A cell nucleus with a haploid set of chromosomes (23 chromosomes in humans) resulting from meiosis (germ-cell division). The male pronucleus is the sperm nucleus after it has entered the ovum at fertilization but before fusion with the female pronucleus. Similarly, the female pronucleus is the nucleus of the ovum before fusion with the male pronucleus.
A preventive measure. The word comes from the Greek for “an advance guard,” an apt term for a measure taken to fend off a disease or another unwanted consequence. A prophylactic is a medication or a treatment designed and used to prevent a disease from occurring. For example, prophylactic antibiotics may be used after a […]
- Prophylactic cranial irradiation
Radiation therapy to the head that is intended to prevent cancer from spreading to the brain.
- Propionibacterium acnes
A ubiquitous skin-dwelling organism that is involved in causing acne. The complete genome of this bacterium was sequenced and analyzed in 2004, providing insights into the bacterial antigens and tissue-damaging enzymes that may cause the inflammatory reactions underlying acne. The genome sequence also clearly revealed many proteins involved in the ability of P. acnes to […]
a prescription sedative-hypnotic drug (brand name Diprivan) that is administered intravenously. Propofol is commonly used in the induction of general anesthesia and can be used both for the induction and maintenance of general anesthesia. When administration of the drug is discontinued, it wears off rapidly, allowing the patient to awaken within a short time. Like […]
- Proportional counter
A device for measuring radioactivity. More technically, a proportional counter counts the emission of radioactive particles which permits the discrimination between particles or rays of different energies.