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“Preparazione della matrice pilifera con reattivo VMA® per analisi immunochimica: confronto con GC/MS”,
No full textCoronary artery anomalies and sudden death: two case reports in young people.
No full textCoronary artery anomalies may cause sudden death. This presentation discusses the clinicopathologic features, the autoptic findings and microscopic features in two cases with different coronary anomalies.
Case 1
A 13-month-old infant, white male, was found unresponsive in his crib. The infant was transported to the hospital, where resuscitative efforts were unsuccessful, and the infant was pronounced dead. Previous clinical history: at the age of 6 months numerous episodes of apnea’s crisis, cyanosis and convulsion and at the age of 7 months, the infant was diagnosed as epileptic. Cardiologic examinations (ECG, echocardiogram, Holter monitor evaluation) and chest X-Ray were normal.
The autopsy revealed a well developed and well nourished 13-month-old white male. All internal organs were in their normal anatomic relationship. The heart, in the fresh state, weighed 45 grams. Upon sectioning, the myocardium was reddish. Atrio-ventricular and semilunar valves were normal. The right coronary artery arose from the left sinus of Valsalva associated to a tunneled passage of the posterior interventricular coronary artery. The first section of this artery presented a take-off and a passage between the aortic and pulmonary root. The coronary circuit was dominant to the right.
The histological examination of the cardiac tissues revealed diffused and biventricular myocytolisis in contractile subendocardial bands characterized by altered, eosinophilic, hypercontracted myofiber. In many areas the myofiber appeared fragmented into irregular, partially acidophilic transverse bands. The immunohistochemical exams, effected on cardiac fragments, resulted positive to the anti - desmin and anti- actin antibodies, and negative to the anti C5 antibodies. Examination of the other organs were unremarkable except for pulmonary edema and polyvisceral stasis.
Case 2
A 22-year-old white male collapsed and died while exercising in a swimming pool; prompt medical assistance and attempted resuscitation were unsuccessful. At the age of 21, he was hospitalized in a Neurological Clinic, where instrumental and clinical data suggested the diagnosis of Friedreich’s ataxia. The subject underwent molecular genetic analysis for the FA gene that revealed neither expansion nor point mutation of the FA gene. One year later, he was hospitalized at another Neurological Clinic where a general examination showed kyphoskoliosis, pes cavus, and a neurologic examination showed nystagmus, hypotonus, distal hypotrophy of the arms and legs, ataxia, areflexia, abnormalities in superficial and deep sensations. Ncv and EMG examinations were compatible with a severe axonal-myelinic sensory-motor neuropathy, while vitamin E, B12, folic acid, antigliadin antibodies, hexosaminidase, transferring isoforms, lactate and pyruvate were all normal. The diagnosis was spinocerebellar heredodegeneration, Friedreich’s type. A treatment with idebenone, CoQ100 and Vitamin E associated with physiotherapy was suggested.
At autopsy the body was that of a well-developed young adult. Skin, ostia, oral and scleral mucosae were normal. On evisceration the heart had a normal intrathoracic position with the following diameters: longitudinal 11 cm, transversal 13 cm and antero-posterior 7 cm; the weight was 475 gr. On opening, the ventricular chamber was 30 mm wide, the wall and the inter-ventricular septum measured 28 mm each. The endocardium was white, smooth and bright, no trombi or vegetations were detected. Atrio-ventricular and semilunar valves were normal. The right coronary artery normally arose from the right ostium. In the left sinus of Valsalva two distinct ostia were detected instead of the left coronary artery ostium. The diameters of the two ostia measured 1,5 and 2,5 mm respectively and were separated by a septum that divided the stem determining a separate origin of the two left coronaries. Incannulation and a careful dissection demonstrated that the larger ostium was one of the circumflex branch, the smaller one the ostium of the anterior branch.
The histological examination of the sections revealed diffuse interstitial fibrosis due to the presence of thin fibrous septa dividing the muscle cells. Miocytes showed fragmentation of the fibers, nuclear enlargement, sometimes pyknosis and cytoplasmatic vacuolization. A section taken from the interventricular septum showed hemorrhagic infiltration of the wall with single erythrocytes between the single myocites and small blood extravasations. Examination of the other organs were unremarkable except for pulmonary edema and polyvisceral stasis.
The autoptic findings and the histological studies effected lead us to conclude that these are both cases of sudden cardiac death in subjects affected by coronary anomalies.
In the first case death was caused by cardiac arrhythmia sustained by myocardial hypoxia induced by an anomalous origin of the right coronary artery from the left Valsalva sinus.
In the second case death was caused by cardiac arrhythmia, sustained by myocardial hypoxia induced by an anomaly of the left Valsalva sinus, divided into two distinct ostium: one in the anterior intraventricular coronary and one in the circumflexed associated with myocardial hypertrophy, in subjects affected by Friedreich's ataxia.
Congenital coronary anomalies constitute a statistical incidence of 0,3-0,8% and represent 0,1-2% of all congenital cardiac conditions worldwide. If we consider the anomaly originating of the right coronary artery from the left Valsalva sinus, as revealed in one of the two cases examined, the prevalence from autoptic studies is reduced to 0.026%.
Congenital anomalies of the coronary arteries present great difficulties in diagnosis because these diseases can be absolutely asymptomatic and, although rarely, can manifest themselves with syncopal episodes or with a fading symptomatology leading to heart failure. However, the prognosis is influenced by the seriously of coronary anomaly.
The anomalous origin of the right coronary artery from the left Valsalva sinus has long been considered a mostly benign disease and only in 1982 three cases of sudden death are described whose cause depends on this type of congenital alteration.
In literature, the stenosis or coronary take-off in the initial tract are interpreted as causing ischemia and sudden death.
The origin of the right coronary artery from the left sinus may be an incidental observation during autopsy. Ischemia is usually precipitated by strenuous, prolonged effort, and this explains why a basal ECG or even a stress test ECG may be negative. Syncopal episodes are the only prodromal symptoms. Repetitive ischemic episodes may cause patchy myocardial necrosis and fibrosis as well as ventricular hypertrophy, which eventually can elicit arrhythmias because of the malignant combination of acute and chronic substrates. This may explain why sudden death, associated with an anomalous origin of a coronary artery from the wrong sinus, may occur in adults even though the anomaly has been present since birth.
An anomalous origin of the left circumflex artery from the left coronary sinus itself with a separate ostium, has also been described in victims of unexpected arrhythmic sudden death. This anomaly was considered a benign condition until cases were reported, both clinically and pathologically, with evidence of myocardial ischemia in the absence of obstructive coronary atherosclerosis or causes other than the malformation itself.
It should be noted that in cases of coronary anomalies sudden death, in children and young adults, often occurs during or following physical exertion. In the second case reported death occurred during physical activity and the anomaly of the left Valsalva sinus, divided into two distinct ostium: one for the anterior interventricular coronary and one for the circumflexed, was associated with cardiac hypertrophy, a pathology present very frequently in subjects affected with Friedreich's ataxia
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
Variations 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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Analysis of Gamma-Hydroxibutyric Acid (GHB) in Blood, Urine and Hair by GC/MS in 19 alcohol dependent subjects treated with oral doses of Alcover
No full textDispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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