Sudden infant death syndrome: Melatonin, serotonin, and CD34 factor as possible diagnostic markers and prophylactic targets

Altered 5-HT2A/C receptor binding in the medulla oblongata in the sudden infant death syndrome (SIDS): Part II. Age-associated alterations in serotonin receptor binding profiles within medullary nuclei supporting cardiorespiratory homeostasis

The failure of chemoreflexes, arousal, and/or autoresuscitation to asphyxia may underlie some sudden infant death syndrome (SIDS) cases. In Part I, we showed that some SIDS infants had altered 5-hydroxytryptamine (5-HT)2A/C receptor binding in medullary nuclei supporting chemoreflexes, arousal, and autoresuscitation. Here, using the same dataset, we tested the hypotheses that the prevalence of low 5-HT1A and/or 5-HT2A/C receptor binding (defined as levels below the 95% confidence interval of controls-a new approach), and the percentages of nuclei affected are greater in SIDS versus controls, and that the distribution of low binding varied with age of death. The prevalence and percentage of nuclei with low 5-HT1A and 5-HT2A/C binding in SIDS were twice that of controls. The percentage of nuclei with low 5-HT2A/C binding was greater in older SIDS infants. In >80% of older SIDS infants, low 5-HT2A/C binding characterized the hypoglossal nucleus, vagal dorsal nucleus, nucleus of solitary tract, and nuclei of the olivocerebellar subnetwork (important for blood pressure regulation). Together, our findings from SIDS infants and from animal models of serotonergic dysfunction suggest that some SIDS cases represent a serotonopathy. We present new hypotheses, yet to be tested, about how defects within serotonergic subnetworks may lead to SIDS.

[Lung pathology in children with a long-term novel coronavirus infection COVID-19]

New coronavirus infection is registered less frequently in children than in adults. Among all patients with COVID-19, the share of children is 8.6%. Clinical practice shows that in children, COVID-19 can be severe and even fatal. Articles have been published reflecting the clinical manifestations of Long Covid in children, while data on pathomorphological examination of the lungs during long-term COVID-19 in children are not available in the literature. On the basis of the Department of Pathological Anatomy with a course of Forensic Medicine and the Pathological-Anatomical Department of the Clinic of St. Petersburg State Pediatric Medical University, an analysis of medical documentation was carried out, autopsy materials were selected from 3 observations of the death of children from COVID-19. The selection criterion was the duration of the disease. A histological examination using standard methods and IHC analysis using antibodies to the nucleocapsid of SARS-Cov-2, CD95, CD31 were carried out on the lung tissue of 3 children aged 2 months to 2 years who died from a new coronavirus infection. Microscopically, all three patients showed microvessels damage, their thrombosis, angiogenesis, as well as signs of diffuse alveolar damage The combination of expression of the SARS-CoV-2 nucleocapsid and the apoptosis marker on the vascular endothelium of the MCR is of interest.

CONCLUSION

The data obtained indicate infection with coronavirus and death of endothelial cells due to apoptosis. Endothelial damage in the microvessels of the lungs is the initiating factor in the development of capillary-alveolar block, tissue hypoxia, and disseminated intravascular coagulation syndrome, leading in some cases to respiratory/multiple organ failure and death.

COVID-19 in Children: Molecular Profile and Pathological Features

Although the World Health Organization has declared the end of the COVID-19 pandemic, doctors continue to register new cases of the disease among both adults and children. Unfortunately, the course of COVID-19 in children can have a severe form, with death being a potential outcome. The absence of published works discussing the pathological morphology of COVID-19 in children prevents the objective analysis of the disease's pathogenesis, including among the adult population. In this vein, the objective of our study is to identify the morphological features of the lungs' involvement and evaluate virus-host interactions in the case of COVID-19 in patients at a pediatric medical practice. We present the results of the study of the lungs of three children who died due to COVID-19, highlighting the predominant involvement of their respiratory organs at different stages of the disease (5, 21, and 50 days). This article presents data obtained from histopathological and immunohistochemical investigations, taking into account the results of clinical and laboratory indicators and intravital and postmortem SARS-CoV-2 PCR investigations. The common finding of all of the examined COVID-19 cases is the involvement of the endothelium in microcirculation vessels, which are considered to be a primary target of various pathogenic influencing factors. We also discuss both the significance of apoptosis as a result of virus-host interactions and the most likely cause of endothelium cell destruction. The results of this study could be useful for the development of endothelium-protective therapy to prevent the progression of disseminated intravascular coagulation syndrome.

Altered 5-HT2A/C receptor binding in the medulla oblongata in the sudden infant death syndrome (SIDS): Part I. Tissue-based evidence for serotonin receptor signaling abnormalities in cardiorespiratory- and arousal-related circuits

The sudden infant death syndrome (SIDS), the leading cause of postneonatal infant mortality in the United States, is typically associated with a sleep period. Previously, we showed evidence of serotonergic abnormalities in the medulla (e.g. altered serotonin (5-HT)1A receptor binding), in SIDS cases. In rodents, 5-HT2A/C receptor signaling contributes to arousal and autoresuscitation, protecting brain oxygen status during sleep. Nonetheless, the role of 5-HT2A/C receptors in the pathophysiology of SIDS is unclear. We hypothesize that in SIDS, 5-HT2A/C receptor binding is altered in medullary nuclei that are key for arousal and autoresuscitation. Here, we report altered 5-HT2A/C binding in several key medullary nuclei in SIDS cases (n = 58) compared to controls (n = 12). In some nuclei the reduced 5-HT2A/C and 5-HT1A binding overlapped, suggesting abnormal 5-HT receptor interactions. The data presented here (Part 1) suggest that a subset of SIDS is due in part to abnormal 5-HT2A/C and 5-HT1A signaling across multiple medullary nuclei vital for arousal and autoresuscitation. In Part II to follow, we highlight 8 medullary subnetworks with altered 5-HT receptor binding in SIDS. We propose the existence of an integrative brainstem network that fails to facilitate arousal and/or autoresuscitation in SIDS cases.

Melatonin as the Cornerstone of Neuroimmunoendocrinology

Much attention has been recently drawn to studying melatonin – a hormone whose synthesis was first found in the epiphysis (pineal gland). This interest can be due to discovering the role of melatonin in numerous physiological processes. It was the discovery of melatonin synthesis in endocrine organs (pineal gland), neural structures (Purkinje cells in the cerebellum, retinal photoreceptors), and immunocompetent cells (T lymphocytes, NK cells, mast cells) that triggered the evolution of new approaches to the unifield signal regulation of homeostasis, which, at the turn of the 21st century, lead to the creation of a new integral biomedical discipline — neuroimmunoendocrinology. While numerous hormones have been verified over the last decade outside the “classical” locations of their formation, melatonin occupies an exclusive position with regard to the diversity of locations where it is synthesized and secreted. This review provides an overview and discussion of the major data regarding the role of melatonin in various physiological and pathological processes, which affords grounds for considering melatonin as the “cornerstone” on which neuroimmunoendocrinology has been built as an integral concept of homeostasis regulation.

Epidemiology of sudden infant death syndrome in Mexico, 2005-2020

BACKGROUND

Sudden Infant Death Syndrome (SIDS) constitutes one of the main causes of mortality in children under one year of age in developed countries; it's frequency to varies geographically. In Mexico the real incidence of SIDS is not known.

METHODS

National databases of deaths in children under one year of age, from 2005 to 2020, were analyzed, due to Sudden Unexpected Infant Death (SUID) [SIDS (R95), accidental suffocation in a sleeping environment (W75), and other ill-defined and unspecified causes of mortality (R99), according to the International Classification of Diseases, tenth revision (ICD 10)]. Mortality rates per year of occurrence due to SUID and their subcategories were calculated. Simple frequencies of SIDS were obtained per year and month of occurrence, state of residence, age, place of death, and access to social security services.

RESULTS

In the study period 473,545 infant deaths occurred; 7,714 (1.62%) deaths were due to SUID; of these, 6,489 (84%) were due to SIDS, which is among the 10 leading causes of infant death in Mexico. The average mortality rate for SUID was 22.4/100,000 live births, for SIDS was 18.8/100,000 live births. Mortality rates within the states were variable, ranging from 2.4/100,000 to 105.1/100,000 live births. In 81% of SIDS records there was no autopsy; 38% of deaths due to SIDS occurred in infants under one month of age, up to 87% of deaths occurred in families without social security services or it was unknown, and 76.2% of deaths occurred at home. Deaths were more frequent during the last months of autumn and during winter.

CONCLUSION

In Mexico there is an underregistry of SIDS as cause of death, along with other SUID categories. Health workers need to be trained to improve diagnosis and data registration, including the practice of autopsies; additionally, it is necessary to implement a public health campaign.