PET/CT of Skeletal Muscle Amino Acid Kinetics
調査の概要
状態
条件
詳細な説明
On 2 separate visits, with approximately 2 weeks in between visits. For each visit the volunteer will be required to fast overnight (no food or drink for 10 hours prior to arrival at UCSF (water is OK)).
Visit 1 will last approximately 5-6 hours. Visit 2 will last approximately 8 hours. Each visit will include the same general procedures, with the second visit varying slightly from the first (described below). Including the 10-hour overnight fast, both visits will entail roughly 15 hours of continuous fasting. After completion of Visit 1, snacks and drinks will be available. For Visit 2, the volunteer will have a protein drink roughly 4-5 hours into the visit, and snacks and drinks will be made available when the visit is over.
After checking in, the volunteer will be admitted to the Imaging Suite. i) Catheters At the beginning of each visit, a nurse will place two flexible plastic catheters in veins in the forearms. The catheters will be used to collect blood samples to measure changes in hormone and amino acid levels. They will stay in place for 5 hours. One of the catheters will also be used to infuse stable isotopes.
ii) Stable Isotopes Stable isotopes of amino acids are naturally occurring and are not radioactive. Stable isotopes are very similar to regular amino acids, except that they are a slightly heavier form (e.g., "heavy water" is a stable isotope of regular water). Stable isotopes are already present in very small quantities in your body. For 5 hours (6am - 11am), we will infuse stable isotopes into a forearm vein to increase the naturally occurring level by 7-10%. We will later be able to measure this change using highly sophisticated instruments. This will allow us to calculate the rate at which body builds muscle.
iii) Muscle Biopsies During each of the visits, we will have either 2 or 3 muscle biopsy samples taken directly from 2 small incisions in the muscle of the thigh. On visit 1, we will have biopsies at 2 time points and on visit 2 there will be 3 biopsies. The muscle biopsy procedure involves the taking of a small piece of muscle tissue from the outside of the upper leg, about 4-6 inches above the knee. The skin is cleaned and injected with local anesthetic (lidocaine, a numbing medicine) to minimize any pain. A small incision about 1 cm will be made in the skin, through which a needle about 0.8 cm is advanced into the muscle. A piece of the muscle is then removed with the needle, the skin is closed with a special medical glue or suture, a dressing is applied and pressure on the biopsy site held for about 10 minutes to stop any bleeding that might occur. The leg is then wrapped in an ACE bandage to prevent any bleeding that might occur.
iv) PET/CT Scan In between the biopsies, the volunteer will be injected into a vein with a dose (12.5 millicurie) of L-[methyl-11C]methionine (11C-MET) to begin the PET/CT imaging. Like the stable isotope talked about in section "ii" above, methionine is a naturally occurring amino acid in the body. However, the form of methionine is radioactive (this allows the scanner to detect its presence in your body). The PET/CT will take detailed pictures of the flow of 11C-MET into the muscles of the legs, which will provide information about new muscle protein being formed. The volunteer will need to lie still on a table with the thighs inside the machine. The table will move and the machine will make clicking and whirring noises as the pictures are taken. It will take about 90 minutes to gather the scan data.
v) Ingestion of protein drink Towards the middle of the 2nd visit, the volunteer will be asked to drink approximately 8 fluid ounces of a drink that contains 15 grams of protein.
研究の種類
入学 (実際)
連絡先と場所
研究場所
-
-
California
-
San Francisco、California、アメリカ、94107
- Imaging Center-Department of Radiology, UCSF
-
-
参加基準
適格基準
就学可能な年齢
健康ボランティアの受け入れ
受講資格のある性別
サンプリング方法
調査対象母集団
説明
Inclusion Criteria:
- Healthy women
- age 65-80 years old
Exclusion Criteria:
- with any musculoskeletal disorders
- with any metabolic disorders
- blood thinning medications
研究計画
研究はどのように設計されていますか?
デザインの詳細
この研究は何を測定していますか?
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
---|---|---|
Determining skeletal muscle Protein synthesis rates, PSR
時間枠:12 months
|
protein synthesis rates as measured by both 11C-MET PET/CT and 13C-Phe uptake
|
12 months
|
協力者と研究者
捜査官
- 主任研究者:Thomas Lang, PhD、University of California, San Francisco
研究記録日
主要日程の研究
研究開始
一次修了 (実際)
研究の完了 (実際)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (見積もり)
学習記録の更新
投稿された最後の更新 (見積もり)
QC基準を満たした最後の更新が送信されました
最終確認日
詳しくは
この情報は、Web サイト clinicaltrials.gov から変更なしで直接取得したものです。研究の詳細を変更、削除、または更新するリクエストがある場合は、register@clinicaltrials.gov。 までご連絡ください。 clinicaltrials.gov に変更が加えられるとすぐに、ウェブサイトでも自動的に更新されます。