| Pd | Symbol for palladium. (05 Mar 2000) |
|---|---|
| PDA | <cardiology, embryology, paediatrics> A condition where the normal channel between the pulmonary artery and the aorta fails to close at birth. In normal foetal circulation the blood bypasses the pulmonary circuit since oxygen and nutrients are acquired through the placenta. After birth, this channel normally closes in response to ventilation of the lungs. Those who are affected may demonstrate poor growth, shortness of breath and rapid respiratory rate. Diagnosis is by echocardiogram and treatment involves the use of indomethacin to stimulate ductus arteriosus closure. Surgical ligation will be required in those cases unresponsive to medical management. (27 Sep 1997) |
| PDD | <neurology, psychiatry> A large group of developmental disabilities which are neurological disorders, usually of unknown cause. Characteristics include reduced abilities to understand language and communicate normally, reduced ability to socially interact with others in a normal manner, and limited variety in activities and interests. Individuals will also often respond in unusual ways to sensations, engage in repetitive activities, and resist changes to the environment or to daily routines. Types of pervasive development disorder include autism, Retts Syndrome, Hellers Syndrome, and Aspergers Syndrome. Acronym: PDD (12 Jan 1998) |
| PDE4D3 phosphodiesterase | <enzyme> One of three variants encoded by pde4d gene; this form is expressed in rat thyroid cells Registry number: EC 3.1.4.- (26 Jun 1999) |
| PDGF | <growth factor> The major mitogen in serum for growth in culture of cells of connective tissue origin. It consists of 2 different but homologous polypeptides A and B (~30,000 D) linked by disulphide bonds. Believed to play a role in wound healing. It is carried in the alpha-granules of platelets and is released when platelets adhere to traumatised tissues. Connective tissue cells near the traumatised region respond by initiating the process of replication. The B chain is almost identical in sequence to p28sis, the transforming protein of simian sarcoma virus, that can transform only those cells that express receptors for platelet derived growth factor, suggesting that transformation is caused by autocrine stimulation. The receptor is a tyrosine kinase. Acronym: PDGF (12 Dec 1998) |
| PDI | <abbreviation> Periodontal Disease Index. (05 Mar 2000) |
| PDL | <abbreviation> Pulsed dye laser. (05 Mar 2000) |
| PDLL | <abbreviation> Poorly differentiated lymphocytic lymphoma. (05 Mar 2000) |
| PDQ | <oncology> A free enquiry service originating in the USA for physicians on all state of the art cancer diagnostic, preventive and treatment methods. The documents are provided by the US National Cancer Institute and includes electronic access of various forms. WWW: CancerNET Acronym: PDQ (12 Jan 1998) |
| PDR | Physicians' Desk Reference (please see entry to physicians' desk reference). Pdr less frequently stands for postdelivery room. (12 Dec 1998) |