A method for the longitudinal sectioning of single hair samples

A simple technique is presented for the longitudinal sectioning of hair samples without the need for any embedding medium. The technique applies to single hair samples that are placed in a groove of a particular depth and can either be scraped or cut to the desired level. Planar sections are obtained that reveal the internal structure of the sample and are ideal for the application of surface analytical techniques for the study of internal transverse and longitudinal distributions of xenobiotics.     

What is the best sample for determining the early postmortem period by on-the-spot flow cytometry analysis?

The level of degradation of DNA as a means for determining the time of death has been proposed as a valid adjunct to the classic thanatochronologic methods. The twofold aim of this work was to determine which organ might reveal both a correlation between the percentage of degradation of the DNA and the time lapse since death, and would be easiest to sample and yield the most reproducible results even in technically unfavorable situations such as on-the-spot investigations at the scene of death. A comparison of the spleen, blood, and liver showed that hepatic tissue best meets these specific needs because it shows a virtually linear correlation between the time elapsed since death and the level of degradation of the DNA, and it can easily be sampled at the scene of death by use of a common biopsy needle.     

A new improved method for extraction of DNA from teeth for the analysis of hypervariable loci

A new method for better recovery of DNA suitable for amplification of hypervariable loci from fragments of teeth, consisting of two steps-scraping and aspiration, and extensive decalcification-is reported. Higher yields of high molecular weight DNA were obtained from the root, pulp, and crown of all kinds of 120 teeth, irrespective of gender, age, and source of teeth. HLA DQA1, 5 poly markers (LDLR, GYPA, HBGG, D7S8, and Gc), and other 12 short tandem repeat loci (HPRTB, F13B, LPL, D13S317, D7S820, D5S818, D21S11, D18S51, FGA, D8S1179, D3S1358, and vWA) could be successfully amplified and typed from recovered DNA.     

Sudden death resulting from lesions of the cardiac conduction system

Sudden unexpected deaths in young persons with noncontributory histories, autopsy results, and drug screen results are a common problem in forensic pathology. As part of the evaluation of such cases, the cardiac conduction system (CCS) should be studied. To determine the type and incidence of lethal CCS lesions, the authors reviewed their files of sudden unexpected cardiac deaths with particular attention to cases with causes of death in the conduction system. Cases of sudden cardiac death in patients aged < or=40 years during a 10-year period (Michigan) and a 4 year-period (Spain) were selected from the files. From this group, cases were identified in which the cause of death was a lethal change in the CCS. The portions of the heart containing the CCS were excised, and at least one hematoxylin and eosin slide and at least one trichrome or elastic trichrome slide per block were studied. In the two centers, 381 cases of sudden cardiac death were identified. The most common causes of sudden cardiac death were arteriosclerotic narrowing of the coronary arteries, cardiomyopathy, and myocarditis. In 82 cases, there was no identifiable cause of death even after complete gross and microscopic autopsy was performed, a medical history was obtained, and a drug screen was performed. In 11 cases, the CCS contained lesions that were considered lethal: narrowing of the atrioventricular node artery by fibromuscular hyperplasia (7 cases) and atrioventricular node tumors (4 cases). The 11 cases accounted for 2.9% of the 381 cases of sudden cardiac death and 11.8% of the indeterminable cases. It was concluded that examination of the CCS in deaths in which the gross and microscopic autopsy, history, and drug screen fail to provide a cause of death can yield a cause of death in a significant percentage of cases. If heart block was not documented during life and no explanatory lesions were found during routine cardiac examination, examination of the CCS can yield valuable information.     

Deaths associated with liposuction: case reports and review of the literature

Tumescent liposuction is a common cosmetic procedure that is performed as an outpatient service in physician's offices and is largely believed to be safe. The protuberant areas of the body containing the undesirable fat deposits are injected with normal saline containing lidocaine and epinephrine for pain control and hemostasis, and the waterlogged cells are suctioned out via cannula through a small incision. We recently encountered three cases in which deaths were attributed to this procedure. Two showed fat embolization in the lung and one died from fluid overload. The osmium tetroxide post-fixed lung sections showed fat emboli in the interstitial capillaries and arterioles. We reviewed the recent literature and found that pulmonary thromboemboli, fat embolization, fluid overload, and lidocaine and epinephrine intoxication are found at autopsy in many cases. Forensic pathologists responsible for determining the cause and manner of death should become familiar with the postmortem findings and risks of liposuction therapy and communicate them to their clinical colleagues and communities.     

Dental age estimation and third molars: a preliminary study

The aim of the present investigation was to reconstruct the chronological age based on the dental developmental stages of third molars evaluated on orthopantomograms. A total of 1175 orthopantomograms were assembled from patients of Caucasian origin between 16 and 22 years of age. Each third molar present was scored by two observers according to a 10-stage developmental scale. The kappa statistics measured the intra- and inter-observer reliability. The general statistical analysis was based on multiple regression analysis in order to obtain multiple regression formulas for dental age estimation based on the number of third molars present on the evaluated orthopantomogram. No regression models were statistically significant when there was only one-third molar present because of the relatively small number of orthopantomograms that fitted this criterion. A strong agreement was found between the intra- and inter-observer measurements. The statistical analysis revealed both for males and females high Pearson correlation coefficients between contralateral third molars and smaller coefficients between antimeres. The obtained multiple regression formulas are only applicable in certain specified conditions, for instance when four third molars are present the following formulas should be used in a Caucasian male "age=10.2000+0.5122UL+0.5273LL" (developmental stage of upper and lower left third molars) or in case of a female "age=13.6206+0.1933UR+0.5080LR" (developmental stage of upper and lower right third molars). This investigation revealed that the chronological age of a Caucasian individual may be estimated based on regression formulas with a S.D. of 1.52 or 1.56 years for males and females, respectively, when all four third molars are present.