Estimating height from the first and second cervical vertebrae in a Spanish population.

One of the roles of forensic anthropology is the identification of skeletal remains and over the years many methods have been developed to obtain specific details of a corpse such as an estimation of age and height. The femur and tibia are ideal for this purpose but unfortunately they are often missing or badly fragmented. For this reason, in this present study, we used the smaller bones of the first and second cervical vertebrae, which are often better preserved than the long bones. Direct measurement of these bones has been found to be misleading, largely due to the remains of a covering of soft tissue, and to overcome this all measurements were taken from tomographic images. The aim of this study is to provide an auxiliary diagnostic method to evaluate the association of different anthropometric measurements taken with tomographic imagery of both the first cervical and second cervical vertebra with body height within a sample of the Spanish population. Measurements were taken from tomographic images taken with a dental CT of 203 healthy individuals from a Spanish population. The best correlation was obtained in the case of unknown sex using four measurements: two of the first cervical vertebra and two of the second vertebra using the following regression formula S=49.02+1.02O+1.58DO+0.49V+0.67I. All formulae provided statistically significant results and can be applied to any skeletal remains belonging to a Spanish population.

The Application of Flow Cytometry as a Rapid and Sensitive Screening Method to Detect Contamination of Vitreous Humor Samples and Avoid Miscalculation of the Postmortem Interval.

Research into maximizing the speed, precision, and reliability of estimating the postmortem interval (PMI) has been a recurring object of investigation and methodologies based on the vitreous humor (VH) have provided good results. However, contamination from causes not readily apparent, such as blood, can occur, and thus lead not only to an erroneous estimation of PMI, but also interfere with the correct identification of other substances in the VH. We have developed a flow cytometry method which quantifies blood contamination and is able to detect erythrocytes in 1:750,000 dilution of contaminated VH which affects the results of hypoxanthine. It is an improvement on the previous more complex mass spectrometry method, being faster, more sensitive, and readily available. As such, it could be proposed for the rapid screening of appropriate samples by detecting and eliminating blood contaminated samples from PMI estimation.

High variation in hypoxanthine determination after analytical treatment of vitreous humor samples.

In the field of legal medicine the correct determination of the time of death is of great importance because an error in calculating the post-mortem interval (PMI) could be crucial in a criminal investigation. The quantification of hypoxanthine (Hx) concentration in the vitreous humor (VH) as a means to estimate PMI is useful when dealing with a recent time interval of death and has several advantages over other biological matrices. However, due to its viscous nature, VH has to be liquefied prior to its analysis, and the different procedures to liquefy it may cause alterations in Hx concentration, and hence in estimation of PMI. The aim of this study was to determine differences in Hx concentration after applying several pre-analytical treatments to different aliquots of the same VH sample. Enzymatic digestion, sonication, centrifugation and heat were the liquefying methods applied to reduce the viscosity of 105 VH samples. Analysis was performed using solid phase extraction and liquid chromatography in tandem with mass spectrometry. Statistically significant differences in the measured Hx concentrations were found between enzymatic digestion and the other three methods analyzed (sonication, centrifugation, and heat). Additionally, high data dispersion was found under heat treatment but was not observed for centrifugation or sonication, where similar and more moderate results were found. We conclude that high variations in Hx determination are observed when enzymatic digestion or heat treatment is used and we therefore recommend sonication or centrifugation to quantify Hx concentration in the VH.

The use of computerized tomography in determining stature and sex from metatarsal bones.

This study evaluates the efficacy of a radiological method to estimate stature from measurements of the first and second metatarsal taken from a collection of metatarsals of a Portuguese Caucasian population in which the measurements were made directly on the bone. The highest coefficient of determination and the lowest standard error were obtained with the physiological length of the second metatarsal (F2), using the equation S=895.4803+10.7848F2. The linear regressions obtained show significant differences between the estimated heights from M1. In addition, we offer a simple method for sex determination based on the maximum length (M1) and width (W1) of the first metatarsal, where W1=x1; (M1/W1)=x2; ß0=55.4767; ß1=-2.5796 and ß2=-4.6898. Here we present a method of measurement using computerized tomography that enables population studies using live volunteers without incurring the difficulties of on the bone measurement.

Estimating adult stature from radiographically determined metatarsal length in a Spanish population.

The ability to determine height in adult life can be crucial in the identification of skeletal remains. Very often, the small bones found among such remains are not only the most numerous, but also the best preserved, a fact which calls for more research into developing methods to estimate height from metatarsals. The aim of this paper is to verify the use of the dimensions of the metatarsals as estimators of adult height in a Spanish population using radiologically determined metatarsal lengths and to propose regression equations and test the formulae for determining adult stature. The present research is based on a study of 228 healthy Caucasoid adults from Galicia (NW Spain). The first and second metatarsals of the left foot were measured by a dorso-plantar X-ray using a digital medical image viewer. The best correlation obtained was with the maximum length of the 1st metatarsal for males. The corresponding regression equation is as follows: S=819.88+12.79 M1. A comparison of our statistical results with those of neighbouring population groups indicates that ours is more accurate. This must be due to the so-called specificity of regression equations in relation to the series on the base from which they were developed.

Applications of Tandem Mass Spectrometry (LC-MSMS) in estimating the post-mortem interval using the biochemistry of the vitreous humour.

It is widely accepted that the quantification of potassium concentrations ([K+]) and hypoxanthine ([Hx]) in the vitreous humour is useful in estimating the time of death within a recent time interval. Despite all the advances made in this area, it is well recognized that difficulties in calibration, validation and the use of different methodologies and instrumentation from different laboratories may lead to obtaining different concentrations from the same sample. The extraction of the vitreous humour itself should also be carried out with a precise technique, taking care during the procedure to avoid causing any vascular injury that might lead to haematic contamination. Any fluid that is not clear could lead to erroneous results and should be discarded. We present a new LC-MSMS method developed for quantitative and qualitative analysis of [Hx] (valid also for guanine and xanthine), and qualitative determination of uric acid in vitreous humour. We also introduce a methodology to assess haematic contamination in order to improve the estimation of time since death. The method was fully validated in terms of linearity, sensitivity, imprecision, analytical recovery, extraction and process efficiency and matrix effect.

Characterization of lesions in hanging deaths.

Hanging is a common method of committing suicide and a routine task in medico-legal autopsies. The hanging mark is the most relevant external sign and its characteristics are well known, but, for unknown reasons, there are major differences in reports on internal findings. We retrospectively studied 228 consecutive cases of hanging deaths. A complete standard autopsy was performed for every case. We investigated the association between the characteristics of the hanging mark and the frequency of bone, cartilage, soft tissue, and vascular injuries with the mode of suspension. Most cases (75.3%) presented some kind of bone or cartilage fracture, but these were unrelated to any of the variables studied. Vascular lesions are clearly more infrequent: intimal injuries were found in the carotid artery (9.1%), the jugular vein (2.2%), and ruptures of the carotid adventitial layer (21.7%). These could be partially associated with the use of a hard fixed noose and body weight.

Adrenal lipomas: incidental autopsy findings.

Two rare cases of lipomas of the adrenal gland are reported. In both cases the tumor was found incidentally at autopsy, in the course of the medicolegal investigation of death. The first case involved a small tumor of the left adrenal gland in a 70-year-old man who died by drowning. In the second case, a previously healthy 45-year-old man died suddenly. At autopsy a lipoma of the right adrenal gland was associated with a pheochromocytoma in the contralateral gland.

Report of a suicidal digoxin intoxication: a case report.

Digoxin is a cardiotonic glycoside that is primarily used in the treatment of heart failure, atrial fibrillation or flutter, and paroxysmal atrial tachycardia. Intoxication due to digitalis excess is a common problem in clinical practice because it is therapeutically effective within a narrow dose range. However, massive intoxication with digitalis glycosides following a suicidal attempt is a rare event. In this report we describe an overdose fatality involving digoxin in a suicidal 82-year-old man, in whom measurement of serum digoxin concentration is available. A toxicological study of our patient, approximately two and a half hours after ingestion of the drug, revealed digoxin concentrations within 12.2-13.2 ng/ml in the blood, while the mean therapeutic serum concentration ranged from 0.5 to 2 ng/ml.

Improved estimation of postmortem interval based on differential behaviour of vitreous potassium and hypoxantine in death by hanging.

Many formulae are available to estimate the relation between the potassium ([K+]) and hypoxantine ([Hx]) concentration in the vitreous humour and the postmortem interval (PMI). Typically these have been based on a correlation test and linear regression using the postmortal interval as the independent variable and [K+] or [Hx] as the dependent variable in order to estimate the confidence interval. However, a recent study has shown that a more precise measurement of PMI can be obtained if [K+] is used as the independent variable. The regression lines obtained from the most recent deceased subjects with forensic relevance received for autopsy in the Institute of Legal Medicine are [K+] = 5.589 + 0.174PMI and [Hx] = 26.459 + 3.017PMI, by changing the variables, we obtain PMI=3.967[K+] - 19.186 (R2 = 0.688, P < 0.001) and PMI = 0.172 [Hx] + 0.170 (R2 = 0.518, P < 0.001). In this paper we propose the cause of death as an extra factor which modifies the relationship and gives even greater precision in estimating PMI. In cases of death by hanging the results are considerably improved with [K+] = 5.224 + 0.225PMI and [Hx] = 15.161+4.957PMI, respectively, and consequently, PMI = 3.631[K+] - 17.334 (R2 = 0.818, P< 0.001) and PMI = 0.153[Hx] - 0.368 (R2 = 0.757, P < 0.001): the slope is less and the precision is obviously enhanced.