The Haem and Nitrite Study - The Effects of Haemoglobin NO-blockade on Nitrite-induced Forearm Vessel Dilatation
The Effects of Free Haemoglobin NO-blockade on Nitrite Forearm Vessel Dilatation Under Normoxia and Hypoxia in Healthy Volunteers
연구 개요
상세 설명
This is a healthy volunteer study.
Following entry into this cross-over trial, participants will be randomized to undergo experiments under either normoxic followed by hypoxic conditions, or hypoxic followed by normoxic conditions.
Subjects will donate whole blood as an autologous unit at a preselected NHSBT donation site. The unit will transported back to the NNUH blood bank after a minimum of 30 days (maximum 35 days) after donation.
Volunteers will be tested for baseline bloods. Volunteers will be randomised to normoxia or hypoxia. The will then undergo a nitrite infusion, followed by an autologous whole blood transfusion and a second nitrite infusion (which will co-infuse at the end of the transfusion). During the protocol, the participants will undergo repeated FBFR measurements using strain-gauge plethysmography.
After a minimum of 12 weeks rest period after their initial donation, participants will cross-over to the opposite oxygen condition (as per initial randomization) and the above protocol will be repeated. All interventions will be performed by fully trained and competent medical staff.
연구 유형
등록 (예상)
단계
- 1단계
연락처 및 위치
연구 장소
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Norfolk
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Norwich, Norfolk, 영국, NR4 7UQ
- 모병
- University of East Anglia
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연락하다:
- Nicholas D Gollop, MRCP
- 전화번호: 1790 01603 591790
- 이메일: n.gollop@uea.ac.uk
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참여기준
자격 기준
공부할 수 있는 나이
건강한 자원 봉사자를 받아들입니다
연구 대상 성별
설명
Inclusion Criteria:
- Male or female, aged greater than or equal to 18 years
- If between 18-20 years of age, calculate total blood volume should be more than >3.5L (http://www.blood.co.uk/giving-blood/who-can-give-blood/)
- Body weight > 50kg weight (8 stone 12lbs)
- Not known to have any significant past medical history and not having regular follow up (Check Donor Selection Guidelines (http://www.transfusionguidelines.org.uk/)
- Willing to provide blood donation and receive autologous blood transfusion
- After assessment for eligibility pass all blood donor eligibility criteria
- Able to provide informed consent
- Should inform overseas travel plan during study period (Check Geographical Disease Risk Index on http://www.transfusionguidelines.org.uk/dsg/gdri) e.g. unable to donate blood for 6 months if travel in a malaria endemic country. Similar guidelines for West Nile virus and T. Cruzi endemic countries.
Exclusion Criteria:
- Significant medical, surgical or psychiatric disease that in the opinion of the Clinical Research Fellow would affect subject safety or significantly impact his/her ability to comply with follow-up. This would include any known clotting disorders.
- Known allergy or intolerance to Nitrites
- Known glucose-6-phosphate dehydrogenase (G6PD) deficiency
- Female subjects must be of non-childbearing potential, defined as follows: postmenopausal females who have had at least 12 months of spontaneous amenorrhea or 6 months of spontaneous amenorrhoea with serum FSH>40mIU/ml or females who have had a hysterectomy, bilateral salpingectomy or bilateral oophorectomy at least 6 weeks prior to enrolment
- Receipt of an investigational drug or biological agent within the 4 weeks prior to study entry or 5 times the drug half-life, whichever is the longer
- Predisposed to acute on chronic limb ischemia evident from a history of claudication or known peripheral arterial disease.
- No past history of significant adverse events post blood donation
공부 계획
연구는 어떻게 설계됩니까?
디자인 세부사항
- 주 목적: 기초 과학
- 할당: 무작위
- 중재 모델: 크로스오버 할당
- 마스킹: 없음(오픈 라벨)
무기와 개입
참가자 그룹 / 팔 |
개입 / 치료 |
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활성 비교기: Normoxia and Nitrite (3umol/min-1)
Sodium nitrite stock solution: 100umol/10ml, prepared to concentration according to oxygen sequence.
Normoxia (3umol/min-1).
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활성 비교기: Hypoxia and Nitrite (1umol/min-1)
This will be repeated as per the normoxia cohort, but at a reduced dose of sodium nitrite (1umol/min-1 for 30 minutes) and the volunteers will be asked to breathe 12% oxygen/88% nitrogen for 1-5 minutes before Plethysmography is performed (to get the volunteer to an oxygen saturation of 83-88% peripherally).
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연구는 무엇을 측정합니까?
주요 결과 측정
결과 측정 |
기간 |
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Change in FBFR during intra-brachial nitrite and haemolysed blood co-infusion in normoxia vs hypoxia.
기간: Up to 18 months
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Up to 18 months
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2차 결과 측정
결과 측정 |
기간 |
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Change in FBFR during haemolysed blood infusion vs baseline
기간: Up to 18 months
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Up to 18 months
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Change in FBFR during nitrite infusion in normoxia vs nitrite infusion in hypoxia
기간: Up to 18 months
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Up to 18 months
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Change in FBFR during nitrite infusion in normoxia vs baseline
기간: Up to 18 months
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Up to 18 months
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Change in FBFR during nitrite infusion in hypoxia vs baseline
기간: Up to 18 months
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Up to 18 months
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Blood analysis (cell free haemoglobin, nitrate, nitrite and nitroso species levels)
기간: Up to 18 months
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Up to 18 months
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공동 작업자 및 조사자
수사관
- 수석 연구원: Michael P Frenneaux, FRCP, FESC, Dean of Medicine, Norwich Medical School, The University of East Anglia, UK
연구 기록 날짜
연구 주요 날짜
연구 시작 (실제)
기본 완료 (예상)
연구 완료 (예상)
연구 등록 날짜
최초 제출
QC 기준을 충족하는 최초 제출
처음 게시됨 (실제)
연구 기록 업데이트
마지막 업데이트 게시됨 (실제)
QC 기준을 충족하는 마지막 업데이트 제출
마지막으로 확인됨
추가 정보
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