1,720,964 research outputs found
Hypoplasia and neuronal immaturity of the hypoglossal nucleus in sudden infant death
No full textOBJECTIVE: To report the case of five month old female baby with a history of episodes of gastro-oesophageal reflux and pneumonia. Her sudden death offered a unique insight into the possible role of delayed neuronal maturation and hypoplasia of the hypoglossal nucleus in representing a likely morphological substrate of sudden death. METHODS: Morphometric analysis was carried out with an Image-Pro Plus Image analyser (Media Cybernetics) on both sides of the brain stem. RESULTS: Hypoplasia and neuronal immaturity of the hypoglossal nucleus were demonstrated, accompanied by hypoplasia of the arcuate nucleus. CONCLUSIONS: Much attention should be paid to the possible role of the hypoglossal nucleus in determining a lethal outcome in infancy through impairment of deglutition and subsequent recurrent episodes of pneumonia, and as a necropsy finding
Absolute shortness of the umbilical cord and hypoplasia of the arcuate nucleus and of the parabrachial/Kölliker-Fuse complex in a case of sudden intrauterine fetal death
No full textObjective – This work intends to describe a case of sudden unexplained late fetal death at 41+4 gestational weeks, following physiological pregnancy, in which alterations of fetal adnexa were observed in association with congenital alterations of brainstem nuclei.
Study design - The victim was subjected to in-depth anatomopathological examination, particularly of the central autonomic nervous system and of the placenta, following specific guidelines.
Results - The histopahological study of the brainstem revealed hypoplasia of the arcuate nucleus in the medulla oblongata and hypoplasia of the parabrachial/Kölliker-Fuse complex in the pons/mesencephalon. The macroscopic examination of fetal adnexa showed absolute shortness of the umbilical cord (length 30 cm, maximum diameter 1.7 cm, minimum diameter 1 cm).
Conclusion - The abnormally short umbilical cord observed in this case, although not enough to lead to sudden death, is likely to have triggered malignant effects, when coupled with severe developmental defects of the arcuate nucleus and of the parabrachial/Kölliker-Fuse comple
Chorioamnionitis and congenital abnormalities of the brainstem (arcuate nucleus and pre-Bötzinger complex hypoplasia) in a case of late unexplained stillbirth
No full textBackground: Fetal death (stillbirth), that occurs every 100-200 pregnancies in industrialized countries, has not significantly decreased in recent years, mostly because of scarce research activities in this field. Fetal death is often, in up to 60-80% of cases, unexplainable, even after routine diagnostic examinations.
Objectives: This work aims to stress the importance of in-depth histopathological investigations of both the autonomic nervous system and the placenta, in sudden fetal death.
Methods: In a case of late fetal death at 40+3 weeks of pregnancy an in-depth histopathological examination of the brainstem and of the placenta was performed.
Results: The case investigated in this work showed severe hypoplasia of the arcuate nucleus as well as of the reticular formation and particularly of the pre-Bötzinger complex. Pulmonary hypoplasia was also present, associated with a picture of severe (grade 3) chorioamnionitis, with inflammatory, mostly granulocytic, infiltrate, vasculitis of the umbilical vein and amniochorionic vessels.
Conclusions: The chorioamnionitis can allegedly contribute to stillbirth, through cytokine release, enhancing any chemoreceptor neuronal dysfunction
Possible role of the nucleus ambiguus in Sudden Infant Death Syndrome (SIDS)
No full textThe pathogenic mechanisms underlying SIDS seem to involve the autonomous nervous system, despite the nucleus ambiguous has been rarely if at all considered. The study was carried out in 16 SIDS cases (7 males and 9 females; ranging in age from 1 to 21 weeks) and 11 age-matched controls died of known caused. A morphometric analysis was performed with an Image-Pro Plus Image analyzer (Media Cybernetics, Silver Spring, MD), evaluating the surface area of nucleus ambiguus (mm2) and its numerical Density of neurons (number of cell/mm2). Profile of neurons of the nucleus ambiguus (nuclear and cytoplasmic area expressed in mm2 nuclear/cytoplasmic ratio (N/C), diameter mean neuronal and diameter mean nuclear expressed in mm and form factor of the neurons were also evaluated. The statistical significance of comparisons between SIDS and control cases was determined using the analysis of variance The level of significance was set at p <0.05. Examination of the nucleus ambiguus on serial sections revealed no hypoplasia, while the neuronal maturity parameters except the N/C ratio were decreased compared to the age-matched controls, as confirmed by two-dimensional morphometric reconstruction on both sides of the medulla oblongata. In conclusion, much attention should be paid to the possible role that a delayed neuronal maturity of the nucleus ambiguus might play in determining a lethal outcome in SIDS. Further studies are needed to gain a better understanding of the complex interactions involved in the pathophysiology of SIDS and the herein presented findings seem to usefully contribute literature information for the possible role of ambiguus nucleus in SIDS
Infant and perinatal pulmonary hypoplasia frequently associated with brainstem hypodevelopment
No full textRecent 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
Cigarette Smoking as a risk factor for coronary artery disease and sudden unexpected death in fetuses and infants
Full text linkMaternal smoking during pregnancy makes it more likely that the baby will be stillborn or die in the first year of life. Cigarette smoke is the most important risk factor for fetal and infant sudden death (SIDS). The risk of stillbirthor death during the infant's first year of life is directly related to the amount the mother smoked. The present study adds significant evidence on the need to avoid cigarette smoking. The pathogenic mechanism of smoke is referable to different factors. The combustion products of nicotine, in addition to their diffuse toxicity, are heterogeneous and cause specific lesion of the automatic nervous system. Gaseous combustion products, such as carbon oxide, lead to atheosclerotic plaques in the cardiovascular district and in the sino-atrial and atrio-ventricular arteries
Study of the human hypoglossal nucleus: normal development and morpho-functional alterations in sudden unexplained late fetal and infant death
Full text linkThis 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
Sudden Intrauterine Unexplained Death (SIUD) «Gray Zone» or borderline
No full textWe report a total of 9 fetuses (3 females and 6 males, ranging in age from 34 to 41 gestational weeks) that died suddenly and unexpectedly, and presented brainstem and cardiac conduction system lesions together with abnormalities of the fetal adnexa. A complete autopsy was performed in each case. Histological examination of the fetal adnexa disclosed the presence of chorioamnionitis (7 cases), an abnormally short umbilical cord (1 case), and placental infection by parvovirus (1 case). These lesions were associated with brainstem lesions, i.e., hypoplasia of the arcuate nucleus, inflammatory infiltrates in the brainstem, hypoplasia of the raphe obscurus nucleus, hypoplasia of the parabrachial Kölliker-Fuse complex, hypoplasia of the pre-Bötzinger complex, agenesis of the facial/parafacial complex, as well as conduction system lesions, i.e., dispersion or septation of the atrio-ventricular junction (9 cases), islands of the conduction system inside the central fibrous body (5 cases) resorptive degeneration (4 cases), cartilaginous meta-hyperplasia (2 cases), Mahaim fibers (1 case). The SIUD «gray zone» are hereby described as those cases in which the lesions of the fetal adnexa alone might not have accounted for the sudden deaths, had it not been for the concomitant presence of brainstem and cardiac conduction lesions. Our cases are consistent with the triple-risk model, a hypothesis introduced for SIDS postulating an underlying biological vulnerability to exogenous stressors or triggering factors in a critical developmental period
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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