Gregorio Santiago Montes Welch, Argentine-born Brazilian cytologist and histologist (Buenos Aires 01 April 1952 – 19 October 2002)

His works on structural biology of extracellular matrix earned him international recognition

Demonstrated that extracellular matrix structures could be distinguished due to many characteristics of fibrillae composition

With L.C.U. Junqueira et al. demonstrated the distribution and architecture of collagen in cartilages, nerves, arteries and skin (1979-89)

Demonstrated definitively that reticular fiber is distinct of collagen fiber

With L.C. U. Junqueira, R.M. Krisztan, K.M. Shigihara, R. Tokoro & P.A.S. Mourão. Histochemical and morphological characterization of reticular fibers. Histochemistry 65:131-41, 1980 

Elucidated the process of uterine cervix softening at parturition

With M. Zugaib, L.C. U. Junqueira, O.M.S. Toledo, R.M. Krisztan & K.M. Shigihara. Morphologhic and histochemical evidence for the occurrence of colagenolysis and for the role of neutrophilic polymorphonuclear leukocytes during cervical dilation. Am. J. Obstet. Gynecol. 138:273, 1980

Established definitively collagen architecture in mammalian cartilages

With N.Z. Zambrano, K.M. Shigihara, E.M. Sanchez & L.C. U. Junqueira. Collagen arrangement in cartilages. Acta Anat. 113:26-38, 1982

Elucidated the nature of skeletal elements in tail fin ray of teleosts showing that they display all the morphological and histochemical features of a cartilaginous tissue

With J. Becerra, O.M.S. Toledo, M.A. Gordilho & L.C. U. Junqueira. Fine structure and histochemistry of the tail fin ray in teleosts. Histochem 75:363-76, 1982 

Showed that collagen molecules are orderly disposed in basal laminae

With L.C.U. Junqueira, R.R. Brentani, O.M.S.Toledo et al. Evidence for collagen molecular orientation in basement membranes. Histochem. J. 15:785-94, 1983  

Described a new type of acellular cartilage found in arterious cone of Potamotrygon sp.

With O.M.S. Toledo & L.C.U. Junqueira. Histochemical and morphological studies on a new type of acellular cartilage. Basic Appl. Histochem. 27:1-8, 1983 

First to describe morphological differences between the distinct types of intermediate filaments 

With L.C.U. Junqueira, P.P. Joazeiro, S.M. O. Vieira, A.B. Costa Silva & A. Cais. Specific attachment of morphologically-distinct intermediate filaments to desmosomes and hemidesmosomes in the epidermis of the tadpole of the anuran Pseudis paradoxus. J. Submicrosc. Cytol. 16:643-8, 1984

METHODS

A horse laparotomy technique

With E.H. Luque & H. Silva. Laparotomia em equinos: nuestra técnica. Gac. Vet. Buenos Aires 42:38-44, 1980  

Proposed a precise method for osteid distinction and characterization

With M.T. Assis Figueiredo, H. Torloni & L.C.U. Junqueira. Differential diagnosis of osteid. A study on human osteosarcoma collagen by the histochemical Picrosirius-polarization method. J. Pathol. 148(2):189-96, 1986  

A modified Weigert’s technique for the demonstration of oxytalan fibres. J. Braz. Assoc. Advan. Science 44:224-33, 1992

With E.M. Negri, S.S. Mori, C.S.V. Barbas & V.L. Capelozzi. A simple method for the differential characterization of alveoli and alveolar ducts in normal and injured lungs (2001)