Context: Heme or haem (from Greek "haima" meaning blood) is a cofactor consisting of an Fe (ferrous) ion contained in the centre of a heterocyclic macrocycle organic compound called a porphyrin, made up of four pyrrolic groups joined together by methine bridges. Not all porphyrins contain iron, but a substantial fraction of porphyrin-containing metalloproteins have heme as their prosthetic group; these are known as hemoproteins. Hemes are most commonly recognized as components of hemoglobin, the red pigment in blood, but are also found in a number of other biologically important hemoproteins such as myoglobin, cytochrome, catalase, heme peroxidase, and endothelial nitric oxide synthase., Hemodialysis, also spelled haemodialysis, commonly called kidney dialysis or simply dialysis, is a process of purifying the blood of a person whose kidneys are not working normally. This type of dialysis achieves the extracorporeal removal of waste products such as creatinine and urea and free water from the blood when the kidneys are in a state of kidney failure. Hemodialysis is one of three renal replacement therapies (the other two being kidney transplant and peritoneal dialysis). An alternative method for extracorporeal separation of blood components such as plasma or cells is apheresis., A disease is a particular abnormal condition, a disorder of a structure or function, that affects part or all of an organism. The study of disease is called pathology which includes the causal study of etiology. Disease is often construed as a medical condition associated with specific symptoms and signs. It may be caused by external factors such as pathogens, or it may be caused by internal dysfunctions particularly of the immune system such as an immunodeficiency, or a hypersensitivity including allergies and autoimmunity., Creatinine (or ; from ) is a breakdown product of creatine phosphate in muscle, and is usually produced at a fairly constant rate by the body (depending on muscle mass)., Porphyria is a group of diseases in which substances called porphyrins build up, affecting the skin or nervous system. The types that affect the nervous system are also known as acute porphyria. Symptoms of acute porphyria include abdominal pain, chest pain, vomiting, confusion, constipation, fever, and seizures. These symptoms typically come and go with attacks that last for days to weeks. Attacks may be triggered by alcohol, smoking, stress, or certain medications. If the skin is affected, blisters or itching may occur with sunlight exposure.
The disease is usually inherited from a person's parents and is due to a mutation in one of the genes that make heme. Some types are autosomal dominant and others are autosomal recessive. One type, porphyria cutanea tarda, may also be due to increased iron in the liver, hepatitis C, alcohol, or HIV/AIDS. The underlying mechanism results in a decrease in the amount of heme produced and a build-up of substances involved in making heme. Porphyrias may also be classified by whether the liver or the bone marrow is affected. Diagnosis is typically by blood, urine, and stool tests. Genetic testing may be done to determine the specific mutation.
Treatment depends on the type of porphyria and a person's symptoms. The treatment of porphyria of the skin generally involves the avoidance of sunlight. The treatment for acute porphyria may involve giving intravenous heme or a glucose solution. Rarely a liver transplant may be carried out.
The frequency of porphyria is unclear. It is estimated that it affects 1 to 100 per 50,000 people. Rates vary around the world. Porphyria cutanea tarda is believed to be the most common type. The disease was described at least as early as 370 BC by Hippocrates. The underlying mechanism was first described by Felix Hoppe-Seyler in 1871. The name "porphyria" is from the Greek , "porphyra", meaning "purple", a reference to the color of the urine that may occur during an attack. , Enzymes are macromolecular biological catalysts. Enzymes accelerate, or catalyze, chemical reactions. The molecules at the beginning of the process upon which enzymes may act are called substrates and the enzyme converts these into different molecules, called products. Almost all metabolic processes in the cell need enzymes in order to occur at rates fast enough to sustain life. The set of enzymes made in a cell determines which metabolic pathways occur in that cell. The study of enzymes is called "enzymology"., The kidneys are two bean-shaped organs found on the left and right sides of the body in vertebrates. They filter the blood in order to make urine, to release and retain water, and to remove waste. They also control the ion concentrations and acid-base balance of the blood. Each kidney feeds urine into the bladder by means of a tube known as the ureter., Blood is a body fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells., Urea, also known as carbamide, is an organic compound with the chemical formula CO(NH). This amide has two NH groups joined by a carbonyl (C=O) functional group., Skin is the soft outer covering of vertebrates. Other animal coverings, such as the arthropod exoskeleton have different developmental origin, structure and chemical composition. The adjective cutaneous means "of the skin" (from Latin "cutis", skin). In mammals, the skin is an organ of the integumentary system made up of multiple layers of ectodermal tissue, and guards the underlying muscles, bones, ligaments and internal organs. Skin of a different nature exists in amphibians, reptiles, and birds. All mammals have some hair on their skin, even marine mammals like whales, dolphins, and porpoises which appear to be hairless.
The skin interfaces with the environment and is the first line of defense from external factors. For example, the skin plays a key role in protecting the body against pathogens and excessive water loss. Its other functions are insulation, temperature regulation, sensation, and the production of vitamin D folates. Severely damaged skin may heal by forming scar tissue. This is sometimes discoloured and depigmented. The thickness of skin also varies from location to location on an organism. In humans for example, the skin located under the eyes and around the eyelids is the thinnest skin in the body at 0.5 mm thick, and is one of the first areas to show signs of aging such as "crows feet" and wrinkles. The skin on the palms and the soles of the feet is 4 mm thick and the back is 14 mm thick and is the thickest skin in the body. The speed and quality of wound healing in skin is promoted by the reception of estrogen., An extracorporeal medical procedure is a medical procedure which is performed outside the body., Apheresis ( ("aphairesis", "a taking away")) is a medical technology in which the blood of a person is passed through an apparatus that separates out one particular constituent and returns the remainder to the circulation. It is thus an extracorporeal therapy., In medicine, dialysis (from Greek , "diàlysis", meaning "dissolution", , "dià", meaning "through", and , "lsis", meaning "loosening or splitting") is a process for removing waste and excess water from the blood and is used primarily as an artificial replacement for lost kidney function in people with kidney failure. Dialysis may be used for those with an acute disturbance in kidney function (acute kidney injury, previously acute renal failure) or progressive but chronically worsening kidney functiona state known as chronic kidney disease stage 5 (previously chronic kidney failure or end-stage renal disease). The latter form may develop over months or years, but in contrast to acute kidney injury is not usually reversible and dialysis is regarded as a "holding measure" until a kidney transplant can be performed or sometimes as the only supportive measure in those for whom a transplant would be inappropriate., Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table and is a highly reactive nonmetal and oxidizing agent that readily forms oxides with most elements as well as other compounds. By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula . This is an important part of the atmosphere and diatomic oxygen gas constitutes 20.8% of the Earth's atmosphere. Additionally, as oxides the element makes up almost half of the Earth's crust., Porphyria cutanea tarda (PCT) is the most common subtype of porphyria. The disease is named because it is a porphyria that often presents with skin manifestations later in life. The disorder results from low levels of the enzyme responsible for the fifth step in heme production. Heme is a vital molecule for all of the body's organs. It is a component of hemoglobin, the molecule that carries oxygen in the blood., Pseudoporphyria ( also known as `` Pseudoporphyria cutanea tarda '' ) is a bullous photosensitivity that clinically and histologically mimics porphyria cutanea tarda . The difference is that no abnormalities in urine or serum porphyrin is noted on laboratories . Pseudoporphyria has been reported in patients with chronic renal failure treated with hemodialysis and in those with excessive exposure to ultraviolet A ( UV - A ) by tanning beds ., Kidney failure, also known as renal failure or renal insufficiency, is a medical condition of impaired kidney function in which the kidneys fail to adequately filter metabolic wastes from the blood. The two main forms are acute kidney injury, which is often reversible with adequate treatment, and chronic kidney disease, which is often not reversible. In both cases, there is usually an underlying cause., Hemoglobin; also spelled haemoglobin (United Kingdom spelling) and abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates (with the exception of the fish family Channichthyidae) as well as the tissues of some invertebrates. Hemoglobin in the blood carries oxygen from the respiratory organs (lungs or gills) to the rest of the body (i.e. the tissues). There it releases the oxygen to permit aerobic respiration to provide energy to power the functions of the organism in the process called metabolism., Subject: pseudoporphyria, Relation: instance_of, Options: (A) adjective (B) animal (C) atmosphere (D) base (E) body fluid (F) cell (G) chemical (H) chemical element (I) chest (J) component (K) composition (L) condition (M) dioxygen (N) disease (O) environment (P) failure (Q) filter (R) fish (S) fluid (T) formula (U) frequency (V) function (W) functional group (X) group (Y) hepatitis (Z) hydrogen ([) injury (\) ion (]) line (^) location (_) mass (`) may (a) medicine (b) member (c) metabolism (d) order (e) organ (f) organic compound (g) organism (h) part (i) person (j) phosphate (k) procedure (l) process (m) product (n) production (o) role (p) set (q) show (r) skin (s) stage (t) standard (u) structure (v) subtype (w) technology (x) temperature (y) three (z) tissue ({) transport (|) treatment (}) two
Output: disease