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Forensic Science International journal homepage: www.elsevier.com/locate/forsciint
Indicators for acute hypoxia—An immunohistochemical investigation in cerebellar Purkinje-cells
¨ ¨ Svenja Bartschat a, Armin Fieguth a, Jasmin Konemann a, Anke Schmidt b, Stefanie Bode-Janisch a,* a b
Hanover Medical School, Institute of Legal Medicine, Carl-Neuberg-Straße 1, 30625 Hanover, Germany Institute of Pathology, Nordstadt Hospital, Haltenhoffstraße 41, 30167 Hanover, Germany
A R T I C L E I N F O
A B S T R A C T
Article history: Received 24 May 2011 Received in revised form 31 July 2012 Accepted 22 August 2012 Available online 12 September 2012 Keywords: Acute hypoxia Immunohistochemistry Purkinje-cells Calbindin-D28k Hypoxia-inducible factor-1a
The Purkinje-cells (PCs) of the cerebellum are highly vulnerable to hypoxic/ischemic insult. CalbindinD28k is a calcium-binding protein that is strongly expressed in PCs. Following hypoxia, a decrease in its concentration has been found in animal models before any morphological change of the PCs took place. Hypoxia-inducible factor-1a (HIF-1a) and vascular endothelial growth factor (VEGF) are increasingly expressed in tissues that undergo durations of hypoxia, and also in brain tissues. We examine whether a change in expression of any of these factors, or a combination of alterations, is an indicator of acute hypoxia. We investigated the intensity of neuronal immunoreactivity of calbindinD28k, HIF-1a and VEGF retrospectively in 141 samples of human cerebellar tissue obtained from autopsies performed at the Institute of Legal Medicine of Hanover Medical School in 2007 and 2008. Three groups were compared. The ﬁrst group comprises individuals (n = 48) who died due to acute hypoxia, such as drowning or asphyxia. The second is a control group comprising individuals who died due to heart failure (n = 56), and the third group comprised individuals who died almost instantly of polytraumata (n = 37). Our study ﬁnds a statistically signiﬁcant decrease in the expression of calbindin-D28k (p < 0.05) in PCs in the acute hypoxia group, relative to the control groups. No changes in the expression of HIF-1a or in the expression of VEGF were observed in any of the groups. Consequently HIF-1a and VEGF were not suitable indicators, whereas detection of a decreasing concentration of calbindin-D28k supports a diagnosis of acute hypoxia. ß 2012 Elsevier Ireland Ltd. All rights reserved.
1. Introduction There is still no decisive way of demonstrating speciﬁc neuropathological ﬁndings in cases of acute hypoxia involving death due to such causes as strangulation or drowning [1,2]. In particular, proof of acute hypoxic or ischemic brain injury and its differentiation from agonal hypoxia is of great interest in forensic neuropathology . The cerebellar Purkinje-cells (PCs) are highly vulnerable to acute hypoxic or ischemic conditions [3–5]. They are rich in calcium, for which pathological elevation in the cytosol and nuclei of neurons plays a key role in hypoxia/ischemia-induced cell death, by activating apoptotic cell death and several degenerative enzymatic pathways . Calbindin-D28k is a protein belonging to the EF-hand calcium-binding protein-family (CaBP), and is expressed in the cytosol of neurons in most brain regions; it is also found in PCs .
* Corresponding author. Tel.: +49 511 532 4570; fax: +49 511 532 5635. E-mail addresses: Jaenisch.Stefanie@mh-hannover.de, ¨ email@example.com (S. Bode-Janisch). 0379-0738/$ – see front matter ß 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.forsciint.2012.08.023
CaBPs are a group of cytoplasmic proteins characterized by a number of helix–loop–helix motives which bind calcium ions with high afﬁnity . These proteins are believed to protect neurons from exitotoxic and apoptotic cell death