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PubMedDate not supplied

Automatic ventricular edge detection for determination of left ventricular volumes, ejection fraction and regional ejection fractions from first pass radioisotope angiography.

An automated method for detection of left ventricular (LV) outline (including the aortic and mitral valve planes) was developed for measurements of end-diastolic volume (EDV), end-systolic volume (ESV), global ejection fraction (EF), and regional EFs from first pass radioisotope ventriculography. The procedure includes: (1) interpolative background subtraction, (2) construction of gradient images, (3) automatic detection of valve planes, and (4) automatic radial search of LV outlines. The correlation between contrast angiography and Tc-99m first pass study was r = 0.84 (SEE = 23.4) for EDV, r = 0.93 (SEE = 12.8) for ESV, r = 0.84 (SEE = 6.91) for EF (via counts) and r = 0.80 (SEE = 8.56) for EF (via area-length method). Tests of intra-observer, inter-observer and inter-study variability revealed low level of variability. The results showed the potential of the automation of data processing for first pass radioisotope ventriculography.

Cardiac Volume↗
PubMed2004

Development of a depressed left ventricular ejection fraction in patients with left ventricular hypertrophy and a normal ejection fraction.

The progression from concentric left ventricular (LV) hypertrophy to heart failure has not been well defined. Of 159 predominantly hypertensive African-American patients with LV hypertrophy and a normal ejection fraction (EF), 28 (18%) developed a reduced EF after a median follow-up of approximately 4 years. Risk factors for this outcome included a history of coronary artery disease, pulmonary edema seen on a chest x-ray, or a subsequent myocardial infarction.

Black or African American↗
PubMed2000

Effect of coronary artery bypass surgery on myocardial perfusion and ejection fraction response to inotropic stimulation in patients without improvement in resting ejection fraction.

The aim of this study was to assess the effect of coronary artery bypass grafting (CABG) on myocardial perfusion and left ventricular (LV) contractile reserve in patients with reduced ejection fraction (EF). We studied 57 patients (age 59 +/- 8 years, 46 men and 11 women) with EF < or = 40% referred for CABG with dobutamine (up to 40 microg/kg/min) stress-reinjection thallium-201 single-photon emission computed tomography, and radionuclide ventriculography at rest and at low-dose dobutamine before and 3 months after CABG. An increase in resting EF > or = 5% occurred in 12 patients (group A) after CABG (EF 34% before and 46% after CABG), whereas no increase occurred in the remaining 45 patients (group B) (EF 34% before and 32% after CABG). A significant increase in EF from rest to low-dose dobutamine radionuclide ventriculography occurred before and after CABG. The magnitude of increase was more significant after than before CABG in group A (12% vs 7%) as well as in group B (13% vs 7%, both p <0.001). Patients in both groups had a significant reduction in stress, rest, and ischemic perfusion scores after CABG. However, the percentage of reduction in resting perfusion defect score was more significant in group A than in group B (60% vs 30%, respectively, p <0.01). It is concluded that CABG induces a significant improvement in resting myocardial perfusion and EF response to inotropic stimulation, even in the absence of improved EF at rest. Patients without improvement in resting EF after CABG have mild improvement in resting myocardial perfusion that may be sufficient to increase EF after CABG during inotropic stimulation, but not at rest. We describe the myocardium with these characteristics as "the reactive myocardium."

Cardiotonic Agents↗
PubMed2003

Is there a referral bias against catheterization of patients with reduced left ventricular ejection fraction? Influence of ejection fraction and inducible ischemia on post-single-photon emission computed tomography management of patients without a history of coronary artery disease.

OBJECTIVES: The objective of this work was to define the relationship between left ventricular perfusion/ function measures and referral rates to catheterization and revascularization early after stress gated myocardial perfusion single-photon emission computed tomography (MPS). BACKGROUND: Although revascularization yields the greatest survival benefit in patients with low ejection fraction (EF) and extensive coronary artery disease, referral patterns to catheterization and revascularization after noninvasive testing are not well defined. METHODS: We identified 3,369 patients without previous myocardial infarction or revascularization who underwent exercise or adenosine stress MPS and who were followed-up (97% complete) for occurrence of early (<60 days) post-single-photon emission computed tomography (SPECT) revascularization. Multivariable logistic regression modeling was used to determine the association of various patient characteristics and test results with performance of catheterization and revascularization as separate end points. RESULTS: In the first 60 days after stress MPS, 445 catheterizations (13.2%) and 254 revascularizations (7.5%) occurred, including 140 coronary artery bypass graft surgeries (4.1%) and 114 percutaneous coronary interventions (3.4%). Both post-stress gated EF and percent of the myocardium ischemic by stress MPS were independent predictors of revascularization. Logistic regression revealed that the likelihood of catheterization increased with both increasing ischemia and decreasing EF (c-index = 0.94, chi-square = 590). Predicted referral rates to catheterization increased with decreasing EF except in patients with severe ischemia (>15% of myocardium), where rates decreased with decreasing EF. Similar modeling of revascularization (c-index = 0.94, chi-square = 329) revealed that the likelihood of revascularization increased with increasing ischemia but, in general, decreased with decreasing EF. CONCLUSIONS: Although post-SPECT referral to both catheterization and revascularization is driven by ischemia, EF has the opposite effect on these two outcomes. Further studies evaluating the appropriateness of these referral patterns are warranted.

Adenosine↗
PubMed2004

Clinical outcomes of patients with impaired left ventricular ejection fraction undergoing autologous bone marrow transplantation: can we safely transplant patients with impaired ejection fraction?

Experience with autologous bone marrow transplantation (ABMT) in patients with impaired left ventricular ejection fraction (LVEF) or heart failure (HF) is limited. We identified 308 consecutive patients who underwent ABMT for Hodgkin's or non-Hodgkin's lymphoma at our institution (1996-2003). Patient characteristics, clinical course and overall survival were compared between patients with preserved ( > or = 50%) or impaired ( < 50%) LVEF. Of the 308 patients identified, 20 had baseline impaired LVEF (four with LVEF < or = 40%, all NYHA class I-II HF). None of the patients with post-ABMT echocardiogram had worsened LVEF (n = 7). Among the 20 patients with impaired LVEF, four patients had reversible cardiac complications post-ABMT (including worsening HF). The two deaths observed in the impaired LVEF group were both due to noncardiac causes. The 5-year survival was similar between patients with preserved and impaired LVEF (P = 0.43). Careful selection of patients with stable, mild-to-moderate HF and impaired LVEF for ABMT can achieve similar long-term survival. As medical care for HF and ABMT improves, the exclusion criteria for ABMT with regard to HF and impaired LVEF should be re-examined.

Adult↗
PubMed1977

[Studies on the protein and amino acid metabolism of laying hens receiving 15N-labelled casein. 5. 15N incorporation into different blood fractions and into the amino acids lysine, histidine and arginine contained in these fractions].

4 colostomizted laying hens were fed 15N labelled casein as a sole source of protein for a period of 6 days. The birds were slaughtered 2 or 6 days after receiving 15N dose. The blood was separated into corpuscular blood components and blood plasma. Then, the amount and content of nitrogen in the blood, the blood fractions and in the amino acids lysine, histidine and arginine and the excess of 15N atom% (15N') were estimated. The average N concentrationin the blood was 3.8%. The crude protein in the blood corpuscles contained 8.7% lysine, 7.1% histidine and 6.4% arginine; the corresponding values for crude plasma protein were 6.3%, 2.2% and 5.7%. The 15N atom% in blood nitrogen was found to be lower in the hens slaughtered 144 hrs after receiving the last 15N dose than in the birds already slaughtered after 48 hrs. The same trend was found for the plasma proteins. The level of excess 15N atom% in the blood corpuscles increased with the length of time elapsing after the withdrawal of 15N casein (over the period of time investigated); a decrease of excess 15N atom% in plasma lysine was noted, however, for the investigated period of time after the last 15N dose. In the corpuscular blood components a higher level of 15N atom% was usually found in histidine relative to that in lysine and arginine; it was higher in the hens slaughtered 6 days after receiving the final 15N dose than in the hens killed 2 days after administration of the last 15N dose.

Amino Acids↗
PubMed1995

Two-dimensional echocardiographic evaluation of left ventricular ejection fraction by the ellipsoid single-plane algorithm: a reliable method for assessing low or very low ejection fraction values?

The reliability of two-dimensional (2D) echocardiographic estimation of left ventricular ejection fraction (EF) is commonly recognized, but no satisfactory data are available about the accuracy of low or very low EF values determined by 2D echocardiography (ECHO-EF). The purpose of our study was to assess the reliability of low ECHO-EF values obtained using a simple time-economical algorithm such as the ellipsoid single-plane area-length method. Radionuclide angiography (RAD-EF) was taken as the standard of comparison. We studied 59 consecutive patients (31 women and 28 men) referred to our echocardiographic laboratory. Both 2D echocardiography and radionuclide angiography were blindly performed within 48 h of one another. EF was calculated by the two methods and then compared. Data were globally analyzed. Furthermore, data were divided and analyzed according to the ECHO-EF cut-off point of 50%. An ECHO-EF value of 50% was chosen to conventionally distinguish between low ECHO-EF values and normal-high ones. Data were plotted, and the line of equality and the regression lines were drawn. Regression line slopes, correlation coefficients, means and standard deviations were calculated. The agreement was analyzed by calculating the mean difference (RAD-EF-ECHO-EF) and the standard deviation of the differences. ECHO-EF was linearly related to RAD-EF even when data were split. In particular, as regards ECHO-EF < or = 50%, the regression line practically overlapped the line of equality, and the two methods showed both a strong correlation and a good degree of agreement.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Heart rate index: an indicator of left ventricular ejection fraction. Comparison of left ventricular ejection fraction and variables assessed by exercise test in patients studied early after acute myocardial infarction.

The present study compares the variables assessed by standard exercise test with the left ventricular ejection fraction (LVEF) measured by multigated radionuclide angiocardiography (MUGA) in 77 patients early after myocardial infarction. The exercise test and MUGA were performed within two weeks after the myocardial infarction. A significant correlation (Spearman's correlation coefficient rs, p less than 0.05) was found between LVEF at rest and the following variables assessed at exercise test: 1) the heart rate at rest, 2) rise in heart rate, 3) ratio between maximal heart rate and heart rate at rest, 4) rise in systolic blood pressure, 5) rate pressure product at rest, 6) rise in rate pressure product, 7) ratio (rHR) between maximal rate pressure product and rate pressure product at rest, 8) total exercise time. The heart rate was corrected for effects caused by age (heart index (HR%)) and a significant correlation was found between 1) the HR% at rest, 2) the rise in HR% and the LVEF. A simple method to identify patients with an abnormal LVEF is described.

Adult↗
PubMed1990

[Parameters of hemostasis during treatments associating fractionated heparin administered subcutaneously to standard and fractionated heparin administered intravenously in the chronic hemodialysis patient].

The hemorrhagic risk of an association of fractioned heparin (Fraxiparine) injected intravenously at the dose of 7500 AXaICU or of unfractionned heparin (UFH) injected intravenously at the usual dose used for a priming dose for hemodialysis (3750 +/- 1280 IU + 1000 IU after 2 hours of dialysis) to the subcutaneous administration of a thrombo-embolism preventive dose of Fraxiparine (7500 AXaICU) was evaluated on the modifications of the following hemostasis parameters: thrombin time, Activated Partial Thrombin Time (APTT), prothrombin time, anti Xa activity in 13 uremic patients on hemodialysis. The association of intravenous and subcutaneous Fraxiparine prevents efficiently the clotting of the extracorporeal circulation without inducing a detectable antithrombinic activity. In contrast, the association of I.V. UFH to subcutaneous Fraxiparine induces a significant increase of the thrombin time and of the APTT. This latter is exclusively explained by the activity of UFH. It is concluded that subcutaneous Fraxiparine at the thromboembolism preventive dose can be associated as well to I.V. Fraxiparine as to UFH without increasing the antithrombinic activity of the plasma.

Aged↗
PubMed1988

A comparison of lung metastases and natural killer cell activity in daily fractions and weekly fractions of radiation therapy on murine B16a melanoma.

C57BL/6J male mice were inoculated with 5 X 10(5) B16a melanoma cells. Seven days post-inoculation, when the tumor had grown to 8.0-10.0 mm in diameter, 120 tumor-bearing mice were randomly divided into three groups: (1) sham-irradiated controls, (2) mice receiving 200 cGy five times a week for 6 weeks, and (3) mice receiving 800 cGy once a week for 4 weeks. Thirty mice in each group were sacrificed 47 days postinoculation. Ten mice in each group were observed for the survival time data. The primary tumor was significantly smaller and the number of lung metastases were significantly fewer in mice treated with 800 cGy once a week compared to mice treated with 200 cGy five times a week. When natural killer (NK) cell activity was assessed against YAC-1 tumor targets, it was found to be significantly higher in mice treated with a single large weekly dose of irradiation. These results show that B16a melanoma responds more favorably to a single large dose of irradiation administered once a week compared to the smaller conventional fraction administered five times a week. This beneficial effect correlates with an increase in NK activity, indicating that there may be a causal relationship.

Animals↗
PubMed1982

[Combination chemotherapy and radiotherapy. Differential effect, on the medullary syndrome, of fractionated irradiation with fractionated drug administration].

The study of the different effects of 5 FU administration before and after fractional irradiation on the medullar syndrome show the importance of the schedule in the effectiveness of the administration of the gamma rays and the cytostatic. As for the intestinal syndrome, the best results were obtained when 5 FU is administrated in one single dose per week 9 hours after the fifth irradiation for a two weeks schedule.

Animals↗
PubMed1993

Macrophage colony-stimulating factor stimulates growth progression of the G1-phase fraction and induces monocytic differentiation of the G2/M-phase fraction in human myeloid leukemia cells.

The human myeloid leukemia cell line (NKM-1) proliferates in response to exogenous macrophage colony-stimulating factor (M-CSF) in serum-free medium. This CSF alone, however, does not induce any feature of cell differentiation in NKM-1 cells. We showed that terminal monocytic differentiation is partially observed only when NKM-1 cells are sequentially treated with 1,25-dihydroxyvitamin D3 and M-CSF, as evaluated by cell morphology, analysis of surface antigens, and phagocytic function. To determine whether there might be an association between the actions of M-CSF and special phases of the cell cycle, we separated D3-treated cells into cycle-specific fractions by centrifugal elutriation. G1-enriched cells were mostly stimulated for growth progression with M-CSF. On the other hand, G2/M-enriched cells were significantly induced into monocytic differentiation. The cell percentage in the G2/M phase has clearly correlated with that of terminally differentiated cells by M-CSF. These results suggest that two distinct actions of M-CSF to stimulate cell proliferation and differentiation could work on different phases of the cell cycle: cell growth in the G1 phase and cell differentiation in the G2/M phase.

Calcitriol↗
PubMed1996

A technique for automatic/interactive assessment of the proliferating fraction of neoplastic cells in solid tumors. A methodological study on the Ki-67 immunoreactive cells in human mammary carcinomas, including a comparison with the results of conventional S-phase fraction assessments by means of DNA cytometry.

Based on a computerized microscopy technique, a method has been devised which allows the practising pathologist to easily and rapidly assess quantitatively the relative number of actively proliferating neoplastic parenchymal cells in a tumor nodule. Our method has been tested on a series of 20 conventionally formalin-fixed and paraffin-embedded female mammary adenocarcinomas, using immunoreactivity with the MIB-1 monoclonal antibody against the cell proliferation antigen Ki-67. The values of the proportion of the MIB-1 immunoreactive cell nuclei were compared with those obtained DNA-cytometrically for the fraction of cells in the S-phase; a good correlation was found, although the MIB-1 values were consistently somewhat higher. A prerequisite for a success of the method was, of course, to achieve standardization of the MIB-1 immunostaining technique. By making simple adjustments of it, it could actually be improved to such an extent that almost the same color calibration and thresholding setup could be used. The measuring technique could be either interactive or automatic. The total number of immunoreactive and non-immunoreactive nuclei, as well as the total nuclear area of both cell types were registered in a computerized device. The data were accumulated sequentially for each measure field. To investigate the reproducibility of the immunostaining, two slides of each case were stained on different occasions. Each slide was measured three times; systemically randomly in the x- and y-axis-directions as well as in the subjectively defined histopathologically "most proliferative" area of the tumor. The values obtained were in good agreement with each other and obviously gave some valuable and objective supplementary pieces of information to that of the conventional clinical and histopathologic assessment of the degree of aggressiveness of a malignant neoplasm.

Adenocarcinoma, Mucinous↗
PubMed1996

Pathology of experimental pneumonic plague produced by fraction 1-positive and fraction 1-negative Yersinia pestis in African green monkeys (Cercopithecus aethiops).

OBJECTIVE: The protein capsule of Yersinia pestis, known as Fraction 1 or F1, is a protective immunogen and is an assumed, but not proven, virulence factor. Our objectives were to determine if inhaled F1-negative and/or F1-positive strains of Y pestis were virulent in the African green monkey and, if so, to differentiate F1-negative from F1-positive monkeys. Because F1-negative strains have been isolated from natural sources and have caused experimental fatal disease, we felt that this information was crucial to the development of future vaccines and diagnostic tests. MATERIALS AND METHODS: Adult African green monkeys were exposed by aerosol to F1-positive (CO92, n=15) or F1-negative (CO92-C12, n=6; Java-9, n=2) Y pestis strains. RESULTS: All monkeys died 4 to 10 days postexposure and had lesions consistent with primary pneumonic plague. Antibodies to F1 antigen and other Y pestis antigens allowed us to differentiate F1-positive from F1-negative Y pestis strains in fixed tissues. CONCLUSIONS: In this study, F1 antigen was not a required virulence factor. Therefore, there may be a need for vaccines and diagnostic assays that are not solely based on the F1 antigen.

Acute Disease↗
PubMed1998

Intracellular and extracellular blood magnesium fractions in hemodialysis patients; is the ionized fraction a measure of magnesium excess?

To establish the best measure for determining magnesium overload, we measured ionized and total magnesium in serum and mononuclear blood cells and total magnesium in erythrocytes in blood of 23 hemodialysis patients, known for their disturbed magnesium homeostasis. When comparing the mean magnesium values obtained in the patient population with those of a control population, all of these magnesium markers, including the biologically active fractions, were significantly (P < 0.05) increased. Because serum total magnesium was not increased in all dialysis patients studied, the population was divided into two groups, according to total serum magnesium > 1.0 mmol/L or less than that. Results in these two populations showed that ionized serum magnesium and ionized magnesium in mononuclear blood cells might give a better indication about the magnesium status of the tested patients than the currently used total serum magnesium data. However, neither of the two markers, especially ionized serum magnesium, was able to discriminate fully between normal magnesium homeostasis and magnesium excess. We therefore conclude that the two ionized magnesium markers offer minimal advantage for this discrimination, and that the total magnesium concentration in serum remains the measurement of choice.

Adult↗