Saturday, May 28, 2011

Strawberry tongue

Some bacteria such as Staphylococcus aureus and Streptococcus pyogenes produce toxins, which act as superantigens, meaning that these toxins (antigens) activate an usually large number of immune cells at the same time unlike other antigens do.
This extensive activation of immune cells leads to production of relatively large amounts of chemicals that mediate inflammation, the results of which include fever, rash and a bright red tongue that resembles a strawberry – strawberry tongue.
Diseases associated with superantigens include, toxic shock syndrome (Staphylococcus aureus toxin), scarlet fever (Streptococcus pyogenes toxin) and Kawasaki disease (an illness involving inflammation of medium sized arteries).
Solanki LS, Srivastava N, Singh S: Superantigens: a brief review with special emphasis on dermatologic diseases. Dermatol Online J, 2008 14(2):3. Go to reference

Strawberry tongue

Thursday, May 26, 2011

Blueberry muffin baby

In adult life, red blood cell production takes place in the bone marrow; however, during normal development of the unborn - in the uterus - formation of red blood cells occurs in organs such as the liver, spleen and skin. Under certain circumstances such as in infection with the rubella virus or cytomegalovirus, red blood cell formation in the skin continues abnormally after birth giving the skin blotches that seem like blueberries on a muffin – blueberry muffin baby/rash.
Additionally, certain cancers and vessel abnormalities may also give the blueberry muffin baby appearance.
Mehta V, Balachandran C, Lonikar V: Blueberry muffin baby: A pictoral differential diagnosis. Dermatol Online J, 2008 14(2):8. Go to reference

Blueberry muffin appearance of neuroblastoma (a cancer) and a muffin

Monday, May 16, 2011

Opsonisation – to prepare for the table

The immune system protects us from non-self material such as bacteria or from self material gone wrong such as cancerous cells. Phagocytes are immune cells that eat (engulf) for example bacteria in an attempt to render them harmless.
Before phagocytes eat bacteria (phagocytosis), the bacteria have to be made more ‘tasty’ by being coated with proteins. Opsonisation a word derived from the Greek term meaning to prepare for the table is the process whereby bacteria become coated with these proteins, called opsonins.
Opsonins include antibodies (immunoglobulins) produced by white blood cells and complement proteins so named because they complement the activities of antibodies.
Underwood JCE and Cross SS (eds.), 2009, General and Systematic Pathology, 5th edition, Churchill Livingstone, Edinburgh, page 207. Go to reference

Phagocyte eating bacteria

Saturday, May 14, 2011

Staphylococcus – grape bunches

Staphylococcus is a genus of spherical bacteria that grows in clusters resembling grape bunches (staphyle – Greek for bunch of grapes), when seen under the light microscope after usually having stained the specimen(s) with Gram stain.  Staphylococcus aureus which can cause for example, respiratory, cardiovascular, gastrointestinal, musculoskeletal, skin or systemic disease is probably the most important human pathogen from the genus Staphyloccous.
A Danish scientist Hans Christian Gram developed a method of staining bacteria, thereby allowing for their characterization - this method has become standard in many medical laboratories.
Todar K.  Todar’s Online Textbook of Bacteriology. Staphylococcus aureus and Staphylococcal Disease. Available Accessed 15-05-2011. Go to reference

Staphylococcus - grape bunches

Saturday, May 7, 2011

Popcorn cell

The popcorn cell is found in a form of lymphoma (malignancy of lymphocytes) known as nodular lymphocyte predominant Hodgkin lymphoma (NLPHL). In this subtype of Hodgkin lymphoma, when tumor tissue sections are seen under the light microscope, some cell nuclei look lobulated resembling popcorn kernels - popcorn cell.
NLPHL is an uncommon form of lymphoma that typically affects males and has a relatively good outcome. Hodgkin lymphoma is named in commemoration of Thomas Hodgkin, a British pathologist, who made early descriptions of this condition.
Wlodarska I et al: Frequent occurrence of BCL6 rearrangements in nodular lymphocyte predominance Hodgkin lymphoma but not in classical Hodgkin lymphoma. Blood, 2003 101(2):706-10. Go to reference

Popcorn cell