Antibodies – large Y-shaped proteins used by the immune system to identify and neutralize foreign objects like bacteria and viruses

Arsenic – a very poisonous metallic element that has three allotropic forms; arsenic and arsenic compounds are used as herbicides and insecticides and various alloys

Autoimmunity – the failure of an organism to recognize its own constituent parts, which results in an immune response against its own cells and tissues

Biological markers – specific biological substances that indicate the presence of a disease, a certain stage of disease, or the predisposition for developing a disease

Brominated fire retardants (BFRs) – replaced PCBs (see below) as the major chemical flame retardant; evidence suggests that BFRs can accumulate in living organisms, possibly causing liver, thyroid and neurodevelopmental toxicity

Cadmium – a metallic element resembling tin, used in plating and in making certain alloys

Central nervous system – the part of the nervous system comprising the brain and spinal cord

Chemokines – various cytokines (see below) produced in acute and chronic inflammation that mobilize and activate white blood cells

Cytokines – proteins that regulate and modulate immune responses

Endocrine system – the body processes that happen slowly, such as cell growth; is instrumental in regulating mood, growth and development, tissue function, metabolism, and sexual function and reproductive processes

Environmental Medical Unit (EMU) – a specially designed and constructed residential or hospital facility for researching the role of exposures in ASDs and other illnesses, and formulating treatment protocols

Epidemic – a disease affecting many persons at the same time, and spreading from person to person in a locality where the disease is not permanently prevalent

Epidemiology – the study of how health outcomes are distributed across populations and what factors are likely to increase risk of disease

Epigenetics – biologic mechanisms that influence gene expression (whether genes are turned on or off)

Genetic susceptibility – an inherited increase in the risk of developing a disease

Glia – the non-neural component of the brain involved in the nervous system

Immune phenotyping – taking measurements of immune system function that give a picture of an individual’s immune profile

Immune system – a complex network of interacting cells, cell products, and cell-forming tissues that protect the body from infection by pathogenic organisms

Immunotoxicants – chemical substances that can cause adverse effects on the immune system

Lead – a bluish-white metallic element found mostly in combination and used especially in pipes, cable sheaths, batteries, solder, type metal, and shields against radioactivity; known to cause damage to the GI tract and nervous system

Limbic system – a complex set of structures in the brain that lies on both sides and underneath the thalamus; neurological damage in some individuals with ASD sometimes occurs in the limbic system

Lymphocytes – any of various white blood cells, including B cells and T cells, that function in the body’s immune system by recognizing and deactivating specific foreign substances called antigens

Methylmercury – any of various toxic compounds of mercury containing the complex CH3Hg that often occur as pollutants from industrial by-products or pesticide residues and are absorbed through the human intestinal wall where they can cause neurological dysfunction in humans

Mucosal immune cells – cells in the mucous membranes, comprising the linings of the gastrointestinal, urogenital and respiratory tracts, which keep invading pathogens out of the interior body cavity

Myelin basic proteins – one of the components found in myelin (a substance that covers and insulates the nerves) and is a marker of its presence; is measured in the spinal fluid to determine if there has been inflammation and myelin breakdown in the central nervous system

Neuronal migration – during early brain development, the process when neurons are born and move over large distances to reach their targets, giving rise to the different parts of the brain

Neurotoxicants – chemical substances that can cause adverse effects on the nervous system
OAT & IgG food sensitivity panel – a type of allergy test for such foods as grains, dairy products, eggs, yeast, and nuts, which can adversely impact those with ASDs and other chronic illnesses

Pathogenesis – the mechanism by which a certain etiological factor causes disease

Perfluorinated chemicals (PFCs) – essentially indestructible toxic chemicals characterized by chains of carbon atoms of varying lengths; used in such brands as Teflon, Stainmaster, Scotchgard and Gore-Tex

Phtalates – substances used in making plastics and certain pesticides; thought to have direct neurotoxic effects or the potential to alter neurodevelopment

Polyaromatic hydrocarbons (PAHs) – a group of chemicals formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances, such as tobacco and charbroiled meat, which can modify immune responses

Polybrominated diphenyl ethers – flame retardants found in furniture foam, computers and TVs, which are known to adversely affect brain development and the thyroid

Polychlorinated biphenyls (PCBs) – a mixture of individual chemicals used as flame retardants, which are no longer produced in the United States, but are still found in the environment; health effects associated with PCB exposure include skin conditions in adults and neurobehavioral and immunological changes in children

Proteomics – the large-scale study of proteins, particularly their structures and functions

Short-chain fatty acids – bacterially produced compounds that when injected in rodents’ brains produce bouts of hyperactivity and repetitive behavior resembling those seen in people with ASD

TH1 – cytokines associated with cell response and inflammation

TH2 – cytokines associated with allergies and asthma

Thimerosal – a mercury-based preservative used in vaccines and some over-the-counter medications

Toxin – any poison produced by an organism

Toxicant – Induced Loss of Tolerance (TILT) – a two-step disease mechanism in which acute exposure to a contaminant subsequently leads to intolerance to other everyday exposures

Transcriptional profiling – a method of collecting and analyzing the genes that are expressed, usually in different backgrounds (normal vs. disease states); can be used to identify patterns of immunological dysfunction common to autism