Real-time surface plasmon resonance imaging measurements for the multiplexed determination of protein adsorption/desorption kinetics and surface enzymatic reactions on peptide microarrays

The kinetics of protein adsorption/desorption onto peptide microarrays was studied using real-time surface plasmon resonance (SPR) imaging. S protein binding interactions were examined using an array composed of five different peptides: N terminal and C terminal immobilized wild-type S peptide (S1 and S2), an alternate binding sequence derived by phage display (LB2), an NVOC-protected S peptide, and a FLAG peptide control sequence (F). Kinetic measurements of the S protein-S1 peptide interaction were analyzed to determine a desorption rate constant (k(d)) of 1.1 (+/-0.08) x 10(-2) s(-1), an adsorption rate constant (k(a)) of 1.9 (+/-0.05) x 10(5) M(-1) s(-1), and an equilibrium adsorption constant (K(Ads)) of 1.7 (+/-0.08) x 10(7) M(-1). SPR imaging equilibrium measurements of S protein to S1 peptide were performed to independently confirm the kinetically determined value of K(Ads). Rate constants for the S2 and LB2 peptides on the array were measured as follows: 1.6 (+/-0.04) x 10(5) M(-1) s(-1) (k(a)) and 1.1 (+/-0.07) x 10(-2) s(-1) (k(d)) for S2, 1.2 (+/-0.05) x 10(5) M(-1) s(-1) (k(a)) and 1.1 (+/-0.03) x 10(-2) s(-1) (k(d)) for LB2. In addition to S protein adsorption/desorption, real-time SPR imaging of peptide arrays was applied to study the surface enzymatic activities of the protease factor Xa. Enzymatic cleavage of the substrate peptide (P1) was shown to follow first-order kinetics and proceed at a rate 10 times faster than that of the mutant peptide (P2), with cleavage velocities of 5.6 (+/-0.3) x 10(-4) s(-1) for P1 and 5.7 (+/-0.3) x 10(-5) s(-1) for P2.     

Goal consensus and collaboration.

There are differences in the extent to which patient and therapist agree on psychotherapy goals and work together in the helping relationship. This article reviews the empirical research on the relation between psychotherapy outcome and patient-therapist goal consensus and collaboration. Research results suggest that psychotherapy outcome is enhanced when agreement on therapeutic goals and collaborative involvement (often assessed by patient cooperation, role involvement, and homework compliance) are present during the course of therapy. When therapists and patients demonstrate cooperative and affiliative behavior, and when patients are actively involved in the patient role, better outcomes can be expected. We discuss therapeutic practices based on these findings, emphasizing the involvement of therapist and patient in a process of shared decision-making where goals are frequently discussed and agreed upon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structure-activity relationship study of 16 a-thiocamptothecins: an integrated in vitro and in silico approach

The instability of the hydroxylactone E ring represents a critical drawback of camptothecins, because the lactone ring is recognized to be essential for stabilization of topoisomerase I‐mediated DNA cleavage. In an attempt to investigate the effect of the thiopyridone pharmacophofore on the molecular and pharmacological features of the drug, we prepared a series of novel 16 a‐thiocamptothecin analogues. Due to the sulfur atom, a destabilization of the hydrogen bond between the hydroxy group in position 17 of the opened E ring and the carbonyl of the pyridone moiety is predicted, thus shifting the equilibrium toward the closed lactone form and increasing the lipophilic properties of the compounds. This feature was associated with superior antiproliferative potency, with reduced interaction with the human serum albumin and with substantial increase of the persistence of the topoisomerase I–DNA cleavable complex. These effects were prominent for thio‐SN38, the most active compound of the series. The favorable interactions at the molecular and cellular level of the reported thiocamptothecins confer promising features, and these compounds warrant preclinical development.     

Extended time on academic assignments: Does increased time lead to improved performance for children with attention-deficit/hyperactivity disorder?

Researchers examined the impact of an extended time accommodation on appropriate classroom behavior and rate of work completion for 33 children with attention-deficit/hyperactivity disorder (ADHD). Participants received standard (30 min) or extended (45 min) time to complete seatwork in a within-subject, crossover design study. Appropriate behavior (i.e., rule-following behavior) and rate of problems completed accurately per minute were compared across conditions. Children completed significantly more problems correctly per minute when given standard time compared with extended time; however, no difference in appropriate behavior was found between the two conditions. Appropriate behavior over time was examined by segmenting each condition into time intervals. Analyses indicated that children's appropriate behavior significantly decreased over time in both conditions. The implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cardiovascular concomitants in ultrasound production during cold exposure in infant rats.

Two experiments explored the cardiovascular consequences of extreme cold exposure and their relationship with ultrasound production in infant rats. Experiment 1 addressed the thermoregulatory and cardiovascular concomitants of ultrasound production during cold exposure in rats pretreated with saline or the ganglionic blocker chlorisondamine (5 mg/kg). For both groups, emission of ultrasound was associated with hypothermia and bradycardia. Experiment 2 explored whether the hypothermia experienced by pups in Experiment 1 is associated with increased blood viscosity, which is an important factor affecting venous return to the heart. Blood viscosity increased significantly as temperature decreased from 38°C to 22°C. These experiments suggest that, during extreme cold exposure, decreased cardiac output and increased blood viscosity combine to diminish venous return. The authors have hypothesized that pups respond to decreased return by recruiting the abdominal compression reaction, a physiological maneuver that propels blood back to the heart, resulting in emission of ultrasound as an acoustic by-product. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factors and clusters for the Brazelton Scale: An investigation of the dimensions of neonatal behavior.

B. M. Lester et al (see record 1982-28799-001) proposed a set of 7 a priori clusters (e.g., orientation and Reflexes) for reducing data from the Neonatal Behavioral Assessment Scale. In the present study, the distributional and psychometric properties of these clusters were examined in 162 neonates. The distributions of 5 clusters were reasonably normal, but 2 were significantly positively skewed. The 2 clusters whose items were recoded so that midrange optimal scores would be high and extreme scores low exhibited poor internal consistency. In addition, 3 clusters contained some items that were only weakly related to others in their respective clusters. A revised set of clusters was constructed based on data from 6 independent samples. The revised clusters exhibited greater internal consistency than the Lester clusters, comparable or stronger test–retest reliability, and a greater degree of orthogonality. The 2 sets of clusters performed similarly in 4 tests of concurrent validity that used examiner persistence, general irritability, birthweight, and gestational age as criterion variable. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A transformational analysis of pretending.

Conducted a study with 66 22-27 mo old children, to examine how young children are able to pretend that one thing is another. A preliminary model based on a common pretend activity (toy animal drinks from empty cup) was proposed. It was argued that the relation "animate x acts on inanimate y" requires 2 transformations by the child when the objects (x' and y') are neither animallike nor cuplike, but requires only 1 transformation when one or the other object retains its animallike or cuplike characteristics. The hypothesis that when one thing is substituted for another (x' for x; y' for y) pretending would vary as a function of the number of substitutions was confirmed. Results suggest that in young children pretend transformations require anchor supports from objects in an immediate stimulus field. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Luria-Nebraska Neuropsychological Battery: Theoretical orientation and comment.

Since the introduction of the Luria-Nebraska Neuropsychological Battery (LNNB), issues related to its understanding, interpretation, and validity have generated much interest. In response to P. A. Spiers's (see record 1981-24833-001) criticism of the battery, the authors suggest that the controversy appears to arise from a divergence in theoretical orientation on the role of quantitative versus qualitative assessment as well as from differences in the understanding of measurement methodology and validity. The present article discusses the theoretical basis from which the LNNB was constructed and describes the process of test interpretation. Previous and current research on use and validity of the battery is presented as it relates to the theoretical and methodological concerns. While basic philosophical differences with other theoretical systems are not likely to be resolved, the authors of the LNNB will continue to emphasize the integration of quantitative and qualitative approaches, both in the use of the LNNB and in the field of neuropsychology in general. It is concluded that the LNNB will continue to be revised on the basis of research findings and experience with the test in different patient populations. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal and cross-situational stability of children's social and play behavior.

Assessed the stability of behavior over 8 3-day periods of 34 preschoolers 31–58 mo old, who were observed using the Parten-Smilansky categories. Cross-situational coefficients were significant at the .01 level for all behaviors. Temporal coefficients were also high when sufficiently long time periods were sampled. Results indicate that under some conditions the Parten-Smilansky instrument will satisfy the requirements of classical psychometric theory. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)