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N Edwards

Publications and source records attributed to N Edwards.

At least 91 records · Page 5Linked to original sources
PubMed1994

In vivo myocardial kinetics of air-filled albumin microbubbles during myocardial contrast echocardiography. Comparison with radiolabeled red blood cells.

Myocardial contrast echocardiography (MCE) is a new technique for assessing myocardial perfusion that uses intracoronary injections of microbubbles of air. Because these microbubbles have a mean diameter of 4.3 +/- 0.3 microns and an intravascular rheology similar to that of red blood cells (RBCs), we hypothesized that their mean myocardial transit rates recorded on echocardiography would provide an estimation of regional myocardial blood flow in the in vivo beating heart. Accordingly, blood flow to the left anterior descending coronary artery (LAD) of 12 open-chest anesthetized dogs (group I) was adjusted to 4 to 6 flows (total of 60 flows), and microbubbles and radiolabeled RBCs were injected into the LAD in a random order at each stage. The mean myocardial RBC transit rates were measured by fitting a gamma-variate function to time-activity plots generated by placing a miniature CsI2 probe over the anterior surface of the heart, and the mean myocardial microbubble transit rates were measured from time-intensity plots derived from off-line analysis of MCE images obtained during the injection of microbubbles. An excellent correlation was noted between flow (measured with an extracorporeal electromagnetic flow probe) and mean myocardial RBC transit rate (y = 2.83 x 10(-3)x + 0.01, r = .96, SEE = 0.02, P < .001). A close correlation was also noted between mean RBC and microbubble myocardial transit rates (y = 1.01x + 0.01, r = .89, SEE = 0.02, P < .001). Despite its theoretical advantages, a lagged normal density function did not provide a better fit to the MCE data than the gamma-variate function.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMed1994

Refinement of the Medicare diagnosis-related groups to incorporate a measure of severity.

This article presents a system under consideration by the Health Care Financing Administration (HCFA) for incorporating a measure of severity of illness into the Medicare diagnosis-related groups (DRGs). DRG assignment is one of the main factors in determining the payment made for hospital inpatient services furnished to Medicare beneficiaries. Specifically, the formula used to calculate payment for a single Medicare hospital inpatient case takes an average payment rate for a typical case and multiplies it by the relative weight of the DRG to which it is assigned. Thus, it is easy to see that the DRG relative weights have a large impact on the payment a hospital receives. In this article, we describe the Medicare DRG prospective payment system (PPS), evaluate the various classification elements available for assessing severity of illness, describe the analyses used in formulating this proposal, and present the proposed DRG severity system.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1991

Autoregulation of the immune response in autoimmune disease and cardiac transplantation by photoinactivated autologous lymphocytes.

These studies demonstrate that photochemotherapy can be successfully evaluated in animal models. The therapy mediates specific suppression of immune responses and appears to operate at the level of the effector T cells. Future studies will focus on isolation and characterization of the host response to photochemotherapy. The extention of this form of therapy to conditions mediated by dysfunctional regulation of effector T cells is already in progress in clinical trials of cardiac allograft transplantation and autoimmune disease. The results of these trials will provide more evidence on the role of this form of therapy in autoregulation of the immune response.

Animals↗
PubMed1991

Community health nursing audit: issues encountered during the selection and application of an audit instrument.

Several issues were encountered by nurse-managers in a community agency while implementing an audit of community health nursing charts. They included the following: (1) what is the purpose of the audit? (2) are the required resources available to implement the audit process? (3) what is the selection process for charts to be audited? (4) how many charts have to be audited? (5) is the audit tool based on relevant and measurable criteria and standards? (6) have the measurement properties of the audit tool been determined, including validity and reliability? The validity, reliability, and weighting of scores of the Craig audit tool are explored. Results of an assessment of this tool's reliability are presented.

Community Health Nursing↗
PubMed1989

Experiences of nursing joint appointments in a teaching health unit.

This article describes the experiences of five community health nursing faculty who are jointly appointed between McMaster University School of Nursing and the Hamilton-Wentworth Department of Public Health Services in Hamilton, Ontario, Canada. The appointees are actively involved in service, education, and research activities within the teaching health unit, a specially funded project of the Ontario Ministry of Health. Various kinds of consultation and expertise are offered by joint appointees to staff and management within the Department of Public Health Services. The amount of time and effort invested in a particular activity or project varies as staff, students, and joint appointees each make their contributions. Several lessons are learned in acting out our diverse roles in this exciting and challenging service environment.

Community Health Nursing↗
PubMed1989

Antileishmanial activities of 2,4-diaminoquinazoline putative dihydrofolate reductase inhibitors.

2,4-Diaminoquinazoline analogs of folate were assessed as antileishmanial agents and as dihydrofolate reductase inhibitors. Against Leishmania major in human macrophages in vitro, two compounds with tertiary amines attached directly to the quinazoline ring were remarkably active. The 50% effective doses were in the picogram per milliliter range (12 to 91 pg/ml), and the in vitro therapeutic indices were approximately 10(5). These compounds were 1,000 times more active on an absolute basis and had a 100 times more favorable therapeutic index than any compound previously tested in this model. Antileishmanial activity was not correlated with activity against Leishmania mexicana promastigote reductase, which suggests that folate utilization in general, rather than reductase activity specifically, was being inhibited.

Animals↗
PubMed1989

Biochemistry of Pentostam resistant Leishmania.

Promastigotes of Leishmania mexicana amazonensis WR 669 clone 4 were made resistant to antimony in the form of Pentostam (sodium stibogluconate) by exposure to media containing increasing concentrations of Sb. The dose of Sb expected to kill 50% of promastigotes and amastigotes of the parent sensitive clone (WR 669) and the resistant clone (WR 669R) was determined by exposure of suspensions in physiologic salt solution for 3 hr. The approximate Ed50s in microgram Sb/ml were: 10,000 for WR 669R promastigotes; 7,000 for WR 669R amastigotes; 200 for WR 669 promastigotes; and 150 for WR 669 amastigotes. Thus, Sb resistance and Sb sensitivity expressed by promastigote clones are also expressed by their respective amastigotes. Studies with 125Sb-Pentostam showed that WR 669R amastigote resistance was not due to altered Sb uptake over 1 hr. When amastigotes pretreated with Pentostam were incubated with 14C labeled metabolic precursors, susceptibility to Sb was correlated with inhibition of glycolytic enzymes and of fatty acid beta-oxidation.

Animals↗
PubMed1989

How to insert a central venous catheter.

Familiarity with the anatomy of the central veins, the equipment to be used and attention to technical detail are fundamental to successful and rapid central venous cannulation. This article provides a concise description of the relevant anatomy, some general advice and a brief account of the common methods of cannulation. Emphasis has been placed on practical detail and commonly encountered pitfalls.

Catheterization, Central Venous↗