Autopsy Findings in Three Patients with von Willebrand Disease Type IIB and Type III: Presence of Atherosclerotic Lesions without Occlusive Arterial Thrombi

It has been reported that pigs with severe von Willebrand disease (vWd) are protected from spontaneous and diet-induced atherosclerosis, but there are very few studies in human patients. Autopsies were carried out on three patients with vWd (one case with the type IIB variant and two cases with type III, a variant similar to that protecting pigs from atherosclerosis), aged 73, 44 and 52 years at the time of death. Hemorrhagic diathesis was an important cause of death for these patients. Atherosclerosis lesions were found in all patients, though of different extent and localization: severe lesions in all vascular areas in the patient with type IIB, few and slighter in all areas in the two patients with type III, except that in one of them there were moderately severe lesions in the coronary arteries. There was no clinical or pathologic evidence of thrombosis in the coronary arteries or other arteries. These data indicate that severe vWd did not protect completely against the development of atherosclerosis, although it is possible that intensive lifelong treatment with plasma concentrates had a modifying influence in these patients.

Cytogenetic Analysis in 28 Radically Operated Non-Small-Cell Lung Cancer: Preliminary Considerations

Twenty-eight radically operated non-small-cell lung cancer patients were analyzed with regard to chromosomal assessment and DNA content: in 13 cases, different quantitative/ qualitative chromosome alterations were found. In particular, in 12 cases marker chromosomes and cytogenetic abnormalities in euploid cells were demonstrated. The prognostic value of these findings will be aim of further studies.

Nicotinic Receptor Abnormalities in the Cerebellar Cortex of Sudden Unexplained Fetal and Infant Death Victims-Possible Correlation With Maternal Smoking

Nicotinic acetylcholine receptors (nAChRs) are cationic channels of the neuronal cell membrane, differentially expressed in the central nervous system which, when activated by endogenous acetylcholine or exogenous nicotine, are able to enhance cholinergic transmission. The aim of this study was to investigate in human perinatal age the immunohistochemical expression of the α7-nAChR subtype, given its involvement in neuronal differentiation and its significant vulnerability to the toxic effects of nicotine. Thirty fetuses (with a gestational age between 25 and 40 weeks) and 35 infants (1–6 months old), suddenly died of known (controls) and unknown causes (unexplained deaths), with smoking and nonsmoking mothers, were included in this study. A negative or low immunoexpression of α7-nAChRs, indicative of their inactivation, was observed in the granular layers of the cerebellar cortex in 66% of the sudden unexplained perinatal deaths and 11% of the controls. A high correlation was also observed between these findings and maternal smoking. Apart from the well-known adverse effects of nicotine exposure during pregnancy, it may also cause significant alterations in cerebellar cholinergic transmission in areas of the brain involved in vital functions. These events may give us insights into the pathogenetic mechanisms leading to sudden unexplained fetal and infant death.

Impaired orexin receptor expression in the Kölliker-Fuse nucleus in sudden infant death syndrome: possible involvement of this nucleus in arousal pathophysiology

OBJECTIVES

As well known, the sudden infant death syndrome (SIDS) is characterized by the sudden death of a seemingly healthy infant during sleep, frequently resulted from a deficit in arousal phase. Awakening from sleep requires a fully developed and functioning neuronal respiratory network to modulate the ventilation as needed. The pontine Kölliker-Fuse nucleus (KFN) plays a pivotal role in breathing control, thanks to its interconnections with the widespread serotonin and noradrenaline neurons in the brainstem. Numerous studies to date have focused on the implication of orexin, a neuropeptide synthesized by neurons of the lateral hypothalamus, with major projections to the brainstem raphé nuclei and locus coeruleus, in arousal, a neurobiological process closely linked to breathing modifications. The aim of our research has been to demonstrate that also the KFN is a fundamental component of the orexin system, actively involved in arousal.

METHODS

We have evaluated the expression and distribution of the orexin receptors (orexin-1 and orexin-2 receptors) particularly in the rostral pons, where the KFN is located, of 25 SIDS cases and 18 controls.

RESULTS

An intense orexin-1 innervation around the KF neurons has been detected in almost all the controls and only in 20% of SIDS cases.

DISCUSSION

On the basis of these results, we believe that: (1) the KFN plays a leading role not only in providing a regular breathing rhythm but also in the coordination of the sleep-to-wake transition; (2) a defective orexin expression in the KFN could prevent arousal, thus assuming a crucial importance in causing SIDS.

Impaired orexin receptor expression in the Kölliker-Fuse nucleus in sudden infant death syndrome: possible involvement of this nucleus in arousal pathophysiology

OBJECTIVES

As well known, the sudden infant death syndrome (SIDS) is characterized by the sudden death of a seemingly healthy infant during sleep, frequently resulted from a deficit in arousal phase. Awakening from sleep requires a fully developed and functioning neuronal respiratory network to modulate the ventilation as needed. The pontine Kölliker-Fuse nucleus (KFN) plays a pivotal role in breathing control, thanks to its interconnections with the widespread serotonin and noradrenaline neurons in the brainstem. Numerous studies to date have focused on the implication of orexin, a neuropeptide synthesized by neurons of the lateral hypothalamus, with major projections to the brainstem raphé nuclei and locus coeruleus, in arousal, a neurobiological process closely linked to breathing modifications. The aim of our research has been to demonstrate that also the KFN is a fundamental component of the orexin system, actively involved in arousal.

METHODS

We have evaluated the expression and distribution of the orexin receptors (orexin-1 and orexin-2 receptors) particularly in the rostral pons, where the KFN is located, of 25 SIDS cases and 18 controls.

RESULTS

An intense orexin-1 innervation around the KF neurons has been detected in almost all the controls and only in 20% of SIDS cases.

DISCUSSION

On the basis of these results, we believe that: (1) the KFN plays a leading role not only in providing a regular breathing rhythm but also in the coordination of the sleep-to-wake transition; (2) a defective orexin expression in the KFN could prevent arousal, thus assuming a crucial importance in causing SIDS.

Decreased argyrophilic nucleolar organiser region (AgNOR) expression in Purkinje cells: first signal of neuronal damage in sudden fetal and infant death

Aims

The nucleolus is an important cellular component involved in the biogenesis of the ribosome. This study was performed in order to validate the introduction of the argyrophilic nucleolar organiser region (AgNOR) stain technique, specific for the nucleoli detection, in neuropathological studies on sudden fetal and infant death.

Methods

In a wide set of fetuses and infants, aged from 27 gestational weeks to eight postnatal months and dead from both known and unknown causes, an in-depth neuropathological study usually applied at the Lino Rossi Research Center of the Milan University was implemented by the AgNOR method.

Results

Peculiar abnormalities of the nucleoli, as partial or total disruption above all in Purkinje cells (PCs), were exclusively found in victims of sudden fetal and infant death, and not in controls. The observed nucleolar alterations were frequently related to nicotine absorption in pregnancy.

Conclusions

We conclude that these findings represent early hallmarks of PC degeneration, contributing to the pathophysiology of sudden perinatal death.

Sudden Infant Death With Area Postrema Lesion Likely Due to Wrong Use of Insecticide

We report a noteworthy case of a 7-month-old infant who suddenly and unexpectedly died during her sleep. After a complete postmortem examination, review of the clinical history, and detailed death scene investigation, the death remained unexplained, leading to a diagnosis of sudden infant death syndrome. However, an extensive review of the brainstem neuropathology revealed a severe alteration in the area postrema (a highly vascular structure lying at the base of the fourth ventricle outside of the blood-brain barrier). The alteration was likely due to massive and repeated to a common household insecticide in the last few weeks of life. These results provide an explanation for this sudden infant death, allowing a differential diagnosis from sudden infant death syndrome.

Developmental alterations of the auditory brainstem centers--pathogenetic implications in Sudden Infant Death Syndrome

Sudden Infant Death Syndrome (SIDS), despite the success of campaigns to reduce its risks, is the leading cause of infant death in the Western world. Even though the pathogenesis remains unexplained, brainstem abnormalities of the neuronal network that mediates breathing and protective responses to asphyxia, particularly in the arousal phase from sleep, are believed to play a fundamental role. This is the first study to identify, in SIDS, developmental defects of specific brainstem centers involved in hearing pathways, particularly in the cochlear and vestibular nuclei, in the superior olivary complex and in the inferior colliculus, suggesting a possible influence of the acoustic system on respiratory activity. In 49 SIDS cases and 20 controls an in-depth anatomopathological examination of the autonomic nervous system was performed, with the main aim of detecting developmental alterations of brainstem structures controlling both the respiratory and auditory activities. Overall, a significantly higher incidence of cytoarchitectural alterations of both the auditory and respiratory network components were observed in SIDS victims compared with matched controls. Even if there is not sufficient evidence to presume that developmental defects of brainstem auditory structures can affect breathing, our findings, showing that developmental deficit in the control respiratory areas are frequently accompanied by alterations of auditory structures, highlight an additional important element for the understanding the pathogenetic mechanism of SIDS.

Myocardial inflammatory infiltrate in human chronic chagasic cardiomyopathy: Immunohistochemical findings

Chagas' disease is the most common form of chronic myocarditis in the world. It is characterized by a progressive chronic myocarditis that leads to cardiomegaly, arrhythmias, cardiac failure, and thromboembolic phenomena. This communication reports studies on the immunohistochemistry of chronic infiltrates in 30 endomyocardial biopsies and in contracting and specialized myocardium of autopsies of four patients suffering from Chagas' cardiomyopathy. Expression of the following antigens was studied: common leucocyte antigen (CLA-CD45R), L-26(CD20), CD68, kappa and lambda light chains and T-UCLH-1 (CD45RO), and MB-1. Streptavidin-peroxidase and streptavidin-alkaline phosphatase with biotinylated anti-mouse IgG were used as detection systems. Double immunostaining for the simultaneous demonstration of T lymphocytes (CD45R0) and macrophages was performed using both immunoenzymatic techniques consecutively. Expression of CD31 was detected for the demonstration of endothelial cells. In endomyocardial biopsies, tissue forms of trypanosomes were not found. The percentage of fibrous tissue was 24.1% ± 12.8% (range 8.2%-49%). Eosinophils were scarce (1/high-power field), but associated with necrotic areas of the myocardium. Mast cells were scarce or absent. They were always situated in fibrotic areas. The most remarkable finding was the presence of infiltrates consisting of macrophages and CLA-positive mononuclear cells. Twenty-six and one-half percent of them were T lymphocytes, and 10.5% were B lymphocytes. Lymphocytic infiltration was particularly associated with necrotic and degenerative myocardial lesions. Thirty percent of the infiltrate was composed of macrophages (positive CD68 cells). The remaining infiltrate was composed of mononuclear cells resembling macrophages and CLA-negative mononuclear cells. Contacts between CD68-positive cells and T lymphocytes were frequently found. CD31 antibodies clearly pointed out normal endothelial cells, in either normal or damaged vessels. No isolated cells positive for these antibodies were found within the mononuclear infiltrate. In autopsied hearts, myocardial lesions consisted of a chronic inflammatory process with fibrotic scars and extensive mononuclear infiltrates. No amastigote nests were found. A statistically significant difference (p < 0.05) was obtained when the percentage of fibrosis was compared in the specialized and contracting myocardiums (51.6% ± 18% vs. 43.4 % ± 8%). Eosinophils were scarce in infiltrates, reaching 5%, and they were associated with necrotic myocardium. Mast cells also were scarce or absent in specialized and in contracting myocardium. Almost all the lymphocytic population was T lymphocytes. Such infiltrates were more prominent in the working myocardium (39%) and in the specialized cells of the left branch of the His bundle than in the atrioventricular node and in the right Hisian branch (34.4%). The 31% of mononuclear cells were CD68 positive, thus corresponding to macrophages. Contacts among T lymphocytes and macrophages were frequently observed. Although much that is concerned with Chagas' cardiomyopathy is controversial, these may be the major ingredients for its pathogenesis: the parasite or a part of it, lymphocytes and macrophages, and fibrosis. Then a multifactorial or "combined theory" may be suggested to explain the sequence of events that lead to the chronic stage of the disease.

Cytoarchitectural and functional abnormalities of the inferior colliculus in sudden unexplained perinatal death

The inferior colliculus is a mesencephalic structure endowed with serotonergic fibers that plays an important role in the processing of acoustic information. The implication of the neuromodulator serotonin also in the aetiology of sudden unexplained fetal and infant death syndromes and the demonstration in these pathologies of developmental alterations of the superior olivary complex (SOC), a group of pontine nuclei likewise involved in hearing, prompted us to investigate whether the inferior colliculus may somehow contribute to the pathogenetic mechanism of unexplained perinatal death. Therefore, we performed in a wide set of fetuses and infants, aged from 33 gestational weeks to 7 postnatal months and died of both known and unknown cause, an in-depth anatomopathological analysis of the brainstem, particularly of the midbrain. Peculiar neuroanatomical and functional abnormalities of the inferior colliculus, such as hypoplasia/structural disarrangement and immunonegativity or poor positivity of serotonin, were exclusively found in sudden death victims, and not in controls. In addition, these alterations were frequently related to dysgenesis of connected structures, precisely the raphé nuclei and the superior olivary complex, and to nicotine absorption in pregnancy. We propose, on the basis of these results, the involvement of the inferior colliculus in more important functions than those related to hearing, as breathing and, more extensively, all the vital activities, and then in pathological conditions underlying a sudden death in vulnerable periods of the autonomic nervous system development, particularly associated to harmful risk factors as cigarette smoking.

Pesticide exposure during pregnancy, like nicotine, affects the brainstem α7 nicotinic acetylcholine receptor expression, increasing the risk of sudden unexplained perinatal death

This study indicates the impact of nicotine and pesticides (organochlorine and organophosphate insecticides used in agriculture) on neuronal α7-nicotinic acetylcholine receptor expression in brainstem regions receiving cholinergic projections in human perinatal life. An in-depth anatomopathological examination of the autonomic nervous system and immunohistochemistry to analyze the α7-nicotinic acetylcholine receptor expression in the brainstem from 44 fetuses and newborns were performed. In addition, the presence of selected agricultural pesticides in cerebral cortex samples of the victims was determined by specific analytical procedures. Hypodevelopment of brainstem structures checking the vital functions, frequently associated with α7-nicotinic acetylcholine receptor immunopositivity and smoke absorption in pregnancy, was observed in high percentages of victims of sudden unexpected perinatal death. In nearly 30% of cases however the mothers never smoked, but lived in rural areas. The search for pesticides highlighted in many of these cases traces of both organochlorine and organophosphate pesticides. We detain that exposition to pesticides in pregnancy produces homologous actions to those of nicotine on neuronal α7-nicotinic acetylcholine receptor, allowing to developmental alterations of brainstem vital centers in victims of sudden unexplained death.

Sudden infant death following hexavalent vaccination: a neuropathologic study

We examined a large number of sudden infant death syndrome victims in order to point out a possible causal relationship between a previous hexavalent vaccination and the sudden infant death. We selected 110 cases submitted to in-depth histological examination of the autonomic nervous system and provided with detailed clinical and environmental information. In 13 cases (11.8%) the death occurred in temporal association with administration of the hexavalent vaccine (from 1 to 7 days). In none of these victims congenital developmental alterations of the main nervous structures regulating the vital functions were observed. Only the hypoplasia of the arcuate nucleus was present in 5 cases. In one case in particular an acquired hyperacute encephalitis of the tractus solitarii nucleus was diagnosed in the brainstem. This study does not prove a causal relationship between the hexavalent vaccination and SIDS. However, we hypothesize that vaccine components could have a direct role in sparking off a lethal outcome in vulnerable babies. In conclusion, we sustain the need that deaths occurring in a short space of time after hexavalent vaccination are appropriately investigated and submitted to a post-mortem examination particularly of the autonomic nervous system by an expert pathologist to objectively evaluate the possible causative role of the vaccine in SIDS.

Disruption of the brain-derived neurotrophic factor (BDNF) immunoreactivity in the human Kölliker-Fuse nucleus in victims of unexplained fetal and infant death

Experimental studies have demonstrated that the neurotrophin brain-derived neutrophic factor (BDNF) is required for the appropriate development of the central respiratory network, a neuronal complex in the brainstem of vital importance to sustaining life. The pontine Kölliker-Fuse nucleus (KFN) is a fundamental component of this circuitry with strong implications in the pre- and postnatal breathing control. This study provides detailed account for the cytoarchitecture, the physiology and the BDNF behavior of the human KFN in perinatal age. We applied immunohistochemistry in formalin-fixed and paraffin-embedded brainstem samples (from 45 fetuses and newborns died of both known and unknown causes), to analyze BDNF, gliosis and apoptosis patterns of manifestation. The KFN showed clear signs of developmental immaturity, prevalently associated to BDNF altered expression, in high percentages of sudden intrauterine unexplained death syndrome (SIUDS) and sudden infant death syndrome (SIDS) victims. Our results indicate that BDNF pathway dysfunctions can derange the normal KFN development so preventing the breathing control in the sudden perinatal death. The data presented here are also relevant to a better understanding of how the BDNF expression in the KFN can be involved in several human respiratory pathologies such as the Rett's and the congenital central hypoventilation syndromes.

Unsuspected imported malaria in a case of sudden infant death

Here we describe the case of a 4-mo-old female who died suddenly without any apparent cause that was initially mistaken as a case of sudden infant death syndrome. Histologic observation of brain sections revealed blue-black bodies in erythrocytes of the blood vessels, suggestive of specific stages of the hematic schizogonic cycle. Further examinations revealed hemozoin and hemosiderin deposits in the parenchyma of all organs, leading to the diagnosis of malaria by Plasmodium falciparum (P. falciparum). The death occurred in Italy, the native country of the infant, two weeks after a Christmas holiday spent in Pakistan, the parents’ birthplace, which has a high malarial endemicity. As this case demonstrates, the diagnosis of malaria should always be considered as a differential diagnosis in subjects, including infants, that die unexpectedly after returning from P. falciparum endemic areas.

Possible role of the α7 nicotinic receptors in mediating nicotine's effect on developing lung - implications in unexplained human perinatal death

Background

It is well known that maternal smoking during pregnancy is very harmful to the fetus. Prenatal nicotine absorption, in particular, is associated with alterations in lung development and functions at birth and with respiratory disorders in infancy. Many of the pulmonary disorders are mediated by the interaction of nicotine with the nicotinic receptors (nAChRs), above all with the α7 nAChR subunits that are widely expressed in the developing lung. To determine whether the lung hypoplasia frequently observed in victims of sudden fetal and neonatal death with a smoker mother may result from nicotine interacting with lung nicotinic receptors, we investigated by immunohistochemistry the possible presence of the α7 nAChR subunit overexpression in these pathologies.

Methods

In lung histological sections from 45 subjects who died of sudden intrauterine unexplained death syndrome (SIUDS) and 15 subjects who died of sudden infant death syndrome (SIDS), we applied the radial alveolar count (RAC) to evaluate the degree of lung maturation, and the immunohistochemical technique for nAChRs, in particular for the α7 nAChR subunit identification. In the same cases, an in-depth study of the autonomic nervous system was performed to highlight possible developmental alterations of the main vital centers located in the brainstem.

Results

We diagnosed a “lung hypoplasia”, on the basis of RAC values lower than the normal reference values, in 63% of SIUDS/SIDS cases and 8% of controls. In addition, we observed a significantly higher incidence of strong α7 nAChR immunostaining in lung epithelial cells and lung vessel walls in sudden fetal and infant death cases with a smoker mother than in age-matched controls. Hypoplasia of the raphe, the parafacial, the Kölliker-Fuse, the arcuate and the pre-Bötzinger nuclei was at the same time present in the brainstem of these victims.

Conclusions

These findings demonstrate that when crossing the placenta, nicotine can interact with nicotinic receptors of both neuronal and non-neuronal cells, leading to lung and nervous system defective development, respectively. This work stresses the importance of implementing preventable measures to decrease the noxious potential of nicotine in pregnancy.

Sudden death of an infant with cardiac, nervous system and genetic involvement--a case report

Abstract

We present a case of sudden death of a 1-month-old male infant with heart, brainstem and genetic polymorphism involvement. Previously considered quite healthy, the child died suddenly and unexpectedly during sleep. The autopsy protocol included an in-depth anatomopathological examination of both the autonomic nervous system and the cardiac conduction system, and molecular analysis of the serotonin transporter gene promoter region, in which a specific genetic condition seems to be associated with sudden infant death. Histological examination revealed the presence of congenital cardiac alterations (hypertrophic cardiomyopathy and an accessory Mahaim fiber in the cardiac conduction system), severe hypodevelopment of all the raphe nuclei and a heterozygous genotype L/S related to the serotonin transporter gene. The sudden death of this infant was the unavoidable outcome of a complex series of congenital anomalies, each predisposing to SIDS.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3480540091031788

Primary Cardiac Fibroma and Cardiac Conduction System Alterations in a Case of Sudden Death of a 4-month-old Infant

A 4-month-old female infant considered to be in good health died suddenly and unexpectedly. Post- mortem examination was requested, with clinical diagnosis of sudden infant death syndrome. At autopsy the infant was described in good health. Histo- logical examination of the heart found a cardiac fibroma compressing the atrio-ventricular node and the examination of the cardiac conduction system showed an accessory fiber of Mahaim (nodo-ventricular) and cartilaginous metaplasia of the cardiac fibrous body. Probably the concomitant presence of cardiac conduction system abnormalities and a septal fibroma, compressing the atrio-ventricular node, could have an important role in causing the sudden death.

Pathophysiology of the human locus coeruleus complex in fetal/neonatal sudden unexplained death

OBJECTIVES

We investigated the locus coeruleus complex in the brainstems of 78 subjects aged from 24 gestational weeks to 8 postnatal months, who died of unknown (sudden unexplained fetal and infant deaths) and known causes (controls). The goals of this study were: (1) to obtain basic information about the morphology of the locus coeruleus complex and the expression of different biological parameters (tyrosine hydroxylase, neuromelanin and apoptosis) during the first phases of human nervous system development; (2) to evaluate possible alterations of this structure in victims of sudden death; and (3) to verify any correlation with risk factors.

METHODS

All the victims were subjected to a complete autopsy, including an in-depth histological examination of the autonomic nervous system and in particular of the locus coeruleus complex, the target of this study. Adrenergic neurons were identified by tyrosine hydroxylase (TH) immunohistochemistry and neuromelanin-containing neurons were specifically visualized by the application of Lillie's method. In addition, the activation of programmed cell death (apoptosis) was studied by investigating DNA fragmentation (TUNEL-positive cells).

RESULTS

Alterations of the noradrenaline system, decreased neuromelanin, hypoplasia, in addition to a high neuronal death rate, were observed almost exclusively in the locus coeruleus complex of fetal and infant sudden deaths, and were significantly correlated to maternal smoking.

DISCUSSION

The developmental defects found in the locus coeruleus complex in victims of sudden unexplained fetal and infant death imply alterations of the vital activities related to the widespread brain connections arising from this neuronal center, including coordination of the sleep-waking cycle and control of the cardio-respiratory system.

Vulnerability of fourth ventricle choroid plexus in sudden unexplained fetal and infant death syndromes related to smoking mothers

The human choroid plexuses in the ventricular system represent the main source of cerebrospinal fluid secretion and constitute a major barrier interface that controls the brain's environment. The present study focused on the choroid plexus of the fourth ventricle, the main cavity of the brainstem containing important nuclei and/or structures mediating autonomic vital functions. In serial sections of 84 brainstems of subjects aged from 17 gestational weeks to 8 postnatal months of life, the deaths due to both known and unknown causes, we examined the cytoarchitecture and the developmental steps of the fourth ventricle choroid plexus to determine whether this structure shows morphological and/or functional alterations in unexplained perinatal deaths (Sudden Infant Death Syndrome and Sudden Intrauterine Unexplained Death Syndrome). High incidence of histological and immunohistochemical alterations (prevalence of epithelial dark cells, the presence of cystic cells in the stroma, decreased number of blood capillaries, hyperexpression of Substance P and apoptosis) were prevalently observed in unexplained death victims (p<0.05 vs. controls). A significant correlation was found between maternal smoking in pregnancy and choroidal neuropathological parameters (p<0.01). This work underscores the negative effects of prenatal exposure to nicotine on the development of the autonomic nervous system, and in particular of the fourth ventricle choroid plexus that is a very vulnerable structure in the developing CSF-brain system.

Neuroanatomical dysmorphology of the medial superior olivary nucleus in sudden fetal and infant death

This study expands our understanding of the organization of the human caudal pons, providing a morphologic characterization of the medial superior olivary nucleus (MSO), component of the superior olivary complex (SOC) that plays an important role in the processing of acoustic information. We examined victims of sudden unexplained fetal and infant death and controls (n = 75), from 25 gestational weeks to 8 months of postnatal age, by complete autopsy and in-depth autonomic nervous system histological examination, particularly of the MSO nucleus, the focus of this study. Peculiar cytoarchitectural features of the MSO nucleus were found in sudden death cases, such as hypoplasia/agenesis and immature hypercellularity, frequently related to dysgenesis of contiguous structures involved in respiratory rhythm-generating circuit, in particular to hypoplasia of the retrotrapezoid and the facial nuclei. We propose the involvement of this nucleus in more important functions than those related to hearing, as breathing and, more extensively, all the vital activities. Besides, we highlight the fundamental role of the maternal smoking in pregnancy as etiological factor in the dysmorphic neuroanatomical development of the MSO nucleus.

Developmental alterations of the respiratory human retrotrapezoid nucleus in sudden unexplained fetal and infant death

The study aims were twofold: 1) identify the localization and the cytoarchitecture of the retrotrapezoid nucleus (RTN) in the human fetus and infant and 2) ascertain if the RTN, given its essential role in animal studies for the maintenance of breathing and chemoreception, showed abnormalities in victims of sudden perinatal and infant death (sudden intrauterine unexplained death/SIUD - and sudden infant death syndrome/SIDS). We examined SIDS and SIUD cases and Controls (n=58) from 34 gestational weeks to 8 months of postnatal age by complete autopsy, in-depth autonomic nervous system histological examination, and immunohistochemical analysis of the PHOX2B gene, a transcriptional factor involved in Congenital Central Hypoventilation Syndrome that has been defined as a marker of rat RTN neurons. We identified a group of PHOX2B-immunopositive neurons within the caudal pons, contiguous to the facial/parafacial complex, in 90% of Controls, likely the homologous human RTN (hRTN). We observed structural and/or PHOX2B-expression abnormalities of the hRTN in 71% of SIUD/SIDS cases vs 10% of Controls (p<0.05). In conclusion we suggest that developmental abnormalities of the hRTN may seriously compromise chemoreception control, playing a critical role in the pathogenesis of both SIUD and SIDS.

Investigation of 5-HTT expression using quantitative real-time PCR in the human brain in SIDS Italian cases

The sudden infant death syndrome (SIDS) is the main cause of postneonatal infant death, being defined as the sudden death of an infant under one year of age that remains unexplained after a complete clinical review, autopsy and death scene investigation. The neurotransmitter serotonin (5-HT) is involved in the regulation of a broad array of behavioral and biological functions. By controlling the reuptake of 5-HT from the extracellular space, the serotonin transporter (5-HTT) regulates the duration and strength of the interactions between 5-HT and its receptors. It has been shown that the activity of the human 5-HTT gene promoter is regulated by polymorphic repetitive elements, resulting in differences in the efficacy of 5-HTT reuptake among the allelic variants: the short (S) allele is associated with lower transcriptional efficiency of the promoter compared with the long (L) allele. Using qRT-PCR we studied the gene expression of 5-HTT in ten SIDS cases, previously analyzed at a molecular level and which showed the genetic S/S profile. In nine cases we observed 5-HTT expression levels comparable to those seen in the control case, while in one case there was a remarkable reduction in the expression of the gene. It is presumable that, despite the presence of the same S/S genotype, the different genetic background could influence the transcript stability and that the polimorphic variant of the 5-HTT gene could respond differently to the external environmental stimuli.

Neuropathology of the area postrema in sudden intrauterine and infant death syndromes related to tobacco smoke exposure

The area postrema is a densely vascularized small protuberance at the inferoposterior limit of the fourth ventricle, outside of the blood-brain barrier. This structure, besides to induce emetic reflex in the presence of noxious chemical stimulation, has a multifunctional integrative capacity to send major and minor efferents to a variety of brain centers particularly involved in autonomic control of the cardiovascular and respiratory activities. In this study we aimed to focus on the area postrema, which is so far little studied in humans, in a large sample of subjects aged from 25 gestational weeks to 10 postnatal months, who died of unknown (sudden unexplained perinatal and infant deaths) and known causes (controls). Besides we investigated a possible link between alterations of this structure, sudden unexplained fetal and infant deaths and maternal smoking. By the application of morphological and immunohistochemical methods, we observed a significantly high incidence of alterations of the area postrema in fetal and infant victims of sudden death as compared with age-matched controls. These pathological findings, including hypoplasia, lack of vascularization, cystic formations and reactive gliosis, were related to maternal smoking. We hypothesize that components from maternal cigarette smoke, particularly in pregnancy, could affect neurons of the area postrema connected with specific nervous centers involved in the control of vital functions. In conclusion, we suggest that the area postrema should be in depth examined particularly in victims of sudden fetal or infant death with smoker mothers.

Severe intra- and periventricular hemorrhage: role of arteriolosclerosis related to maternal smoke

OBJECTIVE

The authors aimed to describe the atherosclerotic lesions of the cerebral arterioles as a substrate of their rupture and bleeding.

METHODS

The study was performed on the brain of nine Caucasian fetal victims of intra- and periventricular hemorrhage, all grade IV, and nine control cases.

RESULTS

In the nine victims of hemorrhage, the arteriolar wall structure was altered, focally transformed into a deposit of amorphous eosinophilic material. Such changes often affected the full thickness of the wall causing rupture and hemorrhage. In eight of these cases and in two victims of the control group, the mothers were heavy cigarette smokers (15-20 cigarettes/day) before and during pregnancy.

CONCLUSION

The authors conclude that intra- and periventricular hemorrhage can be ascribed to the toxic effects of prenatal absorption of nicotine.

Brain iron accumulation in unexplained fetal and infant death victims with smoker mothers--the possible involvement of maternal methemoglobinemia

BACKGROUND

Iron is involved in important vital functions as an essential component of the oxygen-transporting heme mechanism. In this study we aimed to evaluate whether oxidative metabolites from maternal cigarette smoke could affect iron homeostasis in the brain of victims of sudden unexplained fetal and infant death, maybe through the induction of maternal hemoglobin damage, such as in case of methemoglobinemia.

METHODS

Histochemical investigations by Prussian blue reaction were made on brain nonheme ferric iron deposits, gaining detailed data on their localization in the brainstem and cerebellum of victims of sudden death and controls. The Gless and Marsland's modification of Bielschowsky's was used to identify neuronal cell bodies and neurofilaments.

RESULTS

Our approach highlighted accumulations of blue granulations, indicative of iron positive reactions, in the brainstem and cerebellum of 33% of victims of sudden death and in none of the control group. The modified Bielschowsky's method confirmed that the cells with iron accumulations were neuronal cells.

CONCLUSIONS

We propose that the free iron deposition in the brain of sudden fetal and infant death victims could be a catabolic product of maternal methemoglobinemia, a biomarker of oxidative stress likely due to nicotine absorption.

Unexplained stillbirth versus SIDS: common congenital diseases of the autonomic nervous system--pathology and nosology

OBJECTIVE

To contribute to a more balanced assessment of the morphological substrates underlying unexplained perinatal death and SIDS.

METHODS

In-depth histological, immunohistochemical and genetic examinations were performed on the autonomic nervous and cardiac conduction systems in 95 unexpected perinatal deaths, 140 SIDS and 78 controls (44 infants and 34 perinatal death victims).

RESULTS

The study revealed the localization and the nature of a variety of specific congenital abnormalities of the autonomic nervous system, central and peripheral, and of the cardiac conduction system that represent the morphological substrates of the pathophysiological mechanism of sudden fetal death and SIDS.

CONCLUSIONS

The observation of similar anomalies of the autonomic nervous and the cardiac conduction systems in both unexplained perinatal deaths and SIDS indicates their common congenital nature. Therefore, the definitions of these deaths, currently nosographically distinct, should be unified.

Developmental alterations of the spinal trigeminal nucleus disclosed by substance P immunohistochemistry in fetal and infant sudden unexplained deaths

We investigated the immunohistochemical expression of substance P (SP) in the brainstems of 56 subjects aged from 17 gestational weeks to 10 post natal months, who died of unknown (sudden unexplained fetal deaths and SIDS) and known causes (controls). The goals of this study were: (i) to obtain basic information about the expression of SP during the first phases of human nervous system development; (ii) to evaluate whether there are alterations of this neuromodulator in victims of sudden death; and (iii) to verify any correlation with maternal cigarette smoking. Immunohistochemistry demonstrated SP immunoreactivity in the caudal trigeminal nucleus area, with a progressive increase in the density of SP-positive fibers of the corresponding tract during normal development from fetal life to the first post natal months. Delineation of the structure of the human trigeminal nucleus, little investigated so far, provided essential data on its morphologic and functional development. Instead, a negative or low SP expression was detectable in the fibers of this tract in a wide subset of SIDS victims and, conversely, a high SP-expression in a wide subset of sudden fetal deaths. We postulate, on the basis of these results, that SP has a functional importance in the early phases of central nervous system development and in the regulation of autonomic functions. In addition, the observation of a significant correlation between sudden unexplained death, altered SP staining and maternal smoking leads us to suggest a close relation between the absorption of cigarette smoke in utero and a decreased functional activity of the trigeminal nucleus, that can trigger sudden death of the fetus during pregnancy or of the infant in the first months of life.

Ependymal alterations in sudden intrauterine unexplained death and sudden infant death syndrome: possible primary consequence of prenatal exposure to cigarette smoking

Background

The ependyma, the lining providing a protective barrier and filtration system separating brain parenchyma from cerebrospinal fluid, is still inadequately understood in humans. In this study we aimed to define, by morphological and immunohistochemical methods, the sequence of developmental steps of the human ependyma in the brainstem (ventricular ependyma) and thoracic spinal cord (central canal ependyma) of a large sample of fetal and infant death victims, aged from 17 gestational weeks to 8 postnatal months. Additionally, we investigated a possible link between alterations of this structure, sudden unexplained fetal and infant death and maternal smoking.

Results

Our results demonstrate that in early fetal life the human ependyma shows a pseudostratified cytoarchitecture including many tanycytes and ciliated cells together with numerous apoptotic and reactive astrocytes in the subependymal layer. The ependyma is fully differentiated, with a monolayer of uniform cells, after 32 to 34 gestational weeks. We observed a wide spectrum of ependymal pathological changes in sudden death victims, such as desquamation, clusters of ependymal cells in the subventricular zone, radial glial cells, and the unusual presence of neurons within and over the ependymal lining. These alterations were significantly related to maternal smoking in pregnancy.

Conclusions

We conclude that in smoking mothers, nicotine and its derivatives easily reach the cerebrospinal fluid in the fetus, immediately causing ependymal damage. Consequently, we suggest that the ependyma should be examined in-depth first in victims of sudden fetal or infant death with mothers who smoke.

Study of the human hypoglossal nucleus: normal development and morpho-functional alterations in sudden unexplained late fetal and infant death

This study evaluated the development and the involvement in sudden perinatal and infant death of the medullary hypoglossal nucleus, a nucleus that, besides to coordinate swallowing, chewing and vocalization, takes part in inspiration. Through histological, morphometrical and immunohistochemical methods in 65 cases of perinatal and infant victims (29 stillbirths, 7 newborns and 29 infants), who died of both unknown and known cause, the authors observed developmental anomalies of the hypoglossal nucleus (HGN) in high percentage of sudden unexplained fetal and infant deaths. In particular, HGN hypoplasia, hyperplasia, positive expression of somatostatin and absence of interneurons were frequently found particularly in infant deaths, with a significant correlation with maternal smoking.

Developmental alterations of the prefrontal cerebral cortex in sudden unexplained perinatal and infant deaths

The aim of this study was to investigate the developmental patterns of the human prefrontal cortex involved in breathing control in a wide cohort of fetal and infant death victims, aged from the 22(nd) gestational week to 10 months of life, and to evaluate whether morpho-functional disorders are present in this specific cortical area in victims of sudden unexplained death. A further aim was to determine whether prenatal absorption of nicotine could also affect the maturational processes of the prefrontal cortex. A pronounced radial organization of the cerebral wall was evident from the 26(th) gestational week. By 36 gestational weeks this columnar structure disappeared, coinciding with the formation of a laminar cyto-architecture. The mature cortex, observable from the 4(th) month of life, was organized horizontally into six laminae. In 33% of the sudden death victims the prefrontal cortex showed morphological alterations with anomalous laminar patterns and delayed neuronal maturation. A significant correlation with prenatal cigarette exposure was found.

Neuropathology of the intermediolateral nucleus of the spinal cord in sudden unexplained perinatal and infant death

Experimental studies have demonstrated that breathing activity in rats is generated early in embryonic stages in rostral spinal cord, precisely in the intermediolateral nucleus, then establishing a spinal cord-brainstem network. In this study we aimed to individuate and to define the developmental steps of the intermediolateral nucleus, still inadequately known in humans, in the thoracic spinal cord of a large series of perinatal and infant death victims, aged from 17 gestational weeks to 10 months of life. Besides we investigated a possible link between alterations of this nucleus and sudden unexplained perinatal and infant death. The normal developmental pattern of the human intermediolateral nucleus consists of a progressive maturation of its neurons, that change from a round to a polygonal shape with long axons and significantly decrease in number. Various degrees of intermediolateral nucleus hypodevelopment (neuronal immaturity in a normal structure/hypoplasia/agenesis) were found almost exclusively in unexplained fetal and infant death victims. Besides, a significant correlation was found between maternal smoking in pregnancy and the neuropathological results. In conclusion this work underlines the negative effects of prenatal nicotine exposure on the development of autonomic nervous centers checking the vital functions, already in early gestational stages, when the integrity of the intermediolateral nucleus is indispensable for the first breathing bursts.

Optimisation of postmortem tissue preservation and alternative protocol for serotonin transporter gene polymorphisms amplification in SIDS and SIUD cases

The major obstacle to genetic research in SIUD (sudden intrauterine unexplained death) and SIDS (sudden infant death syndrome) cases is the complex characteristics of the human anatomic samples available. In fact, in Italy autopsies are performed at least 24 h post-mortem and tissues can be left in formalin for long fixation times (>4/5 days), thus compromising nucleic acids integrity. In this study we compared the quality of DNA and RNA extracted from tissues differently preserved. As expected, the DNA and RNA from formalin-fixed and paraffin-embedded tissues, formalin-acetic acid-alcohol tissues and ethanol tissues were of poor quality and not adequate for subsequent molecular analysis. The best results were obtained with RNAlater preserved tissues: this buffer was equivalent, if not superior, to freezing method for preservation of postmortem DNA and RNA. In addition, we introduce a new protocol for the amplification of the serotonin transporter gene promoter region (5-HTT) ideal to obtain the increase of specific product, avoiding artifacts formation.

Sudden infant death syndrome and sudden intrauterine unexplained death: correlation between hypoplasia of raphé nuclei and serotonin transporter gene promoter polymorphism

This study, besides to delineate the cytoarchitecture and the localization in the brainstem of the human raphé nuclei, aims to evaluate the correlation between neuropathological raphé defects and serotonin transporter gene (5-HTT) promoter region polymorphisms in a cohort of 28 SIDS victims, 12 sudden intrauterine unexplained deaths (SIUD), and 17 controls. Hypoplasia of one or more nuclei of both the rostral and caudal raphé groups was found in 57% of SIDS, in 67% of SIUD, and only in 12% of controls. Furthermore, a significant correlation among 5-HTT Long (L) allele, hypoplasia of the raphé nuclei, and maternal smoking in pregnancy was observed in sudden fetal and infant deaths. The presence of the L allele represents a predisposing factor for sudden fetal and infant death in association with morphologic developmental defects of the raphé nuclei and prenatal smoke exposure. A further consideration of the authors is that SIUD should not be regarded as a separate entity from SIDS, given the potentially shared neuropathological and genetic bases.

Neuropathology of the Guillain-Mollaret Triangle (Dentato-Rubro-Olivary Network) in Sudden Unexplained Perinatal Death and SIDS

The present study was undertaken to evaluate the possible alterations of the triangle of Guillain and Mollaret (G-Mt), a neuronal brainstem/cerebellum network (from the dentate nucleus to red nucleus and inferior olivary nucleus) already known for its involvement in the pathogenesis of the palatal myoclonus, in sudden unexplained perinatal and infant death. In 44 cases of perinatal and infant death victims, aged from 26 gestational weeks to 10 months of life, we investigated, besides the histological morphology of the three nuclei, the c-fos and apoptotic expression, as well as the possible effects elicited by maternal cigarette smoking.

A significant increase of lesions (hypoplasia and/or increased c-fos and apoptotic neuronal immunopositivity) of the three nuclei was found in unexplained death victims, compared with age-matched controls. These alterations were related to maternal cigarette smoking habit.

We postulated that the G-Mt is an important network involved in the pathogenesis of a wide spectrum of pathological manifestations and that maternal smoking during pregnancy can exert an adverse influence on this complex, even leading to sudden death in vulnerable periods of perinatal or infant development.

Feto-placental atherosclerotic lesions in intrauterine fetal demise: role of parental cigarette smoking

The atherogenic effect of cigarette smoking is already recognizable in coronary arteries of fetuses in the last gestational weeks. In this study we analyzed the atherogenic effect of mother's and father's smoking habit on coronary arteries and even on adnexa of 30 human fresh fetuses died from 32 to 41 gestational weeks. In 12 cases only the mothers of the victims were cigarette smokers, in 7 cases only the fathers were smokers, whereas in 11 cases nobody smoked.We observed pre-atherosclerotic and initial atherosclerotic lesions of the adnexa in 21 cases, of which 11 cases had only mother smokers and 6 cases only father smokers. The atherogenic effect is statistically significant in both smoker groups, but stronger in maternal one. The atherosclerotic lesions found in umbilical and placental arteries are similar to those described in fetal coronary arteries: thickening of the arterial walls caused by proliferation and migration of the smooth muscle cells of the tunica media with loss of polarity and infiltration of the subendothelial connective tissue.

Infant and perinatal pulmonary hypoplasia frequently associated with brainstem hypodevelopment

Recent anatomo-pathological studies have revealed a frequent associated hypoplasia of both arcuate nucleus and lungs in stillbirths. The purpose of this study is to analyze the lung and brainstem development in sudden unexplained perinatal death and sudden infant death syndrome (SIDS). A total of 51 cases were investigated. A complete autopsy was performed in each case. Anatomo-pathologic examination of the central autonomic nervous system included an in-depth study on histological serial sections of the brains where the main structures participating in control of the vital functions are located. The stage of lung development was evaluated by macroscopic and microscopic criteria. In 52.9% of cases, a pulmonary hypoplasia was detected. The pulmonary hypoplasia was significantly more frequent in the SIDS group compared to the sudden perinatal unexplained death groups (p < 0.05). In 72.5% of cases, histological examination of the brainstem on serial sections showed hypodevelopment of the brainstem nuclei, particularly hypoplasia, of the arcuate nucleus (60.8%). In 47.1% of cases, pulmonary hypoplasia was associated with brainstem hypodevelopment.

Carotid barochemoreceptor pathological findings regarding carotid plaque status and aging

BACKGROUND

Carotid barochemoreceptor pathological lesions have been studied in animals, but few human necropsies have been performed. Therefore, data rely on case patients following surgery, radiotherapy and carotid endarterectomy. Almost no data are available regarding whether the effect of aging prevails over pathological conditions, despite the classic description that glomic fibrosis increases with age.

OBJECTIVE

To morphometrically characterize the alterations of the carotid barochemoreceptors and their supplying arteries.

METHODS

Patients (n=23) who had suffered and died from stroke, with and without complicated internal carotid atheromatosis, were divided by age (group 1: older than 80 years; group 2: 65 to 80 years; and group 3: younger than 65 years). Carotid segments were obtained at autopsy. The specimens were stained for light microscopy and immunohistochemistry.

RESULTS

Carotid glomus presented from moderate-to-severe atrophy and fibrosis. A focal decrease in vascularization (CD34-positive) of the glomus (greater than 50%) was observed in areas of atrophy and fibrosis. Damaged nerve endings (S100 protein-positive) were observed at the media of the carotid sinus. Morphometric data showed no differences between groups for glomus area, number of type 1 and 2 cells, and the wall to lumen arteriole ratio. No statistical differences were demonstrated in the pathological findings of the carotid glomus when comparing complicated with noncomplicated plaques or age groups.

CONCLUSION

Severe carotid chemoreceptor damage exists in patients who have died from stroke and suffered from carotid atheromatosis. These findings were independent from aging and plaque type. However, damage was correlated with a marked narrowing of the supplying arterioles as a consequence of hemodynamic and/or metabolic alterations (dyslipidemia, diabetes).

Association of dopamine transporter and monoamine oxidase molecular polymorphisms with sudden infant death syndrome and stillbirth: new insights into the serotonin hypothesis

Recent findings demonstrated the role of neurotransmitters in the aetiopathogenesis of sudden unexpected deaths in infancy. Although genes involved in serotonin metabolism have been proposed as risk factors for sudden infant death syndrome (SIDS), the contribution of additional neurotransmitters and genes different from the serotonin transporter (SLC6A4, 5-HTT) has not been investigated. Considering the common metabolic pathway and synergism between dopamine and serotonin, the role of dopamine transporter (SLC6A3, DAT) and monoamine oxidase A (MAOA) genes in SIDS and stillbirth (sudden intrauterine unexplained death, SIUD) was investigated. Genotypes and allelic frequencies of DAT and MAOA were determined in 20 SIDS and five stillbirth cases and compared with 150 controls. No association was found between DAT polymorphisms and SIDS either at genotype (P = 0.64) or allelic (P = 0.86) level; however, a highly significant association was found between MAOA genotypes (P = 0.047) and alleles (P = 0.002) regulating different expression patterns (3R/3R vs 3.5R/3.5R + 4R/4R) in SIDS + SIUD and controls. Analysis of combined 5-HTTLPR (serotonin transporter linked polymorphic region)/MAOA genotypes revealed that frequency of L/L-4R/4R genotype combination was eightfold higher in SIDS + SIUD than in controls (P < 0.001). Findings are discussed considering the metabolic association among DAT, 5-HTT and MAOA with special emphasis on the linked action of 5-HTT/MAOA in regulating serotonin metabolism of SIDS and SIUD infants.

Unexpected perinatal loss versus Sids-a common neuropathologic entity

Objective: To evaluate the involvement of alterations of the central autonomic nervous system, particularly of the brainstem and cerebellum, in a wide set of victims of sudden and unexplained perinatal and infant death.

Material and Methods: The study population consisted of 63 stillbirths, 28 neonatal deaths and 140 suspected SIDS. The victims were subjected to in-depth anatomopathological examination following appropriate guidelines. The protocol included, in particular, the histological evaluation on serial sections of the cardiorespiratory autonomic nervous system.

Results: A diagnosis of “unexplained death” was established for 217 of the 231 victims (59 stillbirths, 28 newborns and 130 SIDS). In a very high percentage of these deaths (84%) we observed one or more anomalies of the nuclei and/or structures of the brainstem and cerebellum related to vital functions.

Conclusion: Unexpected perinatal loss should not be regarded as a separate entity from SIDS, given the common neuropathological substrates.