hens that were infected with this disease in the preceding year. From the investigations carried out in 1962, 1963 and 1964, the following results were obtained. 1. Among the 20 hens once infected with this parasite, the reinfection was not at all found in the same and the following years by the microscopic examination of blood smear sample made once every week. 2. Among the 22 yearling hens that were completely protected from leucocytozoon infection in the preceding year by the use of pyrimethamine or sulfadimethoxine, it was found by the blood examination that 11 hens (50%) were infected with this disease in the following year. 3. Eleven hens, in the blood of which no gametocyte had been detected in spite of the fact that they had been among the highly infected flock, were not at all infected in the following year. From the results mentioned above, we have come to the following conclusions. Hens recovered from natural infection of leucocytozoon disease acquire the strong immunity later. And the effect of pyrimethamine and sulfadimethoxine used in these experiments are quite perfect

Studies on the Prevention of Leucocytozoon Infection of the Chicken. : II. The Preventive Effect of Furazolidone on Leucocytozoon Infection of the Chicken.

In recent years, leucocytozoon infection of the chicken has spread almost all over this country, and has given the serious damage to the poultry industry. We have been testing various drugs for the prevention of this disease, and in this study we have tested the preventive effect of furazolidone (nf-180) with leucocytozoon infection of the chicken. The procedure and the results obtained are as follows. Day old 200 chicks(♂100, ♀100) of White Leghorn were devided into 5 groups. Every group contains 20 males and 20 females. Group I was given the diet free from furazolidone as control, group 2 was given the diet containing 0.0005 % of furazolidone, group 3 the diet containing 0.001 % of furazolidone, group 4 the diet containing 0.005 % of furazolidone and group 5 the diet containing 0.02 % of furazolidone respectively. The smear samples of blood of all birds were made once every week for the detection of gametocyte of Leucocytozoon caulleryi. Body weights were measured at the same time. The infectivity rates of group 1(control), group 2, group 3, group 4 and group 5 were 64.1 %, 66.7 %, 70.2 %, 79.5 % and 48.6 % respectively. The infectivity rate of group 5 was slightly lower than that of the other groups, but from the practical point of view, it seems that furazolidone is ineffective for the prevention of leucocytozoon infection of the chicken at such concentrations. There were no significant differences between the weight gains of these groups

Studies on the Prevention of Leucocytozoon Infection of the Chicken. : IV. The Ecological Findings of Culicoides arakawae.

The following researchs have been carried out on the behavior of Culicoides arakawae, the intermediate host of leucocytozoon infection of the chicken. From 1961 to 1964, C. arakawae have been collected by a light trap once or twice every week at the hen house of our laboratory and a farmer's hen house at Hataayu, Makiishi in Okayama, city. The following items were also investigated: 1.)the successive change of the number of C. arakawae flied into the hen house in the evening, 2.)the number of C. arakawae caught by an insect net at various heights, 3.)the successive change of the number of C. arakawae caught by a light trap placed in the hen house. The results obtained were as follows. 1. C. arakawae comes flying into the hen house when the mean temperature is higher than 10℃. But, when the mean temperature is higher than 10℃, there are no clear correlation between the temperature, humidity and weather and the number of C. arakawae caught by light trap. The sex ratio of C. arakawae caught by a light trap varies with temperature, and the higher the temperature is, the greater is the percentage of the female. The ratio of engorged females to the whole females also varies with temperature. When the temperature is lower than 20℃, the percentage of engorged females is almost always below 50. When the temperature is higher than that, the percentage is from 70 to 90. 2. The number of C. arakawae caught by a light trap placed in the hen house shows the normal distribution with the central axis at 2 am. 3. It is probably certain that C. arakawae does not hibernate in the imaginal stage in the neighbourhood of Okayama city. 4. The number of C. arakawae come flying into the hen house in the evening, is most numerous during one hour following sunset. And in the summer season, in the flies caught by a light trap placed in the hen house, the percentage of females is usually far greater than that of males, but the sex ratio of C. arakawae, come flying into the hen house, is about 1:1. 5. C. arakawae usually flies below 20 m on the ground

Studies on the Prevention of Leucocytozoon Infection of the Chicken. : I. The Behaviour of Culicoides arakawae to an Insecticide, DA-14-7.

In resent years, leucocytozoon infection of the chicken was found all over Japan except in Hokkaido. And it was revealed by AKIBA (1960) that Culicoides arakawae is the intermediate host of Leucocytozoon caulleryi. But the effective insecticide for C. arakawae is not yet discovered. In this study we have tested an insecticide named DA-14-7. This insecticide was manufactured recently for trial by a pharmaceutical company. The procedure and the results obtained are as follows. Two hen-houses of nearly the same scale were used for this experiment. In the control hen-house no insecticide was sprayed. In the experimental hen-house, emulsion of DA-14-7(diluted 1/20 with water) was sprayed on the ceiling, the wall, the beam, the pillar, the droppings board and other parts except the feeder and watering installations, at the rate of 300 ml. per m2. Oily solution of DA-14-7 was also sprayed on the hen body at the rate of 7 ml. per hen. These sprayings were repeated 5 times. The first spraying was carried out on September the 14th 1961. The second one on the next day. After the second spraying, the third, the fourth and the fifth spraying were carried out every four days. After spraying, the number of C. arakawae caught by light trap in the experimental hen house did not decrease, but the ratios of engorged female flies markedly declined. The ratios of engorged C, arakawae caught in the control hen house and the experimental hen house before spraying were between 83 % and 97 %. Seven hours after spraying, the ratios of engorged flies caught in the experimental hen house were from 6.3 % to 1.1 %, and 24 hours later 18.8 %, and 72 hours later from 34.4 % to 38.4 %. We cannot be satisfied with the effect of DA-14-7 as a repellent for C, arakawae. But, if the effective period of sprayed DA-14-7 is made longer and sprayed in relatively short intervals, the DA-14-7 is effective for protecting the chicken from suffering with C. arakawae, and consequently, the opportunity of the chicken to contact leucocytozoon infection and the degree of infection may be diminished considerably

Potentiality of the Outdoor Activities Database in Early Childhood Education: How Can Practitioners Use the Research Results of Hiroshima University Kindergarten?

本研究の目的は，広島大学附属幼稚園の研究紀要で作られた「森の自然体験データベース」を電子データとして再編すること，それを保育者が使用した感想から改善点を発見すること，そこから保育におけるデータベース活用の可能性を探ることであった。広島県内の保育者を対象として，Microsoft Excel 形式で作られたデータベースを使用してもらい，その感想を質問紙によって尋ねた。また，保育に関する知識を伝達する際の理想的な方法についても併せて質問した。書籍版のデータベースを電子データとして作り直したことによって，検索や絞り込みといった機能を使うことができるようになり，データベースとしての利便性が高まった。しかし，保育に関する知識伝達の理想的な方法は，会話や体験であるという保育者の認識が明らかになったことから，データベースはそれ単独で知識伝達に使用するのではなく，会話や体験を主軸とした知識共有の機会と併用し，既存の知識をより深めたり，不確かな知識を補強したりするために使用することに，活用の可能性が見出された。This study focused on the benefit from the research results of Hiroshima University Kindergarten. We revised the outdoor activity database made by Hiroshima University Kindergarten (2013) which contained the information about children's play; when, how, and by what they play in outdoor environment of the kindergarten. We had 26 practitioners of early childhood education use the database on the Microsoft Excel, and answer the questionnaire which asked them about their opinions of the database. Some of the practitioners thought the database as useful for finding information about children’s play in outdoor environment. But others thought that the ideal medium to share the knowledge about early childhood education with other practitioners was not the documents about children’s outdoor activity but conversation with other practitioners and experience that they play for themselves. We concluded that the database is useful for reinforcing the knowledge