Louis-Charles Malassez
Encyclopedia
Louis-Charles Malassez was a French
anatomist and histologist born in Nevers
, department of Nièvre
.
He studied medicine in Paris
, where he worked as an interne from 1867. He served with the 5th Ambulance Corps during the Franco-Prussian War
, afterwards returning to Paris, where he worked with distinguished physicians that included Claude Bernard
, Jean-Martin Charcot
and Pierre Potain
. In 1875 he attained the chair of anatomy at Collège de France
, and in 1894 became a member of the Académie de Médecine.
Malassez is remembered for research involving histology of the blood, and is credited for design of the hemocytometer
, a device used to quantatively measure blood cells. In the field of dentistry
, he described residual cells of the epithelial root sheath
in the periodontal ligament
. These remaining cells are referred to as epithelial cell rests of Malassez
(ERM).
A genus
of fungi called Malassezia bears his name. The species in the genus include: Malassezia furfur, Malassezia ovalis, Malassezia pachydermatis, Malassezia sympodialis and Malassezia orbiculare. Malassezia furfur is a lipophilic
species that forms on human skin and can cause seborrheic dermatitis
and tinea versicolor
, Malassezia pachydermatis is a species that is associated with otitis externa
in dogs.
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
anatomist and histologist born in Nevers
Nevers
Nevers is a commune in – and the administrative capital of – the Nièvre department in the Bourgogne region in central France...
, department of Nièvre
Nièvre
Nièvre is a department in the centre of France named after the Nièvre River.-History:Nièvre is one of the original 83 departments created during the French Revolution on March 4, 1790...
.
He studied medicine in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
, where he worked as an interne from 1867. He served with the 5th Ambulance Corps during the Franco-Prussian War
Franco-Prussian War
The Franco-Prussian War or Franco-German War, often referred to in France as the 1870 War was a conflict between the Second French Empire and the Kingdom of Prussia. Prussia was aided by the North German Confederation, of which it was a member, and the South German states of Baden, Württemberg and...
, afterwards returning to Paris, where he worked with distinguished physicians that included Claude Bernard
Claude Bernard
Claude Bernard was a French physiologist. He was the first to define the term milieu intérieur . Historian of science I. Bernard Cohen of Harvard University called Bernard "one of the greatest of all men of science"...
, Jean-Martin Charcot
Jean-Martin Charcot
Jean-Martin Charcot was a French neurologist and professor of anatomical pathology. He is known as "the founder of modern neurology" and is "associated with at least 15 medical eponyms", including Charcot-Marie-Tooth disease and amyotrophic lateral sclerosis...
and Pierre Potain
Pierre Potain
Pierre Charles Édouard Potain was a French cardiologist born in Paris.In 1853 he earned his doctorate from the University of Paris, and afterwards worked as an assistant to Jules Baillarger at the mental asylum at Ivry...
. In 1875 he attained the chair of anatomy at Collège de France
Collège de France
The Collège de France is a higher education and research establishment located in Paris, France, in the 5th arrondissement, or Latin Quarter, across the street from the historical campus of La Sorbonne at the intersection of Rue Saint-Jacques and Rue des Écoles...
, and in 1894 became a member of the Académie de Médecine.
Malassez is remembered for research involving histology of the blood, and is credited for design of the hemocytometer
Hemocytometer
The hemocytometer or haemocytometer is a device originally designed for the counting of blood cells. It is now also used to count other types of cells as well as other microscopic particles....
, a device used to quantatively measure blood cells. In the field of dentistry
Dentistry
Dentistry is the branch of medicine that is involved in the study, diagnosis, prevention, and treatment of diseases, disorders and conditions of the oral cavity, maxillofacial area and the adjacent and associated structures and their impact on the human body. Dentistry is widely considered...
, he described residual cells of the epithelial root sheath
Hertwig's epithelial root sheath
The Hertwig's epithelial root sheath is a proliferation of epithelial cells located at the cervical loop of the enamel organ in a developing tooth. Hertwig's epithelial root sheath initiates the formation of dentin in the root of a tooth by causing the differentiation of odontoblasts from the...
in the periodontal ligament
Periodontal ligament
The periodontal fiber or periodontal ligament, commonly abbreviated as the PDL, is a group of specialized connective tissue fibers that essentially attach a tooth to the alveolar bone within which it sits...
. These remaining cells are referred to as epithelial cell rests of Malassez
Epithelial cell rests of Malassez
In dentistry, the epithelial cell rests of Malassez or epithelial rests of Malassez are part of the periodontal ligament cells around a tooth. They are discrete clusters of residual cells from Hertwig's epithelial root sheath that didn't completely disappear...
(ERM).
A genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of fungi called Malassezia bears his name. The species in the genus include: Malassezia furfur, Malassezia ovalis, Malassezia pachydermatis, Malassezia sympodialis and Malassezia orbiculare. Malassezia furfur is a lipophilic
Lipophilic
Lipophilicity, , refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. These non-polar solvents are themselves lipophilic — the axiom that like dissolves like generally holds true...
species that forms on human skin and can cause seborrheic dermatitis
Dermatitis
-Etymology:Dermatitis derives from Greek derma "skin" + -itis "inflammation" and genetic disorder.-Terminology:There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called...
and tinea versicolor
Tinea versicolor
Tinea versicolor is a condition characterized by a rash on the trunk and proximal extremities. Recent research has shown that the majority of Tinea versicolor is caused by the Malassezia globosa fungus, although Malassezia furfur is responsible for a small number of cases...
, Malassezia pachydermatis is a species that is associated with otitis externa
Otitis externa
Otitis externa is an inflammation of the outer ear and ear canal. Along with otitis media, external otitis is one of the two human conditions commonly called "earache". It also occurs in many other species. Inflammation of the skin of the ear canal is the essence of this disorder...
in dogs.
Selected publications
- 'De la numération des globules rouges du sang. I. Des méthodes de numération. II. De la richesse du sang en globules rouges dans les différentes parties de l'arbre circulatoire. Paris 1873
- Sur les lésions histologiques de la syphilis testiculaire. Paris 1881 - (with Jean Jacques Paul Reclus)
- Sur l’existence d’amas épithéliaux autour de la racine des dents chez l’homme adulte et a l’état normal (débris épithéliaux paradentaires. Paris, 1885
- Sur les role des débris épithéliaux paradentaires. In: Archives de physiologie normale et pathologique. Paris, S. 309–340, 1885