Monday, August 29, 2011

Strawberry gums

In Wegener’s granulomatosis (granulomatosis with polyangiitis), a disease that affects multiple organs such as the lungs, kidneys and blood vessels, tissue death may result in enlarged, red gums that appear like strawberries – strawberry gums.
There is a shift away from the use of Wegener because Dr Friedrich Wegener (1907 – 1990) who made descriptions of this disease was a member of the Nazi Party.
Paul R, Moran N: Strawberry gums in Wegener's granulomatosis: a rare presentation. Oral Surgery, 2008 1:50–52. Go to reference

Antineutrophil cytoplasmic antibodies (ANCAs) in Wegener’s granulomatosis

Wednesday, August 24, 2011

Redcurrant jelly - postmortem clot (deeper layer)

When blood becomes stagnant, its solidification by coagulation begins. In stagnant blood, by gravity, the heavier red blood cells settle preferentially to the deeper layer instead of the lighter platelets. This makes the deeper gelatinous layer of a clot that formed after death (when blood is stagnant) red – it resembles redcurrant jelly in appearance.
Underwood JCE and Cross SS (eds.), 2009, General and Systematic Pathology, 5th edition, Churchill Livingstone, Edinburgh, page 149. Go to reference

Red blood cell (erythrocyte), platelet (thrombocyte) and white blood cell (leukocyte)

Friday, August 19, 2011

Amygdaloid nucleus - almond-shaped

The brain is a complex organ that contains several billion neurons (nerve cells) connected to each other by thousands of synapses (connections). In the adult, the brain on average weighs 1.5kg (approximately 2% of body weight). At rest, the brain receives about 15% of the body’s blood and it consumes about 20% of the body’s oxygen.
The amygdaloid nucleus originating from the Greek amydale (almond) eidos (like) is an almond-shaped group of nuclei (localized collection of neurons) within the brain that is associated with emotions, learning, memory, attention and perception.
Baxter MG, Murray EA: The amygdala and reward. Nat Rev Neurosci, 2002 3(7):563-73. Go to reference

Position of amygdaloid nucleus in brain

Saturday, August 13, 2011

Maple syrup urine disease

Maple syrup urine disease is an inherited disorder in which there is a deficiency of the enzyme(s) responsible for the breakdown of certain amino acids. These particular amino acids and their byproducts consequently accumulate causing toxic damage to the brain. Urine from patients with this disease may contain these amino acids and their byproducts giving it a sweet odor that is reminiscent of maple syrup – maple syrup urine disease (MSUD).
Amino acids are the building blocks of proteins.
Podebrad F et al. 4,5-dimethyl-3-hydroxy-2[5H]-furanone (sotolone)--the odour of maple syrup urine disease. J Inherit Metab Dis 1999 22(2):107-14. Go to reference
Go to ripe cheese odor 

Branched chain amino acids - valine, leucine and isoleucine

Tuesday, August 9, 2011

Ice-cream cone sign

The ear functions to capture sound waves from the environment and to convert them into nerve impulses for transmission to the brain. Anatomically, the ear can be divided into three parts, the outer ear which captures sound waves, the middle ear which amplifies and transmits these waves to the inner ear that then converts them into nerve impulses.
The middle ear is an air-filled space that contains the body’s smallest bones, the malleus (hammer), incus (anvil) and stapes (stirrup). These tiny bones (ossicles) transmit sound waves from the outer to inner ear.
When viewed with high resolution computed tomography (HRCT) scanning – a specialized type of X-ray imaging technique – the head of the malleus and the body of the incus resemble an ice-cream cone – ice-cream cone sign.
The ear also functions as an organ of balance.
Chavan GB, Shroff MM: Twenty classic signs in neuroradiology: A pictorial essay. Indian J Radiol Imaging, 2009 19(2): 135–145. Go to reference

Human ear anatomy
Ice-cream cone sign A (arrow)

Sunday, August 7, 2011

Diabetes mellitus – siphon honey

Diabetes mellitus (DM) is a serious condition with complications that include stroke, blindness, heart disease, kidney failure and possible amputation of limbs. DM is not a single disease but a group of entities characterised by persistently high blood sugar (chronic hyperglycemia) and abnormality in the metabolism (handling) of carbohydrates, proteins and fats within the body. DM occurs due to lack of the blood sugar lowering pancreatic hormone insulin or insulin’s ineffectiveness or both.
Diabetes arises from the Greek designation for siphon because people with diabetes can pass lots of urine and mellitus arises from the Latin term for honey as the urine is sweet.
In the 17th century, the English doctor, Thomas Willis described DM thus: “pissing evil” …  “the urine is wonderfully sweet, as if it were imbued with honey or sugar.”
The sweet urine of DM had been previously described by the ancient Hindus and others.
Sanders LJ. From Thebes to Toronto and the 21st Century: An Incredible Journey. Diabetes Spectrum, 2001 15:56-60. Go to reference

Major symptoms of DM

Saturday, August 6, 2011

Lemon sign

On ultrasound scan performed prior to birth usually before 24 weeks of pregnancy, the babies skull may appear like a lemon. This lemon sign may indicate the presence of spina bifida where the neural tube, the precursor of the central nervous system (brain & spinal cord), has failed to close, usually in the lower back region.
Normally, the fetal skull frontal bones curve outwards (convex), however with spina bifida and other conditions, the frontal bones curve inwards (concave) making the skull look like a lemon in shape.
In the common form of spina bifida – myelomeningocele – patients may have bladder and bowel dysfunction, loss of sensation below the level of the lesion as well as an excess of cerebrospinal fluid in the brain’s ventricles (hydrocephalus).
Thomas M: The lemon sign. Radiology, 2003 228(1):206-7. Go to reference

Lemon sign A, Spina bifida B

Friday, August 5, 2011

Red as a beet

Processes important for life such as sexual arousal, salivation, lacrimation (tearing), urination, digestion, defecation (passing stool) - remembered by the mnemonic SSLUDD - are largely regulated automatically and involuntarily by the parasympathetic nervous system (PSNS).
The drug atropine blocks some of the activities of the PSNS by interacting with muscarinic receptors, which are the main receptors targeted in tissues regulated by the PSNS.
Atropine overdose causes hot dry skin due to reduced sweating, red skin due to blood vessel dilatation, dryness from reduced tearing and sweating, visual disturbance because of pupillary dilatation as well as inability to focus and confusion due to effects on the brain. These changes may be summarized as, ‘hot as a hare, red as a beet, dry as a bone, blind as a bat and mad as a hatter’.
Control of the aforementioned processes and others also involves the sympathetic nervous system (SNS) which along with the PSNS by and large constitutes the autonomic nervous system.
Ramjan KA, Williams AJ, Isbister GK, Elliot EJ: 'Red as a beet and blind as a bat' Anticholinergic delirium in adolescents: lessons for the paediatrician. J Paediatr Child Health, 2007 43(11):779-80. Go to reference

Autonomic nervous system: PSNS = blue, SNS = red

Wednesday, August 3, 2011

Anchovy paste

Entamoeba histolytica is a single-celled organism, spread predominantly by ingestion of material contaminated with human feces tainted by this creature. Infection may lead to the formation of liver abscess(es) which contain a soft yellow-brown substance resembling anchovy paste.
Pritt BS, Clark CG: Amebiasis. Mayo Clin Proc, 2008 83(10):1154-9. Go to reference

Entamoeba histolytica life cycle