Glossary

adenovirus	A type of virus that usually causes mild infections like the cold or pink eye. Within the protein shell of the adenovirus is double-stranded DNA, which can be modified to carry modified disease-fighting genes into the human body.
advanced glycation end products (AGEs)	Sticky brown conglomerations caused by cross links of sugar that connect protein molecules together. Eating a high glycemic-load diet hastens AGE formation in the body, accelerating aging. Age spots and cataracts are two examples of AGE-related conditions.
alkaline buffer	An alkaline substance such as sodium bicarbonate used by the body to buffer (neutralize) acid in blood and maintain the correct pH. The body tends to be acid due to diets high in meat or acidic drinks like colas or coffee.
alkaline water	Water with a pH greater than 7 that helps neutralize acids in the body and re-establish a healthy acid/base balance in the blood.
AMPK	AMP-activated protein kinase, an enzyme that has recently been shown to control lipid and glucose metabolism in cells. In animal studies, reducing AMPK levels has resulted in lower appetites and weight loss, while increasing AMPK levels has had the opposite effect. Scientists are investigating how to control AMPK levels in people to help them maintain healthy weights.
antiangiogenesis	The process of inhibiting tumors from creating the new capillary networks needed for their growth. See angiogenesis inhibitors.
angiogenesis inhibitors	Drugs that inhibit the formation of the new blood vessels that tumors need to grow beyond the size of a pea. The formation of new blood vessels (angiogenesis) gives tumors access to additional nutrients and helps cancer cells escape into the bloodstream and set up residence in distant tissues.
antisense therapy	A technique using mirror-image sequences of RNA (called antisense RNA) to stick to abnormal protein-encoding RNA, thereby preventing it from making undesired proteins.
apolipoprotein E	A carrier protein used to transport fat and cholesterol, which are not water-soluble, throughout the body. Apolipoprotein E comes in three main genetic varieties (or alleles)-Apo E2, Apo E3, Apo 4-that vary significantly in their ability to carry fat and cholesterol. See Apo E4.
ApoA-I Milano	Synthetic form of HDL cholesterol. In early clinical trials, infusions of Apo A-I Milano resulted in rapid and dramatic regression of atherosclerotic plaque. Apolipoprotein A-I is the primary protein in high-density lipoprotein (HDL). The genetic variant called Apo A-I Milano was first identified in Milano, Italy, where inhabitants had the paradoxical combination of very low levels of protective HDL-cholesterol as well as low levels of heart disease.
Apo E4	The least efficient of the three genetic varieties of apolipoprotein E (E2, E3 and E4) at carrying fat and cholesterol through the bloodstream. People with the Apo E4 gene have an increased risk of Alzheimer's disease. Over 25 percent of the population carries the Apo E4 gene.
apoptosis	Cell death, which is preprogrammed to occur after approximately 50 divisions of a cell's DNA. Apoptosis is the body's way of ridding itself of damaged, mutated, or unneeded cells. See also telomere and telomerase.
artificial intelligence	The field within computer science focused on building computers that think or react like humans. Subspecialties of AI include pattern recognition (for example, recognizing human speech or visual patterns), robotics, learning, and decision making. Reverse engineering the human brain is expected to provide ideas for AI. In turn, nanobots using AI techniques will enhance human longevity and intelligence.
atherosclerosis	Build-up of cholesterol-laden fatty deposits (atheromas or plaques) in the arteries that limit blood flow. Atherosclerosis in the coronary arteries of the heart is rarely detected until at least 70% of an artery is blocked. Smaller "soft" deposits of plaque are the primary cause of heart attacks (see vulnerable plaque).
ATP	Adenine triphosphate, the primary energy storage molecule in living cells. When enzymes split the bonds in ATP, energy is released for cellular activities.
ATPase	An enzyme that splits ATP into ADP (adenine diphosphate), thus releasing energy. A team at Cornell University is exploring how to use portions of ATPase to build a nanoscale motor.
autoimmune reaction	Activation of an immune response against one's own tissues. Such a reaction can be caused by organ transplants, release of foreign substances into the bloodstream by leaky gut syndrome, and genetic abnormalities.
bioinformatics	A new discipline that uses computer technology to gather, process, make sense of, and manage the flood of biological information now available from genomic testing and other sources.
bioMEMS	Biological MicroElectroMechanical Systems that can be injected into the bloodstream. Scientists are studying many potential uses for bioMEMS devices, including detecting and destroying pathogens, delivering medications to precise locations, and nanoscale imaging. BioMEMS may also be used for tissue engineering, genomics and proteomics, as well as molecular assembly.
bioremediation	The use of organisms such as fungi or bacteria to clean up or remove pollutants. Microorganisms can be genetically altered and synthetic microorganisms created to make them more efficient at this task.
blood brain barrier	A biological system that protects the brain from foreign substances. Tightly spaced cells in the barrier's capillaries are one of the reasons why substances in the blood cannot automatically cross into the brain's tissues.
BRCA1	A gene on chromosome 17 that normally inhibits cell growth. Mutations in this gene significantly increase the risk for breast and ovarian cancer.
catabolic hormones	Hormones naturally found in the body, such as the stress hormone cortisol that stimulate tissues to be broken down. Unlike anabolic hormones, which cause tissues to grow or build, the levels of catabolic hormones remain the same or rise as people get older.
cerebellum	Region of the brain at the back of the head responsible for controlling voluntary muscle movements, maintaining balance, and storing learned movements (muscle skills).
cerebral cortex	Thin layer of neurons on the outer surface of the brain, only 1.5 to 4.5 mm thick, which controls thought processes associated with rational decision-making, planning, and ability to use language. It performs much of what we regard as higher thought processes.
chemokine	An immune-system signaling molecule, typically produced in response to inflammation, such as in the wall of an artery. Chemokines cause monocytes to multiply and turn into macrophrages, the fully matured fighters of the immune system.
cis configuration	In molecular biology, the configuration of an organic molecule so that certain atoms or radicals appear on the same side of a double bond in a molecule (cis is Latin for "same side). Unsaturated fatty acids in a cis configuration bend rather than remain in a straight line as do trans fatty acids.
cochlear implant	A device that, after being surgically placed, bypasses damage in the inner ear and interfaces directly with the auditory nervous system. Like the biological cochlea that it replaces, it detects different frequency components in sound.
coronary calcium score	A measurement of the total amount of hard calcified plaque in the coronary arteries. The score is determined by a three-dimensional CT scan of the heart that images calcium on the artery walls. From this data, a calcium score is calculated for each region of calcified plaque, each coronary artery, and the heart as a whole. Physicians are divided over the usefulness of this score in predicting heart attacks. For people with high cholesterol levels and other risk factors, this score may rise by 40 percent a year. The best way to interpret the calcium score is by comparing your score to other people your same age and gender.
COX-2 inhibitors	A new class of drugs (introduced in 2000) that decreases inflammation by reducing the activity of cyclooxygenase (COX)-2 enzymes, which are involved in the pain and inflammation pathway. A supposed advantage of these drugs is that they do not significantly increase the risk of gastrointestinal bleeding, though clinical results have yielded conflicting results.

cytokine	A protein molecule that helps immune system cells communicate with one another. Immune cells secrete cytokines, which can have both local and global effects.
essential fatty acid (EFA)	A polyunsaturated acid that cannot be created in the human body, but is essential to life. The two EFAs are linoleic and alpha linolenic acid. EFAs are the main building blocks of cell membranes and affect many other functions including the amount of inflammation present and hormone production.
free radicals	Highly unstable molecules that contain an unpaired electron in their outer shells. They steal electrons from other molecules, often triggering a chain reaction of damage.
functional magnetic resonance imaging (fMRI)	An imaging instrument capable of monitoring some brain functions in real time. The fMRI measures the magnetic effects of iron in blood hemoglobin, a measure of the ratio of oxygenated to deoxygenated blood in various parts of the brain. More active regions show increased delivery of oxygenated blood (from vasodilation).
gene	A segment of a chromosome that serves as a set of instructions for building a protein such as an enzyme. Genes are the hereditary building blocks of life, and a large percentage of genes are shared across widely divergent species.
gene expression	Process by which a gene is read and its instructions implemented by the creation of a protein. Many new therapies manipulate gene expression to turn off the expression of disease-causing genes or to turn on desirable genes that may otherwise not be expressed.
gene therapy	Altering the genetic code of an organism by replacing, adding, or blocking the expression of one or more genes in order to cure disease, correct a defect, or serve a particular purpose (such as improving the nutritional value of a food crop).
genome	The sum total of an organism's genetic material.
genomics	The study of the genome. This new field of medicine enables you to discover many of the genes you carry and to customize a lifestyle program for yourself (personal genomics). Within a few years, you will be able to get a microchip or DVD listing all your genes, along with an analysis of those genes and what you can do to avert potential problems.
ghrelin hormone	A hormone, secreted primarily in the stomach that stimulates hunger. Levels of ghrelin rise before meals and drop afterwards. Rapid losses in weight can result in substantial increases in ghrelin levels-an evolutionary adaptation to encourage people to regain fat stores after periods of caloric deprivation.
glycemic index	A measure of the speed with which a food is converted into glucose in the blood. Foods with a high glycemic index include white potatoes, white rice, and white bread. High-glycemic-index foods cause the level of glucose in the bloodstream to rise rapidly.
glycemic load	Number of grams of carbohydrate in a food multiplied by its glycemic index. Glycemic load indicates the amount of insulin that would be released after a given food is eaten Eliminating high-glycemic-load foods from the diet makes it much easier to control appetite and weight.
HDL cholesterol	High-density lipoprotein, also called the "good" cholesterol, because it transports excess cholesterol out of the bloodstream to the liver for excretion. Increasing levels of HDL-C in the blood by lifestyle changes such as increasing exercise and stopping smoking has been shown to reduce the risk of heart attack. New medications now being tested have shown the ability to boost HDL.
heterozygous	Having two different forms of a gene as a result of inheriting different types from each parent.
high-sensitivity C-reactive protein (hs-CRP)	A marker, or indicator, commonly used to measure the level of inflammation in your body.
homocysteine	Toxic byproduct produced when protein foods like red meat and poultry are eaten. Normally, homocysteine is converted to safe compounds through a process called methylation; but genetic methylation defects can result in homocysteine rising to toxic levels, increasing the risk of heart disease, dementia, accelerated aging, and other illnesses.
homozygous	Having two copies of the same gene, one from each parent. Having two copies of the same mutated gene can lead to greatly increased gene expression.
inflammation	Acute inflammation is an immune response around an area of cell infection or injury, often marked by redness, swelling, heat and pain. Chronic inflammation is less obvious, but has been found to be a factor in the development of an increasing number of degenerative diseases such as heart disease, stroke, and Alzheimer's disease.
insulin resistance	Resistance of cells of the body to the effects of insulin. This results in higher blood levels of insulin, which can lead to metabolic syndrome and type 2 diabetes. Long-term, excessive consumption of high-glycemic carbohydrates predisposes to insulin resistance. Avoidance of excess high-glycemic carbohydrates, weight loss, exercise, and consumption of a high-fiber diet help control this problem.
LDL cholesterol	LDL-C is also known as the "bad" cholesterol because, when levels become excessive, cholesterol accumulates inside artery walls, leading to plaque formation and heart disease. Low-density lipoprotein also has the important role of transporting cholesterol from the liver to the body's tissues for membrane repair tasks and serves as a precursor for the formation of steroid hormones.
Mediterranean Diet	A diet typical of the Mediterranean region that emphasizes whole grains, fish, fresh fruits, and vegetables. With this diet, extra virgin olive oil is used extensively, protecting against several types of cancer as well as coronary heart disease. The diet also includes large portions of fresh tomatoes and tomato sauces that are rich in lycopene, a bioflavinoid associated with a lower risk of prostate cancer.
metabolic syndrome	A constellation of symptoms characterized by at least 3 of the following: high blood pressure, abdominal obesity, fasting blood sugar over 99, high triglycerides, low HDL-C. Metabolic syndrome, also known as Syndrome X, can lead to type 2 diabetes and an increased risk of cardiovascular disease.
metastasis	Spread of cancer cells from a primary tumor to distant tissues, where they form additional tumors. Metastasis is the main reason cancer is such a lethal disease.
methylation	A variety of simple chemical processes in the body in which a methyl group (CH<->3<?>) is added to a molecule. See also homocysteine.
microarray	A chip no larger than a dime on which thousands of DNA sequences can be deposited in a prespecified order. Scientists use this tool to study expression patterns of genes. One possible use of microarrays is to explore which genes are involved in the development of a particular disease. Microarrays have also revolutionized the processes of drug screening and discovery. See also gene expression.
mitochondria	The energy factories in cells responsible for creating ATP, the fuel for cell functions. Mitochondria have their own DNA, which includes 13 genes that are subject to higher rates of mutations because they are not protected by the nuclear membrane. See also ATP.
messenger RNA (mRNA)	Messenger RNA, which is transcribed (copied) from DNA, travels outside the nucleus, and then is translated into proteins. Antisense therapy and RNA interference are two ways researchers are exploring to block the mRNA created by damaged or mutated genes so they are unable to make undesired proteins. See antisense therapy.
mutation	Permanent alterations in DNA, often occurring during cell division, that result in a defective cell that is quickly eliminated or one that doesn't function optimally. Some mutations cause disease or accelerate aging. One application of future gene therapy technology will be to replace worn out or damaged DNA in the nuclear genes.
nanobot	Robots, in which the key features are measured in nanometers, or billionths of a meter, that will be injected into the human body to perform vital health missions. Future applications of nanobots are expected to include detection and destruction of pathogens (bacteria, viruses, cancer cells) and clearing away toxins and debris. Eventually nanobots will enter the brain via the brain's capillaries and interact with biological neurons to provide virtual reality from within the nervous system, and to enhance human intelligence.
nanotechnology	A technology in which objects are built from individual atoms or molecules. Technology in which the key features are measured in a small number of nanometers (billionths of meter) is regarded as nanotechnology. Nanotechnology will enable humans to go beyond the limitations of biology.
neural implant	Computerized brain implant designed to bypass, replace, or enhance a brain region. By reverse-engineering (understanding the principles of operation of) regions of the human brain and nervous system, researchers are developing implants for a growing list of regions. By communicating between the ventral posterior nucleus and subthalamic nucleus, for example, an FDA-approved brain implant for Parkinson's can reverse some of the most devastating symptoms of the disease. An implant for people with cerebral palsy and multiple sclerosis is able to control tremors by communicating with the ventral lateral thalamus.
nucleotide	A building block of a DNA molecule, formed from one of four chemicals adenine, thymine, guanine, or cytosine), a molecule of sugar and a molecule of phosphoric acid. These nucleotides are cross-linked to one another like the rungs of a ladder.
peptide	Molecules composed of amino acids held together with so-called peptide bonds.
pharming	A genetic engineering technique in which human genes are inserted into the genome of animals so they will produce desired compounds. An example of a pharm animal is a cow whose milk has been modified to contain a vaccine against hepatitis.
phospholipids	The main lipid component of most cell membranes. Phospholipid molecules are electrically charged at one end and uncharged at the other, which confers unique properties.
plaque	One of a variety of different kinds of deposits in the body. Arterial plaque occurs when LDL cholesterol particles invade the intima (lining) of arteries. When these plaques become inflamed, they can rupture, causing a heart attack or stroke. See vulnerable plaque. Amyloid plaque is a pleated sheet of crystalline debris, composed of improperly folded protein fragments, that is deposited in the brain and may be associated with Alzheimer's disease. Dental plaque refers to soft deposits on teeth. The bacteria in dental plaque promotes tooth decay.
pluripotent	A type of stem cell that has the capacity to turn into many different types of cell the body needs. Researchers can trigger pluripotent stem cells to transform into specific types of cells.
polymorphisms	Gene mutations (the term means many shapes). Polymorphisms can increase (or decrease) the risk of specific diseases. See also single nucleotide polymorphisms.
prostaglandin	Hormone-like substances that control a wide variety of bodily functions, but which are different from other hormones in that they have a very short lifespan. The name refers to the prostate gland because when they were discovered in 1936, researchers thought they were secreted by that gland.
proteomics	The study of proteins, both those found naturally in the body and those created in the laboratory. Over the next decade or two, proteomics therapies will enable patients to receive individualized treatments for diseases based on their genetic structure. See also gene expression.
recombinant technology	Procedures to combine DNA from more than one organism. These modifications can result in substances useful for combating human disease. Recombinant bacteria, for example, have genetic material that codes for a desired protein spliced into their DNA, and then produce the protein. See pharming.
respirocytes	Robotic replacements for red blood cells, designed by nanomedicine scientist Rob Freitas that are thousands of times more efficient than biological red blood cells. With an ounce or two of these robots circulating in your blood, you could go for hours without oxygen.
reverse engineering	Decoding and understanding the principal methods of a system such as the human body or brain in order to devise better means of maintaining or improving that system, or creating a replacement system that is more capable.
ribosome	Cell components, composed of ribonucleic acid and proteins that create amino acid strings according to information from mRNA strands. The amino acid strings are subsequently folded to create proteins. Ribosomes are natural molecular "machines," that may be replaced several decades from now with small computerized robots.
RNAi	RNA interference: an evolving therapy for blocking gene expression. Short double-stranded RNA segments destroy the messenger RNA transcribed from genes. This blocks the native RNA segment's ability to create proteins, effectively silencing the gene. See also antisense therapy.
single nucleotide polymorphisms (SNPs)	The most common form of DNA alteration (polymorphism). SNPs involve only a single nucleotide, but can change the way a gene functions and in some cases predispose you (or make you more resistant) to specific diseases. See also nucleotide.
somatic gene therapy	Changing the DNA in adult (somatic or non-reproducing) cells to treat or prevent disease or to enhance capabilities. Current hurdles to this type of therapy include the proper positioning of the new genetic material on the patient's DNA and monitoring the gene's expression.
starch blocker	A supplement or medication that inactivates the digestive enzyme amylase, needed to digest starch. The starch then passes through the digestive tract undigested.
statin drugs	A popular class of cholesterol-lowering drugs that work by blocking the body's ability to make cholesterol.
stem cells	Cells that are in an immature, not fully differentiated state, but that can develop into more mature specific cell types. During intrauterine development, embryonic stem cells differentiate into all the cells of the growing fetus. Some stem cells remain into adulthood where they can turn into many cell types including red and white blood cells. Researchers use stem cells to grow new tissues and organs, either to repair damage or reverse aging. An advantage of using a patient's own cells for this purpose is that new cells contain the patient's DNA, and will not stimulate an autoimmune reaction. There is an ethical controversy over using fetal tissue for this purpose, but researchers are exploring alternative sources of stem cells in the lab. Locations of stem cells in the adult body are also being identified. See also pluripotent.
Syndrome X	Another term for the metabolic syndrome (TMS).
systems biology	A new discipline that focuses on the relationship and interactions between components in biological processes to develop a better understanding of the overall system. Mathematical models are used to capture the complexity of the biological systems. Advancements in such areas as bioinformatics have improved the ability of systems biologists to build and test these models. See also bioinformatics.
telomerase	An enzyme that synthesizes telomeres and is inactive in most human cells. Cancer cells become immortal by turning on this enzyme; this event combined with other mutations results in cancer and is one reason why cancer so often proves fatal. Blocking this enzyme is a promising strategy in stopping cancer progression. Germ line cells also create teolomerase and are immortal. Researchers are investigating how to manipulate this enzyme to extend the longevity of healthy cells.
telomere	The "caps" on the ends of DNA strands, which shorten as human cells divide, driving cells toward genetic instability and death. Telomeres are composed of repeating codes like a string of beads, in which one bead falls off each time a cell divides, thereby placing a limit on the number of times a cell can replicate before it is programmed for death. Recent research suggests that the length of a person's telomeres is partially determined by genetics.
therapeutic cloning	A process in which an individual's DNA is inserted into the nucleus of an egg cell and then triggered to produce stem cells. The goal is the creation of new tissues or organs to replace defective tissues or organs. It is different from reproductive cloning where the goal is the creation of a clone or genetically-identical copy of an entire individual.
tissue engineering	The techniques involved in growing or regrowing cells, tissues, or entire organs. The goal is to create replacement cells, tissues, and organs such as a heart or liver, built from your own DNA. Typically, researchers position layers of cells for these new organs on scaffolding or molds.
trans-fatty acids	A type of saturated fat that is created by hydrogenating (adding hydrogen to) unsaturated fatty acids. Trans fats are solid at room temperature, have a long shelf life and are widely used in commercial production of crackers, cookies, breads, and snack foods. Margarine is a trans fat. Trans-fats have been identified as culprits in raising LDL-C levels and are particularly damaging to the arteries. See also LDL.
transgenic	Genetically modified organisms created by splicing new genes into the genome of the original organism. Examples include transgenic chickens whose eggs have a high content of healthful EPA and DHA, while some transgenic plants are naturally insect-resistant and don't need pesticides..
vulnerable plaque	Soft plaque in the arteries referred to as vulnerable since it is vulnerable to rupturing and triggering a heart attack. Until recently more attention was focused on the hard calcified plaque in the arteries. However, the less-obstructing but more volatile and inflammatory soft plaque has now been recognized as far more dangerous. Soft plaque is hidden inside the walls of arteries, is hard to detect and often causes no symptoms until it suddenly ruptures. See also plaque.
xenoestrogen	Foreign chemicals not normally found in the human body that mimic the action of estrogen, resulting in an imbalance in hormones and "estrogen excess." This imbalance may increase risk of hormonally sensitive cancers, especially breast cancer in women and prostate cancer in men. Major sources of xenoestrogens are pesticides, plastics, and birth control pills.