Postmortem biochemistry and immunohistochemistry of chromogranin A as a stress marker with special regard to fatal hypothermia and hyperthermia

Forensic neuropathology in the past decade: a scoping literature review

While there has been notable research activity in the field of clinical neuropathology over the recent years, forensic approaches have been less frequent. This scoping literature review explored original research on forensic neuropathology over the past decade (January 1, 2010, until February 12, 2022) using the MEDLINE database. The aims were to (1) analyze the volume of research on the topic, (2) describe meta-level attributes and sample characteristics, and (3) summarize key research themes and methods. Of 5053 initial hits, 2864 fell within the target timeframe, and 122 were included in the review. Only 3-17 articles were published per year globally. Most articles originated from the Europe (39.3%) and Asia (36.1%) and were published in forensic journals (57.4%). A median sample included 57 subjects aged between 16 and 80 years. The most common research theme was traumatic intracranial injury (24.6%), followed by anatomy (12.3%) and substance abuse (11.5%). Key methods included immunotechniques (31.1%) and macroscopic observation (21.3%). Although a number of novel findings were reported, most were of preliminary nature and will require further validation. In order to reach breakthroughs and validate novel tools for routine use, more research input is urged from researchers across the world. It would be necessary to ensure appropriate sample sizes and make use of control groups.

Relationship between clock gene expression and CYP2C19 and CYP3A4 with benzodiazepines

The present study aimed to clarify the expressions and roles of clock genes involved in drug metabolism in patients taking benzodiazepines (BZDs), as well as the drug metabolism regulators controlled by clock genes for each BZD type. The relationships between the expressions of the clock genes BMAL1, PER2, and DBP and the drug-metabolizing enzymes CYP3A4 and CYP2C19 were investigated using livers from BZD-detected autopsy cases. In addition, the effect of BZD exposure on various genes was examined in HepG2 human hepatocellular carcinoma cells. The expressions of DBP, CYP3A4, and CYP2C19 in the liver were lower in the diazepam-detected group than in the non-detected group. Furthermore, BMAL1 expression correlated with CYP2C19 expression. Cell culture experiments showed that the expressions of DBP and CYP3A4 decreased, whereas those of BMAL1 and CYP2C19 increased after diazepam and midazolam exposure. The results of the analyses of autopsy samples and cultured cells suggested that DBP regulates CYP3A4 when exposed to BZD. Understanding the relationship between these clock genes and CYPs may help achieve individualized drug therapy.

'Bushfire Season' in Australia: Determinants of Increases in Risk of Acute Coronary Syndromes and Takotsubo Syndrome

BACKGROUND

Climate change has resulted in an increase in ambient temperatures during the summer months as well as an increase in risk of associated air pollution and of potentially disastrous bushfires throughout much of the world. The increasingly frequent combination of elevated summer temperatures and bushfires may be associated with acute increases in risks of cardiovascular events, but this relationship remains unstudied. We evaluated the individual and cumulative impacts of daily fluctuations in temperature, fine particulate matter of less than 2.5 µm (PM_2.5) pollution and presence of bushfires on incidence of acute coronary syndromes and Takotsubo syndrome.

METHODS

From November 1, 2019, to February 28, 2020, all admissions with acute coronary syndromes or Takotsubo syndrome to South Australian tertiary public hospitals were evaluated. Univariate and combined associations were sought among each of 1) maximal daily temperature, 2) PM_2.5 concentrations, and 3) presence of active bushfires within 200 km of the hospitals concerned.

RESULTS

A total of 504 patients with acute coronary syndromes and 35 with Takotsubo syndrome were studied. In isolation, increasing temperature was associated (r_s = 0.26, P = .005) with increased incidence of acute coronary syndromes, while there were similar, but nonsignificant correlations for PM_2.5 and presence of bushfires. Combinations of all these risk factors were also associated with a doubling of risk of acute coronary syndromes. No significant associations were found for Takotsubo syndrome.

CONCLUSION

The combination of high temperatures, presence of bushfires and associated elevation of atmospheric PM_2.5 concentrations represents a substantially increased risk for precipitation of acute coronary syndromes; this risk should be factored into health care planning including public education and acute hospital preparedness.

Takotsubo Syndrome in New Zealand: Current Knowledge and Future Challenges

Takotsubo syndrome (TS), also known as apical ballooning syndrome is a transient stress-related cardiomyopathy characterised by acute but reversible left ventricular dysfunction. The condition tends to occur in postmenopausal women after a stressful event. At presentation TS typically mimics acute myocardial infarction (MI) and the incidence of TS has been increasing worldwide. This is likely a consequence of an improved awareness of the existence of this syndrome and easier access to early echocardiography and coronary angiography. However, its aetiology remains poorly understood and it is probably still underdiagnosed. Similar to other countries. TS is being increasingly recognised in New Zealand. In this review, we discuss the demographics, clinical features and outcomes of patients with TS in New Zealand. Doing so informs us not only of the pattern of disease in New Zealand but it also provides insights into the condition itself. This article is protected by copyright. All rights reserved.

Effect of methamphetamine on clock genes and drug-metabolizing enzyme expression

This study examined the association between clock gene expression and the effect of methamphetamine (MA) on drug-metabolizing enzymes from the perspective of drug metabolism. The relationship between expression of the clock genes BMAL1 and PER2 and the drug-metabolizing enzymes CYP3A4 and CYP2D6 was investigated using livers from autopsy cases of MA-intoxication deaths. Additionally, the effect of MA exposure on various genes was examined in HepG2 human hepatocellular carcinoma cells. Comparisons of the expression of various genes in MA users according to blood MA concentration revealed that CYP3A4 expression was similar to that of PER2, and CYP2D6 expression was similar to that of BMAL1. In cultured cell experiments, BMAL1 and CYP2D6 expression decreased depending on the time elapsed after MA addition, and PER2 and CYP3A4 expression increased slightly in a concentration-dependent manner. These results were consistent with the findings of autopsy examinations. Expression of CYP3A4 and CYP2D6 under BMAL1 and PER2 suppression, but not CYP2D6 under PER2 suppression alone, was upregulated in response to MA. These results suggest that CYPs are regulated via the clock genes BMAL1 and PER2 during MA metabolism.

Death following extreme temperature exposure: Histological, biochemical and immunohistochemical markers

INTRODUCTION

Defining extreme temperatures as the cause of death remains challenging. It is mostly based on circumstantial, macroscopic and microscopic features.

METHODS

We retrospectively compared groups of cases of fatal hypothermia, fatal hyperthermia and non-extreme temperature-related deaths. We analysed specific histological findings, focusing on samples from the liver, pancreas and kidney.

RESULTS

Between 1 January 2013 and 31 December 2016, 15 autopsies were performed for deaths related to extreme temperatures. They included 11 cases of fatal hypothermia (group A), four cases of fatal hyperthermia (group B) and eight controls (group C). Perinuclear hepatocyte vacuolisation was observed in seven cases of hypothermia, one case of hyperthermia and four controls. Pancreatic cytoarchitecture was well preserved in two cases of hypothermia, one case of hyperthermia and two controls. No particular microscopic feature was found in pancreatic samples. Renal epithelial tubular cell vacuolisation was observed in seven cases of hypothermia and one case of hyperthermia, while it was absent in all controls. Chromogranin A (CgA) was markedly positive in the pancreatic tissue of five cases of fatal hypothermia and one control, and mildly positive in one case of fatal hyperthermia. No significant p-values were observed for any comparisons (p > 0.05), except when hypothermia cases group were compared to the control group for the Armanni-Ebstein phenomenon test (p = 0.0078).

CONCLUSIONS

Although our study did not find a specific microscopic marker, hepatocyte vacuolisation, the Armanni-Ebstein phenomenon and pancreatic CgA positivity, taken together, may be useful tools to confirm hypo- and hyperthermia-related deaths, in addition to circumstantial and macroscopic findings.

Cortisol levels after cold exposure are independent of adrenocorticotropic hormone stimulation

We previously showed that postmortem serum levels of adrenocorticotropic hormone (ACTH) were significantly higher in cases of hypothermia (cold exposure) than other causes of death. This study examined how the human hypothalamic-pituitary-adrenal axis, and specifically cortisol, responds to hypothermia. Human samples: Autopsies on 205 subjects (147 men and 58 women; age 15-98 years, median 60 years) were performed within 3 days of death. Cause of death was classified as either hypothermia (cold exposure, n = 14) or non-cold exposure (controls; n = 191). Cortisol levels were determined in blood samples obtained from the left and right cardiac chambers and common iliac veins using a chemiluminescent enzyme immunoassay. Adrenal gland tissues samples were stained for cortisol using a rabbit anti-human polyclonal antibody. Cell culture: AtT20, a mouse ACTH secretory cell line, and Y-1, a corticosterone secretory cell line derived from a mouse adrenal tumor, were analyzed in mono-and co-culture, and times courses of ACTH (in AtT20) and corticosterone (in Y-1) secretion were assessed after low temperature exposure mimicking hypothermia and compared with data for samples collected postmortem for other cases of death. However, no correlation between ACTH concentration and cortisol levels was observed in hypothermia cases. Immunohistologic analyses of samples from hypothermia cases showed that cortisol staining was localized primarily to the nucleus rather than the cytoplasm of cells in the zona fasciculata of the adrenal gland. During both mono-culture and co-culture, AtT20 cells secreted high levels of ACTH after 10-15 minutes of cold exposure, whereas corticosterone secretion by Y-1 cells increased slowly during the first 15-20 minutes of cold exposure. Similar to autopsy results, no correlation was detected between ACTH levels and corticosterone secretion, either in mono-culture or co-culture experiments. These results suggested that ACTH-independent cortisol secretion may function as a stress response during cold exposure.

Postmortem Diagnosis of Fatal Hypothermia by Fourier Transform Infrared Spectroscopic Analysis of Edema Fluid in Formalin-Fixed, Paraffin-Embedded Lung Tissues

The goal of this study was to investigate whether pulmonary edema could become a specific diagnostic marker for fatal hypothermia using Fourier transform infrared (FTIR) spectroscopy in combination with chemometrics. The spectral profile analysis indicated that hypothermia fatalities associated with pulmonary edema fluid contained more β-sheet protein conformational structures than the control causes of death, which included sudden cardiac death, brain injury, cerebrovascular disease, mechanical asphyxiation, intoxication, and drowning. Subsequently, the results of principal component analysis (PCA) further revealed that the content of β-sheet protein conformational structures in the pulmonary edema fluid was the main discriminatory marker between fatal hypothermia and the other causes of death. Ultimately, a robust postmortem diagnostic model for fatal hypothermia using a partial least-squares discriminant analysis (PLS-DA) algorithm was constructed. Pulmonary edema fluid spectra collected from eight new forensic autopsy cases that did not participate in the construction of the diagnostic model were predicted using the model. The results showed the causes of death of all these eight cases were correctly classified. In conclusion, this preliminary study demonstrates that FTIR spectroscopy in combination with chemometrics could be a promising approach for the postmortem diagnosis of fatal hypothermia.

Pathophysiological significance of clock genes BMAL1 and PER2 as erythropoietin-controlling factors in acute blood hemorrhage

This study aimed to characterize the pathophysiology, including possible correlations, of clock gene expression and erythropoietin (EPO) production in the acute stage of blood hemorrhage. Specimens of human cortical tissues (right and left kidneys) and cardiac blood were collected at autopsy from 52 cases following mortality due to acute-stage blood hemorrhage following sharp instrument injury. BMAL1 and PER2 mRNA levels were determined by reverse transcription-polymerase chain reaction; BMAL1 and PER2 protein levels were assessed using immunohistochemistry; BMAL1 protein levels were quantitatively measured by western blotting; and serum EPO levels were measured by chemiluminescent enzyme immunoassay. Separately, a rat model of hemorrhagic conditions was generated and used to confirm the results obtained with autopsy-derived specimens. A positive correlation was observed between BMAL1 protein and serum EPO levels, but not between BMAL1 mRNA levels and serum EPO levels. We also noted that Per2 mRNA expression became elevated in humans who survived for > 3 h after acute hemorrhagic events, with subsequent decreases in serum EPO levels. The rat model showed that even short (30-min) intervals of blood loss yielded increases in both Bmal1 mRNA and serum EPO levels; longer (60-min) intervals resulted in increases in Per2 mRNA expression along with decreases in serum EPO. Thus, the acute-stage human hemorrhage cases and the rat hemorrhage model yielded similar tendencies for clock gene expression and EPO secretion. In conclusion, our results indicated that clock genes are involved in the regulation of EPO production during the early stages of hypoxia/ischemia resulting from the acute hemorrhagic events.

Updated review of postmortem biochemical exploration of hypothermia with a presentation of standard strategy of sampling and analyses

Hypothermia is defined as a core body temperature below 35°C and can be caused by environmental exposure, drug intoxication, metabolic or nervous system dysfunction. This lethal pathology with medico-legal implications is complex to diagnose because macroscopic and microscopic lesions observed at the autopsy and the histological analysis are suggestive but not pathognomonic. Postmortem biochemical explorations have been progressively developed through the study of several biomarkers to improve the diagnosis decision cluster. Here, we present an updated review with novel biomarkers (such as catecholamines O-methylated metabolites, thrombomodulin and the cardiac oxyhemoglobin ratio) as well as some propositional interpretative postmortem thresholds and, to the best of our knowledge, for the first time, we present the most adapted strategy of sampling and analyses to identify biomarkers of hypothermia. For our consideration, the most relevant identified biomarkers are urinary catecholamines and their O-methylated metabolites, urinary free cortisol, blood cortisol, as well as blood, vitreous humor and pericardial fluid for ketone bodies and blood free fatty acids. These biomarkers are increased in response either to cold-mediated stress or to bioenergetics ketogenesis crisis and significantly contribute to the diagnosis by exclusion of death by hypothermia.

Biochemical detection of fatal hypothermia and hyperthermia in affected rat hypothalamus tissues by Fourier transform infrared spectroscopy

It is difficult to determinate the cause of death from exposure to fatal hypothermia and hyperthermia in forensic casework. Here, we present a state-of-the-art study that employs Fourier-transform infrared (FTIR) spectroscopy to investigate the hypothalamus tissues of fatal hypothermic, fatal hyperthermic and normothermic rats to determine forensically significant biomarkers related to fatal hypothermia and hyperthermia. Our results revealed that the spectral variations in the lipid, protein, carbohydrate and nucleic acid components are highly different for hypothalamuses after exposure to fatal hypothermic, fatal hyperthermic and normothermic conditions. In comparison with the normothermia group, the fatal hypothermia and hyperthermia groups contained higher total lipid amounts but were lower in unsaturated lipids. Additionally, their cell membranes were found to have less motional freedom. Among these three groups, the fatal hyperthermia group contained the lowest total proteins and carbohydrates and the highest aggregated and dysfunctional proteins, while the fatal hypothermia group contained the highest level of nucleic acids. In conclusion, this study demonstrates that FTIR spectroscopy has the potential to become a reliable method for the biochemical characterization of fatal hypothermia and hyperthermia hypothalamus tissues, and this could be used as a postmortem diagnostic feature in fatal hypothermia and hyperthermia deaths.

Usability of Immunohistochemistry in Forensic Samples With Varying Decomposition

Immunohistochemistry (IHC) is an important diagnostic tool in anatomic and surgical pathology but is used less frequently in forensic pathology. Degradation of tissue because of postmortem decomposition is believed to be a major limiting factor, although it is unclear what impact such degradation actually has on IHC staining validity. This study included 120 forensic autopsy samples of liver, lung, and brain tissues obtained for diagnostic purposes. The time from death to autopsy ranged between 1 and more than 14 days. Samples were prepared using the tissue microarray technique. The antibodies chosen for the study included KL1 (for staining bile duct epithelium), S100 (for staining glial cells and myelin), vimentin (for endothelial cells in cerebral blood vessels), and CD45 (for pulmonary lymphocytes). Slides were evaluated by light microscopy. Immunohistochemistry reactions were scored according to a system based on the extent and intensity of the positive stain. An overall correlation between the postmortem interval and the IHC score for all tissue samples was found. Samples from decedents with a postmortem interval of 1 to 3 days showed positive staining with all antibodies, whereas samples from decedents with a longer postmortem interval showed decreased staining rates. Our results suggest that IHC analysis can be successfully used for postmortem diagnosis in a range of autopsy samples showing lesser degrees of decomposition.

Identification of potential markers of fatal hypothermia by a body temperature-dependent gene expression assay

Diagnosis of fatal hypothermia is considered to be difficult in forensic practice and even if findings due to cold exposure are evident, cold exposure is not necessarily a direct cause of death. Identification of useful molecular markers for the diagnosis of fatal hypothermia has not been successful. In this study, to identify novel molecular markers that inform the diagnosis of fatal hypothermia, we focused on skeletal muscle, which plays a role in cold-induced thermogenesis in mammals. We made rat models of mild, moderate, and severe hypothermia and performed body temperature-dependent gene expression analysis in the iliopsoas muscle using next-generation sequencing (NGS). NGS showed that after severe hypothermia, the expression levels of 91 mRNAs were more than double those in mild and moderate hypothermia and control animals. Gene ontology (GO) analysis indicated that these mRNAs are involved in a number of biological processes, including response to stress and lipids, and cellular response to hypoxia. The expression of four genes [connective tissue growth factor (Ctgf), JunB proto-oncogene, AP-1 transcription factor subunit (Junb), nuclear receptor subfamily 4, group A, member 1 (Nr4a1), and Syndecan 4 (Sdc4)] and the level of one protein (CTGF) were induced only by severe hypothermia. These genes and protein are involved in muscle regeneration, tissue repair, and lipid metabolism. These results indicate that heat production to maintain body temperature in a process leading to fatal hypothermia might be performed by the iliopsoas muscle, and that Ctgf, Junb, Nr4a1, and Sdc4 genes are potential diagnostic markers for fatal hypothermia.

Prolactin selectively transported to cerebrospinal fluid from blood under hypoxic/ischemic conditions

Aim

The aim of this study was to determine and to verify the correlation between the amount of prolactin (PRL) levels in the blood and in the cerebrospinal fluid (CSF) by various causes of death as an indicator for acute hypoxia in autopsy cases. It is to confirm the cause of the change in prolactin level in CSF by in vitro system.

Materials and methods

In autopsy materials, the PRL levels in blood from the right heart ventricle and in the CSF were measured by chemiluminescent enzyme immunoassay, and changes in the percentage of PRL-positive cells in the pituitary gland were examined using an immunohistochemical method. Furthermore, an inverted culture method was used as an in vitro model of the blood-CSF barrier using epithelial cells of the human choroid plexus (HIBCPP cell line) and SDR-P-1D5 or MSH-P3 (PRL-secreting cell line derived from miniature swine hypophysis) under normoxic or hypoxic (5% oxygen) conditions, and as an index of cell activity, we used Vascular Endothelial Growth Factor (VEGF).

Results and discussion

Serum PRL levels were not significantly different between hypoxia/ischemia cases and other causes of death. However, PRL levels in CSF were three times higher in cases of hypoxia/ischemia than in those of the other causes of death. In the cultured cell under the hypoxia condition, PRL and VEGF showed a high concentration at 10 min. We established a brain-CSF barrier model to clarify the mechanism of PRL transport to CSF from blood, the PRL concentrations from blood to CSF increased under hypoxic conditions from 5 min. These results suggested that PRL moves in CSF through choroidal epithelium from blood within a short time. PRL is hypothesized to protect the hypoxic/ischemic brain, and this may be because of the increased transportation of the choroid plexus epithelial cells.

Immunohistochemical analysis on aquaporin-1 and aquaporin-3 in skin wounds from the aspects of wound age determination

Immunohistochemical investigation of aquaporin (AQP)1 and AQP3 was performed in human skin wounds obtained from forensic autopsy cases. A total of 55 human skin wounds of different postinfliction intervals were collected as follows: group I, 0-3 days (n = 16); II, 4-7 days (n = 11); III, 9-14 days (n = 16); and IV, 17-21 days (n = 12). In uninjured skin samples, AQP1 and AQP3 could be slightly detected in dermal vessels and keratinocytes, respectively. The percentage of AQP1⁺ vessels and the number of AQP3⁺ keratinocytes were apparently elevated in accordance with wound ages. The number of AQP3⁺ keratinocytes was distinctly evident in groups II and III. Morphometrically, both AQP1⁺ vessel area and AQP3⁺ cell number were markedly increased in group II, compared with other three groups. With regard to forensic safety, AQP1⁺ vessel area of over 5% would imply wound ages of 4-12 days. Moreover, the positive area of > 15% would suggest wound age of 7-10 days. Especially, most samples of skin wounds aged 5-10 days except for only one sample (a 10-day-old wound) showed AQP3⁺ cell number of > 300, and the remaining other samples had that of < 300. Thus, the AQP3⁺ cell number of > 300 would indicate wound ages of 5-10 days. Collectively, immunohistochemical analyses of AQP1 and AQP3 in human skin wounds would support the objective accuracy of wound age determination.

Postmortem biochemistry: Current applications

The results of biochemical analyses in specimens obtained postmortem may aid death investigation when diabetic and alcoholic ketoacidosis is suspected, when death may have been the result of drowning, anaphylaxis, or involved a prolonged stress response such as hypothermia, and in the diagnosis of disease processes such as inflammation, early myocardial infarction, or sepsis. There is often cross-over with different disciplines, in particular with clinical and forensic toxicology, since some endogenous substances such as sodium chloride, potassium chloride, and insulin can be used as poisons. The interpretation of results is often complicated because of the likelihood of postmortem change in analyte concentration or activity, and proper interpretation must take into account all the available evidence. The unpredictability of postmortem changes means that use of biochemical measurements in time of death estimation has little value. The use of vitreous humour is beneficial for many analytes as the eye is in a physically protected environment, this medium may be less affected by autolysis or microbial metabolism than blood, and the assays can be performed with due precaution using standard clinical chemistry analysers. However, interpretation of results may not be straightforward because (i) defined reference ranges in life are often lacking, (ii) there is a dearth of knowledge regarding, for example, the speed of equilibration of many analytes between blood, vitreous humour, and other fluids that may be sampled, and (iii) the effects of post-mortem change are difficult to quantify because of the lack of control data. A major limitation is that postmortem vitreous glucose measurements are of no help in diagnosing antemortem hypoglycaemia.

Death from Hypothermia during a Training Course under "Extreme Conditions": Related to Two Cases

Death from hypothermia following exhaustion or from various complicated pathologies is no longer a frequent cause of death among combat troops. During a training course under "extreme conditions" in the French Alps, two young African officers died. Confronted with these two clinically confirmed cases of hypothermia, the unknown anatomopathological and biological specificities associated with death from hypothermia were highlighted. In these typical and clinically confirmed cases of death from subacute exhaustion hypothermia, none of the signs revealed by the autopsy were specific. Although some recent publications have addressed the utility of postmortem biochemical markers when establishing a diagnosis, with no anamnesis, with no knowledge or analysis of the circumstances of death, and without an in situ examination of the body, it appears difficult, if not impossible, to confirm that death was caused by hypothermia.

Non specific drug distribution in an autopsy case report of fatal caffeine intoxication

Caffeine has long been recognized as an addictive substance that causes autonomic nerve effect, and is known to increase catecholamine secretion from the adrenal glands. In recent years, the risk of ingesting toxic levels of caffeine has increased because of the easy availability of analgesics, CNS (Central Nervous System) stimulant medicine and dietary supplements at shops, health stores and through online purchases. We report the death of a young female resulting from the ingestion for suicide of an online purchased sleepiness-preventing medicine containing caffeine. The autopsy findings included pulmonary edema and congestion plus cutaneous emphysema. The stomach contents included a dark-brown viscous fluid without tablet or food residue. Toxicological examination revealed the presence of caffeine in the right heart blood (154.2 μg/mL) and stomach contents (197.5 μg/mL) (lethal blood level, >80 μg/mL). The highest caffeine content was in the bile (852.3 μg/mL). Biochemical findings showed that catecholamine concentration in the peripheral blood in the iliac vein was elevated. Immunostaining of catecholamine was weak in the adrenal medulla. We recommend highlighting the toxicity risk of ingesting substances with a high caffeine concentration, and we propose that caffeine concentrations should be included in the comprehensive routine forensic toxicological tests for all cases.

Comprehensive investigation of postmortem glucose levels in blood and body fluids with regard to the cause of death in forensic autopsy cases

The serum glucose level is regulated within a narrow range by multiple factors under physiological conditions, but is greatly modified in the death process and after death. The present study comprehensively investigated glucose levels in blood and body fluids, including pericardial fluid (PCF), cerebrospinal fluid (CSF) and vitreous humor, reviewing forensic autopsy cases (n=672). Right heart blood glucose level was often higher than at other sites, and the CSF glucose level was the lowest, showing greater dissociation in acute/subacute death cases. The glucose level was higher in the diabetic (high HbA1c) than in the non-diabetic (low HbA1c) group at each site (p<0.01-0.0001). Fatal diabetic ketoacidosis cases had evidently high glucose levels at each site; whereas in the non-diabetic group, blood glucose level was higher in fatal alcohol abuse, saltwater drowning, electrocution, cerebrovascular disease and sudden cardiac death due to ischemic heart disease. Fatal methamphetamine (MA) abuse, sepsis, malnutrition (starvation) and hypoglycemia due to antidiabetics showed markedly lower blood glucose levels. Ketones in bilateral cardiac blood and PCF were increased in diabetic ketoacidosis and fatal alcohol abuse as well as in most cases of hyperthermia (heatstroke), hypothermia (cold exposure) and malnutrition. These findings suggest that combined analysis of glucose, HbA1c and ketones in blood and body fluids is useful to investigate not only fatal diabetic metabolic disorders but also death processes due to other causes, including alcohol and MA abuse, as well as thermal disorders, sepsis and malnutrition.

Severe heatstroke complicated with Takotsubo cardiomyopathy

Case

A 69 year-old female with history of schizophrenia was transported to our hospital by ambulance due to coma. On arrival, she was hypotensive and tachycardic with a Glasgow coma scale score of 3 and a rectal core temperature of 40°C. Heatstroke was strongly suspected as the cause of the coma and hypotension. Active external cooling with an electric fan and cooled IV fluid administration were started. Her electrocardiogram (EKG) showed ST elevation in V2-6, II, III and aVF. Echocardiography revealed apical ballooning, which indicated Takotsubo cardiomyopathy. Coronary angiography indicated normal coronary arteries.

Outcome

After admission to the intensive care unit, her cardiovascular status gradually improved and she was transferred to the psychiatric ward on day 36.

Conclusion

Heatstroke and Takotsubo cardiomyopathy can share the same pathophysiology. Close evaluation of hemodynamic status and myocardial damage is critical for survival.

Cardiac biomarkers in blood, and pericardial and cerebrospinal fluids of forensic autopsy cases: A reassessment with special regard to postmortem interval

Previous studies suggested possible application of postmortem biochemistry of myocardial biomarkers to the investigation of sudden cardiac death; however, differences from clinical findings should be considered in autopsy materials. The present study involved a comprehensive investigation of cardiac troponin T and I (cTnT and cTnI), and creatine kinase MB (CK-MB) in cardiac and peripheral external iliac venous blood, pericardial fluid (PCF) and cerebrospinal fluid (CSF) for reassessment, with special regard to the estimated postmortem interval in relation to the cause of death, reviewing a large number of forensic autopsy cases (n=1923). These cardiac biomarkers showed cause-of-death- and postmortem-time-dependent differences: blood and PCF levels of each marker were higher in hyperthermia (heatstroke), bathwater drowning and chronic congestive heart disease in cases of postmortem interval (PMI) <12h. After 12h postmortem, these markers were also higher in fatal drug abuse, spontaneous cerebral/subarachnoid bleeding, electrocution and pulmonary embolism. In addition, most other causes of death, including ischemic heart disease, showed substantial elevations, while these markers remained low in acute hemorrhagic death from sharp instrument injury, hypothermia (cold exposure) and sea-/freshwater drowning during PMI of <48h. CSF cTnI and CK-MB showed similar findings. There was no difference between myocardial infarction and other causes of death to be discriminated, including asphyxiation, drowning and fire fatality. These findings are similar to clinical observations in critical ill patients, suggesting that elevated cardiac biomarkers cannot be a specific finding for death from acute ischemic heart disease, but indicate the severity of myocardial injury in postmortem investigation.

Heat Stroke-Induced Sinoatrial Node Dysfunction

BACKGROUND

Heat stroke has been associated with stress-induced cardiomyopathy and electrocardiogram ST segment elevation and depression. Laboratory studies with dogs have demonstrated heat stroke-induced sinoatrial node dysfunction in the setting of hyperkalemia. No prior case report has described heat stroke-induced complete sinoatrial node dysfunction that resolved in the emergency department.

CASE REPORT

An 87-year-old female presented to the emergency department with heat stroke and severe bradycardia. Initial electrocardiogram demonstrated complete sinoatrial node dysfunction. The bradycardia responded to external cardiac pacing and the sinoatrial node dysfunction resolved with aggressive cooling. Emergency physicians should be aware that heat stroke can cause complete sinoatrial node dysfunction and that this bradydysthrmia can be treated with aggressive cooling.

Immunohistochemical analysis on MMP-2 and MMP-9 for wound age determination

We performed immunohistochemical study combined with morphometrical analyses in order to examine the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9 using 55 human skin wounds of different ages: group I, 0-3 days (n = 16); II, 4-7 days (n = 11); III, 9-14 days (n = 16); and IV, 17-21 days (n = 12). Immunopositive reactions for MMP-2 were observed in all human skin specimens including uninjured skin as control. The number of MMP-2(+) macrophages was significantly increased in accordance with wound ages. In contrast to MMP-2, no MMP-9(+) signals were detected in uninjured and wound specimens aged less than 1 day. However, the number of MMP-9(+) macrophages profoundly appeared in groups II and III. Morphometrically, in all of wound samples aged 9-12 days, MMP-2(+) cell number was more than 20. On the contrary, most of the remaining samples had <20 positive cells. However, only one sample (a 7-day-old wound) showed 21 positive cells. Thus, with regard to practical applicability with forensic safety, MMP-2(+) macrophages of >20 would indicate a wound age of 7-12 days. Additionally, 10 out of 12 wound specimens aged 9-12 days showed the MMP-2(+) cell number of >25, implying that MMP-2(+) cell number of >25 would indicate the wound age of 9-12 days. On the contrary, all wound samples aged 3-14 days except for only one sample had MMP-9(+) cell number of >30, indicating that MMP-9(+) cell number of >30 would indicate the wound age of 3-14 days. Collectively, MMP-2 seemed to be more distinct marker, compared with MMP-9.

Forensic molecular pathology: its impacts on routine work, education and training

The major role of forensic pathology is the investigation of human death in relevance to social risk management to determine the cause and process of death, especially in violent and unexpected sudden deaths, which involve social and medicolegal issues of ultimate, personal and public concerns. In addition to the identification of victims and biological materials, forensic molecular pathology contributes to general explanation of the human death process and assessment of individual death on the basis of biological molecular evidence, visualizing dynamic functional changes involved in the dying process that cannot be detected by morphology (pathophysiological or molecular biological vital reactions); the genetic background (genomics), dynamics of gene expression (up-/down-regulation: transcriptomics) and vital phenomena, involving activated biological mediators and degenerative products (proteomics) as well as metabolic deterioration (metabolomics), are detected by DNA analysis, relative quantification of mRNA transcripts using real-time reverse transcription-PCR (RT-PCR), and immunohisto-/immunocytochemistry combined with biochemistry, respectively. Thus, forensic molecular pathology involves the application of omic medical sciences to investigate the genetic basis, and cause and process of death at the biological molecular level in the context of forensic pathology, that is, 'advanced molecular autopsy'. These procedures can be incorporated into routine death investigations as well as guidance, education and training programs in forensic pathology for 'dynamic assessment of the cause and process of death' on the basis of autopsy and laboratory data. Postmortem human data can also contribute to understanding patients' critical conditions in clinical management.

Expression variations of chromogranin A and α1,2,4 GABA(A)Rs in discrete limbic and brainstem areas rescue cardiovascular alterations

Recent interferences of hemodynamic functions via modified brain neuronal mechanisms have proven to be major causes of dementia and sleeping disorders. In this work, cerebral expression differences of the neuroactive vesicular chromogranin A (CgA) and distinct α GABA(A)R subunits were detected in the facultative hibernating hamster. In particular, damaged neuronal fields of hypotensive torpor (TORP) state were correlated to elevated CgA and GABA(A)R α1, α4 mRNA levels in the paraventricular hypothalamic nucleus (PVN), central amygdalar nucleus (CeA) plus solitary tractus nucleus (NTS). Conversely, few neurodegeneration signals of hypertensive arousal (AROU) state, accounted for mostly lower CgA levels in the same areas. This state also provided increased α2-containing sites in amygdala, hippocampal and NTS neurons together with elevated α4-containing receptors in the periventricular hypothalamic nucleus (Pe). Interestingly in our hibernating model, CgA appeared to preferentially feature inhibitory neurosignals as indicated by preliminary perfusion of amygdalar sites with its highly specific antihypertensive derived peptide (catestatin) promoting GABA-dependent sIPSCs. Overall, evident neuronal damages plus altered expression capacities of CgA and α1-, α2-, α4-GABA(A)Rs in CeA, Pe, PVN as well as NTS during both hibernating states corroborate for the first time key molecular switching events guaranteeing useful cardiovascular rescuing abilities of neurodegenerative disorders.

Usefulness of postmortem biochemistry in forensic pathology: illustrative case reports

The aim of this work is to present some practical, postmortem biochemistry applications to illustrate the usefulness of this discipline and reassert the importance of carrying out biochemical investigations as an integral part of the autopsy process. Five case reports are presented pertaining to diabetic ketoacidosis in an adult who was not known to suffer from diabetes and in presence of multiple psychotropic substances; fatal flecainide intoxication in a poor metabolizer also presenting an impaired renal function; diabetic ketoacidosis showing severe postmortem changes; primary aldosteronism presented with intracranial hemorrhage and hypothermia showing severe postmortem changes. The cases herein presented can be considered representative examples of the importance of postmortem biochemistry investigations, which may provide significant information useful in determining the cause of death in routine forensic casework or contribute to understanding the pathophysiological mechanisms involved in the death process.

Stress-induced cardiomyopathy caused by heat stroke

Heat stroke is defined by central nervous system abnormalities and failure of proper maintenance of thermoregulation as a result of high core body temperature ensuing from exposure to high environmental temperatures or strenuous exercise. Common complications include acute respiratory distress syndrome, disseminated intravascular coagulation, acute renal injury, hepatic injury, and rhabdomyolysis. Myocardial injury may also occur during heat stroke, resulting in cardiac enzyme increase and ST-segment changes on the ECG. Such findings might behave as diagnostic pitfalls by mimicking the presentation of coronary artery occlusive myocardial infarction. A previous case report described a patient with heat stroke and ST-segment elevation, in which the definite cause of the ST-segment elevation was unclear; however, acute myocardial infarction caused by coronary artery disease was ruled out according to the clinical signs, serial ECG changes, and serum level of cardiac biomarkers. Stress-induced cardiomyopathy (Takotsubo cardiomyopathy) was suspected, but it could not be confirmed because of the lack of coronary angiography. We herein report a case of heat stroke presenting with ST-segment elevation and cardiogenic shock. Coronary angiography was performed and coronary artery occlusive myocardial infarction was ruled out because of the presence of patent coronary arteries. Left ventriculography showed midventricular and apical hypokinesis, and stress-induced cardiomyopathy was then determined to be the appropriate diagnosis. Heat stroke causes increase of serum catecholamine levels, in which oversecretion and abnormal responses to catecholamines are a possible cause of stress-induced cardiomyopathy. Catecholamines may therefore be the key in linking heat stroke and stress-induced cardiomyopathy.