Webster's New World Medical Dictionary

parrot fever
See 
psittacosis.
Parry disease
See 
goiter, toxic multinodular.
parthenogenesis
Development of a germ
cell without fertilization. A form of nonsexual
reproduction.
partial hysterectomy
See 
hysterectomy, partial.
partial syndactyly
See 
syndactyly, partial.
parturition
See 
labor.
Parvovirus B19
The virus responsible for the dis-
ease known as fifth disease. See also 
fifth disease.
passage, nasal
See 
nasal passage.
passive immunity
Immunity produced by the
transfer to one person of antibodies that were pro-
duced by another person. Protection from passive
immunity diminishes in a relatively short time, usu-
ally a few weeks or months. For example, antibod-
ies passed from the mother to the baby before birth
confer passive immunity to the baby for the first 4-6
months of life.
passive smoking
Inhalation of smoke that
comes from someone else smoking. Passive smok-
ing is associated with the same array of diseases as
actual smoking, with an elevated risk of lung can-
cer and other diseases.
Pasteur, Louis
A French chemist and biologist
who invented pasteurization, developed the germ
theory, founded the field of bacteriology, and cre-
ated the first vaccines against anthrax and rabies.
pasteurization
A method of treating food by
heating it to a certain point to kill disease-causing
organisms but keep the flavor or quality of the food
intact. Pasteurization is used with beer, milk, fruit
juice, cheese, and egg products.
PAT
Paroxysmal atrial tachycardia.
Patau syndrome
See 
trisomy 13 syndrome.