All articles starting with H
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Hemolytic disease of the newborn
Hemolytic disease of the newborn (HDFN, erythroblastosis fetalis): maternal IgG antibodies cross the placenta and destroy fetal red cells, mainly from RhD or ABO incompatibility; prevented by anti-D immunoglobulin, treated with phototherapy and transfusion.
Hemolytic disease of the newborn (ABO)
ABO hemolytic disease of the newborn (ABO HDN, ABO HDFN): neonatal hemolysis from maternal anti-A/anti-B IgG, almost always group O mother with A or B infant; usually mild jaundice treated with phototherapy.
Hemolytic Plaque Technique
Hemolytic plaque technique (Jerne plaque assay, plaque-forming cell assay): 1963 Jerne and Nordin method counting single antibody-secreting cells by complement lysis of sheep red blood cells in agar; predecessor of ELISPOT.
Hemolytic–uremic syndrome
Hemolytic–uremic syndrome (HUS), also called atypical HUS (aHUS) in its complement-mediated form, is a thrombotic microangiopathy with thrombocytopenia, hemolytic anemia, and kidney injury; STEC-HUS follows Shiga toxin E. coli, aHUS follows complement dysregulation treated with eculizumab or ravulizumab.
HEMOPEC trial
HEMOPEC (NCT07070973) is a pilot trial at Gemelli in Rome testing AI-guided Assisted Fluid Management and Hypotension Prediction Index against goal-directed therapy during cytoreductive surgery with HIPEC for ovarian cancer, 52 women, 2025-2027.
Hemoperfusion
Hemoperfusion is an extracorporeal treatment that passes anticoagulated blood through a column of activated charcoal or resin beads to remove poisons, toxins, and inflammatory mediators.
Hemopericardium
Hemopericardium, or hemorrhagic pericardial effusion, is blood accumulating in the pericardial sac, risking cardiac tamponade. Leading causes: invasive cardiac procedures (~31%), aortic dissection, trauma, malignancy, infection, anticoagulants; diagnosed by echocardiography and high-attenuation CT fluid.
Hemopexin
Hemopexin (HPX) is a heme-binding plasma glycoprotein produced mainly by the liver that sequesters free heme with very high affinity and delivers it to the liver, acting as a second-line defense after hemolysis.
Hemophagocytic lymphohistiocytosis
Hemophagocytic lymphohistiocytosis (HLH), including familial HLH and macrophage activation syndrome, is a life-threatening hyperinflammatory cytokine storm syndrome diagnosed by HLH-2004 criteria or HScore, treated with etoposide, steroids, emapalumab, and HSCT, with about 50% adult mortality.
Hemophagocytic syndrome associated with an infection
Infection-associated hemophagocytic syndrome (IAHS), or reactive hemophagocytic syndrome, is secondary hemophagocytic lymphohistiocytosis triggered by a concurrent infection, most often Epstein-Barr virus; diagnosis uses HLH-2004 criteria or HScore, and treatment targets the infectious trigger.
Hemoporfin for injection (Fumeida)
Hemoporfin for injection (Fumeida, 复美达), also called HMME (hematoporphyrin monomethyl ether), is a Chinese class 1.1 photodynamic drug approved in 2016; the first drug worldwide for port-wine stain, given intravenously with 532 nm laser irradiation.
Hemoptysis
Haemoptysis (hemoptysis) is coughing up blood from the lower respiratory tract; 5–14% of cases are life-threatening, usually from bronchial arteries, treated with bronchial artery embolization.
Hemorrhagic fever-renal syndrome
Hemorrhagic fever with renal syndrome (HFRS), also called Korean hemorrhagic fever or epidemic hemorrhagic fever, is a rodent-borne hantavirus disease of Europe and Asia causing fever, hemorrhage, and acute kidney injury, with case fatality from under 1% (Puumala) to 15% (Hantaan).
Hemorrhoid
Hemorrhoids (piles): symptomatic engorgement of the normal anal cushions. Covers Goligher grading I–IV, prevalence (17–31%), fiber evidence, banding versus surgery, 2024 ASCRS guideline shift, and embolization.
Hemorrhoidectomy
Hemorrhoidectomy is the surgical excision of hemorrhoidal tissue, considered the gold standard for grade III–IV hemorrhoids; its main variants are the closed Ferguson technique and the open Milligan–Morgan operation.
Hemosiderin
Hemosiderin (Hämosiderin) is the water-insoluble, iron-rich degradation product of ferritin and a long-term iron storage form; detected by Perls' Prussian blue stain and seen as hemosiderin-laden macrophages after hemorrhage.
Hemosiderosis
Hemosiderosis: intracellular accumulation of hemosiderin, degraded ferritin iron, in reticuloendothelial cells from transfusion, hemolysis, or iron-loading anemia; distinguished from genetic hemochromatosis and treated with chelation.
HEMOSTA-PN trial
HEMOSTA-PN (NCT07232927) is a randomized single-center trial at Ankara University testing FloSeal and Surgicel versus suturing alone in 150 patients undergoing partial nephrectomy for T1a-T1b renal tumors, 2023-2024.
Hemostasis
Hemostasis, the arrest of bleeding from injured vessels, involves vascular constriction, platelet plug formation, and coagulation; explained by the classic cascade and the modern cell-based model of Hoffman and Monroe.
Hemostat
Hemostat (hemostatic forceps, artery forceps): a ratcheted locking surgical clamp with ring handles used to compress blood vessels and stop bleeding; types include Crile, Kelly, Halsted mosquito, and Kocher; developed from Péan's and Spencer Wells' artery forceps.
Hemostatic Techniques
Hemostatic techniques are methods for controlling bleeding: pressure, ligation, clips, cautery, topical hemostatic agents, embolization, endoscopic and surgical hemostasis, and anticoagulation reversal (MeSH D006489).
Hemothorax
Hemothorax: blood accumulating in the pleural space, usually from blunt or penetrating chest trauma. Diagnosed by chest radiograph, E-FAST, or CT; treated with tube thoracostomy, VATS for retained blood, or thoracotomy when bleeding exceeds 1500 mL.
Hemp
Hemp is low-THC Cannabis sativa L. (under 0.3 percent delta-9 THC in US law) grown for fiber, seed, and CBD. Key facts: ancient European cultivation from 4280 BCE, yields up to 25 t/ha dry matter, 2025 US value $739 million, lower environmental impacts than cotton.
Hemp fiber
Hemp fiber is a bast fiber from the stem of Cannabis sativa and one of humanity's oldest cultivated crops, used today for textiles, paper, biocomposites, and building materials.
Hemp loophole
Hemp loophole: US legal gap from the 2018 Farm Bill defining hemp by delta-9 THC only, allowing intoxicating delta-8, THCA, and converted cannabinoids; closed by P.L. 119-37 (2025), effective December 2026.
Hemp oil
Hemp oil (hemp seed oil) is the culinary oil pressed from Cannabis sativa seeds, naturally free of THC and CBD, GRAS-recognized by FDA in 2018, and distinct from hemp-derived CBD oil extracted from flowers and leaves.
Hemp seed (dehulled)
Dehulled hemp seed, also called hulled hemp seed or hemp hearts, is the hulled kernel of Cannabis sativa industrial hemp seed; FDA had no questions on GRAS Notice 765 in December 2018, covering uses at 1-40% in human foods.
Hemp seed protein
Hemp seed protein, protein from Cannabis sativa seeds sold as meal, concentrates (50-75%), and isolates (>85% protein); GRAS in the US via FDA GRN 771 (2018), complete protein high in arginine.
Hempcrete
Hempcrete, also called hemp-lime concrete, is a bio-composite building material of hemp shiv and lime, first mixed in France around 1990 for insulation and wall infill.
Hempel (coatings company)
Hempel is a Danish paints and coatings manufacturer founded in Copenhagen in 1915 and headquartered in Kongens Lyngby, majority owned by the philanthropic Hempel Foundation since 1948.