Estimation of Regional Myocardial Blood Flow Using Computed Tomography: A Stochastic Formulation

Previously, we have presented a deterministic formulation for estimation of regional myocardial blood flow (RMBF) using X-ray computed tomography (CT) [1]. Quantitation of RMBF with the deterministic theory requires computing the zeroth and first moments of extrapolated myocardial contrast enhancement (CT numbers versus time) curves. This extrapolation is a potential source of error in the presence of recirculation, especially in myocardial regions with reduced flows. In the present paper, a stochastic approach for parameter estimation is undertaken, which renders an optimal RMBF estimate based upon the least squares error criteria. Random measurement errors are minimized, curve extrapolation is avoided, and the accuracy of RMBF estimates is predicted. The advantages of the stochastic versus the deterministic approach are demonstrated in the results obtained from the in vivo estimation of RMBF in normal and acutely ischemic myocardium of dogs.     

Children's emotional attributions to self versus other: An exploration of an assumption underlying projective techniques.

Examined the assumption that children attribute socially undesirable or conflictual affects to ambiguous characters that they ordinarily censure when attributing affect to themselves. The quality and intensity of 72 1st, 3rd, and 5th graders' emotional attributions to themselves and to others as characters in affect-laden stories were examined. Each of 5 stories was told twice, once using "you" as the subject of the story and once using an ambiguous character named Mary or John as the subject of the story. Results indicate that Ss attributed a greater number of sad and scared responses and fewer happy responses to the other than to the self. More intense responses were attributed to the other than to the self. Boys attributed more intensely happy and less intensely scared responses to characters than girls did. Results partially confirm the assumption underlying projective techniques and are discussed with reference to the development of children's defenses, to social desirability, and to developmental studies of empathy. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of Annealing on the Microstructure and Phase Chemistry of Directionally Solidified Bi2Sr2CaCu2O8

The effects of annealing on the microstructure and phase chemistry of directionally solidified Bi₂Sr₂CaCu₂O₈ (2212) were studied. Boules grown at fast growth rates are multiphase, contain no 2212, and exhibit some preferred orientation; Sr-deficient 2201 exhibits a (220) texture. These samples, however, do show a significant amount of 2212 after annealing, with (220) texture similar to the texture of the preexisting 2201 phase in the as-grown boules. In contrast, 2212 grown directly from the melt at slow growth rates has (200) texture. Boules grown at moderate growth rates are multiphase and contain 2212 as one of the phases; these boules show an increase in 2212 volume fraction after annealing. Microstructural observations in both cases indicate solidstate formation of 2212 occurs topotactically on or within the preexisting 2201 phase. Boules grown at fast growth rates are oxygen-deficient, since they show an increase in mass with annealing, whereas boules grown at moderate growth rates show no appreciable mass increase with annealing. An estimate of the Cu(I) concentration in the liquid zone during crystal growth at fast growth rates was obtained from gravimetric analysis.     

Change in caregiver depression as a function of the Strong African American Families Program.

A randomized prevention trial contrasted families who participated in the Strong African American Families Program (SAAF), a preventive intervention for rural African American parents and their 11-year-olds, with control families. This article focuses on the program's effect on primary caregivers' depressive symptoms. Among the 167 caregivers with elevated scores on the Center for Epidemiologic Studies-Depression Scale, SAAF participation was associated with reduced depressive symptoms, enhanced parenting, and perceived improvements in youth behavior. Change in parenting (consistent discipline, youth monitoring, and open communication) but not change in youth intrapersonal competencies significantly mediated intervention effects on caregivers' depression. Results support the link between reduced depressive symptoms and stronger family relationships, particularly the importance of enhanced parenting efficacy in alleviating depressive symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pharmacokinetics of Single Domain Antibodies and Conjugated Nanoparticles Using a Hybrid near Infrared Method

Iron oxide nanoparticles and single domain antibodies from camelids (VHHs) have been increasingly recognized for their potential uses for medical diagnosis and treatment. However, there have been relatively few detailed characterizations of their pharmacokinetics (PK). The aim of this study was to develop imaging methods and pharmacokinetic models to aid the future development of a novel family of brain MRI molecular contrast agents. An efficient near-infrared (NIR) imaging method was established to monitor VHH and VHH conjugated nanoparticle kinetics in mice using a hybrid approach: kinetics in blood were assessed by direct sampling, and kinetics in kidney, liver, and brain were assessed by serial in vivo NIR imaging. These studies were performed under “basal” circumstances in which the VHH constructs and VHH-conjugated nanoparticles do not substantially interact with targets nor cross the blood brain barrier. Using this approach, we constructed a five-compartment PK model that fits the data well for single VHHs, engineered VHH trimers, and iron oxide nanoparticles conjugated to VHH trimers. The establishment of the feasibility of these methods lays a foundation for future PK studies of candidate brain MRI molecular contrast agents.     

Severity of nicotine dependence moderates performance on perceptual-motor tests of attention.

Acute abstinence from cigarette smoking by nicotine-dependent smokers has been linked with cognitive deficits, but the role of nicotine dependence per se in these effects is not known. We therefore tested the relationships of nicotine dependence and smoking history with performance in perceptual-motor, timed tests of attention. Nicotine-dependent smokers (n = 37) and nonsmokers (n = 48), 18-55 years old, took both the d2 Test of Attention and the Digit Symbol Test on each of 2 test days. For smokers, testing on one day began after ad libitum smoking (<45 min since last cigarette); and on the other day, it began after overnight abstinence (>13 hr since last cigarette). On each test day, there were two test blocks with an intervening break, when only the smokers each smoked one cigarette. There were no significant effects of abstinence or of smoking one cigarette on the performance of smokers; however, across conditions, the smokers' performance on both tests correlated negatively with severity of nicotine dependence but not lifetime cigarette consumption or cigarette craving. Smokers with high nicotine dependence performed more slowly on both tests than less dependent smokers or nonsmokers. The findings suggest that severity of nicotine dependence and slowness in perceptual-motor tasks of attention share an underlying basis.     

A rivalry of foulness: official and unofficial investigations of the London cholera epidemic of 1854

OBJECTIVE: To describe and explain sex differences in antihypertensive drug use. DESIGN AND METHODS: From 1987 to 1995, two cross-sectional population-based surveys of cardiovascular disease risk factors in The Netherlands were carried out among 56026 men and women aged 20-59 years. Polytomous logistic regression modelling was used to adjust for potential confounders of the association between sex and use of different antihypertensive drugs. RESULTS: The response rate was 40% for men and 46% for women. Of these respondents, 40% (1041) of the hypertensive men and 59% (1403) of the hypertensive women were being treated pharmacologically; 57% (595) of the treated men and 54% (760) of the treated women were on monotherapy for hypertension with a diuretic (men 14.8%, women 37.2%), a beta-blocker (men 59.0%, women 45.3%), a calcium antagonist (men 8.6%, women 5.0%) or an angiotensin converting enzyme inhibitor (men 17.7%, women 12.5%). Among those on monotherapy for hypertension, women were less likely than men to be using a beta-blocker [prevalence odds ratio (POR), female/male=0.34; 95% confidence interval (CI) 0.24-0.47], a calcium antagonist (POR=0.27, 95% CI 0.15-0.48) or an angiotensin converting enzyme inhibitor (POR=0.34, 95% CI 0.22-0.52) than a diuretic. These sex differences persisted after adjustment for all factors that could have influenced the choice of these antihypertensive drugs (indications and contra-indications for the four antihypertensive drug classes). The sex differences in antihypertensive drug use were smaller among hypertensives with a history of cardiovascular disease (adjusted PORs, female/male, for beta-blockers, calcium antagonists and ACE inhibitors, respectively, compared to diuretics were 0.80 with 95% CI 0.20-3.24, 0.40 with 95% CI 0.10-0.48 and 0.64 with 95% CI 0.12-3.39) than among those without such a history. CONCLUSIONS: The different patterns of antihypertensive drug use among hypertensive men and women seem irrational, and cannot be explained by factors known to influence antihypertensive drug choice. Among hypertensives with a history of cardiovascular disease, the sex differences were smaller than among those without such a history. Further research is required to explain the sex differences in the choice of antihypertensive drug by prescribers, and to investigate the consequences of these differences for long-term patient outcomes.     

Interrelationships between and correlates of psychometric and Piagetian scales of sensorimotor iintelligence.

Conducted a study to (a) determine the extent to which psychometric and Piagetian scales correlate during infancy and (b) study the nomological (i.e., correlational) networks of these scales and the degree to which their networks are similar. Correlational analyses on 207 infants (mean age 11 mo) showed that (a) the correlations between psychometric (i.e., Bayley Scales of Infant Development) and Piagetian scales were positive, moderate, and significant and (b) both types of scales yielded virtually identical correlational networks. Motor and physical development and activity level correlated positively and significantly with sensorimotor development, while socioenvironmental variables and measures of interaction with objects accounted for a negligible portion of variance on sensorimotor development. Data indicate that psychometric and Piagetian sensorimotor scales are measures of the same construct. It is pointed out that placing these findings into perspective with the literature on the correlates of intelligence during the later ages provides insight into the failure of infant tests to predict subsequent intellectual functioning. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)