Persius/hicric huggingface dataset:
Paranasal sinus

# Overview
Paranasal sinuses are air-filled spaces, communicating with the nasal cavity, within the bones of the skull and face. Humans possess a number of paranasal sinuses, divided into subgroups that are named according to the bones within which the sinuses lie:
- the maxillary sinuses, also called the maxillary antra and the largest of the paranasal sinuses, are under the eyes, in the maxillary bones (cheek bones).
- the frontal sinuses, over the eyes, in the frontal bone, which forms the hard part of the forehead.
- the ethmoid sinuses, which are formed from several discrete air cells within the ethmoid bone between the nose and the eyes.
- the sphenoid sinuses, in the sphenoid bone at the center of the skull base under the pituitary gland.

# Development
Paranasal sinuses form developmentally through excavation of bone by air-filled sacs (pneumatic diverticula) from the nasal cavity. This process begins prenatally, and it continues through the course of an organism's lifetime.

# Sinuses in animals
Paranasal sinuses occur in a variety of animals (including most mammals, birds, non-avian dinosaurs, and crocodilians). In non-humans, the bones occupied by sinuses are quite variable.

# Biological function
The biological role of the sinuses is debated, but a number of possible functions have been proposed:
- Decreasing the relative weight of the front of the skull, and especially the bones of the face. The shape of the facial bones is important, as a point of origin and insertion for the muscles of facial expression.
- Increasing resonance of the voice.
- Providing a buffer against blows to the face.
- Insulating sensitive structures like dental roots and eyes from rapid temperature fluctuations in the nasal cavity.
- Humidifying and heating of inhaled air because of slow air turnover in this region

# Ailments
The paranasal sinuses are joined to the nasal cavity via small orifices called ostia. These become blocked relatively easily by allergic inflammation, or by swelling in the nasal lining which occurs with a cold. If this happens, normal drainage of mucus within the sinuses is disrupted, and sinusitis may occur.
These conditions may be treated by drugs such as pseudoephedrine, which reduce moisture in the sinuses, or by traditional techniques of nasal cleansing.
Malignancies of the paranasal sinuses comprise approximately 0.2% of all malignancies. About 80% of these malignancies arise in the maxillary sinus. Tumors of the sphenoid and frontal sinuses are extremely rare.

# Other sinuses
The paranasal sinuses are not the only sinuses within the skull; the mastoid cells in the mastoid bone around the middle ear are also a type of sinus.

# Etymology
Sinus is a Latin word meaning a fold or pocket; in particular the front pocket in a toga.
Acetyl chloride
Acetyl chloride, also known as ethanoyl chloride, is an acid chloride (also known as an acyl chloride) derived from acetic acid (ethanoic acid).  It has the formula CH3COCl and it belongs to the class of organic compounds called acyl halides. At room temperature and pressure, it is a clear colorless liquid.  Acetyl chloride does not exist in nature, because contact with water would hydrolyze it into acetic acid and hydrogen chloride. In fact, if handled in open air it gives of white smoke owing to the hydrolysis from the moisture in the air. The smoke is actually gaseous hydrogen chloride which forms small droplets in the air with water vapour.

# Synthesis
Acetyl chloride is synthesized by the reaction of acetic acid (CH3COO-H) with thionyl chloride (O=SCl2) under liberation of sulfur dioxide (SO2).

# Uses
It is a reagent for acetylation in the synthesis or derivatization of chemical compounds.  Examples of acetylation reactions include acylation processes such as esterification (see below) and the Friedel-Crafts reaction).
Frequently such acylations are carried out in the presence of a base such as pyridine, triethylamine, or DMAP, which as catalysts help to promote the reaction and as bases neutralize the resulting HCl.
Acetylation is the introduction of an acetyl group via acylation using a reactant such as acetyl chloride or acetic anhydride.  An acetyl group is an acyl group having the formula
For further information on the types of chemical reactions compounds such as acetyl chloride can undergo, see acyl halide.
Acetylcarnitine
Acetyl-L-carnitine or ALCAR, is an acetylated form of L-carnitine. ALCAR has been claimed to be superior to normal L-carnitine in terms of bioavailability. However, at least one study has suggested that the acetylated form may have a lower oral bioavailability.
It is claimed that ALCAR provides several benefits.  Advocates of acetyl-L-carnitine market it as a life extension supplement. There may be some benefit in cases of end stage renal disease or peripheral arterial disease. When supplemented alongside Lipoic acid, ALCAR appears to reverse some of the damage to mitochondria associated with aging.
The percentage of L-carnitine that is absorbed when taken via oral supplementation is much lower than that from food sources. In one particular study, it was shown that approximately 20% of orally supplemented L-carnitine is absorbed, with a bioavailability of roughly 15%, as compared to a bioavailability of between %60 and %75 when absorbed from food.
Choline supplementation may lead to increased L-carnitine retention.
ALCAR supplementation has been shown to be neuroprotective in instances of cerebral ischemia, periphiral nerve injury,
and to be beneficial in the treatment of Parkinson's disease in animals.
ALCAR supplementation has also been shown to reverse syptoms associated with mental decline in the eldery.
ALCAR is being researched in the treatment of Alzheimer's disease.
Actinic prurigo
Synonyms and keywords: "Familial polymorphous light eruption of American Indians" , "Hereditary polymorphous light eruption of American Indians," "Hutchinson's summer prurigo", and "Hydroa aestivale").

# Overview
Actinic prurigo (also known as "Familial polymorphous light eruption of American Indians," "Hereditary polymorphous light eruption of American Indians, "Hutchinson's summer prurigo," and "Hydroa aestivale") is a common sunlight-induced, pruritic, papular or nodular skin eruption.

# History
Actinic prurigo (AP) was first described by Escalona in Mexico, in 1954.

# Causes
The cause for actinic prurigo is unknown, however researchers believe that protein in our bodies may be a cause to the condition also:
-UV-A and UV-B light seem to be the main provoking agents. This observation is supported by the fact that most patients live at high altitudes (>1000 m above sea level), and the condition improves in many patients when they move to lower altitudes. However, some patients who are affected already live at sea level.18,19,27 Some authors are considering a food photosensitizer or a nutritional selective deficiency as a cause; however, no evidence proves this theory.27

# Symptoms
AP is characterized by itchy, inflamed papules, nodules, and plaques on the skin. Lesions typically appear hours or days after exposure of the skin to UV light, and follow a general pattern of sun-exposed areas. The face, neck, arms, hands, and legs are often affected, although lesions sometimes appear on skin that is covered by clothing and thus not exposed to UV light, thus making AP somewhat difficult to diagnose.
AP, also known as Actinic Prurigo, is a chronic disease. Symptoms usually worsen in the spring and summer as the day lengthens and exposure to exams increase. Exams such as AP World, AP Euro, etc.

# Physical examination

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# Treatment
Currently there is no cure for actinic prurigo, and treatment focuses on relieving the dermatologic symptoms, by way of topical steroid creams or systemic immunosuppressants.
Prescribed treatments include:
- topical creams such as Tacrolimus and Betamethasone.
- systemic immunosuppressants such as Prednisone.
- In some cases, Thalidomide has proven to be effective in controlling the symptoms of actinic prurigo.
All patients with AP are encouraged to minimize sun exposure, and to use strong sunscreen throughout the year, and even on cloudy or overcast days, as UVA light, unlike UVB light, is able to penetrate cloud cover and remains constant throughout the day.
Alternative treatment methods might include UV Hardening, Meditation and/or cognitive behavioral therapy. UV-A desensitization  phototherapy has also been shown to be effective in cases. The U.S. Food and Drug Administration (FDA) has yet to approve these allopathic approaches to medicine, so there remains much to be discovered about this particular illness in the United States.
Actinin alpha 2
Alpha-actinin 2 is a protein which in humans is encoded by the ACTN2 gene. This gene encodes an alpha-actinin isoform that is expressed in both skeletal and cardiac muscles and functions to anchor myofibrillar actin thin filaments and titin to Z-discs.

# Structure
Alpha-actinin 2 is a 103.8 kDa protein composed of 894 amino acids. Each molecule is rod-shaped (35 nm in length) and it homodimerizes in an anti-parallel fashion. Each  monomer has an N-terminal actin-binding region composed of two calponin homology domains,two C-terminal EF hand domains, and four tandem spectrin-like  repeats form the rod domain in the central region of the molecule. The high-resolution crystal structure of human alpha-actinin 2 at 3.5 A was recently resolved. Alpha actinins belong to the spectrin gene superfamily which represents a diverse group of actin-binding cytoskeletal proteins, including spectrin, dystrophin, utrophin and fimbrin. Skeletal, cardiac, and smooth muscle isoforms are localized to the Z-disc and analogous dense bodies, where they help anchor the myofibrillar actin filaments. Alpha-actinin 2 has been shown to interact with KCNA5, DLG1, DISC1, MYOZ1, GRIN2B, ADAM12,  ACTN3, MYPN, PDLIM3, PKN, MYOT, TTN, NMDAR, SYNPO2, LDB3, and FATZ.

# Function
The primary function of alpha-actinin 2 is to crosslink  filamentous actin molecules and titin molecules from adjoining sarcomeres at Z-discs, a function that is modulated by phospholipids. It is clear from studies by Hampton et al. that this crosslinking can assume a variety of conformations, with preferences for 60 and 120 angles. Alpha-actinin 2 also functions in docking signalling molecules at Z-discs, and additional studies have also implicated alpha-actinin 2 in the binding of cardiac ion channels, Kv1.5 in particular.

# Clinical significance
Mutations in ACTN2 are associated with hypertrophic cardiomyopathy, as well as dilated cardiomyopathy and endocardial fibroelastosis. The diverse functions of alpha-actinin 2 are reflected in the diverse clinical presentation of patients carrying ACTN2 mutations.
Actinin alpha 3
Alpha-actinin-3, also known as alpha-actinin skeletal muscle isoform 3 or F-actin cross-linking protein, is a protein that in humans is encoded by the ACTN3 gene.
Alpha-actinin is an actin-binding protein with multiple roles in different cell types. This gene expression is limited to skeletal muscle. It is localized to the Z-disc and analogous dense bodies, where it helps to anchor the myofibrillar actin filaments.

# Fast versus slow twitch muscle fibers
Skeletal muscle is composed of long cylindrical cells called muscle fibers. There are two types of muscle fibers, slow twitch or muscle contraction (type I) and fast twitch (type II). Slow twitch fibers are more efficient in using oxygen to generate energy, while fast twitch fibers are less efficient. However, fast twitch fibers fire more rapidly, allowing them to generate more power than slow twitch (type I) fibers. Fast twitch fibers and slow twitch fibers are also called white muscle fibers and red muscles fibers, respectively.

# Alleles
An allele (rs1815739; R577X) has been identified in the ACTN3 gene which results in a deficiency of alpha-actinin 3 in a significant proportion of the population. The X homozygous genotype is caused by a C to T transition in exon 16 of the ACTN3 gene, which causes a transformation of an arginine base (R) to a premature stop codon (X) resulting in the rs1815739 mutation causing no production of the alpha-actinin 3 protein in muscle fibers. The 577XX polymorphism causes no production of alpha-actinin 3 protein which is essential in fast twitch muscle fibers.
It has been speculated that variations in this gene evolved to accommodate the energy expenditure requirements of people in various parts of the world.:155156

## Athletes
There is an association between the ACTN3 R577X polymorphism in sprint and powerlifting performance at an elite level, and appears to be an association with exercise recovery and lower injury risk.  It appears that the XX genotype is associated with higher levels of muscle damage and a longer time required for recovery.

# Interactions
ACTN3 has been shown to interact with Actinin, alpha 2.
Actinin alpha 4
Alpha-actinin-4 is a protein that in humans is encoded by the ACTN4 gene.
Alpha actinins belong to the spectrin gene superfamily which represents a diverse group of cytoskeletal proteins, including the alpha and beta spectrins and dystrophins.  Alpha actinin is an actin-binding protein with multiple roles in different cell types.  In nonmuscle cells, the cytoskeletal isoform is found along microfilament bundles and adherens-type junctions, where it is involved in binding actin to the membrane.  In contrast, skeletal, cardiac, and smooth muscle isoforms are localized to the Z-disc and analogous dense bodies, where they help anchor the myofibrillar actin filaments.  This gene encodes a nonmuscle, alpha actinin isoform which is concentrated in the cytoplasm, and thought to be involved in metastatic processes.  Mutations in this gene have been associated with focal and segmental glomerulosclerosis.

# Interactions
Actinin alpha 4 has been shown to interact with PDLIM1, Sodium-hydrogen exchange regulatory cofactor 2, Collagen, type XVII, alpha 1, CAMK2A, CAMK2B, MAGI1 and TRIM3.
Actinomycetales
Actinomycetales is an order of Actinobacteria. They are very diverse and contain a variety of subdivisions as well as yet unclassified isolates. This is mainly because some genera are very difficult to classify because of a highly niche dependend phaenotype. For example Nocardia contains several species that are first believed to be distinct species before it was proven that their difference is purely depending on their growth conditions.

# Classification difficult
Actinomycetales are Gram positive, however several species have complex cell wall structures what makes the gram staining unsuitable. Examples: Mycobacteriaceae

# Pathogenic Familiae
Several Actinomycetales are pathogen to humans or animals, plants or other cells. The most popular example of a human pathogen is the Mycobacterium tuberculosis.

# Biotechnologically exploited Familiae
Some species are used in industry and pharma-research because of their properties. Streptomycetaceae have an unique cell morphology, cell cycle and a variety of antibiotics they produce were essential for todays antibiotic discoveries. Corynebacteriaceae, especially Corynebacterium glutamicum is used in biotechnology for production.
Acute (medical)

# Overview
In medicine, an acute disease is a disease with either or both of:
- a rapid onset;
- a short course (as opposed to a chronic course).
This adjective is part of the definition of several diseases and is, therefore, incorporated in their name, for instance, severe acute respiratory syndrome, acute leukemia.
The term 'acute' may often be confused by the general public to mean 'severe'.  This however, is a different characteristic.
Acute hospitals are those intended for short-term medical and/or surgical treatment and care.
Subacute means:
- Between acute and chronic: subacute fever symptoms; subacute endocarditis.

# Acknowledgements
The content on this page was first contributed by: C. Michael Gibson M.S., M.D.
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Acylphosphatase
In enzymology, an acylphosphatase (EC 3.6.1.7) is an enzyme that catalyzes the following chemical reaction:
The chemical reaction catalyzed by acylphosphatase enzymes.
Thus, the two substrates of this enzyme are acylphosphate and H2O, whereas its two products are carboxylate and phosphate.

# Function
This enzyme belongs to the family of hydrolases, specifically those acting on acid anhydrides in phosphorus-containing anhydrides.  The systematic name of this enzyme class is acylphosphate phosphohydrolase. Other names in common use include acetylphosphatase, 1,3-diphosphoglycerate phosphatase, acetic phosphatase, Ho 1-3, and GP 1-3.
This enzyme participates in 3 metabolic pathways:
- glycolysis / gluconeogenesis
- pyruvate metabolism, and
- benzoate degradation via coa ligation.

# Structural studies
Structures of this enzyme have been solved by both NMR and X-ray crystallography. See the links to PDB structures in the info boxes on the right for a current list of structures available in the PDB. The protein contains a beta sheet stacked on two alpha helices described by CATH as an Alpha-Beta Plait fold. The active site sits between sheet and helices and contains an arginine and an asparagine. Most structures are monomeric 

# Isozymes
Humans express the following two acylphosphatase isozymes:
Adams' catalyst
Adams' catalyst, also known as platinum dioxide, is usually represented as platinum(IV) oxide hydrate, PtO2-H2O.  It is a catalyst for hydrogenation and hydrogenolysis in organic synthesis. This dark brown powder is commercially available. The oxide itself is not an active catalyst, but it becomes active after exposure to hydrogen whereupon it converts to platinum black, which is responsible for reactions.

# Preparation
Adams' catalyst is prepared from chloroplatinic acid H2PtCl6 or ammonium chloroplatinate, (NH4)2PtCl6, by fusion with sodium nitrate. The first published preparation was reported by V. Voorhees and Roger Adams. The procedure involves first preparing a platinum-nitrate which is then heated to expel nitrogen oxides.
The resulting brown cake is washed with water to free it from nitrates.  The catalyst can either be used as is or dried and stored in a desiccator for later use.  Platinum can be recovered from spent catalyst by conversion to ammonium chloroplatinate using aqua regia followed by ammonia.

# Uses
Adams' catalyst is used for many applications.  It has shown to be valuable for hydrogenation and hydrogenolysis, dehydrogenation, and oxidation reactions. Hydrogenation occurs with syn stereochemstry when used on an alkyne resulting in a cis-alkene. Some of the most important transformations include the hydrogenation of nitro compounds to amines and ketones to alcohols. When reducing nitro compounds to amines, platinum catalysts are preferred over palladium catalysts to minimize hydrogenolysis. The catalyst is also used for the hydrogenolysis of phenyl phosphate esters, a reaction that does not occur with palladium catalysts. The pH of the solvent significantly affects the reaction course, and reactions of the catalyst are often enhanced by conducting the reduction in neat acetic acid, or solutions of acetic acid in other solvents.

# Development
Prior to the development of Adams' Catalyst, organic reductions were carried out using colloidal palladium, colloidal platinum or platinum black. The colloidal catalysts were more active but posed difficulties in isolating reaction products. This led to more widespread use of platinum black. In Adams' own words:
"...everal of the problems I assigned my students involved catalytic reduction. For this purpose we were using as a catalyst platinum black made by the generally accepted best method known at the time. The students had much trouble with the catalyst they obtained in that frequently it proved to be inactive even though prepared by the same detailed procedure which resulted occasionally in an active product. I therefore initiated a research to find conditions for preparing this catalyst with uniform activity."

# Safety
Little precaution is necessary with the oxide but, after exposure to H2, the resulting platinum black can be pyrophoric.  Therefore, it should not be allowed to dry and all exposure to oxygen should be minimized.
Adapted process
In the study of stochastic processes, an adapted process (or non-anticipating process) is one that cannot "see into the future". It is essential, for instance, in the definition of the Ito integral, which only makes sense if the integrand is an adapted process.

# Definition
Let
- (, F, P) be a probability space;
- I be an index set with a total order  (often, I is N, N0,  or [0, +));
- F- = (Fi)iI be a filtration of the sigma algebra F;
- (S, ) be a measurable space, the state space;
- X : I    S be a stochastic process.
The process X is said to be adapted to the filtration (Fi)iI if the random variable Xi :   S is a (Fi, )-measurable function for each i  I.

# Examples
Consider a stochastic process X :     R, and equip the real line R with its usual Borel sigma algebra generated by the open sets.
- If we take the natural filtration FX, where FtX is the -algebra generated by the pre-images Xs1(B) for Borel subsets B of R and times 0  s  t, then X is automatically FX-adapted. Intuitively, the natural filtration FX contains "total information" about the behaviour of X up to time t.
- This offers a simple example of a non-adapted process X :     R: set Ft to be the trivial -algebra {, } for times 0  t < 1, and Ft = FtX for times 1  t  2. Since the only way that a function can be measurable with respect to the trivial -algebra is to be constant, any process X that is non-constant on  will fail to be F-adapted. The non-constant nature of such a process "uses information" from the more refined "future" -algebras Ft, 1  t  2.
Adenomyomatosis

# Overview
Adenomyomatosis is a benign hyperplastic cholecystosis. It is a relatively common condition (identified in at least 5% of cholecystectomy specimens). Most diagnoses are made in patients in their 50s. Adenomyomatosis is most often an incidental finding, has no intrinsic malignant potential, and usually requires no treatment. Cholesterolosis, the other hyperplastic cholecystosis, consists of deposition of triglycerides and cholesterol esters within the lamina propria, producing a characteristic gross appearance known as "strawberry gallbladder." Cholesterol accumulation in adenomyomatosis is intraluminal, as cholesterol crystals precipitate in the bile trapped in Rokitansky-Aschoff sinuses (intramural diverticula lined by mucosal epithelium).

# Classification
Gallbladder involvement by adenomyomatous hyperplasia is variable in extent and location, with heterogeneous imaging appearances corresponding to diffuse, segmental, and focal adenomyomatosis.
- Exclusion of  may be most problematic in segmental and focal cases
Focal adenomyomatosis may appear as a discrete mass, known as an adenomyoma.
- Exclusion of  may be most problematic in segmental and focal cases
- Focal adenomyomatosis may appear as a discrete mass, known as an adenomyoma.

# Diagnosis

## Ultrasound
- Echogenic intramural foci from which emanate V-shaped comet tail reverberation artifacts  are highly specific for adenomyomatosis, representing the unique acoustic signature of cholesterol crystals within the lumina of Rokitansky-Aschoff sinuses.
Patient #1

## CT
- Abnormal gallbladder wall thickening and enhancement are common but nonspecific CT features of adenomyomatosis.
- Rokitansky-Aschoff sinuses of sufficient size can be visualized; a CT rosary sign has been described, formed by enhancing epithelium within intramural diverticula surrounded by the relatively unenhanced hypertrophied gallbladder muscularis.

## MRI
- The pearl necklace sign alludes to the characteristically curvilinear arrangement of multiple rounded hyperintense intraluminal cavities visualized at T2-weighted MR imaging and MR cholangiopancreatography of adenomyomatosis.
Patient #2: MRI images demonstrate adenomyomatosis at the gallbladder fundus
- T2 SSFSE
- T2 SSFSE
- LAVA post GAD
- T2 fat sat
Metabolic characterization with PET may be a useful adjunct in problematic cases.