犬糸状虫症の皮内反応に関する研究
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概要
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It is said that the value of immunological diagnosis in parasitic diseases is generally small. It is evident however, that the worms are closely related to host tissues and when their excrements, products or dead worms are absorbed by the host, a specific antibody is produced. Immunological diagnostic tests as complement fixation, precipitation and intradermal tests are used in diseases due to Schistosoma Japonicum, Echinococcus, Paragonimus westermani, Fasciola hepatica, Wuchereria bancrofti, etc. Of these tests, the intradermal test is said to be the most valuable clinically. The diagnosis of canine filariasis was made hereto-fore by detection of the microfilaria in the blood. Early diagnosis however, cannot be made by this method as microfilaria is not produced for about 6-7 months after infection by the mosquito in the summer and diagnosis by detection of microfilaria is impossible during this period. Moreover, the appearance of microfilaria is generally inconstant, especially in winter, and detection of microfilaria is difficult in many cases. Cases in which the worms are found by autopsy while undetected in the blood are not rare. In view of these facts, I have produced various antigens from the worm body and found these to be great value in the diagnosis of canine filariasis, particularlly in the early diagnosis, when tested intradermally. I. Production of Antigen The antigen which showed the best result among the various antigens is produced as follows: 1) Five times the quantity of acetone is added to worm body, ground in a homogenizer and the quantity of acetone is added to worm body, ground in for 30 minutes. 2) To the sediment is added 5 times the volume of acetone and centrifugated. 3) To the sediment is added 2 times the quantity of acetone and centrifugated. 4) To the sediment are added 2 times the quantity of acetone and an equal quantity of ether and centrifugated. 5) To the sediment is added 2 times the quantity of ether and centrifugated. 6) Procedure (5) is repeated and the sediment is dried by vacuum-pump. 7) To the dried powder is added saline solution of pH 8.0 in equal volume to that of initial acetone, extracted at -5℃ for 24 hours, centrifugated at 3,000 r.p.m. and the supernatant fluid is separated. 8) This original antigen is diluted properly with saline solution and merthiolate is added in a ratio of 0.01 per cent. II. Administration and Dosage A. The dog is placed on his back in a through and his legs are tied. Hair of the inside of the both thighs, the area of injection, is cut away, the area is cleansed by wiping gently with alcohol-soaked cotton without irritating the skin and the antigen and physiological saline solution as a control are injected intradermally in a dose of 0.1cc respectively in each thigh after drying. The tuberculin syringe is used after sterilization by boiling and drying. Separate syringes should be used for antigen and control solution. B. Determination 1) The intradermal reaction with antigens appears immediately after injection, reaches a peak after 15-25 minutes and fades after 60-120 minutes. Determination is made at the peak from the dimension of the swelling (total of longer and shorter diameter), the degree of redness, the elevation and hardness of swelling considering cautions which are described later. 2) Criterion of Determination The determination from the dimension of the swelling in the peak is made according to the following criterion. Positive: Over 2.8cm (total of longer and shorter diameter) a. 2.8-4.0cm‥‥‥Positive (+) b. 4.1-4.5cm‥‥‥Moderately positive ++ c. 4.6 or more‥‥‥Strongly positive +++ Suspected positive: 2.6-2.7cm (±) Negative: Less than 2,5cm (-) In measuring the dimension of the swelling, calipers for measuring tuberculin reaction is used. Fig. 10 (No.1-No.6) is the changes of the positive intradermal test by time. III. Cautions in Determination a. In the early stage of infection, the skin is generally hypersensitive, particularly for about 160 days after infection and swelling is larger, redness is more intense and elevation is greater with pseudopodlike processus at time. Redness and swelling may be produced even by physiological saline solution as the control. b. In aged dogs, the reaction is generally weak and suppressed. Especially with dilute antigen, the reaction appears with difficulty in many cases. Moreover, in severe filariasis, the reaction may become negative. c. In cases of cachexia, ascites, edema, late stage of pregnancy, suppurative diseases, weakness and senescence, malnutrition, etc., the intradermal reaction may be suppressed or become negative. d. The intradermal reaction by antigens are specific to canine filariasis and there are no similar reactions. e. Antigens are active for one year or more when stored in cool, dark place, or at room temperature. IV. Early Diagnosis by Intradermal Test (I.T.) in Naturally Infected Cases Fig. 18 shows 3 cases of puppy dogs (born in February, 1957) infected naturally be placing in the same room from the beginning of June, the mosquito-season, with an infected dog (microfilaria ++) and possibility of early diagnosis was studied by intradermal test. In July 10, the time in which young worms are in the intermediate growing site the intradermal test was already positive. In September 8, young worms were found in cases No.1 and No.2 by autopsy. In case No.3, the worm was not found in the heart though it was presumed that the worms were in the intermediate growing site. V. Early Diagnosis by Intradermal Test in Artificially Infected Dogs (Table 20) The intradermal test in artificially infected dogs became positive 3 days after infection in the earliest case, and all dogs became positive after 3-42 days.
- 大阪府立大学の論文
- 1963-03-31