Gastão Rosenfeld was a Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

ian physician

Physician

A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...

 and biomedical scientist, one of the co-discoverers of bradykinin

Bradykinin

Bradykinin is a peptide that causes blood vessels to dilate , and therefore causes blood pressure to lower. A class of drugs called ACE inhibitors, which are used to lower blood pressure, increase bradykinin further lowering blood pressure...

, together with Maurício Rocha e Silva

Maurício Rocha e Silva

Maurício Oscar da Rocha e Silva was a Brazilian physician, biomedical scientist and pharmacologist...

 and Wilson Teixeira Beraldo

Wilson Teixeira Beraldo

Wilson Teixeira Beraldo was a Brazilian physician and physiologist, a co-discoverer of bradykinin....

, in 1949.

Rosenfeld was a specialist in the study of biochemistry

Biochemistry

Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...

 of the action of snake

Snake

Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...

 venoms in animals and humans, particularly those of the Bothrops

Bothrops

Bothrops is a genus of venomous pitvipers found in Central and South America. The generic name is derived from the Greek words bothros and ops that mean "pit" and "eye" or "face"; an allusion to the heat-sensitive loreal pit organs. Members of this genus are responsible for more human deaths in the...

 family (lancehead or jararaca). Among other things, he investigated in the Instituto Butantan

Instituto Butantan

Instituto Butantan is a Brazilian biomedical research center affiliated to the São Paulo State Secretary of Health. It is located near the campus of the University of São Paulo, in the city of the same name.-History:...

, in São Paulo, where he worked as an experimental researcher, the action of snake venoms on fibrinolysis

Fibrinolysis

Fibrinolysis is a process that prevents blood clots from growing and becoming problematic. This process has two types: primary fibrinolysis and secondary fibrinolysis...

 and blood coagulation.
Among his contributions to biomedical sciences are the development of a rapid staining for blood

Blood

Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 smears combining May-Grunwald and Giemsa techniques in 1947 (Rosenfeld staining), introduced a new treatment for chronic leukemia

Leukemia

Leukemia or leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum of diseases...

 using personal control of maintenance dosis (1955) and described hementerin, an anticoagulant

Anticoagulant

An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...

 isolated of a Brazilian species of leech

Leech

Leeches are segmented worms that belong to the phylum Annelida and comprise the subclass Hirudinea. Like other oligochaetes such as earthworms, leeches share a clitellum and are hermaphrodites. Nevertheless, they differ from other oligochaetes in significant ways...

 (Haementeria depressa) jointly with Eva Maria Antonia Kelen in 1975.
Dr. Rosenfeld was also an important scientific leader, having been involved in the foundation of the Brazilian Society for the Advancement of Science

Sociedade Brasileira para o Progresso da Ciência

Sociedade Brasileira para o Progresso da Ciência is a Brazilian scientific society created in 1948 by several prominent scientists, with the aim of promoting science, culture and education in the country by means of publications, conferences and political actions on behalf of science's advancement...

, in 1949.

May-Grunwald-Giemsa blood staining technique video