Subvalvular aortic stenosis as a cause of sudden death: two case reports

Sudden death is defined as a death that occurs suddenly, develops during an unpredictable course, and is due to natural or unnatural causes. Although there is no universally standardized definition on how "sudden" a sudden death is, WHO defines sudden death as a death that occurs within 24 hours after the onset of symptoms. The aim of this study is to present 2 rarely reported autopsy cases and to emphasize the importance of systemic autopsy at sudden death. On macroscopic examination, crescent-shaped, thick, fibrous membranes, located 5 mm and 3 mm away from the aortic valves, were detected. Fibrous membranes extended from the ventricular septum to the left ventricular outflow tract, thus apparently narrowing this region. Left ventricular wall and septum were slightly thickened, and there were scattered grayish-white areas of a small diameter. These became more intense in the septum and myocardium of the left ventricle on the anterior plane of the myocardial sections. In both cases, the aortic valves of were thickened and also markedly narrowed on one of them. In this case, the fibrous membrane adhered to the aortic valve and extended to the anterior leaflet of the mitral valve at one side. Both aortic valves comprised 3 leaflets. Other valves and coronary arteries showed no macroscopic pathologic findings. Microscopic examination of both cases demonstrated that the fibrous membrane comprising abundant collagen fibers was situated on the ventricular septum. Hypertrophy, moderate to severe interstitial fibrosis, and focal areas of scarring were observed in the specimens taken from the septal and ventricular myocardium. No abnormality was found on the conduction system examinations. Toxicologic analysis results in blood were negative. Based on the findings, membranous-type (discrete type) subvalvular aortic stenosis, diagnosed during the autopsy, was considered as the cause of sudden death in both cases.     

A probabilistic approach to the joint evaluation of firearm evidence and gunshot residues

The present paper addresses issues that affect both the separate as well as the joint evaluation of firearm evidence (i.e., marks) and gunshot residues (GSR). Mark evidence will be used as a basis to discriminate among barrels through which a bullet in question might have been shot whereas GSR will be used to draw inferences about the distance of firing. Particular attention is drawn to the coherent handling of uncertainties associated with the various parameters considered within each item of evidence. The proposed analysis relies on a probabilistic viewpoint that uses graphical models (i.e., Bayesian networks) as an aid to cope with the complexity induced by the number of variables considered. The paper discusses how an approach based on a probabilistic network environment can be used for the formal analysis and construction of arguments. Emphasis is made on the gain of insight into structural dependencies that may be uncovered when the evaluative process is extended beyond single items of scientific evidence.     

Dental age estimation through volume matching of teeth imaged by cone-beam CT

A custom-made voxel counting software for calculating the ratio between pulp canal versus tooth volume based on cone-beam CT tooth images was developed and evaluated. The aim of this study was to attempt establishing a correlation between the chronological age of a certain individual and the pulp/tooth volume ratio of one of the teeth. Twenty-eight single rooted teeth of 19 individuals with well-known chronological age were scanned by the cone-beam CT (3D Accuitomo, J. Morita, Kyoto, Japan). Next the images were analyzed using the custom-made software. Linear regression analysis was performed. The results of the analysis showed a moderate correlation between the pulp/tooth volume ratio and biological age with a coefficient of determination (R2) of 0.29. Although the present work was limited to a pilot study, the developed technique showed promising results for dental age estimation in a non-invasive manner using cone-beam CT images in living individuals.     

Results of the 2003-2004 GEP-ISFG collaborative study on mitochondrial DNA: focus on the mtDNA profile of a mixed semen-saliva stain

We report here a review of the seventh mitochondrial DNA (mtDNA) exercise undertaken by the Spanish and Portuguese working group (GEP) of the International Society for Forensic Genetics (ISFG) corresponding to the period 2003-2004. Five reference bloodstains from five donors (M1-M5), a mixed stain of saliva and semen (M6), and a hair sample (M7) were submitted to each participating laboratory for nuclear DNA (nDNA; autosomal STR and Y-STR) and mtDNA analysis. Laboratories were asked to investigate the contributors of samples M6 and M7 among the reference donors (M1-M5). A total of 34 laboratories reported total or partial mtDNA sequence data from both, the reference bloodstains (M1-M5) and the hair sample (M7) concluding a match between mtDNA profiles of M5 and M7. Autosomal STR and Y-STR profiling was the preferred strategy to investigate the contributors of the semen/saliva mixture (M6). Nuclear DNA profiles were consistent with a mixture of saliva from the donor (female) of M4 and semen from donor M5, being the semen (XY) profile the dominant component of the mixture. Strikingly, and in contradiction to the nuclear DNA analysis, mtDNA sequencing results yield a more simple result: only the saliva contribution (M4) was detected, either after preferential lysis or after complete DNA digestion. Some labs provided with several explanations for this finding and carried out additional experiments to explain this apparent contradictory result. The results pointed to the existence of different relative amounts of nuclear and mtDNAs in saliva and semen. We conclude that this circumstance could strongly influence the interpretation of the mtDNA evidence in unbalanced mixtures and in consequence lead to false exclusions. During the GEP-ISFG annual conference a validation study was planned to progress in the interpretation of mtDNA from different mixtures.     

大鼠毒鼠强中毒内脏器官Caspase-3与Bcl-2蛋白的表达

目的探讨大鼠毒鼠强中毒的病理机制。方法SD大鼠60只,随机分正常对照组、空白对照组、高剂量中毒死亡组、低剂量中毒组,高剂量中毒死亡组以1.0mg/kg毒鼠强悬浊液灌胃,低剂量中毒组以0.1mg/kg体重毒鼠强悬浊液灌胃。用免疫组织化学技术对中毒大鼠器官检测caspase-3与Bcl-2蛋白的表达,用图像分析技术对检测结果进行分析。结果各器官caspase-3与Bcl-2蛋白的表达变化规律基本相似,即高剂量中毒组大鼠caspase-3与Bcl-2蛋白均呈较强的阳性表达,低剂量中毒组大鼠,Bcl-2与caspase-3于中毒30min后表达不明显,3h时,可见较为明显的阳性信号,Bcl-2在6h～3d达高峰,随后表达下降;caspase-3在24h～5d达峰值,随后下降。Bcl-2峰值早于caspase-3出现。结论Bcl-2与caspase-3参与了毒鼠强中毒的病理生理过程。     

Evaluation of atypical stab and incision wounds in a case of combined suicidal injuries

A fatal case of stabbing and cutting is reported which involved a 37-year-old male who suffered from depressive disorder and had already attempted suicide in the past. The postmortem examination revealed 12 lacerations of the scalp, 5 deep incised wounds on the flexor surface of the right forearm, 3 stab wounds of the back of the head, 12 stab wounds of the chest (with cutting of ribs but no injury of heart and lungs), 35 stab wounds of the abdomen and deep incised wounds of both sides of the neck with hesitation marks and incision of the left internal jugular vein. The significance of criteria to properly establish the manner of death like localization, axis and pattern of the wounds, hesitation marks, defense wounds, pulling aside the clothing to expose the target area, sustained capacity of physical activity and potential lethal effects of the single injuries as well as conclusions from the scene of death are discussed.     

Motor vehicle accident with complete loss of consciousness due to vasovagal syncope

Vasovagal syncope (VVS) is one of the most common causes of complete or partial loss of consciousness, thus it might cause harm to the patients themselves or innocent bystanders while driving a car. In our case report we introduce the case of a 60-year-old man who was admitted to hospital after a serious motor vehicle accident due to loss of consciousness. We demonstrate the process and results of complete cardiologic and neurological assessment. Our case report illustrates the importance of recognition of patients with a high risk for incapacitating symptoms due to VVS, and the use of head-up tilt-table tests to determine the diagnosis and to guide therapy with beta-blocking agents. As transient loss of consciousness during driving may cause potentially fatal accident, it has to be taken into consideration during decision making for issue of driving licenses to patients with VVS.     

Turkish population data on nine short tandem repeat loci: HumCSF1PO,HumTHO1, HumTPOX,HumFES/FPS,HumF13B,HumVWA, D3S1358, D7S820, D16S539

Allele and genotype frequencies for the nine loci, HumCSF1PO, HumTHO1, HumTPOX, HumFES/FPS, HumF13B, HumVWA, D3S1358, D7S820 and D16S539 were determined using Silver STR III System on 223-598 unrelated Turkish individuals from different regions of the country.     

A contribution to the chemical profiling of 3,4-methylenedioxymethamphetamine (MDMA) tablets

A profiling method for the identification of impurities found in seized 3,4-methylenedioxymethamphetamine (MDMA) tablets is presented. Impurities of interest are extracted from an alkaline solution (pH 12.8) by diethyl ether and submitted to gas chromatography (GC)-mass spectrometry (MS) analyses. Identification of impurities is performed by electron impact ionization (Ei) mass spectrometry and confirmation by positive chemical ionization (Ci+) MS or, when possible, MS/MS (MS(2)). Repeat extractions of the same sample give an average relative standard deviation (R.S.D.) of less than 8% within the same day and 15% between days (results were obtained after normalization by the sum of peak areas, each one being acquired by selected ion monitoring (SIM)). Possible application toward batch comparison of samples is discussed. Chromatographic profiles are compared using the cosine function for evaluating similarity and/or dissimilarity among exhibits.