Non-PRO Japanese to English Medical Medical: Pharmaceuticals

It's some kind of grammar problem that I am in trouble with. It may be possibly not appropriate for here, but I would be appreciated if you could help me regarding the following one sentence.
文法の問題なので、ここにはそぐわないかもしれません。しかし、本当に困っています。回答できる方がいたら助けてください。

I could found that in this sentence, the subject is "the study", and the verb is "was made".
"In whom the allergy was confirmed" is a Relative Clause that modifies a noun, "60 patients with a history of peanut allergy".
Everything is clear so far.

However, I can't understand "the threshold dose" and the following, to the end. It seems to be a whole a Noun Clause to me.
Is this part an object for something in this sentence?

「本試験は、ピーナツアレルギーの罹患歴を有する対象者60名として米国国立衛生研究所により行われた。この対象者においては、アレルギーは慢性化していた。」and 以降最後までの訳をお尋ねします。
まとめて名詞句だと思えるのですが、これは何かの目的語でしょうか？
「参加者がスクリーニングを受けた時に二重盲検プラセボ対照試験経口負荷試験によって設定されたピーナッツ粉カプセルの閾値」という名詞句に思われるのですが。。。

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"The study was made by the National Institutes of Health in 60 patients with a history of peanut allergy in whom the allergy was confirmed and the threshold dose of encapsulated peanut flour established by a double-blinded, placebo-controlled oral food challenge when the participants were screened."
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