A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A
Active lesion - Lesion that is new or
growing
Adhesion molecule - A protein that promotes the
binding of one cell to another or to the extracellular
matrix.
Antibody - A protein made by a plasma cell
(mature B cell) that protects the body against foreign invaders
like bacteria and viruses.
Antigen - A substance that is bound by
antibodies. The name ‘antigen’ arises from the ability to
generate antibodies. Viral and bacterial molecules and even the
body’s own molecules can be antigens.
Angiogenesis - The formation of new blood
vessels.
Antigen presenting cell - A specialized cell
that sticks pieces of antigen combined with self ‘display’
molecules on its surface for passing immune cells to survey.
Dendritic cells, macrophages and B cells are the main
antigen-presenting cells.
Astrocyte - A support cell in the central
nervous system (CNS) that attaches to both nerve cells and blood
vessels; provides metabolic, nutritional and physical support.
Astrocytes make the scars on damaged tissue during MS.
B
B cell - An antibody-making lymphocyte (white
blood cell) originating in the bone marrow.
Biological marker (biomarker) - a measurable
indicator of a biological process that can be used as a predictor
of health or disease. Biomarkers that are being evaluated for MS
include those that reflect changes in the immune system, damage
to myelin and nerve cells, disruption of the blood brain barrier,
or myelin repair.
Blinding - a process in clinical trials that
involves concealing information about a test or treatment from
the experimenter, subject, or both (double-blind), in order to
eliminate potential bias – whether intentional or accidental –
from interpretation of the data.
Blood brain barrier (BBB) - A barrier formed by
a continuous layer of tightly connected endothelial cells;
prevents most large molecules and cells found in the blood from
entering the brain tissue.
Brain atrophy- Loss of brain tissue (brain
shrinkage)
C
Central nervous system (CNS) - The brain and the
spinal cord; all parts can be affected by multiple sclerosis.
Cerebral spinal fluid (CSF) - The fluid that
bathes the surfaces of the central nervous system.
Chemokine - A protein beacon that attracts white
blood cells bearing a receptor for the chemokine.
Control - The standard against which experimental interventions are evaluated.
Cytokine - A small messenger molecule that influences the actions of immune system cells; also called a lymphokine or interleukin (IL). There are many different cytokines, each acting only on cells that have receptors for that cytokine.
D
Demyelination - Process during which myelin is
stripped from nerve fibres.
Dendritic cells – A white blood cell that is
bone-marrow derived and specializes in presenting antigen to T
cells.
Differentiation - A series of steps that cells
go through to reach their mature state.
Deoxyribonucleic acid (DNA) - The code of
genetic instructions that shapes the development of every
individual. DNA is shaped as a double helix and is made up of
nucleic acid-sugar complexes loosely bound to proteins.
E
Expanded Disability Status Score (EDSS) - A test
for measuring the disability level of a person with MS; also
known as the Kurtkze Scale after, Dr. John Kurtzke.
Endothelial cell - Lines the heart and blood
vessels of the circulatory and immune systems; forms the blood
brain barrier (BBB).
Experimental autoimmune encephalomyelitis (EAE)
- An MS-like disease created in laboratory mice after they are
injected with CNS tissue or a derivative of myelin basic protein.
F
Functional magnetic resonance imaging (fMRI) -
An imaging technique that looks at blood flow in the brain in
real time to detect areas of activity. Where there is increased
activity, blood flow to that region increases.
G
Gadolinium enhanced lesion (GEL) - Gadolinium is
a chemical compound used to visualize tissue on MRI scans which
are affected by inflammation. Gadolinium cannot normally pass
enter the brain because it is a
large molecule, but when there is active inflammation the barrier
which separates the circulating blood and brain is ‘leaky’ and
gadolinium can get through. Thus, gadolinium makes it possible to
identify new or growing lesions.
Gene - Pieces of DNA that include the genetic
code for making body proteins; located on chromosomes.
Glial cell – Support cells in the nervous
system; oligodendrocytes, astrocytes and microglial cells in the
central nervous system and Schwann cells in the peripheral
nervous system.
H
Health Related Quality of Life (HRQL) - Quality
of life of people with MS based on patient-perceived functional
status and well-being.
I
Immunoglobulin - The membrane-bound version of
antibody that binds antigens and signals the B cell to secrete
antibodies.
Immunoregulation - The control of specific
responses in the immune system.
Inflammation – Normally protective response to
physical/chemical injury, infection or a local immune response
leading to tissue damage where loss of function may accompany
swelling, redness, heat and pain; fluid, white blood cells and
plasma proteins accumulate.
Interferons (IFN) - Cytokines that help cells to
fight viruses. Alpha interferon and beta interferon are made by
white blood cells, fibroblasts and other cells. (Manufactured
versions are useful as MS treatments.) Gamma interferon is
produced by inflammatory T cells and natural killer cells and its
main action is to trigger macrophages to help fight infection.
Gamma interferon makes MS worse.
J
K
L
Lesion - A wound to body tissues. In MS, a
lesion which occurs in myelin of the central nervous system is
called a plaque. See plaque.
Lipid - Fat soluble. A term describing the
ability of molecules, such as fats, fatty acids and soaps, to
dissolve in fat.
Lymphocytes - White blood cells (B cells, T
cells and NK cells) of the immune system that fight specific
infections.
M
Macrophage - An immune cell that is among the
first line of defence against invaders; also acts as antigen
presenting cells. Macrophages are called different names
depending where they are found in the body (e.g. microglial cells
in the brain).
Magnetic resonance imaging (MRI) - A
technological tool that detects energy released from hydrogen
atoms to create anatomical images. MR images of soft tissues of
the body including the brain and spinal cord clearly show MS
lesions and may be used to track disease progress.
Magnetic resonance spectroscopy (MRS) - A
technological tool similar to magnetic resonance imaging but
providing chemical rather than anatomical information. MRS is
most useful when evaluating trials of new treatments by measuring
disease severity and progression.
Mass Spectrometry - A technique used to measure
the mass of molecules or group of molecules.
Mast cell - Originates in the bone marrow;
involved in allergic responses.
Memory B cells - B cells living in the body for
long periods of time; can be triggered to make antibodies.
Microglia - Macrophage-like cells that reside in
the brain; ‘eat’ cellular debris and stimulate immune
responses.
Monocyte - A white blood cell that resides only
in the blood. Once it migrates into the tissues, a monocyte is
called a macrophage.
Morphogen - Diffusable substance that influences
movement and organization of cells during development.
MSQLI - The Multiple Sclerosis Quality of Life
Inventory is a questionnaire designed to evaluate the burden of
disease experienced by people with MS.
Myelin basic protein (MBP) - One of the
principal proteins found in myelin.
Myelin - A collection of proteins and lipids
that make up the myelin sheath; speeds transmission of signals
along nerve fibres.
Myelin is made by cells in the central nervous system called oligodendrocytes. These cells wrap themselves around nerve axons very many times to form a protective myelin sheath. The myelin increases the speed at which nerve signals travel along axons. In MS, myelin is vulnerable to attack from the immune system.
Myelin sheath - 1-200 insulating layers of myelin surrounding nerve fibres in the central and peripheral nervous system.
N
Nerve fibre (axon) - The slender, long branch
extending from a nerve cell that carries nerve impulses to
adjacent nerve cells throughout the body. Most nerve fibres are
surrounded by 1-200 layers of myelin.
Neurodegeneration - Degeneration and death of
neurons
Neuroglia (glial cells) - Supporting,
non-impulse generating cells of the nervous system (e.g.
astrocytes and oligodendrocytes).
Neuron - A cell within the nervous system that
consists of a cell body and the associated membrane extensions,
called dendrites when highly branched, or axons when minimally
branched. Nerve impulses travel along nerve axons.
Neuroprotection – The preservation of the
structural and functional integrity of nerve cells
Neutrophil - A type of white blood cell that
migrates quickly to a site of inflammation to help fight
infections
NK cells - Natural Killer cells are a group of
lymphocytes (not T or B cells) that can kill some virally
infected and tumor cells.
No evidence of disease activity (NEDA) – a new
criterion for assessing the effectiveness of a treatment for MS
on the basis of complete remission across four key
disease measures: relapses, MRI lesions, brain volume loss, and
disability progression. NEDA represents a shift in treatment
expectations with the introduction of new, more effective drugs,
although more research is needed before it can become widely
adopted.
O
Oligodendrocyte - The cell in the CNS that makes
and maintains myelin; wraps its myelin-filled membranes around
nerve fibres (axons).
Oligodendrocyte precursor cell (OPC) - Younger
version of oligodendrocytes
Open label - In an open-label study (usually phase I), both the researchers and participants know of the intervention the participant is receiving (i.e., experimental drug or placebo).
P
Peptide - A chain of amino acid building blocks
strung together. The chain can be two (di-) amino acids, three
(tri-) amino acids, or more (poly-) amino acids in length.
Peripheral nervous system (PNS) - Nervous system
in the body aside from the brain and spinal cord. The PNS can be
affected by MS.
Placebo - a substance used in clinical trials to
resemble an actual treatment or medicine (i.e. a dummy or mock
treatment). Use of a placebo can help determine how much benefit
is being derived from the actual treatment, and how much is due
to the psychological state of the subject (i.e. placebo
effect).
Plaque - An area of myelin loss characteristic
of multiple sclerosis.
Proteolipid Protein (PLP) - One of the major
proteins found in the myelin sheath.
Q
R
Randomization - the process whereby participants
in a study are randomly assigned to different treatment groups in
order to eliminate or reduce bias in any particular group.
Remyelination - Process during which myelin is
re-added to nerve fibres by oligodendrocytes or Schwann cells.
S
Schwann cell - The cell in the peripheral
nervous system that makes and maintains myelin.
Sham - A sham procedure is analogous to a placebo drug. A trial participant may receive a 'sham' or 'fake' surgery, injection, or other procedure that removes the therapeutic step of the procedure being evaluated, as part of the control group.
Stem cell - Unspecialized cell that mature into
a cell that performs a highly specific function. Stem cell can
also divide to produce more stem cells.
T
T cell - Immune cells that fight infections. Two
broad categories are alpha-beta and gamma-delta T cells.
Alpha-beta subsets include helper T cells (CD4+) and killer T
cells (CD8+).
T cell receptor (TCR) - A protein found on the
surface of T cells. Alpha-beta TCR binds to bits of foreign
peptides (or sometimes body peptides, like myelin) attached to
cell surface ‘display’ proteins on antigen presenting cells.
Tumor necrosis factor (TNF) - TNF alpha and TNF
beta; cytokine made by macrophages and some T cells; toxic to
tumor cells; plays role in inflammatory responses.
Transgenic mice - Mice that contain genes from
another source (animal or human); derives from ‘trans’ (other)
and ‘genic’ (genes).
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