Webster's New World Medical Dictionary

Guillain-Barre syndrome
A rare disorder char-
acterized by a misdirected immune response against
the peripheral nervous system associated with pro-
gressive symmetrical paralysis and loss of reflexes,
usually beginning in the legs. In most cases of
Guillain-Barre syndrome, the patient has a complete
or nearly complete recovery. Guillain-Barre syn-
drome is not associated with fever. It usually occurs
after a respiratory infection or may follow other trig-
gering infections or events, including vaccinations.
Treatment includes plasmapheresis, intravenous
gamma globulin (IVIG) and supportive care. See
also 
demyelination; Landry ascending paralysis.
gum disease
Inflammation of the soft tissue
(gingiva) and abnormal loss of the bone surround-
ing the teeth. Gum disease is caused by toxins
secreted by bacteria in the plaque that accumulates
over time along the gum line. Plaque is a mixture of
food, saliva, and bacteria. Early symptoms of gum
disease include gum bleeding, and pain is a symp-
tom of more advanced gum disease, as the loss of
bone around the teeth leads to the formation of gum
pockets. Bacteria in these pockets cause gum infec-
tion, swelling, pain, and further bone destruction.
See also 
acute membranous gingivitis; gingivitis.
gustatory sweating
See 
sweating, gustatory.
Guthrie test
A blood test to screen for phenylke-
tonuria (PKU) and the original impetus for the
screening of newborns for metabolic diseases. See
phenylalanine; phenylalanine hydroxylase defi-
ciency; PKU; PKU, maternal.
gutta percha
A natural material derived from
tree sap that can be formed to various shapes under
heat. Because gutta percha does not cause allergic
reactions, it is often used to pack the empty spaces
left when a root canal is performed.