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Kent R Bailey

Publications and source records attributed to Kent R Bailey.

At least 55 records · Page 3Linked to original sources
PubMed2005

Diastolic stress echocardiography: a novel noninvasive diagnostic test for diastolic dysfunction using supine bicycle exercise Doppler echocardiography.

Left ventricular filling pressures can be estimated reliably by combining mitral inflow early diastolic velocity (E) and annulus velocity (E'). An increased E/E' ratio reflects elevated filling pressures and may be useful in assessing an abnormal increase in filling pressures for patients with diastolic dysfunction. The purpose of this study was to evaluate the feasibility of supine bicycle exercise Doppler echocardiography for assessing left ventricular diastolic pressure during exercise. Mitral inflow and septal mitral annulus velocities were measured at rest and during supine bicycle exercise (25-W 3-minute increments) in 45 patients (19 men; mean age, 59 years) referred for evaluation of exertional dyspnea. None had echocardiographic or electrocardiographic evidence of myocardial ischemia with exercise. Patients were classified according to E/E' ratio at rest: 26 had E/E' < or = 10 at rest (group 1) and 19 had E/E' > 10 (group 2). For group 1, 17 had no increase in E/E' during exercise (group 1A) and 9 did (group 1B). For group 2, E/E' did not increase during exercise. Despite different responses of E/E', there was no significant difference in changes of mitral inflow indices (E, A, E/A, deceleration time) between groups. Although the percentage of dyspnea as a primary reason for stopping exercise was similar for the groups, exercise duration was significantly shorter for groups 1B (7.2 +/- 2.5 minutes) and 2 (7.1 +/- 3.3 minutes) than in group 1A (10.4 +/- 3.7 minutes, P = .0129). Diastolic stress echocardiography using a supine bicycle is technically feasible for demonstrating changes in E/E' (filling pressure) with exercise. Our preliminary results suggest the hemodynamic consequences of exercise-induced increase in diastolic filling pressure can be demonstrated noninvasively with exercise Doppler echocardiography.

Adult↗
PubMed2005

Limited (6-h) ambulatory blood pressure monitoring is a valid replacement for the office blood pressure by trained nurse clinician in the diagnosis of hypertension.

OBJECTIVE: To assess the ability of limited ambulatory blood pressure monitoring as a valid replacement for office blood pressure measurement done to American Heart Association criteria in diagnosing hypertension. METHODS: In all, 105 adults, who had been referred for limited ambulatory blood pressure monitoring, participated in the study. Limited ambulatory blood pressure monitoring consisted of 6 h of blood pressure measurement while ambulatory at the Mayo Clinic, using a SpaceLabs 90207 (SpaceLabs Medical, Issaquah, Washington, USA) collecting six readings per hour for the period of observation. The study participants gave consent for three additional consecutive office blood pressure measurements, using a validated aneroid device, done to American Heart Association criteria, by a single hypertension nurse specialist. RESULTS: Mean systolic blood pressure by limited ambulatory blood pressure monitoring was 137.9+/-14.2 mmHg and for the nurse, 137.9+/-20.1 mmHg. Mean diastolic blood pressure by limited ambulatory blood pressure monitoring was 81.5+/-9.7 mmHg and for the nurse, 74.3+/-11.9 mmHg. The intermethod difference for systolic blood pressure was 0.03+/-12.5 mmHg and diastolic blood pressure, -7.2+/-8.0 mmHg. Using <140/90 as criteria factor, limited ambulatory blood pressure monitoring and the trained nurse agreed 77% of the time on whether the patient was hypertensive. This agreement increased to 81% if the participant's referral blood pressure was >or=140/90. CONCLUSIONS: Limited ambulatory blood pressure monitoring is an excellent replacement for office blood pressure, done to American Heart Association criteria, in diagnosing hypertension. This avoids issues of variability introduced by the observers, such as digit preference and bias, and increases reproducibility of blood pressure measurements. The appropriate normal value for limited ambulatory blood pressure monitoring is <140/90 mmHg compared with <135/85 mmHg used in 24-h ambulatory blood pressure monitoring.

Adolescent↗
PubMed2005

Relative risk of mortality associated with diabetes as a function of birth weight.

OBJECTIVE: Birth weight is a risk factor for both diabetes and mortality. Diabetes is a risk factor for mortality. Whether the excess mortality observed for diabetes varies with birth weight is unclear. RESEARCH DESIGN AND METHODS: Among all 2,508 Rochester, Minnesota, residents who first met research criteria for adult-onset diabetes in 1960-1995, 171 were born locally in-hospital after 1922 (i.e., birth weights available) as singleton, term infants. Each case subject and two age- and sex-matched nondiabetic control subjects (born locally, residing locally when the case subject met the criteria for diabetes) were followed through 31 December 2000 for vital status. RESULTS: Of the diabetic case subjects, 16% (27 of 171) died vs. 7% (25 of 342) of control subjects (P = 0.004). The difference was less for normal-birth-weight (NBW) (2,948-<3,856 g) individuals (12% [12 of 102] vs. 8% [20 of 246], P = 0.31) than for abnormal-birth-weight individuals (low birth weight [LBW] 20% [8 of 39] vs. 2% [1 of 46], P = 0.01; high birth weight [HBW] 23% [7 of 30] vs. 8% [4 of 50], P = 0.16), as confirmed with age- and sex-adjusted Cox proportional hazards (diabetes-associated hazard ratio 1.4 [95% CI 0.69-2.90] for NBW vs. 4.8 [1.7-13.3] for abnormal birth weight, test for interaction P = 0.056). The observed diabetes deaths were greater than expected, based on mortality for the general population (27 vs. 13.3, P < 0.001), with 70% of excess deaths occurring among LBW (8 vs. 2.2, P < 0.001) and HBW (7 vs. 3.1, P = 0.03) individuals. CONCLUSIONS: The excess mortality observed for diabetes appears disproportionately concentrated among abnormal-birth-weight individuals, thus identifying a subset of at-risk diabetic individuals and reinforcing the importance of NBW deliveries.

Aged↗
PubMed2004

Prognostic significance of chronotropic response to dobutamine stress echocardiography in patients with peripheral arterial disease.

Chronotropic response is important during exercise stress testing. Less is known about its role after dobutamine stress echocardiography. In addition, limited information exists regarding the long-term prognostic value of dobutamine stress echocardiography in patients who have peripheral arterial disease. We studied 2,138 patients who had peripheral arterial disease (1,317 men, 70 +/- 10 years old) and who underwent dobutamine stress echocardiography. Follow-up was completed for all-cause mortality and cardiovascular morbidity (nonfatal myocardial infarction and coronary revascularization). Death and cardiovascular morbidity occurred in 961 patients (45%) and 348 patients (16%), respectively, during a follow-up of 6.1 +/- 2.7 years. Failure to achieve 85% of age-predicted maximal heart rate (hazard ratio [HR] 1.34, 95% confidence interval [CI] 1.16 to 1.54, p = 0.0001) and percent of abnormal segments at peak stress (HR/10% increment 1.04, 95% CI 1.01 to 1.07, p = 0.02) were independent predictors of mortality and morbidity (HR 1.35, 95% CI 1.06 to 1.71, p = 0.01 and HR 1.14, 95% CI 1.08 to 1.20, p <0.0001, respectively). The effect of not achieving the target heart rate during normal dobutamine stress echocardiography on 1-, 3-, 5-, and 10-year survival probabilities was comparable to that of ischemia (86% vs 88%, 75% vs 71%, 62% vs 59%, and 33% vs 32%, respectively; p = 0.8). In a stepwise multivariate model, dobutamine stress echocardiography had incremental value over clinical data and echocardiographic data at rest for predicting rates of mortality (model chi-square increase from 301 to 322, p <0.0001) and morbidity (model chi-square increase from 37 to 118, p <0.0001). In conclusion, chronotropic response and extent of abnormal segments at peak dobutamine stress provide incremental prognostic information in patients who have peripheral arterial disease.

Aged↗
PubMed2004

Exercise echocardiographic findings and outcome of patients referred for evaluation of dyspnea.

OBJECTIVES: The purpose of this study was to characterize the outcome of patients referred for exercise echocardiographic evaluation of dyspnea. BACKGROUND: Little information exists regarding outcome of patients with dyspnea. METHODS: We identified 443 patients with unexplained dyspnea, 2,033 with chest pain, and 587 with both symptoms referred for exercise echocardiography. RESULTS: Compared to those with chest pain alone, patients referred for dyspnea alone were older, predominantly men, and had lower workload, lower ejection fraction (EF), more prior myocardial infarction (MI), and abnormal rest electrocardiograms. Patients with both symptoms were similar to those with dyspnea, but more had prior revascularization. Exercise echocardiography showed ischemia in 42% of patients with dyspnea, 19% with chest pain, and 58% with both symptoms. During 3.1 +/- 1.8 years follow-up, cardiac death (5.2% vs. 0.9%, p < 0.0001) and nonfatal MI (4.7% vs. 2.0%, p < 0.0001) occurred more often in patients with dyspnea. Events in patients with both symptoms were similar to those with dyspnea, except for revascularization (20% vs. 13%, p = 0.0004). For patients with dyspnea, independent predictors of events were previous MI (hazard ratio [HR] 3.35, p < 0.0001), male gender (HR 1.94, p = 0.0252), EF (HR 0.95/10% increment, p < 0.0001), and increase in wall motion score index with exercise (HR 4.19/0.25 U, p < 0.0001), but not chest pain. CONCLUSIONS: Patients with unexplained dyspnea have a high likelihood of ischemia and an increased incidence of cardiac events. Exercise echocardiography provides independent information for identifying patients at risk. In patients with known or suspected coronary artery disease, dyspnea is a symptom requiring investigation.

Aged↗
PubMed2004

Plasma brain natriuretic peptide to detect preclinical ventricular systolic or diastolic dysfunction: a community-based study.

BACKGROUND: Preclinical systolic or diastolic dysfunction is associated with increased morbidity and mortality. We postulated that plasma brain natriuretic peptide (BNP) might serve as a biomarker for preclinical ventricular dysfunction (PCVD) but that the discriminatory values for BNP may vary with age and sex. METHODS AND RESULTS: We measured BNP, systolic and diastolic ventricular function, and clinical parameters in 2042 randomly selected residents of Olmsted County, Minn, aged 45 years or older. For preclinical systolic dysfunction, the areas under the receiver operating characteristics curve were higher for those with more severe (0.82 to 0.92) than any (0.51 to 0.74) systolic dysfunction and were similar in men and women and in younger and older persons. For preclinical diastolic dysfunction, the areas under the receiver operating characteristics curve were higher for those with moderate-to-severe (0.74 to 0.79) than any (0.52 to 0.68) diastolic dysfunction and were similar regardless of age or sex. Optimal discriminatory values of BNP varied with age and sex. Considering the prevalence of preclinical systolic or diastolic dysfunction and the predictive characteristics observed, using BNP to screen for PCVD would necessitate echo in 10% to 40% of those screened, with most confirmatory echocardiograms being negative, and would miss 10% to 60% of those affected. CONCLUSIONS: BNP is a suboptimal screening test for PCVD in the population.

Age Factors↗
PubMed2004

Utility of myocardial perfusion imaging in patients with low-risk treadmill scores.

OBJECTIVES: The purpose of this study was to determine whether a previously validated clinical score (CS) could identify patients with a low-risk Duke treadmill score who had a higher risk of adverse events and, therefore, in whom myocardial perfusion imaging would be valuable for risk stratification. BACKGROUND: Current American College of Cardiology/American Heart Association guidelines recommend using a standard exercise test without imaging as the initial test in patients who have an interpretable electrocardiogram and are able to exercise. METHOD: We studied 1,461 symptomatic patients with low-risk Duke treadmill scores (> or =5) who underwent myocardial perfusion imaging. The CS was derived by assigning one point to each of the following variables: typical angina, history of myocardial infarction, diabetes, insulin use, male gender, and each decade of age over 40 years. A CS cutoff > or =5 or <5 was used to categorize patients as high risk (n = 303 [21%]) or low risk (n = 1,158 [79%]). Perfusion scans were categorized as low, intermediate, or high risk on the basis of the global stress score (GSS). RESULTS: High-risk scans were more common in patients with a high-risk CS (26.4% vs. 9.5%, p < 0.0001). The CS and GSS were significant independent predictors of cardiac death. However, in patients with a low CS, seven-year cardiac survival was excellent, regardless of the GSS (99% for normal scans, 99% for mildly abnormal scans, and 99% for severely abnormal scans). In contrast, patients with a high CS had a lower seven-year survival rate (92%), which varied with GSS (94% for normal scans, 94% for mildly abnormal scans, and 84% for severely abnormal scans; p < 0.001). CONCLUSIONS: In symptomatic patients with low-risk Duke treadmill scores and low clinical risk, myocardial perfusion imaging is of limited prognostic value. In patients with low-risk Duke treadmill scores and high clinical risk, annual cardiac mortality (>1%) is not low, and myocardial perfusion imaging has independent prognostic value.

Aged↗
PubMed2004

Risks for atrial fibrillation and congestive heart failure in patients >/=65 years of age with abnormal left ventricular diastolic relaxation.

We sought to determine the risk for the first episodes of atrial fibrillation (AF) and congestive heart failure (CHF) in a cohort of patients aged >/=65 years who had abnormal left ventricular (LV) diastolic relaxation. Records were reviewed for all residents of Olmsted County, Minnesota, who had >/=1 transthoracic echocardiogram performed at the Mayo Clinic between 1990 and 1998, and who were in sinus rhythm and did not have a history of AF, CHF, valvular or congenital heart disease, permanent pacemaker, or stroke. Of 994 patients who qualified and had LV diastolic function assessment, abnormal LV relaxation was identified in 569 (57%), 105 of whom (18%) developed a first episode of AF or CHF over a mean follow-up of 4.0 +/- 2.7 years. Age (p <0.0001), history of myocardial infarction (p <0.0001), history of diabetes mellitus (p = 0.041), electrocardiographic LV hypertrophy (p = 0.0223), and indexed left atrial (LA) volume (p = 0.0003) were independent predictors. A stepwise increase in age-adjusted risk was evident when stratified by tertiles of indexed LA volume (<27 ml/m(2); 27 to 37 ml/m(2); >37 ml/m(2)). Compared with patients with normal LV diastolic function (n = 148, 15%), the risks for first episodes of AF or CHF were not different in those with abnormal diastolic relaxation if LA volume was <27 ml/m(2) (p = 0.303). In conclusion, these data suggest the presence of a wide spectrum of risks for AF or CHF in the elderly who have abnormal LV diastolic relaxation, with the highest risks evident in those with the largest left atria. When LA volume was <27 ml/m(2), however, the risks for these events were not different from those with normal LV diastolic function.

Age Factors↗
PubMed2004

Low-density lipoprotein particle size and coronary atherosclerosis in subjects belonging to hypertensive sibships.

BACKGROUND: Dyslipidemia in hypertensive sibships may be characterized by atherogenic small low-density lipoprotein (LDL) particles. Whether LDL particle size is associated with the extent of coronary atherosclerosis in hypertensive sibships is unknown. METHODS: Subjects (n = 792, mean age 62 years, 60% women) were ascertained through sibships containing at least two individuals with essential hypertension diagnosed before age 60 years. The LDL particle size was measured by polyacrylamide gel electrophoresis. Coronary artery calcium (CAC) was measured noninvasively by electron beam computed tomography, and CAC score was calculated using the method of Agatston et al. Sex-specific multiple regression models were used to assess independent predictors of LDL particle size and the association of LDL particle size with CAC. RESULTS: In all, 76% of women and 77% of men were hypertensive. In each sex, independent predictors of smaller LDL particle size were total cholesterol, triglycerides, and lower HDL cholesterol. In women, greater age was an additional predictor of smaller LDL particle size. After adjustment for age and statin use, LDL particle size was significantly associated with the amount of CAC in women but not in men. After further adjustment for HDL cholesterol, triglycerides, diabetes, smoking, and hypertension, LDL particle size was not independently associated with CAC in either sex. CONCLUSIONS: After adjustment for age and statin use, LDL particle size was found to be significantly related to CAC quantity in women but not in men belonging to hypertensive sibships. In women, LDL particle size may mediate some of the atherogenic effects of low-HDL cholesterol-high-triglyceride dyslipidemia, but does not appear to be independently associated with the extent of coronary atherosclerosis in either sex.

Aged↗
PubMed2004

Participation bias in a population-based echocardiography study.

PURPOSE: To compare the characteristics of participants and non-participants in a population-based study of cardiac ventricular function. METHODS: Subjects aged 45 years and older on January 1, 1997 were recruited from a sampling frame of Olmsted County residents from the Rochester Epidemiology Project. Subjects were asked to complete a 17-page questionnaire and participate in a 4-hour clinical examination that included a brief physical examination, echocardiography, spirometry, and an electrocardiogram. With specific IRB approval, the community medical records of participants and non-participants from the first wave of recruitment were examined by trained nurse abstractors to elicit details of past medical history. RESULTS: Of the first 963 persons invited to participate in the study, 488 (51%) completed all phases of the examination. Participation rates were similar among men and women (53% vs. 49%, respectively). By age, participation rates were lowest among persons aged 75 years and older (44.7% and 34.9%) and 45 to 54 years (45.4% and 44.3%) for men and women. Participation rates were not different according to past history of coronary heart disease, congestive heart failure, or other cardiovascular disease. Persons with a history of chronic obstructive pulmonary disease were less likely to participate (19.4% vs. 51%; odds ratio, 0.36; 95% confidence interval, 0.18, 0.76) after adjustment for age, sex, and comorbid conditions. CONCLUSIONS: These results provide some reassurance that participation bias in this study may have little influence on its overall findings, although this cannot be conclusive.

Adult↗
PubMed2004

Relationships between insulin sensitivity and measures of body fat in asymptomatic men and women.

OBJECTIVE: To assess whether measures of body fat by DXA scanning can improve prediction of insulin sensitivity (S(I)) beyond what is possible with traditional measures, such as BMI, waist circumference, and waist-to-hip ratio (WHR). RESEARCH METHODS AND PROCEDURES: Frequently sampled intravenous glucose tolerance tests were performed in 256 asymptomatic non-Hispanic white subjects from Rochester, MN (age 19-60 years; 123 men and 133 women) to determine the S(I) index by Bergman's minimal model technique. Height, weight, and waist and hip circumferences were measured for calculation of BMI and WHR; DXA was used to determine fat in the head, upper body, abdomen, and lower body. Linear regression was used to assess their relationships with S(I) after sex stratification and adjustment for age. RESULTS: After controlling for age, increases in traditional and DXA measures of fat were consistently associated with smaller declines in S(I) among women than among men. In men, after controlling for age, all of the predictive information of S(I) was provided by waist circumference (additional R2 = 0.39, p < 0.001); none of the DXA measures improved the ability to predict S(I). In women, after adjustment for age, BMI, and WHR, the only DXA measure that improved the prediction of S(I) was percentage head fat (additional R2 = 0.03, p < 0.001). DISCUSSION: Equivalent increases in most measures of body fat had lesser impact on S(I) in women than in men. In both sexes, the predictive information provided by DXA measures is approximately equal to, but not additive to, that provided by simpler, traditional measures.

Absorptiometry, Photon↗
PubMed2004

Relation of markers of inflammation (C-reactive protein, white blood cell count, and lipoprotein-associated phospholipase A2) to the ankle-brachial index.

Markers of inflammation are predictive of cardiovascular events but their association with atherosclerotic burden remains poorly defined. We hypothesized that markers of inflammation, including C-reactive protein (CRP), white blood cell (WBC) count, and lipoprotein-associated phospholipase A2 (Lp-PLA2), would be associated with the ankle-brachial index (ABI), a marker of atherosclerotic burden. Subjects were 247 patients referred for lower extremity arterial evaluation to the non-invasive vascular laboratory excluding those with active infection or lower extremity revascularization within the previous year. ABI was measured at two sites in both legs and the lowest of four measurements was used in the analyses. CRP was measured by a high-sensitivity immunoturbidimetric assay and Lp-PLA2 was measured by ELISA. The mean patient age was 68+/-11 years, and 54% were men. Mean ABI was 0.84+/-0.31 and 49% had an ABI < 0.9. Age, hypertension, fasting plasma glucose, and 'ever' smoking were independently associated with the ABI. Spearman correlation coefficients of inflammatory markers with the ABI were: CRP (r = -0.15, p= 0.02), WBC count (r = -0.27, p = 0.001), and Lp-PLA2 (r = -0.09, p = 0.21). In a multiple regression model that included conventional risk factors and statin use, CRP and WBC count were no longer significantly associated with ABI, whereas Lp-PLA2 was a borderline-significant predictor of lower ABI (p = 0.05). These data indicate that CRP and WBC count are not independently associated with ABI, a marker of atherosclerotic burden in subjects referred for non-invasive lower extremity arterial evaluation. The association of Lp-PLA2 with ABI merits further study.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2004

Lack of association between lipoprotein(a) and coronary artery calcification in the Genetic Epidemiology Network of Arteriopathy (GENOA) study.

OBJECTIVE: To investigate the relationship between lipoprotein(a) [Lp(a)] levels and the extent of coronary atherosclerosis in a cohort that consisted predominantly of hypertensive patients. PATIENTS AND METHODS: Patients were ascertained through sibships that contained at least 2 individuals with essential hypertension diagnosed before the age of 60 years. The 10-year coronary heart disease (CHD) risk was estimated on the basis of the Framingham risk equation. Serum Lp(a) was measured by an immunoturbidimetric assay. Coronary artery calcification (CAC) was measured noninvasively by electron beam computed tomography and CAC score calculated using the Agatston score. RESULTS: Patients included 765 non-Hispanic, white individuals (59% women) participating in the Genetic Epidemiology Network of Arteriopathy study. The mean +/- SD age of the patients was 62 +/- 8 years, and 77% had hypertension. The prevalence of detectable CAC was 87% in men and 60% in women. The CAC scores did not differ significantly across quintiles of Lp(a) levels in either men or women. In a multiple regression model that included conventional risk factors, Lp(a) levels were not related to CAC quantity in either sex. No significant interactions were noted between Lp(a) levels and the conventional risk factors in the prediction of CAC quantity. When stratified on the basis of the 10-year CHD risk, 26.5% of the patients were low risk (< 6%), 60.5% were intermediate risk (6%-20%), and 12.9% were high risk (> 20%). Lipoprotein(a) was not associated with CAC quantity within subgroups based on 10-year CHD risk. CONCLUSION: In this cohort enriched with hypertensive patients, the estimated 10-year CHD risk did not appear to modify the lack of an association between Lp(a) levels and CAC.

Aged↗
PubMed2004

Left atrial volume in the prediction of first ischemic stroke in an elderly cohort without atrial fibrillation.

OBJECTIVE: To determine the clinical importance of left atrial (LA) volume in the prediction of first ischemic stroke. PATIENTS AND METHODS: This retrospective cohort study included randomly selected residents of Olmsted County, Minnesota, aged 65 years or older, who had undergone transthoracic echocardiography at least once at the Mayo Clinic in Rochester, Minn, between January 1, 1990, and December 31, 1998, were in sinus rhythm, and had no history of stroke, transient ischemic attack, atrial fibrillation, or valvular heart disease. Patients were monitored through medical records for first ischemic stroke or death. RESULTS: Of 1554 residents (59% women) aged 75+/-7 years, 92 (6%) had experienced at least 1 ischemic stroke over 4.3+/-2.7 years (incident stroke rate, 1.4 per 100 person-years). Left atrial volume of 32 mL/m2 or greater (hazard ratio [HR], 1.63; confidence interval [CI], 1.08-2.46) was independent of age (HR, 1.04; CI, 1.02-1.07), diabetes (HR, 1.91; CI, 1.07-3.41), myocardial infarction (HR, 1.64; CI, 1.01-2.64), and hyperlipidemia (HR, 1.55; CI, 1.01-2.37) for the prediction of first ischemic stroke. When quartiles of LA dimension were plotted against quartiles of indexed LA volume, a stepwise increase in risk with each quartile increment was evident only for indexed LA volume. Also, an LA volume of 32 mL/m2 or greater was associated with an increased mortality risk (HR, 1.30; CI, 1.09-1.56), independent of age, sex, and stroke status. CONCLUSIONS: In our elderly cohort with no prior atrial fibrillation, LA volume was independently predictive of first ischemic stroke, incremental to age, diabetes, myocardial infarction, and hyperlipidemia. It was also an independent predictor of death.

Aged↗
PubMed2003

Epitope selection from an uncensored peptide library displayed on avian leukosis virus.

Phage display libraries have provided an extraordinarily versatile technology to facilitate the isolation of peptides, growth factors, single chain antibodies, and enzymes with desired binding specificities or enzymatic activities. The overall diversity of peptides in phage display libraries can be significantly limited by Escherichia coli protein folding and processing machinery, which result in sequence censorship. To achieve an optimal diversity of displayed eukaryotic peptides, the library should be produced in the endoplasmic reticulum of eukaryotic cells using a eukaryotic display platform. In the accompanying article, we presented experiments that demonstrate that polypeptides of various sizes could be efficiently displayed on the envelope glycoproteins of a eukaryotic virus, avian leukosis virus (ALV), and the displayed polypeptides could efficiently attach to cognate receptors without interfering with viral attachment and entry into susceptible cells. In this study, methods were developed to construct a model library of randomized eight amino acid peptides using the ALV eukaryotic display platform and screen the library for specific epitopes using immobilized antibodies. A virus library with approximately 2 x 10(6) different members was generated from a plasmid library of approximately 5 x 10(6) diversity. The sequences of the randomized 24 nucleotide/eight amino acid regions of representatives of the plasmid and virus libraries were analyzed. No significant sequence censorship was observed in producing the virus display library from the plasmid library. Different populations of peptide epitopes were selected from the virus library when different monoclonal antibodies were used as the target. The results of these two studies clearly demonstrate the potential of ALV as a eukaryotic platform for the display and selection of eukaryotic polypeptides libraries.

Amino Acid Sequence↗
PubMed2003

Prediction of risk for first age-related cardiovascular events in an elderly population: the incremental value of echocardiography.

OBJECTIVES: We sought to determine if echocardiography enhances prediction of first age-related cardiovascular events. BACKGROUND: Whether echocardiographic assessment improves risk stratification for first cardiovascular events is not well known. METHODS: This retrospective cohort study included randomly selected residents of Olmsted County, Minnesota, age >/=65 years, who had >/=1 transthoracic echocardiograms at the Mayo Clinic between 1990 and 1998, in sinus rhythm, without valvular or congenital heart disease, and followed through medical records for first myocardial infarction (MI), coronary revascularization, atrial fibrillation (AF), congestive heart failure (CHF), transient ischemic attack (TIA), stroke, or cardiovascular death. Patients were excluded if they had any of these events before the baseline echocardiogram. RESULTS: Of 1,160 patients (age 75 +/- 7 years; 746 women) followed for a mean of 3.8 +/- 2.7 years, 333 (29%) first events occurred (70 AF, 67 coronary revascularization procedures, 65 CHF, 48 MI, 38 stroke, 25 TIA, and 20 cardiovascular deaths). In a multivariate model, age (p < 0.001), male gender (p < 0.001), diabetes mellitus (p = 0.005), systemic hypertension (p < 0.001), left atrial volume/body surface area >/=32 ml/m(2) (p = 0.003), left ventricular (LV) mass/height >/=120 g/m (p = 0.014), LV systolic dysfunction (p < 0.001), and LV diastolic dysfunction (p = 0.029) were independent predictors. A risk-scoring algorithm was developed and validated for the prediction of first events. The five-year event-free survival was 90%, 74%, and 50% for low-, medium-, and high-risk groups, respectively. CONCLUSIONS: Echocardiography enhanced prediction of first cardiovascular events in this referral-based elderly cohort. Its role in risk stratification for primary prevention of these events in the community warrants further investigations.

Age Factors↗