All articles starting with P
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Primary hyperparathyroidism
Primary hyperparathyroidism (PHPT): autonomous parathyroid hormone secretion, usually from a single adenoma, causing hypercalcemia; diagnosed biochemically, treated definitively by parathyroidectomy, with cinacalcet for nonsurgical cases.
Primary hypomagnesemia with hypercalciuria and nephrocalcinosis
Primary hypomagnesemia with hypercalciuria and nephrocalcinosis, also called FHHNC or Michelis-Castrillo syndrome, is a rare autosomal recessive tubular disorder caused by CLDN16 or CLDN19 mutations, producing hypomagnesemia, hypercalciuria, nephrocalcinosis, and progressive kidney failure.
Primary hypomagnesemia with secondary hypocalcemia
Primary hypomagnesemia with secondary hypocalcemia, also called hypomagnesemia with secondary hypocalcemia (HSH), is a rare inherited disorder of magnesium absorption that appears in infancy with seizures and tetany.
Primary ideal
A primary ideal is a proper ideal of a commutative ring such that a product in it forces one factor, or a power of the other, into it.
Primary intestinal lymphangiectasia
Primary intestinal lymphangiectasia (Waldmann's disease, PIL) is a rare disorder of dilated intestinal lacteals causing protein-losing enteropathy, edema, and lymphopenia, treated mainly with a low-fat MCT diet.
Primary intra-abdominal hernia
Primary intra-abdominal hernia (internal hernia, ICD-11 DD50.20): congenital herniation of viscera through peritoneal or mesenteric openings inside the abdomen without surgery or trauma; paraduodenal hernias predominate, CT is first-line, strangulation risk is high.
Primary intrahepatic lithiasis
Primary intrahepatic lithiasis (PIHL, primary hepatolithiasis) is a rare disease with stones forming inside intrahepatic bile ducts without known cause, causing recurrent cholangitis; endemic in East Asia, rare in the West, with cholangiocarcinoma risk.
Primary lactase deficiency
Primary lactase deficiency, also called adult-type hypolactasia or lactase nonpersistence, is the genetically programmed post-weaning decline of intestinal lactase affecting about 65-70% of adults worldwide, causing lactose malabsorption and, in roughly half of genetically predisposed people, lactose intolerance symptoms.
Primary lateral sclerosis
Primary lateral sclerosis (PLS) is a rare, sporadic neurodegenerative disorder of adult upper motor neurons causing slowly progressive spasticity, distinct from ALS by pure UMN involvement, 2020 consensus criteria, and much longer survival.
Primary lesions of pinta
Primary lesions of pinta (ICD-11 1C1E.0) are the initial erythematous, non-ulcerating, scaly papules or plaques of Treponema carateum infection, appearing on exposed skin weeks after inoculation, highly infectious, with regional lymphadenopathy and no systemic symptoms.
Primary life support system
The primary life support system, or Portable Life Support System, is the spacesuit backpack that supplies oxygen, removes carbon dioxide, and cools astronauts during spacewalks.
Primary lymphedema
Primary lymphedema is a rare genetic swelling disorder from developmental lymphatic defects, including Milroy disease (FLT4), Meige disease (GJC2), and lymphedema-distichiasis (FOXC2), with over 20 known causative genes.
Primary malignant meningioma
Primary malignant meningioma is a WHO grade 3 meningioma, about 1% of cases, historically called anaplastic, with aggressive behavior and average survival of 2 to 3 years.
Primary mediastinal large B-cell lymphoma
Primary mediastinal large B-cell lymphoma (PMBCL, PMLBCL) is an aggressive thymic B-cell non-Hodgkin lymphoma, 2-4% of NHL, mainly in women aged 30-40, marked by 9p24.1 JAK2/PD-L1 amplification and treated with R-CHOP or DA-EPOCH-R.
Primary melanoma of the central nervous system
Primary melanoma of the CNS, also called malignant melanoma of the meninges, is an ultra-rare meningeal tumor arising from leptomeningeal melanocytes, diagnosed only when no melanoma exists outside the CNS; GNAQ/GNA11-mutated, 0.07% of intracranial tumors.
Primary membranoproliferative glomerulonephritis
Primary membranoproliferative glomerulonephritis (primary MPGN, mesangiocapillary GN) is an ultrarare complement-driven kidney disease (1–3 per million), classified as IC-MPGN or C3 glomerulopathy (C3GN, DDD), with about half of patients reaching kidney failure within 10 years.
Primary migration
Primary migration, also called hydrocarbon expulsion, is the movement of petroleum out of its low-permeability source rock into a reservoir, the first step of the petroleum system.
Primary motor cortex
Primary motor cortex (M1), Brodmann area 4, in the precentral gyrus; the cortical output area for voluntary movement. Contains Betz cells, somatotopic motor homunculus (Penfield and Boldrey, 1937), corticospinal and corticobulbar tracts, contralateral control.
Primary myelofibrosis
Primary myelofibrosis (PMF), also called chronic idiopathic myelofibrosis, is a clonal myeloproliferative neoplasm causing marrow fibrosis, anemia, and splenomegaly; JAK2/CALR/MPL mutations and DIPSS/MIPSS scores guide transplant and JAK-inhibitor treatment.
Primary neuron (sensu Teleostei)
Primary neuron (sensu Teleostei), Cell Ontology CL:0000530, denotes early-born teleost fish neurons with large bodies and pioneer axons, including Rohon-Beard, CaP/MiP/RoP motor, and Mauthner cells, distinct from later secondary neurons.
Primary non-essential cutis verticis gyrata
Primary non-essential cutis verticis gyrata, also called CVG-ID, is a rare genetic disorder with cerebriform scalp folds that cannot be flattened, associated with intellectual disability, epilepsy, and eye abnormalities such as congenital cataract.
Primary non-gestational choriocarcinoma of ovary
Primary non-gestational choriocarcinoma of ovary (NGCO), a rare malignant ovarian germ cell tumor producing hCG, arising without pregnancy, metastasizing to lung, liver, and brain, distinguished from gestational choriocarcinoma by DNA polymorphism analysis and treated with surgery plus BEP chemotherapy.
Primary nursing
Primary nursing is a nursing care delivery model in which one nurse is accountable for a patient's care from admission to discharge, with associate nurses covering absences.
Primary oculocerebral lymphoma
Primary oculocerebral lymphoma, also known as primary vitreoretinal lymphoma, is a rare extranodal non-Hodgkin lymphoma, usually of diffuse large B-cell type, that affects the eye and central nervous system.
Primary oocyte
Primary oocyte: diploid female germ cell (2n, 4C) formed from an oogonium, arrested at prophase I (diplotene/dictyate) of meiosis I, sometimes for decades; completes meiosis I at ovulation to form a secondary oocyte and first polar body.
Primary open-angle glaucoma
Primary open-angle glaucoma (POAG), also called chronic open-angle glaucoma, is a chronic progressive optic neuropathy with an open anterior chamber angle. About 53 million cases in 2020; elevated IOP is the only modifiable risk factor, and treatment lowers IOP with drops, SLT laser, or surgery.
Primary orthostatic tremor
Primary orthostatic tremor (POT, shaky legs syndrome) is a rare tremor disorder with a high-frequency (>12 Hz, typically 13-18 Hz) tremor when standing, relieved by sitting or walking, diagnosed by surface EMG, treated with clonazepam or perampanel.
Primary osteoarthritis of hip
Primary osteoarthritis of hip (ICD-11 FA00.0) is idiopathic degenerative hip joint disease from wear and tear and ageing, not trauma or structural abnormality; common after 50-60, managed with exercise, weight loss, and hip replacement when severe.
Primary osteoarthritis of knee
Primary osteoarthritis of knee is degeneration of an otherwise intact knee joint attributed to genetic, age-related, or use-related factors, distinct from post-traumatic or other secondary forms, affecting an estimated 600 million people worldwide.
Primary palatoplasty
Primary palatoplasty is the surgical closure of a cleft palate, typically performed between 4 and 18 months of age to separate the oral and nasal cavities and enable normal speech.