Post-mortem genetic investigation in sudden cardiac death victims: complete exon sequencing of forty genes using next-generation sequencing.

Sudden cardiac death (SCD) in young people is predominantly caused by genetic causes as cardiomyopathies. Hypertrophic cardiomyopathy is the most common genetic cardiovascular disease and is responsible for the major proportion of SCD in the young. The purpose of this study was to identify the genetic variants present in young SCD victims with HCM characteristics. From the Portuguese records of autopsies performed at the National Institute of Legal Medicine and Forensic Sciences, North Delegation, 16 young (16-50 years) SCD victims whose death was suspected to be a manifestation of HCM were selected. Using next-generation sequencing, the coding regions of 40 genes associated with HCM, candidates, or strongly related to HCM-phenocopies were investigated. The victims included in this study were all males, with a mean age of 33.4 ± 11.7 years, left ventricle mean thickness of 21.5 ± 6.28 mm, and the majority of deaths occurred during sleep (36%). A pathogenic or likely pathogenic variant was identified in six out of 16 (37.5%) victims, in the most common HCM genes (MYBPC3 and MYH7). Our results indicate that molecular autopsy of SCD victims contributes to a more precise identification of a cause of death, and this can be used in the prevention of SCD cases through family screening of first relatives who may carry the same pathogenic variant.

Up-regulation of P2X7 receptor-mediated inhibition of GABA uptake by nerve terminals of the human epileptic neocortex.

OBJECTIVE: Thirty percent of patients with epilepsy are refractory to medication. The majority of these patients have mesial temporal lobe epilepsy (MTLE). This prompts for new pharmacologic targets, like ATP-mediated signaling pathways, since the extracellular levels of the nucleotide dramatically increase during in vitro epileptic seizures. In this study, we investigated whether sodium-dependent high-affinity γ-aminobutyric acid (GABA) and glutamate uptake by isolated nerve terminals of the human neocortex could be modulated by ATP acting via slow-desensitizing P2X7 receptor (P2X7R). METHODS: Modulation of [(3) H]GABA and [(14) C]glutamate uptake by ATP, through activation of P2X7R, was investigated in isolated nerve terminals of the neocortex of cadaveric controls and patients with drug-resistant epilepsy (non-MTLE or MTLE) submitted to surgery. Tissue density and distribution of P2X7R in the human neocortex was assessed by Western blot analysis and immunofluorescence confocal microscopy. RESULTS: The P2X7R agonist, 2'(3')-O-(4-benzoylbenzoyl)ATP (BzATP, 3-100 µm) decreased [(3) H]GABA and [(14) C]glutamate uptake by nerve terminals of the neocortex of controls and patients with epilepsy. The inhibitory effect of BzATP (100 µm) was prevented by the selective P2X7R antagonist, A-438079 (3 µm). Down-modulation of [(14) C]glutamate uptake by BzATP (100 µm) was roughly similar in controls and patients with epilepsy, but the P2X7R agonist inhibited more effectively [(3) H]GABA uptake in the epileptic tissue. Neocortical nerve terminals of patients with epilepsy express higher amounts of the P2X7R protein than control samples. SIGNIFICANCE: High-frequency cortical activity during epileptic seizures releases huge amounts of ATP, which by acting on low-affinity slowly desensitizing ionotropic P2X7R, leads to down-modulation of neuronal GABA and glutamate uptake. Increased P2X7R expression in neocortical nerve terminals of patients with epilepsy may, under high-frequency firing, endure GABA signaling and increase GABAergic rundown, thereby unbalancing glutamatergic neuroexcitation. This study highlights the relevance of the ATP-sensitive P2X7R as an important negative modulator of GABA and glutamate transport and prompts for novel antiepileptic therapeutic targets.

Adenosine A2A receptor and ecto-5'-nucleotidase/CD73 are upregulated in hippocampal astrocytes of human patients with mesial temporal lobe epilepsy (MTLE).

Refractoriness to existing medications of up to 80 % of the patients with mesial temporal lobe epilepsy (MTLE) prompts for finding new antiepileptic drug targets. The adenosine A2A receptor emerges as an interesting pharmacological target since its excitatory nature partially counteracts the dominant antiepileptic role of endogenous adenosine acting via inhibitory A1 receptors. Gain of function of the excitatory A2A receptor has been implicated in a significant number of brain pathologies commonly characterized by neuronal excitotoxicity. Here, we investigated changes in the expression and cellular localization of the A2A receptor and of the adenosine-generating enzyme, ecto-5'-nucleotidase/CD73, in the hippocampus of control individuals and MTLE human patients. Western blot analysis indicates that the A2A receptor is more abundant in the hippocampus of MTLE patients compared to control individuals. Immunoreactivity against the A2A receptor predominates in astrocytes staining positively for the glial fibrillary acidic protein (GFAP). No co-localization was observed between the A2A receptor and neuronal cell markers, like synaptotagmin 1/2 (nerve terminals) and neurofilament 200 (axon fibers). Hippocampal astrogliosis observed in MTLE patients was accompanied by a proportionate increase in A2A receptor and ecto-5'-nucleotidase/CD73 immunoreactivities. Given our data, we hypothesize that selective blockade of excessive activation of astrocytic A2A receptors and/or inhibition of surplus adenosine formation by membrane-bound ecto-5'-nucleotidase/CD73 may reduce neuronal excitability, thus providing a novel therapeutic target for drug-refractory seizures in MTLE patients.

A FT-NIR spectroscopy methodology to estimate firing distance based on the direct analysis of the bullet impact surface.

A new methodology to estimate firing distance based on the direct analysis of organic components of gunshot residues (GSRs) on the bullet impact surface using Fourier transform near-infrared (FT-NIR) spectroscopy is proposed. Mathematical models relating firing distance with spectral information were developed using data obtained from a series of shots performed with a Glock model 17C (114 mm barrel length and 9 × 19 mm cartridges) at different distances, from 20 to 90 cm, against a white 40 × 40 cm square cloth (70% polyester/30% cotton) target. The study was repeated with two different types of ammunition. Spectra were obtained around the bullet entrance hole at 4 perpendicular directions and at 5 radial distances in diffuse reflectance mode with the assistance of a fiber optic probe. Principal component analysis showed that FT-NIRS displayed sensitivity in the recognition of the differences between the GSRs from the two different types of ammunition. Partial least squares regression models allowed the estimation of firing distance for both types of ammunition. Prediction errors lower than 11 cm were obtained for shots up to 90 cm.

Human identification using dental techniques: A case report.

Dental identification of skeletal remains frequently relies on data comparison. Comparative dental identification is used to establish with a high degree of certainty that the remains of a corpse and a person represented by ante-mortem dental records are the same individual. There is no minimum number of concordant points necessary to perform a positive identification; rather, each case is unique and should be treated as such. In this paper, we present a report of a case in which positive identification was made by a paramolar tubercle in both upper first deciduous molars.

Clinical and forensic signs related to ethanol abuse: a mechanistic approach.

For good performance in clinical and forensic toxicology, it is important to be aware of the signs and symptoms related to xenobiotic exposure since they will assist clinicians to reach a useful and rapid diagnosis. This manuscript highlights and critically analyses clinical and forensic imaging related to ethanol abuse. Here, signs that may lead to suspected ethanol abuse, but that are not necessarily related to liver disease are thoroughly discussed regarding its underlying mechanisms. This includes flushing and disulfiram reactions, urticaria, palmar erythema, spider telangiectasias, porphyria cutanea tarda, "paper money skin", psoriasis, rhinophyma, Dupuytren's contracture, multiple symmetrical lipomatosis (lipomatosis Lanois-Bensaude, Madelung's disease), pancreatitis-related signs, black hairy tongue, gout, nail changes, fetal alcohol syndrome, seborrheic dermatitis, sialosis and cancer.

Biomechanical properties of vaginal tissue in women with pelvic organ prolapse.

BACKGROUND/AIMS: To compare biomechanical properties of vaginal tissues between women with and without pelvic organ prolapse (POP) and investigate factors that may influence these properties. METHODS: Forty patients submitted to POP surgery and 15 non-POP cadavers were evaluated. The tissue was excised from anterior and posterior middle third vagina. The biomechanical properties considered were stiffness (E) and maximum stress (S), and they were evaluated by means of uniaxial tension tests. RESULTS: POP patients were associated with higher values of E (13.1 ± 0.8 vs. 9.5 ± 0.7 MPa; p < 0.001) and S (5.3 ± 0.5 vs. 3.2 ± 0.9 MPa; p < 0.001) in the anterior vaginal wall compared to the posterior wall. In contrast, non-POP women presented lower values of E (6.9 ± 1.1 vs. 10.5 ± 1.0 MPa; p = 0.01) and S (2.6 ± 0.4 vs. 3.5 ± 0.4 MPa; p = 0.043) in the anterior wall. The occurrence of POP was the only independent predictor of higher values of E and S in anterior vaginal samples (p = 0.003 and p = 0.008, respectively). Women with severe anterior vaginal prolapse presented higher levels of E and S in the anterior sample compared to those with lower POP stages (p = 0.001 and p = 0.01; respectively). CONCLUSION: Women with POP present significant changes of biomechanical properties in the vagina.

Strength of round and uterosacral ligaments: a biomechanical study.

PURPOSE: To investigate the tensile biomechanical properties of round and uterosacral ligaments. METHODS: Tissue samples were obtained from 15 female cadavers without pelvic organ prolapse. Uniaxial tensile tests were performed to obtain stiffness and maximum stress of round and uterosacral ligaments. Correlations were calculated using the Pearson correlation coefficient. Statistical differences between groups were tested using Student's paired and unpaired t test. RESULTS: There was a great variability in the measurements of stiffness and maximum stress in pelvic ligaments. The round ligaments demonstrated stiffness of 9.1 ± 1.6 MPa (mean ± SEM) (ranging from 2 to 25.6 MPa) and maximum stress of 4.3 ± 0.7 MPa (ranging from 1.2 to 11.5 MPa). The stiffness of the uterosacral ligaments was 14.1 ± 1.4 MPa (ranging from 5.7 to 26.1 MPa) with maximum stress of 6.3 ± 0.8 MPa (ranging from 2.2 to 11.9 MPa). There was a strong positive correlation between stiffness and maximum stress in female pelvic ligaments (ρ = 0.851; p < 0.001). The uterosacral ligaments demonstrated higher stiffness and maximum stress compared to the round ligaments (p = 0.006 and p = 0.034; respectively). Age, body mass index and menopausal status were not associated with the biomechanical proprieties of round and uterosacral ligaments. Nulliparous women had lower uterosacral stiffness (15.5 ± 1.3 vs. 10 ± 1.8 MPa; p = 0.033) and maximum stress (8.2 ± 0.9 vs. 4.2 ± 1.1 MPa; p = 0.028) compared to parous women. CONCLUSION: The uterosacral ligaments are significantly more resistant than round ligaments. Parturition seems to enhance the stiffness and maximum stress of the ligaments.

[Sudden death secondary to acute aortic syndromes in the North of Portugal: medico-legal study]. / Morte súbita secundária a síndromes aórticos agudos no norte de Portugal: estudo médico-legal.

OBJECTIVE: An evaluation is presented on the clinical, pathological and sociodemographic characteristics of a sample of sudden death victims secondary to an Acute Aortic Syndrome (AAS) in the north of Portugal, submitted to medico-legal autopsy, during the period between January 2008 and December 2012. METHODS: Autopsy reports were analyzed in which, through necropsy and histological examination, the confirmed cause of death was an Acute Aortic Syndrome. RESULTS: From the studied cases, 70.3% of the victims were male. The median age was 65,19 ± 14,35 years (minimum of 27 years and maximum of 88 years). Death occurred mainly at home (40,5%) and during the normal activities of daily living (43,1%). There was an history of prodromes in 64,9% of the cases, mainly syncope and pain or respiratory symptoms. In 62,2% of the cases no pain history was reported. In the internal examination three presentation forms were identified: cardiac tamponade (51,4%); hemotorax (16,2%) and intra-abdominal bleeding (32,4%). The occurence of an Acute Aortic Syndrome was related to an aneurysmatic formation in 81% of the cases. Atherosclerotic plaques were identified in 51,4% of the cases and left ventricular hypertrophy was identified in 54,1%. None of the victims had a family history of aortic pathology and 54,1% of them presented a history of arterial hypertension. CONCLUSIONS: Necropsy data analysis of sudden death victims allows a better understanding of the AAS presentation, thus complementing the existent clinical studies. This work reveals how forensic medicine can be a privileged medium for articulation with clinical practice.

Are There Any Differences in Road Traffic Injury Outcomes between Older and Younger Adults? Setting the Grounds for Posttraumatic Senior Personal Injury Assessment Guidelines.

Injury outcomes seem to be more severe in older than younger persons. This may make personal injury assessment (PIA) particularly difficult, mainly because of seniors' previous health frailties. To set the grounds for seniors' PIA guidelines, we compared an older with a younger adult population of trauma victims and, secondarily, identified differences between the groups regarding three-dimensional and medico-legal damage parameters assessment. Using a retrospective study of victims of road traffic accidents, we compared the groups (n = 239 each), assuring similar acute injury severity (ISS standardised difference = 0.01): G1 (older adults); G2 (younger adults). Logistic regression was used to estimate the odds ratio. G1 revealed higher negative consequences when considering the three-dimensional damage assessment, with more frequent and severe outcomes, being a cause of further difficulties in daily living activities, with a loss of independence and autonomy. Nevertheless, regarding the medico-legal damage parameters, permanent functional disability did not show significant differences. This study generates evidence that reveals the need to rethink the traditional methodology of PIA in older persons, giving more relevance to the real-life contexts of each person. It is essential to: obtain complete information about previous physiologic and health states, begin the medico-legal assessment as early as possible, make regular follow-ups, and perform a multidisciplinary evaluation.

"Foam Cone" exuding from the mouth and nostrils following heroin overdose.

A "foam cone" exuding the mouth and nostrils is a recognized consequence of anoxia following pulmonary edema. In this report, we illustrate and explain this phenomenon in victims of heroin overdose.

Epilepsy progression is associated with cumulative DNA methylation changes in inflammatory genes.

Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is the most common focal epilepsy in adults. It is characterized by alarming rates of pharmacoresistance. Epileptogenesis is associated with the occurrence of epigenetic alterations, and the few epigenetic studies carried out in MTLE-HS have mainly focused on the hippocampus. In this study, we obtained the DNA methylation profiles from both the hippocampus and anterior temporal neocortex of MTLE-HS patients subjected to resective epilepsy surgery and autopsied non-epileptic controls. We assessed the progressive nature of DNA methylation changes in relation to epilepsy duration. We identified significantly altered hippocampal DNA methylation patterns encompassing multiple pathways known to be involved in epileptogenesis. DNA methylation changes were even more striking in the neocortex, wherein pathogenic pathways and genes were common to both tissues. Most importantly, DNA methylation changes at many genomic sites varied significantly with epilepsy duration. Such progressive changes were associated with inflammation-related genes in the hippocampus. Our results suggest that the neocortex, relatively spared of extensive histopathological damage, may also be involved in epilepsy development. These results also open the possibility that the observed neocortical impairment could represent a preliminary stage of epileptogenesis before the establishment of chronic lesions or a consequence of prolonged seizure exposure. Our two-tissue multi-level characterization of the MTLE-HS DNA methylome suggests the occurrence of a self-propagating inflammatory wave of epigenetic dysregulation.

Mesial Temporal Lobe Epilepsy (MTLE) Drug-Refractoriness Is Associated With P2X7 Receptors Overexpression in the Human Hippocampus and Temporal Neocortex and May Be Predicted by Low Circulating Levels of miR-22.

Objective: ATP-gated ionotropic P2X7 receptors (P2X7R) actively participate in epilepsy and other neurological disorders. Neocortical nerve terminals of patients with Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis (MTLE-HS) express higher P2X7R amounts. Overexpression of P2X7R bolsters ATP signals during seizures resulting in glial cell activation, cytokines production, and GABAergic rundown with unrestrained glutamatergic excitation. In a mouse model of status epilepticus, increased expression of P2X7R has been associated with the down-modulation of the non-coding micro RNA, miR-22. MiR levels are stable in biological fluids and normally reflect remote tissue production making them ideal disease biomarkers. Here, we compared P2X7R and miR-22 expression in epileptic brains and in the serum of patients with MTLE-HS, respectively. Methods: Quantitative RT-PCR was used to evaluate the expression of P2X7R in the hippocampus and anterior temporal lobe of 23 patients with MTLE-HS and 10 cadaveric controls. Confocal microscopy and Western blot analysis were performed to assess P2X7R protein amounts. MiR-22 expression was evaluated in cell-free sera of 40 MTLE-HS patients and 48 healthy controls. Results: Nerve terminals of the hippocampus and neocortical temporal lobe of MTLE-HS patients overexpress (p < 0.05) an 85 kDa P2X7R protein whereas the normally occurring 67 kDa receptor protein dominates in the brain of the cadaveric controls. Contrariwise, miR-22 serum levels are diminished (p < 0.001) in MTLE-HS patients compared to age-matched control blood donors, a situation that is more evident in patients requiring multiple (>3) anti-epileptic drug (AED) regimens. Conclusion: Data show that there is an inverse relationship between miR-22 serum levels and P2X7R expression in the hippocampus and neocortex of MTLE-HS patients, which implies that measuring serum miR-22 may be a clinical surrogate of P2X7R brain expression in the MTLE-HS. Moreover, the high area under the ROC curve (0.777; 95% CI 0.629-0.925; p = 0.001) suggests that low miR-22 serum levels may be a sensitive predictor of poor response to AEDs among MTLE-HS patients. Results also anticipate that targeting the miR-22/P2X7R axis may be a good strategy to develop newer AEDs.

Uniaxial mechanical behavior of the human female bladder.

INTRODUCTION AND HYPOTHESIS: The objective of the present study was to investigate the tensile biomechanical properties of the human female bladder. METHODS: Tissue samples were obtained from 13 cadavers without pelvic floor dysfunctions. We performed uniaxial tensile tests to measure the stiffness and maximum stress of the bladder tissue. Correlations were calculated using the Pearson correlation coefficient. RESULTS: The bladder tissue stiffness ranged from 1 to 4.1 MPa (mean stiffness, 1.9 ± 0.2 MPa) and the maximum stress ranged from 0.5 to 2.6 MPa (mean maximum stress, 0.9 ± 0.1 MPa). There was a strong positive correlation between stiffness and maximum stress in the bladder tissue (ρ = 0.829, p < 0.001). Tissue from women younger than 50 years presented higher bladder stiffness than did tissue from older subjects (2.1 ± 0.2 versus 1.3 ± 0.1 MPa, p = 0.02). Maximum bladder stress, however, was not associated with age (1.0 ± 0.2 versus 0.7 ± 0.1 MPa, p = 0.349). In addition, body mass index and menopausal status were not associated with these biomechanical properties. CONCLUSIONS: Age may influence the uniaxial mechanical behavior of the human female bladder.

Vaginal tissue properties versus increased intra-abdominal pressure: a preliminary biomechanical study.

BACKGROUND/AIMS: This study aims to evaluate the pelvic floor (PF) tension response during simulated increased intra-abdominal pressure (IAP) and the vaginal biomechanical properties. METHODS: A 3-dimensional computational finite element model for PF was developed based on magnetic resonance imaging from a nulliparous healthy volunteer. The model was used to simulate an IAP of 90 cm H(2)O and to evaluate the PF stresses in the longitudinal and transversal axes. The vaginal samples were obtained from 15 non-prolapsed female cadavers. A uniaxial tensile test to obtain stiffness and maximum stress of vaginal tissue in the longitudinal and transversal axes was performed. RESULTS: The simulated IAP was associated with a similar PF stress state in the longitudinal and transversal axes. The stiffness and maximum stress in vaginal tissues presented a great variability between subjects. There was no difference in the vaginal tissue elasticity (6.2 ± 1.5 vs. 5.4 ± 1.1 MPa; p = 0.592) and maximum stress (2.3 ± 0.5 vs. 2.6 ± 0.9 MPa; p = 0.692) regarding the measurements in the longitudinal and transversal axes. CONCLUSION: The isotropic biomechanical behavior of vagina is in agreement with the PF stress state response during increased IAP.

Reference values for trace element levels in the human brain: A systematic review of the literature.

Some trace elements (TE) are eminently toxic for humans (e.g., Al, Pb, Hg, Cd) and its presence in the central nervous system has been linked to the etiology of neurodegenerative diseases (ND). More recently, the focus has shifted to the potential role of the imbalances on essential TE levels (e.g., Fe, Cu, Zn, Se) within the brain tissue, and they have also been identified as potentially responsible for the cognitive decline associated with normal ageing and the development of some ND, although their definite role remains unclear. Accurately, well-defined reference values for TE levels in human body fluids and tissues are indispensable to identify possible disturbances in individual cases. Moreover, since the brain is a highly heterogeneous organ, with anatomically and physiologically very different areas, a detailed mapping of TE distribution across the brain tissue of normal individuals, with an in-depth analysis of TE levels in the different brain regions, is a mandatory prior work so that the results obtained from patients suffering from ND and other brain diseases can be interpreted. This review aims to compile and summarize the available data regarding TE levels in the different human brain regions of "normal" (non-diseased) individuals in order to contribute to the establishment of robust reference values. Fifty-four studies, published since 1960, were considered. The results showed a great variability between different studies. The potential sources of this variability are discussed. The need for increased harmonization of experimental strategies is highlighted in order to improve the comparability of the data obtained.

Iodine levels in different regions of the human brain.

BACKGROUND: Iodine is a key component of the thyroid hormones thyroxine (T4) and triiodothyronine (T3), which are crucial for proper growth and development of the human body. In particular, a great body of literature has been published on the link between thyroid hormones and brain development and functioning. However, there is a lack of knowledge on the iodine levels in the human brain. The aim of this work was to determine the brain iodine levels and to contribute to the establishment of "reference" levels for iodine in the different anatomical and functional regions of normal (i.e., subjects without neurological or psychiatric diseases) human brain. METHODS: The iodine levels were determined in 14 brain regions of 52 dead subjects without evidence of neurological or psychiatric disease (n = 728 samples). Iodine was extracted from brain samples using a standard procedure and determined by inductively coupled plasma - mass spectrometry (ICP-MS). RESULTS: Four subjects presented abnormally high brain iodine levels (26.0 ±â€¯14.2 µg/g) and were excluded from the overall data analysis. The average brain iodine levels for the remaining 48 subjects was 0.14 ±â€¯0.13 µg/g dry weight. Iodine showed very heterogeneous distribution across the different brain regions, with the frontal cortex, caudate nucleus and putamen showing the highest levels. Interestingly, these brain regions are closely related to cognitive function. Iodine levels also showed a tendency to increase with age. The high levels observed in four subjects seemed to be related to previous exposure to iodine-based contrast agents widely used in radiology and computed tomography exams. CONCLUSIONS: This paper provides important data on iodine levels at different brain regions in "normal" people, which can be used to interpret eventual imbalances in subjects with mental disorders and neurodegenerative diseases.

GC determination of acetone, acetaldehyde, ethanol, and methanol in biological matrices and cell culture.

A gas chromatography with flame ionization detection method (GC-FID) with direct injection, using a capillary column, was validated to determine ethanol, acetaldehyde, methanol, and acetone in different human matrices, such as whole blood, vitreous humour, and urine, with clinical and forensic interest. This method was also employed to quantify these compounds in cell culture medium, thus being useful in basic research. A good peak resolution was achieved, with linear correlation between concentration and peak areas for all the compounds in all the matrices. The inter- and intra-day precisions of the method were always under 15% and 10%, respectively. The accuracy of the method, calculated as the percentage of the target concentration, was within the acceptable limits. The obtained limits of detection were below 0.85 mg/L for acetaldehyde and below 0.75 mg/L for the other considered compounds. The small injection volume and the high split ratios applied, allied to the high performance of the GC column, resulted in very good peak resolution and high sensitivities. This method is easy to perform, making it suitable for the routine of clinical biochemistry and forensic laboratories.

Genetics and criminal behaviour: recent accomplishments.

The past two decades have seen an explosion in research in the fields of violence and behavioural genetics. Advances in human genetics have raised the possibility that genetic mechanisms can explain various aspects of human criminal and aggressive behaviour. However, this new knowledge can pose enormous challenges concerning the moral and legal conceptions of free will and responsibility. This paper reviews the main aspects of behavioural genetics, focusing on criminal and aggressive behaviour and describes the most important genes known to influence this behaviour.

Metals transfer from tobacco to cigarette smoke: Evidences in smokers' lung tissue.

Tobacco use kills millions of people every year around the world. The current level of 11 metals in tobacco was determined and their transfer rate to cigarette smoke was calculated as the difference between the total metal content in cigarettes and the amount present in its ashes. The metals content was also determined in the lung tissue of smokers and non-smokers in order to evaluate the marks that smoking leaves in this tissue. Metals content in tobacco ranged from less than 1µg/g (Co, Cd, Pb, As and Tl) to several hundreds of µg/g (Al, Mn and Ba). The highest transfer rate from tobacco to cigarette smoke was found for Tl (85-92%) and Cd (81-90%), followed by Pb (46-60%) and As (33-44%). Significantly higher levels of As, Cd and Pb were found in the lung tissue of smokers compared to non-smokers, showing that smoking results in an increase of these metals in the lungs and that they contribute to the carcinogenic potential of cigarette smoke. This study presents important data on current metals content in tobacco and its transference to cigarette smoke and provides evidence of their accumulation in smokers' lung tissue.