Assessing attention and impulsivity in the variable stimulus duration and variable intertrial interval rodent continuous performance test schedules using dopamine receptor antagonists in female C57BL/6JRj mice.

RATIONALE: Dopaminergic dysfunction is implicated in disorders of impulsivity and inattention. The rodent continuous performance test (rCPT) has been used to quantify changes in attention and impulsivity. OBJECTIVE: To examine the roles of dopamine receptors in attention and impulsivity behaviours measured in the rCPT variable stimulus duration (vSD) and the variable intertrial interval schedules (vITI) using DA receptor antagonists. METHODS: Two cohorts of 35 and 36 female C57BL/6JRj mice were examined separately in the rCPT, vSD, and vITI schedules, respectively. Both cohorts received antagonists of the following receptors: D1/5 (SCH23390, SCH: 0.01, 0.02, 0.04 mg/kg) and D2/3 (raclopride, RAC 0.03, 0.10, 0.30 mg/kg) in consecutive balanced Latin square designs with flanking reference measurements. The antagonists were subsequently examined for effects on locomotor activity. RESULTS: SCH showed similar effects in both schedules, and the effects were reference-dependent in the vITI schedule. SCH reduced responding, but improved response accuracy, impulsivity, discriminability, and locomotor activity. RAC showed mixed effects on responsivity, but improved accuracy and discriminability. The discriminability improvement was driven by an increase in hit rate in the vITI schedule and a reduction in false alarm rate in the vSD schedule. RAC also decreased locomotor activity. CONCLUSION: Both D1/5 and D2/3 receptor antagonism reduced responding, but the outcome on discriminability differed, stemming from individual effects on hit and false alarm rate, and the weight of omissions within the calculation. The effects of SCH and RAC suggest that endogenous DA increases responding and impulsivity, but reduces accuracy and shows mixed effects on discriminability.

Assessing attention and impulsivity in the variable stimulus duration and variable intertrial interval rodent continuous performance test schedules using noradrenaline receptor antagonists in female C57BL/6JRj mice.

RATIONALE: Noradrenergic dysfunction is associated with disorders of impulsivity and inattention. The rodent continuous performance test (rCPT) quantifies changes in attention and impulsivity. OBJECTIVE: To use NA receptor antagonists to examine the roles of NA on attention and impulsivity behaviours measured in the rCPT variable stimulus duration (vSD) and the variable intertrial interval (vITI) schedules. METHODS: Two cohorts of 36 female C57BL/6JRj mice were examined separately in the rCPT vSD and vITI schedules. Both cohorts received antagonists of the following adrenoceptors: α1 (doxazosin, DOX: 1.0, 3.0, 10.0 mg/kg), α2 (yohimbine, YOH: 0.1, 0.3, 1.0 mg/kg), and ß1/2 (propranolol, PRO: 1.0, 3.0, 10.0 mg/kg) in consecutive balanced Latin square designs with flanking reference measurements. The antagonists were subsequently examined for effects on locomotor activity. RESULTS: DOX showed similar effects in both schedules, improving discriminability and accuracy, and reducing responding and impulsivity, and DOX also reduced locomotor activity. YOH showed prominent effects in the vSD schedule to increase responding and impulsivity, while impairing discriminability and accuracy. YOH did not affect locomotor activity. PRO increased responding and impulsivity, decreased accuracy, but did not affect discriminability or locomotor activity. CONCLUSION: Antagonism of α2 or ß1/2 adrenoceptors caused similar increases in responding and impulsivity and worsened attentional performance, while α1 adrenoceptor antagonism showed the opposite effects. Our results suggest that endogenous NA exerts bidirectional control of most behaviours in the rCPT. The parallel vSD and vITI studies showed a substantial overlap in effects, but also some differences that indicate differing sensitivity towards noradrenergic manipulations.

Assessing the nature of premature responses in the rodent continuous performance test variable intertrial interval schedule using atomoxetine and amphetamine.

BACKGROUND: Rodent operant tests that include premature responses (PR) as a measure of impulsivity commonly use variable intertrial interval (vITI) schedules. The rodent continuous performance test (rCPT) is suitable for a vITI schedule. NEW METHOD: We optimised the analysis for a rCPT vITI schedule with intertrial intervals (ITIs) of 3, 6, and 12 s. Examining the nature of first (FiT) and following touches (FoT) to the blank screen led to a separate quantification of these two behaviours into the first touches level (%FiT) and the following-to-first touches ratio (FoT/FiT). RESULTS: FiTs occurred more frequently in the 12 s ITIs than at shorter ITIs. Within 12 s ITIs, %FiT was only moderately higher during the last half than the first half, suggesting that long ITIs have a minimal effect on impulsivity, but allow a longer time for its detection. %FiT and the FoT/FiT ratio were uncorrelated. %FiT was negatively correlated with response criterion (C) and uncorrelated with discriminability. Conversely, FoT/FiT ratio was negatively correlated with discriminability, without correlation to C. Atomoxetine decreased %FiT but did not affect FoT/FiT ratio. Amphetamine increased %FiT and decreased the FoT/FiT ratio. COMPARISON WITH EXISTING METHOD(S): The results suggest that %FiT is analogous to %PR in related tasks and is a more suitable measure of waiting impulsivity in the rCPT. FoT/FiT ratio is unrelated to %FiT. CONCLUSIONS: Long ITIs increase the detectability of, but has minimal effect on, waiting impulsivity. %FiT is analogous to %PR in related tasks, while the FoT/FiT ratio is a separate behaviour requiring further characterization.

Gabor patterns as stimuli in a rodent visual attention task.

BACKGROUND: Gabor patterns are defined as the product of a sinusoid function and a Gaussian envelope and are commonly used in visual and attentional research due to their ability to selectively stimulate the primary visual cortex. The aim of this study was to investigate whether Gabor patterns can be used as visual stimuli in the rodent continuous performance test (rCPT), a newly developed task to study attentional function and impulsivity. METHODS: Sixteen male C57BL/6 J mice were trained in the rCPT using Gabor patterns as visual stimuli and their performance was compared to sixteen mice that were trained using traditional high-contrast pattern stimuli. Mice were compared during training, baseline, and a variable stimulus duration probe. RESULTS: The Gabor pattern group required more training sessions to reach criteria than the group with high-contrast patterns. At baseline, the Gabor pattern group showed a higher false alarm rate and a lower discriminability index. As task difficulty increased during the variable stimulus duration probe, differences between groups became more pronounced. Specifically, the Gabor pattern group showed decreased hit rate and discriminability index, as well as increased false alarm rate and premature responses compared to the high-contrast pattern group. CONCLUSION: This feasibility study showed that it is possible to use Gabor patterns as visual stimuli in the rCPT, although it increases task demands. We discuss the differences between Gabor patterns and high-contrast patterns in the context of translatability of animal models in visual and cognitive research and give two examples of applicability.

Age differences in health effects of stressors and perceived control among urban African American women.

A conceptual model of the stress process has been useful in examining relationships among a variety of stressors, health status, and protective factors that modify the health-stress relationship. The model can contribute to an understanding of variations in health among people living in urban environments experiencing high degrees of stress. This study examines social contextual stressors in the neighborhood, health outcomes, and perceived control at multiple levels beyond the individual as a protective factor, among a random sample (N = 679) of predominantly low-income African American women who reside on Detroit's east side. Findings suggest that although stress has a consistently negative impact on health, perceived control may buffer against the deleterious effects of stress. The buffering role of perceived control, however, depends on age, the type of stressor examined, and the context or level at which perceived control is assessed (e.g., organizational, neighborhood, beyond the neighborhood). For young women, perceived control was found to be health protective. Among older women, perceived control in the face of stressors was inversely related to health. These findings suggest the need for health and social service programs and policy change strategies to both increase the actual influence and control of women living in low-income urban communities and to reduce the specific social contextual stressors they experience.

Effect of adults' self-regulation of diabetes on quality-of-life outcomes.

OBJECTIVE: To examine the relationships among cognitive representations of diabetes, diabetes-specific health behaviors, and quality of life using Leventhal and Diefenbach's self-regulation model of illness (Leventhal H, Diefenbach M: The active side of illness cognition. In Mental Representation in Health and Illness. SkeltonJA, Croyle RT, Eds. New York, Springer-Verlag, 1991, p. 247-272). RESEARCH DESIGN AND METHODS: This research involved secondary analysis of a mailed survey completed by 296 adults (ages 20-90 years). Structural equation modeling was conducted to investigate relationships among cognitive representations, diabetes-specific health behaviors, and quality of life. Model differences by diabetes type were also investigated. RESULTS: Findings indicated that certain cognitive representation constructs were related to increased diabetes-specific health behaviors, decreased sense of burden, and positive quality-of-life outcomes. Individuals levels of understanding of diabetes and their perceptions of control over diabetes were the most significant predictors of outcomes. However, diabetes-specific health behaviors were related to an increased sense of burden that was negatively associated with quality of life. Multigroup analyses indicated that this self-regulatory model provided a good fit for individuals with type 1 diabetes, those with type 2 diabetes who take insulin, and those with type 2 diabetes who do not take insulin. CONCLUSIONS: These findings advance what is known about cognitive representations of illness and the self-regulation of diabetes as well as the relationships between cognitive representations of illness, quality of life, and behavioral factors. In particular, results from this study suggest the need for further study to address ways of reducing the burden of diabetes associated with health behaviors and decreased quality of life.

Factor replication of the Reduced Laffrey Health Conception Scale.

This study replicated the factor model for the Reduced Laffrey Health Conception Scale (RLHCS), which was originally developed by Laffrey (1986) and reduced by Lusk, Kerr, and Baer (1995). Two independent samples of construction workers (n = 697 and n = 510) were used. The samples were predominately Caucasian males (over 97%), with mean ages of 35 and 38 years, respectively. Principal components factor analysis with direct oblimin rotation and structural equation modeling were used to replicate factors and to test the equality of the three observed covariance matrices (factory workers and two groups of construction workers), respectively. Results replicated the two-factor structure (clinical health and overall wellness) found in the earlier study with factory workers (Lusk et al., 1995) and demonstrated factor invariance across different samples.

Strict adherence to a common rank order of T-cell receptor V beta usage in human leucocyte antigen disparate individuals.

In order to investigate the T-cell receptor (TCR) V beta usage in different T-cell subsets, the authors performed flow cytometric analyses using a large panel of TCR V beta-specific monoclonal antibodies on CD4+, CD8+ CD28+ and CD8+ CD28- T cells from 15 random blood donors, six umbilical cords and seven human leucocyte antigen (HLA) identical non-twin sibling pairs. The authors found that the proportion of T cells expressing each V beta gene product was similar within CD4+ and CD8+ CD28+ T cells from all samples studied. For these T-cell subsets a rank order of V beta usage could be identified which was adhered to by all donors. In contrast, within CD8+ CD28- T cells a wide variation of V beta usage was found between individuals, and no rank order correlation could be detected. Members of HLA identical sibling pairs were found to be no more similar in their usage of V beta gene products than pairs of HLA disparate random blood donors. Groups of individuals sharing HLA antigens were no different from the groups not sharing such antigens in their usage of V beta segments. The results suggest that HLA polymorphisms play no more than a minor part in determining TCR V beta usage.

Preparing for the JCAHO survey.

In summary, the future success of a health care organization's ability to meet changing JCAHO standards will be dependent on the integration of information throughout the organization. The growing demand for reliable and accessible data for all levels of staff has become a daily need in health care. One of the key questions that will be posed by future JCAHO surveyors will center on current abilities to integrate and send information from a variety of sources to those who need the data within the organization. Many organizations are planning and implementing strategic plans to create linkages between existing information systems and further the overall systems knowledge of all staff.

Two stages of care for pleural effusion.

When the patient's pleural space is filled with fluid, palliative treatment measures--thoracic drainage and pleurodesis--and diligent nursing care can help her breathe easier.