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Experimental Studies on Arteriosclerosis Part 2. Histological and Histochemical Findings of Viscera
No full textIn the previous paper the author stated that the arteriosclerosis starting with atheroma degeneration of the inner coat and the arteriosclerosis of Monckeberg type both developed on account of the abnormalities in the cholesterol metabolism in the experiments in which cholesterols had been given in various amounts either orally or parenterally. From detailed histological observations in these experiments the author believes that the common findings in these two are the basic pathological changes such as the swelling of muscular fibers and accompanying fat degeneration, decompositions of glycoproteins, and that these changes are none other than the reflection of the metabolic disturbances in the course of pathological changes. In his experiments with rabbits orally given cholesterols, after precise histological investigations, Leary offers an interesting theory concerning arteriosclerosis that the atheroma degeneration of the aorta is caused by the atheroma formation resulting from the fact that the libar reticulo-endothelial cells after ingesting lipids, deposit themselves on the aortic wall and invade below the endothelial-cell layer of the aorta-inner coat. There are opinions both for and against this hypothesis, and the author has also taken a keen interest in this theory. In this connection the author studied in detail pathological changes in the viscera of the rabbits in which arteriosclerosis had been induced variously by adminstering a large or a small amount of cholesterols orally or intravenously as reported in the previous paper, and arrived at the following conclusions: 1) Arteriosclerosis is one of the signs reflecting the disorders in the fat metabolism in the internal organs of the whole body. It is not a disease solely involved in the arterial system. 2) In the case where the metabolic disorder is progressing rapidly, the artery reveals mainly the sclerorsis of the medionectrotic type along with the degeneration or atrophy of the viscera; and in the case where the metabolic disorders appear gradually, the degeneration is rather of a secondary nature and the formation of foam cells plays a main role and the sclerosis of atheroma-degeneratiion type appears in the artery. 3) Foam cells do not originate only from the reticulo-endothelial cells, but they also originate from reticulum cells, arterial smooth-muscle cells, renal tubular eptithelial cells, interstitial cells of ovarium, and adrenocortical cells; and foam cells of a simillar shape are derived from these various cells, and they tend to conglomerate at one site, forming a mass of cells. Histologic findings on the foam cells found in the region of atheromatosis degeneration of the aorta suggest that these cells are derived from the smooth-muscle cells or fibrocytes in the aorta tissue, but not from the reticuloendothelial cells of liver
Experimental Studies on Arteriosclerosis Part 3. The Changes of Cholesterols and the Total Cholesterols, especially Free Cholesterols, in the Blood of the Rabbits with Experimental Arteriosclerosis
Get PDFMany investigators are studying on the point that cholesterols and fats are greatly involved in the causative mechanism of arteriosclerosis. However, even in the case of an advanced arteriosclerosis cholesterols in blood are not necessarily increased, but quite many show the cholesterol level within the normal range. Furthermore, subsequent research works indicate the problems such at the ratio of cholesterols against phospho-lipids and chylomicron, as well as studies on lipoproteins and electropaper-chromatography are carried out, but conclusive causative factors still remain to be discovered. As reported in Parts 1 and 2 the author recognized the occurrence of arteriosclerosis of the so-called 'adrenalin-injection type' (Monckeberg type) in the aorta of the rabbits injected with cholesterol emulsion or administered with a large amount of cholesterol for consecutive days, and also the occurrence of arteriosclerosis of the so-called 'cholesterol type (atheroma type) in the rabbits orally adminstered with a small amount of cholesterol for sucessive days. Thus the author pointed out that what was believed to be two types of arteriosclerosis caused by two entirely different factors was in fact the arteriosclerosis induced by the same abnormality in the fat metabolism, and deduced that the differences observable in this disease arose from the differences in the chemical constitution of cholesterols in the blood. In the present report an attempt has been made to clarify further the actual characteristics in the occurrence of two kinds of arteriosclerosis by observing what differences in the chemical constitution of fats in the blood would be brought about by different methods of administering cholesterols on one hand and also by studying the changes in cholesterol contents in the blood at the time of nor-adrenalin injection into rabbits on the other, Using 8 rabbits, the present experiments were conducted in three groups; namely, a group (2 rabbits) given oral administration of 0.7 g. cholesterol daily; another group (2 rabbits) given daily intravenous injection of 10 cc. 1% cholesterol emulsion; and still other group (3 rabbits) given daily intravenous injection of 1 cc. 0.1% adrenalin; and at a fixed interval after the adminstration, blood was drawn from the auricular vein, and the total amount of cholesterol and the free cholesterol content were determined by the digitonin method. After weighing these results in conjuction with the histological or cytochemical findings of Parts 1 and 2, the author arrived at the following conclusions: 1. The intravenous injection of cholesterol emulsion the same as the nor-adrenalin injection induces a transient and rapid rise in free cholesterols in the blood and the degeneration of muscle fibers or calcium deposit in the artery. 2. In the case of oral adminstration of cholesterol the total amount of cholesterols increses step by step, but the ratio of the free-cholesterol content against the total amount of cholesterol in creases always within the normal range, showing the foam cell formation in visceral tissues as well as atheroma degeneration under the inner coat of artery in this instance. 3. From these results it is velieved that the rise in the free cholesterol content of blood acts as an important factor causing the degeneration or the necrosis of the media of the artery, developing to the Monckebergs median necrosis of artery, while in the case of the rise in the cholesterol-ester, the cholesterol ester is absorbed by the interstitial cells and disposed, forming a foam cell layer without inducing cell degeneration; and when such an increment is great, the atheroma degeneration of the aorta is brought about
Experimental Studies on Arteriosclerosis Part 1. Patho-anatomical, Histological, Histo-chemical and Polarisation Microscopical Findings of Aorta
No full textThe actual cause of arteriosclerosis is unknown, but various theories are advanced from the results of experimental studies and pathological observations on the human body; and these theories may be roughly divided into two views. Namely, the one that considers the primary, regressive degeneration of the arterial wall to be the basic cause, and the other that contends the disturbances in the fat metabolism, especially in the caholesterol metabolism, to be the primary cause. Indeed experimental studies on the metabolic disturbances have contributed really to the clarification of the cause of this disease. Moreover, from the pathoanatomical and histological standpoints, there are cases of arteriosclerosis the causes of which seem to substantiate these two views. Actually in experiments these two can be induced in animals as different forms of arteriosclerosis, as for instance by the adrenalin injection or by the administration of cholesterols. However, it is still doubtful whether these really occur from fundamentally different mechanisms or not. With the purpose to elucidate this question the author conducted a series of experiments by injecting intravenously 1% cholesterol emulsion to a group of rabbits and by oral administrations of cholesterol to another group (which was subdivided into a group given a daily dosage of 0.25 g. for a long period of time and another group given 3 g. per day), using all together 17 rabbits, and observed changes in the aorta and various viscera. The findings on the aorta are decribed in the present paper. The author successfully induced the arteriosclerosis of atheroma-degerneration type in the rabbits receiving orally a small amount of cholesterol daily for a long time, and the arteriosclerosis of Monckeberg type in the group of rabbits injected with cholesterol emulsion or adminstered orally a large amount of cholesterol every day; and clarified that arteriosclerosis, what had been thought to be of entirely different types, can all develop on account of abnormalities in cholesterol metabolism. It seems that the former arteriosclerosis is mainly induced by the action of cholesterol-ester while the latter by the direct action of cholesterols
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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