Postmortem pericardial natriuretic peptides as markers of cardiac function in medico-legal autopsies

Relationship between N-terminal pro-brain natriuretic peptide concentration and heart-type fatty acid-binding protein in postmortem urine

The clinical use of N-terminal pro-brain natriuretic peptide (NT-proBNP) and blood concentrations of heart-type fatty acid-binding protein (HFABP) is well-established in diagnosing heart conditions. However, their applicability in forensics is controversial due to postmortem changes. NT-proBNP and HFABP are excreted in the urine due to their small molecular weights and may be found in postmortem urine samples; however, their correlation has not been evaluated. In this study, we compared the concentrations of urinary NT-proBNP and HFABP in 386 forensic autopsy cases. The urinary NT-proBNP levels were significantly higher in acute myocardial infarction (AMI), congestive heart failure (CHF), sepsis, and hyperthermia cases, with the highest levels in CHF cases. Similarly, HFABP concentration was significantly higher in CHF, sepsis, and hyperthermia cases, with the highest level observed in hyperthermia cases. However, the difference in urinary HFABP levels between the AMI and control cases was not significant. Our analysis revealed a correlation between postmortem urine NT-proBNP and HFABP levels, and the NT-proBNP/HFABP ratio was high in patients with CHF and sepsis cases and low in those with hyperthermia. The difference between the ratios was possibly due to the combined release of ventricular myocardial cells in response to ventricular wall stress and myocardial injury for NT-proBNP, as well as myocardial and skeletal muscle injuries for HFABP. This study, for the first time, demonstrates the utility of postmortem measurements of urinary NT-proBNP and HFABP levels, offering valuable insights for improving the accuracy of postmortem diagnosis in forensic medicine.

Postmortem biochemistry in deaths from ischemic heart disease

Ischemic heart disease (IHD) is one of the leading causes of morbidity and sudden cardiac death worldwide and is an important public health problem. The presence of ischemia in clinical applications can be detected by ECG, biochemical markers, and radiological methods. Myocardial infarction is also frequently encountered in forensic autopsies. Postmortem diagnosis is determined as a result of histopathological examinations and additional exclusionary examinations (toxicology, microbiology, etc.). However, routine histopathological examinations are insufficient, especially when death occurs in the early period of ischemia. It creates a problem for forensic pathologists and forensic medicine specialists in such cases of sudden cardiac death. Postmortem biochemistry is one of the important and promising disciplines in which forensic applications work in order to diagnose these cases correctly. The issue of whether biomarkers used in the diagnosis of myocardial infarction in clinical studies can be used reliably in postmortem cases has been discussed by forensic medicine researchers for some time. This manuscript aims to review and summarize biomarkers belonging to various categories that have been studied in IHD-related deaths, in biological fluids taken at autopsy, or in animal experiments. Our study shows that the postmortem use of biochemical markers in the diagnosis of IHD yields promising results. However, it should not be forgotten that postmortem biochemistry is different from clinical applications due to its dynamics and that the body causes unpredictable changes in markers in the postmortem process. Therefore, comprehensive studies are needed to evaluate the postmortem stability of these markers in different biological fluids, their significance among various causes of death, and whether they are affected by any variable (Cardiopulmonary resuscitation, Postmortem interval, medications, etc.) before they are routinely applied. It is suggested by the authors that the cut-off values of biomarkers whose significance has been proven by these studies should be determined and that they should be used in this way in routine applications.

N terminal prohormone of brain natriuretic peptide is associated with improved heart rate recovery after treadmill exercise test

Background

Heart rate recovery (HRR) and N terminal-pro B type natriuretic peptide (NT-proBNP) are markers for survival and cardiac function; however, Little is known about their association.

Method

We examined 2540 healthy subjects aged 12-49 years with data from National Health and Nutrition Examination Survey(NHANES) 1999-2002. HRR parameters 1-3 min after exercise were calculated from exercise test results. Baseline characteristics, anthropometric and NT-proBNP, and other risk covariates were obtained.

Result

The results showed that NT-proBNP was positively correlated with HRR2(correlation coefficient (cc) = 0.042 [0.029-0.054], P < 0.001) and HRR3(cc = 0.046 [0.029-0.064], P = 0.001); with further adjustment, the associations remained significant between NT-proBNP and HRR2(cc = 0.030 [0.010-0.049], P = 0.004)/HRR3(cc = 0.029[0.004-0.054], P = 0.025). Our study also found significant correlations between NT-pro BNP and SBP(cc = -0.026 [-0.046∼-0.005], P = 0.017), DBP(cc = -0.037 [-0.062∼-0.012], P = 0.005), and total cholesterol(cc = -0.065 [-0.12∼-0.018], P = 0.009).

Conclusions

Our results suggest that BNP might reduce heart rate after exercise by inhibiting the sympathetic nervous system (SNS), reducing HRR2 and HRR3, as these phases involve the reduction of heart rate through cardiac sympathetic withdrawal. Moreover, the interaction of BNP on the SNS might be related to the effect of BNP on cardiovascular risks.

Artificial Intelligence-Enabled Electrocardiography Detects B-Type Natriuretic Peptide and N-Terminal Pro-Brain Natriuretic Peptide

BACKGROUND: The B-type natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (pBNP) are predictors of cardiovascular morbidity and mortality. Since the artificial intelligence (AI)-enabled electrocardiogram (ECG) system is widely used in the management of many cardiovascular diseases (CVDs), patients requiring intensive monitoring may benefit from an AI-ECG with BNP/pBNP predictions. This study aimed to develop an AI-ECG to predict BNP/pBNP and compare their values for future mortality. METHODS: The development, tuning, internal validation, and external validation sets included 47,709, 16,249, 4001, and 6042 ECGs, respectively. Deep learning models (DLMs) were trained using a development set for estimating ECG-based BNP/pBNP (ECG-BNP/ECG-pBNP), and the tuning set was used to guide the training process. The ECGs in internal and external validation sets belonging to nonrepeating patients were used to validate the DLMs. We also followed-up all-cause mortality to explore the prognostic value. RESULTS: The DLMs accurately distinguished mild (≥500 pg/mL) and severe (≥1000 pg/mL) an abnormal BNP/pBNP with AUCs of ≥0.85 in the internal and external validation sets, which provided sensitivities of 68.0-85.0% and specificities of 77.9-86.2%. In continuous predictions, the Pearson correlation coefficient between ECG-BNP and ECG-pBNP was 0.93, and they were both associated with similar ECG features, such as the T wave axis and correct QT interval. ECG-pBNP provided a higher all-cause mortality predictive value than ECG-BNP. CONCLUSIONS: The AI-ECG can accurately estimate BNP/pBNP and may be useful for monitoring the risk of CVDs. Moreover, ECG-pBNP may be a better indicator to manage the risk of future mortality.

Postmortem biochemical analysis of soluble ST2 in the pericardial fluid of patients with sudden cardiac death caused by ischemic heart disease: a pilot study

Soluble growth stimulation expressed gene 2 protein (sST2) is a myocardial protein induced by biomechanical stress. sST2 is widely present in the serum of patients with heart failure and is recommended as an important indicator to predict adverse outcomes in these patients. However, no postmortem biochemical analysis of sST2 in forensic practice has been reported. The present pilot study aimed to investigate the expression of sST2 in the pericardial fluid of patients with sudden cardiac death (SCD) caused by ischemic heart disease (IHD). In addition, to explore the relationship of sST2 with CK-MB, cTnT, and NT-proBNP, which have been proven to be auxiliary biomarkers for the diagnosis of SCD, we analyzed CK-MB, cTnT, NT-proBNP, and sST2 levels in twenty-one pericardial fluid samples from the Center of Forensic Investigation, China Medical University, with a Roche cobas e 411 electrochemiluminescence automatic immunoassay system and ST2/IL-33R Valukine™ enzyme-linked immunosorbent assay kit. The levels of sST2 in the pericardial fluid of patients with SCD caused by IHD were significantly increased (P < 0.01) and positively correlated with CK-MB and NT-proBNP (P < 0.0001). Receiver operating characteristic curve analysis indicated that the combined measurement of sST2 and NT-proBNP has a higher diagnostic value for SCD caused by IHD than the measurement of either indicator alone. This study preliminarily demonstrated that sST2 in the pericardial fluid was significantly increased in patients with SCD caused by IHD and might be used as a novel auxiliary biomarker for postmortem diagnosis of SCD in forensic practice.

Abnormal fatty acid metabolism and ceramide expression may discriminate myocardial infarction from strangulation death: A pilot study

Determining myocardial infarction (MI) and mechanical asphyxia (MA) was one of the most challenging tasks in forensic practice. The present study aimed to investigate the potential of fatty acid (FAs) metabolism, and lipid alterations in determining MI and MA. MA and MI mouse models were constructed, and metabolic profiles were obtained by LC-MS-based untargeted metabolomics. The metabolic alterations were explored using the PCA, OPLS-DA, the Wilcoxon test, and fold change analysis. The contents of lipid droplets (LDs) were detected by the transmission scanning electron microscope and Oil red O staining. The immunohistochemical assay was performed to detect CD36 and dysferlin. The ceramide was assessed by LC-MS. PCA showed considerable differences in the metabolite profiles, and the well-fitting OPLS-DA model was developed to screen differential metabolites. Thereinto, 9 metabolites in the MA were reduced, while metabolites were up- and down-regulated in MI. The increased CD36 suggested that MI and MA could enhance the intake of FAs and disturb energy metabolism. The increased LDs, decreased dysferlin, and increased ceramide (C18:0, C22:0, and C24:0) were observed in MI groups, confirming the lipid deposition. The present study indicated significant differences in myocardial FAs metabolism and lipid alterations between MI and MA, suggesting that FAs metabolism and related proteins, certain ceramide may harbor the potential as biomarkers for discrimination of MI and MA.

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.

Natriuretic peptides: new challenges — new solutions

Natriuretic peptides (NPs) are one of the most significant biomarkers, the practical use of which increases, and their diagnostic and prognostic value in patients with various chronic noncommunicable diseases is beyond doubt. Since the discovery of these markers, research has been actively carried out to study the biological and pathophysiological roles of NPs in a wide range of diseases, including hypertension and heart failure (HF). These studies showed that A-type and B-type NPs are hormones secreted by the heart in response to pre- or afterload, which prevent high blood pressure and fluid retention. In addition, C-type NPs are produced by the vascular endothelium and act as a local a  mediator with angioprotective properties. Since the NP system is a natural antagonist of the sympathoadrenal and renin-angiotensinaldosterone systems, it is interesting to study novel strategies to use new drug classes for hypertension. These drugs are neprilysin inhibitors, which destroys NPs; their action is to enhance the synthesis of endogenous peptides. Dual angiotensin receptor and neprilysin inhibition is widespread in clinical practice in patients with heart failure with reduced ejection fraction. Neprilysin inhibition has also been shown to be an effective strategy for hypertensive patients. The article discusses the role and value of NP system in  the dia - gnosis of heart failure and blood pressure regulation, and also considers new promising directions for neprilysin inhibition and activation of endogenous NP synthesis.

 

[A retrospective mortality analysis of natural deaths of the 65+ generation based on postmortem autopsies performed at the Institute of Legal Medicine in Frankfurt am Main during two periods]

BACKGROUND AND AIM OF THE STUDY

In Germany, a constant demographic change is taking place, which leads to an increasing aging of the society. The present study aimed to analyze natural deaths occurring at an age of ≥ 65 years, since health vulnerability in this age group is gaining importance.

MATERIAL AND METHODS

Autopsy reports of the Institute of Forensic Medicine, University Hospital of the Goethe University Frankfurt/Main, Germany, were retrospectively evaluated regarding natural death cases of ≥ 65-year-olds in a time comparison (period I: 2000-2002; period II: 2013-2015).

RESULTS

During both periods, a total of 1206 autopsies concerning this age group were performed. Among these, 404 cases (33.5%) of unnatural death and 39 cases (3.2%) of a combination of natural and unnatural death were recorded; in 94 cases (7.8%), the manner of death could not be elucidated. The majority (n = 669; 55.5%) included cases of natural death. In the largest group of these (n = 350; 52.3%), cardiac causes of death were predominant, followed by 132 (19.7%) respiratory and 47 (7.0%) abdominal causes of death. In addition, 37 (5.5%) cases of malignant neoplasms, 33 (4.9%) of ruptures of large vessels, 33 (4.9%) of cerebral, and 37 (5.5%) other cases of natural death were noted. A significant decrease of cardiac causes of death was observed in the comparison of periods I and II. In particular, there was a significant decrease in high-grade occlusive coronary sclerosis. Moreover, there were significant differences between both sexes. Men had significantly more bypasses, stents and heart scars and suffered a myocardial infarction about 10 years earlier than women.

CONCLUSION

The results of the present study are largely consistent with the literature. The decrease in numbers of cardiac deaths may be attributed to increasingly better medical care and to a significantly higher rate of stent implantation. Especially in times of pandemics, the role of forensic gerontology will become more important.

Inferior mesenteric artery laceration associated with blunt abdominal trauma with Casper's sign in a physically abused child: An autopsy case and literature review

There have been few studies of the death of children secondary to child abuse-related abdominal compression, and the detailed pathophysiology of such deaths is therefore unknown. The autopsy findings of a 3-year-old boy who died of hemorrhagic shock due to non-accidental severe blunt abdominal trauma were compared to those of children who died of other non-accidental abdominal injuries. Old and acute subcutaneous hemorrhages, abrasions, and scars were present all over the subject's body. No superficial injuries were found on the ventral midline, but a minor hemorrhage was found in the subcutaneous fat tissue, as well as in the rectus abdominis muscle. The intraperitoneal space contained 450 mL of blood, including coagulated blood. There was a tear in the transverse mesocolon and a crush injury in the small bowel mesentery. The inferior mesenteric artery was transected 0.5 cm from the aortic root. The transverse colon was necrotic, with hemorrhages in the mucosa. Since various organs were ischemic, the cause of death was determined to be blood loss from the inferior mesenteric artery injuries. Blunt abdominal trauma in children usually causes organ damage and intestinal injury, but because it is caused on the posterior surface of the mesentery, vascular injury should also be considered, and an autopsy should be performed. In the case of child abuse-related deaths, damage to the skin surface may not always be present; therefore, imaging tests, histopathological examinations, and biochemical tests should be performed with a focus on the gross anatomy to determine the cause of death and pathology.

Combined determination of B-type natriuretic peptide and high-sensitivity troponin I in the postmortem diagnosis of cardiac disease

Cardiac disease is the most common cause of sudden death in Western countries. It is known that high-sensitivity troponin I (hs-cTnI), widely used for detection of myocardial injury, is a sensitive biochemical marker. B-type natriuretic peptide (BNP) is a reliable tool for diagnosing heart failure, and for establishing prognosis or disease severity. We aimed to evaluate the diagnostic efficacy of the postmortem determination of BNP in serum alone or in addition to other biomarkers, such as hs-cTnI and MB isoenzyme of creatine kinase (CK-MB), to ascertain whether its determination improves the post-mortem diagnosis of heart failure-associated causes of death. This study involved 133 cadavers with a mean age of 58.2 (± 17.6) years and a mean postmortem interval of 12.8 (±6.6) h. Cases were assigned into two diagnostic groups, according to the cause of death: cardiac deaths (N = 62) and control (N = 71). In the cardiac group, two categories were established according to morphological features of the heart: 'ischemic deaths' (N = 39), and 'congestive heart' (n = 23). Both hs-cTnI and BNP were useful in diagnosing cardiac deaths, whereas CK-MB did not have any diagnostic relevance. hs-cTnI is higher in cases which acute ischemia as the principal pathology, while the presence of high BNP values is significantly related with chronic cardiac situations with significant ventricular overload. Our findings show that postmortem determination of hs-cTnI and BNP provides valuable information; hs-cTnI is useful for diagnosis of cardiac deaths, mainly with ischemic implications, and BNP gave better results for the diagnosis of congestive heart failure.

mRNA expression patterns in human myocardial tissue, pericardial fluid and blood, and its contribution to the diagnosis of cause of death

Gene expression has become an interesting research area in forensic pathology to investigate the process of death at the molecular level. The aims of this study were to analyze changes in gene expression patterns in relation to the cause of death, and to propose new molecular markers of myocardial ischemia of potential use for the postmortem diagnosis of early ischemic heart damage in cases of sudden cardiac death (SCD). We determined mRNA levels of five proteins related with ischemic myocardial damage and repair - TNNI3, MYL3, TGFB1, MMP9 and VEGFA - in specific sites of the myocardium, blood and pericardial fluid in samples from 30 cadavers with different causes of death (SCD, multiple trauma, mechanical asphyxia, and other natural deaths). TNNI3 expression in blood, and MMP9 expression in pericardial fluid, were significantly higher when the cause of death was mechanical asphyxia, probably because of the more sensitive response of these proteins to acute systemic hypoxia/ischemia. Specifically, among SCD cases, increased MYL3, VEGFA and MMP9 values in the anterior wall of the right ventricle were found when the confirmed cause of death was acute myocardial infarction (AMI). Higher TGFB1 expression was found in the interventricular septum when AMI was not the cause of death, most likely as a reflection of the short duration of ischemia. Molecular biology techniques can provide complementary tools for the forensic diagnosis of early ischemic myocardial damage and AMI, and may make it possible to determine the duration and severity of myocardial ischemia.

BNP and NT-proBNP as Diagnostic Biomarkers for Cardiac Dysfunction in Both Clinical and Forensic Medicine

Currently, brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are widely used as diagnostic biomarkers for heart failure (HF) and cardiac dysfunction in clinical medicine. They are also used as postmortem biomarkers reflecting cardiac function of the deceased before death in forensic medicine. Several previous studies have reviewed BNP and NT-proBNP in clinical medicine, however, few articles have reviewed their application in forensic medicine. The present article reviews the biological features, the research and application status, and the future research prospects of BNP and NT-proBNP in both clinical medicine and forensic medicine, thereby providing valuable assistance for clinicians and forensic pathologists.

Evaluation of the distribution of nicotine intravenous injection: an adult autopsy case report with a review of literature

We reported the first comprehensive autopsy case of death due to intravenous injection of nicotine. We examined the distribution of nicotine in the body tissues and fluid and exposed the pathophysiology of nicotine poisoning. A 19-year-old woman was rushed to the hospital in cardiorespiratory arrest and was confirmed dead upon arrival. Liquid nicotine, hydrogen peroxide water, and a syringe were found in the hotel room where she stayed. On autopsy, nicotine concentration was the highest (15,023 μg/mg) in the tissue around the injection mark on the right upper arm. Among the body fluids, the intraperitoneal fluid had the highest, whereas the pericardial fluid had the lowest (0.736 μg/mL) nicotine concentration. Among the organs, the brain had the highest (11.637 μg/mg), whereas the fat tissue had the lowest (1.307 μg/mg) nicotine concentration. The concentration of cotinine, which is the metabolite of nicotine, was the highest in the tissue around the injection mark on the right arm (5.495 μg/mg) and was almost the same among the other body fluids and organs. The respective concentrations of nicotine and cotinine were 1.529 μg/mL and 0.019 μg/mL in the left heart blood and 3.157 μg/mL and 0.002 μg/mL in right heart blood. In this case, the nicotine concentrations in blood reached the lethal level. The distributions of nicotine and cotinine, as indicated by the intravenous injection, were related to the distribution of organs that metabolize nicotine and the distribution of nicotinic acetylcholine receptors.

Differential expression of B-type natriuretic peptide between left and right ventricles, with particular regard to sudden cardiac death

The aim of the present study was to investigate the differential expression of B-type natriuretic peptide (BNP) between the left and right ventricle (RV) in sudden cardiac death (SCD). A total of 26 forensic autopsy cases of sudden death (survival time <30 min, postmortem interval <48 h or frozen within 6 h following death) in the present institute were examined. The cases consisted of acute ischemic heart disease (AIHD, n=15) with/without apparent myocardial necrosis as a sign of infarction (acute myocardial infarction, n=6; ischemic heart disease, IHD, n=9), and arrhythmogenic right ventricular cardiomyopathy (ARVC/D, n=5), in addition to traffic accidents and high falls without any pre existing heart disease as control (C, total n=6). BNP was investigated in all cases by the colloidal gold method, hematoxylin-eosin staining, immunohistochemistry (IHC) and the molecular pathological method. The IHC results demonstrated that a positive BNP immunostaining was detected in all groups; however, there was no difference between different causes of death. Pericardial N-terminal (NT)-proBNP concentration was significantly increased in deaths resulting from AIHD and ARVC/D compared with control group. The relative quantification of BNP mRNA demonstrated that relative expression levels of BNP mRNA were significantly increased in the left ventricle (LV) in the AIHD group, and in the RV of the ARVC/D group. The relative quantification difference and ratio of BNP mRNA between LV and RV demonstrated a significantly greater value in the AIHD group compared with control group. BNP mRNA in myocardium and NT-proBNP concentration in pericardial fluid were elevated in SCD patients, and left ventricular dysfunction predominated in AIHD patients, whereas right ventricular dysfunction predominated in ARVC/D patients. The results of the present study suggest the possible use of molecular pathology of BNP for the determination of terminal cardiac function in SCD and analysis of its fatal mechanism in forensic practice.

Sudden cardiac death of Duchenne muscular dystrophy with NT-proBNP in pericardial fluid as a useful biomarker for diagnosis of the cause of death: a case report

Duchenne muscular dystrophy (DMD) is one of the most common and severest muscular dystrophies. Although it can be a cause of death when associated with cardiac muscle and/or respiratory muscles, no cases of sudden deaths in the setting of undiagnosed DMD with cardiac involvement have been reported in the literatures. Previous studies showed that N-terminal-proBNP (NT-proBNP) was a robust laboratory biomarker to diagnose and monitor cardiac failure in clinical situations, suggesting that it may be used as an auxiliary indicator for diagnosis on left ventricular dysfunction in sudden cardiac deaths in forensic settings. Here, we reported a case of 29-year-old man who died suddenly. Autopsy revealed that muscles of the body were almost replaced by fatty and fibrotic tissues. The heart was enlarged with disarray and degeneration of cardiomyocytes in cardiac muscle. Total absence of dystrophin was detected by immunohistochemical staining, which confirmed DMD. Postmortem biochemical test of pericardial fluid revealed a high level of NT-proBNP, indicating dysfunction of the left ventricle before death. The cause of death was certified as an early dilated cardiomyopathy (DCM)/dysfunction of the left ventricle secondary to DMD, suggesting that sudden cardiac death with cardiac dysfunction could be identified by immunohistochemical method in combination with pericardial fluid NT-proBNP determination after systemic autopsy.

Astrocytic clasmatodendrosis in the cerebral cortex of methamphetamine abusers

Postmortem investigation of methamphetamine (MA) abuse is an important task in forensic pathology. The present study investigated morphological changes in the astrocytes in the parietal cerebral cortex of MA abusers. Glial fibrillary acidic protein immunoreactivity in the cerebral cortex was examined in forensic autopsy cases for MA-detected group and control group. Clasmatodendrotic astrocytes (including those with swollen cell bodies and disintegrating distal processes) were frequently observed in the cerebral cortex of MA abusers. Quantitative analysis using a colour image processor showed a concomitant increase in the astrocyte area and astrocyte-to-vessel area ratio (size and number of astrocytes) in the grey matter in acute MA fatality and other MA-involved cases, although the astrocyte area (size) was also increased in cases of asphyxiation. The total astrocyte area (size) in the white matter was significantly higher in MA fatalities and asphyxia than in the other groups involving MA abusers. Those indices were independent of blood MA level, age, sex, survival or postmortem time. These observations suggest the increasing number and hypertrophic changes of astrocytes in the grey matter in MA abusers can be the outcome of long-term abuse, while disintegrating distal processes may exist only in acute fatal MA intoxication.

Biodistribution of diphenhydramine in reproductive organs in an overdose case

Motion sickness medications such as Travelmin^® prescribed in Japan include diphenhydramine (DPH), dyphylline, diphenidol, and/or caffeine. Herein, we report a patient who died due to rhabdomyolysis after ingesting a DPH containing motion sickness medication. A Japanese male in his 30 s reported missing after going out for a drive early in the morning was found dead in his car in the evening of the same day. An autopsy showed moderate edema, congestion, and several petechiae in both lungs. The brain was congested and edematous with no atherosclerosis of cerebral arteries. The prostate and both testes were slightly edematous. Gastric contents included approximately 15 mL of dark-brown fluid without tablets or food residue. Toxicological examination showed that blood DPH levels in all tissues were between 4.90 and 7.27 μg/mL, which represented toxic to lethal levels. DPH (μg/mL) levels were approximately 3-9 times higher in the prostate (73.42) and testes (left, 28.23; right, 30.09) than those in all regions of the brain (range 7.75-12.33). Blood dyphylline, diphenidol and caffeine levels in reproductive organs reached high, but not toxic levels. In conclusion, DPH, dyphylline, diphenidol, and caffeine levels were higher in reproductive organs such as the prostate and testes than in the central nervous system and heart. As we determined in this case, motion sickness medications might accumulate in reproductive organs. Thus, further examination of tissue biodistribution of DPH, dyphylline, diphenidol, and caffeine is necessary to assess their potential long-term effects in these sites.

Serum atrial natriuretic peptide (ANP) as an objective indicator for the diagnosis of neurogenic shock: animal experiment and human case report

In forensic medicine, the diagnosis of death due to neurogenic shock is considered to be an aporia, as lacking objective indicators and presenting atypical symptoms in autopsy. Medico-legal disputes and complaints occasionally result from this ambiguity. To explore potential objective indicators of neurogenic shock, we set up a model of neurogenic shock by applying an external mechanical force on the carotid sinus baroreceptor in rabbits. The serum atrial natriuretic peptide (ANP) level was measured by radioimmunoassay in the control group (n = 8), survival group (n = 15) and death group (n = 5) both before and after the insult. The serum ANP level showed a significant increase after the insult in the death group compared with the serum obtained before the insult (P = 0.006), while the serum ANP level after the insult in the survival group and control group was not statistically significant compared with the serum obtained before the insult (P = 0.332 and P = 0.492, respectively). To verify the repeatability of the model and the postmortem behavior of serum ANP, five healthy adult rabbits underwent the same procedure as the experimental group. The mortality rate was consistent with the former experiment (20 %). There were no significant changes in serum ANP level in vitro and in vivo (within 48 and 24 h, respectively). But there was a significant decrease in serum ANP level at 48 h postmortem in vivo (P = 0.001). A female patient who expired due to neurogenic shock during a hysteroscopy was reported. Neither fatal primary disease nor evidence for mechanical injuries or intoxication was found according to the autopsy. The serum ANP level was assayed as a supplementary indicator and was found to be three-fold higher than the normal maximum limit. Combined with the animal experiment, this case highlights that serum ANP has the potential to be an objective indicator for the diagnosis of death due to neurogenic shock.

Elevation of NT-proBNP and cardiac troponins in sepsis-related deaths: a forensic perspective

In the present study, the levels of NT-proBNP, troponin T, and troponin I were measured in postmortem serum from femoral blood in a series of sepsis-related fatalities that had undergone forensic autopsies. We aimed to assess whether a possible increase in the concentrations of these biomarkers was correlated to macroscopic or microscopic observations that suggest myocardial damage or cardiac dysfunction. Two study groups were retrospectively formed, a sepsis-related fatalities group and a control group. Both groups consisted of 16 forensic autopsy cases. Unenhanced computed tomography scan, autopsy, histological, toxicological, microbiological, and biochemical analyses were performed for all cases in both groups. Levels of procalcitonin, C-reactive protein, NT-proBNP, troponin T, and troponin I were systematically measured in postmortem serum from femoral blood. The preliminary results suggest that the postmortem serum troponin I, troponin T, and NT-proBNP levels are increased in sepsis-related deaths in the absence of any relevant coronary artery disease, myocardial ischemia, or signs of heart failure. These findings corroborate clinical data from previous studies pertaining to the usefulness of troponins and natriuretic peptides as indicators of toxic and inflammatory damage to the heart in cases of severe sepsis and septic shock without concomitant underlying coronary syndromes.

Changes in Surface Charge Density of Blood Cells in Fatal Accidental Hypothermia

The objective of this research was to evaluate postmortem changes concerning electric charge of human erythrocytes and thrombocytes in fatal accidental hypothermia. The surface charge density values were determined on the basis of the electrophoretic mobility measurements of the cells conducted at various pH values of electrolyte solution. The surface charge of erythrocyte membranes after fatal accidental hypothermia increased compared to the control group within whole range of experimental pH values. Moreover, a slight shift of the isoelectric point of erythrocyte membranes towards high pH values was observed. The surface charge of thrombocyte membranes in fatal accidental hypothermia decreased at low pH compared to the control group. However, at pH range 4-9, the values increased compared to the control group. The isoelectric point of thrombocyte membranes after fatal accidental hypothermia was slightly shifted towards low pH values compared to the control group. The observed changes are probably connected with the partial destruction and functional changes of the blood cell structure.

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.

Cardiac troponin T in forensic autopsy cases

The aim of the present study was to describe the findings of postmortem serum and pericardial fluid (PF) cardiac troponin T (cTnT) in various causes of death with regard to the postmortem interval (PMI) and comorbid cardiovascular disease, using 101 autopsy cases with PMI of 8-141 h divided into 9 groups: cardiovascular disease (CVD), other diseases (OD), poisoning (P), asphyxia (A), drowning (D), hypothermia (H), thoracic trauma (TT), other trauma (OT) and fire fatalities (F). The results suggest that cTnT levels may help to differentiate cardiovascular death from poisoning and non-thoracic trauma, as well as to differentiate cardiovascular and other diseases as cause of death from drowning and hypothermia. However, the effect of PMI, unlike comorbid cardiovascular disease, has to be taken into account.

[Cardiac troponin I and the post-mortem diagnosis of myocardial damage]

The aim of this study is to analyse the diagnostic efficacy of post-mortem dosage of cardiac troponine I in cadaver fluids in detection of myocardial damage.

MATERIAL AND METHODS

Our study is prospective, interesting 72 corps autopsied at the Department of Forensic Medicine of the University Hospital Fattouma Bourguiba of Monastir-Tunisia. Were excluded from the study, resuscitated cases and those examined more than 48h after death. Levels of cardiac troponine I were measured in pericardial fluid, cardiac blood and peripheral blood. Statically significant correlations between different variables levels of cardiac troponine I and cardiac damage were studied. Receiver-operator characteristic (ROC) curves were generated and areas under the curves were determined. SPSS (version 12.0) et MedCalc statistical software (version 11.0) were used for statistical analysis. Results were considered to be statistically significant when P<0.05.

MAIN RESULTS

Cardiac troponin I levels in pericardial fluid, cardiac and peripheral blood are correlated significantly between subject with and without observable signs of myocardial damage with a P value respectively at 0.0007, 0.0009 and 0.004. ROC curves analysis showed that the pericardial fluid have the best sensibility and specificity with a cut-off level at 108ng/ml and an area under the curve at 0.925.

CONCLUSION

Our data indicate that cardiac troponin I may be a powerful aid in the diagnosis of myocardial damages. This biological test can be used in triaging sudden deaths before to external examination versus complete autopsy.

Sensitivity and specificity of NT-proBNP to detect heart failure at post mortem examination

NT-proBNP, a marker of cardiac failure, has been shown to be stable in post mortem samples. The aim of this study was to assess the accuracy of NT-proBNP to detect heart failure in the forensic setting. One hundred sixty-eight consecutive autopsies were included in the study. NT-proBNP blood concentrations were measured using a chemiluminescent immunoassay kit. Cardiac failure was assessed by three independent forensic experts using macro- and microscopic findings complemented by information about the circumstances of body discovery and the known medical story. Area under the receiving operator curve was of 65.4% (CI 95%, from 57.1 to 73.7). Using a standard cut-off value of >220 pg/mL for NT-proBNP blood concentration, heart failure was detected with a sensitivity of 50.7% and a specificity of 72.6%. NT-proBNP vitreous humor values were well correlated to the ones measured in blood (r (2) = 0.658). Our results showed that NT-proBNP can corroborate the pathological findings in cases of natural death related to heart failure, thus, keeping its diagnostic properties passing from the ante mortem to the post mortem setting. Therefore, biologically inactive polypeptides like NT-proBNP seem to be stable enough to be used in forensic medicine as markers of cardiac failure, taking into account the sensitivity and specificity of the test.

The role of postmortem cardiac markers in the diagnosis of acute myocardial infarction

Sudden cardiac deaths because of acute myocardial infarction (MI) constitute a significant percentage of the caseload for death investigators, coroners, and forensic pathologists. Clinicians use cardiac markers, highly sensitive and specific for myocardial damage, to screen living patients for acute MI; however, to this point, the utility of these markers in the autopsy setting has not been fully established. The current study included 10 decedents, five who died of acute MI, and five subjects who died of noncardiac disease. Samples of pericardial fluid and blood from multiple sites were tested for creatine kinase, creatinine kinase MB, and troponin-I. Three main conclusions were drawn: the levels of cardiac markers from all patients are significantly higher than the reference range for living patients, there are significant differences in cardiac marker levels between samples from different anatomic locations, and only three cardiac marker/anatomic site combinations were significantly different between the control and study groups.

Cardiac oxidative stress determination and myocardial morphology after a single ecstasy (MDMA) administration in a rat model

Experimental and clinical data indicate that 3,4-methylenedioxy-N-methylamphetamine (MDMA) abuse can produce significant cardiovascular toxicity. A mechanism may be a direct toxic effect of redox active metabolites of MDMA. To evaluate the effect of a single MDMA dose on cellular antioxidant defence system and to investigate the morphology in male albino rats, total glutathione (GSH), oxidised glutathione (GSSG), ascorbic acid (AA), glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD) and malondialdehyde (MDAL) were studied. The effects were evaluated at 3, 6, 16 and 24 h after MDMA administration. Antioxidant enzymes activity was significantly reduced: GPx (-24%) and SOD (-50%) after 3 h and GR (-19%) after 6 h from treatment. AA levels decrease (-37%) after 3 h and (-30%) after 6 h; MDAL level increased (+119%) after 3 h; GSH levels decreased after 3 (31.3%) and 6 h (37.9%) from MDMA treatment. GSSG content was not affected by ecstasy administration. Myocardial contraction band necrosis (CBN) was already visible in rats killed at 6 h. After 16 h, macrophagic monocytes around the necrotic myocardial cells were observed, and within 24 h, this infiltrate became more widespread with an early removal of the necrotic material. Calcium deposits were observed within ventricular cardiomyocytes with intact nuclei and sarcomeres. Single administration of MDMA can significantly alter the cellular antioxidant defence system and produce oxidative stress which may result in lipid peroxidation and disruption of Ca(2 +) homeostasis. The depression in Ca(2+) regulatory mechanism by reactive oxygen species ultimately results in intracellular Ca(2 +) overload, CBN and cell death.

Evaluation of postmortem measurement of NT-proBNP as a marker for cardiac function

Clinical biomarkers of cardiac function could also be monitored postmortem. Among the natriuretic peptides, the aminoterminal portion of pro-brain natriuretic peptide (NT-proBNP) appears to be a more reliable postmortem tool than the BNP, owing to its longer half-life and greater stability. In living persons, NT-proBNP is considered to be a marker of heart failure, and its level rises after cardiac ischemia. The goal of this study was first to evaluate the postmortem stability of NT-proBNP, then to measure the NT-proBNP levels in postmortem cases of heart failure related to coronary ischemia. The goal of this study was also to evaluate the correlations between different specimens collected at autopsy (e.g. blood, serum, vitreous humor and pericardial fluid). The study included 96 cases, which were classified into 4 groups according to the autopsy and histological findings. The NT-proBNP levels were significantly higher in individuals who had suffered from chronic cardiac ischemia, with or without acute coronary events, than in either control cases or those who had suffered from acute thromboembolism or acute rupture of a plaque without chronic cardiac ischemia. The highest levels were registered in individuals who had suffered from acute coronary thromboembolism in association with chronic coronary ischemia. Good correlations in the NT-proBNP levels for the different specimens were observed between samples of femoral blood, serum, and pericardial fluid. Our data indicated that postmortem measurements of NT-proBNP are reliable and compatible with clinical findings.

Alterations of atrial natriuretic peptide in cardiomyocytes and plasma of rats after different intensity exercise

To characterize the effect of long-term exercise training at different intensities on endocrine structure and function of the heart, plasma atrial natriuretic peptide (ANP) levels, expression of ANP in cardiomyocytes, and ultrastructure of cardiomyocytes were examined by radioimmunoassay, immunohistochemistry and transmission electron microscopy in Sprague-Dawley rats trained on a treadmill at different intensities for 8 weeks. The plasma ANP increased gradually with increasing exercise intensity. The immunoreactivity of ANP in cardiomyocytes increased in the moderate- and high-intensity exercise group and decreased in the exhaustive exercise group. The ANP electron-dense granules and the quantity and volume of mitochondria increased in moderate and high-intensity exercise group. The ANP electron dense granules decreased and the mitochondria tumefied in the exhaustive exercise group. The changes of plasma ANP have a tendency of increasing gradually with increase in exercise intensity. Moderate and high-intensity exercise increases ANP synthesis and storage in cardiomyocytes and induces adaptive changes in the ultrastructure of cardiomyocytes. The decrease of ANP immunoreactivity in cardiomyocytes after exhaustive exercise is probably the result of massive depletion and induces damaging changes in the ultrastructure of cardiomyocytes.