PCR (polymerase chain reaction) is a technique in molecular genetics that permits the analysis of any short sequence of DNA (or RNA) even in samples containing only minute quantities of DNA or RNA. PCR is used to reproduce (amplify) selected sections of DNA or RNA for analysis. Previously, amplification of DNA involved cloning the segments of interest into vectors for expression in bacteria, and took weeks. But now, with PCR done in test tubes, it takes only a few hours. PCR is highly efficient so that untold numbers of copies can be made of the DNA.
The familial form of PCT — is inherited as an autosomal dominant trait with males and females affected in multiple generations. The enzyme UROD is reduced in all tissues. The sporadic form of PCT — is more common. The enzyme UROD is only reduced in the liver. It appears sporadically in people with liver disease, […]
Physicians’ Desk Reference (please see entry to Physicians’ Desk Reference). PDR less frequently stands for “postdelivery room”.
- Peak expiratory flow
Abbreviated PEF. The maximum airflow during a forced expiration beginning with the lungs fully inflated. The PEF is reduced in proportion to the severity of the airway obstruction, as in asthma and COPD (chronic obstructive pulmonary disease).
- Peak-flow meter
This hand-held device measures air flow (how fast air is blown out of the lungs). Patients can use peak-flow meters to measure their own air flow regularly. The use of a peak-flow meter allows patients to obtain a much earlier indication of an oncoming attack, for example, of exercise-induced asthma, a type of asthma typically […]
- Peanut allergy
An allergic reaction to peanuts, the leading cause of anaphylaxis, the most severe and potentially life threatening allergic reaction, and the leading cause of death from food allergy in the US and other Western nations. The prevalence of peanut allergy is increasing. This increase may be due to the exposure of infants with rashes to […]