The author wanted to confirm whether or not Necator americanus is communicated through oral membranes and, should this be the case, whether the infection is influenced by the time length of contact with oral membranes. Experiments were conducted to observe whether a larvae can become Necator americanus in the human body by contact with oral membranes. The following results were obtained:
I 1st experiment to apply larvae to oral membranes for 300 seconds.
1) Infection was observed in four out of five volunteers.
2) The four volunteers were free of apparent subjective symptoms in the time period up to expelling.
3) As to objective symptoms, eosinophilie increased in the blood picture of the four volunteers infected.
4) For the four volunteers infected, ova and larvae were found within 58 through 108 days after infection.
5) Necator americanus was obtained from the four volunteers by expelling; 24, 21, 3 and 7 respectively.
6) The rate of collected Necator americanus to the larvae applied was 13.8%, 14.7%, 0, 2% and 3.3%.
II The larvae of N. a. were applied to oral membranes for 90 seconds in 2nd experiment.
1) No infection was observed in all four volunteers.
2) No one complained of subjective symptoms in the time period up to expelling.
3) Change in the blood picture was not observed for all four cases.
4) No Necator americanus could be collected by expelling in all four cases.

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交通事故発生要因の一つである運転行動とその背景の生活条件である運転労働時間との関係を, 質問紙法を用いて, 調査した。その調査対象は交通事故体験者180名, ハイタク運転者44名, トラック運輪運転者83名であった。
調査結果は次の通りである。
1) 一日当たりの運転労働時間すなわち0∼3.0hr/day, 3.1∼8.0hr/day, 8.1∼hr/dayには, 運転操作 (ハンドル, ブレーキ, アクセル, クラッチ, チェンジ・レバー) の差は認められないが0∼3.0hr/dayは他の条件に比較し, 足による運転操作に「欠点」のある傾向を示した。
2) 長時間運転労働者には「運転疲労」と「交通事故発生回数」との間に高い相関を認め, 一方, 短時間運転者には, 「眠気」と「交通事故発生回数」との間に相関のある傾向を認めた。
3) しかし, 8∼10, 10∼12時では疲労感は比較的少ないが (運転行為の影響が大きく) 事故が多い。2-4, 4-6時の深夜早朝時には疲労感は大きいが (交通量が少ないため) 事故は比較的少ない。
4) 12∼14, 14∼16時の時間帯では, 疲労の訴え, 事故回数ともに, 運転労働時間と関係なく大きい。
5) 実数の事故回数より運転単位時間当たりの事故回数を指標とする方が, 運転労働時間と運転行動との関連特性を明確にしている。

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Botulism is a food poisoning which is caused by taking in nerve poison produced by Cl. botulinum which multiplies in foodstuffs.
In Japan, since 1951 occurrence has been mainly in Hokkaido and Tohoku (northern part of Honshu) districts. Up until the present time 63 outbreaks have been reported and 93 people out of 359 patients died.
Toxin produced by Cl. botulinum is classified into 6 different types: A, B, C, D, E and F according to their immunological nature. Of these 6 types of toxin, types A, B, E and F are the cause of poisoning in human beings whereas types C and D affect cattle and fowl.
Botulism in Japan is mainly attributable to fermented preserved foods such as “IZUSHI” and “KIRIKOMI” which utilize raw fish as their component. But it should be mentioned that type B poisoning, which occurred in Miyazaki Prefecture in 1969, is thought to have been caused by imported caviare, 21 people were affected, 3 died.
Therefore, while only type B episodes have been previously reported in Japan, the discovery of types A and B strains in the soil of Tohoku district should make it clear that outbreaks due to other types are now possible. The possibility seems to be higher since a poisoning from imported food has occurred.
The study of botulism in Japan has been conducted mainly on type E which has frequently broken out. The geographical distribution of type E organisms in the soil, the multiplication in “IZUSHI”, the conditions of toxin production, the chemical nature of the toxin, and its remedy using antitoxic serum have all been studied. But the author has taken up the following problems broadly not only on type E toxin but also other types of toxin due to the above mentioned reasons.
Why is botulinus toxin not affected by the proteolytic enzymes in the digestive tract? Though the effect of proteolytic enzymes on the toxin in the digestive tract is a very urgent problem, no unanimous conclusion has been reached.
In other words, no report on the study of the effect of proteolytic enzymes of all the six toxins, already known to us, under the same conditions has yet been published. Bearing this in mind, the author made a study on the effect of various proteolytic enzymes using crude botulinus toxins (cultural super-mates) under simulated natural conditions.
The results obtained are as follows:
(1) With type A, strain 190, type B, strain Lamanna, and type F, strain Denmark which belong to the Proteolytic Group, a remarkable attenuation of their toxicity was observed on both acid and alkaline sides. But inactivation of the toxins due to enzymes was not particularly notable.
(2) With toxin type C, strain Stockholm and type D, strain 1873 which belong to the Non-Proteolytic Group, the effects of fluctuation of PH and the action of various types of enzymes were comparatively slight.
(3) With type B, strain QC, type E, strain Iwanai and type F, strain 70 F which belong to the Non-Proteolytic Group, activation of the toxins was observed by treating them with trypsin at PH 6.0. Generally speaking, except for type F, effects of fluctuation of PH and of various enzymes were slight.
(4) When botulinus toxin is taken orally the toxin changes its toxicity in varying degrees by fluctuation of PH in the stomach and the intestinal tract or by action of digestive enzymes, and it is presumed that a considerable amount of active toxin remains in the digestive tract.

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大気汚染物質による呼吸器官の疾患の発生ないしは進展の機序については, 諸種の要因が複雑に交錯して働いている。動物による実験公害研究では, この錯雑する諸要因を分析して行くことが一つの目的である。大気汚染物質をモデル的に刺戟ガス・有機および無機粉塵・微生物の3大カテゴリーに分け, 無菌動物を用いる実験を計画的に行ない, 得られた成績について特徴的な点を述べれば次のようである。
各種の微量汚染物の呼吸器官内侵入によってこの器官にトレーニング効果が与えられる。無菌モルモットにおいては, 外来微粒体が容易に気管・気管支粘膜を通過する。普通飼育動物ではこの現象が認められない。しかし, 普通モルモットでもSO₂ガスの吸入により異物侵入が容易に行なわれるようになる。呼吸器官のもつ自浄能の程度は, 無菌動物では普通動物よりも低く, またSO₂ガス吸入によって両者ともそれらのもつ自浄能が低減せしめられる。
葡萄球菌 (209P) 浮遊環境中に普通動物を入れても, また普通動物に前もってSO₂ガスを吸入せしめておいて, この菌を吸入せしめても発病を認めない。無菌動物にSO₂ガスを吸入せしめ, 次に菌浮遊環境に入れると約半数の動物が出血性気管支肺炎の病像を呈し, 死亡する。なお, SO₂ガスおよびこの菌の単独投与では死亡せず, 気管支肺炎の病像は認められない。
以上のように, 葡萄球菌による実験的肺炎の発生に関し, 少なくとも, トレーニング効果の有無が作用し, また刺戟ガスの共同作用としてあらわれる自浄能の低下および上皮通過性の促進などが総合的に働いていることが明らかとなった。

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