All articles starting with P
28,818 articles
Prostacyclin synthase
Prostacyclin synthase (PGIS, PTGIS, CYP8A1) is a cytochrome P450 isomerase converting prostaglandin H2 to prostacyclin, the vasodilator and platelet inhibitor; distinct from thromboxane synthase, its functional antagonist.
Prostaglandin
Prostaglandins (prostanoids) are lipid mediators derived from arachidonic acid via cyclooxygenase, including PGE2, PGI2, PGD2, PGF2alpha, and TXA2; discovered by von Euler in 1935, subject of the 1982 Nobel Prize, and targets of NSAIDs and prostacyclin therapy.
Prostaglandin D2
Prostaglandin D2 (PGD2) is a prostaglandin lipid mediator made from arachidonic acid and released in large amounts by mast cells, driving allergic inflammation and bronchoconstriction while also promoting sleep.
Prostaglandin E1
Prostaglandin E1 (PGE1, alprostadil; Caverject, MUSE) is a naturally occurring vasodilator lipid and synthetic drug that raises cAMP in smooth muscle; used mainly as second-line injectable, intraurethral, or topical therapy for erectile dysfunction.
Prostaglandin E2
Prostaglandin E2 (dinoprostone, PGE2) is an inflammatory lipid mediator from arachidonic acid acting via four GPCRs EP1-EP4; EP3/EP4 bind with nanomolar affinity, EP3 mediates fever, and mPGES-1 and EP4 are drug targets.
Prostanna
Prostanna (Προστανά) was a Hellenistic-to-Byzantine city of Pisidia near Eğirdir, Turkey, on Mount Viarus (Eğirdir Sivrisi), attested by a 113 BC Delos inscription, Ptolemy, the 381 council list, and its own bronze coinage.
Prostanoid receptor
Prostanoid receptors (DP, DP2/CRTH2, EP1-4, FP, IP, TP) are G-protein-coupled receptors for prostaglandins and thromboxane A2, grouped into relaxant, contractile, and inhibitory classes by cAMP or calcium signaling.
Prostate
Prostate: chestnut-sized male reproductive gland (~30 g) below the bladder, wrapping the urethra; secretes alkaline fluid making ~25% of semen. Zones (peripheral, central, transitional) explain BPH and cancer origins; PSA screening and MRI guide diagnosis.
Prostate apoptosis response 4
Prostate apoptosis response 4 (Par-4) is a pro-apoptotic tumor suppressor protein, first identified in 1994 in a rat prostate cancer cell line, that kills cancer cells selectively.
Prostate biopsy
A prostate biopsy is a diagnostic procedure that removes small prostate tissue samples with a needle, usually guided by ultrasound or MRI, to diagnose prostate cancer.
Prostate brachytherapy
Prostate brachytherapy: internal radiation therapy placing radioactive seeds (LDR, Iodine-125) or temporary Iridium-192 sources (HDR) in the prostate; used alone for low-risk disease or as an EBRT boost, improving biochemical control with added urinary toxicity.
Prostate cancer
Prostate cancer, malignancy of the prostate gland; most common cancer in US men, second in cancer deaths; diagnosed by PSA, DRE, biopsy, Gleason score; ProtecT trial shows ~97% survival across monitoring, surgery, radiotherapy.
Prostate cancer in dogs
Prostate cancer in dogs is an uncommon, aggressive cancer of the canine prostate gland, most often prostatic adenocarcinoma in older males, usually metastatic at diagnosis with a poor prognosis.
Prostate cancer screening
Prostate cancer screening, mainly the PSA blood test with or without digital rectal exam, detects cancer in symptom-free men; USPSTF gives an individual-decision C grade for ages 55–69, citing small mortality benefit against false positives, overdiagnosis, and treatment harms.
Prostate cancer survivorship and quality of life
Prostate cancer survivorship and quality of life covers long-term prognosis, urinary and sexual outcomes after surgery or radiotherapy, PSA follow-up schedules, and rehabilitation for over 3.5 million US survivors.
Prostate cancer susceptibility loci
Prostate cancer susceptibility loci are inherited genetic variants that raise prostate cancer risk; 451 are cataloged, led by the 8q24 region and the rare HOXB13 G84E variant.
Prostate Health Index
The Prostate Health Index (phi) is a blood test combining three PSA forms into one score, used to estimate prostate cancer risk and reduce unnecessary biopsies.
Prostate massage
Prostate massage (prostatic massage) is pressure on the prostate via the rectum; historically a prostatitis treatment abandoned by urology, now mainly diagnostic (Meares-Stamey test) and for sperm retrieval in anejaculation; contraindicated in acute bacterial prostatitis.
Prostate specific antigen positive
Prostate specific antigen positive (ICD-11 MA14.1B) is the clinical finding of elevated blood PSA, a prostate-made protein raised by prostate cancer, benign prostatic hyperplasia, prostatitis, or recent procedures; it triggers repeat testing, MRI, and biopsy, not a cancer diagnosis.
Prostate stem cell
Prostate stem cell: adult prostate epithelial stem cell with self-renewal generating basal, luminal, and neuroendocrine lineages; human CD133+/α2β1hi basal cells, mouse Lin−Sca-1+CD133+CD44+CD117+ cells, plus CARN and CARB luminal stem cells.
Prostate-specific antigen
Prostate-specific antigen (PSA, KLK3), a prostate protein measured in blood; elevated in cancer, BPH, and prostatitis. Used for monitoring and screening; trials show small mortality benefit with overdiagnosis in 20-50%.
Prostatectomy
Prostatectomy, especially radical prostatectomy, is surgery removing part or all of the prostate with seminal vesicles for localized prostate cancer, done open, laparoscopic, or robot-assisted; comparable 15-year cancer survival to radiotherapy and monitoring.
Prostatic artery embolization
Prostatic artery embolization (PAE) is an interventional radiology procedure that blocks arteries supplying the prostate, shrinking the gland to relieve urinary symptoms of benign prostatic hyperplasia.
Prostatocystitis
Prostatocystitis is inflammation of the bladder, bladder neck, prostate, and prostatic urethra; ICD-11 code GA91.2, ICD-10-CM N41.3, ICD-9-CM 601.3, SNOMED CT 67685000.
Prosthesis
A prosthesis is an artificial substitute that replaces a missing body part or improves how one works; examples include limbs, eyes, joints, false teeth, and jaw replacements.
Prosthesis Coloring
Prosthesis Coloring (MeSH D017797) is the coloring, shading, or tinting of prosthetic components and materials, chiefly in dental and maxillofacial prosthetics, covering shade matching, intrinsic and extrinsic pigmentation, metamerism, and color stability.
Prosthesis Design
Prosthesis design is the engineering and clinical discipline of creating artificial replacements for missing body parts, including limb, facial, and dental prostheses and implanted joint replacements.
Prosthesis Implantation
Prosthesis implantation is the surgical insertion of a prosthesis (MeSH D019919), covering joint, dental, breast, cochlear, heart valve, and osseointegrated limb implants, with risks of infection, failure, and material reactions.
Prosthesis Retention
Prosthesis retention: resistance of dentures, limb prostheses, and maxillofacial prostheses to dislodgment, achieved via adhesion, suction, elevated vacuum, locks, adhesives, or osseointegrated implants.
Prosthesis study
A prosthesis study in elbow orthopedics examines the radial head prosthesis, an implant replacing the radial head after fractures too comminuted to reconstruct, first used in 1941.