IschemiaIschemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems with blood vessels, with resultant damage to or dysfunction of tissue i.e. hypoxia and microvascular dysfunction. It also implies local hypoxia in a part of a body resulting from constriction (such as vasoconstriction, thrombosis, or embolism).
Chronic limb threatening ischemiaChronic limb threatening ischemia (CLTI), also known as critical limb ischemia (CLI), is an advanced stage of peripheral artery disease (PAD). It is defined as ischemic rest pain, arterial insufficiency ulcers, and gangrene. The latter two conditions are jointly referred to as tissue loss, reflecting the development of surface damage to the limb tissue due to the most severe stage of ischemia.
Vascular tissueVascular tissue is a complex conducting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium. All the vascular tissues within a particular plant together constitute the vascular tissue system of that plant. The cells in vascular tissue are typically long and slender.
Cardiac muscleCardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart. The cardiac muscle (myocardium) forms a thick middle layer between the outer layer of the heart wall (the pericardium) and the inner layer (the endocardium), with blood supplied via the coronary circulation.
Vascular cambiumThe vascular cambium is the main growth tissue in the stems and roots of many plants, specifically in dicots such as buttercups and oak trees, gymnosperms such as pine trees, as well as in certain other vascular plants. It produces secondary xylem inwards, towards the pith, and secondary phloem outwards, towards the bark. In herbaceous plants, it occurs in the vascular bundles which are often arranged like beads on a necklace forming an interrupted ring inside the stem.
Vascular plantVascular plants (), also called tracheophytes (trəˈkiː.əˌfaɪts) or collectively Tracheophyta (), form a large group of land plants (300,000 accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants).
Prospective cohort studyA prospective cohort study is a longitudinal cohort study that follows over time a group of similar individuals (cohorts) who differ with respect to certain factors under study, to determine how these factors affect rates of a certain outcome. For example, one might follow a cohort of middle-aged truck drivers who vary in terms of smoking habits, to test the hypothesis that the 20-year incidence rate of lung cancer will be highest among heavy smokers, followed by moderate smokers, and then nonsmokers.
PerfusionPerfusion is the passage of fluid through the circulatory system or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to a capillary bed in tissue. Perfusion may also refer to fixation via perfusion, used in histological studies. Perfusion is measured as the rate at which blood is delivered to tissue, or volume of blood per unit time (blood flow) per unit tissue mass. The SI unit is m3/(s·kg), although for human organs perfusion is typically reported in ml/min/g.
Acute limb ischaemiaAcute limb ischaemia (ALI) occurs when there is a sudden lack of blood flow to a limb, within 14 days of symptoms onset. It is different from another condition which is more chronic (more than 14 days) called critical limb ischemia (CLD). CLD is the end stage of peripheral vascular disease where there is still some collateral circulation (alternate circulation pathways} that bring some blood (but inadequate) to the distal parts of the limbs.
Case–control studyA case–control study (also known as case–referent study) is a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute. Case–control studies are often used to identify factors that may contribute to a medical condition by comparing subjects who have that condition/disease (the "cases") with patients who do not have the condition/disease but are otherwise similar (the "controls").