10 research outputs found

    Serial echocardiographic studies of acute and chronic left ventricular volume overload

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    Study of the value of phono cardiography in clinical medicine

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    The work presented here was originally undertaken with three main objects in view - firstly, to master the technique of phonocardiography; secondly, to decide whether accurate visual records of the heart sounds could be made with reasonable ease; and, finally, to decide what actual value such recordings might have for the practising physician.It is already clear that, in the past, phonocardiographic analysis of the various heart sounds and murmurs occurring in health and disease has been of great interest to the physiologist and the enquiring physician. As a research instrument the phono­cardiograph is of proved value; as an adjunct to the teaching of cardiology its value is also obvious; but whether or not it can take its place beside the electrocardiograph as an apparatus of practical value to the clinician is still undecided.Experience was sought in the study of all varieties of cardiovascular disease and the work was not confined to one particular type of sound, murmur or condition. In this way recordings were made week by week, at first of a fairly simple nature; and thus, in the early months there was a tendency for recordings to be made of gallop rhythms rather than cardiac murmurs, the reason for this being that the low frequency of the heart sounds make them relatively easy to record when com­pared with the high frequency of heart murmurs. Later, as techniques improved and as more satisfactory phonocardiograph machines became available, all types of heart sounds and murmurs were recorded as they were encountered in the daily routine.The only factors that influenced the selection of cases were,therefore, firstly, the fitness of patients and their ability to co-operate without undue fatigue or distress, and, secondly, the desire by the clinician to obtain graphic information of a doubt­ful auscultatory sign which was felt to be of diagnostic import­ance or of medical interest.In this way, third heart sounds were recorded in normal hearts and abnormal auscultatory phenomena such as gallop rhythms accompanying hypertension, congestive cardiac failure, congenital heart disease, myocardial infarction and bundle-branch block and other conditions were studied. The systolic and diastolic murmurs occurring in apparently normal hearts and in the presence of aortic and mitral valvular disease were also recorded as they were encountered and when precise diagnosis was in doubt. In the case of mitral stenosis a particularly extensive study was made as surgical operations for relief of mitfal stenosis were being developed at this time. A wide variety of recordings was also made in other conditions such as congenital heart disease, pericarditis, and other cardio­vascular abnormalities. In particular, specific information was sought on the following points by studying the literature and making a series of recordings from normal subjects and from patients with cardiovascular disease.1) The mechanism of the normal and abnormal heart sounds and murmurs,*their physical and auscultatory characteristics, and their appear­ance when recorded graphically. 2) Whether or not any additional diagnostic information with regard to these sounds and murmurs could be obtained from such record­ings. 3) Whether the auscultatory findings could always be correlated with the appearance of the phonocardiographic tracing. 4) The frequency of occurrence and significance of splitting of the first and second heart sounds. 5) The frequency of occurrence and significance of the physio­logical auricular and rapid filling sounds, and their relation­ship to the extra sounds responsible for clinical gallop rhythm. 6) The prognostic significance of rapid filling, auricular,indeterminate, and systolic gallop rhythms, their correct classification and relation to the different types of heart disease. 7) The recognition and differentiation between right- and left­ sided gallop as originally described by Potain, and since,by others. 8) The heart sounds in bundle-branch block and the possibility of diagnosing right- and left bundle-branch block by auscul­tation and palpation. 9) The differentiation between innocent or unexplained systolic murmur and those due to clear cut organic disease. 10) The analysis of the auscultatory signs of mitral stenosis and incompetence and their value in the assessment of the severity and degree of the mitral lesion present. Also the separate identification and importance of splitting of the second heart sound, the opening snap of mitral stenosis, and the rapid fil­ling gallop, and their relation to other events in the cardiac cycle. 11) The particular significance of the opening snap as a sign of mitral stenosis and its occurrence in mitral incompetence. 12) The practical value of recording auscultatory phenomena in miscellaneous cardiovascular abnormalities, either for diagnostic or teaching purposes.All the 151 patients reported here were examined, care­fully auscultated, phonocardiograms made, and the photographic recordings processed and analysed by the author himself.Only in the section dealing with mitral disease has information been used which was not obtained from the author'sown recordings. In this section some of the final analytical data includes information obtained from a further series of recordings which were subsequently made, after instruction, by the senior electrocardiograph technician. The 66 recordings of 46 patients with mitral disease which are presented in this section, however, were all taken from the author's own series.The clinical and phonocardiographic observations a represented in Volume I of this thesis and are set out in separate sections. Each section deals with a particular aspect of the problem and is preceded by a survey of the literature and concluded by a sectional summary of the observations. Finally,there is a summary of all the observations presented and the conclusions drawn therefrom. The phonocardiographic tracings which illustrate this thesis are presented together in Volume II

    Experimental study of nasality with particular reference to Brazilian Portuguese

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    Renal responses to lower body positive pressure in the conscious primate : implications for acute and chronic volume homeostasis

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    Computer analysis of left ventricular cineangiograms

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    The heart is in continuous and rhythmic motion. For centuries this unique property has fascinated clinicians and scientists, although their attempts to get a better insight in the mechanisms which govern heart wall motion were seriously hampered by the almost complete absence of effective measurement tools. A dramatic change took place in the course of this century thanks to the technological revolution which changed cardiology more than any other of the biomedical sciences. The introduction of roentgen rays into medical practice enabled physicians for the first time to observe the beating heart in the intact human being. In cases of myocardial infarction, assessed by the new electrocardiographic technique, the fluoroscopy screen revealed abnormal motion of the epicardial contour. Numerous tools and methods were designed and developed to preclude the subjectivity and inaccuracy inherent with naked eye observation of heart wall motion. However, as only the epicardial contour could be determined, the information thus obtained remained limited. In 1929 Forssman introduced a catheter into his right heart. This act set the pace for the development of angiocardiography which after a hesitating start became one of the fastest growing areas in the medical field. As a consequence of the rapidly increasing number of cardiac catheterizations paralleled by an explosive growth of the amount of data obtained during each procedure, automated data processing became indispensible. In 1967 cardiologists of Stanford University in Palo Alto, California, described their flrst experiences with the use of a computing device in the cardiac catheterization procedure. This example was soon followed by cardiologists and technicians of the Thoraxcenter who developed a computer system, tailored to their catheterization laboratory, which became operative in 1973 and comprised facilities to process pressure signals on line and under control of the operator. To pursue the automation of data processing in the catheterization laboratory two more systems had to be developed: a system to detect automatically coronary artery contours and an analysis system for left ventriculograms. For this automated detection of the left ventricular endocardial contour from cineangiograms, a hard-wired system was designed and constructed. It was called the "Contouromat'. The aim of this thesis is to describe work to evaluate and validate this tool and its applicability in clinical practice and research. The first question which arises is whether an automated angie processing system has any benefit. Indeed in some clinics left ventriculo

    Digital kymography for the analysis of the opening and closure intervals of heart valves

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    The opening and closure intervals of heart valves are important factors regarding an optimal blood flow. Using endoscopic video recordings of heart valves, digital kymography can be a method to visualize and to describe the opening and closure intervals. Based on an adequate segmentation of the kymograms, a quantitative description becomes available for the opening and closure characteristics. Furthermore, by normalizing the measured results, comparisons of mean heart valve oscillations can be achieved. Here, a comparison of artificial with native heart valves obtained under physiological conditions, indicates clear differences in the opening and closure intervals

    Assessing physical fitness and physical activity in population-based surveys

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    Edited by Thomas F. Drury.Includes bibliographical references and index.National Center for Health Statistics. Assessing Physical Fitness and Physical Activity in Population-Based Surveys. Thomas F. Drury, ed. DHHS pub. No, (PHS) 89-1253. Public Health Service. Washington. U.S. Government Printing Office. 1989Part I. Historical Perspectives -- 1. General Population Surveys of the National Center for Health Statistics: An Overview / Nancy D. Pearce -- 2. Cardiovascular Endurance, Strength, and Lung Function Tests in the National Health and Nutrition Examination Surveys / Arthur J. McDowell -- 3. Assessments of Body Composition, Dietary Patterns, and Nutritional Status in the National Health Examination Surveys and National Health and Nutrition Examination Surveys / Dorothy Blair,Jean-Pierre Habicht,andLeeAlekel -- -- Part II. Fundamental Perspectives on Health-Related Physical Fitness and Cardiopulmonary -- Health -- 4. Design Issues and Alternatives in Assessing Physical Fitness Among Apparently Healthy Adults in a Health Examination Survey of the General Population / Jack H. Wilmore -- 5. An Integrative Approach to the Noninvasive Assessment of Cardiovascular and Respiratory Function During Exercise / Karlman Wasserman -- -- Part III. Fundamental Perspectives on Energy Balance, Dietary Patterns, and Physical Activity -- 6. General Considerations Related to Assessing Energy Turnover: Energy Intake or Energy Expenditure / E. R. Buskirk -- 7. Issues Related to Measuring Energy Balance for the National Health and Nutrition Examination Survey / Dorothy Blair -- 8. Measuring Dietary Patterns in Surveys of Physical Fitness and Activity / Catherine E. Woteki -- 9. Design Issues and Alternatives in Assessing Physical Activity in General Population Surveys / Thomas Stephens -- -- Part IV. Special Subpopulation Issues -- 10. Fitness and Activity Assessment of Children and Adolescents / Oded Bar-Or -- 11, Evaluating Fitness and Activity Assessments From the National Children and Youth Fitness Studies I and II / James G. Ross -- 12. Assessing Fitness and Activity Patterns of Women in General Population Studies / Barbara L. Drinkwater -- 13. Exercise Testing and Physical Activity Assessment of Persons with Selected Cardiac Conditions / Nanette Kass Wenger -- 14. Health-Related Fitness of the Older Adult / Everett L. Smith and Catherine Gilligan -- -- Part V. Lessons From Community, National, and International Studies -- 15. Lessons from Tecumseh on the Assessment of Physical Activity and Fitness / Henry J. Montoye -- 16. Fitness and Activity Assessments Among U.S.Army Populations: Implications for NCHS General Population Surveys / James A. Vogel -- 17. Fitness and Activity Measurement in the 1981 Canada Fitness Survey / Thomas Stephens and Cora Lynn Craig -- 18. An International Perspective on Critical Issues in Fitness Testing of U.S. Adults / Roy J. Shephard -- -- Part VI. Contexts of Evaluation -- 19. Genetic Considerations in Physical Fitness / Robert M. Malina and Claude Bouchard -- 20. Biochemical Correlates of Fitness and Exercise / William L. Haskell -- 21. Evaluating the Health Effects of Demanding Work on and off the Job / James S. House and David A. Stiti -- 22. Effects of Physical Activity and Fitness on Health / Arthur S. Leon -- 23. Measurement and Evaluation of Health Behaviors in Relationship to Physical Fitness and Physical Activity Patterns / Steven N. Blair and Harold W. Kohl -- 24. Evaluating Interrelationships Among Physical Fitness and Activity Assessments / Ronald E. LaPorte -- 25. Cardiovascular Epidemiological Research Uses of Fitness Assessments / Erika S. Sivarajan and Victor F. Froelicher -- 26. Epidemiologic Uses of General Population Assessments of Physical Activity Patterns / Robert T. Hyde and Ralph S. Paffenbarger, Jr. -- -- Part VII. Measurement and Analysis Strategies -- 27. Use of Latent VariableModels in Measuring Physical Fitness and Physical Activity / George W. Bohrnstedt and Joseph Lucke -- 28. Applying Regression and Factor Analysis of Categorical Variables to Fitness and Exercise Data / Bengt Muthen and Lynn Short -- 29. Latent Class Analysis / Allan L. McCutcheon -- -- Appendix. Framingham Leisure Time Physical Activity Questionnaire / Andrew L. Dannenberg and Peter W. F. Wilson1989833

    Dichotomic role of NAADP/two-pore channel 2/Ca2+ signaling in regulating neural differentiation of mouse embryonic stem cells

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    Poster Presentation - Stem Cells and Pluripotency: abstract no. 1866The mobilization of intracellular Ca2+stores is involved in diverse cellular functions, including cell proliferation and differentiation. At least three endogenous Ca2+mobilizing messengers have been identified, including inositol trisphosphate (IP3), cyclic adenosine diphosphoribose (cADPR), and nicotinic adenine acid dinucleotide phosphate (NAADP). Similar to IP3, NAADP can mobilize calcium release in a wide variety of cell types and species, from plants to animals. Moreover, it has been previously shown that NAADP but not IP3-mediated Ca2+increases can potently induce neuronal differentiation in PC12 cells. Recently, two pore channels (TPCs) have been identified as a novel family of NAADP-gated calcium release channels in endolysosome. Therefore, it is of great interest to examine the role of TPC2 in the neural differentiation of mouse ES cells. We found that the expression of TPC2 is markedly decreased during the initial ES cell entry into neural progenitors, and the levels of TPC2 gradually rebound during the late stages of neurogenesis. Correspondingly, perturbing the NAADP signaling by TPC2 knockdown accelerates mouse ES cell differentiation into neural progenitors but inhibits these neural progenitors from committing to the final neural lineage. Interestingly, TPC2 knockdown has no effect on the differentiation of astrocytes and oligodendrocytes of mouse ES cells. Overexpression of TPC2, on the other hand, inhibits mouse ES cell from entering the neural lineage. Taken together, our data indicate that the NAADP/TPC2-mediated Ca2+signaling pathway plays a temporal and dichotomic role in modulating the neural lineage entry of ES cells; in that NAADP signaling antagonizes ES cell entry to early neural progenitors, but promotes late neural differentiation.postprin
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