We evaluated the effectiveness of daily chlorhexidine gluconate (CHG) bathing in decreasing skin carriage of Klebsiella pneumoniae carbapenemase–producing Enterobacteriaceae (KPC) among long-term acute care hospital patients. CHG bathing reduced KPC skin colonization, particularly when CHG skin concentrations greater than or equal to 128 μg/mL were achieved.

There is increasing recognition that set-shifting, a form of cognitive control, is mediated by different neural structures. However, these regions have not yet been carefully identified as many studies do not account for the influence of component processes (e.g., motor speed). We investigated gray matter correlates of set-shifting while controlling for component processes. Using the Design Fluency (DF), Trail Making Test (TMT), and Color Word Interference (CWI) subtests from the Delis-Kaplan Executive Function System (D-KEFS), we investigated the correlation between set-shifting performance and gray matter volume in 160 subjects with neurodegenerative disease, mild cognitive impairment, and healthy older adults using voxel-based morphometry. All three set-shifting tasks correlated with multiple, widespread gray matter regions. After controlling for the component processes, set-shifting performance correlated with focal regions in prefrontal and posterior parietal cortices. We also identified bilateral prefrontal cortex and the right posterior parietal lobe as common sites for set-shifting across the three tasks. There was a high degree of multicollinearity between the set-shifting conditions and the component processes of TMT and CWI, suggesting DF may better isolate set-shifting regions. Overall, these findings highlight the neuroanatomical correlates of set-shifting and the importance of controlling for component processes when investigating complex cognitive tasks. (JINS, 2010, 16, 640–650.)

Numerous studies have demonstrated explicit and working memory deficits related to posttraumatic stress disorder (PTSD), but few have addressed longitudinal changes in memory functioning. There is some evidence to suggest an interactive effect of PTSD and aging on verbal memory decline in Holocaust survivors (Yehuda et al., 2006). However, the longitudinal trajectory of neuropsychological functioning has not been investigated in Vietnam veterans, a younger but substantial population of aging trauma survivors. We administered tests of visual and verbal memory, and working memory to derive different dependent measures in veterans between the ages of 41 and 63, the majority of whom served in the Vietnam War. Twenty-five veterans with PTSD and 22 veterans without PTSD were assessed over two time points (mean age at follow-up = 54.0; mean inter-test interval = 34 months). The PTSD+ group, consisting of veterans with chronic, primarily combat-related PTSD, did not show a significant change in PTSD symptoms over time. Compared to veterans without PTSD, veterans with PTSD showed a greater decline in delayed facial recognition only, and this decline was extremely subtle. (JINS, 2009, 15, 853–861.)

We used a precision two-circle goniometer mounted to the stage of a compound microscope to determine the optical alignment and to measure the entrance aperture diameter of individual cuticular cones in the dioptric array of the lateral eye of juvenile horseshoe crabs in order to learn about the development of the visual field. Our results show that the extent of the visual field of juvenile horseshoe crabs with prosomal lengths about 20% ofadult size (14–21 mm) is about 70% that of the visual field of adult horseshoe crabs (prosomal lengths: 100+ mm). The visual field of such juvenile animals covers between 77 and 85 deg vertically and 140 and 145 deg horizontally. Assuming that the dioptric array is uniform and square packed, the average interommatidial angle of the juvenile animals is between 5.6 and 6.0 deg as compared to 4.6 deg for an adult animal. The diameter of the entrance aperture of individual cuticular cones increases markedly with increasing animal size. In addition, we noted a statistically significant trend for entrance aperture diameters to increase from anterior to posterior within the eye for animals of all sizes. There may be a slight trend for entrance aperture diameters to increase from dorsal to ventral within the eye. Our results indicate that the extent of the visual field and the resolution of the lateral eye approach adult values in advance of animals' reaching sexual maturity.

Good cognitive performance requires adherence to rules specific to the task at hand. Patients with neurological disease often make rule violation (RV) errors, but the anatomical basis for RV during cognitive testing remains debated. The present study examined the neuroanatomical correlates of RV errors made on tests of executive functioning in 166 subjects diagnosed with neurodegenerative disease or as neurologically healthy. Specifically, RV errors were voxel-wisely correlated with gray matter volume derived from high-definition magnetic resonance images using voxel-based morphometry implemented in SPM2. Latent variable analysis showed that RV errors tapped a unitary construct separate from repetition errors. This analysis was used to generate factor scores to represent what is common among RV errors across tests. The extracted RV factor scores correlated with tissue loss in the lateral middle and inferior frontal gyri and the caudate nucleus bilaterally. When a more stringent control for global cognitive functioning was applied using Mini Mental State Exam scores, only the correlations with the right lateral prefrontal cortex (PFC) remained significant. These data underscore the importance of right lateral PFC in behavioral monitoring and highlight the potential of RV error assessment for identifying patients with damage to this region. (JINS, 2009, 15, 354–364.)

The purpose of this study was to examine the relationships between lobar volumes and set shifting. We studied 101 subjects, including 36 normal controls, 16 patients with probable Alzheimer's disease, 30 patients with frontotemporal dementia (FTD), and 19 patients with semantic dementia (SD), using a shifting paradigm that carefully controlled for component abilities. Subjects were administered two conditions of the Delis–Kaplan Executive Function System (D-KEFS) Design Fluency Test. In the control condition (DF:Control), examinees generated as many unique designs as possible in 60 s by drawing lines connecting only unfilled dots. In the switching condition (DF:Switch), examinees generated designs by drawing lines alternating between filled and unfilled dots. We used BRAINS2 software to generate volumes of the right and left frontal, temporal, and parietal lobes. Partial correlations and multiple regressions showed that, after controlling for Mini-Mental State Examination and DF:Control, only the right and left frontal lobe volumes significantly correlated with the DF:Switch, most clearly in the FTD and SD groups. Follow-up analyses indicated that frontal contributions to shifting were not related to working memory. Results highlight the importance of carefully controlling for component cognitive processes when studying executive functioning. (JINS, 2007, 13, 386–392.)

Higher rates of alcohol use have been reported in HIV+ individuals compared to the general population. Both heavy alcohol use and HIV infection are associated with increased risk of neuropsychological (NP) impairment. We examined effects of heavy active alcohol use and HIV on NP functioning in a large sample of community-residing HIV+ individuals and HIV− controls. The four main study groups included 72 HIV− light/non-drinkers, 70 HIV− heavy drinkers (>100 drinks per month), 70 HIV+ light/non-drinkers, and 56 HIV+ heavy drinkers. The heavy drinking group was further subdivided to assess effects of the heaviest levels of active alcohol use (>6 drinks per day) on NP functioning. A comprehensive NP battery was administered. Multivariate analysis of covariance was employed to examine the effect of HIV and alcohol on NP functioning after adjusting for group differences in age and estimated premorbid verbal intellectual functioning. The analyses identified main effects of heavy drinking and HIV on NP function, with greatest effects involving the contrast of HIV+ heavy drinkers and the HIV− light drinkers. Synergistic effects of heaviest current drinking and HIV infection were identified in analyses of motor and visuomotor speed. Supplementary analyses also revealed better NP function in the HIV+ group with antiretroviral treatment (ART) and lower level of viral burden, a finding that was consistent across levels of alcohol consumption. Finally, heavy alcohol use and executive functioning difficulties were associated with lower levels of self-reported medication adherence in the HIV+ group. The findings suggest that active heavy alcohol use and HIV infection have additive adverse effects on NP function, that they may show synergistic effects in circumstances of very heavy active alcohol use, and that heavy drinking and executive functioning may mediate health-related behaviors in HIV disease. (JINS, 2005, 11, 70–83.)

This study tested the hypothesis that the hippocampus has a relatively specific role in retaining information over delays. Thirty-seven subjects with probable Alzheimer's disease were evaluated with a verbal memory task and structural MRI. Cortical gray matter but not hippocampal volume predicted immediate free recall. In contrast, hippocampal volume was the best predictor of how well information was retained over a delay, even after controlling for levels of immediate recall. Results suggest that the role of the hippocampus is relatively specific to the consolidation of new memories. (JINS, 2004, 10, 639–643.)

HIV infection often results in MRI-detectable brain atrophy and white matter signal hyperintensities (WMSHs). Magnetic resonance images were obtained from 31 HIV+ male patients and 10 high-risk controls. Variation within the HIV+ group on neuropsychological (NP) impairment and stage of systemic disease were relatively independent, allowing examination of the relative association of MRI measures with NP impairment versus with systemic stage of disease. HIV+ patients compared to high-risk controls evidenced global atrophy, reduced caudate nuclei volume, and a trend to gray matter volume loss but no difference in white matter volume or in WMSHs. These effects were progressive with CDC clinical stage such that patients at CDC stage A had values very close to those of controls, while patients at CDC stage C had the most abnormal values. In contrast, the relationship between these MRI variables and severity of NP impairment was much less dramatic, with the mildly to moderately impaired HIV+ subjects showing MRI volume effects greater than or equal to those of the severely impaired HIV+ subjects. These results suggest that MRI-detectable brain atrophy secondary to HIV infection is not the primary substrate underlying the progressive NP impairment in HIV disease. (JINS, 1997, 3, 276–287.)