Piercing the surface: A mechanical analysis of stabbing with household tools.

Estimating the applied power during a stabbing incident, or estimating the minimal force necessary to penetrate the body with a certain weapon is a challenging task in forensic practice. A thorough forensic evaluation of stabbing forces needs objective numerical experimental data. Stabbing tests of 12 different weapons - including knives, a pair of scissors, a fork, screwdrivers, a rasp, a corkscrew, and a utility knife blade - were performed with a Mecmesin MultiTest-dV material tester on pork loin and ballistic gel to estimate the stabbing forces and dynamics. Penetration force (Fp ) and maximal force (Fmax ) were recorded, and the registered force curves were analyzed. Fmax was 159.8-212.07 Newton (N), 30.56-30.58 N, 168.9-185.48 N for various knives; 171.39-190.43 N for the pair of scissors, 233.6 N for the fork; 532.65-562.65 N, 370.31-367.19 N and 314.51-432.89 N for various screwdrivers, 44.14-56.62 N for utility knife during pork loin stabbing. The butter knife, corkscrew and rasp were not able to penetrate the pork loin, and the curved fork bent during stabbing. The results prove that weapon characteristics greatly influence the force necessary for penetration. Maximal stabbing force depends mostly on tip sharpness, and the force sharply decreases after penetration occurs, which indicates that edge sharpness is not as important as tip characteristics during stabbing perpendicular to skin surface. The penetration force during stabbing with a pair of scissors is comparable to the penetration force of knives. Stabbing with screwdrivers generally needs larger force than average knives but depends greatly on screwdriver size.

Misconnected chest tube: An extremely unusual fatal complication of secondary pneumothorax.

A rare and fatal complication of suction drainage of secondary spontaneous pneumothorax is reported. The patient, likely by a mistake, arbitrarily connected the oxygen supply tube to the thoracic drain. The sharp increase of intrapleural pressure combined with the atmospheric intraalveolar environment caused diffuse lung injury and cardiopulmonary collapse without a direct lung injury. The conflicting interests of patient autonomy and patient safety require further consideration.

Simultaneous fatal poisoning of two victims with 4F-MDMB-BINACA and ethanol.

PURPOSE: Methyl-2-(1-(4-fluorobutyl)-1H-indazole-3-carboxamido)-3,3-dimethylbutanoate (4F-MDMB-BINACA) is a newly emerging synthetic cannabinoid receptor agonists (SCRA) first described in 2018 in both Europe and the United States. Two fatal cases are reported caused by simultaneous consumption of 4F-MDMB-BINACA and ethanol. METHODS: The victims were brothers who were both found deceased after consuming 4F-MDMB-BINACA and ethanol. Post-mortem toxicological analyses of blood and urine were carried out by supercritical fluid chromatography tandem mass spectrometry (SFC-MS/MS) and headspace gas chromatography with flame ionization detection (HS-GC-FID). RESULTS: The concentration of 4F-MDMB-BINACA in the postmortem blood was 2.50 and 2.34 ng/mL, and blood alcohol concentration was 2.11 and 2.49 g/L, respectively. CONCLUSION: According to the reported cases and reviews of the scientific literature, concurrent ethanol consumption should amplify the toxicity of SCRAs. The threshold SCRA concentration for fatal overdose can be estimated ng/mL level (0.37-4.1 ng/mL according to the reported cases) in cases in which 1.5-2.5 g/L of ethanol is present in the blood.

Forensic assessment of a life-threatening penetrating abdominal air gun injury.

Air guns are considered mostly harmless by the public opinion, but projectiles shot from common air guns can penetrate skin and thus able to cause severe, even life-threatening injury. The prevalence of air gun injuries is constantly high, but severe injuries occur rarely. Forensic evaluation of air gun injuries can be challenging since the shot wound characteristics produced by combustion in case of firearm injuries are missing. Despite these difficulties, the topic of air gun injuries is mostly overlooked in forensic literature, and there are no guidelines available which can help the assessment of specific cases. A case of an air gun injury is reported, where the projectile penetrated the abdominal wall and created multiple bowel injury. The complex assessment of all available information (macroscopic and microscopic appearance of entrance wound, types of injuries, CT findings, and crime scene reconstruction) helped to uncover the truth about the circumstances of the injury.

Application of 3D printing in assessment and demonstration of stab injuries.

In stabbing related fatalities, the forensic pathologist has to assess the direction of wound track (thus, the direction of the stabbing) and the weapon's possible characteristics by examining the stab wound. The determination of these characteristics can be made only with a high level of uncertainty, and the precise direction of the stabbing is often difficult to assess if only soft tissues are injured. Previously reported techniques used for the assessment of these wound characteristics have substantial limitations. This manuscript presents a method using today's easily accessible three-dimensional (3D) printing technology for blade-wound comparison and wound track determination. Scanning and 3D printing of knives is a useful method to identify weapons and determine the precise stabbing direction in a stabbing incident without compromising the trace evidence or the autopsy results. Ballistic gel experiment, and dynamic stabbing test experiments prove the method can be applied in safety, without compromising the autopsy results. Identification of the exact knife is not possible with complete certainty but excluding certain knives will decrease the number of necessary DNA examinations, hence it can lower the burden on forensic genetic laboratories. The method addresses many of the shortcomings of previously used methods of probe insertion or post-mortem CT. Insertion of the printed knife into the wound gives a good visual demonstration of the stabbing direction, thus easing the forensic reconstruction of the stabbing incident. After combining the 3D printing with photogrammetry, the achieved 3D visualization is useful for courtroom demonstration and educational purposes.

Fatal suicidal injury of a radiocephalic arteriovenous fistula.

A 59-year-old man was found dead in his living room. His body was covered with blood, but the only injury found was a 31-mm-long, transverse incision on the radial surface of the left forearm. Autopsy revealed that the injured vessel was an enlarged cephalic vein from a radiocephalic arteriovenous fistula (RC-AVF) that had been created 23 years before for hemodialysis. Cephalic vein injury is usually not fatal, but circumstantial evidence, autopsy, and histological findings suggested that hemorrhagic shock and death occurred within a short time after the self-inflicted incised wound. This may be explained by the blood flow rate in the RC-AVF, which can reach 12 ml/s; this is 25 times higher than the normal cephalic vein blood flow.

Lethal case of myocardial ischemia following overdose of the synthetic cannabinoid ADB-FUBINACA.

The serious adverse effects of synthetic cannabinoids (SCB), the lack of human pharmacological data on SCBs, and the increasing number of SCBs with diverse structures are growing public health concerns. A fatal case of myocardial ischemia after ADB-FUBINACA overdose is reported. A 41-year-old male died after consuming a brown, powder-like drug. Autopsy revealed pallor in the left ventricle of the subendocardial two-third of the myocardium, and histological examination revealed early signs of myocardial ischemia: few wavy myocardial fibers, contraction band necrosis in the subendocardial region, and patchy subendocardial complement component 9 (C9) positivity. Toxicological analysis detected a high concentration of the indazole carboxamide derivative SCB ADB-FUBINACA (peripheral blood: 105 ng/mL) and a low concentration of the synthetic cathinone (SC) derivative stimulant N-ethylpentylone (NEP). The literature concerning ADB-FUBINCA overdoses is reviewed, and the possible mechanism of death and the cardiac effects of SCBs are discussed. Effects of SCBs are unpredictable, but they are potentially cardiotoxic, capable causing arrhythmias, cardiac hypertrophies, and myocardial ischemia. The cardiotoxicity of SCBs can be attributed to vasospasms, decreased myocardial contractility, and increased cardiac workload and oxygen demand. Based on the autopsy, histology, and toxicology, it could be reasonably suggested, that ADB-FUBINACA have been a significant contributor to the myocardial ischemia seen in histology. The mechanism of death was likely fatal arrhythmia induced by the patchy myocardial ischemia. Due to the low concentration of NEP, it's role in the fatal outcome is improbable.

An unusual case of suicide: Near decapitation by a modified table saw.

Table saws are dangerous tools able to create severe injuries. In accidental injuries, the most commonly injured body parts are fingers (85.9%) while amputations occur in 10% of cases. Accidental neck or head injuries account for only 3.1% of all injuries. Table saws cause nearly half of all saw-related amputations. There are approximately 30,000 cases of table saw-related injuries in the United States annually, but only a few table saw-related suicides have been reported in the scientific literature. In regard to suicides, usually the head or the neck is targeted. Usually, only the soft tissues of the neck are injured because the blade height limits the cutting depth and the victim falls down from the table saw before complete transection. A rare case of suicide committed by a modified table saw that resulted in near decapitation is presented. Previously reported cases of suicides by table saw are also reviewed.

Application of photogrammetry in forensic pathology education of medical students in response to COVID-19.

As the coronavirus disease 2019 (COVID-19) pandemic forced universities to switch to distance online education, there was an urgent need to find some virtual/digital alternatives in order to continue teaching. Opportunities such as watching pre-recorded autopsy videos or creating and analyzing post-mortem computed tomography or magnetic resonance imaging with various 3D surface imaging techniques are usually time-consuming and cost-intensive. Photogrammetry, which allows the creation of 3D textured surface models from a series of overlapping photographs taken from varying viewpoints, is a less common approach compared with post-mortem imaging. We created 3D autopsy case models for a special online forensic pathology course in which students could try the models. Then, formal feedback was requested regarding the possible application of this method in education. Most of the students were satisfied with the new method and ranked photogrammetry higher than the other available methods. Our results indicate that photogrammetry has a high potential in undergraduate education, especially in the case of distance education or in those countries where declining autopsy rates have resulted in a decline in the use of the autopsy as an educational tool. Photogrammetry can also be used as a supplementary tool in traditional autopsy-based education and has potential applications in various fields of medical education.

The effect of hepatic steatosis and fibrosis on liver weight and dimensions.

The liver is the most commonly injured abdominal organ, accounting for around half of abdominal organ injuries. The emergence of liver injury is determined by the injury mechanism, force, and tissue vulnerability. The vulnerability of the liver depends on the strength of the capsule and parenchyma, as well as the weight and dimensions of the liver. The common hepatic diseases, like steatosis, fibrosis, and cirrhosis, can change the organ weight and dimensions, but their exact correlation is not well known. This study was designed to evaluate the correlation between liver diseases, weight, and dimensions. The liver weight, horizontal, vertical, and antero-posterior length were measured obtained by 213 forensic autopsies. The recorded data were compared with body height, age, and liver histology. Body height positively correlated with liver weight (R2 = 0.252), but the correlation was much stronger in the case of livers without structural disease (R2 = 0.450). The liver size seems to significantly decrease with age (R2 = 0.081), but the effect is mostly due to structural alterations that are proven by histology. The comparison of the liver weight in various histological groups clearly indicated that steatosis increases the liver size, but fibrosis does not (if no steatosis is present at the same time). In general, liver dimensions increase proportionally to the liver weight. However, hepatic steatosis causes disproportional enlargement: it does not have a significant effect on the horizontal dimension and has only a minor effect on the vertical dimension. Steatosis affects disproportionally the dimensions with a strange tendency to expand liver anteroposteriorly.

The effect of steatosis and fibrosis on blunt force vulnerability of the liver.

The aim of our study was to examine the possible effect of steatosis and fibrosis on the blunt force vulnerability of human liver tissue. 3.5 × 3.5 × 2-cm-sized liver tissue blocks were removed from 135 cadavers. All specimens underwent microscopical analysis. The tissue samples were put into a test stand, and a metal rod with a square-shaped head was pushed against the capsular surface. The force (Pmax) causing liver rupture was measured and registered with a Mecmesin AFG-500 force gauge. Six groups were formed according to the histological appearance of the liver tissue: intact (group 1), mild steatosis (group 2), moderate steatosis (group 3), severe steatosis (group 4), fibrosis (group 5), and cirrhosis (group 6). The average Pmax value was 34.1 N in intact liver samples (range from 18.1 to 60.8 N, SD ± 8.7), 45.1 N in mild steatosis (range from 24.2 to 79.8 N SD ± 12.6), 55.4 N in moderate steatosis (range from 28.9 to 92.5 N, SD ± 16.0), 57.6 N in severe steatosis (range from 39.8 to 71.5 N, SD ± 11.9), 63.7 N in fibrosis (range from 37.8 to 112.2 N, SD ± 19.5), and 87.1 N in the case of definite cirrhosis (range from 52.7 to 162.7 N, 30.3). The Pmax values were significantly higher in samples with visible structural change than in intact liver sample (p = 0.023, 0.001, 0.009, 0.0001, 0.0001 between group 1 and groups 2 to 6 respectively). Significant difference was found between mild steatosis (group 2) and cirrhosis (group 6) (p = 0.0001), but the difference between mild, moderate, and severe steatosis (groups 2, 3, and 4) was not significant. Our study demonstrated that contrary to what is expected as received wisdom dictates, the diseases of the parenchyma (steatosis and presence of fibrosis) positively correlate with the blunt force resistance of the liver tissue.

Brain death of an infant caused by a penetrating air gun injury.

Air guns are shooting projectiles (pellets) from the expansion of compressed air without involving any chemical reactions. Air guns are often regarded as harmless by the public, but these weapons can produce severe, sometimes lethal injuries, especially in children. A case of a penetrating head injury of an eleven-month-old infant, caused by an ordinary air gun pellet, is presented. The air gun pellet created an exceptionally severe brain injury, and brain death. The factors influencing the severity of air gun injuries - muzzle velocity, muzzle energy, skull thickness - are discussed.

Suicide by Intentional Air embolism.

Venous air embolism occurs when air enters the venous system. The main causes of venous air embolism include medical procedures, neck and head trauma, and injuries of the genitals. Self-induced suicidal (and intentional) air embolism is extremely rare. The authors report a rare case of a suicidal air embolism committed using a self-made tool composed of a plastic bottle and an infusion set, injecting nearly 2000 mL of air into the cubital vein. The toxicological analysis suggested that midazolam, together with air, was also injected into the circulation using the same bottle and infusion set.

[An extremely rare cause of bilateral tension pneumothorax]. / Különleges eredetu feszülo légmell.

CASE REPORT: A middle-aged man presented with the diagnosis of typical spontaneous pneumothorax in the left chest. His management was initiated as usual with a chest drain and he had an uneventful recovery with good expansion of the affected lung up until the third postoperative day. But due to a fatal accident, the patient connected the oxygene supply tube into his thoracic drain. This high pressure caused a left, and a consequent bilateral pneumothorax with massive subcutanous emphysema, being the cause of a preterminal status. Cardio-pulmonary resuscitation was unsuccesfull and the patient died. Intentional suicide was excluded by forensic investigations. DISCUSSION: According to our knowledge, no similar case with this mechanism of tension pnemuthorax has been published in the literature so far. The pathophysiology is similar to lung damage due to high-pressure ventillation with consecutive tension pneumothorax.