Electric injury-induced Purkinje cell apoptosis in rat cerebellum: Histological and immunohistochemical study

The Possible Protective Effect of Taurine on Bisphenol Induced Structural Changes on the Cerebral Cortex of Rats: Histological and Immunohistochemical Study

INTRODUCTION

Bisphenol A (BPA) is a chemical compound that has been used in many industries, such as paints and dental sealants. Taurine is a semi-essential amino acid with antioxidant, anti-inflammatory, and anti-apoptotic actions.

AIM

This study aimed to evaluate the possible protective effect of taurine on BPA-induced structural changes in the cerebral cortex of rats using histological and immunohistochemical methods.

METHODS

35 Wistar rats (180-200 gm) were divided into control: 10 rats; Group I: 5 rats received corn oil (0.5 mL/day); Group II (Bisphenol low dose; BPAL): 5 rats received a low dose of BPA (25 mg/kg/three times/week); Group III (Bisphenol high dose; BPAH): 5 rats received a high dose of BPA (100 mg/kg/three times/week; Group IV: (BPAL + taurine): 5 rats received taurine 100 mg/kg/day and BPAL (25 mg/kg/three times/week); Group V: (BPAH + taurine): 5 rats received taurine 100 mg/kg/day and BPH (100 mg/kg/ three times/week).

RESULTS

BPAL& BPAH groups showed significant dose-dependent histological changes of the neuropil, pyramidal, and neuroglial cells at H&E stained sections, significantly increased GFAP, caspase- 3 immunohistochemical reaction with cells positive for Ki67 with many mitotic figures. BPAL + taurine and BPAH + taurine groups showed amelioration of the previously mentioned results.

CONCLUSION

Taurine ameliorated the structural changes induced by BPA in the cerebral cortex of rats.

An instance of homicide by electrocution with hand-made electrode plates

Homicide by electrocution is rare in forensics, and the identification of the cause of death can be quite difficult when the electric device is removed from the scene. We present an instance where the police were unsure of homicide in the initial investigation. The offender used hand-made electrode plates for electrocution, which produced unique electric marks different from those produced by common electric devices such as electric wires. To the best of our knowledge, this is the first report of homicide by electrocution with electrode plates. We believe that the macroscopic and microscopic findings in this instance are quite valuable for forensic practitioners.

Prolonged electrolysis injures the neural development of zebrafish (Danio rerio)

Recently, electrolysis technology has been widely applied in nitrogen and phosphorus removal in river water due to its high efficiency, but its effects on aquatic animals, especially on their neurodevelopmental system, are still unclear. In this study, zebrafish (Danio rerio) embryos were used as model organisms and were put into an electrolytic reaction device with a Ti/IrO₂/RuO₂ mesh plate as the anode and a Ti mesh plate as the cathode to explore the effects of prolonged electrolysis on the nervous system. The neural development of zebrafish embryos was injured when the current density was greater than 0.89 A/m². Compared with the control group, the movement speed of zebrafish larvae (120 h postfertilization, hpf) was significantly reduced from 65.48 ± 23.69 to 48.08 ± 22.73 mm/min in a dark environment with an electric current density of 0.89 A/m² in the electrolysis group. In addition, the acetylcholinesterase activity of zebrafish larvae (120 hpf) gradually decreased from 7.60 ± 0.55 to 6.00 ± 0.01 U/mg prot and the dopamine concentration was reduced from 46.96 ± 0.85 to 40.86 ± 1.05 pg/mL with an electric current density from 0 to 0.89 A/m² in the electrolysis groups. Furthermore, the expression of nerve-related genes (syn2a, mbp, nestin, and AChE) was significantly inhibited when the current density was more than 0.89 A/m². However, there were few adverse effects on the neural development of zebrafish embryos when the current density was less than 0.86 A/m². Thus, a current density of 0.86 A/m² is a reference value to reduce the harm to the neural development of fish when electrolysis technology is used in river water pollutant treatment.

An experimental rat model of electric shock injury with isolated electric shock and water conduction: the histopathological changes on the skin and internal organs and the effect on biochemical parameters

It is difficult to determine the cause of death in electric shock injuries when no trace can be determined on the skin, and this is accepted as a reason for negative autopsy. We aimed to determine useful parameters in the definition of the cause of deaths associated with electric shock and particularly those formed with water conduction. This study used a total of 42 rats, applied with fatal electric shock formed of isolated electric shock at 220 V and with water conduction. The serum NT-ProBNP and H-FABP levels were examined together with histopathological changes in the brain, cerebellum, brainstem, heart, liver and skin and the Bax, caspase-3 and HSP-60 antibody status in these tissues. A statistically significant difference was determined between the groups in respect of the serum H-FABP values and the immunohistochemical staining of the samples taken from the organs. In conclusion, this study is the first in literature with an experimental model of electric shock with water conduction. Using immunohistochemical and biochemical markers in deaths associated with isolated electric shock and electric shock with water conduction, the results of this study can contribute to the clarification of one of the reasons for negative autopsy in forensic medicine.

Advances in forensic diagnosis of electric shock death in the absence of typical electrical marks

Electrical injury is a relatively uncommon but potentially devastating form of multi-system injury with high morbidity and mortality. In common electric injury cases, it is usually difficult to find characteristic changes of electric injury in major organs by using routine histopathological test methods unless there are landmark traces of electric injury, known as electric marks. How to determine electric shock death, especially in the absence of typical electrical marks on the body surface in some cases (which account for about two-thirds of electric injury cases), remains a challenging problem in forensic practice. Our summary shows that many current related studies have focused their efforts to find characteristic histopathological changes in major organs of the body caused by electric injury. Based on the results obtained through comparison of the literature, we find that it may be more urgent and important to find the optimal autopsy or sampling sites in cases with no typical electric marks, knowing that these sites may often reflect the most significant histopathological changes of electric injury, for instance anatomy and sampling of the anterior wrist and the medial malleolus in cases involving the hand-to-foot electric circuit pathway. In this article, we make a summary of advances in identification methods of electric injury, hoping that it could provide some new insights for further research in this field.

Disabling VEGF-Response of Purkinje Cells by Downregulation of KDR via miRNA-204-5p

The vascular endothelial growth factor (VEGF) is well known for its wide-ranging functions, not only in the vascular system, but also in the central (CNS) and peripheral nervous system (PNS). To study the role of VEGF in neuronal protection, growth and maturation processes have recently attracted much interest. These effects are mainly mediated by VEGF receptor 2 (VEGFR-2). Current studies have shown the age-dependent expression of VEGFR-2 in Purkinje cells (PC), promoting dendritogenesis in neonatal, but not in mature stages. We hypothesize that microRNAs (miRNA/miR) might be involved in the regulation of VEGFR-2 expression during the development of PC. In preliminary studies, we performed a miRNA profiling and identified miR204-5p as a potential regulator of VEGFR-2 expression. In the recent study, organotypic slice cultures of rat cerebella (postnatal day (p) 1 and 9) were cultivated and VEGFR-2 expression in PC was verified via immunohistochemistry. Additionally, PC at age p9 and p30 were isolated from cryosections by laser microdissection (LMD) to analyse VEGFR-2 expression by quantitative RT-PCR. To investigate the influence of miR204-5p on VEGFR-2 levels in PC, synthetic constructs including short hairpin (sh)-miR204-5p cassettes (miRNA-mimics), were microinjected into PC. The effects were analysed by confocal laser scanning microscopy (CLSM) and morphometric analysis. For the first time, we could show that miR204-5p has a negative effect on VEGF sensitivity in juvenile PC, resulting in a significant decrease of dendritic growth compared to untreated juvenile PC. In mature PC, the overexpression of miR204-5p leads to a shrinkage of dendrites despite VEGF treatment. The results of this study illustrate, for the first time, which miR204-5p expression has the potential to play a key role in cerebellar development by inhibiting VEGFR-2 expression in PC.

Effects of ascorbic acid treatment on developmental alterations in calcium-binding proteins and gamma-aminobutyric acid transporter 1 in the cerebellum of lead-exposed rats during pregnancy and lactation

In the present study, we investigated the effects of lead (Pb) and ascorbic acid co-administration on rat cerebellar development. Female rats were randomly divided into the following groups: control, Pb, and Pb plus ascorbic acid (PA) groups. From one week prior to mating, female rats were administered Pb (0.3% Pb acetate in drinking water) and ascorbic acid (100 mg/kg, oral intubation). The chemical administration was stopped on postnatal day 21 when the morphology of the offspring's cerebellum is similar to that of the adult brain. The blood Pb level was significantly increased following long-term Pb exposure. Ascorbic acid reduced Pb levels in the dams and offspring. Nissl staining demonstrated that the number of Purkinje cells was significantly reduced following Pb exposure, while ascorbic acid ameliorated this effect in the cerebellum of the offspring. Calcium-binding proteins, such as calbindin, calretinin, and parvalbumin were commonly expressed in Purkinje cells, and Pb exposure and ascorbic acid treatment resulted in similar patterns of change, namely Pb-induced impairment and ascorbic acid-mediated amelioration. The gamma-aminobutyric acid transporter 1 (GABAT1) is expressed in the pinceau structure where the somata of Purkinje cells are entwined in inhibitory synapses. The number of GABAT1-immunoreactive synapses was reduced following Pb exposure, and ascorbic acid co-treatment prevented this effect in the cerebellar cortex. Therefore, it can be concluded that ascorbic acid supplementation to mothers during gestation and lactation may have potential preventive effects against Pb-induced impairments in the developing cerebellum via protection of inhibitory neurons and synapses.

A Pilot Study on the Diagnosis of Fatal Electrocution by the Detection of Myocardial Microhemorrhages

In electrocutions, death may be caused by alterations in the heart conduction system provoking ventricular fibrillation. This study aims to identify histological cardiac markers of high- and low-voltage electrocution. Two groups of decedents were evaluated: group A included 14 fatalities caused by high- or low-voltage electrocution and group B (control) included 14 fatalities due to other traumatic or disease causes. Myocardial sampling with microscopic examination was performed on all the hearts using the hematoxylin and eosin and Masson's trichrome stains to investigate morphological characteristics that could indicate the damage caused by high- and low-voltage electrocutions. Interstitial myocardial hemorrhagic infiltration was the only differentiating finding, which was shown only in high-voltage electrocution. This pathological finding has not been previously reported, and it may be specific to high-voltage electrocution deaths. Further studies are warranted.

Ascorbic Acid Supplementation Prevents the Detrimental Effects of Prenatal and Postnatal Lead Exposure on the Purkinje Cell and Related Proteins in the Cerebellum of Developing Rats

We investigated the effects of lead (Pb) and ascorbic acid co-administration on rat cerebellar development. Prior to mating, rats were randomly divided into control, Pb, and Pb plus ascorbic acid (PA) groups. Pregnant rats were administered Pb in drinking water (0.3% Pb acetate), and ascorbic acid (100 mg/kg) via oral intubation until the end of the experiment. Offspring were sacrificed at postnatal day 21, the age at which the morphology of the cerebellar cortex in developing pups is similar to that of the adult brain. In the cerebellum, Pb exposure significantly reduced Purkinje cells and ascorbic acid prevented their reduction. Along with the change of the Purkinje cells, long-term Pb exposure significantly reduced the expression of the synaptic marker (synaptophysin), γ-aminobutyric acid (GABA)-synthesizing enzyme (glutamic acid decarboxylase 67), and axonal myelin basic protein while ascorbic acid co-treatment attenuated Pb-mediated reduction of these proteins in the cerebellum of pups. However, glutamatergic N-methyl-D-aspartate receptor subtype 1 (NMDAR1), anchoring postsynaptic density protein 95 (PSD95), and antioxidant superoxide dismutases (SODs) were adversely changed; Pb exposure increased the expression of NMDAR1, PSD95, and SODs while ascorbic acid co-administration attenuated Pb-mediated induction. Although further studies are required about the neurotoxicity of the Pb exposure, the results presented here suggest that developmental Pb exposure disrupted normal development of Purkinje cells by increasing glutamatergic and oxidative stress in the cerebellum. Additionally, ascorbic acid co-treatment is beneficial in attenuating prenatal and postnatal Pb exposure-induced maldevelopment of Purkinje cells in the developing cerebellum.

Forensic tools for the diagnosis of electrocution death: Case study and literature review

Diagnosis of death by electrocution may be difficult when electric marking is not visible or unclear. Accordingly, the body of a man who appeared to have died from accidental electrocution was carefully forensically analysed. Macroscopic and microscopic analysis of the current mark was carried out using a variable-pressure scanning electron microscope equipped with energy dispersive X-ray microanalyser to highlight skin metallisation, indicating the presence of iron and zinc. The histological findings of electrocution myocardial damage were supported by the results of biochemical analysis which demonstrated the creatine kinase-MB and cardiac troponin I elevation. The effects of electric current flow were also highlighted by perforations of endothelial surface of a pulmonary artery using scanning electron microscope, and all the results were analysed by the main tools suggested in the literature.