Oxidative-Nitrosative Stress and Myocardial Dysfunctions in Sepsis: Evidence from the Literature and Postmortem Observations.

BACKGROUND: Myocardial depression in sepsis is common, and it is associated with higher mortality. In recent years, the hypothesis that the myocardial dysfunction during sepsis could be mediated by ischemia related to decreased coronary blood flow waned and a complex mechanism was invoked to explain cardiac dysfunction in sepsis. Oxidative stress unbalance is thought to play a critical role in the pathogenesis of cardiac impairment in septic patients. AIM: In this paper, we review the current literature regarding the pathophysiology of cardiac dysfunction in sepsis, focusing on the possible role of oxidative-nitrosative stress unbalance and mitochondria dysfunction. We discuss these mechanisms within the broad scenario of cardiac involvement in sepsis. CONCLUSIONS: Findings from the current literature broaden our understanding of the role of oxidative and nitrosative stress unbalance in the pathophysiology of cardiac dysfunction in sepsis, thus contributing to the establishment of a relationship between these settings and the occurrence of oxidative stress. The complex pathogenesis of septic cardiac failure may explain why, despite the therapeutic strategies, sepsis remains a big clinical challenge for effectively managing the disease to minimize mortality, leading to consideration of the potential therapeutic effects of antioxidant agents.

A Pathophysiological Insight into Sepsis and Its Correlation with Postmortem Diagnosis.

BACKGROUND: Sepsis is among the leading causes of death worldwide and is the focus of a great deal of attention from policymakers and caregivers. However, sepsis poses significant challenges from a clinical point of view regarding its early detection and the best organization of sepsis care. Furthermore, we do not yet have reliable tools for measuring the incidence of sepsis. Methods based on analyses of insurance claims are unreliable, and postmortem diagnosis is still challenging since autopsy findings are often nonspecific. AIM: The objective of this review is to assess the state of our knowledge of the molecular and biohumoral mechanisms of sepsis and to correlate them with our postmortem diagnosis ability. CONCLUSION: The diagnosis of sepsis-related deaths is an illustrative example of the reciprocal value of autopsy both for clinicians and for pathologists. A complete methodological approach, integrating clinical data by means of autopsy and histological and laboratory findings aiming to identify and demonstrate the host response to infectious insults, is mandatory to illuminate the exact cause of death. This would help clinicians to compare pre- and postmortem findings and to reliably measure the incidence of sepsis.

Use of contrast media in diagnostic imaging: medico-legal considerations.

Contrast media (CM) are used in imaging techniques to enhance the differences between body tissues on images. The ideal contrast medium should achieve very high concentration in the tissues without producing any adverse effects. Unfortunately, this has not been possible so far and all CM have adverse effects. The increasing use of CM is likely to give rise to a wide range of pitfalls, including compliance with and appropriateness of indications for the use of CM themselves, the choice of the 'best' contrast agent, off-label use, evaluation of special populations of patients, and competence to tackle emergency scenarios following the administration of CM. Even more prominent, and potentially more important, is the issue of informed consent which brings with it a duty to inform patients awaiting the administration of CM with regard to the nature of the procedure, the existence of alternative procedures, the extent of the risks relating to the use of CM and, finally, the risks relating to refusal of the procedure. All these issues may give rise to concerns about liability for failure to offer adequate information to patients or to carefully evaluate and balance the potential risks and benefits of the procedure or, finally, for being unprepared in the event of adverse reactions to CM, especially when these are severe and life-threatening. Educational and training programmes for radiologists are likely to shape change in the medical liability environment in the coming years.

Retrospective analysis of anaesthesia-related deaths during a 12-year period: looking at the data from a forensic point of view.

Anaesthesia-related death is one of the most complex events to be studied in forensic pathology because of its rarity and its doubtful presentation. Particularly, the difficulties in assessing the cause of deaths in such circumstances are underlined. A scale must be considered in order to determine the causal role of anaesthesia in the process leading to death. Indeed, beyond deaths exclusively explained by anaesthetic care, there are deaths that are not anaesthesia-related and deaths explained by surgery and co-morbidities in which the role of anaesthetic care has to be carefully investigated. A retrospective analysis of 3138 autopsies is presented with the aim of better understanding the patho-physiological process of anaesthesia-related mortality and to determine the causal role of anaesthesiological care in the process leading to death, thus assessing the real incidence of deaths due to anaesthesia (0.16%). In the present study, the number of deaths generically anaesthesia-related (33 cases) accounts for 2.06% of autopsies due to medical malpractice claims and 1.05% of all autopsies. The number of deaths totally related to anaesthesic care is rather low with 0.32% of autopsies due to medical malpractice claims and 0.16% of all autopsies. Anaesthesia-related deaths were due to lack of or delay in intubation (2 cases), acute cardio-respiratory failure (2 cases) and anaesthetic-induced hepatotoxicity (1 case). The importance of a careful forensic investigation (clinical and familial history, medical records, complete autopsy and toxicology), which can lead to a clear understanding of anaesthesia-related deaths, is also stressed.

Acute administration of 3,4-methylenedioxymethamphetamine (MDMA) induces oxidative stress, lipoperoxidation and TNFα-mediated apoptosis in rat liver.

Liver toxicity is one of the consequences of ecstasy (3,4-methylenedioxymethamphetamine MDMA) abuse and hepatocellular damage is reported after MDMA consumption. Various factors probably play a role in ecstasy-induced hepatotoxicity, namely its metabolism, the increased efflux of neurotransmitters, the oxidation of biogenic amines, and hyperthermia. MDMA undergoes extensive hepatic metabolism that involves the production of reactive metabolites which form adducts with intracellular nucleophilic sites. MDMA-induced-TNF-α can promote multiple mechanisms to initiate apoptosis in hepatocytes, activation of pro-apoptotic (BID, SMAC/DIABLO) and inhibition of anti-apoptotic (NF-κB, Bcl-2) proteins. The aim of the present study was to obtain evidence for the oxidative stress mechanism and apoptosis involved in ecstasy-induced hepatotoxicity in rat liver after a single 20 mg/kg, i.p. MDMA administration. Reduced and oxidized glutathione (GSH and GSSG), ascorbic acid (AA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and malondialdehyde (MDA), an indicator of lipid peroxidation, were determined in rat liver after 3 and 6h after MDMA treatment. The effect of a single MDMA treatment included decrease of GR and GPx activities (29% and 25%, respectively) and GSH/GSSG ratio (32%) with an increase of MDA (119%) after 3h from ecstasy administration compared to control rats. Liver cytosolic level of AA was increased (32%) after 6 h MDMA treatment. Our results demonstrate a strong positive reaction for TNFα (p<0.001) in hepatocytes and a diffuse apoptotic process in the liver specimens (p<0.001). There was correlation between immunohistochemical results and Western blotting which were quantitatively measured by densitometry, confirming the strong positivity for TNF-α (p<0.001) and NF-κB (p<0.001); weak and intense positivity reactions was confirmed for Bcl-2, SMAC/DIABLO (p<0.001) and BID reactions (p<0.001). The results obtained in the present study suggest that MDMA induces loss of GSH homeostasis, decreases antioxidant enzyme activities, and lipoperoxidation that causes an oxidative stress that accompaines the MDMA-induced apoptosis in liver cells.

The NADPH oxidase NOX2 as a novel biomarker for suicidality: evidence from human post mortem brain samples.

Recent evidence points towards a role of oxidative stress in suicidality. However, few studies were carried out on the sources of reactive oxygen species (ROS) in subjects with suicidal behaviour. We have previously demonstrated that the NADPH oxidase NOX2-derived oxidative stress has a major role in the development of neuropathological alterations observed in an animal model of psychosis. Here, we investigated the possible increase in NOX2 in post mortem brain samples of subjects who died by asphyctic suicide (AS) compared with controls (CTRL) and subjects who died by non-suicidal asphyxia (NSA). We found that NOX2 expression was significantly higher in the cortex of AS subjects than in the other two experimental groups. NOX2 immunostaining was mainly detected in GABAergic neurons, with a minor presence of NOX2-positive-stained cells in glutamatergic and dopaminergic neurons, as well as astrocytes and microglia. A sustained increase in the expression of 8-hydroxy-2'-deoxyguanosine, an indirect marker of oxidative stress, was also detected in the cortex of AS subjects, compared with CTRL and NSA subjects. A significant elevation in cortical interleukin-6 immunoreactivity in AS subjects suggested an involvement of cytokine-associated molecular pathways in NOX2 elevations. Our results suggest that the increase in NOX2-derived oxidative stress in the brain might be involved in the neuropathological pathways leading to suicidal behaviour. These results may open innovative insights in the identification of new pathogenetic and necroscopic biomarkers, predictive for suicidality and potentially useful for suicide prevention.

Cardiovascular effects of cocaine: cellular, ionic and molecular mechanisms.

Cocaine is a widely abused drug responsible for the majority of deaths ascribed to drug overdose. Many mechanisms have been proposed in order to explain the various cocaine associated cardiovascular complications. Conventionally, cocaine cardiotoxicity has been thought to be mediated indirectly through its sympathomimetic effect, i.e., by inhibiting the reuptake and thus increasing the levels of neuronal catecholamines at work on adrenoceptors. Increased oxidative stress, reactive oxygen species, and cocaine-induced apoptosis in the heart muscle have suggested a new way to understand the cardiotoxic effects of cocaine. More recent studies have led the attention to the interaction of cocaine and some metabolites with cardiac sodium, calcium and potassium channels. The current paper is aimed to investigate the molecular mechanisms of cocaine cardiotoxicity which have a specific clinical and forensic interest. From a clinical point of view the full knowledge of the exact mechanisms by which cocaine exerts cardio - vascular damage is essential to identify potential therapeutic targets and improve novel strategies for cocaine related cardiovascular diseases. From a forensic point of view, it is to be underlined that cocaine use is often associated to sudden death in young, otherwise healthy individuals. While such events are widely reported, the relationship between cardiac morphological alterations and molecular/cellular mechanisms is still controversial. In conclusion, the study of cocaine cardiovascular toxicity needs a strict collaboration between clinicians and pathologists which may be very effective in further dissecting the mechanisms underlying cocaine cardiotoxicity and understanding the cardiac cocaine connection.

Role of oxidative stress in cocaine-induced cardiotoxicity and cocaine-related death.

Cocaine-induced cardiovascular disorders such as hypertension, thrombosis, myocardial dysfunction, cardiac dysrhythmias and endocarditis have received widespread attention in the context of cocaine abuse. The number of sudden deaths from cardiac causes, including myocardial infarction, ventricular tachyarrhythmia or aortic dissection, is also increasing. This manuscript will highlight the recent employment of study about cocaine cardiotoxicity and oxidative stress. Evidence has revealed that cardiac oxidative stress is a prominent early event of cocaine administration, which severely compromises the cardiac antioxidant cellular system and causes cardiac antioxidant cellular system injuries. Oxidative damage such as peroxidation of membrane phospholipids and depletion of nonenzymatic antioxidants such as glutathione have been found in the myocardium of chronic cocaine-treated animals and in patients. The data indicate that cocaine administration compromised the heart's antioxidant defense system. About the mechanisms involved in the cellular damage, the evidence that cocaine causes apoptosis in the heart comes from in vivo study. In animals model after short-term and long term-cocaine administration, the investigators demonstrates the role of Reactive Oxygen Species as a trigger of cardiac injury induced by cocaine. Cocaine also increased infiltration of inflammatory cells in the heart, and apoptotic cells were predominantly found near inflammatory cells. The role of oxidative stress in cocaine-induced apoptosis in the heart is wide studied and documented.

Side effects of cocaine abuse: multiorgan toxicity and pathological consequences.

Cocaine is a powerful stimulant of the sympathetic nervous system by inhibiting catecholamine reuptake, stimulating central sympathetic outflow, and increasing the sensitivity of adrenergic nerve endings to norepinephrine (NE). It is known, from numerous studies, that cocaine causes irreversible structural changes on the brain, heart, lung and other organs such as liver and kidney and there are many mechanisms involved in the genesis of these damages. Some effects are determined by the overstimulation of the adrenergic system. Most of the direct toxic effects are mediated by oxidative stress and by mitochondrial dysfunction produced during the metabolism of noradrenaline or during the metabolism of norcocaina, as in cocaine-induced hepathotoxicity. Cocaine is responsible for the coronary arteries vasoconstriction, atherosclerotic phenomena and thrombus formation. In this way, cocaine favors the myocardial infarction. While the arrhythmogenic effect of cocaine is mediated by the action on potassium channel (blocking), calcium channels (enhances the function) and inhibiting the flow of sodium during depolarization. Moreover chronic cocaine use is associated with myocarditis, ventricular hypertrophy, dilated cardiomyopathy and heart failure. A variety of respiratory problems temporally associated with crack inhalation have been reported. Cocaine may cause changes in the respiratory tract as a result of its pharmacologic effects exerted either locally or systemically, its method of administration (smoking, sniffing, injecting), or its alteration of central nervous system neuroregulation of pulmonary function. Renal failure resulting from cocaine abuse has been also well documented. A lot of studies demonstrated a high incidence of congenital cardiovascular and brain malformations in offspring born to mothers with a history of cocaine abuse.

Data available on the extent of cocaine use and dependence: biochemistry, pharmacologic effects and global burden of disease of cocaine abusers.

Drug use is seen more as an individualistic behaviour and is therefore not readily conceived of from a population perspective. There is general recognition of several phases and degrees of drug abuse, from initiation and early-use patterns to long-term chronic use. Cocaine and its derivative "crack" cocaine provide an example of both the globalization of substance use and the cyclical nature of drug epidemics. Cocaine is a powerful CNS (Central Nervous System) stimulant but exerts its action in a several types of adverse health effects, including acute toxic effects (i.e. overdose, accidental injury and violence), dependence, cardiovascular disease, cirrhosis, bloodborne bacterial and viral infections, and mental disorders. Of interest, many people who use Cocaine will use also other drugs; therefore, ascribing adverse health effect to a certain drug might be difficult. Any mucous membrane can act as a port of entry for cocaine and the systemic effect is greatly influenced by the route and speed of administration. The effects of Cocaine mainly depend on the user's addiction, the dose received and the mode of assumption. Laws restricting the availability of cocaine saw a decrease in consumption in these countries until the 1960s. The number of cocaine users worldwide ranged from 14 million to 21 million (0.3-0.5% of the population aged 15-64 years). The largest market was North America, then western and central Europe and South America.

Heart disease induced by AAS abuse, using experimental mice/rats models and the role of exercise-induced cardiotoxicity.

The anabolic-androgenic steroids (AAS) are all synthetic derivates of testosterone and are commonly used as sport performance enhancers in athletes. The heart is one of the organs most frequently affected by administration of anabolic steroids. A direct myocardial injury caused by AAS is supposed to determine marked hypertrophy in myocardial cells, extensive regional fibrosis and necrosis. A number of excellent studies, using animal models, were performed to evaluate the cardiac effects of AAS. It is known that exogenous administration induced cardiac hypertrophy in vitro and in vivo, and when combined with exercise, anabolic steroid use has been shown to change exercise-induced physiological cardiac hypertrophy to pathophysiological cardiac hypertrophy. However the molecular mechanisms are still poorly understood. It's described that sudden cardiac death, myocardial infarct; ventricular remodelling and cardiomyopathy do to AAS is related to apoptosis and oxidative stress when associated with exercise. Mechanical stimuli and circulating humoral factors (TNF-α, HSP-70, IL-1ß) released by the heart and peripheral organs are responsible. Testosterone and derivates can work through genomic (activation of specific androgen receptor, interaction with coactivators and co-repressors transcription factors, gene regulation) and non-genomic mechanism (membrane-receptor-second messenger cascades). Chronic AAS abuse results in different patterns of pathologic alterations, which depend on type, dose, frequency, and mode of use. The difficulty in interpreting experimental data on animals (mice and rats) lies in the diversity of experiments (the diversity of substances, which show different properties, different mice / rats by sex and age, duration of treatment with AAS, dosages used, type, scope and exercise duration).

Side effects of AAS abuse: an overview.

Anabolic - androgenic steroids (AAS) were originally developed to promote growth of skeletal muscle. AAS abuse is commonly associated with bodybuilders, weightlifters, and other athletes. The issue of AAS toxicity is not yet completely understood since the adverse effects outline a varied scenario with side effects reported affecting many organs and systems in humans. The true incidence of AAS related medical problems is not known, due to several drawbacks in human studies. The entity of side effects depends on the sex, the dose, the duration of treatment, whether they are taken during exercise training or under sedentary conditions, and the susceptibility of the individuals themselves to androgen exposure partly depending on genetic factors. Both the acute and the chronic effects can lead to toxicity, but generally the serious and even fatal effects depend on the time and the duration of AAS administration. A limitation of human studies is represented by the fact that information about the intake of steroids are, generally, self reported and it is hardly possible to assess the exact dosage. AAS are often used in combination with other dugs or substances, so it is difficult to separate their toxic effects from those caused by the other drugs abused. Hence experimental studies conducted on animal models are mandatory to investigate the mechanisms underlying to AAS toxicity and the organ alterations due to these substances. Finally, clinicians should be aware of the complex and varied pattern of toxicity so as to be able to perform correct diagnoses and treatments.

Immunohistochemical characterisation and TNF-α expression of the granulomatous infiltration of the brainstem in a case of sudden death due to neurosarcoidosis.

Neurosarcoidosis carries a mortality of 10%, over twice that of sarcoidosis overall, although it has been rarely reported as a cause of sudden death. The current evidence suggests that sarcoidosis results from an enhanced immune reaction to a variety of antigens, non-self or self which causes CD4 (helper-inducer) T-cell accumulation with a ratio of helper-inducer T cells to suppressor-cytotoxic T cells usually high in affected organs, activation and release of inflammatory cytokines, and formation of granulomatous lesions. Numerous cytokines and other mediators are produced by both activated macrophages and T lymphocytes bearing the CD4-helper phenotype during the granuloma responses. A number of data suggest that interferon-gamma (IFN-gamma) and cytokines such as TNF-α, IL-2, and IL-18 play a critical role in the formation of granulomas. In this article, we describe the clinical and pathological characteristics of a patient who suddenly died due to acute respiratory failure. Neurosarcoidosis with massive and extensive involvement of the brainstem was established as the cause of death. Western blot analysis in the patient demonstrated the TNF-α presence as a 51-kDa protein in the brain tissue. The immunohistochemical analysis showed a poor positiveness for CD4 in all samples around the granulomas, as well as moderate positiveness for CD8, CD15, and CD20; CD45 and CD68 showed a strong positiveness in all the brain samples. Histological findings, immunohistochemical analysis, and proteomic studies addressed the diagnosis of neurosarcoidosis with involvement of the nucleus of the solitary tract in the brainstem and central hypoventilation as the cause of death.

Anabolic androgenic steroids abuse and liver toxicity.

In the athletes the wide use of Anabolic Androgenic Steroids (AAS) cause series damage in various organs, in particular, analyzing the liver, elevation on the levels of liver enzymes, cholestatic jaundice, liver tumors, both benign and malignant, and peliosis hepatis are described. A prolonged AAS administration provokes an increase in the activities of liver lysosomal hydrolases and a decrease in some components of the microsomal drug-metabolizing system and in the activity of the mitochondrial respiratory chain complexes without modifying classical serum indicators of hepatic function. Liver is a key organ actively involved in numerous metabolic and detoxifying functions. As a consequence, it is continuously exposed to high levels of endogenous and exogenous oxidants that are by-products of many biochemical pathways and, in fact, it has been demonstrated that intracellular oxidant production is more active in liver than in tissues, like the increase of inflammatory cytokines, apoptosis and the inhibitors of apoptosis NF- κB and Heat Shock Proteins.

Anaphylactic latex reaction during anaesthesia: the silent culprit in a fatal case.

The true incidence of anaphylactic latex reactions and their associated morbidity and mortality remain poorly defined. It is noteworthy that a number of groups of individuals are at risk for anaphylactic reactions to latex during surgical and medical procedures; one of these groups is represented by the obstetric and gynaecologic population. A case of unrecognized first anaphylactic reaction to latex in a pregnant woman patient who underwent a caesarean section is presented. The diagnosis of latex allergy was missed and the following day the woman underwent a surgical re-exploration complicated by fatal cardiovascular arrest. At post-mortem examination, pulmonary mast cells in the bronchial walls and capillary septa were identified and a great number of degranulating mast cells with tryptase-positive material outside the cells was documented. A post-mortem latex-specific IgE test showed a high titre (14.00 U/I). Latex-induced fatal anaphylactic shock was recorded as the cause of death. This case highlights some of the practical difficulties in the initial diagnosis and subsequent investigation of fatal anaphylactic reaction during anaesthesia. Anaphylaxis is often misdiagnosed because many other pathologic conditions may present identical clinical manifestations, so anaphylactic shock must be differentiated from other causes of circulatory collapse. Although latex allergy usually has a delayed onset after the start of the surgery and most often a slow onset too, it should be always suspected if circulatory collapse and respiratory failure occur during surgery, even if the patient does not belong to a risk group; in the presence of identified risk factors for latex allergy a well-founded suspicion must be stronger, leading to an immediate discontinuation of the potential trigger.

Suicide due to oral ingestion of lidocaine: a case report and review of the literature.

The Authors describe a rare case of suicide in a 31-year-old woman, due to oral ingestion of lidocaine; the histological and toxicological findings are discussed to provide useful information to the present experience with this particular modality of death. Histological examination revealed generalized stasis. In the myocardium we observed segmentation of the myocardial cells and/or widening of intercalated discs and associated group of hypercontracted myocardial cells with "square" nuclei in line with hyperdistended ones. Non-eosinophilic bands of hypercontracted sarcomeres alternating with stretched, often apparently separated sarcomeres, small foci of paradiscal contraction band necrosis, and perivascular fibrosis were observed too. Lidocaine was detected in the subject's urine through immunoenzymatic screening. Toxicological analysis by solid-liquid extraction and gas chromatography-mass spectrometry (GC-MS) analysis, was carried out to identify and quantify the individual substances present in the biological fluids and organs. Lidocaine concentrations were as follows: blood 31 microg/mL, gastric content 2.5 g, liver 10 microg/g, kidney 12 microg/g, brain 9 microg/g, spleen 24 microg/g, lung 84 microg/g, heart 9 microg/g, urine 9 microg/mL, and bile 6 microg/mL. No other drugs or alcohol were detected. When blood lidocaine reaches toxic levels, serious toxic symptoms associated with the central nervous system and cardiac system are noted. The overdose of lidocaine produces death from ventricular fibrillation or cardiac arrest. In this case, according to macroscopic and microscopic findings, the cause of death was most likely cardiac and possibly related to ventricular fibrillation.