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Janet Gray, Ph.D.
Janet Gray, Ph.D.

As author of our 2008 and 2010 State of the Evidence reports, Dr. Gray drives the science behind all our work.

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Clear Science Glossary

Acoustic neuroma: A benign, generally slow-growing tumor that forms on the nerve that connects the ear to the brain.

Adducts: DNA that has been modified by the addition of molecules from another compound.

Adjuvant: Treatment given in addition to surgery and radiation to treat breast cancer that may have spread to other parts of the body. It may include chemotherapy, targeted therapy and/or hormone therapy.

Amino acids: Building blocks of proteins, including enzymes. Amino acids are broken down from food and reassembled into proteins coded in gene.

Angiosarcoma: A form of cancer that starts from cells that line blood vessels or lymph vessels.

 Ano-genital distance: The distance from the anus to the genitalia, which reflects the length of the perineum. The perineum is longer in males than females, so ano-genital distance serves as a sensitive indicator of endocrine disruption, especially of androgen (testosterone, dihydrotestosterone) function.

Backscatter: Low-level X-rays used to create a two-sided image by reflecting the waves in the direction in which they originated.

Backscatter technology: Low level x-rays used to create a two sided image by reflecting the waves in the direction in which they originated.

Body mass index: A measure that relates body weight to height. 

Carcinogenesis: The production of cancer.

Cell-signal transduction: Hormones and other compounds interact with cell receptors, which then leads to a cascade of cellular responses.

Chemical cell pathway regulators: Chemicals and receptors that facilitate communication within and between cells.

Chlorination levels: Chlorine is an element that combines with other elements to create chemical compounds. Compounds with more chlorine molecules have higher chlorination levels.

Circadian rhythm: Physical, mental and behavioral changes that occur in a daily cycle.

Computed tomography (CT): A series of detailed pictures of areas inside the body taken from different angles. The pictures are created by a computer linked to an X-ray machine. Also called CAT scan, computerized axial tomography scan, computerized tomography, and CT scan.

Confounding factors: A factor that may co-occur with both an exposure of concern and a health outcome. In research on population-based health, confounding factors make it difficult to determine if the cause of a health outcome is the cause under study or related factors. Study design and statistics can help clarify these issues.

Contralateral breast cancer: Following original diagnosis of breast cancer in one breast, a secondary cancer is found in the other breast.

CT angiography: A procedure that uses X-rays to create a series of detailed pictures of the blood vessels and blood flow inside the body.

Endometrium: The inner membrane lining the uterus.

Epithelial branches: Branches of the membrane tissue in the mammary system that form milk ducts.

Epithelium: In the mammary gland, a thin layer of cells (including stem, stroma and myoepithelial cells) all of which constitute the outer structure of the ducts.

Estrogen-like form: The form of a molecule that can mimic estrogen.

Expression: In genetics, "expression" refers to whether a gene is "turned on" and therefore producing proteins and shaping physiology.

Fluoroscopy: An X-ray procedure that makes it possible to see internal organs in motion.

Genomics: The mapping of DNA sequences, including genes,  for understanding both structural and functional properties of the sequences.

Genotoxic: Factors that are damaging to genetic material.

Half-life: The amount of time required for a given substance to lose half of its toxicity or effectiveness.

High-throughput assays: Roboticized chemical tests that rapidly assess numerous characteristics of numerous individual chemicals.

Hodgkin’s and non-Hodgkin’s lymphoma: Cancers of the lymphatic system, a network of thin vessels and nodes throughout the body that serves as part of the immune system.

Homeostasis: The maintenance of a stable state in the body even when external conditions change, e.g., the maintenance of body temperature in mammals.

Hormone composites: Combinations of different hormones in pharmaceutical use.

Isolates: Purified or separated forms of a component of a mixture. For example, phytoestrogrens like genestein may be isolated (forming an isolate) from whole soy.

Lumpectomy: Surgery to remove a breast lump and a small amount of surrounding tissue.

Lymphatic system: Glands (nodes) and vessels in the body that help defend against foreign invaders like bacteria and other foreign substances.

MCF-10A cells: A specific line of human breast cells that have been cultivated from breast tissue and immortalized for use in experiments.

MCF-7 cells: A specific line of human breast cancer cells that have been cultivated from breast tumors and immortalized for use in experiments.

Mechanism:  The underlying process through which a chemical exposure or physiological change exerts an effect on the body.

Mediated: When a middle factor lies between an initial cause and the final effect.

Mediating: A process that occurs between an initial cause and final effect.

Mediator: An agent that occurs between the initial cause and final effect.

Meta-analysis: sophisticated statistical analyses of a large number of studies, taken together.

Metabolite: A product of the breakdown of natural or synthetic chemicals by the cells of the body.

Metabolites: A product of the breakdown of natural or synthetic chemicals by the cells the body.

Millimeter wave screening: Millimeter wave radio frequency reflect energy back from the body to create a three-dimensional image.

Mitochondrial: Mitochondria are organelles within the cell that generate energy in the cell. Mitochondria have unique genetic characteristics that are passed down exlusively from the mother, and that can effect gene expression.

Neural: Having to do with nerves or the nervous system, including the brain and the spinal cord.

NHANES: The National Health and Nutrition Examination Survey: Studies designed to assess the health and nutritional status of adults and children in the United States, based upon a representative sample of residents. The study includes a biomonitoring component to measure environmental chemicals in people.

Non-genomic: Effects at the cellular level that are not exerted by genes.

p53 tumor suppressor gene: A tumor-suppressor gene that normally inhibits the growth of tumors. This gene is altered in many types of cancer. 

PAH-DNA adduct: Chemical compounds formed by interactions between PAH compounds and DNA that indicate an increased likelihood of cancer formation in the tissue.

Pectoralis muscle: Muscles attached to the front of the chest wall and upper arms.

Perfusion: Bathing an organ or tissue with a fluid. In regional perfusion, a specific area of the body (usually an arm or a leg) receives high doses of anticancer drugs through a blood vessel.

Population-based case-control study: A study of a group of individuals taken from the general population who share common characteristic or health condition. Those with the health condition are considered "cases" and they are studied in comparison to individuals without the condition, or "controls," who are similar in other ways (age, gender, ethnicity).

Profile: The pattern of genetic variations a person has that shapes characteristics, including disease susceptibility.

Proliferation: Growth and reproduction of cells.

Prospective cohort: A study that follows groups that differ on characteristics (cohorts) over time, typically before the development of a disease or health outcome.

Prospective Cohort Study: A research study that follows over time groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke and those who do not smoke) and compares them for a particular outcome (such as lung cancer.)

Prospective studies: A study that begins prior to the onset of disease or a health effect.

Quiescence: A period of rest or dormancy.

Radionucleotides: Building blocks of DNA that are labeled with radioactivity so they can be traced.

Randomized clinical trial: Studies in which a specified patient population is randomly assigned to different treatment groups. Studies can test new treatments compared to old treatments or new treatments compared to no treatments. 

Scoliosis: A condition marked by a side-to-side curve of the backbone.

Tamoxifen: A drug that modifies the actions of estrogen.

The yeast assay: A test that uses yeast cells that respond to estrogen to evaluate the degree to which a compound mimics or blocks estrogen.

Tyrosine: An amino acid that is used to synthesize proteins and as a building block for some  neurotransmitters.