Histopathological, histochemical and biochemical postmortem changes in induced fatal hypothermia in rats

Abstract

Reaching a postmortem diagnosis of hypothermia is challenging in forensic practice. Therefore, this study was conducted to detect the histopathological, histochemical and biochemical changes that occur in adult albino rats following exposure to induced fatal hypothermia. Twenty-four adult albino rats were divided into the negative control, moderate hypothermia, severe hypothermia and hypoxia groups. Rats in the control group were euthanized when those in the moderate hypothermic group died. Blood samples were collected via heart puncture, and the cerebrum, heart, suprarenal gland, kidney, liver and skeletal muscle were removed to investigate the biochemical, histochemical and histopathological changes. Postmortem assessment depicted significant changes in lipid peroxidation, represented by increased malondialdehyde levels in the studied organs of the rats in hypothermic and hypoxia groups. Histopathological examination of the rats' organs revealed degeneration and necrosis in the hypothermia and hypoxia groups. Sections taken from the severe hypothermic rats revealed a loss of normal cardiac tissue architecture, necrotic changes in the pyramidal cells in the cerebral cortex, and massive necrosis, mainly in the tubules of the renal cortex and medulla. These findings suggest that histological changes might be used as biochemical markers for postmortem diagnosing of fatal hypothermia, particularly in severe hypothermic conditions. KEY POINTS• Death by hypothermia is a serious public health problem worldwide.• Confirming a diagnosis and determining the cause of death in cases of hypothermia are among the most difficult practices in forensic medicine. • Death by hypothermia might be associated with structural abnormalities in various organs. • Studies using different tissue staining techniques will enable an overall illustration of the role of histopathological changes in body organs as indicators of hypothermia.

Advanced Diagnostic Tools in Hypothermia-Related Fatalities—A Pathological Perspective

“…A spectrum of hypothermia grades, from grade I to IV, are registered, in association with various pathophysiologic lesions. Accordingly, hypothermia grade I (mild) is encountered when the core temperature ranges between 35 and 32 • C, hypothermia grade II (moderate) is registered when the core temperature ranges between 32 and 28 • C, and hypothermia grade III (severe) is diagnosed when the core temperature is lower than 28 • C. The last stage, hypothermia grade IV (profound), is encountered when the core temperature is lower than 24 • C, correlated to a functional poikilothermic state [2,[18][19][20]. Considering the profound hypothermia stage registered in our study group, it contributed to the fatal progression due to severe complications, despite the eventual patient hospitalization and therapy [3].…”

“…Thermal stress has variable features in forensics practice, representing a domain of interest for research, considering its complex interrelationships with pathological diagnosis and causes of death. The body's exposure to low environmental temperatures represents a stress factor, which increases the metabolic rate and leads to the excessive production of reactive oxygen species (ROS) [2]. ROS induce oxidative stress, as a consequence of overcoming cellular antioxidative defense mechanisms [2].…”

“…The body's exposure to low environmental temperatures represents a stress factor, which increases the metabolic rate and leads to the excessive production of reactive oxygen species (ROS) [2]. ROS induce oxidative stress, as a consequence of overcoming cellular antioxidative defense mechanisms [2]. Additionally, thermal stress is associated with tissue hypoxia and the disruption of the physiological activity of vital organs, such as the brain, lungs, heart, and kidneys [1,3,4].…”

Microbial community succession in the intestine of mice with deep partial-thickness burns

“…Dorsal skin tissue samples from the control group (1 day post-burn) and naked skin tissue exposed to boiling water from the burn group were fixed in formalin and then embedded in paraffin. Slices with 3 μm thickness were made and stained with hematoxylin and eosin (H&E) for histopathological examination ( Xie et al, 2018 ; Ibrahim et al, 2022 ).…”

Study of the Subacute Toxicity of Dry Bark of Albizia ferruginea (Mimosaceae) (Guill. &Perr.) Berth. in Wistar Albino Rats

“…The blood from the dry tube made it possible to obtain serum which was stored at -4 °C for the assay of biochemical parameters. Analysis of the lipid profile (total cholesterol, HDL-cholesterol and triglycerides), liver function (total proteins, bilirubin, alkaline phosphatase, ALAT and ASAT), renal function (creatinine and urea) and blood sugar was performed using kits from Fortress diagnostics (United Kingdom), with procedures based on colorimetric method [12][13][14][15]. The liver, kidneys, spleen, lungs and the heart were obtained, rinsed with 0.9% salt solution, then weighed and stored in formol 10% for histological analyzes.…”