Search PubMed⌕ Search

Biomedical subjects

A M Katz

Publications and source records attributed to A M Katz.

At least 19 recordsLinked to original sources
PubMed2001

Circulation Research: origin and early years.

Circulation Research, first published in 1953, was created by the American Heart Association as "the authoritative new journal for investigators of the basic sciences as they apply to the heart and circulation." This review of the early years of the journal highlights the contributions of the first four Editors: Carl J. Wiggers, Carl F. Schmidt, Eugene M. Landis, and Julius H. Comroe, Jr. The success of Circulation Research is seen not only in the high quality of the articles published in its pages but also in the remarkable improvements in prevention and treatment of cardiovascular disease that have occurred over the past half century.

American Heart Association↗
PubMed2000

A council of elders: creating a multi-voiced dialogue in a community of care.

In an era of 'medical care delivery systems', there is an increasing need for the patient's voice to be heard, for it to be invited, listened to, and taken seriously. This challenge is particularly evident in geriatrics education, a domain of clinical training in which educators and clinicians alike must struggle to overcome adverse attitudes towards the elderly ('ageism'). In this paper we introduce a 'Council of Elders' as an educational innovation in which we invited community elders to function as our 'Senior Faculty', to whom medical residents present their challenging and heartfelt dilemmas in caring for elder patients. In the conversations that ensue, the elders come to function not simply as teachers, but collaborators in a process in which doctors, researchers, and elders together create a community of resources, capable of identifying novel ways to overcome health-related difficulties which might not have been apparent to either group separately. Using the first meeting of the Council as an exemplar, we describe and discuss the special nature of such meetings and also the special preparations required to build a dialogic relationship between participants from very different worlds--different generations, different cultures (including the professional culture and the world of lived experience). Meetings with the council have become a required part of the primary care residency program--a very different kind of 'challenging case conference' in which moral dilemmas can be presented, discussed and reflected upon. It is not so much that elders give good advice in their responses--although they often do--as that they provide life world and value orientation as young residents gain a better sense of the elder's experience and what matters most to them. This project has been particularly worthwhile in addressing the problem of ageism--a way to render visible stereotypes and adverse physician values, with implications for decision-making with the patient, not for the patient.

Aged↗
PubMed2000

Updated mortality among diverse operating segments of a petroleum company.

OBJECTIVES: To update mortality for 34 560 employees from diverse operating segments of a Canadian petroleum company; and to investigate potential relations with occupational factors. METHODS: Employees from 1964-83 were linked to the Canadian mortality data base to provide 11 years additional follow up. There were 6760 deaths and 750 683 person-years of follow up compared with 3909 and 428 190, respectively, in the earlier study. Analyses used standardised mortality ratios (SMRs) to compare worker cause specific mortality with the Canadian general population. Duration of employment and latency analyses were performed for causes previously found to be increased in this and other petroleum cohorts, as well as any findings of interest. RESULTS: For the period 1964-94, employees experienced significantly low overall mortality (SMR=0.86 men, SMR=0.80 women). Kidney cancer, which has been increased in some studies of petroleum workers, was not increased. Acute non-lymphocytic leukaemia in exposed operating segments was consistent with the expected or only slightly, non-significantly increased. The most notable finding was increased deaths from mesothelioma among refinery and petrochemical workers (SMR 8.68; 95% confidence interval (95% CI) 5.51 to 13.03), most of whom were long term employees in jobs with presumed exposure to asbestos (mechanical and pipefitters). Deaths from multiple myeloma among marketing and distribution workers, which were previously increased, remained increased (SMR 2.08; 95% CI 0.95 to 3.95) in the update period 1984-94; however, there was no clear pattern by duration of employment or latency. Aortic aneurysms, which also were previously significantly increased among marketing and distribution workers approached the expected in the update period (SMR 1.18; 95% CI 0. 65-1.98). Analyses by duration of employment showed suggestive trends for aortic aneurysms, but earlier studies of this cohort have not found a relation between aortic aneurysms and exposure to hydrocarbons. CONCLUSION: The additional 2851 deaths and 322 493 person-years of follow up strengthened the assessment of mortality patterns relative to occupational factors. With the exception of mesothelioma, no clear work related increases in disease were identified.

Canada↗
PubMed1999

Interval-force relation is unaffected by the presence of cardiomyopathy or coronary artery disease in patients with atrial fibrillation.

BACKGROUND: We tested the hypothesis that cycle length-dependent cardiac contractility in atrial fibrillation is primarily governed by the negative interval-force relation in patients with normal and depressed systolic function. METHODS AND RESULTS: We performed two-dimensional guided M-mode echocardiography in 41 patients (mean age, 69 +/- 4 years; range, 48 to 92 years; 19 men, 11 women). Twelve patients had objective evidence of left ventricular systolic dysfunction (CMP; mean ejection fraction, 37% +/- 7%) in the absence of coronary artery disease (CAD), 13 patients had documented CAD (mean ejection fraction, 43% +/- 6%), and 16 patients had normal resting left ventricular systolic function (mean ejection fraction, 58% +/- 7%). Simultaneous beat-to-beat blood pressure, end-systolic and end-diastolic dimension, circumferential velocity of fiber shortening (Vcf), and end-systolic wall stress (ESWS) were calculated for all patients. All three groups showed a significant linear relation between beat-to-beat Vcf and Vcf corrected for afterload (represented as the Vcf/ESWS ratio) and preceding cycle length. There was, however, no significant difference in the relation between either of these variables and cycle length among the three groups. There was also no difference in the rate of change in either Vcf or Vcf corrected for afterload (Vcf/ESWS ratio) from beat-to-beat among the three groups. Control patients with normal systolic function showed greater Vcf at any given cycle length compared with patients with CMP or CAD. CONCLUSION: Our data show that, for each beat in atrial fibrillation, Vcf and Vcf/ESWS ratio are decreased after shorter cycle lengths and increased after long cycles, but there is no significant attenuation of this effect in patients with systolic dysfunction with or without coronary disease compared with controls. Thus, the negative interval-force relation, the predominant determinant of beat-to-beat variation in contractility in atrial fibrillation, is preserved in patients with CAD or reduced left ventricular systolic function.

Aged↗
PubMed1999

Cardiac arrhythmias.

Explore the source record for details and available documents.

Arrhythmias, Cardiac↗
PubMed1999

Lyme disease: summary notes.

The intention of the Summary Notes section is to provide the practitioner and trainee with a current, concise reference source to dermatologic diseases and to serve as a form of Continuing Medical Education. Each installment will deal with a specific disease. When included, the pretest questions indicate some of the areas to be covered and will challenge your present knowledge of the material before reading further. The self-assessment post-test questions appear on page 308; the answers are on page 316.

Female↗
PubMed1998

Discovery of phospholamban. A personal history.

Early efforts to identify mechanisms by which sympathetic stimulation increases myocardial contractility led to studies of effects of beta-adrenergic agonists and cyclic AMP on the cardiac contractile proteins and sarcoplasmic reticulum (SR); initial positive reports, however, could not be confirmed. The discovery that cyclic AMP-dependent protein kinases (PK-A) mediated intracellular actions of cyclic AMP led at least four groups to test the hypothesis that phosphorylation of the cardiac SR played a role in the actions of beta-adrenergic agonists. Three of them (Wollenberger, Wray et al., and LaRaia & Morkin) demonstrated that cardiac SR was a substrate for PK-A phosphorylation; however, the lability of the Ca2+ pump in these membranes made it difficult to demonstrate a functional significance of this finding. Our group, which had extensive experience in measuring SR Ca2+ transport, began by examining the ability of PK-A to activate the SR Ca2+ pump "poised" at half-saturating Ca2+ concentrations. Our initial positive result led to the discovery that a 22,000-dalton protein, named phospholamban by Phyllis B. Katz, mediated effects on Ca2+ transport by the SR that could explain both the inotropic and lusitropic effects of sympathetic stimulation.

Adrenergic beta-Agonists↗
PubMed1998

Is the failing heart energy depleted?

This article takes three different approaches to the question of whether the failing heart is in an energy-starved state. A brief historical overview introduces the issue and points out problems in both models and methods. Second, current information regarding the energetic state of the failing heart is examined. Finally, the mechanistic and therapeutic implications of a defect in energy production are described.

Adenosine Diphosphate↗