Differential diagnosis between freshwater drowning and saltwater drowning based on intrapulmonary aquaporin-5 expression

Abstract

The intrapulmonary expression of aquaporin-5 (AQP5) was examined in an experimental drowning model and forensic autopsy cases to discuss the possibility for differentiation between freshwater drowning (FWD) and saltwater drowning (SWD). In animal experiments, mice were classified into four groups: (group I: FWD; group II: SWD; group III: postmortem immersion (PI); and group IV: cervical dislocation as controls. In group I, intrapulmonary AQP5 expression was significantly suppressed at both gene and protein levels, compared with the other three groups, and there was no significant difference in AQP5 expression among groups II to IV. In the next series, we examined AQP5 gene expression in human lung samples obtained from forensic autopsies at less than 48 h postmortem (nine FWD cases, five SWD cases, and 14 other cases). Although AQP5 mRNA could be detected in all lung samples under the employed experimental conditions, the intrapulmonary gene expression of AQP5 in FWD was significantly attenuated compared with the other groups. These observations imply that AQP5 expression in type I alveolar epithelial cells was suppressed by hypotonic water to prevent hemodilution from the physiological aspect. Moreover, the analysis of intrapulmonary AQP5 expression would be forensically useful for differentiation between FWD and SWD, or between FWD and PI.

Time-dependent appearance of intrathrombus neutrophils and macrophages in a stasis-induced deep vein thrombosis model and its application to thrombus age determination

“…The molecular and cellular pathophysiology of the wound healing process is applied for wound age determination. Recently, the immunohistochemical detection and RNA analyses of several molecules (e.g., extracellular matrix components, growth factors, cytokines, and adhesion molecules) has become a powerful method for forensic practices such as wound age determination or postmortem diagnosis [3][4][5][6][7][8][9][10][11][12][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]. To the best of our knowledge, there have been only two forensic studies on thrombus age estimation Fig.…”

Injuries due to Asphyxiation and Drowning

“…They have been investigated in experimental drowning and case studies by immunohistochemical methods in the lungs, brain and kidneys ) and by intrapulmonary gene expression (Hayashi et al 2009). Preliminary results emphasise the potential of aquaporins in differentiating antemortem from postmortem submersion and freshwater from saltwater drowning.…”

Determining time of death: temperature-dependent postmortem changes in calcineurin A, MARCKS, CaMKII, and protein phosphatase 2A in mouse

“…Intrinsic factors such as the age, sex, physiological, and pathological state of the deceased and extrinsic factors, such as temperature, humidity, and insect or animal activity. For example, Hayashi et al, have shown that different results were obtained for aquaporin-5 from lung tissue after drowning in freshwater versus salt water [2]. Such studies also emphasize that the selection of tissue for postmortem analysis is paramount.…”