Minneapolis Veterans Administration Medical Center

Minneapolis, MN, United States

Minneapolis Veterans Administration Medical Center

Minneapolis, MN, United States
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Lam C.H.,University of Minnesota | Lam C.H.,Minneapolis Veterans Administration Medical Center | Hansen E.A.,Minneapolis Veterans Administration Medical Center | Hansen E.A.,Minneapolis Veterans Administration Hospital | And 4 more authors.
Neuroscience | Year: 2012

We used an immortalized arachnoid cell line to test the arachnoid barrier properties and paracellular transport. The permeabilities of urea, mannitol, and inulin through monolayers were 2.9±1.1×10-6, 0.8±.18×10-6, 1.0±.29×10-6cm/s. Size differential permeability testing with dextran clarified the arachnoidal blood-cerebrospinal fluid (CSF) barrier limit and established a rate of transcellular transport to be about two orders of magnitude slower than paracellular transport in a polyester membrane diffusion chamber. The theoretical pore size for paracellular space is 11å and the occupancy to length ratio is 0.8 and 0.72cm-1 for urea and mannitol respectively. The permeability of the monolayer was not significantly different from apical to basal and vice versa. Gap junctions may have a role in contributing to barrier formation. Although the upregulation of claudin by dexamethasone did not significantly alter paracellular transport, increasing intracellular cAMP decreased mannitol permeability. Calcium modulated paracellular transport, but only selectively with the ion chelator, EDTA, and with disruption of intracellular stores. The blood-CSF barrier at the arachnoid is anatomically and physiologically different from the vascular-based blood-brain barrier, but is similarly subject to modulation. We describe the basic paracellular transport characteristics of this CSF "sink" of the brain which will allow for a better description of mass and constitutive balance within the intracranial compartment. © 2012.

Bekwelem W.,University of Minnesota | Connolly S.J.,McMaster University | Adabag S.,Minneapolis Veterans Administration Medical Center | Duval S.,University of Minnesota | And 7 more authors.
Circulation | Year: 2015

Background - Nonvalvular atrial fibrillation is a major cause of thromboembolic events. In comparison with atrial fibrillation-related stroke, extracranial systemic embolic events (SEEs) remain poorly defined. Methods and Results - All suspected SEEs reported among 37 973 participants of 4 large contemporary randomized clinical trials of anticoagulation in atrial fibrillation were independently readjudicated for clinical and objective evidence of sudden loss of perfusion of a limb or organ. Over 91 746 patient-years of follow-up, 221 SEEs occurred in 219 subjects. The SEE incidence was 0.24 of 100 and stroke incidence was 1.92 of 100 patient-years. In comparison with patients with stroke, those with SEE were more often female (56% versus 47%; P=0.01) and had comparable mean age (73.1±8.5 versus 73.5±8.8 years; P=0.57) and mean CHADS2 scores (2.4±1.3 versus 2.5±1.2; P=0.33). SEEs more frequently involved the lower extremity (58%) than visceral-mesenteric (31%) or upper extremity (10%). SEE-related care involved clinic assessment alone in 5%, 30% were hospitalized without procedures, 60% underwent endovascular or surgical intervention, and 5% underwent amputation. Within 30 days, 54% of patients recovered fully, 20% survived with deficits, and 25% died. Thirty-day mortality was greater after visceral-mesenteric than lower- or upper-extremity SEE (55%, 17%, and 9%, respectively, P≤0.0001). The relative risk of death throughout follow-up was 4.33 (95% confidence interval, 3.29-5.70) after SEE versus 6.79 (95% confidence interval, 6.22-7.41) after stroke in comparison with patients without either event. Conclusions - SEE constituted 11.5% of clinically recognized thromboembolic events in patients with atrial fibrillation and was associated with high morbidity and mortality. SEE mortality was comparable to that of ischemic stroke and varied by anatomic site. © 2015 American Heart Association, Inc.

Slager S.L.,Rochester College | Rabe K.G.,Rochester College | Achenbach S.J.,Rochester College | Vachon C.M.,Rochester College | And 20 more authors.
Blood | Year: 2011

Prior genome-wide association (GWA) studies have identified 10 susceptibility loci for risk of chronic lymphocytic leukemia (CLL). To identify additional loci, we performed a GWA study in 407 CLL cases (of which 102 had a family history of CLL) and 296 controls. Moreover, given the strong familial risk of CLL, we further subset our GWA analysis to the CLL cases with a family history of CLL to identify loci specific to these familial CLL cases. Our top hits from these analyses were evaluated in an additional sample of 252 familial CLL cases and 965 controls. Using all available data, we identified and confirmed an independent association of 4 single-nucleotide polymorphisms (SNPs) that met genome-wide statistical significance within the IRF8 (interferon regulatory factor 8) gene (combined P values ≤ 3.37 × 10-8), located in the previously identified 16q24.1 locus. Subsetting to familial CLL cases, we identified and confirmed a new locus on chromosome 6p21.3 (combined P value = 6.92 × 10-9). This novel region harbors the HLA-DQA1 and HLA-DRB5 genes. Finally, we evaluated the 10 previously reported SNPs in the overall sample and replicated 8 of them. Our findings support the hypothesis that familial CLL cases have additional genetic variants not seen in sporadic CLL. Additional loci among familial CLL cases may be identified through larger studies. © 2011 by The American Society of Hematology.

Curtis J.R.,University of Alabama at Birmingham | Delzell E.,University of Alabama at Birmingham | Chen L.,University of Alabama at Birmingham | Black D.,University of California at San Francisco | And 6 more authors.
Journal of Bone and Mineral Research | Year: 2011

Medication compliance may be a surrogate for factors that improve health outcomes such as fractures. Little is known about the size of this potential "healthy adherer" effect. We evaluated the hypothesis that compliance with placebo is associated inversely with bone loss and fractures among women participating in the Fracture Intervention Trial (FIT). Compliance with placebo and alendronate was evaluated using daily medication diaries. Women were defined as having high compliance if they took 80% or more of dispensed study medication. Change in bone mineral density (BMD) was assessed using mixed models comparing women with high versus lower compliance with placebo. Cox proportional-hazards models analyzed the association between placebo compliance and various types of fractures. Among 3169 women randomized to placebo, 82% had high compliance. Compared with women with lower placebo compliance, bone loss at the total hip was lower in compliant placebo-treated women (-0.43%/year versus -0.58%/year, p=.04). Among placebo-treated women, there were 46 hip, 110 wrist, 77 clinical vertebral, and 492 total clinical fractures. Compared with women with lower placebo compliance, women with high placebo compliance had a nonsignificant reduced risk for hip fracture [adjusted hazard ratio (HR)=0.67, 95% confidence interval (CI) 0.30-1.45]. This trend was not observed for other fractures. Medication compliance may be a proxy for factors that confers benefit on reducing hip fracture (but not other types of fractures) independent of the effect of the medication itself. Nonrandomized studies of interventions designed to maintain or improve bone density and/or hip fracture may need to consider medication compliance as a confounder to better estimate true intervention effects. Copyright © 2011 American Society for Bone and Mineral Research.

White T.,University of Minnesota | White T.,Center for Magnetic Resonance Research | White T.,Erasmus University Rotterdam | Magnotta V.A.,University of Iowa | And 19 more authors.
Schizophrenia Bulletin | Year: 2011

Background: Emerging evidence implicates white matter (WM) abnormalities in the pathophysiology of schizophrenia. However, there is considerable heterogeneity in the presentation of WM abnormalities in the existing studies. The object of this study was to evaluate WM integrity in a large sample of patients with first-episode (FE) and chronic schizophrenia in comparison to matched control groups. Our goal was to assess whether WM findings occurred early in the illness or whether these abnormalities developed with the illness over time. Methods: Participants included 114 patients with schizophrenia (31 FE and 83 chronic patients) and 138 matched controls. High-resolution structural and diffusion tensor images were obtained on all participants. Measures of fractional anisotropy (FA) were calculated for the 4 cortical lobes and the cerebellum and brain stem. Results: FA was significant lower in patients vs controls in the whole brain and individually in the frontal, parietal, occipital, and temporal lobes. FA was not significantly different in the brain stem or cerebellum. FA differences were significant only in patients with chronic schizophrenia and not in the FE group. Conclusions: We found global differences in the WM microstructure in patients with chronic but not FE schizophrenia. These findings suggest progressive alterations in WM microstructure. © 2010 The Author.

Forbey J.D.,Ball State University | Ben-Porath Y.S.,Kent State University | Arbisi P.A.,Minneapolis Veterans Administration Medical Center | Arbisi P.A.,University of Minnesota
Psychological Assessment | Year: 2012

The ability to screen quickly and thoroughly for psychological difficulties in existing and returning combat veterans who are seeking treatment for physical ailments would be of significant benefit. In the current study, item and time savings, as well as extratest correlations, associated with an audio-augmented version of the computerized adaptive Minnesota Multiphasic Personality Inventory-2 (MMPI-2-CA) are examined in a group of 273 male veterans, ages 26-87 years. Results indicated an average item savings of approximately 103 items (18.6%), with a corresponding time savings of approximately 12 min (24.3%), for the MMPI-2-CA compared with conventional computerized administration of the test, as well as comparability in terms of test-retest coefficients and correlations with external measures. Future directions of adaptive personality testing are discussed. © 2011 American Psychological Association.

Pierpont G.L.,Minneapolis Veterans Administration Medical Center | Pierpont G.L.,University of Minnesota | Adabag S.,Minneapolis Veterans Administration Medical Center | Adabag S.,University of Minnesota | Yannopoulos D.,Minneapolis Veterans Administration Medical Center
Annals of Noninvasive Electrocardiology | Year: 2013

Expanded use of exercise heart rate recovery (HRR) has renewed interest in the pathophysiology of heart rate control. This study uses basic physiologic principles to construct a unique model capable of describing the full time course of sympathetic and parasympathetic activity during HRR. The model is tested in a new study of 22 diverse subjects undergoing both maximal and submaximal treadmill exercise. Based on this analysis, prolongation of HRR involves changes within the sinus node, changes in sympathetic function, in parasympathetic function, and in the central mechanisms regulating autonomic balance. The methods may provide unique insight into alterations in autonomic control in health and disease. ©2013, Wiley Periodicals, Inc.

Lam C.H.,University of Minnesota | Lam C.H.,Minneapolis Veterans Administration Medical Center | Hansen E.A.,Minneapolis Veterans Administration Medical Center | Hubel A.,University of Minnesota
Tissue Engineering - Part A | Year: 2011

Introduction: The arachnoid tissue is a critical component of cerebrospinal fluid removal. Failure of that function results in hydrocephalus, a serious medical condition. The purpose of this study was to characterize arachnoid cell transport in culture and on three-dimensional collagen scaffold. Methods: Arachnoid cells were harvested from rat brainstems and cultured onto bilayered bovine collagen scaffolds. Cell growth and phenotype (protein expression and morphometry) were determined. Permeability and hydraulic conductivity were quantified. Results: Cells harvested from the anterior brainstem surface exhibited arachnoid cell phenotype (positive for vimentin, desmoplakin, and cytokeratin), readily penetrated the collagen scaffold, and doubled approximately every 2-3 days. The transepithelial electrical resistance value for a monolayer of cells was 160 Ω cm2 and the permeability of indigo carmine was 6.7×10-6±1.1×10-6 cm/s. Hydraulic conductivity of the collagen construct was 6.39 mL/min/mmHg/cm2. Conclusion: Cells isolated from the anterior brain stem exhibited the same phenotype as those found in the native tissue and exhibited aspects of barrier function found in vivo. These studies suggest that an ex vivo model for the arachnoid granulation can be developed. © Copyright 2011, Mary Ann Liebert, Inc.

Chiros C.,Minneapolis Veterans Administration Medical Center | O'Brien W.H.,Bowling Green State University
Journal of Behavioral Medicine | Year: 2011

Acceptance and chronic pain is an emerging topic both for research and intervention. Initial studies have demonstrated that acceptance is correlated with higher quality of daily emotional, social, and physical functioning in chronic pain populations. The purpose of the present study was to clarify the nature of the relationship between acceptance, appraisals that are relevant to chronic pain (i.e., control and catastrophizing), and coping among migraine headache sufferers. Seventy four participants with migraine headaches completed self report measures assessing appraisal, coping strategies, acceptance, and pain related disability. Sixty three participants also completed a 28-day daily dairy assessing headache activity, catastrophizing, control, acceptance, and coping strategies. Hierarchical regression and multilevel modeling were used to examine the relations between these variables. Results indicated that higher levels of pain-related acceptance were associated with lower levels of catastrophizing and pain-related interference, and increased perceived control. Participants who endorsed higher levels of pain-related acceptance also reported engaging in a higher level of activity and indicated they used fewer coping strategies on a daily basis. Acceptance continues to show promise as a way of viewing pain that lessens the detrimental impact of certain types of thoughts (i.e., catastrophizing), and leads to increased participation in daily life. © 2011 Springer Science+Business Media, LLC.

Westermeyer J.,Minneapolis Veterans Administration Medical Center
Torture : quarterly journal on rehabilitation of torture victims and prevention of torture | Year: 2011

First to compare two methods of inquiry regarding torture: i.e., the traditional means of inquiry versus a checklist of torture experiences previously identified for these African refugees. Second, we hoped to identify factors that might influence refugees to not report torture on a single query when checklist data indicated torture events had occurred or to report torture when checklist data indicated that torture had not occurred. Consisted of queries to 1,134 community-dwelling East African refugees (Somalia and Ethiopia) regarding the presence-versus-absence of torture in Africa (single query), a checklist of torture experiences in Africa that we had previously identified as occurring in these groups, demography, non-torture traumatic experiences in Africa, and current posttraumatic symptoms. Showed that 14% of the study participants reported a torture experience on a checklist, but not on a single query. Nine percent responded positively to the single query on torture, but then failed to check any torture experience. Those reporting trauma on an open-ended query, but not on a checklist, had been highly traumatized in other ways (warfare, civil chaos, robbery, assault, rape, trauma during flight out of the country). Those who reported torture on the checklist but not on the single query reported fewer instances of torture, suggesting that perhaps a "threshold" of torture experience influenced the single-query report. In addition, certain types of torture appeared more apt to be associated with a singlequery endorsement of torture. On regression analysis, a single-query self-report of torture was associated with traumatic experiences consistent with torture, older age, female gender, and nontorture trauma in Africa. Inconsistent reporting of torture occurred when two methods of inquiry (one openended and one a checklist) were employed in this sample. We believe that specific contexts of torture and non-torture trauma, together with individual demographic characteristics and severity of the trauma, affect the self-perception of having been tortured. Specific information regarding these contexts, demographic characteristics, and trauma severity are presented in the report.

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