The taphonomy of blood components in decomposing bone and its relevance to physical anthropology.
OBJECTIVE
The variation and persistence of blood components, in particular red blood cells (RBCs), within bone tissue during the decomposition process, especially at the early stages and in different taphonomic conditions, has never been thoroughly investigated, regardless of the fact that knowing how blood survives or degrades within bone could be of help in solving many anthropological issues, such as trauma analysis and interpretation.


METHODS
This research investigated the influence of time and taphonomy on the persistence and detectability of blood components in parietal bone fragments (of different post mortem periods and taphonomic conditions) through histological (Hematoxilin and Eosin, HE) and immunohistochemical (Glycophorin A, GYPA) analyses.


RESULTS
The immunohistochemical investigation for GYPA showed the presence of RBCs under the form of erythrocyte debris or residues otherwise morphologically unidentifiable using only HE staining. Hence, while well-defined RBCs can be observed only in the first week of decomposition, afterward these structures can be detectable with certainty only by immunohistochemical analysis, which reveals discrete quantities of RBC residues also in dry bone (post mortem interval, or PMI, of 15 years), but not in archaeological samples, in which the greater PMI and the different taphonomic conditions together could be the answer behind such difference.


CONCLUSIONS
This study highlights the usefulness and potential of immunohistochemical detection of GYPA in RBC investigation and gives a realistic idea of the persistence and detectability of erythrocytes in different osteological taphonomic conditions, in contrast to results reported by some authors in literature. Another important result concerns the detection of RBC residues in dry bone, which opens the way to the possible use of RBCs in trauma interpretation.
Dipartimento Di Scienze Biomediche per La Salute, LABANOF, Laboratorio Di Antropologia E Odontologia Forense, Sezione Di Medicina Legale, Università Degli Studi Di Milano, Milan, 20133, Italy.
Annalisa
A
Cappella
Dipartimento Di Scienze Biomediche per La Salute, LABANOF, Laboratorio Di Antropologia E Odontologia Forense, Sezione Di Medicina Legale, Università Degli Studi Di Milano, Milan, 20133, Italy.|Fellow of the Genetics, Molecular and Cellular Biology Ph.D. program of the University of Pavia.
Barbara
B
Bertoglio
Dipartimento Di Scienze Biomediche per La Salute, LABANOF, Laboratorio Di Antropologia E Odontologia Forense, Sezione Di Medicina Legale, Università Degli Studi Di Milano, Milan, 20133, Italy.
Elisa
E
Castoldi
Dipartimento Di Scienze Biomediche per La Salute, LABANOF, Laboratorio Di Antropologia E Odontologia Forense, Sezione Di Medicina Legale, Università Degli Studi Di Milano, Milan, 20133, Italy.
Emanuela
E
Maderna
Department of Health, Animal Science and Food Safety, Università Degli Studi Di Milano, Milan, 20133, Italy.
Alessia
A
Di Giancamillo
Department of Health, Animal Science and Food Safety, Università Degli Studi Di Milano, Milan, 20133, Italy.
Cinzia
C
Domeneghini
Dipartimento Di Scienze Biomediche per La Salute, LABANOF, Laboratorio Di Antropologia E Odontologia Forense, Sezione Di Medicina Legale, Università Degli Studi Di Milano, Milan, 20133, Italy.
Salvatore
S
Andreola
Dipartimento Di Scienze Biomediche per La Salute, LABANOF, Laboratorio Di Antropologia E Odontologia Forense, Sezione Di Medicina Legale, Università Degli Studi Di Milano, Milan, 20133, Italy.
Cristina
C
Cattaneo
D001842:Bone and Bones / Q000737:chemistry*; D003643:Death; D004912:Erythrocytes / Q000737:chemistry*; D018732:Forensic Anthropology; D005580:Fossils; D006021:Glycophorins; D006801:Humans
D006021:Glycophorins
decomposition; erythrocyte detection; microtaphonomy; skeletal remains