A measure of closeness of agreement between a test result and an accepted reference value.The degree of conformity of an indicated value to an accepted standard value, or ideal value. links Accuracy Rating - A number of quantity defining a limit that errors will not exceed when a device is used under specified operating conditions. Accuracy rating can be expressed in a number of forms, i.e. in terms of the measured variable (± 1°C), percent of span (± 0.5% of span), percent of upper range value (± 0.5% of upper range value F.S.), percent of scale length (± 0.5% of scale length), or percent of actual output reading (± 1% of actual output reading). Measured Accuracy - The maximum positive and negative deviation observed in testing a device under specified conditions and by a specified procedure. It is usually measured as an inaccuracy and expressed as accuracy, typically in terms of the measured variable, percent of span, percent of upper range variable, percent of scale length, or percent of actual output reading. See accuracy, accuracy rating.
The application of probability and statistical methods to calculate the risk of occurrence of any event, such as onset of illness, recurrent disease, hospitalization, disability, or death. It may include calculation of the anticipated money costs of such events and of the premiums necessary to provide for payment of such costs.
Adverse Drug Event syn: Adverse Drug Error : Any incident in which the use of a medication (drug or biologic) at any dose, a medical device, or a special nutritional product (for example, dietary supplement, infant formula, medical food) may have resulted in an adverse outcome in a patient.
An untoward, undesirable, and usually unanticipated Event, such as death of a patient, an employee, or a visitor in a health care organization. Incidents such as patient falls or improper administration of medications are also considered adverse events even if there is no permanent effect on the patient
Aldosterone is a steroid hormone synthesized from cholesterol by the enzyme aldosterone synthase. It is formed in the outer-section (zona glomerulosa) of the adrenal cortex of the adrenal gland, as the cells of other sections don't have the corresponding enzyme. It is the sole endogenous member of the class of mineralocorticoids. It helps regulate the body's electrolyte balance by acting on the mineralocorticoid receptor.
An explicit step-by-step procedure for producing a solution to a given problem. Specifically, a mathematical equation typically executed using a computer program (or set of programs) that is designed to systematically solve a certain kind of problem.
Angina pectoris (chest pain): A type of pain usually described as choking, squeezing, or suffocating, usually present in the chest, throat, jaw, shoulders, arms or elbows. Most commonly associated with blockage of the heart arteries. adj: Stable AnginaAngina , Unstable Angina
Angiotensin II is the final active messenger of the renin-angiotensin pathway Angiotensin II binds to AT1 receptors to cause vasoconstriction and fluid retention, both of which lead to an increase in blood pressure. The angiotensin II receptor blockers lower blood pressure by blocking the AT1 receptors.
Artificial neural networks- a tool for clinical decision: a computerised mathematical model for understanding and predicting complex and chaotic dynamics in complex biological systems. A type of artificial intelligence that attempts to imitate the way a human brain works. Rather than using a digital model, in which all computations manipulate zeros and ones, a neural network works by creating connections between processing elements, the computer equivalent of neurons. The organization and weights of the connections determine the output. Neural networks are particularly effective for predicting events when the networks have a large database of prior examples to draw on.
Acute Physiology and Chronic Health Evaluation, a scoring system using routinely collected data and providing an accurate, objective description for a broad range of intensive care unit admissions, measuring severity of illness in critically ill patients.
Apolipoprotein A-I (apoA-I) is the primary protein constituent of HDL, defining its size and shape, solubilizing its lipid components, removing cholesterol from peripheral cells, activating the LCAT enzyme, and delivering the resulting cholesterol esters to the liver.
Absolute Risk Reduction: is the difference in the event rate between control group (CER) and treated group (EER): ARR = CER - EER.
Case-control Study involves identifying patients who have the outcome of interest (cases) and control patients without the same outcome, and looking back to see if they had the exposure of interest.
imprecision: distance of agreement between independent results of measurement obtained under stipulated conditions. Imprecision is a qualitative concept, a quantitative counterpart of iprecision. Imprecision is computed as a standard deviation or a coefficient of variation of the measurement results. Imprecision depends critically on the specified conditions. Standard deviation expressing imprecision may depend on the value of the measurand; the phenomenon is called heteroscedasticity.
computer entry and management of data. Quality assurance. Report generation. Integration of multitests results pereingin the single patient. Dialogue and consultancy to the ward and clinicians. Dialogue and consultancy to the patients and family. Clinical report delivery. Specimen storage.method re-evaluation. Protocols re-evaluation. Guidelines re-evaluation. Personnel safety. Personnel formation and updating. Errors evaluation and prevention.
Assay Preanalytical Factors in Medicine Laboratory
Specimen Collection, Handling, and Transport to the Laboratory. . Specimen Identification. Test Identification.Specimen Accessioning. Client Communication and Education. Personnel Safety. Laboratory Environment. Personnel Requirements.
Area Under Curve -A statistical means of summarizing information from a series of measurements on one individual. It is frequently used in clinical pharmacology where the AUC from serum levels can be interpreted as the total uptake of whatever has been administered. As a plot of the concentration of a drug against time, after a single dose of medicine, producing a standard shape curve, it is a means of comparing the bioavailability of the same drug made by different companies.
Continuous measurement of a process, product, or service compared to those of the toughest competitor, to those considered industry leaders, or to similar activities in the organization in order to find and implement ways to improve it. This is one of the foundations of both total quality management and continuous quality improvement. Internal benchmarking occurs when similar processes within the same organization are compared. Competitive benchmarking occurs when an organization's processes are compared with best practices within the industry. Functional benchmarking refers to benchmarking a similar function or process, such as scheduling, in another industry.
Inclusive terms used to quantify the positive expected results or outputs of a proposed activity, project, or program expressed in monetary or non-monetary terms. Ideally, estimates of all benefits, outputs, or effectiveness expected to be received or achieved as a result of undertaking a proposed activity, program, or project. adj: clinical Benefit ,economic Benefit, Social Benefit, incremental Benefit. see: Risk/Benefit
Beta blockers or beta-adrenergic blocking agents are a class of drugs used to treat a variety of cardiovascular conditions and some other diseases.Beta blockers block the action of epinephrine and norepinephrine on the ß-adrenergic receptors in the body (primarily in the heart, peripheral blood vessels, bronchi, pancreas, and liver). There are three types of beta receptors: ß1-receptors located mainly in the heart, and ß2-receptors located all over the body, but mainly in the lungs, muscles and arterioles. ß3-receptors are less well characterised, but have a role in fat metabolism.
The probability distribution associated with two mutually exclusive outcomes; used to model cumulative incidence rates and prevalence rates. The Bernoulli distribution is a special case of binomial distribution
the Variability observed when a quantity is measured in different specimens from the same individual obtained over a time span.this variability is due to both imprecision of the measurement procedure, the metrological variability, and the rhythmic and random fluctuations of the quantity value around a virtual homeostatic set point, the intra-individual biological variability.
A characteristic that is objectively measured (by biochemical, or imaging methodology, including molecular medicine) and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention.
• Biomarker is a cellular, or molecular indicator of exposure, health effects, or susceptibility.
• Biomarker can be detected, or described, by chemical, physical, and physico-chemical methodologies
• Biomarker can be represented by a measure (biochemical), or a morphology (imaging), or a function
• Biomarkers can be used to inform about an internal dose, a biologically effective dose, an early biological response, an altered structure or function, a susceptibility
Body Mass Index: a number that doctors use to determine the risk of cardiovascular disease created by a person being overweight. BMI is calculated using a formula of weight in kilograms divided by height in meters squared (BMI =W [kg]/H [m2]). There is a tendency to susbtitute in the adults the BMI by the Waist to Hip ratio
Brain Natriuretic Peptide Type B. links : Pro-pro BNP, pro BNP, BNP-32, pro-BNP77/08, B405+B288 Atrial and Ventricular cardiomyocites produce proANP (1-126) and proBNP(1-108) rispectively. Which are subsequentely cleaved in Amino Terminal NT terminals with different numer of aminoacids. Myocite stretch and volume overload both stimulate the release of ANP and BNP as well as thir amino-termonal counterparts.
The force or pressure exerted by the heart in pumping blood; the pressure of blood in the arteries. adj: Diastolic pressure, The pressure of blood inside arteries when the heart is at rest. Systolic pressure: The pressure of blood inside arteries when the heart contracts.
Ultrasound technique to test for elasticity of the brachial artery after a release of a restriction placed on the upper arm for a period of time. This is a proposed diagnostic test for Cardio Vascular Diseases - CVD.
A brain tumor is any intracranial mass created by an abnormal and uncontrolled growth of cells either normally found in the brain itself (neurons, glial cells - astrocytes, oligodendrocytes, ependymal cells, lymphatic tissue, blood vessels), in the cranial nerves (myelin producing cells Schwann cells), in the brain envelopes (meninges), skull, pituitary and pineal gland, or spread from cancers primarily located in other organs (metastatic tumors).
Coronary Artery Disease: A condition caused by thickening of the walls of the arteries that supply blood to the heart muscle. When these arteries become blocked, the heart is deprived of oxygen and can become damaged. Severe cases can result in heart atta
A mathematical calculation related to the amount of calcium determined by multiplying the area of calcified plaque by a weighting factor based on the CT number or Hounsfield unit of the calcified plaque. Weighted volume of calcium.
Set of operations that establish, under specified conditions, the relationship between values of quantities indicated by a measuring instrument or measuring system, or values represented by a material measure or a reference material and the corresponding values realized by standards
A table showing the performance of each calibrator with respect to the calibration response curve, giving for each calibrator:
- Concentration: The nominal calibrator concentration. - the Ybar: the average response - the XCalc: the estimated concentration from the average response for the calibrator. - Nominal: the result from XCalc divided by the value of the nominal concentration, expressed as a percentage. - Replicates: the number of replicates for the calibrator.
The local injection of pure inflammatory mediators induces venular or capillary leakage. Vascular leakage in aseptic inflammation is biphasic, first venular, then capillary; the capillary phase is induced by the inflammatory reaction itself, possibly through a form of diffuse angiogenesis."
Plaque inflammation in the carotid arteries is a major risk factor for Stroke. Atherosclerotic plaque typically develops around the region of the internal and common carotid artery bifurcation. Knowledge of the differential wall motion displacements across the carotid bifurcation in normal and in diseased arteries may thus be useful in the study of atherosclerotic disease. An important clinical application is the identification of high-risk plaques that are vulnerable to rupture, leading to stroke. It is hoped the vulnerable plaque may be predicted by identifying pertinent features of the carotid plaque wall motion behaviour throughout the cardiac cycle.
Carotid vessel narrowing is a relatively poor predictor of strokerisk; most patients with severe carotid artery narrowing remain stroke-free for over 5 years without treatment, although surgery or medication may be employed when significant carotid plaque is found
Various ultrasound techniques have been used to detect and track the vessel wall motion. Computational techniques have mainly been based on analysis of the B-mode greyscale images , M-mode [, analyses of the raw RFultrasound data and Doppler techniques . Tissue Doppler Imaging (TDI) is a relatively new commercial technique, originally developed for imaging the myocardium, which has found increasing applications in echocardiography. TDI is basically a colour Doppler technique that has been optimised to provide images of tissue motion rather than blood flow, and is capable of high spatial and temporal resolution. The signal processing techniques employed to extract the tissue velocity information from the RFultrasound data are typically based on time domain cross-correlation techniques or autocorrelation techniques.
Classification and Regression Tree: basically a bivariate, explorative methodology using binary recursive partitioning to classify patients in homogeneous, clinically important “risk groups” and is also particularly suitable to detect complex interactions.
is a transmembrane glycoprotein expressed by B lymphocytes, but also detected on other cell types or tumors, particularly carcinomas. As for CD40L, CD40 is part of a large protein family, the TNF-receptor family. The CD40L trimer is expected to bind three CD40 molecules, very much in the same way the TNFbeta trimer binds three TNF-55R receptors.
chest pain is a symptom of a number of serious conditions and is generally considered a medical emergency. The nature of the pain and the circumstances of it appearance together the medical examination and semeyotic should distinguish angina, the pain of myocardial infarction, the pain associated with a dissecting aneurysm, a pleuric pain, a chest trauma, and other clincal situations
n-Chimerin: GTPase activating protein that is specific for RAC GTP-BINDING PROTEINS. It is expressed primarily in the brain and may be involved in signal transduction. The alternatively spliced form of CHIMERIN 1 (alpha-2 Chimerin) contains an additional src homology domain and is expressed in both the brain and testes.
A distribution in which a variable is distributed like the sum of the the squares of any given independent random variable, each of which has a normal distribution with mean of zero and variance of one. The chi-square test is a statistical test based on comparison of a test statistic to a chi-square distribution. The oldest of these tests are used to detect whether two or more population distributions differ from one another.
a lipid that occurs naturally in the body, in animal fats and in dairy products, and that is transported in the blood. Limited quantities are essential for the normal development of cell membranes. Links: Total Cholesterol : TC. HDL Colesterol: HDL-C. LDLCholesterol: LDL-C
Choline is generated by the cleavage of membrane phospholipis by phospholipase Whole Blood Choline - WPCHO and olasma Choline (PCHO) concentrations increase after stimulation of phospholipase D (PLD) and the activation of surfaces receptors in choronary plaque destabilization
A treatment regime, agreed upon by consensus, that includes all the elements of care, regardless of the effect on patient outcomes. It is a broader look at care and may include tests and x-rays that do not affect patient recovery. syn: Clinical path.
risk of errors and adverse events occurring with the health system can be divided into the following five areas:
· The risk of individual clinical incompetence or malpractice:
· The risk of systems failure:
· Risks imposed by cost constraints:
· Patients’ perception of risk:
· Risks inherent in clinical procedures:
Patients, healthcare professionals, health managers and health organisations are together asked to help in defining the most effective way of managing risk generally and in relation to individual cases as well as identifying where the responsibility for different levels of risk should lie.
Pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects.
Clinical Trials, Phase I
Studies performed to evaluate the safety of diagnostic, therapeutic, or prophylactic drugs, devices, or techniques in healthy subjects and to determine the safe dosage range (if appropriate). These tests also are used to determine pharmacologic and pharmacokinetic properties (toxicity, metabolism, absorption, elimination, and preferred route of administration). They involve a small number of persons and usually last about 1 year. This concept includes phase I studies conducted both in the U.S. and in other countries
Clinical Trials, Phase II
Studies that are usually controlled to assess the effectiveness and dosage (if appropriate) of diagnostic, therapeutic, or prophylactic drugs, devices, or techniques. These studies are performed on several hundred volunteers, including a limited number of patients with the target disease or disorder, and last about two years. This concept includes phase II studies conducted in both the U.S. and in other countries.
Clinical Trials, Phase III
Comparative studies to verify the effectiveness of diagnostic, therapeutic, or prophylactic drugs, devices, or techniques determined in phase II studies. During these trials, patients are monitored closely by physicians to identify any adverse reactions from long-term use. These studies are performed on groups of patients large enough to identify clinically significant responses and usually last about three years. This concept includes phase III studies conducted in both the U.S. and in other countries.
Clinical Trials, Phase IV
Planned post-marketing studies of diagnostic, therapeutic, or prophylactic drugs, devices, or techniques that have been approved for general sale. These studies are often conducted to obtain additional data about the safety and efficacy of a product. This concept includes phase IV studies conducted in both the U.S. and in other countries.
The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival.
A detrimental patient condition that arises during the process of providing health care, regardless of the setting in which the care is provided. For instance, perforation, hemorrhage, bacteremia, and adverse reactions to medication (particularly in the elderly) are four complications of colonoscopy and its associated anesthesia and sedation. A complication may prolong an inpatient's length of stay or lead to other undesirable outcomes.
Factors that can cause or prevent the outcome of interest, are not intermediate variables, and are not associated with the factor(s) under investigation. They give rise to situations in which the effects of two processes are not separated, or the contribution of causal factors cannot be separated, or the measure of the effect of exposure or risk is distorted because of its association with other factors influencing the outcome of the study.
Copeptin is a glycopeptide comprising the C-terminal part of the AVP prohormone Arginine Vasopressin - AVP which is a key regulator of water balance, but its instability makes reliable measurement difficult and precludes routine use.
Cost-benefit analysis is the process of weighing the total expected costs vs. the total expected benefits of one or more actions in order to choose the best or most profitable option.Converts effects into the same monetary terms as the costs and compares them
A wide variety of strategies or methods whose primary goal is to control the rising cost of health care, thus making health care more affordable. These strategies and methods may include, but are not limited to government regulation, managed care programs, payment policies, global budgets, rate setting, consumer education, and utilization management. link: Cost minimazation
see Cost-Benefit Analysis
Often, this involves monetary calculations of initial expense vs. expected return. For example, a product manager may compare manufacturing and marketing expenses to projected sales for a proposed product, and only decide to produce it if he expects the revenues to eventually recoup the costs.
The observation of a defined population at a single point in time or time interval. Exposure and outcome are determined simultaneously. Decision Analysis is the application of explicit, quantitative methods to analyse decisions under conditions of uncertainty.
The crude probability of death measures the mortality patterns actually experienced in a cohort of cancer patients on which many possible causes of death are acting simultaneously. This option estimates the probability of dying from cancer and dying from other causes in a cohort of cancer patients. The measure uses expected survival (obtained from the expected life tables) to estimate the probability of dying from other causes in each interval.
The comparative mortality (or morbidity) figure is a simple summary of the incidence rate ratios between the observed and standard population which is obtained by dividing the directly standardised rate for the observed population by the crude rate for the standard population. In practice the CMR is sometimes expressed as percentage.
Coefficient of Variation-CV in the probability theory and statistics, it is a measure of dispersion of a probability distribution. It is defined as the ratio of the standard deviation to the mean: The coefficient of variation is a dimensionless number that allows comparison of the variation of populations that have significantly different mean values. It is often reported as on a scale of 0 to 100% by multiplying the above calculation by 100. A coefficient of variation of 1 percent would indicate that an estimate could vary slightly due to sampling error, while a coefficient of variation of 50 percent means that the estimate is very imprecise.
These are cell-derived chemicals that are secreted by various types of cells and act on other cells to stimulate or inhibit their function. Chemicals derived from lymphocytes are called “lymphokines.” Chemicals derived from lymphocytes that act on other white blood cells are called “interleukins,” that is, they interact between two types of leukocytes.
A statistical analytic technique used with discrete dependent variables, concerned with separating sets of observed values and allocating new values. It is sometimes used instead of regression analysis
The Duke treadmill score is a quantitative means of expressing cardiac risk derived entirely from the exercise ECG. It incorporates depth of ST depression, treadmill time (METS) and angina on the treadmill. The score is calculated as duration of exercise in minutes - (5 x the maximal net ST-segment deviation) during or after exercise, in millimetres - (4 x the treadmill angina index). The angina index has a value of 0 if there is no angina during exercise, 1 if the patient had nonlimiting angina and 2 if angina was the reason the patient stopped exercising. High risk scores of < - 10 give a 5 year survival rate of <75%, intermediate score of -10 to 4+ give a 5 year survival risk of 75 - 95% and low risk scores of > + 5 give a 5 year survival rate of > 95%.
The dobutamine stress echo test involves taking dobutamine under close monitoring. TThe test is used to evaluate heart and valve function when the patient is unable to exercise on a treadmill or stationary cycle.
A method of studying the heart's structure and function by analyzing sound waves bounced off the heart and recorded by an electronic sensor placed on the chest. A computer processes the information to produce a one-, two- or three-dimensional moving picture that shows how the heart and heart valves are functioning. links: Transesophageal echocardiography - A diagnostic test that analyzes sound waves bounced off the heart. The sound waves are sent through a tube-like device inserted in the mouth and passed down the esophagus (food pipe), which ends near the heart. This technique is useful in studying patients whose heart and vessels, for various reasons, are difficult to assess with standard echocardiography.
The extent to which actual outcomes are achieved, in terms of the planned outcomes, via relevant outputs, programs or administered expenses. The effectiveness of an output or program should be distinguished from its efficiency, which concerns the adequacy of its administration.
Endothelium in Atherogenesis: the early endothelium damage is prompeted by several factors icluding oxidised LDL, with protective effect of HDL; activated neutrophiles and macrophages adher to the damaged endothelium; activated macrophages become foam cells by uptake of oxidized LDL, and synthetize Angiotensin II to promotes oxidative stress caused by reactive oxygene species (ROS) ant stimulate the formation of VICAM, and promotes growth of Vascular Smooth Cells (VSM)
Electrophysiological study. A test that uses cardiac catheterization to study patients who have arrhythmias (abnormal heartbeats). An electrical current stimulates the heart in an effort to provoke an arrhythmia, which is immediately treated with medication. EPS is used primarily to identify the origin of arrhythmias and to test the effectiveness of drugs used to treat abnormal heart rhythms.
Error of commission: an error which occurs as a result of an action taken. Examples include when a drug is administered at the wrong time, in the wrong dosage, or using the wrong route; surgeries performed on the wrong side of the body; and transfusion errors involving blood cross-matched for another patient.
Error of omission: an error which occurs as a result of an action not taken, for example, when a delay in performing an indicated cesarean section results in a fetal death, when a nurse omits a dose of a medication that should be administered, or when a patient suicide is associated with a lapse in carrying out frequent patient checks in a psychiatric unit. Errors of omission may or may not lead to adverse outcomes.
Evaluation has several distinguishing characteristics relating to focus, methodology, and function. Evaluation assesses the effectiveness of an ongoing program in achieving its objectives, Evaluation relies on the standards of project design to distinguish a program's effects from those of other forces. Evaluation aims at program improvement through a modification of current operations. adj: clinical evaluationevaluation, economic evaluation
Is the proportion of patients in a group in whom an the event is observed. Thus, if out of 100 patients, the event is observed in 27, the event rate is 0.27. links: Control Event Rate (CER) and Experiemental Event Rate (EER) are used to refer to this in control and experimental groups of patients respectively.
EBM Is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence-based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research.
False Positive :A test result that incorrectly says the analyte, disease, or condition is present when it is actually not present. False positives can be due to human error, test error, or substances in the sample that interfere with the test.
False Negative: A test result that incorrectly says the analyte, disease, or condition is not present when it actually is present. False negatives can be due to human error, test error, or substances in the sample that interfere with the test.
Positron Emitting Tomography with (18)F-fluorodeoxyglucose (FDG). This procedure detects active malignant lesions, and may also be used to stage and monitor the response to therapy of malignant disease.
Glycogen Phosphorylase BB is a glycolytic enzyme tha plays a role in the regulation of carbohydrate metabolism. GPBB is associated with glycogen in a comples, and in ischemia glycogen is broken down and GPBB become free. In myocardial ischemia its early release is and indicator of irreversible ,yocardial damage
Demographic and epidemiologic changes that have occurred in the last five decades in many developing countries and that are characterized by major growth in the number and proportion of middle-aged and elderly persons and in the frequency of the diseases that occur in these age groups. The health transition is the result of efforts to improve maternal and child health via primary care and outreach services and such efforts have been responsible for a decrease in the birth rate; reduced maternal mortality; improved preventive services; reduced infant mortality, and the increased life expectancy that defines the transition
hypoxia-inducible transcription factors (HIF) -1 and -2, oxygen-regulated -subunits of two principal mediators of adaptation to critically low oxygen levels. Hypoxia-inducible factor-1 (HIF-1) is a heterodimeric peptide that is a key regulator of genes such as heme oxygenase (HO)-1 expressed under hypoxic conditions. We hypothesized that HO-1 plays an important role in regulating proinflammatory mediator production under conditions of ischemia-reperfusion.
An amino acid (one of the building blocks that makes up a protein normally found in small amounts in the blood.High levels of homocysteine in the blood may promote the buildup of fatty plaque in the arteries and teherefore are considered an independent graded risck for CAD
An Incremental Cost EffectivenessRatio is calculated as ¿ cost / ¿ outcome between several procedures or therapies where the USPHS has defined a goal toward economic efficiency set at <$50,000 per life year saved
Intermediate-Density Lipoporteins - IDL are a class of lipoproteins formed from the degradation of very low density lipoproteins, constituted essentially of triacylglycerols and cholesterol esters. They are cleared from the plasma into the liver by receptor-mediated endocytosis, or further degraded to form low density lipoproteins. They are usually 25 to 35 nm in diameter.
Two events are independent if the occurrence of one of the events gives us no information about whether or not the other event will occur; that is, the events have no influence on each other.In probability theory we say that two events, A and B, are independent if the probability that they both occur is equal to the product of the probabilities of the two individual events.
1. A measure used to determine, over time, performance of functions, processes, and outcomes. 2. A statistical value that provides an indication of the condition or direction over time of performance of a defined process or achievement of a defined outcome
Contrast-enhanced magnetic resonance imaging detected infarct-related signal changes as early as 1 h after AMI in humans, whereas the sensitivity of edema-related signal changes was not sufficient during this very early stage.
Inflammation is the first response of the immune system to infection or irritation and may be referred to as the innate cascade. Inflammation is characterized by the following quintet: redness (rubor), heat (calor), swelling (tumor), pain (dolor) and dysfunction of the organs involved (functio laesa). The first four characteristics have been known since ancient times and are attributed to Celsus; functio laesa was added to the definition of inflammation by Rudolf Virchow in 1858.
International Normalized Ratio (INR) - The accuracy of the Prothrombin Time (PT) is known to be very system-dependent. The World Health Organization has addressed this system variability problem by the establishment of primary and secondary international reference preparations of thromboplastin and the development of a statistical model for the calibration of thromboplastins to derive the International Sensitivity Index (ISI) and to equate all thromboplastins to the reference thromboplastin through the following equation: INR = (patient PT/mean normal PT)isi
Interleukins are a group of cytokines that are expressed by white blood cells (leukocytes, hence the -leukin) as a means of communication (inter-). A list of interleukins with function:
IL-1: (secreted by macrophages), induces acute phase reaction
IL-2: (secreted by T cells) stimulates growth and differentiation of T cell response.
IL-3: (secreted by T cells), stimulates bone marrow stem cells.
IL-4: involved in proliferation of B cells, and the development of T cells and mast cells. Role in allergic responses.
IL-5: role in stimulation of B cells, eosinophil production, IgA production
IL-6: (secreted by macrophages) induces acute phase reaction
IL-7: involved in B, T and NK cell survival, development and homeostasis
IL-8: Neutrophil chemotaxis
IL-9: stimulates mast cells
IL-10: inhibits Th1 cytokine production
IL-11: acute phase protein production
IL-12: NK cell stimulation, Th1 cells induction
IL-13: Stimulates growth and differentiation of B-Cells, inhibits Th1 cells and the production of macrophage inflammatorycytokines
IL-17: Induces production of inflammatorycytokines
IL-18: Induces production of Interferon-Gamma (IFNy)
Low-density lipoprotein (LDL) refers to a class and range of lipoprotein particles, varying somewhat in their size and contents, which carry cholesterol in the blood and around the body, for use by various cells.It is the final stage of VLDL (very low-density lipoprotein) witch is produced by the liver. The LDLLDL contains the apoprotein B-100 (Apo B-100) among is plasma lipids. links: sdLDL , large buoyant LDL
refers to bilateral and either a patchy or diffuse areas of hypodensity of the cerebral white matter (WM) on CT or hyperintensitivity on T2-weighted MRI: probably it is caused by chronic cerebral ischemia
Functions constructed from a statistical model and a set of observed data which give the probability of that data for various values of the unknown model parameters. Those parameter values that maximize the probability are the maximum likelihood estimates of the parameters
Linear discriminant anlysis: is the likelihood that a given test result would be expected in a patient with the target disorder compared to the likelihood that the same result would be expected in a patient without that disorder.
Lp(a) consists of a particle of low-density lipoproteincholesterol (LDL-C) linked by a disulfide bond to a large hepatically derived glycoprotein, apolipoprotein(a), which is structurally similar to plasminogen. In theory, then, Lp(a) could promote cardiovascular disease in two ways: its apolipoprotein(a) moiety could promote thrombogenesis and its LDL-C moiety could promote atherogenesis.
Cirrhosis of the liver is a chronic, diffuse degenerative disease in which the parenchyma deteriorates; the lobules are infiltrated with fat and structurally altered; dense perilobular connective tissue forms; and often areas of regeneration develop. As the cirrhotic process continues, blood flow through the liver becomes blocked; portal hypertension may occur.
A system in which specific performance objectives are jointly determined by subordinates and their superiors, progress towards objectives is periodically reviewed, end results are evaluated and rewards are allocated on the basis of this progress.
a) Two samples in which the members are clearly paired, or are matched explicitly by the researcher. b) Those samples in which the same attribute, or variable, is measured twice on each subject, under different circumstances. Commonly called repeated measures. Sometimes, the difference in the value of the measurement of interest for each matched pair is calculated, for example, the difference between before and after measurements, and these figures then form a single sample for an appropriate statistical analysis.
A type of analysis in which subjects in a study group and a comparison group are made comparable with respect to extraneous factors by individually pairing study subjects with the comparison group subjects (e.g., age-matched controls).
Matrix metallo-proteinases - MMPs are a group of enzymes thought to be responsible for both normal connective tissue matrix remodelling and accelerated breakdown associated with tumor development. The distribution of 3 major matrix metallo-proteinases was studied in human mammary pathology: collagenase (MMP1) which degrades fibrillar interstitial collagens, a 72-kDa gelatinase (MMP2) which mainly degrades type IV collagen and denatured collagens, stromelysin (MMP3) which has a wider range of action, degrading several matrix components including the core proteins of proteoglycans, laminin and non-helical regions of collagens, 92kDa gelatinase/type IV collagenase, gelatinase B (MMP9).
The Metallo Proteinases may be one of the older classes of proteinases and are found in bacteria, fungi as well as in higher organisms. They differ widely in their sequences and their structures but the great majority of enzymes contain a zinc atom which is catalytically active. In some cases, zinc may be replaced by another metal such as cobalt or nickel without loss of the activity. see also: Matrix metallo-proteinases - MMPs
Metabolic equivalents - 1 MET is equivalent to a metabolic rate consuming 3.5 milliliters of oxygen per kilogram of body weight per minute. or
1 MET is equivalent to a metabolic rate consuming 1 kilocalorie per kilogram of body weight per hour.
Failure of the mitral valve to close properly, causing blood to flow back into the heart's upper left chamber (the left atrium) instead of moving forward into the lower left chamber (the left ventricle).
A narrowing of the mitral valve, which controls blood flow from the heart's upper left chamber (the left atrium) to its lower left chamber (the left ventricle). May result from an inherited (congenital) problem or from rheumatic fever.
A type of fat found in many foods but mainly in avocados and in canola, olive, and peanut oils. Monounsaturated fat tends to lower LDLcholesterol levels, and some studies suggest that it may do so without also lowering HDLcholesterol levels
In epidemiology, the morbidity rate is a ratio that measures the incidence and prevalence of a specific disease. Within the framework of a given time period (typically, but not necessarily, one year) it gives the number of people who are afflicted with that disease per unit of population. It is usually expressed as a number of people afflicted per 1,000, 10,000, or 100,000 people.
Magnetic Resonance Imaging : A technique that produces images of the heart and other body structures by measuring the response of certain elements (such as hydrogen) in the body to a magnetic field. When stimulated by radio waves, the elements emit distinctive signals in a magnetic field. MRI can produce detailed pictures of the heart and its various structures without the need to inject a dye.
A set of techniques used when variation in several variables has to be studied simultaneously. In statistics, multivariate analysis is interpreted as any analytic method that allows simultaneous study of two or more dependent variables
An analysis where the effects of many variables are considered. Can select a subset of variables that significantly contribute to the variation in outcome
Relative Risk = Event rate in treatment group divided by the event rate in the control group. Also known as riskratio. RR is used in randomized trials and cohort studies.
Noises superimposed on normal heart sounds. They are caused by congenital defects or damaged heart valves that do not close properly and allow blood to leak back into the chamber from which it has come.
A heart attack. The damage or death of an area of the heart muscle (myocardium) resulting from a blocked blood supply to the area. The affected tissue dies, injuring the heart. Symptoms include prolonged, intensive chest pain and a decrease in blood pressure that often causes shock. Myocardial Injury
Myosin light chain Isoform - (MLC-I) is a cardiac contractile protein with molecular mass of 22 kD. In severe CHF myofibrils may degenerate and subsequently the myofibrils component may be released in the circulation.
A pteridine derivative present in body fluids; elevated levels result from immune system activation, malignant disease, allograft rejection, and viral infections. Neopterin also serves as a precursor in the biosynthesis of biopterin.
Nuclear Factor (NF)-kappaB. belongs to the Toll-like receptors (TLRs) family. It is a substrate of NFkB Kinase Activity, Enzyme activates DNA-binding activity of nfkb by directly phosphorylating its p65 and p50 subunits; does not phosphorylate ikb; may have a central role in mediating various signals to nfkb.
The patient undergoes pairs of treatment periods organised so that one period involves the use of the experimental treatment and one period involves the use of an alternate or placebo therapy. The patients and physician are blinded, if possible, and outcomes are monitored. Treatment periods are replicated until the clinician and patient are convinced that the treatments are definitely different or definitely not different.
When small changes yield disproportionate effects not easily prectictable. While the solutions of linear equations can in general be described as a superposition of other solutions of the same equation and this makes linear equations particularly easy to solve and reason about, nonlinear equations are more complex, and much harder to understand because of their lack of simple superposed solutions. For nonlinear equations the solutions to the equations do not in general form a vector space and cannot (in general) be superposed (added together) to produce new solutions. This makes solving the equations much harder than in linear systems.
A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data.
A catecholamine hormone that functions as a neurotransmitter in the sympathetic nervous system, producing alpha-adrenergic (vasoconstriction) and beta(1)-adrenergic stimulation (increase myocardial contractility, heart rate, automaticity, and AV conduction), and beta(2)-adrenergic activity (peripheral vasodilation).(NCI)
The condition of being significantly overweight. It is usually applied to a condition of 30 percent or more over ideal body weight. Obesity puts a strain on the heart and can increase the chance of developing high blood pressure and diabetes.
Are a ratio of events to non-events. If the event rate for a disease is 0.1 (10 per cent), its nonevent rate is 0.9 and therefore its odds are 1:9, or 0.111. Note that this is not the same expression as the inverse of event rate
Osteopontin - OPN, produced by osteoblasts is a glycosylated phosphoprotein with a high acidic amino acid content a. It is thought that osteopontin may act as a bridge between osteoblasts and the apatite mineral of the bone Osteopontin-K is a kidney protein, similar to osteopontin and probably also involved in cell adhesion . It binds calcium and interacts with the vitronectin receptor, avbeta3 integrin. It has been shown to bind covalently to fibronectin via transglutaminase-catalyzed cross-linking. In vivo, elevation in OPN levels are seen during sepsis and metastatic cancers.
The result of the performance (or nonperformance) of a function(s) or process(es). . Outcomes may be described as: immediate, intermediate or final, direct or indirect, intended or unintended. Outcomes in a logic model typically have an action word associated with them (eg, increased or improved) and represent the consequences of the activities and outputs. When referring to CVD, this is a term given to mean significant events – such as heart attacks, strokes or sudden death – measured within long-term, major clinical studies.
The oxidative conversion of low-density lipoproteins (LDL) to oxidized low-density lipoproteins (oxidized LDL) is now considered to be a key event in the biological process that initiates and accelerates the development of the early atherosclerotic lesion.
Pattern recognition receptors, or PRRs, are a class of proteins which are employed by the cells of the immune system to identify molecules common to microbial pathogens but not present in mammalian cells. They are key elements in innate immunity as well as influence the development of adaptative immunity. Among the molecules recognised by these PRRs are: lipopolysaccharide (LPS) of gram negative bacteria, peptidoglycans and lipotechoic acids from Gram positive bacteria, mannose residues, bacterial DNA, N-formylmethionine, viral double-stranded RNA and fungal glucans.
Cardiac Perfusion Scan is a test to estimate the amount of blood reaching the heart muscle during rest and exercise. This may also be called a thallium or technetium sestamibi (MiBi) scan. It is typically done to determine the cause of unexplained chest pain or to determine the location and amount of injured heart muscle after a heart attack.
Inflammation of the outer membrane surrounding the heart. When pericarditis occurs, the amount of fluid between the two layers of the pericardium increases. This increased fluid presses on the heart and restricts its pumping action
Positron Emission Tomography A test that uses information about the energy of certain elements in your body to show whether parts of the heart muscle are alive and working. A PET scan can also show if your heart is getting enough blood to keep the muscle healthy.
Platelets or thrombocytes are small flat disks, which are produced by megakaryocytes. They adhere to exposed subendothelial collagen within seconds of injury to form a hemostatic plug. Low platelet counts predispose an animal to hemorrhage.
The predictive value of a test is a measure (%) of the times that the value (positive or negative) is the true value, i.e. the percent of all positive tests that are true positives is the Positive Predictive Value.
__TP___ X 100 = Predictive Value of a Positive Result (%)
TP + FP
__TN___ X 100 = Predictive Value of Negative Result (%)
FN + TN
Results of conception and ensuing pregnancy, including live birth, stillbirth, spontaneous abortion, induced abortion. The outcome may follow natural or artificial insemination or any of the various reproduction techniques, such as embryo transfer or fertilization in vitro.
For Class III medical devices and devices that employ novel methods of treatment and are not substantially equivalent to currently marketed medical devices, manufacturers must submit a Premarket Approval Application to the FDA. A PMA is much more complex and time-consuming to prepare than a 510(k). A PMA submission typically contains a significant quantity of clinical, animal testing, manufacturing, and other data, all of which the FDA carefully scrutinizes.After a PMA is submitted, the FDA usually assembles a scientific advisory panel to study the PMA . The panel, comprising physicians and other experts in fields relevant to the submission, may hold a public meeting during which the PMA is reviewed and discussed. After evaluating the data in the PMA, the panel will recommend to FDA that it be approved, approved with conditions, or not approved.
FDA’s primary consideration in determining when a new IVD requires a PMA is the level of risk to patient health that information obtained from use of the IVD may have in the event of an erroneous test result. In this context, FDA seeks to understand whether the proposed new IVD will be used in a manner that will uniquely and substantively affect diagnostic or therapeutic interventions for a particular disease or condition
510(k) Premarket Notification. Medical devices that are substantially similar to products already on the market can usually obtain FDA clearance via the agency's premarket notification process, known as a 510(k).. This review process is required for a few class I devices, most Class II devices and some Class III devices. In a 510(k) filing, the FDA requires that medical device manufacturers provide information and data (which may include clinical data) demonstrating that the new device is substantially equivalent to previously marketed devices and does not raise any new questions with respect to safety or efficacy.
Activities that prevent a natural phenomenon or a potential hazard from having harmful effects on either persons or property. Primary, secondary and tertiary. Primary prevention is an active assertive process of creating conditions and or personal attributes that promotes the well being of people. Secondary prevention is early detection and intervention to keep beginning problems from becoming more severe. Tertiary prevention is the effort to rehabilitate those affected with severe disorders and return them to the community.
Proform of Eosinophil Major Basic Protein (pro-MBP) . 23.8 kDa secreated pro-form of MBP found in the placenta and serum of pregnant women as well as the 13.8 kDa mature form of the protein which is found in the matrix of the eosinophil large specific granual. Pregnancy Associated MBP
The cause of death must be defined for cause specific survival or probability of death using cause of death information.Cases that have died but do not fall in your defined definition of dead are considered to be censored at their time of death for net survival or died from other causes for crude probability of death.
P-selectin: 140kDa. It contains nine consensus repeats and extends approximately 40 nm from the endothelial surface.P-selectin is expressed in a-granules of activated platelets and granules of endothelial cells.Within minutes of stimulation of the endothelial cells by inflammatory mediators such as histamine, thrombin, or phorbol esters, P-selectin is surface-expressed. Expression of P-selectin also occurs from the surgical trauma endured during preparation of the tissues for intravital microscopy.
One form of cost–effectiveness analysis, cost–utility analysis, allows the comparison of different health outcomes (such as prolongation of life, prevention of blindness or relief of suffering) by measuring them all in terms of a single unit — the quality-adjusted life-year (QALY). To do this, any state of health or disability is assigned a utility on a scale ranging from 0 (immediate death) to 1 (a state of perfect health). The outcome of any health intervention can then be calculated as the product of the increase in utility that it may cause and the time in years over which it may be enjoyed. When allocating scarce resources, those interventions that are expected to produce fewer QALYs for any given cost are given a lower priority.
The QT interval represents the duration of ventricular depolarization and subsequent repolarization, beginning at the initiation of the QRS complex and ending where the T wave returns to isoelectric baseline. Because of its inverse relationship to heart rate, the QT interval is routinely transformed (normalized) by means of various formulae into a heart rate independent “corrected” value known as the QTc interval. The QTc interval is intended to represent the QT interval at a standardized heart rate of 60 bpm. A delay in cardiac repolarization creates an electrophysiological environment that favors the development of cardiac arrhythmias, most clearly torsade de pointes, but possibly other ventricular arrhythmias as well.
While the degree of QT prolongation is recognized as an imperfect biomarker for proarrhythmic risk, there is a qualitative relationship between QT prolongation and the risk of TdP, especially for drugs that cause substantial prolongation of the QT/QTc interval.
quality assurance: all those planned and systematic actions necessary to provide adequate confidence that a product, process or service will satisfy given requirements for quality. quality control: operational techniques and activities that are used to fulfil given requirements for quality
A test in which a harmless radioactive substance is injected into the bloodstream to show information about blood flow through the arteries. Damaged or dead heart muscle can often be identified, as can serious narrowing in an artery
"RANTES is an acronym for Regulated on Activation, Normal T Expressed and Secreted. A cytokine that is a member of the interleukin-8 superfamily of cytokines. RANTES is a protein. It is a selective attractant for memory T lymphocytes and monocytes. It binds to CCR5, a coreceptor of HIV. . It is also known as CCL5.
Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In MULTIPLE REGRESSION the dependent variable is considered to depend on more than a single independent variable.
In the context of government and public services regulation (as a process) is the control of something by rules, as opposed to its prohibition. In economics, it is part of the government relationship with markets, often seen as the opposite of deregulation. Regulatory Agency: the agency or government department that has responsibility over the legislation (acts and regulations) for a given sector of the government.
Relative Frequency is another term for proportion; it is the value calculated by dividing the number of times an event occurs by the total number of times an experiment is carried out. The probability of an event can be thought of as its long-run relative frequency when the experiment is carried out many times. If an experiment is repeated n times, and event E occurs r times, then the relative frequency of the event E is defined to be: rfn (E)= r / n
In strategic planning, a resource-allocation decision is a plan for using available resources, especially in the near term, to achieve goals for the future. Or in other words, it is the process of allocating resources among the various projects or business units.The plan has two parts: (1) the basic allocation decision; and (2) contingency mechanisms. The basic allocation decision is the choice of which items to fund in the plan (and the level of funding)and which to leave unfunded: the resources are allocated to some items, not to others.There are two contingency mechanisms: (1) a priority ranking of items excluded from the plan, showing which items to fund if more resources should become available; (2) a priority ranking of some items included in the plan, showing which items should be sacrificed if total funding must be reduced.
A disease, usually occurring in childhood, that may follow a streptococcal infection. Symptoms may include fever, sore or swollen joints, skin rash, involuntary muscle twitching, and development of nodules under the skin. If the infection involves the heart, scars may form on heart valves, and the heart's outer lining may be damaged
is the potential harm that may arise from some present process or from some future event. It is often mapped to the probability of some event which is seen as undesirable. Usually the probability of that event and some assessment of its expected harm must be combined into a believable scenario (an outcome) which combines the set of risk, regret and reward probabilities into an expected value for that outcome.
a scientifically based process consisting of the following steps: (i) hazard identification, (ii) hazard characterization, (iii) exposure assessment, and (iv) risk characterization. syn: Risk analysis, Risk diagnosis other: Risk recurrence
Risk Factor - RF: an element or condition involving a certain hazard or danger. When referring to heart and blood vessels, a risk factor is associated with an increased chance of developing cardiovascular disease, including stroke
A process consisting to simplify and combine three processes: Risk assessment, Risk management and Risk communication performed to understand the nature of unwanted, negative consequences to human and animal health, or the environment
Reactive oxygen species (ROS) are normally produced as a product of metabolism, and, as their name implies, they are highly reactive with surrounding biological components. The ability of ROS to damage DNA and other critical molecules underlies their reputation for causing deleterious cellular effects and their association with aging, carcinogenesis, and atherosclerosis.
The S-100B protein is released by injured astrocytes. After passage through a disintegrated blood-brain barrier (BBB) the molecule can be detected in the peripheral circulation. We investigated the association between the extent of brain injury and S-100B concentration in serum in cerebral injury caused by cerebral ischemia and cerebral fungal infection.serum levels of S-100B reflect the time course of tissue injury in cerebral ischemia and cerebral infection to a similar extent. Thus, S-100B may be a useful marker to assess cerebral tissue injury.
soluble CD40 Ligand soluble forms of CD40. CD40 signaling in endothelial and smooth muscle cells, monocytes, and platelets promotes a wide array of proatherogenic and prothrombotic functions in vitro and in vivo
Is the proportion of people with disease who have a positive test. Sensitivity of a test is the percentage of all patients with disease present who have a positive test.
__TP___ X 100 = Sensitivity (%)
TP + FN
An unexpected occurrence involving death or serious physical or psychological injury, or the risk thereof. Serious injury specifically includes loss of limb or function. The phrase, "or the risk thereof" includes any process variation for which a recurrence would carry a significant chance of a serious adverse outcome. Such events are called "sentinel" because they signal the need for immediate investigation and response.
A hormone, also called 5-hydroxytryptamine, in the pineal gland, blood platelets, the digestive tract, and the brain. Serotonin acts both as a chemical messenger that transmits nerve signals between nerve cells and that causes blood vessels to narrow.
A condition in which body function is impaired because the volume of fluid circulating through the body is insufficient to maintain normal metabolism. This may be caused by blood loss or by a disturbance in the function of the circulatory system
A quality-of-life scale developed in the United States in 1972 as a measure of health status or dysfunction generated by a disease. It is a behaviorally based questionnaire for patients and addresses activities such as sleep and rest, mobility, recreation, home management, emotional behavior, social interaction, and the like. It measures the patient's perceived health status and is sensitive enough to detect changes or differences in health status occurring over time or between groups
The "natural" pacemaker of the heart. The node is a group of specialized cells in the top of the right atrium which produces the electrical impulses that travel down to eventually reach the ventricular muscle, causing the heart to contract
When a sign/test has a high sensitivity, a negative result rules out the diagnosis; e.g. the sensitivity of a history of ankle swelling for diagnosing ascites is 92 per cent, therefore is a person does not have a history of ankle swelling, it is highly unlikely that the person has ascites.
Is the porportion of people free of a disease who have a negative test. Specificity of a test is the percentage of all patients without disease who have a negative test.
__TN___ X 100 = Specificity (%)
FP + TN
When a sign/test has a high specificity, a Positive result rules in the diagnosis; e.g. the specificity of fluid wave for diagnosing ascites is 92 per cent. Therefore, if a person has a fluid wave, it is highly likely that the person has ascites.
Statins inhibit an enzyme called HMG-CoA reductase that controls the rate of cholesterol production in the body. These drugs lower cholesterol by slowing down the production of cholesterol and by increasing the liver's ability to remove the LDL-cholesterol already in the blood.
A sudden disruption of blood flow to the brain, either by a clot or a leak in a blood vessel.form Ischemic stroke - A type of stroke that is caused by blockage in a blood vessel.Silent, Stroke Unit, Major, Minor (ms); infact cerebral, ischemic, Hemorragic complication, Recanalization, Reperfusion, reocclusion
Death that occurs unexpectedly and instantaneously or shortly after the onset of symptoms. The most common underlying reason for patients dying suddenly is cardiovascular disease, in particular coronary heart disease
Superoxide is a reactive anion and free radical, formally O2-. It has an unpaired electron, is not particularly stable, and spontaneously decomposes into peroxide and oxygen over time. In phagocytes, superoxide is produced in large quantities by the enzyme NADPH oxidase for use in oxygen-dependent killing mechanisms. links: Superoxide Dismutase
FDA may grant marketing approval for a biological product on the basis of adequate and well-controlled clinical trials establishing that the biological product has an effect on a surrogate endpoint that is reasonably likely, based on epidemiologic, therapeutic, pathophysiologic, or other evidence, to predict clinical benefits or on the basis of an effect on a clinical endpoint other than survival or irreversible morbidity.
Ongoing monitoring using methods distinguished by their practicability, uniformity, and rapidity, rather than by complete accuracy. The purpose of surveillance is to detect changes in trend or distribution to initiate investigative or control measures. Active surveillance is systematic and involves review of each case within a defined time frame. Passive surveillance is not systematic. Cases may be reported through written incident reports, verbal accounts, electronic transmission, or telephone hotlines, for example.
Thromboxane B2 the inactive form of Thromboxane: a substance made by platelets that causes blood clotting and constriction of blood vessels. There are two thromboxanes. Thromboxane A2 (TXA2) is active but is very unstable and has a half-life of only 30 seconds before it undergoes hydrolysis to form thromboxane B2 (TXB2) which is inactive. The thromboxanes are derived from arachidonic acid and are related to prostaglandin.
The efficiency of a test is the percentage of the times that the test give the correct answer compared to the total number of tests.
____TP + TN______ X 100 = Efficiency of a Test Result (%)
TP + TN + FP + FN
Thrombomodulin is an integral protein that contains one chondroitin/ dermatan sulphate chain. It binds to thrombin and act as a cofactor in the activation of protein C catalyzed by thrombin. Glycosaminoglycan chain is not necessary for the activation, but it may be important in preventing thrombin bound to thrombomodulin to cleave fibrinogen. Its core protein contains a short cytoplasmic domain that has a homology with LDL-receptor
The occlusion or blockage of blood flow within a vessel caused by blood that has clotted within the vessel. Occlusions are thrombi composed of platelets, fibrin, erythrocytes, and leukocytes and may be superimposed on or adjacent to atherosclerotic plaques. adj: coronary artery ThrombosisThrombosis, cerebral Thrombosis
Toll-like Receptors (TLRs) type I transmembrane proteins that recognize pathogens and activate immune cell responses as a key part of the innate immune system. In vertebrates, they can help activate the adaptive immune system, linking innate and acquired immune responses. TLR are pattern recognition receptors (PRRs), binding to pathogen-associated molecular patterns (PAMPs), small molecular sequences consistently found on pathogens.
tissue Plasminogen Activator: naturally occurring substance in the body tissues that activates the enzyme plasmin that is able to dissolve blood clots. Human tPA, produced in bacteria by genetic engineering, has, like Streptokinase, been used to dissolve blood clots in the coronary arteries of heart-attack victims.
The most common fatty substance found in the blood; normally stored as an energy source in fat tissue. High triglyceride levels may thicken the blood and make a person more susceptible to clot formation. High triglyceride levels tend to accompany high cholesterol levels and other risk factors for heart disease, such as obesity
Methods of detecting genetic etiology in human traits. The basic premise of twin studies is that monozygotic twins, being formed by the division of a single fertilized ovum, carry identical genes, while dizygotic twins, being formed by the fertilization of two ova by two different spermatozoa, are genetically no more similar than two siblings born after separate pregnancies.
a Biomarker that is measured in an analytical test system with well-established performance characteristics and for which there is an established scientific framework or body of evidence that elucidates the physiologic, toxicologic, pharmacologic, or clinical significance of the test results.
Method validation should be performed before a test procedure is placed into routine use. Validation may be accomplished by thoroughly testing reference materials or by comparison of results of tests performed by an alternative method. For each method, the diagnostic department should verify the manufacturer’s claims and any adjustments before initiating patient evaluation. Method validation should provide evidence of: accuracy, imprecision, sensitivity, specificity, linear reportable range , linearity, referemce material. Validation in Biochmistry, Validation in Imaging
The (population) variance of a random variable is a non-negative number which gives an idea of how widely spread the values of the random variable are likely to be; the larger the variance, the more scattered the observations on average Stating the variance gives an impression of how closely concentrated round the expected value the distribution is; it is a measure of the 'spread' of a distribution about its average value.Variance is symbolised by V(X) or Var(X)
The differences in results obtained in measuring the same phenomenon more than once. Excessive variation frequently leads to waste and loss, such as the occurrence of undesirable patient health outcomes and increased cost of health services. Common-cause variation, also called endogenous cause variation or systemic cause variation, in a process is due to the process itself and is produced by interactions of variables of that process is inherent in all processes, not a disturbance in the process. It can be removed only by making basic changes in the process. Special-cause variation, also called exogenous-cause variation or extrasystemic cause variation, in performance results from assignable causes. Special-cause variation is intermittent, unpredictable, and unstable. It is not inherently present in a system; rather, it arises from causes that are not part of the system as designed.
Arginine vasopressin (AVP) also argipressin or antidiuretic hormone (ADH), is a human hormone released when the body is low on water; it causes the kidneys to conserve water, but not salt, by concentrating the urine and reducing urine volume. It also raises blood pressure by inducing moderate vasoconstriction.
describes structural changes in LV in response to chronic alterations loading conditions with three major patterns: concentric remodelling with growth cardiomycite thickness; eccentric hypetrophy with myocite lenghtening; post myocardial infarction with a remodelling of the non infarcted areas. In all patterns there is a contribution by fibrosis.
Vulnerable plaque is formed in the following way: Fat droplets are absorbed by the artery, which causes the release of proteins (called cytokines) that lead to inflammation.The cytokines make the artery wall sticky, which attracts immune-system cells (called monocytes).The monocytes squeeze into the artery wall. Once inside, they turn into cells called macrophages and begin to soak up fat droplets. The fat-filled cells form a plaque with a thin covering. When this inflammation is combined with other stresses, like high blood pressure, it can cause the thin covering over the plaque to crack and bleed, spilling the contents of the vulnerable plaque into the bloodstream. The sticky cytokines on the artery wall capture blood cells (mainly platelets) that rush to the site of injury. When these cells clump together, they can form a clot large enough to block the artery.
von Willebrand factor (vWF) mediates platelet adhesion to injured endothelium, the first step in hemostasis. It also helps maintain factor VIII levels. When vWF is deficient, patients have a bleeding disorder called von Willebrand disease (vWD). vWD is the most common hereditary bleeding disorder, of which several subtypes are recognized The von Willebrand factor is a large multimeric glycoprotein found in blood plasma. Mutant forms are involved in the aetiology of bleeding disorders [ 1 ]. In von Willebrand factor, the type A domain (vWF) is the prototype for a protein superfamily. The vWF domain is found in various plasma proteins: complement factors B, C2, CR3 and CR4; the integrins (I-domains); collagen types VI, VII, XII and XIV; and other extracellular proteins [ 2 , 3 , 4 ]. Proteins that incorporate vWF domains participate in numerous biological events (e.g. cell adhesion, migration, homing, pattern formation, and signal transduction), involving interaction with a large array of ligands