1,720,985 research outputs found
Madres fumadoras y aterosclerosis prenatal.
Full text linkLa hipercolesterolemia y el tabaquismo son factores de riesgo exògenos reconocidos para el desarrollo de aterosclerosis. La historia natural de la aterosclerosis se basa principalmente en studios experimentales en animales mantenidos con una dieta alta en colesterol. La lesion fundamental es la infiltraciòn lipìdica del tejido conectivo subendotelial de la intima y la subsecuente infiltraciòn de cèlulas con funciones reparadoras, principalmente monocitos y céllulas musculares lisas (CML). Sobre la base de estudios epidemiològicos se sabe que el tabaquismo es uno de los factores de riesgo cardiovascular
Perinatal and Infant early atherosclerotic coronary lesions related to maternal smoking
No full textBackground: The observations reported in the literature regarding the fetal origin of coronary artery lesions are rare and controversial.
Aim: To identify the features of early atherosclerotic coronary artery lesions in late fetal stillborns and infants and the possible atherogenic role of maternal cigarette smoking.
Methods: We examined by autopsy 22 unexpected fetal deaths and 36 sudden infant death syndrome victims. In 28/58 of the cases mothers were smokers. Serially cut sections of major epicardial coronary arteries were stained with hematoxylin-eosin, Azan, Alcian blue and acetic orceine, and were immunotypified for CD68, CD34, α-SM-Actin, PCNA, c-fos, and apoptosis.
Results: In 10/12 of fetuses and in 15/16 of infants of smoking mothers, multifocal coronary lesions of varying entity were detected. Only in 5 cases (2/10 fetus and 3/20 infants) arterial lesions were observed in infants with non-smoker mothers (p<0.0001). Alterations ranged from focal areas with mild myointimal thickening in prenatal life to early soft parietal plaques in infants. Smooth muscle cells (SMCs) showed loss of polarity, infiltrating subendothelium, mostly with rupture of the internal elastic lamina. No neoangiogenesis was observed. These early lesions, presented c-fos gene activation in the SMCs of the tunica media, and in some of these, positivity of the SMCs for apoptosis was also observed; suggesting that c-fos gene over-expression could might promote a proliferative process, as testified by the PCNA positivity.
Conclusion: Early intimal alterations of the coronary arteries are already detectable in the prenatal and infancy period and are significantly associated with maternal cigarette smoking
Immunotypification of perinatal and infant early atherosclerotic coronary lesions
No full textPlasma cholesterol concentration and cigarette smoking have been well established as the major exogenous risk factors for the development of atherosclerosis. The observations reported in the literature regarding the fetal origin of coronary artery lesions are rare and controversial.Aim: To identify the features of early atherosclerotic coronary artery lesions in late fetal stillborns and infants and the possible atherogenic role of maternal cigarette smoking. Methods: We examined 22 unexpected fetal deaths and 36 sudden infant death syndrome victims, all between 32nd week of gestation and one year of age. All underwent autopsy. In 28/58 of the cases the mothers were smokers before and during pregnancy. The four major epicardial coronary arteries were isolated along their whole length, embedded in paraffin and serially cut for histologic examination. The sections were stained with hematoxylin-eosin, Heidenahin trichromic (Azan), Alcian blue (pH 0.5 and 2.5) and Weigert, and immunohistochemical studies, for CD68, CD34, anti-actin, PCNA, c-fos expression, and apoptosis (TUNEL method). Results: In 10/12 of fetuses and in 15/16 of infants of smoking mothers, multifocal coronary lesions of varying entity were detected. Only in 5 cases (2/10 fetus and 3/20 infants) arterial lesions were observed in infants with non-smoker mother (p<0.0001). The alterations ranged from focal areas with mild myointimal thickening in prenatal life to early soft parietal plaques in infants, partially reducing the arterial lumen up to 30-40%. The smooth muscle cells (SMCs) presented loss of polarity, forming columns perpendicular to the axis of the media and infiltrating the subendothelial connective tissue, mostly with rupture of the internal elastic lamina. Increased amounts of mucoid ground substance were also observed at this level. Macrophages were detected in the intimal border of the lesions, penetrating the endothelium. No neoangiogenesis was observed. These early atherosclerotic lesions, presented c-fos gene activation in the SMCs of the tunica media, and in some of these, positivity of the SMCs for apoptosis was also observed; suggesting that c-fos gene over-expression could promote a proliferative process, as testified by the PCNA positivity.Conclusion: Early intimal alterations of the coronary arteries are already detectable in the prenatal period and are significantly associated with maternal cigarette smoking
Expression of c-fos, p53 and PCNA in the unstable atherosclerotic carotid plaque
No full textBackground: The process by which a fibrofatty plaque evolves into a fibrotic lesion or into an unstable, lipid-rich plaque is poorly understood. In this study our aim is to deepen the knowledge of the cellular proliferation mechanisms that characterize the initial phases of destabilization of the unstable carotid plaque. Methods: 32 specimens from carotid endarterectomies were employed to assess by immunohistochemical methods, either in stable (n=10) or unstable (n=22) atherosclerotic plaques, the proliferating cell nuclear antigen (PCNA), the proto-oncogene c-fos, and the oncoprotein p53. Results: 18/32 atherosclerotic plaques (all unstable), showed c-fos immunopositivity (P<0.0001). Ten lesions, three stable and seven unstable, were PCNA+, while 13 cases were positive for p53 (three stable and 10 unstable plaques). When comparing symptomatic vs. asymptomatic patients, the most striking finding was the coincidence between c-fos, PCNA and p53 protein positivity observed only in unstable plaques of seven out of eight patients, all with previous episodes of stroke or transient ischemic attacks. On the other hand, none of the above mentioned positivity was detected in the 24 asymptomatic patients (P<0.0001). Conclusions: These findings indicate an important role of these biomarkers in vascular biology. A series of molecular pathways of disease development and progression common both to atherosclerosis and cancer, support that the world’s two most common diseases are more closely aligned than previously believed
Carotid barochemoreceptor pathological findings regarding carotid plaque status and aging
No full textBACKGROUND:
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)
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
Severe carotid barochemoreceptor involvement in stroke
No full textPhysiopathology of barochemoreception is hindered by the scarce information on its morphology in disease. The baroreflex is of major importance for the maintenance of arterial pressure during orthostatic stress. The purpose of this paper was to characterize the morphological alterations of carotid glomus in old patients who died from stroke and suffering obstructive carotid atheromatosis. METHODS: Bilateral carotid segments were obtained at autopsy from 17 patients (51-89 years old). Specimens were stained with hematoxylin and eosin; Azan trichrome, Grimelius silver stain for catecholamine detection, and were immunophenotyped for CD34 and S-100. Similar segments of both carotid arteries of six patients (62-77 years old) who died by accidents were used as controls. RESULTS: The carotid glomus of patients who died from stroke presented atrophy and fibrosis (2.59+/-0.5 vs. 1.17+/-0.39 in the control group; p<0.0001). There was a loss of chief cells and of the argyrophilic staining granules. A focal diminution of glomus vascularization was observed in the areas of atrophy and fibrosis (2.73+/-0.45 vs. 1.5+/-0.52 in the control group; p<0.0001). The arterioles to glomus showed severe fibrointimal proliferation, disruption of internal elastic lamina and luminal narrowing, and luminal thrombi. CONCLUSION: A severe carotid glomic damage does exist in old patients who died from stroke and suffering from carotid atheromatosis, independent from aging, of note, a "culprit" marked narrowing of the corresponding arterioles was observed
The role of maternal cigarette smoking habit in the onset of early coronary atherosclerotic lesions in fetuses and infants
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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