Micro-CT features of intermediate gunshot wounds severely damaged by fire.

Incineration or extensive burning of the body, causing changes in the content and distribution of fluids, fixation and shrinking processes of tissues, can alter the typical macroscopic and microscopic characteristics of firearm wounds, hampering or at least complicating the reconstruction of gunshot fatalities. The present study aims at evaluating the potential role of micro-computed tomography (micro-CT) for detecting and quantifying gunshot residue (GSR) particles in experimentally produced intermediate-range gunshot wounds severely damaged by fire. Eighteen experimental shootings were performed on 18 sections of human calves surgically amputated for medical reasons at three different firing distances (5, 15 and 30 cm). Six stab wounds produced with an ice pick were used as controls. Each calf section underwent a charring cycle, being placed in a wood-burning stove for 4 min at a temperature of 400 °C. At visual inspection, the charred entrance wounds could not be differentiated from the exit lesions and the stab wounds. On the contrary, micro-CT analysis showed the presence of GSR particles in all burnt entrance gunshot wounds, while GSR was absent in the exit and stab wounds. The GSR deposits of the firearm lesions inflicted at very close distance (5 cm) were mainly constituted of huge particles (diameter >150 µm) with an irregular shape and well-delineated edges; at greater distances (15 and 30 cm), agglomerates of tiny radiopaque particles scattered in the epidermis and dermis layers were evident. Statistical analysis demonstrated that also in charred firearm wounds the amount of GSR roughly correlates with the distance from which the gun was fired. The obtained results suggest that micro-CT analysis can be a valid screening tool for identifying entrance gunshot wounds and for differentiating firearm wounds from sharp-force injuries in bodies severely damaged by fire.

Social grasping: from mirroring to mentalizing.

Because the way we grasp an object varies depending on the intention with which the object is grasped, monitoring the properties of prehensile movements may provide access to a person's intention. Here we investigate the role of visual kinematics in the implicit coding of intention, by using functional brain imaging while participants observed grasping movements performed with social versus individual intents. The results show that activation within the mirror system is stronger during the observation of socially intended movements relative to individual movements. Moreover, areas that form the mentalizing system are more active during social grasping movements. These findings demonstrate that, in the absence of context information, social information conveyed by action kinematics modulates intention processing, leading to a transition from mirroring to mentalizing.

MicroCT detection of gunshot residue in fresh and decomposed firearm wounds.

Gunshot residue (GSR) evidence may be altered or obscured by after-death events such as putrefaction, autolysis, and/or damage by animals. The present study aimed at evaluating and comparing the amount and differential distribution of GSR utilizing microcomputed tomography (microCT) analysis of fresh and decomposed gunshot wounds. A total of 60 experimental shootings at three different firing distances (5, 15, and 30 cm) were performed on human calves surgically amputated for medical reasons. Thirty specimens (10 for each tested distance) were immediately formalin-fixed, while the other 30 specimens were enclosed in a cowshed for 15 days, before formalin fixation (air temperature ranging from 11°C to 38°C). MicroCT analysis with three-dimensional image reconstruction detected GSR particles in all the investigated entrance wounds. In fresh specimens, GSR was concentrated on the skin surface around the entrance hole and in the epidermis and dermis layers around the cavity, while in decomposed specimens, the high density particles were detected only in the dermis layer. No GSR was detected in exit wounds of both fresh and decomposed specimens regardless of the tested firing distance. Statistical analysis demonstrated that also in decomposed wounds the amount of GSR roughly correlated with the distance from which the gun was fired, exhibiting, however, a higher variability than in fresh samples. The obtained results suggest that microCT analysis can be a valid screening tool for differentiating decomposed entrance and exit gunshot wounds.

Estimation of the firing distance through micro-CT analysis of gunshot wounds.

Estimation of the firing range is often critical for reconstructing gunshot fatalities, where the main measurable evidence is the gunshot residue (GSR). In the present study intermediate-range gunshot wounds have been analysed by means of a micro-computed tomography (micro-CT) coupled to an image analysis software in order to quantify the powder particles and to determine the firing distance. A total of 50 shootings were performed on skin sections obtained from human legs surgically amputated for medical reasons. For each tested distance (5, 15, 23, 30 and 40 cm), firing was carried out perpendicularly at the samples using a 7.65-mm pistol loaded with jacketed bullets. Uninjured skin sections were used as controls. By increasing the firing distance, micro-CT analysis demonstrated a clear decreasing trend in the mean GSR percentage, particularly for shots fired from more than 15 cm. For distances under 23 cm, the powder particles were concentrated on the epidermis and dermis around the hole, and inside the cavity; while, at greater distances, they were deposited only on the skin surface. Statistical analysis showed a nonlinear relationship between the amount of GSR deposits and the firing range, well explained by a Gaussian-like function. The proposed method allowed a good discrimination for all the tested distances, proving to be an objective, rapid and inexpensive tool for estimating the firing range in intermediate-range gunshot wounds.

Adrenal vein sampling for primary aldosteronism: the assessment of selectivity and lateralization of aldosterone excess baseline and after adrenocorticotropic hormone (ACTH) stimulation.

BACKGROUND: Adrenal vein sampling is crucial for identifying the primary aldosteronism subtypes, but the cutoff values for ascertaining selectivity of catheterization and lateralization of aldosterone secretion remain controversial. OBJECTIVES: To investigate the safety of adrenal vein sampling, the cutoff values for the selectivity and lateralization indexes, and the effect of adrenocorticotropic hormone stimulation on selectivity index and lateralization index performance. DESIGN: We assessed the proportion of selective adrenal vein sampling at different selectivity index cutoff values in 151 consecutive patients with primary aldosteronism undergoing bilaterally simultaneous adrenal vein sampling. Aldosterone-producing adenoma was diagnosed on the basis of the evidence of primary aldosteronism and lateralized aldosterone secretion, adenoma at pathological examination, and normokalemia, and correction of primary aldosteronism and cure or improvement of hypertension at follow-up. In 44 patients with bilaterally selective adrenal vein sampling and unequivocal diagnosis of aldosterone-producing adenoma on the basis of all these criteria, we examined the cutoff values of the lateralization index for assessing the lateralization of aldosterone excess and the effect of adrenocorticotropic hormone stimulation on selectivity index and lateralization index. RESULTS: Adrenal vein rupture occurred in one case (0.7%). Bilaterally selective adrenal vein sampling decreased steadily (from 79.9 to 40.2%) with increase in the selectivity index cutoffs from 1.1 to 5.0. Likewise, the proportion of correctly identified aldosterone-producing adenomas decreased (from 95.5 to 43.2%) with increase in lateralization index cutoffs from 1.125 to 5.0. Adrenocorticotropic hormone improved the assessment of selectivity but exerted a confounding effect on lateralization index. CONCLUSION: Adrenal vein sampling is safe; increasing the selectivity index cutoffs lowers the number of usable adrenal vein samplings; higher lateralization index cutoff values lead to missing a proportion of aldosterone-producing adenomas. The improved selectivity rate provided by adrenocorticotropic hormone stimulation should be weighed against the loss of correct lateralization.

Porous alginate/poly(ε-caprolactone) scaffolds: preparation, characterization and in vitro biological activity.

In bone tissue engineering, scaffolds with controlled porosity are required to allow cell ingrowth, nutrient diffusion and sufficient formation of vascular networks. The physical properties of synthetic scaffolds are known to be dependent on the biomaterial type and its processing technique. In this study, we demonstrate that the separation phase technique is a useful method to process poly(ε-caprolactone) (PCL) into a desired shape and size. Moreover, using poly(ethylene glycol), sucrose, fructose and Ca2+ alginate as porogen agents, we obtained PCL scaffolds with three-dimensional porous structures characterized by different pore size and geometry. Scanning electron microscopy and porosity analysis indicated that PCL scaffolds prepared with Ca2+ alginate threads resemble the porosity and the homogeneous pore size distribution of native bone. In parallel, MicroCT analysis confirmed the presence of interconnected void spaces suitable to guarantee a biological environment for cellular growth, as demonstrated by a biocompatibility test with MC3T3-E1 murine preosteoblastic cells. In particular, scaffolds prepared with Ca2+ alginate threads increased adhesion and proliferation of MC3T3-E1 cells under basal culture conditions, and upon stimulation with a specific differentiation culture medium they enhanced the early and later differentiated cell functions, including alkaline phosphatase activity and mineralized extracellular matrix production. These results suggest that PCL scaffolds, obtained by separation phase technique and prepared with alginate threads, could be considered as candidates for bone tissue engineering applications, possessing the required physical and biological properties.

Diaphragmatic sulci and portal fissures.

Diaphragmatic sulci in the superior surface of the liver were found in 40% of cases at autopsy. All sulci were located in the right lobe and in 47% they were multiple. In order to evaluate possible predisposing factors for these accessory sulci, their topography and characteristics were observed in unfixed livers; moreover, intravenous injections of radio-opaque resins were performed in the portal and hepatic veins (HVs). After formalin fixation, the livers underwent CT and MR scans and a three-dimensional (3D) elaboration of the images was performed. Radiological examination revealed a correspondence between the topography of the sulci and the course of the right and middle HVs and their main tributaries in 67%. The corrosion casts showed the location of the sulci at the level of the boundaries between the ramifications of the terminal branches of the portal triad, where the HVs are located, in 73%. These findings suggest that, rather than the action of 'special' or hypertrophied muscle bundles, the pressure exerted by the diaphragm as a whole may be responsible for the production of sulci at the level of weak zones, represented by the portal fissures, where the watershed superficial hepatic parenchyma, owing to the absence of all but the smallest vascular branches, exhibits a lower resistance to external pressure.