Reduction of postmortem angiography-induced tissue edema by using polyethylene glycol as a contrast agent dissolver

Postmortem investigation is increasingly supported by computed tomography (CT) and magnetic resonance imaging, in which postmortem minimal invasive angiography has become important. The newly introduced approach using an aqueous contrast agent solution provided excellent vessel visualization but was suspected to possibly cause tissue edema artifacts in histological investigations. The aim of this study was to investigate on a porcine heart model whether it is possible to influence the contrast agent distribution within the soft tissue by changing its viscosity by dissolving the contrast agent in polyethylene glycol (PEG) as a matrix medium. High-resolution CT scans after injection showed that viscosities above c. 15 mPa s (65% PEG) prevented a contrast agent distribution within the capillary bed of the left ventricular myocardium. Thereby, the precondition of edema artifacts could be reduced. Its minimal invasive application on human corpses needs to be further adapted as the flow resistance is expected to differ between different tissues.     

Further evidence of the validity of the Suicide Risk Assessment Scale for prisoners

The Suicide Risk Assessment Scale (SRAS; nine items) is useful in correctional settings but needed further validation. First, 44 inmates originally screened as suicidal with the SRAS were evaluated by institutional psychologists according to five criteria: suicidal urgency, risk, appropriateness of referral, need for short- or long-term watch. On the whole, the SRAS was judged to be as effective as a more elaborate test. Second, 242 suicidal and non-suicidal inmates were tested with the SRAS. Their results correlated better with suicidal risk (.71) than with urgency (.50). Receiver operating characteristic (ROC) analysis even showed that the SRAS performed better than a more elaborate test in predicting risk.     

Importance of radiological diagnosis applied to necroscopy

The authors evaluate the consequences of incomplete necroscopic examinations wherein it was impossible to apply radiological resources to locate firearm projectiles. The study includes 8185 reports from the Instituto Médico-Legal Afranio Peixoto in Rio de Janeiro, Brazil, representing the totality of corpses processed from January to December 2001; of these, 3122 were gunshot victims, 309 of which were buried with unremoved projectiles, being liable to future judicial reappraisal. During the same period, there were 23 exhumation requests by police authorities, 12 of them querying the existence of projectiles. The authors looked into the formal reasons assumed by the medico legal experts to conclude their reports from incomplete examinations, and suggest that gunshot necroscopic examinations should follow specific protocols, as incomplete autopsies will require further exhumations, at unnecessary additional costs.     

Analysis of STR loci in Cartagena, a Caribbean city of Colombia

Allele frequencies, together with some parameters of forensic interest were estimated for nine STRs included in the AmpF/STR Profiler kit (CSF1PO, D3S1358, D5S818, D7S820, D13S317, FGA, TH01, TPOX and vWA) in a sample of 215 unrelated individuals from Cartagena (Colombia). For all loci, no significant deviations from Hardy-Weinberg equilibrium were observed. Comparative analysis results between our data and those from other Colombian and African population samples revealed significant differences, except with two Colombian Caribbean Coast sub-regions.     

Discrepancies between forensic identification kits explained by a laser power supply shutdown

The occurrence of two null alleles for the same individual was suspected because of the discrepancy at two loci (vWA and THO1) between genotypes characterized by the mean of two different commercial kits. Reanalysis of the samples indicated there was no null allele, and that this abnormality was indeed related to an automatic laser power shutdown. The laser power supply was set to a value (6.4V) too close to the automatic shutdown threshold (6.0V). The alleles were undetected because of the absence of emission at the time of migration of the two alleles through the detection device. However, since no alarm is triggered in such an event, the users should monitor their laser power supply values.     

Use of drugs of abuse in less than 30-year-old drivers killed in a road crash in France: a spectacular increase for cannabis, cocaine and amphetamines

A collaborative study was conducted in France in order to determine the prevalence of cannabinoids, opiates, cocaine metabolites and amphetamines in blood samples from drivers killed in road accidents in 2003 and 2004 and to compare these values with those of a previous study performed during the period 2000-2001 involving 900 drivers. Blood samples were provided from 2003 under 30-year-old drivers, killed in a traffic accident. Drugs of abuse were determined by gas chromatography-mass spectrometry using the same analytical procedures in all the 12 laboratories. The most frequently observed compounds were by far cannabinoids, that tested positive in 39.6% of the total number of samples. Delta9 tetrahydrocannabinol (THC), the most active of the principle constituents in marijuana (cannabis sativa), was detected in the blood of 28.9% drivers and was the single drug of abuse in 80.2% of the positive cases. It was associated with amphetamines in 7.4% and with opiates and cocaine in 1.9 and 4.8%, respectively. Amphetamines were present in 3.1% of the total number of samples, cocaine metabolites in 3.0% and opiates in 3.5%. When comparing these results with those of a previous study performed 3 years before, a significant increase is observed for THC (28.9% versus 16.9%), cocaine metabolites (3.0% versus 0.2%) and amphetamines (3.1% versus 1.4%). This study demonstrates the critical necessity of implementing in France as soon as possible systematical roadside testing for drugs of abuse.     

Solid-phase microextraction for the determination of cocaine and cocaethylene in human hair by gas chromatography-mass spectrometry

A method for the simultaneous determination of cocaine (COC) and cocaethylene (CE) in human hair was developed, using solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) as analytical technique to identify and quantify the drugs. Selected ion monitoring (SIM) mode was used to obtain higher sensitivity. The deuterated-labeled analogues were used as internal standards. The detector response was linear for the drugs studied over the range 0.4-15 ng/mg, with correlation coefficients higher than 0.995. The coefficients of variation oscillated between 0.65% and 14.18% and the accuracy was in the range from 0.73% to 11.20%. The limits of quantitation and detection were found to be acceptable. Finally, this method was applied to 15 hair samples from cocaine users, obtaining positive results in all cases. The mean concentrations were 5.39 ng/mg (range: 0.43-8.98 ng/mg) for cocaine and 1.11 ng/mg (range: 0.42-2.23 ng/mg) for cocaethylene.     

Post-traumatic venous and systemic air embolism associated with spinal epidural emphysema: multi-slice computed tomography diagnosis

A 30-year-old man was admitted with chest trauma after a road traffic accident. The patient was paraplegic and suffered from transient monoparesia of the left arm. The chest X-ray revealed a severe right tension pneumothorax and thoracic spine fractures. Emergency right thoracic drainage was carried out followed by angiography. Unfortunately the patient died and an autopsy was not permitted. Consequently post-mortem multi-slice computed tomography (MSCT) was performed, revealing presence of air inside the right cerebral arteries, bilateral pneumothorax accompanied by a severe right tension pneumothorax, bilateral haematic pleural effusion, pneumomediastinum and bilateral lung contusions. Air was also observed within the right coronary artery, ascending aorta and right ventricle. Thoracic and cervical spinal epidural emphysema were diagnosed. Venous air embolism followed by arterial air embolism producing paradoxical embolism was diagnosed. To the best of our knowledge, this is the first case illustrating by post-mortem MSCT such simultaneous complications after chest trauma as spinal epidural emphysema and cerebral and coronary air embolism.     

Genetic variation of 15 STR autosomal loci in the Maracaibo population from Venezuela

Allele frequencies for 15 short tandem repeats (STRs) autosomal loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818 and FGA, included in the AmpFLSTR Identifiler, Applied Biosystems) were studied in the city of Maracaibo, Venezuela and were compared with other published Latin-American populations for the same loci. Population and forensic parameters were estimated.