Human health and medicine

Platelet Count

Platelet count: number of platelets per microliter of blood, part of the CBC. Normal adult range 150,000-400,000/µL; low counts (thrombocytopenia) raise bleeding risk; EDTA clumping causes pseudothrombocytopenia.

Platelet function testing

Platelet function testing, also called platelet function tests, is a group of laboratory assays measuring platelet aggregation and activation to diagnose bleeding disorders and monitor antiplatelet drug effects.

Platelet transfusion

A platelet transfusion infuses donated platelets to prevent or treat bleeding caused by thrombocytopenia or platelet dysfunction, with about 2.2 million doses given yearly in the United States.

Platelet-rich plasma

Platelet-rich plasma (PRP), also called platelet-rich fibrin or platelet concentrate, is an autologous blood product with platelets concentrated above baseline, used in orthopedics, wound care, dermatology, and fertility, with mostly low-quality clinical evidence.

Plateletpheresis

Plateletpheresis (platelet apheresis) collects platelets from one donor with a cell separator while returning other components; yields up to five whole-blood doses, repeatable 24 times yearly, also used therapeutically for thrombocytosis.

Platform trial

A platform trial is a clinical trial design testing multiple treatments against a shared control group, with treatments entering or leaving under a master protocol.

PLATIDE-PCI trial

PLATIDE-PCI (NCT02748330) is a completed phase 4, single-center randomized trial at Peking Union Medical College Hospital comparing ticagrelor versus clopidogrel platelet inhibition (VerifyNow PRU) in about 40 type 2 diabetic patients after elective PCI.

Oct 22, 2026

Platinum(IV) prodrug

A platinum(IV) prodrug is an inert, six-coordinate platinum(IV) complex that is reduced inside cells to release an active platinum(II) anticancer drug such as cisplatin, satraplatin being the best-known candidate.

PLATO trial

PLATO (PLATelet inhibition and patient Outcomes) trial: 18,624-patient AstraZeneca randomized trial of ticagrelor versus clopidogrel in acute coronary syndrome; positive 2009 result, later disputed US subgroup and adjudication controversy.

Platyspondylic dysplasia, Torrance type

Platyspondylic dysplasia, Torrance type (PLSD-T, Torrance-Luton type) is a rare autosomal dominant lethal skeletal dysplasia caused by COL2A1 C-propeptide mutations, with severe limb shortening, platyspondyly, short ribs, and hypoplastic ilia; rare survivors reach adulthood.

PLB-985

PLB-985 (CVCL_2162) is a human myeloid leukemia cell line established in 1987, later shown to be a subclone of HL-60; differentiated into neutrophil-like cells, it is used for NADPH oxidase, chemotaxis, degranulation, and NET studies.

Oct 20, 2026

PLCG2-associated antibody deficiency and immune dysregulation

PLAID (PLCG2-associated antibody deficiency and immune dysregulation), also called FACU or FCAS3, is a rare autosomal dominant PLCG2 deletion disorder causing infant-onset cold urticaria from evaporative cooling, antibody deficiency, infections, and autoimmunity; distinct from APLAID, which lacks cold urticaria.

Plecanatide

Plecanatide (Trulance) is a 16-amino-acid uroguanylin analog and guanylate cyclase-C agonist, FDA-approved in 2017 at 3 mg once daily for adult chronic idiopathic constipation and IBS-C, with diarrhea as the main adverse effect.

Plectin-related limb-girdle muscular dystrophy R17

LGMD R17 (formerly LGMD2Q, MIM #613723) is an autosomal recessive limb-girdle muscular dystrophy caused by PLEC variants, mainly the exon 1f c.1_9del deletion, causing proximal weakness without skin involvement.

Pleomorphic adenoma

Pleomorphic adenoma (benign mixed tumor), the most common salivary gland tumor, up to 75% of parotid tumors; PLAG1/HMGA2 fusions, pseudocapsule with microscopic extensions, recurrence after enucleation 15–45%, risk of carcinoma ex pleomorphic adenoma.

Pleomorphic xanthoastrocytoma

Pleomorphic xanthoastrocytoma (PXA), a rare BRAF V600E-driven astrocytic brain tumor of children and young adults, WHO grade 2 or 3, usually temporal lobe, treated by resection.

Plethysmography

Plethysmography is the measurement and recording of volume changes in a body part, organ, or whole body, applied to lung volumes, body composition, and limb blood flow.

Pleural biopsy

Pleural biopsy is a diagnostic procedure that samples the pleura lining the chest wall to find the cause of a pleural effusion, most often tuberculosis or pleural cancer.

Pleural cavity

Pleural cavity: potential space between visceral and parietal pleura around each lung, holding serous fluid under negative pressure; filters fluid from parietal capillaries, drains via lymphatic stomata; disorders include pneumothorax and pleural effusion.

Pleural effusion

Pleural effusion is abnormal fluid buildup in the pleural space between lung and chest wall; normal volume is 5–10 mL. Main causes are heart failure, infection, malignancy, and pulmonary embolism; classified as transudate or exudate by Light's criteria.

Pleural empyema

Pleural empyema, also called empyema thoracis, is pus in the pleural space, usually parapneumonic. Three stages, RAPID score, small-bore drainage, tPA/DNase, VATS; 20% one-year mortality.

Pleurectomy

Pleurectomy is a surgical operation that removes part of the pleura, the membrane lining the chest wall and covering the lung, used for pneumothorax, empyema, and mesothelioma.

Pleurisy

Pleurisy, also called pleuritis, is inflammation of the membrane lining the chest wall that causes sharp chest pain worsening with breathing; viral cases usually resolve within two to four weeks.

Pleuro-pericardial cyst

Pleuro-pericardial cyst, also called pericardial or spring water cyst, a rare congenital mesothelium-lined mediastinal cyst, about 1 in 100,000, usually asymptomatic, right cardiophrenic angle, treated by resection.

Pleurodesis

Pleurodesis: procedure fusing parietal and visceral pleura to prevent recurrent pleural effusion or pneumothorax, by talc (poudrage or slurry), doxycycline, or surgical abrasion; talc is the leading agent, with particle size governing ARDS risk.

Pleuropulmonary blastoma

Pleuropulmonary blastoma (PPB), also called PPB family tumor and dysplasia syndrome tumor, is a rare malignant childhood lung/pleural mesenchymal tumor with cystic type I/Ir and solid type II/III forms, usually caused by germline DICER1 mutations, distinct from adult pulmonary blastoma.

Oct 22, 2026

PLGA nanoparticles

PLGA nanoparticles are submicron drug carriers made from poly(lactic-co-glycolic acid), a biodegradable and biocompatible FDA-approved copolymer, widely used for controlled and targeted delivery of small molecules, proteins, vaccines, and nucleic acids.

PLHPN trial

PLHPN (NCT03877107) was a French bicentric single-group trial testing whether depletive lumbar puncture improves overactive bladder symptoms in idiopathic normal pressure hydrocephalus, with shunt surgery urinary outcomes as a secondary endpoint.

Plihari vatika

Plihari vatika (Plīhāri vaṭī, प्लीहारि) is an Ayurvedic herbo-mineral pill for splenomegaly and hepatomegaly, listed in API Part II Vol III and AFI (AFI000936), dosed 250–500 mg twice daily.