RESUMO
Hematoxylin is a basic dye derived from the heartwood of Palo de Campeche ( Haematoxylum campechianum), the logwood tree native to Mexico and Central America. Haematoxylum means "bloodwood" in reference to its dark-red heartwood and campechianum refers to its site of origin, the coastal city of Campeche on the Yucatan Peninsula, Mexico. Hematoxylin is colorless but it turns into the color dye hematein after oxidation (ripening). The dyeing property of logwood was well-known to the natives of the Yucatan Peninsula before the arrival of the Spaniards who brought it to Europe shortly after the discovery of the Americas. An important trade soon developed related to growing and preparing hematoxylin for dyeing fabrics. Pirates discovered that one shipload of logwood was equivalent to a year's value from any other cargo, and by 1563, more than 400 pirate vessels wandered the Atlantic Ocean and attacked Spanish galleons transporting gold, silver, and logwood from the Americas to Europe. Hematoxylin and eosin is a staining method that dates back to the late 19th century. In 1865 and 1891, Böhmer and Meyer, respectively, first used hematoxylin in combination with a mordant (alum). Later, with the use of anilines by Ehrlich, the repertoire of stains expanded rapidly resulting in the microscopic descriptions of multiple diseases that were defined by their stainable features. Today hematoxylin, along with eosin, remains the most popular stain in histology.
Assuntos
Hematoxilina/história , Coloração e Rotulagem/história , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , América do Norte , ÁrvoresRESUMO
The Gallego general tissue stain is used in histology and histopathology and stains beautifully connective tissue, in which all nuclei are stained in magenta red, epithelial cytoplasm in red-yellow, connective tissue is stained in brilliant green, muscle in olive green, and keratinized epithelium and blood in grass green. There is also Gallego's method for differential staining of elastic tissue that enables a complete differentiation between elastic and collagenous connective tissue. The elastic tissue is stained in brilliant fuschin red, while collagen is stained in brilliant green. Abelardo Gallego was born in Spain on September 10, 1879. He was appointed as professor of Pharmacology and Therapeutics at the Faculty of Veterinary Medicine at the University of Santiago de Compostela, Spain, and in 1921 became full-time professor of Histology and Pathology in Madrid supported by Ramón y Cajal. Gallego conducted extensive research into veterinary pathology. Don Abelardo was a quiet, reserved, but friendly, sensitive, optimistic and persistent person. Weakened by a bout of bronchitis, Gallego died aged 51 on February 3, 1930, and was buried at the Almudena Cemetery, in Madrid. Gallego was one of the most outstanding scientists of Spanish veterinary medicine and some of his achievements are reviewed.