Inhibition of monoamine oxidase B prevents reactive astrogliosis and scar formation in stab wound injury model.

Reactive astrocytes manifest molecular, structural, and functional alterations under various pathological conditions. We have previously demonstrated that the reactive astrocytes of the stab wound injury model (STAB) display aberrant cellular gamma-aminobutyric acid (GABA) content and tonic GABA release, whereas the active astrocytes under enriched environment (EE) express high levels of proBDNF. However, the role of monoamine oxidase B (MAO-B) in reactive astrogliosis and hypertrophy still remains unknown. Here, we investigate the role of MAO-B, a GABA-producing enzyme, in reactive astrogliosis in STAB. We observed that the genetic removal of MAO-B significantly reduced the hypertrophy, scar formation, and GABA production of reactive astrocytes, whereas the MAO-B overexpression under glial fibrillary acidic protein (GFAP) promoter enhanced the levels of GFAP and GABA. Furthermore, we found that one of the by-products of the MAO-B action, H2 O2 , but not GABA, was sufficient and necessary for the hypertrophy of reactive astrocytes. Notably, we identified two potent pharmacological tools to attenuate scar-forming astrogliosis-the recently developed reversible MAO-B inhibitor, KDS2010, and an H2 O2 scavenger, crisdesalazine (AAD-2004). Our results implicate that inhibiting MAO-B activity has dual beneficial effects in preventing astrogliosis and scar-formation under brain injury, and that the MAO-B/H2 O2 pathway can be a useful therapeutic target with a high clinical potential.

p75NTR Promotes Astrocyte Proliferation in Response to Cortical Stab Wound.

Astrogliosis after brain trauma can have a significant impact on functional recovery. However, little is known about the mechanisms underlying astrocyte proliferation and subsequent astrogliosis. In this study, we established a cortical stab wound injury mouse model and observed dramatic astrocyte activation and nerve growth factor receptor (p75NTR) upregulation near the lesion. We also found profound alterations in the cell cycle of astrocytes near the lesion, with a switch from a mitotically quiescent (G0) phase to the G2/M and S phases. However, no changes in the level of astrocyte apoptosis were observed. Cell cycle progression to the G2/M and S phases and CDK2 protein levels in response to cortical stab wound was inhibited after p75NTR knockdown in mouse astrocytes. Conversely, p75NTR overexpression in mouse astrocytes was sufficient in promoting cell cycle progression. In conclusion, our results suggested that p75NTR upregulation in astrocytes after brain injury induces cell cycle entry by promoting CDK2 expression and promoting astrocyte proliferation. Our findings provided a better understanding of astrocytic responses after cortical stab wound injury in mice.

An avenue to miscarriage: a case report.

Two men were wrongfully convicted of murder in 2017 and sentenced to life imprisonment. After a physical altercation inside a flat, the victim (A) was found dead approximately 60 m away outside a residential address. He had sustained a number of injuries including a stab wound to the left side of his neck which was found to have divided the right carotid artery. The location where A was found was not regarded as a crime scene and not subjected to a specialist forensic examination by scientists as it was assumed that the fatal injury was sustained in the flat. The pathologist, who subsequently carried out the autopsy on A, was not asked to attend the scene. A review of the blood distribution at the scene in conjunction with the pathology findings indicated however that the fatal neck wound had been inflicted outside the flat, near to where the victim was found. An appeal against the convictions for murder was upheld in 2021 and a re-trial ordered. Following this second trial, both accused were acquitted of murder and released from custody. The new pathology and blood pattern evidence introduced at the second trial was a major part of the defense strategy which led to the acquittal of the accused. The case illustrates that a more inclusive and detailed crime scene strategy had been undertaken, including an assessment of the bloodstains present, in conjunction with discussion with the pathologist, then the likelihood is that the two men subsequently charged with murder would have been eliminated as suspects and a miscarriage of justice would have been avoided.

Insights to enhance the examination of tool marks in human cartilage.

This work deals with the examination of tool marks in human cartilage. We compared the effectiveness of several cleaning methods on cut marks in porcine cartilage. The method cleaning by multiple casts achieved the significantly highest scores (P = 0.02). Furthermore, we examined the grain-like elevations (dots) located on casts of cut cartilage. The results of this study suggest that the casting material forms these dots when penetrating cartilage cavities, which are areas where the strong collagen fibres leave space for the chondrocytes. We performed fixation experiments to avoid this, without success. In addition, 31 casting materials were compared regarding contrast under light-microscope and 3D tool marks scanner. Under the light-microscope, brown materials achieved significantly higher values than grey (P = 0.02) or black (P = 0.00) whereas under the 3D scanner, black materials reached higher contrast values than grey (P = 0.04) or brown (P = 0.047). To compare the accuracy and reproducibility of 6 test materials for cartilage, we used 10 knives to create cut marks that were subsequently scanned. During the alignment of the individual signals of each mark, the cross-correlation coefficients (Xmax) and lags (LXmax) were calculated. The signals of the marks in agarose were aligned with significantly fewer lags and achieved significantly higher cross-correlation coefficients compared to all tested materials (both P = 0.00). Moreover, we determined the cross-correlation coefficients (XC) for known-matches (KM) per material. Agarose achieved significantly higher values than AccuTrans®, Clear Ballistics™, and gelatine (all P = 0.00). The results of this work provide valuable insights for the forensic investigation of marks in human costal cartilage.

Sharp force trauma with two katana swords: identifying the murder weapon by comparing tool marks on the skull bone.

This paper describes the variety of information that a tool mark analysis on human tissue can provide based on a case of multiple sharp violence. The perpetrator attacked the victim with a sharp-edged weapon against the head, leaving several deep wounds on the back of the skull bone. Three of those marks on the skull bone could be used for a forensic tool mark examination. Silicone casts of the marks were compared by light microscopy with casts of test marks of Japanese katana swords found at the crime scene. One of the swords could be identified as the one responsible for the marks. In addition, the marks and the test marks were scanned in 3D and examined in a visual on-screen comparison confirming the results from the light microscopic examination. Furthermore, a mathematical approach in which the signatures of the marks from the skull bone and the test marks from the sword were compared by cross correlation confirms those findings. In addition, the aforementioned results were used to determine the orientation of the sword in relation to the cranial bone at the time of the respective impact.

Unplanned Complex Suicide by Self-Stabbing and Rail Suicide: A Case Report and Review of Literature.

Investigation of a complex suicide is a challenging task, particularly when the combination of modalities adopted is rare and unplanned. There is often a significant likelihood of labeling the case as a homicide. We present an interesting case of unplanned complex suicide with self-stabbing and head injury resulting from intentionally being struck by a train. There were also hesitation cuts evident over the neck and left wrist. This case highlights the importance of studying the nature and characterization of the wounds, examination of clothes, and examination of the scene to safely conclude the cause and the manner of death.

Sharp bone trauma diagnosis: a validation study using epifluorescence microscopy.

Identifying tool mark and involved weapon in sharp force trauma is essential to understanding the circumstances of death. But accuracy and reliability of such expert testimony remains unknown, and validation studies are rare in forensic literature. That is why, we conducted an experiment in order to determine error rates and predictive values on identifying the right implement through different types of knife-inflicted trauma. Human bone cut marks were analysed through epifluorescence microscopy. The samples were examined through a randomised, blinded, controlled study by three researchers with varying degrees of experience with direct and indirect observation of cut marks (photography). Our results showed that identifying the weapon involved is possible thanks to numerous criteria analysis. Correct classification rates were high and misclassifications rare. Asymmetric blades obtained better results than symmetric blades. Predictive values were also calculated, and the negative one reached very high levels, near 100% with regard to all the implements. Positive predictive values were more variable. But even if individual diagnoses remain in doubt, triage can be done and tools not implicated in injury can be eliminated with certainty. Moreover, our work clearly highlighted the importance of experience in such activities. A high level of experience is fundamental to obtain the best values, especially in such a context where evidence reliability is extremely important for forensic admissibility testimony in the court.

Fatal deer attack in a rutting season.

Animal inflicted fatal or near fatal injuries are well described in the forensic literature, with the most frequently described cases involving dogs, large cats and bears. To our knowledge, a deer inflicted fatality has not been described in the forensic literature previously. This article reports a case of a 64-year-old male, who was found lying in a pool of blood near an enclosure for stags and hinds at the end of October. There were mechanical defects on his jacket and trousers, which appeared to be torn or penetrated, as well as multiple lacerations and stab wounds in different parts of his body. The type and location of the injuries the man had sustained strongly suggested that another person had been involved in the incident that had led to his death. The cause of death was deemed as external exsanguination due to multiple stab wounds to large vessels. After evaluating all of the information regarding the circumstances around the death, the case was classified as a deer attack related fatality, and the manner of death was determined to be accidental. The man was most probably attacked by one of the deer while he was refilling the animal feeder. A substantial increase in the levels of selected hormones, especially testosterone, during the rutting season explains the increased levels of aggression shown by the deer that led to a fatal outcome for the decedent.

Axe injury pattern in homicide.

Chop or slash wounds are produced by sharp-edged tools such as an axe, or a machete. This paper presents a case of a violent death of a 57 year-old-man. Autopsy revealed deformation of the right side of the head. A total of 23 slash, stab and cut wounds as well as contused lacerations were identified on the scalp as well as the face and the neck. In addition, superficial abrasions and bruises were identified on the skin. The immediate cause of death was due to extensive brain contusion following fragmentation of the neurocranium. The injuries resulting in the death of the victim were sustained during an assault on the head with an axe, which was used both as a slashing tool and a blunt instrument.

Influence of white matter injury on gray matter reactive gliosis upon stab wound in the adult murine cerebral cortex.

Traumatic brain injury frequently affects the cerebral cortex, yet little is known about the differential effects that occur if only the gray matter (GM) is damaged or if the injury also involves the white matter (WM). To tackle this important question and directly compare similarities and differences in reactive gliosis, we performed stab wound injury affecting GM and WM (GM+) and one restricted to the GM (GM-) in the adult murine cerebral cortex. First, we examined glial reactivity in the regions affected (WM and GM) and determined the influence of WM injury on reactive gliosis in the GM comparing the same area in the two injury paradigms. In the GM+ injury microglia proliferation is increased in the WM compared with GM, while proliferating astrocytes are more abundant in the GM than in the WM. Interestingly, WM lesion exerted a strong influence on the proliferation of the GM glial cells that was most pronounced at early stages, 3 days post lesion. While astrocyte proliferation was increased, NG2 glia proliferation was decreased in the GM+ compared with GM- lesion condition. Importantly, these differences were not observed when a lesion of the same size affected only the GM. Unbiased proteomic analyses further corroborate our findings in support of a profound difference in GM reactivity when WM is also injured and revealed MIF as a key regulator of NG2 glia proliferation.

Wnt signaling regulates proliferation and differentiation of radial glia in regenerative processes after stab injury in the optic tectum of adult zebrafish.

Zebrafish have superior abilities to generate new neurons in the adult brain and to regenerate brain tissue after brain injury compared with mammals. There exist two types of neural stem cells (NSCs): neuroepithelial-like stem cells (NE) and radial glia (RG) in the optic tectum. We established an optic tectum stab injury model to analyze the function of NSCs in the regenerative condition and confirmed that the injury induced the proliferation of RG, but not NE and that the proliferated RG differentiated into new neurons after the injury. We then analyzed the involvement of Wnt signaling after the injury, using a Wnt reporter line in which canonical Wnt signaling activation induced GFP expression and confirmed that GFP expression was induced specifically in RG after the injury. We also analyzed the expression level of genes related to Wnt signaling, and confirmed that endogenous Wnt antagonist dkk1b expression was significantly decreased after the injury. We observed that Wnt signal inhibitor IWR1 treatment suppressed the proliferation and differentiation of RG after the injury, suggesting that up-regulation of Wnt signaling in RG after the stab injury was required for optic tectum regeneration. We also confirmed that Wnt activation by treatment with GSK3ß inhibitor BIO in uninjured zebrafish induced proliferation of RG in the optic tectum. This optic tectum stab injury model is useful for the study of the molecular mechanisms of brain regeneration and analysis of the RG functions in physiological and regenerative conditions.

Comparison of the detrimental features of microglia and infiltrated macrophages in traumatic brain injury: A study using a hypnotic bromovalerylurea.

Microglia and blood-borne macrophages in injured or diseased brains are difficult to distinguish because they share many common characteristics. However, the identification of microglia-specific markers and the use of flow cytometry have recently made it easy to discriminate these types of cells. In this study, we analyzed the features of blood-borne macrophages, and activated and resting microglia in a rat traumatic brain injury (TBI) model. Oxidative injury was indicated in macrophages and neurons in TBI lesions by the presence of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Generation of mitochondrial reactive oxygen species (ROS) was markedly observed in granulocytes and macrophages, but not in activated or resting microglia. Dihydroethidium staining supported microglia not being the major source of ROS in TBI lesions. Furthermore, macrophages expressed NADPH oxidase 2, interleukin-1ß (IL-1ß), and CD68 at higher levels than microglia. In contrast, microglia expressed transforming growth factor ß1 (TGFß1), interleukin-6 (IL-6), and tumor necrosis factor α at higher levels than macrophages. A hypnotic, bromovalerylurea (BU), which has anti-inflammatory effects, reduced both glycolysis and mitochondrial oxygen consumption. BU administration inhibited chemokine CCL2 expression, accumulation of monocytes/macrophages, 8-OHdG generation, mitochondrial ROS generation, and proinflammatory cytokine expression, and markedly ameliorated the outcome of the TBI model. Yet, BU did not inhibit microglial activation or expression of TGFß1 and insulin-like growth factor 1 (IGF-1). These results indicate that macrophages are the major aggravating cell type in TBI lesions, in particular during the acute phase. Activated microglia may even play favorable roles. Reduction of cellular energy metabolism in macrophages and suppression of CCL2 expression in injured tissue may lead to amelioration of TBI.

How taphonomic alteration affects the detection and imaging of striations in stab wounds.

Stabbing with a kitchen knife is a common method of homicide in Europe. Serrated knives may leave tool markings (striations) in tissues. Documentation of striations is necessary for their use as forensic evidence. Traditional methods (physical casting and photography) have significant limitations, and micro-computed tomography (micro-CT) has been trialled in cartilage to "virtually cast" wounds. Previous research has shown the proportion of striations in cartilage falls following decomposition. This project has investigated the effects of taphonomic alteration and documentation methods of striations in porcine skin. Fresh, decomposed, mummified, burnt and waterlogged stab wounds in a porcine analogue were excised and imaged using photography, stereo-optical microscopy and micro-CT. The proportion of striations in each taphonomic group was determined from the images by independent analysts. Striations were observed more frequently in serrated blade wounds, although they were also identified in non-serrated blade wounds. The proportion of wounds showing striations declined following decomposition. An inversely proportional linear correlation between advancing decomposition and proportion of striations existed. Dehydration (mummification and burning) rendered serrated and non-serrated blade wounds indistinguishable. Water composition affected the preservation of striations. Identification of striations gradually declined after decomposition in tap water, but persisted to a point when left in brackish water. All three techniques imaged striations; however, the optimum technique was stereo-optical microscopy due to practical advantages and specific limitations affecting photography and micro-CT. This study demonstrates the effects of taphonomic alteration on striations and suggests stereo-optical microscopy is the optimum method for their documentation.

Unusual Suicide by a Speargun Shot Through the Mouth: A Case Report.

We report an unusual case of suicide committed with a speargun shot through the mouth, causing a penetrating brain injury. The special features of the present case are not only related to the method chosen for the purpose but also to the difficulties encountered in confirming the diagnosis. Although this type of suicide has been previously reported, this case is particularly interesting in terms of the shooting mechanism and manner of death. Because of the length of the weapon, which was apparently used and found at the scene, a suicidal manner of death first seemed unlikely and the possibility of a simulated suicide was raised. It seemed impossible for the decedent to have shot himself without a mechanism to launch the shaft through the mouth. However, a complete forensic approach eventually allowed for a plausible mechanism of self-infliction, confirming the suicide diagnosis.

The detection of metallic residues in skin stab wounds by means of SEM-EDS: A pilot study.

The morphological analysis of stab wounds may often not be accurate enough to link it with the type of wounding weapon, but a further evaluation may be performed with the search for metallic residues left during the contact between the instrument and the skin. In this study, Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) was applied to the study of cadaveric stab wounds performed with kitchen knives composed of iron, chromium and nickel, in order to verify the presence of metallic residues on the wound's edge. Two groups of 10 corpses were selected: group A, including victims of stab wounds and a control group B (died of natural causes). Samplings were performed on the lesions and in intact areas of group A, whereas in group B sampling were performed in non-exposed intact skin. Samples were then analysed with optical microscopy and SEM-EDS. In group A, optical microscopic analysis showed the presence of vital haemorrhagic infiltration, while SEM-EDS showed evidence of microscopic metal traces, isolated or clustered, consisting of iron, chromium and nickel. Moreover, in two cases organic residues of calcium and phosphate were detected, as a probable sign of bone lesion. Control samples (group A in intact areas and group B), were negative for the search of exogenous material to optical microscopy and SEM-EDS. The results show the utility and possible application of the SEM-EDS in theidentification of metallic residues from sharp weapons on the skin.

Penetrating cardiac trauma: A retrospective case series from Karachi.

Penetrating cardiac trauma is a medical emergency that commonly affects young men throughout the world. A retrospective review of the records of all patients presenting with cardiac injury was done from January 2000 to December 2015 at our institute. There were 10 cases of such trauma, all of whom were males, 17 to 48 years of age. The most common mechanism of injury was gunshot wounds followed by stab wounds. The Mean Revised Trauma Score was 7.23±0.855. Only 2 out of the total 10 patients died (20% mortality). The Right Ventricle followed by the Left Ventricle was the most common site of injury. Median Sternotomy was the surgical procedure of choice in managing these patients. Pericardial tamponade and Haemothorax were common intra-operative findings. Patients having penetrating cardiac injury presenting with detectable signs of life on arrival to the hospital can be rescued by early surgical intervention.

Injury potential of thrown sharp kitchen and household utensils.

We examined the possibility of inflicting serious injuries with sharp objects in an experimental setting by throwing four sharp objects from different distances and with different throwing techniques. Using an overarm-handle (OA/H), overarm-blade (OA/B), underarm-handle (UA/H), underarm-blade (UA/B) and thrust (T/H) throwing technique, 10 adults (sex ratio 1:1) threw a chef's knife, a skinning knife, a paring knife and office scissors from 4 m and 2 m distance at synthetic abdomen models made of 10% gelatin covered with synthetic skin. The amount of hits and penetrations of the target and their penetration depth were noted, as was the rotation of the blade tip towards the target along its flight trajectory. The chef's knife injury/hit ratio was 0.167/4 m and 0.160/2 m; the skinning knife recorded an injury/hit ratio of 0.087/4 m and 0.153/2 m; the paring knife of 0.087/4 m and 0.113/2 m; and the scissors 0.087/4 m and 0.067/2 m. Mean penetration depths were as follows: the chef's knife: 4 m, 4.42 cm, 2 m, 3.41 cm; the skinning knife: 4 m, 4.19 cm, 2 m, 4.11 cm; the paring knife: 4 m, 1.62 cm, 2 m, 1.55 cm; and the scissors: 4 m, 2.08 cm, 2 m, 0.95 cm. Handle-throw penetration-depths were: 4 m: 3.77 cm and 2 m: 2.86 cm; blade-throw depths were: 4 m: 3.14 cm and 2 m: 2.69 cm. Overarm-throw penetration-depths were: 4 m: 3.62 cm and 2 m: 3.25 cm; and underarm-throw penetration-depths were 4 m: 3.30 cm and 2 m: 2.30 cm. No thrust-throws with the paring knife and scissors could pierce the target. The tips pointed toward the target at angles of 60°-120°, earlier in handle-throws than blade-throws, especially with the paring knife and the scissors. When thrown, especially with a handle-held technique, heavier objects pierced more often and more deeply. Thrust-throws at short distances are unlikely to pierce a human.

"Defense" type wounds in suicide.

"Defense" type wounds are sustained when a victim is attempting to ward off an attacker, or a weapon. A 39-year-old woman is reported who was found deceased with incised wounds to the dorsa of both hands that resembled defense wounds. Examination of the flexor surfaces of both wrists, however, revealed horizontal incised wounds typical of self-infliction. Perfusion of the subclavian arteries produced leakage of water from peripheral veins within wounds on both hands and the right wrist. Death was due to exsanguination from incised wounds of the hands and right wrist; manner suicide. This case demonstrates the difficulties that may arise in differentiating self-inflicted from assaultive wounds. On occasion suicidal sharp force injuries may be multiple and in atypical locations. In these circumstances a high index of suspicion for homicide must be maintained.

Stab wounds of the chest caused by penetration of duralumin rods.

Sharp force injuries are uncommon in routine forensic practice. While the majority of these cases are homicides or suicides, a significant minority of accidental deaths means that a careful investigation of the circumstances of the death is necessary. We present the case of a young man who presented with stab and cut injuries due to a duralumin rod embedded in his chest. Examination of the body revealed that death was due to penetration of the thoracic aorta by a duralumin rod. Careful investigation of the circumstances surrounding the death was able to confim a case of accidental death due to falling from a ladder onto tomato seedlings that were supported by duralumin rods.

Single stab injuries.

Determining the manner of death in cases involving multiple stab injuries from a knife is generally straightforward. The medico-legal investigation of a stabbing death caused by a single stab injury from a knife comprises a smaller but potentially more problematic subset of forensic cases. We reviewed our institute's experience with single stab injuries and endeavored to identify features identified at the post-mortem examination which may aid in the differentiation between cases of homicide, suicide and accidental death. The single stab injury was to the left chest in the majority of deaths from homicide and from suicide. Clothing was nearly always involved in cases of homicide, but was also seen in cases of suicide. The knife was found in situ in 9 of the 11 cases of suicide involving a chest injury, but was not seen in any of the cases of homicide. There were no cases of an accidental single stab death from a knife in our records. Clinical data on accidental stab injuries was sought via a search of the medical records of a major tertiary referral hospital. A single non-fatal case of an accidental single stab injury from a knife was identified after the conclusion of our study period. Accidental stab injuries from a knife causing injury or death are rare.