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PubMed2005

Reliability of the long-range power-law correlations obtained from the bilateral stride intervals in asymptomatic volunteers whilst treadmill walking.

Stride intervals measured during steady-state walking are irregular. These stride interval fluctuations are not random but exhibit long-range power-law correlation (alpha) such that a given stride interval is 'influenced' by earlier variations in the stride intervals. To estimate alpha, one requires a minute long sequence of right or left side stride interval data. However, to obtain a reliable alpha point estimate, the minimal stride sequence length is unknown. Additionally, it is unknown if the right and left side alpha are equivalent. In this study, the within-day and the right and left side reliabilities of alpha point estimates were examined in 23 volunteers performing three 8-min treadmill walks. In addition, eight volunteers were retested on three additional days to estimate between-day reliability. The standard error of measurement (S.E.M.) and the within- and between-day intraclass correlation (ICC) values, and their 95% confidence intervals, each calculated using the combined right and left leg 8-min alpha estimates were acceptable [0.047 (0.044-0.051); 0.914 (0.882-0.932) and 0.769 (0.689-0.815), respectively]. The left alpha (0.688 +/- 0.93) was greater than the right alpha (0.664 +/- 0.094), albeit this finding was underpowered (0.55). The alpha point estimates obtained from the full 8-min walks provided minimal S.E.M. and maximal within- and between-day ICCs. However, the minimal S.E.M. was statistically indistinguishable from the 6- and 7-min walk durations and all of the within-day and between-day ICCs were similar except for the 3- and 8-min between-day ICCs. This study suggests that data from four 3 min, three 6 min or two 8 min walk duration trials provide reliable alpha point estimates from a short series of short treadmill walks.

Adolescent↗
PubMed2004

Evidence for two independent distributions of serum immunoglobulin E in atopic families: cognate and non-cognate IgE.

Genetic studies of IgE-mediated atopic disease have produced conflicting results, due largely to variable phenotype definitions. Total IgE concentrations and 14 allergen skin prick tests (SPT) were determined in 1099 members of families with history of atopy. Log10 [Total IgE] values were normally distributed in both atopic (SPT [+]) and non-atopic (SPT [-]) groups. The mean Log10 [Total IgE] value was higher in the atopic group, although the standard deviations of the distributions were the same. The mean Log10 [Total IgE] value of the non-atopic distribution was subtracted from the individual Log10 [Total IgE] values of the atopic group giving an allergen-specific fraction. There was a strong positive correlation between the specific IgE fraction and the number (#) SPT [+] results, defined as Cognate IgE. Among the atopics, subtracting the Cognate IgE value from total IgE yielded Non-Cognate IgE. The Cognate and Non-Cognate IgE distributions were statistically uncorrelated. Evidence is presented for two serum IgE fractions that are statistically and physiologically independent of one another in atopic families; a Cognate IgE fraction associated with atopic sensitization and a Non-Cognate IgE fraction unrelated to atopic disease. Elevated serum IgE is a consequence, not a predisposing cause, of allergen sensitization.

Adult↗
PubMed2006

Diabetes mellitus impairs myocardial oxygen metabolism even in non-infarct-related areas in patients with acute myocardial infarction.

BACKGROUND: Although diabetes is associated with poor clinical outcomes after acute myocardial infarction, to date there have been no reports focusing on the myocardial oxygen metabolism in these patients. Thus, we evaluated the myocardial oxygen metabolism in patients with and without diabetes suffering from acute myocardial infarction using carbon-11 acetate positron emission tomography. METHODS: 20 patients (13 diabetic patients [group A] and 7 non-diabetic patients [group B]) underwent carbon-11 acetate positron emission tomography soon after the onset of acute myocardial infarction. The myocardial oxygen metabolism was evaluated within the infarct-related area and in the non infarct-related area. 6 healthy volunteers (group C) and 6 diabetic patients without coronary artery disease (group D) also participated as controls. RESULTS: There were no significant differences in gender, age, infarct-related artery, peak level of serum creatine phosphokinase, left-ventricular ejection fraction at onset, or the defect severity on myocardial perfusion images between group A and group B. In group A, the clearance rate (Kmono) of carbon-11 acetate in infarct-related area (0.042+/-0.010) was not significantly different from that in group B (0.049+/-0.016). In contrast, Kmono in non infarct-related area in group A (0.059+/-0.010) was significantly lower than that in group B (0.076+/-0.009; p=0.002), group C (0.072+/-0.004; p=0.026) and group D (0.078+/-0.005; p=0.001). CONCLUSIONS: These data indicate that the myocardial oxygen metabolism even in non infarct-related area in diabetic patients was impaired after the onset of acute myocardial infarction.

Adult↗
PubMed2006

Admission B-type natriuretic peptide assessment improves early risk stratification by Killip classes and TIMI risk score in patients with acute ST elevation myocardial infarction treated with primary angioplasty.

BACKGROUND: TIMI risk score for ST elevation acute myocardial infarction (STEMI) and Killip classes are simple tools for early risk stratification. AIM: This study aims to evaluate the hypothesis that admission of BNP adds prognostic information to Killip classes and TIMI risk score in patients with STEMI treated with primary percutaneous coronary intervention (PCI). METHODS: BNP concentrations in blood samples obtained on admission in 126 consecutive patients (mean age 58.8+/-10.7 years old) with STEMI were assessed with means of point-of-care test before PCI. A 42-day follow-up for total mortality was performed. RESULTS: BNP levels increased significantly with increasing Killip classes and TIMI risk score. Addition of BNP to Killip classes and to TIMI risk score increased area under the ROC from 0.704 to 0.887 and from 0.852 to 0.918, respectively. There was a significant increase in mortality in the subgroups by Killip classes and BNP: 1.1% for Killip I and BNP < 331 mg/ml; 16% for Killip I or BNP > or = 331 mg/ml; 55.6% for Killip I and BNP > or = 331 mg/ml; p<0.0001; and in subgroups by TIMI risk score and BNP: 0% for TIMI risk score < 4 and BNP < 331 pg/ml; 2.8% for TIMI risk score > or = 4 and BNP < 331 pg/ml; 12.5% for TIMI risk score < 4 and BNP > or = 331 pg/ml; and 50% for TIMI risk score > or = 4 and BNP > or = 331 pg/ml; (p<0.0001). In multivariate model BNP was a prognostic variable for mortality, independent from TIMI risk score. CONCLUSIONS: Admission of BNP adds significant prognostic information beyond that of Killip classes and TIMI risk score in patients with STEMI treated with PCI.

Adult↗
PubMed2006

Chronic kidney disease in patients with chronic heart failure--impact on intracardiac conduction, diastolic function and prognosis.

BACKGROUND: In patients with chronic heart failure (CHF), chronic kidney disease (CKD) is associated with increased morbidity and mortality, but contributing mechanisms are not well defined. This study tested the impact of CKD on intracardiac conduction, diastolic function and prognosis in patients with underlying CHF. METHODS: We prospectively enrolled 269 patients with stable CHF, of whom 135 had CKD (estimated glomerular filtration rate (eGFR)<60 ml/min/1.73 m(2)). Echo measurements comprised left ventricular dimensions/volumes, ejection fraction, mitral E/A-ratio, deceleration time and tissue Doppler mitral annular velocities (S', E', A'). PQ and QRS intervals were derived from the 12-lead ECG. A cardiac event (cardiac death or urgent cardiac transplantation) was defined as combined study end point. RESULTS: Patients with CKD had longer PQ and QRS intervals, and were in a poorer NYHA functional class as compared to patients without CKD. In patients with CKD, the mitral annular E' velocity was lower, the mitral E/E'-ratio was higher and a restrictive mitral filling pattern was more frequent. By linear regression analysis, PQ and QRS intervals and the mitral E/E'-ratio were inversely related to the eGFR. During a follow-up of 507+/-375 days, 39 patients suffered a cardiac event. In CKD patients, outcome was markedly poorer as compared to those without CKD (event-free survival rate 51% vs. 87% in those without KD, p=0.001) CONCLUSIONS: In patients with CHF, CKD is associated with impaired intracardiac conduction and progressive diastolic dysfunction. Both mechanisms may contribute to increased morbidity and mortality of such patients.

Age Distribution↗
PubMed2006

Racial differences in prevalence of coronary obstructions among men with positive nuclear imaging studies.

OBJECTIVES: The purpose of this research was to compare coronary obstruction between clinically similar African Americans (AA) and white persons undergoing coronary angiography. BACKGROUND: African Americans have higher rates of coronary death than whites, but are less likely to undergo coronary revascularization. Although differences in coronary anatomy do not explain racial difference in revascularization rates, several studies of clinically diverse persons undergoing coronary angiography have found less obstructive coronary disease in AA than clinically similar whites. METHODS: We studied 52 AA and 259 white male veterans who had both a positive nuclear perfusion imaging study and coronary angiography within 90 days of that study in five Department of Veterans Affairs hospitals. We used chart review and patient interview to collect demographics, clinical characteristics, and coronary anatomy results. Before angiography, we asked physicians to estimate the likelihood of coronary obstruction. RESULTS: The treating physicians' estimates of coronary disease likelihood were similar for AA (79.5%) and whites (83.0%); AA were less likely to have any coronary obstruction (63.5% vs. 76.5%, p = 0.05) and had significantly less severe coronary disease (p = 0.01) than whites. African Americans continued to be less likely to have coronary obstruction in analyses controlling for clinical features, including the physician's estimate of the likelihood of coronary obstruction. CONCLUSIONS: These results suggest that AA have less coronary obstruction than apparently clinically similar whites. Further studies are required to confirm our findings and better understand the paradox that AA are less likely to have obstructive coronary disease and more likely to suffer mortality from coronary disease.

Adult↗
PubMed2006

Simple measures of dietary variety are associated with improved dietary quality.

The objective of this study was to identify a measure of dietary variety that was associated with improved dietary quality and easily understood by consumers. Dietary quality was measured by nutrient adequacy and intakes of added sugars, saturated fat, cholesterol, and sodium. We developed four definitions of dietary variety: (a) a count of basic commodities consumed; (b) a count of food codes reported; (c) a count of five Food Guide Pyramid (FGP) food groups consumed; and (d) a count of 22 FGP subgroups consumed. The analysis sample included 4,964 men and 4,797 women aged 19 years and older who participated in the Continuing Survey of Food Intakes by Individuals 1994-96. For each day of dietary data, we examined associations of each type of dietary variety with several measures of dietary quality using Spearman's correlations and multivariate linear regression models. After adjusting for energy intake and the number of FGP food group servings, all types of dietary variety were positively associated with mean nutrient adequacy across 15 nutrients, but associations were strongest for commodity-based variety and for 22 FGP subgroup consumption variety. Likewise, all variety measures were inversely associated with intakes of added sugars and saturated fat, with commodity-based variety and 22 FGP subgroup variety the strongest. We conclude that variety measured using 22 FGP subgroups is preferable because it is a good predictor of dietary quality, is relatively simple to calculate, and is easy to explain to consumers.

Adult↗
PubMedDate not supplied

The frequency and factors linked to a urinary tract infection coding in patients undergoing hip fracture surgery.

OBJECTIVE: To study the frequency and factors linked to having an International Classification of Diseases, Ninth Revision (ICD-9) diagnosis of urinary tract infection (UTI) in patients undergoing hip fracture surgery. METHODS: A retrospective observational study of a cohort of all patients admitted to a university teaching hospital with a principal ICD-9 diagnosis of a hip fracture during 3 consecutive calendar years. RESULTS: A total of 138 subjects (67% were 65 years or older) underwent hip fracture surgery during the study period. Twelve percent of subjects had an ICD-9 UTI diagnosis during the hospitalization period. The incidence of UTI diagnosis was greater in subjects who were 65 years or older compared with younger subjects (16% vs 4%, P < .05), females compared with males (18% vs 5%, P < .05), subjects admitted to a medical floor compared with subjects admitted to a surgical floor (45% vs 10%, P < .001), and in subjects with biochemical evidence of dehydration on admission compared with those without such evidence (20% vs 7%, P < .05). The incidence of an ICD-9 UTI diagnosis correlated positively with the number of days subjects received nothing per mouth (NPO) after surgery (P < .0001). Subjects who had a UTI diagnosis scored higher on the Goldman Cardiac Risk index (P < .05) indicating they were sicker. Using logistic regression analysis, only the number of days a patient was kept NPO after surgery was an independent predictor of having a UTI diagnosis (B = -1.34, P = .043). Presence of biochemical evidence of dehydration on admission was another possible predictor with a P value approaching significance (B = 0.3, P = .07). Subjects with a UTI diagnosis had longer mean (+/- SD) length of hospital stay (8.7 +/- 8 vs 5.4 +/- 3 days, P < .05) and greater incidence of delirium (35% vs 8%, P < .0001) compared with subjects without a UTI diagnosis. CONCLUSIONS: Urinary tract infection ICD-9 diagnosis is frequent among patients undergoing hip fracture surgery and is linked to prolonged length of hospital stay and to increased incidence of delirium. Number of days patients were kept off oral intake after surgery was an independent factor associated with a UTI diagnosis during the hospitalization period in this patient population.

Adolescent↗
PubMed2006

A novel real-time system to monitor cell aggregation and trajectories in rotating wall vessel bioreactors.

Rotating wall vessel bioreactors (RWVs) constitute dynamic suspension culture venues for tissue engineering. Quantitative real-time assessment of the kinetics of cell-cell aggregation in RWVs can yield mechanistic information about the initial steps leading to the assembly of individual cells into tissue-like constructs. In our imaging system, fluorescently labeled cells suspended in a HARV-type RWV were irradiated by a laser-beam. Emission was recorded by a camera mounted at 90 degrees to the excitation plane. Using macro lenses, the system identified approximately 5 microm particles from a 5 cm working distance, distinguished aggregated 20 microm microspheres from larger (45 and 90 microm) microspheres, and plotted local trajectories of microspheres and cells. Sizes of PC12 cells assessed by our system matched conventional measurements. We validated the system's ability to follow HepG2 and PC12 aggregation in real time over 24h of RWV culture. Taken together, our system provides the means to measure and analyze in real time the processes that lead to the 3D tissue-like assembly of diverse cell types into spheroids. Future studies include development of intelligent feedback algorithms, allowing automatic control over RWV rotational speed required to maintain aggregating cells and nascent tissue in continual free fall.

Animals↗
PubMed2006

Normal-eye Zernike coefficients and root-mean-square wavefront errors.

PURPOSE: To compare aberrometry measurements from multiple sites and compute mean Zernike coefficients and root-mean-square (RMS) values for the entire data pool to serve as a reference set for normal, healthy adult eyes. SETTING: Northeastern State University, Tahlequah, Oklahoma, USA. METHODS: Data were collected from 10 laboratories that measured higher-order aberrations (HOAs) in normal, healthy adult eyes using Shack-Hartmann aberrometry (2560 eyes of 1433 subjects). Signed Zernike coefficients were scaled to pupil diameters of 6.0 mm, 5.0 mm, 4.0 mm, and 3.0 mm and corrected to a common wavelength of 550 nm. The mean signed and absolute Zernike coefficients across data sets were compared. Then, the following were computed: overall mean values for signed and absolute Zernike coefficients; polar Zernike magnitudes and RMS values for coma-like aberrations (Z(3)(+/-1) and Z(5)(+/-1) combined); spherical-like aberrations (Z(4)(0) and Z(6)(0) combined); and 3rd-, 4th-, 5th-, and 6th-order, and higher-order aberrations (orders 3 to 6). RESULTS: The different data sets showed good agreement for Zernike coefficients values across most higher-order modes, with greater variability for Z(4)(0) and Z(3)(-1). The most prominent modes and their mean absolute values (6.0-mm pupil) were, respectively, Z(3)(-1) and 0.14 microm, Z(4)(0) and 0.13 microm, and Z(3)(-3) and 0.11 microm. The mean total higher-order RMS was 0.33 microm. CONCLUSIONS: There was a general consensus for the magnitude of HOAs expected in normal adult human eyes. At least 90% of the sample had aberrations less than double the mean values reported here. These values can serve as a set of reference norms.

Adult↗
PubMed2004

Reporting point and interval estimates of effect-size for planned contrasts: fixed within effect analyses of variance.

UNLABELLED: The purpose of this tutorial is threefold: (a) review the state of statistical science regarding effect-sizes, (b) illustrate the importance of effect-sizes for interpreting findings in all forms of research and particularly for results of clinical-outcome research, and (c) demonstrate just how easily a criterion on reporting effect-sizes in research manuscripts can be accomplished. The presentation centers on within-effect analyses of variance including the one-way design for testing pre-post hypotheses and the two-way parallel-groups design for making direct comparisons of competing treatment protocols (e.g., experimental treatment versus control). The presentation is supported with worked examples and a web site containing templates for software applications. EDUCATIONAL OBJECTIVES: The reader will be able to: (1) explain the rationale for the increased use of estimates of effect-size in reporting results in published research manuscripts; (2) describe what an effect-size is (generally considered) and provide a rationale for its importance; (3) distinguish among the many forms of effect-size and apply their features to the most appropriate choices under specific research circumstances; and (4) appropriately report and interpret effect-sizes.

Algorithms↗
PubMed2005

Concordance of preferences for end-of-life care between terminally ill cancer patients and their family caregivers in Taiwan.

There is a dearth of information in the literature about the concordance of preferences for end-of-life care between terminally ill patients and their family surrogates outside the Western countries. The purpose of this study was to examine the extent of concordance in preferences for end-of-life care goals and life-sustaining treatments between Taiwanese terminally ill cancer patients and their primary family caregivers. A total of 617 dyads of patients-family caregivers across 21 hospitals throughout Taiwan were surveyed. Overall agreements on the goals for end-of-life care and preferences for initiating life-sustaining treatments ranged from 62.4% to 96.9% (average: 71.0%). Kappa values for the extent of concordance ranged from 0.13 to 0.46 (average: 0.29), indicating poor to moderate consistency in personal preferences. Family caregivers had a significantly more aggressive attitude toward each examined life-sustaining treatment for their ill family members than the patients' own stated preferences. In societies, such as in Asian countries, where physicians' respect for patient autonomy is frequently subordinate to the power of family, disagreements between a patient and family about end-of-life care may result in the patient's preferences being overridden at the end of life. To effect real change and to gain increased agreement on preferences for end-of-life care, an open dialogue between patients and their primary family caregivers should become standard.

Adult↗
PubMed2004

Severe vesicoureteral reflux and chronic renal failure: a condition peculiar to male gender? Data from the ItalKid Project.

Primary vesicoureteral reflux (VUR), one of the principal causes of chronic renal failure (CRF), occurs as a result of two distinct and sex-related mechanisms: congenital renal hypoplasia, which is prevalent in males, and acquired renal scarring in females. We used data from the ItalKid Project, a prospective population-based CRF registry of patients undergoing conservative treatment, to evaluate the gender distribution and severity of primary VUR, the age at diagnosis, and the diagnostic and therapeutic methods adopted in children with CRF. The prevalence of males (77.5%), the severity of VUR (grade IV-V), and the early age at diagnosis (18% prenatally) seem to suggest that congenital renal damage is the major cause of pediatric CRF.

Age Distribution↗
PubMed2004

Arterial switch with full-flow cardiopulmonary bypass and limited circulatory arrest: neurodevelopmental outcome.

OBJECTIVES: Neonatal cardiac surgery has been associated with unfavorable neurodevelopmental events. We investigated a patient cohort operated on predominantly with full-flow cardiopulmonary bypass (150 mL x kg(-1) x min(-1), alpha-stat, alpha-blockade, median arrest = 6 minutes, temperature of 22 degrees C) as the major support strategy for neonatal arterial switch operations (transposition of the great arteries and intact ventricular septum). METHODS: Seventy-four patients and "best-friend" control subjects were assessed 109 months (range, 48-166 months) postoperatively with general medical and neurologic evaluation, IQ testing, formal movement scores, and detailed parent-teacher behavioral-social reports. Fetal, neonatal, and perioperative data were collated. RESULTS: The prevalence of perioperative seizures was 6.8% (4/5 cases occurring preoperatively). The incidence of all perioperative neurologic abnormalities was 20%. Patients who had a neurologic event were (as a group) older at the time of operation and had a lower arterial blood pH before the operation. Selected perioperative factors (not related directly to cardiopulmonary bypass variables) predicted early (before discharge) neurologic outcome in a multivariate model. At late assessment, patients were more likely than control subjects to have a mild neurologic abnormality (P = 0.002). Full-scale IQ scores (Wechsler Preschool and Primary Scale of Intelligence and Wechsler Intelligence Scale for Children-Third Edition) were higher in control subjects (101.9 [SD = 13] vs 108.6 [SD = 12], P =.0007), with both groups having scores greater than the population-based test means. Full-scale IQ scores related most significantly to years of paternal education (beta = 1.51, P =.0078) but were also influenced by perioperative neurologic abnormalities, birth weight, and circulatory arrest time. Patients had higher motor impairment scores (Movement Assessment Battery) than control subjects (P =.0004). Parents (Achenbach Child Development Checklist) assigned higher total social-behavioral competence scores to control subjects (P =.05). Teachers (Achenbach Teacher Report Form) suggested that patients were more likely to be perceived as having various speech and expressive language problems, as well as minor behavioral problems. CONCLUSION: With the perioperative strategies used, not all survivors can be considered (neurodevelopmentally) normal at late follow-up, although the risk of important impairment is low. Perioperative events might have long-term prognostic value. On the basis of this study and published data regarding other strategies, continued application of full-flow cardiopulmonary bypass is justified, with the proviso that further investigation is required.

Age Distribution↗
PubMed2005

Voice-over: perceptual and acoustic analysis of vocal features.

Voice-overs are professional voice users who use their voices to market products in the electronic media. The purposes of this study were to (1) analyze voice-overed and non-overed productions of an advertising text in two groups consisting of 10 male professional voice-overs and 10 male non-voice-overs; and (2) determine specific acoustic features of voice-over productions in both groups. A naïve group of listeners were engaged for the perceptual analysis of the recorded advertising text. The voice-overed production samples from both groups were submitted for analysis of acoustic and temporal features. The following parameters were analyzed: (1) the total text length, (2) the length of the three emphatic pauses, (3) values of the mean, (4) minimum, (5) maximum fundamental frequency, and (6) the semitone range. The majority of voice-overs and non-voice-overs were correctly identified by the listeners in both productions. However voice-overs were more consistently correctly identified than non-voice-overs. The total text length was greater for voice-overs. The pause time distribution was statistically more homogeneous for the voice-overs. The acoustic analysis indicated that the voice-overs had lower values of mean, minimum, and maximum fundamental frequency and a greater range of semitones. The voice-overs carry the voice-overed production features to their non-voice-overed production.

Adult↗
PubMed2005

The bisexual branching process with population-size dependent mating as a mathematical model to describe phenomena concerning to inhabit or re-inhabit environments with animal species.

We consider the bisexual Galton-Watson branching process with population-size dependent mating as a mathematical model adequate for the description of some natural phenomena. More specifically we are interested in studying some questions about the problem of populating an environmental with new animal species or re-populating it with species which have previously disappeared.

Algorithms↗
PubMed2006

The material mapping strategy influences the accuracy of CT-based finite element models of bones: an evaluation against experimental measurements.

Aim of the present study was to evaluate the influence on the global model's accuracy of the strategy adopted to define the average element Young's modulus in subject-specific finite element models of bones from computed tomography data. The classic strategy of calculating the Young's modulus from an average element density and the one that averages the Young's moduli directly derived from each voxel Hounsfield Unit were considered. These strategies were applied to the finite element model of a real human femur. The accuracy of the superficial stress and strain predictions was evaluated against experimentally measured values in 13 strain-gauge locations for five different loading conditions. The results obtained for the two material distributions were statistically different. Both models predicted very accurately the superficial stresses, with regression coefficients higher than 0.9 and slopes not significantly different from unity. The second strategy definitely improved the strains prediction accuracy: the regression coefficient raised from 0.69 to 0.79; the average and peak errors decreased from 45.1% to 31.3% and from 228% to 134% of the maximum measured strain, respectively. The stress fields predicted inside the bone were also significantly different. A new software implementing the second strategy was made available in the public domain.

Bone Density↗