bluuebunny/crossref_metadata_2025 huggingface dataset:
Sympathetic vasomotor control does not explain the change in femoral artery shear rate pattern during arm-crank exercise
Authors: Thijssen Dick H. J. , Green Daniel J. , Steendijk Sjoerd , Hopman Maria T. E.
Published: November 2008

During lower limb exercise, blood flow through the resting upper limbs exhibits a change characterized by increased anterograde flow during systole, but also large increases in retrograde diastolic flow. One explanation for the retrograde flow is that increased sympathetic nervous system (SNS) tone and concomitant increased peripheral resistance generate a rebound during diastole. To examine whether the SNS contributes to retrograde flow patterns, we measured femoral artery blood flow during arm-crank exercise in 10 healthy men (31 ± 4 yr) and 10 spinal cord-injured (SCI) subjects who lack sympathetic innervation in the legs (33 ± 5 yr). Before, and every 5 min during 25-min arm-crank exercise at 50% maximal capacity, femoral artery blood flow and peak anterograde and retrograde shear rate were assessed using echo Doppler sonography. Femoral artery baseline blood flow was significantly lower in SCI compared with controls. Exercise increased femoral artery blood flow in both groups (ANOVA, P < 0.05), whereas leg vascular conductance did not change during exercise in either group. Mean shear rate was lower in SCI than in controls ( P < 0.05). Peak anterograde shear rate was higher in SCI than in controls ( P < 0.05), whereas peak retrograde shear rate did not differ between groups. Arm-crank exercise induced an increase in peak anterograde and retrograde shear rate in the femoral artery in controls and SCI subjects ( P < 0.05). This suggests that the SNS is not obligatory to change the flow pattern in inactive regions during exercise. Local mechanisms may play a role in the arm-crank exercise-induced changes in flow pattern in the femoral artery.
Myogenic constriction and dilation of isolated lymphatic vessels
Authors: Davis Michael J. , Davis Ann M. , Ku Christine W. , Gashev Anatoliy A.
Published: November 2008

We tested the hypothesis that lymphatics would exhibit myogenic constrictions and dilations to intraluminal pressure changes. Collecting lymphatic vessels were isolated from rat mesentery, cannulated, and pressurized for in vitro study. The lymphatic diameter responses to controlled intraluminal pressure steps of different magnitudes were tested in the absence and presence of the inflammatory mediator substance P, which is known to enhance lymphatic contractility. Myogenic constriction, defined as a time-dependent decrease in end-diastolic diameter over a 1- to 2-min period following pressure elevation (after initial distension), was observed in the majority of rat mesenteric lymphatic vessels in vitro and occurred over a relatively wide pressure range (1–15 cmH2O). Myogenic dilation, a time-dependent rise in end-diastolic diameter following pressure reduction, was observed in over half the vessels equilibrated at a low baseline pressure. Myogenic constrictions were independent of the cardiac-like and time-dependent compensatory decline in end-systolic diameter and increase in amplitude observed in almost all vessels following pressure elevation. Substance P increased the percentage of vessels exhibiting myogenic constriction, the magnitude and rate of constriction, and the pressure range over which constriction occurred. Our results demonstrate that myogenic responses occur in collecting lymphatic vessels and suggest that the response may aid in preventing vessel overdistension during inflammation/edema.
ProteinO-GlcNAcylation: a new signaling paradigm for the cardiovascular system
Authors: Laczy Boglarka , Hill Bradford G. , Wang Kai , Paterson Andrew J. , White C. Roger , Xing Dongqi , Chen Yiu-Fai , Darley-Usmar Victor , Oparil Suzanne , Chatham John C.
Published: November 2008

The posttranslational modification of serine and threonine residues of nuclear and cytoplasmic proteins by the O-linked attachment of the monosaccharide β- N-acetylglucosamine ( O-GlcNAc) is a highly dynamic and ubiquitous protein modification. Protein O-GlcNAcylation is rapidly emerging as a key regulator of critical biological processes including nuclear transport, translation and transcription, signal transduction, cytoskeletal reorganization, proteasomal degradation, and apoptosis. Increased levels of O-GlcNAc have been implicated as a pathogenic contributor to glucose toxicity and insulin resistance, which are both major hallmarks of diabetes mellitus and diabetes-related cardiovascular complications. Conversely, there is a growing body of data demonstrating that the acute activation of O-GlcNAc levels is an endogenous stress response designed to enhance cell survival. Reports on the effect of altered O-GlcNAc levels on the heart and cardiovascular system have been growing rapidly over the past few years and have implicated a role for O-GlcNAc in contributing to the adverse effects of diabetes on cardiovascular function as well as mediating the response to ischemic injury. Here, we summarize our present understanding of protein O-GlcNAcylation and its effect on the regulation of cardiovascular function. We examine the pathways regulating protein O-GlcNAcylation and discuss, in more detail, our understanding of the role of O-GlcNAc in both mediating the adverse effects of diabetes as well as its role in mediating cellular protective mechanisms in the cardiovascular system. In addition, we also explore the parallels between O-GlcNAc signaling and redox signaling, as an alternative paradigm for understanding the role of O-GlcNAcylation in regulating cell function.
PI3Kγ-deficient mice have reduced levels of allergen-induced eosinophilic inflammation and airway remodeling
Authors: Lim Dae Hyun , Cho Jae Youn , Song Dae Jin , Lee Sang Yeub , Miller Marina , Broide David H.
Published: November 2008

In this study, we have examined the role of phosphoinositide 3 kinase γ (PI3Kγ), a class Ib PI3K, in contributing to airway remodeling utilizing PI3Kγ-deficient mice exposed to chronic allergen challenge. Wild-type (WT) mice sensitized to ovalbumin (OVA) and chronically challenged with OVA for 1 mo developed significantly increased levels of eosinophilic inflammation and airway remodeling. In contrast, PI3Kγ-deficient mice challenged with OVA had significantly reduced numbers of bronchoalveolar lavage and peribronchial eosinophils compared with WT mice. There was no significant difference in the number of bone marrow or circulating peripheral blood eosinophils when comparing WT mice and PI3Kγ-deficient mice, suggesting that trafficking of eosinophils into the lung was reduced in PI3Kγ-deficient mice. PI3Kγ-deficient and WT mice had similar levels of IL-5 and eotaxin-1. The reduced eosinophil recruitment to the airway in PI3Kγ-deficient mice challenged with OVA was associated with significantly reduced numbers of TGF-β1+ peribronchial cells, reduced numbers of pSmad 2/3+ airway epithelial cells, and pSmad 2/3+ peribronchial cells, as well as significantly reduced levels of peribronchial fibrosis (quantitated by trichrome staining and image analysis as well as by lung collagen levels). In addition, the area of peribronchial α-smooth muscle staining was significantly reduced in PI3Kγ-deficient compared with WT mice. Overall, this study demonstrates an important role for PI3Kγ in mediating allergen-induced eosinophilic airway inflammation and airway remodeling, suggesting that PI3Kγ may be a novel therapeutic target in asthma.
New asthma biomarkers: lessons from murine models of acute and chronic asthma
Authors: Di Valentin Emmanuel , Crahay Céline , Garbacki Nancy , Hennuy Benoit , Guéders Maud , Noël Agnès , Foidart Jean-Michel , Grooten Johan , Colige Alain , Piette Jacques , Cataldo Didier
Published: November 2008

Many patients suffering from asthma are not fully controlled by currently available treatments, and some of them display an airway remodeling leading to exaggerated lung function decline. The aim of the present study was to unveil new mediators in asthma to better understand pathophysiology and propose or validate new potential therapeutic targets. A mouse model of asthma mimicking acute or chronic asthma disease was used to select genes undergoing a modulation in both acute and chronic conditions. Mice were exposed to ovalbumin or PBS for 1, 5, and 10 wk [short-, intermediate-, and long-term model (ST, IT, and LT)], and gene expression in the lung was studied using an Affymetrix 430 2.0 genome-wide microarray and further confirmed by RT-PCR and immunohistochemistry for selected targets. We report that 598, 1,406, and 117 genes were upregulated and 490, 153, 321 downregulated at ST, IT, and LT, respectively. Genes related to mucous secretion displayed a progressively amplified expression during the allergen exposure protocol, whereas genes corresponding to growth and differentiation factors, matrix metalloproteinases, and collagens were mainly upregulated at IT. By contrast, genes related to cell division were upregulated at ST and IT and were downregulated at LT. In this study, besides confirming that Arg1, Slc26a4, Ear11, and Mmp12 genes are highly modulated throughout the asthma pathology, we show for the first time that Agr2, Scin, and Cd209e genes are overexpressed throughout the allergen exposure and might therefore be considered as suitable new potential targets for the treatment of asthma.
Depletion of phagocytes in the reticuloendothelial system causes increased inflammation and mortality in rabbits withPseudomonas aeruginosapneumonia
Authors: Kurahashi Kiyoyasu , Sawa Teiji , Ota Maria , Kajikawa Osamu , Hong Keelung , Martin Thomas R. , Wiener-Kronish Jeanine P.
Published: November 2008

Phagocytes of the reticuloendothelial system are important in clearing systemic infection; however, the role of the reticuloendothelial system in the response to localized infection is not well-documented. The major goals of this study were to investigate the roles of phagocytes in the reticuloendothelial system in terms of bacterial clearance and inflammatory modulation in sepsis caused by Pseudomonas pneumonia. Macrophages in liver and spleen were depleted by administering liposome encapsulated dichloromethylene diphosphonate (clodronate) intravenously 36 h before the instillation of Pseudomonas aeruginosa into the lungs of anesthetized rabbits. Blood samples were analyzed for bacteria and cytokine concentrations. Lung injury was assessed by the bidirectional flux of albumin and by wet-to-dry weight ratios. Blood pressure and cardiac outputs decreased more rapidly and bacteremia occurred earlier in the clodronate-treated rabbits compared with the nondepleted rabbits. Plasma TNF-α (1.08 ± 0.54 vs. 0.08 ± 0.02 ng/ml) and IL-8 (6.8 ± 1.5 vs. 0.0 ± 0.0 ng/ml) were higher in the depleted rabbits. The concentration of IL-10 in liver of the macrophage-depleted rabbits was significantly lower than in normal rabbits at 5 h. Treatment of macrophage-depleted rabbits with intravenous IL-10 reduced plasma proinflammatory cytokine concentrations and reduced the decline in blood pressure and cardiac output. These results show that macrophages in the reticuloendothelial system have critical roles in controlling systemic bacteremia and reducing systemic inflammation, thereby limiting the systemic effects of a severe pulmonary bacterial infection.
Type 5 phosphodiesterase expression is a critical determinant of the endothelial cell angiogenic phenotype
Authors: Zhu Bing , Zhang Li , Alexeyev Mikhail , Alvarez Diego F. , Strada Samuel J. , Stevens Troy
Published: November 2008

Type 5 phosphodiesterase (PDE5) inhibitors increase endothelial cell cGMP and promote angiogenesis. However, not all endothelial cell phenotypes express PDE5. Indeed, whereas conduit endothelial cells express PDE5, microvascular endothelial cells do not express this enzyme, and they are rapidly angiogenic. These findings bring into question whether PDE5 activity is a critical determinant of the endothelial cell angiogenic potential. To address this question, human full-length PDE5A1 was stably expressed in pulmonary microvascular endothelial cells. hPDE5A1 expression reduced the basal and atrial natriuretic peptide (ANP)-stimulated cGMP concentrations in these cells. hPDE5A1-expressing cells displayed attenuated network formation on Matrigel in vitro and also produced fewer blood vessels in Matrigel plug assays in vivo; the inhibitory actions of hPDE5A1 were reversed using sildenafil. To examine whether endogenous PDE5 activity suppresses endothelial cell angiogenic potential, small interfering RNA (siRNA) constructs were stably expressed in pulmonary artery endothelial cells. siRNA selectively decreased PDE5 expression and increased basal and ANP-stimulated cGMP concentrations in these conduit cells. PDE5 downregulation increased network formation on Matrigel in vitro and increased blood vessel formation in Matrigel plug assays in vivo. Collectively, our results indicate that PDE5 activity is an essential determinant of angiogenesis and suggest that PDE5 downregulation in microvascular endothelium imparts a stable, enhanced angiogenic potential to this cell type.
Low-dose Fixed Combination of Bisoprolol/Hydrochlorothiazide as First Line for Hypertension: A Review of the Rationale and Clinical Evidence
Authors: Papadopoulos Dimitris P. , Papademetriou Vassilios
Published: November 2008

Essential hypertension is a heterogeneous multifactorial disease. Data from the National Health and Nutritional Examination Survey and from the World Health Organization have clearly demonstrated that, worldwide, less than 30% of hypertensive patients are adequately controlled by our currently accepted blood pressure goals. Although monotherapy is often unable to achieve blood pressure goals, the use of fixed low-dose combination drugs as alternative treatment seems to be related to a better antihypertensive efficacy and higher response rates in the low range of doses as the result of complementary mechanisms of antihypertensive effects. Indeed clinical trials have shown that initial low-dose combination therapy is superior as compared with treatment by the stepped-care and the sequential monotherapy approach, while recently, low-dose combination therapy for initial antihypertensive therapy instead of the stepped-care approach or of sequential monotherapy has been recommended. This review summarizes the beneficial effect of low-dose bisoprolol/hydrochlorothiazide combination in the treatment of patients with stage I and II hypertension.
Dealing With Disadvantage
Authors: Bottrell Dorothy
Published: November 2008

This article analyzes how peer and extended networks provide young people with support and resources for dealing with disadvantage. Centering girls' accounts of growing up in the Glebe public housing estate, the difficulties they face, their critiques and aspirations are interpreted as resilience, supported by the social capital of their networks. However, the girls' accounts also explicate youth resistances to school and inevitable trouble through participation in the broader local youth network, raising questions for conceptualizations of social capital. Conflicting orientations of the networks are analyzed in terms of bonding and bridging forms of social capital. However, in specific contexts of school and community, the interrelations of social and cultural capital suggest the significance of recognition as a mechanism for differentiation of young people and for effecting marginalization and privilege.
When a Parent Goes Off to War
Authors: Mmari Kristin , Roche Kathleen M. , Sudhinaraset May , Blum Robert
Published: November 2008

The objectives of this study were (1) to explore the consequences of parental deployment for adolescents and their families and (2) to identify potential strategies that may help adolescents cope with a parent's deployment. Eleven focus groups were conducted among adolescents in military families, military parents, and school personnel in military-impacted schools at five military bases. Findings reveal that one of the most prominent sources of stress for families is adjusting and readjusting to new roles and responsibilities. Notably, this stress was primarily felt after the deployed parent returned. School personnel also commented that many teachers and counselors are not prepared to deal with deployment issues among the military students. These findings suggest that parents need to be better prepared to handle the stresses after a deployed parent returns. School personnel also need special training, and military-impacted schools need to offer additional opportunities for students to discuss deployment issues.
Racial/Ethnic Differences in Weight Perceptions and Weight Control Behaviors Among Adolescent Females
Authors: Haff Darlene R.
Published: November 2008

Using data from the 2001 Youth Risk Behavior Surveillance Survey, this study examined select sociodemographic and psychosocial correlates of weight perceptions and weight control behaviors among Black, Hispanic and White females (n = 6,089). Results showed little difference across ethnic groups for perceptions of body weight with slightly over 50%, 30% and 12% describing their weight as about right, overweight, or underweight, respectively. There was striking discordance between weight perception and reported weight gain or loss among White girls. Regression analysis showed indicators of depression and feeling unsafe predictive of weight loss behaviors across all groups while GPA and forced sex were significant for Whites and Hispanics. Television watching and physical exertion were not significant. Findings suggest prevention of depression and victimization as the principal means of reducing maladaptive weight control behaviors across all ethnic groups and surveillance for inappropriate weight loss behaviors among White and Hispanic girls with higher GPA’s
Energy Absorption Is Reduced With Oleic Acid Supplements in Human Short Bowel Syndrome
Authors: Compher Charlene W. , Kinosian Bruce P. , Rubesin Stephen E. , Ratcliffe Sarah J. , Metz David C.
Published: November 2008

Background: Oleic acid premeal supplements have been described as a method to trigger the ileal brake and thus lengthen transit time and the opportunity for nutrient absorption. The aims of this study were to determine whether oleic acid supplements would lengthen transit time and improve absorption of nutrients in study participants with short bowel syndrome as well as affect diarrhea or patient weight.Methods: A double‐blind, controlled, random‐order crossover trial was conducted in 8 study participants with longstanding and severe short bowel syndrome, employing blue food color appearance, breath hydrogen testing, and radio‐opaque markers as measures of transit time. Absorption of energy, protein, fat, and fluid was conducted by classic nutrient balance methods. Diarrhea was estimated by daily stool weight and number of bowel actions. Although 8 patients were enrolled, only 7 completed the study.Results: Transit time was not significantly different between oleic acid and placebo treatment, although peptide YY levels trended higher with the oleic acid treatment. Energy absorption was reduced 14% by oleic acid, significantly more than the 3% reduction by placebo. Fat, protein, and fluid absorption was not changed significantly. Neither diarrhea nor patient body weight was changed by oleic acid. Conclusions: Energy absorption is reduced by oleic acid supplements in severe short bowel syndrome. The study may have lacked power to determine whether oleic acid affects diarrhea or body weight.
Valuing and representing information: the paradox of undervaluing information and overvaluing information producers
Authors: Sakalaki Maria , Kazi Smaragda
Published: November 2008

Information's increasing importance in contemporary societies raises questions concerning laymen's valuation of information and of professionals producing information. The main hypotheses were: (a) potential sellers will underestimate information's value compared to that of material goods; (b) when potential buyers' involvement is high (that is high investment and high risk), sellers will demand even lower prices for information; (c) some important current functions and meanings of information are not assimilated in social representations of information; (d) by contrast, participants must overvalue the remuneration of professionals producing pure information (invention) compared to those who apply this information to produce material goods. An experimental study confirmed hypotheses (a) and (b). A second study to investigate the structure of information's social representations showed that the representation's central core is mainly composed of categories referring to traditional media, functions and technologies; contemporary functions and technologies are less frequent or absent. A third experimental study confirmed hypothesis (d).
Understanding the determinants of EKR usage from social, technological and personal perspectives
Authors: Lin Tung-Ching , Huang Chien-Chih
Published: November 2008

With the capacity to provide the necessary infrastructure to implement knowledge management processes, electronic knowledge repositories (EKRs) have gradually evolved into a backbone for many organizations, and have become a topic of much concern in recent MIS studies. Among the diverse theories commonly employed to target the issue are social capital theory, social cognitive theory, and task technology fit (TTF). Social capital theory primarily addresses issues of what components constitute a social network and how they influence an individual's behavior, necessitating the introduction of social cognitive theory as the foundation for the interpretation of personal cognition. Task technology fit theory, which highlights the fit between the technological characteristics and the user's task character, is also a key factor in determining the EKR usage. This paper integrates these three theories to investigate and compare the main influences on EKR usage from personal, social and technological perspectives. Through a sampling survey of 194 EKR users, EKR self-efficacy, trust, and task technology fit are found to have substantial influences on the EKR usage. Among these three main factors, EKR self-efficacy plays the most important role in determining EKR usage.
The dark side of information: overload, anxiety and other paradoxes and pathologies
Authors: Bawden David , Robinson Lyn
Published: November 2008

This review article identifies and discusses some of main issues and potential problems — paradoxes and pathologies — around the communication of recorded information, and points to some possible solutions. The article considers the changing contexts of information communication, with some caveats about the identification of `pathologies of information', and analyses the changes over time in the way in which issues of the quantity and quality of information available have been regarded. Two main classes of problems and issues are discussed. The first comprises issues relating to the quantity and diversity of information available: information overload, information anxiety, etc. The second comprises issues relating to the changing information environment with the advent of Web 2.0: loss of identity and authority, emphasis on micro-chunking and shallow novelty, and the impermanence of information. A final section proposes some means of solution of problems and of improvements to the situation.
Normalisation of immune cell imbalance after pharmacological treatments of patients suffering from obsessive-compulsive disorder
Authors: Marazziti D , Mungai F , Masala I , Baroni S , Vivarelli L , Ambrogi F , Catena Dell’Osso M , Consoli G , Massimetti G , Dell’Osso L
Published: November 2008

Abstract

Recent data have shown the presence of immunological alterations in adult patients suffering from obsessive-compulsive disorder (OCD). The objective of this study was to examine the possible effects of 12 months of treatment with different serotonergic drugs, such as clomipramine and selective serotonin reuptake inhibitors (SSRIs) on peripheral immunological cells of 18 OCD patients. Both the absolute number and percent of CD4+, CD8+, CD3+, CD19+ and CD56+ cells were measured in peripheral blood before and after treatment by means of a Facstar Flow Sorter apparatus. At baseline, all patients showed a significant increase of CD8+ and decrease of CD4+ lymphocytes when compared with a similar group of healthy control subjects; after the treatment, CD8+ and CD4+ cells, respectively, decreased and increased significantly, and the CD4+/CD8+ ratio increased, when compared with baseline values, in parallel with the clinical improvement. These data suggest that the alterations of immune cells reported in patients with OCD at baseline may be reverted by treatment with SRIs and should be considered a state-dependent marker, perhaps related to a condition of stress.
Sex-related differential response to clomipramine treatment in a rat model of depression
Authors: Kokras N. , Antoniou K. , Dalla C. , Bekris S. , Xagoraris M. , Ovestreet DH , Papadopoulou-Daifoti Z.
Published: November 2008

Research in affective disorders is often performed without considering sex differences, although women are predominantly affected. Consequently, the potential sex-dependent action of antidepressants remains elusive. We investigated whether Flinders sensitive line (FSL) of rats, a model of depression, would present sex-differentiated responses to antidepressant treatment. FSL and Sprague—Dawley rats were treated with clomipramine 10 mg/kg/day for 14 days. Subsequently, they were subjected to either a single session of the forced swim test or an estimation of serotonergic function in the prefrontal cortex, hippocampus, amygdala and hypothalamus. Male FSL displayed increased immobility duration, decreased active behaviours, increased serotonin tissue levels and a reduced serotonin turnover rate in most brain areas studied. Female FSL showed a distinct profile, consisting of decreased immobility latency, increased climbing duration, limited serotonergic deviations and no difference in the serotonin turnover rate in comparison with controls. Interestingly, despite baseline differences, clomipramine treatment reversed all relevant behavioural responses and increased the serotonin turnover rate in both sexes. However, the latter effect was remarkably more pronounced in females. It is concluded that, in this animal model of depression, chronic clomipramine treatment attenuated baseline sex differences in the phenotype while maintaining or intensifying the sex differentiation in the serotonergic endophenotype.
Moderate alcohol disrupts a mechanism for detection of rare events in human visual cortex
Authors: Kenemans JL , Hebly W. , van den Heuvel Ehm , Grent-'T-Jong T.
Published: November 2008

Moderate doses of alcohol (blood alcohol concentration [BAC] of about 0.05%) may result in acute impairments at various levels of information processing. A number of reports have documented detrimental effects of moderate alcohol on the mismatch negativity (MMN), the electrocortical manifestation of a rapid (100 ms poststimulus) mechanism dedicated to the detection of unexpected auditory change (e.g., Jääskeläinen, et al., 1995). Recently, we and others identified a partial visual counterpart of the MMN, sometimes called the rareness-related negativitity (RRN). Analogous to the MMN, the RRN evolves at about 100 ms after the unexpected change and was localized in visual cortex (Kenemans, et al., 2003). Rapid detection of unexpected events is important for everyday-life conditions like driving, prompting the question whether the visual RRN shows sensitivity to moderate alcohol similar to the MMN. In all, 16 subjects were tested either under moderate alcohol or under placebo. Unexpected visual change was implemented by presenting 2.4 versus 0.6 c/d gratings in pseudorandom sequences according to a deviant (10%)/standard (90%) schedule. The alcohol effects on MMN reported before were replicated. Furthermore, the RRN, defined as the difference between deviant and standard event-related potentials between 120 and 170 ms at Oz, was present under placebo but not under alcohol. It is concluded that moderate alcohol does indeed impair the rapid detection in visual cortex of unexpected changes. In contrast, electrocortical correlates of lower level sensory processing were still significantly present under alcohol.
Prevalence of trait anxiety in a sample of depressed inpatients and its influence on response to antidepressants
Authors: Heijnen WTCJ , van den Broek WW , Mulder PGH , Birkenhäger TK
Published: November 2008

Depression and anxiety frequently occur together or in extension of each other. According to a previous study in depressed inpatients, a high trait anxiety level correlated with a positive response to the diazepam test (DT) and a low trait anxiety level with a negative response to the test. The aim of this study is to investigate whether positive reaction to the DT is related to a positive response to fluvoxamine and whether a negative reaction to the test is related to positive response to imipramine. The DT was performed in 130 patients diagnosed with a depressive disorder. Following the DT, the patients were randomly assigned to double-blind treatment with either imipramine or fluvoxamine. Doses of both antidepressants were adjusted to attain predefined blood levels, and the outcome was evaluated 4 weeks after attaining these blood levels. Twenty-two patients had a positive response to the DT, whereas 108 patients had a negative response. Although a positive DT is correlated with a high level of trait anxiety, no differences in depressive symptomatology and antidepressant response were found between patients with a positive and a negative DT.
Noradrenergic function in pathological gambling: blunted growth hormone response to clonidine
Authors: Pallanti S. , Bernardi S. , Allen A. , Chaplin W. , Watner D. , DeCaria CM , Hollander E.
Published: November 2008

The noradrenergic system has been linked to impulsive behaviour in animals and humans, yet little data on noradrenergic system exist in specific impulse control disorders. To explore the role of the noradrenergic system in pathological gamblers (PG), we assessed neuroendocrine growth hormone (GH) response to the α2-adrenergic receptor agonist clonidine and placebo in PG and controls. The net effects of clonidine are a decrease in neurotransmission by depressing locus coeruleus activity and stimulation of GH secretion through activation of post-synaptic α2-adrenergic receptors in the hypothalamus. Twenty-nine PG subjects, free of other comorbid conditions, and 27 healthy controls received a double-blinded, placebo-controlled, single dose of oral clonidine (0.15 mg/kg). Data observed included GH, clonidine levels and levels of the main noradrenergic metabolite, 3-methoxy-4-hydroxy-phenylglycol (MHPG). The area under the curve for GH response to clonidine was significantly lower (separate variance t with 44.3 df = 2.626, P = 0.012, d = 0.58) in the PG group (199.6) than in the control group (426.3). PG had significantly blunted GH responses compared with controls at 120 and 150 min post-clonidine. These results are consistent with the idea that the subsensitivity of post-synaptic α-2 receptors is possibly attributable to higher-than-normal noradrenergic secretion in PG. This peripheral noradrenergic dysfunction could be consistent with attenuated cortico-frontal noradrenergic function as shown in positron emission tomography (PET) studies of PG.
The Decline of In Loco Parentis and the Shift to Coed Housing on College Campuses
Authors: Willoughby Brian J. , Carroll Jason S. , Marshall William J. , Clark Caitlin
Published: November 2008

Many universities have changed their policies regarding the nature of on-campus housing—shifting from gender-specific to coed dorms. This study examines the scope of that transition in the United States. From a sampling of 100 universities in the United States, including the nation's 50 largest universities, it was found that the vast majority of on-campus housing is currently coed in nature. Anecdotal information provided by the housing offices at these universities suggests that this transition is largely driven by student demand and financial considerations. Implications for future research and university policy making are discussed.
Equity Sensitivity and Organizational Citizenship Behavior in a Team Environment
Authors: Akan Obasi H. , Allen Richard S. , White Charles S.
Published: November 2008

This study examines the relationship between the equity sensitivity orientation of individuals and their exhibition of organizational citizenship behaviors in a team setting. Equity sensitivity theory posits that individuals differ in their equity orientation. Individuals on the benevolent end of the scale do not mind if they are giving more than they are receiving. Conversely, individuals at the entitled end of the spectrum prefer to be in a situation where they are receiving more than they are giving. Participants were administered the Equity Sensitivity instrument (ESI) at the beginning of a team project to determine their equity orientation. At the conclusion of the team project, participants were asked to evaluate their teammates' citizenship behaviors. Through a regression analysis, a significantly positive relationship was found between equity sensitivity scores and team citizenship behaviors. Those participants holding a more benevolent orientation were significantly more likely to exhibit citizenship behaviors as reported by their teammates.
Chemically Assisted Damage of Concrete: A Model of Expansion Under External Sulfate Attack
Authors: Basista M. , Weglewski W.
Published: November 2008

A micromechanical model is proposed to simulate the deformation of cementitious composites exposed to external sulfate attack. The model involves coupled physico-chemical processes of nonsteady diffusion with reaction, topochemical reaction of ettringite formation, expansion of ettringite inclusions, microcracking of hardened cement paste and percolation of sulfates through heavily deteriorated mortar. The Fick's second law with reaction term is assumed to govern the transport of the sulfate ions. The Eshelby solution and the equivalent inclusion method are used to determine the eigenstrain of expanding ettringite crystals in microcracked hardened cement paste. The degradation of transport properties is studied in the effective medium and the percolation regime. An initial boundary value problem (2D) of expansion of a mortar specimen immersed in a sodium sulfate solution is solved and compared with available test data.
Gradient-enhanced Coupled Plasticity-anisotropic Damage Model for Concrete Fracture: Computational Aspects and Applications
Authors: Abu Al-Rub Rashid K. , Voyiadjis George Z.
Published: November 2008

It is widely studied that classical continuum damage theory for concrete fracture exhibits an extreme sensitivity to the spatial discretization in the finite element simulations. This sensitivity is caused by the fact that the mathematical description becomes ill-posed at a certain level of accumulated damage. A well-posed problem can be recovered by using a gradient-enhanced damage model in which a material length scale is introduced as a localization limiter. In this work, a nonlocal gradient-enhanced fully coupled plastic-damage constitutive model for plain concrete is developed. Anisotropic damage with a plasticity yield criterion and a damage criterion are introduced to be able to adequately describe the plastic and damage behavior of concrete. In order to account for different effects under tensile and compressive loadings, nonlocal damage variables that account for the progressive degradation of mechanical properties under stress states of prevailing tension and compression and two internal length scales, one for tension and the other for compression, are introduced as localization limiters. Therefore, two nonlocal damage criteria are used: one for compression and a second for tension such that the total stress is decomposed into tensile and compressive components. In order to solve the time step problem, a decoupled elastic predictor and plastic corrector steps are performed first in the effective configuration where damage is absent, and then a nonlocal damage corrector step is applied in order to update the final stress state. The algorithmic treatment of both tension and compression is presented in a unified way. A simple procedure to calculate the gradient of the tensile/compressive damage variables is described which can be used directly without the need of intensive numerical modifications of an existing finite element code. The effectiveness of the proposed local model has been demonstrated in both uniaxial and biaxial tension and compression problems and compared with experimental data. Numerical results obtained with the proposed nonlocal model are compared with experimental results concerning bending of three-point notched and four-point notched concrete beams. As the mesh is refined, convergence of numerical results is observed both in terms of damage patterns and of the global response.
Damage-Induced Anisotropy with Damage Deactivation
Authors: Abdul-Latif A. , Mounounga T. B.
Published: November 2008

Based on a well-established micromechanical model of damage initiation in low-cycle fatigue (LCF) already developed in Abdul-Latif (1994), a new extension is proposed for describing the damage deactivation effect. With a small strain assumption, it is assumed that the local damage variables initiate at the crystallographic slip system level. It is considered that the damage is active only if micro-cracks (MC) are open, while damage affects differently the mechanical properties of polycrystals during its closure (inactive phase). The anisotropic damaged (activation and deactivation) behavior concept is adopted only at the macroscopic level. With a fourth-order damage tensor, the deactivation damage effect under multiaxial cyclic loadings is modeled describing the related phenomenon of the induced-oriented anisotropy. Several numerical simulations are conducted describing the overall damaged behavior of polycrystals in biaxial LCF. The responses of a given grains aggregate are recorded and then discussed. As a conclusion, the model describes fairly well the damage activation and deactivation effect in plastic fatigue, notably under multiaxial complex loading paths.
The Numerical Analysis of the Intrinsic Anisotropic Microdamage Evolution in Elasto-Viscoplastic Solids
Authors: Glema Adam , Łodygowski Tomasz , Sumelka Wojciech , Perzyna Piotr
Published: November 2008

The objective of the present article is to show the formulation for elastic-viscoplastic material model accounting for intrinsic anisotropic microdamage. The strain-induced anisotropy is described by the evolution of the intrinsic microdamage process — defined by the second-order microdamage tensor. The first step of the possibility of identification procedure (calibration of parameters) are also accounted and illustrated by numerical examples.
Rational Damage Model of 2D Disordered Brittle Lattices Under Uniaxial Loadings
Authors: Rinaldi Antonio
Published: November 2008

The article presents a statistical rational model of damage for 2D disordered spring networks under a generic uniaxial loading. The validation is carried out by using the output from numerical simulations of compression and tension tests along the coordinate axes x and y. The findings demonstrate that the rational model works flawlessly in the hardening and softening phases, both for compression and for tension. A clear and intuitive definition of the damage parameter D (stated in two alternative forms) is obtained in terms of the combination of three random fields {ε*p, η p, np}, which fully encapsulate the complexity of the damage and act as input parameters of the rational model. The analysis of these parameters shed new light on the homogeneous—heterogeneous phase transition of disordered brittle materials and opens up new possibilities in studying and modeling damage processes. The limits of the scalar formulation are also outlined. Simplified models of the rational model are derived and discussed to prove that the apparent complexity of {ε*p, η p, np} can be administered by identifying ad hoc simplifying assumptions. The theory is developed for a 2D network but the underlying ideas are general.
Mouse Bsep ATPase Assay: A Nonradioactive Tool for Assessment of the Cholestatic Potential of Drugs
Authors: Kis Emese , Rajnai Zsuzsanna , Ioja Enikő , Herédi Szabó Krisztina , Nagy Tünde , Méhn Dóra , Krajcsi Péter
Published: November 2008

The mouse ortholog of the human bile salt export pump (BSEP) transporter was expressed in a baculovirus-infected insect cell (Sf9) system to study the effect of membrane cholesterol content on the transporter function. The transport activity of cholesterol-loaded mouse Bsep-HAM-Sf9 vesicles was determined in a vesicular transport assay with taurochenodeoxycholate (TCDC), a known BSEP substrate. Mouse Bsep transports TCDC at a high rate that can be sensitively detected in the ATPase assay. Cholesterol upload of the Sf9 membrane potentiates both TCDC transport and TCDC-stimulated ATPase activities. Inhibitory effect of BSEP interactors on probe substrate transport was tested in both vesicular transport and ATPase assays using cholesterol-loaded membrane vesicles. A good rank order correlation was found between IC50values measured in TCDC-stimulated mBsep ATPase assay and in the human BSEP vesicular transport assay utilizing taurocholate (TC) as probe substrate. This upgraded form of the mouse Bsep-HAM ATPase assay is a user friendly, sensitive, nonradioactive method for early high-throughput screening of drugs with BSEP-related cholestatic potential. It may complement the human BSEP-mediated taurocholate vesicular transport inhibition assay. ( Journal of Biomolecular Screening 2009:10-15)
Coregulation in Salivary Cortisol During Maternal Holding of Premature Infants
Authors: Neu Madalynn , Laudenslager Mark L. , Robinson JoAnn
Published: November 2008

Purpose: The purpose of this study was to examine coregulation between mothers and preterm infants in hypothalamic-pituitary-adrenocortical (HPA) system activity, as indicated by salivary cortisol levels, while mothers held their infants. The research questions were (a) does mother—infant coregulation in HPA activity occur during holding? and (b) if mother— infant coregulation in HPA activity exists during holding, do type of holding, antenatal steroids, sound level, and maternal touch influence this coregulation? Sample: The sample consisted of 20 mother— infant dyads with infants at a mean postconceptional age of 34.7 weeks (+0.7) and average postnatal age of 15 days (+9) at the time of cortisol sampling. Design: The design was exploratory using convenience sampling. Maternal and infant cortisol levels were obtained at Time 1 (baseline) and Time 2 (end of holding); at each time, the absolute differences in levels between mother and infant were determined. Coregulation was operationalized as less difference between maternal-infant cortisol levels immediately after holding (Time 2) as compared to before holding (Time 1). Results: The two variables with the highest correlation with the Time 1/Time 2 difference score included antenatal steroids and ambient sound level, which were entered into a linear regression equation as predictor variables. A coregulatory relationship in cortisol levels existed between mothers and infants during holding, which was moderated by sound levels. Nurses in the neonatal intensive care unit (NICU) can facilitate the mother—infant relationship, as reflected in coregulatory measures, by promoting a quiet environment, particularly around mothers who are holding their infants.
Social anxiety in a multiple sclerosis clinic population
Authors: Poder K , Ghatavi K , Fisk JD , Campbell TL , Kisely S , Sarty I , Stadnyk K , Bhan V
Published: November 2008

Background

Little is known about social anxiety in MS.

Objective

We estimated the prevalence of social anxiety symptoms and their association with demographic and clinical features in a clinic-attending sample of patients with MS.

Methods

Patients attending the Dalhousie MS Research Unit for regularly scheduled visits completed the Social Phobia Inventory (SPIN), the Hospital Anxiety and Depression Scale (HADS), and the Health Utilities Index (HUI). Neurological disability was determined by ratings on the Expanded Disability Status Scale (EDSS).

Results

A total of 251 patients completed self-report scales of anxiety and depression symptoms. In all, 245 (98%) provided sufficient data for analysis. In all, 30.6% ( n = 75) had clinically significant social anxiety symptoms as defined by a SPIN threshold score of 19. Half of those with social anxiety had general anxiety (HADSA ≥ 11) and a quarter had depression (HADSD ≥ 11). Severity of social anxiety symptoms was associated with reduced health-related quality of life and not related to neurological disability.

Conclusions

Social anxiety symptoms are common in persons with MS, contribute to overall morbidity, but are unrelated to the overall severity of neurologic disability. Greater awareness and routine systematic inquiry of social anxiety symptoms is an important component of comprehensive care for persons with MS.
Head injury is not a risk factor for multiple sclerosis: a prospective cohort study
Authors: Pfleger CCH , Koch-Henriksen N , Stenager E , Flachs EM , Johansen C
Published: November 2008

Background

The idea of physical trauma being involved in the causation of multiple sclerosis (MS) had been discussed since the earliest description of the illness. Despite the ongoing debate, the proposed association between physical and especially head trauma and MS failed to be proved or to be refuted conclusively.

Objective

To determine whether head trauma is associated with an increased risk of developing MS.

Method

A cohort of 150,868 subjects, 95,111 men, and 55,757 women registered in the National Danish Patient Registry with hospital admission for cerebral concussion, contusion, or skull fracture between 1977 and 1992, aged under 55, was selected. This trauma cohort was linked with the Danish MS Registry and followed up to the end of 1999 to retrieve subjects who had onset of MS after the year of the head trauma. We calculated the expected number of subjects, who, under a null-hypothesis, would subsequently develop MS, by using population age-, year-, and sex-specific MS-incidence densities from the Danish MS Registry.

Results

For men and women combined, the observed to expected number of MS cases (possible cases included) with onset after the head injury was 182/193.6 (standardized incidence ratio [SIR], 0.94; 95% CI, 0.81–1.09) and for possible MS excluded, 171/164.7 (SIR, 1.04; 95% CI, 0.89–1.21). In an analysis of a sub-cohort of 16,425 subjects with severe trauma (contusion, traumatic cerebral hemorrhage, and base or skull fracture), the observed to expected numbers, including possible MS, were 15/15.3 (SIR, 0.98; 95% CI, 0.55–1.62) and with possible MS excluded, 13/12.9 (SIR, 1.01; 95% CI, 0.53–1.73). As for the total group and for any of the subgroups and for men and women separately, none of the SIRs differed statistically significantly from unity. Neither were there any trends, which could be missed by type II errors.

Conclusion

Head injury of any severity does not affect the risk of acquiring MS later in life.