Blunt liver injury with intact ribs under impacts on the abdomen: a biomechanical investigation

Elucidating the hepatoprotective mechanisms of cholic acid against CCl4-Induced acute liver injury: A transcriptomic and metabolomic study

ETHNOPHARMACOLOGICAL RELEVANCE

Cholic acid (CA) is one of the main active ingredients in Calculus Bovis, a traditional Chinese medicine, which helps to regulate the heart and liver meridians, clearing the heart, opening the mouth, cooling the liver and calming the wind. However, the molecular mechanism of its liver protective effect is still unclear.

AIM OF THE STUDY

Growing attention has been directed towards traditional Chinese medicine (TCM), particularly Calculus Bovis, as a potential solution for liver protection. Despite this interest, a comprehensive understanding of its hepatoprotective mechanisms remains lacking. This research seeks to explore the potential protective properties of cholic acid (CA) against CCl4-induced acute liver injury (ALI) in mice, while also examining the mechanisms involved.

MATERIALS AND METHODS

In the experiment, a mouse model was employed to ALI using CCl4, and the potential therapeutic effects of orally administered CA at varying doses (15, 30, and 60 mg/kg) were assessed. The study employed a multi-faceted approach, integrating liver transcriptomics with serum metabolomics, and conducting thorough analyses of serum biochemical markers and liver histopathological sections.

RESULTS

Oral CA administration markedly reduced the organ indices of the liver, spleen, and thymus in comparison with the model group. It also elevated the expression of superoxide dismutase (SOD) in serum while diminishing the concentrations of ALT, AST, MDA, IL-6, and TNF-α. Moreover, CA ameliorated the pathological damage induced by CCl4. Integrated metabolomic and transcriptomic analyses indicated that the hepatoprotective action of CA on ALI is mediated through the modulation of lipid metabolic pathways-specifically, metabolisms of glycerophospholipid, arachidonic acid, as well as linoleic acid-and by altering the expression of genes such as Ptgr1, PLpp1, Tbxas1, and Cyp2c37.

CONCLUSIONS

The current investigation offers insights into the hepatoprotective mechanisms by which CA mitigates ALI caused by CCl4 exposure, thus supporting the further evaluation and development of CA-based therapeutics for ALI.

Impact of Stoma Baseplate Convexity on Tension and Compression Around the Stoma Site: A Finite Element Analysis

For patients living with intestinal or urinary stomas, skin barriers play an essential role in protecting the peristomal skin and preventing peristomal complications. Convex baseplates press into the peristomal skin and are suitable for retracted stomas that do not protrude, peristomal skin with creases, folds, or dips, and stomas where frequent leaking can occur with flat pouching systems. However, there is a lack of data on the magnitude and location of tension applied to the abdomen by convex baseplates. We evaluated the impact of a range of convex baseplates applied to a simulated stoma site. A comparative finite element analysis investigation was conducted to evaluate the impact of eight different convex stoma system baseplates applied to an idealised flat abdomen, representing skin, subcutaneous tissue, and musculature layers. The baseplates considered had varying convexity with depths of 3.5 mm and 7 mm and internal structural diameters between ~30 mm and ~60 mm. The convex product range provided tension in the skin (maximum principal strain) and compression through the fat layer (minimum principal strain). Large differences in the locations and magnitudes of skin tension and fat layer compression were seen between the baseplates under analysis, with both the depth and diameter of convexity influencing the strain experienced across the abdominal topography. The results generated highlight the importance of having an appropriate range of convexity products available and selecting an appropriate option for use based on the stoma type and condition of the peristomal skin.

Assessment of Frequency, Patterns, and Causes of Blunt Abdominal Trauma in a North Indian Cohort: An Autopsy-Based Study

Introduction The abdomen is one of the most frequently damaged areas in trauma patients and is commonly encountered in road traffic accidents (RTAs). The present study evaluates the frequency, etiology, causation, and form of injury in blunt abdominal trauma (BAT) cases who had autopsies. Method An autopsy-based observational prospective study was conducted at the Department of Forensic Medicine and Toxicology, Nalanda Medical College and Hospital Patna, India, during the period from October 2018 to September 2020, which included a total of 940 autopsy cases showing blunt abdominal injuries. A predesigned proforma for the postmortem evaluation of BAT victims was used to collect the required information on the cases. Descriptive statistics were performed, and the data were presented as frequency (%) and mean±SD. Chi-square tests were performed to compare categorical variables between groups. Results BAT accounted for 120 (12.76%) cases of all autopsies performed. The majority of victims were male (92.48%). Victims aged 21-30 years (31, 25.83%) were the ones most usually engaged in BAT cases. Among the mechanisms accountable for BAT, RTAs were the most common (99, 82.50%), followed by assault (16, 13.30%). In most of the cases, the liver was injured (107, 89.16%), followed by the spleen (60, 50.00%) and kidney (24, 20.00%). The majority of blunt abdominal injury-related deaths were accidental (100, 83.33%), followed by homicidal (15, 12.5%) and suicidal cases (5, 4.17%). Hemorrhage and neurogenic shock were the most prevalent causes of mortality, particularly if the individual died within a few hours. Conclusion RTAs are the most frequent cause of BAT in autopsy cases, and the liver is the most affected organ. The majority of deaths occur within the first 24 hours of injury. Since blunt abdominal injuries have the propensity to increase morbidity and mortality, appropriate emphasis on their precise diagnosis and satisfactory therapy is mandated.

Patho-mechanical comparative morpho-characterization of contre-coup injuries of liver by cadaveric experimental simulation for medico-legal and forensic implications

BACKGROUND

Liver is the most common organ to get injured in cases of blunt force trauma to the abdomen (BFTA). It is the 2nd commonest organ after brain to sustain injuries out of all the trauma related fatalities. However, the literature about contre-coup injuries to the liver due to BFTA is scarce in-spite of the high mortality rates seen out of injury to this particular organ.

PURPOSE

The authors intended to systematize the characteristic morphogenesis of the contre-coup injuries of the liver on the basis of the patho-mechanics involved in various types of BFTA.

METHODOLOGY

One hundred and sixty three cases of BFTA were identified, and interpretation was attempted for the contre-coup rupture of the liver seen in twenty out of all the trauma related fatalities that presented for post-mortem examination during the study period. However, the mechanics of the pattern of the rupture injuries to the liver were indiscernible. This motivated the authors to conduct the comparative characterization of injuries to the liver by experimental simulation of BFTA after necessary permission via inflicting pre-calculated forces on unclaimed cadavers.

RESULTS

The patterns of contre-coup rupture/s of liver were established in all the twenty-eight out of one sixty-three cases of BFTA. The rupture depicted patterns of injury in the situations of - 1) strong hits with a limited surface trauma, 2) very strong hits with a generalized surface trauma, 3) and collision with a solid surface resulting due to fall onto the side of the abdomen. The causative mechanism discerned was deformation of the liver, followed by its parenchymal rupture due to the shear and strain types of force/s consequent upon tissue compression. The minimum force and energy of impact required for the liver to rupture was estimated to be 2000 N and 141.5 J.

CONCLUSION

This series of the simulation experiments revealed two variants of liver rupture in the contre-coup impact zone. The pattern of injury was maintained in cases, those studied at post-mortem examinations, but the relief ruptures were found to vary depending upon the overall mechanics of the traumatic forces involved in the simulation experiments performed on the cadavers. The anti-shock ruptures were formed during shock trauma, and shockproof ruptures were not seen in cases of underlying compressive forces. The morphogenetic characterization of the relief rupture surface of the liver was also delineated in relation to its surface orientation to the spine on the basis of the terms "large" and "very large" depicting the quantum of force/s delivered out of an impact or blow.

Location of liver lacerations resulting from deceleration injuries and a proposal for their classification

<b>Aim:</b> The aim of the study was to verify during forensic autopsies the occurrence of liver lacerations resulting from deceleration traumas in the locations reported in professional literature, and also to check whether they are located near the left coronary ligament and its extension, i.e. the left triangular liver ligament. </br></br> <b> Methods:</b> The liver injuries were assessed on the base of cases of forensic autopsies, performed at the Department of Forensic Medicine of the Medical University of Lodz from 1^st September 2011 to 15^th April 2014. In order to analyze the collected data, descriptive methods and statistical inference methods were used. </br></br> <b>Results:</b> Three types of liver rupture turned out to be characteristic and statistically significant: 1 – on the diaphragmatic surface of the right lobe between its two sectors; 2 – within the left lobe to the right (in segment IV) or to the left (in segment III) of the falciform ligament; 3 – located near the left coronary ligament (in segment II). </br></br><b> Conclusion:</b> Typical location of liver lacerations after deceleration trauma, i.e. the right triangular ligament and falciform ligament, are confirmed in the analysed autopsy material. The place not previously described in the literature, which should be regarded as a characteristic location of a liver rupture after deceleration trauma is the diaphragmatic surface of segment II of the left lobe.

Current state and progress of research on forensic biomechanics in China

Forensic biomechanics gradually has become a significant component of forensic science. Forensic biomechanics is evidence-based science that applies biomechanical principles and methods to forensic practice, which has constituted one of the most potential research areas. In this review, we introduce how finite element techniques can be used to simulate forensic cases, how injury criteria and injury scales can be used to describe injury severity, and how tests of postmortem human subjects and dummy can be used to provide essential validation data. This review also describes research progress and new applications of forensic biomechanics in China.Key pointsThe review shows the main research progress and new applications of forensic biomechanics in China.The review introduces eight cases about the application of forensic biomechanics, including the multiple rigid body reconstruction, the finite element applications, study of mechanical properties, traffic crash reconstruction based on multiple techniques and analysis of morphomechanical mechanism about blood dispersal.Though forensic biomechanics has a great advantage for the evaluation of injury mechanisms, it still has some uncertainties owing to the uniqueness of the human anatomy, the complexity of biological materials, and the uncertainty of injury-causing circumstances.

[Mechanism of blunt spleen injury: a finite element analysis]

OBJECTIVE

To explore the biomechanical mechanism of blunt spleen injury based on finite element analysis.

OBJECTIVE

A fist finite element model was used to simulate the impact at 4-8 m/s in the spleen area of THUMS4.0 human body model from the front of the left costal area, the left anterior axillary line and the rear scapular line. The strain distribution and damage of the spleen under different conditions were observed. The simulation results were compared with the clinical cases of spleen rupture to analyze the mechanism of spleen injury.

OBJECTIVE

The damage location and strain distribution of the spleen could vary under different conditions. Due to the special anatomical location of the spleen, a blunt impact at the speed of 4-8 m/s on the front side did not easily cause spleen injury, and the strain was distributed mainly in the front of the spleen and the spleen hilum; a similar blunt impact on the left side was likely to cause spleen diaphragmatic surface injury, the splenic visceral surface could be injured by the compression of the medial tissue and organs and the traction of the splenic pedicle, and the strain was distributed in the spleen diaphragmatic and visceral surfaces; an impact on the back side was likely to cause injuries in the posterior portion and hilum of the spleen, and the strain was mainly concentrated in the injured area.

OBJECTIVE

Blunt spleen injuries caused by punches on the abdomen are mostly caused by direct impact on the ribs, the compression by the surrounding tissues and organs and the traction by the spleen pedicle.

Contrecoup Injury associated with Fatal Portal Vein Bleeding: A Case Report

A 64-year-old male visited our emergency department due to severe right flank pain after falling from a 2-meter height. Contrast-enhanced CT revealed a right hemothorax with multiple fractures in the right ribs and iliac bone. A small hematoma in the right perihepatic space was noted, but there was no hepatic laceration on CT. Initial surgical management led to continuous uncontrolled bleeding around the porta hepatis, and subsequent arterial angiography could not demonstrate a bleeding focus. However, immediate follow-up CT showed contrast extravasation on the left side of abdomen, and a percutaneous transhepatic portal venogram revealed active bleeding from the left portal vein. Although the wound was embolized with a glue, the patient suffered from a cardiac arrest and finally expired. In conclusion, during evaluation of abdominal trauma patients, portal vein bleeding and contrecoup injuries should be considered when hepatic arteriography findings are nremarkable.

Biomechanical properties of abdominal organs under tension with special reference to increasing strain rate

Currently, abdominal finite element models overlook the organs such as gallbladder, bladder, and intestines, which instead are modeled as a simple bag that is not included in the analysis. Further characterization of the material properties is required for researchers to include these organs into models. This study characterized the mechanical properties of human and porcine gallbladder, bladder, and intestines using uniaxial tension loading from the rates of 25%/s to 500%/s. Small differences were observed between human and porcine gallbladder elastic modulus, failure stress, and failure strain. Strain rate was determined to be a significant factor for predicting porcine gallbladder elastic modulus and failure stress which were found to be 9.03 MPa and 1.83 MPa at 500%/s. Human bladder was observed to be slightly stiffer with a slightly lower failure stress than porcine specimens. Both hosts, however, demonstrated a strain rate dependency with the elastic modulus and failure stress increasing as the rate increased with the highest elastic modulus (2.16 MPa) and failure stress (0.65 MPa) occurring at 500%/s. Both human and porcine intestines were observed to be affected by the strain rate. Failure stress was found to be 1.6 MPa and 1.42 MPa at 500%/s for the human and porcine intestines respectively. For all properties found to be strain rate dependent, a numerical model was created to quantify the impact. These results will enable researchers to create more detailed finite element models that include the gallbladder, bladder, and intestines.

A METHOD TO CALCULATE THE AIS TRAUMA SCORE FROM A FINITE ELEMENT MODEL

In the real world, traumatic injuries are measured using the Abbreviated Injury Scale (AIS), however, such a scale cannot be computed to date or the injury precisely located by using human computer models. These models use stresses and strains to evaluate whether serious or fatal injuries are reached, which unfortunately bear no direct relation to AIS. This paper proposes to overcome this deficiency and suggests a unique Organ Trauma Model (OTM) able to calculate the risk to life of any organ injury, focussing in this case on real-life pedestrian head injuries. The OTM uses a power method, named Peak Virtual Power (PVP), and defines a brain white and gray matters trauma response as a function of impact direction and impact speed. The OTM was tested against four real-life pedestrian accidents and proved to predict the head trauma severity and location. In some cases, the method did however under-estimate the trauma by 1 AIS level because of post-impact haemorrhage which cannot be captured with Lagrangian Finite Element solvers. The OTM has the potential to create an important advance in vehicle safety by adding more information on the risk of head trauma.

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.

Quantitative Analysis of Tissue Damage Evolution in Porcine Liver With Interrupted Mechanical Testing Under Tension, Compression, and Shear

In this study, the damage evolution of liver tissue was quantified at the microstructural level under tensile, compression, and shear loading conditions using an interrupted mechanical testing method. To capture the internal microstructural changes in response to global deformation, the tissue samples were loaded to different strain levels and chemically fixed to permanently preserve the deformed tissue geometry. Tissue microstructural alterations were analyzed to quantify the accumulated damages, with damage-related parameters such as number density, area fraction, mean area, and mean nearest neighbor distance (NND). All three loading states showed a unique pattern of damage evolution, in which the damages were found to increase in number and size, but decrease in NND as strain level increased. To validate the observed damage features as true tissue microstructural damages, more samples were loaded to the above-mentioned strain levels and then unloaded back to their reference state, followed by fixation. The most major damage-relevant features at higher strain levels remained after the release of the external loading, indicating the occurrence of permanent inelastic deformation. This study provides a foundation for future structure-based constitutive material modeling that can capture and predict the stress-state dependent damage evolution in liver tissue.

State of the art in post-mortem forensic imaging in China

The autopsy and histopathologic examination are traditional and classic approaches in forensic pathology. In recent years, with the tremendous progresses of computer technology and medical imaging technology, the developed post-mortem computer tomography, post-mortem magnetic resonance imaging and other new methods provide non-invasive, intuitive, high-precision examining methods and research tools for the forensic pathology. As a result, the reconstruction of the injury as well as the analysis of injury mechanism has been essentially achieved. Such methods have become popular in the research field of forensic science and related work has also been carried out in China. This paper reviews the development and application of abovementioned post-mortem forensic imaging methods in China based on the relevant literature.

Radiological findings in an ancient Iranian salt mummy (Chehrābād ca. 410-350 BC)

OBJECTIVE

To study pathologies, peri- and postmortal alterations as well as the general preservation state of an ancient Iranian salt mummy.

MATERIALS AND METHODS

Several mummified remains from two different time periods (1500-2500 BP) were found in the Chehrābād salt mine in Iran. Computed tomography was performed on Salt Man #4 (410-350 BC), the best preserved out of the six salt mummies (Siemens, Sensation 16; 512 × 512 matrix; 0.75-5 mm slice thickness, 240-mA tube current, 120-kV tube voltage, and 0.976-mm pixel size).

RESULTS

Radiological analyses showed an excellent state of preservation of an adolescent body. Several normal variants such as aplasia of the frontal sinus as well as a rare congenital deformation of the 5th vertebral body (butterfly vertebra) have been observed. The individual shows multiple fractures, which is consistent with the theory that he died due to a collapse in the ancient salt mine.

CONCLUSIONS

The salt preserved the soft tissue as well as parts of the inner organs remarkably well. However, further investigations including histology are needed to reveal additional details of the health status of this unique salt mummy.

Comparison of gunshot entrance morphologies caused by .40-caliber Smith & Wesson, .380-caliber, and 9-mm Luger bullets: a finite element analysis study

Firearms can cause fatal wounds, which can be identified by traces on or around the body. However, there are cases where neither the bullet nor gun is found at the crime scene. Ballistic research involving finite element models can reproduce computational biomechanical conditions, without compromising bioethics, as they involve no direct tests on animals or humans. This study aims to compare the morphologies of gunshot entrance holes caused by.40-caliber Smith & Wesson (S&W), .380-caliber, and 9×19-mm Luger bullets. A fully metal-jacketed.40 S&W projectile, a fully metal-jacketed.380 projectile, and a fully metal-jacketed 9×19-mm Luger projectile were computationally fired at the glabellar region of the finite element model from a distance of 10 cm, at perpendicular incidence. The results show different morphologies in the entrance holes produced by the three bullets, using the same skull at the same shot distance. The results and traits of the entrance holes are discussed. Finite element models allow feasible computational ballistic research, which may be useful to forensic experts when comparing and analyzing data related to gunshot wounds in the forehead.

The severity of liver injury following blunt trauma does not correlate with the number of fractured ribs: an analysis of a national trauma registry database

PURPOSE

Rib fractures are a marker of severe injury, predicting a higher incidence of associated injuries. The purpose of this study was to assess whether an increasing number of rib fractures predicts the severity of liver injury in blunt trauma patients.

METHODS

We performed a retrospective cohort study involving blunt trauma patients with concomitant liver injuries and rib fractures who were registered in a national trauma registry.

RESULTS

Of 57,130 patients with blunt torso injuries, 14,651 patients sustained rib fractures, and 2,899 patients suffered liver injuries. Concomitant liver injury occurred in 1,087 of the patients with rib fractures (7.4%), while 1,812 patients sustained liver injury without rib fractures (4.3%). The presence of six or more rib fractures predicted a higher incidence of liver injury. Among the patients with liver injury, those with concomitant rib fractures had a higher Injury Severity Score (ISS), but similar mortality rates. Among the patients with concomitant rib fractures and liver injury, there was no relationship between the number of fractured ribs and the severity of the liver injury.

CONCLUSIONS

Although the presence of rib fractures was associated with an increased probability of liver injury in patients with blunt torso trauma, there is no relationship between the number of fractured ribs and the severity of liver injury.

Abdominal Organ Location, Morphology, and Rib Coverage for the 5(th), 50(th), and 95(th) Percentile Males and Females in the Supine and Seated Posture using Multi-Modality Imaging

The purpose of this study was to use data from a multi-modality image set of males and females representing the 5(th), 50(th), and 95(th) percentile (n=6) to examine abdominal organ location, morphology, and rib coverage variations between supine and seated postures. Medical images were acquired from volunteers in three image modalities including Computed Tomography (CT), Magnetic Resonance Imaging (MRI), and upright MRI (uMRI). A manual and semi-automated segmentation method was used to acquire data and a registration technique was employed to conduct a comparative analysis between abdominal organs (liver, spleen, and kidneys) in both postures. Location of abdominal organs, defined by center of gravity movement, varied between postures and was found to be significant (p=0.002 to p=0.04) in multiple directions for each organ. In addition, morphology changes, including compression and expansion, were seen in each organ as a result of postural changes. Rib coverage, defined as the projected area of the ribs onto the abdominal organs, was measured in frontal, lateral, and posterior projections, and also varied between postures. A significant change in rib coverage between postures was measured for the spleen and right kidney (p=0.03 and p=0.02). The results indicate that posture affects the location, morphology and rib coverage area of abdominal organs and these implications should be noted in computational modeling efforts focused on a seated posture.