Persius/hicric huggingface dataset:
Pascal Photocoagulator
The PASCAL Photocoagulator is an integrated semi-automatic pattern scan laser photocoagulation system designed to treat ocular diseases using a single shot or predetermined pattern array. The device is for ophthalmologists, particularly those that focus in vitreo-retinal surgery, a type of eye surgery.

# History
The Pascal method of photocoagulation was initially developed at Stanford University. OptiMedica founders worked together at Coherent, and based on their experience in the  ophthalmic laser industry, recognized the need for improved safety, precision, comfort and speed of photocoagulation procedures for eye diseases.

# Ophthalmic Laser Delivery Systems
Most ophthalmic laser delivery systems include:
- a laser source such as the Nd:YAG laser used in Pascal
- a delivery device such as a slit lamp or laser indirect ophthalmoscope (LIO)
- a control system for selecting power and duration
- a method for selecting spot size
The Pascal system is fully integrated with a touch screen GUI, advanced slit lamp optics, slit lamp mounted micromanipulator, and ergonomic features for the physician and patient.

# Pascal Method - Pattern Scanning
In scanning applications, a control system applies an electrical current proportional to the desired location of a beam of light to a high speed, sensitive, limited rotation motor called a galvanometer (commonly referred to as a galvo). A scanner is a galvo with a mirror attached to it. When the current is changed, the scanner quickly steers the laser beam to the desired location. Closed loop circuits ensure that the desired position is precisely reached.
In Pascal, control selections such as pattern and spot size from the graphical user interface are translated into (F,X,Y) coordinates. Three scanners deliver laser light to the retina in multi-spot patterns by controlling the x-position (X), y-position(Y) and fiber selection(F) for the placement and size of the laser beam.
The use of a FPGA from National Instruments enables fast scanning speed and a short response time of 4 microseconds for critical measurements and controlled feedback.

# Indications for Use
Pascal Photocoagulator was approved in 2005 by the FDA through a 510(k) for treating vascular and structural abnormalities of the retina and choroids including
- Proliferative and non proliferative diabetic retinopathy
- Choroidal neovascularization
- Branch and central retinal vein occlusion
- Age-related macular degeneration
- Lattice degeneration
- Retinal tears and detachments
- Iridotomy
- Iridectomy
- Trabeculoplasty in angle closure and open angle glaucoma
Pascal photocoagulator also has  for international sale.

# Awards
- In 2007, OptiMedica received the R&D 100 award for the Pascal Photocoagulator. The award recognizes the innovative technology as one of the top 100 products introduced to the marketplace in the last year.
- The Pascal Photocoagulator was recognized with a 2007 Medical Design Excellence Award gold medal in the surgical equipment, instruments, and supplies category.
Thoracoacromial artery

# Overview
The thoracoacromial artery (acromiothoracic artery; thoracic axis) is a short trunk, which arises from the forepart of the axillary artery, its origin being generally overlapped by the upper edge of the Pectoralis minor.

# Branches
Projecting forward to the upper border of the Pectoralis minor, it pierces the coracoclavicular fascia and divides into four branchespectoral, acromial, clavicular, and deltoid.

# Mnemonic
One mnemonic used to remember the four branches is "Cadavers Are Dead People".

# Additional images
- The axillary artery and its branches.
Penicillin V potassium

# Overview
Phenoxymethylpenicillin, commonly known as penicillin V, is a penicillin antibiotic that is orally active. It is less active than benzylpenicillin (penicillin G) against Gram-negative bacteria. Phenoxymethylpenicillin is more acid-stable than benzylpenicillin, which allows it to be given orally. It exerts a bactericidal action against penicillin-sensitive microorganisms during the stage of active multiplication. It acts by inhibiting the biosynthesis of cell-wall peptidoglycan. It is not active against beta-lactamase-producing bacteria, which include many strains of Staphylococci.
Phenoxymethylpenicillin has a range of antimicrobial activity against Gram-positive bacteria that is similar to that of benzylpenicillin and a similar mode of action, but it is substantially less active than benzylpenicillin against Gram-negative bacteria.

# Category
Penicillin antibiotic

# US Brand Names
PENICILLIN V POTASSIUM tablet

# FDA Package Insert
Description

# Mechanism of Action
Penicillin V exerts a bactericidal action against penicillin-sensitive microorganisms during the stage of active multiplication. It acts through the inhibition of biosynthesis of cell-wall mucopeptide. It is not active against the penicillinase-producing bacteria, which include many strains of staphylococci. The drug exerts high in vitro activity against staphylococci (except penicillinase-producing strains), streptococci (groups A, C, G, H, L and M), and pneumococci. Other organisms sensitive in vitro to penicillin V are Corynebacterium diphtheriae, Bacillus anthracis, Clostridia, Actinomyces bovis, Streptobacillus moniliformis, Listeria monocytogenes, Leptospira, and Neisseria gonorrhoeae. Treponema pallidum is extremely sensitive.
Penicillium roqueforti
Penicillium roqueforti is a common saprotrophic fungus, that is widespread in nature and can be isolated from soil, decaying organic substances and plant parts. The major industrial use of this fungus is the production of blue cheeses, flavoring agents, antifungals, polysaccharides, proteases and other enzymes.
While the fungus has been a constituent of Roquefort, Stilton and other blue cheeses and eaten by humans since about 500 AD, there is considerable evidence to indicate that most strains are capable of producing harmful secondary metabolites (alkaloids and other mycotoxins) under certain growth conditions (Peabody, 1985; Sharpell, 1985).
The chief industrial use of the fungus P. roqueforti is the production of Roquefort cheese. Strains of the microorganism are also used to produce compounds that can be employed as antibiotics, flavors and fragrances (Sharpell, 1985), uses not regulated under the Toxic Substance Control Act (TSCA). Its texture is chitinous.
The organism can also be used for the production of proteases and speciality chemicals, such as methyl ketones (Larroche et al, 1989) and 2-heptanone (Larroche and Gros, 1989; Jong and Gantt, 1987). Other strains of Penicillium species are also useful in biodeterioration (Peberdy, 1985) which may be used in applications subject to TSCA reporting.
Pentavalent antimonial

# Overview
Pentavalent antimonials (also abbreviated pentavalent Sb or  SbV) are a group of compounds used for the treatment of leishmaniasis.  They are also called pentavalent antimony compounds.

# Types
The first pentavalent antimonial used was urea stibamate: first introduced in the 1930s, it fell out of favour in the 1950s due to higher toxocity compared to sodium stibogluconate.
The compounds currently available for clinical use are:
- sodium stibogluconate (Pentostam; manufactured by GlaxoSmithKline; available in US and UK), which is administered by slow intravenous injection.
- meglumine antimoniate (Glucantim; manufactured by Aventis; available in Brazil, France and Italy), which is administered by intramuscular injection.
The pentavalent antimonials can only be given by injection: there are no oral preparations available.

# Alternatives
In many countries, widespread resistance to antimony has meant that amphotericin or miltefosine are now used in preference.

# Side effects
Cardiotoxity, reversible renal insufficiency, pancreatitis, anemia, leukopenia, rash, headache, abdominal pain, nausea, vomiting, arthralgia, myalgia, thrombocytopenia and transaminase elevation.
Peptide plane flipping
Peptide plane flipping is a type of conformational change that can occur in proteins by which the dihedral angles of adjacent amino acids undergo large-scale rotations with little displacement of the side chains. The plane flip is defined as a rotation of the dihedral angles , at amino acids i and i+1 such that the resulting angles remain in structurally stable regions of Ramachandran space.  The key requirement is that the sum of the i angle of residue i and the i+1 angle of residue i+1 remain roughly constant; in effect, the flip is a crankshaft move about the axis defined by the C-Cl and N-C bond vectors of the peptide group, which are roughly parallel.  As an example, the type I and type II beta turns differ by a simple flip of the central peptide group of the turn.
Peptide plane flips have been observed in the dynamics of native state protein tertiary structures by comparing crystal structures of the same proteins in multiple conformations. However, the most important role of plane flipping is thought to be in the process of early protein folding rather than native-state local fluctuations.
Peptide plane flipping provides a relatively low-energy pathway from alpha sheet or left-handed alpha helix to beta strand conformations. This has been suggested as a mechanism in the conformational changes of amyloid beta and related amyloidogenic peptides implicated in protein misfolding diseases such as Alzheimer's disease. These peptides may pass through an alpha-sheet intermediate in forming the beta-sheet-rich amyloid fiber assembly.
Periodontitis overview
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# Overview
Periodontitis, is the name of a collection of inflammatory diseases affecting the tissues that surround and support the teeth. Periodontitis involves progressive loss of the bone around teeth which may lead to loosening and eventual loss of teeth if untreated. Periodontitis is caused by bacteria that adhere to and grow on tooth surfaces (microbial plaque or biofilms), particularly in areas under the gum line. Periodontitis is very common in most populations but the severe forms of the disease are less common. Dentists diagnose periodontitis by inspecting the tissues around the teeth with a probe and by radiographs to detect bone loss around the teeth. Although the different forms of periodontitis are bacterial diseases, a variety of factors affect the severity of the disease. Important "risk factors" include smoking, poorly controlled diabetes, and inherited (genetic) susceptibility.

# Epidemiology and Demographics
Periodontitis is a very common disease affecting approximately 50% of U.S. adults over the age of 30 years.

# Risk Factors
One of the most predominant risk factors of periodontal disease is tobacco use. Another very strong risk factor is one's genetic susceptibility. Several conditions and diseases, including Down syndrome, diabetes, and other diseases that affect one's resistance to infection also increase susceptibility to periodontitis.

# Diagnosis

## Physical Examination
Dentists or dental hygienists "measure" periodontal disease using a device called a periodontal probe. This is a thin "measuring stick" that is gently placed into the space between the gums and the teeth, and slipped below the gum-line. If the probe can slip more than 3 millimetres length below the gum-line, the patient is said to have a "gingival pocket" around that tooth.

# Treatment

## Secondary Prevention
Typically dental hygienists (or dentists) use  special instruments to clean (debride) teeth below the gumline and disrupt any plaque growing below the gumline. This is a standard treatment to prevent any further progress of established periodontitis.  Studies show that after such a professional cleaning (periodontal debridement), bacteria and plaque tend to grow back to pre-cleaning levels after about 3-4 months.  Hence, in theory, cleanings every 3-4 months might be expected to also prevent the initial onset of periodontitis.
Perioperative bleeding
Synonyms and keywords: perioperative hemorrhage

# Overview
Excessive perioperative bleeding is a major complication following surgery and is associated with increased morbidity and mortality. Common causes include inherited bleeding diathesis or platelet disorders, major surgical procedures, and coagulation abnormalities related to certain conditions (eg, uremia, liver failure, sepsis) and medications.

# 2013 ESA Guidelines for the Management of Severe Perioperative Bleeding (DO NOT EDIT)

### Evaluation of Coagulation Status

### Evaluation of Platelet Function

### Preoperative Correction of Anemia

### Optimizing Macrocirculation

### Transfusion Triggers

### Oxygen Fraction

### Monitoring Tissue Perfusion

### Transfusion of Labile Blood Products

### Cell Salvage

### Storage Lesions

### Coagulation Management

### Antifibrinolytics and Tranexamic Acid

### Correction of Confounding Factors

### Emergency Radiological/Surgical Interventions to Reduce Blood Loss

### Cost Implications

## Algorithms in Specific Clinical Fields

### Cardiovascular Surgery

### Gynecological (Non-Pregnant) Bleeding

### Obstetric Bleeding

### Orthopedic Surgery and Neurosurgery

### Visceral and Transplant Surgery

### Acute Upper Gastrointestinal Bleeding

### Coagulopathy and Renal Disease

### Pediatric Surgery

### Antiplatelet Agents

### Heparin

### Fondaparinux

### Vitamin K Antagonists

### New Oral Anticoagulants

### Comorbidities Involving Hemostatic Derangement

## Patients with Congenital Bleeding Disorders

### von Willebrand Disease

### Platelet Defects

### Hemophilia A and B

### Rare Bleeding Disorders

# Sources
- 2013 ESA Guidelines for the Management of Severe Perioperative Bleeding
Semipermeable membrane
A semipermeable membrane, also termed a selectively-permeable membrane, a partially-permeable membrane or a differentially-permeable membrane, is a membrane that will allow certain molecules or ions to pass through it by diffusion and occasionally specialized "facilitated diffusion." The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute. Depending on the membrane and the solute, permeability may depend on solute size, solubility, properties, or chemistry. An example of a semi-permeable membrane is a lipid bilayer, on which is based the plasma membrane that surrounds all biological cells. Many natural and synthetic materials thicker than a membrane are also semipermeable.  An example of this is the thin film on the inside of an egg.
One example of a semipermeable membrane is a phospholipid bilayer, a group of phospholipids (consisting of a phosphate head and 2 fatty-acid tails) arranged into a double-layer, with the hydrophilic phosphate heads exposed to the water content outside and within the cell and the hydrophobic fatty-acid tails hidden in the inside. The phospholipid bilayer is the most permeable to small, uncharged solutes. Protein channels float through the phospholipids, and, collectively, this model is known as the fluid mosaic model.
In the process of reverse osmosis, Thin film composite membranes (TFC or TFM) are used. Thin film composite membranes are semipermeable membranes manufactured principally for use in water purification or desalination systems. They also have use in chemical applications such as batteries and fuel cells. In essence, a TFC material is a molecular sieve constructed in the form of a film from two or more layered materials.
Membranes used in reverse osmosis are, in general, made out of polyimide, chosen primarily for its permeability to water and relative impermeability to various dissolved impurities including salt ions and other small molecules that cannot be filtered. Another example of a semipermeable membrane is dialysis tubing.
Permissive hypercapnia

# Overview
Permissive hypercapnia is hypercapnia, (i.e. high concentration of carbon dioxide in blood), in respiratory insufficient patients in which oxygenation has become so difficult that the optimal mode of mechanical ventilation (with oxygenation in mind) is not capable of exchanging enough carbon dioxide. Carbon dioxide is a gaseous product of the body's metabolism and is normally expelled through the lungs.
In acute respiratory distress syndrome (ARDS), permissive hypercapnia (allowing increased CO2 retention) by decreasing the tidal volume on the ventilator (usually 10-15 mL/kg/min) to 8 mL/kg/min may decrease barotrauma by decreasing ventilatory peak airway pressures and leads to improved respiratory recovery.  The permissive hypercapnia leads to respiratory acidosis which has negative side effects, but given that the patient is in ARDS, improving ventilatory function is more important.
Since hypoxemia is a major life threatening condition and hypercapnia is not, one might choose to accept the latter. Hence the term, "permissive hypercapnia."

# Symptoms
Symptoms of early hypercapnia (i.e. where PaCO2 is elevated but not extremely so) include;
- Flushed skin
- Full pulse
- Extrasystoles
- Muscle twitches
- Hand flaps, and possibly a raised blood pressure.
In severe hypercapnia (generally PaCO2 greater than 10 kPa or 75 mmHg), symptomatology progresses to disorientation, panic, hyperventilation, convulsions, unconsciousness, and eventually death.

# Related Chapters
- Acute respiratory distress syndrome
- Mechanical ventilation
Peter Butler (surgeon)

# Overview
Peter E M Butler, FRCSI, FRCS (born 1 September 1962) is a Professor of plastic surgery at University College London, consultant plastic surgeon, clinical director of surgery and head of the face transplantation team at the Royal Free Hospital in London, England.

# Education and training
He is a graduate of the Royal College of Surgeons in Ireland and Physicians of Ireland obtaining diplomas MB BCh LRCPSI in 1987. He did his general surgical training in Dublin and became a fellow of the Royal College of Surgeons in Ireland (FRCS) in 1991 and the Royal College of Surgeons of England (FRCS) in 1992. He has an active clinical and laboratory based research program. One of his main areas of research is facial transplantation. The work he has been involved in has received awards from the New England Society of Plastic and Reconstructive Surgeons, the American Society of Plastic and Reconstructive Surgeons, the Plastic Surgery Research Council, USA and the British Association of Plastic Surgeons.

# Face transplantation
Peter Butler began the experimental work leading towards facial transplantation in 1993 at the Massachusetts General Hospital and Harvard Medical School, this work continues today. On returning to the UK he set up the clinical research programme in facial transplantation in 2002. This programme was one of the first in the world. Two other teams existed at that time one at Louisville, Kentucky, USA and the other at the Cleveland Clinic, Ohio, USA. In 2004 a team led by Dr. Maria Siemionow at the Cleveland Clinic became the first institution to approve this surgery.  There was considerable resistance to facial transplantation taking place in the UK. 
In October 2006, after overcoming the ethical hurdles Peter Butler's team received permission from the North London Research Ethics Committee to go ahead with a series of four full face transplant operations to be carried out at the Royal Free Hospital. 
Some news outlets have speculated that their team is likely to be the first to perform such a transplant.
However, Dr. Butler stated in an October 27 press release that their team "will not be rushed" and "It may be many months before we are ready to carry out an operation. The costs of the operation is to be funded by a charity, 'The Face Trust", set up by Peter Butler in 2006.  Patient selection for facial transplantation is currently ongoing.

# Personal life
Peter is married to Annabel Heseltine, well known daughter of former British deputy prime minister Michael Heseltine. He has four children, Mungo, Isabella, Rafferty and Monty.
He is the eldest son of Professor Norman Butler the former head of the school of Dentistry at Trinity College Dublin.

# Additional Links
-  The Face Trust
-  BBC Report
-  Science Museum
- Information on Peter Butler
Pineal choriocarcinoma
Synonyms and keywords: Pineal embryonal cell carcinoma; Pineal gland tumor; Brain tumor

# Overview
- Pineal choriocarcinoma is a relatively rare, malignant, highly vascular neoplasm and accounts for a small proportion of all intracranial germ cell tumors. It is an aggressive tumor and has a propensity to metastasise systemically. Pure pineal choriocarcinoma tumors secrete -HCG.
- On microscopic histopathological analysis, pineal choriocarcinoma is characterized by presence of intimately related syncytiotrophoblasts and cytotrophoblasts without formation of definite placental type villi. Syncytiotrophoblasts are large multi-nucleated cells with eosinophilic cytoplasm. They often surround the cytotrophoblasts, reminiscent of their normal anatomical relationship in chorionic villi. Cytotrophoblasts are polyhedral, mononuclear cells with hyperchromatic nuclei and a clear or pale cytoplasm.
- Pineal choriocarcinoma accounts for 5% of all pineal masses.
- The peak age at diagnosis for pineal choriocarcinoma is 20-30 years.
- Common complications of pineal choriocarcinoma include:
- CSF metastasis
- Intraventricular hemorrhage
- Coma
- Systemic metastasis
- The clinical presentation of pineal choriocarcinoma is mainly from the obstructive hydrocephalus secondary to compression of the tectum of the midbrain and obstruction of the aqueduct. Symptoms of pineal choriocarcinoma include headache, vomiting, ptosis, and weakness.
- Compression of the superior colliculi can lead to a characteristic gaze palsy, known as Parinaud syndrome.
- Common physical examination findings of pineal choriocarcinoma include papilledema, signs of precocious puberty, restricted extraocular movements, sluggish pupillary light reflex, stiff neck, hemiparesis, and abducent nerve palsy.
- Laboratory findings consistent with the diagnosis of pineal choriocarcinoma include abnormal CSF analysis, demonstrating xanthochromia.
- Head CT scan and brain MRI may be helpful in the diagnosis of pineal choriocarcinoma.
- On head CT scan, pineal choriocarcinoma is characterized by a round, calcified, homogeneous, enhancing mass in the third ventricle associated with the dilation of the lateral and third ventricles and periventricular lucency.
- On brain MRI, pineal choriocarcinoma is characterized by hyperintensity on T1-weighted images and signal drop-out and blooming on T2- sequences.
- Biopsy is generally done to confirm the diagnosis of pineal choriocarcinoma.
- The mainstay of therapy for pineal choriocarcinoma is radiotherapy and/or chemotherapy. Sometimes, surgical resection may be done.

# Management of Pineal Choriocarcinoma
Plexiform neurofibroma
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A plexiform neurofibroma is a tumor of the peripheral nerves which is common in individuals with neurofibromatosis type I, and indeed is diagnostic of that condition. The tumor occurs when Schwann cells multiply out of control within the nerve sheath. While typically benign, the tumor occasionally may become malignant. The tumors are often painful or disfiguring and may lead to disability.