Persius/hicric huggingface dataset:
Mastoid process

# Overview
The mastoid process is a conical prominence projecting from the undersurface of the mastoid portion of the temporal bone. It is located just behind the external acoustic meatus, and lateral to the styloid process. Its size and form vary somewhat; it is larger in the male than in the female.
This process serves for the attachment of the Digastric, Sternocleidomastoid, Splenius capitis, and Longissimus capitis muscles.
The word is derived from the Greek 'masto-', alluding to its resemblance to the breast.
Maternal effect
A maternal effect, in genetics, is the phenomenon where the genotype of a mother is expressed in the phenotype of its offspring, unaltered by paternal genetic influence. The phenotype of an individual therefore reflects the genotype of its mother, rather than the genotype of the individual.
This maternal effect is usually attributed to maternally-produced molecules, such as mRNAs, that are deposited in the egg cell. Maternal effect genes often affect early developmental processes. An example in Drosophila melanogaster morphogenesis is axis formation, in which mRNA such as Bicoid and nanos is of maternal origin and loaded into the egg prior to fertilisation. Another mechanism for the specific expression of genes from one parent is stable epigenetic modification of germ line genes in one of the sexes. This form of a parental effect is termed genomic imprinting.
"Maternal effect" should not be confused with maternal inheritance, in which some aspect of an offspring's genotype is inherited solely from the mother. This is often attributed to maternal inheritance of mitochondria or plastids, each of which contains its own genome. Maternal inheritance is distinct from maternal effect inheritance because in maternal inheritance the individual's phenotype reflects its own genotype, rather than the genotype of a parent.
In contrast, a paternal effect is when a phenotype results from the genotype of the father, rather than the genotype of the individual. The genes responsible for these effects are components of sperm that are involved in fertilisation and early development. An example of a paternal-effect gene is the ms(3)sneaky in Drosophila, males with a mutant allele of this gene produce sperm that are able to fertilise an egg, but the snky-inseminated eggs do not develop normally. However, females with this mutation produce eggs that undergo normal development when fertilised.
Maternity blues
For patient information on Post-partum depression, click here

# Overview
The maternity baby blues, maternity blues or baby blues is a condition that 75-80% of mothers can experience after childbirth with a wide variety of symptoms which generally involve mild depression. Baby blues is not postnatal depression, unless it is abnormally severe.

# Cause
After the placenta is delivered, the placental "hormone factory" shuts down causing radical changes in hormone levels, and the woman can suffer symptoms due to withdrawal from the incredibly high pregnancy levels of oestrogen, progesterone and endorphins. Combined with this shift in hormone levels is the physical, mental and emotional exhaustion - as well as sleep deprivation typical of parenting a newborn. All of these factors contribute to the condition.
It can also be normal for the ovaries (having been virtually inactive for the last six months of the pregnancy) to take a number of weeks to return to producing normal pre-pregnancy hormone levels.
This condition may also be associated with thyroid dysfunction. 

# Symptoms
- Weepiness and bursting into tears.
- Sudden mood swings.
- Anxious and hypersensitive to criticism.
- Low spirits and irritability.
- Poor concentration and indecisiveness.
- Feeling 'unbonded' with baby.
- Restless insomnia.

# Baby Pinks
Instead of suffering the baby blues, some women experience baby pinks when they are overly and illogically on top of the world (a mild to severe form of mania). These symptoms can be a trigger for a pending depressive imbalance, such as postnatal depression or postnatal psychosis.
Maxillary nerve
The maxillary nerve (superior maxillary nerve), or second division of the trigeminal, is a sensory nerve.
It is intermediate, both in position and size, between the ophthalmic nerve and the mandibular nerve.

# Path
Anterior to the trigeminal ganglion, the maxillary nerve passes through the cavernous sinus and exits the skull through the foramen rotundum.
It begins at the middle of the trigeminal ganglion as a flattened plexiform band, and, passing horizontally forward, it leaves the skull through the foramen rotundum, where it becomes more cylindrical in form, and firmer in texture.
It then crosses the pterygopalatine fossa, inclines lateralward on the back of the maxilla, and enters the orbit through the inferior orbital fissure; it traverses the infraorbital groove and canal in the floor of the orbit, and appears upon the face at the infraorbital foramen.
At its termination, the nerve lies beneath the quadratus labii superioris, and divides into a leash of branches which spread out upon the side of the nose, the lower eyelid, and the upper lip, joining with filaments of the facial nerve.

# Branches
Its branches may be divided into four groups, according as they are given off in the cranium, in the pterygopalatine fossa, in the infraorbital canal, or on the face.

## In the cranium
- Middle meningeal nerve

## In the pterygopalatine fossa
- Zygomatic nerve (zygomaticotemporal nerve, zygomaticofacial nerve)
- Two small branches to the pterygopalatine ganglion (sometimes called the sphenopalatine ganglion)
- Posterior superior alveolar nerve

## In the infraorbital canal
- Anterior superior alveolar nerve
- Middle superior alveolar nerve

## On the face
- Inferior palpebral nerve
- External nasal nerve
- Superior labial nerve

# Additional images
- Oblique section through the cavernous sinus.
- Dermatome distribution of the trigeminal nerve
- Distribution of the maxillary and mandibular nerves, and the submaxillary ganglion.
- The right sympathetic chain and its connections with the thoracic, abdominal, and pelvic plexuses.
Maximum density
The maximum density of a substance is the highest attainable density of the substance under given conditions.

# Attaining maximum density
Almost all known substances undergo thermal expansion in response to heating, meaning that a given mass of substance contracts to a low volume at low temperatures, when little thermal energy is present.  Substances, especially fluids in which intermolecular forces are weak, also undergo compression upon the application of pressure.  Nearly all substances therefore reach a density maximum at very low temperatures and very high pressures, characteristic properties of the solid state of matter.

# Irregular maximum densities
A few substances break the typical thermal expansion rules, instead contracting in response to increased temperature.  An example of such a substance is zirconium tungstate in the cubic phase, which contracts continuously up to 1050 K.  Cubic zirconium tungstate's maximum density would be reached at the temperature where either contraction stops (that is, where the sample's volume stops decreasing) or the substance decomposes.

# Maximum density of water
An especially notable irregular maximum density is that of water, which reaches a density peak at 3.98 C under standard conditions of pressure because of the low-density crystal structure of typical ice.  This has important ramifications in Earth's ecosystem; see Water (molecule)#Density of water and ice.
McLeod syndrome

# Overview
McLeod syndrome (or McLeod phenomenon) is a genetic disorder that may affect the blood, brain, peripheral nerves, muscle and heart. It is caused by a variety of recessively-inherited mutations in the XK gene on the X chromosome. The gene is responsible for producing a specific protein (Kell antigen) on the red blood cell surface.

# Clinical Features
Patients usually begin to notice symptoms in their 50s and the course is usually slowly progressive. Common features include peripheral neuropathy, cardiomyopathy and hemolytic anemia. Other features include limb chorea, facial tics, other oral movements (lip and tongue biting), seizures, a late-onset dementia and behavioral changes.

# Laboratory Features
McLeod syndrome is one of three disorders in which acanthocytes may be found on the peripheral blood smear. Blood evaluation may show signs of hemolytic anemia. Elevated creatine kinase can be seen with myopathy in McLeod syndrome.

# Radiologic and Pathologic Features
MRI shows increased T2 signal in the lateral putamen with caudate atrophy and secondary lateral ventricular dilation. Necropsy shows loss of neurons and gliosis in the caudate and globus pallidum. Similar changes may also be seen in the thalamus, substantia nigra and putamen. The cerebellum and cerebral cortex are generally spared.

# History
McLeod syndrome was discovered in 1961 and, as with the Kell antigen system, was named after the first patient in which it was found: a Harvard dental student Hugh McLeod, whose red blood cells were observed to be hemolysed during blood donation, and his red cells were found to be acanthocytic (spiky) under the microscope.

# Genetics
The McLeod phenotype is a recessive mutation of the Kell blood group system. The McLeod gene encodes the XK protein, which is located on the X chromosome, and has the structural characteristics of a membrane transport protein but an unknown function. Absence of the XK protein is an X-linked disease.
Mutational variants result in McLeod syndrome either with or without neuroacanthocytosis: the gene on the X chromosome for McLeod syndrome is physically close to the gene for chronic granulomatous disease. As a result, individuals with one disease may have both.

# Epidemiology and disease associations
McLeod syndrome is present in 0.5 to 1 per 100,000 of the population. McLeod males have variable acanthocytosis due to a defect in the inner leaflet bilayer of the red blood cell, as well as mild hemolysis. McLeod females have only occasional acanthocytes and very mild hemolysis; the lesser severity is thought to be due to X chromosome inactivation via the Lyon effect. Some individuals with McLeod phenotype develop myopathy, neuropathy or psychiatric symptoms, producing a syndrome that may mimic chorea.
McLeod syndrome can cause an increase in the enzymes creatine kinase (CK) and lactate dehydrogenase (LDH) found in routine blood screening.

# Treatment
There is no cure for McLeod syndrome, but treatment is supportive depending on symptoms. Medication may assist management of epilepsy, cardiac and psychiatric features, although patients may respond poorly to treatment for chorea.
Meatal stenosis
For patient information page click here
Steven C. Campbell, M.D., Ph.D.

# Overview
Urethral meatal stenosis is a narrowing (stenosis) of the opening of the urethra at the external meatus, thus constricting the opening through which urine leaves the body from the urinary bladder.

# Causes, incidence, and risk factors
Many authors have stated that meatal stenosis in males is caused by circumcision.  It occurs in 0.9% - 10%  of circumcised males and, according to Van Howe, is generally only found in circumcised males.  When the meatus is not covered by the foreskin, it can rub against urine soaked diapers resulting in inflammation and mechanical trauma.  Eventually, the delicate epithelial lining of the outer urethra is lost, leaving only a pinpoint hole at the tip of the glans. Meatal stenosis may also be caused by damage to the frenular artery during circumcision. 
  Meatal stenosis may also be associated with phimosis in uncircumcised males. It may also be caused by lichen sclerosus.
In females, this condition is a congenital (present from birth) abnormality which can cause urinary tract infections and bed-wetting (enuresis).

# Symptoms
- Abnormal strength and direction of urinary stream
- Visible narrow opening at the meatus in boys
- Discomfort with urination (dysuria and frequency)
- Incontinence (day or night)
- Bleeding (hematuria) at end of urination
- Urinary tract infections

# Signs and tests
In boys, history and physical exam is adequate to make the diagnosis. In girls, VCUG (voiding cystourethrogram) is usually diagnostic. Other tests may include:
- Urine analysis
- Urine culture
- CBC, basic metabolic panel
- Renal and bladder ultrasound

# Treatment
In females, meatal stenosis can usually be treated in the physician's office using local anesthesia to numb the area and dilating (widening) the urethral opening with special instruments.
In boys, it is treated by a second surgical procedure called meatotomy in which the meatus is crushed for 60 seconds with a straight mosquito hemostat and then divided with fine-tipped scissors.  Recently, home-dilation has been shown to be a successful treatment for most boys. 

# Prognosis
Most people can expect normal urination after treatment.

# Complications
Persistent urinary problems including abnormal stream, painful urination, frequent urination, urinary incontinence, blood in the urine, and increased susceptibility to urinary tract infections can be complications.

# Prevention
"In a recently circumcised male infant, try to maintain a clean, dry diaper and avoid any exposure of the newly circumcized penis to irrititants (sic)." 
Meir and Livne suggest that use of a broad spectrum antibiotic after hypospadias repair will "probably reduce meatal stenosis ",  while Jayanthi recommends the use of a modified Snodgrass hypospadias repair. Viville states that "prevention is based essentially upon more caution in the use of indwelling urethral catheters."

# Source
- Meatal stenosis
- Meatal stenosis
de:Meatusstenose
Median eminence
The median eminence is part of the inferior boundary for the hypothalamus part of the human brain.  A small swelling on the tuber cinereum posterior to the infundibulum - atop the pituitary stalk - the median eminence lies in the area roughly bounded on its posterolateral region by the cerebral peduncles, and on its anterolateral region by the optic chiasm.
The median eminence is one of the seven areas of the brain devoid of a blood-brain barrier (see also circumventricular organs).

# Physiology
The median eminence has an important physiological importance, as it is integral to the hypophyseal portal system, which connects the hypothalamus with the anterior lobe of the pituitary gland.  It is in this structure that the secretions of the hypothalamus (releasing and inhibiting regulatory hormones) collect before entering the portal system.
Medical massage
Medical Massage may include some of the same techniques offered in some wellness massage sessions, but is primarily the application of specific treatment protocols targeted to the specific problem(s) the patient presents with physician's diagnosis and administered after a thorough assessment/evaluation by the medical massage therapist.
Birthed out of
1) the need for highly skilled, hands-on therapists in treating those with injuries and chronic pain,
2) the present explosion of information in the injury-rehabilitation field which began with the ground-breaking work of Dr. Janet G Travell (1901-1997,)1 and 
3) the benefit patients receive when medical massage therapists and doctors work together,
there is now a new National Certification2 for medical massage therapists in the United States.
Medical massage is useful in addressing conditions such as:
- Carpal Tunnel syndrome
- Sciatica
- Piriformis Syndrome
- Rotator cuff injuries
- Pain associated with bulged or injured spinal disks (medical massage cannot 'fix' the disk, but can help alleviate much of the pain associated with the injury).
- Migraines/headaches
- Pain associated with pregnancy
- Constipation
- Range of motion issues
- Fibromyalgia
- Back and Neck pain
- Plantar Fasciitis (involving pain in the foot)
- Repetitive use injuries such as those listed and Tennis elbow, Golfer's elbow
- TMJ
- Pain associated with restricted fascia
- Pain associated with postural imbalances
- Muscle cramps
- Restless Legs Syndrome
- Sports injuries
- Edema (swelling)
- Injuries sustained in traumas such as falls or automobile accidents
- Thoracic Outlet Syndrome (numbness/tingling in hands/arms)
Though national certification exists for medical massage therapists, currently there is no licensure for medical massage therapists in any state, like there is in many states for general massage therapists. Any massage therapist can claim to be a medical massage therapist, and thus credentialling needs to be examined on a case-by-case basis. For example, if a therapist claims to be a medical massage therapist, check their certifications to see if they have been certified as such, or to see if they have equivalent certifications.
Meibomian gland
The meibomian glands (or tarsal glands) are a special kind of sebaceous glands at the rim of the eyelids, responsible for the supply of sebum, an oily substance that prevents evaporation of the eye's tear film, prevents tear spillage onto the cheek, and makes the closed lids airtight. There are approximately 50 glands on the upper eyelids and 25 glands on the lower eyelids.
The glands are named after Heinrich Meibom (1638-1700), a German physician.

# Proteins
In humans, more than 90 different proteins have been identified in meibomian gland secretions.

# Dysfunction
Dysfunctional meibomian glands often cause dry eyes, one of the more common eye conditions. They may also cause blepharitis, as the dry eyeball rubs off small pieces of skin from the eyelid, which can get infected. Inflammation of the meibomian glands (also known as meibomitis, meibomian gland dysfunction, or posterior blepharitis ) causes the glands to be obstructed by thick secretions, the resulting swelling is termed a chalazion. Besides leading to dry eyes, the obstructions can be degraded by bacterial lipases, resulting in the formation of free fatty acids, which irritate the eyes and sometimes cause punctate keratitis.
Melena overview

# Overview
Melena or melaena refers to the black, "tarry" feces that are associated with gastrointestinal hemorrhage. The black color is caused by oxidation of the iron in hemoglobin during its passage through the ileum and colon.

# Historical Perspective

# Classification

# Pathophysiology
Melena, is stool with blood, that has been altered by the gut flora, and appears black/"tarry".

# Causes
The most common cause of melena is peptic ulcer disease. Any other cause of bleeding from the upper gastro-intestinal tract, or even the ascending colon, can also cause melena.  Melena may also be a sign of drug overdose if a patient is taking anti-coagulants, such as warfarin. A less serious, self-limiting case of melena can occur in newborns two to three days after delivery, due to swallowed maternal blood.

# Differentiating Melena overview from Other Diseases

# Epidemiology and Demographics

# Risk Factors

# Screening

# Natural History, Complications, and Prognosis

## Natural History

## Complications

## Prognosis

# Diagnosis

## Diagnostic Criteria

## History and Symptoms

## Physical Examination

## Laboratory Findings

## Imaging Findings

## Other Diagnostic Studies

# Treatment

## Medical Therapy

## Surgery

## Prevention
Melilotus albus
Melilotus albus (Bokhara Clover, Honey Clover, Tree clover, Sweet Clover, White-flowered Sweet Clover, White Sweet Clover, White Melilot), is a legume sometimes grown for forage. White sweet clover is a major source of nectar for an apiary.
Its characteristic sweet odour, intensified by drying, is derived from coumarin.
It has been used in herbal medicine. It contains dicoumarol that is an anticoagulant.
White Sweet Clover is native to Europe and Asia. It was introduced to North America in the 1600s for cattle forage purposes and is now widespread throughout Canada and the United States.  There it has become invasive and can out compete native plant species. White sweet clover can grow up to 2 meters in height and can produce abundant amounts of seeds that readily float and disperse in water. This has allowed the plant to colonize natural habitat such as riparian areas all across much of North America.
It is nonetheless favoured for honey production and for its nitrogen fixing ability in preparing agricultural soil for future crops.
Mesenteric cyst
Contributors:  Cafer Zorkun M.D., PhD.

# Overview
- Histologic classification of mesenteric or omental cysts: 
Lymphangioma: endothelial lining
Enteric duplication cyst: Enteric lining and double-muscle lining with neural elements;
Enteric cyst: Enteric lining (mucosa with no muscle layer
Mesothelial cyst: mesothelial lining
Nonpancreatic pseudocyst has no lining, with a fibrous wall.
- Lymphangioma: endothelial lining
- Enteric duplication cyst: Enteric lining and double-muscle lining with neural elements;
- Enteric cyst: Enteric lining (mucosa with no muscle layer
- Mesothelial cyst: mesothelial lining
- Nonpancreatic pseudocyst has no lining, with a fibrous wall.
- The most common type of mesenteric or omental cyst is lymphangioma, followed by a nonpancreatic pseudocyst, a duplication cyst, a mesothelial cyst, and an enteric cyst.

# Differential Diagnosis
- Cystic mesothelioma
- Cystic spindle cell tumor
- Teratoma

# Diagnostic Findings
Patient #1
Images courtesy of RadsWiki
Patient #2
Images courtesy of RadsWiki
Patient #3: Lymphangioma
Images courtesy of RadsWiki
Metabolic waste

# Overview
Metabolic wastes or excretes are substances left over from metabolic processes, which cannot be used by the organism (they are surplus or have lethal effect), and must therefore be excreted. This includes nitrogen compounds, water, CO2, phosphates, sulphates, indoles, medicals, food additives etc. Animals treat these compounds as excretes. Plants have chemical "machinery" which transforms some of them (primarily the nitrogen compounds) into useful substances, and it has been shown by Brian J. Ford that abscised leaves also carry wastes away from the parent plant. In this way, Ford argues that the shed leaf acts as an excretophore (= organ carrying away excretory products).
All the metabolic wastes are excreted in a form of water solutes through the excretory organs (nephridia, Malpighian tubules, kidneys), with the exception of CO2, which is excreted together with the water vapor throughout the lungs. The elimination of these compounds enables the chemical homeostasis of the organism.

# Nitrogen wastes
The nitogen compounds through which the very toxic nitrogen is eliminated from the organism are ammonia, urea and uric acid. All of these substances are product from the protein metabolism.
Ammonia forms with the oxidation of amino groups (NH2), which are removed from the proteins when they convert into carbohydrates. It is a very toxic substance and only one nitrogen atom is removed with it. A lot of water is needed for the ammonia excretion. Thus, the marine organisms excrete ammonia directly in the water (aminothelic organisms), while the terrestrial (mainly amphibians and mammals) convert ammonia into urea, a process which occurs in the liver.
Urea is a less toxic compound than ammonia; two nitrogen atoms are eliminated through it and less water is needed for its excretion. Urea is a protein metabolism product at vertebrates and part of the invertebrates. These organisms are called ureothelic.
Uric acid is a protein metabolism product of terrestrial invertebrates, birds and terrestrial reptiles. This is the reason of which these animals are called uricothelic organisms. In humans and anthropoides, this acid is purine metabolism product. Uric acid is less toxic than ammonia or urea; it contains four nitrogen atoms and a small amount of water is needed for its excretion. Out of solute, it precipitates and forms crystals.

# Water and carbon dioxide
These compounds form during the catabolism of carbohydrates and lipids, and in some other metabolic reactions of the amino acids.
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