Forensic Sci Med Pathol (2008) 4:143–145 DOI 10.1007/s12024-007-9020-x

ABSTRACT

Abstracts British Association in Forensic Medicine Summer Meeting, Liverpool, England, June 2007

Accepted: 12 November 2007 / Published online: 9 January 2008 Ó Humana Press Inc. 2008

Introduction The summer meeting of the British Association in Forensic Medicine (BAFM) was held in June 2007 in Liverpool and was hosted by Dr P. Johnson. This two-day meeting was attended by both BAFM members and nonmembers with representatives from member countries of Europe. The theme of the meeting, owing to the venue, was ‘‘water.’’ The morning session featured key talks from invited speakers whose presentations covered the use of diatoms in forensic science, chemical markers for drowning, police case from the Liverpool docks and submarine medicine and rescue. The afternoon session featured a presentation by the BAFM student prize winner as well as members papers. The meeting abstracts submitted by the speakers are found in this section. Further information concerning the BAFM and its activities can be obtained from its website http://www.bafm.org/

Diatoms and their use in forensic science Eileen J. Cox Department of Botany, The Natural History Museum, London, e-mail: [email protected] Characterised by their distinctive siliceous cell walls, diatoms are probably the most abundant and diverse group of microalgae, distributed throughout the world in

all types of aquatic environments. Cell wall morphology is diverse and sometimes complex, but under strong genetic control. It has traditionally formed the basis of species identification and classification, supported by extensive taxonomic literature. While cosmopolitan as a group, individual diatom species are often quite restricted in their habitat distribution and therefore widely used in environmental monitoring. Thanks to the dissolution resistance of their cell walls, they are also well preserved in lake sediments and particularly amenable for palaeolimnological studies. The ubiquity and diversity of diatoms, combined with their habitat specificity, also render them useful forensic tools. Method Some of the problems of diatom species definition will be described, illustrating how cell size reduction or changing environment may modify morphology and lead to different names being given to parts of a single life history. The development of diatom indicator systems will be outlined, and the value of experimental studies to test and clarify ecological tolerances discussed. Discussion Uses of diatoms in forensic science develop from their diversity and ecological specificity. They are particularly useful in revealing whether items have been in contact with water (and the type of water) or with traces of manufacturing materials, since diatomites (fossil diatom deposits) are used in a variety of processes. (Species composition varies with diatomite origin). Diatoms may be helpful in resolving cases of drowning, although false negatives are possible. There have also been attempts to use diatom colonisation on submerged corpses to establish time of death.

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Birth trauma: the limitations of post-mortem MRI in its investigation and the combined examination by forensic and paediatric pathologists Alfredo Walker*, Elspeth Whitby**, Marta Cohen*** *Department of Forensic Pathology and Legal Medicine, Forensic Science Service, Medicolegal Centre, Watery Street, Sheffield; **Academic Radiology, University of Sheffield, Sheffield S10 2JF, UK; ***Department of Histopathology, Sheffield Childrens NHS Foundation Trust, Sheffield S10 2TH, UK Birth trauma (BT) represents the injuries sustained by the newborn during labour and delivery. Its incidence is estimated 2–7 per 1,000 live births. Predisposing factors for BT include fetal macrosomia, cephalopelvic disproportion, dystocia, prolonged labour and breech presentation. We present two unusual cases of BT and describe the use of post-mortem MRI as an ancillary investigation in this setting. Post-mortem MRI on its own as a preautopsy diagnostic tool had limited sensitivity in these two cases as it had failed to detect the significant birth-related pathology of a ruptured tentorium cerebelli (case 1) and separation of the cervical spine through the C6/7 intervertebral disc space (case 2). These findings were only made on full autopsy which remains the gold standard of post-mortem examinations. Case 1: Term male neonate born by spontaneous vertex delivery weighing 4,095 g. The mother had history of dietcontrolled gestational diabetes and the pregnancy was uneventful. The second stage was prolonged and the baby was born unresponsive, floppy, bradycardic, and pale. He died after extensive resuscitation and the case was referred to the Coroner. A post-mortem MRI examination was performed prior to a full autopsy. The MRI revealed a subgaleal haematoma and herniation of the left uncus. At autopsy there was a ruptured tentorium cerebelli with subdural haemorrhage in the posterior cranial fossa that had drained through the foramen magnum into the spinal cord. The ruptured tentorium had not been detected on the initial MRI examination and was only considered retrospectively by the radiologist after the full autopsy results were made known. Unilateral uncal herniation was seen as an indirect radiological sign of a ruptured tentorium. Chorioamnionitis due to E. coli was also identified. Case 2: Term female neonate born after an uneventful pregnancy and spontaneous onset of labour. The delivery was complicated by shoulder dystocia and necessitated

Forensic Sci Med Pathol (2008) 4:143–145

intervention with forceps. She was born floppy, pale, unresponsive and required resuscitation. Intubation was difficult and complicated by cervical emphysema. A heart rate was attained at 7 min. She was nursed in an ITU and remained hypotensive and developed anaemia, signs of hypoxic-ischemic encephalopathy with seizures, liver and renal failure. An EEG trace of the brain was flat. Death was certified 18 h after birth. A joint paediatric and forensic post-mortem examination was requested. Both a skeletal survey and an MRI were performed prior to autopsy. The skeletal survey identified an elongated head with considerable scalp swelling, overlap of the sutures but no moulding and normal bone density with no underlying bone disease. Lateral views of the neck identified an increased thickness of the pre-vertebral soft tissues due to either laryngeal trauma or bleeding from the spine. The report of the post-mortem MRI examination identified severe subcutaneous oedema of the head, a left parietal extradural haemorrhage, a posterior fossa subdural haemorrhage with intracerebellar haemorrhage in the left hemisphere and a high signal around the soft tissues of the larynx of uncertain aetiology of which haemorrhage was one possible cause. At autopsy, there were patterned and unpatterned bruises of the face, head and neck, ‘‘boggy’’ swelling of the head, bilateral extradural haemorrhages over the parietal lobes, subdural haemorrhage of the posterior cranial fossa and lower cervical spine, rupture of the anterior spinal ligament and intervertebral disc at C6/7 level with extensive haemorrhage into the anterior neck muscles and a subglottic laryngeal tear. The autopsy also identified a subcapsular haematoma of the right lobe of the liver, multifocal necrosis of the left lobe of the liver and features of generalised hypoxia–ischaemia at birth. Retrospective review of the MRI in light of the autopsy findings then identified an abnormal orientation of the C5/6 junction with damage of the anterior ligament and possible corresponding intervertebral disc rupture. Retrospective review of the skeletal survey identified vertical separation of the cervical spine at the C5/6 level with increased width of the space. The two described cases highlight the limitations of a post-mortem MRI examination in detecting significant pathology and the continued relevance of the full conventional autopsy in detecting significant birth-related trauma especially in those cases where a joint examination by forensic and paediatric pathologists is indicated. The main benefits of the post-mortem MRI are that it allows an in situ inspection of the brain while provides a permanent digital record of each case that can be used to obtain a second opinion in court.

Forensic Sci Med Pathol (2008) 4:143–145

Chemical markers for drowning Jose E. Azparren Instituto Nacional de Toxicologı´ a y Ciencias Forenses, C/Luis Cabrera 9, 28002 Madrid, Spain, e-mail: [email protected], [email protected] Introduction The chemical markers of drowning have been used to diagnose drowning. However, the usefulness of many of them has been questioned, since the associated effects of blood putrefaction could mask the marker variation in blood. Method Strontium determination in the left and right ventricle blood, together with diatoms investigation in closed organs and pathological examination of organs, has been performed in more than 800 individuals found dead in water. Moreover, iron, haemoglobin, chloride and magnesium, were analysed in left and right ventricle blood from fresh water drownings which were not

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diagnosed by strontium. Strontium, magnesium and iron were analysed by atomic absorption spectrophotometry. A Zeeman 3030 AAS for strontium and a Varian 220FS flame atomic absorption spectrophotometer for iron and magnesium were used. Chloride and haemoglobin were analysed by spectrophotometric methods. Diatoms were investigated by microscopic examination after acidic or enzymatic digestion. Discussion In sea water drownings, strontium can not only diagnose all the drownings, but also is able to differentiate drownings in their variety of asphyxia from other types of deaths in water associated with a low water aspiration during vital period or from an individual death before entering into the sea water. In fresh water drownings, strontium can only diagnose approximately 33% of drownings, while the use of chemical markers as iron or magnesium based on haemodilution of left ventricle blood, can only assure a correct diagnosis when recent blood samples are available.